Professor Gmelin's Analysis of Helvine. 275 



alumine is retained by this latter, whereby the reaction with 

 cobalt is almost entirely destroyed. The earth, which was 

 dissolved by carbonate of ammonia, proved to be pure glycine. 

 When dissolved in sulphuric acid, and mixed with sulphate of 

 potash, there was formed no trace of alum. Alumine, on the 

 other side, being a little soluble in a considerable excess of 

 carbonate of ammonia, it seems, in the present case, to have 

 likewise left its solubility in this menstruum, by its chemical 

 combination with glycine, in the same manner as it, at least 

 partly, loses its solubility in pure potash by its chemical 

 combination with magnesia, d, The brown precipitate (in c.) 

 was dissolved in muriatic acid, whereby chlorine was evolved. 

 From this solution the iron was precipitated by succinate of 

 ammonia, and 0.1425 gr. of oxide of iron obtained = 0.12825 

 gr. of protoxide = 7.990 p. c. e, The liquor was then preci- 

 pitated by an excess of subcarbonate of potash, 0.7267 gr. of 

 oxide of manganese were obtained = 0.65484 gr. of protoxide 

 = 40.800 p. c. This oxide was dissolved in muriatic acid, 

 the solution rendered neutral by evaporation, precipitated by 

 a hydrosulphuret of ammonia. The liquor separated by the 

 filtre from the sulphuret of manganese, and evaporated 

 in order to chive off the excess of the hydrosulphuret, 

 was boiled with a solution of subcarbonate of potash ; but 

 no precipitate fell down, f, The carbonate of potash (in 

 e.) having been supersaturated by muriatic acid, and the car- 

 bonic acid expelled by heat, there was formed a small preci- 

 pitate by caustic ammonia, which, collected upon a filtre and 

 ignited, weighed 0.0038 gr. = 0.237 P- c -> a "d examined by 

 nitrate of cobalt, proved to be glycine, g; According to the 

 first analysis, 100 p. of helvine contain 14 p. of sulphuret of 

 manganese, which must therefore be deducted from the 40.8 

 p. c. ; and helvine is according to the analysis composed of — 



