New Outlines of Chemical Philosophy. 95 
port on this subject (Examination of Kirwan, p. 17), ‘is the 
formation, the decomposition, and recomposition of water. And 
how can we doubt of it, when we see that, in burning together 
fifteen grains of inflammable air, and eighty-five of vital air, we 
obtain exactly an hundred grains of water, in which, by decom- 
position, we find again the same principles, and in the same 
proportions? If we ‘doubt of a trath established uy experiments 
so simple and palpable, there would be nothing certain in na- 
tural philosophy.’ 
“* Notwithstanding the confidence thus strongly expressed by 
these able and experienced chemists,” says Dr.Priestley, “I must 
_ take thie liberty to say, that the experiments to which they al- 
lude appear to me very liable to exce ption, and the doctrine of 
phlogiston easily accounts for all that they have observed. 
“Their proof that water is decomposed, and resolved into two 
kinds of air, is, that when steam is made to pass over red-hot 
iron inflammable air is produced, and the iron acquires an ad- 
dition of weight, becoming what is called Jinery cinder, but 
what they call oxid of iron ; supposing that there is lodged in it 
the oxygen which was one of the constituent parts of the water ex- 
pended in the process, while the other part, or the hydrogen, with 
the addition of heat, assumed the form of inflammable air. 
‘*But-in order to prove that this addition of weight to the iron 
is really oxygen, they ought to be able to exhibit it in the form 
of dephlogisticated air, or of some other substance into which 
oxygen is allowed to enter; but this they have not done,” &c. 
—Dr. Priestley on Phlogiston, p. 42. 
“© An argument against the decomposition of water from the 
different proportions of the elements of which it is supposed - 
to consist, according to different experiments. 
a According to the new theory, water consists of two princi- 
ples, oxygen and hydrogen; and they are separated by iron, or 
charcoal, in a red heat, uniting with one of them, and” suffering 
the other to escape; and therefore if in any case a quantity of 
water be wholly expended in forming air, and only one of the 
kinds be found, it will be that this water does not consist of two 
elements. Now, according to one of my experiments, water 
would appear to consist of only one of the kinds of air, and 
according to another of the other. 
** 1 have shown that by a slow supply of water in sending 
_ steam over red-hot charcoal, the whole of the produce is inflam- 
mable air, without any mixture of fixed air, or the production 
of any thing, aérial, fluid, or solid, into which oxygen can be 
supposed to enter, 
“4 © From 
