Dr. Eajon on the AJcent of Vapour. 397 
weather, even when the thermometer is below 
the freezing point ? Though I cannot allow of 
fuch a folution as above mentioned, I can, 
however, readily admit of a ftrong attraftion 
betwixt air and water; for no air is found with¬ 
out water, and no water without air. 
Water, which is eight hundred times heavier 
than air, by a very fmall degree of heat, may be 
converted into vapour, which vapour is one 
thoufand eight hundred times lighter than air, 
according to Mr. Watt. It confcquently follows, 
that vapour will rife up in the atmofphere, to 
the height of its own fpecific gravity; but, long 
before it could reach to fo high a region, it would 
be condenfed by cold, and return to the earth 
in rain, were it not for the latent heat* it con¬ 
tains, and the ele&ric matter in the air. 
Whatever I mention concerning Eleflricity, 
is from fadls, and not from any theory, written 
about it, which is above my comprehenfion. But 
as the terms now in ufe, viz. pofkive and 
negative, or plus and minus, are generally belt 
underftood, I fhall exprefs myfelf by them. 
* That heat enters into vapour, and becomes an ingre* 
dient in it, is certain. For example : if we diftil a pound 
of fleam, the water in the refrigeratory will be heated by 
it, as much as by a pound of water heated one thoufand 
and twelve degrees; fo eight hundred degrees of heat 
appear, though the fleam is not fenfibly hotter than boil¬ 
ing water, which is two hundred and twelve. £xj>. 
The 
