410M r. R.Phillips' 's Analysis of a peculiarSubmuriate of Ironic. 



to 13*6 of muriatic acid, showing the composition of the salt 



to be, Oxide of bismuth 87'0 



Muriatic acid 13-6 



100-6 



The atom of oxide of bismuth being 80, and that of mu- 

 riatic acid 37, it appears that this salt is constituted of 

 Three atoms of oxide of bismuth... 80x3 = 240 or 86*6 

 One atom of muriatic acid = 37 13*4 



277 100-0 



Dr. Thomson found that the carbonate of bismuth is a tris- 

 carbonate, similar in constitution to the subnitrate and sub- 

 muriate as above stated. 



It is well known that the oxide of bismuth is of a yellow 

 colour ; and this I have always found to be the case when it 

 is procured by decomposing the subnitrate by an alkali ; but 

 when the submuriate is employed, the colour of the oxide 

 frequently differs exceedingly ; sometimes it is yellow like that 

 from the subnitrate, frequently grayish black, and I once ob- 

 tained it of a deep bluish black colour. 



The cause of these variations of colour I have not been 

 able to discover, nor is there any circumstance occurring be<- 

 fore the actual decomposition, which gives any indication of 

 what colour the oxide will be. I have used portions of the 

 same solution of nitrate of bismuth in preparing the sub- 

 nitrate and submuriate ; and equal weights of the salts ob- 

 tained, one by water and the other by common salt, were 

 boiled in similar quantities of the same solution of soda; 

 the subnitrate gave the usual yellow oxide, and the oxide 

 from the submuriate was yellowish at first, but it soon be- 

 came grayish, and finished by being nearly black. 



In other cases when using bismuth taken from one mass, 

 and dissolving and precipitating as before, the submuriate 

 has, like the subnitrate, yielded a yellow oxide. The only 

 circumstances which appear to be constant are, that the sub- 

 nitrate always gives a yellow oxide; and any one portion of 

 submuriate always yields a dark coloured oxide, though, as 

 already observed, the submuriate obtained at different times, 

 even when using portions of the same mass of bismuth, gives 

 very different results. 



I could not detect any impurity in the bismuth ; indeed had 

 this or the accidental action of sulphuretted hydrogen black- 

 ened the oxide of the submuriate, it must have produced a 

 similar effect upon the oxide from the subnitrate, which how- 

 ever 



