ON CHEMICAL NOMENCLATURE. 7 
periments are so perfectly analogous, it is to be presumed 
that the invisible process which we do not see, may also be 
perfectly analogous, and that if facts exactly alike are ex- 
plained differently, there must be a defect in the explanation. 
If, for instance, the true electro-chemical composition of the 
sulphate of potash should not be KO + SO^, as is generally 
supposed, but K-f-SO''',* and it appears very natural that 
atoms, so eminently electro-negative as sulphur and oxygen, 
should be associated, we have, in the salt in questiort, potas- 
sium combined with a compound body, which, like cyanogen 
in K-j-C^ N,t imitates simple halogen bodies, and gives a salt 
with potassium and other metals. The hydrated oxacids, 
agreeably to this view, would be then hydracids of a compound 
halogen body, from which metals may displace hydrogen, 
as in the hydracids of simple halogen bodies. Thus we 
know that SO^, that is to say, anhydrous sulphuric acid, is a 
body whose properties, as respects acidity, differ from those 
which we should expect in the active principle of hydrous 
sulphuric acid. 
The difference between the oxisalts, and the halosalts is 
very easily illustrated by formulae. In KIFF — fluoride 
of potassium, there is but one single line of substitu- 
tion, that is to say, that of KIFF, whilst in KOOOOS (sul- 
phate of potash) there are two, K|OOOOS and KO|OOOS of 
which we use the first in replacing one metal by another, for 
instance, copper by iron ; and the second in replacing one 
oxide by another. 
I do not know what value you may attach to this deve- 
* In the Berzelian symbols, K stands for kalium, or potassium, S for 
sulphur, O for oxygen, and 03 for three atoms of oxygen, 04 for four 
atoms of oxygen. 
f That is to say, if the salt called sulphate of potash, be considered as 
compound of potassium, and a quadroxide of sulphur, instead of being 
viewed as a protoxide of potassium, or potash, and tritoxide of sulphur, or 
sulphuric acid. 
This is the formula for cyanide of potassium, consisting of potassium, 
K, and cyanogen, or two atoms carbon and one uf nitrogen, C2 N. 
