THE LATE PETER EWART, ESQ. 131 
of the absorption of heat attendant on increase of 
volume. 
From these general conceptions of the nature 
of steam, or more comprehensively, of matter 
_as subsisting in the state of elastic fluidity, an 
earnest and enquiring mind could scarcely fail to 
press onwards to the highest doctrines of the 
Atomic Philosophy. Mr. Ewart had the merit of 
recognizing the truth and beauty of this grand 
generalization, long anterior to its full and uni- 
versal acceptance ; he had never, it is true, ren- 
dered himself familiar with the minute technical 
details of chemistry,—with the aspect, proper- 
ties, and habitudes of individual bodies. But 
the mechanical sciences constituted the best 
preparatory discipline for the study of the ‘“* New 
System of Chemical Philosophy ;” and in a close 
friendship of nearly half a century with its illus- 
trious author, permitting the fullest and most un- 
reserved discussion and interchange cf thought, 
he had enjoyed access to the fountain head of 
these higher doctrines. Mr. Ewart read before 
this society in September 1812, and afterwards 
published in the Annals of Philosophy, vol. VL, 
p- 371, a clear and forcible statement of the main 
