Technical chemistry

1885 Journal of the Chemical Society Abstracts  
Chem. Nezos, 51,241-244) .-The authors strongly advocate the use of alum for the purification of water, alleging that it not only clarifies but also removes disease germs and ptomaines. By adding 2 grams of d u r n to 60 litres of a rather turbid drinking water, a precipitate settled, and perfectly d e a r water was obtained after 48 hours. The dried precipitate contained per cent. C 16-50, H 2.02, N 0.77, ash 59-28, the latter consisting of small amounts of silica and alumina, large amouiits
more » ... a, large amouiits of iron oxide, and considerable quantities of phosphoric acid. The clear water contained the merest trace of aluminium, and a further addition of alum caused no precipitation in it. Reducing Action of Coke on Nitric Acid. By G. LUNGE (OingZ. poZyt. J., 256, 96).-To confirm the observation that the socalled " nitrous vitriol " of the Gay-Lussac towers only contains nitrous acid, if the gases on entering the tower contain considerable quantities of nitrogen tetroxide, the author tested the action of coke on nitric acid, and found that the nitric acid dissolved in sulphuric acid i n contact wit,h coke is reduced to nitrogen trioxide slowly a t the ordinary temperature, but' quickly and practically completely a t a slightly elevated temperature, such as usually exists in the Gay-Lussac tower. Whether the reduction is effected directly by the 937 carbon or by sulphurous anhydride produced by the action of the coke on sulphuric acid, the experiment does not show. Obtaining Sulphur from Hydrogen Sulphide. (Dirtgl. p l y t. J., 256, 143.)-'The Oesterreichische Sodafabrilc in, Hruschau has patented a process for recovering the sulphur froin sulphuretted hydrogen, which consists in passing the latter through heated sulphates of the alkalis or alkaline earths, the result being the combination of the oxygen contained in these salts with the hydrogen of the gas, and the formation of free sulphur, the residue containing the respective metallic sulphides. By blowing at,mospheric oxygen into the latter, and continuing the heating process, the metallic sulphide is oxidised into the sulphate, which is then used for another operation. Manufacture of Strontium Hydroxide and Sodium Hydrosulphide. By C. F. CLAUS (J. Pharm. [ 5 ] , 11, 434).-The process is based on the decomposition of strontium monosulphide into hydroxide and hydrosulphide under the influence of water; the hydroxide crystallises out. The mother-liquor containing hydrosulphide may be treated with sodium sulphate, separating the strontium sulphate precipitated, and evaporating the solution to obtain sodium hydrosulphide (to obtain a colourless product, iron vessels must be avoided) : or the liquid is mixed with magnesium sulphate, and heated to eliminate all the hydrogen sulphide ; the mixture of strontium sulphate and magnesium hydroxide is then exposed to a current of carbonic anhydride, by which strontium carbonate and magnesium sulphate are produced. Calculation of Glass Batches. By E. TSCHEUSCHNER (Dingl. poZyt. J., 256,[75][76][77][78][79][80][81][82][83][84] .-Although the chemical constitution and the composition of glass has been the subject of research during the last ten years, the results do not appear to have led to a solution of the question relating t o the formation of glass batches. It is a generaliyaccepted fact that the various constituents of glass are present in R ratio corresponding to a double union of a trisilicate of an alkali and an alkaliue earth ; but the proportion between these compounds, although subject to wide differences, still remains undetermined. The author has attempted to solve this problem, and establish a relationship between the proportion of alkalis and earths and the stages of silicification. If in the analysis of glass the amount of alkalis, earths, and silicic acid (expressed in equivalent quantities) be summarised, the first designated as AO, the second as BO, and the third as SiO" the formula aAO + y E 0 + zSiOZ, is obtained for the composition of the glass ; the coefficients a, y, z being numbers which are subject to variations within certain limits. For the normal composition these Coefficients would assume the values a = y = 1, z = 6 = 3 (3 + .?I). The formula .z = 3 (x + y) which determines the quantity of sihcic acid to be added to a glass containing a certain amount of alkalis and earths only holds good if a = y. For instance, applied to the glasses analysed by Weber (ibid., 232, 349 ), the following numbers art) A R~H (Bied. Centr., 1885, 275-277). By C. HACCIUS (Ried. Centr., 1885, 265--270).-This drink, prepared by the addition of kephir ferment to milk, consists (three days old) of-Casei'n. Albumin. Peptones. albtimino'ids. Sugar. Alcohol. Lactic acid. 2.567 O*i680 0.Preparation of New Colouring Matters. (Dz'ngZ. pobyt. J., 256, 134--139.)-For the production of a new blue colouring matter from resorcinol, R. Benedikt proposes melting resorcinol with sodium ni trit,e at 130". The dye separates from the aqueous solution of the melt in the form of dark red flakes which are readily soluble in alcohol, and give a, blue colour on treatment with concentrated sulphuric acid. When heated with zinc-dust and an alkali, the colour is reduced, but reappears on exposing the filtered solution to the air. By this property, the colouring matter is distinguished from Weselsky's diazoresorcinol,
doi:10.1039/ca8854800936 fatcat:vf3qiobtobhjzkp2kbtsc5jujm