(Discusses the subjects of breathing and ventilation, clothing, bathing and sleep.) In discussing the question of health, we have given the greater part of the space to the subject of diet, for the reason that experience has convinced us that diet is two-thirds of health, and that nearly always in disease you find errors of diet playing a part. There are, however, other important factors of health, now to be discussed.
Everything of which the body makes use is taken in the form of food and drink, with the exception of one substance, the oxygen we get out of the air. Every time we draw a breath we take in a certain amount of oxygen, and every time we expel a breath, we drive out a certain amount of a gas called carbon dioxide, which is what the body makes of the fuel it burns. The body can get along for several days without water, and for two or three months without food, but it can only get along for two or three minutes without oxygen. It should be obvious that when the body expels carbon dioxide, with a slight mixture of other more poisonous gases, and sucks back what it expects will be a fresh supply of oxygen, it wants to get oxygen, and not the same gases it has just expelled, nor gases which have been expelled from the lungs of other people.
In the days when primitive man lived outdoors, he did not have to think about this problem. When he breathed poison from his lungs, the moving air of nature blew it away, and the infinite vegetation of nature took the carbon dioxide and turned it back into oxygen. And even when man built himself shelters, he was not cunning enough to make them air-tight; he had to leave a big hole for the smoke to get out, and smaller holes through which to get light. But now our wonderful civilization has solved these problems; we make our walls of air-tight plaster, and we have invented a substance which will admit light without admitting air. So we have the "white plague" of tuberculosis, and so we have innumerable minor plagues of coughs and colds and sore throats.
In the summer time the solution of the problem is easy. Have as many doors and windows in your home as possible, and keep them open, and have nothing in your home to make dust or to retain dust. But then comes stormy and cold weather, and you have to close your doors and windows, and keep your home at a higher temperature than the air outside. How shall you do this, and at the same time get a continual supply of fresh air?
I will take the various methods of heating one by one. The problem in each case is simple and can be made clear in a sentence or two.
First, the open fireplace. This is a perfect solution, if you have enough fuel, and do not have to worry about the waste of heat. An open fireplace draws out all the air in the room in a short time, and you do not have to bother about opening doors or windows; you may be sure that the air is getting in through some cracks, or else the fire would not burn.
Second, a wood or coal or gas stove in the room, provided with a proper vent, so that all the gases of combustion are drawn up the chimney. This changes the air more slowly than an open fireplace, but it does the work fairly well. All that you have to be careful about is that your vent is sufficiently large and is working properly. If your fire does not "draw," you will have smoke or coal-gas in the house, and this is bad for the lungs; but worse for the lungs is a gas that you can neither see nor smell nor taste, the deadly carbon monoxide. This gas is produced by incomplete combustion, and whenever you see yellow flames from gas or coal, you are apt to have this poisonous substance. Small quantities of it are sufficient to cause violent headaches, and repeated doses of it are fatal. Men who work in garages which are not properly ventilated run this risk all the time, because carbon monoxide is one of the products of imperfect combustion in the gas engine.
Next, the furnace. A furnace sends fresh warm air into your house; the only trouble is that it takes out all the moisture, and some authorities say that this is bad for the lungs and throat. I do not know whether this is true, but all furnaces are supposed to have a water chamber to supply moisture to the air, and you should keep a pan of water on every stove or radiator in your house.
Next, steam heat, which includes hot-water heating. This is one of the abominations of our civilization, and one of the methods by which our race is committing suicide. There is nothing wrong about steam heat in itself; the room is warmed in a harmless way; but the trouble is it stays warm only so long as the doors and windows are kept shut. You are in an air-tight box, and can be warm provided you do not mind being suffocated. The moment you open a door or window, you have a cold draft on your feet, and if you wish to change the air entirely you have to let out all the heat; so, of course, you never do change it entirely, but go on breathing the same air over and over, and every time you breathe it the condition of your body is a little more reduced.
The solution of this problem is not to heat the air in the room, but to use your steam coils to heat fresh air, and then drive this air, already warmed, into the room, at the same time providing a vent through which the old air can be pushed out. This is the hot air system of heating, and it requires some kind of engine or dynamo, and therefore is expensive. It has been installed in a few office buildings and theaters. One of the most perfect systems I ever inspected is in the building of the New York Stock Exchange, where the air is warmed in winter, and cooled in summer, and freed from dust, and exactly the right quantity is supplied. It is a humorous commentary upon our civilization that we take perfect care of the breathing apparatus of our stock-gamblers, but pay no attention to the breathing apparatus of our senators and congressmen, whose one business in life is to use their lungs. The stately old building with its white marble domes looks impressive in moving pictures and on illustrated postcards, but it has no system of ventilation whatever, and is a death-trap to the poor wretches who are compelled to spend their days, and sometimes their nights, within its walls. This contrast is one symptom of the rise of industrial capitalism and the collapse of political democracy.
We have reserved to the last a method of heating which is the worst, and can only be described as a crime against health: the use of gas and oil stoves set out in the middle of the room, without a vent, and discharging their fumes into the room. These stoves are simply instruments of slow death, and their manufacture should be prohibited by law. In the meantime, what you have to do is to refuse to live in a room or to work in an office where such stoves are used. I have heard dealers insist that this or the other kind of gas or oil stove was so contrived as to consume all the fumes. Do not let anybody fool you with such nonsense. There has never been any form of combustion devised which consumes all the fumes. No such thing can be, because the products of combustion are not combustible. The so-called "wickless blue flame" stoves do burn all the oil, and a properly regulated gas stove will burn all the gas, but that simply means that it turns the oil and gas into carbon dioxide, the very substance which your lungs are working day and night to get out of your body.
Moreover, there is no oil or gas stove which ever burns perfectly all the time, either because there is too much gas or insufficient air. Oil and gas stoves sometimes give a partly yellow flame. You can cause them to give a yellow flame at any time by blowing air against them, and that yellow flame means imperfect combustion, and a probability of the deadly carbon monoxide. These facts are known to every chemist and to every student of hygiene, and the fact t............