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Proceedings of the Chemical Society, Vol. 6, No. 76 |
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Proceedings of the Chemical Society, London,
Volume 6,
Issue 76,
1890,
Page 1-6
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摘要:
Issued 23/1/1890, PROCEEDINGS OF THE CHEMICAL SOCIETY. No. 76. Session 1889-90. .January 16th, 1890. Dr. W. J. Russell, F.R.S., President, in the Chair. Messrs. Wallace C. Nickels and J. A. Nettleton were formally admitted Fellows of the Society. Certificates were read for the first time in favour of Messrs. Frederick Alfred Anderson, B.Sc., Lesney House, Erith, Kent ; G. Russell Beardmore, Warwick House, Upper Street, Islington ; Robert Frederick Blake, 37, Hartington Street, Dublin Road, Belfast ; Bertram Blount,, Laboratory, Broadway, Westminster ; Henry Herbert Bunting, 82, Netherwood Road, Kensington, W. ; Paul Alexander Cobbold, Warwick School, Warwick ; John S. Lumsden, 5, Paradise Road, Dundee ; Frederick Mills, Revan Crescent, Stockton-on-Tees ; Hobert Richard Rothwell, 82, Mawson Street, Ardwick Green, 3Inn-chester ; Edward Sergeant, 75, Park Road, Bolton ; Basil William Valentin, Aston Brewery, Birmingham.The following papers were read :-1. “A new method of estimating the oxygen dissolved in ~at~.” By J. C. Thresh, D.Sc., M.B. The process is based on the observation that whereas, in absence of oxygen, nitrous acid and hydrogen iodide interact to form iodine, water and nitric oxide ; in presence of oxygen the nitric oxide becomes re-oxidised, and, serving as a carrier of the oxygen, an amount of iodine equivalent to the oxygen present is liberated, in addition to that resulting from the initial action of the nitrous acid: hence, de-ducting the amount liberated by t,he nitrous acid and by the ox~gcn 2 dissolved in the solutions used from the t,otnl amount, the difference will be that corresponding to the oxygen dissolved in the water examined.The solutions used are: (1) a solution containing -5 gram sodium nitrite and 20 grams potassium iodide in 100 C.C.; (2) a solution of 7-75 grams sodium thiosulphate in 1litre, 1C.C.of which corresponds to 0.25 milligram of oxygen ; (3) a clear solution of starch ; and (4) diluted pure sulphuric acid (1 : 3). The apparatus required is a verr simple one. It consists of a wide- mouth, white glass bottle of about 500 C.C. capacity, provided with a caoutchouc stopper, through which four holes are boyed. Through one passes the neck of a cylindrical ‘‘ separator ” funnel of known capacity, and through the second a tube drawn out to a fine point, which is connected by a short length of caoutchouc tubing with the tliiosulphate burette ; while inlet and exit tubes for coal gas are passed through the third and fourth holes, the exit tube having attached to it a sufficient length of caoutchouc tubing to permit of connexion being established between the bottle and the separator when the stopper of the latter is withdFawn. The separator is filled with the water to be examined, and 1 C.C.of the nitrite-iodide and 1 C.C.of the acid solution are added; if the pipette be held vertically, with its end just below the surface of the water, the solutions flow in a sharply defined column to the lower part of the separator, so that an infinitesimally small quantity (if any) is lost in the water which overflows when the stopper is inserted.The admixture of the liquids having been effected by inverting the apparatus several times, a sharp current of coal gas is passed into the bottle to displace the air, the escaping gas being allowed to burn at a jet attached to the exit tube. Fifteen minutes after adding the solutions to the water the flame is extinguished, a cork is attached in place of the jet and is inserted in place of the stopper of the separator, and the water is then allowed to flow into the bottle ; the exit tube having been disconnected from the funnel and the gas set fire to, tliiosulphate is run in until the colour of the iodine is nearly destroyed ; about 1 C.C.of starch is then added from the separator and the titra- tion is completed.‘The effect of the nitrite, dilute acid and starch solutions is readily determined by removing the separator and adding 5 C.C. of each in succession and then titrating ; the effect of the oxygen in the thiosulphate may be allowed for on the assumption that as much oxygen is dissolved in it as distilled water would contain at the same temperature. It appears that there is no advantage in passing the coal gas through alkaline pyrogallol. The author states that concordant resultls are easily obtained, and that the results in the case of freshly distilled water closely agyee 3 with those recently published by Sir Heizrj Roscoe and Mr.Lunt (cf. Chern. SOC.Proc., 1889, 124 ; Tvans., 1889, 552). Thus :-Temp. Thresh. Roscoe and Lunt. 10" 7-81 7.77 15 7.02 6.96 20 6.17 6.22 25 .5%9 5-60 3 I 5.45 5.43 T>lSCUSSION. Mr. WARINGTONsaid tlhat on the occasion of Mr. Holland having suggested in the Chemical News a method of estimating nitrites in water by means of potassium iodide, he had pointed out that the method was fallacious in presence of air ; the delicacy of the iodine test for nitrites was doubtless ascribable to the occurrence of the series of changes of which Dr. Thresh had availed himself. Mi-. GREEN stated that he also had called attention to the influence of oxygen about four pears ago, in a communication to the University College Chemical Society.Dr. STEVENSONsaid that he was not satisfied with the method of estimating nitrites in water proposed by the author ; a comparison with other methods would be desirable. JONESMr. CHAPMAN drew attention to the use of manganous hydrate in estimating the oxygen dissolved in water. 2. " Note on a milk of abiiormal quality." By F. J. Lloyd. The author is led to give the yesults of his examination of the milk afforded by two cross-bred shorthorns, as its quality appears to be altogebher remarkable (compare table) ; there being no evidence either that the cows were suffering from disease, or that they were insufficiently or improperly fed, he is of opinion that the normal quality of their milk is such as has never before been recorded.Several complete analyses, made with the object of discovering whether the loss fell on any special constituent, show that this is not the case, the caseine, sugar and other constituents, except the mineral mafters, being equally affected. DISCUSSIOS. Dr. STEVENSON expressed the opinion that the animals in question were in some way suffering from malnntrition, or were subject to qome latent disease. Mr. WARINGTONsaid that the amount of total solids was not below Cornpositio71 of the Nilk, I No. 40. No. 41. Yield of milk. Morning. Evening. Morning. Evening.Da,te. I-13th NOT. 3 -41 8 -47 14.34 --19th ,, --8-10 22nd ,, 3.39 8 -39 12 *88 8 -41 5th Dec. 3.44 8 -28 13.60 10th ,, 2 *17 7 ‘87 12 -98 8 -25 ~17th ,, 2.98 7.58 8.14 12-00 8 *26 1’7th Jan.2 5’0 7 *50 7.68 11 -32 5 the accepted lowest value ; whilst Professor KINCHremarked that equally low results had been obtained in certain cases at the Agricul- tural College, Cirencester. Professor THOMSONmentioned the case of a cow having the propen- sity of eating heather tops affording a milk containing a lower pro-portion of total solids than that of other cows of the herd which had not the propensity. Mr. LLOYD,in reply, said that in the cases considered by him the small amount of solids other than fat was what he desired to bring under notice; the total solids often varied, but the variation was chieflj- in the amount of fat, not in the solids other than fat.3. “The sulphates of antimony.” By R. H. Adie, B.A. Having previously studied the compounds of arsenious oxide witlt SO3, the author has now examined those of antimonious oxide. His results are summarised in the following table, in which is indicated the composition of the products obtained from the two oxides on treatment with the acid formulated in the first column. s0, A s203,8S03 Sb203,9S03 2H,S0,,S09 A~203,4SO3 ShOs,4SOs HZS0, SbzO3,3SO3 9H2S04,3H20to H2SOa,H20 or Sb(SO,),t:2:g3}H,S0,,2H,O -Sb203,2S03,H20 or Sb(OH)SO, H2S04,4H20 -Sb203,2S03,3H?O or Sb(OH)S04,H,C) Action on sulphate of alcohol.. Sbz03,2S03I or SbO(S0,)2 Cold water.. ............... As@, 2SbzO3,SO3,xay. Hot water.. ................. -7Sb,O3,2SO3,yaq. Where x = 4to 16 and y = 2 to 16.On comparing the two series of compounds it appears that:- (i.) With H2SOaand weaker acids, Sb203 forms a different ordeis of sulphates from AsZO3,while it resembles it in forming acid sul- phates when subjected to the action of stronger acids. Thus the former yields the characteristic group salt, Sb,(SOa)3,in place of the basic As20(S0J2 afforded by the latter. The limits of existence, both as regards dilution and temperature, are much narrower for the arsenic than for the antimony salt. The practically complete forma-tion of Sb,( SO,), in one crystallisation also contrasts with the €oinmattion of A&( SO,), only by repeated crystallisation. 6 (ii.) Arsenious oxide does not form any basic sulphates conta,ining water, while the more metallic antimonious oxide does form hydrated sulphates in acids weaker than HZS0*,H20.This acid is the limit of existence of Sb,(S04), in solution, and of any arsenic sulphate what- ever.At the meeting on March 20th, Professor Judd, P.R.S., will deliver a lecture on the evidence aforded by petrographical research of the occwwence of chemical change under great pressures. At the next meeting, on February Bth, there will be a ballot for the election of Fellows, and the following papers will be read :-“ The oxides of nitrogen.” By Professor Ramsay, F.R.S. “ Studies on the constitution of tri-derivatives of naphthalene.” By Dr. Armstrong and W. P. Wynne. HARRISON AND SONS,PRINTERS IN ORDINARYTO HER MAJESTY, ST. MARTIN’S LANE.
ISSN:0369-8718
DOI:10.1039/PL8900600001
出版商:RSC
年代:1890
数据来源: RSC
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