The amount of other elements may be set down as follows:—Chlorine, 4 ozs.; sodium, 3 ozs.; sulphur, 2½ ozs.; fluorine, 2 ozs.; potassium, 1 oz.; magnesium, 12 grs.; silicon, 2 grs.
Estimates vary, however, and, as a matter of fact, the quantities of the elements in different men are by no means the same, nor are they always from day to day the same in any one individual. But, taking the whole of these last-named substances, they probably seldom exceed three-quarters of a pound, yet the machine would come to a dead stop without them.
Without iron, for instance, the blood could not carry oxygen, as it does, from the lungs to the remotest parts of the organism. There are only 48 grains, or one-tenth of an ounce, of iron in the blood; in the whole body there is only sufficient to make four or five tacks—vital tacks, for if you took them away from the body of the strongest man he would drop dead.
Sodium and potassium are equally necessary, and so are sulphur, chlorine, and fluorine.
But the part these take in the processes of life is better seen by observing what combinations they form and what ends these combinations serve. No element exists in the body alone and separate, except, indeed, some accidental traces of oxygen, nitrogen, and a few particles of carbon breathed in by the lungs. They are all present in compounds of extraordinary complexity, mostly put together in the vegetable world, as everyone knows, by some mysterious power of the sun.
And, as was said, all the force of the body is derived from breaking these complex compounds down into simpler combinations. We don't get all the good possible out of them, for we cannot dissociate them into separate elements, because elements have a horror of living separate, and it would take something more powerful than a man's bodily organs to make them do so.
A PILE OF
144 PENCILS.
65 TIMES AS
MANY AS THESE CAN BE MADE FROM THE 21½ LBS. OF CARBON IN THE BODY.
Simple water is the most important compound of all—at least, the most abundant—consisting of hydrogen two parts, and oxygen one part. There are from 90 to 96 lbs., or say a barrel of 9½ gallons, of pure water in a ten-stone-ten man. It has a large number of uses, but the main use is rather curious.
The greater part of bone and fat is what might be called lifeless tissue. The substance that makes the body alive is protoplasm, which forms the chief bulk of muscle, brain, nerves, lungs, heart, etc. And protoplasm exists in the shape of millions of minute globules set side by side, and more or less welded together. But these could no more live out of water than could a shoal of herrings. So that, wherever in the body protoplasm is—and it is almost everywhere—not only is it submerged in water, but it actually passes its whole existence in running water.