We hear of the lean condition in which the poor bears emerge from their six months' wintering, during which they subsist on the fat which they have acquired the previous summer. Even so, in our long winters, multitudes of delicate people subsist on the daily waning strength which they acquired in the season when windows and doors were open, and fresh air was a constant luxury. No wonder we hear of spring fever and spring biliousness, and have thousands of nostrums for clearing the blood in the spring. All these things are the pantings and palpitations of a system run down under slow poison, unable to get a step farther. Better, far better, the old houses of the olden time, with their great roaring fires, and their bedrooms where the snow came in and the wintry winds whistled. Then, to be sure, you froze your back while you burned your face; your water froze nightly in your pitcher; your breath congealed in ice-wreaths on the blankets; and you could write your name on the pretty snow-wreath that had sifted in through the window-cracks. But you woke full of life and vigor,--you looked out into the whirling snowstorms without a shiver, and thought nothing of plunging through drifts as high as your head on your daily way to school. You jingled in sleighs, you snowballed, you lived in snow like a snowbird, and your blood coursed and tingled, in full tide of good, merry, real life, through your veins,--none of the slow-creeping, black blood which clogs the brain and lies like a weight on the vital wheels! "Mercy upon us, papa!" said Jenny, "I hope we need not go back to such houses?" "No, my dear," I replied. "I only said that such houses were better than those which are all winter closed by double windows and burnt-out air-tight stoves." * * * * * The perfect house is one in which there is a constant escape of every foul and vitiated particle of air through one opening, while a constant supply of fresh outdoor air is admitted by another. In winter, this outdoor air must pass through some process by which it is brought up to a temperate warmth. Take a single room, and suppose on one side a current of outdoor air which has been warmed by passing through the air chamber of a modern furnace. Its temperature need not be above sixty-five,--it answers breathing purposes better at that. On the other side of the room let there be an open wood or coal fire. One cannot conceive the purposes of warmth and ventilation more perfectly combined.