i88o.] The Baconian Philosophy of Heat, 687 
tions ; and, accordingly, from the days of Aristotle, or his 
precursors — whom, in the phrase of Bacon, Aristotle “ had 
destroyed, as Ottoman emperors do their brethren, for to 
reign in greater security ” — through almost all subsequent 
centuries, we have numerous expressions of opinion and 
statements of arguments intended to describe or demonstrate 
the nature of heat. Yet how unprofitable and even depressing 
a task would it be to follow out the history of these state- 
ments and discussions, even if we confined our attention to 
such as proceeded from persons of great and well-merited 
fame ! Galileo and Gilbert, Bacon and Descartes, Boyle 
and Newton, Boerhaave and Crawford, Lavoisier and 
Laplace, as well as a host of others, have simultaneously 
or successively put forth views, sometimes nearly coincident, 
sometimes most widely discordant, as to this prolific subject 
of debate and research ; yet the upshot of all this was, in 
our own century, a stolid acquiescence partly in avowedly 
untenable theories, partly in seemingly irremediable ignorance. 
The most bulky works on the subject of heat produced 
within this last-named period — whether they boasted the 
title of “theories,” like those of Fourier and Poisson, or 
were of a practical character, like those of Peclet and De 
Pambour, almost confessedly slurred over the question as to 
the nature, essence, or, in Baconian language, the “form” 
of heat. Their writers took it simply for granted that heat 
is a something somehow capable of measurement, as proved 
empirically, and of exhibiting certain phenomena into whose 
precise mechanism or origin it was needless to inquire, it 
being sufficient to know by experience that they exist. Thus, 
after more than two thousand years of meditation, contention, 
and investigation, we were landed again in total ignorance, 
at least so far as the purpose of philosophy is to comprehend, 
not merely to analyse, Nature. Yet within the intricate 
coil, made of cobweb speculation rather than of solid 
scientific fibre, into which had been spun the didta of 
successive generations of physicists on the philosophy of 
heat, there may be traced — to borrow a German simile 
taken from an English practice — a red thread of truth, 
which, originating apparently with Bacon, had been continued 
uninterruptedly, though without gaining in consistency, 
down to our own period. For a long time as good as buried 
in the superincumbent layers of the twisted fabric of error, 
this unwarped thread of truth has happily been seized upon 
and strengthened by some philosophers flourishing at the 
present time, owing to whose labours the views of Bacon 
have not only been drawn forth from their unmerited 
VOL. II. (THIRD SERIES). 2 X 
