ATOMIC WEIGHT OF JAPANESE TELLURIUM. 127 



(except that the final titration was not effected in a dark room, but 

 in feeble day light). 



I made only the three determinations here given, neglecting a 

 trial for practice, with good result, in which high accuracy w r as not 

 sought for. The following are the results : — 



The details of Exp. II. are : — Silver weighed off, 4-1548 grams ; 

 time of continuous shaking by water-motor, 4 hours ; precipitate, 

 thoroughly pulverulent ; silver solution added, 0*4 cc, which pro- 

 duced no turbidity ; potassium bromide solution required, 0*8 cc.= 

 0*54 cc. silver solution. Since there had been taken silver in excess, 

 equivalent to 0'14 cc. silver solution, and, therefore, 0*00014 grams 

 silver, the actual quantity of silver required by the 4*3059 grams 

 bromide had been 4'1547 grams. Then : — 



79-963x4-1547x100 „, lon; . 



107-938 X4-3U59 = <^% br0mme 



and- 



107-938x4*3059 

 4-1547 



-79-963)= 127*61 at, wt. tellurium. 



In Exp. I., the silver weighed out was not so closely apportioned, 

 and several cubic centimeters of the volumetric solution had to be 

 used ; otherwise, it agreed with II., as did also III. in its details. 



When it is considered that Brauner and I have obtained by the 

 same method identical results, although he worked with tellurium 

 that had presented itself in combination with metals, while I have 

 worked with that occurring in native sulphur of high purity, except 



