1825.] Mr, Phillips's Analysis of Tartarixed Ahtimony. 373 



when M. Thenard published the result of his analysis in the 

 38th volume of the Annales de Chimie, p. 301. 



Before, however, I offer any observations on this analysis, I 

 shall state the atomic weights of the constituents of tartarized 

 antimony, Bitartrate of potash consists of 2 atoms of acid 66 

 X 2 = 132, and 1 atom of potash 48, and consequently the 

 atomic weight of the anhydrous bitartrate is 180; these are the 

 results of Dr. Thomson's experiments, and I believe them to be 

 perfectly accurate ; according to Berzelius's table of equiva- 

 lents, the proportions of acid and base are nearly as above given, 

 but he states the salt to contain 4" 74 per cent, of water, and, 

 therefore, 180 of the anhydrous salt must unite with 8*95 of 

 water ; so nearly 9, that we may conclude, if the experiments 

 be correct, that the crystals of bitartrate of potash contain 1 atom 

 of water. Dr. Thomson, however, in a very important work 

 which he has very recently pubhshed,* considers this salt to 

 contain 2 atoms of water ; but, for reasons which I shall 

 now state, I still consider the determination of Berzelius to be 

 correct: having prepared some pure bitartrate of potash, I suf- 

 fered it to dry by exposure to the air; 189 grains of this salt, 

 containing, of course, hygrometric moisture, were boiled in water 

 with 54 grains = 1 atom of dry carbonate of soda ; the solution 

 was slightly alkaline, but upon adding 3 grains of bitartrate of 

 potash, it reddened vegetable blues strongly; now if the salt 

 had contained 2 atoms of water, it would have required more 

 than 198 grains of bitartrate of potash, instead of less than 192, 

 to have supersaturated 54 of carbonate of soda. I heated some 

 crystals of the common bitartrate at a temperature but little 

 below that required for their decomposition ; they lost only 0"95 

 per cent, and I, therefore, conclude that this salt cannot be ren- 

 dered anhydrous by heat. With respect to the atomic weight of 

 antimony and its compounds, I also adopt Dr. Thomson's num- 

 bers, viz. 44 for the metal, 52 for the protoxide, and 60 for the 

 peroxide and sulphuret. 



M. Thenard analyzed tartarized antimony in the following 

 manner: — 100 parts of the crystals were subjected to heat, by 

 which they lost 8 parts of water, the remaining 92 parts were 

 dissolved in water, and the oxide of antimony was precipitated 

 by sulphuretted hydrogen ; 50 grains of dry precipitate were 

 obtained, which were calculated to contain 38 parts of oxide, 

 such as it exists in the salt : by means of acetate of lead, 100 

 grains of tartrate of lead were procured, which are estimated to 

 contain 34'of tartaric acid ; and, lastly, 100 parts of the salt being 

 treated with nitric acid, there were obtained 30 of nitrate of 



• An Attempt to establish tlic first Principles of Chemistry by Experiment. By 

 Thomas Thonibon, MV. FRS. Regius ProfeBSor of Chemistry in the University of 

 Glasgow, &c. 



