J2 
MUTUAL DECOMPOSITION. 
Mutual do- P®*‘3ture which do not aflfect equally the elements of the salts, 
comp/)s'fion and the variety in the nature of the solvents, are sufficient to 
of the inwlu- , ,, , 
bio neiiiral explain all those cases formerly designated by the name of ano- 
salts, &o, nialies. But in that at present in question, these two circum- 
stances are the same. It is at the temperature of the ebullition 
of water, and in the midst of this liquid, that the opposite phe- 
nomena are produced. 
I shall further observe, that neither of these decompositions 
can be attributed to the simultaneous concourse of affinities of 
the dements which are united when they take place. The 
author of the chemical statics, (Berthollet) with the assistance 
of some very ingenious experiments and considerations, has 
shewn, that the difference of solubility of the compositions 
which may result from the mixture of two soluble salts, is 
always sufficient to explain their decomposition, and that it is 
useless to refer to the consideration of the different degrees of 
affinity of their elements, and besides that thc'y cannot be 
exactly appreciated by any known method. 
The experiments related at the commencement of this me- 
moir prove, in a very evident manner, that the decomposition 
of the insoluble salts by the soluble carbonates can no longer 
depend upon a similar concurrence. In fact, it is now W'ell 
known, that the soluble sub-carbonates have such proportions, 
that their principles may be exchanged exactly with those of 
all the neutral insoluble salts ; so that if the decomposition 
were complete, the result would be on one side, an insoluble 
sub-carbonate analogous in its proportions to the soluble sub- 
carbonates, and on the other, a neutral salt of potash or soda. 
Now, if the decomposition depended upon the simultaneous 
concurrence of the divellent affinities, these powers being sup- 
posed constant between the same principles, there would be no 
reason why the decomposition should not proceed to the very 
end in the same manner; and as no insoluble salt can totally 
decompose a soluble sub-carbonate, it becomes a consequence 
that this decomposition should depend upon some other cause. 
From the inverse experiment, that is to say, the decomposition 
of 
