1819.] and on some other Subjects of Chemical Theory. 289 
mability without any acid quality ; with oxygen, it forms first an 
inflammable oxide, and with a larger proportion a weak acid ; 
but combined with both hydrogen and oxygen, in different pro- 
portions, it forms in the vegetable acids compounds having a 
high acidity. These acids, therefore, are not to be regarded, 
according to the theory of Lavoisier, as composed of a compound 
base of carbon and hydrogen, acidified by oxygen, but of a 
simple base, carbon, acidified by the joint action of oxygen and 
hydrogen. 
Muriatic acid itself presents the same result. Oxymuriatic 
acid must be considered, according to this doctrine, as a com- 
pound of an unknown radical (Murton, if the term may be 
allowed) with oxygen, analogous in this respect to sulphurous 
acid, except that in the latter there is an excess of base, in the 
former an excess of oxygen: and oxymuriatic acid, with the 
addition of hydrogen, forms the ternary compound muriatic acid, 
as sulphurous acid with the same addition forms hydrosulphuric 
acid, with a deposition of the excess of sulphur. There is 
accordingly the strictest analogy between muriatic acid and 
those other acids, the sulphuric, nitric, &c. which contain both 
oxygen and hydrogen; while there is none, as Berzelius 
_ remarked, between it and those, such as the prussic acid or 
‘sulphuretted hydrogen, which contain merely hydrogen. This 
principle solyes the difficulty which has always presented itself 
in the relation of muriatic and oxymuriatic acids on Lavoisier’s 
theory of acidity—that the latter, though it has received an 
addition of oxygen, is inferior in acid power to the fornier. It 
is so precisely, as the binary sulphurous acid is one of less energy 
of action than the ternary hydrosulphuric acid, or as the carbonic — 
is less powerful than the oxalic acid. The proper analogy is that 
of the oxymuriatic with the sulphurous acid, and the muriatic 
with the sulphuric ; and under this point of view there is no 
anomaly, but strict conformity. And thus also is accounted for, 
what is at variance with the hypothesis of Gay-Lussac, the total 
want of analogy between chlorine and sulphur, which he classes 
together, except in the single circumstance of acidity being 
communicated to both by hydrogen; while there exists a close 
analogy between sulphurous acid and oxymuriatic acid in their 
thost essential properties—their gaseous form, their specific 
gravity, their suffocating odour, their power of destroying vege- 
table colours, their solubility in water, their remaining combined 
with it in congelation, their acidity, their combining weights, and 
their being attracted to the positive pole of the voltaic series; 
and any deviation from this analogy evidently arises from the 
excess of oxygen in oxymuriatic acid.* 
* It is curious with regard to the most important of these analogies, that of the 
equivalent or combining weights, that oxymuriatic acid stands next to sulphurous 
_ acid ; the former in Dr. Wollaston’s scale being 44, while the latter will be found 
tobe 40. The acidity of oxymuriatic acid is fully established by the most unequi- 
Vou. XIII. N° IV. T 
