1825.] Mr. Phillips's Analysis of Tartarized Antimony. 377 



as Dr. Thomson has, 3 atoms of protoxide of antimony from 

 this salt. 



A. 100 grains of brilliant small crystals of tartarized antimony 

 reduced to powder were heated during eight hours at the tem- 

 perature of 212°; they lost only 2-1 grains; but as bitartrate of 

 potash retains the water of crystallization when exposed to a 

 much greater heat, I subjected 100 grains of tartarized antimony 

 reduced to powder to a higher temperature. Taking the 

 mean of several experiments, I found that the salt lost 7*38 per 

 cent, by several hours' exposure to a sand heat. When one 

 portion, which had lost 7*4 per cent, in this way, was heated by 

 a spirit-lamp, so as to suffer a further diminution of 0'4, it was 

 decomposed, and becoming of a brown colour, it emitted the 

 smell of decomposing tartaric acid. I consider, therefore, 7*4 

 per cent, as the quantity of water. 



B. I attempted to ascertain the quantity of oxide of antimony 

 in two different modes. First, I decomposed a solution 100 

 grains of the crystals by carbonate of soda, assisted with heat ; 

 the mean of two experiments gave 41 '35 per cent.; but the 

 alkahes being imperfect precipitants of antimony, I treated the 

 solution afterwards with sulphuretted hydrogen, which gave a 

 mean of 2-8 of precipitate dried at a moderate temperature, and 

 which I conceived to be hydrosulphuret of antimony composed 

 of I atom of sulphuretted hydrogen 17+1 atom protoxide of 

 antimony 52 = 69 ; if then 69 contain 52 of oxide 2-8 = 2-11, 

 which, added to 41-35, gives 43-46 as the quantity contained in 

 100 parts of the salt. 



C. After this, and in order to confirm the above statement, I 

 treated two solutions each of 100 grains of tartarized antimony with 

 sulphuretted hydrogen gas ; the precipitates after being dried on 

 a sand he-at gave a mean of 51'25 grains. Now, if we admit, as 

 above supposed, that this precipitate is hydrosulphuret of anti- 

 mony, and of which it possesses the appearance, tartarized 

 antimony contains only 38-6 instead of 4346 of protoxide of 

 antimony as by Experiment B, for 69 : 52 :: 51-25 : 38-6. It 

 may be further observed that the quantity of precipitate obtained 

 in C, as well as the inference as to the quantity of oxide which it 

 contains, agree very nearly with the previous determinations of 

 Tlienard. 



These discordant results, repeatedly obtained, puzzled me 

 exceedingly, and I adopted two modes of determining the 

 quantity of oxide existing in the dried hydrosulphuret. 



1). I dissolved 45-6 grains of protoxide of antimony in a solu- 

 tion of bitartrate of potash, and then preci|)itate(l it by sulphur- 

 etted hydrogen, after washing and drying in the same mode 

 as before, the precipitate weighed 52-8 grains ; and, as it had 

 the appearance of being an hydros>ilphuret of antimony, I sus- 

 pected that it was subhydrosulphuret consisting of 1 atom of 

 sulphuretted hydrogen, and 2 atoms of oxide of antimony, on 



