,4 



small quantity of residual pentacliloride having been poured 

 off, the solid mass is dried on a porous plate over solid caustic 

 potash in vacuo. The oxy chloride thus obtained is a per- 

 fectly white crystalline substance, exceedingly hygroscopic, 

 so that when exposed to the air for a few minutes it becomes 

 a pasty mass which rapidly changes to a liquid. It readily 

 dissolves in an aqueous solution of tartaric acid, whilst it is 

 decomposed by water and is perfectly insoluble in carbon 

 disulphide. The melting point of the substance is 85° C. as 

 a mean of well agreeing determination made with four differ- 

 ent preparations. When heated in a retort until it boils, 

 chlorine gas is evolved, whi]st pentacliloride and trichloride 

 of antimony distil over, a residue of antimony pentoxide 

 remaining in the retort. 



A modification of Rose's well known method of precipita- 

 tion first as insoluble antimoniate of soda, and then as 

 antimony sulphide was employed for the determination of 

 the antimony ; the precipitated sulphide was (1) oxidised to 

 SbaOi either by treatment with pure fuming nitric acid or 

 by heating with from 10 to 20 times its weight of pure 

 mercuric oxide, and (2) the sulphide was completely reduced 

 to metallic antimony by heating gently in a current of hy- 

 drogen until sulphuretted hydrogen ceases to be evolved. 

 In the estimation of chlorine it was found that when silver 

 nitrate is added to a solution of an antimony oxy chloride 

 acidified by nitric acid, a small trace of antimony is invari- 

 ably carried down with the silver chloride. In order to free 

 the precipitate from antimony, the silver chloride is first 

 heated gently in a current of hydrogen when the silver is 

 reduced, and, on stronger ignition the whole of the antimony 

 is volatilized as the hydrogen compound. Thus 1-277 grams 

 of an alloy containing 2'5 parts of antimony to 97*5 parts of 

 silver was found to lose on heating in hydrogen, 0'0321 

 grm. corresponding to 97-48 % of silver. 



The accuracy of each of the above methods was tested by 



