194 Mr. 0. D. Allen on Ccesium and Rubidium. 



verted into chloride, fused, and weighed without exposure to 

 the air. 



II. 1*3772 grm. gave 0*7149 grm. chloride of rubidium. 



In the following statement these results are reduced to per 

 cents., and compared with the calculated composition of bitar- 

 trate of rubidium as expressed by the formula 



J 8 H 4 8 \ 

 H RbJ 



4 





Calculated. 



A 



Found. 



A 



C 8 . . 

 H 6 . . 

 O 11 . . 

 RbO . 



f 



. 48-00 

 . 5-00 

 . 88-00 

 . 93-36 



20-48 



2-13 



37-55 



39-84 



I. II. 



20-62 

 2-17 



400 



234-36 100-00 



The solubility of this salt in hot and cold water was deter- 

 mined by evaporating on the water-bath solutions saturated at 

 the given temperatures and weighing the residues. 



I. 11*9254 grms. of solution, saturated at the boiling-point, 

 gave a residue of 1*2555 grm. 



One part of the salt accordingly requires 8*5 parts of boiling 

 water for solution. 



II. 17*535 grms. of solution, saturated at 25° C, gave a 

 residue of 0*205 grm. 



III. 16094 grms. of solution, saturated at 25° C, gave a 

 residue of 0*188 grm. 



One part of the salt thus required respectively 84'53 and 84*6 

 parts of water at 25° C. for solution. 



The biiartrate of casium forms crystals closely resembling the 

 rubidium-salt, but in my experiments they were usually of smaller 

 size. 



The salt obtained by concentrating the solution from which 

 all the rubidium had been separated was to all appearance pure. 

 It was recrystallized, and after drying at 100° C, at which tem- 

 perature it suffered no loss of weight, was analysed in the same 

 manner as the bitartrate of rubidium. 



I. 0*4718 grm. gave 00786 grm. water, and 0*294 grm. car- 

 bonic acid. 



II. 0*5966 grm. gave 0*101 grm. water, and 0*372 grm. car- 

 bonic acid. 



III. 1*3086 grm. gave 0*7708 grm. chloride of caesium. 

 Assuming. the combining proportion of caesium to be 123*35, 



as determined by Bunsen, the following statement exhibits the 



