Modifying the force of Chemical Attraction, 237 
exerted by each. This hypothesis admits of the following 
illustration. 
aR. Oe a oe ee Oe 
The letters (a) represent atoms of lime ; the letters (e) at- 
oms of carbonic acid, and all of them together, a quantity of 
carbonate of lime, which has experienced the decomposing 
agency of heat. The double letters (@) represent atoms of 
carbonate of lime undecomposed; upon the carbonic acid 
(e) of which a force is exerted by the surrounding particles 
of uncombined lime (a) to prevent its escape. force 
exerted by each uncombined (a) upon the (e) of the carbo- 
nate, is very small when compared with that exerted by the 
(a) in proper chemical union; and capable of being overcome 
by the weak affinity of water or other agent—a e. 
united force of all the uncombined (a’s) though amounting 
cases, and its existence in most, is here fully admitted. 
But passing by this, which is merely an hypothesis, desti- 
tute of proof and incapable of it, we return to the principal 
subject of this paper: That it is a law of extensive ica- 
tion, that the quantity of matter modifies the force of chemi- 
cal attraction, and compensates for a weak affinity. The 
recollection of every practical chemist, will est to him 
other examples analogous to the above, and poimting to the 
same conclusion, but perhaps no facts are more to our pur- 
pose than those collected by Berthollet, and laid by him asa 
foundation on which to build his theory of chemical affinity, 
if once the mistakes and misapprehensions prevailing re- 
strating its correctness, besides calling into view some im- 
portant facts with which chemists had long been familiar. 
