278 A Comparison of the Old and New Theories [Aprit, 
If this be the case with the oxide of sulphur, we need not be sur- 
prised that it can only be exhibited in a state of combination. When 
the muriate of sulphur is decomposed by water, all the oxygen of 
the sulphur combines with one-half of the sulphur, and forms sul-. 
phurous acid; while the other half of the sulphur appears to be re- 
duced. According to the new doctrine, the water is decomposed, 
the hydrogen forming with chlorine muriatic acid, and the oxygen 
with a portion of the sulphur, sulphurous acid. The superiority of 
the new doctrine, therefore, consists in this, that it has no occasion 
to suppose the existence of a lower degree of oxidizement of sulphur 
(an opinion in other respects not improbable). But we shall soon 
destroy this apparent superiority, and turn the weapons of the new 
opinion against itself. ‘ 
The substance discovered by Dr. Marcet and myself by the action 
of aqua regia on sulphuret of carbon is sufficiently known, Accord- 
ing tothe old doctrine, it must be considered as a combination of 
three acids free from water, namely, muriatic acid, sulphurous 
acid, and carbonic acid. ‘The quantity of oxygen in the last two is 
equal to each other; and that im the muriatic acid as great as in 
both the others. According to the new doctrine, this body must 
consist of one proportion of phosgene (the name given to the body 
formed by the combination of carbonic oxide and chlorine) and one 
proportion of a compound of chlorine, sulphur, and oxygen. But 
the proportion of sulphur and oxygen in this compound is quite the 
same as in the oxide of sulphur admitted by the old doctrine in the 
muriate of sulphur (the sulphur is combined with half as much 
oxygen as in sulphurous acid). Hence it is obvious that the new 
doctrine must admit the existence of the same oxide in order to 
explain the nature of the compound in question. ‘The new doctrine, 
therefore, in this point of view, has no superiority whatever over 
the old doctrine. 
5, Chlorine combines with Phosphorus in two Proportions. 
The compounds formed by the action of oxsymuriatic acid on 
phosphorus are, according to the old doctrine, compounds of mu- 
riatic acid and phosphorous or phosphoric acids free from water, 
When water comes in contact with them, it decomposes them, and 
reduces them to the state in which they exist when united with 
water. But according to the new doctrine these compounds are 
peculiar acids free from water, in which the phosphorus constitutes 
the base, or the electro-positive ; and chlorine, the electro-negative 
ingredient. These acids are capable of uniting only with one base, 
namely, emmoniacal gas. By all other bases they are decomposed, 
a phosphate and a chloride being formed. The old doctrine appears 
to me in this case to be both simpler and more correct; as it con- 
siders the ammoniacal salt as a double salt without water, and com- 
posed of two acids united to one base; and the compounds of these 
two acids with other bases, either as equally double salts, or as mix- 
