Chemical Notation of Laurent and Gerhardt. 365 
: Examples, Notation of Berzelius. - Our notation. 
Sulphuret of hydrogen, H,S S (H,) 
Sulphuret of potassium, KS $(K,) 
Chlorid of hydrogen, H, Cl, Cl (H) 
Chlorid of potassium, KCl, Cl (K) 
Sulphuric acid, 80,,H,0 SO, (H,) 
Sulphate of potash, SO,, KO S0,(K,) |. 
Bisulphate of potash, SO,,KO+S0,,H,O SO, (HK) — 
Sulphate of zine and potash, SO,, KO-+S0,,ZnO SO, (ZK) 
Nitric acid, N,0,,H,0 NO, (H) 
Nitrate of potash, N,O,, KO NO, (K) 
The principal difference consists in the notation of salts, which 
we regard as unital in their constitution, as systems in which the 
metal may be exchanged for another, without affecting the ar- 
rangment of the molecular structure. (We write generally the 
metal in parentheses.) According to this view, the acids, prop- 
erly called, (the hydrated oxacids, and the hydracids,) are salts, 
in which the metal is represented by hydrogen; the oxyds and 
sulphurets have the same claim to the title of salts as the sul- 
phates and nitrates. The so-called anhydrous acids we loo 
upon as a peculiar class of bodies, (anhydrids,) which become 
acids by the fixation of the elements of water. 
We farther assume that one and the same body may have two 
or several equivalents. According to us the idea of an equivalent 
implies that of a similarity of function, and it is known that one 
and the same element is often capable of playing the part of two 
or of several other very different elements; it may then happen 
that each one of these different functions corresponds to different 
proportions of the first element. On the other hand, we some- 
tim Ss see different weights of the same metal, as, for example, 
iron, copper or mercury, replace the hydrogen of acids to form 
salts, which although containing the same metal, are different in 
their properties. The metals have then different equivalents. 
Ferrous sulphate, SO, Fe 
Ferric sulphate, SO, Fe} = 3S0,,Fe,0, 
Thus in the ferric sulphate there are but two-thirds the quantity of 
iron which exists in the ferrous sulphate ; but these two-thirds of 
Fe are the equivalent of H, K, Na, Zn, ete., and also of the Fe 
in the ferrous salts; but when two-thirds of Fe replace H in 
sulphuric acid, or K in the sulphate of potash, we obtain a salt 
Which without ceasing to be a neutral sulphate, possesses proper- 
ties very different from those of the ferrous sulphate where Fe 
=. §0,,; FeO Berzelian 
formulas, 
