ACIDS. 
403 
This reciprocal alteration in the elementary constitution of 
the acid and base is conceived, by Berzelius, to take place 
even in the combination of ammonia with hydracids. For 
example, when hydro chloric, that is, muriatic acid, is com 
bined with ammonia water, to form sal ammoniac, which, 
on the old Lavoisierian theory was considered as muriate of 
ammonia with water of crystallisation, the hydro chloric 
acid really undergoes decomposition, the ammonia combines 
with its hydrogen, and is converted into ammonium, and this 
latter combines with the chlorine, and forms chloride of am 
monium. The case is the same, when chlorine gas is united 
with ammoniacal gas : so that sal ammoniac is a chloride of 
ammonium, as common salt is a chloride of sodium. 
The resemblance between the compounds properly deno 
minated salts, and those formed by the radicals of hydracids 
and of bases, is so complete that it is impossible, without 
offering violence to their external characters, to regard them 
as belonging to dissimilar clásses of bodies. Nevertheless, 
in a theoretical point of view, there is a wide difference be 
tween the compounds of oxidated acids and bases, and 
those of combustible bodies without oxygen ; and it may, 
therefore, be argued from this, that the present theory sup 
poses arrangements which have no existence in reality. 
Dulong has attempted to reconcile