摘要:

ABSTRACTS OF CHEMICAL PAPERS. Analytic a1 Chemistry. Estimation of Free Oxygen. By FR.MOHR(Zeitschr. anal. Chem. xii 138-142). HYPOSULPHUROUS ACID (Schutzenberger’s hydrosulphurous acid) is used by the author as the measure for free oxygen. This body can be pre- pared by dissolving sodium sulphite in water introducing zinc-foil into the solution adding acetic acid and leaving the whole to stand for an hour in a well-stoppered bottle. The solution is titrated by means of a solution of ferric chloride or iron alum coloured with potassium sulphocyanate. 1C.C. of oxygen should correspond to about 10C.C. of the standard solution. In order to prevent the atmospheric oxygen from coming in contact with the reducing salt the author recommends covering the liquid in the burette with a thin layer of benzene 5 to 10 mm.in height. Benzene may also be used for protecting standard solutions of sodium thiosnlphate sulphurous acid or similar liquids which take up oxygen or carbonic acid from the air. An ammoniacal solution of copper preserved under a layer of ben- zene may likewise be employed for the titration of the hyposulphurous acid. Care must be taken however not to disrupt the layer of benzene by shaking &c. whilst the strength is being determined. Mohr checked the results obtainable by the new method by those obtained by using as the reducing agent ferrous oxide in an alkaline solution as described in his “Titrirmethoden.” To 300 C.C. of a well-water he added 0.3 grm. of ammonio-ferrous sulphate and then ammonia.After allowing the water to stand for half-an-honr he dissolved the green ferrous oxide in excess of sulpkturic acid and titrated with decinormal permanganate solution. 11.21 C.C. were thus employed showing that 4.47C.C. of free oxygen were present in a litre of the water. A second experiment gave 4.9 C.C. of oxygen. The same water titrated as above with hyposulphurous acid gave only 2.98 C.C. of oxygen per litre. Hence it would appear that the new method is not trustworthy on account of the exceedingly oxidizable nature of the test-liquid. Not only is it necessary to prepare the solution freshly ANALYTICAL CHEMISTRY. 187 each time,-an operation which takes about an hour ; but it is not possible t,o use it without danger of oxidation even the height through which a drop is made to fall or the extent of the surface of the liquid causing perceptible differences in the results.On this account pre- ference is given to the old over the new method. w. v. The Estimation of Nitrogen. By S. W. JOHNSON (Ann. Chem. Pharm. clxix 69-74). AFTER alluding to the tedious process for preparing the soda-lime ordi- narily employed in Varrentrapp and Will's method for making nitrogen determinations and the inconveniences attending its use the author proposes to substitute a mixture of sodium carbonate or sulphate with calcium hydrate. Details are given of nine determinations made with these mixtures which proved very satisfactory ;neither calcium hydrate alone nor a mixture of the hydrate with sodium chloride answered.The author gives the preference to the mixture containing sodium car- bonate the latter being easily prepared by heating the commercial "bicarbonate " until it ceases to give off aqueous vapours. C. E. G. Amonio-nitrometry a New Method of Estimating Ammonia, Organic Nitrogen and Nitric Acid in Water Earth &c. By M. PIUGGARI (Compt. rend. lxxvii 481483). THE author first determines the free ammonia either with Nessler's reagent or by adding one or two drops of phenol to 5or 6 c c. of sodium. hypocblorite and comparing the violet-blue colour produced with a normal solution. The nitrogen existing as organic matter is then oxidised by heating with a mixture of silver chloride and caustic potash to 50"-60" for several hours; it is then reduced to ammonia with potash and aluminium foil and estimated as before.By alter-nate reduction and oxidation nitrogen in the three forms of com-bination may be estimated in litre. one portion. The author uses half a W. R. Estimation of Sulphur in Iron and Steel. By T. J. MORRELL (Chem. News xxviii 229). THEestimation of sulphur in iron is sometimes conducted by acting upon the metal with hydrochloric acid and precipitating some metallic sulphide by the evolved sulphuretted hydrogen. The author finds that if an ammoniacal solution of a cadmium salt be used to arrest the sulphuretted hydrogen the precipitated cadmium sulphide may be weighed directly and thus the usual oxidation and estimation as barium sulphate dispensed with.Test analyses are given proving the accuracy of the results. J. W. ABSTRACTS OF OHEXLCAL PAPERS. Estimation of Carbon in Pig Iron. By C. H. PIESSE (Chem. News xxviii 19s). THEmethod generally adopted for the estimation of carbon in iron has been modified by the author in the following manner :-The improve-ment relates chiefly to the manipulation. The solvent for the iron is prepared by dissolving SO0 grams of cupric chloride in 900 C.C. of a saturated solution of sodium chloride to which 50 C.C. of distilled water an3 50 C.C. of hydrochloric acid are subsequeiitly added. 10 C.C. of this solution are used for 1.0 gram of iron. When the solution of the iron is complete the carbonaceous residue is thrown upon a filter made by placing horizontally in the throat of a small funnel a nearly circular piece of glass or porcelain a'bout 3 inch in diameter.This plate is covered with a layer of fine asbestos and the latter wetted with solu-tion of sodium chloride so as to compress it firmly together. When the filter is properly prepared the solution passes through perfectly bright. The carbon having been washed and dried the funnel is inverted over a mortar containing copper oxide and the glass plate pushed from behind with a wire so as to cause it to fall with the asbestos &c. into the mortar. Attention having been paid to any carbon adhering to the funnel or to the glass plate the latter is re- moved and the contents of the mortar thoroughly mixed ; the mixture is then transferred to a combustion tube and the analysis completed in the ordinary manner.J. W. Estimation of Potash. By Fit. MOHR (Zeitschr. anal. Chem. xii 137). INSTEAD of being weighed on a tared filter potassium platinum chlo- ride may be fused with twice its weight of sodium oxalate in a plati- num crucible. The fused mass is extracted with water neutralised with acetic acid and the chlorine determined by means of a deci-normal silver nitrate solution. w. v. The Estimation of Lead in Ores. By JUL.LOWE (Dingl. polyt. J. ccix 139). INextracting lead from its ores with nitric acid any sulphide of lead which may exist in the ore is converted by oxidation into sulphate which remains undissolved. If the insoluble residue be treated several times with an aqueous solution of hyposulphite of soda the lead sul- phate is extracted and may be precipitated by snlphuretted hydrogen or ammonium sulphide.W. R. Use of Potassium Bisulphate to Detect the Presence of Galena. By E. JANNETTAZ (Compt. rend. lxxvii 838-839). WHILSTexamining a specimen of tellurinm ore for selenium the author mixed the powder& mineral with potassium bisulphate. This ANALYTICAL CHEXISTRY. gave rise to a powerful odour of sulphuretted hydrogen which was ultimately traced to the presence of galena. It appears that uncom- bined galena alwsys emits a strong odour of sulphuretted hydrogen when pulverised along with the bisulphate. The sulphides of antimony iron mercury and silver do not give this reaction.C. E. G. On Superphosphates containing Iron and Alumina and their Analysis. By A. RU MPL ER (Zeitschr. anal. Chemie xii 151-1 63). IFprecipitated ferric phosphate after drying between blotting paper is added to syrupy phosphoric acid until no more is dissolved the forma- tion of an acid ferric phosphate FezOs.6H20.3Pz0, corresponding with monocalcic phosphate Ca0.2HzO.P2O5 is indicated ;thus the solution after filtering through asbestos gave on analysis 7-98 per cent. of ferric oxide and 20.13 per cent. of phosphoric anhydride i.e. 1equivalent of the former to 2.84 of the latter. In other experiments a rather larger proportion of ferric oxide was found the acid phosphate seeming to dis- solve tribasic ferric phosphate. This solution of acid phosphate is decomposed by heat with precipitation of a basic salt which is not redissolved on cooling and is insoluble in concentrated phosphoric acid.It is also decomposed by a large excess of water tribasic ferric phos- phate being precipitated and pure phosphoric acid remaining in solution. Non-volatile organic acids and their salts prevent this decoml)osition and the presence of mineral acids renders a larger quantity of water necessary for complete decomposition. This reaction furnishes a method for the preparation of pure tribasic ferric phosphate ; also for the estimation of iron and phosphoric acid by dissolving a precipitate of basic ferric phosphate after weighing in hydrochloric acid precipitating with soda dissolving in concentrated phosphoric acid diluting boiling and then weighing the precipitated tribasic phosphate ; the increase in weight is due to the amount of phosphoric acid com-bined with the excess of ferric oxide in the first precipitate and from this the amount of iron and phosphoric acid can be calculated.The presence of ferric phosphate and the corresponding alumina salt in superphosphates explains why superphosphates made from materials rich in iron as Lahn phosphorite or in alumina as Navassa phosphate never dry if the heat produced in their manufacture is too great owing to the formation of basic phosphate and free phosphoric acid. That the usual method of extraction for the estimation of soluble phosphate by means of digesting with cold water does not give correct results with such superphosphates is shown in the following experi- ments on superphosphates containing much iron.Column 2 shows the percentage of phosphoric acid obtained by rubbing up 20 grams of the superphosphate with 5 C.C. of water filtering and repeating the pro- cess each time with 5 C.C. of water until all the soluble phosphoric acid was removed clearing the filtrate with nitric acid and estimating in a portion. Columns 3-6 show the amount in solution after titrating the quantities mentioned with water and digesting between two and three hours with a litre of water. ABSTRACTS OF CHEMICAL PAPERS. 1. 2. 3. 4. 5. 6. Tot*al P,05 50 grams 40 grams 20 grams 10 grams Pz05. washed out. to 1 litre. to 1 litre. to 1 litre.to 1 litre. I.. .. 14.46 11.94 -10.60 -I1 .. 14-23 12.35 12.21 -11.39 111.. -13.09 -12.20 11.55 -This shows that the more water the superphosphate is digested with the less phosphoric acid goes into solution owing to the more complete decomposition of the acid ferric phosphate as was confirmed by fur-ther experiments of the author. Experiments were made with the addition of ammonium oxalate to the water in which a superphosphate was digested ;but this was found to dissolve the reduced phosphates so that unless a less energetic salt can be found which will prevent the decomposition of the acid phosphate and at the same time not dissolve the reduced phosphates the method of extracting the soluble phosphates from superphospfiates containing iron and alumina by digestion must be abandoned in favour of wash-ing out the soluble phosphates with as small a quantity of water as possible each time.E. K. Estimation of Alumina and Iron in Phosphates. By A. ESILMAN (Chem. News xxviii 208). THIS process is founded on the fact that in presence of an excess of sodium thiosulphate and acetic -acid alumina phosphate precipitates in the tribasic form of constant composition at the boiling temperature. The precipitate is mixed with sulphur and on ignition yields pure phosphate 122.5 parts of which are equal to 51.5 parts of alumina. The process requires the presence of an excess of phosphoric acid and is available whatever be the quantities of iron lime or magnesia present. One defect of it is the invariable precipitation of traces of iron with the alumina pbosphate but its accuracy is not thereby materially impaired.In ten experiments by the author the quantity of alumina found did not differ in any case more than -01 gram from the quantity added. The solution ought to be dilute and not very hot and should contain a tolerable amount of free acid. An excess of sodium thiosulphate is added then acetic acid in liberal excess. Ten or fifteen minut,es are allowed for the complete deoxidation of the iron and then the ,solution is boiled for about the same length of time. The filtration and washing of the precipitate are done hot and rapidly and after drying the latter is ignited in a porcelain crucible. The iron can be determined in the filtrate from the alumina phos- phate after decomposition of the thiosulphate by boiling with excess of hydrochloric acid but the author prefers employing a separate por- tion for that object.J.B. ANALYTICAL CHEMISTRY. Detection of Adulteration in Tea. By A. H. ALLEN (Chem. News xxviii 210). THE percentage of tannin gum and insoluble matter considered care- fully will enable the analyst to form a very accurate opinion as to the presence or absence of exhausted leaves &c. The estimat,ion of the tannin is of the first importance and for this purpose a standard solu-tion of gelatin is recommended but it is necessary to see that the sample contains no sloe leaves or catechu. A sample of very superior black CoDgou gave the following results which are placed in juxta- position with results obtained from a portion of the same sample after being infused once in a teapot and redried :- Original tea.Exhausted tea. Moisture ............ 9.2 11.1 Insoluble matter. ..... 58.7 87.5 Gum ................ 10.5 3.8 Tannin (by gelatin) .. 15.2 3.3 A second sample of genuine black tea of more than average quality gave 12.5 per cent. of tannin. Among the substances used for facing coloured teas are magnesia and magnesium silicate. The author has several times found the latter on green teas of peculiarly smooth appearance and slippery feel. It was detected by heating the sedi- ment with hydrochloric acid and then with solution of caustic soda. The residue was ignited and fused with alkaline carbonate ; the first product dissolved in acid evaporated to dryness and redisPolred in weak acid ; the solution treated with ammonia and ammonium oxalate ; the precipitate filtered off; and the clear liquid tested for magnesia in the usual way by sodium phosphate wheii an abundant precipitate was obtained proving the presence of magnesia as silicate.J. B. Estimation of Sulphurous Acid in Hops. By B. GRIEs sMAY E ~t (Dingl. polyt. J. ccix 227). THE sulphurous acid is usually determined by reduction to sulphuretted hydrogen with zinc. As it is diacult to obtain zinc absolutely free from sulphur the author employs sodium amalgam of which 0.5 to 0.7 of a gram suffices for a determination. W. R. Alizarin as an Indicator in Volumetric Analysis.By E. SCHAAL (Deut. Chem. Ges. Ber. vi 1180). A SOLUTION of alizarin in distilled water becomes red on addition of only 3T$5m of an alkali and may be used for determining the amount of free alkalis in spring water without concentrating .it. To prepare a neutral solution an excess of alizarin and one drop of phenol are dis- solved boiled with potash and the liquid is filtered. The solution becomes yellow on adding 0.0007 of hydrochloric acid. When this solution is used in alkalimetry it is advisable to add an excess of acid ABSTRACTS OF CHEMICAL PAPERS. and titrate this with standard soda the neutral point being reached as soon as the liquid becomes pale pink. On adding an acid to an alka- line solution the change of colour takes place more gradually and moreover the reaction is disturbed by the presence of lime alumina &c.c. s. Phospho-tungstic Acid as a Precipitant for Organic Bases. By C. SCHEIBLER (Dingl. polyt. J. ccix 141). MARIGNAC proposed metatungstic acid discovered by him as a precipi-tant for organic bases in acid solution; he found also that ordinary sodium tungstate after boiling with phosphoric acid possesses the same property. This he ascribed to the foi*mation of sodium meta- tungstate. The author has found that a new acid is formed. If sodiurn ditungstate be boiled with half its weight of phosphoric acid of specific gravity 1.13 and allowed to stand for a few days crystals are deposited which contain phosphoric and tungstic acids. The acid may be isolated from the barium salt in brilliant octohedrons.From the neutral sodium tungstate another acid may be prepared which crystal- lises in cubes. This acid gires a flocky precipitate in a solution con- taining TTZi&(t'iTof strychnine or mGg6'iT of quinine. In impure solu-tions the colouring matter is precipitated first and may be removed by filtration and the base in the iiltrate may be obtained pure by precipi- tation with pliosphotungstic acid which is removed with caustic lime or barpta. Phosphotungstic acid may prove of use as an antidote to the poisonous vegetable alkalo'ids though no attempts have as yet been made to prove this experimentally. W. R. Action of Stannous Oxide Dissolved in Soda on Gun-cotton. By R. BOTTGER (Dingl.polyt. J. ccix 315). IFwell-prepared gun-cotton be boiled for ten minutes in a iiolution of stannous oxide in sodium hydrate it dissolves to a clear yellowish liquid which deposits pure cellulose when acidulated with hydrochloric acid. This method may be used for determining the quality of gun-cotton as pure cotton-wool is not changed by similar treatment. W. R. Estimation of Albumin Compounds of the Albuminoids with Tannin. By I;. GIRGENSOHN (N. Repert. Pharm. xxii 557-559). THE author finds that the following method for the estimation of albumin gives as exact results as precipitation by alcohol. The solu-tion containing the albumin is mixed with half its volume of 20 per cent. solution of common salt and tannin solution is then added in slight excess ;the precipitate is collected on a weighed filter and washed with water till free from salt and then with boiling alcohol until no more tannin can be detected in the filtrate the precipitate is then pure TECHNICAL CHEXISTRY.albumin. In estimating the albumin in urine uric acid must be first removed by adding acetic acid and leaving the liquid to stand in the cold. The albumin in the urine of nephritic patients differs from that occurring in accidental albuminaria in its combination with tannin the former combining with 37 per cent. of tannin and the latter with 28 per cent. The albumin of eggs of serum and pathological secretions in general combines with 28 per cent. of tannin. E. K.

ISSN:0368-1769    

DOI:10.1039/JS8742700186

出版商:RSC    

年代:1874

数据来源: RSC

摘要:

TECHNICAL CHEXISTRY. Technical Chemistry. Amounts of Real Acid contained in Sulphuric Acid of various Densities. By J. KOLB(Dingl. polyt. J. ccix 368-278 THEauthor finds that the impurities contained in the ordinary com- mercial acid viz. nitrogen oxides nitric acid sulphurous acid and lead sulphate do not materially affect the gravity of the acid as determined for technical purposes. The following table embodies his results :-~~~ ~ -100 parts by weight contain 1litre contains in kilograms Degrees lpecific -Anhy-Acid Acid Beaum6. ravity. Bnhy-Acid Acid drous drous if 60". If 53". acid. Ip904. If 60". If 53". acid. -_ ---0 1-0oo 0.7 0 *9 1'2 1-3 0 -007 0 woo9 0.012 0 +013 1 1-007 1-5 1*9 2 -4 2-8 0 *015 0.019 0 024 0 *028 2 1*014 2 *3 2 *8 3.6 4.2 0 *023 0 -028 0 -036 0 -042 3 1.022 3'1 3.8 4.9 5 *7 0.032 0 -039 0.050 0 -058 4 1-029 3 -9 4.8 6 -1 7.2 0 040 0 -049 0.063 0 '074 5 1*037 4.7 5 *8 7 -4 8.7 0 -049 0.060 0 -077 0 -090 6 1-045 5.6 6 *8 8 *7 10 '2 0.059 0 '071 0 .091 0 '101 7 1'052 6.4 7.8 10*o 11*7 0 -067 0.082 0 -105 0.123 8 1*060 7 -2 8.8 11-3 13 *1 0.0'76 0 *093 0 -120 0.139 9 1.067 8 *O 9 *8 12 -6 14 *6 0 '085 0 -105 0*134 0 '156 10 1'075 8.8 10.8 13 -8 16'1 0 *095 0 *116 0 -148 0 '1'73 11 1-083 9 -7 11*9 15 a2 17 *8 0 -105 0 -129 0 -165 0,193 12 1-091 10 -6 13 -0 16 *7 19 -4 0 *116 0 -142 0.182 0 -211 13 1-000 11-5 14-1 18-1 21 '0 0 '126 0 *155 0 *199 0 '231 14 1*lo8 12 *4 15 *2 19.5 22 *7 0 '137 0 -168 0 *216 0.251 15 1*116 13 *2 16 -2 20 -7 24 *2 0 -147 0 '181 0 *231 0 *270 16 1*125 14 *1 17-3 22 .2 25 -8 0 *159 0 -195 0 -250 0 -290 17 1*134 15*1 18 -5 23 -7 27 -6 0 -172 0 '210 0 -2G9 0'313 18 1*142 16*O 19 -6 25 -1 29 -2 0.183 0 *224 0 287 0 -333 19 1-152 17*o 20 -8 26 *6 31 '0 0 -196 0 *239 0 *306 0 '357 20 1'162 18*O 28 -2 28.4 33 '1 0 *209 0*258 0 -330 0.385 21 1.171 19 -0 23 *3 29 -8 34 -8 0 *222 0 '273 0 *349 0 -407 22 1-180 20 *o 24 -5 31 -4 36 *6 0 *236 0 -289 0 -370 0 '432 23 1'190 21 *1 25 .a 33 *o 38 -5 0 -251 0 '307 0 *393 0'458 24 1*200 22 -1 27 -1 34 -7 40.5 0 *265 0 -325 0.416 0 -486 25 1*210 23 *2 28 *4 36 *4 42 -4 0.281 0 '344 0-440 0 *513 26 1-220 24 -2 29 *6 37 *9 48 -2 0 295 0 -361 0 *463 0 '539 27 1-231 25 *3 31 -0 39 -7 46 $3 0.311 0 382 0 -489 0,570 ABSTRACTS OF CHEMlCAL PAPERS.~~ ~ 100 parts by weight contain 1litre contains in kilograms Degrees jpecitic _.__ ____. BcaumB. :ravity Anhy-Acid Acid Anhy-drous I2SO.I. tf 60" ,f 53". drous &SO,. Acid Acid acid. acid. )f 60". tf 53". 28 1*241 26 *3 32 '2 41 *2 48 *1 0 -326 0.400 0511 0 *597 29 1*258 27 *3 33 -4 42 -8 49 *9 0 *342 0 -418 0 -536 0 -615 30 1*263 28 *3 34 *7 44 '4 51 '8 0 -357 0 '438 0 *561 0 -654 31 1'274 29 -4 36 '0 46 '1 53 *7 0 *374 Q 459 0 '587 0.684 32 1-285 30 *5 37 *4 47 *9 55 '8 0,392 0 *481 0.616 0 *717 33 1-297 31 -7 38 *8 49 -7 55 -9 0-411 6 *503 0 *645 0 T51 34 1'308 32 -8 40.2 51 -1 60 *O 0.429 0 -526 0 -674 Q -785 35 1-320 33 *9 41 -6 53 '3 62 -1 0 *447 0 *549 0.704 0 *820 36 1-332 35 -1 43 *O 55 '1 64 *2 0 -468 0 573 0.737 0 -856 37 1*345 36 -2 44 -4 56 -9 t?6 -3 0 *487 0 -597 0 +765 0 -892 38 1'357 37.2 45 -5 58.3 67 -9 0 *506 0 *617 0 -791 0 *921 39 1*370 38 *3 46 *9 60 -0 70 *o 0 -525 0 *642 0 *822 0 -959 4.Q 1*383 39 -5 48 '3 61 *9 72 '1 0 *546 0 '668 0 -856 0 -997 41 1-397 40 -7 49 8 63 -8 74 *8 0 -569 0 -696 0 -891 1.038 42 1-410 41 -8 51 *2 65 -6 76 *4 0 -589 0 '722 0 '925 1,077 43 1'424 42 *9 52 *8 67 '4 78 *5 0 *611 0.749 0 -960 1-108 44 1.439 44*1 54 -0 69 .1 80 06 0 *634 0T77 0-99% 1.159 45 1'453 45 *2 55 -4 70.9 81-7 0 *657 0 -805 1-030 1'202 46 1*468 46 *4 56 -9 72 *9 84 *9 0.681 0 *a35 1*070 1.246 47 1-483 47 -6 58 -3 74.7 87 -0 0 -706 0 -864 1*lo8 1-290 48 1.498 40.7 59 *6 76 '3 89 -0 0 '730 0 *893 1*143 1*333 49 1-514 49 *8 61 *O 78 -1 91 '0 0 -754 0 -923 1*182 1*378 50 1*530 51 *O 62 -5 80 '0 93 -0 0 *780 0 *956 1*224 1*427 51 1-540 52 -2 64 *O 82 '0 95 -5 0 -807 0 *990 1*268 1*a77 52 1-563 53 *5 65 -5 83 '9 97 08 0 *836 1-024 1-311 1*529 53 1-580 54 *9 67 *O 85 '8 00 -0 0 -867 1-059 1-355 1-580 64 1*597 56 *O 68 4 87 *8 02 *4 0 *894 1*095 1'402 1-636 55 1-615 57 *1 70 *O 89 '6 04 *5 0 -922 1.131 1*447 1*688 56 1*634 58 *4 71 -6 91 *7 06 *9 0.954 1-170 104.99 1-747 57 1-652 59 -7 73 -2 93 *7 09 '2 0 986 1-210 1 548 1*804 58 1-671 61 *O 74 -7 95 *7 11-5 1*019 1 *248 1'599 1*863 59 1*691 62 *4 76 *4 97 '8 14 .O 1*055 1-292 1.654 1*928 60 1-711 63 '8 78 *1 00.0 16 *6 1-022 1*336 1-711 1-995 61 1932 65 *2 79 -9 .04 *3 19 *2 1*129 1-384 1,772 2 -065 62 1'753 86 *7 81-7 04 -6 21 *9 1*169 1-432 1*838 2 -137 63 1'774 68 *7 84 *1 .07 *7 55 45 1*219 1-492 1.911 2 *226 64 1-796 70.6 86 -5 .10-8 29 *1 1-268 1*554 1,996 2 -319 65 1*819 73 '2 89 *7 .14-8 33 *8 1-332 1*632 2 -388 2 *434 66 1*842 81*6 .oo'0 .28'0 .49 *3 1-503 1-842 2 -058 2 *750 --7 M.M. P. M. A Revolution in the Soda Manufacture. By R. WAGNER (Ding. polyt. J. ccix 282-285). UNDER the above heading the author draws attention to the "ammonia process " of manufacturing soda. This process consists in decomposing a solution of sodium chloride by means of ammonium bicarbonate. By heating the resulting ammonium chloride with caustic lime am- monia is generated which is again converted into bicarbonate by TECHNICAL CHEMISTRY. the carbonic acid produced by heating the sodium bicarbonate which in its turn is thus reduced to carbonate.The advantage of this pro- cess consists in the direct transformation of sodium chloride into the carbonate ; the non-precipitation of ot,her metals than sodium from the mother-liquors ; the absolute freedom from sulphur-compounds ; the simplicity of the plant ; the small amount of fuel and labour required ; and the absence of noxious gases evolved during the manufacture. M. M. P. M. The Constitution of Bleaching Powder. By C. GOPNER (Ding. polyt. J. ccix 205-224). THE author endeavours to show that the varying composition of bleaching powder as well as the variable amount of calcium chloride in it is due at all events to some extent to the presence of carbonic acid present during it,s manufacture.The carbonic acid comes from the undecomposed carbonate in the lime used the carbonic acid ab- sorbed from the air by the lime and from the carbonates present in the manganese used to produce the chlorine. Hydrochloric acid is also carried over with the chlorine to a greater or less extent and assists in the formation of calcium chloride. The author’s experiments lead him to conclude that hypochlorous acid does not exist as such in bleaching powder. The bleaching agent is CaOCl,. The paper is too long for abstraction. G. T. A. Utilisation of Alum Shale. By SIDNEY W. RICH(Chem. News xxviii 222). THE development of improved processes for the manufacture of alum and other salts of alumina at large centres of industry has caused the aluminous shales of Whitby Guisborough and elsewhere to remain for a long time without being utilised.The author proposes to con- vert the shale under patent into crude aluminium sulphate and to employ the product so obtained more especially for the purification of sewage. The advantages possessed by alumina in the clarification of sewage, and the impossibility of using alum or pure aluminium sulphate having been discussed the process for the conversion of the shale is next described. A current of sulphurous anhydride from a pyrites burner is passed together with air and moisture through an opening at the bottom of a cell qr tower down which a charge of hot freshly-burnt shale is caused slowly to descend. Owing to the high temperature and the joint presence of the several agents the sulphurous anhydride is transfornied into sulphuric acid and the larger portion of the shale converted into soluble aluminium sulphate.This crude sulphate is lixiviated immediately it is removed from the cell and while it is at a high temperature ; in this manner a highly-concentrated liquor is obtained without involving the expense of evaporation. J. W. 196 ABSTRACTS OF CHEMICAL PAPERS. Chemical Investigation of the Thuringian Slates in the Neighbourhood of Lehesten near Grafenthal. By H. MADER (Arch. Pharm. [3] iii 197-215). THESEslates vary greatly in appearance and colour. Some are equal to the best English slate in a commercial point of view while others are worthless.The object of the present paper is to inquire whether the differences in colour quality &c. can be determined from their chemical composition and whether analysis can be used as a means of estimating their technicai value. The methods followed in the analysis of the slates which are detailed -at length are the ordinary ones. The results of the examination of twenty specimens are given at length. The paper is to be continued. G. T.A. Note on & New Method of Tempering Steel. Regeneration of Burnt Iron. By H. CARON-(Compt. rend. lxkii 836-838). THEordinary method of hardening steel by plunging it whilst red hot into cold water is apt to cause flaws in the metal which are not removed by the subsequent process of annealing. The author avoids this by plunging the red hot metal into water previously heated. A temperature of 55" sufficesfor springs for needle guns giving at once a flexibility and temper equal to that obtained by the most careful hardening and annealing. Regeiwratiom of Burnt Iron.-Iron which has become brittle by over- heating in forging has its properties entirely restored by plunging it whilst red rot into a saturated solution of common salt. C. E. G. The Occurrence of Chromium in Platinum. By A. VOGE L (N. Rep. Pharm. xxii 392). TRACES of chromium were found in platinum ores and also in scraps of platinum wire foil &c. G. T.A.

ISSN:0368-1769    

DOI:10.1039/JS8742700193

出版商:RSC    

年代:1874

数据来源: RSC

摘要:

197 PAPERS READ BEFORE THE CHEMICAL SOCIETY. V1.-On the Preparation of Standard Trial Plates to be wed &z vergying the Conqositioiz of the G‘oinmp. By W. CHANDLER Chemist of the Mint. ROBERTS INthe early stages of the civilization of a nation unmixed metals are employed for the currency and the increase of metallurgical skill has usually been attended with the introduction of alloys for the coinage. When gold coins were first introduced into England by Henry 111 the metal was 24 carats fine that is pure gold. Henry VI used an alloy containing 995.0 parts of fine metal and the standard of 916.66 parts of fine gold in 1,000 of the alloy was established by Henry VIII and has remained unaltered to the present day. The composition of the British silver coins does not differ from that of those issued in the time of Edward I in the annals of whose reign this alloy which contains 925 parts of fine silver in the 1,Q00,is alluded to as the “old standard of England.” The actual manufacture of coins was usually entrusted to a p1-i-vileged body of men termed moneyers who were compelled under severe penalties to produce coins of alloys which were only permitted to vary within certain narrow limits from the composition of standard trial plstes ; and the comparison with these plates of pieces set aside from each day’s work constituted the sale guarantee to the Sovereign of the purity of the coins and of the fidelity with which the coinage operations had been conducted.Amongst the Cotton manuscripts is preserved the account of a ‘‘ trial of the pyx ” of gold nobles in the 23rd year of Edward I11 (1350) ;the coins were to be compared with one ounce of florins of Florence kept in the Treasury for standards and according to Ruding the first men- tion of trial plates occurs in records of the 17th year of Edward IV (1477).I append a tabular statement of the pomposition of the trial plates of which portions have been preserved in the Mint. STANDARD TRIALPLATES. Gold. I Silver. Gold ,.993 -5 14’17 994.8 Silver.. 5 *15 14’7’7 925 .o Silver . .923 5 Copper 1-35 Copper. . 76.5 VOL. XXVII. P ROBERTS ON THE PREPARATION 198 STANDARD (coTttinued). TRIALPLATES Gold. Silver. prescribed by Actual compo- Standard Date. Stan dayd Date.prescribed by Actual compo- law. sition. sition. law. Gold . .915 *5 Silver . . 885 -5 1527 916 *66 Silver.. '78'3 PTn-Copper .114 -5 Copper 6.2 certain I--Gold . .954 *4 Silver . .763 -6 Probably 958*4 Silver.. 34 *8 1542 '7'75 1 Copper .236 '4 1543 Copper 10.8 Gold,. 913 *7 Silver . ,927 *O 916.66 Silver. . 60 *8 1553 925 Copper. '73 -0 ,,~ Copper 25.7 -/- I 1560 994.8 Silver.. 5 -7 1560 1 Gold . a 994 -3 Silver . .930 -2 925 *o Copper 69.8 Copper --Probably Gold . .990 -3 Silver . .252 *O Silver.. 9.7 1600 250 Copper . '748 *O i 1576 992*2 Copper --Gold . .915 -9 Silver . .75'7 *4 1593 916 -66 Silver.. 52 -1 No date Copper .242 *6 Copper 31.9 Gold . .990 -3 Silver . .925 *1 1605 994 *8 Silver..8.3 1601 925 -0 Copper. 74.9 Copper 1.4 -_____. Gold . .913 -0 Silver . ,922 *7 1649 916 -66 Silver.. 51 *1 1604 925 *O Copper. 77 *3 Copper 35.9 --_.___ Gold ,.900*9 Silver . .923 *7 1660 994 *8 Silver * 3 a7 1649 925 *O Copper. 76.3 Copper 5.4 -I--Gdd . .912 -9 Silver . .924 -2 1660 916 -66 Silver. . 53 -3 1660 Copper. 75 *8 Copper 33.8 Gold . .914-6 Silver . .922 -0 1688 916 *66 Silver Copper . '78'0 Copper } 85 '4 1688 Gold . .917 *1 1707 916 -66 Silver. . 59.5 1707 y25.0 j Silver .. 922.0 l Copper 23.4 Copper. 78'0 I I---. .-Gold . . 916 -1 I Sil~er. .928 -9 1728 916 *66 Silver. . 50 -4 1728 925'0 1 Copper. 71.1 Copper 33-5 OF STANDARD TRIAL PLATES ETC. TRIALPLATES STANDARD (co?&ued).Gold. I Silver. --_ Standard Date. prescribed by sition. law. Gold . .915 *3I Silver . .925 '0 1820 916 *66 Silver.. 3'7.6 1829 925 Copper '75.0 Copper 46.5 Gold . .916'61I ! Silver 924'96 I 1873 916'66 Silver.. -1873 1 925'0 Copper 75'04 -Copper 83'39 1873 3upplementary Pure gold. 1873 Supplenientarj Pure silver. plate Froni this it will be evident that although the standards of fineness were always prescribed by law these plates nevertheless have at times been very inaccurate. But small portions of the plates prepared in 1829 remain unused and T have been instructed by the Lords of the Treasury to prepare new plates both of gold and silver. Gold Plate. It should be mentioned that when the last gold plate was made the alloying metal was itself an alloy of equal parts of silver and copper ; but since about the year 1837 copper alone has been used for this pur- pose ; and it is of course necessary that the trial plate and the coinage should be absolutely identical in composition.Fortunately the gold- copper alloys employed in minting present but a very slight variation in molecular arrangement provided the utmost care has been taken to ensure a thorough admixture of the constituent metals while in a molten state. It was only necessary therefore to melt together pure gold and copper the purity of which was guaranteed by its high electric conduc- tivity. Of course repeated meltings were necessary before the results of assays proved that the relative proportions of the gold and copper had been correctly adjusted.Ultimately a plate was obtained and the results of assays from its different parts are shown in the accompanying diagram from which it will be evident that its composition ranges from 916.5 to 916.7 parts of fine gold in 1,000 of the alloy the mean variation from standard (516.66) being ur,$-jsath of the whole mass. &I a t t h i e s s en proved t-hat the gold-copper alloys may be considered to u2 ROBERTS ON THE PREPARATION be “solidified solutions of allotropic modifications of the metals in each other,” a view which these results tend to confirm and I am persuaded that the homogeneity of this alloy may now be considered to be clearly established. GOZD-COPPER ALLOY.For New Trial Plate. 6.6 6-6 6 ‘7 6.6 6*6 6.7 6.7 6.65 6.5 6-6 6’6 6 ‘62 6.6 6 *6 6.7 6 $6 6.65 6-64 6.6 NoTE.-The figures 91 are omitted in each of the above statements of the results of assay. Thus 916.6is given as 6.6. Silver Plate. The preparation of the silver trial plate was attended with much difficulty as the standard silver alloy appears to be a mechartical rtzizture of two solutions and the cooling of such an alloy is attended with a remarkable molecular re-arrangement in virtue of which certain com-binations of the constituents of the molten alloy become segregated from the mass the homogeneous character of which is thereby destroyed. In order to explain this it is necessary to refer to an important series of experiments conducted in the Mint at Paris by Levol with a view to ascertain the nature and define limits of this molecular mobility.OF STANDARD TRIAL PLATES ETC. In one experiment an alloy containing 77.33 per cent. of silver and 22.67 per cent. of copper was cast in a cnbical mould of 42 mm. in the side. A portion cut from the centre of the mass gave on assay 78,318 p. c. of silver while a portion cut from one of the angles was found to contain only 77.015 p. c. of silver showing a difference of 1.303 p. c. Lerol prored that it is only the alloy containing 71,893 p. c. of silver and 28.107 p. c. of copper tlhat is absolutely homogeneous. He also finds that while the alloy containing 71,893 p. c. of silver is homogeneous in all alloys containing more silver than this amount the centre of the solidified mass is richer than the exterior; on the other hand in alloys of fineness lower than 71.893 p.c. the centre contains less silver than the external portions. SILVEB-COPPER ALLOY. Plate Rolled from 1,000 ozmces of Metal. 4 '8 6.4 8'4 5'7 5'2 5.6 5.0 4'8 4'2 4'9 5'0 4'8 5'2 4'4 4'7 4'6 4'9 5'3 6-1 5'2 5'3 4'9 4 '9 7'I 7'0 4'8 7'5 5'1 4.6 4'9 5'4 5'7 4'8 4'8 5'1 5'2 4'8 5'1 5.6 5'1 5 'I 4'8 4'8 5'3 5'1 4'8 5'7 5'2 4 '8 5' I 5'2 5'3 5.1 4 '9 5 '2 5'2 5'0 I NOTE.-The figures 92 are omitted in each of the above statements of the results of assay. Thus 925.0 is given as 5.0. Prom the foregoing remarks it will be evident that it is impossible to cast a bar or plate of this alloy of uniform composition and therefore it was necessary to resort to an artifice in order to obtain a "standard ROBERTS ON THE PREPARATIOS ETC.trial plate” of the necessary dimensions. 1,000 ounces of standard silver were cast into a plate 30 em. long 25 em. wide and 5 em. thick. This mass was placed upon the bed of a planing machine and all its outer surface to a depth of 4 mm. removed. The remaining metal was then rolled into a sheet 1.5 m. long 45 em. wide and 1.8mm. thick which is represented in the diagram. Portions of metal were then removed from all parts bf the sheet and assayed and the results proved that the silver had conceiitrated itself in the centre of the mass and that the portion detached could alone be used as a trial plate.The mean of all the assays taken on this portion gave 924.96 as the composition of the plate which therefore only varies from standard by -,lo __ ,th part of the whole mass. Such then are the plates which I have prepared in accordance with the Coinage Act of 1870 and in conclusion I would offer a few re- marks as to their practical use. The object of the annual “trial of the pyx ” is to satisfy the public that the coins issued from the Mint are accurate both in respect of weight and fineness and this guarantee is furnished by means of a periodical examination made by the Free- men of the Goldsmiths’ Company under direction of the Crown. In former days the “ trial of the pyx ’’ was of thc greatest practical im- portance not only as a safeguard against debasements of the coinage which in early times could be carried on with far less risk of detection than at present but also as a means of relieving from responsibility the Mint Master who was a contractor for t’he coinage and had given large security for the proper discharge of his duties.At the present day however difficult it may be for a Mint Master to issue coins materially defective in weight or fineness without the certainty that the error will be detected it is nevertheless advisable to continue a public trial which ensures the absolute accuracy of the coinage accord- ing to the law in force respecting it and which will at all times act as a wholesome check upon the proceedings of the Mint.The fineness of the coins examined at the “ trial of the pyx ’’ is determined by comparison with the trial plates and as we hare seen plates of mixed metals although containing mathematically exact proportions of the metals of which they are composed are liable to exhibit in parts some divergence from the precise standard of fine- ness ;and even the minute differences of the new plates assume serious proportions when calculated on the amount of gold coin which passed through my hands last year which was no less than 119 tons. It therefore becomes necessary to provide a standard of reference which shall be more trustworthy and I have much pleasure in stating that the Lords of the Treasury acceded to a proposal I made in 1870 to supplement the standard plates by plates of metal of as nearly as possible absolute purity.I now submit plates of fine gold and fine HANNAY ON A SPECIFIC GRAVITY APPARATUS ETC. 203 silver; the gold plate* was precipitated from more than 460 litres of chloride of gold by means of oxalic acid; and the experiments which have been instituted to establish its purity have given my c01-Ieague Mr. Ridsdale and myself no little anxiety and considering its bulk it certainly is the purest gold with which I am acquainted. With regard to the silver M. Stas? has described a method for preparing silver of the highest possible degree of purity and it was only necessary for me to follow implicitly his directions. The method I used consisted ill the complete reduction of an ammoniacal solution of nitrate of siIver by ammoniacal cuprous sulphite.

ISSN:0368-1769    

DOI:10.1039/JS8742700197

出版商:RSC    

年代:1874

数据来源: RSC

摘要:

HANNAY ON A SPECIFIC GRAVITY APPARATUS ETC. 203 VI1.-On a Spec%& Gravity Apparatus for Temperatures other than Atmospheric. By J. B. HANNAY. THEfollowing paper contains a description of a new specific-gravity apparatus which was devised for taking specific gravities both above and below the ordinary temperatnre of the atmosphere. On trying all the apparatus already contrived I found none of them conformed to all the conditions required as mentioned below so I set about devis- ing an instrument which would at least more nearly fulfil them. The following were the qualifications required :-1st. It must admit of very accurate and easy adjustment. 2nd. It must prevent the evaporation of volatile liquids and if possible without the use of caps or stoppers.3rd. It must admit of being immersed in water in such a way that all the liquid in the apparatus is below the level of the medium by which it is brought to the required temperature. 4th. It must be in a handy form for use and if possible dispense with a sus-pending wire or in other words be in such a form as to admit of being hung by itself from the hook of the balance. 5th. It must admit of determining the specific gravity below the temperature of the atmosphere. This last is a very important point especially in expan- sion experiments because when a liquid has been adjusted at a low temperature it must be allowed to rise to the ordinary temperature of * The specific gravity of the entire mass of metal weighing 70 ounces was taken with the greatest possible care by Mr.Rigg and the results are as follows :-Before rolling.. .................................. 19.2945 After once passing through the rolls ................ 192982 + ‘‘Les Lois des Proportions Chimjques,” par J. 8. Stas 13. 32. 204 HANNAY ON A SPECIFIC GRAVITY APPARATUS the room before it can be weighed otherwise moisture will condense upon it and in so rising the liquid expands and overflows the bulb if sufficient space has not been left for it. The accompanying sketch shows the first apparatus constructed. It was filled by sucking up the liquid (by a tube attached) Fig. 1. like using a pipette and then placed in a vessel of water hav- ing the two tubes projecting.* The liquid expands only in the wider tube and the excess is withdrawn by touching the point of the small tube with fil-ter.paper.This apparatus had some very serious objections ; it did not entirely prevent eva- poration of the disulphide ; it required a suspending wire and did not admit of expansion of the liquid when adjusted at low temperatures. After blowing and trying several modified apparatus I at length determined upon the Fig. 2. form shown in Fig. 2 as completely fulfilling all the required con-ditions and being moreover simple and easy to make. Any person having B little experience in glass-blowing may form one for himself. The ap-paratus as shown in Fig. 2 consists of two bulbs connected by a tube C which al-though thick in the glass is narrowed down The apparatus given in the sketch is similar to that described by Dr.Sprengel in the Chem. Xoc. Jourm. for June 18’73 in principle though different in shape. I have lately made one the same as that described by Dr. Sprengel and after several triale I find that it is open to all the objections against the one in the sketch although if comparison be admitted I prefer the form of Dr. Sprengel’s apparatus to that of mine. It may perhaps be as well to mention in this place that the work above detailed was carried out fully a year ago and therefore long previous to t,he publication of Dr. Sprengel’s paper. FOR TEMPERATURES OTHER THAN ATMOSPHERIC. 205 to a very fine capillary tube on the narrowest part of which is a mark to which the level of the liquid is adjusted.From the lower bulb (which is the larger) a fine tube B descends then turns up vertically then curves over above the level of the smaller bulb and is again recurved at the point A. From the small upper bulb a tube E ascends then is turned into a sharp curve downwards and after a gentle recurve ends at F. The method of using the apparatus is as follows :-The point A is dipped into the liquid whose specific gravity is required and suction is applied to raise the liquid to the mark on the small tube at C. The tube A is then removed from the liquid and a little more suction applied to raise the liquid over the bend of the tube A and thus leave the part AB full of air. The liquid then stands at D in the small bulb and at B in the tube the capillary attraction in B causing it to rise higher than D.But the volume of the liquid is exactly what the -bulb holds from A to C because no more entered after the end of the tube was removed from the liquid. Then as the weight of water it contained had previously been determined at a kuown temperature it is only required to hang it from the balance hook by the bend E and weigh and calculate the specific gravity in the ordinary manner. That the adjustment of the volume of liquid in this apparatus may be performed with great exactness will be quite appa- rent-in fact it will be seen that it fulfils all the conditions required above and is besides admirzbly suited for taking the specific gravity of spontaneously inflammable liquids.For this purpose a current of hydrogen gas is passed through the apparatus from F to A till all the air is expelled. The end A is then passed through a slit in the stopper of the vessel holding the inflammable liquid (also in a non-oxidizing atmosphere) then suction is applied and the adjustment weighing &c. done as usual." The method I used for keeping up a constant temperature was that described by Dr. Carmichael but I modified his apparatus in * In a paper communicated to the British Association (Bradford Meeting) Mr. Alfred Tribe describes a modification OP Regnault's specific gravity apparatus for which he claims the advantage of ascertaining with ease the specific gravity of inflammable liquids. The sole object of the modification is to allow of the liquid being poured quickly into the bulb.Now if Mr. Tribe signifies by "inflammable liquids I' substances such as ether alcohol &c. I cannot see why they require the modification he suggests because as they are not spontaneously inflammable they may be-and I may say generally are-introduced in the ordinary way by a small funnel tube the mouth of which may be easily covered to prevent the evaporation of volatile liquids. On the other hand if Mr. Tribe means spontaneously inflammable liquids such as zinc ethide I cannot see how his apparatus will anawer at all and for those which emit dense fumes this apparatus is of no more use than the ordinary one with the covered funnel tube. The apparatus above described however is admirably adapted for any of these liquids.206 HANNAY ON A SPECIFIC GRAVITY APPARATUS such a manner as to enable me to adjust the temperature to any required degree within a certain range of temperature without much trouble. Figure 3 shows the apparatus as I used it the difference bet’ween which and the original mill at once Pig. 3. be seen on referring to Dr. Carmichael’s communication. The convoluted tube E Fig. 3 and the bifurcated tube AB for the passage and regulation of the gas are similar to the original. The difference is that in the apparatus here represented the tube C for the regulation of the height of the mercury is graduated and the piston-rod is screwed so that all that is required when regulating it for any temperature is to raise or lower the piskon till the lower side cuts the figure indicating the temperature required when in a short time the thermometer will be stationary at the desired temperature.With this apparatus great steadiness may be obtained the high specific heat of the water in which t,he convoluted tube and specific gravity bulb are immersed preventing it from fluctuating. After long-continued use the mercury in the apparatus becomes slightly evaporated in which case all that is necessary is to screw the piston up to 0 on the scale and if the mercury falls below the mark on the narrowed part of the tube it must be made up to the exact mark. If this is attended to the apparatus gives remarkably constant results. In Fig. 4 I have given a sketch of the combined apparatus used in taking the specific gravity.A is a flask holding the liquid whose specific gravity is required C is the screw for regulating the supply of gas through the tubes D and E to the large Bunsen burner H ; and F is a thermometer. B and G are the two tubes of the bulb which is shown immersed in the water. The only piece of apparatus which calls for description in this place is that marked IKL which was used for regulating the level of the liquid in the bulb. It consists of a wide tube with a screw piston the under side of which is made of ebony (metal being inadmissible because of the mercury) while the upper side is brass with a socket in the centre in which the end of the screw L works. When the screw is turned to the right the piston rises and the mercury in K falls and so sucks the liquid into the bulb through B and when the screw is turned to the left the reverse occurs.The part of the suction apparatus at I has a lateral opening over which is stret,cheda piece of thick india-rubber tubing (used for vacuum-pumps) FOR TEMPERATURES OTHER THAN ATMOSPHERIC. 20'7 in which a pin-hole is made through which the t'ube G is passed. In this way the tube of the bulb is fitted air-tight to the suction apparatus. Fig. 4. Ihave adopted this form of suction apparatus in place of the ordinmy india-rubber bulb method on account of its much greater exactness and certainty of action when only a very small displacement is required. For ordinary purposes the apparatus may be adjusted by the mouth in this way.A piece of delivery-tube about 250 mm. long is closed at one end and a lateral opening blown about 10 mm. from the end. This is covered as in the above apparatus with thick india-rubber tubing pierced with a pin-hole into which the tube G (Fig.4) is forced then by applying suction by the mouth to the open end of the tube the liquid may be adjusted very exactly. (For liquids which evolve disagreeable or corrosive vapours this method is not good as the mouth then suffers.) When the apparatus is filled in this way the suction is only required to commence the filling and for adjustment because as will be seen from Fig. 4,the level of the liquid in A is higher than the bulb so that it acts as a syphon and fills itself.For the sake of perspicuity I have omitted in my drawing the shade used to prevent draughts from dis-turbing the lamp and a piece of thick wire-gauze placed over the rose-burner to distribute and modify the heat from the Bunsen lamp. 208 GLADSTONE AND TRIBE'S RESEARCHES ON THE When the bulbs are well cleaned and dried by a current of filtered air to exclude dust particles I find that by this apparatus the specific gravity of a carefully purified liquid may be determined considerablj above its boiling point because as in D onny's experiment the attraction between the particles of the liquid and between the liquid and the glas is such that unless foreign matter-which yields particles of gas and so affords an evaporating surface within the liquid-be introduced it does not boil when the pressure of its vapour equals that of the atmo- sphere. I find for instance that the specific gravity of carbon disul- phide may easily be obtained at 62" C. which is 19" above its boiling point and with care it might be obt,ained at a much higher tem-perature.

ISSN:0368-1769    

DOI:10.1039/JS8742700203

出版商:RSC    

年代:1874

数据来源: RSC

摘要:

208 GLADSTONE AND TRIBE'S RESEARCHES ON THE VIII.-Besearches on. the Actio?t of the Copper-zinc Couple on Organic Bodies. Part IT. On Iodide of 8111~1. By J. H. GLADSTONE F.C.S. Ph.D. F.R.S. AL ALFRED TRIBE AFTER investigating the action of our copper-zinc couple on the iodides of propyl we turned aside from the series containing the CnHPn+l radicals in order to examine its action on the corresponding member of the series which contains the CnHZn-lradicals. Action of the Dry Couple on Ally1 Iodide. On pouring the liquid iodide of allyl upon the metallic couple there is a sensible rise of temperature but the action whatever it may be stops quickly unless extraneous heat be applied. At 100' the decomposition is moderately rapid little or no gas is evolved and the only organic products appear to be a liquid which has the properties of di-allyl and anon-volatile resin apparently isomeric with allylene.In one experiment a flask containing 5 C.C. (9 grams) of the iodide with the usual amount of the copper-zinc couple (see Journ. Chem. Soc. 1873 p. 969) was heated in a bath of boiling water for two hours. During this time there distilled over a slightly coloured liquid which weighed 2.6 grams. On re-distilling this liquid the first portion that came over about one-third of the whole was colourless mobile lighter than water and capable of combining with sulphuric acid to form a brown treacly mass. The remaining two- thirds consisted principally of undecomposed allyl iodide. Neither of these portions contained a trace of zinc.The flask was then heated to 200" for half-an-hour but no further allyl iodide or any other volatile body was driven off and the residue was treated with water. This ACTION OF THE COUPLE ON ORGANIC BODIES. issolved out the iodide of zinc but left a resinous body which was isoluble in alcohol but readily soluble in ether. Its ethereal solution n eva,poration gave a brownish substance which when dried at loo" reighed 0.31 grm. An ultimate analysis was made of 0.2060 grm. rhich yielded 0.6805 CO and 0.181 H,O. This indicates it to be a ydrocarbon and probably of the composition n( C3H4),the slight xcess of carbon being probably due to some carbonization having taken llace during the drying of the body as was rendered the more likely 19its somewhat brown colour.Calculated C3H4. Found. Carbon.. ...... 90.00 90.10 Hydrogen.. .... 10.00 9.76 100*00 99.86 The iodide of zinc formed in this experiment was determined and it howed that 6.8 grams of the iodide had been decomposed; and the pantities of the two organic products lead to the conclusion that the najor part was split up by the action of the couple into iodide of zinc ,nd diallyl thus:- 2(C3H51)+ Zn = ZnIz + {::%. vhile about a fifth part was in some way deprived of hydrogen but nstead of forming gaseous allylene C3H1;,it formed apparently an someric or polymeric modification. If this C3H4 were due to the {g:::, plitting up of diallyl its complementary hydrocarbon would If course be produced as in the case of the C,H2,+1 series; but this vas never the case and we are disposed to attribute the reduction #ooxide of zinc unavoidably present in the couple especially as a trace ,f water was always observed during the reaction.Unwilling to relinquish the hope of obtaining zinc-ally] we tried ,he action of the couple on the iodide in presence of ether. A decom-losition was found to take place at the ordinary temperature and to lroceed rapidly. In one experiment where 9 grams of the iodide were nixed with twice its volume of pure ether at 12" the temperature mmediately rose ;the flask was immersed in water at 12"for 15minutes Lnd on removing it the temperature again rose but in 10 minut,es it lad cooled. Little or no gas was evolved and the products of the ,eaction were entirely in solution.An estimation of the iodine in :ombination with zinc showed that 8.43 grams of the iodide or nearly ,he whole quantity had been decomposed. Now if the reaction under c H5 ;hese circumstances were simply 2C3H51+ Zn = ZnTz + { c:H,' the 210 GLADSTONE AND TRIBE’S RESEA4RCHESON THE atomic ratio of the iodine to the zinc in the solution would be 1 0.5 ; but if a reaction should take place similar to that which occurs with the monad positive radicals of the alcohol series viz. C,HJ + Zn = ZnC,H,T then it is evident that the atomic ratio of the iodine to the zinc would be 1 1. In the experiment detailed above the ratio was found to be 1 0.387. Thinking that this excess of zinc might arise from the presence of some alcohol or water in the ether employed though it had been distilled three times from sodium a portion of the same ether was boiled with sodium for 2+ hours and then carefully distilled from the same metal.To obviate any injurious rise of tem-perature on mixing the materials the flask was kept immersed in water at 11”,and it was suffered to remain untouched for two hours. The reaction was complete. The ethereal solution on shaking with water gave a precipitate of zinc oxide and the ratio of the iodine and zinc was found to be 1 0.584 the same as in the previous experiment. On another trial in which the temperature was kept still lower and the decomposition not allowed to proceed to completion the ratio was found to be 1 0.600.This excess of zinc can scarcely therefore be attributed to the pre- sence ofany alcohol or water in the ether employed. Moreover had it been so there would have been found as will be presently shown about 120 C.C. of propylene. No gas however was evolved. Yet this is inconclusive for ether itself is capable of dissolving propylene indeed we found it to dissolve 12.8 times its volume at 13” and therefore the gas would scarcely make its appearance as such. But this objection is susceptible of an answer for a mixture of alcohol and water just capable of dissolving the ether separates about half the gas from SG~U-tion and no effervescence was observed when the ethereal solution was thus diluted. This excess of ratio and the separation of oxide of zinc on the addition of water are after all inconclusive grounds for assuming that some allyl-iodide of zinc is produced; and our attempts to get any indication of free zinc allyl completely failed.pu”o fuming was ever seen nhd we could separate from the ethereal solution no organic com- pound except the liquid having the properties of diallyl and the non- volatile hydrocarbon before described. Zinc alone acts very slowly on allyl iodide in presence of ether. Action of the Couple oii Ally1 Iodide nizd Water. Pure granulated zinc was found to have no effect on allyl iodide in presence of water at the ordinary temperature. Our usual zinc-foil had a little action and the copper-zinc couple a great deal ; thus in two comparative experiments continued for 24 hours 32 C.C.of gas were evolved by means of the formw 550 C.C. by tliu latter. ACTION OF TIlE COUPLE ON ORGANIC BODIES. 211 5 C.C. (9 grams) of the iodide were added to the ordinary quantity of the couple wet with water. There was an immediate evolution of gas which continued for 48 hours when 918 C.C. had been collected. The temperature was about 17". The gas burnt with a very bright flame dissolved readily in absolute alcohol combined with Sromine and fuming sulphuric acid absorbed 99 per cent. of it,. It needs no further proof that the hydrogenation of the C,H had not proceeded so far as to produce either dipropyl {:zEi or propyl hydride C,H,; but had stopped at the first stage giving rise to t,he olefhe C3H6 propy lene. The reaction would appear to be- C,H,I + H,O + Zn = ZnI.HO + C3H6 and the theoretical amount of gas producible from 9 grams would be 1200 C.C.Action of Zinc on Ally1 Iodide and Alcohol. The couple acts so violently on iodide of allyl when mixed with alcohol that our experiments were confined to the action of zinc alone and even this becomes unmanageable unless means are employed for keeping down the temperature. 5 C.C.of the iodide with 10 C.C. of absolute alcohol were added to 10 grams of pure granulatedzinc. Evolution of gas commenced imme- diately. The flask was at once immersed in water at 14" and the action ceased in six minutes by far the greater portion of the gas having been produced in the first two minutes. The gas collected as usual over water measured 1035 C.C.Alcohol of spec. grav. 0.805 was found to act more slowly on account of the retarding influence of the water and when it is more dilute the water interferes with the completion of the reaction through the for-mation of a crust of compact oxide on the zinc most probably from the decomposition of the iodo-ethylate of zinc produced. (See Joum. Chern. Soc. May 1873.) A very convenient method for preparing pure propylene is to place some granulated zinc in a flask provided with a delivery tube and thistle-funnel cover the zinc with absolute alcohol and add iodide of allyl as the gas is required.* Some gas prepared in this manner was purified by passing through aqueous alcohol and water successively. It burnt with a smoky flame combined with bromine to form an oily body boiling pretty constantly at 143" and dissolved rapidly and completely * The nearest approach to this method is that of Tollens and Heiniger only they employ hydrochloric acid in addition which gives impnre gas. BOLAS ON FERROUS ANHYDRO-SULPHATE. in absolute alcohol and fuming sulphuric acid. The sole reaction therefore with alcohol would appear to be CsHJ + C2H60+ Zn = Zn { c2F0+ C,H,.

ISSN:0368-1769    

DOI:10.1039/JS8742700208

出版商:RSC    

年代:1874

数据来源: RSC

摘要:

BOLAS ON FERROUS ANHYDRO-SULPHATE. 1X.-COMMUNICATION FROM THE LABORATORY OF CHARING-CROSSHOSPITAL. On Ferrous Anhydro-Sulphate. By T. BOLAS. IN a recent number of the Chemical News (vol. xxviii 249) 1 de-scribed a modification of the ferrous sulphate test for nitric acid and subsequently (vol. xxviii 283) pointed out a method of making this test quantitative. For this purpose a mixture prepared by adding 10 per cent. of a saturated aqueous solution of ferrous sulphate to oil of vitriol is made use of; as this mixtnre cools it deposits a white powder which when examined with the microscope was found to consist of small prismatic crystals resembling in form those of Glauber’s salt. These crystals when exposed to the air soon absorbed water and split up into minute granular crystals.In order to obtain the prismatic salt in a state fit for analysis it was rapidly collected by means of a Bunsen’s filter and was then spread on a very porous tile which had been heated for some time to dull redness and had been allowed to cool over sulphuric acid. The whole being now placed over oil of vitriol the air was exhausted and after a few days the salt was found to be dry and as free from sulphuric acid as could be expected. Portions of salt thus prepared were analysed with the following results .-I. 1.027 grms. substance gave -3517 grms. Fe,03. 11. 1.0790 grms. substance gave -361 grms. Fe203. 111. -2255 grms. substance gave ~462grms. BaS04. IV. -1804grms. substance gave *3706grms. BaSOa. Found. Calculated.I. 11. 111. IV. Mean. Ft! . . 56 24.13 23.97 23.42 -23.69 S2 . . 64 27.59 -28.14 28.21 28.17 07 . . 112 48.28 ---100*00 BOLAS ON FERROUS ANKYDRO-SULPHATE. A small excess of sulphur and a slight deficiency in the iron might naturally be expected owing to the fact that a trace of sulphuric acid must remain spread over the surface of the crystals. The above numbers however clearly indicate the formula FeS,O, and put the formula FeH2S20s quite out of the question as this requires only 22.40 per cent. of iron. It is scarcely possible that more iron than the theoretical amount should be found in a case of this kind. For a similar reason the salt in question cannot be supposed to be a mecha- nical mixture of ferrous sulphate and sulphuric acid.When ferrous anhydro-sulphate is treated with water heat is pro-duced and the salt is first converted into green vitriol FeS04.7H20 and is afterwards dissolved. When exposed to moist air it yields as previously mentioned minute granular crystals which were at first supposed to consist of green vitriol. In order to test this supposition a portion of the ferrous anhydro-sulphate was spread on a porous tile and placed together with a vessel of water under a bell-jar. When the action appeared complete and the remaining salt was zi,ppzLrently dry portions were analysed with the following results :-I. *5861grms. substance gave *1790Fe,O,. 11. -4255 grms. substance gave -3905 grms. BaS04. Calculated. Pound. -I. 11. Fe .... 56 21.54 21.37 -HI ....12 4.61 -S...... 32 12.31 -12.60 Ol0 .... 160 61-54 -100~00 These numbers correspond with a salt having the composition FeS04.6H20,or that of green vitriol minus one molecule of water and it is probable that the retention of a trace of free sulphuric acid pre-vented the absorption of the seventh molecule of water. This is fendered probable by the fact that the salts FeS04 FeS04.2H20 FeS04.3Hz0 FeS04.4Hz0 and FeS04.5Hz0 are formed by the action of sulphuric acid on green vitriol or its solution (B onsdorf Kuhn Mitscherlich Marignac); and moreover according to Brandes ferrous sulphate becomes converted into green ritriol on exposure to moist air. The state of the water in these compounds affords ground for specu-lation and perhaps some light may be thrown on this point by experi-ments made with other salts. I find that aqueous solutions of several other sulphates are precipi- tated by the addition of oil of vitriol and I am at present engaged in the examination of these precipitates. VOL. XXVII. Q -\

ISSN:0368-1769    

DOI:10.1039/JS8742700212

出版商:RSC    

年代:1874

数据来源: RSC

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214 X.-On Tetranickelous Phosphide. By ROBERT Ph.D. SCHENK INa former paper I stated that triferrous phosphide is produced by the action of nascent phosphoretted hydrogen upon freshly precipitated ferrous hydrate. I have now subjected nickelous hydrate to the same treatment that is I have poured a solution of nickelous chloride into a boiling solution of potash to which phosphorus had been added. A brownish precipitate is formed almost immediately which is com- pletely soluble in dilute acids. But after about five minutes a black soluble substance insoluble in acids begins to be formed the quantity of which increases as the action of the phosphoretted hydrogen is continued. After about an hour and a-half I stopped the evolution of phosphoretted hydrogen by removing the flame and adding a con- siderable quantity of water to the contents of the dish.I allowed the precipitate to settle down which it does rather slowly decanted the alkaline liquid and washed once with a fresh quantity of water. The lumps of phosphorus at the bottom of the dish were removed and the remaining phosphorus was got rid of by boiling with pure potash. After having poured off the alkaline liquid I added dilute snlphuric acid when the bulk of the precipitate disappeared. The black sub- stance remaining in the form of small lumps was boiled for a short time with dilute hydrochloric acid and then washed successively with water alcohol ether and bisulphide of carbon. It was then dried in a current of carbonic acid at first at loo" and then in a chloride of calcium tube gently over the flamc.The analysis made in the same way as that of the triferrous phosphide gave 66.64 per cent. of nickel and 16.78 per cent. of phosphorus. The atomic ratio of nickel and phosphorus was accordingly 2.08 to 1. But as the nickel and phos- phorus together did not amount to more than 83.42 per cent. of the whole and as I did not expect that the substance had during the process of purification been oxidised to the extent of 16.5per cent. I thought that by the action of phosphoretted hydrogen upon nickelous hydrate an oxyphosphide might have been produced especially asthe above numbers did not differ much from those required by the formula NiaP,04. The best way to prevent the formation of such an oxyphos- phide appeared to me to act upon a solution of nickel.I therefore alternately added so much t'artaric acid to a solution of nickelous chloride that it was no longer precipitated by potash and acted upon this solution with phosphoretted hydrogen as described before. The precipitate obtained was purified in the same manner and different samples gave on analysis the following results :- SCHENK ON TETHANICKIZLOUS PHOSPHIDE. 215 I. 11. 111. \ Ni.. .. 76.76 73.97 80.46 79.85 P .... 19.38 19.17 18.76 18.25 96.14 93-14 99.22 98.10 The oxide of nickel obtained by fusion of the phosphide with a mixture of nitre and the carbonates of potassium and sodium was always dissolved in aqua regia and tested for phosphoric acid with ammonium molybdate.In 111 phosphoric acid was present in the nickelous oxide whilst none was found in I and 11. The atomic ratio of nickel and phosphorus in these Sam-ples was- I. 11. 111. 2.08 to 1 2.02 to 1 2.25 to 1and 2.3 to 1 These numbers did not leave much doubt that the substance was mainly a compound of the composition Ni4P2 which formula requires 79.19 per cent. of nickel and 20.80 per cent. phosphorus. But it was evident that the substance in some stage of its preparation underwent a partial oxidation. I then prepared a fresh sample and used for drying it a current of hydrogen instead of carbonic acid hoping that at all events any oxidation that might have taken place before would be undone by the heating in hydrogen. On ignition in hydrogen the substance changed its black to a dark greyish colonr diminished considerably in volume and became much harder.Three analyses gave the following results :-I. -1577 grams gave 0.1575 NiO and 0-11.55 MgZP207. 11. -188 9) 0.1873 , 0.1385 ,, 111. *116 -0.115 7, 7 9 These numbers agreeing with the following percentages :-The formula Ni4P2 I. 11. 111. requires Ni.. .. 78.57 78.43 -79.19 P .... 20.42 20-57 19.8 20-81 prove that the composition of the substances is indicated by the formula Ni,P,. This compound tetranickelom phosphide hua not been prepared before. In 111,I dissolved the substance as far as possible in aqua regia ; but as thc solution proceeded so slowly that ~116grams were not com- pletely dissolved after eight hours I added some sulphuric acid.I did not fear any loss of phosphorus on this account as Preese in his research on the phosphides of iron had observed that they were dis-Q2 SCHENK ON TETRANICKELOUS PHOSPHIDE. solved by sulphuric acid without any loss of phosphorus. The phos- phoric acid was then determined by the ammonium molybdake process. ASI worked with so small quantities of substance that a loss of 4 milligrams of magnesium pyrophosphate would involve a loss of 1per cent. of phosphorus the difference from the theoretical percentage of phosphorus is easily explained. This tetranickelous phosphide dissolves very sIowly in dilute hydro- chloric acid. Towards concentrated nitric acid it behaves like iron whilst it dissolves almost immediately in the dilute acid.In a mixture of hydrochloric and nitric acids it dissolves sometimes slowly some- times quickly as also in sulphuric acid. It is not magnetic. I never obtained a large quantity; in one case in which I had continued the treatment with phosphoretted hydrogen for an hour and a-half I obtained not more than 1.2 grams from 11grams of nickelous chloride. Afterwards on experimenting with hydrated phosphides of copper I found that the chief source of that oxidation which I had found so difficult to prevent was the water retained by the phosphides after having been dried at 100". The hydrogen of part of this water is set free at a higher temperature whilst the oxygen combines with the phosphide. Hoping that I should obtain a purer product by expelling this water at a lower temperature I dried a fresh sample first at loo" and then for about half-an-hour at 150" in a current of carbonic acid.The product contained 77.75 per cent. Ni and 18.22 per cent. of phosphorus and some water the quantity of which I did not determine. Here the atomic ratio of nickel and phosphorus was 2.2 to 1. This excess of nickel was due I believe to the fact that I had not treated the substance long enough with acid to extract other nickel compounds. I boiled the substance again with dilute hydrochloric acid and dried it as before at loo" then at 150" and then for a very short time gently over the flame. Then I obtained 78.30 per cent. of nickel and 19.8 per cent. of phosphorus. These numbers show at least the advantage of drying the substance as much as possible at a moderate temperature before driving out the last trace$ of the water. The method of preparing this compound is no doubt capable of certain improvements which for various reasons I have not been able to introduce in this case but I shall try several modifications as soon as I resume this research on metallic phosphides.

ISSN:0368-1769    

DOI:10.1039/JS8742700214

出版商:RSC    

年代:1874

数据来源: RSC

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217 ABSTRACTS OF CHEMICAL PAPERS PUBLISHED IN BRITISH AND FOREIGN JOURNALS. General and Physical Chemistry. On some Metallic Spectra (Lead Gold Chloride Thallium Lithium). Note by LECOQ (Compt. rend. DE BOISBAUDRAN lxxvii 1152-1154). Lead.-When the induction spark passes between two freshly cleaned poles of lead the spectral lines are all narrow but as oxidation pro- ceeds shaded bands appear. The following lines disappear during the oxidation ; the numbers given express wave-lengths in ninth-meters 'y 560.7 554.4 y 537.0. The next four become much fainter B 600.1 6520.1 438'6 424.5 ; the lines 416.7 and 300.3 are but little enfeebled and a 405.6 is not affected. The introduction of a condenser strengthens precisely those lines which are weakened by oxidation.Gold 0hZoride.-Using the induction spark with a solution of gold chloride the relative brightness of the narrow lines varies with con- centration of solution length of spark and direction of current. Both with gold chloride and platinum chloride a moderately strong solution yields a finer spectrum than a saturated solution. Thallium.-A new faint line of wave-length 568 is visible in a flame richly coloured with thallium but it could not be obtained by using the spark with a solution. Lithium.-By employing the spark with fused lithium carbonate the author has succeeded in observing the line 413 the existence of which he had predicted on theoretical grounds. M. J. S. Sensibility of Silver Bromide for the so-called Chemically Inactive Rays.By H. VOGEL (Deut. Chem. Ges. Ber. vi 1302-1306). THE author finds that dry silver bromide plates are sensitive to the rays of the spectrum two millimeters beyond D. Wet plates are very sensitive between G and F but show only a faint sensibility at E. By using a collodion prepared by dissolving corallin in alcohol dry silver bromide plates are rendered very sensitive to the indigo rays less so in the blue weakly sensitive at F but become again very sensi- tive in the yellow. On substituting aniline green as a collodion the plates become sensitive even to the red rays. It is thus shown that the optical absorptive powers of the admixed substance play an important part in the sensibility of photographic plates. M. M. P. M. 218 ABSTRACTS OF CHEMICAL PAPERS.Use of the Magic Lantern for Physico-Chemical Lecture Experiments. By H. VOGEL (Deut. Chem. Ges. Ber. vi 1345- 1347). THE author proposes to employ the magic lantern with a lime-light or petroleum lamp to exhibit photographs of apparatus &c. or wood-cuts on thin paper fastened to glass slides with photographic varnish. Changes of temperature produced by chemical reactions can also be conveniently shown by throwing the image of the stem of the thermo- meter on the screen. C. E. 0. On the Mode of Intervention of Water in Chemical Actions and on the Relations Existing between Amnity and Elec-tromotive Force. By M. BECQUEREL (Second Memoir) (Compt. rend. lxxvii 1130-1137). WHENsulphuric acid commuiiicates with water by a capillary orifice an electric current is produced (Corn,.rertd. lxxvi 1037). The electromotive force diminishes as the degree of hydration of the acid is increased. From S03.2H0 to S03.6H0the ratio between the electromotive force of any couple and the one next below it is 1.17 ; from SO3.6HO to S03.10H0 it is 1.05 and from this strength to SO3.2OH0the average ratio is 1.0128. The same is true of solutions of potash but the electromotive forces appear here to be nearly double those in the case of the acid. The ratios are practically the same in both cases and the curves representing the intensity of the electro- motive forces are hyperbolic. Also in the action of sulphuric acid on potash the electromotive forces and the ratios between them diminish the latter very slowly.The electromotive force due to the combination of SO3with KzO cannot apparently be deduced from these series of determinations since different terms yield results varying from 74.5 to 105.7. The cause of this difference is unknown. These electro-capillary currents appear to play an important pa'rt in the economy of organic nature since it is found that simply plugging the stem of a plant into distilled water is sufficient to generate a current in a wire completing the circuit. The water in every case becomes positive. The author gives the following summary of his results :-The mixture of two neutral saline solutions produces a series of hydrates by means of which double decomposition is carried on.The same takes place when acid and alkaline solutions are mixed the resulting electromotive force being increased by the direct reaction of the acid and alkali. The determination of the electromotive forces serves not only to compare the intensities of affinities but 60 follow the variations cor- responding to dilution with water. M. J. S. GENERAL AND PHYSICAL CHEMISTRY. Change in the Electromotive Force of Galvanic Couples by Heat. By AUGUST (Pogg. Ann. cxlix 394-399). VOLLER INCREASE of temperature within the range from 0" to looo causes an increase of electromotive force in the following couples :-(1.) Zinc and sulphuric acid about -05. (2.) Carbon and nitric acid not very considerable. (3.) Platinum and nitric acid equal to the increase in the case of No.1. (4.)Copper and sodium chloride considerable and continuous ; up to 78" about *17more than the value at 21". In the following couples increase of temperature causes a diminution of electromotive force. (1.) Zinc and zinc sulphate continuous ; up to 90" about -08 of the value which it had at the initial temperature 28". (2.) Zinc and sodium chloride continuous about the same amount as in No. 1. (3.) Copper and copper sulphate very considerable; up to 91" about -43 of the initial value at '22". (4.) Copper and zinc sulphate very considerable ; up to 80" about -33 of the initial value at 25". The author concludes that the chemical nature of the elements of a couple is not the exclusive determining cause of the increase or diminution of the electromotive force of that couple.With the exception of No. 4 in the first series all the liquids whose electro- motive force where they are in contact with zinc or copper is lessened by an increase of temperature are solutions of neutral salts ; while those liquids whose electromotive force under the same circumstances is raised are acids. M. M. P. M. Cooling Effects Produced by Capillarity in Connection with Evaporation. (Second Note.) By C. DECHARME (Abstract) (Compt. rend. lxxvii 1157). THEspray of a highly volatile liquid projected against a porous surface by means of a "vaporiser," produces an abundance of arborescent crystals which when melted yield nothing but pure water. Carbon sulphide chloroform rectified ether and ethyl bromide all yield this result.A jet of spray of either of these liquids directed against the bulb of a thermometer lowers the temperature from + 10" to -17" or -22" except chloroform which only depresses the temperature to -8". M. J. S. Specific Heat of Gases. By N. FLAWITZKY (Deut. Chem. Ges. Ber. vi 1207). THIScommunication refers to the relations between the specific heat of gases under constant volume and pressure their molecular weight the number of atoms in the molecule and the external work which ABSTRACTS OF CHEMICAL PAPERS. is performed by heat,ing a unit of weight of the gas one degree. These relations are developed from the law of Avogadro. W. A. T. Mechanical Explanation of the Maximum Density of Water.By YIARRONDE MONDESIR (Compt. rend. lxxvii 1154-1157). EACH molecule of wafer is supposed to contain four spherical atoms with their centres in one plane and the atoms rotating harmonically in that plane. This movement of rotation represents the latent heat of water and amounts to about 80 heat-units per kilogram. At 4"and above the planes tangent to the atoms are imagined to meet at right angles forming a prism with square horizontal section but below 4* the square is supposed to undergo orientation and become converted into a rhombus the sides of which are longer and the area greater than that of the square." At 0" the atoms in each molecule touch at five points and the rotation then ceasing the molecules become solid.Further the contraction of water by cooling is considered to affect only the volume of the atoms and to be uniform down to the freezing point. The coefficient of expansion is taken as 0.00046 for 1"C. The observed increase of volume on cooling from 4"to zero is therefore ob-tained on dividing the increased volume of the prism due to orientation by the hypothetical expansion of the atom when heated through 4". This would make the ratio of the volume at 0" to that at 4" equal to 1,00335. At. J. S. On the Change of Volume of Solid Bodies occasioned by the Formation of Chemical Compounds in the same state of Aggregation. By W. MUELLER (Pogg. Ann. cxlix 33-44). THEcontraction experienced by equal volumes of metals in their com- bination with the same percentage by weight either of oxygen or certain compound radicals as Sod C103 COs H202,Nos CrOa is con-sidered by the author as a measure of the chemical affinities satisfied as by arranging the metals in series according to this contraction he found that they followed each other either exactly or very nearly in the same order in which they would have to be placed for ofher reasons.R. S. On the Nature of Electrieity (conclusion). By E. E DLUND (Pogg. Ann. Erganzungsband vi 241-262). Description of a New Electrical Machine according to Holtz's Principle. By H. LEPSER (Pogg. Ann. cxlix 587). New Tangent-Compassand Rheocord. By F. C. G. MGLLER (Pogg. Ann. el 93-105). * It is impossible to make this clear without the diagrams accompanying the paper. INORGANIC CHEMISTRY. On the Action of Heat on Gravitating Masses. By W. CROOKES (Proc. Roy. Soc. xxii 37-42). On Temperature and the Measurement of Temperature. By G. REc KN AGE L (Pogg. Ann. Erganzungsband vi 2 75-302). On the Thermic and Mechanical Expansion of Solid Bodies. By A. KURZ(Pogg. Ann. Erganzungsband vi 314-318). A Quantitative Investigation of certain Relations between the Gaseous the Liquid and the Solid States of Water-Sub-stance. By JAMES (Proc. Roy. SOC.,xxii 27-36). THOMSON

ISSN:0368-1769    

DOI:10.1039/JS8742700217

出版商:RSC    

年代:1874

数据来源: RSC

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INORGANIC CHEMISTRY. Inorganic Chemistry. Mechanical Explanation of the varying Quantivalence of (Deut. Chem. Ges. Nitrogen Phosphorus &C. By WALTER Ber. vi 1402). THEatoms may be viewed as flat rotatory wheels (Drehecheiben) which are again made up of many small discs. If it be assumed that when three atoms of chlorine and one atom of phosphorus are asso- ciated the latter is in the centre of a plane triangle at the angles of which the chlorine atoms are placed so that these oscillate towards the phosphorus atom whilst this latter vibrates above and below the plane of the triangle it may be shown from the analytic equations that two more atoms of chlorine may be made to approach the upper and under halves of the phosphorus atom respectively without destroying the equilibrium of the arrangement.More than two chlorine atoms may also be thus introduced without destroying the equilibrium but the probability of such an introduction is very small. C. R.A. W. Note by the Abstractor.-The author’s view does not seem to account for those cases of varying quantivalence in which an artiad becomes a periasad or vice versd such as nitric oxide NO and ammonia NH3 or the chlorides of tungsten described by Roscoe. U. R. A. W. The Purification of Hydrogen Gas. By CH. VIOLETTE (Compt. rend. lxxvii 940-942). ITis generally stated that the hydrogen gas obtained by the action of sulphuric acid upon commercial zinc contains carbon hydrides and that the latter are not removed by the ordinary process of purifica-tion.Inasmuch as the accuracy of some experiments such as those of Frankland respecting the luminosity of hydrogen under pressure turns upon the purity of the gas employed the author thought it advisable to re-investigate the question. ABSTRACTS OF CHEMICAL PAPERS. The hydrogen purified by passing through lead nitrate silver sul-phate caustic potash and oil of vitriol was conducted over red-hot copper oxide; the water formed was condensed in a U-tube and the gaseous products were passed into baryta-water. In the first series of experiments the water produced had an acid reaction and the baryta-water was rendered turbid ; but as a similar result was obtained when pure electrolytic hydrogen was employed the phenomenon was closely investigated and found to be due to the presence of selenium in the copper oxide.The latter impurity having been eliminated a repetition of the experiment produced no opacity in the baryta water neither did the water generated of which at least 35 grams were obtained give any acid reaction. Hydrogen gas there- fore after proper purification may be considered to be free from any hydrides of carbon. J. W. Active Hydrogen and Oxygen. By R. Bo E TT GE R (Deut. Chem. Ges. Ber, vi 1396). A THIN palladium plate covered with palladium-black on both sides by means of a battery and charged with occluded hydrogen may be kept for weeks in alcohol or ether without losing the hydrogen saving that a few bubbles come off at first ;but if quickly removed dried and wrapped in gun-cotton it glows in a few seconds the gun-cotton explodes and the hydrogen burns for a few seconds with a pale flame.In ether the gas bubbles which come off seem to consist partly of ethylene formed by deoxidation. Potassium nitrate is soon reduced to nitrite by the charged palladium. Similarly the oxygen obtained from a mixture of potassium per- manganate and sulphuric acid is eminently active readily inflaming ethereal oils alcohol &c. &c. C. R. A. W. Relation of Ozone and Water to each other. By EM. SCHONE (Deut. Chem. Ges. Ber. vi 1208 and 1224-1230). THEchief aim of the author was to determine whether and in what way ozone acts upon water. The ozone used was prepared by the silent discharge wibh Babo’s apparatus and in a few cases with that of Houzeau.The oxygen was generally obtained by electrolysis and the greatest care was taken to free the water used from organic matter and the oxygen from nitrogen. Nitrogen is oxidised by ozone to nitric acid and it is owing to this fact that many chemists have obtained negative results in their experi- ments on the absorption of ozone by water. The following are the results obtained by the author:- (1.) Ozone does not oxidise water into peroxide of hydrogen. (2.) Ozone is absorbed by water in considerable quantity even at the ordinary temperature. The observed maximum was -0189gram or 8-81C.C. (reduced) ozone (0,)per litre. (3.) Ozone in contact with water suffers no qualitative alteration. INORGANIC CHEMISTRY.(4.) The quantity of ozone in ozonised oxygen is diminished by passing the gas through water. By collecting dry ozonised oxygen over water about one-fourth of the ozone is removed. By longer con- tact with water the loss of ozone is greater. (5.) Since in the passage of ozonised oxygen through water far more ozone disappears than is absorbed by the water during the time and as the loss of ozone contimies even when the water is saturated with it it would seem that water has in this case the power of break- ing up ozone. (6.) If ozonised oxygen is left at rest in contact with water at the ordinary temperature for some days it becomes changed into ordinary oxygen. (7.) The change of ozone into ordinary oxygen in the above manner is accompanied by an increase in volume This result accords with that obtained by heat in the researches of Andrews and Tait and by Soret.The author also noticed that after placing his hands in the water saturated with ozone they retained the peculiar smell of ozone for some time. Houzeau noticed the same thing with regard to flannel and other bodies. As regards the ozone-water of commerce the author has had no opportunity of investigating it himself; but concludes from the state- ments of Waldmann Bottger Rammelsberg and others that the substance in it which reacts on potassium iodide is not ozone. Ozone-water however can be prepared whether it will retain real ozone long enough to be used as a commercial article is not settled but the author is conducting experiments on the point.The absorption- coefficient for ozone given by Carius viz. a = ,635 for 1 to 2.5"; a = ,373 for 16.5" is too high. The supposition of Carius that rain-water absorbs ozone from the air is very doubtful since the presence of nitrogen would prevent it. A tabular arrangement of the author's experiments is added to the paper. G. T. A. Note on the Quantity of Ammonia contained in the Air at Different Heights. By P. TRUCHOT (Compt. rend. lsxvii 1159-1161). THE determinations were made at three altitudes ; at Clermont-Fer- rand 395 meters above the sea level; on the Puy-de-Dome at 1446 meters and on the summit of the Pic de Sancy at 1884meters. Two to five cubic meters of air were used for each determination.At Clermont-Ferrand the results varied from 0.93 to 2.79 milligrams per cubic meter the highest results being obtained on misty days and the lowest on clear days. The single determination made on the Puy-de-Dome on a bright day gave 3.18m.g. and the results obtained at the higher elevation were 5.55 m.g. on a day when the summit was covered with mist and 5-27 m.g. on a subsequent fine day. The general result appears there- ABSTRACTS OF CHEMICAL PAPERS. fore to be that the quantity increases with the elevation and is also greater in cloudy than in clear air. M. J. S. Absorption of Ammonia by Saline Solutions. By F. M. RAOULT (Compt. rend. lxvii 1078-1080). SALINE solutions may be divided into three classes according to their behaviour with ammonia (1.) Solutions decomposed by ammonia ; (2.) Those which deposit some of their dissolved salt ; (3.) Those unacted upon.The coefficient of absorption of ammonia by some members of this last class and by water alone has been determined. The results confirm those given in this Journal [l],xii 147. Potash sglutions dissolve less ammonia than water does and less the more they are concentrated. Thus at 16’ and 760 mm. pressure, 100 C.C. of water dissolve 60 grams of ammonia whereas 100 C.C. con-taining 2425 grams KzO dissolve only 30 grams of the gas and the same volume of a saturated solution of potash dissolves only one gram. Solutions of soda have the same coefficients as those of potash. Solu-tions of sodium nitrate and ammonium nitrate have the same coefficient as water.Dry sodium nitrate however absorbs no ammonia whereas dry ammonium nitrate dissolves a considerable quantity. Solutions of calcium nitrate dissolve more ammonia than water does. This is not due to the formation of a new compound for the residue left after evaporation to dryness at the ordinary temperature contains no ammonia. Neither is there any decomposing action on the salt ; for the absorption at different pressures follows Dalton’s law and the same amounts of heat are disengaged as with water. With those saline solutions the boiling point of which does not exceed 110” the following general law prevails :-The dayerenee between the coeficient of solubility of ammonia directly inwater and in solutions of the same salt of diferent strengths is proportional to the weight of salt contained in a constant volume measured before the gas is absorbed.B. J. G. Specific Heat of Diamond and Gmphite. By H. F. WEBER (Deut. Chem. Ges. Ber. vi 1188). THEfollowing values were found as the specific heats of graphite and diamond at 0” and 300” respectively:- 0”. 3oo‘. Graphite Diamond ........ ........ 0.17 0.10 0-35 0.28 The curves indicating the increase of specific heat with the temperatures approximate upwards and probably coincide at the point where diamond changes into graphite ; the values increase so rapidly that they soon pass the number 0.52 which would give the usual “atomic heat,” 6.3 ; whence it may be inferred that the atom of carbon splits up into INORGANIC CHEMISTRY.225 smaller quantities at high temperatures [this statement is a direct con-tradiction in terms C. R. A. W.] From Regnault's values for the specific heat of carbon dioxide (calculated under constant volume) the author calculates the following values for the specific heat of the carbon present by subtracting from the specific heat of the carbon dioxide that of the oxygen present ; the differences approximate closely to the specific heats of diamond at the same temperatures. Temperature. Carbon in carbon dioxide. Diamond. -10+ 57 0.0935 0-1692 0.0953 0.1579 158.6 0.2512 0-2391 The difference noticed between the numbers in the second and third columns may be ascribed to incipient dissociation.C. R. A. W. Reduction of Carbon Dioxide to Monoxide by Ferrous Phosphate. By E. N. HORSFORD (Deut. Chem. Ges. Ber. vi 1390). ANethereal solution of chlorophyll is separated by hydrochloric acid into a blue and a green layer the first of which contains iron lime and phosphoric acid i.e. the constituents of vivianite zinc and sul- phurous acid dest,roy the blue colour. That we are here on the track of the formation of leaf-colouring matter is indicated by the fact that carbon dioxide sealed up in a tube with ferrous phosphate is gradually decomposed carbon monoxide being formed in small quantities (about one-sixth after several days) the iron salt at the same time becoming blue. This action will likewise go on in the dark. C. R. A. W. Chlorides and Oxychlorides of Sulphur.By A. MICHAELIS (Ann.Chem. Pharm. clxx 1-42). IN this volume p. 20 the author's results are given in part. He believes tjhat a definite compound having the composition expressed by the formula CC14 actually exists because- 1. The product obtained by saturating the compound S2C12,with chlorine at -22" gives numbers closely agreeiag with those required by the above formula. 2. This product undergoes double decomposition and yields a definite and calculable amouzt of a definite chemical compound. When dry chlorine perfectly free from hydrochloric acid is passed through S,C& at Oo vapours of sulphur trioxide SO3 being simul- taneously passed into the liquid a reaction hkcs place the products of which are thionyl chloride and pyrosulphuryl chloride.The amounts of these products closely agree with those required by the equation-sc1 + s,o = SOCl + s205c12. ABSTRACTS OF CHEMICAL PAPERS. There is also produced a small quantity of sulphur dioxide probably resulting from the action of excess of SCl on SO3 thus-scl + so3 = SOCl + so + c1,. This is the more probable because there is always found a slight exces8 of SOCL over the calculated amount. The rationale of this reaction the author believes to be as follows :-A small quantity about 9 per cent. of sulphur tetrachloride is formed at O" and this is quickly acted upon by the sulphur trioxide in accordance with the first formula given above. A further quantity of sulphur tetrachloride is produced to be again transformed into the same products and so on.A similar action is supposed to occur when an inactive gas such as carbon dioxide is passed through sulphur tetrachloride. The product of this action at 0" is as Hiibner and Geuther have shown sulphur dichloride. The author has shown that at this temperature sulphur tetrachloride decomposes and that the liquid contains only about 9 per cent. of the true tetrachloride (see table at p. 20) ; the free chlorine is carried off by the carbon dioxide and whenever this is removed from the sphere of action a fresh quantity of the tetrachloride is decomposed and so on. The oxychloride of sulphur S203C14 (see p. 21) differs from all other oxychloridcs in that it yields phosgene gas when acted upon by carbon disulphide-7s,osc14 + 5cs2= 3cOcl2 + 2c0 + 6S02 + 7sZcl2+ 4sOc1,.The author considers that the existence of sulphur tetrachloride is a further proof of the quadrivalence of sulphur in most compounds. He admits that in some compounds sulphur must be regarded as sexvalent while in others it plays the part of a bivalent element. Which of these values is to be assigned to it in any particular com-pound must be fixed by a regard to the reactions both of formation and of decomposition which this compound uz7dergoes. The author gives a list of rational formula of the sulphur acids and some of their derivatives which appear to show their relationships very clearly but for these the original paper must be consulted. M. M. P. M. Sulphur Oxytetrachloride.By A. MICHAELIS and C. MATHIAS (Deut. Chem. Ges. Ber. vi 1452-1453). INa former paper (see page 21 of this Journal) it was shown that sulphur oxytetrachloride changes after long keeping into a yellow liquid. This liquid distils at 73" and is decomposed by water with formation of hydrochloric sulphuric and sulphurous acids. Analysis leads to the formula SZO3C1, which is identical with the empirical formula of the solid tetrachloride. The vapour-density is half of that calculated from the above formula. By distilling this liquid with sulphur trioxide the authors obtained INORUANIC CHEMISTRY. 227 pyrosulphuryl chloride (S2O5Cl,) and sulphuryl chloride (SOzC1z). AS thionyl chloride (SOCl,) is decomposed by sulphur trioxide with pro- duction of S205C1, while sulphonyl chloride is unacted upon under the same circumstances the authors conclude that the liquid consists of a mixture of equal molecules of thionyl chloride and sulphuryl chloride S,O,Cl = SOCI + SOZCI,.Sulphur oxytetrachloride is therefore in all probability a molecular combination which may exist either as a solid or a liquid. M. M. P. M. Rotatory Power of the Hyposulphates. By E. BICHAT (Compt. rend. lxxvii 1189-1191). INopposition to the observations of De Senarmont Pape has stated that the hyposulphates of potassium calcium strontium and lead exert a rotatory power upon a ray of polarised light ; moreover while the experiments of Rammelsberg and Gmelin tend to show that the crystals of potassium hyposulphate are biaxial and belong to the ortho- rhombic system Pape affirms that all of them are uniaxial and belong to the hexagonal system.The author has endeavoured to re- concile these conflicting opinions. He confirms the results of Pape as regards the rotatory action of the hyposulphates ; the rotmatory power of quartz being represented by 100 that of potassium hyposulphate = 40 lead hyposulphate = 24 strontium hyposulphate = 8. Healso shows that potassium hyposulphate belongs to the hexagonal system. Further experiments however proved that contrary to the results obtained by Pape and conformable with the general theory the crystals of potas-sium and lead hyposulphates are hemihedral and this latter quality is well known to be associated with and almost invariably accompanied by an action upon polarised light.J. w. Formation of Metallic Sulphides by Means of the Sulphides of Ammonium and the Alkali-metals. By E. PRIWOZNIK (Deut. Chem. Ges. Ber. vi 1291-1295). THE author confirms the results of Heumann (see page 1105 of last volume). He finds that when metallic copper is exposed for some time to the action of ammonium sulphide under a bell-jar small red spots are formed upon i$ which under the microscope appear to be groups of cinnabar-coloured needles. When exposed to the air .these crystals become brown and ultimately black in colour. Finely divided cupric oxide is also partially converted into this red body which is identical with that described by Peltzer and has the formula Cu,(NH,),S,.The corresponding potassium compound is produced by treating copper scales with a solution of potassium sulphide which has been saturated with sulphur when boiling. This substance when washed with petroleum spirit and dried over sulphuric acid forms glistening garnet-coloured crystals. Lead oxide when treated with yellow ammonium sulphide is slowly ABSTRACTS OF CHEMICAL PAPERS. converted into a crystalline sulphide ; under similar circumstances cadmium oxide is also converted into sulphide. Manganese sulphide is produced by treating manganous or manganic oxide with yellow ammonium sulphide but ferric oxide under the same conditions undergoes no change. M. XI. P. M. New Sulphur Salts. By R.SCHNEIDER (Pogg. Ann.cxlix 381-394). THEauthor has alreadyshown (this Journal [Z] ix,313) that the sodium in disodium-platinum sulphoplatinate-Na,S .Na,S .Pt"S.Pt"S) PtivSz-can be easily replaced by a bivalent metal; he now describes a salt in which the four sodium atoms are replaced by one quadrivalent pla- tinum atom. Platinurn sulphoplutinate PtivSz( Pt"S.Pt"S) PtivS2 is prepared by acting on disodium-platinum sulphoplatinate with excess of a dilute solution of sodio-platinic chloride ; this salt crystallises iu a form isomorphous with the disodio-platinum sulphoplatinate. The crystals are blackish-grey ; in dry air they slowly absorb oxygen sul- phuric acid being formed this decomposition proceeding more quickly in moist air. Heated in a dry tube the dry salt gives a sublimate of sulphur spongy platinum remaining in the tube Heated in excess of air the salt glows sulphur dioxide is given off followed by dense fumes of sulphuric acid and the residue consists of pure platinum.Acids even aqua regia have very little action on this substance. In the salts of the series X"S.X"S.X'S.X'S)ZivS2 (page 1197 of last volume) the author has succeeded in replacing platinum by iridium and sulphur by selenium ; no details are given Potmsium-ziwc Su&hide.-By fusing 1 part of zinc sulphide with 24 parts of potassium carbonate and 24 parts of sulphur at a full red heat for ten minutes a salt is formed which when washed with water appears as iridescent crystalline plates seemingly belonging to the rhombic system and giving numbers which closely agree with the for-mula KzS.3ZnS.This substance is unchanged in the air or 'when heated in a limited supply of air or hydrogen. Heated in excess of air the outer layer only is oxidized. The potassium sulphide cannot be dissolved out either by hot or cold water ; mineral acids very easily decompose the salt. The potassium -in this substance can easily be replaced by heavy metals producing the salts Ag2S.3ZnS by CuS.3ZnS &c. Sodium-zinc Sulphide.-This salt is prepared in a manner similar to that just described for the potassium salt sodium carbonate being used instead of potassium carbonate. When washed with a small quantity of water it forms a light flesh-coloured crystalline powder. Excess of water removes a great part of the sodium sulphide.The salt easily qxidizes in moist air. Sodium-cadmium Sulphide.-When 1 part of cadmium sulphide is fused with 12 parts dry sodium carbonate and 12 parts sulphur and the fused mass is treated with water a yellow crystalline powder remains insoluble. This salt is very difficult to purify ; water dissolves out the sodium INORGANIO CHEMISTRY. 229 sulphide while dilute alcohol does not entirely remove the sodium sul-phate which has been formed in the fusion. By indirect means the formula Na&.SCdS has been established for this salt. This substance is undecomposed when strongly heated in a stream of hydrogen in moist air it takes up oxygen forming sodium thiosulphate. M. M. P. M. Action of Ammonia on Peroxide of Silver.By R. BOETTGER (Deut. Chem. Ges. Ber. vi 1398). ELECTROLYT~Csilver peroxide when shaken with solution of ammonia evolves nitrogen and forms Berthollet's fulmindting dver which re- mains dissolved in the liquid; on evaporating this liquid in an iron spoon an explosion occurs and only a small quantity is left. If silver peroxide is brought in contact with oil of cloves deflagration ensues metallic silver being formed. C. R. A. W. Beryllium Pfatinochloride. By A. WEL KOw (Deut. Chem. Ges. Ber. vi 1288-1289). WHEN a dilute solntion of beryllium chloride and platinic chloride is slowly evaporated dark yellow eight-sided prisms crystallise out belonging to the quadratic system and consisting of BePtCls + 8H20. This salt is very hygroscopic and deliquesces in moist air; it is soluble in alcohol but not in ether.When heated to 100" it loses half of its water while the other half escapes only above 150°,hydro-chloric acid being given off at the same time. c. s. Relationship of the Magnetic Metals. By W. F. BARRETT (Phil. Mag. [4] xlvi 478-480). THEphysical relationship of the magnetic metals iron nickel and cobalt is shown in the accompanying table. Atomic Specific Atomic Substance. Densit,y. weight. heat. heat. By heat. By strain. ,Par heat. Sound. Iron.. .... 7.8 56.0 0-1138 6 *38 .0926 '0387 -168 15.3 Nickel .. . . 8.3 58.5 0.1091 6 -33 *Of399 *0394 *131 14-9 1 Cobalt.. .. 8-5 58.5 0.1070 6 '26 -0981 -0456 -172 14.2 --r-r- They likewise present a xemarkable similarity in many of their chemical properties.Both iron and nickel become passive when immersed in strong nitric acid; the action of the eoncentrated acid upon cobalt may with great probability be attributed to the large quantity of iron which it invariably contains. The protosalts of iron are bluish-green ;of nickel emerald-green ; VOL. XSVII. R ABSTRACTS OF CHEMICAL PAPERS. and of cobalt (when warmed) bright green ; the author associates the change of colour in cobalt salts with the fact that heat increases the magnetic power of-this metal. The association of cobalt and nickel in the native condition and of all three metals in meteoric iron is too well known to require further comment. J. W. Certain Remarkable Molecular Changes occurring in Iron wire at a LOW Red Heat.By W. F. BARRE'L'T (Phil. Mag. [4] xlvi 472-478). SOME years ago Mr. Gore noticed the fact that when an iron wire was heated to bright incandescence and then allowed to cool a momentary elongation of the wire occurred just after contraction had commenced. The same experimenter stated that the effect was perfectly uniform and always occurred at a particular temperruture and that no anoma-lous action was observed during the heating of the wire. He also showed that in the case of a heated iron bar a sudden increase to mag- netic capacity took place at a certain temperature during cooling. The author prosecutes the inquiry from this point. Twenty Grove's cells were found most suitable for bringing a moderately thick iron wire to the required t'emperature and the momentary elongation of the wire was amplified and observed either by means of an index attached to one extremity of the wire or by the use of a screen and small re- flecting mirror.With a hard iron or steel wire a movemeut in the reverse direction was ohtained during heating the momentary retrac-lion occurring as closely as could be judged at the same temperature at which the eZongation takes place in cooling. ExperirrierdaZ Results.-1. The scale being divided into 50 parts the index stood at zero the wire being cold. As the temperature of the latter rose the index passed to 24 retreated to 22 then passed on-wards steadily to 34 the wire being now hite-hot. On breaking contact with the batt>ery the index returned regularly to 20 then suddenly rose to 27 after which it continued its backward course till it finally rested at 2 the wire being again cold.2. Wire cold contact made ; index rose from 0 to 25 jerked back to 23 then rose to 33 ; wire bright red. 3. Wire bright red contact broken ; index fell from 33 to 19,jerked forward to 25 then fell to 4 ; wire cold. Similar results were uniformly obtained but the critical instant at which the momentary jerk occurred appeared to vary with the thick- ness of the wire. By operating in a darkened room it was observed that at :I certain moment during the cooling of the wire a sudden accession of tenipernture occurred so that it glowed once more with a bright-red heat ['his spontaneous reheating of the wire was ascer-tained to take place simultaneously with the momentary elongation and was proved to be an increase in thermal as well as in luminous radiation.A device for clearly exhibiting this latter phenomenon to an audience is described. The author does not offer any explanation of the above extraordinary lNORGANIC CHEMISTRY. phenomena but proposes to extend the investigation and to ascertain the behaviour of iron wires of different degrees of purity and to operate with cobalt and nickel wires; also t,o ascertain the precise magnetic condit,ion of the ironat the moment at which the jerk occurs together with its electric resistance and thermo-electric position. He alludes to Professor Tait's experiments in connection with the last question and points out the probability of an association between the foregoing facts and the anomalous thermo-electric deportment of iron at a high temperature.J. W. Affinity in Solutions of Ferric Chloride. By A. M~LLER (Pogg. Ann. ErgZnzungs-band vi 262-275). THEauthor finds that in a solution of ferric chloride 100 C.C. of which contain -02 of an atom of Fe203,10 per cent. of the chloride is converted into acetate by the action of acetic acid while in a solution containing twice the amount of ferric chloride 9 per cent;. only is converted into acetate. In a solution of ferric sulphate of the same strength as the ferric chloride just ment'ioned 18 per cent. of the iron is converted into acetate; it therefore follows that at medium temperatures in an aqueous solution hydrochloric acid possesses an affinity equal to twice that of sulphuric acid.It is only when the tension of hydrochloric acid is raised by an increase of temperature that sulphuric acid is able to drive it out of combination with its salts. The specific intensity of the colour of a ferric chloride solution is increased by the addition of acetic acid about +Gth part of the increase caused by the addition of hydrochloric acid. This action depends on the concentration of the liquid. This seems to correspond with the fact noted above that acetic acid converts double as much ferric chlo- ride into acetate in a dilute as in a strong solution. The author repeats his former statements with regard to the influ- ence of temperature and time upon the intensity of colour of ferric chloride solution (see page 847 of last volume).M. M. P. M. Action of Water on Lead Pipes. By BELGRAND (Compt. rend. lxxvii 1055-1062). No complaint of injury to health from the use of lead conduits for drinking wat'er was made till within the last few years although this metal was largely used in ancient and mediEva1 times for the purpose. It is estimated from official sources that the number of lead pipes used for drinking water in Paris is about 39,500. The mean length of each is forty meters. The longest time that water remains in the pipes is about nine hours. Le Blanc at the author's request made experiments in which ingots of lead weighing 25 grams each were im- mersed in 250 C.C.of water for a longer time than nine ho-urs. With distilled water white crystals of hydrated lead oxide were soon deposited. With eleven different kinds of water suppiied to Paris and R2 ABSTRACTS OF CHEMICAL PAPERS. the environs no action was exerted on the lead Even rain water unless it had been collected after prolonged showers whereby the air had been washed failed to act on lead. A very small amount of salt then will prevent lead from acting on water. Moreover the leaden mains upon being taken up are always found to be perfectly smooth and uncorroded. One specimen exhibited was 200 years old. A very slight adhering crust of apparently calcium carbonate coats the inte- rior preventing the lead from coming in contact with the water.Tinned lead pipes are equally unacted upon but are expensive and apt to contain obstructions from the fusion of the tin in soldering. B. J. G. Action of Air and Water upon Lead. By J. FORDOS (Compt. rend. lxxvii 1099-1102). THEauthor considers that the danger of lead poisoning by the use of pipes of that metal for conveying drinking water has been very much exaggerated. He thinks that the cleansing of wine and medicine bottles with lead shot and water to be a more likely source of harm. When a bottle containing lead shot and water is shaken the liquid rapidly becomes turbid aud deposits a white film of lead carbonate on the sides of t.he bottle. Several rinsings fail to remove this film which may contain in an ordinary medicine phial 5 milligrams of lead.White and red wine quinine wine and vinegar placed in bottles which had previously been rinsed several times after shaking up with shot and water were found to have dissolved some load. B. J. G. Action of Water on Lead. By J. DUMAS (Compt. rend. lxxvii 1054). THEauthor agrees with the views expressed in the last paper as to the probable bad effect of cleansing bottles with lead shot; but he considers the fear lest potable waters should dissolve lead from pipes to be perfectly groundless since the presence of an extremely small quantity of certain salts in the water is sufficient according to his ex- periments to prevent the solution of the metal B. J. G. Action of Water from the Seine and the Ourcq upon Lead. By J.FORDOS (Compt. rend. lxxvii llSS-llSS>. THE water used in the experiments above described was drawn from the 0urcq.X The following experiments have since been made:-Into a bottle holding 250 C.C. were introduced 50 grams of lead shot No. 4,and 100 C.C. of distilled water. In a similar bottle were placed the same quantity of shot and 100 C.C. of water from the Ourcq. Agitation was kept up for the same length of time in each case. The lead was attacked in both bottles though most * Water from this river was among those tried by Dumas and found by him to have no action on lead.-B. J. (3. INORGANIC CHEMISTRY. quickly in the first. With large shot the action was slower. With No. 10 or very small shot it was quicker. With shot which had been already employed in a similar experiment’ the action takes place sooner than with fresh shot.Seine water behaved exactly like water from the Ourcq. The film formed on the bottles contained lead lime and carbon dioxide. As a rule the water did not contain lead in solu- tion after the film had been formed. The author thinks the calcium bicarbonate is decomposed by the heat and electricity developed by the striking together of the shot. The carbon dioxide set free com- bines with the lead hydrate formed by the oxygen present. The two carbonates would be then precipitated. The deposit in leaden water pipes supposed by Belgrand (p. 231) to be simply calcium carbonate has a similar constitution to that of the films above described. Although water might pass through pipes after such a deposit had become fixed without carrying away lead in solution yet some of the lead carbonate might at its first formation be carried away in sus-pension.B. J. G. Action of Water on Lead and other Metals. By AD. BOB~ERRE (Compt. rend. lxxvii 1272). INSTANCES are given in support of the theory that the action of water on metals is greatly accelerated by the presence of air. When a ship’s sheeting is corroded the water-line is the part that suffers most. The rapid corrosion of a lead cistern which came under the author’s notice is traced to the fact that it was repeatedly emptied and then quickly refilled from a jet with a heavy fall of water. In another indance the interior of a leaden water-pipe was coated with lead carbonate.This is attributed to the presence of air in the many chambers formed by the numerous bends which the pipe took. When water containing magnesium chloride is distilled through metallic pipes its action upon them is greatly inkensified by the hydro- chloric acid given off. Such a water when distilled with excess of lime scarcely attacks the metallic condenser. The author’s experiments confirm the theory of Fordos (page 232) that the compound resulting from the action of water on lead is very often in suspension in the water. B. J. G. Action of Water on Lead Plates. By H. MARAIS (Compt. rend. lxxvii 1529). IFthin plates of lead be immersed in water containing bicarbonates lead carbonate is deposited in three days. If the water in the above experiment be saturated with carbon dioxide under pressure lead in dissolved to the extent of ,012 gram per litre. B. J G.

ISSN:0368-1769    

DOI:10.1039/JS8742700221

出版商:RSC    

年代:1874

数据来源: RSC

摘要:

ABSTRACTS OF CHEMICAL PAPERS. Mineralogic a1 Chemistry. Artificial Formation of Fluor Spar and Heavy Spar. By T. SCHEERER (J. pr. Chem. vii 63). and E. DRECHSEL WHEN pulverised fluor spar or amorphous calcium fluoride obtained by precipitation is fused in a platinum crucible with chloride of calciuni potassicm or sodium and the fused mass is left to cool very slowly crystallised calcium fluoride is obtained which may be separated from the soluble salts by boiling with water. It then remains in trhe form of regular octohedral crystals a few of which are isolated and perfectly formed while the greater number are joined end to end forming rectangular branches. But the cubic form which is that of natural fluor spar is not obtained in this way either alone or in combination with the octohedron.Such forms may however be produced by operating in the wet way namely by heating neutral calcium silicofluoride with solution of calcium chloride for several hours to 2<O0 in a sealed glass tube en- closed for safety within an iron tube. The tube is then found to be lined with microscopic crystals of calcium fluoride having the form of octohedrons more or less modified with cubical faces. The reaction by which they are formed is :-CaSiF + 2CaC1 + 2H20 = 3CaF2 + SiOz + 4HCl. Lastly calcium fluoride may be obtained in octoliedral crystals with- out any cubic modifications by heating the amorphous fluoride with water slightly acidulated with hydrochloric acid in a sealed tube to 240" for ten hours. Barium sulphate in spite of the extreme difficulty with which it dissolves in water exhibits a strong tendency to crystallise in the wet way all precipitates consisting of it appearing indeed either to be composed of microscopic crystals or at least to assume the microcrys- talline character after a short time.Somewhat larger crystals some- times united in groups may be obtained by mixing a very dilute solution of barium chloride with a slight excess of sulphuric acid and heating the mixture for twelve hours to 245". The frequent simultaneous occurrence of fluor spar and heavy spar in mineral veins renders it a matter of interest to imitate such com- binatioiis artificially. After several unsuccessful trials the desired result was obtained by the following method.A U-shaped glass tube having its middle limb proportionately long and wide was nearly filled with water and its end loosely stopped with plugs of filter-paper one enclosing a quantity of barium fluoride the other gypsum. These salts were consequently wetted by the water absorbed by the paper and slowly dissolved the resulting solutions of barium fluoride and calcium sulphate sinking through the water in the upright arms of the tube and coming together in the horizontal arm In the course of a week considerable quantities of crystals were deposited on the walls of the tube all however-in consequence of the inferior solubility of the MINERALOGICAL CHEMISTRY. barium fluoride-being situated considerably nearer to the end at which that salt was placed.They consisted partly of dendritic groups of small crystals like fir-branches obliquely joined and pointed not referrible to any monometric form-partly of tabular forms and among them wedge-shaped plates like those which are characteristic of certain varieties of heavy spar. All these three forms blended into one another and evidently belonged to the same substance. That this sub- stance was barium sulphate appears from the fact that unmistakeable crystals of fluor spar were formed at the same time. These latter were almost all in well-defined cubes some implanted on the heavy spar others separate or collected in groups in its neighbourhood. Examina-tion with the microscope showed numerous fir-like aggregations of wedge-shaped crystals of heavy spar with small cubes of fluor spar.Chemical analysis of this crystalline mixture showed also that it con-sisted of barium sulphate and calcinm fluoride. With regard to the various crystalline types of fluor spar the pre- ceding experiments show that slow formation at comparatively low temperatures favours the cubic form whilst quick formation at higher temperatures gives rise to octohedrons. H. W. Crystalline Form of Brookite. By A. SCHRAUF (Jahrbuch fur Mineralogie 1873 754). THISmineral hitherto regarded as rhombic appears from the author's recent investigations to be monoclinic with rhombic habit. This character explains the complete isomorphism of brookite with wolframite and as in the case of the latter several types of brookite may be dis- tinguished :-I.a b c = C.840269 1 1.0926735. Angle of inclined axes = 90" 35$'. To this type belong crystals from Tavistock and from Chamouni. Twins occur having the axis of combination perpendicular to the orthopinacoid. The crystals exhibit numerous faces the orthopinacoid predominating. 11. a b c = 0.84693 1 0.93795. Angle of inclined axes = 90' 39' 20". Crystals from Ulster; here also occur twins combined according to the preceding law. 111. a b c = 0.841419 1 0.943441. Angle of inclined axes = 90" 6 30". To this type belong most of the forms hitherto described as rhombic. Two twin-formations haye been recognised; one (from Wales) with the axes of rotation perpendicular to 00 Pcx,,the other (from Russia) with the axis of rotation perpendicular to OP.Schrauf distinguishes sixteen forms of brookite most of them ex- hibiting a great number of faces and likewise refers arkansite and eumannite to brookite. H. W. ABSTRAOTS OF CHEMTCAL PAPERS. Minerals found in the Neighbourhood of Waltsch in Bohemia. By BORICEY (Jahrbuch fur Mineralogie 1873 162). 1. Hyalite Arragonite ad Apatite.-The neighbourhood of Waltsch has long been known as a locality of fine hyalites (iv 204) and of fibrous and cauliform arragonite ; more recently apatite has been found associated with these minerals. The apatite and hyalite occur most frequently in druses the apatite forming the lowest layer ; then follow hyalite and apatite alternately ; and the uppermost layers are formed of hemispherical and botryo'idal concretions consisting of apatite and scales of liyalite or of an intimate mixture of the two minerals having an opalescent aspect.Hyalite also occurs in the basalt of Waltsch in scaly-fibrous forms which are pseudomorphs after apatite and in radial groups of needles which are pseudomorphs after arragonite. 2. Cornptonite,Phillipsite and Chabasite. -These minerals are found in drusy cavities of the leucite-nephelin basalt to the south-west of Waltsch. The comptonite occiirs in smal nearly colourless crystals exhibiting the usual combination co~m .coPco .cop with a very obtuse macrodome of 177" 35'. It forms thin yellowish- and greyish-white druses covered here and there with a very soft thin botryo'idal crust of stilpnosiderite mostly converted into limonite on which are im-planied small isolated crystals of phillipsite.These latter form int_ersecting twins with coincident principal axes of the combination co Pa. m&. P. Some of the drusy cavities of the basalt are lined with very small crystals of chabasite mostly intersecting twins of R. In the midst of them was found a single crystal of phillipsite covered with very small crystals of chabasite. The order of succession is therefore comptonite phillipsite chabasite. 3. 0steolite.-The solid basalts of Waltsch also contain plates of osteolite several inches thick which can be split into parallel layers. The substance of these plates which is white or yellowish has an earthy fracture and a specific gravity of 2.821 consists essentially of basic calcium phosphate mixed with a little calcium carbonate and is doubtless a product of the decomposition of the apatite contained in the basalt.4. Phosphates of the Basaltic Tzfa.-This tufa is very rich in calcium phospFte which occurs mixed with carbonate partly in greyish- greenish- or yellowish-white porous he-grained earthy masses ha- versing the tufa in beds and veins from a few inches to more than a foot in thickness partly in detached compact nodules of flesh-red reddish-white or yellowish-white colour smoot,h on the surface unc- tuous to the touch on the fractured surface adhering to the tongue and giving a strong reaction of phosphoric acid. Hardness of the nodules = 2-3.Specific gravity of the flesh-red fragments =2.7497 of the reddish-white =2.990. Analysis gave a for the light-coloured b for the flesh-red fragments :- MINERALOGICAL CHEMISTRY. 237 P205. CaO. MgO. Al2O3 Fe203. Insol. residue. Loss byignition. Undetermined matter. a... . . 34.09 52.13 1.23 0.54e 0.83 4.64 6.54 = 100 6.. . .. 29.49 43.70 - 3.90 9-74 ’7.66 5.51 = 100 H. W. Analysis of a Mineral from Orawicza. By J. V. JANOVSKY (Deut. Chem. Ges. Ber. vi 1454-58). THEmineral was covered with a crust of vesuvianite ; after removing this it appeared to be a green olivine-like substance infusible before the blowpipe flame. Sp. gr. = 2.997. The mineral contains in 100 parts-Loss by SiO% A120,. Fe203. FeO. CaO. MgO. ignition. 32.39 18.53 1.25 3.61 37.65 6.69 0.51 = 100.63 The oxygen proportion is 6 3 5 which leads to the formula WSi05 + RsSi209 according to which the mineral must be regarded as composed of a trisilicate and a two-fifths silicate.It is therefore a gehlenitc. The thin crust of vesuvianite had the following composition :-SiOz. A1203. Fe203. FeO. CaO. MgO. H2O. H20. 36-31 23.36 2.99 0.51 25.32 5.19 3.35 2.12 = 99.15 The oxygen proportion is 2 1 1 leading to the formula- R~%zS~~O,82Si3012 + 3(R2Si0,) = Rammelsberg’s general formula for vesuvianite is H.R,W,Si ; the formula which may be deduced for this specimen is H.R6&Si6. On the outside of the gehlenite is an amorphous granite-coloured Crust which analysis shows to be an aluminium silicate containing calcium and magnesium carbonates.Eliminating the lime and mag- nesia the formula of this substance is as follows :-+A1 >*Si,O, + 1OAq. $Fe M. M. P. M. Analysis of a Greenland Mineral. By J. V.JANOVSKT (Deut. Chem. Ges. Ber. vi 1453-54). THEmineral is a triclinic felspar ; it is colourless but mingled with small green needles. The powdered mineral is with difficulty attacked by sulphuric or hydrochloric acid. Before the blowpipe it melts only at the edges. Sp. gr. = 2.638. me analysis 1s as follows:- ABSTRACTS OF CHEMICAL PAPERS. Oxygen. Silica ............ 57.63 - 30.74 Alumina .......... Iron oxide ........ 24.32 3.92 12.51 Calcium oxide ..... 7-65 2.186 Magnesium oxide .. Potassium oxide. ... 0.68 4.03 0.684 Sodium oxide ......2.41 Loss by ignition .... 0.12 From the relative proportion of oxygen 7 :3 :1,the author concludes that the mineral is a labradorite. The proportion of potassium to sodium is 2 :1; in labradorite this proportion is generally 1 1. M. M. P. M Some Minerals from the Bismuth Lode of Meymac. By AD.CARNOT (Bull. SOC. Chim. [2],xx 487). THE author a mining engineer enumerates several interesting minerals occurring in the new bismuth lode situated near Meymac Department of the CorrBze. Native bismudh and bismuth sulphide the latter having a fibrous texture and blue-black colour. Bismuth oxide or hydrocarbonate resulting from the alteration of the sulphide and preserving the same fibrous structure. Antimonial bismuth mispickel lead carbonate and sulphate.Lead molybdate in small tabular crystals and woZfram containing a large quantity of tantalic acid. CaZcium tungstatcz in lamellar masses ; also hydyated tungstic acid containing variable proportions of the calcium salt the latter having suffered decomposition by the vitriolic solutions resulting from the alteration of pyrites. The results of analyses of the above minerals will be shortly com- municated. J. W. Study of the Carboniferous Deposits of the Basin of the Donetz and of Toula (Russia). By A. Sc H E u R E R-KE sTN E R and CH. MIGUNIER (Compt. rend. lxxvii 1385-1387). DOLLFUS THE carboniferous deposits of Russia in the neighbourhood of the Donetz basin are very extensive and have been recently explored.They are of exceptional purity leaving on combustion only 2 or 3 per cent. of ash. In estimating the heat of combustion of these and of other specimens of coal the authors remark that the numbers obtained are generally higher than those obtained according to the law of Dulong; while lignites invariably give numbers inferior to the results of calculation. They append the experimental figures calculated on the pure combus-tible material. MINERALOGICAL CHEMISTRY. Oxygen and Carbon. Hydrogen. nitrogen. 1. Grouchesski anthracite .... 96-66 1.35 1-99 2. Mioncki coal ............ 91-45 4.5 4-05 3. Galoubosski coal. ......... 82-67 5.07 12.26 4. Toula lignite ............ 73.72 6.09 20.19 Calculated by Calculated Heat Crude Calculated summing the heat according to the of combustion.material. On of combination law pure material. of the elements. of Dulong. 1.............. 7855 8259 8277 8190 2. ............. 8546 8695 8946 8773 3.. ............ 7505 8021 8434 7904 4.............. 5794 7687 8063 7191 I ~~ These experiments show that it is impossible to calculate the value of combustible from a mere knowledge of its elementary composition. A comparison between Ronchamp (France) and Mioucki coal proves that while their percentage composition is nearly iden tical the differ- ence in their calorific power is 450 heat-units or 5 per cent. The explanation appears to reside in the difference of their proximate com- position. J. W. Observations on the Structure of Meteoric Iron.By J. LAWRENCE (Compt. rend. lxxvii 1193). SMITH A MASS of meteoric iron which was found beneath the surface of the ground and from its appearance had doubtless remained embedded for a long time gave the following parcentage composition :-Fe. Ni. co. P. cu. 87.02 12-29 0.65 0.02 trace = 99.98 Its weight was 4 kilograms; specific gravity 7.821. A polished surface treated with nitric acid 01’ bromine-water gave no indication of the Widmansttittian figures which are SO characteristic of meteoric iron. In explanation of this latter circumstance the author states that when in meteorites the percentage of nickel is large the above- mentioned figures are very fkequently absent and in confirmation enumerates several specimens averaging from 15 to 60 per cent.of nickel ill which these circumstances obtain. It is not however asserted that such is universally the case. It is well known that in the solidification and crystallisation of iron containing foreign matter there is a tendency to eliminate more or less completely the foreign constituents towards the exterior of the crystals SO that in those cases in which the substance becomes an agglomeration of crystals it is chiefly between the faces of‘the latter that the foreign constituents are foulld mixed of course and often combined with the predominating material. The graphite eliminated from cast-iron is a case in point. ABSTRACT6 OF CHEMICAL PAPERS. Applying this reasoning to the case of meteoriciron the author shows in the first place that phosphorus (or sulphur) is almost invariably present; that subsequently during the cooling of the mass there has been a tendency to eliminate the phosphorus to the boundaries of the crystals in the manner above mentioned ; that the homogeneity of the mass being thus destroyed its different parts become differently sensible to the action of chemical reagents and that in this manner the mottling of the surface along the lines of crystallisation is produced which is known by the name of the Widmanstattian figures.Several remark- able instances of this elimination of sulphur and phosphorus have been observed. The author possesses a specimen in which an oval cavity of about 2.5 c.m. diameter exists. The interior of this cavity is filled with troilite (iron sulphide) to within a millimeter or so of the surface ;and between the exterior surface of the troilite and that of the interior of the cavity is a thin layer of schreibersite (Ni2Fe4P) containing scarcely a trace of sulphur.In other places also layers of the same phosphide of greater OF less thickness are found ; under these circumstances the general substance of the iron contains scarcely a vestige of sulphur or phosphorus. The author likewise states that in two instances he bas found solid ferrous chloride in the interior of a meteorite and that he has no doubt but that the chloride existed as an original constituent of the meteorite. J. W. The Eruptive Rocks of Styria. By R. v. DRASCHE (Jahrbuch fur Mineralogie 1873 768-772). The Quartziferous Andesites of Transylvania and Hungary. By C. DOELTER (Ibid. 772-774). (Ibid., The Gneiss and Granite of the Alps. By B. STUDA 774).

ISSN:0368-1769    

DOI:10.1039/JS8742700234

出版商:RSC    

年代:1874

数据来源: RSC