MARVELS OF THE HUMAN MACHINE.

King Country Chronicle, Volume VI, Issue 466, 18 May 1912, Page 6

MARVELS OF THE HUMAN MACHINE.

THE WORK A MAN MAY DO.

In the course of an interesting paler, Dr. W. R. O. Latson has enterad into some interesting computations concerning the energy and fuel of, the human machine. For instance, a full-grown man should consume every day five thousand grains of bread, seven • thousand grains of milk, three thousand grains of potatoes, six hundred grains of butter, thirtythree thousand grains of water. This makes a total of food and drink equal nearly to eight pounds. The matter thus taken into the body is normally balanced by an equal quantity of waste thrown off. For the escape of this waste there are four avenues : the lungs, which throw off twenty thousand grains daily ; the skin, which excretes ten thousand grains, and the kidneys and intestines, which eliminate twentyiour thousand and twenty-six hunlred respectively. Of the water taken, the lungs and skin together carry off just about one-half, the Sidneys about forty-four per cent., and the intestines the rest.

All this means that there passes through the body within the course of a year almost a ton and a half of solid and liquid matter. The body rebuilds itself with a portion of this 2ach day, discarding a corresponding quantity of waste. Thus we see that the body is constantly changing—constantly breaking down and at the same time being rebuilt.

The body is a prodigious worker—the most compact and powerful engine known. In a single day the body of a healthy man does work equal to lifting a weight of thirtysix hundred tons one foot from the ground. A man at hard labour, a longshoreman, for instance, helping to load a ship, will do a work- of two hundred and fifty foot-tons a day. So it will be understood that the body in its general activity does the work of fourteen or fifteen men.

This is many times what any manmade engine can do.

VAST WORK OF THE HALFPOUND HEART. In order to make this more clear, let us for a moment glance at the work of the heart. The heart is nerely a hollow muscle, consisting of two pumps, one of which sends )lood to the lungs, the other pumpng blood through the tissues. Each side of the heart holds two ounces Df blood ; and as the heart contracts ibout seventy-five times a minute, this means that one hundred and fifty ounces, or about one and onesixth gallons of blood, passes through each side of the heart every minute. That is, about seventy gallons every aour,, sixteen hundred and eighty gallons every , day, six hundred and three thousand gallons in a year, is pumped by each of the ventricles .'cavities), making the total work of ;he heart for the year one million, :wo hundred and six thousand gallons. Think of the work done by the leart in ten years, in twenty, or in i lifetime ! And the heart weighs ibout half a pound. ! The stream of blood leaving the leart. travels six himcred and twenty3ne feet a minute,,- seven miles an lour, one hundred and sixty-eight miles a day, sixty-one thousand miles i year. No man ha/s ever travelled ;o far as his own "blood has. For .he blood to make tne entire double circuit from heart to lungs, then sack to the heart, thence to the -.issues, and finally back to the heart igain, requires in the adult about twenty-three seconds.

In. the smaller body of the child the circuit is made much more rapid:y, and the heart beats correspondingly fast. For instance, at birtl the heart beats at about one hundred and thirty-six. to the minute ind the blood makes its entire figureeight circuit in about twelve seconds At three years old the heart rate is Dne hundred and eight, a nd the blood stream makes its journey in about ifteen seconds ; at live the pulse is nighty-eight and the blood circuit requires eighteen rseconds.

WHAT HAPPENS WHEN YOU SOB

Nothing is more interesting than the body's method of economy. Foi instance, in its work of taking ir oxygen and throwing off carbondioxide it needs space, surface. Anc so there has been evolved a .method by which in the lungs the inhaled ail reaches a surface of sixteen hundred square feet —that as, an area equa. to the floor of -a room forty feel square. The peculiar little openings or vesicles, by which this economy o' space is gained, ar&.six hundred mil lions in number. There passes intc and out of the lungs in one- day nc less than four hunjdred cubic feet o air. Each outgoing breath contains two cubic inches of carbondioxide and contaminates live thousand cubic inches, about half a barrel, of air The lungs exhale every day ai amount of carbon that if caught anc solidified would about equal a lumi of coal weighing h.alf .a pound.

The air breathed ouir is moving a' a speed of forty-t,hree leches a sec ond, anc'. is inhaled -.at a speed o fifty-two inches -.a secomL In a sudden intsß.e of breath, as tia a sob oi gasp of surprise,, the speed ..of the inhalation may be much greater—ten. or even- twenty '.feet a second. The external .surface of the bods has an irea of about twenty square feet, aj.-d contsiins seven million minute c penings, -perspiratory glands, out thr-tugh which the blood pusheii certain of its poisonous ingredients The ski:i. has a .respiratory as well **»

to say, the skin Is a sort or auxiliary lung. Through a healthy skin we take in about one-sixth as much oxygen as through the lungs. Lastly, the body as a whole is an electric battery, producing an appreciable amount of electricity ; also a chemical laboratory separating many snbstances into their constituent elements and forming many complex and highly powerful fluids, such as gastric juice, bile and pancreatic fluid, also elaborating many chemicals, such as water, alcohol, sugar, and so on. Verily, we arc "fearfully and wonderfully made." —"Popular Science Sittings."