290 Boswortli — lodometric Determination of Silver. 









Table 



III. 







Silver 

 taken 



KH 2 As0 3 added 

 Silver 



I 3 1 



Lised 

 Silver 



Silver 

 found 



Error 



in terms of 



silver 



grm. 



cm. 



grm. 



cm. 



grm. 



grm . 



grm. 







Reduction of precipitated AgCl 





0'1017 



15 



0-1619 



5-40 



0-0599 



0-1020 



+ 0-0003 



0-1017 



15 



0-1619 



5-44 



00603 



0-1016 



—o-oooi 



0-1017 



15 



0-1619 



5-40 



0-0599 



0-1020 



+ 0-0003 



0-1017 



15 



0-1619 



5-42 



0-0601 



0-1018 



+ 0*0001 



0-1017 



17 



0-1834 



7-44 



0-0825 



0-1009 



— 0-0008 



Reduction of 



±5 



AgCl precipitated in the presence 



of 0-09 grm. 



of copper. 



0-1017 



15 



0-1619 



5-41 



0-0600 



0-1019 



+ 0-0002 



0-1017 



15 



0-1619 



5-44 



00603 



0-1016 



—o-oooi 



0-1017 



15 



0-1619 



5-39 



0-0598 



0-1021 



+ 0-0004 



c 



Reduction of AgCl precipitated in the presence of 2 grm. of lead 

 0-1220 16 0-1726 4.57 0'0507 0+219 — 0*0001 



0-1108 15 0-1619 4-60 0'0510 0+109 +0"0001 



D 



Reduction of AgCl precipitated from a solution containing 0'09 grm. of 

 copper and 0"2 grm. of lead 



0-1017 15 0-1619 5-45 0'0604 0-1015 — 0'0002 



or in the form of the precipitated chloride, by adding an excess 

 of standard potassium arsenite, boiling in alkaline solution to 

 accomplish the reduction of the silver salt to metallic silver, 

 and titrating the excess of potassium arsenite with iodine. 

 The silver value of the iodine used is to be subtracted from 

 that of the potassium arsenite originally taken, the result 

 giving the amount of silver present. 



SIMON NEWCOMB. 



The death of Simon Newcomb at his home in Washington 

 on July 12, 1909, after a long and painful illness, terminated a 

 life of extraordinary activity. His last contribution to his 

 theory of The Motion of the Moon was finished a few weeks 

 only before his death and was consciously hastened on account 

 of his knowledge of the speedy approach of the end. 



Simon Newcomb was born in Wallace, Nova Scotia, March 

 12, 1835. His father, John Benton Newcomb, was of Amer- 

 ican descent whose ancestors had settled in Canada in 1761. 



