212 Mr. R. W. Pearson on the Determination of Bismuth 



solution of bichromate of potash^ the precipitate warmed, filtered, 

 and weighed. It contained : — 



According to the chromate of bisO ^.r.27-1 



muth obtained . . . . j ° * 



Amount actually present . . . 4*8270 grs. 



Difference .... '0001 gr. of bismuth. 



E. A liquid which contained 4'983 grains of bismuth asso- 

 ciated with 5'271 grains of lead was precipitated, and the result- 

 ing chromates of lead and bismuth then treated with caustic 

 potash of spec. grav. 1-33. The liquid contained — 



According to the chromate of bis- \ ^.0004^ 

 muth obtained j ° *' 



Amount actually present . . . 4*9830 grs. 



Difference .... '0006 gr. of bismuth. 



The following experiments relate to the determination of bis- 

 muth by volume. 



a. 6*544 grains of chemically pure bismuth were dissolved in 

 the necessary quantity of pure nitric acid, and the solution eva- 

 porated to a pasty mass and diluted with distilled water to the 

 mark which indicated 3272 grains liquid. Consequently 1000 

 grains contained 2 grains of metallic bismuth. 



"^'^'llen tested according to method^ „ nnrvK 

 .. 1 , ^ ■ ^2*0005 grs. 



it was found to contam . . J 



Amount actually present . . . 2*0000 grs. 



Difference .... '0005 gr. of bismuth. 



b. 2*114 grains of bismuth were treated in a similar manner 

 with pure nitric acid. To this solution several grains each of 

 sulphate of zinc, nitrate of silver, nitrate of mercury, and sul- 

 phate of tin were added. The mixture was diluted to about 1000 

 gi'ains. 



Found according to Method I. . 2*1143 grs. 

 Found according to Method II. . 2*1 136 grs. 



Mean 2*1139 grs. of bismuth. 



c. A liquid of an intense dark colour, containing 4*354 grains 

 of bismuth mixed with varying quantities of copper, iron, mo- 

 lybdenum, and antimony, was treated in the usual way with a 

 standard solution of bichromate of potash, the point of saturation 

 being indicated by a bismuth solution, as previously described. 



Found by Method c . . . 4*35 grs. 

 Amount actually present . . 4*24 grs. 



Difference . . . , , 0*11 gr, of bismuth. 



