

: Till: AMERICAN ACADEMY. 



plane in the form of a c. To tin- i- 1 by means of a rubber 



short bulb tube about 12 nun. in diameter, terminating in a 

 longer tub.- which bas a bore of slightly over I mm. The bulb of this 

 -iti"n tube) is loosely tilled with clean absorbent cotton 

 which has been kept over Bulphnric acid to insure uniform dryness. 

 Instead of tin; bulb tube, tbe rubber Btoppei of the exit tube d 



• ibing ofaboat \J mm. diameter, in wl 

 i- placed tin- absorbent cotton, ami to which, by means of another 

 rubber ittached the deposition tube. 



FlGl BE A. 



simplicity and compactness of this apparatus allow a number of 

 determinations to be carried on at the same time by the use of several 

 important^ however, that the buttles be of the same - 

 advisable to have the rest of the apparatus of a- Dearly 

 definite ible. 



Reagents. We have used zinc and hydrochloric acid in preference 



Bine and sulphuric acid, as the action goes on more regularly and 



without the addition of a sensitizer. The chance for the formation of 



sulphide is also less. The zinc, known as bertha spelter, is 



.m the New Jersey Zinc Company of New York, and baa been proved 



• .ve tests to b e free from arsenic. It contains not over 0.019 



