300 
diluted to about 50 ¢.¢., heated to boiling, treated with a few drops of 
sodium bisulfite solution and then with slight excess of ammonitim sulpho- 
cynate, stirred three minutes, filtered (Gooch), washed, dried at 130°, 
cooled and weighed. Found for copper, 25.42%; calculated, 25.46. 
4. Hstimation 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 cc. 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 150°, cooled and weighed. Found 
for chlorine 60.64; calculated 60.63. 
DePauw University. 
