156 A. L. Day and R. B. Sosman — 



KahlbauwbS Cobalt. 



Two 25 g. portions of the metal in the form of powder 

 were dissolved in 150 cc water+35 cc concentrated II 2 S0 4 . The 

 analysis was quite similar to that of the nickel. In the H 2 S 

 group were found : Cu=8'9 mg. = 0*0178 per cent. PbS0 4 = 

 12-9 mg. Pb = '0176 per cent. In the (NH 4 ) 2 S group man- 

 ganese was tested for as in the nickel. Kone was found. 

 Fe 2 3 = 0-9 mg. Fe = '0006 per cent. As the tests for M 

 and Zn were unsatisfactory, another portion of 25 g. was dis- 

 solved in dilute sulphuric acid and precipitated by H 2 S. The 

 filtrate from the sulphides was filtered and freed from excess 

 of H 2 S by evaporation. Then it was diluted to 1 liter and 

 divided into two portions. Both were neutralized by sodium 

 carbonate. In the one, manganese was sought for by ammonium 

 persulphate. In the other nickel was looked for. A little 

 ammonia was added and then an alcoholic solution of dimethyl- 

 glyoxime. A precipitate containing much cobalt was obtained. 

 This was worked over for nickel but none was found. For 

 sulphur the method used in the analysis of nickel w r as followed. 

 BaS0 4 = 14-4 mg., blank = 5'1 mg., difference = 9'3 mg., 

 S = 0-013 per cent. 



Analysis of Cobalt. 



Ag 



none 



Cu____ 



-0178$ 



Au 



a 



Bi .... 



none 



Pt 



a 



Cd____ 



a 



As 



a 



Zn____ 



i( 



Sb 



a 



m 



a 



Sn .... 



a 



Fe .... 



-0006$ 



Pb 



-OllQfo 



Mn__._ 



none 







S 



.... -013$ 





•049$ 





Aluminum. 







Owing to the difficulty of handling this metal, small portions 

 (10 g.) only were taken for analysis. Heavy metals, except 

 arsenic and antimony, were sought for in the hydrochloric 

 acid solution by ordinary methods. Only a trace of copper 

 was found. 



Phosphorus, Arsenic, and Sidphur. — For these elements, a 

 separate portion was dissolved in caustic alkali in a special appa- 

 ratus entirely of glass. The vessel was first filled with purified 

 hydrogen and then the alkali was introduced and the gases 

 evolved were passed through silver nitrate solution. At the 

 end, the gases remaining in the vessel were displaced by hydro- 

 gen. The precipitated silver was worked over for the different 

 elements. Wo As nor 8b. A separate portion was used for 

 sulphur. BaS0 4 = 1-4 mg. S = '002 per cent. 



