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 rotten 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 breath our own breaths over and over again; and we pay the penalty of it in a thousand ways unknown to our ancestors, through whose rooms all the winds of heaven whistled, and who were glad enough to shelter themselves from draughts in the sitting-room by the high screen round the fire, and in the sleeping-room by the thick curtains of the four-post bedstead, which is now rapidly disappearing before a higher civilisation. We therefore absolutely require to make for ourselves the very ventilation from which our ancestors tried to escape. But, ladies, there is an old and true proverb, that you may bring a horse to the water, but you cannot make him drink. And in like wise it is too true, that you may bring people to the fresh air, but you cannot make them breath it. Their own folly, or the folly of their parents and educators, prevents their lungs being duly filled and duly emptied. Therefore the blood is not duly oxygenated, and the whole system goes wrong. Paleness, weakness, consumption, scrofula, and too many other ailments, are the consequences of ill-filled lungs. For without well-filled lungs, robust health is impossible.