412 Intelligence and Miscellaneous Articles. 



announced by the Italian chemist entirely corroborates his own nu- 

 merous observations on the same subject ; and the following he 

 states to be the results of his experiments : — 



1. Calomel which is perfectly free from sublimate, digested with 

 its own weight of hydrochlorate of ammonia, or any other alkaline 

 chloride, in distilled water at a temperature of 100° to 104° Fahr., 

 during 24, 36, or even 48 hours, underwent no change of colour. 

 The faltered liquor did not, by means of any reagent, appear to con- 

 tain a trace of a mercurial salt. 



Some pigeons which were made to drink of this same liquor for 

 several successive days suffered no inconvenience : the calomel lost 

 no sensible weight. 



2. The same mixture exposed to a temperature of 122° to 140° 

 Fahr., yielded a liquor which acted precisely in the same way with 

 reagents and on the animal ceconomy as the foregoing. 



3. By continued boiling, however, and under the influence of a 

 great excess of chloride, the conversion took place, but only parti- 

 ally. — Journal de Chimie Medicate, Septembre 1842. 



METHOD OF DISTINGUISHING ZINC FROM MANGANESE IN SO- 

 LUTIONS CONTAINING AMMONIACAL SALTS. BY M. OTTO. 



If solutions of chloride of zinc and chloride of manganese, con- 

 taining much hydrochlorate of ammonia, be rendered alkaline by so- 

 lution of ammonia, the addition of the smallest quantity of solution 

 of hydrosulphuric acid precipitates white hydrated sulphuret of zinc, 

 whilst no effect is produced by it in the solution of manganese, 

 more being required to obtain a precipitate of the sulphuret of the 

 latter metal. If acetic acid be then added to the solutions, the sul- 

 phuret of manganese dissolves very readily, whilst that of zinc re- 

 mains undissolved. M. Otto advises the use of hydrosulphuric acid 

 and not hydrosulphate of ammonia, because the latter, always con- 

 taining persulphuret, may occasion mistakes, since acetic acid sepa- 

 rates sulphur from it. if, for example, it be required to determine 

 whether iron filings contain brass, they are to be dissolved in aqua 

 regia, the peroxide of iron is to be precipitated by ammonia, the 

 liquor is then to be acidulated, the copper precipitated by hydrosul- 

 phuric acid, and ammonia is then to be added to the filtered liquor, 

 which usually still contains a sufficient quantity of hydrosulphuric 

 acid. If a white precipitate be formed which does not dissolve in 

 acetic acid, it shows that zinc is present. M. Wackenroder has 

 especially recommended the solubility of sulphuret of manganese in 

 acetic acid, to separate manganese from other metals. — Journal de 

 I'harm. et deChem., Sept. 1842. 



ON MM. VARRENTRAPP AND WILL 8 METHOD OF DETERMINING 

 AZOTE IN ORGANIC ANALYSES. BY M. REIZET. 

 M. Reizet has submitted to examination the new process recom- 

 mended by MM. Varrentrapp and Will, for determining the azote in 

 organic substances. This process is based on the general law of the 



