hitelligerice and Miscellaneous Articles. 237 



evaporation, a small quantity of oxide of lead may escape conversion 

 into sulphuret by hydrosulphuric acid ; and th^ circumstance may 

 lead to considerable errors. 



If sulphuret of ammonium be added to a dilute solution of lead, 

 sulphuret of lead is formed, which completely and readily redissolves 

 in moderately strong nitric acid and in hydrochloric acid : a current 

 of hydrosulphuric acid gas may be passed for a long time in these 

 solutions, especially in that of hydrochloric acid, without any effect; 

 but when the solution is diluted with water black sulphuret of lead 

 is precipitated, and after the addition of a sufficient quantity of wa- 

 ter the precipitation is complete. 



If oxalic acid be added to a solution of chloride of strontium acidu- 

 lated with a sufficient quantity of hydrochloric acid, it does not be- 

 come turbid ; but this effect is produced by the audition of a small 

 portion of lime. — Ibid. 



SOLUBILITY OF SALTS IN PERNITRATE OF MERCURY. 



M. Wackenroder finds that the chloride, bromide, iodide, cyanide, 

 and sulpho-cyanide of silver are soluble in pernitrate of mercury, 

 and that the ferrocyanide, sulphuret, and seleniuret of silver are in- 

 soluble in the mercurial salt. These solutions are of a peculiar and 

 uncommon nature. For example, neither nitric acid nor nitrate of 

 silver precipitates anything from the solution of cyanide of silver in 

 pernitrate of mercury ; but a sufficient quantity of hydrocyanic or 

 hydrochloric acid, or metallic chlorides, precipitate from it cyanide 

 or chloride of silver. On the contrary, hydrochloric acid, chloride 

 of sodium or hydrochlorate of ammonia, readily precipitate chloride 

 of silver from this solution ; an excess of nitrate of silver also pre- 

 cipitates this salt completely, which nitric acid does not precipitate. 

 The chloride, bromide and iodide of mercury also dissolve readily in 

 pernitrate of mercury. Chloride of mercury can be separated from 

 these solutions by a great excess only of chloride of sodium. — Ibid. 



ON LAUROSTEARINE. BY M. MARSSON. 

 M. Bonastre found bay-berries to contain volatile oil, resin, gum, 

 a fluid fatty matter and a solid fatty matter, which last he called stea- 

 rine, and a peculiar crystallizable substance which he named laurine. 

 As the characters assigned to this last substance resemble those of 

 the stearoptens, its true nature appears to remain unascertained. 

 By the recommendation of M. Liebig, the investigation was under- 

 taken by M. Marsson, who discovered a fatty substance differing 

 from those previously known, and which he has distinguished by the 

 name of laurostearine. It was obtained by treating bay-berries re- 

 duced to powder, three or four times with boiling alcohol, filtering 

 it as quickly as possible, washing the substance deposited by cooling 

 with cold alcohol, purifying it at first by fusion in a salt-water 

 bath, and filtering while hot, in order to separate an uncrystallizable 

 resinous matter, and afterwards by repeated crystallizations from 

 alcohol. 



