摘要:

THE QUARTERLY JOURNAL OF THE CHEMICAL SOCIETY OF LONDON B. C. BRODIE F.R.S. A. W.HOFMANN PH.D. F.R.S. THOMAS GRAHAM F.R.S. J. STENHOUSE LL.D. F.R.S. LONDON HIPPOLYTE BAILLIERE 219 REGENT STREET AND 290,BROADWAY NEW YORK U.S. PARIS J. B. BAILLIERE RUE HAUTEFEUILLE. MADRID BAILLY BAILLIERE OALLE DBL PRIWCIPE. 1856. LONDON Printed by SPOTTISWOOD~ lk CO. New-street-Square. CONTENTS OF THE EIGHTH VOLUME. PAOB Investigation of the Vegetable Tallow from a Chinese Plant the Stillingis sebifera." By Nevi1 Story Maskelyne M.A. F.CS.g. ........................... 1 On the Absorption of Chlorine in Water. By Henry E. ROSCOO,B.A. Ph.D. 14 Electrolysis. By A. Natthiessen Ph.D. ... . .. . . ....... . . .,...,..... . . ... . ... .. 27 On a peculiar Efflorescence of the Chloride of Potassium. By R. Warington 30 Palladium. By Richard Adie . . . .. . . . . . .. . . . . . ... . . ................ . . .. . ... ... . . . 36 Proceedings at the Meetings of the Chemical Society . . . . .. . ... . ,... . . ,. . .,.,. . ...... 38 On (the Preparation of the Metals of the Alkalies and Alkaline Earths by On the Thermo-Electrical Currents generated in Elements where Bismuth is used to form the Joint. By Richard Adie ...... .......................... ... ... a3 On Thermo-Electric Joints formed with the metals Antimony Bismut.h and Not,iccs of Papers contained in other Journals :-On Osmotic Force. By Thomas Graham F.R.S. &c. . . .......... . . . ..... . . .... 45 Chemical Composition of the Waters of the Metropolie during the Autumn and Winter of 1854. By Robert Dundas Thomson M.D. F.R.S. L. & E..... . . 95 On Platinised Charcoal. By John Steshouse LL.D. F.R.S. ..................... 105 On the Peparation of Strontium and Magnesium. By A. Matthiessen Ph.D.. . 107 Report of the Council of the Chemical Society .........................,.. . . ... ......... 109 Balance-sheet of the Chemical Society .. . . . . . . . . .,. . . . . . . . .... . ....,..... . ... . . . . . . . . .... 116 Proceedings at the Meetings of the Chemical Society ... ... ............ ............... 116 Notices of Papers contained in other Journals :-Report on the Supply of Spirit of Wine Free from Duty for Use in the Arts and Manufactures.,.By Professors Graham Hofmann and Redwood ... .. .. . .... 120 On the Preparation of Lithium. By Professor;Bunsen.. .. . . ........ .... . . . . . ... 143 011 the Action of Iodide of Phosphorus upon Glycerine. By MM. Berthelot and De Luca ... . .. .. . ...".......,.. ............ .. .... . .. . ... .. . ....... .. .. .... 145 CONTENTS . 11.4 0 H On the Formation of Alcohol from Olefiant Gas . By M .Berthelot .............. 148 On the Substitution of the Aldehyde-radicals in Ammonia . By J.Natanson .... 150 Compoiinds of the Ketones with Alkaline Bisulphites . By Dr .Liilipricht ........ 154 On Caprylic Aldehyde . By Dr . Limpricht ...................................... 155 Chemical Notices . By H.Liinpricht ..........................................157 On Compound Ureas . By N .Zinin and F. Moldenhauer ........................ 158 On a new Mode of Formation of Ethylamine Amarine. and Lophine. By A .Gijssmanri.............................................................. 161 OnTelluromethyl. By F .WiShler and J.Dean.................................. 164 On Cuminic Alcoliol . By C .Kraut ........................................... 166 On Benzoic AlcoLol . By S.Cannizzaro ........................................ 169 On the Anilides of Pyrotartaric Acid . By E.Arppe ............................ 172 On Nitraniline and Paranitraniline . By E.Arppe .............................. 175 On the Anilides of Tartaric Acid . By E.Arppe ................................179 On Salicylic Acid . By R.Piria ............................................... 182 On some Compounds of Hydrosulphate of Mustard.oi1 . By H.Will ............ 183 On Phillyrin . By C .Bertagnini ................................................ 187 On Mangostin . By W.Schmid ................................................ 190 On the Action of Hydriodic Acid upon Glycerine . By MM .Berthelot and De Luca 192 Photochemical Researches . By Professor Bunsen and H.E.Roscoe,B.A. P1i.D. 103 On the Colour of Chloride of Copper in different States of Hydration . ByJ .H.Gladstone Yh.D. F.R.S. ...................................................... 211 Notices of Papers contained in other Journals :-On a method of Volumetric Analysis of very general Application .By R.Bunsen 219 Researches on Oxygen in the Nascent State . By A.Houzeau .................. a37 On Aluminium . By H.Ste.-Claire Deville ...................................... 239 On Glucinum and its Compounds . By H.Debray .............................. a42 On some Salts of Cadmium. By Carl von Hauer .............................. 250 On the Pr eparation of the Sulphochloride of Mercury in the Dry Way . ByR.Schneider .............................................................. 257 On an easy Method of Purifying Sulyhuric Acid from Arsenic. By A .Buchner .. 258 On the Mellonides . By J.Liebig .............................................. 259 On some Compounds of Stibethylium. By R.Mwig............................2g0 On Butylic Alcohol . By A .Wurtz ............................................ 2G4 On Butylic Mercaptan and Butylic Urethane . By E.Humann .................. 274 On Amylic Alcohol . By L.Pasteur ........................................... 277 On Hypogaeic Acid a new fatty acid ohtained from Earthnut-oil . By A .Gliss-mann arid H.Scheven .................................................... 279 On Papaverine. By T.Anderson .............................................. 289 On the Volatile Bromine-compound obtained in the Technical Preparation of Bromine. By M .Hermann................................................ 206 On the Volatile Oil of “Ptychotis Ajwan.” By R.Haines. M.B................ 289 On Azobenzole and Benzidine . By Alfred Noble ....................................292 A Few Notee on Barium. By A.Mstthiessen Ph.D. .............................. 294 On the Hydro-electric Currents generated by Couples formed of Bingle Metals . By Richard Adie ........................................................................ 295 Proceedinga at the Meetings of the Chemical Society ................................297 CONTENTS. V Notices of Papers contained in other Journals :-PAGE On Coumaramine. a new Organic Base derived from Nitrocoumarine . By A .Frapolli and L .Chiozza.................................................. 301 Investigation of some Derivatives of Naphthalin . By L.Dusart ................ 303 Note on a New Mode of producing Propylene . By L.Dusart ....................305 On Tartrate of Lime and a Reaction of Tartaric Acid . By A .Casselmann........ 306 On Arabin . By C .Neubauer .................................................. 307 Examinatiou of the Products of Distillation of pure Stearate of Lime. By Professor Heints .......................................................... 308 Titles of Chemical Papers in British and Foreign Journals ........................ 309 Index .............................................................................................371

ISSN:1743-6893    

DOI:10.1039/QJ85608FP001

出版商:RSC    

年代:1856

数据来源: RSC

摘要:

DR. ROSCOE OX K-On the Absorption of Chlorine in Wkter. By HENRYE. ROSCOE,B.A. PH.D. AT the beginning of this century Dalton and Henry set up the hypothesis that the amounts of gas dissolved by a liquid vary as the pressure under which the absorption takes place. As however this relation between the absorbed gas and the pressure could not be deduced from Dalton and Henry’s own experiments and still less from the later ones of Saussure it has been regarded by chemists as an ungrounded hypothesis until Professor Bunsen,* in his late research showed that it had a foundation in a true law. A series of very careful experiments which Dr. Carius and Dr. Schonfeld have carried out with the absorptiometcr described by Bunsen not only give fresh proofs of the exactitude of the law but show beyond doubt that it is applicable to gases of very great solu- bility.It thus appears of great interest to examine the absorptiometrical relations of gases at the limits of the temperatures at which the same are capable of entering into chemical combination with the solvent. Dr. Schonfeld ’has examined sulphurous acid in this respect and has found that the law is followed even at temperatures which ap- * Phil. Mag. Web. and Mbch 1856 ; Ann. Ch. Pharm. xciii. 1. TBE ABSORPTION OF CFILORINE IN WATER. proach the point where this acid forms a crystalline hydrate with the solvent. In the following research I shall describe the absorptioinetrical relation which exists between chlorine and water at temperatures approaching that at which hydrate of chlorine is formed.As the absorption-coefficient of this gas has already been accurately deter- mined at Schiinfeld I have been able to confine myself to the examination of mixtures of gas of known composition containing chlorine. The first mixture of gases examined was that evolved by the elcctrolysis of concentrated hydrochloric acid. The electrolysis was conducted in a small flask of about 100 cubic centimeters’ capacity filled with hydrochloric acid into which two poles of conducting carbon dipped. A glass tube with the upper end drawn out was fastened on to the neck of the flask by means of a caoutchouc ring and through the tube were melted two platinum wires which conirnuni- cated below with the carbon poles and above with the battery.The gas obtained by a current of four of Bunsen’s elements was washed by passing through a series of bulbs containing water blown on a glass tube and placed in an oblique position. The composition of the gas thus obtained by electroIysis must first be determined. For this purpose the gas was dried over fused chlo- ride of calcium and lcd into a tube of known capacity drawn out at both ends until there could be no doubt that the last traces of atmospheric air were driven out. After accurate observation of the temperature and pressure the tube filled with the mixture of gas was closed with the necessary precautionary measures and one end opened under a solution of iodide of potassium ; and in order to effect the rise of the liquid this was done at a lower temperature than that at which the gas was collected.The iodide of potassium was imw-diately absorbed and a quantity of iodine equivalent to the free chlorine present was separated out. From this free iodine the amount of chlorine present in the tube was determined by Bun sen’s volumetric method.* Two experiments with gas collected at separate occasions gave- 1. 11. t a = 0.0024869 a = 0.002443 t =92.0 t =67.0 t,=59.9 t =58.3 n = 5. n = 2. * Ann. Ch. Plinrm. lxxxvi. 265 ; Chem. SOC.Q.u. J. vi. 90. t The sigiiification of the various lettere will be seen by reference to the origiual research. DR. ROSCOE ON From these numbers the volume of chlorine V C. 0' reduced to and 0.76 pressure of mercury contained in the tubes used in the experiments is found in cubic centimeters by means of the formula- a (nt-tJ c1 0.0031823 I.= ' in which Og0O328.23is the weight in grms.of 1 cubic centimeter of chlorine at 0" C. and 0.76 pressure of mercury. The first experiment gave 16.24; the second 87.36 cub. cent chlorine at 0" C. and 0.76 pressure of mercury If the total capacity of the tube be called C,the barometric pressure at the time of closing P and the temperature during the same time I theincontained0.76andC 0' gas reduced to ofthe total volume tube is found by the following formula :-C. P (') (1+0.00366 T)0*76= For Experiments (1) and (2) the following values were found :-I. 11. C . . 38-81 c n 190.24 Y .Om*7415 . . . Om*7265 T . . 21O.6 C. . . . 11"-1C. This gives the total volume of the first tube 32.58; of the second 174.65. If now the respective volumes of chlorine found by gradu- ation be subtracted from the total volumes the volume of hydrogen gas present in the mixture will be obtained. The coinposition of the two mixtures of gas was therefore,-I. 11. Calculated. Chlorine . 49.85 50.02 50.00 Hydroges . 50.15 49-98 50.00 100*00 100*00 100*00 As the liquid subjected to electrolysis only contained hydrochloric acid and water the products of decomposition formed could only contain chlorine hydrogen oxygen or the oxides of chlorine or hydrogen. The absence of .free oxygen can be safely inferred from the experiments just cited for every volume of oxygen which is set free by the electrolysis of water is necessarily accompanied by two volumes of hydrogen whilst chlorine and hydrogen are set free in equal volumes by the electrolysis of hydrochloric acid.If therefore water were decomposed in the above manner the analysis would not THE ABSORPTION OF CHLORIXE IN WATER. have shown equal volumes of chlorine and hydrogen but an excess of the latter which as already stated was not the case. For the same reason peroxide of hydrogen cannot be formed in the decomposition as the presence of this body would cause a still greater proportional excess of hydrogen. It only remains therefow to be shown that in the mixed gas no oxygen-compounds of chlorine are present. Let us in the first place to take a particular case examine if the gas could contain hypo- chlorous acid.2 vols. of hypochlorous acid consist of 2 vols. of chlorine and 1vol. of oxygen ; 1 vol. of oxygen is equivalent to 2 vols. of chlorine and sets free in the volunietric process exactly as much iodine as 2 vols. of chlorine. This process leaves it therefore quite undecided whether 4 vols. of chlorine or 2 vols. of hypochlorous acid were present ;and further because in the electrolytic decomposition of 4 vols. of hydrochloric acid as in electrolytic formation of 2 vole. of hypochlorous acid exactly the same amount 4 vols. of hydrogen must be set free it is clear that the volumetric process will always show equal volumes of chlorine and hydrogen whether the gas be rendered impure by the presence of hypochlorous acid or not.The question as to the presence of this latter gas is however easily answered when a direct estimation of chlorine with solution of silver is made together with a volumetric determination. The silver detcr- mination shows only the amount of chlorine and not the oxygen of the hypochlorous acid and therefore may give only half as large an amount of chlorine as the volumetric process. The two following experiments show that the amount of chlorine found by the volu- metric method agrees so exactly with that found by the silver deter- mination that the absence of hypochlorous acid may be certainly deduced. By similar reasoning the absence of all other volatile oxides of chlorine can be proved.Three tubes were filled with the gas as formerly described. The first was opened under iodide of potassium and analysed by the volumetric process ; the two others were opened under tolerably con- centrated sulphurous acid by means of which the whole of the chlorine was reduced to hydrochloric acid and precipitated in presence of excess of nitric acid as chloride of silver. The elements for the first tube were- cc =0.0024869 n =2 1 =59.3 t =76.1 and T=14O.7 P=Orn*74G4 C=43.20 From these are obtained- VOL. VlII.-NO. XXIX. C DR. ROSCOE ON I. Volumeof chlorine at 0" C. and 0.76 found by the volumetric process . . 20.290 cc. 11. Ditto ditto calculated . . 20.131 , The elements for the second tube were- Weight of chloride of silver.. . 0-3980 ,) silver (with ash) . . 0*00:31 and T=14"*7 P=0*7464 C=66*70 From these are obtained- I. Reduced volume of chlorine found by silver determination . . 31-26 cc. 11. Ditto ditto calculated . . 31.018 , The elements for the third tube were- Weight of chloride of silver. . . 0.3834 , silver (in ash) . . 0-0026 and T=14°g07 P=0*7464 C=64.27 From these are obtained- I. Reduced volume of chloriue found by silver determination . . 30.034cc. II. Ditto ditto calculated . . 29.949 , After all these experiments and considerations it may be fairly concluded that the electrolytic gas really consists of a pure mixture of equal volumes of chlorine and hydrogen. As the absorption-coefficients of chlorine and hydrogen for water are known a simple volumetric determination of an aqueous solution saturated at a particular temperature with the gaseous mixture is all that is required to determine if chlorine obeys the law of absorption and if so up to what distance from the point at which hydrate of chlorine is formed.For if u represent the absorption-coefficient of chlorine P the barometer pressure v the volume of chlorine anbv the volume of hydrogen contained in the mixed gas which is passed through a volume h of water until it is saturated the amount of chlorine P dissolved in the water must have the following value if the law of absorption is applicable :-h.u.Pv =v* (3) 0.76 (v+ vl) THE ABSORPTION OF CHLORINE IN WATER. It will be as well to give here for reference the absorption-co- efficients for chlxine and water (t~) as found by Dr.Schonfeld :-C. 0' Coefficient. C. 0' Coefficient. C. 0' Coefficient. 10. . . . 2'5852 21. . . . 2.1 148 31. . .. 1.7104 11. . . . 2.5413 22. ... 2-0734 32. . . . 1.6712 12. . .. 2-4077 23. . .. 2.0322 33. .. . 1'6322 13. . . . 2.4543 2d. . .. 1.9912 34. . . . 1.5924 14. . . 2.4111 25. . . . 1.9504 35. . . . 1*5S50 15. . . . 2.3681 26. . . . 1.9099 36. . . . 1.5166 10. .I. 2-3253 27. . . 18895 37. . . . 14785 17. . . . 2'2828 28. . . . 1.8295 38. . . 1-4406 18. . . . 2.2405 29. . . . 1.7895 39. . . . 1-4029 19. . . . 2'1984 30. ... 1.7499 40. . . . 1.3655 20. ... 9.1565 Three experiments," made at different temperatures with the same volume (9.834 cc.) of saturated solntion gave the following results :-(1) (2) (3) n= 2-n = 1.n = 1-t,=48.9 t,=10.0 t,= 55 t =58.6 t =6'7.6 t =60.3 T-14'*4 I'= 21O.O i? =25O.O u =00024430 Calciilated from formula (3). Hence the vol. chlorine at 0"C. and 0-76at 14'04 is 14.70 . . 1 1.65 > 1 1) , , 21O.O ,,12.643.. 11.35 9 9 9 > , 25O.O ,,11.99 .. 9.36 These figures show that the amounts of chlorine found in the satu- rated solution differed considerably from the amount which should be contained therein according to the law of absorption. Let us now proceed to the consideration of the caizses which might possibly effect this increased absorption of chlorine. It has been already shown that the gas employed in the experiments did not contain any amount of oxides of chlorine which could" possibly pro- duce this greatly increased coefficient of absorption.It is however quite possible that chlorine should act towards water as it does towards so marly bases and a formation of hydrochloric acid and * It is almost unnecessary to state that all the experiments on mixtures of chlorine and hydrogen were conducted in a darkened room a candle being the only light present. DR. ROSCOE ON oxide of chlorine take place. It is possible that the compounds thus formed were not present in the gaseous mixture because they were retained in solution by the liquids with which they came in contact. Such a partial decomposition of the water by chlorine into hydro- chloric and hypochlorous acids would most satisfactorily account for the above irregularities.This question may be easily settled by an experiment founded upon the law of absorption. If we suppose that when chlorine is dissolved in water hydrochloric acid and any volatile oxide of chlorine is formed it is easily seen that not only the volu- metric process but also a direct silver determination must give exactly the same results as would be found if the liquid contained only free chlorine. A totally different result will however be obtained if any gas which obeys the law of absorption-as for instance carbonic acid- be passed into a saturated solution of chlorine in water. If merely chlorine be present it will be driven out by a stream of carbonic acid and replaced by this gas in the proportion of their relative absorption- coefficients.If on the contrary hydrochloric acid and a volatile oxide of chlorine are present together with free chlorine the chlorine and oxides of chlorine will be driven out in an amount different from that of the hydrochloric acid which when dissolved in alarge quantity of water is not volatile. Thus a relation between the components will be brought about by which the volumetric and silver determinations cannot give like results because the original relation by which the hydrochloric and hypochlorous acids are present in the proportion capable of forming chlorine and water does not now exist. The following experiment in which a stream of carbonic acid was passed in the dark through a solution of chlorine freshly prepared without access of light shows that after the current of gas had passed through for three hours the amounts of chloriiie obtained by volu- metric and silver determinations agreed exactly.The gas was first passed into a bottle containing the chlorine solution next into a second bottle containing distilled water and the resulting solution in both bottles was examined. ANALYSIS FROM THE FIRST BOTTLE. Volumetric method- a=O.0024869 (1) n=2 ti=50'5 t-72-0 (2) n=2 t,=53.4 t=71*0 THE ABSORPTION OF CHLORINE IN WATER. Silver determination- (1) Chloride of silver . . 0-2617 Silver . . . 0*0010 (2) Chloride of silver . . 0.2443 Silver .. 0.0050 These elements give- Reduced volume of chlorine found by the volumetric method . . (1) 20.421 (2) 19.962 Ditto ditto silver determination 20.517 19.599 ANALYSIS FROM THE SECOND BOTTLE. Volumetric method- OL =O.OOfZ4869 (1) n=2 t,=46*8 t=71*9 (2) n=2 t,=48*0 t=71*7 Silver determination- (1) Chloride of silver . . 0.2701 Silver . . 0.0012 (2) Chloride of silver . . 0-2594 Silver . . . 0-0005 These elements give- v (1) Reduced volume of chlorine found by the volumetric method . . 21.185 20.836 Ditto ditto silver determination 21.346 20.303 The supposition of a decomposition of water by chlorine to account €or the observed phenomena is therefore likewise unfounded. As an objection might be raised to this experiment that the oxides of chlorine are not volatile enough to be carried over from their solu- tion by a foreign gas I have examined the action of carbonic acid on a mixture of oxides of chlorine.The mixture of' all the various oxides of chlorine which is obtained by heating chlorate of potash with con- centrated sulphuric acid was dissolved in water and a known volume of the solution submitted to volumetric analysis ; this volume was found to be equivalent to 50.3 burette divisions of normal iodine solution. A rapid stream of carbonic acid was then passed through the solution which after fifteen minutes was again volumetrically analysed and the same volume of solution was found to be equal to DR. ROSCOE ON 24.0divisions; after the current of gas had passed for thirty minutes more the same volume corresponded to only 3.7 divisions.The rapidity with which the values of the volumetric determinations de- creased with the amount of gas passed through shows how easily the oxides of chlorine are expelled from their solutions by other gases and hence the former objection is entirely removed. A similar result is arrived at when the mixture of hydrogen and chlorine after being washed is allowed to saturate a volnme of water. It is here also easy to show that no oxides of chlorine have passed over for in the following experiment the same amount of chlorine was obtained by volumetric and by silver determination :-Chlorine and hydrogen absorbed in 9.843 cc. of water at 38’ and 0”-7339pressure Volumetric method- u =0*0024430 (1) n=l t,=31*8 t=72.4 (2) n=l t,=31.9 t=72.0 Silver deterrnination- ( 1) Chloride of silver .. 0.1117 Silver . . 0.0016 (2) Chloride of silver . . 0.1087 Silver . . 0.00‘48 Mean reduced volume of chlorine from volu- metric method . . 8.700 cc. Ditto ditto silver determination . 8.8966 , In order that no possible cause may be left undetermined I have examined the action of free hydrochloric acid upon the solution of chlorine. It was possible that the formation of hydrochloric acid from the hydrogen and chlorine might induce a larger absorption of chlorine and thus the phenomena be explained.. It was however found that the presence of hydrochloric acid lessened instead of increasing the absorption-coefficient of chlorine.Water containing T&$h of ils bulk of concentrated- hydrochloric acid was saturated with chlorine at 14O and Om.7366 pressure and the absorption-coefficient calculated according to the formda,- THE ABSORPTION OF CHLORINE IN WATER. The experiment gave when h=9.834-(1) n=2 t,=62*1 t=74*9 a=0*0024869 (2) n=B t1=60*0 t=73*9 Hence the Coefficient obtained is . . 1.9786 Coefficient for pure water . . 2.3911 One assumption alone remains after all these experiments namely that near the temperature at which the formation of hydrate of chlo-rine begins the atoms of chlorine exert an attraction on those of the other gas present and on the water similarly to the law of Mariotte at the point of condensation and that thereby the accuracy of the law of absorption is lessened.In order to form an idea of the amount of this molecular disturbance it is possible to calculate the volume of chlorine which for any given temperature does not obey the law of absorption. The equations for this calculation are obtained from the volumes of chlorine which are absorbed in water firstly for pure chlorine and secondly for a known mixture of this gas with hy-drogen. Let Y be the reduced volume of chlorine absorbed in A volumes of water when pure chlorine is used; Frl the volume of chlo-rine dissolved in h volumes of water when the mixed gas is used ; a the amount of chlorine in the mixed gas ;vl the volume of hydrogen in the latter ; P the observed barometric pressure; y the reduced volume of chlorine obeying the law of absorption which is contained in the unit of water; x the reduced volume of chlorine which by reason of the molecular action is supposed to be withdrawn from the law of absorption.The following equations give the values of x and y :-(5) V=hy+hx (6) ""0.76 h,yPv (v+v,) +h,x Y (7) x= x-y By meansof these formulz the values of x and y for various tem- peratures have been calculated from the following determinations :- DR. ROSCOE ON Chlorine and Hydrogen-a=0.0024869 h =9.834 I. T"=13'*5 P=0°7431 n=2 t =39*2 t=53.85 11. T0=140*3 P=0*7414 n=2 t,=48.9 t=58*6 111. T0=2l0.0 P=0.7402 n=l t,=10.0 tz67.6 IV. TO=25O-O P=0.7431 n=1 t,= 5.5 t=60*3 V. To=3O0-0 P=0.7320 n=l t,= 4.8 t=53*2 VI.To=38'.O P=0*'7339 n=l t,=31*85 t=72*2 Hence for- 13'05 . . y=1 7831 ~t?=0.6496 14O.3 . . y= '1.7641 x =0.6291 20°*1 . . y=1.6721 x:=0.4880 2PO . . y=1*6287 x =0.4861 25O.O . . y=1.5984 z=0.3589 3OO.O . . y=1.3633 x =0.3866 38O.O . . y=1*0625 x= 0.3771 In order to determine whether the amount of this molecular dis- turbance was dependent upon the nature of the gas with which the chlorine is in contact mixtures of known vohmes of chlorine and carbonic acid were examined and in a similar manner the values of x and y calculated from the experiments. The great difficulty of mixing a known volume of chlorine with a known volume of another gas was overcome by the following simple arrangement :-A large glass tube of about 130 to 150 cubic centimetres' capacity was drawn out the glass thickened at either end and pieces of glass rod ground to fit air-tight into the apertures.The capacity of the tube was then accurately determined and it was afterwards completely filled with carbonic acid and closed. The tube thus filled was opened under a saturated solution of chlorine freshly prepared in the dark and a part of the carbonic acid driven out by the saturated solution. The tube containing the mixture of chlorine water and carbonic acid gas was next well shaken in a water-bath of known temperature and one of the stoppers partly opened to allow the excess of gas to escape. By means of this agitation the statical equilibrium of absorption was established between the chlorine and carbonic acid dissolved in the water and the chlorine and carbonic acid present in the free gas.An effect of this process was an increased volume of free gas. This increased volume was allowed to escape and thereby the original pressure obtained and the agitation and other operations were re- peated until no more gas was evolved and the pressure remained THE ABSORPTION OF CHLORISE IN WATER. constant; or in other words until the equilibrium ensued. The free and absorbed gas must be present in a proportion which may be cal- culated from the law of absorption. This proposition is found by the formulz 1 and 2 used in the former case. The experiments were made in the following manner:-After the tube had been com-pletely agitated it was weighed in order to obtain the volume of water employed and the amount of dissolved chlorine was determined by the volumetric method.The chlorine contained in the gas was also estimated in the same way the tube being cooled with ether and opened under iodide of potassium. A deduction was also made for chlorine con-tained in the residual water the volume of which was found 'by a second weighing after the volumetric examination of the water. By these observations all the data for the calculation of x and y are given. To obtain from a series of experiments the values of x and y the same formulze were used viz. y Y h y= 1- h,. Pv ' Y x=--yh 0.76 (u+ u,) where is as before the volume of pure chlorine dissolved in the h unit of water ;5 the volume of chlorine dissolved in the unit of water hl from the mixed gases chlorine and carbonic acid v the volume of chlorine in the gas and ul the volumeof carbonic acid.Two experiments thus conducted with varying volumes of chlorine carbonic acid and water at the same temperature show very closely approximative results :-EXPERIMENT I. 2"=29'*5 P=0*7428 Capacity of tube=82-62 cc. ; Weight of tube empty= 16.745 ; Weight of tube water and gas =33.005 ; Volumetric analysis of the solution n = 1; t,= 3-5; t= 70.8 ; Weight of tube and residual water= 17.192; Volumetric analysis of the gas n= 2 ; t,= 44.8; t=64.8. From these elements we obtain- T,=15*098 U= 18.120 h,= 16.265 ~+~,=67.455 Hence y= 1.141; x=0.6287.26 DR. ROSCOE ON THE ABSORPTION OF CHLORINE IN WATER. EXPERIMENT 11. E29O.5 P=0*7514 Capacity of tube and weight of tube empty same as I. Weight of tube and solution =34.69 ; Volumetric analysis of the solution :%= 2 ; t,=58.0 ; t=68.0 ; Weight of tube and residual HO=17*160; Volumetric analysis of the gas n=2; t,=43*0; t=68-1. From these elements we obtain-V,=17455 w =19.939 h,3.17.945 W+ V,=64.775 Hence y=1*1456 x=0*6241. The following table shows the values of x and y for various tem- peratures as calculated from the experiments with chlorine and carbonic acid :-13O-5 . . . y=1.7940 . . . x=0.5955 14O.4 . . . y=1*7948 . . . x=0.5963 17O.5 . . . y=1*7990 . . . x=0.4599 20'05 . . . y=1*4024 . . . x=0*7638 22O.O .. . y=1*3129 . . . x=Oo7605 25O.O . . . y=lm2214 . . . x=0.7191 29O.O . . y=1*1022 . . . 3=0*6675 290-5 . . . y=i.i438 . . . x:=ome4 36O.O . . . . y=0.8230 . . . x=0.6283 Mean value of x for all the experiments 06399. From these experiments it is clear that for the same temperature the amount of chlorine not obeying th; law of absorption varies with the nature of the other absorbed gas and that the absorption-co- efficient of chlorine is also altered by this circumstance. Itl is seen from the first table of the coefficients for chlorine an4 hydrogen that the amount of chlorine present a8 not obeying the law diminishes as the temperature increases from the point at which hydrate of chlorine is formed. In the determinations with carbonic acid and chlorine on the other hand this diminution is not seen at the temperature at which the experiments were made.

ISSN:1743-6893    

DOI:10.1039/QJ8560800014

出版商:RSC    

年代:1856

数据来源: RSC

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DR. MATTBIESSEN ON THE METALS OP THE ALKALIES &c. 27 111.-On the Preparation of the Metals of the Alkalies and Alkaline Earths by Ekctrolysis. By A. MATTHIESSEN, PH.D. THEfollowing research carried out at the suggestion of Professor Bunsen in his laboratory upon the Electrolytic Decomposition of the Salts of the Alkalies and Alkaline Earths seems to show that the statements given in the Handbooks concerning the preparation and properties of the metals of the alkaline earths are for the most part false. Indeed it is more than probable that the metals calcium and strontium have never before been isolated ; for all the experimenters who have supposed that they have prepared the metals describe them as silver-white whereas the globules of metal as large as a pea which I have observed have the colour and lustre of gold alloyed with silver.The preparation of barium strontium and calcium presents many singular difficulties ; for if galvanic currents of various intensities be passed through the fused chlorides of these metals by means of two large carbon poles as used by Bunsen for the preparation of mag-nesium,* a number of small flames are observed not only at the negative but also at the positive pole whether at a high or low tem- perature. These small flames are occasioned by the metal in the form of a powder burning rising at the anode and carried to the cathode by the current of chlorine evolved there. At t4e same time a small quantity of basic chloride is formed round the anode which hinders the further passage of the current.No metallic globules are found on opening the cooled crucible and only exceptionally does a part of the chloride evolve hydrogen on moistening with water. As the mass of chloride surrounding the negative pole had a strongly alkaline reaction there can be no doubt that the diminution of the strength of the current was owing to the formation of lime. This is explained by the fact that the chlorides when fused in a vessel com-posed of a silicate soon become alkaline under the influence of atmo- spheric moisture. Professor Bunsen in his Electrolytic Researches has shown that the density of the current is the chief condition under which the electri- city is able to overcome the chemical affinities of different substances.It was very probable therefore that with a current of greater density the formation of the oxides would be prevented as Bunsen found in the preparation of chromium in the moist way.? Experiment showed * Bunsen on Magnesium (Ann. Ch. Pharm. lxnii. 137). t Pogg. Ann. xci. 610. 28 DR. MATTHIESSEN ON THE PREPARATION OF THE METALS OF that this hypothesis was perfectly correct; for if an iron wire of the size of a needle be used instead of the large carbon negative pole globules of potassium sodium calcium strontium &c. &c. are easily reduced; so that in future the preparation of theqe metals will be an easy experiment for the lecture-table. Although so easily reduced it is difficult to obtain the nietal in a coherent mass and to separate it from the surrounding chloride.The reduced metal being specifically lighter than the fused salt it rises to the surface and burns before it can be collected. If one attempts to collect the metallic globules by means of a bell-shaped vessel of glass the metal reduces the silicon which separates out in the form of a black powder and prevents the metal fusing. I propose three methods for avoiding these difficulties,-Firstly by using a platinum wire as negative pole this however gives an impure metal or rather an alloy with platinum which being specifi- cally heavier than the fused chlorides sinks to the bottom of the vessel and is there found as a metallic ball. Secondly by fusing together the chlorides of two metals mixed in equivalent proportions these double chlorides melt at a temperature so low that even potassium and sodium are not volatilised in the melted mass.Tf the heat is regulated in such a manner that a solid crust is formed cin the top of the melted mass only round the negative pole a large quantity of metal is found 011 it after cooling the crucible. The third method consists in the separation of the metal on the immediate sur- face of the melted chlorides by means of a pointed iron wire as pole on to which the fused metal hangs a thin film of melted chloride serves as a varnish to protect it from oxidation. It naturally depends on the metal to be obtained which of the three methods is most applicable. I shall now proceed to describe the preparation and properties of calcium.One method-which is however very uncertain but which if it succeeds gives globules of calcium larger than peas-is the fol- lowing :-A mixture of two equivalents of chloride of calcium and one of chloride of strontium with a small quantity of chloride of ammo-nium is €used in a Hessian crucible; an iron cylinder serving as positive pole is placed in the melted mass; within the iron cylinder is then placed a small porous cell previously made red-hot and after- wards filled with the same mixture fusedin a porcelain crucible. A thin iron wire or fine carbon point serves as the negative pole in the porous cell If the porous cell be filled with mixture from 3 inch to 1 inch higher than the outer crucible it is easy to regulate the fire so that a solid crust shall be formed in the inner cell whilst the outer mass remains liquid.If a current from six of Bunsen’s elements be allowed THE ALKALIES AND ALKAIJNE EARTHS BY ELECTROLYSIS. 29 to pass through the mixture thus arrangedfor half an hour to an hour a large amount of reduced calcium is obtained. I have however only obtained the metal by this method once or twice in globules ; in all the other experiments the metal was reduced in the form of a powder which was present in some parts of the mixture in such quantity that upon being scraped with a knife it showed the colour and lustre of gold alloyed with silver. Such pieces when thrown in water cause a violent evolution of hydrogen and when pulverised under strong alco- hol which dissolves the chlorides leave a metallic powder only slowly oxidable which when rubbed in an agate mortar gives gold-coloured streaks.This method on account of its uncertainty cannot be re- commended and I therefore proceed to describe a more simple and safe one by which calcium is obtained in small globules. The same mixture of salts is used and melted in a small porcelain crucible in which a carbon positive pole is placed and a thin harpsichord wire (wound round a thicker one) dipping only under th6 surface of the melted salt is connected with the zinc of the battery. In order to obtain the beads of calcium which hang on to the fine wire the negative pole must be withdrawn about every two to three minutes along with- the stnall crust which forms around it.The surest method however to obtain the metal although in very small beads is by placing a pointed iron wire merely so as to touch the surface of the liquid the great heat evolved owing to the resistance to the current causes the reduced metal to fuse and drop off from the point of the iron wire and the bead is recovered fi-om the liquid by means of a small iron spatula. The properties of metallic calcium are the following :-It is a light- yellow metal of the colour of gold alloyed with silver; on a freshly filed surface the lustre somewhat decreases the yellow colour which becomes more apparent if the light be reflected several times from two surfaces of calcium a thin film of oxide produces the same effect. The hardness approaches that of gold being from 2to 3.It is par- ticularly ductile and may be cut filed or hammered out to plates having the thickness of the finest paper a piece not larger than a mustard-seed having been flattened to. the size of 10 to 15 square millimetres showing only a few cracks at the border. Concerning the specific gravity of calcium I shall return to it shortly in my paper on strontium and barium. In dry air the metal retains its dour and lustre for a few days only but in presence of moisture the whole mass is slowly oxiclised. Heated on platina foil over a spirit-lamp it burns at a red heat with an excessively bright flash about equal in intensity to the voltaic arc. Calcium is only slowly acted upon MR. R. WARINGTON ON A PECCLIAR by dry chlorine but when heated burns in that gas with a most brilliant light as also in iodine bromine oxygen sulphur &c.With phosphorus it combines without ignition forming phosphide of calcium. Heated mercury dissolves it to a white amalgam. Water is rapidly decomposed by the metal with evolution of great heat and hydrogen ; diluted nitric hydrochloric and sulphuric acids cause a still more rapid decomposition the first acid often causing ignition. Concen-trated nitric acid even when heated almost to boiling does not attack the metal the action not beginning till the liquid boils. By using water as the liquid element calcium is negative to potassium and sodium but positive to magnesium. Nevertheless calcium is not reducible by potassium or sodium from its chloride.This is easily proved by the following experiment :-If 1equivalent of chloride of sodium and 2equivalents of chloride of calcium or equal equivalents of chIorides of calcium and potassium be melted in a small porcelain crucible over a Berzelius spirit-lamp owing to the easy fusibility of the mixtures the metals potassium and sodium may be easily pre- pared by electrolysis when the following precautions are taken :-The heat must be so regulated that a solid crust forms on the surface around the negative carbon pole whilst the mixture remains fused allowing the free evolution of chlorine round the positive pole by this means after the decomposition has continued for about twenty minutes and the cooled crucible has been opened under rock-oil a large amount of potassium or sodium almost chemically pure is generally obtained. If the same experiment be repeated at a white heat in a charcoal fire with an iron wire as negative pole small globules of potassium or sodium are seen burning on the s’urface which when analysed are found to be also almost chemically pure. From these experiments it appears that the metal formerly obtained by the reduction of chloride of calcium with the alkaline metals can- iiot be calcium but was most probably a mixture of potassium or sodiuni with aluminium silicon &c.

ISSN:1743-6893    

DOI:10.1039/QJ8560800027

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年代:1856

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MR. R. WARINGTON ON A PECCLIAR IV.-On a peculiar Eflorescence of the Chloride of Potassium. By ROBE RT WA RI N GTO N . As the chloride of potassium is not usually classed among the efflo-rescent salts in any of the numerous systems or manuals of chemistry the following observations may not be without interest to some of the members of the Chemical Society. EFFLORESCENCE OF THE CHLORIDE OF POTASSIUM. Thia subject was first brought under my notice some few years since by a gentleman in the establishment at the Apothecaries' Hall who had been endeavouring at his own lodgings to manufacture artificial ultramarine in the course of which he had attempted (I believe in a common stove) to fuse silica with carbonate of potash the fusion however had evidently from the appearanceof the substance obtained been imperfectly effected,-from the want I presume of suf-ficient heat ; and the resulting mass had been afterwards treated with hydrochloric acid.Not having obtained the kind of material that had been anticipated owing to the incomplete manner in which the operation had been conducted the whole was set aside for some time when attention was again attracted to it by the appearance of an efflorescent growth which had taken place in the mass and which had ruptured it into fissures in various directions these fissures being filled with bands of a fibrous saline growth very similar in appearance to the well-known double sulphate of iron and alumina or hair ealt of the disintegrated alum shale of Hurlet and Campsie.It was in this state when it was placed in my hands and being anxious as a preliminary to ascertain to what extent this efflorescence would go on it was placed in a shallow dish loosely covered with a small cone of paper to keep off the dust and set aside in a closet. Under these circumstances the beautiful silky growth continued gradually to increase until the crystals had reached a very considerable length and presented an appearance very similar to the tufts of the cotton grass or the long cellular filaments of the thistle down projecting in all directions from the porous matrix of the partially hydrated silica. These filamentous crystals were readily soluble in distilled water yielding a clear and perfectly neutral solution ; and on submitting them to analysis they proved to be entirely composed of chloride of potassiuni.Thus 2 grs. of these effloresced filaments were dissolved in water and the solution evaporated to dryness to ascertain that no trace of silica was present redissolved in water acidulated by nitric acid and precipitated by a solution of nitrate of silver this precipitate col- lected and well washed weighed after drying 3.78 grs. of chloride of silver. The filtered solution and washings were then treated with hydro- chloric acid to throw down the excess of silver salt which precipitate was separated by a filter and the clear liquor evaporated to dryness to decompose all the nitrates. The dry salt was next redissolved in water a little hydrochloric acid added and then precipitated by a solution of bichloride of platinum in excess and the whole again a2 MR Re WARINGTON ON CHLORIDE OF FOTASSLUM.evaporated carefully to dryness. The crystalline product was then washed with ether-alcohol to remove all excess of the test and the double chloride of platinum and potassium thus obtained dried it weighed 6.4 grs. We have therefore :-Chloride of silver . . 3.78= 0.932 chlorine. Chloride of platinum and potassium . 6.40 = 1.028 potassium. 1 -960 Theory. 0-9491 1.0509 When this efllorescent salt is submitted to examination by the microscope it presents many very interesting phenomena each apparently single thread is then found to be built up as it were of an aggregation of smaller filaments intimately united together and a8 I shall presently show having a cubic structure.Viewed by a high magnifying power a very curious appearance is exhibited. The single filaments are seen to be dotted alonp their whole length with slight depressions and these depressions are found to be perfectly equidistant the one from the other over certain given lengths ; thus they are most widely separated at the lower part of the thread or its base and become more approximated for certain intervals of distance as the fibre elongates and gradually becomes smaller in its transverse dimensions. This phenomenon I am induced to believe indicates the step or point at which the growth of each individual crystal has originated and therefore marks its point of attachment with the one previously formed so that the filament ultimately re- sulting may be considered as a series of microscopically minute cubic crystals growing one upon the other continuously and that the intervals of distance by which these depressions are separated from each other will indicate the diameter of the single cubic needle at that particular spot.These intervals of distance measured by a micro-meter in the field of the microscope were found to range from T+o%th to daath of an inch. Again when these filaments are fractured they present a cleavage plane at right angles to the length of the fibre. They also prove to be single refractors or equiaxial crystals,-that is when viewed by polarised light in the field of the microscope placed between the polarising and analysiiig plates or prisms thcy cxhibit no depolarising MR.R. ADIE ON THERMO-ELECTRICAL CURRENTS &C. 33 power nor allow the least ray of light to pass through them in the dark field thus again confirming their structure as being cubical. I may mention here also that Gmelin in his excellent “Manual of Chemistry,” observes that the chloride of potassium frequently crys- tallises from its solutions in cubes prismatically elongated. This appears then to be another instance of the peculiar crystalline growth under the same cubic form which sometimes occurs in solu- tions of the iodide of potassium and a memorandum of which I laid before the Society on the evening of May 3 1852,s The remaining point which presented itself to my attention was to ascertain in what manner I could best preserve this beautiful efflo- rescent growth permanently so as at the same time to admit of its transport without injury to the delicate silky fibres which I had found were liable to fracture by the slightest touch.After some preliminary trials I at last adopted the plan exhibited in the specimen before you in which a thick cream of plaster of Paris and water was first carefully introduced into the interior of the specimen jar so as to cover the bottom to the depth of about half an inch without soiling the sides; and while tbis was still in its semi-fluid state the mass of silica with its impregnating saline matter was carefully imbedded in it and the vessel being loosely covered was set aside. I should state also that the crop of the efflorescent salt which existed on the surface of the mass was first moistened with water in order that it niight be dis- solved and reabsorbed by the porous matrix before being cemented in the bottom of the jar. After a short time the efflorescence gradually commenced anew the crystals slowly rising in tufts of beautiful silky fibres and filling the whole of the lower part of the jar until the filaments had many of them reached the length of from four to five inches. VOL. V1II.-XO. XXIX.

ISSN:1743-6893    

DOI:10.1039/QJ8560800030

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年代:1856

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MR. R. ADIE ON THERMO-ELECTRICAL CURRENTS &C. 33 V.-On the Thermo- Electrical Currents generated in Elements where Bismuth is used to form the Joint. By R I c H A R D ADI E Liverpool. THEuse of bismuth as a solder for thermo-electrical couples appeared to me to be worthy of trial for a variety of metals in order to show the extent to which the action of couples might be governed by the nature of their joint. The arrangement of the bars and wires of me-* Chem. SOC.Qu.J. v. 136. VOL. V1II.-XO. XXIX. D 34 MR. R. ADIE ON 'CHB THERMO-ELECTRIC CURRENTS ffENERATED tals to be tested was to solder them together by means of srriall pieces of bismuth and to form the other extremities of the bars into a circuit with a galvanometer. To each pair under examination heat was applied first on the right hand side and then on the left hand side of the joint when the effeet on the direction of the thermo-elec- tric current generated was observed by the galvanometer.After this manner 72 thermo-electric couples were examined. The following is a summary of the effects observed. In nine metals when two bars of the same metal were joined by bismuth solderings the positive electrical current flowed in an oppo-site direction to that of the heat current. These metals were gold silver platinum copper zinc cadmium antiniony iron and soft steel. In three metals used singly with bibwuth solderings the direction in which the heat crossed the joint and that of the electricity were the same. These metals were palladium lead and tin.Twenty-eight pairs of different elements soldered by bismuth being combinations of the metals tested singly showed the direction in which the heat erossed the joint to be opposite to that of the electricity as in the case of the nine single metals tested,-total thirty-seven pairs. One pair of different metals soldered by bismuth showed heat and electricity to cross the joint in the same direction as in the instance of the three single metals tested. Thirty-one pairs of different metals soldered by bismuth showed the direction of the passage of the heat across the joint not to govern the electrical current ; they acted according to their ascertained thermo-electrioal relation independently of the side of the jaint on which the heat was applied.On looking over these results I was led to examine the instances of the three single and one double pair of elements to see why they differed from the thirty-seven other cases where the direction of the electrical current was governed by the passage of the heat across the joint. Their peculiarity appeared to me to arise from the tendency the bismuth had to alloy with these metals and thus form joints of a mixture of metals which gave them an indefinite character. I conse-quently sought to arrange these fbur cases with bismuth joints of a definite kind. EXPERIMENT €.-Two slips of palladium were soldered together with a thin film of bismuth for the joint; their other extremities were connected with a galvanometer. When heat was applied the passage of the heat an8 electricity across the joint was in the same direction as I had previously noted.The soldered joint was broken asunder ; IN ELEMENTS WHERE BISMUTH IS USED TO FORM THE JOINT. 85 the palladium surfaces cleaned free from the bismuth solder ; and to form a joint a thin piece of bismuth was placed between the two slips of metal and secured in its position by firm tying by this means a couple was obtained where the bismuth had a definite surface. When heat was applied first on the right and then on the left hand side of the joint the heat and electricity crossed it on opposite direc- tions in the same manner as they had done in the thirty-seven cases where the direction of the electrical current was governed by a bismuth- soldered joint.EXPERIMENT 11.-Two pieces of lead-wire were formed into a couple with a small piece of bismuth tied firmly between them. In this case the passage of the heat and electricity across the joint was in opposite directions. EXPERIMENT 111.-Two pieces of tin-wire gave a result similar to No. 11. EXPERIMENT 1V.-A wire of lead and a wire of tin with a piece of bismuth tied between them for a joint gave a similar result to Nos. I. TI. and 111. These four experiments comprise the cases noted in the summary where the passage of the heat and electricity across the joint was in the same direction; they now show the heat and electricity to cross the joint in opposite directions,-a change which has been effected by avoiding the mixture which soldering of these metals would prodnce.To obtain pieces of bismuth for inserting in the joints for the above experiments the point of a bar of that metal was held in the flame of a candle until large tear-like drops fell from it these were received on a smooth surface below in the form of thin circular discs. The discs admitted of being cut into small pieces. The weight of bismuth put in the joints for the above experiments varied from&th to &th of a grain; yet this small quantity of bismuth sufficed to render active pieces of lead and tin which without the bismuth joint would only afford a trace of a thermo-electrical current. The general result proved by thew experiments is that the source of the thermo-electrical current is the surface of a joint,-a fact which gives additional value to an observation I made and which was published in the Edinburgh Philosophical Magazine for 1848 that a pair of bismuth and antimony bars soldered together by pure bis- muth and long employed to generate a powerful therrno-electric current produced a disintegration of the bismuth at its surface of contact with the antimony.

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DOI:10.1039/QJ8560800033

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年代:1856

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36 MR. R. ADIE ON THERMO-ELECTRIC JOIN'CS FORMED WITH W.-On Thermo-ElecfricJoints formed with the metals Aiztirnony Bismuth and Palladium. By RICHARDADIE Liverpool. 1.-A EXPEHIMENT bar of antimony 8 inches long was broken in the centre and soldered together again with pure bismuth ;while the solder was fluid the two pieces of antimony were pressed firmly togethcr so that the coating of bismuth in the joint should be as thin as possible. When the right side of the joint was heated the left became the positive thermo-electric element ;and when the left side was heated the right side stood positive. This efl'ect where the bismuth has no sensible thickness is the same as if a long bar of that metal had intervened between the two pieces of antimony. ~xpmumwr11.-A slip of palladium cut into two had a bismuth joint prepared as thin as possible like the experiment No.I. When the right side of the joint was heated the left in this case became negative; and when the left side was heated the right became negative. EXPERIMENT 111.-The same two pieces of palladium as in the last experiment with a bismuth joint one-tenth of an inch in thick- ness. When heat was applied on the right side of the joint the left side was positive the result showing that the increase in the thick- ness of the bismuth joint had rendered the effect similar to that which would have been produced by a long bar. 1V.-A EXPERIMENT slip of palladium and a bar of antimony formed the couple for this experiment joined together by a thin bismuth joint.The recognised action of these metals when heated together is that palladium beconies positive. When heat was ap-plied to the antimony side palladium was positive; and when heat was applied to the palladium antimony stood positive for fifteen seconds; but as the heat penetrated through the joint the palladium assumed the positive position which it retained. The result of this experiment I consider as valuable for illustrating the action of the first and second surface of a joint; for when the heat is applied to the palladium we have for a short space the first surface in action with antimony positive then a reversal of the current when the heat reaches the second surface. EXPERIMENT V.-A bar of antimony was tied firmly down to a bar of bismuth with a small scale of sulphuret of silver inserted be- tween them for a joint.When the antimony was heated to near 400° THE Bf ETALS ANTIMONY BISMUTH AND PALLADIUM. an attached galvanomcter indicated the passage of a feeble current with the bismuth positive or in its natural thermo-electric position ; and when the heat was applied to the bismuth bar near the joint the galvanometer showed bismuth the negative metal with a feeble current passing. This experiment is not so satisfactory as the one with a sulphuretted silver wire connected with the bismuth being more liable to fail from the couple becoming active at too low a tempe-rature or from the temperature required approaching near the melting-point of bismuth; but it has the advantage of exhibiting the two most opposite thermo-electric elements in an inverted position.My object in giving the results of these experiments is to show cases whcre a thin coating of bismuth in a joint acts in several ways. 1st. The same as if it had been a bar of that metal in Experiment I. Instances of this kind are numerous among thermo-electric couples where the antagonistic negative and positivc properties of the two elements are not strongly marked as in the single metals in zinc and silver in gold and in many of its combinations copper &c. 2nd. Where a thin bismuth joint did not act as if it were a bar and yet the direction of the flow of heat across the joint governed that of the electrical current generated. Cases of this kind are rare.With lead and tin I have met with very feeble currents of a like cha- racter but the arrangement given is the most certain form of the experiment. 3rd. Where a thin bisniuth joint acted for a brief period of time as if it had been a ions bar and then acted like a couple in its recognised thermo-electric position independent of the met hod of applying the heat. I have noticed this property in other thermo- electric couples where palladium formed one of the elements. The permanent action of the joint after a lapse of fifteen seconds whcre the recognised thertnb-electric relation of the elements is maintained notwithstanding the thin bismuth joint or the direction in which the heat is made to cross it is one of frequent occurrence we meet it in the combination of metals which have decided antagonistic thermo-electric positions such as palladium platinum zinc iron antimony &c.; but Experiment V. shows that such ele- ments may have their natural thern~o-electric position inverted by a joint offering greater resistance.

ISSN:1743-6893    

DOI:10.1039/QJ8560800036

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年代:1856

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PROCEEDINGS AT THE MEETINGS OF THE CHEMICAL SOCIETY. January 15 1855. Dr. A. W. WILLIAMSON, Vice-president in the Chair. The following gentlemen were introduced and admitted Fellows of the Society :-Nevi1 Story Maskelyne Esq. M.A. Oxford. H. J. Smith Esq. B.A. Oxford. Charles Loudon Bloxam Esq. King’s College London. Charles W. Heaton Esq. 26 Lime Street. Fletcher Norton Esq. 5 Stanhope Street Hampstead Road. The following donations were announced :-“The Journal of the Society of Arts :” from the Society. “The Pharmaceutical Journal :” from the Editor. ‘I Report of the Art-Union of London :” from the Society. ‘I The Art-Union Almanack :” from the Society. The following gentlemen were duly elected Fellows of the Society :-Matthew Warton Johnson Esq.Charles Tookey Esq. 3,Mytre Street Clarernont Square. PROCEEDINGS OF THE CHEMICAL SOCIETY. The following papers were read :-I( On Thermo-Electric Joints formed with the metals Antimony Bismuth and Palladium :” by Richard Adie of Liverpool. (‘Investigation of the Vegetable Tallow from a Chinese Plant the ‘Stillingia sebifera’ :” by Nevi1 Story Maskelyne M.A. F.G.S. “On the Absorption of Chlorine in Water:” by H. E. Rooeoe B.A. Ph.D. February 5 1855. Dr. H. BENCEJONES, Vice-president in the Chair. The following donations were announced :-“The Literary Gazette :” from the Publishers. “ The Journal of the Photographic Society :” from the Society. “ The Pharmaceutical Journal :” from the Editor. “ l‘he Transactions of the Royal Scottish Society of Arts Val.fV. :” from the Society. “Transactions of the Royal Society of Edinburgh Vol XXI. Part 1 for 1853 and 1854;” and ‘‘Proceedings of the Royal Society of Edinburgh 1853 and 1854 :” from the Royal Society of Edinburgh “Traiisactiona of the Royal Society of London for 1851,1852 1853 and parbof 1854 :” from the Royal Society. “List of the Council and Fellows &c. of the Royal Society Nov. 30,1853 :” from the Royal Society. “Illustrated Catalogue of the Calculi and other Animal Concretions contained in the Museum of the Royal College of Surgeons Parts 1 and 2 :” from the Royal College of Surgeons. (‘An Account of the Organic Chemieal Constibuentd OT Iriter-mediate Principles of the Excrements of Man and Animals ia the healthy state; by W.Marcet M.D. :” from the Author. “The Journal of the Franklin Institute for Novembm and De-cember 1854:” from the Institute. “ Sitzungsberichte der kaiserlichen Akademie der Wissenschaften mathematisch-naturwissenschaftliche Classe,” Band 12 Heft 5 ; Band 13 Heft 1and 2. Register zu den ersten 10&inden der Sitzungsberichte geognos- tische Karte der Umgebungen von Krerns und von Manhardsberge.” PROCEEDING8 OF THE CHEMICAL SOCIETY. “Jahrbuch der kaiserlich-koniglichen geologischen Reichsanstalt,” 1854 No. 2 April May June Wien. “Jahrbucher der kaiserlich -koniglichen Central-Anstalt fiir Meteorologie und Magnetismus von Karl Kreil Wien :” Band 1 1848 aud 1849; Band 2 1850. “ Ueber die Nicht-einfachheit der Metalle des Schwefels der Kohle des Chlors von K ot ik o v sky Wien.” ‘‘ Ofversigt af Kongl Vetenskaps Akademiens forhandlingar ; Tionde irgkgen 1853 Stockholrne.” ‘‘Bulletin de la Soci6t6 Vaudoise des Sciences Naturelles :” Tome 3 Bulletin 30; Tome 4 Bulletin 32.The following gentlemen were duly elected Associates of the Society :-Frederick St ohm an n University College. Frederick Ver smano University College. The following papers were read :-‘<On a peculiar Efflorescence of Chloride of Potassium :” by Robert Warington. “On the Preparation of the Metals of the Alkalies and Alkaline Earths by Electrolysis :” by A. Matthiessen Ph.D. February 19 1855. Dr. A. W. WILLIAMSON, Vice-president in the Chair. The following donations were announced :-“The Literary Gazette :” from the Publishers.The Journal of the Society of Arts :” from the Society. “The Edinburgh Medical and Surgical Journal :” from the Pub- lishers. “ The Journal of the Franklin Institute :” from the Institute. The American Journal of Science and Arts :” from the Editors. A paper was read :-“On the Thermo-Electrical Currents generated in Elements where Bismuth is used to form the Joint :” by Richard Adie of Liverpool. PROCEEDINGS OF THE CHEMICAL SOCIETY. March 5 1855. COLONEL PHILIPYORKE,President in the Chair. The following donations were announced :-‘‘The Literary Gazette :” from the Publishers. “The Journal of the Society of Arts :” from the Society. ‘‘The Journal of the Photographic Society :” from the Society.‘(The Pharmaceutical Journal :” from the Editor. ‘I The Quarterly Journal of the Geological Society :” from the Society. ‘‘The Journal of the Franklin Institute :” from the Institute. Afr. John Jones Bancroft of Ruthen North Wales was duly elected a Fellow of the Society. Dr. W. Odling made a verbal communication on “Chemical Notation.” March 19 1855. Dr. G. D. LONGSTAFF, Vice-president in the Chair The following donations were announced :-‘I The Literary Gazette :” from the Publishers. ‘‘The Journal of the Society of Arts :” from the Society. ‘‘The Journal of the Photographic Society :” from the Society. Dr. W. A. Miller delivered a discourse upon the “Action of Water on Lead.” March 30 1855.Dr. A. W. WILLIAMSON, Vice-president in the Chair. The Report of the Council and the Audited Account of the Treasurer were read. hlr. E. W. Brayley and Dr. W. Odling having been appointed Scrutators the meeting proceeded to the election of Council and Officers for the ensuing year and the following gentlemen were declared to have been duly elected :- PROCEEDXNOS OF THE CHEMICAL SOCIETY. PRESIDENT. W. A. Miller M.D. F.R.S. VICE-PRESIDENTS (WHO HAVE FILLED THE OFFICE OF PRESIDENT.) W. T. Brande F.R.S. Thomas Graham F.R.S. C. G. B. Daubeny M.D. F.R.S. Colorfel Philip Yorke F.R.S. VICE-PRESIDENTS. Warren De la Rue Yh.D. F.R.S. G. D. Longstaff M.D. H. Bence Jones M.D. F.R.S. A. W. Williamson Ph,D. SECRETARIES. B. C.Brodie F.R.S. Theophilus Redwood Ph.D. FORE1GN SECRETARY. A. W. Hofmann Ph.D. F.R.S. TREASURER. Robert Porrett F.R.S. OTHER MEMBERS OF THE COUNCIL Thomas Anderson M.D. Charles Heisch Esq. G. B. Buckton F.L.S. Hugh Lee Pattinson F.R.S. DugaZd Campbell Esq. John Stenhouse LL.D. F,R.S. J. H. Gladstone Ph.D. F.R.S. R. D. Thornson M.D. F.R.S. W. C. Henry M.D. F.R.S. Robert Warington Esq. William Herapath Esq. John Thomas Way Esq. The thanks of the meeting were voted to the President Officers and Council for their services during the past year.

ISSN:1743-6893    

DOI:10.1039/QJ8560800038

出版商:RSC    

年代:1856

数据来源: RSC

摘要:

NOTICES OF PAPERS CONTAINED IN OTHER JOURNALS. BYHENRYWATTS, B.A. F.C.S. On Osmotfe Force.* By Thomas Graham F.R.S. &c. THEexpression ‘‘Osmotic Force” (from &q-& impulsio)has reference to the endosmose and exosmose of D u t r oche t. The force of liquid diffusibility will still act if we interpose between the two liquids a porous sheet of animal membrane or of unglazed earthenware; for the pores of such a septum are occupied by water and we continue to have an uninterrupted liquid communication between the water on one side of the septum and the saline solution on the other side To impel by pressure any liquid through the pores of such a septum may be extremely difficult from the interference of frictional resistance and the attraction of capillarity.But these last forces act on masses and not on molecules and the ultimate particles of water and salt which alone diffuse appear really to permeate the channels of the porous septum with little or no impediment. A comparative experi- ment on diffusion with and without septa is easily made by means of a widemouthed phial which is filled completely with saline solution and then immersed in water in one experiment with the mouth of the phial open and in the other experiment with the mouth covered by membrane. In a fixed time such as seven days a certain quantity of salt leaves the phial by diffusion. This quantity was reduced to one-half when the strong and thick membrane of the ax-gullet was used to cover the mouth of the phial; and it was not affected in a sensible degree by passing through a thinner membrane consisting of ox-blad- der with the outer mugular coat removed.In the last experiment the actual diffusates were 0.631 grm. common salt in the absence of the membrane and 0.686 grm. common salt with the membrane interposed which may be considered as the same quantity. The diffusion of a salt appears ta take place therefare without difficulty or loss through the substance of a thin membrane although the mechanical flow of a liquid may be nearly stopped by such an obstacle It is well to bear in mind the last fact in the coosideration of what * Phil. Trans. 1854 1’77. PROFESSOR QRAHAAI ON is seen in an endosmotic experiment. An open glass tube with one end expanded into a bell form and covered by tight membrane forms a vTssel which may be filled with a saline solution and immersed in a jar of pure water.The volume of liquid in this osmometer soon begins to increase and is observed to rise in the tube while the simiiltaneous appearance of salt in the water of the jar may easily be verified. M. Dutrochet described the result as tbe movement of two unequal streams tbrough the membrane in opposite directions the smaller stream being that of the saline solution flowing outwards and the larger that of pure water flowing inwards. The double current has been always puzzling but the expression of the fact becomes more conceivable when we say (as we may do truly) that the molecules of the salt travel outwards by diffusion through the porous membrane.It is not the whole saline liquid which moves outwards but merely the molecules of salt their water of solution being passive. The inward current of water on the other hand appears to be a true sensible stream or a current carrying masses. The passage outwards of the salt is inevitable and being fully accounted for by diffusibility requires no further explanation. It is the water current which requires consideration and for which a cause must be found. This flow of water through the membrane I shall speak of as osmose and the unknown power producing it as the osmotic force. It is a force of great inten- sity capable of supporting a column of water many feet in height as shown in Dutrochet’s well-known experiments and to which naturalists are generally disposed to ascribe a wide sphere of action both in the vegetable nnd animal kingdoms.Cannot liquid diffusion itself it may first be asked contribute to produce osmose ? Diffusion is always a double phenomenon and while molecules of salt. pass in one direction through the membrane molecules of water no doubt pass by diffusion in the opposite direction at the same time and replace the saline molecules in the osmometer. Water also is probably a liquid of a high degree of diffusibility; at least it appears to diffuse four times more rapidly than alcohol and four or six times more rapidly therefore than the less diffusive salts. A possible consequence of such inequality of diffusion is that while one grain of a certain salt diffuses out of the osmometer foixr or six grains of water may diffuseinto the osmometer.Liqiiid diffusion I believe generally tends to increase the volume of liquid in the osmometer and a portion if not the whole of the small osmose of chloride of sodium sulphate of magnesia alcohol sugar and many other organic substances may be due to the relatively low diffusibility of such liquefied bodies compared with the diffusibility of water. But many substances it will immediately appear are replaced in experi- ments of endosmose not by four or six but by several hundred times their volutne of water and manifestly some other force besides diffusion is at work in the osmometer. OSMOTIC FORCE. An explanatiori of osmose has been looked for in capillarity by Poisson Magnus and by Dutrochet himself.Combining diffusion with this idea we might imagine that the pure water which first occupies the pores of the septum suffers a sudden and great loss of its capillarity-force when the salt of the osmometer enters the pores by diffusion and niixes with the water they contain. Experiments pub- lished by Dutrochet give a capillary ascension to pure water of 12 millimeters and to a solution uf common salt of density 1.12 6.14 millimeters or only one-half of the former ascension. If a porous septum occupied by such a saline solution had the same solution in contact with one surface and pure water in contact with the other surface (the actual condition of the septum in an osmotic experiment) tbe pure water should enter its pores from its high capillary attraction and like a solid piston force out the saline solution from them the saline solution so displaced would go to swell the liquid within the osmometer.When the pure water now again occupying the pores catne in time to acquire salt by diffusion the displacement would be repeated and a continuous osmose or flow of water inwards be in fact established. This explanation is attended with certain physical difficulties but it is unnecessary to discuss these as the experimental basis of the hypothesis is unsound. The great inequality of capillarity assumed anion5 aqueous fluids does not exist. Many saline solutions which give rise to the highest osmose are I find undistinguishable in capil- larity from pure water itself.To obtain constant results with saline solutions the capillary tube must be retained for some minutes in the saline solution at a boiling temperature and afterwards be cooled without removal from the liquid otherwise the indications are singu- larly irregular and most fallacious. The near equality in capillarity of solutions of the most different composition is very apparent in my observations which are placed together in the following series of capillary ascensions :-Capillary ascension of several liquids in the same glass tube. Miilimeters. Water at 58' F. . 17-75 Water at 66O . . 1755 Carbonate of potash 0.25 per cent. in water at 63' 17.2 Carbonate of potash 10 per cent. in water at 66O. 17.55 Carbonateof soda 1 per cent.at 61° . . 17-55 Carbonate of soda 10 per cent. at 55' . 16.85 Sulphate of potash 1 per cent. at 58' . 17.15 Sulphate of potash saturated solution at 58' . 16.3 Sulphate of soda 1 per cent. at 55' . . . 17.75 Sulphate of soda 10 per cent. at 58' . . 16-95 Hydrochloric acid 1 per cent. at 63' . . 17.5 PROPGSSOR GRAHAM ON Millimeters. Sulphuric acid 0-1per cent. at 63' . . 17.4 Sulphuric acid 1 per cent. at 63O. . . . 16.35 Sulphuric acid 5 per cent. at 63' . 16.65 Sulphuric acid 10 per cent. at 63' . . 16-25 Sulphuric acid undiluted (HO SO,) at 63' . 8.1 Oxalic acid 1 per cent. at 66' . . . 17.35 I Oxalic acid 4 per cent. at 62' . . 17.2 Ammonia 0.1 per cent.,.at 66' . . 16.65 Ammonia 1 per cent.at 66' . . . 16.15 Ammonia 12 per cent. (0.943 sp. gr.) at 66' . 15-05 Sugar 10 per cent. at 65' . . . 16.3 Alcohol 0.8per cent. (0.9985 sp. gr.) at SO0 . 15.5 Alcohol 495 per cent. (0.992 sp. gr.) at 63' . 13.2 Alcohol 7.8 per cent. (0-987sp. gr.) at 60" . 11-05 Alcohol 71 per cent. (0.869 sp. gr.) at 63' . . 6-Alcohol falls in the greatest degree below water in capillarity yet the former eubstance is one of the least remarkable for the power to occasion osmose. The newer facts to be related also in- FIG. 1. crease the difficulties of the capillary theory of osmose. My own experiments on osmose were made with both mineral and organic septa. 1. A convenient earthenware or baked clay osmometer is easily formed by fitting a glass tube and cover to the mouth of the porous cylinder often used as a cell in Grove's battery as in Fig.1; the cylinder was geneidly five inches in depth by 1.7 inch in width inside measure and was capable of holding about six ounces of water. Gutta percha is much preferable to brass as the material for the cap or cover. The glass tube above was also compara- tively wide being 0.6 inch or 15 milli-meters in diameter and was divided into millimeters. It was not more than 6 inches in length. Each of the divisions or degrees amounted approximatively to +th part of thecapacity of the clay cylinder. In conducting an experiment the cy- linder always previously moistened with pure water was filled with any saline solu- tion to the base of the glass tube and immediately placed in a jar of distilled OSMOTIC FORCE.water of which the level was kept adjusted to the height of theliquid in the tube of the osmometer throughout the whole experiment so as to prevent inequality of hydrostatic pressure. The volume of water in the jar was comparatively large fifty to eighty ounces. The rise or fall of the liquid in the tube was noted hourly for five hours. This rise commenced immediately and was pretty uniform in amount for each hour during the short period of the experiment. The object aimed at was to observe the osmose of the solution before its composition was materially altered by dilution and the escape of salt by diffusion. The quantity of salt diffused from the osmometer into the water-jar during the experiment was also observed.After every experi- ment the osmometer was washed out by distilled watcr which was allowed to permeate the porous walls of the cylinder under the pressure of a column of water of about 30 inches in height for eighteen hours. All the experiments were made at a temperature between 56' and 64'. The clay osmometer attained a considerable degree of uniformity in its action when the Same saline solution was diffused from it once in each of two or three successive days with a washing between each experiment. A single observation is not much to be relied upon as the first experiment often differs considerably from the others. Om per cent. solutions were always used when the propor- tion of salt is not specified.Much larger proportions of salt have hitherto been generally employed but it was early observed that the osmose absolutely greatest is obtained with small proportions of salts in solution. One part of salt to 400 water gives a higher osmose in earthenware than any other proportion for the great majority of sub-stances. Osmose appeared indeed to be peculiarly the phenomenon of dilute solutions. With the same proportion (1per cent.) of different substances the osmose varied from 0 to 80 degrees. Occasionally instead of a rise of liquid in the tube a fall was observed; the fall ntay be spoken of as negative osmose to distinguish it from the rise or positive osmose. Soluble substances of every description were tried and find a place in the following classes :-1.Suhtances of small osmotic power in porous earthenware; osmose under 20 of the millimeter degrees (tns.) This class appears to include nearly all neutral organic substances such as alcohol pyroxylk spirit sugar glucose mannite saliein amygdztlin salts of quinine and morphine tannin urea ; also certain active chemical substances which are not salts nor acids; chlorine water bromine water. The great proportion of neutral salts of the earths and metals proper also belong to the same class such as chloride of sodium of which the positive osmose was greatest in a solution containing no more than 0.125 per cent. being 19 ma. with that proportion of salt but falling off and often becoming slightly negative with 1 per cent. PROFESSOR QRAHAM ON and higher proportions of salt in solution.Chloride of potassium is similar. Nitrate of soda gave an osmose of 8 nitrate of silver of 18 ms. The salts of the magnesian oxides are all low and sometimes slightly negative. Chlorides of barium and strontium both gave IS ms.; nitrate of strontia 5 rns. ; sulphate of magnesia 0.5 per cent. 2 ms. ; 2 per cent. 3 ms. ; sulphate of zinc was very similar + 2 to -2 ms. from 0.5 to 2 per cent. ; chloride of mercury 1per cent. gave 6 and 8 ms. in two experiments. 2. Substances of an intermediate degree of osmotic force ; osmose from 20 to 35 degrees. Sulphurous acid gave 20 ms. Certain vege- table acids have a similar osmose. Tartaric acid in solutions of 0.25 1 and 4 per cent.gave 24 26 and 28 ms. ; citric acid 1 per cent. 30 ms. Also monobasic acids such as hydrochloric acid nitric acid acetic acid have the same moderate osmotic action in porous earthen- ware. -3.Substances of considerable osmotic power in porous earthenware; osmosefrom 35 to 55 ms. In this class are found the polybasic mineral acids sulphuric acid 0.5 per cent. gave even 63 ms. ; 2 per cent. 54 ms. or nearly the same osmose as the smaller proportion of acid. In another earthenware cylinder the following observations on the osmose of sulphuric acid were successively made :-Millimeters. 0.1 per cent . 43 and43 1 per cent. . 40and40 4 per cent. . 41 and 39 10 per cent. . 38and39 The results exhibit much similarity of osmose through a great range (1to 100)in the proportion of acid.So small a quantity of this acid as one part in 1000 water appears to give as great an osmose as any larger proportion of acid. Certain neutral salts sulphate of potash sulyhate of soda sulphate of ammonia belong to the same class. With sulphate of soda the osmose for the different proportions 0*125,0*25, 1 and 4per cent. of salt was 46 47 36 and 24 ms. respectively ; the osmose diminishing with the increased proportion of salt. Of sulphate of potash 0.25per cent. gave 51 ms.; 1per cent. 46 ms. and 4 per cent. 38 ms. showing no great change from one quarter to 4 per cent. ; chromate of potash 1per cent. gave an osmose of 54 nis. 4. Substances exhibiting the highest degree of osmotic power in porous earthenware.OSMOTIC FORCE. Salts of the alkalies possessing either a decided acid or alkaline reaction and certain neutral salts of potash. Binarseniate of potash gave 66 ms. ;Rochelle salt 82 ms. With binoxalate of potash the osmose observed in an earthenware osmometer was- Millimetera. For 092 per cent. . . 3.2 0.05 per cent. . . 55 0.1 per cent. . . 63 0.25 per cent. . . 70 (highestj 1 per cent. . . 63 2 per cent. . . 56 Of salts having alkaline properties phosphate of soda gave 70.5; borax carbonate of soda and bicarbonate of soda all gave numbers which ranged above 60 ms. in various osmometers. To the same class also belong certain strong acids phosphoric acid giving an osmose of 62 ms.glacial phosphoric acid of 73 ms. The caustic alkalies have probably too strong a disorganizing action upon the septum to allow osinose to proceed undisturbed. They give a positive osmose when present in a minute proportion but very soon attain their term moyen and then become slightly negative. Caustic soda 0.01 per cent. gave 24 ms. ;0.02 per cent. 29 ms. ; 0.05 per cent. 31 ms. which was the highest osmose observed; 0.1 per c_ent. 22 ms. ; 0.25 per cent. 3 ms. ; 1per cent. and 2 per cent. of caustic soda gave both -10 ms. It appears most clearly that highly osmotic substances are also chemically active substances. Both acids and alkaline substances possess the affinities which would enable them to act upon the silicates of lime and alumina which form the basis of the earthenware septum.Lime and alumina were aecordingly found in solution after osmose and the corrosion of the septum appeared to be a necessary condition of the flow. It was found impossible to exhaust the whole soluble matter of the walls of the earthenware osmometer by washing either with water or with a dilute acid for the process of decomposition appeared to be interminable. After such washings the action of an osmometer was often greatly modified upon salts of moderate osmose such as chloride or sodium ; and similar changes gradually took place in the osmometers when used in ordinary experiments with saline solutions. It is on this account that I avoid the lengthened detail of numerous experiments which were made with the earthenware osmometer and confine myself to general statements.Further the potash salts were also largely kept back or absorbed by the earthenware a pheuomcnon of the same class as the retention VOL. VII1.-NO. XXIX. E PROFESSOR GRAHAM ON of alkalies by aluminous soils which has been studied by Mcssrs. Thoinson and Way. Other septa which were not acted upon by the salts were found deficient in osmotic activity although possessed of the requisite degree of porosity. Gypsum compressed charcoal and tanned sole- leather gave rise to no osmose when permeated by saline solutions. White plastic clay had an osmotic power which was quite insig- nificant when conipared with that of baked clay now the former may be considered as an aluminous compound upon which the de- composing action of water has been already exhausted while the latter is in a form more liable to decomposition in consequence of an effect of heat upon the constitution of the aluminous silicates of the clay.A plate of Caen stone which is an impure limestone was greatly more active with a solution of carbonate of potash than apiate of pure white marble was. The effect of impurities in making lime- stone suitable for osmose did not escape the observation of D utrochet ; it was referred by him to the attraction of alumina for water. Mere capillarity therefore is insufficient to produce the liquid move- ment while the vis motrix appears to be some form of chemical action. For the proper appreciation of a chemical theory of the osmotic force I would now invite attention to a purely speculative subject namely the molecular constitution of water and saline solutions.Allowing that water in the state of vapour is corrcctly represented as a compotind of one equivalent of oxygen and one of hydrogen it may still be true that the molecule of Ziqztidwuter is a varying aggregate of many such molecules or is n times HO. But if so much is conceded a new and peculiar grouping of the atoms of oxygen and hydrogen becomes not only possible but probable. Instead of arranging them in a series of pairs of H +0 H +0 in our compound molecule we may give a binary form to that molecule in which a single atom of oxygen is the negative or chlorous member and the whole other atoms united together form a positive or basylous radical.In thismdical we have a certain multiple of HO with ortc H in excess the last condition being most usual in compound radicals such as ethyl methyl benzoyl &c. which have all a single unbalanced equivalent of hydrogen ; H,O,= (k!m+lOm)+0. Further this new oxide should be more easily decomposed than oxide of hydrogen HO. The basicity of the radical (Hm+ depends upon the disproportion of the equivalents of oxygen and hydrogen in its constitution there being one of hydrogen in ~XCCYS. Now that disproportion becomes less as we ascend as in 3H+20 11H +100 1OlH+1000; and the more feeble the basyl-atom it may be supposed to retain less forcibly its fellow oxygen-atom or other negative element with which it iscombined.When water therefore has to undergo decomposition in a voltaic circle it will naturally assunie the molecular OSMOTIC FORCE. wrangement supposed as being the binary form which is most easily divisible into a positive and negative element or that in which water is most easily decomposed. This molecular view has been brought forward at present principally for the aid which it gives in conceiving what is known as electrical endosmose. This interesting phenomenon first well developed by our colleague Mr. Porrett has very lately been defined with great clearness by M. Wiedemann.* The water which accumulates at the negative pole (or follows the hydrogen) in the electrolysis of the pure liquid is found to be exactly proportional to the amount of circulating affinity ; that is with every equivalent of hydrogen that is discharged at the negative pole the same quantity of water arrives there and will force its way through a porous diaphragm to reach that destination.The reason now suggested is that the travelling basylous atom in the voltaic decomposition IS not hydrogen simply but the voluminous basylous molecule (H,+lOm) above described; which again breaks up at the negative pole into hydrogen and water (Hm+lOm) =mHO and H. But even although such a representation of the circumstances of electrical endosmose may not be fully admi'tted the phenomenon itself is of great service to us as showing that in the occurrence of chemical decompositions affecting ultimate particles sensible volumes of water may be involved and set in motion.Further in considering the action of chemical affinity between bodies in solution between an acid and alkali for instance we are apt to confine our attention to the principal dctors in the combination and to neglect entirely their associated water of hydration. Yet both the acid and base may have large trains of water attached to them by the tie of chemical union. Sulphuric acid certainly evolves heat with the fiftieth equivalent of water that is added to it and probably in dilute solution that acid is capable of having a still greater number indeed an indefinitely large number of equivalents of water conibined with it. In fine there is reason to believe that chemical affinity passes in its lowest degrees into the attraction of aggregation.The occurrence of chemical deconiposition within the substance of a porous resisting septum may be calculated to bring into view the movement and disposal of the water chemically associated in large quantities with the combining substances ; as the interposition of a porous diaphragm in electrical endosmose makes sensible a translation of water in voltaic decompositions which is not otherwise observable. 11. The osmose of liquids has hitherto been principally studied in septa of an.imnZ membrane which from their thinness their ready permeability combined with a sufficient power of resistance to the f Pogg. Ann. lxxsvii. 321. PROFESSOR GRAHAM ON passage of liquids under pressure have great advantages over mineral subst an ces.The great proportion of the experiments of the present inquiry were also made with animal membrane. The membrane osmometer employed which is only a modification of the classical instrument of Dutrochet was prepared as follows :-The mouth of a little glass bell-jar A (fig.2) had first loosely applied to it a plate ofperforated zinc B slightly convex and then the membrane was tied tightly over the latter for the sake of support (fig. 3). The FIG.2. FIG.3. B quantity of metal removed in the perforations of the zinc plate amounted to 49 per cent. of the weight of the zinc. This plate was always varnished or painted to impede if not entirely prevent the solution of the metal by acid fluids.The usual diameter of the bulb was about 3 inches or 75 millimeters and its capacity equal to 5 or 6 oz. of water. The tube C was usually not more than 6 inches in length but comparatively wide its diameter being about 7-5 millimeters that is one-tenth of the diameter of the mouth of the bulb and it was divided into millimeters. The action of an osniomcter depends chiefly upon the extent of membrane-surface exposed and very little upon the capacity of the instrument. Hence the relation of diameters (or areas) between the bulb and tube was adopted in preference to the relation in capacity the area of the section of a tube being one-hundredth of the area of the disc of membrane or rather it was reduced by calcu-lation to this relation by means of a coefficient for each instrument.OSMOTIC FORCE. Hence a rise of liquid in the tube amounting to 1.00 millimeters indicates the adrnission into the bulb of a sheet of water of 1 millimeter (one twenty-fifth part of an inch) in depth over the whole surface of the membrane and so in proportion for aoy otber rise in the tube. These millimeter divisions {ms.) of the tube mark therefore deqrees of mmose which have an absolute and equal value in all instruments. The bulb of the instrument filled with the solution to be operated upon was placed within a cylindrical glass jar of distilled water con- taining at least sixty ounces (fig. 4) and during the experiment inequality of hydrostatic pressure was carefully avoided by maintain- ing the surface of the water in the jar at the level of the liquid in the tube.The osnionieterwas supported upon a tripod of perforated and painted zinc at a height of about 4 inches from the bottom of the glass cylinder. The osmose was observed hourly for five hours during which time it advanced in general with coiisiderable uniformity. In an experiment with fresh ox-bladder as the septum and a solution of 1 per cent. of carbonate of potash in the osmometer the rise in five consecutive hours was 10 12 11 14 1.3 millirneter degrees and in five hours iniinediately following 13 12 9 11 and 12 niilIimcter degrees making sixty degrees in the first and fifty-seven degrees in the second period of five hours. The quantity of salt which diffused outwards during the experiment of five hours was also frcquently determined usually by evaporating the liquid of the water-jar to dry- ness; it rarely exceeded one-tenth part of the salt originally present in the osmometer.The membrane itself was also weighed before it was applied to the osmometer and again when its use was discontinued which was generally after six or eight experiments had been made with the membrane. A loss of the substance of the membrane was always observed varying from 20 to upwards of 40 per cent. of its original weight. The outer miiscular coat of bladder soon becomes putrescent and from changes in its consistence and the large quantity of salts and YROPESSOR GRAHAM ON other soluble substances which it yields by decomposition gives occa- sion to much irregularity in the experiments.The great change in the amount of osmose often produced by merely turning the memhrane observed by M. Mat teucci and others depends often I believe upon the soluble matter of the muscular coat being thrown outwards or inwards according as the membrane is applied. The muscular coat was on this account removed from the ox-bladder employed and the serous membrane remaining found to acquire greatly increased activity and also to act with much greater regularity in successive experiments. The membrane so prepared could be used for weeks together without the slightest putrescence of any part of it. Two of these thin mem-branes or a double membrane were often applied. The weight of a disc of single membrane 44 inches in diameter in a dry state varied from about 0.5 to 1.2 gramme.The soundness of the membrane of an osmometer and its degree of permeability were always roughly tested Before an experiment by filling the bulb without its tube completely with water hanging it up in air and observing how frequently a drol) fell from the instrument. The time between each drop' varied with suitable membranes from one to twenty minutes. The times in which water permeated the same membranes by osmose varied between much narrower limits perhaps from one to two. The quantity of salt which traversed different membranes by diffusion was also found to be in proportion to the osmotic permeability of the membranes and not to their nicchanical porosity.To wash the membranes they were maceiated in distilled water after every experiment for not less than eighteen hours without being ever removed from the glass bulb. A membrane also was never allowed to dry but was kept humid as long as it was in use for experiments. Osinose in membrane presented many points of similarity to osrnose in earthenware. The membrane was constantly undergoing decom- position soluble organic matter being found both in the fluid of the osmometer and in the water of the outer jar after every experiment ; and the action of the membrane appeared to be exhaustible although in a very slow and gradual manner. Those salts and other substances of which a small proportion is sufficient to determine alarge osmow are further all of the class of chemically active substances while the great mass of neutral organic substances and perfectly neutral monobasic salts of the metals such as the alkaline chlorides possess only a low degree of action.When a solution of the proper kindris used in the osmometer the passage of fluid proceeds with a velocity wholly unprecedented in such experiments. Take for instance the rise in five hours exhibited in a series of experiments upon solutions of several different proportions of carbonate of potash made in succession with the same membrane in the order in which they are related. OSBfOTIC FORCE. 55 Millirnet eps. With 0.1 per cent. carbonate of potash a rise of 182 With 0.1 per cent. carbonate of potash a rise of 120 With 0.1 per cent.carbonate of potash a rise of 199 With 0.5 per cent. carbonate of potash a iise of 246 With 0.5 per cent. carbonate of potash a rise of 194 With 1 per cent. carbonate of potash a rise of 205 With 1 per cent. carbonate of potash a rise of 207 Or the rise in the same tinie with another membrane which had been pqeviously exposed to a steam heat of 212' for ten minutes without impairing its activity. Milliinetew. With 1 per cent. carbonate of potash at 60' F. a rise of 402 With 0.1 per cent. carbonate of potash at 60' F. a rise of 196 With 0.1 per cent. carbonate of potash at 60' F. a rise of 153 With 2 per cent. carbonate of potash at 60' F. a rise of 511 With 4 per cent. carbonate of potash at 60" F. a rise of 781 With 10 per cent.carbonate of potash at 60' F.,a rise of 863 In thc last experiment a rise of fluid in the tube of upwards of 30 inches occurs in five hours and so much water is impelled through the membrane as would cover its whole surface to a depth of 8.6 millimeters or one-third of an inch. Both membranes bat particularly the first show the comparatively great activity of small propoldions of salt the average osmose of 0.1 per cent. of carbonate of potash in the first osmometer being 167 millimeter degrees and of 1 per cent. 206 millimeter cleyrees. Now the quantity of carbonate of polash which diffuses out of the osmometer into the water-jar was determined by the alkalimetrical method in the second and third of the 0.1 per cent. observations first related and found to be in both cases 0.018 gratnme (0-28 grain) ; the quantity of water also which entered in return can be calculated from the known capacity of the tube of the osnioinetw of which each niillimeter division represented 0.060 gr:imnie of water ; and conseqaen tly 167 divisions represent 10.020gramrnes (155 grains) of water.We have in 0.1 per cent. solution,- Mcan diffusate of carbonate of potash . 0.018 grm. = 1 Mean osmose (of water) . 10.020 grms.=556 The conelusion is that while the membrane was traversed during the five hours of an experiment by 1 part of carbonate of potash passing outwards it was traversed by 556 parts of water passing inwards. In the two experiments with 1 per cent. solution of carbonate of potash in the same osmometer the diffusates were 0.192 and 0.198 gramme of carbonate of potash which are sensibly ten times greater than the diffusates of the 0.1per cent.solution. But the mean osmose PROFESSOR GRABA lf ON of the 1 per cent. solutions is greater than that of the 0.1 per cent. solutions only in the proportion of 206 to 167 or as 1to 0.81. The ratio in question however varies greatly in different membranes. We have consequently in 1 per cent. solution,- Mean diffusate of carbonaie of potash . 0.195 grm. = 1 Mean osmose (of water) . . 13.360 grms. =63.4 Whatever therefore be the nature of the chemical action occurring in the membrane which influences osmose a minute amount of that action appears to be capable of producing a great mechanical effect.All idea of contractility or organic structure being the foundation of the osmotic action of membrane was excluded by the observation that similar large effects could be obtained from a septum of pure coagulated albumen. A convenient albumen osmometer is constructed by covering the opening of the bulb of the former instrument by ordinary thin cotton calico which is best applied wet and painting over the outer surface of the calico two or three times with undiluted egg albumen an hour being allowed to elapse between each application of the albumen. The instrutnent is then suspended in the steam rising from boiling water for a few minutes so as to completely coagulate the albumen. The albnniinated calico may then be macerated for twenty-four hours before use by placing the osmometer in cold water to dissolve out the soluble salts of the albumen.It should be preserved always in a humid state. Before application to the calico the albumen in many cases was neutralised with acetic acid and filtered the more completely to obliterate every trace of organic structure. The osniose in a particular instrunient of this kind was at 50° for Millimeters. 1 per cent. carbonate of potash 1 per cent. carbonate of potash1 per cent. carbonate of potash 0.1 per cent. carbonate of potash0.1per cent. carbonate of potash . . . . . . 211 . 367 . 387 . 127 . 124 The correct rate is rarely obtained in the first observation as seen above in osmometers of albumen as well as of other materials.The albumen plate has generally a greater thickness than prepared membrane which appears to diminish proportionally the quantity of salt which escapes by diffusion. The diffusate in the three experiments above of 1 per cent. carbonate of potash was 0.024 0.038 and 0.042 grm. of the salt. The largest proportion of carbonate of potash (0.042grm.) which was OSMOTIC FORCE. obtained in the last of the three experiments was replaced by 23.220 grms. of water or 552 times the weight of the salt. An obvious and essential condition of osmose is difference of com-position in the two fluids in contact with the opposite sides of the porous septum. With the same solution or with pure water in con- tact with both surfaces of a membrane there may be no chemical action but it will be equal on both sides and although probably attended with movements of the fluids pet nothing will be indicated as the movements being equal and in opposite directions must neu- tralise each other.Difference of composition in the two fluids is necessary in order that there may be inequality of action upon the two sides of the membrane. It is difficult however with respect to the chemical action to ascertain either its true sphere or its exact nature. No substance appears to be permanently deposited in the membrane during osrnose even by easily decomposed metallic salts such as salts of lead and niercury. The action upon the membrane is probably of a solvent nature and its seat may possibly be ascertain- able when two membranes are used together.Some observations made on the comparative loss of weight of the outer and her mem- brane have not however shown any remarkable difference. But this again may arise from the great proportion of the loss in both mem- branes being due to the ordinary solvent action of water alone and the operative solvent action of the osmotic salt being comparatively minute in amount; or it may depend and I ilin most inclined at present to take this view upon the chemical actions being of a different kind on the two sides of the membrane and not upon the inequality simply of one kind of action. Such a supposition was suggested by the fact which will immediately appear that osmotic activity and easy decomposition are properties often found together in binary compounds.The basic and acid agents then developed are both capable of acting upon albuminous septa. We may imagine for instance in the osmo-tic action of a neutral salt the formation within the thickness of the septum of a polar circle one segment of which (composed of the bi- nary molecules of the salt) presents a basic molecule to the albumen at the inner surface of the septum and an acid molecule to the albu-men at the outer surface the circle being completed through the substance of the septum which forms the second segment. Both surfaces of the septum would be acted iipoii but at one side we should have combination of the albumen with an alkali on the other side with an acid. This however must be taken as a purely ideal representation of the condition of the scpturn in osmose.I have not discovered such a polar condition of the septum and I doubt whe- ther the galvanometer could be properly applied to exhibit it as the placing of the poles of that instrument in the dissimilar fluids exist- ing on opposite sides of the septum would alone be sufficient to give 58 PROFESSOR GRAHAM ON rise to voltaic polarisation. At present 1 must confine myself to the enunciation of certain general empirical conclusions respecting the operation of chemical affinity in osmotic experiments. With animal septa frequent examples of the outward flow of liquid from the osrnometer present themselves causing the liquid column to fall instead of rise in the tube. This phenomenon (exos- mose) I have spoken of as negative osmose.The observation of Dutrochet that oxalic acid in the osrnometer and also tartaric acid at a certain point of concentration give rise to negative osmose I have been able to generalise in so far as acids have universally either a nc,gative osmose or lie at the very bottom of the positive class. Oxidic acid gave in membrane for 1 per cent. acid -1448 nis. and -14lms. ;and for 0.1 per cent. -10 and -27ms. In another membrane 1per cent. of the same acid alone gave -136 ms. ; with the addition of 0.1 per cent. hydrochloric acid -181 and -168 ms. By the addition of 0.1 per cent. of chloride of sodium a salt which in small proportions is nearly neutral to osmose the negative ostnose of 1 per cent.oxalic acid fell in the same membrane to -45 ms. and with the addition of 0.25 per cent. of chloride of sodium the osmose was +6 ms. or became slightly positive. The negative osmose of 1 per cent of oxalic acid in a membrane where it amounted to -56 and -57 ms. in two experiments became with the addition of 0.1 per cent. of albumen -46 ms. ; of 0.25 per cent. of albumen -20 ms.; of 0.25 per cent. of gelatin -59 ms. and of 0.25 per cent. of sugar -53 ms. In albuminated calico the osniose of 1 per cent. of oxalic acid was also negative namely -19 -16 and -20 ms. in three successive observations. With the addition to the oxalic acid of 0.1 per cent. hydrochloric acid the osmose became -46 and -58 ms. ;and with the addition of 0.1 per cent. of sulphurous acid the osmose becanie -62 and -58 ms.Of hydrochloric acid introduced into the membrane-osmometer in the small proportion of 0.1 per cent. the negative osmose was -92 -37 and -27 ins. in three successive experiments. The negative osmose of hydrochloric acid was still more powerfully counteracted than that of oxalic acid by the association of a minute proportion of chloride of sodium with the acid. The negative osmose of this acid appears to be extremely precarious. It is reversed by a great variety of neutral soluble substances and on that account can rarely be ob- served at all with bladder undivested of its muscular coat. In a certain prepared membrane sulphuric acid 0.1 per cent. gave an osmose of -4 +8 and +7 ms. Nitric acid 0.1 per cent.gave an osmose at 58O of +8 and +23 ms. OSMOTIC FORCE. 59 Tribasic phosphoric acid 1per cent. gave -6 and -7 ms. at 61' and 63'. The diffusates of phosphoric acid in the same experiments amounted to 0.143 and 0.130 grm. The glacial or monobasic phosphoric acid 1per cent ,gave +137 and +131 my. at 55O which is a considerable positive osmose an interesting circutnstance when taken in connexion with the deficient acid character of that modification of phosphoric acid. The same acid 0.1 per cent. gave a positive osmose in the last memhrane of 28 and 23 ms. Citric acid 1per cent. gave 39 and 36 ms. ; 31 and 31 ms. at 63'; the first in membrane and the second in albumen. The same acid 1per cent. after being fused by heat gave at 63' -38 and -33 nis.in membrane ; 0 m. and -2 nis. in albumen. A small proportion of fused citric acid 0.1 per cent. gave on the other hand a slight positive osmose namely 15 ms. and 2 ms. in the previous membrane and albumen osmonieters respectively. Tartaric acid 1per cent. give 18 and 19 ms. in membrane at 68' ; with 20 ms. in albumen at 62'. The same acid after being fused by heat gave -68 and -61 ms. in membrane at 57' showing a molecular change from fusion as in citric acid. The diffusate in the last two experiments was 0.123 grm. and 0.132 grm. of acid. In albumen the osmose of fused tartaric acid remained slightly posi-tive being 5 and 2 ms. for 1 per cent. at 60° and 5 and 3 ms. for 0.1 per cent. at the same temperature. Racernic acid 1per cent.gave 4 11 and 7 ms. in three experi- ments at 55O in the last-used membrane ;with 15 and 22 ins. at the same temperature in albumen ;or was always slightly positive like tartaric acid. Aceticacid in the proportions of 0.1 0.5 and 1per cent. gave scnsibly the same small positive osmose 25 to 28 ms. at 57' to 62' in membrane. A saturated solution of carbonic acid in water gave 25 and 26 ms. in membrane with 20 and 22 ms. in albumen both at 65'. The last solution diluted with an equal bulk of water gave an os-mose of 15 and 11 ms. in meuibrane and 16 ma. twice in albumen both at 63'. Terchloride qf gold is negative in its osmose like the stronger acids giving -49 and -54 ms. in membrane at 66' with much reduction of metallic gold in the substance of the membrane.BichZoride of platinum made as neutral as possible by evaporation gave for the 1per cent. solution -32 and -30 ms. in membrane at 61'. For the 0.1 per cent. solution a positive osrnose of 27 14 and 5 ms. in three successive experiments made with the last membrane 60 PROFESSOR GRAHA3f ON at 64' 65' and 62'. The same 1 per cent. solution gave in albumen at Sl" a positive osmose of 54 and 50 ms.; the0.1 per cent. solution also at 64' gave 4:3 ms. Albumen appears thus to be less adapted for bringing out the negative osmose of various substances than mem- brane is. In membrane bichloride of tin 0.1 per cent. gave 24 ms. at 61' 1per cent. -46 and -71 Ins. at 59'. The addition to the last of 0.5 per cent. of sulphiiric acid gave -63 ms.or did not alter the character of the osmose. But partial neutralisation of the 1per cent. tin solution by ammonia on the other hand gave 0 m. or destroyed all osmose. One per cent. of bichloride of tin gave only a small negative osmose in albumen namely 5 ms. twice at 59'. Oxalic acid carries the highly negative character of its osmose into the hinoxalute v'potash of which 1per cent. of anhydrous salt gave in membrane -112 and -99 ms. at 6%'; 0.1 per cent. -30 ms. at 60". One per cent. of the same salt in albuminated calico gave -20 ms. at 60". A saturated solution of binoxalate of potash con- taining 2.5 per ceut. of salt gave -15 MS. in the last osmometer. Bisulphate of potash 1per cent. gave 4 and 7 ms. in membrane at 96'; in albumen 7 3 and 6 ms.at 56'. A solution of bitartrate of potash saturated in the cold also gave a small positive osmose namely 4 and 2 ms. in membrane and 20 and 17 ms. in albumen both at 56'. Other supersalts tried gave also a srnall positive osniose such RS binarseniate of potash and bi- chromate of potash. It becomes doubtful therefore whether any of the supersalts of potash are negative except the acid oxalates of that base. Neutral organic sitbstances dissolved in water appear to be generally deficient in the power to give rise in membrane to that osrnose which depends upon a small quantity of the soluble substance such as 1per cent. or a still less proportion. The osmose obtained in ox-Gladder employed without removing the muscular coat was in 1per cent.solutions of the substances salicin 5 ms. tannin 3 ms. urea 4 ms. gelatin 9 ms. amygdalin 6 ms. lactine 7 ms. gum-arabic 18 ms. and hydrochlorate of morphine 4 ms. The relations to osinose of alcohol and sugar were more fully ex-amined. With these and other chemically inactive substances the osmose although small for 1per cent. increases progressively with larger proportions of the substance and also bears a close relation to the proportion of substance diffused outwards circumstances which give a mechanical character to the ostnose. It is with such suh-stances that the influence of diffusibility iipon osmose is most likely to betray itself. They have a peculiar interest in the study of the phenomenon as they present a certain small but remarkably uniform OSMOTIC FORCE.amount of osinose without the known intervention of any strong chemical affinities. Alcohol.-In describing an experiment I shall endeavour to put forward all the circumstances which can be supposed to influence in any way the result. In the table which follows Column I. contains the proportion of absolute alcohol by weight which is dissolved in the water of the osmometer. A 10 per cent. solution is prepared by weighing 10 gramrnes of the substance and then adding water to it so as to make up the liquid to the volume of 100 grammes of water. It is necessafy to make up in this way solutions used in experiments of diffusion and osniosc in order to preserve a true relation in solutions containing the difl'erent proportions of substance for it is a fixed volume (not weight) of these solutions which must be used in the osmometer.We come thus to have with a 20 per cent. solution of alcohol exactly twice as much alcohol in the osmometer as with a 20 per cent. solu- tion of alcohol and so of other proportions. The membrane of the osmorneter is always to be considered as fresh or as used for the first time in the first experiment narrated and the observations to be made siiccessively as they stand in the table. The length of maceration in cold water to which the membrane has been exposed previous to the osmotic experiment as before de- scribed is given in Column V. By the most frequent time of one day is to be understood the space of eighteen hours which intervened between experiments on successive days.The hydrostatic resistance of the membrane given in Column VT. is the length of time in minutes observed to elapse between the fall of two drops from the bulb of the osmometer filled with distilled water and hung up in air as already described. The temperature of the water in the glass cylinder during the experiment is noted in Column VII. ;the rise of fluid in the tube of the osmometer or osmose in millimeter divisions of the tube appears in Column .TI.,and the absolute amount of the same osmose is expressed in Column 111.in granimes or more strictly in gramme measures of water Lastly the weight of diffusate found in the water of the glass cylinder appears in Column IV.These last two data the osmose and diffusate both in grammes afford the means of comparing the weight of substance which has escaped from the osmometer with the weight of water which has entered the osmometer in the same time. It is necessary however to recollect that the apparent osniose or rise observed is only the excess in volume of the liquid which has entered over the volunie of the liquid which has left the osmometer. To obtain the full volume of water which has entered (the true osmose) it is therefore neces- sary to add the bulk of the substance diffused to the osmose observed. PltOPESSOR GRAHAM ON TABLE1.-Alcohol in Osmometer A of double membrane during five hours. I. 11. 111. IV. v. VI. V1I. ~ Alcohol in solution. Rise or osmose in millimeter degrees.Rise or oRmose in pmmes of water. Dif€~sat e Of alcohol in grammes. Previous maceration Of membrane. Iydrosta tic resistance Of niembrane. Cempera-t ure Fahr. per cent. 025 12 - - days.1s min. S 0 63 c.25 7 - - 1 8 63 1 1 10 15 - - 3. 1 6 8 66 66 2 2 20 22 - - 2 1 6 6 67 69 5 45 1.984 0.522 2 6 72 5 45 I .98d 0.452 1 8 70 10 70 3.072 - 1 8 67 10 76 3.328 - 1 8 67 20 2 0 107 109 4.672 4-800 - 1 1 8 8 (i7 67 A second series of observations was made simultaneously in another membrane osmometer in order to ascertain the degree of concordance to be expected in such experiments. TABLE11.-Alcohol in Osmometer B of double membrane for five hours. 11. I. -111. IV. v. QI. VII. -~ _.-Rise or Rise or Diffiisate Previous -Eydrostatic Alcohol osmose in osmo3e in Of maceration resistance Tempera-in millimeter ;rammes of alcohol in of of ture solution.dcgrees. water. grammes. membrane. nembrane. Ftthr. ---.__-0 per cent. day8. min. 1 14 I 2g 22 63 1 14 -1 12 03 2 19 -1 8 00 2 19 I 1. 8 60 5 46 -1 8 67 5 54 2.432 1 8 69 10 90 4.028 2 6 72 10 96 4.332 1 8 70 20 120 5.396 1 8 67 20 123 5.472 1 4 67 20 137 6.156 1 4 67 20 142 6-384 I 4 G7 It will be observed that the osmose increases with the proportion of alcohol but not in so rapid a ratio ; the osruosc of thc 20 per cent. OSMOTIC FORCE. 63 solution being about oiily ten times greater than that of the 1 per cent. solution in both series. The hydrostatic resistance of the mem-brane B falls off in a remarkable manner in the later experiments indicating an increased facility of permeation which may influence the increased osrnose in the last two observations of this series.The results otherwise of the two series exhibit a fair amount of correspon-a dence both in the degree of osmose and the amount of diffusate for the same proportions of alcohol in the two osmometers. It should he added that in several instances the water in the jars was changed after the third hour of the experiment with the higher proportions of 10 and 20 per cent. The alcohol was determined after it had been concentrated by two distillations by means of Drinkwater's table of densities. Several experiments were made to determine the proportion of the diffusate of alcohol from 5 and 20 per cent.solutions respectively of that substance in membrane osmometers. The mean proportion was as 1 to 3.02,which is mentioned here as I was led at first to a different conclusion by earlier and imperfect experiments. Sugar.-The osniose of sugar in membrane was examined very fully in the hope that the simple effect of diffusion would be exhibited without being modified by any chemical action in a substance so ent ire1 y neutral. Crystallised canc-sugar wad made use of. TABLE 111.-Sugar in Osmonieter D of double membrane for five hours. I. 11. 111. IT. V. VI. VII. Sugar Rise in Same in Diffusate of kmpera-in millimeter grammes of sugar in Previous lydrostatic ture solution. degrees. water.grammee. maceration. resistance. Fahr. 0 per cent. days. min. 1 21 1.027 -1 4 64 1 8 0-395 0.150 0 24 83 1 19 0'948 0.140 1 3+ ti3 2 19 0.048 0.178 1 23 66 > 19 0.048 0.1 82 1 24 66 u A 30 1.900 0.438 1 2+ 67 5 49 2.370 0.480 1 2$ 60 10 66 3.239 1.1 10 2 2$ 72 10 79 3-871 0.853 1 23 70 10 76 8-713 0.840 1 3 67 20 121 5'976 1.376 1 3 07 20 117 6.688 1'485 1 3 67 It was very desirable to find whether the deviations from a re-gulay progression seen in the numbers for the osmose and diffusate in PROFESSOR GRAHAM ON the preceding results are essential or accidental and peculiar to the present membrane. It was also desirable to find whether a membrane would stand the repetition of such a series of experiments and continue to give similar results.A double series of experinients were accord- ingly made with new membrane. TABLE 1V.-Sugar in Osmometer E of double membrane for five hours. I. 11. 111. IV. V. TI. VII. -__I ~ Sugarin solution. Rise in millimeter degrees. Same in Zrammes of water. Diffusate of sugar in -grammes.-Previous maceration. lydrostaticresistance. 'empera. ture Fahr. per cent. 0.25 3 0.240 - day8. 2 min. 10 0 63 0.25 9 0.420 0.050 1 10 63 1 12 0-531 0.110 1 8 G6 1 11 0.472 0. LOG 1 10 6fS 2 24 1-OGO 0,205 1 8 67 2 31 1-357 0.608 1 8 69 6 65 2.89 1 0.600 2 8 72 5 ti3 2.773 0-555 1 8 70 10 69 3.933 1.073 1 10 87 10 10 104 !I B 4.602 4'248 0.967 - 1 1 10 10 67 67 20 133 5.900 1.457 1 10 67 20 106 4.720 2.643 10 10 64 20 118 5.25 1 I656 1 6 ti4 1 19 0.828 1.105 1 6 08 1' 19 0-826 - 1 6 (i5 2 24 1062 0.153 1.6 85 2 25 1.121 0.162 1 6 64 6 37 1.652 0.435 2 8 G8 r> 33 1.425 0.470 1 8 67 10 89 3.068 0.757 2 8 67 10 76 3-368 - 1 8 69 20 110 4.H07 - 1 8 70 20 112 4.956 1.540 2 3 70 The diffusates of sugar (Column IV.) were obtained by evaporating the fluid of the water-jar to dryness at 212O and therefore contain organic matter dissolved out of the membrane ; the weight of each of the diffusates is increased by this addition a few thousandths but not in such a quantity as to affect the result to an extent that is at all material except in the first diffusate recorded that from the 0.25 per cent. solution. Although the results exhibit several irregularities yet starting from the 1 per cent.observation in the first series of Table IV. the amount both of osmose and diffiisate appears compatible with an arithmetical progression in the observations from 1 to 10 per cent. Thus the average rise in thc 1 per cent. solution is 11.5 millimeter OSMOTIC FORCE. degrees and in the 10 per cent. solution 96.3 ms.; the average diffusate in the 1per cent. solution is 0.108 gramme and in the 10 per cent. solution 1,020gramme. But with the 20 per cent. solution both osmose and diffusate fall off greatly and the osmose more than the diffusate. The osmose of the 20 per cent. solution may be taken as 125 ms.,-the mean of the first and third Observations 133 and 118 the intermediate ob- servation 106being obviously exceptional possibly from the unusually long maceration of the membrane immediately preceding that experi- ment.Hence the osmose only rises froin 96.3 ms. to 125 ms. while the proportion of sugar in the osrnometer was increased from 10to 20 per cent. The mean diffusate of sugar also increases with the same change only from 1.020 gramme to 1.585 graninie. In the second series of observations with the same membrane given in the lower part of the same Table both the osmose and diffusate fall off to an extent which is perhaps pretty fairly repre- sented by the 10 per cent. solution which gives a mean osmose of 72.5 ms. against 96.3 nis. in the former series and a diffusate of 0.757 gramme against 1.020 gramme in the former series.A rough proportioiiality between the two series of observations is sufficiently indicated. Two observations are recorded in the last series which must not be allowed to mislead. These are the coinpariltively high osmose of 19 ms. for the 1 per cent. solution which is accidental and arises from the 1per cent. experirncnts having beeu immediately preceded by the high propoition of 20 per cent. The other observation referred to is the high diffusate of the last 20 per cent. solution at the bottom of the table which has no doubt been occasioned by the sudden dimi- nution in the hydrostatic resistance of the membrane from 8 to 3 in that which is the last experiment of the series. Tie membrane indeed appears to be giving way after its long use for the osmometer had been exposed to the action of water for thirty-five days without inter- mission.The reason why the diffusion and osrnose are smaller in the second series of experiments than in the first series (nearly as 3 to 4),is (I believe) that the membrane softens and swells somewhat by the pro- tracted action of water ;a change in the structure of the membrarie which impedes diffusion by increasing the length of the channels through which the salt has to travel. It may now be interesting to discover the proportion between the water which enters and the sugar which leaves the osmometer in these experiments. That proportion appears not to vary greatly in the range froin the 1 to the 10 per cent. solution. For a mean result the sum of the eight cliffmates between 1 and 10 per cent.inclusive in the first series of observations of Table IV. may be taken VOL. vIIr.-RTo. XXIX. F PROFESSOR GRAHAM ON I. 11. 111. -VI. VII. V. . Sugar Rise in Same in Diffusate of' Tempera-in millimeter grammes of sugar in Previous Hydrostatic ture solution. degrees. water. grammes. maceration. resistance. Fahr. I ---IT. 0 per cent. day. min. 1 16 0.684 0'124 1 2 59 1 22 0.912 0-156 1 10 60 4 31 1'31 1 0.476 1 1 61 4 42 1.767 0-505 1 1 63 4 34 1.423 0 542 1 1 63 10 92 3.876 1.285 1 0.50 63 10 106 4 369 1.179 I 0.66 64 i 10 90 3'762 1.193 1 1 63 OSMOTIC FORCE. This osmometer is remarkable for the variable but generally very small amount of its hydrostatic resistance a condition of the septum which is apt to increase the diffusate owing to the expulsion of a portion of the solution by the pressure of the dense solution.The diffusates of sugar (Column IV.) may be considered as nearly pro- portional to the per-centage of sugar in the osmometer. The osmose of the 4 and 10 per cent. solutions are also nearly proportional the means being 36 and 96 ms.; but the osmose of the 1per cent. solu-tion is sensibly in excess. A slight excess it1 the early experiments with an albumen osrnometer is it may be remarked not unusual and appears to be due to the considerablequantity of soluble matter with an alkaline reaction which the fresh albumen affords to the water in the osmometer this soluble matter then acting as an osmotic body.SuZphate of Magnesia.-This salt was selected to illustrate the os-mose of neutral salts. The sulphate of magnesia is neutral to test- p!per. It.appears further to be incapable of passing into the con- dition of a stable supersulphate or subsulphate by combining with an excess of either acid or base and is not decomposed in diffusion. Such properties secure to a salt aremarkable indifference,orabsence of chemical activity and recommend sulphate of magnesia for our present purpose. In a fresh double membrane 1per cent. of sulphate of magnesia (anhydrous) gave the small osmose of 13 and 14 nis. at 63O in two experiments. A full series of observations was made by means of the osmometer F used above with sugar but with the osmotic septum of course changed.TABLE V1.-Sulphate of Magnesia in Osmometer F of double membrane for five hours. I. 11. v. VI. VII.- Sulphate of magnesia (anhSdrous) Rise in millimeter degrees. Sarqe in ;rammes oj water. Diffusate of salt in grammes. Previous naceration. Hydro-static asistance Cempera-t we,Fahr. per ccnt. 2 30 1.254 - days.2 min. 10 0 72 2 33 1.868 0.2G5 1 10 70 5 7.1 3.078 0 510 1 10 67 5 76 8 192 0.553 1 10 67 10 158 6.384 1.020 1 10 67 10 134 5.529 O*YG2 1 10 67 20 238 9.9 18 1.623 10 15 64 20 283 11.836 1.687 1 3.5 64 1 23 0-969 0.219 1 5 68 1 20 0-855 0.120 1 5 65 2 30 1-254 0.227 1 5 65 2 29 1-197 0.283 I 5 64 5 69 2.907 0.490 2 6 66 5 68 2'850 0.485 1 6 67 10 10 132 140 5.529 5'87 1 0,959 0.845 2 1 6 6 67 69 20 277 11.628 - 1 6 70 20 29 1 12'108 2,012 a 6 70 PROFESSOR GRAHAM ON The diffusate increases in a somewhat less ratio than the proportion of salt in the osrnometer in both of the two series of observations con- tained in the preceding Table.But a similar falling off in the amount of diffusate from the higher proportions of salt takes place in the diffusion of the same salt from open phials as appeared in former experiments on the diffusion of sulphate of magnesia." The different solutions then operated upon and the ratio between the diffusates they gave were as follows :-Solutions of srIphate of mag-desia diffused . . 2 4 8 16 24per cent. Ratio of diffisate of these solutions . . 2 3.671 6.701 11-785 ism8 The proportions of sulphate used in the present osmotic experi- ments were different but ratios may be found for them by interpolation and are given below.We are thus enabled to make the following comparison of the diffusion from different proportions of sulphate of magnesia (1) in the abselice of membrane; (2) in the first series of osmotic experiments given in the preceding Table; (3)in the second series of observations of the same Table :-Sulphate of magnesia in solution . . 2 5 10 20 percent. (1) Ratio of diffusates without membrane 2 4.43 8-21 13.73 (2)Ratio of diffusates with membrane . 2 4.12 7.48 12.b (3)Ratio of diffusates with membrane . 2 4.24 7.82 17.34 If the last number (17-34)given for the 20 per cent. solution of the later osmotic series be excluded and it is manifestly in consider- able excess froin some accidental cause the three sets of ratios must be allowed to exhibit considerable agreemelit.The membrane appears to have a slight effect in reducing the diffusates of the higher proportions of salt; and this reduction is greater in the early experiments (2)than iii the late experiments (3), made with the same osmometer. The comparative diffusion of different proportions of sulphate of magnesia appears therefore not to be much deranged by the intervention of membrane. The average osmose of sulphate of magnesia likewise exhibits a pretty uniform progression. In the first series of experiments of Table VI. we find for the different proportions of salt in solution an osmose of 31.5 74.5 143,and 260.5 ms.; numbers which are in the ratio given below :-Sulphate of magnesia in solution . 2 5 10 20 per cent. Ratioof osmose (firstseriesof experiments) 2 4973 9-08 16-54 In the later experiments of the same Table the different proportions of salt (omitting the first and last proportions) give an average osmose of 29*5,68*5 and 136 ms.,of which the ratios may be stated as follows Sulphate of magnesia in solution . . 2 5 10 per cent. Ratio of osmose (second series of experiments) 2 4-64 9.22 * Phil. Trans. 1850 p. 822. OSMOTIC FORCE. The osmose appears here to follow more closely in its value the proportion of salt in solution than the diffusate can be said to do either in open vessels or through membrane; so far therefore the osmose and diffusate do not preserve a constant proportion to each other with this salt.No correction need be applied to the observed osmose of sulphate of magnesia as this salt does not sensibly increase the bulk of the water in which it is dissolved. The weight of diffusate in Column IV. may therefore be immediately compared with the weights of water in Column 111. It then appears.that in the first series of the osmotic observations in the Table- In 2 per cent. solution 1 sulph. magnesia is replaced by 5.16 water. In 5 per cent. solution 1 sulph. magnesia is replaced by 5-74water. In 10 per cent. solution 1 sulph. magnesia is replaced by 6.01 water. In s?O per cent. solution I sulph. magnesia is replaced by 6-57 water. According to the average of the whole proportions sulphate of magnesia is replaced by 5 87 times its weight of water.While in the later observations of the same Table- In 2 per cent solution 1 sulph. magnesia is replaced by 5.33 water. In 5 per cent. solution 1 sulph. magiiesia is replaced by 5.9 water. In 10 per cent solution 1 sulph. magnesia is replaced by 6-32 water. According to the average of the whole proportions of salt in these Iater observations sulphate of magnesia 1s replaced by 5-85times its weight of water. The want of uniformity exhibited above in the relation between the quantities of water and salt goes some way to prove that the osinose of sulphate of magnesia in membrane is not pure diffusion for the ratio between the exchanging water and salt (the d@usion-voZzcrnes) should then remain constant.On the other hand the approxiniation to uniformity favours the idea of the existence of a numerical relation between the osmose and diffusate. So also may the circumstance be considered that sugar and sulphate of magnesia which approximate as seen above in thcir osmose were found before to have a similar degree of diffusibility.* The facts appear to afford a strong presumption but no demonstrative proof of the intervention of diffusion in governing the results of osmose in such neutral substances. The influence of diffusion becomes more difficult to trace in the osmose of three other neutral salts which I shall now introduce. What has been represented as the chemical agency now begins to interfere more sensibly although not to govern the results entirely as it appears to do in less strictly neutral salts.Chloride of Sodium.-The osmose of chloride of sdum possesses a certain interest independently of such theoretical considerations. * Phil. Trans. 1850,p. 10. 70 PROFESSOR GRAHAM ON TABLE VIL-Chloride of Sodium in Osmometer C of double membrane for five hours. I. 11. 111. IT. V. VI. VII. Chloride Rise in Same in Diffusste of t'empera-Of millimeter gramrnes of salt in Previous €ydroststic ture sodium. degrees. water. grammea. maceration. resistance. Fahr. 0 per cent. days. min. 0.25 12 0.552 -2 16 63 0.26 8 0.368 0.008 1 16 (3.3 1 3 0 138 0-230 1 6 66 1 13 0.598 0'242 1 8 66 2 11 om6 0.506 1 6 ti7 2 16 0.736 0.51 1 1 3 6!) 5 4G %34 1.513 2 3 72 5 51 2.30 1.468 1 2 71 20 78 3.496 2.994 1 15 67 10 82 8160 2'648 1 2 67 20 165 7-36 6'645 I.2 67 20 167 7.452 6-190 1 2 67 Chloride of sodium is known to diffuse with nearly double the rapidity of sulphate of magnesia in the smaller proportions of salt and with a still higher velocity in the larger proportions of salt; accordingly the diffusates in the last Table exceed those of sulyhate of magnesia in a corresponding ratio. The osmose appears pretty uniform but with a tendency to fall below the average rate of the salt in the low proportions such as 1and 2 per cent. and to exceed the same rate in the higher proportions of salt. In a septum of single membrane the osmose of a 10 per cent. solution was observed to rise to a high amount.TABLE VII1.-Chloride of Sodium in Osmometer H of single membrane for five hours. I. I 11. I 111. IT. v. I VI. 1 VII. Salt Rise in Same in DXusate of Previous Hydrost,atic 1 TeE::,ra-in millimeter grammes of salt in maceration. resistance. solution. degrees. water. grammes. Fahr. --1 ~~~ per cent. day. min. 1 2 21 1.04 0.9 1'7 1 16 2 24 1-20 0.956 1 16 68 10 272 13.28 6.502 1 16 10 I 311 15.68 7.850 1 13 ;6 OSMOTIC FORCE. An observation was made on the osmose of a high proportion of salt with another single membrane differing from the last in offering considerably less hydrostatic resistance. TABLE 1X.-Chloride of Sodium in Osnionieter I of single membrane for five hours.I. 111. IV. --11. ---Salt Rise in Same in Diffusate of in millimeter grammes of salt in solution. degrees. water. grammes. per cent. 10 198 1 10 LO4 To these I add a series of observations of the osmose of the same salt in albumen with the view of exhibiting the phenomenon in septa of that material. The well-preserved proportionality of the diffusate is remarkable. TABLE X.-Chloride of Sodium in Osmometer K of albuminated calico for five hours. per cent. 1 1 16 27 - 0.141 0.219- days. 4 1 min . 8 8 0 65 62 4 39 CI 1 2 GO 4 34 - 0.625 3 2 56 10 10 10 43 61 72 -- 1.580 1-615 1.597 1 1 1 3 3 3 50 60 61 I 27 - 0.153 I 2.5 63 1 0.1 0-1 22 27 29 -- 0-141 0-016 0.018 2 1 1. 4 2.5 4 63 03 64 Chlorideof Barium.-Chloride of barium in its rate of diffusion from open vessels much resembles the chloride of sodium.Con-siderable analogy between the same salts is also observed in osmotic experiments. 72 PROFESSOR GRAHAM ON TABLEXI.-Chloride of Barium in Osmometer L of double men1brane for five hours. V. I. 11. I 111. IV. ---VI. VII. Salt Rise in Same in Diffusate Previous 3sdrostatic 'empera-in ture, in millimeter grammes of gra:n mes. naceration. resistance. Fahr. solution. degrees. water. --0 per cent. daj 8. min. 8 35 1.476 -2 .I0 52 2 45 1*8B6 0.675 1 10 70 5 94 3.930 1.708 1 8 (5 7 5 111 4 074 1.040 1 6 67 5 74 3-116 1.203 1 10 07 20 154 6.478 449 1 1 10 67 10 133 5'376 3'895 10 26 64 10 1% 3'74 2'92'3 I 4 64 20 2u7 1 1.2 14 6-860 1 8 08 20 283 11.79 7'030 1 b 65 1 60 2'542 0'275 1 8 65 1 'id 3'1 16 0'230 1 8 04 5 74 3'118 0-602 2 8 tici 5 74 3.116 1.887 1 9 67 10 162 G-396 3'795 2 8 67 30 15i 6'478 4.040 1 8 69 20 337 14-186 -1 8 70 20 320 13-448 8.130 1 8 70 TABLE XI1.-Chloride of Calcium in Osmometer M of double membrane for five hours.I. 11. 111. IT. v. -VI. VII. salt Riee in Same in Diffusate Previoue [ydrostatic 'empera-in millimeter 5rammes of lIl maceration. resis trance. ture solution. degrees. water. grammes. Fahr. 0 per cent. days. min. 2 6 0.258 -2 8 72 2 6 0.258 0-795 1 8 70 I) 45 1.935 2'29 1 8 67 5 60 2'64 1-88 1 3 67 5 51 2'24 2'636 1 8 67 10 228 9.92 4'256 1 8 67 10 188 8.24 3'607 10 13 64 10 176 7.76 3.11 1 6 64 20 389 17'2 6.075 1 3 68 20 398 17.6 -1 3 65 2 24 1'04 0.668 1 4 G5 2 27 1'2 0.625 1 4 64 5 81 3'6 1-51 2 2 5 66 5 s3 3'68 1'467 1 5 67 10 185 8'16 3'158 2 5 67 10 IS2 8 8'317 1 5 69 20 406 18 6.695 1 5 70 20 416 18.4 6.992 1 3 70 OSMOTIC FORCE.Chloride of Calciurn.-The diffusion of chloride of calcium in open vessels has been observed to fall below that of chloride of barium as 7-5 to 6.5." But in membrane judging from the following observations the diffusion of chloride of calcium is the more rapid of the two. The osmose has also a tendency to rise particnlarly in the larger proportions of chloride of calcium. The replacing water often exceeds twice the weight of the salt diffused. (See Table XIT. p. 73.) These three chlorides.possessing about double the diffusibility of sugar and sulphate of magnesia should bereplaced by half as much water as the latter substances. Some approach to this ratio may be perceived amid niuch irregularity in the observed osrnose of the chlorides. Proceeding now to the salts in which the osmose appearing to depend upon chemical properties preponderates greatly over osmose from diffusion T may introduce these substances under the metals which they contain for the sake of their relations in composition. POTASSIUM AND SODIUM. Hydrate of Potash.-A highly intense osmose appears to be determined by caustic alkali but it is necessary to apply the smallest proportions of alkali to avoid the rapid dissolution of the membrane.In double membrane 0.01 per cent. of hydrate of potash or 1 alkali in 10,000 water gave an osmose of 61 and 58 ms. By four times as much alkali or 0.025 per cent. an osmose of 49 and 67 ms. was produced. These are the greatest effects. On increasing the proportion of hydrate of potash to 0.5 per cent. the osmose sunk to 22 and 26 ms.; with 1 per cent. of hydrate of potash to 13 ms. The permeability to hydrostatic pressure was always very great being never less than one drop in a minute. By the action of the alkali in the last experiment the permeability was increased from three to nine drops and the membrane entirely ruined. A similar experiment with hydrate of potash was made in albuminated calico with similar osmotic results. In the 0.01 per cent.solution an osmose of 76 and 58 ms. was observed; in 0.025 per cent. solution 87 and 126 ms.; in 0.5 per cent. solution 15 and 12 ms. ;and in 1 per cent. solution -lOms. or a small negative osmose. The permeability both before and after the last experiment was represented by one drop in one minute; in both the half per cent. experiments the permeability was one drop in three minutes; in the preceding 0.025 per cent. solutions one drop in 24 minutes and at the beginniug one drop in ten and five minutes with the 0.01 per cent solutions. The alkali first became sensible to the test-paper in the water-jar in the diffusion of the 0.025 per cent. solutions. During both series of experiments the temperature ranged from 58' to 62'. Carbonate of Potash.-The high osmose of this salt bas already * Phil.Trans. 1850,pp. 817 819. 74 PROFESSOR GRAHAM ON been often referred to in illustration of the influence of alkaline salts. The following experiments may be compared with those upon the neutral substances lately discussed particularly in regard to their diffusates. They show also the comparative influence of membrane applied single and double to an osmometer. TABLE XII1.-Carbonate of Potash in Osmometer B of single membrane for five hours. I. IV. v. VI. VII. 11. 111. ----PI-Propor-Rise in Same in millimeter grammes of Diffusate in Previous Hydrostatic Tempera-tion grammes. maceration. resiatance. ture of salt. degrees. water. Fahr. --_I__---0 per cent. day. min. 2 635 28.676 0.514 1 20 66 2 695 31.256 0.548 1 20 68 10 892 40 128 2.897 1 16 68 10 900 40.508 I 3.045 I 1 I 16 I 68 third hour and replaced by distilled water to prevent the reaction of that portion of the salt which had already reached the jar upon the progress of diffusion from the osmometer both in the preceding and the following series of experiments.TABLE X1V.-Carbonate of Potash in Osmoineter D of double membrane for five hours. I. 1 11. 1 111. 1 IV. I v. j VI. 1 VII. .--A -Propor-Rise in tion millimeter of salt. degrees. --7 0 per cent. day. min. 2 449 21.683 0.324 1 10 66 2 484 23.621 0.400 1 16 68 10 619 30.178 2.764 1 16 68 10 595 28.993 3.150 1 12 68 In the double membrane the average ostnose of the 2 per cent.solution is reduced to 466 ms. from 665 ms. in the single membrane. The change is similar in the 10 per cent. solution namely a reduction to 607 from 896 ms. ; a reduction of nearly one-third of the osmose in the double membrane for both proportions of salt. The difference of the diffusates is much less marked; for they OSMOTIC FORCE. may be said to be the same for the 10 per cent. solutions namely 2.966 grms. in the single and 2.957 grrns. in the double membrane; and for the 2 per cent. solution 0.531 grm. in the single and 0.326 grm. in the double membrane. The diffusion of carbonate of potash as seen here in membrane will be found to correspond well with that of chloride of sodium (Table VII.) as the diffusion of the same two salts in open vessels is known to present a near approach to equality.The great osmose or current of fluid inwards might be supposed to diminish the outward movement of the salt under diffusion by washing back the salt into the osmometer. But the diffusates of the 10 per cent. solutions appear to have suffered uo remarkable reduction from that or any other cause. The diffusate of carbonate of potash which usually passes through membrane appears however to be low In the 1 per cent. solution formerly referred to it was 0.195 grm. In the series of observations likewise already referred to the diffusate of carbonate was also low but remarkably uniform namely 0.018 grni. for 0.1 per cent. solution 0.092 grrn. for 0.5 per cent. solution and 0.196 grm. for the 1per cent.solution. But these determinations were all made by the alkalimetrical method and when in subsequent observations the potash was also determined by weighing it as sulphate the proportion of diffusate was found sensibly increased. It hence appears that carbonate of potash acts chemically upou the membrane and that a portion of the alkali diffuses out in a neutralised state. Thus in five successive experiments with the 1 per cent. solution in fresh double membrane the diffueates by the alkalimetrical method were 0.208 0.254 0.264,0.215 and 0.189 grm. carbonate of potash; while the actual quantity of alkali found by direct analysis corresponded in the last four observations to 0.318 0.353 0287,and 0.242grm. The quantity of carbonate of potash which has suffered change in passing through the membrane is 0.064 0*089 0.072 and 0.053 grm.in these four experiments respectively. The diffusates of carbonate of potash increased by those quantities approach too closely to those of chloride of sodium to warrant the supposition of any peculiar repression by membrane of the diffusion of carbonate of potash which otherwise appeared probable. The observations last commented upon belong to a nnmber under- taken with the view of ascertaining three points of interest which may excuse a fuller statement of the experiments. These points were first the influence upon osmose of the air dissolved in solutions of carbonate of potash which might be supposed to take a part in the chemical action of the membrane ; secondly the effect of frequent repetition of the experiment in exhausting the osmotic activity of metnbrane; and thirdly the relation in osmose of an alkaline carbo- nate and phosphate.PROFESSOH QRAH AM ON TABLE XV.-Solutions in Osrnometer L of double membrane for five hours. Rise in Tempera-Salt in osmometer. millimeter ture Fahr. degrees 0 Carbonate of potash 1 per cent. ........ 439 63 Same deprived of air by boiling ........ 376 64 Same deprived of air by boiling ........ s53 65 Same solution unboiled ........... 325 63 Same solution uiiboiled . ........ 268 56 Phosphate of soda (2NaO €iO PO,) 1 per cent. ... 1.76 55 Same ....... 194 58 Same 0.1 per cent. ...... 190 56 Same 0.1 per cent....... 1so 0n Carbonate of potash 0-1per cent. ....... 176 57 Same 0.1 per cent. ...... 227 65 Same 1 per cent. ...... 208 58 Same I per cent. ...... 335 64 Same 1 per cent. ...... 312 62 It will be remarked that the highest osmose (439ms.) is obtained in the first experiment and that the osmose falls off pretty regu- larly to the fifth experiment (268 ms.) The change in the aeration of the solution in the second aud third experiments cannot be said to interfere with this progression. The influence of free oxygen on the membrane is not therefore indicated as a cause of osmose. It may be added that the converse experiment of depriving the fluid of the water-jar of air by boiling led also to a negative result. It will be remembered further that the osmose of oxalic acid was not interfered with by an addition of sulphurous acid which was likely to counteract the action of oxygen if such an action existed in osmose.When phosphate of soda is substituted for carbonate of potash both 1 per cent. the osmose declines from 268 to 176 ins. The phosphate of soda being repeated the osmose rises a little namely to 194 ms. The one-tenth per cent. solution of the same salt which follows main- tains here the considerable osmose of 196 and 190 ms. On returu-ing again to the application of carbonate of potash in the instrument the osmose gradually rises and regains 335 ms. for the 1per cent. so-lution of that salt. From these repetitions of osmose it may be inferred that whatever be the nature of the chemical action on membrane which prompts os-mose that action is by no means of a rapidly exhaustible character.It may be added with regard to the osmotic action of extremely dilute solutions of carbonate of potash that the osmose is lowered rapidly in proportions bclow one-tenth of a per cent. of that salt. The osmoseof 0.01 per cent. of carbonate of potash in double mern- brane aiiiounted only to 19 23 and 17 ms.in three successive experi- OSMOTIC FOitCE. 77 ments. The osmotic action of carbonate of potash must therefore be inferior to that of hydrate of potash in the extreme degrees of dilution. In the experiments of the preceding series the influence of a salt often appears not to terminate with its presence in the osmometer but to extend to following experiments made with other salts or made with different proportions of the original salt.If this arises from portions of the first salt remaining in the membrane they must be portions which are not easily washed out. The substance of membrane may possibly have an attraction for highly osmotic salts capable of with- drawing small quantities from solution. When the membrane how- ever is removed from the osmometer after such experiments as are referred to slightly washed and then incinerated only minute traces of the salt last used are commonly discovered; if indeed the salt has not entirely disappeared. Phosphate and Carbonate of Soda.-The osmose of the carbonate of soda appears to be quite similar to that of carbonate of potash.A considerable amount of information respecting the two soda-salt s named is conveyed in thefollowing series of experiments which include s also observations on the serum of ox-blood. TABLE XV1.-Solutions in Osmometer F of double membrane for five hours. Rise in Salt in osmometer. millimeter Tempera-degrees. ture Fahr* 1 1-0 Phosphate of soda 1 per cent. ......... 312 65 Same 1 per cent. ............. 31 I 56 Same. 0.1 per cent. ............ 205 55 Same 0.1 per cant. ............ 218 58 Carbonate of soda 0.1 per cent. ........ 294 RA Same 0.1 per cent. ............ 251 58 Same 0.01 per cent. ............ 50 57 Same 0.01 per cent. ............ 39 65 Same 1 per cent. ............. 306 58 %me 1 per cent. .............337 64 Phosphate of soda 1 per cent. ......... 193 62 Same 1 per cent. ............. 186 61 Serum of ox-blood nndiluted ......... 39 59 Same ................. 3-1 61 Same diluted with equal vol. of water ...... 31 61 The phosphate and carbonate of soda when alternated in the same osmometer show considerable steadiness in their respective rates of osrnose. The inferior osmotic quality of serum is remarkable considering the alkalinity of that fluid. The loss of osmose in serum is due I PROFESSOR GRAHAM ON believe to the presence of chloride of sodium. The latter substance possesses an extraordinary power of reducing the osmose of alkaline salts which was observed in a variety of circumstances but which it will be sufiicient to illustrate by the following series of experiments in an albumen osmometer.TABLE XVI1.-Solutions in Osrnometer N of albuminated calico for five hours. Rise in Diffussbe Previous Hydro-Tempera-Salt in osmometer. aillimcte igramma macera-static t,ure degrees. y analysis tion. *esistancc Fahr. days. min. Carbonate of soda. lpercent 139 0.1317 0-092 1 3 07 Same 1 per cent.. . . . 1so 0.156 O-lO(i 1 6 59 Same 2 percent.. . . . 141 0-242 1 6 65 Same 4percent.. . . . 143 0.570 -1 8 02 Same 10 per cent. . . . 204 1.502 1’450 1 12 SO Same 10 per cent. . . . 163 1.432 1-3dO 3 6 56 Same 1 per cent.. . . . ,138 0.216 0. I47 1 6 59 Same 1 per cent.. . . . 136 0.198 0.156 1 3 60 Same 0.1 per cent. . . . 188 -0.005 1 10 61 Same 0.1 per cent.. . . 179 -1 6 63 Carbonate of soda 0.1 per cent. +chloride of soda I 32 -2 6 63 1 per cent. . . . . .j Same+same . . . . 36 -1 6 GR Chloride of sodium lpercent 25 0.384 -1 0 64 Same 1 per cent. . . . . 18 0-325 1 3 Ci5 Carbonate of soda 1 per’ cent. +chloride of soda 69 -1 5 63 1 per cent. . . . . 1 -Same + same . . . . . 56 3 8 56 Carbonate of soda 1 per cent 167 0.190 0.164 1 G 65 Same 1per cent. . . . . 163 0.212 0-185 1 4 58 Same 0.1 per cent. . . . 152 -1 20 66 Same 0*1per cent. . . . 152 -1 20 68 The osmose of the 0.1 per cent. solution of carbonate of soda is lowered by the addition of 1per cent. chloride of sodium from 179 ms. to 32 nis. The osmose of 1 per cent. carbonate of soda with the addition of an equal proportion of chloride of sodium is 56 ms.and of 1 per cent. carbonate of soda alone immediately following 157 ms. The osmose of these mixtures appears to be assimilated to that of chloride of sodium itself which comes out as 18 and 25 ms. in the same series of observations. The rise of an alkaline liquid in the osmometer appears to be equally repressed by chloride of sodium placed outside or dissolved in the fluid of the water-jar. In illustration of this statement I may adducc a short series of OSMOTIC FORCE. Rise in Salt in osmometer. millimeter degrees. Carbonate of potash 0.25 per cent. ........... 76 Same 0.25 per cent. ................ 06 Carbonate of potash 1 per cent. a.gaiust alcohol 1 per cent. in jar 108 Same 1 per cent.against sugar 1 per cent. in jar ..... 104 Same 1 per cent. against chloride of sodium 1per cent. in jar . 18 Same I per cent. against pure water in jar ........ 114 Same 1 per cent. against chloride of sodium 1 per cent. in.jar . 18 Carbonate of potash 1 per cent. +chloride of' sodium 1per cent. against water in jar ............... 64 Carbonate of potash 1 per cent. alone against pure water in jar 134 Same repeated .................. 114 Now another neutral salt sulphate of potash will be found to have the reverse effect upon the osmose of an alkaline carbonate support- ing and promoting the latter. Such results show how far we still are from a clear comprehension of the agencies at work in membra- nous osmose. Another property of chloride of sodium equally singular is that the association of this salt (by itself so indifferent) with small proportions of hydrochloric acid such as one-tenth per cent.deter- mines a positive osmose in membrane which is sometimes very considerable. The osmotic action of the alburninated calico of Table XVII. is moderate in amount but remarkably uniform. The small tenth per cent. solution assumes a preeminence in activity which is very curious. It was often observed in the inquiry that the small proportions of active salts were more favoured in albuniinated calico than in mem- brane; may it not thence be inferred that it is in the albumen plate that the chemical agency operates to most advantage ? Taking the mean cliffusates of chloride of sodium and carbonate of soda from the lower part of the same Table we have 0.354 chloride of sodium against 0.201carbonate of soda or 1 of the former to 0.568 of the latter.The diffusates of the same two salts in open vessels were more nearly in the proportion of 1 to 07. The compa- rative diffusion of carbonate of soda appearsto be rather repressed than promoted by the septum. The neutralisation of a portion of the alkaline salt during the 0s- 80 PROFESSOR GRAHAM ON niotic process is again indicated. The portion of carbonate of soda thus lost in the 1 per cent. solution appears to diniinish on repetition of the experiment. At the head of the Table the loss iu two experi- ments is 0.065 and 0.050 grm. ; lower down 0.069 and 0.042grm. ; and near the bottom of the Table 0.026 and 0.027 grm.The loss with the 10 per cent. solution is 0.110 and 0.092 grm. or not more than double the loss in the preceding 1 per cent. solutions of carbo-nateof soda. Subhates of Potash and Soda.-The sulphate of potash was made the subject of frequent experiment with the view of obtaining light on thenature of osmose at the commencement of the inquiry. But it is not well fitted for such a purpose its action in the ostnonieter proving at first of a most perplexing character. With thick ox-bladdz sulphate of potash dissolved in the proportion of 1 per cent. usually exhibited considerable osmose ; that is about one-half of the osniose of carbonate of potash in similar circumstances. The osmose of the sulphate had however a peculiar disposition to increase in successive repetitions of the experiment with the same membrane.The osmose of this salt might also be doubled by allowing bladder in substance to macerate for some time in the solution before the osmotic experiment soluble matter from the membrane manifestly influenced the result considerably in all experiments with sulphate of potash. When the removal was effected of the muscular coat of bladder the chief source of its soluble matter the osmose of the salt in question fell greatly in amount instead of rising like that of the carbonate of potash. In the prepared membrane sulphate of potash presented a small moderate osmose like chloride of sodium. But the salt niust be ex- actly neutral to test-paper and the membrane also free from foreign saline matter otherwise very different results are obtained.In a double membrane 1 per cent. of the neutral sulphate gave 21 and 20 ms. ;but the same solution made alkaline by the addition of no more than one ten-thousandth part (0.01 per cent.) of carbonate of potash started up to 101 and 167 ms. a much greater osmose than the proportion of carbonate of potash present gave afterwards by itself in the same membrane namely 19 23 and 17 ms. The influ- ence of the alkali is so persistent that the membrane macerated in water for a night after the last experiments still gave 65 ms. with 1 per cent. of pure sulphate of potash. The osmotic activity of sulphate of soda is equally excited by a trace of alkali and both sulphates exhibit the same character in albu- men as well as in membrane.This remarkable result of the combined action of the two salts is so likely to elucidate the chemical actions prevailing in osmos? that a fuller series of illustrative experiments may he recorded. The septum was of double calico well albuininated and presented a good resistance to hydrostatic prcssure. OSMOTIC FORCE. 81 TABLE X1X.-Solutions in Osmometer Q of albuminatcd calico for five hours. Rise in Tempera-Salt in osmometer. millimetei t ure degrees . Fahr. 0 Sulphate of potash 1 per cent. .... ..... 1s 53 Same .................. 21 57 Sulphnte of potash 1 per cent. +carbonato of potash 0-01per cent. ............... 189 62 Same +same ...............81 36 Same +same ............... 73 61 Same +carbonate of potash 0.1 per cent. ...... 254 01 Same -+sam0 ............... 263 59 Carbonate of potash 0.1 per cent. alonn ...... 92 57 Carbonate of potash 0.1 per cent. alone ...... 95 57 Sulphate of soda 1 per cent. +carbonate of potash 0.1 percent. ................ 2.57 62 Same +same ............... 237 54 Saine +carbonate of soda 0.1 per cent. ...... 294 54 Carbonato of soda 0 I per cent. alone ....... 90 5’7 Same .................. 127 58 The influence of the two alkaline carbonates in giving a high osrnme to the sulphates appears to be pretty nearly equal. The primary source of the great osniosf may prove to be the action on membrane of the alkaline carbonates which is promoted in some way by the presence of sulphate of potash as it is retarded by the presence of chloride of sodium.On the other hand the moderate amount of osmose which appears to be proper to these sulphates is completely negatived by the most rniiiiite addition of a strong acid. Thus 1per cent. of sulphate of potash with the addition of one ten-thousandth part (0.01per cent.) of hydrochloric acid had its osniose reduced in the first experiment to 8 ms. and in the second experiment to -5 ms. the osmose be-coming actually negative. On one occasion a specimen of well-ciystallised sulphate of potash gave when dissolved a still more sensible negative osinose namely -28 ms. On applying litmus to the solution it was found to possess an acid reaction. But the addition of 0.01 per cent.carbonate of potash was suficient to change thc acid into an alkaline reaction and to give rise to a positive osmose amounting to 54 ms. It occurred to me to macerate a fresh menibmne in water contain- ing one-thousandth part (0.1 per cent.) of hydrochloric acid for two days before applying the niembrane to the osmometer and then to wash the membrane with distilled water till all acid reaction’disappeared. With 1per cent. of neutral sulphate of potash this menibrane gave in succession 17 442 35,and 62 ms. ;with sulphate of soda 1 per cent. following 30,25,and 25 ms.;and with sulphate of zinc (anhy- VOL. VIII. --NO. XXIX. G PROFESSOR GRAHAM ON drous) 1per cent. after the last sa!t 14 and 21 ms. These last results show a certain degree of' unsteadiness in the osmose of the alkaline sulphates probably arising from the osmose of these salts depending so much upon adventitious circuinstances.The diffusates were carefully weighed first when fully dried at 2124 and again when ignited. The difference in the wcighings arose from the presence of organic matter dissolved out of the membrane of which it gives the quantity probably somewhat exaggerated. First diffusate 0.328 grm. sulphate potash. Second diffusate 0.362 grm. sulphate potash 0.019 organic matter. Third diffusate 0.351 grm. sulphate potash 0.031 organic matter. Fourth diffusate 0.366 grm. sulphate potash 0.025organic matter. Fifth diffusate 0.356 grm. sulphate soda 0.011 organic matter. Sixth diffusate 0.339 grm.sulphate soda 0.019 orsanic matter. Seventh diffusate 0.334 grm. sulphate soda 0.009 organic matter. Eighth diffusate 0.239grm. sulphate zinc. Ninth diffusate 0.260grm. sulphate zinc. The diffusates of the two alkaline sulphates are remarkably uniform the diffusate of sulphate of soda falling a little under that of sulphate of potash but not so much as in open vessels. The diffusate of sul-phate of zinc is still smaller but relatively too high as it should not much exceed one-half of that of sulphate of potash judging from the diffusion of these salts in the absence of membrane. The organic matter accompanying the salt falls off in quantity in successive experi- ments but continued to exist to the last although it was not deter-niiried in the experiments with sulphate of zinc.The diameter of the disc of membrane was 123 millimeters and its original weight air- dried 0.559 grm. Oxalate of Potash Chromate and Bichrornate oj Potash-The only property of sulphate of potash which seems to be connected with the positive osmose of that salt is its bibasicity as a sulphate. The alkaline character promotes positive osmose and this character appears to be a distinction of polybasic salts The common tribasic phosphate of soda is strongly alkaline to test-paper and the bibasic pyro-phosphate of soda enjoys the same property in a still higher degree. The sulphates of potash and soda are certainly neutral to test-paper but they may be looked upon as potentially alkaline froni the easy severation of the second equivalent of fixed base and its replacement by water witnessed in all bibasic salts.In monobasic salts on the contrary a proclivity to the acid character may be suspected. Thus although the chloride of potassium and nitrate of potash appear as neutral to test-paper as the sulphate of potash ig yet the chlorides and nitrates of the magnesian bases are more decidedly acid than their sulphates. It is just possible then on this view that the osmotic infe- riority of chloride of sodium and the power of that salt to counteract the positive osmose of carbonate of potash may be exhibitions of acid character belongiug to the former salt. The observations of the rise OSMOTIC FORCE. in the osmonieter of chloride of sodium and also of the chlorides of barium and calciuni previously described also have the appearance of being the effect of diffusion modified by a slight chemical osmose of a negative character proper to these salts.The polybasic coiisritution of oxalate of potash is well marked and its positive osmose will be found below to be considerable although the specimen of salt employed was strictly neutral to test-paper. This salt also like sulphate of potash is shown not to counteract the high positive osmose of an ailtalifie carbonate. The chromate of potash although carefully purified by crystallisa-tion retained a slight alkaline reaction. On this account small addi- tions were made to it of bichrornate of potash in some experiments but without materially diminishing the very sensible positive osniose of the former salt.A neutral chromate has of course the same bibasic character as a sulphate. TABLE XX.-Oxalate and Chromate of Potash in Osmometer F of double membrane for five hours. Solution of salt. Rise in ninimete Previoue macera- Hydro-8tatic Tempera-ture degrees. tion. --_ esistance Fahr. 1 per cent. osalate of potash ... Same........... 164 153 days. 1 1 min. 11 10 0 65 ti .5 0.1 per cent. osalate of potash . . Sante ........... 1 per cent. oxdate of potash +0.1 per cent. carLonate of potash .. Same +same ........ 92 90 262 337 1 2 8 1 5 6 5 5 63 Bi 58 60 0.1 per cent. carbonate of potash . Same ........... 1 per cent. oxalate of potash +0.1 per cent. carbonate of potash . . Smie +same ........ 322 273 294 246 1 1 1 2 3 3 3 3 62 68 62 55 1 per cent.bichrornate of potash . Same ........... 24 19 1 2 3 1 54 56 1 per cent. chromate of potash . . Same ........... 109 106 1 1 1 1 82 58 1 per cent. chromate of potash =0.1 bicliroinate of potash .... Same ........... 91 3!) 2 1 1 I 57 6in The average rise for the 1 per cent. solution of each of the salts placed in the osmometer in a pure state is bichromate of potash 21.5 ms. chromate of potash 107.5 ms. and oxslate of potash 138.5 ms. The average diffusate for the chromate of potash is 0.3165 grm. and for the bichromate of potash 0.2855 grm. Like solutions were submitted to osmose at the same time in a sep- tum of albumen for the sake of comparison with the preceding memo brane osmometer. PROFESSOR GRAHAM ON TABLE XX1.-Oxalate and Chilomates of Potash in Osmometer K of albuminated calico.Solution of salt Rise in iillimetei iiegrees. ?revious macera-tion. Hydro-static esiatance rempera-ture Fahr. 1 per cent. oxalate of potash . . Same ........... 195 173 days. I 1 min. 15 15 0 65 65 0-1 per cent. oxalate of potash .. Same ........... 1 per cent. oxalate of potash +0.1 per cent. carbonate of potash .. Same +same ........ 91 I00 161 211 1 2 8 1 15 20 15 16 63 60 56 60 0.1 per cent. carbonate of potash . Same ........... 1 per cent. oxalate of potasb +0.1 per cent. carbouate of potash .. Same +same ........ 109 120 195 188 1 1 1 2 15 25 15 15 62 68 63 55 1 per cent. bichromate of potash . Same ........... 36 34 1 2 15 10 54 56 1 per cent.chromate of potash .. Same ........... I per cent. chromate of potash +0.1 per cent. Licliromate of potash . Same ........... 129 123 95 I02 1 1 2 I 13 10 10 10 62 58 07 ti0 The average rise for the 1 per cent. solution of each of the salts is for bichroniate of potash 35 ms. for chromate of potash 126 ms. and for oxalate of potash 184 Ins. all a little higher than in the previous membrane osmometer. The diffusate is lower than before probably owing to the less permeability of the albuminous septum the weight of chromate of potash diffused being 0-2475 gramme and of bichro-mate of potash 0*24<4 gramme. T4e two chromate8 have been found to possess nearly equal diffusi- bility in open vessels and to correspond closely in that property with sulphate of potash.The oxalate of potash exhibits a considerable osrnose when present in the small proportion of one-thousandth part (0.1 per cent.) namely 91 ms. in membrane and 95.5 ms. in albumen. This is the surest indication of considerable osmotic capacity. Bin-oxalate of potash and free oxalic acid are both remarkable for high negative osmose. Barium Strontium Culciurn Magnesium.-The salts of these metale never appear capable of producing strong positive osmose when dissolved in a proportion of less than 1 per cent. On the contrary some of the salts of this class particularly the nitrates exbibit a ten-dency to negative osmose. Hydrate of Baryta gave a small positive osmose for minute pro-portions of salt which disappeared as the proportion of salt was in-creased exhibiting an analogy in this respect to hydrate of potash.The results for hydrate of baryta in double membrane n-ere 6 4,1 OSIMOTIC FORCE. and 1 degrees of osrnose for the 0.1,0-25 and 0.5 per cent. solutions. In albumen the same solutions gave 0 -8 -23 and -17 ms.; and the 1 per cent. solution gave -25 ms. Hydrate of Lime exhibited similar characters to the last base. Undiluted lime-water gave in double membrane -20 ms. and -1 IYI. ; while the earne diluted with four volumes of water gave a positive osi~lose:of 31 and 18 ms. In albumen the undiluted lime-water gave -48 and -30 ms. ; the 'same diluted with four volumes of water gave 0 m. and I m. Chloride of Sirontiurn 1per cent. gave in double membrane '19 27 and 26 ms.; following chloride of barium in the same membrane 13 and 21 ms. Nitrate of baryta in the same membrane gave 12 24 and 29 ms. ; nitrate of strontia following the latter 27 and 31 MS. Nitrate oj'lime in membrane twice gave 19 ms. following chloride of calcium with 12 and 20 ms. ; in albumen nitrate of lime gave 2 and 2 ms. The 2 per cent. solution of the same salt in membrane gave only 6 and 6 ms. in two experiments. Chloride of Mu,ynesium gave in membrane -2 ms. and in albumen 6 tns. both experiments being made with the 1per cent. solution which isalways to be understood when no particular percentage is stated. Nitrate of Magnesia gave in membrane -24 and -20 ms. Both of these magnesian salts were prepared by saturating the acid with excess of magnesia.The tendency of monobasic salts of the magne- sian class to chemical osmose of a negative character appears to be small in the salts of barium and strontium to rise in those of calcium and to culminate in the salts of magnesium itself. Aluminium.-Nothing is more remarkable than the high positivi osmose of certain salts of alumina. These salts emulate the alkaline carbonates in this respect. The property too appears to be charac- teristic of the sesquioxide type and distinguishes the salts of sesqui-oxide of iron,sesquioxide of chromium and the higher oxide of uranium as well as alumina Sulphate of AZumiw.-'Phe sulphates of this type do not exhibit a high degree of osmose although they are probably more osmotic than the magnesian sulphates asa class.Sulphate of alumina 1 per cent. gave inmembrane 57 and 67 ms. and for 0.1 per cent. 24 and 31 ms. The diffusate was sniall amounting in the second observation of the 1 per cent solution to 0*(]33'gramme of tersulphate of alumina together with an excess of 0.005 grm. of sulphuric acid according to analysis. Chloride of Aluminium,.prepared by treating hydrochloric acid with an excess of hydrated alumina was found by analysis to approach very nearly to the proportions of the definite compound Al Cl,. The fol- lowing results with that salt were successively obtained in an osmo- meter of single nienibraiie :- PROFESSOR GRAHAM ON With 1 per cent. iiae of 540 ms. at 50' Fahr. With 1 per cent. rise of 570 ms.at 49' ,, With 1 per cent.rise of 450 ms. at 47' ,, With 1 per cent. rive of 635 ms. at 49' ,, With 0.1 per cent. rise of 510 ms. at 54' ,, With 0.1 per cent. rise of 285 ms. at 48' ,, With 0.1 per cent. rise of 410 ms. at :)6' ,, The numbers which are all high vary considerably among them- selves as often happens when osinose is intense and is observed in a single membrane. The temperatures of the water-jar are added in these and most other observations recorded although it was difficult to draw any positive conclusion respecting the influence of heat upon the osmose of small * proportions of salt. M'itb large proportions of neutral salts where diffusibility prevails the osmose appeared to in-crease with the temperature as does the proportion of salt diffused.With respect to the condition of the membrane used above the first experiment was conducted in the membrane freshly dissected and previous to any maceration or washing whatever with a similar osmotic result it will be observed as in the later experiuients made with the membrane after being repeatedly macerated. In experiments of diffusing chloride of aluminium in open vessels deconiposition of that salt was observed with escape of free hydro- chloric acid. The decomposition appeared however to affect much less of the chloride of aluminium than it does of the acetate of alumina. In an albumen osmometer chloride of aluminium gave an osmose of 245 233 and 229 ms, at 57' 58' and SO' with diffusates of 0,085 0,123,and 0,095gramrne of salt calculated from the quantity of chlorine found in the diffusate.In the last experiment the solution was coloured with litmus ap- parently without affecting the amount of osmose. Acetate of Alumina was prepared by precipitating pure sulphate of alumina by means of the acetate of lead. Mr. Crum has shown that in this reaction one equivalent of acetic acid becomes free and that the acetate of alumina produced has the form AI2O3+2C4H3O3. A specimen of the pure binacetate prepared by Mr. Crum ex- hibited an equally high osmose as the salt mixed with free acid ob- tained by precipitation which is used below. TABLE XXI1.-Acetate of Aluniina in Osrnometer G of double membrane for five hours. Proportion Rise in Same in Previous Hydrostatic TeE::y-millimeter gramrnes of Diffusatein maceration.redistance. of salt. ciegries. * water. gramme'. Fah. 1 1 i 1 per cent. 3. 232 9-728 days. 2 I 264 11.0U6 1 3'5 65 0.1 195 8208 1 3'5 64 0.1 130 5'472 2 3 66 0-1 0.1 199 146 Ci-68H 6.132 1 >- 3 3 67 87 OSMOTIC FORCE. In the second and third experiments of the Table the solutions were coloured distinctly blue by means of the ordinary sulphate of indigo without interfering much apparently with the osmose. The diffusates when given are as binacetate of alumina and were calculated from the alumina found in the water-jar. In the last three observations of the one-tenth per cent. solution the diffusate of salt is in proportion to the rcplacing water as 1 to 152 131 and 137. In ostnometer F of single membrane acetate of alumina gave a diffusate not exceeding one-third or one-fourth of the diffusate from sulphate of potash in similar circumstances.Thus in three observa- tions of the aluriiinoiis salt the osniose was 356 393 and 397 ins. with the corresponding diffusates of 0.102 0.114 and 0.080 grainme of binacetate of alumina ; while two experiments on sulphate of potash which were intercalated between the second and third of the preceding observations gave diffusates of 0.325 and 0.425gramme of sulphate of potash. The osmose of acetate of alumina does not appear to be sensibly affected by previous experiments made in the same membrane with sulyhuric acid but to fall greatly when an equal proportion of eul- pbate of potash is diffused along with the acetate of alumina.Of the following numbers -4 8 7 237 7 and 18 the first three and thc fifth which are small are the osmose of 0.1 per cent. sulphuric acid alone; the fourth which is large that of 1 per cent. of acetate of alumina and the sixth that of 1 per cent. of acetate of alumina mixed with 1per cent. of sulphate of potash all in the same meni- brane. The diffusate of' the pure acetate of alumina was 0487 gramme which is low for a 1 per cent. solution as compared with the diffusates from the one-tenth per cent. solutions of sulphuric acid which were 0*039,0*04!2, 0.046 and 0.044 gramme of sulphuricacid. The addition of an equal weight of chloride of sodium to the 1 er cent. solution of acetate of alumina lowered the osmose of the Patter salt in osrnometer k' from 397 to 1267 Ins.This is a small amount of interference compared with that exercised by the sulphate of potash in the same membrane. Pure binacetate of alumina was found to be largely decomposed when diffused in open vessels the acetie acid escaping and leaving behind the allotropic soluble alumina of Mr. Crum. This last substance is remarkable for its low diffusibility; but this subject will require fur- ther discussion on a future occasion. Iron. Protosulphate of 1ron.Tfiis salt appeared like sulphate of magnesia to exhibit only the exchange by diffusion of one part of salt for five or six parts of water; the rise of fluid in the osmometer also increasing pretty uniformly with the proportion of salt. Thus in double membrane of good resistance 1 per cent.of this salt (always supposed anhydrous) gave 21 and 30 ms. ; 4 per cent. 60 and 8-1!ms. at a temperature betwcen 61' and 64' Fahr. PROFESSOR GltAHAlU ON Protochloride of Iroa.-This salt separates itself from some other magnesian chlorides and gives rise to a positive chemical osmose which is considerable iu amount. 1’0learn whether this arose from the passage of iron into the higher oxide or not sulphurous acid and hydrosulphuric acid were mixed with the protochloride of iron ;but as will be seen below without lessening the osmose. TABLExxIII.-One per cent. Solutions of several Magnesian Chlorides in Osniornetttr F of double membrane for five hours. Rise in Hgdro-Tempera-Sdt in osmoineter.iilliineter static ture degrees. esistance. Fahr. ~ ~~ ~ ~~~~ 0 rnin. Chloride of magnesium ......... 3 2 59 Chloride of zinc ........... 44t3 2 61 Sanie ............... 54 2 ti2 Chloride of manganese ......... 2-1 1-75 62 Same ............... 34 1-5 ti3 Protochloride of irou .......... 1fi0 1 ti1 Same ............... 19T 1 64 Same ... ........... 4.33 2 ti5 Protochloride of iron +0-1per cent. sulphurous acid ........ ...... 404 4 62 Protochloride of iron sctturatei with SH ... S32 4 ti 4 Pmtochloricle of iron alone ....... 155 4 81 The osmose of protochloride of iron is large but singularly unsteady in amount rising from 160 to 435 ms. and falling again to 155 111s. In another double membrane of rather small resistance (1min.), the osmose of the same salt was only 94,91 and 97 ms.Between the first and second of these experiments the membrane was washed with alcohol and ether but without changing the character of the osmose. In experiments made with this last membrane the 2 per cent. solution of protochloride of iron gave 151 and 157 ms.; and the 5 per cent. solution 189 ms. ;or the osmose did not rise in pro- portion to the quantity of salt in solution Nitrate of Sespuioxide of Iron formed by saturating dilute nitric acid by hydrated sesquioxide of iron gave in single membrane the high osmose of 322 and 359 ms. for 1 per cent. of salt; and 153 followed by 107 ms. for 0.1 per cent. of salt. The acetate of the same oxide give when a deep red colour 207 ms.and when it had become nearly colourlesu from the spontaneous precipitation of a portion of its oxide 194 ms. or sensibly the same osmose. Mangalme.-Sulpbate of manganese appeared to have no decided chemical osmo~e giving in double membrane of moderate resistance (2min.) for 1 per cent. of salt 34 51 and 50 ms. ;for 4 per cent. of salt 53.and 51 ms. and for 10 per cent. of salt 37 and 59 ms. The low osmose of the larger proportions ofthis salt is exceptional and would require confirmation. OSMOTIC FOICE. The chloride of manganese has already been shown to be of low osinose in membrane (24 and 34 ms. Table XXIIT.) ;in albumen the same salt gave 13 and 14 ms. Cobalt.-The chloride of this metal appeared to possess no decided chemical osmose 1 per cent.giving in double membrane 21 and 27 ms. ;0.1 per cent. 20 ad !?3ms. and 1 per cent. agaih 44 ms. NickeL-The sulphate of oxide of nickel resembled that of niagnesia and protoxide of iron. In double membrane 1per cent. gave 12 and 10 nis. ;4 per cent. 38 and 38 ms. j 10 per cent. 72 and 106 ms. The chloride of nickel however appeared to have a tendency to chcniical osmose like the protochloride of iron and gave in double mernbrane 52 89 and 95 nis. Zinc.-None of the salts of this metal can be said to exhibit decided chemical osrnose ;sulphate of zinc giving 34 and 29 ms. nitrate of zinc 18 and 32 ms. and chloride of zinc 48 and 54 ms. all in double meinbrane. Cadmiurn.-The nitrate of cadmium appeared to affect chemical qsmose; the 1per cent.solution of this salt giving in double mem- brane 90 124 and 137 ms. Copper.-Copper appears to possess the capacity for chemical osmose in its salts generally with the exception of the sulpbate. But no sul-phate appears to be remarkable for osmotic activity. The comparative osinose of four salts of copper in the same membrane is given below. TABLE XXIV.-Solutions of 1per cent. of Salts of Copper in Osmometer E of double membrane for five hours. Rim in Salt in solution. millimeter Hydroetatic Pemperature degrees. resistance. Fahr. 0 min. Chloride of copper ........ 351 I (i0 Salphate of copper ........ 45 LO 59 Nitrate of copper ........ 154 10 60 S:tme ............ 204 12 62 Acetate of copper ........ 14P 10 02 Same ............102 10 63 Same ............ 102 10 c,1 The rate of osuiose is general a little deranged on passing from one salt to another in the same membrane and in consequence the second or third experiment is always to be preferred to the first made with the same salt. The preferable numbers for the osmose of the pre- ceding salts would therefore be sulphate of copper 48 ms. acetate 102 iiitrate 204 and chloride 351. The number for the sulphate however is probably too high being raised by the previous chloride. The salts of several of the magnesian metal exhibit a much lower osmose in albumen than in mcmbrane. In an osmometer of the first PROFESSOR GRAHAM ON description nitrate of copper giure only 22 and 27 tns.; acetate of copper 22 and 25 ms.or no inore osmose than is obtained from the corresponding salts of lime and magnesia. Lead-The salts of this metal arc' prahably equally osmotic with those of copper. The nitrate and acetate of lead only were exa-mined. The osmose of these two salts obtained in the same mem- brane was as follows TABLE XXV.-Solutions of 1per cent. of Salts of Lead in Osmo-meter M of double membrane for five hours. m:':i&r l Hydrostatic Temperature Il Salt in solut,ion. degrees. resistance. Fahr. 0 min. Nitrate of lead ......... 174. 2 64 Same ............ 211 2 65 Same .. ......... 1!)7 2 62 Acetate oflead ......... 100 2 64 Same ............ '31 2 61 Proportion Rise in Bame in millimetei grammes of Diffusate in Previous Hydrostatic Tempera-of salt maceration.resistance. ture, pam41es* in solution. degrees. water. Fahr. G per cent. min. 1 91 0 2 61 l-1 127 I I 1 64 1 125 1 1 03 1 157 3 8 ti3 1 157 9 12 63 2 184 1 18 83 2 195 1 12 68 5 209 -1 12 66 5 229 1 12 67 --I-10 2 13 6'3 10 250 10'56 3.288 72 I OSMOTIC FORCE. 91 These experiments lead to the estimation of the osmose of nitrate of lead as follows :-in the 1 per cent. solution an osiiiose of 157 ms. in the 2 per cent. solution 195 ins. in the 5 per cent. solution 229 ins. and in the 10pei..cent. solution 250 ms. This it is to be observed is but a sniall increase for the higher proportions of salt. The diffuaate for the 10 per cent. solution of this salt may be considered of an average proportional amount.The replacing water then exceeds the salt diffused ouly about three and a half times. It is curious that the hydrostatic resistanceof the membrane increases so decidedly as the experiments advance in the osmose of this and several other metallic salts particularly nitrates. It is not to be sup- posed however that this change has any material influence upon the osniose. C-runium.-The nitrate of uranium presented a high degree of osniose. This result scarcely affects the question of the constitution of the metallic oxide present in that salt as a high osmose is exhibited both by the salts containing an oxide of the type R,O, and by a portion at least of the class of protoxides. Viewed as an aluminous salt the nitre of nranium has a basic composition (Ur 0 NO,) a Circumstance which suggested the addition of free nitric acid to that salt in some experiments.The small proportion of one-tenth per cent. of nitric acid will be seen to have a moderate influence and 1per cent. of nitric acid to have an overpowering influence in reducing the extraordinary osmose of this salt. TABLEXXVII.-Solutions of Nitrate of uranium in Osrnometer bl of double membrane for five hours. Rise in Diffuaate Previous Hydro-Tempera-1 1 Proportion of salt in solution. millimeter in macera-static ture degrees. grammes. tion. resistance. Fahr. 0 dys. min. 1 per cent. nitrate of uranium 288 0.078 1 1 60 3 per cent. nitrate of tiraniurn 458 0.102 3 1 61 Sime + 1 per cent.nitric acid 44 0.205 1 1 63 Saaie+ same . . . . . 70 0-136 1 3 66 Same +0-1 per cent.nitricacid 804 0.078 1 3 62 SiiTllC! + same . . . . . 282 0-108 1 3 The inferior osniose of the first observation in the Table arose from the osrnose of the early hours of the esperinient being less than those of the later hours the osmose for the five hours in succession being 36 46 67 77 and 63 ms. This progression combined with the additional circumstance to be observed that the diffusate is below the average in the same experiment suggests the idea of an absorbing or retaining power in the niembrane for the salt which must first be satisfied before the osmose and diffusion can proceed in a regular manner. The diffusate is throughout small like that of an alumiuous salt.PROFESSOR GRAHAM ON In an albumen osmometer the osniose of the same salt was incon-siderable namely 49 and 53 ms.; but that oamose was not further reduced by thc addition of nitric acid. 5'irz.-The protochloride of tin exhibits a high degree of osmose like so many other metallic protochlorides. The I per cent. solution gave in double meinbralie an ostnose of 235 253 289 and 275 ms. The bichloride of tin following immediately in the same membrane gave only 27 ms. But the osmose of the bichloride of this metal is essentially negative even when the salt is made as neutral in corupo-sition as possible. It has been already described. Antimony.-The double tartrate of potash and antimony proved rather remarkable for low osmose.In the first experiment with a double membrane the osmose of the salt in question was 38 ms. but the osmose fell in the second and third repetitions to 12 and 17 ms. The 4 per cent. solution of the same salt gave no more than 23 and 7 ms. Mercury.-The osrnose of the salts of both oxides of this metal is always positive and generally considerable. The osmose appeared to be of least amount in the chloride (corrosive sublimate) to increase in the protonitrate and to assume its greatest magnitude in the pernitrate. Tbe first salt has a stability in solution which the latter two salts do not enjoy. Extraordinary osmose is here therefore associated with facility of decomposition as in so many other instances. The influence of the presence of acids and of chloride of sodium upon the osmose of chloride of mercury was tried in the search for facts which might throw light on the osmotic process.An acid in small proportion appears to favour rather than otherwise the osmose of chloride of mercury. Chloride of sodium on the other hand exerts its usual repressing influence upon the process. TABLE XXVIIL-Solutions of Mercury in Osmometer C of double membrane for five hours. Rise in Previous Hydro-Teinpera-Proportion of salt inRolution. millimeter macera-static ture, 1 1 degrees. tion. resistance. Fahr. 0 days. min. 1 per cent. of chloride of mercury . . 1J 6 4 P 00 Same. ........... 121 3 4 61 0.1 per cent. of cliloride of mercnry . 62 1 4 63 Same. ...........40 1 5 06 1 per cent. cf chloride of mercury +0.1 per cent. of hydrochloric acid ... 163 Same +same ......... 132 Same +o 1 per cent. of nitric acid .. 152 Same +same ......... 132 Same+0.5 per cent. of chloride ofsodium 72 Same +same ......... (i0 OSMOTIC FORCE. Adopting the second experiments as the most trustworthy we have for 1 per cent. of chloride of mcrcury an osmose of 121 ms. and for the same associated with half its weight of chloride of sodium 60 ms. The osmose of chloride of mercury in albumen was very trifling being only 5 and 9 ms. ;chloride of mercury diffused in sensible quantity however through both the albutnen and membrane. Yrotonitrate of mercury gave in double membrane an osmose of 232 346 and 350 ms.; in albumen milch less namely 47 63,and 61 ms.Pernitrate of mercury gave in double membrane 425 and 476 rns. for the 1 per cent,. solution and 296 ms. for the one-tenth per cent. solution results which indicate osniotic power of the highest intensity. The membrane preserved a considerable action after the last experi- ments although macerated in water for a night and imparted thereafter to a salt nearly neutral to osmose (nitrate of silver) a rise of 222 and 166 111s. In albumen pcrnitrate of mercury again was low giving 32 and 54 ms. for 1 per cent of the salt and 34 and 4.6 ms. for the one-tenth per cent. solution. SiZvrr.-It is interesting to observe how this rtietal separates itself frorn mercury and the rnagnesian elements and takes its place with the alkaline metals in the property of osmose as in other chemical characters.Nitrate of silver appeared to possess a moderate positive osmose like a salt of potzsh or soda. For the sake of comparison the silver salt was followed by nitrate of soda in the experiments below. TABLEXX1X.-Solutions in Osmometer G of double membrane for five hours. Rise in Previous Hydro-Tempera-Salt in osmometer. millimeter1macera-static ture, i degrees. tion. Iredance] Fahr. days. min. n 1 per cent. of nitrnte of silver ... 36 z 2 A4 Same. ........... 34 1 2 (ij 0.1 per cent. of nitrate of' silver ... 27 1 2 62 Same. ........... 22 1 2 64 1 per cent. of nitrate of soda .... 7 2 2 61 Same.. .......... 2 1 2 I 64 94 PROFESSOR GRAHAM ON Osmose in membrane of 1 per cent.solutions expressed in millilneter Oxalic acid . . . . . . -148 Chloride of zinc . . . . . . 45 Hydrochloiicacid(O.1percent.) -92 Chloride of nickel . . . . . €9 Terchloride of gold . . . . -54 Nitrate of lead . . . . . . 204 Richloride of tin . . . -46 Nitrate of cadmium . . . . 137 Bichloride of platinum . . -30 Nitrate of'uraninm . . . . . 458 Nitrate of magnesia . . . -22 Nitrate of copper . . . . . 204 Chloride of magnesium . . -2 Chloride of copper . . . . . 351 Chloride of sodium . . . + 12 Protochloride of tin . . . . 219 Chloride of potassium . . . 18 Protochloride ofiron . . . . 435 Nitrate of soda . . . . . 14 Chloride of mercury . . . . 121 Nitrate of silver . . . . . 34 Protonitrate of mercury .. . 350 Sulphttte of potash . . . . 21 to 60 Pernitrate of mercury . . . . 476 Sulpliate of magnesia . . 14 Acetate of sesquioxide of iron . 194 Chloride of calcium . . . 20 Acetate of alumina . . . . 393 Cliloricle of barium . . . . S1 Chloride of aluminum . . . . 640 Chloride of strontium . . . 2G Phosphate ot'soda . . . . . 311 Chloride of cobalt . . . . 26 Carbonate ofpotash . . . . 489 Chloride of manganese . -34 It will be observed tbat acid and alkaline salts are found at opposite ends of the series or while the acids possess negative osmose the alkaline salts exhibit positive osmose in the highest degree. The remark will suggest itself that in osmose water always appears to pass to the alkaline side of the membrane; as water also follows hydrogen and the alkali in the electrical endosmose.The chemical action miiat be different on the substance of the membrane at its inner and outer surfaces to induce osmose; and according to the hypothetical view which accords best with the phenomena the action on the twb sides is not unequal in degree only but also differcnt in kind. It appears as an alkaline action on the albumirioua substance of the membrane at the inner surface and as an acid action on the same substance at the outer surface. The most general empirical conclusion that can be drawn is that the water always accumulates on the alkaline or basic side of the membrane. The analogy does not fail even when the osmometer is charged with an acid solution and the osmose is negative.The stream is then outwards to the water which is a basic body compared with the acid within the membrane. The high positive osmose of the salts of the alumina type is exceedingly remarkable. The property is coinuion to salts of alumina sesquioxide of iron sesquioxide of chromium and the corresponding oxide of uranium. Now the property in these salts is small where thc salt is stable as in the sulphates but becomes great where the affinity between the acid and base is comparatively weak as in the chlorides nitrates and acetates of these bases salts wbich can be shown to be largely decomposed in the experiment by the action of diffusion. Here then as with the prcceding class of osmotic bodies the osmose of the water is towards the basic side of the membrane.But the most curious circumstance with reference to this empirical OSMOTIC FORCE. generalisation is observed in the magnesiau class of salts. The barytic subdivision of t-his class including all the soluble salts of baryta strontia and lime appear to be entirely unosmotic or they oscillate between a small positive and small negative osmose. Such salts are neutral in their reaction and further have no disposition whatevcr to form subsalts. The salts of the earth magnesia itself offer the same characters. But in the salts of certain other oxides of the magnesian group an intensely osmotic character is developed particularly in the salts of copper protoxide of lead and protoxide of tin with the excep- tion of the soluble sulphates of these bases.Now those named are the members of the magnesian class most apt to break up into free acid and a basic salt. Like the aluininous salts therefore they are capable of investing the inner surface of the membrane with basicity the necessary condition of positive osmose Nitrate of uranium does not require. to form a subsalt as it is already constitutionally basic. The osniotic peculiarity of nietaphosphoric acid formerly referred to also harmonises with the same view. Neutral nionobasic salts of the alkaline metals such as the chlorides of potassium and sodium and tlie nitrates of potash soda and silver which possess a strict and unalterable neutrality appear to have little or no true osmotic action. The salts named together with the neutral magnesian sulphates and certain neutral organic substances such as alcohol and sugar give occasion it is true to an increase in the fluid of the osmometer but only to the moderate extent which the exchange of diffusion-volumes might be supposed to produce.The comparative diffusibility of all these substances is well known with the exception unfortunately of that of water itself which I could only deduce by an indirect method in my previous inquiries respecting liquid diffusion. As salts generally appeared to diffuse in water four tinies more rapidly than they did in alcohol the diffusibility of water was then assumed as probably four times greater than that of alcohol and con- sequently five or six times greater than that of sugar or sulphate of wagnesia.Diffusion is thus made to account for the substances last named being replaced in the osrnometer by five or six times their weight of water. This “ diffusion-osmose” appears to follow in its amount the proportion of salt in solution with a certain degree of regularity. The ‘‘ chemical osniose” of substances on the other hand is found of high intensity with small quantities of the substance such as 1per cent. or even 0.1 per cent. and to aupent very slowly with increased proportions of the substance in solution. A small proportion of common salt accompanying carbonate of potash has been seen to possess a singular influence in diminishing the positive osmose of the last-named alkaline salt; while a mixture of small proportions of coninion salt and hydrochloric acid exhibits with the membrane in certain conditions an intense positive osmose which lieither of these siibstances possesses individually.The bibasic salts of potash again such as the sulphate and oxalate PROFESSOR GRAHAM Oh’ OSMOTIC PORCE. although strictly neutral in reaction begin to exhibit a positive osmotic power in consequence it may be supposed of their resolvability into an acid salt and free alkaline base. Tbe sulphate of potash when strictly neutral has in different mem- branes a variable but always moderate positive osmose an osmose which the slightest trace of a strong acid may cause to disappear entirely or even convert into a small negative osmose. On the other hand a minute addition of an alkaline carbonate to the sulphate of potash appears to give that salt a positive osmose of a high order.It was seen that the mixed salts produce much more osniose than the sum of the osrnose of the two salts used apart from each other. It may appear to some that the chemical character which has been assigned to oamose takes away from the physiological interest of the subject in so far as the decomposition of the membrane may appear to be incompatible with vital conditions and osmotic movement con-fined therefore to dead matter. But such apprehensions are it is believed groundless or at all events premature. All parts of living structures are allowed to be in a state of incessant change,-of decom-position and renewal. The decomposition occurring in a living membrane while effecting osmotic propulsion may possibly therefore be of a reparable kind.In other respects chemical osmose appears to be an agency particularly well adapted to take part in the animal ceconomy. It is seen that osmose is peculiarly excited by dilute saline solutions such as the animal jriiccs really are and that thealkaline or acid property which these fluids always possess is another most favour- able condition for their action on membrane. The natural excitaiion of osmose in the substance of the membranes or cell-walls dividing such fluids seems therefore almost inevitable. In osniose there is further a remarkably direct subetitut,ion of one of the great forces of nature by its equivalent in another force-the conversion as it may be said of chemical affinity into rriechanical power.Now what is more wanted in the theory of animal functions than a mechanism for obtaining motive power from chemical decom- position as it occurs in the tissues ? In minute microscopic cells the osmotic movements should attain the highest velocity being entirely depcndent upon extent of surface. May it not be hoped therefore to find in the osmotic injection of fluids the deficient link which intervenes between chemical decomposition and muscular contraction ? The intervention of the osmotic force is also to be looked for in the ascent of the sap of plants. The osmometer of albuminated calico appears to typify the vegetable cell ; the ligneous matter of the latter being the support of a film or septum of albuminous matter in which the active properties of the cell reside.With a vegetable salt like oxalate of potash above and pure watei* below such a septum an upward movement of the lower fluid would neccssarily ensue.

ISSN:1743-6893    

DOI:10.1039/QJ8560800043

出版商:RSC    

年代:1856

数据来源: RSC

摘要:

INDEX. A. Acetureid acetyl-urea othgl-urea 150. Acetylammonium oxide of 150. -sulphule of 15 2. Acid acetic osmose uf 59. -arsenious and its salts volumetric estimation of 236. -citric osmose of 69. -ferric volumetric estimation of 232. c_hydriodic on the action of upon gly- ceriue by Berthclot and de Luca 192. -hydrochloric osmose of 58. -hypopzeic on a new fatty ilcid obtained from earth-nut oil by A. Goasruarin and 14. Scheven 279. -iodic volumetric estimation of 232. -manganic volumetric estimation of 232. -nitrophthalinic 303. -nitric action of on papaverine 283. on the act.ion 'of upon tartanil and tartanilide 181. -osmose of 58. -oxalic osmose of 48. -palmitic from StiZZinyia se&fenz 5. -phosphoric osmose of 59.-pyrotartaric on the anilides of by E. Arppe 172. -pyrotartanilic 172. -pjrotartonitranilic 174. -racemic anilides of 181. osmose of 59.-salicylic on by R. Piria 182. -seleuic volumetric estimation of 232. -sulphobutylic 27 1. -sulphuric on an easy method of puri-fying Comarsenic by A. Buchner 258. -sulphurous and sulphuretted hydrogen volumetric determination of 227. -tannic action of with paranitraniline 178. -tartanilic 180. -tartaric on the auilides of by E. Arppe 179. on a new reaction of 306. osmose of 59. -vanadic volumctric estimation of 232. Adic R. on the thermo-electrical currents generated in elements whew bismuth is nsed to form the joints 33. -011 thcrmo-electric joints formcd ivif h the metals antimony bismuth aid palln-dium 36.Adie R. on the hydro-electric cumtits generated by couples formed of a sin,xle metal 295. Alcohol action of chloride of zinc on butylic, 266. -on amylic by L. Pasteur 277. -on benzoic by S. Cannizznro 169. -on butylic by A. Wurtz 264. -on cuminic by C. Kraut 106. -on the formation of from olctialrt gas by 31. Berthelot 148. -osmosc of 61. Aldehyde on caprylic by II. Li mpr i c h t 155. -radicals on the substitution of the in ammonia by J. Natanaon 150. Alkalies on the preparation of the metals of the and alkaline earths by electrolysis, by A. Matthiesseo 27. Alumina ace& of osmose of 86. -siilphate of osmose of 85. Aluminium chloride of osmose of 86. -on by H. Deville 239. -properties of 241.Amarine on a new mode of formation of and of ethylamine and lophine by A. Gossmann 161. Ammonia amount of in Southwark and Lambeth waters 142. -carbonate of gluciua and 247. -on the substitution of the aldehyde radicals in by J. Natanson 160. -oxalate of glucina and 249. -pyrotartanilate of 173. -tartanilate of. 181. Ammonium chloride of cadmium aud 253. -oil of mustard with hydrosulphate of 184. -sulphate of cadmium and 255. Analysis on a method of volumetric of very general application by R.Bunseu 219. Audcrson T. on papaverine 283. 372 1NL)EX. Anilides of racemic aeid 181. -on the of tartaric acid by E.Arppe, 179. Antimouy-salts osmose of 92. -on therino-electric joints formed with arid with bismuth and palladium by R.Adie 36. Arabin on by C. Neubauer 307. Ar!)pe E. on nitraniline and paranitrani- line 175. -on the anilidesofpgrotartaric acid 172. -on the anilides of tartaric acid 179. Arsenic on an easy method of purifying sul- phuric acid from by A. Biichner 268. Azobenzole and beozidine by A. Noble 292. B. Barium chloride of cadmium and 26 4. -chloride of osmose of 71. -a few notes on by A. Matthiessen 294. -oil of mustard with hydrosulyhate of 186. -oil of mustard with sulphide of 186. Bnryta hydrate of osmose of 84. -salt of hypopeic acid 281. -tartaoilete of 181. Benzidint arid azobenzole by A. Noble 292. Benzoyl-urea 160. Bcrtapnini C. on phillyrin 187. Berthelot and de Luca on the action of hydriodic acid upon glycerine 192.-. on the action of iodide of phos-phorus upon glycerine 145. I_ ou the formation of alcohol from olefiarit gas 148. Bismuth on the thermo-electric currents generated in elements where is used to form the joint. by R. Adie 33. -on the therino-clectric joints formed with the metals antimony palladium and by R. Adie 36. Bisulphites componnds of the ketones with alkaline by H. Lirnpricht 154. Broliiiue action of on papaverine 284. -and chlorine together volumetric de- termination of 226. -on the volatile bromine-compound ob-taiued in the technical preparatiou of by M. Hermann 286. -volumetric deterrniuation of 224. Buchner A. on an easy method of purify-ing sulphuric acid from araeuic 258.Bunsen R. arid H. E. Roscoe photo- chemical researches 193. -on a method of volsmetric analysis of very general application 219. Bunse n on the preparation of lithium 143. Butyl 266. -acetate of 271. -bromide of 267. -carboriate of 269. chloride of 266. iodide of 267. _Initrate of 270. -sullhate ,of 270. Rutylamine 272. Butyryl-urea 160. C. Cadmium on some salts of by C. von Hauer 251. -ammonio-chloride of 252. -and ammonium chloride of 253. -and barium chloride of 254. -aud potassium chloride of 253. -and sodium chloride Gf 254. -bromide of and bromide of potassium, 255. 7nitrate of 251. -salts osmose of 89. 7sulphate of 251-2. -and ammonium sulphate of 255. -and potassium snlphate of 266.-and sodium sulphate of 257. Calcium chloride of osmose of 73. -oil of mustard with hydrosulphate of 187. -preparation of by electrolysis 28. Cannizzaro S. on benzoic alcohol 169. Casselmanri A. on tartrate of lime and a new reaction of tartaric acid 306. Cerium and lanthanum volumetric separa- tion of 232. Charcoal on platinised by J. Stenhouse 105. Chemical Society proceedings at the meet- ings of the 38 116 297. Chiozza L. and Frapolli A. on cou-maramine a new organic base derived from iiitrocoumarine 301. Chlorates volumetric estirnatiou of 229. Chloriue action of ou papaverine 285. -and bromine together volumetric de- termination of 225. -and iodine together volumetric de- termination of 224.-on the absorption of in water by H. E.Roscoe 15. -volurnetric determination of 223 Chlorites aud hypochlorites volumetric de- terrniuation of 226. Chromates volumetric estimation of 227. Cobalt lead manganese and nickel voln- metric estimation of the peroxides of 2 .O. -vilts usmose of 89. INDEX. 373 Copper on the eolour of chloride of in different states of hydration by J. 11. Gladstone 211. -osychloride of 213. -salt of hypogseic acid 281. osmose of 89. Counrd report of the 109. Coumaramine 301. D. Dean J. and F. Wohler on telluromethyl, 164. Debrap H. on glucinum and ils coni- pounds 242. De Luca and Berthelot on the action of hydriodic acid upon glycerine 192.Deville H. on aluminium 239. Dusart L. on some derivatives of naph-thalin. 303. -ou a new mode of producing propylene 305. E. Earth-nut oil on hypogaeic acid a new fatty acid obtained from 279. Efflorescence on a pecnliar of the chloride of potassium by R. Warington 30. Ether butylic 268. -hypogeic 281. -vino-butylic 269. Ethylamine on a new mode of formation of and of amarine and lophine by A. Goss-mann 161. Ethylene easy method of preparing chloride of by H. Limpricht 157. F. Frapolli A. and Chiozza L. on cou-maramine a new organic base derived from nitrocoumarine 301. G. Gladstone J. H. on the colour of chloride of copper in different states of hydration, 211. Gluciua 244. -carbonate of 246.-and ammonia carbonate of 247. -aud potash carbonate of 247. -oxalate of 247. -aud ammonia oxalate of 248. -and potash oxalate of 217. -sulphate of 245. Glucinum on and its compounds by 13. Debray 242. Glperine on the action of iodide of phos-phorw upon by Berthelot and de Luca 145. -on the action of hpdriodic acid upon by Berthelot aud de Luca 192. Gold and platinum salts osmose of 93. -terchloride of osmose of 69. Gossmann A, and Scheven H. on hypo-gacic acid a new fatty acid obtained from earth-nut oil 279. -on a new mode of formation of ethy-lamine amarine and lophine 161. . Graham T.,on osmotic force 43. H. Hauer C.von on some salts of cadmium, 251. Haines R. on the volatile oils of Ptychotis Ajwan 289. Heintz W.on the products of the de- composition of stearate of lime 308. Hermann M. on the volatile bromine- compound obtaiued in the technical pre- paration of bromine 286. Houzeau A. researches on oxygen in the nascent state 2.17. Humann E. ou butyIic mercaptan and butylic urethane 274. Hydrochlorate of nitraniline 176. Hydro-electric currents on the generated by couples formed of a single metal by R. Adie 295. Hydrogen sulphuretted and sulphurous acid volumetric determination of 227. Hydrosulphate of mustard oil on some com- pounds of by H. Will 183. -of ammonium oil of mustard with 184. -of barium oil of mustard with 186. -of calcium oil of mustard with 187. -of potassium oil of mustard with 184. -of sodium oil of mustard with 185.Hgpochlorites and chlorites volumetric de-termination of 226. Hypogaic ether 281. I. Iodine action of on papaverine 283. -volumetric determinstion of 222. -and chlorine together volumetric de- termination of 224. Iodopropylene 145. Iron nitrate of sesquioxide of osmose of 88. 7protochloride of osmoae of 88. -protosulphate of osmose of 87. 374* INDEX. K. Ketones compounds of the with alkaline bisiilphites by H. Limpricht 154. Ktaut C. on cuminic alcohol 166. L. Lnnthanum and cerium volumetric separa- tion of 232. Lead maoganese nickel and cobalt volu- metric estimation of the peroxides of 230. -salts osmose of 90. Leocin preparation of from the aldchyde of valerianicacid by H. Limpricht 157.Liebig J. on the mellonides 259. Lime hydrate of osmose of 85. -nitrate of osmose of 85. Limyricht €I., 011 an easy method of pre-paring chloride of ethylene by 157. -on the cornpounds of the ketones with alkaline bisulphites 154. -on caprylic aldehyde 155. -on the metaldehyde of valerianic acid 157. -on the preparation of leucin from the aldehyde of valerisnic acid 157. Lithium on the preparalion of by R. Bun-sen 343. Lophine on a new mode of formation of etbylamine amarine and by A. Goss-mauu 161. Lijwig R. on some compounds of stibethy-lium 260. M. Magnesia nitrate of osmose of 85. -sulphate of osmose of 67. M:rguesium chloride of osmose of 85. -on the preparcition of strontium and by A. Matthiessen 107.Maupncse lead nickel and cobalt volu- metric estimation of the peroxides of 230. c_silts osmose of 88. Mangostin on by W. Schmid 190. Maskclyue N. S. investigation of the vegetable tallow from a Chinese plant the '' Stillingia sebifera," 1. Matthiessen A. 011 the preparatiou of strontium aud magnesium 107. -oii the preparation of the metals of the alkalies and alkaline earths by elec- trolysis 27. -a few notes on barium 294. hlellonides on the by J. Liebig 259. JIercaptan on butylic and btitylic urethane by E. Hurnann 274. ?bfcrcury chloride of stibetliyliurn iilirl 262. Mercury iodide of etibethylium and 261. -on the Preparation of the sulphochlo- ride of in the dry way by R. Schneider 257. _c. salts osmose of 92.Metaldehyde on the of vtllenanic acid by H. Limpricht 157. Metropolis chemical compositiou of the waters of the during the autumn arid winter of 1854 by R. D. Thomson 91. hioldenhauer Y. and N. Zinin on com- pound ureas 158. Mustard oil on some compounds of hydro-sulphate of by H. Will 183. -with hydrosdphate of ammonium 184. with hydrosulphste of barium 186. with hydrosulphate of calcium 187. -with hydrosulphate of potassium 184. with hydrosulphate of sodium 185. -with sulphide of barium 186. with oulphide of potassium 185. N. Naphthalin on some derivatives of by L. Dusart 303. Natanson J. on the substitution of the aldchyde radicals in ammonia 150. Neubauer C. on arabin 307. Kickel lead maiiganese and cobalt volii- metric estimation of the peroxides of 230.-salts osmose of 89. Nitraniline on and paranitraniline by E. Arppe 175. -hydrochlorate of 176. -nitrate of 177. -sulphate of 177. Nitrate of paranitraiiiline 178. Nitrocoumarine 301. Noble A. on azobenzole and bcnzidine 292. 0. Oils on the volatile of Ptycholis Ajzcan by R. Haines 289. Olefiant gas ou the formation of alcohol from by M. Berthelot 148. Osmotic force on by T. Graham 43. Oxide ferrous volumetric estimation of alone and in conjunction with ferric oxide 234. Oxychloride of copper 213. Oxygeii researches on in the nascent state by A. Huuzeaii 237. Ozone voluiiietric estirnalion of 232. INDEX. 375 P. Palladium on thermo-electric joints formed with the metals antimony bismuth and .by R. Adie 36. Palmitate of baryta 8. -copper 10. -lead 9. -magnesia 9. -silver 10. -soda 8. -oxide of ethyl 11. -lipylic oxide 7. Palmitic ether 11. Palmitine 7. Pelmitone 11. Papaverine on by T. Anderson 283. Paranitraniline on nitraniline and by E. Arppe 175. Pasteur L. on amylic alcohol p. 277. Yhillygenin 188. Phillyrin on by C. Bertagnini 187. Photochemical resewches by R. Bunsen and H. E. Roscoe 193. Phosphorus on the action of iodide of npon glycerine by Berthelot and de Luca 145. Phthalidine 303. Piria R. on salicylic acid 182. Platinisd charcoal on by J. Stenhouse 105. Plnti~ium bichloride of osmaie of 69. -chloride of stibethylium and 262.-salts of nitraniline 176. Potash carbonate of glucina and 247. -carbonate of osmose of 73. -chromate of osmose of 82. -oxalate of glucina and 247. -bichromate of osrnose of 82. -bisulphate of osmose of 60. -hydrate of osmose of 73. -oxalate of osmose of 82. -and soda sulphates of osmose of 80. Potassium bromide of cadmium and bro-mide of 255. -chloride of cadmium and 253. -sulphate of cadmium and 256. -oil of mustard with sulphide of 183. 7oil of mustard with bydrosulphate of 184. -tartrate of 306. -products of decomposition of stearatc of 308. -on a peculiar dliorescence of the cliloride of by R. Warington 30. Propylene gas 147. -formationof propylicalcohol from 149. -on a new mode of producing by L.Dusart 303. Pfyclrotis Ajlcnn on the volatile oils of hy H. Haines 289. 'yrotartanil 172. 'yrotartanilate of ammonia 173. 'yrotartonitranil 174. R. Soscoe H. E. bud R. Bunsen photo- chemical researches 193. -H. E. on the absorption of chlorine in water 15. S. Schmid W. on mangostin 190. 3cb neider R. 011 the preparation of sulphorhloride of mercury in the dry way 257. Silicium new form of 242. Silver-salts osmose of 93. -tartanilate of 181. Soda aid potash sulphatesof osmose of 80. -phosphate and carbonate of oSmose of 77. -lime action of on papaverine 286. Sodium chloride of osmose of 69. -chloride of c,:dmium and 254. -sulpbate of cadmium and 257. -oil of mustard with hydrosulphatc of 185.Spirit of wine report on Che snpply of fme from duty for iise in the arts and manu- factures by Professors Graham Hof-mann and Redwood 120. Stearate of lime iwodncts of decornpositioi of stearate of 308. Strarone 308. Stell house J. on pliitinised charcoal 105. Stibethglium on some compounds of by R. LOlViF 260. -bromide of 263. -iodide of 260. -sulphide of 263. -chloride of 262. -and mercury chloride of 262. -and platinum chloride of 262. -atid mercury iodide of 261. -hydrated oxide of 263. Stillingia sebifera investigation of the verre- table tallow from a Chinese plant thr by N. S. Maskelyne 1. Strontium chloride of osmose of 85. -on the preparation of and magucsiuiri by A. Matthiessen 107. Sugar osmose of 63.Sulphate of nitraniline 177. -of paranitraniline 178. Sulphide of barium oil ofmustard with 186. -of' iwlassium oil of ~i~ustard witit 165. 376 INDEX T. V. Tartanil 180. -on the action of nitric acid upon and tartanilide 181. Tartanilide 179. -on the action of nitric acid upon tar-tauil aud 181. Tartanilate of ammonia 181. -of baryta 281. -of silver 181. Tartrate of parauitraniline 178. -of lime and a new reaction of tartaric acid by A. Casselmann 306. Telluromethyl on by F. Wohler and J. Dean 164. Therrno-electric currents on the generated in elements where bismuth is used to form the joint by K. Adi e 33. -joiuts on formed with the metals antimony bismuth and palladium by R. Adie 36. Thornson R.D. on the chemical composi- tion of the waters of the metropolis during the autumn and winter of 1854 97. Tin-salts osmose of 92. U. Uranium-salts osmose of 91. Urethane on butylic mercaptan and butylic 274. Ureas on compound by N. Zinin and F. Moldenbauer 168. Valerianic acid on the metaldehyde of by H. Limpricht 157. preparation of leucin from the aldehyde of by H. Limpricht 157. -investigation of the from a Chi-nese plaut the “ Stillingia sebifera,” by N. S. Maskelyne 1. Valeryl-urea 160. Volumetric analysis on a method of of very general application by R. Bunsen 219. W. Warington R. on a peculiar efflorescence of the chloride of potassium 30. Water on the absorption of chloriue in by H. E. Roscoe 15.’ Waters chemical composition of the waters of the metropolis during the autumn arid winter of 1834 by R.D. Thomson 97. -softening process for 104. Will H. on some compounds of hydro-sulphate of mustard-oil 183. Wohter P. and J. Dean on telluro-methyl 164. W iir tz A. on butylic alcohol 264. Z. Zinc action of chloride of on butylie alcohol 265. -salts osmose of 89. Ziuin N. and F. Moldenhauer on com- pound ureas 138. END OF VOL. VIII. Losn.Jx Printed by SPOTTISWOODE 8; Co. Serv-btrect-Sf(iiarc.

ISSN:1743-6893    

DOI:10.1039/QJ8560800371

出版商:RSC    

年代:1856

数据来源: RSC