12G 



M. CHIKASHH.-JE. 



The balance used is one by Sartorius (his 1st quality), which 

 has been hitherto only sparingly used for special cases. The weights 

 are of quartz and platinum, from Gerhardt, and were found by me to 

 have been closely adjusted. 



The tellurium bromide was prepared by adding the tellurium to 

 the bromine, in a tube, exactly as described by Brauner. In such a 

 tube, he directly sublimed it, but I had to transfer it to another 

 longer tube. The procedure was to slide into this tube nearly to the 

 bottom an open tube loosely fitting it, down this to drop the powdery 

 crude tetrabromide, and then withdraw it, leaving the walls of the 

 sublimation tube unsoiled. This tube, at once closed by a cork, was 

 then contracted about 25 cm. from its closed end and again about 12 

 cm. further off, where it was cut off from the corked end, and the 

 narrowed mouth attached by caoutchouc tubing to the drying tube 

 connected with a Sprengel pump. The tube was placed in the 

 furnace with its first contraction just outside ; the bromide before 

 sublimation occupied the hinder third of the tube within the furnace. 

 Sublimation was in all other respects effected just as described by 

 Brauner, a little dibromide being sublimed off at 200° into the outer 

 part of the tube, and the tetrabromide sublimed at a temperature kept 

 closely at 300° into the anterior part of the tube within the furnace. 

 Practically nothing remained unsublimed, which showed that the 

 transference of the undisiilled bromide from tube to tube had been 

 effected with impunity, this compound not being noticeably hygro- 

 scopic, and the air, at the time, being cold and very dry. The sub- 

 limation furnace was an exact copy of Brauner's. 



The tellurium bromide was weighed off and dissolved in tartaric 

 acid in one vessel, added to the silver nitrate, shaken for hours in the 

 bottle, with a conical, polished, pointed, stopper projecting into it, 

 and then finished off volumetrically, all just as described by Brauner 



