It is impossible to over-estimate the importance of the influence exercised on the human system by the temperature of the climate in which we live, both in and out of doors, and by the ventilation and drainage, or the want of ventilation and drainage of the dwellings in which we live.

A moderately dry air is usually the most healthy; and, if the temperature is moderate, is most grateful to the feelings; whereas, a damp atmosphere, particularly if accompanied by an easterly or north-easterly wind, is very trying to the system, particularly to persons who possess a sensitive skin, or are liable to attacks of coughs and colds. It was long supposed that severe weather in winter was the most healthy, and so satisfied was the popular opinion on this point that "A green Christmas, a fat Churchyard," had become a common proverb in England. Since the collection of health statistics, however, by the Registrar General, all this has been found to be a mistake, the greatest number of deaths occurring in Winter, next in Spring, then Autumn, and the fewest of all in Summer. And, as far as observations have been made in Canada, and the Northern States of America, the same rule holds good.

There can be no health without pure air. It is wonderful how little attention is paid to this circumstance, even by many whose means will allow of their adopting any measure that health or comfort may render necessary. In fact, in thousands of instan-ces,the possession of increased means seems to have led to diminished health. Five and twenty years ago most of the country houses in Canada, whether log or frame, were built with large open lire-places; stoves were scarce; and a roaring wood fire not only kept the room warm and dried the atmosphere, but the draft caused thereby effectually ventilated the building, and carried up the chimney any wandering vapours and unwholesome smells. Of late years, however, this is very much changed; log houses and open fire-places in the country have almost disappeared: the latter being replaced by stoves,-frequently far too large for the rooms they are intended to warm. The houses themselves being built very much tighter than formerly, there is little draft. Persons accustomed to sit many hours a day in these hot, tight rooms, soon get accustomed to them, and feel chilly when the door is opened, and a rush of cool, fresh air is admitted; but a person coming from the open air feels the room hot, unpleasant, close and suffocating. People living in these hot, close rooms soon begin to suffer in health. The skin becomes dry and yellow, and no one can have helped noticing how wonderfully prevalent neuralgic pains in the head and face have become in Canada within the last few years, mainly caused by exposure to the intense heat of stoves, and that varied by an equal exposure to the biting influence of cold winds without proper protection. A winter or two since, a fine healthy young man called on me, complaining of intense pain in his head and jaws; he fancied it was toothache, and was anxious to have two or three teeth extracted. On investigating the matter, I found he was occupied all day in the woods, in getting out timber, and, as long as he was in the open air, he suffered no inconvenience from this unpleasant visitor; but, when he returned home in the evening, as soon as he got into the hot room, the attack came on, sometimes keeping him awake a good part of the night. Of course, in such a case as this, Losing the teeth would not remove the complaint.

Compositors in printing offices, Living in close, hot rooms, suffer much therefrom. and many of them have their lives sadly shortened in consequence. Many of our school rooms and other public buildings are badly ventilated,;and when these are also over-crowded, as frequently happens, the health of those who are compelled to frequent them suffers accordingly. At the very moment I am writing this, one of our Canadian judges is laid up, and unable to attend to his duties, from the effect of exposure to the foul influences of an unwholesome atmosphere while presiding at the Assizes in one of our Court-houses.

One of the medical practitioners in India, writing of the influence of over-crowding in producing Cholera, says: "The disease commits its greatest ravages in crowded ill-ventilated barracks, bazaars, densely populated towns, crowded school-rooms, native huts-into which there is but one opening, and that closed at night. Whole families are sometimes swept away from exposure to this exciting cause. At Juggernaut it is an annual visitant. The town of Pooree contains 35,000 inhabitants, and the number of pilgrims sometimes amounts to 150,000. The inhabitants are usually quite healthy before the occurrence of the festival, which takes place in June or July. But immediately on the arrival of the pilgrims, and when the lodging-houses are literally crammed with inmates, cholera suddenly breaks out, and in the space of a few days, hundreds are cut off." "This," he adds, "is not an occasional or incidental occurrence; it is an invariable one; and the disease which has thus been generated as suddenly disappears on the dispersion of the crowd."

In warming houses, many people make a strange, and unfortunately a very serious mistake. Some years since, some crochetty genius propounded the doctrine that a building should be heated from the ceiling downwards, instead of from the floor upwards, unmindful of the fact that heat ascends, and that it will ascend, in spite of you, and also oblivious of the good old maxim, "keep the feet warm and the head cool." This individual, whoever he was, has had too many followers, and it is quite common now to enter a room, where the stove is not only too large for the space it is intended to warm, but the stove is even surmounted with a large drum, on a level with a person's head when sitting down. The consequence is that the air near the floor is cold, and about the upper part of the room fearfully hot; the natural result to those sitting in such rooms is cold feet and hot heads, followed frequently by colds, coughs, headache, neuralgia, fevers, loss of teeth, and various other disorders. There can be no health without plenty of fresh air, and also plenty of daylight.