74 , M. Berzelius on Compounds^ 
of saturation which are improbable, if not contrary to expe- 
rience. 
It may be observed, that the quantity of water found in this 
double salt was greater than that contained in the two salts se- 
parately ; and, as it is to be "presumed that the strong base, 
rather than the weak one, would combine with a more than 
usual quantity of water, this bicarbonate of potash must have 
contained three times as much water as in its isolated state ; and 
the water in each of the two salts must have contained three times 
as much oxygen as the base. The composition of this double 
•» A* 
salt may therefore be expressed by the formula KC^ Aq® -{- 
2 Mg C® Aq® * : from which we conclude its exact composi- 
tion to have been, 
Potash, 
18.28 
Magnesia, - 
16.00 
Carbonic acid. 
34.1^ 
Water, 
31.60 
I have been minute in describing the examination of a salt 
which may appear uninteresting and obscure ; but I thought it 
right to be so, because a careful and exact examination of what 
allows itself to be determined with ease, enables us to judge of 
what ought to happen in cases where a similar examination is 
not equally possible. The analysis of this double salt is highly 
important in two points of view. In the first place, it shews 
that two salts formed by the same acid, at different degrees of 
saturation, with different bases, may uuite and constitute a 
double salt. And this fact confirms those formulas, which have 
been deduced from the analyses of several substances in the mi- 
neral kingdom; of the emerald, for example, the apophyllite, 
the mesotype, the tremolite, and others ; the composition of 
which being found with sufficient accuracy, connects silica with 
earths which serve it as salsifiable bases, and exhibits siliciates 
in different degrees of saturation. Secondly, our analysis proves 
that the quantity of water which exists in a double salt, is not 
always the same as that which exists in its component salts, taken 
These symbols have already been explained^ — T ransl* 
