IOWA ACADEMY OF SCIENCES. 
117 
does not greatly influence the point of equilibrium, though 
the evidence in this regard is not conclusive. Solubility 
usually increases with temperature, and we should expect 
Figure 2. 
more zinc sulphide to dissolve in a given time at the 
higher temperature, and that, therefore, the effect of the 
reaction, 
ZnCl r fH f S^=Zn-f2HCl 
from left to right would be less in any given period. The 
decrease in the active mass of hydrogen sulphide at the 
higher temperature should, leaving change in ionization 
out of account, contribute to the same result. There are, 
'Time in hours 
