New’ Outlines of Chemical Philosophy. 39 
* According to the new theory, water consists of two principles, 
hydrogen and oxygen. . Now before we begin to inquire into the 
truth of this theory, it will be necessary to understand the mean- 
ings of those terms. Dr. Henry observes that “ every gas, it 
must be remembered, has at least two ingredients; the one 
gravitating matter, which, if separate, would probably exist in 
a solid or a liquid form; the other an extremely subtile fluid, 
termed caloric. In the example before us, caloric (and perhaps 
electricity and light) is a common ingredient both of hydrogen 
and oxygen gases; but the two differ in having different bases, 
The basis of the one is called hydrogen, of the other oxygen 5 
and water may, therefore, be affirmed to be a compound, not 
of hydrogen and oxygen gases, but of hydrogen and oxygen*.” 
Dr. Murray observes that * the action of electricity affords a 
mode of resolving water into its constituent gases, and of com- 
bining those again so as to reproduce itt.” 
Now according to these statements, water is a compound 
of hydrogen and oxygen ;—and hydrogen and oxygen are the . 
component parts of water! This is nothing more than arguing 
in a circle; yet such is the basis on which is built the much 
celebrated fabric of the French doctrine of the composition of 
water. : 
As the component parts of water, according to the French 
hypothesis, consist of two ponderable matters, why are they not’ 
exhibited in a solid or a liquid form, divested of that supposed 
** extremely subtile fluid termed caloric?” But this, I believe, 
has never been effected; and therefore, till this be done, the ex- 
istence of those mutters can only be looked upon as an ingenious 
opinion, founded on conjecture. 
If we were to reason from what we know, we might say that 
water is the basis of the two gases; but if we were to reason 
from principles the truth of which we do not know, we might 
then indeed conclude with M. Lavoisier and his ‘associates, that 
the bases of the two gases in question are two unknown pon- 
derable bodies called hydrogen and oxygen {. 
_We need only take a transient view of some of the grandest 
phenomena of Nature, to be convinced that the decomposition 
and recomposition of water are common operations. The water 
which falls from the clouds upon the surface of the earth is fre- 
quently converted into two invisible gases, by the two elements 
of combustion contained in the earth or upon its surface; and 
these gases ascending iuto the atmosphere become a part of it. 
* Henry’s Elements of Chemistry, vol. i. p. 206. 
+ Murray’s Elements of Chemistry, vol. i. p. 504. t 
{ Dr. Henry observes that “ we have no knowledge of the properties of 
oxygen in a state of complete separation.”—Heary’s Chem. vol. i, p. 177. 
: 4 
When 
