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[163] 
tity of vapours carried up, and the degrees of heat 
in the upper parts of the atmofphere ; for the vapours 
will always afcend, till they meet with air fo cold, or 
fo thin, that it is not able to keep didolved all that 
comes up; hence clouds are generally higher in 
fummer than in winter. When clouds are much 
increafed^ by a continued addition of vapours, and 
their particles are driven clofe together by the force 
of the winds, they will run into drops heavy enough 
to fall down in rain ; fometimes the clouds arc fro- 
zen before their particles are gathered into drops, and 
then fmall pieces of them, being condenfed and 
made heavier by the cold, fall down in thin flakes 
oi f now y which appear to be fragments of a frozen 
cloud. But if the particles be formed into drops 
before they are frozen, they fall down in hail-Jiones. 
When the air is replete with vapours, and a cold 
bieezc fprings up, which it often does from the fea, 
the folution^ of thefe vapours is checked, and clouds 
are formed in the lower parts of the atmofphere, and 
compofe what we call a 7nijl or Jog, This generally 
happens in a cold morning; but when the fun has 
been up for fome time, the warm air again dilTolves 
thofe watery particles, and it frequently clears up. 
In a hot fummer’s day, the air lying over wet 
marfliy ground, is copioufly faturated with aqueous 
Vapours ; but the air growing cooler after fun-fet, 
will not be able to keep all thofe vapours diflblved, 
but mufl: let fome part of them coalefce into very 
fmall vifible particles, that form thofe fnijis^ which 
appear to rife from marfliy grounds in a fummer’s 
evening. The vapours near the ground, being more 
denfe and copious, will be firfl; affected by the cold, 
Y 2 and 
