AIR.

65

and wide, that the air may have a free current through them.They ought likewise to be kept very clean. Nothing tendsmore to pollute and contaminate the air of a city than dirtystreets.

It is very common in this country to have church-yards inthe middle of populous cities. Whether this be the effect ofancient superstition, or owing to the'increase of such towns,is a matter of no consequence. Whatever gave rise to thecustom, it is a bad one. It is* habit alone which reconcilesus to these things ; by means of which the most ridiculous,nay, pernicious customs, often become sacred. Certain it is,that thousands of putrid carcasses, so near the surface of theearth, in a place where the air is confined, cannot fail to taintit ; and that such air, when breathed into the lungs, mustoccasion diseases.

Wherever air stagnates long, it becomes unwholesome.Hence the unhappy persons confined in jails not only con-tract malignant fevers themselves, but often communicatethem to others. Nor are many of the holes, for we cannotcall them houses, possessed by the poor in great towns, muchbetter than jails. These low dirty habitations are the verylurking places of bad air and contagious diseases. Such aslive in them seldom enjoy good health ; and their childrencommonly die young. In the choice of a house, those whohave it in their power ought always to pay the greatest at-tention to free open air.

The various methods which luxury has invented to makehouses close and warm, contribute not a little to render themunwholesome. No house can be wholesome unless the airhas a free passage through it. For which reason housesought daily to be ventilated by opening opposite windows,and admitting a current of fresh air into every room. Beds,instead of being made up as soon as people rise out of them,ought to be turned down and exposed to the fresh air fromthe open windows through the day. This would expel anynoxious vapor, and could not fail to promote the health ofthe inhabitants.

In hospitals, jails, ships, &c. where that cannot be con-veniently done, ventilators should be vised. The method ofexpelling foul, and introducing fresh air, by means of vendlatorss is a most salutary invention, and is indeed the mostuseful of all our modern medical improvements. It is capable6* E