408 Mr. R. Phillips's Analysis of a peculiar Submuriate 



binary compound which is decomposed by the addition of 

 either the acid or base ; and the last-mentioned circumstances 

 show, that there are two submuriates of peroxide of iron, in 

 addition to that now described, and differing from it in being 

 insoluble in water. 



Another subsalt which I have examined, is the submuriate 

 of antimony: this compound has been long known and em- 

 ployed by the name of Powder of Algaroth, yet I have not 

 found an analysis of it in any chemical author. 



To ascertain its composition, 100 grains were boiled in a 

 solution of 200 grains of crystallized carbonate of soda, by the 

 action of which, the muriatic acid is perfectly separated ; the 

 protoxide of antimony obtained, weighed 92 grains; the solu- 

 tion was slightly supersaturated with nitric acid, and by this, 

 0*5 of a grain of oxide, which had been dissolved by the car- 

 bonate of soda, was precipitated. To the solution, nitrate of 

 silver was added, which gave 31*6 grains of chloride, equiva- 

 lent to 8 of muriatic acid. On repeating this experiment, 

 92*4 of oxide and 30 of chloride were procured, giving 7*6 

 as the proportion of acid. 



The mean of these experiments shows that submuriate of 

 antimony is composed of 



Protoxide of antimony 92*4-5 



Muriatic acid 7*80 



100-25 

 Estimating the atomic weight of protoxide of antimony at 52, 

 and that of muriatic acid at 37, it appears that submuriate of 

 antimony is constituted of 



Nine atoms of protoxide of antimony 52 x 9 = 468 or 92*67 

 One atom of muriatic acid = 37 7-33 



505 100*00 

 Subnitrate of bismuth, as occupying a place in the London 

 Pharmacopoeia, is a salt of some importance. I have met with 

 only two notices of its composition ; one, confessedly theore- 

 tical, is in Mr. Brande's Table of Proportionals, and the other 

 is given by Mr. Reid, in his Elements of Chemistry, in the form 

 of a diagram ; these authors both represent the salt in ques- 

 tion as a dinitrate: this I shall presently show is not the 

 case; indeed, according to Dr. Thomson, the dinitrate is a 

 crystalline salt. 



In the Pharmacopoeia this subnitrate is directed to be pre- 

 pared, by dissolving an ounce or 480 grains of bismuth in a 

 fluid ounce and half, or about 680 grains of strong nitric acid 

 diluted with half its bulk of water. This proportion of acid 



is 



