30 
MEMOIR OF LAMARCK. 
particularly on those of Combustion ; of the raising 
of Water in the State of Vapour ; of the Heat pro- 
duced by the Friction of solid Bodies against each 
other,” &c. &c. A condensed view of the opinions 
promulgated in that work, and some others on the 
same subject, is thus given by Cuvier. According 
to our author, “ Matter is not homogeneous; it 
consists ‘ of simple principles, essentially different 
among themselves. The connexion of these prin- 
ciples in compounds varies in intensity; they mu- 
tually conceal each other, more or less, according as 
each of them is more or less predominant. The 
principle of no compound is ever in a natural state, 
but always more or less modified : as, however, it is 
not agreeable to reason that a substance should 
have a tendency to depart from its natural condition, 
it must be concluded, that combinations are not 
produced by Nature, but that, on the contrary, she 
tends unceasingly to destroy the combinations which 
exist, and each principle of a compound body tries 
to disengage itself according to the degree of its 
energy. From this tendency, favoured by the pre- 
sence of water, dissolutions result: affinities have 
no influence ; and all experiments by which it is 
attempted to be proved that water decomposes, and 
consists of many kinds of air, are mere illusions, 
and that it is fire which produces them. The 
element of fire* is subject, like the others, to modi- 
fication when combined. In its natural state, every- 
* Memoir on tlie substance of fire, considered as a chemical 
agent in analysis.— Journal de Physique , Floreal , An. vii. 
