180 Miscellaneous Intelligence. 



which solution of ammonia has of oxidizing and dissolving metallic 

 copper. — Edin. Jour, of Sci. i. 75. 



18. Action of Nitric Acid and Charcoal. — Professor Silliman for- 

 merly pointed out the production of hydrocyanic acid by the action of 

 nitric acid and charcoal. M. Frisiani has also observed the same 

 effect produced, in a very striking manner, during the action of nitric 

 acid on the residuum obtained by calcining sulphate of baryta with 

 vegetable charcoal, and removing every thing soluble in water by 

 repeated washings. A strong odour of hydrocyanic acid was pro- 

 duced, and when the action was made to take place in a VVoulfes bot- 

 tle, the tube of which passed into a solution of potash, the liquor col- 

 lected, when rendered slightly acid, and precipitated by persulphate 

 of iron, gave a precipitate, which washed with muriatic acid became 

 Prussian blue. Nitrates of the earths, or alkalies, boiled with vege- 

 table charcoal, gave no result of this kind. When the nitrates and 

 charcoal were mixed in the dry way and heated, the action was, 

 of course, violent, but no important results were obtained. — Gio. de 

 Fis. vii. 240. 



19. Camelio7i Mineral.— n't. Marabelli, of Pavia, finds that in the 

 preparation of camelion mineral, by potash and oxide of manganese, 

 the protoxide, or rather the carbonate obtained by precipitating any 

 of the salts of manganese, by carbonate of potash, is infinitely pre- 

 ferable to the native peroxide usually employed, however finely the 

 latter maybe divided. Dr. M. is of opinion that the preparation 

 contains aprotoxide of manganese, and that hence itis that protoxide 

 is preferable to peroxide : but this opinion will hardly hold against 

 the experiments of Chevillot, Edwards, and others — .Gio. de Fiiica, 

 vii. 22. 



20. Conceyitration of Alcohol by Bladders. — 'The effect produced 

 by inclosing diluted alcohol in a bladder is well known, namely, 

 the concentration of the alkali. This fact was first observed by 

 Soemmering, and it has even been proposed to improve wines by an 

 application of it, as, for instance, by closing the mouths of bottles 

 with it instead of corks. It is now stated that M. Soemmering has 

 succeeded by the same means in separating the water from alcohol 

 entirely, so as to have the latter quite pure or absolute. The pro- 

 cess is to put alcohol of 75° of the areometer of Soemmerin.i into 

 an ox's bladder, or else into a calf's bladder coated with isinglass, 

 ■which is to be hung over a sand bath ; in a few days the alcohol 

 will lose one quarter of its volume, and be found quite free from 

 water (absolute alcohol.) — Gio de Fisica, vii. 239. 



21. PureHi/drogen — Properties of Amalgam of Zinc. —M. Bischof 

 has remarked that an amalgam of zinc treated with a solution of 

 potash furnishes hydrogen gas of a purity surpassing that obtained 



