ble intensity, to which
even the choleras of our times are mild. The back streets, the
hospitals, the gaols, the barracks, the camps--every place in which any
large number of persons congregated, were so many nests of pestilence,
engendered by uncleanliness, which denied alike the water which was drunk
and the air which was breathed; and as a single fact, of which the tables
of insurance companies assure us, the average of human life in England
has increased twenty-five per cent. since the reign of George I., owing
simply to our more rational and cleanly habits of life.

But secondly, I said that when our ancestors got on well, they did so
because they got ventilation in spite of themselves. Luckily for them,
their houses were ill-built; their doors and windows would not shut. They
had lattice-windowed houses, too; to live in one of which, as I can
testify from long experience, is as thoroughly ventilating as living in a
lantern with the horn broken out. It was because their houses were full
of draughts, and still more, in the early middle age, because they had no
glass, and stopped out the air only by a shutter at night, that they
sought for shelter rather than for fresh air, of which they sometimes had
too much; and, to escape the wind, built their houses in holes, such as
that in which the old city of Winchester stands. Shelter, I believe, as
much as the desire to be near fish in Lent, and to occupy the rich
alluvium of the valleys, made the monks of Old England choose the river-
banks for the sites of their abbeys. They made a mistake therein, which,
like most mistakes, did not go unpunished. These low situations,
especially while the forests were yet thick on the hills around, were the
perennial haunts of fever and ague, produced by subtle vegetable poisons,
carried in the carbonic acid given off by rotting vegetation. So there,
again, they fell in with man's old enemy--bad air.

Still, as long as the doors and windows did not shut, some free
circulation of air remained. But now, our doors and windows shut only
too tight. We have plate-glass instead of lattices; and we have replaced
the draughty and smoky, but really wholesome open chimney, with its wide
corners and settles, by narrow registers, and even by stoves. We have
done all we can, in fact, to seal ourselves up hermetically from the
outer air, and to breathe our own breaths over and over again; and we pay
the penalty of it in a thousand ways unkn