in the Atlantic States of North America. 113 
which has been in contact with water, can neither be cooled 
nor rarefied, without being rendered cloudy by the precipie 
tation of aqueous particles. It follows, that the air displaced 
suddenly from the surface of the Gulf of Mexico, by the in-. 
flux of cold air from the north-east, never rises higher than the 
elevation mentioned by Humboldt as infested by clouds. Of 
course it never crosses the table land, which, at the lowest, is 
2000 feet higher. 
Our north-western winds are produced, no doubt, by the 
accumulation of warm moist air upon the surface of the ocean, 
as those from the north-east are by its accumulation on the 
Gulfof Mexico. But in the case of the Atlantic, there are no 
mountains to roll back upon our hemisphere the air displaced 
by the gales which proceed from it, and to impede the im- 
pulse, thus received, from reaching the eastern continent. Our 
own mountains may procrastinate the flood, and consequently 
render it more lasting and violent, when it can no longer be 
restrained. The direction of the wind is naturally at right 
angles to the boundary of the aquatic region producing it, and 
to the mountainous barrier which delays the crisis. af 
The course of the North American coast is, like that of its _ 
mountains, from north-east to south-west; and the gales in, 
question are always nearly north-west, or at right angles to , 
the mountains and the coast. The dryness of our north-west 
wind may be ascribed not only to its coming from. the frozen | 
zone, where cold deprives the air of moisture, but likewise to 
the circumstance above suggested, that the air of the ocean is 
not, like that of the Gulf, forced back over our heads to deluge 
us with rain. “ 
Other important applications may be made of our chemical 
knowledge. Thus, in the immense capacity of water for heat, 
especially when vaporized, we see a great magazine of nature 
provided for mitigating the severity of the winter—To cool 
this fluid, a much greater quantity of matter must sustain a 
proportionable increase of its sensible heat—Aqueous vapour 
is incessantly a vehicle for conveying the caloric of warmer 
climates to colder ones. Mistaking the effect for the cause, 
snow is considered as producing cold, by the ignorant; but it 
has been proved, that as much heat is given out during the 
condensation of aqueous vapour as would raise twice its weight 
of glass to a red heat. Water, in condensing from the aéri- 
form state, will raise ten times its weight one hundred degrees. 
The quantum of caloric which can raise ten parts one hun- 
dred degrees, would raise one part one thousand degrees nearly 
(or to a red heat visible in the day); and this is independent 
of the caloric of fluidity, which would increase the result. 
Vol. 67. No. 334. Feb. 1826. i Further, 
