MUTUAL 1>KCOMPOS1T10N. 
19 
grees of cohesion belonging to each insoluble salt as the cause isfiitual de- 
of these decompositions. It* may, in fact, be conceived, that coniposiuou 
‘ Ol li.f lUSolU' 
the cohesion of two salts equally insoluble, may be verv differ- ble neutral 
Sckl td CCC 
ent j and that if an insoluble salt comes in contact with a .si .u- * 
ble salt, of which the principles, by being reciprocally ex- 
changed with those of the former, can produce another inso- 
luble salt, possessed of a much greater cohesion, there will be a 
decomposition. 
If, then, it were possible, by any method, to appreciate the 
different degrees of cohesion belonguig to e.ich insoluble salt, 
in the same manner as the different degrees of solubility of 
those which are soluble are estimated, the decomposition of 
those salts which contain the above-mentioned conditions, 
would be foreseen with as much facility as ih.tt of the soluble 
salts. Now the results of the decomjrosition of the itisoluble 
carbonates by the insoluble salts, presents a simple method, if 
not of estimating the absolute intensity of ibis power, at least 
of ascertaining the differences whii h ar.' seen, in this re-pect, 
in tire insoluble salts. When a soluble salt cea.ses to decompose 
au insoluble carbonate, there is an equilibrium between the 
power with w hieh the in.soluble salt tends to precipitate itself, 
and the excess of alkali developed in the solution ; and the result, 
as we have already said, is, that the greater this tendency to 
precipitation, the more the excess of alkali which is developed 
will be considerable If, therefore, for each insoluble salt, there- 
lation were determined which exists between thequantity which 
Is regenerated, and the total quantity of salt that might have 
been formed by the entire precipitation of the acid, then by 
comparing the various relations obtained for all those salts 
formed w'ith the same base, a scale of their cohesion might be 
easily arranged, and according to the rank w hich a given salt 
would fiold in this scale, it might be known what were the 
soluble salts that would decompo-e it. 
1 have already ascertained a considerably large number of 
these relation.s, and their indicatidns have been fully confirmed 
by experiments. But 1 shall delay presenting this work to the 
Class until it has included, if not all the known rails, at least 
the greatest part of those which are frequently met with iij 
analysis. C 2 METE- 
