602 On the: Expansion of Elastic Fluids by Heat. 
measure of the increments of heat; if it: be, 
the hypothesis fails; but if equal increments 
of heat cause a greater expansion in mercury 
in the higher than in the lower epabe 
and that in a small degree, the fact noticed 
above instead’ of being an objection will a 
roborate’ the hypothesis.—Dr. Crawford deters 
mines thé expansions’ of mercury to! be very 
nearly‘in proportion to the increments of heat; 
M. De Luc. makes oe to be less for a given 
quantity of heat in the lower than in the higher 
part. of the scale; and in a ratio that agree 
with this hypothesis, Now as every other liquid 
we are acquainted with is found to_expand more 
in the higher than im the lower, temperatures ; 
analogy is in favour of the conclusions of De 
Luc,. that. mereury dogs the same. ye ‘ 
Q Q © » > o 
EXPLANATION OF THE PLATE 
3 + - A. % ~ ry : O° *”) 
_ The annexed plate is intended to illustrate the author "9 
ecnception of. the €onstitution of the atmosphere’ ii 
different marks or characters of the’ iparticles’ of the ga 
are merely arbitrary, and intended for distinctions, = 
i 
| 
: 
} 
| 
simple atmospheres are given nearly on'their real densities, 
and the particles are arranged at equal distances from eac 
other. to the compound atmosphere the same arrangemen 
is madd of each kind of particles as. in the simple ; Bae the 
particlés of differént kinds do not arrange, at réguibt 
distances from each others because: it is supposed they 
do not repel eachother," 
