Fulltext access denied for pi 1695194465359_45_1882 and pageNo 400
            

274 New Compounds of Brazilein and Hematein. {Fn with the rest of the apparatus except at the instant of a deposited. This precipitate is colle®ed and pressed, measurement. The screw of the fine adjustment formerly 40 grms, are dissolved in a litre of hot waiter, and 30 to described serves also this’purpose. The vacuum is found 160 c.c. of acetic acid (sp. gr. 1°04) added. The solution :0 be even more permanent than that of a barometer. is heated for some time on a steam bath, and then allowed D. An auxiliary pressure tube is employed for prelimi- to cool. The amorphous residue of Hzamatein is filtered nary adjustment. The bore of this tube is but a milli- of, re-extraded with hot dilute acetic acid several times metre, which secures two important advantages. and the combined filtrates evaporated on the steam bath, E. The eudiometer tube is graduated with fine lines not when glittering crystals of Hematein separate out. These over the eight-thousandth of an inch wide, in half milli- are filtered off, washed with acetic acid, then with water, metres. The graduation is affe@ed with no relativeerrors and dried. Thus prepared, Hazmatein is sparingly soluble of the hundredth of a millimetre. A reading microscope in water, alcohol, ether, and acetic acid ; it dissolves is carried on a cylinder so solidly conne@ed with the iron readily in alkalies. Analyses indicated the formula tripod of the apparatus that ten pounds produce a relative Ci16H;.06. The crystals are evidently identical with those flexure of only a tenth of a millimetre. This microscope jescribed by Haberstadt and Reis (Ber., xiv., 611), is brought nearly to the level of the mercury in the eudio- Hzematein is destroyed by hot sulphuric acid; it, however, meter when the column in the pressure tube reaches just dissolves readily in cold concentrated sulphuric acid, pro. to the Jolly-point. The microscope is made to give dis- ducing a dark reddish brown solution. By adding hot tin¢t vision of the graduation, and by Grunow’s catheto- glacial acetic acid very gradually to this solution until jt meter fine adjustment, the terminal lines of the eye-piece is diluted to the extent of two or three times its bulk, an micrometer are made to coincide with two millimetres orange crystalline precipitate is gradually thrown down. of the graduation. The focussing movement now moves This, on analysis, gave the formula C16H;206503. The the microscope so that distin vision is had of the menis. authors suggest the name sulphate of hamatyl ; it is cus, and the level of the mercury is read to the hundredth insoluble in alcohol, ether, and benzol, but is slightly of a millimetre on the eye-piece micrometer, whose soluble in strong acetic acid and cold ammonia. By livisions now represent the divisions of the tube carried ligesting this substance with water and alcohol, a reddish forward into its interior. A four inch objective, with an brown crystalline powder was obtained, having the pro amplification of about sixty diameters, is thus utilised. bable formula (C16H1206);50;. By the action of hydro. F. The probable error of this reading of the level of chloric acid in sealed tubes on Hzamatein a body was the meniscus cannot be separated from other probuble srepared having the formula CH 105Cl, crystallising in errors incident to the observation, but the sum total of all ‘minute scarlet needles. By the adion of hydrobromic the errors whatever is equivalent to no more than a pro. acid a similar substance containing bromine was obtained. bable error of one-hundredth of a millimetre in this deter- From commercial Brazil extrads, by a similar process to mination : and in the calibration of the apparatus, made hat employed in the preparation of Hamatein, Brazilein before much pra&ice in the use of this reading arrange. wag obtained ; dried at x00° its composition is— ment, the probable error of a reading was the hundredth Ci6H 1,04, H,0 : of a millimetre. . o To Rn EY By the adi G. The probable error of a single determination of dried at 130° it was obtained anhydrous. By the action oXygen in air is less than the four-hundredth of one pes of sulphuric, hydrochloric, and hydrobromic acids, com: Centum. pounds were prepared corresponding to those prepared H. The method of measurement is adapted to rapid Tom Hematein. The tin@orial power of these Row computation, The whole redution of three measurements Sompounds is much greater than that of the Spm in an analysis, 50 as to get the per centum of oxygen, Hematein and Brazilein, and the colours are much fas % takes less than two and a half minutes, . Although the authors did not form from Hamatein a body similar to the coerulein obtained from gallein, they are of the opinion that Heematein probably belongs to the clase of phthalleins, Mr. WARINGTON then read a paper ** On the Determina: tion of Nitric Acid as Nitric Oxide by means of its Reaction with Ferrous Salts (Part I1.).” The author described and exhibited the apparatus at present employed by Schleesing. The nitrate mixed with ferrous chloride and hydrochloric acid is introduced into a very small tubulated retort, the extremity of which dips under mercury. The air is ex oelled by a stream of carbonic acid. The retort is then boiled for eight minutes, and the gas evolved collected in asmall jar containing caustic potash. This nitric oxide is converted into nitric acid by treatment with water and oxygen, and finally titrated with alkali. The method ‘ails, however, with extremely small quantities of nitrates and in the presence of certain kinds of organic matter. The prejudicial effe& of the organic matter is removed te some extent by boiling the contents of the retort to dryness but with very small quantities of nitric acid the results were still too low. The author, by various improvements and modifications described below, has been able to estimate 98 to 100 per cent of the nitrogen, even when half a milligramme of nitrogen as nitre was used. Perfect exclusion of oxygen from the apparatus is essential, This is effected by mixing the hydrochloric acid used in the carbonic acid generator with cuprous chloride, and pro tecting its surface with a layer of oil. The carbonic acl is always kept under pressure, 50 that any leak must be outwards. The nitric oxide is estimated by gas analysis, preference being given to absorption over caustic pois, after successive treatments with oxygen and pyrogallol. In the introdu&ion of the oxygen a gas delivery tube if PROCEEDINGS OF SOGIETIES. Tue following certificates were read for the first time :— |. Ferrier, J. Hodgkin, W. O. Nicholson, H. H. Robinson, G. H. Sharpe, G. Tarmay. During the evening a ballot was held, and the following gentlemen were declared by the Scrutators, Dr. Japp and Mr. J. M. Thomson, duly eleted Fellows of the Society :-— R. Alexander, B. Brauner, J. J. Dobbie, C. J. Ellis, W. L. Goodwin, D. E. Johnstone, T. W. Lovibond, R. W. Pullar, R. N. Wolfenden. The PRESIDENT then called on Mr. C. E. GROVES to read a paper entitled ** Note on B-Naphthaquinone.” See p. 267. Mr. A. G. PERKIN then read a paper entitled * Contributions from the Dye-house of the Yorkshire College : On some New Compounds of Brazilein and Haematein,” by ]. F. HumMEL and A. G. PERKIN. Commercial logwood extract is dissolved in hot water, and on cooling, ammonia i8 added in slight excess. This solution is exposed to the air for two or three days, or air is aspirated through for several hours, A dark purplish granular precipitate of the ammonia compound of Hzmatein is gradually