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JOEINSON ON CERTAIN POLSIODIDES. 183 XXI.--On certain Polyiodides. By GEORGE STILLINGFLEET JOHKSON, Daniel1 Scholar of King’s College, London. IN December, 1876, I read to the Chemical Society a paper in which I described the compound now known as triiodide of potassium. The graphic formula for this body, on the assumption that iodine is triatomic, may be thus represented, if its formula be taken as KIJ :- I K--I(JI I P 2184 JOHNSON ON CERTAIN POLYIODIDES. But, inasmuch as the compound HgI, is well known, it occurred to me that the triiodide of potassium might perhaps be more correctly repre- sented as dipotassic hexiodide, with the formula &I6. In this case its graphic formula would be written thus :- 1-1 ‘1-1’ K-IL---LI-K Now, if K216 be the true formula for the salt, it is evident that substi- tution-compounds might be obtained by displacing one atom of potas- sium with one atom of some other monatomic element, or perhaps of two atoms of potassium in KJI2 by one atom of a diatomic element. With the view then to prepare some such substitution-compounds, I made the investigation whose results are now recorded.The metal silver was first selected, as being monatomic, and having an iodide freely soluble in strong solutions of potassic iodide. My first attempt was to make a solution containing silver, potas- sium, and iodine in the proportions required by the formula AgKI,. The iodides of silver and potassium were readily dissolved in the pro- portions indicated, and the boiling aqueous solution prevented from depositing crystals on cooling by the addition of a little alcohol; but, long before the required amount of free iodine had been dissolved, a large quantity of the silver was always precipitated as AgI, and this precipitate could only be dissolved by a further addition of potassic iodide.Moreover, the constituents of AgKI, could not be brought into solution together by first mixing them in the dry state, and then stirring with a small quantity of water. Iodides of silver and potassium and free iodine were next dissolved in proportion to form AgKJ,,. All the constituents were easily dis- solved in a small quantity of water by the aid of heat, and nothing separated out on cooling. When t,his solution was allowed to eva,po- rate slowly over sulphuric acid, crystals of argento- potassic iodide, slightly coloured by free iodine, first separated, next crystals of potas- sium triiodide, slightly contnminated with silver iodide, and, finally, crystals containing from 10 to 1 2 per cent.of argentic iodide and 53 per cent. of iodine, which was set free as vapour by the application of a gentle heat. The formula indicated by the analysis of these crystals is AgK3112.KI, which requires 12.27 per cent. of argentic iodide, 3&69 per cent. of pofassic iodide, and 53.04 per cent. of iodine in excess over that contained in KI and AgI. Accordingly, a solution was made containing the above ingredients in the proportions men- tioned. No argento-potassic iodide or potassium triiodide separated from this solution on evaporation; but three sets of crystals were removed from it, all having the same composition.The results of analysis are as follows :-JOHNSON ON CERTAIN POLYIODIDES. 185 Analysis of Crystals I1 :- The iodin,e, in excess of that contained in HI and AgI, was de- termined by titration with it standard solution of hyposulphite (thio- sulphate) of soda, starch being used as an indicator. (a.) 0.292 gram required 11.7 C.C. of hyposulphite solution, of This represents 0.14859 gram iodine, or 50.88 per cent. (b.) 0.345 gram required 13% C.C. of the above hypo-solution, equi- Analysis of Crystals I11 :- (n.) 0.515 gram required 21.45 C.C. of hyposulphite solution, of This number is equivalent to 0.259974 gram iodine, or 50.67 per (b.) 0.467 gram required 19-55 C.C. of the above solution of hypo, The mean of these nnmbers gives 50.77 per cent.of iodine in excess over KI and AgI. In order to determine the silver iodide, a weighed portion of the compound was treated with a slight excess of solution of sulphurous acid gas, the yellowish liquid thus formed diluted freely with water, and the argentic iodide allowed to settle, collected on a weighed filter, washed, and weighed. (a,) 2.001 grams (Crystals 11) yielded 0.234 gram AgI, or 11.694 ( b . ) 2.783 grams (Crystals 111) gave 0.324 gram AgI, or 11.642 per The mean of these numbers is 11.668 per cent. The potassium in the compound was estimated as sulphate. h weighed portion of the crystals was treated with sulphurous acid in excess, and the whole of the iodine precipitated by nitrate of silver. The argentic iodide was next removed by filtration, and excess of silver separated from the filtrate by hydrochloric acid and a second tiltration.The clear liquid thus obtained was evaporated to a small bulk, mixed with dilute sulphuric acid, and evaporated to dryness. The residue thus obtained was treated with carbonate of ammonia, and ignited till its weight was constant. (n.) 3.718 grams (Crystals 11) gave 0.642 gram K2S04, equivalent ( b . ) 2.944 grams (Crystals 111) gave 0.511 gram K2S04 = which 1 C.C. is equivalent to 0.0127 gram iodine. valent to 0.17526 gram iodine, or 50.8 per cent. which 1 C.C. = 0.01212 gram iodine. cent. equivalent to 0.236946 gram iodine, or 50.73 per cent. The results were as follows :- per cent. cent. to 0.288193 gram K, or 7.75 per cent.0.2293879 gram K, or 7.79 per cent.186 JOHNSON ON CERTAIN PGLYIODIDES. The mean of these numbers gives 7.77 per cent. potassium. The t o l d iodine contained in the salt was ascertained by addition of solu- tion of sulphurous acid in excess, and precipitation by nitrate of silver, the argentic iodide being collected on a weighed filter, washed, and weighed. (n.) 5.123 grams (Crystals 11) gave 7.812 grams of argentic iodide, (6.) 2.783 grams (Crystals 111) gave 4.239 grams AgI = 2.291 The mean of these numbers gives 82.36 per cent. of iodine. The wuter present was determined by deducting the amount of iodine in excess oyer KI and AgI, as determined by titration with hyposulphite, from the total loss which the crystals underwent when gently heated. The compound loses about half its water by efflorescence when dried over sulphuric acid, but may be dried without loss of water over chloride of calcium.(a.) 2.307 grams lost 1.266 grams by heat = 54.87 per cent., which (b.) 2.555 grams lost 1.405 grams by heat = 54.99 per cent., leaving The mean of the above numbers gives 4.27 per cent. H20. The formula of the potassio-argentic polyiodide determined from the above analyses is- The results are as follow :- equivalent to 4.222 grams iodine, or 82.41 per cent. grams I, or 82-32 per cent. leaves 4.21 per cent. H,O. 4-33 per cent. H20. AgKJl2.KI + 5HzO. The concordance between the results of analysis and the require- ments of the formula will be seen in the following table :- AgKJ~2.KI.5H20. Theory. Found. 82.33 7.8 82.41 82.36 { 82.32 7.77( i:;: Iodine (total).. . . . . . . Potassium .. . . . . . . . . - - 99.99 99.76JOHNSON ON CERTAIN POLTIODIDES. 187 Theory. Found. 50.88 starch) ........... Iodine (free to act upon 50.73 Mean of two K KI 33*13 33*007{ determinations. 11.694 AgI ................ 11.72 11,668 { 11.642 ................ H,O ................ 4-48 4-27 { 2::; 7 - 99-99 99.715 Though this salt, is efflorescent when placed over strong sulphuric acid, it nevertheless deliquesces in the air. A small quantity of water dissolves it entirely, and it may be recrystallised from this solution by evaporation over sulphuric acid. The crystals occur in groups with a stepped arrangement ; are almost black, wifh a peculiar lustre, and are very deliquescent. When treated with excess of water, iodine and argentic iodide are separated, whilst potassic iodide and some free iodine remain in solution.The formula of the above compound might be written thus: AgK16.K216.Kl,5H20, if we assume that the formula of the periodide of potassium is K216 ; one atom of potassium in KJ, being displaced by one atom of silver; or the formula might be written thus, 4K13.AgI.5H20, on the assumption that the salt is a moZecular compound. Seeing the close analogy between the metals potassium and thallium as regards their behaviour with iodine, each forming two iodides, in which the iodine appears to be of different atomicity, viz. :- TI1 corresponding with KI and TlJ, ,, ,> K216, though, if the formule of the lower iodides be doubled, they, too, may be graphically represented, on the assumption that I is triatornic, thus :- K--I=I-K.My next endeavour was to produce a compound between the perio- dides of thallium and potassium, having some such formula as KzT12112 : in this, however, I was not successful, the only compound of potassium, thallium, and iodine, which appears to have a definite nature, being one which was discovered by Willm (Jahresb., 1864, 251). I reproduced this salt and analysed it, but the results of my analysis point to a somewhat simpler formula than that proposed by188 JOHNSON ON CERTAIN POLPIODIDES. Rammelsberg (Pogg. Ann., cxlvi, 592), viz., 3KI.2TlT3 + 3H20, whilst they have led me to adopt t8he same formula as the discoverer, viz., T1T3.KI, except that I believe the salt to contain two niolecules of water of crystallisation, my formula standing thus :- K13.TlI + 2H,O.The iodine in excess of that present as T1I and KT, and the waktcr of crystallisation, were determined by the application of a gentle heat to a known weight of the crystals, and by weighing the residual iodides of potassium and thallium. (u.) 1.692 grams of the dried crystals lost 0.625 gram, or 36.93 per (6.) 0.6475 gram lost 0.2385 gram, or 36.83 per cent. ( c . ) 2.8515 grams lost 1.052 grams, or 36.89 per cent. The mean of the above determinations is 36-883 per cent. The tl~allious iodide was estimated by washing the yellow mass, left after igniting the crystals, with boiling water upon a weighed filter, drying at 100" C., and weighing the residual iodide of thallium. (a,) 0.6475 gram of the dry crystals gave 0.271 gram TlI, or 41-85 ( b .) 1.872 gram gave 0-193 gram TlI, or 42.3 per cent. Mean 42.105 per cent. Discrepancy due to sparing solubility of the thallious iodide. The following analysis was made with a view to discover the relativo proportions of potassium and thallium in the salt. The iodides Gf these two metals, left after igniting a known weight of the dried crystals, having been accurately weighed, were converted into sulphates by evaporating to dryness, after the addition of excess of dilute sulphuric acid ; and the weight of the mixed sulphates was noted. 2.8515 grams of the dry salt gave 1.7995 grams of iodides of potassium and thallium after ignition. The weight of mixed sulphates obtained from these iodides was 1.228 grams. Now if the formula of the salt be, as I believe it is, K13.TlI + 2H20, or K21G.2T11 + 4H20, the above quantity of it would yield 1-226 grams of sulphates of thallium and potassium.The thallium was precipitated from the aqueous solntion of these mixed sulphates as basic chromate (Tl,Cr04), by the addition of solu- tion of bichrorntlte of potash and a slight excess of ammonia, and the chromate of thallium was collected and weighed. 0:937 gram of Tl,CrO, was thus obtained, which corresponds with 0.7288 gram of thallium, or 25-55 per cent. The formula requires 25.91 per cent. ; but this discrepancy is accounted for by the sparing solubility of the basic chromate of thallium. The results are as f o l h :- cent . per cent. The formula, K2Ts.2T11 + 4H20 requires-JOHNSON ON CERTAIN POLPIODIDES.Theory. Found. T -I- ROO . - - - - - - 189 Of course there is no proof that the composition of the above salt is not T1,1a.2KI + 4H@, for whether t,hallious iodide be dissolved in solution of potassium triiodide or thallic iodide (TlI,) in solution of potassic iodide, the crystals which separate have the same form and composition, the only point worthy of notice being that the former solution is effected much more readily than the latter; but it seems clear that one of these two formula: must be accepted in preference to those of Willm and Rammelsberg. Before the isolation of potassium triiodide, Pif f a r d (Zeitschr. Chew. T’harm., 1861, 151) supposed that the solution of iodine in aqueous pot,assium iodide contained a definite periodide, because it gave a dark- coloured precipitate with a solution of acetate of lead, which pre- cipitate, according to him, did not part with ioc?ine to solvents. On the other hand, Dosios a.Weith (Zeitsch. f. Chem., 1869,379) found that this dark precipitate did give up iodine to solvents, and hence regarded it as PbI,, mixed with free iodine, but did not analyse it. I obtained the above precipitate, collected it;, washed it, and pressed it between blotting-paper. When dry, it appeared as a dark purple powder, which certainly imparted a purple tinge to carbon disulphide ; but it seemed to me more important that it was constantly decom- posed by washing, for lead could always be found in the washings, and its composition was variable. (See Watts’ Diet., 2nd Sup., p.677.) It occurred to me, however, to employ a different solvent, viz., alcohol in the preparation of this compound. Accordingly I made a saturated solution of sugar of lead in boiling alcohol, and added it whilst hot to a strong alcoholic solution of potassium triiodide ; a very slight precipitate (PbI,) separated at once; the hot liquid was rapidly filtered, and deposited on cooling a number of small but. well-formed cry st als . The salt thus formed is permanent in the air, i.e., it is not in the least deliquescent. It may be kept indefinitely in well-stoppered bottles without change, but it evolves the odour of iodine, and, if ex- posed, very gradually loses its lustre. The crystals appear to be square prisms, or elongated cubes, and are usually aggregated in clumps.By recrystallisation from hot alcohol, however, and gradual evaporation of the mother-liquor over sulphuric acid, I succeeded in obtaining some fairly large isolated crystals. Each crystal has six190 JOHXSON ON CERTAIN POLYIODIDES. faces, of which two (always opposite one another) have a dark purple reflection, whilst the remaining four reflect a greenish-golden light ; they appear t o be dichroic. The lustre is almost metallic ; the crystals yield a dark-brown powder. When the crystals are dropped into water, they undergo no change in form, but the water is coloured faintly brown, just as it would be by free iodine ; whilst the crystal loses its lustre and acquires a dull brownish appearance. The salt may be entirely, though slowly, dissolved in cold saturated solution of potassic iodide, ammonic chloride, or ammonic acetate.It also dis- solves gradually in cold aqueous alcohol, but more readily in hot alcohol, from which it may be recrystallised easily. The spec@ gravity of the compound could only be approximately a'scertained, since no liquid could be found which was quite without action on the salt, By weighing in dilute sulphuric acid, which gave it a protecting coating, consisting chiefly of iodine and PbSOa, the number 3.084 was obtained. The formula of the salt is somewhat complicated, as will be seen from the following results. The elements present are Pb, C, H, 0, I(, and I. The Zead was determined as snlphate. (a.) 1.5408 grams of the dry crystals, treated with excess of sul- phuric acid, evaporated to dryness, gave a residue which (after being digested with boiling water for some hours, washed with boiling water, and dried on a weighed filter at 100" C.) weighed 0.750 gram.This is equivalent to 48.67 per cent. PbSOa, or 33.249 per cent. Pb. ( b . ) 0.7915 gram, dissolved in alcohol and water, diluted and pre- cipitated with solution of sulphurous acid, the precipitate being washed and weighed as before, gave 0.384 gram of PbS04, or 48.51 per cent., equivalent to 33.14 per cent. Pb. The carbon was estimated as CO, by combustion with chromate of lead, the hgdrogen being collected and weighed as water at the same time ; rolled copper wire was employed to collect the vapour of iodine, which was plentifully evolved during the combustion with chromate of lead.(a.) 0.5585 gram of the powdered salt gave 0.057 gram H,O, and 0.176 gram COz, equivalent to 0.0063 gram hydrogen and 0,048 gram carbon, or 1.112 per cent. hydrogen and 8.59 per cent. of carbon. (b.) 1.673 grams gave 0.176 gram water, and 0.532 gave COz, equivalent to 0.01844 gram hydrogen and 0.14509 gram carbon, or 1.1 per cent. of hydrogen and 8-67' per cent. of carbon. The powdered salt was mixed with pure oxide of copper and ignited, first gently, then strongly, till fumes of iodine ceased to be evolved. The resulting mass was digested in boiling water f o r many hours ; and the turbid liquid The potassium was determined as sulp($ate.JOHNSON ON CERTAIN POLYIODIDES. 191 thus obtained was filtered and evaporated to dryness after the addition of sulphuric acid, bisulphate being converted into neutral sulphate by igniting the residue with ammonic carbonate.(a.) 3.3815 grams of the powdered salt yielded 0.35 gram. KzSOa = 10.35 per cent,, or 4.646 per cent. of potassium. (6.) 2.307 grams of the recrystallised powdered salt gave 0.241 gram R2S04, equivalent to 10.446 per cent. of sulphate of potash, or 4.69 per cent. of potassium. The totaZ iodine present was ascertained by mixing a known weight of the dry crystals with excess of a solution of pure ferric chloride, free from CI and HK03 (prepared by passing chlorine over red-hot iron filings), and submitting the mixture to distillation, the iodine being retained in a solution of potassic iodide, which was afterwards titrated with a standard solution of sodic hyposulphite, starch being used as an indicator.(a.) 1.6908 gram Pb-salt gave a solution of I inKI, which required 54.5 C.C. of a solution of hyposulphite, of which 1 C.C. was equivalent to 0.1343 gram iodine. Hence 0.731635 gram iodine had sublimed over, or the compound contains 43.28 per cent. ( 6 . ) 0.57 gram gave a solution which required 18.45 C.C. of the above hypo-solution, equivalent to 0.2477835 gram iodine, or 43.47 per cent. The iodine contained in the salt, which was free to act upon starch, was estimated by dissolving known weights of the dry crystals in strong cold solution of acetate of ammonium, and titrating with standard hyposulphite. (a,) 0.5397 gram, dissolved in aqueous acetate of ammonia, required 10.2 C.C. of hyposulphite solution, of which 1 C.C. = 0,01343 gram iodine. This is equivalent to 0.136986 gram iodine, or 25.38 per cent. ( b . ) 0.2442 gram required 4.65 C.C. = 0.0624495 gram iodine, or 25.57 per cent. Sulphates of Potassium and Lead. The potassium and lead contained in the salt were determined toge- ther by first gently igniting n known weight of the crystals, to expel the iodine in excess over PbI, and KI, and to diminish subsequent loss by spirting; and afterwards adding excess of dilute sulphuric acid and evaporating to dryness, the residue being carefully weighed. (a.) 0.531 gram gave 0.316 gram of mixed sulphates, or 59.51 per cent. ( b . ) 0.789 gram gave 0.469 gram of mixed sulphates, or 59.44 per cent.192 MUIR ON CERTAIX BISMUTH COMPOUNDS. The mean of the determination of K and Pb separately requires The empirical formula deduced from these analyses is 58.987 per cent. Pb!3C36H54O?8K6I17. Pbe = 1656 Required. Found. 33.249 33,229 33.195 { 33.14 C36 = 432 8.669 8.630 { :::: H54 = 54 1.083 1.106 { ::;l2 8.990 9*031{ ence. Ee = 234.6 4,707 4.668 { :::& by differ- 0 2 8 = 448 43-47 11, = 3159 43.322 43*370 { 43.28 4983.6 100*000 100*000 Required. Found. Free iodine (assuming that the 25.55 25.46 { 25.38 48.67 48-59 { 48-51 salt contains 5K13). ....... 25.43 PbSOl .................... 48.633 Mixed snlphates ............ 59.119 59.47 { i:::: 10.446 K2SOt .................... 10.486 10.398 { The formation of a rational formula has at present baffled all my endeavours.

ISSN:0368-1645    

DOI:10.1039/CT8783300183

出版商:RSC    

年代:1878

数据来源: RSC

摘要:

192 MUIR ON CERTAIX BISMUTH COMPOUNDS. By M. M. PATTISON MUIR, F.R.S.E., Praelector in Chemistry, Caius College, Cambridge. 1. I n the sixth part of these investigations I have pointed out one or two points of analogy and difference between the trichlorides of bismuth and phosphorus (Chem. Xoc. Jour., 1877, ii, 136). The former is less completely oxidised than the latter, when acted upon by air or by nitrogen trioxide, the chloride being in the state of fusion. Michaelis (Jenaische Zeitschr., vi, 239, vii, 110) has shown that a t high temperatures phosphorus trichloride is capable of decomposingMUIR ON CERTAIN BISMUTH COJIPOUXDS. 193 very stable compounds ; in these decompositions the trichloride acts as a reducing agent. I have examined the action of bismuth tri- chloride upon a few of those substances, the action of which upon the corresponding phosphorus chloride was investigated by M i c h a e lis.Sulphur chloride and phosphorus trichloride, when heated in sealed tubes to 160°, are decomposed in accordance with the reaction, szc12 + 3Pc13 = Pc1, + 2Psc13. A quantity of sulphur chloride was heated in a sealed tube with excess of bismuth trichloride for 10 hours at 170 to 175". The tube then contained crystals of separated sulphur ; the bismuth trichloride remained altogether unacted upon. AccordingtoMichaelis,the reaction 3PC1, + SO,= 2POC1, + PSCI, takes place when sulphur dioxide and phosphorus trichloride are passed through a red-hot tube. Bismuth trichloride was heated over a Bunsen lamp in a current of dry sulphur dioxide ; the greater part of the trichloride was quickly volatilised and deposited again in the cold portion of the tube; the sublimate consisted of pure bismuth frichloride; the residue in the boat presented the appearance and possessed the properties of the oxychloride described in Part VI of these papers (Chem. Soc.Jouvn., 3877, ii, 136). Estimation of chlorine showed that the residue, the amount of which was small compared with the weight of trichloride used, really consisted of this oxychloride. An experiment, in which sulphur dioxide and vapour of bismuth trichloride were passed through a red-hot tube, gave the same results. Chromyl dichloride and phosphorus trichloride react very energeti- cally upon one another. Michaelis gives the equation 4Cr02C12 + GPCl, = 2CrzC16 + PC1, + 3Poc1, + Pz05, as expressing the results of this reaction.When bismuth trichloride and chromyl dichloride are mixed, no action takes place; on warming the mixture, the bismuth salt gradually dissolves. When the dark-red liquid is left for some days over sulphuric acid, the chromyl dichloride is gradually absorbed by the acid, and a dark-red semi-solid mass is produced, which continues t o evolve vapours of the dichloride, t o a greater or less extent, for a long time. If exposed t o the air, this dark-coloured mass quickly deliquesces, with production of bismuthyl chloride (BiOC1) and a solution containing chromic and hydrochloric acids, but entirely free from bismuth. The same decomposition is more quickly brought about by the addition of water to the semi-solid mass.Ether dis- solves out a small quantity of bismuth trichloride from this ma= ; the solution is free from chromium. Absolute alcohol causes the pro- duction of a green liquid containing chromium and chlorine, but free194 NUIR ON CERTAIN BISMUTH COMPOUNDS. from bismuth. These reactions, I think, show that no chemical action has taken place between the bismut,h and chromyl chlorides, but that the substance obtained is merely a solution of the bismuth salt in chromyl dichloride. 2. These reactions are in keeping with the facts that bismuthous chloride is less completely oxidised, under similar conditions, than the corresponding phosphorus compound ; and that no bismuthic chloride analogous to phosphoric chloride (PCI,) exists. 3.In a paper lately communicated to the Society (p. 170 of this volume) I have described a process for det'ermining bismuth volu- metrically, based upon the production of an ox a1 a t e having the formula, Bi,CIO,. This oxalate is produced by boiling the normal oxalate, Bi2C60L2, with water. Sonchay and Lenssen (Awn,. Chem. Pharm., cv, 245) have described normal bismuth oxalate as a salt containing 7 i molecules of water, 64 of which are given up by heating to 100." In Watts's Dictionaq (vol. iv, p. 253), the formula of this salt is given as Bi2C6012.15Hz0: this is evidently a mistake. In the old notation the formula was Bi2C12021.15H0, which in the new becomes Bi2C6012. 7 $H,O. According to Souchay and Lenssen, the salt loses 14.3 per cent. of its weight when heated to 100".A quantity of bismuth oxalate was prepared by precipitating a slightly acid solution of bismuth nitrate with excess of a saturated solution of oxalic acid. The precipitate was washed with a very dilute solution of oxalic acid, dried by long-continued pressure between porous paper, and analysed. The oxalic acid was determined by titration with standard perman- ganate ; water was determined by heating in an air-bath, and bismuth by difference. (1.) 0,471 gram required 67.2 C.C. permanganate = 0.1565 gram (2.) 0.659 gram required 95.1 C.C. permanganate = 0.2215 gram (3.) 1.363 grams lost 0.1745 gram after 5$ hours' drying a t 100'. c20,. C?O& 1 C.C. permanganate = 2.329 mgm. C204. Calculated for Found. Bi23C,0j.6H20. Bi23C2O4.'i'+H20. I. 11. 111. c200...... .. 33-33 32.23 33-23 33.61 - Bismuth. . . . 53.03 51.29 53.77 c Water.. . . . . 13.64 16.48 - - 12.81 When the oxalate was heated to 130" for an hour, the coloupNUIR ON CERTAIN BISMUTH COMPOUNDS. 195 changed to reddish-violet, the total loss amounting to 14.09 per cent. After 3+ hours at the same temperature, the loss amounted to 14.38 per cent., the violet colour having become considerably deeper. At 150" decomposition proceeded with greater rapidity. These results are more in keeping with the formula contahing 6 molecules of water than with that given by S ouch ay and L ens s e u, which requires 'i'i molecules, The water is evidently driven off at a temperature of 110" or so ; and at a point not much above this, if one may judge from the change in the colour of the salt, decomposition begins. The chemists already quoted state that bismuth oxalate is decomposed at temperatures above loo", with production of an acid oxalate and hypobismuthous oxide (Bi,Oz).I heated a quantity of the oxalate, prepared as already described, in a closed crucible over a low Bunsen flame ; the salt became black, and then began to assume a yellow colour; the heating was stopped; the residue washed with hydrochloric acid and exposed in a moist state to the air for several hours ; no trace of the white hydrate which is produced by the oxida- tion, under similar conditions, of hypo bismuthous oxide, was obtained. Examined under the lens, the residue was seen to consist largely of metallic bismuth ; on heating, it was slowly converted into bismuthous oxide.The hydrochloric acid washings showed no traces of oxalic acid. It would thus appear that at a temperature considerably below redness bismuth oxalate is decomposed in a closed crucible, the oxalic acid being destroyed, and metallic bismuth being produced by the re- ducing action of the carbon particles, and perhaps also by carbon monoxide given off from the decomposing salt. 4. Sonchay and Lenssen (Zoc. cit.) have described a basic oxalate of bismuth produced by boiling the normal oxalate with water until the supernatant liquid ceases to exhibit an acid reaction. To the oxalate thus obtained these chemists have assigned a formula which, translated into the new notation, becomes BizCa09.H20. Hein t z (Pogg. Ann., lxiii, 90) has examined the same salt and assigned to it the formula Bi2C40,.1+H20. According to Souchay and LensPen this oxalate loses no water at loo", but begins to decompose at 132".According to Heintz, decomposition begins at 200" to 210°, and is attended with evolution of carbon dioxide only. I prepared a quantity of the salt in accordance with the method already quoted. The analysis was conducted by dissolving in dilute hydrochloric acid, and titrating with standard permanganate solution. 1. 0.833 gram required 104.5 C.C. permanganate = 0,24338 gram C204 = 0.5808 gram Bi. 2. 0.6805 gram required 84.4 C.C. permanganate = 0.19657 gram C204 = 0.41691 gram Bi.196 MUIR ON CERTAIN BISXUTH COJIPOUSDS. 1 C.C. permanganate = 2.329 mgm. C,04. Bi2C409. Bi2C,0g.H20. Bi,C,OJkH,O. I.11. Mean. Calculated for Found. C20,. . . . . . 28.76 27.94 27.55 29-22 28.89 2905 Bismuth . . 68.63 66.66 65.73 69.72 68.93 69-32 Water . . . . - 2.86 4.23 - - - In the foregoing analyses the bismuth was determined from the re- sults of the titration with permanganate ; whatever be the amount of wat'er in the salt, the relation between C204 and Bi remains unaltered. Inasmuch as C,Oa corresponds with Bi, it is easy to calculate the per- manganate in terms of bismuth after it has been standardised against oxalic acid or an oxalate. 0.849 gram was dried at 100" for some hours, but without suffer- ing any diminution in weight. Dried for 1+ hours at 150") the salt was slightly blackened, and lost 0.007 gram = 0.83 per cent. After a second hour the loss amounted t o 0.008 gram = 0.94 per cent., the salt being rather more blackened than before. After an additional hour at 185-190", the salt became dark brown throughout, and lost 0.019 gram = 2.24 per cent.When heated over a Bunsen lamp, the oxalate was gradually converted into bismuthous oxide. These num- bers certainly agree best with the supposition that this oxalate con- tains no water of crystallisation. At that temperature at which it begins to lose weight, it also begins to undergo decomposition. 5. The propertiesof the two oxalates of bismuth, so far as the action upon them of acids and other reagents is concerned, have been de- tailed by Souchay and Lenssen with tolerable fulness. I find that, by mere contact with cold water, the normal is slowly converted into the basic oxalate. 6.The two oxalates of bismuth may be regarded either as derived from oxalic acid or from two of the hydrates of bismuth. From the former point of view the salt described in par. 3 is regarded as three molecules of oxalic acid, in which the whole of the bydrogen has been replaced by bismuth- The basic salt is derived from two molecules of oxalic acid in which two hydroxyl groups are replaced by oxygen, that is to say, from an acid which bears exactly the same relation to oxalic acid that dichromic doe8 to chromic acid, or pyrosnlphuric to sulphuric acid. By repla-MUIR ON CERTAIN BISMUTH COMPOUNDS. 197 cing the whole of the hydrogen in this dioxaZic acid by bismuthyl (BiO) we shall have the bismuth salt (BiO)zC407- If the oxalates be regarded as derivatives of bismuth hydrates, the normal salt will be obtained from the hydrate Biz(OH)6 by replacing the hydrogen entirely by the group C202, thus- BiTO i0>C,O, while the basic salt will be obtained from the hydrate Bi,O(OH), by a similar replmement, thus- From whichever point of view these oxalatm are regarded, the basic salt is completely analogous to Lowe's dichromate of bismuth (see Chem. Xoc.Jour., 1876, ii, 19; and 1877, i, 649-651). The normal salt must obviously be called bismuth oxalate; for the basic salt I would propose the name of bismuthyl dioxalate. The cor- responding antimony1 dioxalate has been described by Souchay and Lenssen. 7. I have already described several attempts which I have made to prepare salts of the so-called bismuthic acid (Bi,O,.H,O).In one of the oldest papers upon bismuth salts, the preparation of three so-called bismuthates of potassium is detailed. Jacquelain (J. pr. Chem., xiv, l), in the year 1838, described experiments which resulted in the production of three salts, to which he assigned the for- mulze (new notation) BBi407.K20 ; 4Biz04.Kz0 ; and 7Bi20,.2Kz0 respectively. I have again carried out two of the experiments made by Jacquelain exactly in the manner described by him. A quantity of caustic potash was fused in a silver crucible, and bis- muthous oxide was thrown in small successive quantities into the molten mass. The oxide dissolved very readily, the liquid becoming first greenish-yellow, then yellow-brown, and finally dark red-brown. The latter colour was attained when a considerable amount of bis- muthous oxide had been added, and when the whole had been strongly VOL.XHXIIT. Q198 MUIR ON CERTAIN BISMUTH COMPOUNDS. heated for 10 or 15 minutes. Tbese observations are entirely in keeping with those made by Jacquelsin. On allowing the fused mass to cool, a black solid was obtained, which appeared under a lens as a non-homogeneous mass containing grey or greyish specks. J a c que 1 ai n describes the fused mass as presenting the appearance of aventurin, and as containing quantities of crystals. I have re- peated the experiment several times, and each time have obtained a similar result. The black mass is very deliquescent; it is readily acted upon by water, with production of a strongly alkaline solution containing no bismuth, and a brownish-red residue, which, when washed with cold water until the washings cease to turn red litmus blue, is entirely free from potassium.The black mass is slowly decomposed by alcohol, with production of a brownish residue and an alkaline liquid free from bismuth. When thrown into fused potash, the black solid is very quickly dissolved. Jacquelain says that it is much more quickly dissolved than bismuthous oxide. I have not observed much difference be- tween the solubilities of the two substances in fused potash, so far as can be judged by the eye alone. The formula which Jacquelain assigns to the fiubstance which he obtained by adding bismuthous oxide to fused potash is 2Bi407.K20. The numbers obtained by Jacquelain agree tolerably well with this formula ; they are as follow :- Calculated. Found.Bismuth = 84.07 86-16 Oxygen = 11.21 11.56 Potash = 4-71 2.38 There is a considerable discrepancy between the amount of potash found and the amount calculated. Jacquelain’s formula, moreover, does not appear at all a probable one. If it be adopted, we must regard the substance as composed of bismuthous and hypobismnthic oxides combined with potash ( Biz03.Biz04)z.Kz0. The substance ob- tained as already described comports itself towards reagents exactly as a mixture of bismuthous oxide with one of the higher oxides would be expected to do. The two salts to which Jacquelain assigns the formulae 4Bi2O4.K20 and 7BizOa.2K20 respectively, are prepared, according to him, by the action of chlorine upon caustic potash-solution holding bismuthous oxide in suspension. The second salt is produced when a strong pot.- ash-lye is employed.If the percentage composition of the two salts be calculated, it is found that the numbers are very nearly the same for both. Jacquelain’s actual results for the second salt agree quite as well (indeed rather better) with the first, as with the second formula.MUIR ON CERTAIN BISNUTH COMPOUNDS. 199 I have attempted to prepare the salt 4Bi20,.K20 by following exactly the directions given by J a c qu el a i n, only employing bromine as oxidiser in place of chlorine, as the former is much easier to mani- pulate. The result was a dark puce-coloured heavy powder, which, after washing with cold water until the washings were no longer alka- line to test.paper, contained small quantities of potassium. Ou boil- ing this substance with water, the water again acquired an alkaline reaction, which reaction became more apparent the longer the boiling was continued. After being boiled with successive quantities of water until the latter ceased to exhibit an alkaline reaction, the substance was found to be perfectly free from potassium. On treating it with a little strong nitric acid, red biamuthic hydrate was produced. These results, taken along with the fact-insisted on by Jacque- 1 ain-tbat in the fusion cif bismuthons oxide with potash, an oxide higher than Bi,Os is certainly produced, and continues to exist at tempera- tures above that at which either Bi20a or BizO, is decomposed, can be best explained, it seems to me, by supposing that a loose combination of potash with Bi,Oa or Bi,O, is actually produced, but that this com- bination is very readily decompwed.In the first instance washing with cold water seems to effect decomposition ; in the second boiling water is necessary. I am aware that the expression " loose combina- tion " is a bad one on account of its vagueness, but I do not know of a better. The general result appears then to be that the higher hydrates of bismuth exhibit exceedingly feeble acid properties, so feeble as cer- tainly not to entitle them to the name of acids. These oxides do not combine with acids to form salts: hence they occupy a neutral posi- tion between the more marked positive oxides on the on8 hand, and the negative oxides on the other.8. I thought it might be possible to form sulphobismuthates. With this end in view, several experiments were carried out, but they have all led to negative results. The experiments were briefly as follows :- An attempt was made to produce a sulphide of bismuth higher than Bi2S, by passing sulphuretted hydrogen through water holding bis- muthic oxide (Bi,O,) in suspension. A dark red powder was pro- duced, which contained only 1 per cent. of sulphur. Treatment with alkali removed the sulphur, leaving bismuthic oxide. Another attempt to prepare a sulphide higher than bismuthous sul- phide was made by fusing carbonate of potassium, sulphur, carbon, and bismuthous sulphide together. The result was potassium sulphide in addition to the material employed in the fusion.Lastly, an attempt to prepare a salt of bismuthous sulphide by fusing metallic bismuth, potassium carbonate, and sulphur led only to the for- mation of bismuthous sulphide and potassium sulphide. The fused Q 2200 XUIR ON CERTAIN BISMUTH COMPOUSDY. mass, treated with water, yielded a solution free from bismuth, the residue, after washing with water, yielded a solution free from potas- sium. Schneider (Zeitsch. f. Chem. [ a ] , v, 630) stat8es that a soluble double sulphide, K2S.Bi2S3, is formed by the foregoing process. I have altogether failed to produce such a compound. 9. I have carried out a few experiments with bismuthous iodide, which it may be well to record in this place. The iodide was pre- pared by the wet method (Rammelsberg, Pogg. Ann., xlviii, 166, and Arppe, Pogg.Ann., lxiv, 248), also by Schneider's dry method (Pogy. An%., xcix, 470), which consists in heating 'together a mixture of bis- muthons sulphide and iodine. Rammelsberg says that a solution of potassium iodide converts bismuthyl chloride (BiOC1) into bismuthous iodide, and that in the preparation of the latter s+lt it is therefore immaterial whether the solution of bismuth contain precipitated oxychloride or not. The second part of this remark I find to be perfectly correct, but there is an error in the first part. Pure bismuthyl chloride (BiOCl) was digested at the ordinary tem- perature for several hours with a large excess of a solution of potassium iodide, but not a trace of bismuthous iodide was produced. The addition of a few drops of hydrochloric or nitric acid caused the forma- tion of a yellow liquid, but still no solid bismuthous iodide was formed.A solution of bismuth in excess of nitric acid was added to another portion of the oxychloride ; the first few drops caused thc production of ;t yellow liquid, the addition of a larger quantity produced a preci- pit(ate of bismuthous iodide. Hence it is evident that bismuthyl chlo- ride is not decomposed by potassiuni iodide solution. The addition of excess of potassium iodide solution to a mixture of bismuth chloride, bismuth oxychloride, and hydrochloric acid probably first causes the conversion of the dissolved bismuth into iodide, which is at once for the most part precipitated, with simultaneous production of potassium chloride. As potassium chloride is an easily soluble salt, a portion of the hydrochloric acid previously employed in holding the bismuth in solution -ill be free to dissolve fresh portions of bismuth by acting on the oxychloride present ; the bismuth thus dissolved will be a t once converted into iodide, and as such removed from the sphere of action ; and these processes will continue until the whole of the bismuth is precipitated in the form of iodide.In keeping with this explanation is the fact which I have noticed, that if a small quantity of potassium iodide solation be added to a somewhat large quantity of bismuthyl chloride, and a few drops of hydrochloric acid be then poured on the mixture, the bismuth is slowly converted into iodide. There appear to be some discrepancies in the accounts given of the action of water uponbismuthous iodide.I find that the iodide producedMUIR ON CERTAIN BISJiUTH COMPOUNDS. 201 by precipitation is decomposed with tolerable facility by cold water with production of the red oxyiodide, BiOI. The complete decom- position requires the agitation for some minutes of the precipitated iodide with three or four successive quantities of water. If hot water be employed, the decomposition is very much hastened. The iodide produced by subliming a mixture of bismuthous sulphide and iodine is decomposed by cold water only very partially, and only after pro- longed contact; even when boiled with water the decomposition of the iodide is very slow. Bismuthous iodide is therefore a much more stable salt than either the corresponding chloride or bromide.When heated in a closed crucible, the iodide is for the most part sublimed unchanged, but a small quantity of the oxyiodide, BiOI, is produced, as noticed by Schneider (J. pr. Chew,., lxxiv, 424). I n this re- spect the iodide differs from the other haloid bismuth compounds. In a paper communicated to the Society (" On Certain Bismuth Com- pounds," Part TI, Chem. SOC. J., 1877, ii, p 137) I have compared the oxidising action of air upon fused bismuthous chloride with the action upon fused bismuthous bromide. I n the case of the latter salt the oxidation is carried further than in the case of the former. The iodide is, however, oxidised much more slowly than either the chloride or bromide. Hydrochloric acid, i t is stated, dissolves bismuthyl iodide (BiOI) readily ; nitric acid causes the production of free iodine, while the bis- muth goes into solution. I find that the addition of a very small quantity of hydrochloric acid to bismuthyl iodide brings about the production of bismuthous iodide, which is for the most part precipi- tated, and bismuthous chloride, which goes into solution. The addi- tion of a few drops of sulphuric acid also causes the production of bismuthous iodide and a liquid holding bismuth in solution. Nitric acid when added in very small quantity exerts a Rimilar reaction, but the bismuthous iodide produced is very quickly decomposed, with solu- tion of bismuth and separation of iodine. I also find that hydriodic acid acts slowly upon bismuthyl chloride, with production of bismuthous iodide. The two following equations in all probability represent the production of bismuthous iodide from the oxyiodide and oxychloride respectively :- 3BiOI + 6HCl = 2BiC1, + BiI, + 3H20. 3BiOCl + 6HJ = 2Bi13 + BiC1, + 3H20. Just as potassium iodide solution is without action upon bismuthyl chloride, so is potassium chloride solution without action upon bismu- thy1 iodide.

ISSN:0368-1645    

DOI:10.1039/CT8783300192

出版商:RSC    

年代:1878

数据来源: RSC

摘要:

202 XXIII --Ox Aroma& Nidrosamifies. B ~ O T T O N. WITT, Ph.D. IK 1864 Griess published in the Philosophical Transactions his great paper on the diazo-compounds, in which he so thoroughly described the action of nitrous .acid on primary aromatic amines that subsequent research has brough% to light no new facts of importance. In 1874 I made a few experiments on the action of nitrous acid, and especially its ethers, on secondmy and tertiary amines, and was aston- ished to find that very beautiful substances were foimed in these reactions. A few weeks after I had communicated my results to the Chemical Society of Zurich, B ae y e r and Car o published their paper on nitrosodimethyianiline, the final product of the action of amylic nitrite on dimethylaniline; I have therefore in my research con- fined myself to the action of nitrous acid and its salts on secondary %mines.The facts observed are shortly recorded in the Bem'ciite of the Berlin Chemical Society ; and a detailed account of the formation and properties of diphenylnitrosamine has been given in my inaugural dissertation. Since the publication of the latter, in 187.5, I have studied more carefully some complicated reactions of diphenylnitro- samine, and the object of this paper is to bring before the Society a description of the phenomena observed, of the new substances pre- pared, and a short statement of my theoretical views on the subject. Whenever a secondary amine is acted upon by nitrous acid, water and a nitrosamine are formed. The term 4' nitrosamine " I apply to any substituted ammonia which contains, instead of at least one atom of hydrogen, the univalent nitrosyl group, -NO, in immediate con- nection with the ammoniacal nitrogen.Thus the action of nitrous acid on diethylamine forms diethylnitrosamine- C*& C2H5 I I NH I I CZH5 + NO.OH = HZ0 + N.NO; c2H5 whilst diphenylnitrosamine is obtained by bringing diphenylamine into contact with ethylic or amylic nitrite- C6H5 C6H5 I I NH + NO.OCzHs = N.NO + C2H,.OH, I c ' a 5 I ca5WITT ON AROMATIC NITROSAMINES. 203 or by the action of nitrous vapours on diphenylamine, or of metallic nitrites on the hydrochloride of diphenylamine. Diphenylnitrosamine is a substance remarkable for its great power of crystallisation. It can be easily obtained in large honey-coloured monoclinic crystals, melting at 665", easily soluble in alcohol, ben- zene, and similar solvents, and giving a striking reaction with concen- trated snlphuric acid, in which it rapidly dissolves, imparting to it a beautiful blue coloration, large quantities of pure nitric oxide gas being given off.Powerful reducing agents cause the formation of ammonia and reproduction of diphenylamine ; but by careful reduc- tion it may be converted into diphenylhydrazine, one of a beautiful series of new bases recently discovered by Emil Fischer. The action of aniline, or any other primary monamine, on diphenylnitros- amine iE1 violent; if carefully controlled, however, the result is simple enough, being represented by the following equation :- c6H5 I ca5 CsH, N I I II N.NO + 2(NH,.CsHa) = NH + N + HzO.I I I CSH, c& NH I A corresponding amount of diphenylamine is regenerated, whilst the nitroso-group is employed in the formation of diazobenzene, which immediately combines with another molecule of aniline, forming diazo- amidobenzene. The latter then undergoes the usual ti-ansformation into amidoazobenzene. Under certain circumstances a secondary re- action takes place, giving rise to a beautiful substance of the formula C,H& which is remarkable for a peculiar reaction. If heated with concentrated sulphuric acid to the boiling point of the latter, a, fine blue colonring-matter is obtained, possessing a beautiful crimson fluoremence and a characteristic absorption spectrum with three dark bands. If, instead of pure ethylic or amylic nitrite, the ordinary prodnct obtained by leading nitrous vapours into ethylic alcohol be employed in the preparation of diphenylnitrosamine, or if nitrous vapours be introduced into a solution of diphenylamine, the products obtained differ greatly from diphenylnitrosamine, and a few experiments suffice to prove that they are mixtures of different substances in varying proportions.Their separation is, however, a matter of extreme diffi- culty : for gradual decomposition sets in if repeated recrystallisation is resorted to, and it was not until I found a means of preparing each of the different substances, independently and separately, that I could204 WITT ON AROMATIC MTROSAMINES. attempt a successful inquiry into their constitution. Here I encoun- tered another serious difficulty : all these substances, when subjected to organic analysis, suddenly give off large quantities of nitrous vapours; and this takes place so ra;pidly that even the use of a number of spirals of metallic copper does not always completely de- compose the gas.On the other hand, the introduction of a large amount of metallic copper is detrimental to the accumy of the analysis, as recently pointed out by Lietzenmayer (Ber., xi, 306). When the nitrous vapours are given off a, peculiar kind of very denRe charcoal remains behind, the final combustion of which can be aceom- plished only by the prolonged passage of oxygen through the tube. Owing to all these difficulties my analytical data are marcely within such close limits as I could have wished, although I have made quite an unusual number of combustions with the greatest care and by methods which, from long experience, I know to be perfectly tmst- worthy.On the other hand, I have in almost all cases determined not only carbon and hydrogen, but also nitrogen by the volumetric method. It will be easily understood that analyses attended with such serious difficulties could not suffice to clear up the nature of my new sub- stances, and I therefore had recourse to a closer study of their mode of formation. I soon found that ordinary ethylic nitrite contains invariably large quantities of nitric acid, the presence of which was easily accounted for, when I convinced myself that none of the methods employed for the production of what is commonly called nitrous anhydride, N203, produce this compound; and that by far the hrger portion of the product obtained by the action of nitric acid of different strengths on either arsenious anhydride, or starch, or treacle, is nitric tetroxide, N204, which may be regarded as a mixed anhydride of nitric and nitrous acid.In contact with water or alcoliol it furnishes both nitrite and nitrate, and this accounts for the invariable presence of nitric acid in all nitrous ethers prepared by the introduction of nitrons vaponrs into the corresponding alcohol. The nitric acid present proved also to be the cause of the peculiar difference between the action of pure and ordinary ethylic nitrite on diphenylamine. This conclusion arrived at, I completely abandoned the use of ordi- nary nitrite, and with the purpose of obtaining a thorough insight into my experiments only employed mixtures of known quantities of pure nmylic nitrite and nitric acid ; acting with this reagent upon weighed quantities of diphenylamine and moderating or accelerating the reac- tion by the use of various solvents.I f 20 grams of finely powdered diphenylamine be placed in a dry flask and a mixture of 15 C.C. of nitric acid, sp. gr. 1.424, 35 gmms of pure amylic nitrite, 100 C.C. of methylated alcohol,WITT ON AROMATIC NITROSAMINES. 205 be poured upon it, the diphenylamine dissolves instantaneously with a dark coloration, and a rise of temperature is perceptible; the flask is kept in constant motion, and the reaction, if necessary, accelerated by gentle heating. Suddenly crystals begin to settle out ; and if the flask be now placed in iced water, a beautifully crystalline deposit i R obtained.When crystals cease to form, the precipitate is filtered off and carefully washed with spirit, dried and recrystallised from chloroform. It forms beautiful plates of light yellow colour fusible a t 133.5", easily soluble in chloroform, benzene, hot alcohol, and glacial acetic acid. The analytical data obtained with this substance are the follow- ing :- I. 11. 111. IV. V. VI. VII. C . . . 39-90 59.70 59.84 60.03 59.60 - - H .. 420 4.30 430 440 440 - - N... - c - - - 18.60 18.10 This substance may easily be recognised as a nitrosamine ; for it imparts a fine violet coloration to pure concentrated sulphuric acid, at the same time giving off nitric oxide gas.Now as the three available ahmicities of the nitrogen in diphenylamine are thus proved to be engaged in a manner identical with diphenylnitrosamine, the only possible conclusion was, that some substitution had taken place in one or both of the two phenyl groups of the diphenylnitrosamine, and that the new substance was the nitrosamine of a substituted diphenyl- amine. We possess, as I have shown before, a means of regenerating the secondary amine from a nitrosamine by the action of aniline, which was resorted to and proved to be effectual ; and equally good results were obtained by splitting off the nitroso-group by means of alcoholic potash. Whichever process was applied, it resulted in the formation of a new substance crystallising from dilute alcohol in small glistening scales of a pale yellow colour, melting at 132". This substance does not colour sulphuric acid, but it dissolves with a fine red colour in alcoholic potash ; subjected to organic analysis i t proved to be mono- ni trodip hen y lamine : - Theory for Experiment.CSHpNH.CBEd.NOZ. I. 11. C ........ 67.20 67.20 67.32 H ........ 4.66 5-06 5.35 N ........ 13.09 0 ........ 14.95 99.90 - - - - -206 WITT ON AROMATIC NITROSAMINES. The product, from which this mononitrodiphenylamine wm ob- tained, is therefore mononitrodiphenylnitrosamine ; the following num- bers- C .................... 39-30 H .................... 3.70 N .................... 17.30 0 .................... 19.70 CsH5. N . NO. C sH4. N 0 2 = IOO*OO indicated for this substance by theory agree as closely with the results actually obtained rn can be expected under the dificulties which the analysis of these substances offers.Mononitrodiphenylnitrosaine, when dissolved in glacial acetic acid and subjected to the action of bromine, yields a precipitate of a canary-yellow colour, which is easily soluble in benzene and crystal- lises from this solvent in long silky needles fusible at 208-5-209". If this substance be again treated with bromine, and heated with it for some time on the water-bath, another product is formed crystallising from benzene, in which it is not so easily soluble as the first product, in heavy, well-shaped small prisms, melting at 214-5-215". Mononitrodiphenylamine is a colonring matter, though a very weak one. The colonring properties of this substance are due to the entrance of a nitro-group into diphenylamine, which at the same time renders the imido- hydrogen replaceable by metals- Silk may be dyed yellow in its solution.Mononitrodiphenylamine. Potaeeium mononitro- dipheny lamine. But as soon as the imido-hydrogen is replaced by the nitroso-group, the colonring properties of the compound are destroyed, the influence of the nitro-group being paralysed. This may be easily demonstrated by introducing mononitrodiphenylnitrosamine into a very cold solution of potash in alcohol. In the first instance no coloration is observed. But on heating, or even on standing for a short time, a dark scarlet coloration appears, due to the elimination of the nitroso-group and the formation of mononitrodiphenylamine, which, as already observed, is a colonring matter.If the proportions of nitric acid and amylic nitrite be altered, and the spirit be exchanged partly or entirely for another solvent, whichWITT ON AROMATIC NITROSAMINES. 207 expedites the reaction, more nitro-groups may be introduced into the molecule of diphenylnitrosamine. The following method has been found to give satisfactory results. 17 grams of diphenylamine are introduced into a dry flask sur- rounded by iced water. Then a mixture of- 50 C.C. of glacial acetic acid, 40 C.C. of nitric mid, 1.424, 50 C.C. methylated spirit, 48 grams nitrite of amyl, is added all at once. The diphenylamine dissolves with a dark colour, and very soon small granular crystalline aggregates begin to settle out.When the precipitate no longer increases, it is filtered off on the filter- pump, the mother-liquor is carefully removed, and the precipitate washed with spirit and finally with ether. It is then dried at the ordinary temperature, and appears, when dry, as a sandy powder of light yellow colour. Recrystallisation may be effected from chloro- form, in which the new compound is but sparingly soluble, but I have not been able to detect, any difference in the analytical results ob- tained with either the recrystallised or the crude product. Their behaviour with reagents and their characteristic appearance are also very much the same. The reaction of this body with sulphuric acid, in which it dissolves with a dirty violet coloration, giving off nitric oxide at the same time, proves it to be a nitrosamine.The analytical results, however, do not agree with any simple formula, but the num- bers for at least the carbon and hydrogen are intermediate between those required for di- and for tri-nitrodiphenylnitrosamine- Theory for Experiment. C12HSN405* CI,H;N,O,I. Crude. Recrystalbed. I. 11. 111. 0.. .... 50-00 43.25 46.95 - 47.01 H...... 2.75 2.10 3.99 - 3.18 19-04 - N.. .... 19.45 21.05 - 0.. .... 27.80 33.60 - - - - 100*00 100*00 I therefore concluded that the new substance, although apparently uniform and not separable by repeated recrystallisation, was contami- nated with some impurity, and hoped to effect a more successful puri- fication on removing the nitroso-group by means of alcoholic potash or aniline. For this purpose 20 grams of the product were placed in a flask, together with 100 C.C.of spirit, and 50 C.C. of a 20 per cent. solution of potassic hydrate in alcohol. On heating, a splendid purple coloration208 WITT ON AROMATIC NITROSAMINES. appeared, which gradually increased in intensity until all was dis- solved. Dilute hydrochloric acid was now added until the colour had changed to a bright orange, and, finally, a large quantity of water was introduced; the precipitate was collected on a calico filter, washed carefully, pressed, and treated with about 400 C.C. of boiling methylic alcohol. The solution was filtered from the part which remained undis- solved (A), and on cooling deposited crystals of an obviously impure product (B). If aniline be employed for the removal of the nitroso-group, the following method may be adopted :- 20 grams of the new product, 30 grams of pure hydrochloride of aniline, 25 grams of aniline, 50 C.C.of spirit, are hated for about half an hour on the water-bath. Plenty of dilute hydrochloric mid is then added, and the precipitate boiled out three successive times with extremely dilute nitric acid. All the amidoazo- benzene is thm removed, and may be found in the extract. What remains undissolved is treated with methylic alcohol as before, and the part insoluble in the boiling alcohol (A) treated separately from that which deposits on cooling (B). The latter, B, is successively extracted with small quantities of boiling methylated spirit and glacial acetic acid, and both solutions removed by hot filtration.After this treatment the new substance requires one crystallisation from ethylic, or, better, isobutylic alcohol to be quite pure. It then forms long, thick, pointed needles of great brilliancy and lustre, of a dark yellow colour, with a slight bluish dichroism, fusible at 214". They dissolve in alcoholic potash with a bright purple colour, which is destroyed by the addition of cold wafer, but reappears on boiling. Analysis proved them to be dinitrodiphenyl- amine :- Theory Experiment. For C12H9N304. I. 11. 111. IV. C ........ 55-60 56.50 54.90 56.39 - H ........ 3.50 4.80 409 4.07 - N.. ...... 16-20 - - - 16.M 0 ........ 24.70 - - - - The substance A, insoluble in methylic aloohol, was boiled out two or three times with this solvent, and then recryshllised from pure sylene.From this hydrocarbon it is deposited elowly in small, indistinctWITT ON AROMATIC NITROSAMINES. 209 granular crystals of a vermillion colour, fusible at 211.5'. It dissolves in alcoholic potash with scarlet colour, and the solution behaves in a similar manner to the purple solution of the body first described. On analysing it I found that if was isomeric with the yellow substance, and corresponds also to the formula of dinitrodiphenylamine :- For ClJ&,Na04. I. 11. In. IV. C 36.80 56-32 - - ........ 55-60 H.. ...... 3.50 4.25 4.17 - - Nb... ..... 16.20 - - 9790 16.29 0. ........ 24.70 Theory Experiment. - - - 100~00 This fact ie by no means surprising. If we suppose that, in the dinitrodiphenylamines obtainable by direct nitration, the two nitro-groups enter two different phenyl-group, there are still three dif€erent anbstanm likely to arise :- NO* 0 NH Dipamnitro- Diortbnitro- Orthapmnitm- diphenylamine.diphenylamine. diphenylamine. The metaposition is out of the question, ~ E J a nitro-group entering into an a;l'omatic molecule never occupies a meta-position to a, basic group already present. The two dinitrodiphenylamines here described most likely correspond to the firat and third formulae, for they both arise from further nitration of the same mononitrodiphenylamine, which, in all probability contains its one nitro-group in the p m - position. All the substances hitherto described give, when treated with nitric acid of the highest concentration, hexanitrodiphenylamine, a sub- stance originally discovered by E.Kopp, more closely investigated by Gnehm, and repeatedly introduced as an orange dye into commerce. On careful nitration diphenylnitrosamine gives, as I observed some time ago, and Gn e hm recently published, tetranitrodiphenylamine. Thus diphenylamine, through the agency of its nitrosamine, aliows of210 WITT ON AROMATIC NITROSAMINES. the introduction of one nitro-group after the other up to six, with exception of three and five, into its molecule, and we now know, irrespectively of isomerides obtained with picric chloride and dinitro- chlorobenzene by Clemm and P. T. Austen, the following nitro- derivatives of diphenylamine :- Mononitrodiphenylamine, C12H,,,N202. Dinitrodiphenylamine, CI2H9N,Oa (two iaomers). Tetranitrodiphenylamine, Cl2H7N5O8.Hexanitrodiphenylamine, Cl2K5N7Ol2. I do not doubt that my new method of nitrating substances in dilute solutions with the aid of alkylic nitrites, will be found applicable in a, great many cases, where nitration has hitherto offered unusual diffi- culties. It would also appear that this method furnishes some sup+ port to the theory already advanced, that the formation of nitroso- compounds always precedes the introduction of the nitro-group into the molecule of aromatic substances. Thus far I have described as much of my research on the action of nitrous acid on secondary amines as has become fit for publication since my last communication to the Berichte. I should have preferred to wait until I could have given some account of the reduction-pro- ducts of my new nitro-compounds, and investigated more closely their brominated derivatives, had it not been for an incident which made it desirable to publish without delay.In February, Mr. Meldola communicated to the Chemical News a note on “A New Colouring-matter,” and, at the same time, was good enough to send me two specimens of his preparations, one represent- ing the substance arising from the action of nitric tetroxide on diphenylamine in an acetic acid solution, the other the product obtained from the first by the action of aldoholic potash. On closely examin- ing and comparing our specimens, we found the first product to repre- sent a mixture of the nitrosamines described in this paper, whilst the second was a mixture of the nitrated diphenylamines, which corre- spond to the nitroso-compounds. On ascertaining that the subjects of our investigations were identical, and that the action of nitrous acid on diphenylamine and other secondary amines had occupied me for several years, Mr. Meldola was kind enough to relinquish his claim to the continuation of this research, for which I have much pleasure in thanking him : at the same time I wish to’ point out that the prac- tical application of mono- and di-nitrophenylamine as a dye-stuff, called citronine, is solely and entirely due to Mr. Meldola. The shades obtained on silk with citronine are truly magnificent, and no other artificial colour can compete with it as regards this particular tint ; unfortunately, owing to the inefficiency of tho nitro-group as a chro- mophor, and to the extreme weakness of the salt-forming groups inPERKIN ON SOME NEW DERIVATIVES, ETC. 211 citronine, it is not a strong colonring-matter, and this, combined with its insolubility in water, renders it of less general applicability than it otherwise deserves. Still, it is a very interesting fact, that in citro- nine an artificial colonring-mtter has for the first time been found, which, if it were not for the little difficulties just mentioned, might with advantage replace turmeric and qnercitron. I have the intention of bringing before the Society, in a second paper, the results which 'I hope to obtain in the continuation of this research.

ISSN:0368-1645    

DOI:10.1039/CT8783300202

出版商:RSC    

年代:1878

数据来源: RSC

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PERKIN ON SOME NEW DERIVATIVES, ETC. 211 XXIV.-Ort some New Derivatives of Anisoil (Anisol). By W. H. PERKIN, F.R.S. A SHORT time since I showed that methylparoxyphenyl-acrylic, -crotonic, and -angelic acids, when heated,-or, better, in the case of the two latter acids,-when converted into the hydrobromo-additive com- pounds, and then treated with sodium carbonate, yield para-deriva- tives of anisoil. I have now extended my experiments to the corre- sponding ortho-acids, and obtained the following results. Or f hovinglanisoi2. On boiling F-methylorthoxyphenylacrylic acid, it gradually decom- poses, carbonic anhydride being given off, and an oil distilling over. “his is purified by washing with dilute potassium hydrate and distillation with water; but with the view of obtaining it in a still purer state, i t was thought desirable to see if an additive derivative of the acid could be formed, which would decompose when treated with an alkahe solu- tion, and yield this body.For this purpose dry precipitated methylorthoxyphenylacrylic mid was placed in contact with hydriodic acid, sp. gr. 1.94, for two or three days, the mixture being frequently agitated. The resulting product was drained from the excess of hydriodic acid by means of a filter-pump. It was found best not to wash it, &s it is very unstable, and soon decomposes when in contact with water. It was then added in small quantities to a cold saturated solution of sodium carbonate, the mixture being well stirred and not allowed to get warm during the reaction, otherwise considerable quantities of a pol ymerised product are formed; this, however, rjometirnes happens even when great care is taken.The resulting milky fluid is then placed in a retort and boiled212 PERKIN ON SOME NEW DERIVATIVES until no more oily product distils over. The distillate is then warmed to promote the separation of the oil into a layer, whichis then collected and dried with potwium carbonate. On analysis if gave the follow- ing numbers : '- -2138 of substance gave -6364 of CO, and * l a 8 of H,O. Theory for CSHloO. Experiment. Carbon ............ 80.59 80.42 Hydrogen .......... 7.40 7.43 The formation of this substance, which I propose to call orthovinyl- awiso21, may be written thus :- Methylorthoxyphenylac~~c acid. Ort hovinylanieo'il. Hydriodomethylorthoxyphenylacrglic acid.Orthovinyhimdil. . Orthovinylanisoil polymerises so quickly when heated, that its boiling point could not be determined with certainty, but it seems to be between 195" and 200" C. When heated to 150" for about an hour, it solidifies to a transparent glassy substance, which is easily soluble in benzene, but insoluble in alcohol. This solid product when heated strongly distils, orthovinylanisoil being regenerated. The odour of orthovinylanisoll is very different from that of its isomeride, paravinylanisoll, being somewhat similar to that of high- boiling coal-tar naphtha, but more fragrant and not so strong. * Its specific gravity is- at 15" 1.0095 at 30" 1.000 When agitated with bromine-water it decolorises the latter, forming a nearly solid product.Heated with dilute nitric acid, it changes to a yellowish-brown heavy oil, becoming quite thick on cooling ; this product is partially soluble in aqueous potassium hydrate. With con- centrated sulphuric acid it becomes solid and of a bright-red colour. Orthallylanisooi. Methylorthoxyphenylcrotonic acid, when left in con tact with hydro- bromic acid, sp. gr. 1.74, for two or three days, combines with i t ; but the resulting acid, unlike the corresponding para-compound, when treald with an alkaline carbonate and then distilled, yields but a * Compared with water at the mme temperature.OF ANISO~L ( AXISOL). 213 small quamtity of oily prodact ; a large quantity of an uncrystallisable acid is, however, found in combination with the alkali; this is pro- bably an oxy-acid. If, however, hydriodic acid, sp.gr. 1.94, be used in place of hydrobromic, the resulting acid yields a large quantity of an oil when treated with an alkaline carbonate or acetate. A specimen of this dried over potassium carbonate and then distilled gave, on analysis, the following numbers :- I. -1894 of substance gave -5647 of COz and -1384 of H20. 11. -2178 of substance gave *6482 of CO, and -1631 of HZO. Theory for C10H120. I. 11. Hydrogen ...... 8-10 8.11 8.3 E sperimen t. Carbon ........ 81.08 81.3 81.17 This substance I propose to call orthaZlylanisoiZ ; the formula may be expressed thus :- Hy driodomethylorththoxyphenylcrotonic acid. Orthallylaniso'il. + HI + CO,. Orthallylanisoi'l is a highly refracting liquid boiling without poly- merising at 222-223" C.Its specific gravity is- at 15" 09972 at 30" 9884 at 45" *9793. Its odour is similar to that of its vinylic homologue, but fainter, When cooled in ft freezing mixture of snow and hydrochloric acid, it thickens but does not solidify. Cold nitric acid, sp. gr. 1.3, does not appear to act upon it in the cold, but on heating the mixture, red fumes are given off, and a brownish-yellow viscid oil, gradually solidifying to a resinous mass, results. With con- centrated sulphuric acid it becomes solid and of a red colour ; but on addition of water, it changes to a white opaque product soluble in benzene. Ort ho bzcteny lanksoil. Methylorthoxyphenylangelic acid, when treated with hydrobromic acid, combines with it, but the resulting compound yields only a very VOL.XXXIII. B It combines with bromine, forming a thick heavy oil.214 PERKIN ON SOME DERIVATIVES sniall quantity of oily product when treated with an alkaline carbon- ate ; but if hydriodic acid be employed, the yield of pi*oduct is good. The specimen of oil analysed was distilled with water and dried over potassium carbonate. -2083 of substance gave *6228 of CO, and -1634 of H,O. Theory for CIIHIOO. Experiment. Carbon ............ 81.48 81.54 Hydrogen .......... 8.64 8.71 The formation of this substance, which I propose to call orthobutenyl- anisozl, may be cxpressed thus :- Hydriodome thy lorthoxy phenylangelic acid. . Orthobutenylanisoil. + HI + CO,. Orthobutenylanisoil boils at 232-234" without polymerisiug. Its specific gravity is- at 15' -9817 at 30" *9740.When cooled in snow and hydrochloric acid, it does not solidify, but becomes thick. Like its homologues it combines with bromine, and also becomes solid and of a red colour when treated with concentrated snlphuric acid, the product losing its colour when washed with water. Boiled with dilute nitric acid it becomes yellow, but is only slowly acted upon, Strong nitric acid acts upon it with violence and dis- solves it; water precipitates from this solution a brown resin, which is mostly soluble in aqueous potassium hydrate. Paravinylanisoil. I mentioned in my paper, already referred to, that I endeavoured to produce paravinylanisoil from methylparoxyphenylacrylic acid by treating it with hydrobromic acid, hoping to obtain an addition-pro- duct which would decompose with alkaline carbonates in the usual manner ; but no result was obtained, as the methylparoxyph.eny1acrylic acid decomposed when brought in contact with hydrobromic acid.As, however, I have succeeded in obtaining orthovinylanisoil by a modifi- cation of this process, vie., by substituting hydriodic for hydrobromic acid, I applied this form for the preparation of this body. Dry precipitated methylparoxyphenylacr$ic acid, when left in con-OF ANISOk (ANJSOL). 215 tact with hydriodic acid, sp. gr. 1.94, for two or three days, combines with it? and the product, when drained from the excess of hydriodic acid and treated with an alkaline carbonate, yields the desired pro- duct. Unfortunately a good deal polymeriscs and becomes solid. The pure paravinylanisoil, however, was easily separated from this by distillation with water.Thus obtained, it differed but little from that prepared by the distil- lation of methylparoxyphexiylacrylic acid ; it was, however, somewhat purer, fts its fusing point was higher, viz., +3" instead of -1". Its specific gravity is- at 15" 1.002 at 30" -9956. It will be, perhaps, worth while to notice in what respects the para- and ortho-derivatives of anisojil I have obtained differ from each other. The difference in the boiling points appears to be about 10'. Paravinylanisoil ........ 204-205' Orthovinylanisoll ........ uncertain Parallylanisojil .......... 232" Parabutenylaniso'il ...... 242-245" Orthallylanisoil.. ........ 222-223' Orthobutenylanisoll ...... 232-234" The density is also slightly higher in the ortho-derivatives. 15' 30" 4s" - Paravinylanisojl ...... 1.0029 -9956 Ortho ,, ...... *9972 09884 09793 Parabntenylanisojil .... - -9i33 - Ortho ,, .... *9817 -9740 - Ortho ,, ...... 1.0095 1.000 Parallylanisoil ...... - *9852 *9761 - The ortho-compounds also refuse to crystallise, even when placed in a freezing mixture ; the para-derivatives crystaJlise freely. a-Methylorthoxyphenylacrylic acid obtained from coumarin, when treated with hydriodic acid and then with an alkaline carbonate, yields an oil which is appnently identicrtl with the orthovinglanisoll pre- pared from the B-acid. I am at present investigating this remarkable a-acid, and endeavouring to obtain some of its homologues.

ISSN:0368-1645    

DOI:10.1039/CT8783300211

出版商:RSC    

年代:1878

数据来源: RSC

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216 XXV.-Note on the Action, of Ammonia on Anthrapicrpuriw . By W. H. PERKIN, F.R.S. Is a paper on anthrapurpurin published in the Journal of this Societ? (vol. xxvi, p. 432), I mentioned that an ammoniacal solution of that colonring matter, when heated in a sealed tube to 100" C., changed in colonr from purple to indigo-blne, hydrochloric acid throwing down from this solution a dark purple precipitate which redissolved in am- monia with a blue colour. This substance dyes alumina mordants a purple, and weak iron mordants an indigo-blue colour. This substance I find is an unstable body easily convertible into anthrapurpurin. This is easily shown by acidifying a portion of the blue ammoniacal solution with hydrochloric acid ; at first a precipi- tate is formed, which dissolves on heating, but after a short time the liquid becomes turbid, owing to the precipitation of anthrapurpurin.Also if strong aqueous potassium hydrate be added to the blue solu- tion, it at first turns to a bright purple-red colour, but on boiling changes to a blue-violet, due to anthrapurpurin. If instead of heating the sealed tubes containing an ammoniacal solution of anthrapurpurin to loo", a temperature of 160-180" be employed, a purple solution results. On acidifying this with hydro- chloric acid, c chocolate-coloured precipitate forms. This, when washed and boiled with a solution of barium hydrate, mostly dis- solves, forming a, purple solution. On acidifying this, a precipitate is formed which, after washing with water and drying, was digested with alcohol. The resulting dark red solution on being concentrated deposited the new body in crusts of a dark greenish or black colonr, sometimes with a greenish metallic aspect, and only indistinctly crys- talline.When powdered it is of a chocolate colour. On analysis it gave the following numbers :- I. -286 of substance gave *687 of C02 and 0095 of H2O. 11. -313 of substance gave 15 c.c of nitrogen. Temp. 22". Bar. 754 mm. Theory for CI4H9NOI. I. 11. Carbon . . . . . . 65.88 65.50 - Hydrogen. . . . 3-53 3-65 - Nitrogen . . . . 5-49 - 5.38 Experiment .PAUL AND KINGZETT ON THE TANNINS. 217 This substance may be called anthraprpurnniide or amidon lizarin, though it differs entirely from the amidoalizarin produced by the action of uascent hydrogen on nitroalizarin (Jourrt.Chem. Soc., 1876, ii, 581). C14H502 OH + NH, = C14H502{ E2 + OH2. { :: OH Its formation may be expressed thus- Anthrapurpuramide is not very easily soluble in alcohol. The solu- tion in this solvent is of a clear dark orange-red colour. It is nearlj- insoluble in water. Solutions of the alkalis and alkaline earths dissolve it with a purple colour. Boiling solntion of potassium hydrate does not decompose it. It does not dye mordants. When nitrous acid is slowly passed through its boiling alcoholic solution, a brown precipitate separates. This, when collected and washed, dissolves in a solution of barium hydrate, forming a brownish- red solution. On filtering this, and adding hydrochloric acid, a pre- cipitate is obtained, and this when washed and dissolved in hot glacial acetic acid, yields a brownish-yellow solution, which on stand- ing deposits crystals of crude isoanthrafkavic acid. I had not suffi- cient material to purify for analysis, but from the fact that it yields anthrapurpurin on fusion with potassium hydrate, there can be no doubt of its identity.

ISSN:0368-1645    

DOI:10.1039/CT8783300216

出版商:RSC    

年代:1878

数据来源: RSC

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PAUL AND KINGZETT ON THE TANNINS. 217 XXVI.-Notes on the Tannins. By B. H. PAUL, Ph.D., and C. T. KINGZETT. IN a paper recently published by Mr. H. R. Proctor, he has shown that no two processes for the estimation of tannin give similar or comparable results, although when the same process is tried against products of the same nature, the results obtained by each process are tolerably constant, that is to say, cutch may be compared with cutch, mimosa with mimosa, and tannin with tannin, so long as the same process is employed; but even in this case tannin cannot be com- pared with cntch. In the course of professional practice we have had occasion to examine various tanning materials, in such a way 8s to enable us, if possible, to value one kind of material against another ; and, to make218 PAUL AND KINGZETT ON THE TANNINS.a long story short, it may be said our results fully sustained Mr. Proc- tor’s statements. We could compare cutch with cutch, but not with ordinary gallotannic acid, as it is called, and even when each kind of substance was re-examined by different processes, varying results were obtained. Thus a sample of tannic acid (sold as pure) showed with Gerland’s antimonial process 76 per cent. of pure tannin ; by the volumetric process, employing lead acetate and using potassium ferri- cyanide as an indicator, 179 per cent. ; and by the indigo process it showed (using the figures worked out by Nenbauer) 135 per cent. tannin, which figure, corrected for admixed gallic acid by the gela- tin and salt treatment, became 93 per cent.real tannin. A number of perfectly unmeaning results were therefore obtained, and the difficulty was made still greater when cutch and extract of mimosa bark were similarly compared. Although the term “ tannin ” appears to indicate that the astrin- gent character of different plants is due to the presence of a common substance, this supposition is not only erroneous to a large extent, but it becomes delusive when an attempt is made to base analytical methods upon it. The commercial value of different materials can so far be ascertained only by the practical tanner. If the various kinds of tannin were all glucosides, it might be possible to arrive at some sort of valuation by determining the amount of glucose which they are capable of yielding. It was this idea that led to the experiments detailed in the paper.S trecker stated that ordinary gallotannic acid (from gall-nuts) was a glucoside, splitting up when boiled with dilute acid as fol- lows :- C27H22017 + AH20 = 3C7H605 + C6HlZ06, but H. Schif f has recently shown that ‘tannic acid as ordinarily pre- pared is only digallic acid, splitting up thus, C,lHloO, + H20 = W7H605; and this view has been confirmed by Stenhouse in a study of the action of bromine upon tannin. S chiff‘, however, expresses the opinion that the unaltered natural tannin of gall-nuts may prohably be a glucoside, not of gallic acid but of digallic acid, and that it is to some extent decomposed by the mode of preparation (comp. foot-note, Ann. Chem. Pliarm., clxx, 175). In that case its decomposition would be represented by the equation- C31Hs022 + 2H20 = CsHi206 + 2CJ31009.These statements of Schiff led us to examine a number of com- mercial samples of tannin, by boiling them with dilute acids and examining the products for glucose. The solution thus obtained re- duced Fehling’s solution, although in every case it was found to bePAUL AND KINGZETT ON THE TANNINS. 219 quite free from sugar, and to contain only gallic acid. Moreover, the freedom of the original samples of tannin from any glucoside was shown by the fact that they gave no purple coloration with strong sul- phuric acid alone, although when sugar was added the coloration came out strongly. This result is in accordance with the circum- stance, mentioned by Schiff in a supplementary note to his paper, that tannic acid is now prepared commercially with dry ether, and not with ether containing water or with a mixture of ether and dilute alcohol.It seems, therefore, to be a matter of some doubt whether tannin is after all a glucoside even in its natural state, because if it were so, a process su6cient to effect its decomposition so far as to eliminate glucose, would scarcely stop at that stage, but would also presumably give gallic acid and not digallic acid. As we could find nowhere any statements regarding the constituents of cutch and mimosa bark extract, further than that they both yield a peculiar acid named rnimotumic acid, some experiments were made also with these materials. Cutch of commerce is a hard, brownish-black, shining substance, prepared in India and elsewhere from the Acacia Cutechic, and other trees.The method of procedure employed in our experiments consisted in boiling cutch for a number of hours with a quantity of dilute sul- phuric acid (2-5 per cent.). During this operation 5 per cent. of a dark brown insoluble matter forms, which appears to be an imper- fectly changed substance, judging from its general characters and from the fact that it gives the reactions of a glucoside, only in a less degree than the original cutch. The sulphuric acid solution admits of treat- ment in two ways. I t may be precipitated either by acetate of lead or by baryta-water, both of which reagents remove the same acid substance, and leave glucose of an unfermentable character in the filtrate.This glucose was estimated at 25 per cent. on the original cutch. Mimosa bark is the product of the Acucia miinosu, and furnishes in part the cutch of commerce. Extracts made of this bark gave, by the processes just described, similar results, the sugar obtained being estimated at about 8 per cent. on the bark. The peculiar acid removed by precipitation with acetate oE lead or baryta-water deserves a few words. If lead be employed, the acid may be obtained by decomposition of the precipitate with sulphu- retted hydrogen, ar?d removal of the sulphuric acid from the concen- trated filtrate by means of carbonate of barium or carbonate of lead. If baryta-water be employed, it is best to decompose the precipi- tate with sulphuric acid, and then to remove the excess of acid from the filtrate in the same way.220 PAUL AND KINGZETT ON THE TANNINS.The solution of organic acid thus obtained is of a faint red colour, 1. An intensified red colour on addition of ammonia. 2. A dark colour with ferric chloride, but only a trace of precipi- 3. No appreciable reaction with ferrous sulphate. But a, solution rendered neutral with soda became much darker l. With ferric chloride a dark-coloured precipitate. 2. With ferrous sulphate a bluish-black precipitate. It also gave precipitates with other reagents. On evaporating a solution of' the free acid, oxygen was evidently absorbed, and a dark brown matter deposited on the sides of the dish. In fact it was impossible to concentrate the solution or to work profit- ably with i t any further. Without attempting to describe the charac- ters of the insoluble matter formed during the boiling of cutch with sulphuric acid, the foregoing notes may be summarised as follows :- 1. The supposition that tannin, as it exists in gall-nuts, is a glucoside is rendered doubtful, and the sugar met with in some samples of tannic acid is more probably referable to an impurity, as Ro c h 1 e d er and K a- walier assumed. Schiff leans to the opiuion that the tannin in gall- nuts is a glncoside, but he states that the gnllotannic acid met with in ccjmmerce is not a glucoside, but digallic acid. 2. The astringent principle common to cutch and extract of mimosa bark is shown to be either a glucoside or associated with a substance of that nature, since they both yield unfermentable sugar, together with a peculiar acid distinct from gallic acid. The specimen of sugar exhibited has been purified by redissolving in water, precipitation with ammoniacal lead acetate, and decomposi- tion of the precipitate with sulphuretted hydrogen. and shows the following reactions :- tate. itself, and gave-

ISSN:0368-1645    

DOI:10.1039/CT8783300217

出版商:RSC    

年代:1878

数据来源: RSC

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ANNIVERSARY MEETING, March 30th, 1878. Dr. Gladstone, F.R.S., President, in the Chair. The following report was read by the President :- The history of the Chemical Society during the past twelve months has been an eventful one. For some time previously proposals had been made for extending its functions beyond what had hitherto been contemplated ; this grtve rise to much serious deliberation, but about the commencement of last year, many circumstances combined to show that such considerable changes were either impracticable under the present charter, or undesirable ; and the subsidence of the discussion left the Council free to devote their attention to various internal reforms. It is hoped that those changes, which have already been carried into execution, together with such as await their completion this evening, may help to consolidate the work of the Society.In the meanwhile the more strictly scientific part of the Society’s operations has been steadily carried on; and the commencement of the actual benefits resulting from the establishment of the Research Fund, has given a special feature to this year’s proceedings. I propose to refer to these vtrious points in some little detail. At the last meeting my predecessor in this chair felt it his dnty to lay before the members the serious difficulties that had arisen from the action of a section of the Fellows ; the conversation that followed was advantageous by informing the Council of the views entertained by different gentlemen present, and the new Council set themselves at once to consider how far any of these objections might be recognised as real, and therefore might be remedied.Committees were nominated for revising the bye-laws ; and for improving, if possible, the publica- tion of the Journal. An extraordinary general meeting was called shortly afterwards on the requisition of several of the Vice-presidents and other prominent Fellows of the Society. It took place on the 31st of May, and the statements which the Council laid before the meeting seemed to remove, in a great measure, if not entirely, any dissatisfaction that had previously existed. The whole subject of the bye-laws has received the very careful attention of the Council, involving the expenditure of much time and VOL. XXXIII. 8222 ANNIVERSARY MEETING, thought.The proposedmodifications are now in the hands of the Fellows, and await their adoption, or otherwise, this evening. The verbal changes are numerous, but the real alterations affect mainly the mode of electing Fellows, and of appointing auditors. There has been an entire alteration in the constitution of the Publi- cation Committee. It was originally intended that leading members of the Society should revise the work of the abstractors: hence the committee was made a large one, so as to represent all the different sections into which chemical papers might be divided. It was soon found, however, that this was attended with great difficulties ; and the duty of revision practically fell into the hands of the Editor. At the same time the very largeness of the Publication Committee lessened the feeling of responsibility in its individual members.It was there- fore determined to reduce the number to the five officers of the Society, with six other members. The remuneration given to the abstractors was rendered more adequate to the services required of them; and additional rules were made for their guidance, with a view especially to brevity and uniformity in the expression of results of analysis and of formulae. A separate pagination has been adopted for the papers and for the abstracts, so that when bound up, the Society’s work may appear in a continuous form. Other regulations have been made for expediting the publication of papers read at our meetings ; and our excellent editor, Mr. Watts, made a vigorous and successful effort, towards the close of the year, to bring the work of abstracting up to date.This has involved the printing of an extra number of our Journal, which is on the point of being in the hands of our Fellows. As the duties connected with the abstraction of papers are in- creasingly laborious, the Society has determined to appoint a Sub-editor with special functions, and they have been fortunate in securing for this purpose the services of Mr. C. E. Groves. A twelvemonth ago the Research Fund, which had been started by the munificence of Dr. Longstaff, and had been augmented by large donations from some of the City Companies, amounted to $3,333 13s. It has now reached the sum of S4,320 1%. It has been thought better to award in the form of grants only the interest of this money ; but several grants have thus been made, and there have already been communicated to the Society two papers resulting from the assistance we have thus been enabled to render. The first by Dr.Wright and Mr. Luff, “ On Some Points in Chemical Dynamics ;” the second by Mr. G. S. Johnson, “ On Certain Poly-Iodides.” The Society’s Research Fund is considered to be a matter of so much interest, and will probably be so beneficial in the future, that it has been thoughtANNIVERSARY MEETING. 223 advisable to publish a separate report. It is hoped that the circula- tion of it will induce many other chemists, especially those to whom the pursuit of our science has become a source of wealth, to contribute handsomely fo the fund. Mr. Abel’s address last year alludes to a scheme for the formation of an independent Institute of Professional Chemists.This has since been incorporated (2nd October) nnder the title of the “ Institute of Chemistry of Great Britain and Ireland,” with the two following objects :-a. To promote and encourage a thorough study of chemistry, and all branches of science allied thereto, in their application to the arts, to agriculture, to public health, and to technical industry. b. To adopt such measures as may be necessary for the advancement of the profession of chemistry, and particularly for the maintenance of the profession of the consulting and analytical chemist, on a sound and satisfactory basis. It will thus be seen that its scope is totally different from ours. We deal with chemiatry in all its branches as a science ; the Institute takes cognizance only of its practical applica- tions.We are not interested in chemistry as a profession, while the Institute seeks to improve the status of practising chemists. It will thus be seen that the two societies are perfectly distinct, but may be mutually helpful. We therefore wish all prosperity to the new Insti- tute. It held its first general meeting in our rooms, on February the lst, under the presidency of Professor F r a n k l a n d ; many of the leading members of our Society have a place among its Officers and Council; while, as may be expected, a large number of chemists seek the advantages that may be derived from connection with it, as well as from our Fellowship. The Treasurer’s report will show that the financial position of the Society is not unsatisfactory, especially considering that tb e number of Fellows who have been elected during the past twelve months has been below the average.The funds have had an important addition from the legacy of the late C. Lamhert, amounting to the sum of $1,000, in consequence of which the Council have been enabled to increase the investments by $1,500. The number of Papers read before our Society during the past year has amounted to 65, besides two Lectures by gentlemen who have paid special attention to the subjects of general interest upon which they discoursed. The titles of the Papers were as follows:- I. “ On the Estimation of Manganese in Spiegeleisen, and of Man- ganese and Iron in Manganiferous Iron Ores : ’’ by E.Riley. 11. ‘‘ On a Method of Detecting small quantities of Bismuth : ” by M. M. P. Muir. s 2224 ANNIVXRSARY MEETING. 111. “ On certain Bismuth Compounds. Part V:” by M. M. P. Muir. IV. “ Notes on Madder Colouring Matters, Munjistin, Purpurin, and V. “On some points in Gas Analysis: ” by J. W. Thomas. VI. “Experiments on the Decomposition of Nitric Oxide by Pyro- gallate of Potash: ” by W. J. Russell and W. Lapraik. GII. “Contributions to the History of the Naphthalene Series. No. I. Nitroso-&Naphthol:” by J. Steuhouse and C. E. Groves. VIII. ‘‘ On Asbestos Cardboard and its uses in the Laboratory : ” by W. N. Hartley. IX. “ On a Slight Modification of Hofmann’s Vapour-Density Apparatus : ” by M. M. P. Muir and S. Saguira. X. ‘‘ Note on the Fluid contained in a Cavity in Fluor Spar : ” by J.W. Mallet. XI. “ Examination of Substances by the Time Method : ” by J. B. Hannay. X I . “On the Dehydration of Hydrates by the Time Method. Part I. Iron and Aluminium Hydrates : ” by W. Ramsay. XIII. ‘‘ On the Tpansformation of Aurin into Rosaniline : ” by R. S. Dale and C. Schor lemmer. XIV. ‘‘ On certain Bismuth Compounds. Part VI : ” by M. M. P. Muir. XV. ‘‘ On the Theory of the Luminous and Non-luminous Flames : ” by J. Philipson. XVI. ‘‘ On the Gases enclosed in Lignite, Coal, and Mineral Resins from Bovey Heathfield :” by J. W. Thomas. XVII. ‘‘ On Apparatus for Gas Analysis : ” by Dr. $ran kland. XVIII. ‘‘ On Narcotine, Cotarnine, and Hydrocotarnine. Part V : ” XIX. “ On Otto of Limes: ” by C. H. Piesse and Dr.Wright. XX. “On Primary Normal Heptyl Alcohol and some of its Deri- XXI. “On the Transformation of Aurin into Rosaniline: ” by R. XXII. “ On Diamyl :” by H. Grimshaw. XXIII. “ On the Action at a High Temperature of certain Vola- tile Metallic Chlorides on certain Hydrocarbons : ” by Watson Smith. XXIV. “ On Thsllious Platinocyanide : ” by R. J. Friswell and A. J. Greenaway. XXV. ‘‘ On Crystalliaed Barium Silicate: ” by E. W. PrBvost. XXPI. “Note on Anethol and its Homologues: ” by W. H. Purpuroxanthic Acid: ” by E. Schunck and H. Roemer. by C. R. A. Wright. vatives : ” by C. F. Cross. S. Dale and C. Schorlemmer. P e r kin.ANNIVERSARY W,ETL,VQ. 225 XXVIT. “ Note on Persulphocyanic Acid :” by R. W. Atkinson. XXVIII. “On the Oxidation-Product8 of Aloins:” by W.A. T i Id en. XXIX. ‘‘ On some Hydrocarbons obtained from the Hornologues of Cinnarnic Acid, and on Anethol and its Homologues:” by W. H. Perkin. XXX. ‘‘ On two new Methods for estimating Bismuth Volumetri- calls : ” by M. M. P. Muir. XXXT. ‘( On the Oxidation of Ditolyl : ” by T. Carnelley. XXXIT. ‘‘ Note on a New Manganese Reaction : ” by J. B. Hannay. XXXIII. ‘‘ On some points in Chemical Dynamics : ” by C. R. A. Wright and A, P. Luff. XXXIV. “On the Chemistry of Cocoa Butter, Part I. Two new Fatty Acids:” by C. T. Kingzett. XXXV. ‘( On the Influence exerted by Time and Mam in certain Reactions in which Insoluble Salts are produced : ” by M. M. P. Mnir. XXXVI. ‘( On Nitrification : ” by R. Warington. XXXVII, (‘ On Potable Waters: ” by E. J. Mills.XXXVIII. ‘( On some Derivatives of Allyl-acetone: ” by J. R. XXXIX. ‘‘ On a Fourth Method for estimating Bismuth Volume- XL. ‘‘ On the Gas of the Grotta del Cane :” by T. Graham Young. XLI. ‘‘ Note on Tetrabromide of Tin : ” by T. Carnelley and L. T. O’Shea. XLII. ‘( On the Bromo-derivatives of Camphor: ” by H. E. Arm- strong and Mr. Mlttthews. XLIII. u On the Action of Iodine on Camphor : ” by H. E. Arm- strong and Mr. Easkell. XLIV. “On the Constitution of Terpenes and Camphor:” by Dr. Armstrong. XLV. ‘( On the Hydrocarbons obtained from Pinw Sykestris, with Remarks on the Constitution of the Terpenes : ” by W. A. Tilden. XLVI. “On Citric Acid as a Constituent of Unripe Mulberry Juice:” by C. R. A. Wright and G. Patterson. XLVII. “On Cuprous Chloride and the Absorption of Carbonic Oxide and Hydrochloric Acid Gas: ” by J.W. Thomas. XLVILI. “On the Luminosity of Benzol when burnt with Non- luminous Combustible Gases: ” by E. Frankland and L. T. Thorne. XLIX. “On the Action of Reducing Agents on Potassium Per- manganate: ” by F. Jones. Crow. trically:” by M. M. P. Muir.226 ANNIVERSARY MEETING. L. “ On the Action of Sulphuric Acid on Copper:” by Spencer LI. “ On the Analysis of Sugar : ” by G. Jones. LII. “ On the by W. Ramsay. LIII. “On the AlkaloiIds of the Aconites, Part 11. On the Alkaloids contained in Aconitzcm Ferox ; ” by C. R. A. W r i g h t and A. P. Luff. LIV. “Notes on the Tannins:” by B. H. P a u l and C. T. Kingae t t. LV. “ Notes on the Estimation of Phosphorus in Iron and Steel : ” by E. Riley. LFI.“ An Inquiry into the Action of the Copper-Zinc Couple on Alkaline Oxy-Salts: ” by J. H. Gladstone and A. Tribe. LVII. “On a new Method for the Determination of Boiling Points : ” by W. Jones. LVIII. “ On some new ‘Derivatives of Anisoil: ” by W. H. Perkin. LIX. “ Note on the Action of Ammonia on Anthrapurpurin : ” by W. H. Perkin. LX. “ On certain Polyiodidea : ” by G. S. Johnson. LXI. ‘‘ On an improved Form of Wash-bottle : ” by T. Bayley. LXII. “ On the Preparation of Glycollic Acid : ” by R. T. Plump- LXIII. “ On Nitrosamines : ” by 0 t t o N. W i t t. LXIV. “ On a new Process for the Estimation of Cyanides : ” by LXV. “ On cerfain Bismuth-compounds,” Part VII : by M. M. P. Picker i n g. Decomposition-prodncts of Quinine : ” ton. J. B. Hannay. Muir. Lectures.“ On the Discrimination of Crystals by their Optical Character : ” ‘‘ On Laboratory Experiences on board the ‘ Challenger ’ : ” by J. by Prof. N. S. Maskelyne, F.R.S. Y. Bnchanan, F.R.S.E. Several of these communications have been illustrated experiment- ally before our audience, a course of proceeding which always adds much to the interest and profit of the evening. The Preparation-room which now exists affords the authors of papers a better opportunity of doing this than wm previonsly the case. The statistics of membership of the Society are as follows :-ANKIVERSARY MEETING. 227 Number of Fellows last anniversary ........ 916 Since elected and paid admission fees ...... 49 965 Removed on account of arrears ...... 13 Withdrawn ........................ 5 Deceased ..........................9 - 27 Present number of Fellows ...... 938 Number of Foreign Members last anniversary 36 Deceased .............................. 1 Present number of Foreign Members.. 35 1 - - Associate elected since last anniversary.. .... The loss sustained by the clertth of Fellows has not been heavy, but it includes one eminent foreign member, M. Regnaul t ; as well as Messrs. Richard Apjohn, J. P. Gassiot, J. J. Griffin, Wil- liam Gossage, Thomas Hall, E. L. Koch, Martin Murphy, Dr. H. M. Noad, andMr. E. F. Teschemacher. Mr. Richard Apjohn, M.A., was the son of Professor Apjohn, of Dublin, and from his boyhood evinccd a great interest in those branches of science to which his father is devoted. He was educated first at t.he Royal School, Enniskillen, but entered Trinity College, Dublin, in 1866, and during his first year took the highest honours in mathematics. In 1871 he continued his studies in Germany, in the laboratories of Professors Kekul6 and Clausius.I n December, 1872, he was chosen Prselector of Chemistry in Caius College, Cambridge. I n 1876 that university conferred on him the degree of M.A., honoris cuusa, his lectures having been previously recognised. He also held the post of Public Analyst for Cambridgeshire, Huntingdonshire, and the Isle of Ely. He died in London, on September 12th, 1877, in the 30th year of his age, his death being the result of a fall from a bicycle. His best-known papers relate to the occurrence of vanadium and titanium in the trap-rocks of different countries, and to the analysis of a meteoric stone, and the detection of vanadium in it.The latter paper is published in our Journal for February, 1874. His death was heard of with much regret, as that of a young chemist of unusual promise. In 1870 he graduated as first Gold Medallist. Mr. John P e t e r Gassiot, D.C.L., LL.D., F.R.S., was born on the 2nd April, 1797, and devoted himself to scientific pursuits, while an active member of the firm of Martinez, Gassiot, and Co., of Loudon and Oporto. His friendship with Faraday, and his connection with an electrical society formed about 1838, drew his attention especially to228 ANNIVERSARY MEETING. electric phenomena, and he spared no expense in obtaining the best apparatus that would serve to solve the problems which suggested them- selves to his mind.His spare evenings were almost always spent in the laboratory which he had fitted up in his private residence on Clnpham Common, in which also he took great pleasure iii exhibiting beautiful experiments to the scientific reunions for which his house was famous. He helped the cause of science also by his generous patronage, and the interest he took in the pursuits of others; and I am glad of the opportunity of acknowledging the encouragement I, for one, received from him when I was just commencing my professional career. He was one of the original founders of our Society ; he took a very active part in the management of the affairs of the Royal Society, and of the British Association for the Advancement of Science. He was the originator of the Royal Society Scientific Relief Fund, and Chairman of the Committee of the Kew Observatory, which he eventually muni- ficently endowed.For many years past he had been a masgistrate of the county of Surrey; and in the city of London he was one of the leading advocates of progress in most of the social and political move- ments of the day. Latterly, he had been obliged to relinquish all active duties on account of failing health, and he retired to the Isle of Wight, where he died on the 15th of August, 1877, in the 81st year of his age. His scientific researches do not properly belong to the science of chemistry, except so far as voltaic electricity pertains to our province. I n the years I840 and 1844 he published in the Philo- sophical Transactions some experiments made with the view of obtain- ing a spark before the circuit of the voltaic battery mas completed ; and others which removed the anomaly that had puzzled previous ex- perimenters, who found that the static effects of a battery did not increase with its chemical action.By experimenting with a Grove's battery OF 100 glass cells, and paying particular attention to their in- sulation, he Rhowed that the spark, the repulsion of an electroscope, the power of charging a Leyden phial, &c., did actually increase, and he thus disposed of the strongest objections to the chemical theory of the pile. Among the various points he examined was the decompo- sition of water under pressure, and he showed that even up to a, pressure of probably 447 atmospheres, water is electrolysed, and conducts without apparently offering any extra resistance to the current.He subsequently investigated the beautiful phenomena of the stratification of the electric discharge through highly attenuated gases, first observed by his friend, Mr. (now Justice) Grove; and showed, amongst other things, that the s t r k did not depend on the intermittence of the discharge, but accompanied all electric discharges in the so-called vacuum tubes; and that when the attenuation was pushed to it high degree of rarity, no electricity would pass at all.ANNIVERSART MEETING. 229 These researches formed the subject of the Baberian lecture of 1858. Among the last of his investigations were those with powerful spectroscopes, with which he solved certain physical problems.Nr. J o h n Joseph Griffin was born in Loudon in 1802, and was originally brought up to the trade of a bookseller in the firm of Messrs. Tegg and Co. He commenced business with his eldest brother in Glasgow as a bookseller and publisher, and a dealer in chemical apparatus. The publishing business was separated from the philosophical department in 1852, the one continuing under the care of his nephew, as Charles G r i f f i n and Co., while he established the well-known firm of J. J. Griffin and Sons. He received his chemical training at Paris and at Heidelberg ; and in early d a p he published a translation of Hein rich Rose’s “ Handbuch der Analyt- ischen C hemie.” He also partially edited the ‘‘ Encyclopedia Metro- politana,” of which his firm were the publishers.He was one of the original promoters of our Society, and was earnest in his endeavours to introduce scientih method into commercial processes, and to popularise the study of chemistry, with which latter object he wrote “ Chemical Recreat.ions,” a book which has had a successful career. He was also the author of ‘‘ A Treatise on the Blowpipe,” “ A System of Crystallography,” “ The Radical Theory in Chemistry,” “ Centi- grade Testing as applied to the Arts,” “ The Chemical Testing of Wines and Spirits,” and other papers. He took much interest in simplifjing and improving the apparatus in common use. He died at Park Road, Haverstock Hill, on the 9th June last, in the 76th year of his age. Mr. William Gossage, J.P., was born in the year 1799, and was the youngest of a family of thirteen children.His early education could not have been extensive, as he left school at the age of 12 years. He was subsequently apprenticed to an uncle at Chesterfield, who was a chemist and druggist. While there, he not only made himself ac- quainted with the principal chemical books of that day, but also, with the assistance of a French refugee, acquired a competent knowledge of the French language. The ardour of the teacher was not, however, equal to that of his pupil ; and as he sometimes failed to be up at four o’clock in the morning for the purpose of giving his lesson, an alarum was invented for him by Mr. Gossage, which was afterwards patented. On leaving Chesterfield, Mr. Gossage commenced business as a druggist at Leamington, and entered upon the manufacture of Leam- ington salts.In 1830 he was appointed chemist to the Stoke Prior Salt and While there he married.230 ANNIVERSARY MEETI.KG. Alkali Works in Worcestershire. In those days open furnaces were employed, and no attempt was made to condense the hydrochloric acid. Alkali works thus became a great nuisance as the trade extended ; and the attention of practical men was directed to the abating of this nuisance and the saving of the acid. These objects were attained by Mr. Gossage through the invention of his condensing towers, which were perfectly successful, and are now employed by every manufac- turer of salt cake in the kingdom. Similar towers were also used after- wards for the oxidation of red liquors. Mr.Gossage was also the first to appreciate the waste of manga- nese that occurred in the old process for the production of chlorine in making bleaching powder, and one of the patents he took out evidently foreshadows that with which Mr. Weldon’s name is associated. In 1841 Mr. Gossage removed to Birmingham, where he was occupied in the manufaeture of white lead. In 1844 he commenced copper smelting in South Wales, and devoted much attention to the recovery of sulphur from the waste gases given off in calcining the ore. I n 1848 he returned to Stoke Prior, and two years later moved to Widnes, where he established himself as an alkali manufacturer, and erected mills for crushing the limestone used in working Le Blanc’s process. He also established smelting works for extracting copper and silver from the burnt Irish pyrites, which had hitherto been thrown away by the siilphuric acid makers as waste.It was here that in 1853 he first applied his condensing towers to the oxidation of black-ash liquors; and in the same year he patented a process far obtaining caustic soda directly from them, which is now in general use. Tallow being very dear in 1854, in consequence of the Russian War, &fr. Gossage turned his attention to the mauufactureof soap. After experiencing many difficulties, he succeeded in producing excellent and cheap soaps from palm oil, silicate of soda, and other materials. He subsequently commenced the manufacture of other descriptions of soap, and the works were gradulally extended until they became the largest in England.In 1837 Mr. Gossage read a paper on the history of the alkali manufacture before the British Association at Manchester ; and a sup- plementary one in 1870 at Liverpool. He was elected a Fellow of this Society in 1862 ; and in 1866 was placed on the Commission of the Peace for the County Palatine of Lancaster. As an employer, he was just and considerate ; as a manufacturer, honourable and energetic ; and as a friend, genial and sincere. Thomas Hall was born in London in September, 1818. His parents came from Rerwick-upon-Tweed, from which town the familyANNIVERSARY MEETING. 231 removed, in consequence of his father obtaining an appointment under the Admiralty at Somerset House. Educated chiefly at University College, Mr. H a l l was remarkable when very young for his love of imparting knowledge to others, and when a boy of 17 years of age he had already given several courses of instruction to working men at the London Mechanics’ Institution, Chancery Lane, in recogni- tion of which services he was made a Honorary Member, and the “ Thanks of the Committee ” were voted to him by a resolution dated 23rd November, 1835.Soon afterwards he proceeded to qualify for the legal profession, matriculated, and took his degree of Bachelor of Arts in the University of London. The intention of following the law was, however, put aside by his seeing an advertisement referring to a vacancy in the then newly- established City of London School ; he applied for the post, and was elected Assistant; Classical and Mathematical Master in the year 1837.When the Royal College of Chemistry opened, Mr. H a l l entered as one of Dr. Hof mann’s first pupils, and after a short course of study there, and at the evening classes of Dr. J o h n Ryan at the Royal Polytechnic Institution, he, in turn, succeeded in inducing the Rev. Dr. Mortimer, late Head Master, and the Committee of the City of London School, to form a, class for scientific instruction under his auspices, and, by way of experiment, a course of lectures ‘‘ On Heat and the General Properties of Matter,” was given in Easter Term, 1847. These lectures proved so attractive that they paved the way for the introduction of chemical studies as part of the curriculum of the school, and for twenty-one years Mr. Hall laboured so hard at his favourite theme, that the City School, with its 650 boys, becamo in some sort a feeder to the Institution in Oxford Street, and a regular succession of pupils was thereby induced to enter the scientific pro- fession and proceed for further study to the Royal College of Che- mistry.Amongst those who are indebted to Mr. Hall for their earliest training in science, are some of the Officers of this Society, and a score or more of its Fellows. During the London vacations Mr. H a l l occasionally visited the schools and laboratories of the Contineut, for the purpose of gaining information as to the system of education pursued ; and his thorough knowledge of the French language enabled him to adapt the system of his friend Dr. Ahn to English wants, and to publish, in conjunc- tion with his brother, Mr.J o h n Paxton Hall, the well-known little work entitled “ Hall’s First French Course,” which was fol- lowed by a “ Second French Course ” for the use of more advanced students. Later on, when illness compelled his retirement from the City of London School (in the year 1868), Mr. Hall spent his winters abroad, and seemed ever ready to improve his knowledge of foreign232 ANNIVERSARY MEETINQ. languages, in the acquisitlion of which he found great pleasure. On his leaving the City School, testimonials were presented to him both by his scientific pupils and by graduates of the Universities who had formerly benefited by his instruction. The Court of Common Council awarded him a pension, which he only lived to enjoy for about eight years, by which time the malady from which he suffered (Bright’s disease) had so undermined his constitution, that he was brought home with difficulty from Switzerland, and died on the 10th July, 1877, a t his son’s house in Ryde, Isle of Wight, in the 59th year of his age.A few days later his remains were interred a t Abney Park Cemetery in the presence of several friends and former pupils. Mr. H a l l was twice married, and leaves two children by each mar- riage, besides the widow, to mourn his loss. He will be remembered for his genial disposition, and for the hearty devotion and enthusiasm which characterised his work, giving encouragement to his pupils, and inaugurating within the city of London the most complete system of scientific training that had hitherto been introduced into a school course.It remains only to be mentioned that Mr. Hall spent some time in devising and perfecting a ship’s pyrometer, which was int,ended to be used for indicating any sudden rise of temperature in the hold of a vessel loaded with coal or other inflammable cargo. Mr. Michael Murphy, who died on the 23rd April last at the age of 48 years, was born a t Ennis, in Ireland, and was intended by his parents to enter the priesthood ; b u t their purpose being frustrated, he determined, when only 16, to go to England and carve out his own fortune. He walked in three days from Limerick to Dublin, and then on to Kingstown to catch the steamer for Liverpool. Not meeting with any employment there, he went to Newton, and accepted an engage- ment a t Muspratt’s Chemical Works.When the College of Che- mistry was started at Liverpool, he was removed thence and placed in the laboratory : and he continued his connection with this Institu- tion till, after the death of Dr. M u s p r a t t in 1871, almost the entire responsibility of its management rested upon him from 1855 onwards. I n 1854-55, Muspratt’s “ Dictionary of Chemistry as applied to the Arts and Sciences,” was issued, the bulk of the editorial work devolv- ing upon Mr. Murphy, who devoted 16 hours a day to it during the two years it was passing through the press. From 1864 to 1866, he was Honorary Secretary to the Liverpool Chemists’ Association. He was about to enter upon the manufacture of oxide of cobalt for the supply of the potteries, and had just completed the erection of extensive chemical works at the Old Swan, Liverpool, when he was overtaken by death in 1877, leaving a widow and two daughters to mourn his loss.ANNIVERSARY MEETING.233 Henry Minchin Noad, Ph.D., F.R.S., was born June 22nd, 1815, at Shawford, near Frome, Somerset. He was the second son of Mr. Humphrey Minchin Noad, a wealthy cloth manufacturer, and his mother was half-sister t o George Canning. He was educated at the Grammar School of Frome, with the intention of entering the Civil Service of India. After the death of his distinguished relative, the hopes of a good appointment rested mainly on the friendship of Mr. Huskisson, but these were frustrated by the fatal accident to that statesman at the opening of the Liverpool and Manchester rail- way. At school he listened to a course of scientific lectures, which ap- pears to have laid the foundation of his taste for such pursuits.After leaving school he fitted up a laboratory in his father’s factory, where he worked at chemistry and electricity with lightning conductors and water-batteries. When only 19 years of age, his knowledge of science and his command of language became known, and he was invited to lecture first at Frome, and subsequently at Bath and Bristol. He re- ceived encouragement in his experiments from Dr. Wil k inson of Bath, Mr. Andrew Cross, and many others. While assisting his father in his business, he found time to experiment and to publish some of his results, as well as his book on electricity. In 1839 he married his cousin, and in 1845, at the death of his father, he was left free to follow as a profession those pursuits which had been his recrea- tion and delight from his boyhood.At once he came to London, and studied under Hofmann in the newly founded Royal College of Chemistry. I n I848 he was appointed to the Chair of Chemistry i n the Medical School of St. George’s Hospital, which he held till the time of his death. Soon after he obt’ained this lectureship, he visited Germany, and obtained his doctorate at the University of Giesaen. He was elected a Fellow of the Royal Society in 1856. He was also connected with the British Association. Dr. Noad was well known both as an author and as an investigator. In 1839 he published his “ Lectures on Electricity,” which soon became a recognised text-book, passing through four editions, and in 1857 giving place to a “ Manual of Electricity,” in two volumes ; this became a standard book on all that related to the science of electricity and magnetism, and the electric telegraph of twenty years ago.He also produced a “ Student’s Text-book of Electricity,” and in 1872 revised the new edition of Sir Snow Harris’ “ Rudimentary Mag- netism.” In 1848 he wrote a valuable treatise for the Library of Useful Knowledge, entitled “ Chemical Manipulation and Analysis, Qualitative and Quantitative ; ” while quite recently he re-wrot,e Normandy’s “ Commercial Handbook of Chemical Analysis,” a volume intended to meet the wants of the analyst, while discharging234 ANNIVERSARY MEETING.his duties under the Adulteration Act. During the few years preced- ing his arrival in London, we find him examining the peculiar voltaic conditions of iron and bismuth, describing some properties of the water-battery, and elucidating that curious phenomenon the “ passive ” state of iron. While with Hofmnnn in London, his activity was directed into channels more peculiarly his master’s, and we find him studying the products of the oxidation of cymene. The results were in part communicated to the Chemical Society at the time, and partly more fully elaborated and published in the “ Philosophical Trans- actions ” in later years. Among other organic products, legumin and vitellin also formed materials for his investigation about this time ; but after a while he relinquished organic chemistry to occupy him- self in another field. In 1850-51, he conducted, conjointly with the late Mr.Henry Gray, an inquiry into the composition and functions of the spleen. The essay resulting from this investigation gained the ‘‘ Astley-Cooper ” prize of 1852. We next find him devoting himself to the chemistry of iron manufacture, and in 1860 he contributed the article “ Iron ” t o Hunt’s edition of Ure’s Dictionary. The ex- perience gained during many years’ study of this branch of applied chemistry increased his sphere of usefulness, and led to his being ap- pointed consulting chemist to the Ebbw Vale Iron Company, the Cwm Celyn and Blaina, the Aberdare and Plymouth, and several other ironworks in South Wales. In 1866 he was appointed Examiner of Malt Liquors to the India Office, and in 1872 an Examiner in Chemistry and Physics at the Royal Military Academy, Woolwich, both of which appointments he held until his death.At the time of his fatal illness he was engaged in an elaborate series of experiments in connection with the brewing of malt liquors. Dr. Noad took little part in public proceedings, but the upright- ness and worth of his personal character wem highly esteemed by those friends who had the advantage of his private acquaintance. Edward Frederick Teschemacher, the son of the well-known analyst of that name, was born at Highbury on January 23rd, 1843. His ancestors were distinguished for their eminence in science. His mother’s father was Richard Phillips, one of the founders of our Society, and its President in 1849 and 1850,.Her uncle was William Phillips, the associate of Conybeare in geological studies; and his own uncle Jam e s T e s c h e m a c h e r was the fellow labourer with Dan a in the United States of America. The subject of the present memoir began his chemical studies under Dr. Hofmann at the Royal College of Chemistry in 1859, and con- tinued them under Professor Williamson at the laboratory of Uni-ANNIVERSARY MEETIhTG. 235 versity College, where he took the Gold Medal for Chemistry in 1861. He then entered his father’s laboratory to acquire a special technical knowledge of his profession, and remained there (his father dying in 1862) until he was taken into partnership by Mr. J. Denham Smith, the surviving member of the firm, in 1867.He was a rapid and accurate analyst, and his published papers deal principally with practical analysis. That on the Estimation of Potash by the Chloride of Platinum method was published in 1867 ; thst on the Estimation of Sulphur by Barium in 1871 ; and one on the Deter- mination of the Amount of Morphia in Opium appeared in 187’7, only a few months before his death, which took place on the 13th Sep- tember. He became a fellow of our Society in 1864, and subsequently of the Geological and Royal Geographical Societies. He was married in 1873, and has left a family of three children. Henry Victor Regnault was born at&-la-Chapelle, July 21, 1810. He lost both his parents when he was only eight years old, and his yout’h was spent in a hard battle against, poverty in the effort to maintain not only himself but his sister.While still a lad, he wan- dered to Paris, and there obtained a situation as assistant in the large drapery establishment known as Le Grand CondB. Here ability and fidelity won for him friends, and at the age of 20 he was enabled to gratify his longing for a scientific education, and enter the Ecole Polytechnique. After a course of two years there, in 1832, he joined the Ecole des Mines, and spent three years in his studies, including visits to Belgium, Germany, and Switzerland. In 1835 he entered Berthier’s laboratory, and in 1838 was made Joint Professor of Assaying at Lyons. Here he entered upon the field of research in organic chemistry which had just sprung into existence as a branch of chemical science, under the hands of Liebig, Wohler, Laurent, Dumas, and others, While many of the chemists of the day were engaged in theoretical disputes, and the battle between the electro- chemical theory and the newly advocated type theory was being hotly waged, Regnault devoted himself to the accumulation of the facts needed by the disputants on both sides.Among his investigations at this time may be mentioned those on the composition of meconine, piperine, cantharidine, and other alkalojids ; the composition of pectic acid; the identity of equisetic with maleic acid; the properties of naphthalene-sulphonic acid, &c. By the action of sulphuric anhydride on ethylene, he obtained the carbyl sulphate, C2H4S206, which Magnus prepared subsequently from alcohol.His most valuable researches, however, were on the halogen derivatives in the ethyl-group, especially interesting at the time of their appearance, when the theories of sub-236 AXNIVERSARP MEETIN 0. stitution were being timidly advocated. Among these compounds, now familiar reagents, mere monochlore thylene chloride, C H, C 1. UH CI,, obtained by the action of chlorine on ethylene chloride, as well as the higher chlorinated derivatives, which offered one of the most striking instances of substitution. These were followed shortly after (1838) by the clsssical investigations on the action of chlorine on ethSl chloride, C,H,Cl, in which one by one all the hydrogen atoms were successively replaced by chlorine, until the limit C,Cl, was reached. Regnault showed that the isomeric substitution-products obtained from chloride of ethyl and from Dutch liquid, possessed very different properties, a fact which proved that the substitution effected did not destroy the niolecular grouping of the original substances.He also established the change of ether, C,H,,O, into perchlorinated ether, c4c1,oo. Another interesting series of preparations gave the substituted ethylenes by the action of alkalis on saturated halogen derivatives, ethylene bromide, for example, yielding vinyl bromide and hydrobromic acid. By this method R e gn a u l t discovered vinyl bromide, iodide, and chloride, dichlorethg-lene, and trichlorethylene. Finally must be mentioned his discovery of carbon tetrachloride, by passing chlorinc into boiling chloroform.It is difficult for us a t the present day to estimate the importance ol these discoveries forty years ago ; and few series of researches havc stood the test of time so well as those carried out by Regnault in his Lyons laboratory. The eighteen papers in the AnTLaZes cle Cliimis et clt Physique, which contained the result of his researches, attracted th attention of the scientific world to the hitherto unknown provincial professor. I n 1840 he was elected to the Chemical Section of thc French Academy, and was appointed professor in the Ecole Polytech- nique. I n the following year he was elected to the chair of physics at the Collhge de France. I n 1847 he became Ingenieur en Chef de Mines, and a few years lat’er received the order of Officer of the Legior of Honour.With his removal to Paris, the field of Regnanl t’s investigations was changed. Like our own F a r a d a y , after having obtained renown as a chemist, he suddenly turned physicist. He was scarcely estab- lished there, when he began his famous series of experiments on Specific Heat. A few years previously Dulong and P e t i t had deter- mined the specific heat of a number of elements by means of their calorimeter, based on their method of cooling, and obtained data suffi- ciently accurate to warrant the establishment of their law that the product of the specific heat of an element and its atomic weight is P constant. R e g n a u l t , after having submitted their method to careful examination, found it useless for the exact determination of the specificANNIVERSARY MEETING.237 heat of solids, and invented in its place the calorimeter bearing his name. It is based on the method of mixtures, viz., of heating a known weight of a substance to st known temperature, immersing it in a known weight of water at a known temperature, and determining tbe temperature of the mixture. With this apparatus Regnaul t deter- mined the specific heat of the liquid and solid elements, and of a great variety of compounds. From the comparison of these results he de- duced the general law that for all compounds of the same formula and similar chemical constitution the product of the specific heat and the atomic weight is the same. He also confirmed the hypothesis that the elements require the same amount of heat in order to be raised to a, certain temperature, whether free or in combination, and showed, by his more exact results, the general truth of Du l o n g and I'e ti t's law.In order to overcome the difficulties of determining the specific heat of gases, Regnault employed an ingenious apparatus in which the gases passed through a spiral inclosed in a known weight of water. The volume of gas, its temperature on entering and leaving the appa- ratus, and the alteration in the temperature of the water, supplied the necessary data. By this means he experimented with about thirty- five of the principal gases and vapours, and established the two im- portant laws, 1, that the specific heat of any gas a t constant pressure, whether simple or compound, is the same a t all pressures aud tem- peratures ; and, 2, that the specific heats of different simple gases are in the inverse ratio of their relative densities.Regnault prepared also an interesting table of the specific heats of various substances in t,he solid, liquid, and gaseous forms, from which it appears that the specific heat of a body is commonly greater in the liquid than in the solid state, and always greater than in the gaseous state. In his experiments upon heat, R e g n a u l t was led to devise methods of measuring high temperatures accurately, and invented the well- known air thermometer, which can be used a t all temperatures below that at which glass softens, and the mercury and hydrogen pyrome- ters. He carried out also an elaborate series of experiment,s on the density and absolute expansion of mercury fl'om 1" to 360", the results of which are of primary importance in the correction of thermometers and barometers, as well as in a multitude of physical experiments.Still more elaborate and exhaustive are the series of determinations in connection with water, its specific heat a t various temperatures, the tensicn of its vapour a t various temperatures, and the latent heat of its vapour at various pressures, all intended for practical application in the construction of steam cngines. For the determination of the tension of steam, R e g n a u l t contrived a simple apparatus based on the fact that thc maximum tension of steam a t the boiling point ir; equal to the external pressure, by the aid of which he was able to con- VOL. IISXIII. T238 ANNIVERSARY MEETING.striict his, table of tensions from 0.32 mill. a t 32" t o 20,926 mill. a t 230". The experiments with this apparatus were extended to a number of volatile liquids, with the design of testing the truth of Dalton's supposition, that the tension of the vapours of all liquids is the same a t temperatures equally distant from their boiling points, and the re- sults showed that it was only approximately correct. A variety of interesting results were also obtained from mixtures of gases and vapours, including the laws that a liquid does not give off a vapour of so high a tension in presence of a permanent gas as in a vacuum, and that while the tension of the vapours of a mixture of liquids not dis- solving each other is equal to the sum of the tensions of the liquids a t the same temperature, the tension arising from a, mixture of mutually solvent liquids is less than the slim of the individual tensions. Perhaps the most important of Regn a u l t's experimental invesCJiga- tions was that on the coefficient of expansion for air and other gases, as well as on the compressibility of gases.Dalton, Gay-Lussac, and R u d b e r g had obtained numbers for the coefficients of expansion, differing widely from one another. It mas reserved for Regnault to establish, by the most delicate experiments, the number -03663 as the coefficient of expansion of air, and to show in addition that the law of Dalton and Gay-Lussac, with regard to the regularity of expansion among gases, was only approximately correct. A similar result was obtained in his investigations on the accuracy of Boyle and Mariot t e's law on the compressibility of gases.R e g n a n l t also made a variety of interesting experiments on the phenomena produced by heat, and his hypsometer and hygrometer should be mentioned on account of their simple and practical character. Some valuable investigations on the phenomena of respiration were made by him in connection with Reiset, and, together with Dumas, he cai-ried out a research on illuminating gas. His most valuable experimental results are collected together in vol. xxi of the 1Clrei)zoires of the French Academy, and a continuation is to be found in vol. xxvi. Regnault published in 1847 a treatise on Chemistry, which has passed through numerous editions in France, and been translated into German, English, Dutch, and Italian.He was made a Fellow of the Royal Society in 1852, and obtained the Rumford and Copley medals of that body in 1848 and 1869 respec- tively. I n 1854 he was appointed director oE the famous porcelain manufac- tory of SBvres, and after that date much of his time was devoted to improvements in ceramic processes. During the Franco-German war lie received a sad blow, in the death on the battle-field of his second son, Henri Regnault, a promising artist, and universal favourite inANNIVERSARY MEETING. 239 Paris. He returned t o his laboratory at S h e s , after &he declaration of peace, to find that. his standard apparatus and papers, with the result of his last great research on the phenomena of heat accompanying the expansion of gases, derived from over 600 observations, had been destroyed.Since that time grief and increasing infirmities forced him to renounce his wonted pursuits. He died on the 19th of January, 1878? the anniversary of his son's death. As a scientific investigator, Regnault did not possess the brilliant originality of many of his fellow-physicists. It was as a patient, thorough, conscientious observer that he won his way t o the foremost rank. Possessing a wonderful ingenuity in the invention of mechani- cal appliances for the purposes of observation, and a perfect familiarity with the mathematical department of physics, he was enabled, by means of his unflagging enthusiasm and unbending resolution, t o place the modern physicist and chemist in possession of an invaluable collec- tion of constants, which are in daily use, not only in the laboratory of research, but for a large variety of industrial purposes.* A vote of thanks t o the President for his able address was proposed by Mr.De La Rue. Dr. Frankland, in seconding the vote, referred to the establish- ment of the Institute, stating that he was at first anxious to have it founded in connection with the Chemical Society; this was found, however, to be impossible ; and he was at one time afraid that a sepa- rate body might injure the interests of the Society ; he was glad to say that his fears weye groundless, and he had every reason to believe that the founding of the Institute would furnish the Society with many welcome Fellows. The vote of thanks was put and carried.The President, in returning thanks, said that he had endeavoured to do his best for the Society, and thanked the Members of the Council, the Ofhers, and Fellows for their constant and unremitting kindness to himself. The Treasurer, Dr. Rus sell, then gave a statement as t o the con- dition of the Resea,rch Fund. Report of the Research Fund Committee. The Research Fund Committee have to report that since the last annual meeting of the Society, the following ten grants have been made :- * I am laygely indebted for this biographica1 sketch to the funeral orations reported in the Comptes Relzdzcs of the French Academy, and to the notice in ATature of January 31. T ' 22 40 ANNIVERSARY MEETING. S50 t o Dr. "Vr.ight for the investigation of certain problems in $25 to Mr.G. S. Johnson, for a research on Double Salts with $24 to Mr. E. Neison, for a research on Octyl Compounds. S2S to Mr. W. Carleton Williams, for a research on Hydrocar- boils containing the group Isopropyl twice. $19 t o Mr. George Harrow, for a research on Derivatives of Ace- toacetic Acid. A second grant of $50 to Dr. Wright, for the continuing of his researches on Chemical Dynamics. $25 t o Dr. Armstrong, for an investigation of Camphor and Allied Compounds. $20 to Dr. Carnelley, for st research on the Hydrocarbons, Di- phenyl, Ditolyl, Tolylphenyl, &c., and their Derivatives. $10 to Mr. P h i l l i p s Bedson, for a research on Derivatives of Phenylacetic Acid, and on the Constitution of Isatin. SS to Mr. J. K. Crow, for a research on the Action of Zinc-ethyl on the Chloride of Vanadium.Of the above grants the first five were made in July last, and the Committee are glad to be able to state that important and interesting results in connection with these investigations have already been obtained. Dr. W r i g h t published, in the January number of the Society's Journal, the first report on " Researches on some points in Chemical Dynamics." Mr. Johnson has also communicated to the Society a paper on the Tri-iodides of Potassium, which will shortly appear in the Journal. Mr. Neison informs the Committee that he has made satisfactory progress with his research ; that he has prepared considerable quan- tities of pure octylic alcohol and octylene, as well as of octylic bro- mide and iodide, and has examined certain oxidation-compounds ; and hopes to communicat'e his results to the Society before the end of the present session.Mr. Cnrleton Williams states that his research has made progress, and that he has prepared pure di-isobutyl and amyl-butyl, and has examined their physical properties ; that he has also succeeded in separating the primary and secondary alcohols from the mixture of isomeric chlorides obtained by the action of chlorine on di-isobutyl, and is now studying the action of bromine on di-isobutyl, and the pro- ducts formed by the oxidation of the above alcohols. Mr. C r o w is engaged in carrying out his research in the laboratory of Professor Fr e s en iu s, at Wiesbaden, Chemical Dynamics. Potassium Tri-iodide.ANNIVERSARY MEETING.241 The total sum thus expended this year amounts to S.245. The subscriptions and donations received during the year amount to $986 19s. Among the contributors are four City Companies, viz., the Worshipful Company of Drapers, of Mercers, of Skinners, and of Grocers, and the Committee are happy to state that the remaining part of this year’s subscriptions has been principally contributed by those engaged in chemical manufactures ; especially would they mention a donation of 61229, and an annual subscription for five years of g37 2s., from the Alkali Manufacturers’ Association. The above Association, although they in no way made it a condition, expressed a wish that Inorganic Chemistry should receive due consideration in making the grants from this fund.At the conclusion of the report it was announced that Mr. De L a R u e had offered the sum of 3.200 to be given to the Research Fund, on the condition that it was to be devoted t o any one important research. A vote of thanks to the Treasurer for his report., and to Mr. De L a R u e for his handsome donation, was proposed by Dr. Odling, seconded by Mr. Neison, and carried unanimously. The Treasurer then read his Report of the condition of the funds of the Chemical Society (see page ‘244). A vote of thanks to the Treasurer for his lucid and satisfactory statements was proposed by Mr. Abel, seconded by Mr. E. Riley, and carried unanimously. Dr. Odling then rose to move that the report of the President be received. Mr. Neison, in seconding the motion, referred to the want of re- agents in the Preparation Room, and the desirability of distributing the General Index of papers to all Fellows free of charge; he also made some remarks as to the present mode of electing and admitting Fellows.In reply, Dr. Russell said that there had been no demand for re- agents, but if such a demand did arise, there would be no difficulty in snpplying them. Dr. Armstrong said that he always made a, point o€ communi- cating, if possible, with authors so as to have anything they might want ready for their use. Mr. Crookes then proposed a vote of thanks t o Mr. W a t t s , “ our talented and conscientious editor.” Mr. Howard seconded the vote, which mas carried unanimously. Before electing the Council, &c., Dr. Odling asked the Secretary for information as to an alternative, which he ventured to designate an opposition, list which had been circulated; it was such an exact copy of the list issued by the Council that many Fellows thought that both lists had come from the same source.242 AXNTVERSARY MEETING.Dr. Armstrong replied that the persons issuing the list were unknown to him. Mr. Riley thought that the name of the Fellow who issued the list ought to have been attached to it, to prevent mistakes. Mr. Neiaon said that he had issued the list on his own respon- sibility, and that he much regretted if any one had been deceived by it. He thought, as he had proposed Mr. Kingzett at the last meet- ing, that every one would have known where the list came from; besides, an additional name on the list would have rendered the ballot- ing paper illegal.The election of Officers was then proceeded with, Messrs. Beale and Thorns on having been appointed scrutators. The following were elected :- President.-J. H. Gladstone, Ph.D., F.R.S. Vice-Presidemk-F. A. Abel, C.B., F.R.S.; Sir B. C . Brodie, F.R.S. ; Warren De LaRue, D.C.L., F.R.S.; E. Frankland,D.C.L., F.R.S.; A. W. Hofmann, D.C.L.,F.R.S.; W. Odling, M.B., F.R.S.; Lyon Playfair, Ph.D., C.B., F.R.S.; A. W. Williamson, Ph.D., F.R.S.; T. Andrews, M.D., F.R.S.; W. Crookes, F.R.S.; F. Field, F.R.S.; N. S. Mstskelyne; H. E. Roscoe, Ph.D.,F.R.S.; R. Angns Smith. Secretaries.-W. H. Perkin, F.R.S., and H. E. Armstrong, Ph.D F.R.S. Foyeiglz Xecretnry .-H u g o Mull e r, Ph.D., F.R. S. Treasurer.-W. J. Russell, Ph.D., F.R.S.The other Members of Council are.-I. Lowthian Bell, KP., F.R.S.; 31. Carteighe; A. H. Church; W. N. Hartley; C. W. Heaton; David Howard, G. Matthey; E. R i l e y ; W. A. Tilden; R. V. Tuson; R. Warington; C. R. A. Wright, D.Sc. The meeting then passed the Bye-laws as amended by the Council, with a few verbal alterations.DR . THE TREASURER IN ACCOUNT WITH THE CHEMICAL SOCIETY FROM MARCH 27. 1877. TO MARCH 27. 1878 . Salary of Librarian .............................................................. Rooks and Periodicals ........................................................... Binding Books and Periodicals ................................................ Printing Authors’ Copies ......................................................... Royal Society’s Proceedings ................................................... Reports of the Meetings ......................................................... Miscellaneous Print.ing ......................................................... .. Library Attendant ................................................ Jnsurance of Society‘s Furniture and Books .............................. Stationery, Postage, Envelopes, Receipt Books . &c ................... Expenses connected with 1 ectures ......................................... Collector‘s Commission on Subscriptions ................................. Treasurer’s Stamps, Draft Stamps and Clerical Aid Inhabited House and Income-tax .......................................... Legal Expenses ................................................................. ..................House Expenses . Provision of Refreshments a t Neetings .................................... Heating of Building ............................................................... Lighting of Building ............................................................ Cleaning of Building ............................................................ Petty House Expenses ......................................................... Wages of House Porter ......................................................... Gratuity to Gate Porter ......................................................... Petty Cash Disbursements ...................................................... Purchase of E l , 000 Metropolitan Board of Works 33 p .c . Stock Purchase of E100 do . do . ... nalance a t Coutts’ ............................................................... in hands of Treasurer ................................................ ... ,, Balance a t Bank March 27th. 1877 ...................... in hand of Treasurer ............................ .. 50 0 0 62 0 0 51 1 7 2 13 1 1 2 -- 24 1 3 1 18 7 0 35 8 1 0 19 6 8 10 6 7 37 6 0 2 2 0 0 9 3 861 1 5 1 0 4 3 7 ___I__ Receipts by Admission Fees. Subscriptions. awl Lif Compositions. f r o m March 14th. 1877. to Marc1 21st. 1878 . 5 Life Compositions ........................................ 50 Admission Fees .......................................... 9 Subscriptions for 1875 ................................. 33 . . . . 1876 ................................. 199 . . . . 1877 .................................. 556 . . . . 1878 .................................. Sale of Journal ................................................. .. Gcneral Index ....................................... Subscriptions for Proceedings of Royal Society From Public Analysts for use of Gas. Coal. &c ..... Dividend on Consols (24. 000) ............................ Metropolitan Board of Works 3 t pe cent . Stock ............................... London and North Western Railwa: Debenture Stock ......................... Legacy from C . Lambed. Esq . (amount received) .. .... .. .. Asseta . s s . a . Balance at Coutts’ .......................... 861 15 10 .. in hands of Treasurer ............ 4 8 7 Three per cent . Consols ..................... 4. 000 0 0 London and North Western Hailway Debenture Stock .......................... 788 0 0 Metropolitan Board of Works 3+ per cent . Stock ................................. I, 500 0 0 8 s . (1 . 1. 218 6 3 0 1 5 4 100 0 0 200 0 0 66 0 C 388 0 C 1. 048 13 C 263 7 7 4 5 0 18 o a .. .. 118 10 0 25 18 6 31 2 6 L s . d . 1. 219 1 7 1. 820 13 C 267 12 7 52 0 C 3 1 0 C 175 11 0 1. 000 0 0 I- . 538 8 2 Expenses on Account of Journul . I , : s . d Salary of the Editor ............................................................... Periodicals fur use of Abstractors ......................................... Print in g of Journal ............................................................... Distrilmtion of Jouriial ......................................................... Honorarium to ISditor ............................................................ Expenses on. Accozcnt of Libyary . Fees to Abstractors of Papers Incidental expenses of Editor ................................................ ............................................... - 260 0 0 219 1 8 9 5 0 0 43 1 8 6 817 6 6 126 0 7 60 0 0 .. CR . s s . d . 1. 512 4 4 177 8 4 25 19 5 3 9 6 0 23 11 0 3 9 7 0 1 9 1 4 2 0 0 1 1 5 2 4 1 0 0 41 18 6 9 1 0 0 5 5 9 147 19 5 . 013 15 0 511 17 6 865 19 5 . 538 8 2 -~D R. TREASURER OF THE CHEMICAL SOCIETY IN ACCOUNT WITH THE RESEARCH FUND. FROM MARCH 27, 1877, TO MARCH 27, 1878. CEC. J2 s. a. Balance at bank March 27, 1877 .................. 275 8 7 Subscriptions and donations ...................... 986 19 0 Dividend on North British Railway Stock .......... 39 10 0 Metropolitan Board of Works 3Q per cent. Stock ............................ 82 1 11 $1,383 19 6 ,, --- Assets. g s. d . Metropolitan Board of Works 3$ per cent. Stock .............................. 2,900 0 0 North British Railway Stock.. .......... 1,000 0 0 Balance at Bankers .................... 219 7 0 $4,119 7 0 1877. S s. d. May 31. By purchase of $500 Metropolitan Stock . . 508 2 6 July. By grants made ........................ 135 0 0 Feb. By grantsmade ........................ 110 0 0 By balance ............................ 219 7 0 187’8. By purchase of &400 Metropolitan Stock . . 411 10 0 #21,383 19 6

ISSN:0368-1645    

DOI:10.1039/CT8783300221

出版商:RSC    

年代:1878

数据来源: RSC

摘要:

245 XXVI1.-A New Process for the Volumetric Estimation of Cyanides. By J. B. HANNAY, F.R.S.E., Assistant Lecturer on Chemistry, The Owens College, Manchester. THE processes a t present in use for the volumetric estimation of cyanides by solution of silver and iodine requiring, as they do, the absence of such frequently-occurring substances as ammonia and alkalis, and depending on solutions prone to change, are in so far faulty ; and as besides it is often desirable t o estimate the cyanide in an alkaline solution already containing silver cyanide, I have con- sidered that the description of a process (which I have used for some years), and which is interfered with by no commonly occurring bodies, may have some interest for this Society. The process is the converse of that for the estimation of mercury, of which I published an account (C'hem.Xoc. Jour., June, 1873, pol. xxvi, p. 565) some years ago, and which has just received such complete confirmation (Chenz. Soc. Jozw., December, 1877, vol. ii, p. 679) a t the hands of Professor Tuson and Mr. Neison; in fact, it was the publication of their paper that induced me to write the present note. The process for the estimation of cyanogen in compounds depends on the anomalous behaviour of mercuric cyanide with alkalis ; so that, if to an alkaline solution containing cyanogen a mercuric salt is added, no precipitlate takes place until all the cyanogen is combined with mercury ; that is to say, as long as the decomposition 2KCN + HgCl, = Hg(CNX+ 2KC1 goes on, all the mercury existing as cyanide is not affected by alkalis.The cyanide is dissolved in water, placed in a beaker on a black slab (or black velvet), rendered alkaline preferably with ammonia, and a standard solution of mercuric chloride is added in successive quantities, with frequent stirring, until a permanent bluish-white opalescence is produced. The end of the reaction is sharply marked, and half a drop of a centinormal solution is sufficient to produce a strong opalescence. To test the accuracy of the process, as well as to find if other sub- stances had any interfering action, a solution of potassic cyanide, con- taining 0.00G51 gram per C.C. (decinormal), was prepared, and the strength checked by silver estimation. A decinormal solution of mercuric chloride was also prepared, containing 0.0271 of the chloride per C.C.A portion of this solntion was reduced to half strength, that is, containing0.01355 per c.c., so that one C.C. of this was equal to one C.C. of the cyanide. It was found that 20 C.C. of the cyanide gave a246 HANNAP ON A NEW PROCESS, ETC, pcrceptible opalescence, when a small fraction over 20 C.C. of the mercury solution had been added ; the excess mas less than -03 of a C.C. in an average of five estimations. To find how little would really show the turbidity, I prepared a centinormal solution, and reducing it to half strength, 1 found that 20 C.C. of the decinormal cyanide required 200.1 C.C. of the mercury solution to producs a decided opalescence; but that was the bighest, other experiments requiring between -05 to :08 C.C.of excess. This indicates a quantity of .0000651 of the cyanide, or an error of 005 percent. A large number of experiments were made on the action of alkalilie sulphates, chlorides, and nitrates, but with the same result as Tuson and Neison have already shown. I also found that very large quantities of ammonium salts prevent the appearance of the opalescence when small quantities of cyanides have to be esti- mated; but as the above anthors have shown that the interference begins only when 15 times more ammonium salt is present than of mercury, i t will be seen that in ordinary chemical analysis such a state of affairs seldom arises. The kind of impurities in which I was more inter- ested, however, were those present in samples of commercial potas- sic cyanide, principally potassic cymate and thiocyanate, as caustic alkalis and alkaline carbonates are entirely without action.Solutions of the cyanate and thiocyanate were prepared, coutaining 9 5 gram per c.c., and the following experiments were tried. Cyanate : 20 C.C. of the cyanide were measured off, and 10 C.C. of the cyanate solution added ; and after rendering alkaline with ammonia, mercuric chloride (decinormal half strength) was added, when it was found that 8 single drop over 80 C.C. caused an opalescence. Two other experiments were tried, using 20 C.C. and 50 C.C. of the cyanate; the two took 20.05 and 20.08 to produce an opalescence. The fractions were done by com- pleting the process with centinormal solution: thus it will be wen that cyanic acid has no effect on the process.Three other experiments were done, using very dilute solutions, but still there was practically no effect. Thiocyanate: as before, 20 C.C. of cyanide and 10 C.C. of thiocyanate were rendered alkaline with ammonia and the mer- cury solution added. Two others with 30 C.C. and 50 C.C. of thiocyanate respectively took 20.6 and 21 C.C. of mercury solution. I suspected that the thiocyanate could not be quite pure, so I recrystallised some of what had appeared to be pure salt, and I found that it now had no effect; three quan- tities of 20 C.C. each, with 10.30 and 50 C.C. of thiocyanate, taking 20.01, 20.04, 20.07 for the production of the opalescence. It will thus be seen that thiocyanic acid has also no effect upon this process. As it is often desirable to estimate cyanides in a solution containing silver, as in electro-platers' baths, I added silver nitrate to three quan- tities of cyanide solution in the following proportions :- It took 20.2 C.C. of the mercury.TILDEN ON TERPIN AND TERPINOL. 247 1. To 20 c.c., a quantity not sufficient to cause a precipitate. 11. ,, just sufficient to cause a precipitate. 111. ,, a large excess. On adding a little ammonia to I and dissolving the precipit,ates I1 and I11 in ammonia, each took a very small fraction over 20 C.C. of mercuric chloride solution to produce an opalescence. This shows that silver salis do not interfere with the process. It will thus be seen that we have now a process by which cyanogen in combination can be estimated accurately, even in the most complex mixtures ; and as mercuric chloride can easily be obtained pure and keeps unaltered in solution, the process is one of great facility.

ISSN:0368-1645    

DOI:10.1039/CT8783300245

出版商:RSC    

年代:1878

数据来源: RSC

摘要:

TILDEN ON TERPIN AND TERPINOL. 247 XXVIII.--On Terpin and Terpinol. (Preliminary.) By WILLIAM A. TILDEN, D.Sc., Lmd. TERPINOL is the name given by L i s t to the liquid obtained by the action of dilute acids upon terpin hydrate, but the statements of Wig- gers (Ann. Che,m. Pharm., 1846, i, 251), L i s t (ibid,, 1848, 362), and 0 p p e n h e i m (ibid., 1864, 149), regarding the composition and pro- perties of this substance are at variance with one another. Tcrpinol is described by L i s t as a liquid of specific gravity *852, boiling constantly at 168". On the other hand, Oppenheim states that when terpinol is distilled it begins to boil at 165", and that the temperature gradually rises to 208". Moreover, 0 ppen heim asserts that distillation causes a decomposition in terpinol in such a manner that the first portions of' the distillate contain more carbon and less hydrogen and oxygen than the last.The analyses of Wiggers and L i s t indicate the formula C2,H3,0 or (C,oH1,)20H2. My experiments lead me to conclusions differing materially from those of the chemists to whom I have referred, and although the sub- ject is by no means complete, I beg leave to bring before the Society such results it5 I have obtained. Cqstallised Terpin, CloHPoOz.0H2. This beautiful compound was prepared by a process essentially the same as t,hat given many years ago by Wiggers. I find that it is advantageous to use a rather large proportion of nitric acid. A mix- ture of 1 measure of nitric acid (sp. gr. 1*4), 1 measure of methylated spirit, and 2 i measures of rectified turpentine oil becomes very warm,248 TILDEN ON TERPIN AND TERPINOL.and in about two days loses the smell of turpentine. If such a mixture is then poured out into an open dish, a small quantity of methylated alcohol being added every few days, it deposits crystals which in about a fortnight amount t o one-third of the weight of the turpentine employed. I have ascertained that no crystalline compound is formed under similar circumstances from the terpenes of the orange group ; also that the same compound is obtained whether American or French turpen- tine oil be employed. The crystals from both sources agree in melting point, in crystal- line form, and in giving an alcoholic solution which does not act upon a ray of polarised light. More crystals are obtained by prolonged exposure.Action of Dilute Hydrochloric Acid upon Teipirt. Separate experiments were made upon the terpins obtained from the two kinds of turpentine oil. The productf is, however, always the same, and it will be necessary therefore to quote only one experiment. TO 53t grems of crystallised terpin, boiled up with 700-800 C.C. of water, 12 drops of hydrochloric acid were added. I n a few minutes the crystals had disappeared, and the liquid, now turbid from the pre- sence of oily matter, was distilled. A distillate of peculiar and fragrant odour was obtained. When about half the liquid had passed over, a little water containing 12 more drops of hydrochloric acid was added to the residue in the flask, and the distillation continued until all the oil had distilled over.I retain the name terpinol for the oily pro- duct. When this terpinol was submitted to distillation, the temperature went up immediately to above 200", and all but a few drops came over between 205" and 215". When redistilled it came over again between the same limits of temperatnre, but no product of more definite boiling point was obtained. It undergoes no change of properties by distillation ; neither is it changed appreciably in composition. Two analyses were made, the one of the crude product dried by chloride of calcium, but not re- distilled (1) ; the other of the liquid redistilled, and collected between 205" and 215". 1. *18925 gram gave -5445 of CO, and -2080 of OH,. 2. -2803 gram gave *8110 of CO, and *3CIIO of OH,.These results give percentages of carbon and hydrogen, which closely approximate to the numbers calculated from the formula C,,H,,O or CIoH,,.H2O. 1. 2. Calculated. C . . . . 78.3 78.9 7 7.9 H.... 12.2 11.9 11.7TILDEN ON TERPIN AYD TERPINOL. 249 The formula CzoH,,O or (C1,Hl,),OH, requires C 82.75, H 11.72 per cent. Whether the formula CloHleO correctly represents the molecular weight of this compound is a question which cannot be finally deter- mined till the vapour-density has been taken and further experiments made. For the present I am much disposed to consider that this formula should be doubled, and that terpinol should be regarded as the anhydride or ether of terpin, beaying in fact a relatlion to that compound similar to the relation of common ether to ethylic alcohol.Terpin being- terpinol must be written Almost conclusive evidence of this is snpplied by the action of hydro- chloric acidj which does not give a monochlorcde, as might be expected if terpinol had the constitution expressed by CloH17( OH). Terpinol is a colourless, somewhat viscid liquid, inactive upon the polarised ray, and having a t 16" a specific gravity -9274. When dry hydrochloric acid gas is passed into it, the liquid becomes very hot, and assumes an intense purple colour. It ultimately sets into a mass of crystals, which after strong pressure become perfectly white. These crystals were analysed, and found to contain 33.94 per cent. of chlo- rine. The compound is therefore identical with the dihydrochloride, CIOHl8 obtained by saturating terpin with hydrochloric acid gas ; also by saturating with hydrochloric acid R solution of turpentine in ether or alcohol.This compound is entirely converted into terpinol by boiling for an hour 01' two with water. When this dichloride is boiled for a few minutes with a solution of sodium in absolute alcohol, a precipitate of common salt is thrown down ; and on adding water to the liquid an oil separates, which be- comes slightly yellow on exposure t o air. In contact with ordinary strong hydrochloric acid, it is instantly converted into a crystalline mass of dichloride. It was found to contain 24.9 per cent. of chlorine. The formula CloH18 { gFzH5 requires 16.24 per cent. of chlorine. I am therefore in doubt whether this compound was formed, or whether the liquid examined was a solution of the dichloride in the compound They melt a t 50".{ :;y Terpinol is miscible with alcohol in all proportions. If the alcoholic250 TILDEN ON TERPIN AND TERPINOL. solutiou is acidified with nitric acid and placed in a dish, it deposits in a few hours abundant crystals of terpin. This fact, and the peculiar odour of the liquid left in the preparation of terpin by the ordinary process, lead me to the belief that terpinol is formed at a certain stage of the reaction between turpentine oil, alcohol, and nitric acid. Cl0H1, + C?H,OH + HONO, = C10H160 + C,H,ONO,. Terpinol. The liquid which has begun to deposit crystals, when separated, washed free from nitric acid, and heated, evolves nitric oxide and then distils chiefly between 200" and 230".I look upon t-he production of terpin as probably accomplished through the intermediate formation of a compound of terpinol with the elements of ethyl nitrate, which is subsequently decomposed by water. Terpin. The same saccession of changes may be supposed to be repeated indefinitely. Action of Sdphuric Add on Terpin. 76 grams of terpin crystals were placed in a large flask, together with about 50 grams of sulphuric acid diluted with seven or eight times its bulk of water. Steam was passed through the mixture, till a.11 the oily matter had distilled over. After separating from the water the product was found to distil entirely between 177" and 187". After redistilIation a portion was collect,ed between 176" and 177", and analysed. It gave 84.7 per cent.of carbon and 11.8 per cent. of hydrogen. The formulze ( CI0H,,)@H2 and C~oHls require respectively 82.75 and 88.2 per cent. of carbon. The product was therefore presumed to be a mixture of terpinol with a hydrocarbon. It was boiled for two to three hours with about two volumes of water and one volume of oil of vitriol. The product fractioned and finally distilled from sodium gave about one-third of its bulk at 176-178", and this portion when burnt gave numbers corre- sponding with 87.33 per cent. of carbon and 11.8 of hydrogen in one experiment, and 87.43 per cent. of carbon and 11-79 of hydrogen in a second. Its vapour-density was taken by Hof mann's method in aniline vapour, and was found to be 68.8.TILDEX ON TERPIN AXD TERPINOL. 251 This, then, is evidently a hydrocarbon, having the formula C10H16.Theory. C ...... 88.2 H...... 11.8 Density.. 68 It seems to stand in the same relation to terpin as ethylene to common alcohol, and it is probably formed by a similar reaction. It is, how- ever, exceedingly difficult to get rid of the last traces of terpinol which accompany it. After very careful purification, another specimen boil- ing at the same temperature, namely, at 176-1$8", had a specific gravity of -8526 at 15". This compound is optically inactive. Treated with hydrochloric acid it gave no crystalline deposit, but after expo- sure in a dish for severa.1 days, the liquid left a fow crystals of the dichloride CloH,,C12. These were attributed to the presence of it small quantity of terpinol in the specimen operated upon.No crystalline nitroso-compound could be obtained by the action of nitrosyl chloride. When dilnt.ed yith chloroform, cooled, and mixed with two equiva- lents of bromine, it gave a dibromide which on heating splits up into hydrobromic acid and cymene, yielding a quantity of the latter com- ponnd equal to half the weight of the hydrocnrbon operated upon. In many respects this hydrocarbon agrees with the terpene charac- teristic of Russian turpentine oil, and described in a recent paper of mine (J. Chem. Soc., Februa,ry, 1878). It differs, however, from that compound in having no action on polarised light, and to the extent of about 4" or so in the observed boiling points. The oxidation products are of course very important, and I have ascertained that both terpinol and terpinylene, as this hydrocarbon may be called, yield, besides other acids, an appreciable quantity of toluic acid melting at 176". I do not regard this as a serious obstacle to the acceptance of the formula for the terpenes I have lately pro- posed. Assuming these hydrocarbons to consist of an open chain, which is liable to be closed by the removal of hydrogen from the ter- minal carbon atoms, it is not improbable that this closing of the chain may be effected during processes of oxidation. But that this occurs in a fortuitous and irregular manner is shown by the very small amount of the toluic or terephthalic acid ever obtained from any of the CI0HlG group. Cymene, CIoHl4, in which we must admit the closed benzene ring, yields under the same circumstances something like a third of its weight.

ISSN:0368-1645    

DOI:10.1039/CT8783300247

出版商:RSC    

年代:1878

数据来源: RSC

摘要:

252 XXIX.-The Poisonous Princ+le of Uyechites Suberecta. By JAMES JOHN BOWREP, Analytical Chemist to the Government of Jamaica. THE plant which has yielded the substances to be described in this paper is very common in Jamaica, occurring sometimes in clumps standing by itself, but far more commonly climbing over fences, or clinging to low growing shrubs. Its dark-green leaves and large bright yellow flowers render it very couspicuous in the hot, dry dis- tricts in which it flourishes. In the island it is called “ Nightshade,” in consequence of its deadly character, but Professor Daniel Oliver has kindly identified it for me as Urechites suberectn, .Muell. Arg. (Echites Neriandm Griseb). My attention was specially directed to this plant by the wonderful tales told of its poisonous powers in the hands of those acquainted with its properties, it being stated that they could so administer it as to cause the very speedy death of the victim, or so as to kill only after the lapse of weeks or months.It is believed to have been used with comparative frequency in the time of slavery, as a means of getting rid of obnoxious masters, and is supposed to be occasionally used at the present time as an inshment of crime. The leaves are intensely hitter and very acid, producing a sensation on the lips and tongue of being swollen and blistered, though their aspect is quite unchanged. The powder of the leaves applied to the nostrils causes violent sneezing, hence it was necessary to take pre- cautions in powdering them, or unpleasant effects followed. These active properties are possessed by all the green parts of the plant and by the flowers, but exist very slightly, if aC all, in the woody portions.My researches have been confined to the leaves and green tips of the plant, from which I have obtained three substances, characterised in a high degree by their physiologically active qualities. These active bodies I have named Urochitoxin, Amorphous Urechitoxin, and Urechitin. Preparation of Urechitoxin and Amorphous Urechitoxin. The active principle of the plant is dissolved out by water, but the extraction is very incomplete, even when large quantities of water are used, while a great amouiit of iuactive matter is also taken up which complicates the subsequent purification. Alcohol easily and com- pletely removes the bitter substance, but unless it be nearly absolute, it also takes up much extractive matter; on the other hand, if veryBOWREY ON THE POISONOUS PRIKCIPLE, ETC.253 strong, it dissolves green resinous matter, which is, however, easily got lid of by dilution. These observations led me to the following process :-The leaves and green tips were first air-dried, and then at 100" C., as long as they gave off moisture, air also heated to 100" C. being passed over them to hasten the drying. The now very crisp and brittle leaves were finely powdered as rapidly as possible, so as to avoid absorption of moisture from the atmosphere, and the powder was extracted with spirit of at least 98 per cent. alcoholic strength. If maceration was continued €or a sufficiently long time, a comparatively small volume of spirit rendered the extraction practically complete. The dark-green tincture obtained was distilled to recover part of the spirit; but if it was well made, and therefore very strong, distillation was advantageously dispensed with ; whether or no, the next step was t o add about an equal bulk of boiling water, pouring it into the tinc- ture gradually, and stirring vigorously meanwhile ; this caused a green coloured resinous precipitate, which was removed by filtration, and after washing with spirit of 50 per cent. alcoholic strength, was found to be devoid of bitter taste.The clear filtrate, now of a yellow-brown colour, was mixed with the washings, and a strong solution of basic acetate of lead added as long as a yeEZow precipitate fell, care being taken not to add more than just enough for this purpose, or a loss of urechitoxin resulted from its partial precipitation together with the coloured precipitate.This loss is due simply to dilution of the spirit by the lead solution. The yellow precipitate was filtered off, and washed once or twice with spirit of 50 or 60 per cent.; prolonged washing would remove all bitter matter from it, but is not economical. The mixed clear yellow filtrate and washings were next freed from lead by means of snl- phuretted hydrogen and filtration, and as much urechitoxin is carried down by the lead sulphide, it must be well washed with hot spirit of 50 or 60 per cent. On evaporation in a vacuum over sulphuric acid, the acid liquors deposited small white crystals ; when their quantity ceased to increase, the mother-liquor was removed by means of the filter- pump, and evaporated to dryness over oil of vitriol in a vacuum, yielding a resin-like mass of crude amorphous urechitoxin.The crystals were washed on the filter with spirit of 20 per cent., and then dissolved off in a little boiling 30 per cent. spirit. The solution was quite colourless, and on cooling microscopic crystals of urechitoxin separated out in such quantity as to render the whole mass pansty ; they were collected on a Bunsen's filter, washed with a little cold 30 per cent. spirit, and dried in a vacuum. The mother-liquor and washings evapomted in a vacuum over oil of vitriol yielded a further crop of urechitoxin, and a little amorphous urechitoxin.The crude amorphous urechitoxin mentioned above was dissolved in POL. XXXIII. U254 BOWREY ON THE POISONOUS PRINCIPLE a little absolute alcohol, to get rid of any inert extractive matter present, the solution evaporated at a gentle heat until syrupy, and while it was still-warm, hot water was added gradually, the mixture being vigorously stirred all the time, so as to bring the water into contact with every part of the resulting soft resin. After removing the water, the resinous mass, if nearly colourless, was heated on the water-bath for a few minutes, then placed over oil of vitriol, and a vacuum produced as quickly as possible ; this caused it to swell and froth up, and speedily lose all moisture, the product being a porous, easily powdered, light amber-coloured mass of amorphous urechitoxin. If, however, the resin precipitated by the hot water was dark in colour, it was dissolved in spirit of 50 or 60 per cent., and purified animal charcoal added until most of the colour was removed, the charcoal separated by filtration, and the filtrate evaporated nearly to dryness at a gentle temperature, and finally dried in a vacuum as de- scribed above.I found it impossible entirely to bleach solutions of amorphous urechitoxin by means of animal cbarcoal, and even sufficient charcoal to remove most of the colour abstracts a large proportion of the poison ; it is therefore necessary to wash the charcoal with boiling spirit of about 60 per cent., in order to avoid a considerable loss of amorphous ui*echitoxin.Urechitoxin aud urechitin are also removed, more or less, from their solutions by animal charcoal. Much of the urechitoxin and amorphous urechitoxin I have prepared has been obtained by the foregoing method, but samples have also been made by the following modified and less troublesome process. After the removal of the lead by sulphuretted hydrogen, the liquid was distilled in a vacuum, nearly to dryness, at a temperature not exceed- ing 35", whereby a soft resinous residue, perfectly homogeneous and free from crystals, was obtained ; it was mixed with several times its bulk of spirit of 15 per cent., and allowed to stand for several days, when its appearance was found greatly changed ; it now consisted of a mas8 of microscopic crystals of urechitoxin, mixed with more or less ;imorphous urechitoxin in the form of minute oily drops.The weak spirit was of a dark colour, being charged with the more highly- coloured portions of the residue ; it was drawn off by the filter-pump, and the crystals freed from amorphous urechitoxin by washing with successive small quantities of 20 per cent. spirit, and finally with a little 30 per cent. The final operations to obtain the two forms of the poisonous principle in a pure state were the same as those already described. Prom the perfectly dried leaves of the ZTrechites suberecta I have obtained as much as 1 per cent. of urechitoxin, and nearly 3 per cent. of mixed urechitoxin and amorphous urechitoxin. On an average theOF URECHITES SUBERECTA. 255 fresh leaves lose four-fifths of their weight on being completely dried; they must therefore contain rather more than one-half per cent.of their active principle. In one operation a much larger proportion of water than that re- commended above was mixed with the tincture, and no care was taken to conduct the evaporation at a low temperature, or to prevent access of air, the large amount of liquid present being driven off by the heat of an ordinary water-bath. The result was an unsatisfactory yield of amorphous urechitoxin, while no crystalline product whatever was obtained. After a satisfactory process for the preparation of urechitoxin had been worked out, the various samples obtained were mixed and re- crystallised from 30 per cent. spirit, the yield being about two ounces of dry crystals : Sample A.A small portion of A was recrystallised three times from 80 per cent. spirit, the crystals being freed from their mother-liquor each time by washing with spirit of the same strength: the result was Sample B. Another sample, C, was prepared by slow crystdlisation from a solution of a portion of Sample A in 60 per cent. spirit. When but a fraction of the amount in solution had sepamted the crystals were collected, washed, and dried. Samples A and B consisted of microscopic crystals perfectly clear and transparent singly, but snow-white in mass. The crystals in C were much larger, being nearly half-an-inch long. Preparation of Dechitin. The fact that occasionally no urechitoxin and but little amorphous urechitoxin was obtained from the dried leaves, coupled with some ob- servations made in the preliminary experiments of this research, led me to suspect that the poisonous principle of tohe plant underwent some change either in the process of drying or in the subsequent manipulations.If not, why was it that occasionally nothing but the amorphous form was obtained ? The experiments now to be detailed shed some little light on this question, and led to the discovery of the form of the poison which I have called urechitin. Five pounds of fresh leaves were finely minced and then exhausted in a displacement apparatus with successive quantities of nearly abso- lute alcohol, in all fifteen pounds of spirit being used. The tincture which came through first was dark brown, then followed some of a dark green, while the portions which came through as the exhaustion approached completion were light green : these were put on one side.On mixing the brown and dark green tinctures, much green matter n 2256 BOmTREY ON THE POISONOUS PRINCIPLE separated, which, after being washed with 50 per cent. spirit, was found to be free from bitter taste ; it was removed by filtration, and the clear yellow-green filtrate run into a bolt-head connected with another and larger one immersed in ice. The air was next pumped out of the vessels, and the smaller one surrounded with warm water ; distillation now proceeded briskly at temperatures ranging from 28" to 38". As the alcohol passed over, crystals contaminated with a little green resinous matter separated. The distillation was continued until the liquid began to froth over into the condensing vessel; the crystals were then collected on a filter, and the mother-liquor re- turned to the bolt-head and distillation in a vacuum again started, froth- ing being prevented by gradually running in the light-green tincture which had been put on one side ; this weak tiucture was run in so that the vacuum was not injured, and at such a rate as just to avoid frothing.By this manipulation the distillation was carried on to dry- ness at a temperature not exceeding 38". The dry residue was treated with nearly absolute alcohol in considerable quantity, whereby all bitter substance was dissolved, and much brown gummy matter left behind. The alcoholic solution was diluted with enough hot water to reduce its alcoholic strength t o about 40 per cent. ; this caused the precipitation of much inert green matter, which was removed by filtration, and was washed with a little hot 40 per cent.Rpirit. The washings and filtrate were returned to the bolt-head (from which of course the inert gummy matter had been cleaned out), and on standing deposited some white crystals, the quantity of which was greatly increased by distilling off the alcohol in a vacuum, as already described. When all the spirit had passed over, the crystals, which were now of a dirty green colour in mass, were collected on a filter and washed with water. The filtrate was of a brownish-yellow colour and very bitter; on evaporation it left a, not very considerable residue giving the colour reaction of the poisons (to he described further on), but as if much foreign matter was present.The crystals were dissolved in 80 per cent. spirit, and an alcoholic solution of basic acetate of lead added as long as it caused a precipi- tate, which was then removed by filtration and washed with strong spirit. The mixed filtrate and washings were next freed from lead by a stream of snlphuretted hydrogen and filtration, then distilled in a vacuum until most of the alcohol had passed over. A quantity of nearly colourless crystals of urechitin having separated during the distillation, they were collected and put on one side for further purification. The mother-liquor, on evaporation to dryness, yielded a comparatively small amount of what appeared to be amorphous urechitoxin containing a few crystals of urechitin.The purification of the crystals mentioned above was effected in the It has not yet been further examined.OF URECHITES SUBERECTA. 257 following manner ; they were ground in a mortar with barely enough nearly absolute alcohol to form a thin paste, and the mixture, after standing in a closed vessel for several hours, was thrown on a Bunsen'a filter, the alcoholic solution drawn through as completely as possible, and the powder washed with successive small volumes of the same alcohol as long as it came through coloured. The mixed alcoholic fil- trates had a light yellow colour, and on slight dilution with water, deposited some pure white crystnls, which were collected and added to the powder on the filter. On further dilution, more crystals were precipitated, but now mixed with much resinous matter (? amorphous urechitoxiu), from which I did not sccceed in separating them.The mass of white powder and crystals were dissolved at a tempera- ture of 60" in barely su5cient 70 per cent. spirit, and the clear solution allowed to cool very slowly ; by next morning a fine crop of perfectly colourless crystals had formed, which were collected, washed withnlittle 60per cent. spirit, dried in a vacuum over quick lime, and bottled. The mother-liquor was slightly coloured, a Eittle animal charcoal served to decolorise it, after which it was distilled in a vacuum as long as alcohol came over ; the crystals which formed as the alcohol passed off were collected (the watery mother-liquor held hardly anything in solu- tion), dissolved in strong hot spirit; and warm water was added so as to reduce the alcoholic strength of the solution to about 40 per cent.Crystals began to form at once and increased in quantity as the solu- tion cooled; they were filtered off and washed. Their mother-liquor, on still further dilutiou, deposited more crystals having the same ap- pearance and properties as those first foriued; the two crops were therefore mixed, dried over quick-lime in a vacuum, and labelled, " Urechitin, Sample B." On farther treatment, the liquors from '8 yielded a small amount of a bitter resin resembling amorphous urechitoxin, and also a minute quantity of a crystallisable body like urechitoxin, but the amount obtained was too little to enable me to determine if the two were really identical.The water in the fresh leaves complicating the extraction of the urechitin, I made an experiment to ascertain whether drying at ordi- nary temperatures would alter the result obtained from the fresh leaves. Five pounds of leaves were allowed to dry in the air as long as the? lost weight, their weight ultimately falling to 22+ ounces ; an experiment on a few grains of these air-dried leaves proved that at a temperature of 100" they woald lose nearly three ounces more. The 22+ ounces were reduced to a fine powder, and exhausted with nearly absolute alcohol, seven pounds of which served to remove all soluble matter. The tincture was treated much in the Bame manner The bottle was labelled, '' Urechitin, Sample A."258 BOWREY ON THE POISONOUS PRIXCIPLE as that from the five pounds of fresh leaves, but no basic acetate of lead was used in this experiment ; in fact, nothing but alcohol, water, and a little animal charcoal were employed to obtain the urechitin in the pure state.A small sample of fine bold crystals, pro- duced by a very partial and slow evaporation, in the cold, of a solu- tion in 80 per cent. spirit of the total quantity of crystals obtained. Procured from the mother-liquor of Sample C by diluting it with hot water until its alcoholic strength was reduced about one half. The solution was frequently shaken as it cooled, and deposited the crystals more massive, though somewhat irregular, than any other sample I have prepared excepting C. A small sample of minute crystals separated from the mother-liquor, and washings of D, by distilling off the alco- hol in a vacuum.As this sample proved by its reaction and also by the numbers it gave on combustion, to be contaminated with a small quantity of some other substance, I shall not again mention it. These three samples weighed 167 grains, equal to a yield of 0.48 per cent. of the weight of the fresh leaves used. As the loss of urechitin in the process of purification plainly fhr more than equalled the weight of impurity present in Sample B, it is safe to conclude that the fresh leaves contain at least one-half per cent. of urechitin. This operation gave me three samples of crystals, viz. :- Urechitin, Sample C. Urechitin, Sample D. Urechitin, Sample E. Urec7iitoxim contains no nitrogen. The carbon and hydrogen were determined in each of the three samples after drying at 100" C., with the following results :- Obtained.Percentage. Taken. co,. HfO. C. H. A. 0.2370 gram 0.5914 gram 0.1682 gram 61-15 7.89 0.2266 ,, 0.5088 ,, 0.1610 ,, 61.24 7-89 B. 0,2039 ,, 0.4580 ,, 0,143 ,, 61.26 7.86 0.2876 ,, 0.6478 ,, 0.2044 ,, 61.43 7.90 C. 0.1650 ,, 0.3709 ,, 0.1165 ,, 61.31 7.85 These figures prove the three samples to be practically identical, and give a mean of C 61.28, H 7-88, 0 30.84, as the percentage composi- tion of urechitoxin. The formula, C13HZoO6, is the simplest which fairly well represents these percentages :- C 60.94 C 61.28 C13H2005 requires H 7.81 . Analysis gives{H , 7188 { 0 31.25 0 3084 From spirit of about 30 per cent. alcoholic strength nrechitoxin usually crystallises in thin four-sided prisms, bounded at each end byOF URECHITES SUBERECTA.259 two planes, from very weak spirit or water in sharp pointed needles ; it does not crystdlise readily from strong spirit, indeed I doubt if crystals can be obtained from alcohol approaching absoluteness. The crystals break across their length very readily. After being dried between folds of bibulous paper, urechitoxin still retains abont 8 per cent. of water, which is lost over oil of vitriol or more rapidly at loo", no further loss results from heating to 120'. If the dry crystals be exposed to the atmosphere for a few hours, they gain from 8 to 9 per cent. on their dry weight. The exact amount of gain seems to depend on the t.emperature, the increase of weight in the laboradtory at Kingston, Jamaica, with an average temperature of 29", being one-ninth less than that noticed in some experiments made in the South Kensington Research Laboratory, with an average temperature, during the period of exposure, of 16.5".The gain in an atmosphere saturated with water was practically the same as that in the ordinary atmosphere of the laboratory. Mechanically dry urechitoxin is readily deprived of dl water at 200" without its crystalline appearance being alteted ; but if it little more moisture be present than it naturally takes up from the air, that temperature will cause it to melt into a clear gum-like mass, from which it is very difficult to remove all moisture, unless it be first cooled and finely powdered. Urechitoxin and its solutions are intensely bitter; half a C.C.of a water solution containing one part in 40,000 is strongly bitter, and a similar quantity of a solution of one in 100,000 hits a distinct, some- what astringent taste, but is hardly bitter. If left in contact with the lips or tongue for a short time, the poison produces a tingling, smarting sensation, and the affected parts feel swollen. If the smallest particle enters the nostrils it causes violent sneezing. It is very poisonous, as the facts given in my paper on its physiological action plainly prove ; in one experiment less than one milligram of it subcutaneously injected proved fatal to a cat in 16 hours ; in another an injection of three milligrams was fatal to a strong cat in one hour and a quarter. Urechitoxin in excess, left in contact with water for several days, gives a solution containing one part of the poison in about 1,500 of the solvent ; it is much more soluble in boiling water, in which the excess melts to a clear soft resin ; the solution, on cooling and standing for a few hours, deposits tt rather considerable crop of crystals, but permanently retains in solution about one-thousand th of its weight of urechitoxin. It may be well to mention here that whenever I speak of definite weighta or proportions of " urechitoxin," the dry substance is referred t o ; the loose combination which it forms with about 9 per cent.of water, I distinguished as " Hydrated Urechitoxin."260 BOWR.EY ON THE POISONOUS PRINCIPLE The solubility of iirechitoxin in spirit of various strengths, was de- termined by placing excess of the hydrated substance with the spirit in a corked flask which was frequently agitated.After standing for a day and two nights, the saturated solution was filtered off and a weighed quantity evaporated in a warm place, and finally heated in a water-oven as long as weight was lost. The temperature of the labo- ratory was about 15' during the preparation of the solutions. The following are the results obtained, the numbers being parts by weight of spirit required to dissolve one part of dry urechitoxin :- 965.0 spirit containing 10 volumes per cent. of alcohol. 875.0 ,7 7, 15 71 ,? 9 , 585.0 77 Y 1 20 99 9 9 :? 198.0 ,, 7, 30 99 9 , 9 , 65.0 ,, 99 4?0 9 , 97 9 , 140 ,, Y, 50 9 9 ,? 9 , 4.3 9 , ,> 60 9 , ? ? ?7 2.0 3) ,, 70 ? 9 7, 97 1.4 ?? ,? 80 9 9 ,Y 9 , The saturated solutions in 60, 70, and 80 per cent.spirit were clear, but thick and syrupy. The poison is taken up to saturation by 70 and 80 per cent. spirit in a few minutes. The stronger alcoholic solutions deposit urechitoxin in a pseudo-amorphons form on addition of water, or even on exposure to the air. The solution formed by placing excess of dry urechitoxin in contact Kith spirit is much stronger than that resulting from the use of the hrdrated substance, thus : 123 parts of 30 per cent. spirit dissolved 1 part of urechitoxin. 9.5 ,7 50 79 9 , 9 7 It is much more soluble in hot spirit; some of 30 per cent. was heated to its boiling point,, and dry urechitoxin gradually added. It seemed as if i t would be taken up indefinitely.As each portion was dropped into the spirit, it appeared to melt and blend rather than to dissolve. All the urechitoxin at hand waa used, and a clear solution like strong gum-water obtained, which cooled without crystallising, but on standing a short time, crystals began to form, a stream of light liquid ascending from each one. In the course of a few hours the solution was converted into a magma of minute crystals, in which but little liquid was visible, and the tube might be inverted without any- thing escaping. In this experiment 1 part of urechitoxin was dissolved by 1.6 parts of the hot 30 per cent,. spirit. When dry urechitoxin in excess was left in contact with dry ether of 0.720 sp. gr., 1 part was dissolved by 565 of the solvent : but when the hydrated crystah were mixed with the same ether saturated withOF URECHITES SUBERECTA.261 water, 2,230 parts were needed for solution. Dry urechitoxin placed in benzene required 3,820 parts for solution. By chloroform the dry substance is taken np indefinitely, forming a soft resin-like mass ; the hydrated poison is not so readily soluble, but is all but miscible. Amylic alcohol takes up dry urechitoxin as freely as does chloroform, but not so rapidly. When the hydrated crystals were mixed in excess with amylic alcohol, and the solution was filtered after standing for 24 hours, 1 part of urechitoxin was found to have dissolved in 3.7 parts of amylic alcohol. Urechitoxin is exceedingly soluble in glacial acettic acid. If a strong solution be diluted with water, the poison is to a great extent imme- diately precipitated in a pseudo-amorphous condition ; on standing, the dilute acid gradually deposits a further quantity in the crystalline form.The psetido-amorphous urechitoxin left in contact with the weak acid, or with water or dilute spirit, gradually and entirely changes into ordinary urechitoxin, apparently without undergoing solution. I apply the term pseudo-amorphous to the non-crystalline urechitoxin obtained by fusing the crystals in water, or by evaporation of their solution in chloroform, &c., indeed to any urechitoxin in a, non-crystalline state which by appropriate means can be changed into crystals, while I re- strict the term amorphous to a substance resembling nrechitoxin in many respects, but which I have entire13 failed to convert into a crys- talliqe form.Pseudo-amorphous nrechitoxin is reconverted into the ordinary urechitoxin by crystallisation from spirit, or by the prolonged contact of water or weak spirit in quantities far too small for its solution. Strong solutions of urechitoxin are very apt to deposit the pseudo- amorphous body, and i t is so deposited from all solutions evaporated at it high temperature. Sometimes a drop or two of a solution oE urechitoxin evaporated in the cold, for examination under the micro- scope, will give a residue in which no crystals can be detected ; but by allowing a little water or very weak spirit to evaporate in contact with it, the residue will eventually be wholly converted into crystals. Pseudo-amorphous urechitoxin is easily powdered ; the powder mixed with cold water becomes soft and aggregates together.I f the mixture be well incorporated by vigorous stirring for a few minutes, and then filtered, a cold supersaturated solution is obtained, which in a few hours throws down the excess in the crystalline form. Rapidly heated to between 170" and 180", nrechitoxin fuses with- out change; but if its temperature is gradually raised, it loses its crystalline appearance at about 150°, and at 160' is fully fused. By this slow heating it becomes slightly coloured, and its weight is diminished about three-quarters of a per cent. ; it is, moreover, per- manently changed into an amorphous form of the poison. A similar2 62 BOWREY ON THE POISONOUS PRINCIPLE change takes place to a small extent when its solutions are heated.This observation was made in recovering the urechitoxin used in deter- mining its solubility, &c. This was done by crystallisation from hot 30 per cent. spirit, the mother-liquor from one operation being used to recover a subsequent quantity, and so on. Finally the mother- liquor was partially evaporated on a water-bath. On cooling, horn- ever, very few crystals formed ; on still further evaporation and again cooling, no crystals were deposited. The liquor was now practically free from alcohol, yet very bitter. It was evaporated to dryness in a vacuum, leaving a resinous mass which refused to yield crystals to any treatment, and which perfectly resembled amorphous urechitoxin. In strong cold aqueous hydrochloric acid urechitoxin dissolves freely fo a colourless solution, which very speedily changes to yellowish- green, then becomes opalescent, and deposits crystals and more or less amorphous colouring matter.The reaction is complete in a few hours ; if heat be applied it takes place immediately, but at the same time some other action is induced, in consequence of which a much smaller yield of crystals, or even none at all, is obtained. All bitterness is de- stroyed by this reaction. The crystals are much less soluble in spirit than urechitoxin ; they crystallise in microscopic prisms and plates of a very light yellow colour, are tasteless, and give the urechitoxin colour reaction with greater brilliancy than the pure poieon. I have not yet obtained it pure enough in quantity suficient for analysis ; but by using fuming aqueous hydrochloric acid, diluted with one volume of water and two volumes of absolute alcohol, as the solvent for the urechitoxin, and allowing sufficient time, a quantity of a crystalline substance uncontaminated with amorphous matter was obtained.This body I have named urechitoxetin ; a description of it is given fur- ther on. The strongly acid filtrates from the completed action of hydrochloric acid on urechitoxin contain nothing bitter, but hold in solution a body which immediately reduces boiling alkaline cupric solutions, causing precipitation of red cuprous oxide. By removal of the acid and sub- sequent evaporation in a vacuum, this body or mixture of bodies was obtained as a non-crystallisable treacly fluid, of a dark colour, and possessing no marked taste, but smelling of burnt sugar. It awaits further investigation.A change somewhat similar to that produced by hydrochloric acid has been noticed to occur in water solutions of the poison left €or a long time in closed vessels. For instance, a solution containing 1 part of urechitoxin in 10,000 of water remained unchanged f o r several weeks, but in the course of months a substance resembling the mould which so frequently forms in solutions of tartaric acid, was de- veloped, and fine crystals precipitated. Neither the liquid nor the crys-OF URECHITES SUBERECTA. 263 tals now had any bitter taste ; the latter were comparatively insoluble in spirit, but gave the urechitoxin colour-reaction with great bril- liancy.Solutions of caustic potash and soda have no immediate effect on urechitoxin, but I have noticed that strong solutions of the poison in spirit which have been allowed to remain in an alkaline state for a considerable time lose their bitterness. In strong nitric acid it dissolves readily and quietly to a light yellow solution, which gives off red fumes on being heated, at the same time becoming lighter in tint. Colowr-reaction. Urechitoxin dissolves readily in strong pure sulphuric acid to a light orange-yellow solution having a tint of brown in it. If this SO- lution be diluted with water, a dirty light yellow precipitate is thrown down. If, however, it is allowed to stand in a closed vessel, it gradii- ally becomes of a, redder and redder tint, passing through carmine to mauve, and finally into purple, These changes are much hastened by heat, and if the heat be continued the colour passes into a brown of great depth.Water added to the purple solution causes a dirty orange-coloured precipitate. The colour changes are also produced by the addition of a small quan- tity of either of the following substances : nitrates, nitrites, chlorates, bleaching powder, bromine, and iodine. Ferrocpanide of potassium does not cause the colour changes, while ferricyanide brings the colours out slowly and without the brightness of tint produced by the reagents mentioned above. Chromates and bichromates change the yellow of the sulphuric acid solution to a very light yellow-green, the green gradually becoming stronger as the mixture stands, no doubt from the reduction of chromic acid.Permanganate of potash, added cautiously, first bleaches the solu- tion almost completely, then brings out a fine but not strong violet tint, which finally passes into a dirty brown colour. I prefer nitric acid for the production of the colour changes, and a8 excess destroys all colour, I am in the habit of using an oxidising agent prepared by adding about a drop of nitric acid to 100 C.C. of sul- phuric. acid. If a drop of sulphuric acid is placed on 0.01 milligram of urechitoxin lying in a white basin, a yellow solution is produced, in which the changes of colour to mauve are distinctly seen on adding a minute drop of the oxidising liquid. Even 0.001 milligram will with careful manipulation give the reaction distinctly.Tunic acid causes a white precipitate in a water-solution of urechi- toxin (1 part in 1,500), which is redissolved on addition of potash2 64 BOWREY ON THE POISONOUS PRINCIPLE or acetic acid; but no precipitate falls if the solution be slightly more dilute. The tannate is very soluble in spirit. The various forms of the poisonous principle of the Urechites smberectn are much more soluble in water when contaminated with extractive matters derived from the plant than when in a pure state. These impure solutions give dense curdy precipitates with tannic acid. Every bittes. water so- lution obtained from the plant, whether immediately or after the action of selective solvents, &c., I have found to give a precipitate with tannic acid, while no precipitate was formed in solutions devoid of bitterness.Urechit oxet in. The urechitoxetin prepared, as already described, by the action of alcoholic hydrochloric acid on urechitoxin, was carefully purified by repeated crystallisation from spirit, the final product being a quantity of light dull-yellow microscopic crystals with a silky lustre. They are readily and completely dried at loo", and on exposing the dry crystals to the air for 48 hours, they take up but 0.2 per cent. of mois- ture. On analysis the purified and perfectly dry urechitoxetin gave the following results :- Obtained. Percentage. Taken. coz. H2O. C. H. 02147 gram 0.6091 gram 0.1642 gram 77.37 8.50 02580 ,, 0.7338 ,, 0.1959 ,, 77.57 8-44 0.1920 ,, 0.5423 ,, 0.1464 ,, 77.45 8-32 The mean percentage composition obtained is C 77.46, H 8.49, 0 14.05, while the formula Cd4H5,0s requires C 77.42, H 8.50, 0 14.08.Urechitoxetin has no marked taste, and is physiologically inactive : hence I have not investigated its properties to any great extent, and will merely mention a few of the more marked. It is practically in- soluble in water and in weak spirit, nor does it dissolve to any large amount in spirit of 80 per cent., unless it be heated ; much crystal- lisev out as the solution cools. It appears to resemble urechitoxin in a certain proneness to pass into an amorphous modification. It dissolves in sulphuric acid to a light orange-yellow solution ; if the solution is very strong, the colour is orange-red, but the increase in depth of tint is by no means proportioned to the amount dissolved : for after the redder tint is once reached, no marked gain in colour is seen on adding very much more urechitoxetin.On adding a minute quantity of nitric acid to the yellow solution, the same colour-changes are produced aa urechitoxin similarly treated exhibits, but they are much clearer and brighter. If the oxidising agent be added to a strong solution, the increase of colonr is very remarkable, the oxidised solution appearingOF URECHITES SUBERECTA. 265 black and opaque except in a very thin stratum. Heat brings out the colour changes, and they also appear if the solution in sulphuric acid be allowed to stand in a closed vessel in the cold, but several days pass before the purple tint is reached. Water added to a fresh solution in pure sulphuric acid throws down a light canary-yellow precipitate, while if added after the purple colour has developed, the precipitate is dirty orange.Excess of oxidising agent quickly bleaches a sulphuric acid solution of urechitoxetin without showing the various colours with any clearness. Amorp how Ur ec hit oxin. In the preparation of urechitoxin from leaves of Urechites euberectcc dried at loo", several samples of amorphous urechitoxin were ob- tained, great care was taken to remove all inactive matter, and as in their physiological and general chemical properties they closely resembled each other, I hoped they would prove to be of definite composition ; analysis has, however, disappointed this expectation, the percentage of hydrogen found in different samples varjing from 7.85 to 8.19, and the carbon fram 62.02 to 64.46.Some recent ex- periments lead me to suspect that several bodies exist having the physiological activity of urechitoxin, some of them, no doubt, being ready formed in the plant, while others are produced by chemical changes. If this suspicion is correct, the samples of amorphous ure- chitoxin I have prepared are uncertain mixtures of two or more of these bodies. Amorphous urechitoxin is, in appearance, intermediate between a resin and a gum; it has a light, dull yellow colour, and is readily powdered. It resembles urechitoxin in its toxic action, and is nearly, if not quite as poisonous; introduced into the mouth or nostrils it seems even more active, but this results simply from its greater solubility.In cold water it becomes soft ; excess placed in weak spirit gradually melts into an oil-like liquid ; it is miscible with strong spirit. It reacts with reagents in the same manner as does urechitoxin, but gives no cystaZZine product when acted on by hydrochloric acid, and perhaps its colour reaction is less vivid. Urec hitin. This substance usually crystallises in long fonr-sided prisms, bounded at each end by two planes, but frequently more complicated forms appear. The crystals are transparent and colourless ; they break very easily at right angles to their longest axis. As deposited from alcoholic solutions, the crystals contain 6 per cent, of water, which is readily driven off at loo", no further loss resulting from266 BOWREY ON THE POISONOUS PRINCIPLE coz.0.5132 gram 0.6465 )) 0.3892 ,, 0.3952 ,, 0%02 ,, 0.7044 ,, 0-6004 ,, 0'5277 ,, 0.5263 ,, exposure to a temperature of 120" C. The anhydrous poison does not recover more than 1 per cent. of water if left in contact with cold damp air. Analysis of the crystals after drying at 100" gave the following results :- Urechitin contains no nitrogen, &O. ----- 0 -1592 gram 0'2002 ), 0.1123 ), 0'1235 ), 0.2176 02182 ,) 0.1850 ), 0.1633 ,, 0.1639 ,, Taken. Sample A. 0 ,2113 gram 0,2671 ,, 0*1480 )) Sample B. 0.1622 ,, Sample C. 0.2887 ,, 0.2905 ,, 0.2474 ,, Sample D. 0.2169 ,, 0.2167 ,, ~~ - Obtained. Percentage. C. 66 -24 66 -01 66 *19 66 4 5 66 *15 66 -13 66 -19 66 *35 66 -24 -- H. 8 -37 8 *33 8 43 8 -46 8 -38 8 -35 8 '31 8 *36 a -38 These figures show the four samples to be identical, and give a mean of C 66.22, H 8.38, and 0 25-44), as the centesimal composition of urechitin.The formula, C2&0t1, closdy represents the analytical results :- C 66.22. { 0 25.40. C,H4,02 requires H 8-30 . Obtained H 8.38. { 0 25.30 C 66.40 Urechitin in the solid form is tasteless, but its alcoholic solutions are equal t o those of urechitoxin in bitterness, and it also resembles this substance in its toxic action and power. In cold water and cold spirit of less than 40 per cent. alcoholic strength, it is practically in- soluble. Boiled in water it shows no sign of fusion; the liquid filtered hot and allowed to stand for a considerable time deposits a very small quantity of the poison in the crystalline state.Its solubility in various liquids was determined in the same manner as that of urechitoxin, with the subjoined results, the numbers being parts by weight of the solvent required to hold one part of urechifin (weighed after drying a t 100") in solution. The determinations were made at a temperature of about 16.5O. 1,580 spirit containing 50 per cent. of its volume of alcohol. 610 I9 60 99 ?? 190 ?9 70 9 , 9 , 88 ?9 80 $9 ?? 35 very nearly absolute alcohol.OF URECHITES SUBERECTA. 267 227 dry ether, sp. gr. 0.720. 420 same ether saturated with water. 140 amylic alcohol. 466 benzene. 2.7 chloroform. 167 boiling 30 per cent. spirit, the solution beginning to deposit crystals immediately on its temperature falling. Urechitin differs from urechitoxin in not taking a pseudo-amorphous form 4 its solutions i n the various menstrua already mentioned de- posit it in the crystalline form wbether they be evaporated slowly and at low temperatures, or on the water-bath.It is also precipitated in crystals on adding water to its solution in strong spirit or glacial acetic acid. It is freely soluble in this acid, though not to the same extent as urechitoxin, but it does not dissolve in dilute mineral acids. When a small quantity, in a thin test-tube, was suddenly immersed in oil already heated to 220" it changed in appearance, but did not absolutely fuse ; the tube was withdrawn, and when the temperature had risen to 260" it was again immersed; the poison now fused immediately, and on cooling was like colourless glass; it dissolved readily in hot strong spirit, and on evaporation the usual crystals of nrechitin were obtained.Another portion was gradually heated ; no alteration was visible until the temperature was over 180°, when the crystals began to colour here and there, but showed no signs of melt- ing. When the bath was nearly 195" points of fusion were ob- served where the colouring had become most marked; the tempe- rature was kept about 1 9 7 O , and the change gradually progressed, while fumes were evolved which condensed on a cold surface to clear drops having a strong acid reaction. Ultimately the whole fused to a dark-brown mass, which was disposed to froth up as if gas were being generated in it. It was now removed from the oil-bath, and was found to have lost one-tenth of its weight.The cold fused mass was next treated with a few drops of cold strong spirit, in which it dis- solved readily, with the exception of some crystals, which proved to be urechitin still unchanged by the heat. The alcoholic solution failed to yield crystals to any method ofatreatment, but on evaporation v gave a substance closely resembling some of my samples of so-called amorphous urechitoxin; it was intensely bitter, and gave the colour- reaction well, but was less soluble than any other amorphous sample of the poison I have prepared. Urechitin is acted on by strong aqueous hydrochloric acid much in the same way as urechitoxin; it is, however, not so freely soluble, and the solution on standing becomes much more strongly green. Crystals268 BOWRET OS THE POISONOUS PRIhXIPLE, ETC.are deposited which, as far as I have examined them, resemble those resulting froin the action of the acid on urechitoxin; but the liquid from which the crystals have been deposited does not, after neutralim- tion, so readily reduce alkaline cupiic solutions as does that €om ure- cliitoxin. With sulphuric acid and oxidising agents, urechitin gives the same series of colours as urechitoxin, but they are hardly so bright, and are certainly inferior to those given by urechitoxetin. The difference is most marked in the fresh solution in pure sulphuric acid, which is of ft brownish-yellow instead of the reddish-yellow d o u r of the mechitox- etin solution ; the brown is very decided if the solution is strong. On diluting the freshly-made solution with water, a dirty green precipitate falls; if the water be added after the colour-changes have been developed by nitric acid, a precipitate similar in colour to that given by urechitoxin or urechitoxetin, viz., dirty orange, is thrown down.I have noticed that, by mixing sugar with urechitoxetin before trying its colour reaction, results very much like those yielded by urechitoxin and nrechitin can be obtained. That the \.rtrious bitter poisonous substances described in this paper are glucosides I think is certain, but I do not consider sufficient data have been accumulated to allow a molecular formula to be assigned to either urechitin, urechitoxin, or urechitoxetin. The formulse given in this paper are merely the simplest that express the numbers obtained by analysis, and it may well be that none of them represent the mole- cule, bnt that some much heavier formulae differing but slightly in percentage numbers are correct.The facts here recorded, together with others observed in the course of the research, lead me to think that if sufficient time were devoted to experimenting on Urechites suberecta, it might yield as many sub- stances, and as confusing rksults as Digitalis purpurea. I have con- fined myself in this paper mainly to two definite crystalline bodies, and have left uuenumerated several less definite though interesting substances, which have been noticed during the research. For instance, in one experiment on the preparation of urechitoxin, I got a small quantity of a substance as soluble in pure water as gum arabic, and possessing the toxic powers of the plant in a high degree; but having failed hitherto to obtain it in such a condition as would leave no reason to doubt that it was a definite compound and not a mixture, I do not think that honouring it with a name and detailed descrip- tion, would tend to anything except confusion. That the poisonous properties of Urech,ites suberecta are mainly due to urechitin is, I consider, established by the mode of its preparation, as it is unlikely that chemical change would be induced by tho use of nothing more than water, alcohol, and a temperature never exceedingHANNAY ON A NEW MANGANESE REACTION. 269 38'. On the other hand, I have no doubt that urechitoxin is a product of chemical change from urechitin, a change wrought by the much more violent method of its preparation. To guard against mistake, it may be well to add that whenever I speak of a substance as devoid of bitkerness, tasteless, and so on, without mentioning whether it was in the solid form or in solution, it is to be understood that it was experimented with in both con- ditions. I have succeeded in detecting these poisons when present in very minute quantities in complex mixtures by processes which their solubilities will suggest to any one familiar with the ordinary methods of detecting vegetable poisons in toxicological investigations ; but as my experiments on the best methods of discovering them are not completed, I will not refer to their detection here. In conclusion, I wish to state that the preparation of the various substances described was carried out in the Government Laboratory, Kingston, Jamaica, where most of the qualitative results were also worked out, while nearly all of the quantitative experiments were performed in the Research Laboratory, South Rensington, a.nd that my best thanks are due to Dr. Frankland for kindly permitting me fo work there.

ISSN:0368-1645    

DOI:10.1039/CT8783300252

出版商:RSC    

年代:1878

数据来源: RSC