352 Wisconsin Academy of Sciences. Arts, and Letters. 
in the absence of further experimental proof to the contrary— 
to be due to the same cause which underlies all differentiation 
of substances and which, the better to conceal our lack of knowl¬ 
edge, we call chemical affinity. 
This action of hydrochloric acid gas dissolved in dry ben¬ 
zene upon dry zinc endured then five hours and thirty-six min¬ 
utes, possibly longer. Dr. Rem sen wished to get nascent hy¬ 
drogen for reducing purposes in a solvent containing neither 
water, oxygen nor chlorine. While the hydrogen produced in 
my experiments may or may not serve this purpose, 1 the fact is 
established that we do get a gas evolved from the zinc; and 
within certain limits the dryer the materials the longer the 
action endures. 
The following gentlemen were present at this last experi¬ 
ment:—Prof. W. W. Daniells, Prof. L. Kahlenberg, Prof. G. 
M. Wilcox, of Armour Institute, M,r. Shinn, Mr. Femeckes, 
Mr. Huddle, and Mr. Brinsmaid. Prof. Lenlier and Prof. 
C. F. Burgess examined the coating on the metals after the 
action had ceased. 
Laboratory of Physical Chemistry, 
University of Wisconsin, 
Madison, Wis., 
Jan. 19, 1903. 
1 1 purpose to try the reducing power of the hydrogen thus obtained at 
an early date. 
