CHAPTER LVII. HOT HOUSES AND CONSUMPTION. If any individual in the wide world needs to breathe the pure atmospheric mixture of the Most High,--I mean a compound of gases, consisting, essentially, of about twenty parts of oxygen and eighty of nitrogen,--it is the consumptive person. Mr. Thackrah, a foreign writer on health, says, "That though we are eating animals, we are breathing animals much more; for we subsist more on air than we do on food and drink." And yet I know of no class of people, who, as a class, breathe other mixtures, and all sorts of impurities, more than our consumptive people. First, their employments are very apt to be sedentary. Under the impression that their constitutions are not equal to the servitude of out-of-door work, agricultural or mechanical, they are employed, more generally, within doors. They are very often students; for they usually have active, not to say brilliant minds. And persons who stay in the house, whether for the sake of study or anything else, are exceedingly apt to breathe more or less of impure air. Secondly, it is thought by many that since consumptive people are feeble, they ought to be kept very warm. Now I have no disposition to defend the custom of going permanently chilly, in the case of any individual, however strong and healthy he may be; for it is most certainly, in the end, greatly debilitating. It would be worse than idle--it would be wicked--for consumptive people to go about shivering, day after day, since it would most rapidly and unequivocally accelerate their destruction. And yet, every degree of atmospheric heat, whether it is applied to the internal surface of the lungs through the medium of atmospheric air, or externally to the skin, is quite as injurious as habitual cold; and this in two ways: First, it weakens the internal power to generate heat, which, no doubt, resides very largely in the lungs. Secondly, it takes from them a part of that oxygen or vital air which they would otherwise inhale, and gives them in return a proportional quantity of carbonic acid gas, which, except in the very small proportion in which the Author of nature has commingled it with the oxygen and nitrogen of the atmosphere, is, to every individual, in effect, a rank poison. Hence it is that those who have feeble lungs, or whose ancestors had, should pay much attention to the quality of the air they breathe, especially its temperature. And this they should do, not only for the _sake_ of its temperature, but also for the sake of its purity. Such a caution is always needful; but its necessity is increased in proportion to the feebleness of the lungs and their tendency to suppuration, bleeding, etc.