On some Combinations of Platina. S63 



•xideof Iron, then precipitated with benzoate of ammonia. 

 This precipitate, washed and calcined, left within a trifle 0*10 

 of a gramme red oxide of iron. The solution was evaporated 

 to dryness. On the redissolu'ion of the remauiing salt in 

 water, there appeared some traces of oxide of iron, derived 

 from benzoate of iron, which during the washing could 

 have been dissolved, and there was besides a multitude of 

 black and lifiht traces of coal, from the destruction of the 

 benzoate acid during the drying of the salt. After these 

 had been separated, the solution was precipitated with car- 

 bonate of potash by digestion, which produced white car- 

 bonate of manganese ; this became black after a strong 

 and long calcination; joined to whnt had stopt on the filter, 

 it weighed 0-795 of a gramme. Dissolved in muriatic acid, 

 it showed no remarkable traces of iron by re-agents. 



It appears from these experiments, that the method pro- 

 posed by Professor Berzelius, to separate iron and man- 

 ganese by means of benzoates, not only answers perfectly 

 the purpose, but also presents to us a hitherto unknown 

 agent for the most accurate purification of nickel, cobalt, 

 and most of the metals and earths from iron, on the sole 

 condition that the solutions are precisely neutralized and 

 diluted, while at the saine time the iron is oxidated to 

 maximum. The influence of this discovery, on all analy- 

 tical experiments, where iron so frequently occurs and re- 

 mains so stubbornly, must be evident to all who are in the 

 practice of such labours. It should however be noticed, 

 that after having precipitated the iron from a solution con- 

 taining several kinds of earth and oxides of itietals toirethcr, 

 then the benzoate added in excess ought to be destroyed 

 by boiling the solution with some acid, to obviate anv cini- 

 fusion caused by the benzoic acid on the continuation of 

 the analysis. 



XLVni. On some Comhinalions of Platina. By Edmund 

 Davy, Esq., of the Royal Institution. Communicated 

 ly the Author. 



[Continued from p. 220.] 



2. Of the Precipitate obtained from aqueous Solutions of 

 PluLina by phosphorefted Hydrogen Gas. 



An my former experiments on the combinations of plaiina 

 with phosphorus*, I did not ascertain the aL;cncy of plios- 



• See Philosophical Magazine for July. 



R4 jihoretted 



