188 Browning — Separation and Detection of Strontium. 



large or small amounts, the result was uniformly a faint cloudi- 

 ness gathering after standing sometime to a minute precipitate 

 of a granular character. In the case of the calcium the detec- 

 tion could be carried easily to 0*0005 grin, of the oxide, and 

 satisfactory results were obtained with 0*0002 grm. The charac- 

 ter of the precipitate in the case of calcium was moreover, 

 distinctive, it being in every case light and flocky, and collect- 

 ing in floating masses. With the precautions noted very satis- 

 factory results can be obtained by this method, not the least 

 advantage being the rapidity with which a determination can 

 be made. It will be noticed that in some cases calcium and 

 strontium are recorded as the nitrates and in others tabulated 

 as oxides. When either strontium or calcium were used in 

 large quantities the pure nitrate was weighed out directly ; 

 when very small amounts were used these were taken from the 

 standardized solutions of the nitrates used in the quantitative 

 work, the standards of which had been recorded in terms of 

 the oxide. The strontium and calcium salts used in this work 

 were specially purified by the methods detailed in my previous 

 paper. 



Seeies I. 



Deposit after 

 1st boilins:. 



( 1) 

 ( 2) 

 (3) 



( 4) 

 ( 5) 

 (6) 



( *) 



( 8) 



( 9) 

 (10) 



(11) 

 (12) 

 (13) 



SrO taken. Ca(NOs) 2 taken. 

 # 1 grm. 

 0-2 

 0'2 



0- 



0-0003 

 0-0003 

 0-0005 

 0-0005 

 0-0010 

 0-0010 

 0-0005 

 0-0007 

 0-0008 



0-1 

 0-05 



Trace. 



Slight. 



Slight, 



Distinct. 



Faint trace. 



Faint trace. 



Distinct. 



Distinct. 



Distinct. 



Distinct. 



Distinct. 



Distinct. 



Distinct. 



Deposit after 

 2nd boiling. 



None. 



None. 



None. 



Faintest trace. 



Faint trace. 



Faintest trace. 



Distinct. 



Distinct. 



Distinct. 

 Distinct. 

 Faintest trace. 

 Faint trace. 

 Distinct. 



Series II. 



Sr(N0 3 ) 2 



( c 4 o- 



( 3) 0- 

 ( 4) 

 ( 5) 

 ( 6) 

 ( ?) 

 ( 8) 

 ( 9) 0- 



(10) 0- 



(11) o- 



(12) 0- 



taken. 



001 grm. 

 1 



2 " 



CaO taken. 



0-001 grm. 

 0-0005 " 

 0-0002 " 

 0-0001 " 

 0-00005 " 

 0-0005 " 

 0-0002 " 

 0-0001 " 

 0-0002 " 



Result. 

 Faint granular cloudiness. 



Decided flocky floating masses. 



Plain 

 Faint 

 Decided 



a 



Plain 



Decided 



