in the Compounds of Zinc and Antimony. 237 
the great law of chemistry. The definite proportion I regard as 
a maximum toward which the chemical force strives, a maximum 
from which the deviations in. most cases are small, although in 
subject, which the 7 has aimed to establish, is supported by 
the analogies of natu 
When the a ptemieal law has been discovered, of which the 
“ane atees law was merely the outward manifestation, as Kep- 
ler’s laws were merely the phenomena of the law of universal 
gravitation, the very variations have been seen to be necessary 
consequences of the law itself, and if even the dynamical law, 
whieh governs chemical phenomena, shall be discovered, it is most 
_ probable that the variations from the law of definite proportions 
will become as much a matter of calculation as the perturbations 
of Astronomy. In both cases the perturbation is apparently due 
The argument from analogy becomes stronger, when we co 
> sider the oe numbers. I have shown in a former a civ 
that these numbers may be connected by a very simple numeri- 
eal law, but here, as in other cases, we find merely a tendency to- 
wards the law, not an absolute agreement with it, the differences 
between = theosetical and the experimental equivalents being 
in many cases too ae to be covered by errors of observ gun 
cesses it will be noticed that they seldom perfectly agree ; so 
Whatever view may be taken of the subject it will now become 
a matter of the highest importance to ascertain how far, if at all, 
the determinations of the chemical equivalents have been influ- 
enced by similar causes to those which have produced the varia- 
tions described in this memoir. This influence can only be de- 
tected ne multiplying the determinations, by as many different 
processes as possible, and submitting the results to a rigorous 
Miathouiatigdl scrutiny. : 
If the doctrine of this memoir is correct and the chemical 
equivalents are redlly liable to variation it will have an important 
ery 
_” # This Journal, vol, xviii, p. 229, 
