Page:Notes on the State of Virginia (1853).djvu/181

Rh also on pavements of brick or stone. 4. It is more copious in proportion as the walls are thicker; the reverse of which ought to be the case, if this hypothesis were just. If cold water be poured into a vessel of stone, or glass, a dew forms instantly on the outside; but if it be poured into a vessel of wood, there is no such appearance. It is not supposed, in the first case, that the water has exuded through the glass, but that it is precipitated from the circumambient air; as the humid particles of vapor, passing from the boiler of an alembic through its refrigerant, are precipitated from the air, in which they were suspended, on the internal surface of the refrigerant. Walls of brick or stone act as the refrigerant in this instance. They are sufficiently cold to condense and precipitate the moisture suspended in the air of the room, when it is heavily charged therewith. But walls of wood are not so. The question then is, whether air in which this moisture is left floating, or that which is deprived of it, be most wholesome? In both cases the remedy is easy. A little fire kindled in the room, whenever the air is damp, prevents the precipitation on the walls; and this practice, found healthy in the warmest as well as coldest seasons, is as necessary in a wooden as in a stone or a brick house. I do not mean to say that the rain never penetrates through walls of brick. On the contrary, I have seen instances of it. But with us it is only through the Northern and Eastern walls of the house, after a northeasterly storm, these being the only ones which continue long enough to force through the walls. This, however, happens too rarely to give a just character of unwholesomeness to such houses. In a house, the walls of which are of well-burnt brick and good mortar, I have seen the rain penetrate through but twice in a dozen or fifteen years. The inhabitants of Europe, who dwell chiefly in houses of stone or brick, are surely as healthy as those of Virginia. These houses have the advantage, too, of being warmer in Winter and cooler in Summer than those of wood; of being cheaper in their first construction, where lime is convenient, and infinitely more durable. The latter consideration renders it of