With Chromium Trichloride and with Uranyl Chloride. 251 
thus showing that they agree in this respect with other green 
solutions of chromic chloride. 
Jt is a curious circumstance that the green chromic sul- 
phate has been considered* to contain less water than the 
violet modification, while with our cesium salts exactly 
the reverse is true, the green salt containing the larger 
amount of water. It is also remarkable that, while violet 
chromic solutions are turned green by heat, our violet salt, 
nevertheless, is produced in hot solutions and the green 
salt in cold ones. The theory advanced by Kriiger and 
maintained by van Cleefft that the green color of chromic - 
sulphate solutions is due to the formation of a basic salt and 
free acid or an acid salt, seems hardly applicable to the green 
exsium salts, ince it crystallizes from solutions saturated with 
hydrochloric acid in which a basic salt would seem to be an 
impossibility. In view of these apparently conflicting facts, it 
seems necessary to draw the conclusion that the differences in 
color exhibited by chromic compounds and their solutions are 
due to more than one cause, probably to the formation of basic 
salts in certain cases, and also, in other instances, to a change 
in water of crystallization which is evidently accompanied by 
a molecular transformation. 
Uranyl chloride and cesium chloride.—A careful series of 
experiments with cesium chloride and uranyl chloride has 
resulted in the discovery of but a single salt. This compound, 
2CsCl. UO,Cl,, corresponds, except that it contains no water, 
to the previously described salts, 2K Cl. UO,Cl,.2H,O, 2K Br. 
eb 20, 2N EC). UO.C), .2H,0 and 2NH,Br.UO,Br, . 
2H,O, but some fluorides of other types have been described. 
The compound under consideration forms apparently ortho- 
rhombic, yellow erystals which are usually small and blade-like 
in shape. The products used for analysis were made under 
the following conditions: Crop A, by making a concentrated 
aqueous solution of 10g. of cesium chloride and 50 g. of 
uranyl chloride, then running in gaseous hydrochloric acid 
until crystals began to form and cooling; Crop B, by the 
same method as above, using 50 g. of cesium chloride and 10 g. 
of uranyl chloride; Crops C and D, by spontaneous evapora- 
tion of solutions containing 50 g. of cesium chloride and 15 g. 
of uranyl chloride; and E, by the evaporation of a solution of 
15g. of cesium chloride and 50g. of uranyl chloride. The 
results were as follows: 
Calculated for 
A. B. C. 13) HK. 2CsCl. U0.Cl.. 
eee 04a, Sadao” 40:07 Meeres” |. 39°15 
UO, -- 40°37 41:14 =40°96 =41°85 43°39 39°95 
Ores!) 52063 7) Arn) 20°85°e 2084 «20°59 20°90 
* Vide van Cleeff, J. pr. Ch., II, xxiii, 58. + Loe. cit. 
