344 'Wisconsin Academy of Sciences, Arts, and Letters. 
duced into' the benzene and the bottle (6) fitted in place as 
shown in Figure 1, and the hydrogen chloride gas run into 1 the 
benzene. 
In order that the train might be filled with hydrogen chloride 
gas, the lower ends of the tubes 5 and 7 were joined (before 
inserting them in bottle 6) by a glass tube connected on by rub¬ 
ber tubes and the gas passed until the air in the apparatus 
might reasonably be considered expelled. When bottle 6 con¬ 
taining the benzene was placed in position this glass tube was 
removed and the hydrogen chloride gas necessarily came in con¬ 
tact with the air and took moisture from it. 
I have described this manipulation carefully because it 
makes clear that moisture was not excluded in this experiment. 
The phosphorus pentoxide drying tubes used were not longer 
than six inches and about one inch in diameter and cotton plugs 
of about % to y 2 inch depth were used between the layers of 
pentoxide. The hydrogen chloride was run in at a rapid rate, 
too 1 . Mr. Falk assured Dr. Jones in my presence that the ex¬ 
periment was conducted in every way like the one Dr. Eemsen 
described at the Washington meeting, and Dr. Eemsen himself, 
on seeing the apparatus, passed no criticism. 
The zinc used was c. p. wire from Merck. One piece, 
cleaned with emery •cloth, was cut in two, and one-half heated 
half an hour at 120° G. in an air bath. The other piece was 
not heated. This variation was made to see if the action upon 
the zinc were due to a surface layer of moisture upon it. 
The results obtained were as follows: At first- the zinc was 
vigorously attacked, no difference in action being observed upon 
the heated or the unheated samples. This evolution of gas 
gradually decreased and at the same time a white coating 
formed on the zinc, growing thicker and thicker. Aften ten 
minutes the action had abated considerably, and after thirty 
minutes very minute bubbles were coming off at long intervals. 
I detected these bubbles rising from the zinc after forty min¬ 
utes had elapsed, and without the aid of a lense, but Mr. Falk 
could not see them so I have set aside the forty minute period, 
though I am not at all sure that the action ceased even then. 
That is as long as I watched it. 
