158 A. L. Day and R. B. Sosman — 



with hot dilute nitric acid, transferred to a filter and washed 

 with water. The filtrate and washings were then evaporated 

 to dryness with hydrochloric acid, while the antimonic acid 

 was digested repeatedly with yellow sodium sulphide till the 

 soluble portion was dissolved. The residue, after a little 

 washing, was dissolved in nitric acid, evaporated to dryness, 

 freed from nitric by hydrochloric acid, and the chlorides united 

 with the first extract. The whole was precipitated by hydrogen 

 sulphide. The washed sulphides were then extracted with 

 colorless ammonium sulpiride. From this solution the sulphides 

 were thrown down by acid, filtered and washed. Then they 

 were dissolved in hot dilute caustic potash. The solution was 

 boiled with perhydrol for complete oxidation, and arsenic 

 sought for by Fischer's method, viz., reducing by ferrous 

 ammonium sulphate and distilling in a current of hydrochloric 

 acid gas. No As. 



A separate portion of 5 g. was taken for tin. McCay's 

 method was tried.* Sn0 2 = 1*3 rag. Sn = 1*0 mg. = -02 per 

 cent. 



A separate portion of 25 g. was used for sulphur. The 

 metal was oxidized by nitric acid as before, and the soluble 

 portion separated and evaporated. The residue was then heated 

 with a small excess of sodium carbonate and filtered. The 

 residue was also boiled out several times with sodium carbonate 

 solution. The two solutions were then acidified with hydro- 

 chloric acid and treated with barium chloride. The portion 

 soluble in nitric acid gave a slight precipitate, which was fur- 

 ther purified, after the usual washing and drying, by fusion with 

 sodium carbonate. The water extract containing the soluble 

 sulphate was acidified and precipitated a second time. 

 £aS0 4 = trace. 



Analysis of Antimony. 



As_ none Cd none 



Sn 0-02 (?) Ni 



Ag none Co ._ " 



Pb _. trace (?) Mn " 



Cu .- 0-004 Zn __. 



Bi none Fe ■__ 0-007$ 



S ._ trace (?) 



•m 1 io 



In the following table, the results of these and previousf 

 analyses of metals for the temperature scale are summarized : 



* Private communication. 

 . f Day and Clement, loc. cit., p. 454. 



