BY CHARLES KINGSLEY
Charles Kingsley (1819-1875): An English clergyman and author. Young people know him best from "Greek Heroes" and "Water Babies, a Fairy Tale for a Land Baby." "Hypatia," "Westward Ho," "Alton Locke," and "Yeast" are the most popular of his novels.
This selection is from "Health and Education," a book of simple talks on hygienicand scientific subjects.
I wish to call this talk "The Two Breaths," not merely "The Breath;" and for this reason: every time you breathe, you breathe two different breaths; you take in one, you give out another. The composition of those two breaths is different. Their effects are different. The breath which has been breathed out must not be breathed in again.
If you want to see how different the breath breathed out is from the breath taken in, you have only to try a somewhat cruel experiment, but one which people too often try upon themselves, their children, and their work-people. If you take any small animal with lungs like your own-a mouse, for instance-and force it to breathe no air but what you have breathed already; if you put it in a close box, and while you take in breath from the outer air, send out your breath through a tube into that box, the animal will soon faint; if you go onlong with this process, it will die.
Take a second instance: if you allow a child to get into the habit of sleeping with its head under the bedclothes, and thereby breathing its own breath over and over again, that child will assuredly grow pale, weak, and ill.
Take another instance, which is only too common: if you are in a crowded room, with plenty of fire and lights and company, doors and windows all shut tight, how often you feel faint-so faint, that you may require smelling-salts or some other stimulant. The cause of your faintness is just the same as that of the mouse"s fainting in the box: you and your friends, and as I shall show you presently, the fire and the candles likewise, having been all breathing each other"s breaths, over and over again, till the air has become unfit to support life. You are doing your best to enact over again the Highland tragedy, when at a Christmas meeting thirty-six persons danced all night in a small room with a low ceiling, keeping the doors and windows shut. The atmosphere of the room was noxious1 beyond deion; and the effect was, that seven of the party were soon after seized with typhus fever, of which two died.
You are inflicting on yourselves the torments of the famous Black Hole of Calcutta2; and, if there was no chimney in the room, by which some fresh air could enter, the candles would soon burn blue- as the stories tell us they do when ghosts1Noxious: hurtful; harmful; unwholesome.
2Black Hole of Calcutta: a cell in a fort at Calcutta into which one hundred and forty-six English prisoners were put; one hundred and twenty-three of whom died before morning from lack of air.
appear; your brains become disturbed; and you yourselves run the risk of becoming ghosts, and the candles of actually going out.
Of this last fact there is no doubt; for if, instead of putting a mouse into the box, you will put a lighted candle, and breathe into the tube, as before, however gently, you will in a short time put the candle out.
Now, how is this? First, what is the difference between the breath you take in and the breath you give out? And next, why has it a similar effect on animal life and a lighted candle?
The difference is this. The breath which you take in is, or ought to be, pure air, composed, on the whole, of oxygen and nitrogen, with a minute portion of carbonic acid gas.
The breath which you give out is an impure air, to which has been added, among other matters which will not support life, an excess1 of carbonic acid gas.
That this is the fact you can prove for yourselves by a simple experiment. Get a little lime water at the chemist"s, and breathe into it through a glass tube; your breath will at once make the lime water milky. The carbonic acid gas of your breath has laid hold of the lime, and made it visible as white carbonate of lime,- in plain English, as common chalk.
Now, I do not wish to load your memories with scientific terms: but I beseech you to remember at least these two- oxygen gas and carbonic acid gas; and to remember that, as surely as oxygen feeds the fire of life, so surely does carbonic acid put it out.
1 Excess: undue amount; too much.