Wells and Boltwood—Cesium Chloride, ete. 249 
ArT. XXVI.—On the Double Salts of Cusiuwm Chloride with 
Chromium Trichloride and with Uranyl Chloride; by 
H. L. WeEtts and B. B. Bottwoop. 
NEUMANN* has made an extensive investigation of the 
double salts formed with chromium trichloride and the chlo- 
rides of several other metals, not, however, including cesium. 
He obtained a violet double salt in each case with ammonium, 
potassium, rubidium, beryllium and magnesium, corresponding 
to the general formula, 2M’ Cl. CrCl, . H,O, while with lithium, 
sodium, calcium, strontium, barium, zine and cadmium he was 
unable to prepare any double compounds. The double fluo- 
rides, 2NH,F.CriF’,. H,0O, and 2KF.CrF,.H,O, which are 
analogous to Neumann’s salts, have been mentioned by Wag- 
ner,t who also prepared the compounds 4NaF.2CrF,.H,O 
and 8NH,F.CrF,. The existence of the latter salt has been 
confirmed by Petersen. 
Since Neumann had not prepared any cesium-chromium 
chloride, and because, from the well-known comparative insolu- 
bility of czesium double salts, it seemed possible that a greater 
variety of compounds would be obtained with this than with 
other metals, we have undertaken an investigation in this direc- 
tion. As the result of a systematic search, however, we have 
added only a variation in water of crystallization to Neumann’s 
general formula. 
Two salts have been obtained. One of these, 2CsCl. CrCl,. 
H,O, is violet in color, corresponding exactly to Neumann’s 
compounds, while the other, 2CsCl. CrCl, .4H,O, is green. 
The violet salt was prepared by saturating warm aqueous solu- 
tions containing various proportions of the two simple chlo- 
rides with gaseous hydrochloric acid. The green salt was 
obtained from cold solutions by the use of hydrochloric acid, 
and without its use by evaporation over sulphuric acid. 
The salt 2CsCl. CrCl, . H,O forms aggregates of very minute 
erystals of a magnificent red-violet color. It is stable in the 
air and does not lose its water at 160°. It is very slowly 
soluble in cold water, forming a green solution from which 
the green salt is deposited upon evaporation at ordinary temper- 
atures. The four crops analyzed were prepared with amounts 
of cesium chloride and chromic chloride varying from 15g. of 
the first and 50¢. of the second to 50¢. of the first and 10¢. 
of the second. Gaseous hydrochloric acid caused a deposition 
of the salt from warm solutions. The products, after careful 
* Liebig’s Annalen, ecxliv, 329. + Berichte, xix, 896. 
ier. Cis, Lie Od. 
