48 JOURNAL OP THE 



chlorides. These solutions were at first clear, but on 

 boiling- 5 — 15 minutes, at first a slight turbidity was 

 noticed. This increased on boiling* until a g-ood precip- 

 itate was formed. With potassium chloride this pre- 

 cipitate was curdy and incomplete. PaykulP speaks 

 of the formation of double chlorides in the dry way. 

 These precipitates which are very probably similar 

 compounds are now being* investigfated in this labora- 

 tory. It was noted that ammonium chloride did 

 not interfere with the determination, as it was easily 

 volatilized when the crucible was igfnited over the blow- 

 pipe. The fixed alkalies however interfered, g-iving" 

 higfh results. These compounds are of interest. 



The following- determinations were made in the pres- 

 ence of ammonium chloride : 



//. With Sodium Thiosulphitc. 



Sodium thiosulphite, if added as solid crystals to a 

 zirconium chloride solution, previously neutralized with 

 ammonium hydroxide, and then boiled for several min- 

 utes, caused complete* precipitation. The solid thiosul- 

 phite was added up to ten and even twenty per cent, of 

 the solution. The precipitate did not form immediate- 

 ly on addition of the solid thiosulphite, even if the so- 

 lution was hot, but was rapidly produced after a few 

 moments heating-. The precipitate, which settled 

 quickly, was filtered hot and washed with hot water 



(1) Ber. VI. 1467. 



