and Laboratory Methods. 



1297 



cold then hot. Draw off the mother Uquor and test the precipitate with Ho SO 4. 



Try the three elements in test drops acidulated with nitric acid. To the drop 

 from which barium oxalate does not separate add sodium acetate. 



Try oxalic acid on a salt of magnesium, then add an excess of acetic acid to 

 the test drop and examine again. 



Test salts of Zn, Cd, and Pb. 



Make a mixture of Ca, Sr, Ba. Add H2C2O4. Repeat the experiment in 

 HNO, solution; after a few moments, draw off the clear solution, concentrate 

 slightly and add sodium acetate. 



Try the effect of the presence of ferric chloride on the precipitation of the 

 oxalates of Ca, Sr, Ba; first each element separately, then in mixtures of Ca and 

 Ba ; Sr and Ba ; Ca, Sr, Ba. 



If barium borate is at hand, try testing it for Ba. E. M. Chamot. 



Cornell University. 



Simple Washing Device. 



A copper tube twenty-four inches long and two inches in diameter, placed 

 horizontally, is connected with the faucet through a half-inch tube let in midway 

 above. The ends are closed. Below are let in twenty quarter-inch pipes one 

 inch long. Over these are slipped rubber tubes, each carrying a nozzle of glass 

 brought nearly to a point. The nozzle is pushed through the cheese-cloth 

 fastened by rubber bands over the mouth of the bottle containing material to be 

 washed. The bottle is made to stand in a hole in the plank forming the base of 

 the support for the main pipe. The water then turned on descends through the 



twenty feed-pipes, washing through any bottles which may be set into the 

 apparatus. The whole arrangement stands in the sink. No pinch-cocks are 

 needed for feed-pipes not in use. 



The apparatus was designed by Mr. Ames, is not expensive, and proves 

 very handy. 



The bottles used and to be highly recommended are " sample-tubes " of 

 rather thick glass, straight all the way up, two and three-fourths by one and one- 

 fourth inches. Material is carried in the same bottle without removal, from 

 collection up to the paraffin bath. Robert G. Leavitt. 



Ames Laboratory, North Easton, Mass. 



