568 Intelligence and Miscellaneous Articles. 



as to render the condensation of the acid more certain. Without 

 the use of ice the preparation of the anhydrous acid should by no 

 means be attempted ; and even then, the operation, and all experi- 

 ments with this substance, should be conducted with the greatest 

 care and precaution. — Handworterbueh der Chemie, vol. ii. p. 406 ; 

 and Chemical Gazette for Oct. 15, 1846. 



PURIFICATION OF ZINC. BY M. DE SMEDT. 



The author proposes the following process for obtaining zinc in a 

 state of purity : — Treat the zinc of commerce with concentrated 

 nitric acid, which leaves the tin insoluble in the state of peroxide, 

 and the antimony in that of antimonious acid, while the arsenic be- 

 comes arsenic acid, and the zinc, cadmium and iron are dissolved ; 

 the solution is to be filtered to separate the oxides of tin and anti- 

 mony, and great excess of carbonate of ammonia is to be added to 

 it, which precipitates the iron, and the cadmium as a carbonate, 

 while the arsenic acid remains in solution. The solution is to be 

 poured off and evaporated to dryness, and the residue is to be cal- 

 cined to destroy the ammoniacal salt ; the oxide of zinc is to be dis- 

 solved in nitric acid, and carbonate of potash added to the solution ; 

 the zinc is precipitated and the arsenic acid remains in solution in 

 the state of arseniate. The carbonate of zinc is to be carefully 

 washed, in order to separate very small portions of arseniate which 

 may be mixed with it; it is then to be heated to redness in a cru- 

 cible to convert it into oxide, which is afterwards reduced to the 

 metallic state by means of hydrogen and heat ; for this purpose the 

 oxide is placed in a strong glass or porcelain tube, heated to redness, 

 and is to have a current of pure dry hydrogen gas passed over it. — 

 Journ. de Chem. Med., Aout 1846. 



ACTION OF NITRIC ACID ON BRUCINE, — PRODUCTION OF 

 NITROUS .ETHER, AND CACOTHELINE. 



M. Gerhardt states that M. Laurent has confirmed the accuracy 

 of his statement, that nitrous sether is developed when nitric acid is 

 made to act upon brucine. He operated on about 230 grains of bru- 

 cine, and after having passed the gas generated over lime, he con- 

 densed it by means of a mixture of common salt and ice. He obtained 

 about 15 grains of a very fluid liquid, lighter than water, and which 

 possessed the odour of nitrous aether : this liquid was distilled to 

 the last drop, without being made to boil, at a temperature of about 

 60°Fahr. 



When nitric acid has ceased to act, at common temperatures, upon 

 brucine, this alkali is converted into an orange-red substance, which 

 M. Laurent succeeded in causing to crystallize. This new substance 

 he calls cacotheline ; analysis showed its formula to be C 21 H.' 2 - N 4 O 10 . 

 If from 1 equivalent of brucine and 3 equivalents of nitric acid there 



