of Iron, and of some other Subsalts. 409 



is considerably too large, and the excess prevents the preci- 

 pitation of a large portion of the subnitrate by water: thus 

 when 480 grains of the metal were dissolved as above directed, 

 water threw down only 257 grains of subnitrate; a solution 

 of common salt precipitated afterwards 307 grains of sub- 

 muriate, and ammonia then gave 27 grains more of the latter 

 subsalt. 



It will be observed, that the subnitrate precipitated by 

 water is to the submuriate thrown down by common salt, only 

 about as 100 to 120 ; and that this deficiency of subnitrate is 

 occasioned by the great excess of acid, is found by using cry- 

 stallized nitrate of bismuth : in this case the subnitrate ob- 

 tained by water was to that of the submuriate procured by 

 common salt, nearly as 100 to 33, instead of 120. To ana- 

 lyse subnitrate of bismuth, 200 grains were boiled in a solu- 

 tion of soda; taking the mean of several experiments, 81*92 

 per cent of oxide of bismuth were left: to determine the pro- 

 portion of nitric acid, a similar quantity was heated in water 

 with excess of lime; after filtering the solution, carbonic acid 

 gas was passed into it, until the carbonate of lime formed be- 

 gan to redissolve; the excess of carbonic acid was expelled 

 by ebullition, and the nitrate of lime being decomposed by 

 carbonate of soda, 17 per cent, of carbonate of lime were ob- 

 tained as the mean of two experiments, which quantity is equi- 

 valent to 18*36 of nitric acid. 



According to these experiments, this subsalt consists of 



Oxide of bismuth 81*92 



Nitric acid 18*36 



100*28 

 The atom of oxide of bismuth being 80, and that of nitric 

 acid 54, it appears that subnitrate of bismuth is constituted of 



Three atoms of oxide 80 X 3 = 240 or 81*64 

 One atom of acid = 54 18*36 



294 100*00 

 I have also subjected the submuriate, formerly called ma- 

 gistery of bismuth, to examination ; it was prepared by adding 

 a solution of common salt to one of nitrate of bismuth. In 

 analysing this salt, I adopted a similar process to that em- 

 ployed with the submuriate of antimony ; viz. ebullition in a 

 solution of soda, saturation with nitric acid, and precipitation 

 by nitrate of silver. 



One hundred grains treated in this manner gave 87 grains 



of oxide of bismuth, and 54 of chloride of silver, equivalent 



N.S. Vol.8. No. 48. Dec. 1830. 3G to 



