316 OBSERVATIONS ON MURIATIC ACID, 
tion, nor capable of existing as a separate binary compound. 
The insulated binary compound of the radical of muriatic acid 
with oxygen is oxymuriatic acid, as the binary compound of 
sulphur and oxygen is sulphurous acid, and of nitrogen and 
oxygen, nitrous and nitric oxides, 
Iodine, the discovery of which and its relations, is for a 
time given predominance to the new doctrine of chlorine, con- 
forms sufficiently to these views. Some have considered it as 
a body belonging to the same class as chlorine ; others regard 
it as more seaippond to sulphur. It has little analogy to 
either, except in stad property of forming acids with oxygen | 
and with hydrogen. It differs remarkably from chlorine in its 
comparative inertness, its solidity, specific gravity, and great 
weight of its equivalent quantity. And it differs from sulphur 
in its want of inflammability, its solubility in water, and its be- 
ing attracted to the positive pole of the voltaic series. All 
these analogies are preserved, and its relations connected, by 
considering it as an oxide, which, both from its specific gravity, 
the colour of its compounds, and the great weight of its equi-. 
valent quantity, has probably a metallic base ; and which ac~ 
quires acidity by an addition of hydrogen on the one hand, 
and on the other by the addition of oxygen, or of oxygen and 
hydrogen. In these respects, and in many of its chemical pro- 
perties and relations, a considerable analogy exists between it 
and oxide of arsenic or oxide of tellurium. Or if it were to be 
classed as a simple substance, (on the ground of its not having 
been decomposed,)—which forms an acid with hydrogen, 
and another with oxygen and hydrogen; it does not in these 
respects offer any deviation compared with other acidifiable 
bases, or afford an argument of much weight in support of the 
undecomposed nature of chlorine. 
The 
