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Abstracts of the Proceedings of the Chemical Society, Vol. 4, No. 55 |
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Proceedings of the Chemical Society, London,
Volume 4,
Issue 55,
1888,
Page 69-74
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摘要:
ABSTRACTS OF THE PROCEEDINGS OF THE CHEMICAL SOCIETY. No. 55. Session 1888-89. June 7th, 1888. Mr. W. Crookes, F.R.S., President, in the Chair. Professor Ferguson and Messrs. John Campbell Fell and Thomas E. Lindsey were formally admitted Fellows of the Society. Certificates were read for the first time in favour of Messrs. Walter Bromley Cooley, 5, Dudley Street, Wolverhampton ; Archibald Carlyle Mounsey Ingram, 5, Buchanan Terrace, Paisley ; Walter M. Gardn er, Brookfield Terrace, Headingly, Leeds ; Frank Pullinger, B.A., Alexander Park, Oldham ; Clement T. Rhodes, 18,Bute Street, South Kensington. The following were elected Fellows of the Society :-Messrs, Joseph Campbell, John Dunn, William Burns-Featherstone, Albert L. Guiterman, James C.Hamilton, James Mair, B.Sc., John James Morgan, Edward W. A. Augustine Mayhew, Frederick Ernest Pollard Albert John Sach, Mark S. Wade, M.D. The following papers were read :-45. " The Chemical action of some Micro-organisms." By R. Warington. The organisms whose action has been studied were B. subtilis; two bacilli isolated from soil; one from a visible growth in a solution which had nitrified ; a micrococcus isolated from another culture in which it was present as an impurity ; 18 organisms, many pathogenic received from Or. Klein, F.R.S., and one from Dr. W. R. Smith. 1.The Hydrolysis of Urea.-The ability of each organism to render a sterilised 25 per cent. solution of urine alkaline was tested. In every case but two there was either no increase of alkalinity in one week at 22", or the increase was so slight that it coulci not be safely concluded that ammonia was produced.In the case of the M. wew isolated by 70 Dr. Smith, a rather considerable increase of alkalinity took place. A somewhat smaller but very distinct increase occurred with B. JIuorescens non Ziquescens. A much larger increase of alkalinity than in either of these instances was obtained when the urine was seeded with a fragment of arable soil. 2. Hshaviour in Nilk.-The curdling of milk by micro-organisms is effected either by the production of lactic acid, or apparently by the formation of a rennet-like ferment. The amount of lactic acid required to curdle milk depends on the temperature, the amount being smaller the higher the temperature.Among the organisms examined five have distinctly acidified milk, but in very different degrees. Staphylococcus cccndidus produces too little acid to cause curdling, even when the milk, after acidification, is placed in boiling water. The bacillus of infantile diarrhea and B. temno produce a greater acidity, curdling milk speedily at 32", but fail entirely to curdle it at 22". M. gelatinosus curdles milk speedily at 22", and even at 10"after many days. The two organisms, E. jluorescens Ziquescens and Koch's cholera spirillum curdle milk readily at 22", without producing any appreciable acidity ; the latter organism will indeed curdle milk made alkaline with sodium carbonate without destroying the alkalinity. We have here, appa- rently, a typical case of curdling by means of a ferment. Two of the acidifying organisms which curdle milk, M.gelatinosus and M'. wew, act apparently in part by means of a ferment, as the acidity produced by them when the milk is curdled is quite insufficient in itself to effect curdling at the temperature of the experiment. Soil from an arable field readily curdles milk, even at loo, but without producing at the time an appreciable acidity; it acts plainly by a ferment. During the action of soil on milk much gas is evolved, even at 10". No gas was observed during the action of any of the organisms examined, save in an experiment with the bacillus of infantile diarrhma at 37". Five organisms, B. subtilis, B.attthracis, B. JIoccus, B. toruli-formis, and Finkler's comma are active peptonisers. The milk, after a few days at 22", becomes clear immediately beneath the sur-face, and this clear space slowly extends till the whole of the milk has lost its opacity. On moving the tube after the action has begun, it is found that the opaque portion is more or less gelati- nised. The clearing of the milk is due to the gradual dissolution of the jelly. The clear fluid is rich in peptone. It has been supposed that the liquefaction of gelatin by bacteria is due to the production of a, fermeut. The whole of the liquefying bacteria experimented on show evidence of the formation of ferments when grown in milk. The organisms which simply acidify do not liquefy.Soil peptonises 71 after curdling, the curd first formed slowly redissolving. A small class of organisms, B. jIuoresce"rLsnon liquescens and the bacillus of septicEmia (mouse and guinea pig), render milk after a time decidedly alkaline, and the milk from this cause loses much of its opacity, but no other change is produced. Several organisms grow freely in milk without altering its appearance or its reaction to litmus-paper. Cultivation in milk is an excellent method of distinguishing micro-organisms, the possible results being very varied, especially when the effect of temperature is observed. 3. Reduetiom of Nitrates.-Nearly the whole of the organisms examincd have been cultivated both in broth containing nitre and in a 20 per cent.solution of urine containing nitre, and generally at two temperatures, 20-23" and 32-37". The experiments were made in half-filled bottles with cotton-wool stoppers. The amount of nitrate reduced in urine was always small and varied probably on account of the variable composition of the medium. The reduction of nitrate in broth was frequently both rapid and very considerable. In cases in which the organisms would bear a high temperature the reduction was always more energetic at the higher than at the lower tempera- ture. The organisms which appeared to possess the greatest power of reducing nitrates to nitrites were- B. fzoccus, B. jhorescens non liquescem, B. of swine fever, M. urew, M. gelatinosus, Staph. candidus, Staph.luteus. Next to these stand the following, which also reduce nitrates freely :-B. termo, B. of typhoid fever, B. of infantile diarrhea, B. of cholera, B. of septicaemia, B. anthracls, B. Denicke's comma, Staph. albus liquescem. Far below these comes B. subtilis, which produces no nitrite in the urine solution, but always yields, after some time, a trace of nitrite in broth at the lower temperature, and a much more marked amount at the higher temperature. Streppococcus scarlatinm yields a mere trace of nitrite in broth cultures. The following organisms failed entirely to effect reduction to nitrites :-B. fzwrescens liquescens, B. tordiformis, B. sulpl~ureus, B. Finkler's comma, B. comma noma, M. aureus. Most of the non-reducing organisms were also cultivated in broth containing nitre covered by a layer of paraffin oil, by which means the access of oxygen was to a considerable extent excluded.In no case was any reduction of nitrates observed. No evolution of gas was noticed in any of the above cultivations. In experiments made in solutions seeded with arable soil, air being excluded, the reduction of nitrates was complete, gas being evolved, neither nitrate nor nitrite remaining. 4. Oxidation of Ammonia to Nitrate.-Solutions of various compo- sitions were employed, in all of which the addition of a little soil pro- 72 duced active nitrification. Nearly all the organisms already enume- rated were sown in one or other of the solutions, and some in several different solutions.In no case was nitrification certainly observed. Minute traces of nitrate were in some instances found, but these always failed to increase. The author now proposes to commence a systematic study of the organisms contained in soil. DiscussIoN. Dr. PERCY said that he also had so far searched in vainFRAR'BLAND for the nitrifying organism ; but he could not agree that no one had been successful. Heram3 had succeeded in isolating two or three organisms which were stated not only to induce the formation of nitrite in urine solutions, but also in mineral solutions containing ammonium salts. He had, however, himself shown that Herams was undoubt,edly wrong in attributing nitrifyiiig powers to a number of organisms, his mistake arising from his ignorance of the fact that nitric acid is normally present in urine.The effects of organisms in milk had been very fully described by Hueppe, who had shown that, coagulation might take place independently *of the presence of acid. He was not satisfied with the method adopted by Mr. Warington for sterilising milk-perhaps the most difficult of all fluids to sterilise ; sterilisation might, however, be effected by heating on five successive days at a temperature of 65-70"-and it had long been known that milk so treated differed from steam-sterilised milk. Had Mr. Waring-ton repeated the experiments sufficiently often to be sure of the results being constant ? micro-organisms were often extremely Capri- cious in their chemical action. Thus, under certain conditions, M.prodigiosus entirely changed its character-becoming colourless, but the colourless form would regain the pigment-producinp power on changing the cultivating medium. Mr. WARINGTONin reply said that he was under the hpression that Heraeus had found nitrification to take place only in those cases in which soil was introduced into the experimental fluids. The results he had obtained when using milk were perfectly constant, and he had met with no failures in sterilising ; this probably was attributable to the fact that he had used fresh country milk milked directly into sterilised bottles. He had observed the change in colour of M. pro-digioszcs, but Dr. Klein, to whom he submitted his cultures, had found that the forms were distinct, and that only white organisms could be obtained from the pure white form.46. "The optical and chemical properties of Caoutchouc." By J. H. Gladstone, Ph.D., F.R.S., and Walter Hibbert, F.I.C. This is an extension of the observations on caoutchouc published in 73 Dr. Gladstone’s paper on Essential Oils (Chem. SOC.T~ans.,1886, 609). The substance experimented on was obtained from the best commercial Para rubber. Many attempts were made to separate the two supposed modifications, and tooremove an oxidised product. The most promising method seemed to be to dissolve the rubber in cold chloroform, and precipitate partially with a little alcohol, but no good separation was eBected, and the results of analysis gave usually about 3 per cent.of oxygen. One small specimen, very carefully prepared and dried, contained carbon and hydrogen in almost exactly the pro- portions Clo:H16,with only 0.5 per cent. deficiency. Optical analyses are given of 17 preparations dissolved in benzene. They were prepared from different specimens in different wa,ys, and variously dried, and two of them were second precipitates from chlo- roform or ether solutions. The refraction and dispersion equivalents vary considerably, but they all agree in showing that the C,,H,, must have more than one pair of carbon-atoms doiibly linked. All the dispersion equivalents, and 11 of the refraction equivalents also exceed what theory requires for two pairs of carbon-atoms so com-bined, namely, refraction equivalent, 75.2, and dispersion equivalent, 4.8.They fall short of what would be required by three pairs, at any rate in the case of refraction (theory, refraction equivalent, 77.4, and dispersion equivalent, 5*6),but the presence of a little oxygen in the substance examined would reduce the refraction and dispersion considerably. The observations on the best specimen already described give the highest figures, the mean of which are, refraction equivalent, 77.23, and dispersion equivalent, 5.50. There is little doubt, therefore, that the main constituent of caoutchouc is a com-pound which has three pairs of carbon-atoms doubly linked. If this be the case, the molecular formula cannot be C5Hs, like isoprene, or Cl5HZ4,like cedrene, as these would give respectively one and a-half and four and a-half pairs of carbon-atoms, united by double linking.It cannot contain the hexagonal ring, but must be expressed graphically by a chain formula. This may account for the wide difference of pro-perties between caoutchouc and the various essential oils. The action of the ha,Iogens on caoutchouc dissolved in chloro- form was examined. Chlorine gave rise to a substance which could be obtained in yellow scales, the best preparation giving figures which seem to point to CloHl~C18.Bromine in weak solution acts upon caoutchouc in chloroform, and by volumetric methods it was deter- mined that 136 grams of the caoutchouc used combine with 303 grams of bromine on an average, which indicates CloH16Br4as the first pro- duct of the action.The prolonged action of bromine causes the sepa- ration of hydrogen bromide, and the formation of a compound precipitable by ether as a white solid, C,,H1,Br5. It seems not impro- 74 bable that this is formed from a compound, C,oH,6Br,, by the elimina- tion of HBr. Iodine has no action. The action of heat was also studied. The caoutchouc hydrocarbon dissolved in toluene remains unchanged optically on exposure to a temperature of 200”. As is known, the various oils given by dry distillation contain cmbon and hydrogen in the same proportions as the original caoutchouc, but the structural re-arrangement is most materially modified, as indi-cated by the following optical constitutional formula :-Caoutchouc ..“&C6”C,H16, Caoutchene .. Ck”C6H16, Isoprene . . . . Ca”CH8, Heveene ... . nnC2”C3H8. 47. “An Apparatus for maintaining it constant pressure when dis- tilling under reduced pressure.” By W. H. Perkin, F.R.S. The essential parts of the apparatus are a barometer tube in con-nection with the exhausted apparatus, and a valve through which air is admitted when by the action oof the pump the pressure becomes reduced below the prescribed point. A copper rod armed with a platinum point passes through the upper end of the barometer tube and can be adjusted at any desired height ; so soon as the mercury rises and touches the point of the rod, an electric circuit is completed and the valve is raised and air admitted.The valve is a glass sphere in a glass seating, the sphere being suspended from the armature of an electromagnet ;the sphere has a weight attached to it which causes it a$ once to fail back when the circuit is broken. Even under a prepne of 60 mm.-the lowest obtained with the water-pump used- the apparatus renders it possible to maintain the pressure constant to within a millimetre. At the next meeting, on June 21st, the following papers will be read :-“ Chlorofumaric and Chloromaleic Acids.” By W. H. Perkin, F.R.S. “Combustion by means of Chromic Anhydride.” By C. P. Cross and E. J. Bevan. “ The Sulphonation of Metaxylene.” By G. T.Moody, D.Sc. ‘‘ Researches on Naphthalene-derivatives.” By Dr. Armstrong and W. P. Wynne.‘‘ A New Method for the preparation of mixed Tertiary Phosphines.’2 By J. N. Callie. riABEISON AND SONS, PRINTERS IN ORDINARY TO HER MAJESTY, ST. MARTIN’S LANE.
ISSN:0369-8718
DOI:10.1039/PL8880400069
出版商:RSC
年代:1888
数据来源: RSC
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