24 JOURNAI, OF THE 
mination may have been due to the sample or to manipu- — 
~ jJation. Which was at fault cannot well be decided now. 
The new determinations give 
Calc. for ZrOCl,.3H,O. 
Zr. 38.99 39.12 
Cl. 29.98 30.66 
This oxychloride is therefore, after drying, identical 
with the one obtained by crystallization from water after 
it also has been dried. 
The amorphous (7) form, insoluble in concentrated hy- 
drocloric acid but easily soluble in water has been anal- 
yzed by Paykull and he has calculated the formula 
27rOC1,.13H,O. This insoluble oxychloride is nearly 
always present during the process of purification by re- 
crystallization from hydrochloric acid. Repeated boilings 
with hydrochloric acid fail to dissolve it. A sample was 
prepared by allowing a very concentrated aqueous solu- 
tion of the oxychloride to fall drop by drop into concen- 
trated hydrochloric acid. It was washed with hydro- 
chloric acid and then boiled. After pouring off the 
acid the mass was washed with a mixture of nine parts 
ether and one part alcohol. It was dried between filter 
paper. Little assurance could be felt that this mode of 
drying removed all the hygroscopic moisture. It was 
analyzed in this condition. Another portion was placed 
over caustic alkali (after pressing between filter paper) 
and yet another portion was dried at 105° in a stream of 
hydrogen chloride. 
The analysis of the portion dried between filter paper 
was as follows: (no difference was observed in that over 
caustic alkali after two days). 
Cale. for ZrOCl»s.6H9O. 
Zr. 31072 31.70 
Cl. 20.81 21.01 
This is therefore in close accord with the formula 
ZrOCl,.6H,O. The portion dried under hydrogen cilo- 
ride was small and only the zirconium was determined. 
The percentage of this corresponded fairly with ZrOCl,. 
3H,O. 
