Oxychloride of Antimony. 43 



By boiling with a solution of carbonate of soda, or by heating 

 nearly to redness with the dry salt, it is decomposed. By satu- 

 rating the solution with pure nitric acid, filtering and, precipitat- 

 ing with nitrate of silver, I obtained for the amount of chlorine 

 per cent, in four experiments 11.32, 11.26, 11.22, 11.215, re- 

 spectively. Notwithstanding the close agreement of the last two 

 results obtained by different methods, the highest probably 

 comes nearest the truth, as by washing a minute portion of the 

 chloride present in the crystals may be decomposed. 



It requires great care and considerable practice to be able to 

 determine the amount of antimony within half a per cent. Some 

 discussion has lately arisen as to the possibiHty of approximat- 

 ing nearly to the true quantity by precipitating it from its solu- 

 tion in muriatic acid by sulphuretted hydrogen ; and Rose has 

 stated, that when the gas is transmitted in large excess, the sul- 

 phuret of antimony may be completely freed from chloride, and 

 the metal determined to about half a per cent. This result, 

 however, is not always to be depended upon. From solutions 

 perfectly saturated with sulphuretted hydrogen, I have several 

 times collected precipitates, which, when dried and then gently 

 heated in a close tube, gave off white fumes of chloride. Though 

 therefore, the antimony may, by this process, be pretty nearly 

 determined, the result obtained should if possible be checked by 

 recourse to some other method of analysis.* 



As the amount of oxygen in the oxychloride is determined 

 from the loss, the estimation of its quantity is liable to a double 

 error, arising from the weights both of the chlorine and anti- 

 mony obtained by analysis. I had therefore recourse to two 

 other methods in order to verify and control the per-centage of 

 antimony obtained by precipitation from the solution containing 

 it. 1st, 30.32 grains dissolved in muriatic and diluted with a so- 

 lution of tartaric acid, gave with sulphuretted hydrogen 32.02 

 grains of sulphuret = 76.82 per cent, of metallic antimony. 

 2d, digested with pure nitric acid, it is decomposed with evolution 



" The iodide of antimony (31 + 2 Sb) seems to have a similar affinity for 

 the sulphuret as the chloride has, or a similar tendency to mix with it and re- 

 sist the action of sulphuretted hydrogen, for if the iodide be dissolved in mu- 

 riatic ac-id, diluted largely with water and decomposed by excess of sulphu- 

 retted liydrogen, the dry sulphuret, when heated in a close tube, gives a co- 

 loured vapour which condenses into a red crystalline crust of the iodide. 



