350 



diluted to about 50 c. c, heated to boiling, treated with a few drops of 

 sodium bisulfite solution aud then with slight excess of ammonium sulpho- 

 cynate, stirred three minutes, filtered (Gooch), washed, dried at 130°, 

 cooled and weighed. Found for copper, 25.42% ; calculated, 25.46. 



4. Estimation of chlorine in sodium chloride. A small sample of 

 Kahlbaum's purest sodium chloride, 0.2102 gram, was dissolved in about 

 50 c. c. of water in a 150 c. c. beaker, acidified with a few drops of nitric 

 acid, treated with slight excess of silver nitrate solution, stirred two min- 

 utes, filtered (Gooch), washed, dried at 130°, cooled and weighed. Fouud 

 for chlorine 60.64 ; calculated 60.63. 



DePauio University. 



