A handbook of invalid cooking

by Mary A. Boland

Air is the greatest or, as one writer says, the most immediate necessity of life. We could live without it only a few seconds. We constantly use it, whether sleeping or waking, and perhaps this accounts in part for the utter carelessness and indifference which most people have for the quality of that which they breathe. Even those persons who know something of the nature of air, make but little effort to provide themselves with a constantly pure supply.

Effects of Breathing Bad Air. If the effects of breathing bad air were immediate, there would then be an immediate remedy for the present total lack of any systematic means of ventilation in most houses. But the effects of breathing bad air are, like those of some slow and insidious poison, not noticeable at once, and often manifested under the name of some disease which gives no clue to the true cause.

Dr. Van Rensselaer, in the Orton Prize Essay on Impure Air and Ventilation, makes the statement that statistics show that of the causes of mortality the most important and farthest-reaching is impure air.

Amount of Air Required for one Person. Sanitarians have agreed that each individual requires at least 3000 cubic feet of air every hour. A room 10 × 15 × 20 holds 3000 cubic feet of air, which should be changed once every hour in order that one individual shall have the required amount. If three persons are in the room, it must be changed three times.

The effect of bad ventilation is well illustrated by the condition of the horses in the French army some years ago. With small close stables the mortality was 197 in every 1000 annually. The simple enlargement of the stables, and consequent increase of breathing-space, reduced the number in the course of time to 68 in every 1000, and later, from 1862 to 1866, with some attention paid to the air-supply, the number fell to 28½ per 1000.[13]

Necessity for a Constant Supply of Pure Air. When we consider that the food we eat and digest cannot nourish the body until it has been acted upon by oxygen in the lungs, and that this action must be constant, never ceasing, it will help us to understand the necessity for a constant supply of air such as shall furnish us a due proportion of the life-giving principle, oxygen, and which shall not contain impurities that interfere with its absorption.

We take into the lungs a mixture of nitrogen, oxygen, and carbonic acid. We give out a mixture which has lost some of its oxygen, and gained in carbonic acid. Now, unless the amount of oxygen is what it should be, the blood will not gain from an inspiration the amount it should receive, consequently it will be but imperfectly purified and able but imperfectly to nourish the body. So the whole system suffers, and if a person for a long time continues to breathe such an atmosphere, the condition of the body will become so reduced as to produce disease. Even though in other ways one lives wisely, all the factors of health multiplied together cannot withstand the one of impure air. We eat food three or four times daily. Some of us are very particular about its quality. We breathe air every instant of our lives, but generally we give but little consideration as to whether it is pure or impure.

Ventilation. No attempt will be made here to explain different devices for ventilation, but only to touch upon the principle it involves. Its objects are (1) to remove air which has been breathed once; (2) to remove the products of combustion, whether from fires, lamps, gas, or other sources; (3) to carry away all other substances which may be generated from any cause, in a room or building, as the impurities from manufacturing, those arising from decaying matter, and micro-organisms. In a climate where artificial warmth is necessary a part of the year, it is difficult to warm and ventilate a room at the same time, without causing unpleasant drafts; but with some knowledge of the necessity of ventilation, and of the properties of air, one may in some measure work out a scheme of ventilation adapted to the circumstances in which he finds himself.

There are always the doors and windows, which may be thrown wide open at intervals, and in many houses there are fireplaces. If a window be opened at the bottom at one side of a room, and another be opened at the top on an opposite side, a current of air will be established from the first window, passing through the room and out at the second. This plan will do very well in warm weather when the temperature outside is about the same as that of the room, but it would be impracticable in cold weather. Then we may resort to the very simple plan of placing a board about eight or ten inches wide across the window at the bottom and inside of the sash. Then when the lower half of the window is raised, a space is left between the upper and lower sashes, through which the air passes freely as it enters, and, being sent into the room in an upward direction, causes no draft. The board is for the purpose of closing the window below, and should fit quite close to the sash.