All large cities and towns have their best districts in the West;[38]
which choice the French _savans_, Pelouze, Pouillet, Boussingault, and
Elie de Beaumont, attribute to the law of atmospheric pressure. “When,”
say they, “the barometric column rises, smoke and pernicious emanations
rapidly evaporate in space.” On the contrary, smoke and noxious vapours
remain in apartments, and on the surface of the soil. Now, of all
winds, that which causes the greatest ascension of the barometric
column is the east; and that which lowers it most is the west. When the
latter blows, it carries with it to the eastern parts of the town all
the deleterious gases from the west; and thus the inhabitants of the
east have to support their own smoke and miasma, and those brought by
western winds. When, on the contrary, the east wind blows, it purifies
the air by causing to ascend the pernicious emanations which it cannot
drive to the west. Consequently, the inhabitants of the west receive
pure air, from whatever part of the horizon it may arrive; and as the
west winds are most prevalent, they are the first to receive the air
pure, and as it arrives from the country.