The different state of dryness of the air appears thus to be of a greater moment than the difference of temperature, and this is the reason why our sensations do not always coincide with the thermometer. You readily understand how much more difficult it is to manage one's heat-household in a hot than in a cold climate. Our means for warming ourselves are better than those for carrying off our heat. Therefore the European race has a hard fight under the equator. The working power of the body depends on a certain amount of consumption, by which a certain amount of heat is necessarily created, which has to leave the body in a regular way. The Hindoo who has to draw the European's pankha, bears the heat better in proportion as he takes less food and creates less heat in himself, but then his working-power is also quite proportionate to the total of his consumption.
The European's struggle in a hot climate and his dangers of degeneracy will remain the same as long as he has no better means of cooling himself by some or all of the known three routes. Houses with thick stone-walls are tolerably efficacious. These walls rarely get warmer than the average temperature of the year. They cool the air which comes into the house, and act on the inmates in the way we have seen when speaking of the room which is not warmed through. A good means would be some contrivance by which the air in the house could be deprived of its water.
I could not help inflicting upon you this rather long introduction, nor could I possibly abbreviate it, as, without the little knowledge which I have tried to impart to you about the cooling of the human body, you would not be enabled to obtain a proper insight into the functions of our clothing and our dwellings. Therefore I believe myself to have had a good claim on your patience and indulgence.
One of man's principal defensive weapons in his struggle for existence is his clothing. The place it takes in the history of civilization and its connection with physiology are not often thought of. People speak about it generally from a moral and aesthetic point of view, but the main purpose of clothing is seldom approached in conversation—I mean the purely hygienic one. I deem this to be a misfortune, because this forgetting of the chief point has subjected mankind to the rule of small and frivolous considerations, and the manners and fashions of the period get frequently the better of the hygienic fitness of the clothing. Morality and beauty do not depend on dress. They cannot be created or preserved by it. These great qualities could even exist without it, but the human body as it is could not, or only barely and imperfectly, exist in our climate without the protection of clothing, which is more indispensable for our health than for our beauty and morality.
So manifold are the changes brought about in our system by clothing ourselves, that I am unable to give you more than some incomplete parts of the subject.