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Proceedings of the Chemical Society, Vol. 11, No. 158 |
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Proceedings of the Chemical Society, London,
Volume 11,
Issue 158,
1895,
Page 221-244
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摘要:
Jsszted 14/1/1896. PROCEEDINGS OJ? THE CHEMICAL SOCIETY. EDITED BY THE SECRETARIES. No. 158. Session 1895-96. December 19th, 1895. &. A. G. Vernon Harcourt, President, in the chair. Messrs. E. H. Hills, Philip J. Hartog and Edgar S. Hanes mere formally admitted Fellows of the Society. Certificates were read for the first time in favour of Messrs. W. H. Barker, 26, Belgrave Road, Longton, Staffs. ; Maurice Blood, 15, Clyde R,oad, Bristol; James Craig, 6, Montague Street, Gt. Western Road, Glasgow ; Charles James Pemeller Fuller, Mona, House, Horwich, Lanes. Of the following papers those marked * mere read :-*151. “ The liquefaction of air and research at low temperatures.” ByJames Dewar, LL.D., F.R.S. The author reviewed all the forms of apparatus that had been used in low temperature research, pointing out that the best and most economical plant for the production of liquid air or oxygen was one based on the general plan of the apparatus used by Pictet in his cele- brated experiments on the liquefaction of oxygen in the year 1878. Instead of usiiig Pictet’s combined circuits of liquid sulphur dioxide and carbon dioxide maintained in continuous circulation by means of compression, liquefaction, and subsequent exhaustion, it has been found preferable to select ethylene after Cailletet and Wroblewski, for one circuit, and to join with it either nitrous oxide, or, better, carbon dioxide.Further, instead of making the oxygen to be liquefied by heat-ing potassium chlorate in an iron bomb directly connected with the refrigerator, and t,hereby readling high gas pressures, it has been found more convenient to use gas previously compressed in steel cylinders.The stopcock that Pictet employed to draw off liquid and produce sudden expansion was in his apparatus placed outside the refrigerator proper, but it is now placed inside, so as to be kept cool by the gases undergoing expansion. This improvemelit was introduced dong with that of isolating the liquid gases by surrounding them with their own vspohr in the apparatus made wholly of copper, described and fiqured in the Proc. Roy. I?zst. for 1886. In all con-tinuously working circuits of liquid gases used in refrigerating appa- ratas the regenerative principle applied to cold first introduced bJ-Siemens, in 2857, and subsequently employed in the freezing machines of Kirk, Coleman, Solvay, Linde, and others has been adopted. Quite independently, Professor Kamerlingh Onnes, of Leiden, has used the regenerative principle in the construction of the cooling circuits in his Cryogenic laboratory (see Paper by Dr.H. Kamerlingh Onnes, on the “Cryogenic Laboratory at Leiden, and on the Production of very low Temperatures,” Amsterdam Akademie, 1894). Apart, therefore, from important mechanical details, and the conduct of the general working, nothing new has been added by any investigator to the principles involved in the con- struction and use of low temperature apparatus since the year 1878. The Phil.Mug. of February, 1895, contains a fantastic claim put forward by Professor Olszewski, of Cracow, that because lie used in 1893 a steel tube combined with a stopcock to draw off liquid oxygen, he had taught the world, to use his own language, “the method of getking large qumtities of liquid gases.” But when, in addition, Olszewski alleges, four years after the event, that the ex- periments made at the Royal Institut’ion since 1891 are cliiefly borrowed from Cracow, and that he is entitled to the credit of all low temperature research subsequent to 1891, because of his steel fube and stopcock invention, one can only wonder at the meagre additions to knowledge that in our time are unhesitatingly brought forward as original, and more especially that scientific men could be got to give them any currency in this country.Such persons should read the late Professor Wroblewski’s pamphlet, entitled “ Comment l’air a kt6 Iique66 ” (Paris, Libraire du Luxembourg, 1885), and make themselves generally acquainted with his work before coming to hasty conclusions on claims of priority brought forward by the Professor of Chemistry at Cracow. Lipupfying Apparatus.-The author proceeded to describe the con- struction and show the working of a laboratory apparatus for the production of liquid oxygen and other gases, represented in section (Fig. 1). With this dimple srrangement 100 C.C. of liquid oxygen can readily be obtaiued, the cooling agent being carbon dioxide, at the 0 0'00 0 0 0 0 0 0 0 FIG.1.-A, air 01' oxygen inlet ; B, carbon dioside inlet ; C,carbon dioxide valve ; D, regcnercltor coils ; F, air OP oxygen erpsnsioii valve ; G7vacuuni reasel with liquid oxygen ; Lf, carbon dioside atid air outlet ; 13,nil*coil ; e,carbon dioxide coil.temperature of -79”, no exhaustion being used. The gaseous oxygen, cooled before expansion by passing through a spiral of copper tubs immersed in solid carbon dioxide, passes through a fine screw stopcock under a pressure of 100 atmos., and theuce backwards over the coils of pipe. The liquid oxygen begins to drop in about a quarter of an hour from starting. The general arrangement of the circuits will be easily iznderstood from the sectional drawing. The pressure in the oxygen cylinders at starting is generally about 150 atmos., and the best results are got by working down to about 100. This little apparatus will enable liquid oxygen to be used for denioiistration and research in all laboratories.VaczwnVessels.-It has been shown in previous papers* that a good exhaustion reduces the influx of heat to one-fifth part of what is convejed when the annular space in such double-walled vacuum vessels is filled with air. If the interior walls are silvered, or excess of mercury is left in the vessel, the influx of heat is diminished to one-sixth part of the amount entering without the metallic coating. The total effeci of the high vacuum and silvering is to reduce the ingoing heat to 1/30th part, or, roughly, 3& per cent, Vessels con- structed with three dry air spaces only reduced the influx of heat to 35 per cent.An ordinary mercury vacuum vessel is kherefore 10times more economical for storing liquid air, apart from considerations of manipulation, than a triple annular-spaced air vessel. It has been suggested that the metallic coating of mercury does 110 good, because Pictet has found that all kinds of matter at low temperatures become transparent to heat. The results above mentioned dispose of this assumption, and direct experiment proves that no increase in the transparency of glass to thermal radiation takes place by cooling to the boiling point of air.? &Zit1 Air.-As Professor Olszewski has recently alleged that air does not solidify at the lowest pressures (Phil Mag., February, 1895), the author’s former experiments were repeated on a larger scale.If a litre of liquid air is placed in a globular silvered vacuum vessel and subjected to exhaustion, as much as half a litre of solid air can be obtained and maintained in this condition for half an hour. At first the solid is a stiff, transparent jelly, which, when examined in the * ‘6 On Liquid Atmospheric Air,” Proc. Roy. Iast., lS93; “ Scientific Uses of Liquid Air,” ihid., 1894. + As this is passing tlirougli the press, I observe that M. Cailletet, at the last meetiag of the Freiich Academy (Cmzptes Iikndus), presented a paper by M. sol-c.ay of Brussels, in which my device of vacuuiu vessels is attributed to bf. Caillefet,, and tacitly accepted by him ! In 1873 I liacl dreaclg used a highly ex-hausted vessel, of similar shape to the vacuous test tube, in calorimetric experiments.see paper on “ The Phjsical Constants of Hjdrogeninm,” Trans. Roy. SOC.Ed, vol. 27- 225 magnetic field, has the liquid oxygen drawn out of it to the poles. This proves that solid air is a nitrogen-jelly containing liquid oxygen. Solid air can only be examined in a vacuum or in an atmosphere of hydrogen, because it instantly melts on exposure to the air, giving rise to the liquefaction of an additional quantity of air. It is strange to see a inass of solid air melting in contact with the atmosphere, and all the time welling up like a kind of fountain. Samples qf air liquejied in seazed jasks.-In a previous paper " On the relatire behaviour of chemically prepared and of atmo-spheric nitrogen " PROC.,December, 1894, the plan of manipu-lating such samples was described.Two flasks of dry air t'hat had stood over phosphoric anhydride mere liquefied side by side, tihe only difference between the samples being that one was free from carbonic acid. The one gave a liquid that was perfectly clear, the other was t'urbid from the 0.04 per cent. of carbon dioxide. The temperature was now lowered by further exhaustion of the liquid air surrounding the tubes until both liquids became solid. The flasks were then sealed off for the purpose of examining the coin- position of the air that had not been condensed. The one sample contained oxygen, 21.19 per cent., and the other 20.7 per cent.This is an additional proof to the one previously given, that, substantially, the oxygen and nitrogen in air liquefy simultaneously, even under gradually diminishing pressure, and that in these experiments all the known constituents of air are condensed together. These results finally disproved the view expressed in A Syslem of Inorganic, Chemistry (1891, p. 70), by Professor Ramsay, where he says : "Air has been liquefied by cooling to -192O, but as oxygen and nitrogen have not the same boiling points, the less volatile oxygen doubtless liquefies first." In the author's former experiments, the substance now known as argon, became solid before nitrogen, but chemical nitrogen and air nitrogen, with its 0.1 per cent.of argon, behaved in substan- tially the same way on liquefaction. Liquid nitlaic oxide.-Great interest attaches to the behaviour of nitric oxide at low temperatures. Professor Olszewski has examined the liquid and describes it as colourless. Dr. Scott has prepared in different ways samples of nitric oxide. These have been transferred to liquefaction flasks, where they were left in contact with potash, sulphuric acid, or phosphoric acid for many days before use. Each of the samples, when cooled, gave a nearly white solid, melting into a blue Ziquid. The colour is more marked at the melting point than at t'he boiling point. Liquid nitric oxide is not magnetic ; neither is the solid phosphorescent. Colour in the oxides of nitrogen evidently begins with the second oxide.Solid nitric oxide does not show any chemical action in liquid oxygen, provided the tube containing it is completely immersed; but if the tube full of liquid oxygen is lifted inlo the air, almost instantly a violent explosion takes place. Xpeci$c Gravities taken i.n liquid oxygen.-In a good vacuum vessel specific gravities may be taken in liquid oxygen with as great ease as in water. Some 20 substances were weighed in liquid oxygen, and the apparent relative density of the oxygen determined. The results were then corrected, using Fizeau’s values for the variation of the coefficientof expansion of the solids employed, and thereby the real density of liquid oxygen calculated.The resulting value was 1.1375, bar. 766.5, in the case of such different substances as cadminm, silver, lead, copper, silver iodide, calc-spar, rock crystal. Direct deter- rninahions with an exhausted glass cylindrical vessel displacing about 22 C.C. gave 1.1378. Fizem’s parabolic law for the variation of the coefficient of expansion holds down to -183’. The solid which showed the greatest contraction was a block of compressed iodine, the one that contracted least being a compressed cylinder of silver iodide. Wroblewski gave the density of liquid oxygen at the boiling point as 1,168,whereas Olszewski found 1.124. The mwk- tion of density is about ~O.OOl2,for 20 mm. barometric pressu~e. Much work requires to be done in the accurate determination of the physical constants of liquid gases.Liquid Air.-A large silver ball weighed in liquid air gave the density of the latter as 0.910,and the corresponding density of nitrogen at its boiling point 0.850. It is difficult to be quite certain that the con- stituents of liquid air are in the same proportion as the gaseous ones, so that further experiments must bs made. Liquid air kept,in a silvered vacuum vessel gradually ihes in boiling point from the instant of its collection, the rate of increase during the first hour being nearly directly proportional to the time. As the increase amounted to 1’ in 10 minutes the boiling point of oxygcn ought to have been reached within two hocrs. The density of liquid air, however, does not reach that of pure oxygen even alter 30 hours’ storage.The large apparatus can be arranged to deliver liquid air containing 49 per cent. of oxygen, which gives off gas containing 20 per cent. of oxygen, rising after six hours to 72.6 per cent. Combustion in Liquid Oxygen.-A small ignited jet of hydrogen burns continuously below the surface of liquid oxygen, all the water produced being carried away as snow. There is a considerable amount of ozone formed, which concentrates as the liquid oxygen evaporates. In the same way graphite or diamond, when properly ignited, burns continuously on the surface OF liquid oxygen, producing solid carbonic acid and generating ozone. If liquid oxygen is ab- sorbed in wood charcoal, or cottou wool, and a part of the body heated to redness, combustion can start with explosive violence.227 Gas jets containing liquid.-The experiments of Jonle and Thornson and Regnault on the temperature of gas jets issuing under low pressures are well known. The following observa,tions refer to the pressure required to produce a lowering of temperature sufficient to yield liquid in the gas jet. The apparatus used in the study of highly compressed gas jets is represented in Fig. 2 ; where C is a vacuum tube which holds a coil of pipe about 5 mm. in diameter along with carbon dioxide 01-liquid air for cooliiig the gas before expansion, and A is it small hole in the silver or copper tube about + mm. in diameter, which takes the place of a stopcock.When carbon dioxide gas at a pressure of 30 01' 40 atmos. is expanded through such an aperture, liquid can be seen where tlhe jet impinges on the wall of the vacuum tube along with a considerable amount of solid. If oxygen gas escapes from the small hole at the pressure of 100 atmos., having been cooled previously to -79" in the vessel C, a liquid jet is just visible. It is interesting to note in passing that Pictet could get no liquid oxygen jet below 270 atmos. This was due to his stopcock being massive and outside the refrigerator. If the oxygen is replaced by air no liquid jet can be seen unless the pressure is raised to 180 atmos. If the carbon dioxide is cooled by exhaustion (to about 1inm. pressure) or -115", then liquid air can easily be collected in the small vacuum vessel D, or if tbe air pressure is raised above 200 atmos., keeping the cooling at -79" as before.The chief difficulty is in collecting the liquid owing to the rapid current of gas. The amount of liquid in the gas jet is small and its collection is greatly facilitated bj-directing the spray on a part of the meta!lic tube above the little a FIG. 2. FIG.8. FIF. 4. 228 hole or by increasing resistance to the escaping gas by placing some few turns of the tube, like Bin the figure, in the upper portion of the vacuum tube, or generally by pushing in more tube in any form. A vacuum vessel shaped like an egg-glass also works well. This practi-cally economises the cool gas which is escaping to reduce the tempera- ture of the gas before expansion, or, in other words, it, is the cold regenerative principle.Coleman pointed out long ago that his air machine could be adapted to deliver air at as low a temperature as has yet been produced in physical research. Both Solvay and Linde have taken patents for the production of liquid air by the application of cold regeneration, but the latter has the credit of having succeeded in constructing an industrial apparatus (the plans of which are not yet published) that is lowered in temperature to -140°, or to the critical point of air in about 15 hours, and from which liquid air containing i0 per cent. oxygen is collected after that time. For better isolation, the pipe can be rolled between two vacuuni tubes, the outer one being about 9 inches long arid 13inch diameter, as shown in Fig.3. The aperture in the metal pipe has a little piece of glass tube over it which helps the collection of the liquid. With such a simple apparatus arid an air supply at 200 atrnos. with no previous cooling, liquid air begins to collect in ubout sue minutes, but the liquid jet can be seen in between two and three minutes. It is not advisable to work below 100 atmos. In Fig. 4 the metallic tube in the vacuum vessel is placed in hori-zontal rings, leaving a central tube to allow the glass tube C: to Pam, which is used to cool bodies or examine gases under compression. The inner tube can be filled for an inch with liquid air under a pres-sure of 60 atmos. in about three minutes.Generally, in the experi- ments, about 4to 4 cubic feet of air passes through the different sized needle holes per minute when the pressure is about, 200 atmos. As the small hole is apt to get stQpp ed, for general working it is better to use ;Ineedle stopcock, worked from the outside by a screw passing through the middle of the coil of pipe. A double coil of pipe has advantages in the conduct of some experiments. The eaciency is small, not exceeding the liquefaction of 2 to 5 per cent. of the air passing, but it is a quick method of reaching low temperatures arid easy to use for cooling tubes and collecting a few hundred C.C. of liquid air, espe- cially if the compressed air is delivered ab the temperature of -79" before expansion. With larger vacuum vessels and larger regenerat- ing coils no doubt the yield of liquid could be increased.The liquid air resulting from the me of this form of apparatus contains about 50 per cent. of oxygen. If the air is cooled with solid carbonic acid previous to its reaching the vacuum tube coil of pipe, the only change is to reduce the percentage of oxygen to 40. Successive samples of 229 liquid taken during the working had nearly the same compositioll. If the arrangement shown in Fig. 2 is used, with silver tube, about +x in. bore, and a foot or two coiled in upper part of the vacuum vessel, liquid air containing 25 per cent. of oxygen was obtained. On the other hand, the percentage of oxygen can be increased by a, slight change in the mode of working.In the above experiments air is taken at the ordinary temperature, which is a little above twice its critical temperature, and is partially transformed in a. period of time which, in my experiments, has never exceeded 10 minutes, simply and expeditiously into the liquid state st its boiling point, -194O, or a fall of more than 200” has been effected in this short period of time. Experiments on ~~drogelt.-Wroblewski mzde the first conchire experiments on the liquefaction of hydrogen in January, 1884. He found that the gas cooled in a tube to the boiling point of oxygen, and expanded quickly from 100to 1atmos., showed the same appearance of sudden ebullition as Cailletet had seen in his early oxygen experi- ments.No sooner liad the announcement been made than Olszewski confirmed t’he result by expanding hydrogen from 190 atmos., pre- xriously cooled with oxygen and nitrogen in a, vacuum. Olszcwski declared in 1884 that he saw coloiir]ess drops, and by partial expansion to 40 atmos. the liquid hydrogen was seen by him running down the tube. Wroblewski could not confirm these results, his hydrogen being always what he called a ‘’ liqnide dynamiqne.” He proposed to get “static” liquid hydrogen by the use of hydrogen gas as a cooling agent. From this time nntil his death, in the year 1888, Wroblewski devoted his time to a laborious research on the isothermals of hydrogen at low temperatures. The data thus arrived at, enabled him by the llse of Van der Waal’s formulae, to define the critical constants of hydrogen, its boiling point, density, etc., and the subsequent experiments of Olszewski have confirmed the accuracy of t8he results.In a paper published in the Phil. Mug., September, 1884, “ On the Liquefac- tion of Oxygen and the Critical Volumes of Fluids,” the suggestion was made that the critical pressure of hydrogen was wrong, and that instead of being 99 atmos. (as deduced by Sarrau from Amagat’s iso- thermals) the gas had probably an abnormally low value for this constant. This view was substantially contirmed by Wroblewski finding a critical pressure of 13.3 atmos., or about one-fourth that of oxygen. The Chemical News (September 7,1894), contains an account of the stage the author’s hydrogen experiments had reached at that date.The object was to collect liquid hydrogen at its boiling point, in an open vacnum vessel, which is a milch more difficult problem than seeing the liquid in a glass tube under pressure and at a higher temperature. In order Lo raise the critical point of hydrogen to 230 about -200" from 2 to 5 per cent. of nitrcgen or air was mixed with it. This is simply making an artiiicial gas conttLining a large proportioii of hydrogen, which is capable of liquefaction by the use of liquid air. The results are summed up in the following extract from the paper. "One thing can, however, be proved by the use of the gaseous mixture of hydrogen and nitrogen, viz., that by subjecting it to a high compression at a tempeyature of -200" and expanding the resulting liquid into air, a much lower temperature than anything that has been recorded up to the present time can be reached. This is proved by the fact that such a mixed gas gives, under the conditions, a paste or jelly of solid nitrogen, evidently giving off hydrogen because the gas coming off burns fiercely.Even when hydrogen ccntaining only some 2 to 5 per cent. of air is similarly treated the result is a white, solid matter (solid air) along with a clear liquid of low density, which is so exceedingly volatile that no known device fcr collecting has been successful." In Professor Olszewski's paper "On the Liquefaction of Gas " (Phil. Mag., 1895,), after detailing the results of his hydrogen experiments, he says, "The reason for which it has not hitherto been possible to liquefy hydrogen in a static state, is that there exists no gas having a density between that of hydrogen and nitrogen, and which might be, for instance, 7-10 (H = 1). Such a gas would be liquefied by means of liquid oxygen or air as cooling agent, and afterwards used as a recognised menstruum in the liquefaction of hydrogen." Science will probably have to wait a very long time before this sugges-tion of how to get " static " liquid hydrogen is realised.The proposal Wroblewski made in 1884 of using the expansion of hydrogen as a, cooling agent to effect the change of state is far more direct and practicable. Liquid Hydyogen Jet and Solid Oxygsn.-Hydrogen, cooled to -194" (80" abs.t.) the boiling point of air, is still at a temperature which is two and a half times its critical temperature, and its direct liquefaction at this point would be comparable to that of air taken at 60°, and liquefied by the appaiatus just described. Now, air supplied at such a high temperature greatly increases the difficulty and the time required for liquefaction. Still, it can be done, even with the air supply at loo", in the course of seven minutes and this IS the Lest proof that hydrogen, if placed under really analogous con- ditions, at -194" must also liquefy with the same form of appa-ratus. Hydrogen, cooled to -Woo, was forced through a fine nozzle undci-140 atmos. pressure, and yet no liquid jet could be seen.If the hydrogen contained a €ew per cent, of oxygen the gas jet was visible, and the liquid collectbed, which was chiefly oxygen, contained hydrogen in solution, the gas given off for some time being explosive. 231 If, however, hydrogen, previously cooled by a bath of boiling air, is Rllowed to'expand at 200 atmos. over a regenerative coil similar to that shown in Fig.2, but longer, a liquid jet can be seen after the circulation has continued for a few minutes along with a liquid which is in rapid rotation in the lower part of the vacuum vessel. The liquid did not accumulate, owing to its low specific gravity and the rapid current of gas. These difficulties will doubtless be overcome by the use of a clifferently shaped vacuum vessel and by better isolation.The liquid .jet can, however, be used as a cooling agent like the spray of liquid air obtained under similar circumstances, and, this being practicable, the only difficulty is one of expense. In order to test in the first instance what the hydrogen jet could do in the production of lower temperatures, liquid air and oxygen were placed in the lower part of tbe vacuum tube just covering the jet. The result was that in a few minutes about 50 C.C. of the respective liquids mere transformed into hard white solids resembling avalanche snow, quite different in appearance from the jellylike mass of solid air got by the use of the air pump, The solid oxygen had a pale, bluish colour, showin? by reflection all the absorption bands of the liquid.The temperatures reached and other matters will be dealt with in a separate communi- cation. There is no reason why a spray of liquid hydrogen, at its boiling point in an open vacuum vehsel, should not be used as a cooling agent in order to study the properties of matter at some 20" or 30' above the absolute zero. The sole difficulty is the cost. PZzc.oyine.-This is the only widely distr*ibuted element that has not been liquefied. Some years ago Wallach and Hensler poiuted out that an examination of the boiling points of substituted halogen organic compounds led to the conclusion that, although the atomic weight of fluorine is 19 times that of hydrogen, yet it must in the free state approach hydrogen in volatility.This view is confirmed by the specitic refractive index which Gladstone showed was rather lower than hydrogen. If the chemical energy of fluorine at low tem-peratures is abolished like that of other active substances, then some kind of glass or other transparent material not so brittle as ca!cium fluoride could be employed in the form of a tube, and its liquefaction achieved by the use of hydrogen as a cooling agent. During the conduct of these investigations, able assistance has been rendered by Blr. Robert Lennox, whose name has been so often mentioned in the Royal Iiistitution lectures. Valuable help has also been given by Mr. J. W. Eeath, Assistant at the Royal Institution. DIscvssror;. Professor RAMSAPremarked that Professor Olszewski had succeeded in liquefying hydrogen, and from unpublished information received 232 from Cracow, he was able to state that a fair amount of liquid had been obtained, iiot as a froth, but in a state of quiet ebullition, by sulronnding a tube containing compressed hydrogen by another tube also containing compressed hydrogen :tt the teniperature of oxygen boihny at a very low pressure.On allowing the hydrogen in the middle jacket suddenly to expand, the hydrogen in the innermost tube liquefied, and was seen to have a meniscus. Its critical point mid its boiling point, under atmospheric pressure, were determined by means of a resistance thermometer. There would appear to be no difficulty in distinguishing the meniscus of hydrogen, where the iiquid is 50 times as heavy as the gas, for it is perfectly easy to see a meniscus with such a liquid as ether, at temperatures so near the critical point that the liquid has only three or four times the density of the gas.Mr. ELOUNTsaid that the first account of the Linde process for liquefying air had been published in the early autumn of 1895 in the form of a paper read by Herr Schrotter before the Association of German Engineers at Aachen. Briefly, it consisted in taking advant- age of the fact that air, iiot being a perfect gas, is permanently cooled when allowed to expand through a narrow opening without doing external work. The lowering of temperature was expressed p -p 289by Joule and Thomson’s formula, t = -?---! * ( -where t is the fall in temperature in degrees centigrade p2is the pressure of the air before it passes the opening,p, is the pressure of the air after passing the opening, and TIis the absolute temperature of the air before passing the opening.The effect was made cumulative by causing the air thus cooled to cool that which was about to pass through the opening. This was effected by the use of two long concentric tubes, the inner conveying the air to be cooled, and the annular space between the two being traversed by the cooling air. Circulation was maintained by means of an ordinary air compressor, and the tern. perature fell until the critical temperature was reached, A subsidiary compressor supplied fresh air to the cycle to replace that liquefied. The process was interesting because it differed fundamentally from those usually employed for the liqucfaction of difficultfly condensible gases, in two respects, viz.(1) it dispensed with the use of inter-mediate cooling agents, and (2) it applied a method for the cumula- tive withdrawal of heat analogous to the converse process of heat regeneration. Trials of the process had been made on a considerable scale, and there appeared to be no difficult,y in liquefying air cheaply and in quantity. Lord PLAYFAIRsaid, as a Past-president of the Society iie was aware that it is not the practice to move a vote of‘ thanks to the reader of 233 a,paper, so that he must not conclude with a motion to that effect But he was sure that he mas expressing the sentiments of all present;, when he said that they were grateful for the admirable exposition and splendid experiments which they had heard and seen.It is known to them all that an undesirable controversy ha5 been going on as to how much originality there is! in the researches of Professor Dewar, whom he had the honour of claiming as an old student and assistant when he was Professor in Edinburgh. He had wasted his time in reading these attacks, and they have hadno influence on his mind, or rather that they had influenced him to send a subscription to the Royal lnstitution towards the cost of the apparatus. The di2gram of Pictet's apparatus, now shown, certainly gives to the general chemist the most original conceptions as to bow the problem OP liquefying gases should be attacked.But if Pictet were now with them, and could see the great advances which had been made on his ideas, he would be the first to recognise their importauce, and to congratulate Professor Dewar. It is only in mythology that Minerva full grown, and panoplied in complete aymour, is born from the brain of Jupiter after a prolonged gestation. In human brains one discovery suggests another, and we proceed to the goal of knowledge step by step. The world now feels that Watt's discoveries, in im- proving the steam-engine, gave an enormous impulse to civilization. But the men of his day were petty enough to deny him merit, and they went to a court of justice to prove that every one of his dis- coveries had previously been made by other men, and more strange still, the court agreed with them and solemnly declared that Watt had done nothing to improve the steam-engine. Every discovery can be connected with previous discoveries.Would the merit of Rayleigh and Ramsny be lessened as the discoverers of argon because Cavendish had it undoubtedlyas the residue in his tube in his famous experiment on air ? It is to be hoped that Professor Dewar will go on with his magnificent experiments on the liquefaction of gases, and with the researches which come from them, without caring for the mosquitoes of science which buzz about his ears. Dr. ARMS'I'ROXGsaid that, after what had fallen from Lord Play-fair, he would venture to express the opinion that the attacks made on Professor Dewar during the past few months were disgraceful.In these days we should encourage as far as possible all who weye engaged iu such dangerous and di8cult work, not decry their labours. The history of the Rojal Institution in the past, in so far as concerned the liquefaction of gases, was a glorious one, and lie bad no doubt that when the work done there more receutly came to be considered without prejudice, it would be regarded as equally important. In fact there was evidence of this already. Professor 234 Onnes, of Leiden, who, with most limited appliances and means, had already accomplished so much in the field of research at low tempera-tures-an acknowledged expert in these matters-in a recent publi- cation, in which justice was done to dl workers, clearly tecognised that much credit was due to Professor Dewar for his various improve- ments.He did not consider it necessary to thank Professor Dewar, but thought that his assistants should not be forgothen. Messrs. Leiinox and Heath, had done much service in connection with the work generally, and especially in making the present demonstration possible. Professor DEWAR, in reply, stated that he could have no knowledge of unpublished work on the liquefaction of hydrogen. The mere fact of liquefaction was first definitely given by Wroblewski, although Cailletet had made an earlier experiment of the same kind. His paper contained a quotation from Professor Olszewski’s communication made to the PhiZosophicnZ Hagazine in February, 1895, in which Olszewski distinctly says that he had not succeeded in getting liquid hydrogen in the “ static” condition.Further, in a later paper, pub-lished in the same journal, for August, 1895, no mention is made of getting a “ fair amount of liquid in a state of quiet cbullitioii ” or of seeing a “meniscus.” Even the method of working, to which reference has been made, is not mentioned, far less the result of the experiment’s made by the speaker in 1894. He was unable to undeiv-stand why such a point should be made of seeing a meniscus, con- sidering that the liquid can be seen. The remarks about the diiii- culty of separating liquid hydrogen from the gas had reference to a fine rain of fluid in a rapidly rushing stream of gas passing througli vacuum vessels, and has no relation whatever to critical point pheno- mena to which reference had been made.If the liquid oxygen and air-jets shown have any resemblance to the Linde apparatus described by Mr. Blount), chemists, for once, may be congratulated that a small laboratory apparatus works in some respects better than a large indus- trial plant. The Linde apparatus after working 15 hours is capable OE reducing the temperature of air to its critical point, whereas iu the present small apparatus liquid air is produced in five minutes. Such a process cannot replace the use of “cooling agents” when considerable quantities of liquid air have to be produced in a short period of time as in ordinary laboratory work.It is a mistake to attribute to Linde the idea of using the “ cumulative withdrawal of heat,” for the first time, in his apparatus but he has succeeded in making a workable industrial machine and that is a very important step. The late Professor Wroblewski, as early as the year 1884, predicted that liquid air would be the refrigerating agent of the fiiture ; his prophecy seems about to be realised. 235 152. ‘(Researches on tertiary benzenoid amines. I. Derivatives of dimethylaniline,” By Clara de Brereton Evans, B.Sc. It is now established in the case of primary and secondary benzenoid amines, that the production of derivatives containing a substituent in the hydrocarbon nucleus is often preceded by that of the correspond- ing derivative in which the substituent is present in the amino-group ; and inasmuch as compounds of the latter readily pass over into those of the former class, it is not improbable that their formation is a necessary step in that of many derivatives of benzenoid amines.AS it is impossible, however, that similar derivatives should be formed from tertiary amines, the behaviour of these is of interest as throwiag light on the influence which nitrogen itself exercises ; and that this may be altogether different from that of nitrogen associated with hydrogen is clear from a coniparison of benzenoid amines wit+l1 azophenes (compare Proc., 1892, 128) such as pyridine and quinoline, as these latter manifest a comparative indifference towards agents generally which is quite remarkable.The experiments to be described have brought to light the fact that tertiary benzenoid amines manifest a somewhat similar in-difference. Dimethylaniline is readily sulphonated by means of chlorosulphonic acid, yielding only thepara-acid ; it is somewhat less readily, but yet easily sulphonated by means of a single molecular proportion of ordinary sulphuric acid, but if a larger proportion of acid be used, the action takes place less readily, sulphonation being incomplete at the end of helve hours at 180” when 5 molecular proportions of acid are used, although it is complete within$ue hours when a single pro- portion is taken. Practically nothing ‘bat the para-acid is formed.To procure the meta-acid, it would seem that it is necessary to use fuming sulphuric acid-a point of some interest in connection with the moot question as to the manner in which isomeric sulphonic acids are generated. The behaviour of diethylaciline is similar to that of dime thylani line. The behaviour of the para-acid towards bromine is remarkable. It first yields a monobi-onzo-acid. On adding bromine to a solution of this bromo-acid in muriatic acid, it crystalline orange-colourecl perbromide, C,H,Br(NMe,) (SO,H)*Br,, is precipitated. This is readiIy and simply deprived of its bromine by exposure to air, by boiling with water, and in contact with ammonia, sulphurous acid or potassium iodide. If digested with muriatic acid on tlie water bath in a closed vessel, it yields a small amount of tribromomethyl- aniline and some tetrabromodimethylaniline, together wi tli much unchanged monobromo-acid ;if digested with excess of bromine, it is 236 entirely converted-but by no means easily-into tetrabromodimethyl-aniline.Under no condition, apparently, does it yield a dibromo-sulpho-acid or tribromodimethylaniline ; in this respect its behaviour is most remarkable in comparison with that of ordinary sulphanilic acid, which is extremely sensitive to the action of bromine, being very readily converted into tribromaniline. The meta-acid, in like manner, readily yields a parabromo-acid identical with that obtaiiied on sulphonating parabromodimethyl- aniline, and this is converted into a dibromo-scid by the further action of bromine.Rut all athempts to prepare a tribromo-acid correspoiiding to that which is so readily obtained from anilinemetn-sulphonic acid were unsuccessful. No perbromide is obtained from the metabromo-acids. On nitration with nitric acid, dimetbylanilineparasulphonic acid yields a, mixture of orthoparadinitrodimethylaniline, together with orthonitroparasulphonic acid, the latter being the chief product. The meta-sulphonic acid yields a dinitrosulphonic acid. On warming solution in dilute acetic acid of the orthonitroparasulphonic acid with bromine, ft substance crystallising in red prisms, melting at 102", is produced, which apparently is a bromonitromethylnniline.The behaviour of the diethylanilinesulphonic acids is similar to those of dimethylaniline. The perbromide derived from the bromo- parasulphonic acid is better characterised even than that derived from the dimethylated acid. A full description of the various compounds referred to in this note will be given in a complete paper; it may be stated that all are exceedingly well defined substances. Experiments are in progress having for their object the comparison of the ortho-acids of dimethyl- and diethylaniline with the isomeric meta- and parasulphonic acids ; and others are being made with the sec0ndai-y amines to ascertain if their behnviour be, as is probable, similar to that of primary amines rather than intermediate between that of primary and tertiary.It is also proposed io largely extend these observations to other tertiary aniinobenzenoid compounds, such as the dimetbyltoluidines, dimethylamidophenol and dimethylamidobenzoic acid. For the supply of a large quantity of material used in these experi- ments, 1)r. Armstrong is indebted to the SociBtB your Z'Industrie CAinzique ci R$le. 153. "Experiments on the formation of the so-called ammonium amalgam." By James Proude and W. H, Wood, F.I.C. The fact, first clearly established by Wetherill, that sodium amal- gam does not form the so-called ammonium amalgam when added to 237 an aqueous solution of ammonia, enables sodium amalgam to be used as a test for the presence of ammonium salts, even in the presence of ammonia.Solutions of phenol and of pyrogallol in aqueous ammonia were shown to contain compounds of the nature of ammonium salts; whilst sodium phosphate, calcium chloride, and magnesium sulphate, with aqueous ammonia, gave rise to no mercurial froth, showing absence of ammonium salts. Ammonium sulphatc, nitrate, and acetate when fused gave no mercurial froth on tohe addition of sodium amalgam. Ammonium chloride, oxalate, acetate, benzoate, tartrate, and succinate, dissolved in absolute alcohol, rectified spirit, and methylated spirit, in no case gave a definite mercurial froth with the sodium amalgam, either cold or hot., though the acetate and benzoate dissolved in rectified spirit, and the chloride in rnethylated spirit, showed indications of swelling c>f the mercury.Water, therefore, appears to be necessary to the production of a definite froth. The sp. gr. of the well-formed mercurial froth is not higher than 0.730, since it floats in methylated ether of that density. 154. " The molecular volunes of organic substances in solution." ByW.W.J. Nicol, M.A.,D.Sc. In lr383, and again in 1892, the author directed attention to the probability that a study of the moIecular volumes of organic sub- stances in solution would lead to results from which the atomic volumes of the various elements could be determined with an ease and accuracy impossible by Kopp's method of determining the volume at the boiling point. The paper contains an account of determinations made on 14esters in dilute solution in various solvents.The chief conclusions drawxi are as follows :-I. The volumes of isomeric esters are approsimately the same. 2. The volume of CH, is it constant for each solvent, being 16.8 in xylene, 17.0 in benzene, 17.3 in 88 per cent. alcohol, except 3. In the case of ethyl oxalate aud spccinate, where the value is about a unit less, owing probably to contraction resulting from the separation of the two carboxyl groups. 4. The nature of the solvent has a marked effect on the molecular volume, w liich is less in the solvent with the higher molecular weight. 238 155. “2 :1P-Naphthylaminesulphonicacid and the corresponding chloro- naphthalenesulphonic acid.” By Henry E. Armstrong and W.P. Wynne. Tobias has rcceiitlj- shown (Germ. Pat., 74,688, B’ebruary 19, 1893) that the acid obtained by one of us (Armstrong, Ber., 15, 1882, 202) by the action of chlorosulphonic acid on P-naphthol at the ordinary temperature is not ,@-naphthylsulphuric acid, CloH,*O*S03H,but the isomeric 2 : 1-/?-naphtholsulphonic acid, and in the same patent has described the amido-acid obtained by heating the hydroxy-acid with strong aqueous ammonia under pressure at 220-230’. Being desirous of examining the amido-a,cid, the authors applied to Dr. Tobias for a sample, and he not only sent them a carefully purified specimen of the sodium salt of the P-naphthylaminesulphonic acid, but cour-teously forwarded their letter to the Parbwerke vorm. Meister, Lncius and Briiuing, who, with characteristic liberality, furnished them with i~ coiisiderable quantity of the technical product.After purification, the acid mas found to have all the characters described in the patent ; its sodium sztlt, as there st’ated, cr~stallises from dilute alcohol in monohydrated scales. The acid was converted by the Sandmeyer method into the corre- sponding 2 :l-~-c7;lo~ona~hthaler~esu~honi~acid:which has not hitherto been described, and is the twelfth of the foiirteen isomerides which it is theoretically possible to isolate. This acid yields an easily soluble, mono-hydrated, microcrystalline barium salt, a monohydrated pntas-siwn salt crystsllising in thin scales, and a monoligclrated sodium salt crystallising in loiig, slender needles.The chloride, C1*C,,H,.SOzC1, crystallises from a mixtnre of benzene and light petroleum in large, tabular forms, and from acetic acid in diamond-shaped scales melting ai 76’ ; it yields an ami,lc crystsllising in slender needles melting at 153”, and on distillation with phosphorus pentachloride is converted into 1: 2-dichloronaphthalene, melting at 35’. On sulphonation with four times its weight of cold 20 per cent. anhydrosulphuric acid, the 2 : 1-/3-naphthylaminesulphonicacid is converted into the 2 : 1 : 4‘-P-naphthylaminedisulphonic acid, pre- viously described by the authors as the minor product of sulphonatioii of the Dahl 2 : 4’-~.napht.hylaniinesulphonicacid under similar con- ditione (Proc., 1890, 129).The investigation of the 2 : 1-p-naphthylaminesi~lphonicacid and its derivatives is being continued. 156. I‘ 1 :3-a-Naphthylarninesulphonicacid and the corresponding chloro- iiaphthalenesulphonic acid.” By Henry EmArmstrong and W. P. v\, ynne. In the course of their study of the formation of isomeric: naphtha- 239 lene derivatives, the authors had occasion to attempt the repetition of Cleve’s work on the nitration of naphthalene-/3-sulphonic acid, since of the three acids obtained by him in t’his way, one was stated to /\/\SO& have the constitution I I 1 , the other two being the iso- \/\/NO2 meric heteronucleal ol-nitro-acids. Whilst successful in obtaining two tieteronucleal acids, of which they determined the constitution, they were unable to prepar’e the homonucleal compound by the nitration of potassium naphthalene-/3-sulphonate(Proc., 1889, 17).Particular interest attached to the question whether this acid was formed, inasmuch as-to repent the words used at the time-“it has always been found that a heteronucleal a-derivative is formcd in cases in which the corresponding benzene derivative would afford a meta-derivative.” Although thus unsuccessful, they were, as they then said, “ loth to accept the apparently logical interpretat’ion of their results, as they were unacquainted with the precise conditions under which Cleve worked . . . . and as it is within their own experience that slight variations in treatment, such as may escape notice, may materially affect the result,” and expressed the hope that, Cleve would supply further details as to the procedure adopted by him.Scbsequently it came to their knowledge that the homonudeal acid also could not be detected in the prodnct obt’ained on nitrating sodium naphthalene-p-suiphonnte on the large scale. Moreover, Erdmann and Suvern have failed to obtain the corresponding chlo- ride by nitratirig naphthalene-/hulphonic chloride (AnnuZen, 275, 252). It is particularly instructive, therefore, to record the fact that the so-called [-1-3 naphthylaminesulphonic acid which Cleve prepared by reducing the homonncleal nitro-acid he obtained by nitrating scjdium naphthalene-/3-sulphonate (Bey., 19, 2179 ; 21, 3271) is identical with the 1:3-a-nnphthylaminesulphonicacid of Kallc arid Co.’s Germau Patent 64979, prepared from a-naphthylamine-[E-1-disulphonic acid- s NH., which the aut,horshave shown has the constitution 1890, 15)-by partially hydrolysing it with diluted sulphuric acid, and which, as Friedlander has recently shown, may also be obtained by partially reducing the said disulphonic acid with sodium amalgam (Ber., 28, 1951).Through the kind offices of Dr. Hepp. the authors are much in-debted to Messrs. Kalle and Co. for a supply of this acid in the pure 240 form; the experiments they have made with it confirm Cleve's statements as to t'he properties of Chis acid and the derived 1:3-z-chloronnpht~halenesulphonic acid in every particular. There is nothing to add to the description of the salts of the amido-and chloro-acids as givon in Cleve's later pper, but the authors have been able to carry the identification of the acids a stage further, since they find that, the dichloronaphthalene, melting at 61.5'-obtained from the chloronaphthalenesulphonic chloride melting at 106O-on eulphonation gives products characteristic of 1:3-dichloro-naphthalene (Proc., 1890, 82) and not of the 1:2'-isoineride of about the same melting point with which it was for a while confused.157. Studies on the constitution of tri-derivatives of naphthalene,No.15. The disulphonic acids obtained by sulphonating 1 : 3-a-naphthylamine- and 1 :3-~-chloronaphthalene-sulphonicacids." By Henry E. Armstrong and W.P. Wynne. As already mnounced (Proc., 1890, 18, 131, 133; Brit. Assoc. Report, 1893, 382, footnote), the authors are engaged on experiments having for their object the determination of the comparative influ- ence exercised by the radicles C1, OH and NH2 in naphthalene derivatives on the formation of disulphonic acids. Certain results arrived at in the case of &derivatives have already been comniuni- cafed (Proc., 1890, 128, et seq.), but progress with the work was retarded so long as the characteristics of the reference conipounds -the trichloronaphthalenes-were in doubt. The fourteen theo-retically possible isomerides being now known and characteriscd (Proc., 1895, 84), the authors hope shortly to complete their investi- gation of the products obtained 011 sulphonating the known naph- thy lamine- and chloronaphthalene-sulphonic acids.In the mean-while, in view of the interest attaching to the 1:3-a-naphthylaniine-sulphonic acid, they think it well to put on record the resultas obtained on sulphonating it and the corresponding cliloro-acid, so far as their experimeiits have gone. When dry 1:3-a-naphthylaminesulphonicacid is stirred into four times its weight of 20 per cent. anhydrosulphuric acid at ft tempera-ture not exceeding 20°, it is converted in the course of 12 hours into what appears to be a single disulphonic acid. The normal potas-sium salt being very soluble, the acid was isolated in the form of the dihydrated acid potassium salt, which crystallised in radiate groups of short, brittle needles.On reduction by the hydruzine method it gave naphthalene-1 : 2'-dieulphonic acid (Proc., 1890, 126) since the chloi*ide obtained from it cry staked from acetic acid in glistening scales, meltling at 122", convertible by pliosphorus pcntacliloride into 841 1 :8'-dichloronaphthalene melting at 63*5",and giving on sulphona- tion the characteristic chloride melting at 117' when opaque (Proc., 1890,83). By the Sandmeyer process, it was converted into a chloro-naphthnlenedisulphonic acid, the chloride of which, Cl.C,oH5(SO,Cl),, crystailised from a mixture of benzene and light petroleum in radiate groups of prismatic needles, and from acetic acid in small prisms, me1 ting at 130",which on distillation with phosphorus penta- chloride gave 1:3 :4'-trichlorouaphthalene crystallising from alcohol in long, slender, flat needles, melting at 103'.When dry potassium 1:3-a-chloronaphthalenesulphonate is sul-phonated under the conditions described in a previous note (Proc., 1890, 131) by adding it to the theoretical quantity of sulphuric anhydride used in the form oil 20 per cent. anhydrosulphuric acid and heating the warm mixture at 100' for. an hour, it is con-verted into a chloroItaphthnlenedisulphonic acid identical with that just described. No trace of an isomeric acid was detected. AS in previous cases, details as to the composition of the salts, &c., are reserred for bhe complete paper. It follows, therefore, that, under the conditions described, the di- sulphoiiic acids obtained both from the 1:3-a-arnido- and the 1: 3-a-chloro-monosulphonic acids have a corresponding constitution expressed by the symbols NH, c1/v\ /v\IIy\/Is' LIBRARY, The attention of Fellows using the Library is called to the following list of books taken from it without filling up the necessary form.The Library Committee trust that they will be returned as soon as possible. Poggendorf. Erganz. Bde. 3 and 4. Die Chemische Industrie, Bde. 14 and 15. Wagner. Tabellen der iin Jahre 1882 bestimmten physikal. Crmstanten chemisch. Korper. 1884. Clerk Maxwell. Theory of Heat. 1872. Srnithsonian contributions to Knowledge, vol. xvii. War Dept., U.S. Three Westher Maps, November 19th, 1872.Bulard. Observations of Mcteord. 1851. Heliochromie. 1884, Headrich. Arcana Philosophia. 1697. Thomson. History of Chemistry, vol. ii. 1831. Wilson, G. (edited by Macadam). C1iemistr.y. E. Reynolds. Experimental Chemistry, Pt. 111. Cook. Contributions froni the Chemical Lab. at Harvard. 1877. Teplow . Die Schwingurigsknoten. 1.885. Debus. Ueber einige Fundamentalsatze der Chemie. 1894. Regnault. Kurzes Lehrbuch. 1881. Newth. Chemical Lecture Experiments. 1892. Dundonald. Trinidad Petroleum. 1857. Cossa. Richerche Chimiche e 1SiIicroscop. 1881. Hussak. Anleitung zum Bestimmen, &c. 1885. Lefort. Trait6 de Chemie Hydrologique. 1S73. Bischof, G. Elements of Chem. Geol., vol. iii, only. Czjzek. Geognostiche Kzrte. Daubeny.Miscellanies. Brieger. Untersuch. uber Ptomaine, Pi. I11 only. 1886. Prescott. Chem. of Nitrogen. 1887. Abenius. Undersokningar. 1891. Christison. Poisons. 1832. Kensington. Composition of Foods, Waters, &c. 1877. Gerber, &c. AKalyse des Milch. 1879. Gerber, (trans. by Endemann). Chem. Analysis oE Con. Milk. 1882. Wolff. Landwirthschaftliche Futterungslehre. 1877. Mayer. Die organische Bewegung, &c. 1845. Arinuaire de Montsouris. 1891. Becchi. Raggi di Esperienze agrarie. 1870-6. Marchand. Botanique Cryptogamique. 1883. Hartig. Nadelholzbaiime. 1878. Wagner, (ti-ans. by Henderson). Increase of produce through Nitrogenous Manure. 1888. Kerguelen's Land C01leetion. 1879. Schroeder and Reuss. Die Reschadidung der Vegetation dnrch Rauch. 1883.E'rieke. Origio of Species. 1861. Bell. Chemistry of Tobacco. 1887. Thor;pe. Qumtitative Analysis. 1883. Winkler, (trans. by Lunge). Gas Aualysis. 18P5. Frankland, E. Water Aualysis. 1880. Ritter. Manuel de Chemie. 1874. Woodman and Tidy. Forensic Medicine. 1877. Raumert. Gerichtlichen Chemie, Erste Abtbl. 1889. Uaiber. Harn Untersuchung. 1892. Lovett. Testing for Noxious Vapours. 1883. 24-3 Ure. Dictionary, vol. 3. Knapp. Chemical Technology, vol. 3. 1851. Techn logy, Der Weinbau, (Mohr). 1865. Bolley's Technology, Die trocknenden Oele, (hides). 1883. Pennetier. Leqons sur le3 mntihres prem%res orgamiques. 1882. Jones. Asbestos, Production and Use. 1888. V. Fellenberg. Analysen v. antiken Bronzen.1888. Schwendler. Report on Electric Light Experiments. 1878. Munroe. Index to Literature of Explosives, Part 1. 1886. Abel. Explosive Agents applied to Indujtrial Purposes. 1880. Miiller. Planzenfaseer. 1876. Naumann. Wassergaserzeugung, &c. 1882. Diirre. Die Anlage . . ..,.der Eisenbiitten. 1880-4. Bolitho. Mining Atlas. 1880. Wiesner Die Rohstoffe des PAanzeiireiches. 1873. Nortin Les Sulfocyanures Commercinux. 1883. Zonner. Die Essig€abrication. 1876. Year book of Pharmacy, '91 and '92. Wittrich, (trans. by v. Heyden). Medic. Studien u. Salicylsaure, &c. 187Ei. DnBois Reymond. Zwei Vortriige. 1882. HELMHOL TZ MEMORIAL LECTURE. The Helmholtz Memorial Lecture will be; delivered by Professor G. F. Fitzgerald, F.R.S., at an extra meeting of the Society to be held on Thursday, January 23>1896, at 8 P.M.At the next meeting, on Thursdatg, January 16th, thc following papers will be read :-“ The acetylene theory of the luminosity of hydrocaron flames.” By Professor Vivian B. Leaes. “ The action of sodium alcoholate 011 the acid amides.” By J. B. Cohen, Ph.D., and W. H. Archdeacon, B.Sc. “ Note on the electrolytic conductivity of formanilide and thiofor-msnilide.” By T. Ewan, B.Sc., Ph.D. “Action of sugars on ammoniacal silver nitrate. By James9 Henderson, B.Sc. ‘‘ Solution and diff nsion of certain metals in mercury .” By W. T. Humphrey s. “ On some of the ethereal salts of active and inactive monobenzoyl, dibenzoyl, diphenyl, acetyl, and dipropion yl-glyceric acids.” By Professor Percy Frankland, F.R.S., and J. MacGregor, M.A. “ On the rotation of optically active bodies in organic solvents.” By Professor Percy Frankland, F.R.S. and R. H. Pickard, B.Sc. “ The action of hydrogen chloride on ethyl alcohol.” By J. C. Cain, D.Sc. “ Transformation sf the alkyl ammo nium cyanates illto the cop responding ureas.” By Professor Walker, D.Sc., aid James 1%. Appleyard. HAERISOX AND So~s,Printers in Ordinary to Her Majesty, St. Martin’s Lane.
ISSN:0369-8718
DOI:10.1039/PL8951100221
出版商:RSC
年代:1895
数据来源: RSC
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