82 



Dr. G. H. Bailey. 



[May 9, 



Zr0 2 0-332 0-485 



AgCl 0-661 1-096 



whereas the silver chloride should be about 2 J times the amount of 

 the Zr0 2 . Paijkull (' Paris Soc. Chim. Bull.,' vol. 20, p. 65) dried 

 the salt between filter-paper, and found the composition of the crystals 

 to be ZrOCl 2 .8H 2 0, the amorphous form precipitated by excess of 

 HC1 being 2ZrOCl 2 .13H 2 0. 



Basic oxy chlorides, Zr 3 4 Cl 4 (Endemann), Zr 2 3 Cl 2 , Zr 2 OCl 6 

 (Troost and' Hautefeuille), ZrOClOH, Zr 8 8 Cl 7 (OH) 9 (Endemann), 

 have also been described. 



The salt examined by me was prepared by repeated crystallisa- 

 tion from concentrated hydrochloric acid, washed with hydrochloric 

 acid till the washings were colourless and showed no trace of iron, 

 and then the free acid removed — 



(a.) By washing with a mixture of 1 part of alcohol and 10 parts 



of ether. 

 (&.) By gently heating the salt. 



(c.) By exposing the finely powdered salt at ordinary temperature 

 in a vacuous desiccator over potash, until no HC1 appeared 

 when air was passed over it. 



The analysis was performed by dissolving the salt in water and 

 precipitating the zirconia with ammonia, then acidulating with nitric 

 acid, and precipitating the chlorine by means of silver nitrate. 



In the following tables are given Berzelius's determinations and 

 those obtained by using the methods (a) and (c). 



(b) is omitted, since it was found that a constant and progressive 

 diminution of chlorine occurred during the process. It will be suffi- 

 cient for the purpose to state simply the relation of Zr0 2 to AgCl 

 obtained. 



Zr0 2 . : AgCl. 



(1) Berzelius's determination, ... , 1 : 1991 



1 : 2-260 



{a) Washed with ether and alcohol ....... 1 : 2-206 



1 : 2-179 



1 : 2-226 



1 : 2-260 



(c) Exposed in vacuo over KHO 1 : 2*264 



Without washing 1 : 2*245 



1 : 2-309 



1 : 2-285 



ZrOCl 2 (Zr = 90) calculated 1 : 2-.350 



The whole of the specimens analysed dissolved in water to a clear 

 solution, with a slightly acid reaction. The determination which 



