112 McClenahan — Hydrous Thallic Chloride. 



Taking into consideration all the observed phenomena which 

 have been described, it appears that the water in the hydrous 

 thallic chloride T1C1 3 *4H 2 is held in the complex in three dif- 

 ferent ways, and that the relation may be reasonably expressed 

 by the symbol T1C1 3 -H 2 0'H 2 (>2H 2 0, the fourth molecule of 

 water being removed less easily in an atmosphere of hydrogen 

 chloride than in air. We have, therefore, the sequence of 

 changes during dehydration represented by the following 

 symbols : 



In air. 



In HC1. 



T1C1 9 -H 2 0H 2 0-2H 2 



TlCl 3 H 2 OH 2 0-2HO 



T1C1 3 H 2 OH 2 



T1C1 3 H 2 0HC1-2H 2 



T1C1 3 H 2 



T1C1 3 -H 2 



TlCl • 



T1CL. 



These symbols and the phenomena which they cover may be 

 represented upon the. hypothesis of quadrivalent oxygen by 

 Cushman's symbol and its derivatives. 



**\ o = ci— 6 — t/ H— ci = CI — 6 — T1 X \** 



\ci=o/g 



H\ 



H /CI = o //H 

 = ci— o— tv \** 



- 



H 



i 



— - 



i 



H 



/CI * 

 .TV H— C1 = C1 — 0- 



\ci d 



? /CI 

 CI— 0— TV 



Cl-Tl/gJ 



-Tl; 



The author wishes to express his appreciation of the kind 

 advice of Prof. F. A. Grooch in the preparation of this paper. 



