LIGHT #4axp. HEAT. 5 
quitting eafily in part thofe which are; the part afumed 
and fixed remaining till the body is diffolved ? 
Is it not this fluid which keeps afunder the particles of 
air, permitting them to approach, or feparating them more 
in proportion as its quantity is diminifhed or augmented? 
. Is it not the greater gravity of the particles of air, 
which forces the particles of this fluid to mount with the 
matters to which it is attached as fmoke or vapour?’ 
Does it not feeny to havea great affinity with water, 
fince it will quit a folid to unite with that fluid, and go off 
with it in vapour; leaving the folid cold to the touch, and 
the degree meafurable by the thermometer? 
The vapour rifes attached to this fluid, but at a certain 
height they feparate, and the vapour defcends in rain re-= 
taining but little of it, in fnow or hail lefs. What be- 
comes of that fluid? Does it rife above our atmofphere, and 
mix with the univerfal mafs of the fame kind? 
Or does a fpherical fhell or ftratum of it, denfer, as lefs 
mixed with air, attracted by this globe, and repelled or 
pufhed up only to a certain height from its furface by the 
‘greater weight of air, remain there furrounding the globe. 
and proceeding with it. round the fun? 
In fuch cafe, as there may be a continuity or commu~ 
nication of this fluid through the air quite down to the 
earth, isit not by the vibrations given to it by the fun that 
light appears to us; and may it not be, that every one of 
the infinitely {mall vibrations, ftriking common matter 
with a certain force, enters its fubftance, is held there by 
attraction, and augmented by fucceeding vibrations, till 
the matter has received as much as their force can drive 
into it 
Is it not thus that the furface of this globe is continually 
heated by fuch repeated vibrations in the day, and cooled 
by the efcape of the heat when thofe vibrations are difcon- 
tinued in the night, or intercepted and reflected by clouds? 
Is 
