Wells and Dujoee — Caesium- Cupric Chlorides. 93 



but with more dilute solutions one or both of the hydrous salts 

 are usually deposited on standing or on spontaneous evapora- 

 tion. The following analyses represent different crops made 

 under considerable differences of conditions : 



Calculated for 

 Found. Cs 2 CuC] 4 . 



Cs 56-33 56-14 56-18 56*42 



Cu 13-52 13-45 13-47 13-48 13'46 



CI 30-07 29-99 30-04 30*03 30-12 



99-77 9965 99-69 100-00 



Hydrous % : 1 Ccesium-Cupric Chloride, CsJJuCl^.^HJ)-: 



— This salt is bluish green in color, and it loses its water very 



rapidly on exposure to the air with a change of color to bright 



yellow. It is a well crystallized, transparent salt, but its form 



was not made out on account of its instability. It is difficult 



to prepare it, at least at summer temperatures under which this 



investigation has been made, and we have only occasionally 



observed it. It is formed by allowing solutions containing 



nearly the required proportions of caesium and copper chlorides 



to evaporate spontaneously. A sample quickly pressed on 



paper gave the following analysis : 



Calculated for 

 Found. Cs 2 CuCl 4 .2H 2 



Caesium 51-28 52-40 



Copper . 12-53 12-50 



Chlorine 28-00 



Water 7-20 # 7-10 



Another sample, which had been exposed to the air too long, 

 gave 6-02 per cent of water, and the dehydrated compound 

 gave the following analysis : 



Found. Calculated. 



Caesium 56*09 56-42 



Copper 13-68 13*46 



3 : % Ccesium-Cicpric Chloride, Cs i Cu^Cl n . 2H„0 : — This 

 compound was obtained from solutions of nearly the required 

 proportions of csesium and cupric chlorides. It usually forms 

 only at ordinary temperatures, and if the solution is too con- 

 centrated, one or both of the anhydrous salts will be deposited 

 while it is warm. The salt forms triclinic crystals, often one 

 or two centimeters in diameter. The large crystals are deep 

 brown in color, small ones and fragments are very much paler 

 while the powder is yellow. It is nearly stable at ordinary 

 temperatures, but gradually loses its luster on long exposure. 

 All the water goes off readily at 100°. The following analyses 

 of separate crops were made : 



