The Discovery of the Atomic Theory. 55 
the work of Mr. Higgins, and can only notice the circumstance 
on the authority of Davy.” 
To which the learned Editor has subjoined a note of his own 
in the following words: 
© The work of Higgins on Phlogiston is certainly possessed 
of much merit, and anticipated some of the most striking sub- 
sequent discoveries. But, when he wrote, metallic oxides were 
so little known, and so few exact analyses existed, that it was 
not possible to be acquainted with the grand fact that oxygen, 
&c. always unite in determinate proportions which are multiples 
of the minimum proportion. The atomic theory was taught by 
Bergman, Cullen, Black, &c., just as far as it was by Hicaidd. 
The latter indeed states some striking facts respecting the gases, 
and anticipated Gay-Lussac’s theory of volumes ; but Mr. Daiton 
first generalized the doctrine, and thought of determining the 
weight of atoms of bodies. He showed me his table of symbols, 
and the weight of the atoms of six or eight bodies, in 1804; and, 
I believe, ‘the same year explained the. subject in ondon; i ina 
course of lectures delivered in the Royal Institution. The sub- 
ject could scarcely be broached sooner. But about the same 
time several other persons had been struck with the numbers in. 
my table of metallic. oxides published in my Chemistry; and the . 
doctrine would have certainly been started by others ?f Dalton 
had missed it.” 
That learned Editor by this publication has endeavoured to 
deprive Mr. Higgins of the honour due to the first author of 
the atomic theory, a doctrine now so generally received and uni- 
versally admired, and of which Sir H. Davy, Berzelius, and others 
have spoken in terms of unqualified approbation. 
Dr. Thomson has in a part of his note endeavoured to bestow 
the credit of that theory upon Mr. Dalton, and in anether part 
to fritter away the merits and importance of the discovery. And 
that the discovery is important, and that merit is due to the 
author, I think, is fully established by the opinion of such men as 
I haye mentioned. 
I shall now proceed to show, i reference to dates and facts, 
that the merit of that discovery ‘exclusively belongs to Mr. Hig- 
gins, and that Dr. ‘Thomson was not justifiable i in making the 
assertions in his note. 
It is well known, that for several years the attention of the 
chemical world was directed to the consideration of the phlo- 
gistic and antiphlogistic doctrines. Whilst these questions were 
agitated by their respective advocates, Mr. Higgins, without 
adopting either the one theory or the other, commenced, upon 
the true ground of experiment and analysis, to examine the foun- 
dation of both, and the atomic theory was one result of that in- 
D4 ; vestigation, 
