on the Origin of the Doctrine of Definite Proportions, 8c. 409 
alone*. The same law holds good as to oxygen and carbon, 
the gas will not increase or diminish on uniting to two portions 
of the latter. ; 
By the foregoing means have I been enabled to ascertain the 
relative weights of the ultimate particles of matter, and there is 
no other way whatever left to arrive at so desirable and so im- 
portant an object. I should presume that the specific gravity of 
the ultimate particles of all bodies is the same, their size con- 
stituting the difference of their weights. 
I*shall terminate this part of the subject by the following 
extract, taken from my Comparative View (pages 255, 256) : 
Metals in their simple state are insoluble in water ; but com- 
bined with acids they are soluble. Iron and sulphur chemically 
united form an insoluble mass; iron and oxygen form also an 
insoluble compound; but iron, oxygen and sulphur will form a 
very soluble compound. Azote in its simple state has no sen- 
sible affinity to metals ; yet when combined with a sufficiency 
of oxygen it will unite to them and render them soluble. It is 
clear from these facts, although oxygen alone will not render 
metals soluble in water, that it is through its mediation a third 
body will unite and form a soluble compound. But which of the 
three substances has the solvent power most inherent in it, is 
what we cannot pretend to explain.” 
I only produce the foregoing passage in consequence of seeing 
something on the same principle adduced by Dr. Murray in his 
chapter on Attraction (page 64), in which he quotes Berthollet 
on the same subject, as explaining the cause of the solubility of 
saline substances, &c. ; yet he takes no notice of the above re- 
marks made at so early a period of the progress of chemical 
science. 
The Doctor, in order to deal fairly, should add some of the 
above cases, as he calls them, to the few he has quoted in his note: 
but no doubt he was aware, had he done so, that little or none 
would have been left for Dalton, Gay-Lussac, Berthollet, and 
Dr. Wollaston, who have written long after me on those interest- 
ing subjects, and of course have no claim to originality. 
It is extraordinary with what avidity the various principles 
which I advanced in my Comparative View have been picked 
up, without the sinallest reference to that work. In short, there 
never was a publication so completely plagiarized; I could enu- 
merate six authors who had taken facts and ideas from it, which 
they brought forward as discoveries of their own. Most of those 
I have noticed on former occasions, which was a’ disagreeable 
task to my feelings. 
And as to Dr. Muarvay, although, as I said before, my system 
* Comparative View, page 80. 
runs 
