Pattern*—Solutions of Hydrochloric Acid in Solvents . 345 
The bottle wag then opened to the air, but the zinc was not 
acted upon immediately after opening, as Dr. Remsen stated 
at Washington; in this first experiment I did not take time by a 
watch, but it took several minutes of contact with the air before 
the zinc was attacked. This long time and considerable 
amount of moisture required to start the action upon zinc is not 
due to slow diffusion of water from the top of the benzene solu¬ 
tion down to the zinc-—as I showed in an experiment to be de¬ 
scribed later, by shaking up the solution from time to time. 
The bottle was then corked and left till Tuesday morning when 
all action had ceased. The bottle was again opened and after 
about five or six minutes’ contact with the air, gas began to come 
off from the zinc; as more and more water came in, this action 
increased in violence. The water is used up here before the 
hydrogen chloride is exhausted. 1 
On Tfiesday morning, at my suggestion, Mr. Falk platinized 
one end of a piece of zinc wire (Merck’s) and dried it for two 
hours at 120° O. in an air bath; magnesium from Bender & 
Hobein was scraped clean, but not heated; aluminum and cad¬ 
mium, obtained from Elmer & Amend, were treated like the 
magnesium and all four metals were placed in benzene dried 
over sodium as before described, all the manipulations being 
exactly the same as on the preceding day (Monday, Jan. 5, 
1903) ; and hydrogen chloride gas was passed into the benzene. 
The phosphorus pentoxide in the drying and protection tubes 
was not renewed; the same had been used the day previous and 
a considerable quantity of gas passed through it. Eo one in 
the laboratory would maintain that it was efficient in removing 
the moisture from the hydrogen chloride gas. 
The Results.— Zinc was acted upon vigorously for three min¬ 
utes, then the evolution of gas decreased till in ten minutes no 
1 In my first experiment upon the action of hydrogen chloride upon zinc 
in benzene solution, in this paper, I stated that upon opening the flask to 
the air no acceleration in the rate at which zinc is attacked was observed. 
This observation is correct, I merely took out the stopper [of the flask 
containing the benzene and immediately replaced the stopper. The in¬ 
terior of the flask filled with the white cloud usually seen when dry hydro¬ 
gen chloride is brought in contacr with moisture, so that presence of 
water is certain. And yet I could detect no further action upon the zinc. 
