And herein it is that medical skill is needful in this dreadful disease, and ought to be frequently and largely invoked. If the estimate which has been made by Prof. Hooker, of Yale College, that one in five of the population of the northern United States die of consumption, is correct, then not less than two millions of the present inhabitants of New England, New York, Pennsylvania, and Ohio, are destined, as things now are, to die of this disease. What a thought! Can it be so? Can it be that two millions of the ten millions now on the stage of action in the northern United States, are not only _predisposed_ to droop and die, but are laid under a constitutional necessity of so doing? Must the igniting spark be applied? Must the disease be "touched off" with hot or impure air, by hard colds, by excitements of body and mind, and in a thousand and one other ways? People are not wholly ignorant on this great subject. Would they but _do_ as well as they _know_, the fatal igniting spark would be much oftener and longer withheld; and, indeed, in many instances, would never prove the immediate cause of dissolution. The lamp of life would burn on--_sometimes, it may be, rather feebly_--till its oil was wholly exhausted, as it always ought. Man has no more occasion, as a matter of necessity, to die of consumption, than the lamp or the candle. This, if true,--and is it not?--should be most welcome intelligence in a country where, at some seasons and in particular localities, one-fourth of all who die, perish of this disease. In March, 1856, twenty-one persons out of eighty who died in Boston in a single week, were reported as having died of consumption; and in June of the same year, the proportion was nearly as great. In Newton, a few miles from Boston, the proportion for the last ten years has been also about one in four. But place the proportion for the whole northern United States, at one in five only, or even one in six. Yet even at this rate, the annual mortality for New York or New England, must be about twelve or fourteen thousand. Yet it seems to excite little if any surprise. But when or where has the cholera, the yellow fever, or the plague depopulated a country of three millions of people, for each succeeding year, at the rate of twelve thousand annually, or one hundred and twenty thousand every ten years?