96 H. L. Wells — Caesium- Cuprous Chlorides. 













Calculated 







Found. 







for CsCuBr 3 . 



Cs .... 



29-93 



29-09 







30-43 



30-48 



Cu___. 



14-72 



15-09 



14-73 



14-81 



14-53 



Br ... . 



55-09 



54-96 







64-96 



54.99 



99-74 99-14 100'20 100-00 



Sheffield Scientific School, September, 1893. 



Art. XI. — On the Cwsium- Cuprous Chlorides; by H. L. 



Wells. 



The salts to be described were prepared by beating solutions 

 containing caesium chloride and cupric chloride with copper 

 wire, and sufficient hydrochloric acid to prevent the formation 

 of basic salts ; then, after the copper in solution was chiefly in 

 the form of cuprous chloride, cooling to crystallization. 



When the solutions were dilute, caesium, chloride being in 

 in excess, very slender white prisms were obtained under wide 

 variations of conditions. The crystals became yellowish while 

 being dried with paper, but they were apparently nearly stable 

 in the air when dry. It was found that the salt was decom- 

 posed by water. Two different products were analyzed. 



Calculated for 

 Found. CsCl . Cu 2 Cl,. 



Caesium 36-93 36-36 36.29 



Copper 34-33 34-17 34*64 



Chlorine 28-95 28"87 29-07 



The results show that the formula CsCn 2 Cl 3 belongs to this 

 salt. 



On using more concentrated solutions, also with an excess of 

 caesium chloride, thin, rectangular, colorless plates were pro- 

 duced, sometimes 10 or 20 mm in diameter. The range of con- 

 ditions under which this salt is produced is wide, and large 

 crops of it are easily prepared. As the concentration of the 

 caesium chloride solutions was increased the same compound 

 appeared in the form of blade-like crystals with pointed ends. 

 By dissolving this salt in water the previously described com- 

 pound is produced by crystallization. The surface of the 

 crystals becomes yellow on drying, but when dry it appears to 

 be very stable. The first two analyses represent separate 

 crops of the rectangular plates, the third a crop of the blade- 

 like crystals. 



