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mixed Gases are passed through the sphere of action of 
the Copper Salt. Conversely, that the activity of a molecule 
of Copper Salt depends upon the speed with which fresh 
matter is presented to it and the products are removed 
from it.” 
II. That in long parallel tubes of the same diameter the 
number of opportunities of action in the same time is nearly 
the same at all the velocities of the current of Gas.” 
III. “ That in long parallel tubes of different diameters 
the number of opportunities of action of each molecule of 
Copper Salt is the same with the velocities of the current 
of Gas are in converse proportion to the squares of the 
tubes’ diameters.” 
lY. “ That in porous masses the opportunities of action 
increase with increased velocities with the current of Gas 
in nearly direct proportion.” 
Y. “ That other conditions remaining the same, the per- 
centage of Hydrochloric Acid decomposed in any given time 
varies with the square root in proportionate volumes of 
Oxygen and Hydrochloric Acid.” 
YI. “ That the Cupric Chloride formed bears no definite 
proportion to the quantity of Chlorine produced.” 
YII. *‘That as the sphere of action includes molecules 
not in contact with the Copper Salt, therefore Hydrochloric 
Acid must be decomposed under circumstances where the 
union of either element with the Copper Salt is impossible ; 
that is, that the decomposition must in part, if not entirely, 
be caused by the result of the forces engaged, and therefore 
direct from Hydrochloric Acid of Oxygen to water of 
Chlorine. The amount of chemical change occurring in any 
given time is not merely a measure of the chemical forces 
engaged, but is in reality a resultant of all the forces en- 
gaged, physical and mechanical as well as chemical.” 
This idea he calls the parallelogram of forces, which he 
considers analagous to that in mechanics. By this new 
