CRITICAL EXPERIMENTS FOR DETERMINATION OF POTASSIUM, ETC. 585 



recrystallisation work. The water-determinations (carried out with 2*2 and 2*4 

 grms. of substance in I. and II. respectively) gave the following results : — 



Found in I. II. 



Per cents, of water, 0*353 0-269 



The analyses were made with about 2*4 and 2*7 grms. of substance, dried 

 at 100°. Their results, when combined with the synthetical results for the 

 fixed chlorine, and reduced to Cl 2 = 70 "91 parts of the latter, were as 

 follows : — 



I. 

 II. 



Total Chlorine. 





Platinum. 



Substance Analysed 

 M. 



213-08=60099 x 



CI 



19601 



489-35 



212-84=6-0032 x 



CI 



195-82 



488-69 



ng the small excesses of chlorine found, we have for 







I. 



H. 



Platinum, 



. 



19601 



195-82 



2KC1, 



. 



14918 



149-18 



4 x CI of loose chlorine, 



. 



141-82 



141-82 



Water (as above), 



* 



1-72 



1-31 



Total, 



488-73 



488-13 



M., . 





=489-35 



488-69 



Unaccounted for, 





0-62 



0-56 



These deficits might be allowed to pass as the cumulative effects of observa- 

 tional errors; but possibly they may be owing to an element of uncertainty in 

 the above numbers for the quantities of water. The samples " B," after having 

 been weighed out for the determination of their water, were kept within their 

 weighing- tubes,* over oil of vitriol, for a considerable time, before these 

 determinations came to be carried out. On reweighing the weighing tubes and 

 contents, they were found to have lost (" I ".) 1-3 and (" II.") 2-1 mgs. Assuming 

 these losses to have been suffered merely by the tubes and boats, the 

 percentages of water come out as above reported. Assuming them to have 

 been suffered by the chloroplatinates, their percentages of water rise to 

 (" I. ") = 0-412, and (" II") = 0-356. The corresponding weights per M parts of 



chloroplatinate then are — 



i. ii. 



Water 201 1-74 



Total components, .... 489-02 488-56 



Deficits wow, 0-33 0-13 



which is more satisfactory. 



* Made each out of two lipless test-tubes sliding over one another. 

 VOL. XXXIII. PART II. 4 R 



