Separation of Strontium from Calcium. 



55 



it. The residue was then dried at a gentle heat over a radia- 

 tor to remove arnyl alcohol, dissolved in a few drops of water, 

 treated with a drop of nitric acid to assure the condition of ni- 

 trate, and evaporated to dryness. After dissolving in a few drops 

 of water 30 cm. 3 of the alcohol were added, and the boiling 

 repeated. The residue was filtered off upon the same felt 

 through which the first portion had been decanted, and washed 

 with amyl alcohol, care being taken to remove all particles of 

 the residue from the beaker by careful rubbing. The crucible 

 and residue were heated in an air bath at 150° C. as before, 

 and then weighed. The filtrate from the two treatments and 

 the washings were treated differently in two series of experi- 

 ments. In Series II, the filtrate was precipitated with sul- 

 phuric acid, ethyl alcohol being added to secure thorough mix- 

 ture. The precipitated sulphate was filtered off upon asbestos, 

 heated to low redness and weighed. In Series III, the alco- 

 holic filtrate was evaporated to a small volume, transferred to 

 a weighed platinum crucible and evaporated. The residue was 

 ignited to burn off organic matter, treated with sulphuric acid 

 and ragain ignited at low redness and weighed. 



SrO taken. 



SrO found. 



Sei 

 Error. 



?IES II. 



CaO taken. 



CaO found. 



Error. 





(corrected.) 





(corrected. 





(12) 0-1235 grm. 



0-1 239 grm 



. -0004 a;™ 



.+ 1290 grm. 



0-1271 grm. 



0-0019 grm 



(13)0-1237 " 



0-1228 " 



•0009" '• 



- 0-1246 "" 



0-1226 " 



0-0020 " 



(14)0-1239 " 



0-1239 " 



•0000 " 



0-1248 " 



0-1223 " 



0-0025 " 



(15)0-1974 " 



0-1972 " 



■0002 " 



- 0-0502 " 



0-0492 " 



o-ooio " 



(16)0-1979 " 



0-1978 " 



•0001 " 



- 0496 " 



0-0482 " 



0-0014 •' 







Seeies III. 







(17) 0-0148 " 



0-0155 " 



0-0007 " 



+ 0-0256 " 



0-0254 " 



•0002 " 



(18) 0-0183 " 



0-0183 " 



o-oooo " 



1030 " 



0-1015 " 



•0015 *' 



(19)0-0364 " 



00366 " 



0-0002 " 



+ 0516 " 



0-0511 " 



•0005 " 



(20) 0-0365 " 



0-0365 " 



o-oooo ,! 



0-0515 " 



0-0513 " 



•0002 " 



(21)0-0493 " 



0-0494 " 



0001 " 



+ 00515 " 



0-0502 <; 



•0013 " 



(22) 0497 " 



0-0497 " 



00000 " 



00519 " 



00511 " 



•0008 " 



(23) 0-0497 " 



0-0503 " 



0-0006 " 



+ 0-0249 " 



0-0245 " 



•0004 " 



(24) 0-0729 " 



0-0732 '' 



0-0003 " 



+ 0257 " 



0-0251 " 



•0006 " 



(25) 0-0730 " 



00732 " 



0-0002 " 



+ 00255 " 



0-0255 " 



•0000 " 



(26) 0-0744 " 



0-0744 " 



0000 " 



0-0258 " 



0-0260 " 



•0002 " 



(27) 0-0912 " 



0-0910 '• 



0-0002 " 



— 0-1286 " 



0-1276 " 



•0010 " 



The average error in the determination of strontium in both 

 series is less than 0-0001 grm. + on the oxide ; that of the cal- 

 cium amounts to 0O017 grm.— on the oxide in Series II, and 

 to 0*0005 grm.— in Series III. 



In both processes the correction for the solubility of stron- 

 tium nitrate in amyl alcohol, determined as previously de- 

 scribed, was applied — 0'0020 grm. being added to the weight 

 of the strontium oxide found after the double treatment with 

 amyl alcohol, and 0-0035 grm. being deducted from the appar- 

 ent weight of the calcium sulphate found before calculating it 



