An experiment that is often tried in operating rooms furnishes a vivid illustration of the omnipresence of these invisible, yet potent, foes of life. In order to impress upon young surgeons the importance of maintaining antiseptic conditions, they are instructed to thoroughly wash their hands and arms in antiseptic soap and water; then they are told to leave their arms exposed for a few minutes, after which a microscopic examination of the bared skin will result in exposing the presence of myriads of germs. Many of these are, of course, harmless; some are even “friendly”—since they make war upon the dangerous kinds. But others are the deadly organisms which find lodgment in the lungs and cause pneumonia and tuberculosis; or the thirty odd varieties of bacilli which cause the various kinds of grippe and influenza and “colds,” which plague the civilized man; or others which, finding entrance into the digestive tract, are the cause of typhoid and other deadly fevers.
So it appears that we live within our bodies somewhat in the same fashion as isolated barons lived in their castles in the Dark Ages, beleaguered constantly by hordes of enemies that are bent upon our destruction—these being billions upon billions of disease germs. Every portion of the body has its defenses to protect it against these swarms. The skin is germ-tight in health; and each of the gateways to the interior of the body has its own peculiar guard—tears, wax, mucous membrane, etc. As Dr. Edward A. Ayers points out,—“Many of these entrances are lined with out-sweeping brooms—fine hairs similar to the ‘nap’ or ‘pile’ of carpet or plush—which constantly sweep back and forth like wheat stalks waving in the breeze. You cannot see them with the low-powered eye, but neither can you see the germs. They sweep the mucous from lungs and throat, and try to keep the ventilators free from dust and germs. Behind the scurf wall and the broom brigade of the mucous membranes, the soldier corpuscles of the blood march around the entire fortress every twenty-eight seconds” (the time occupied by the blood in its circulation through the body).
HEALTHY BODIES ARE GERM-PROOF
And again (to quote another authority, Dr. Sadler), “All the fluids and secretions of the body are more or less germicidal. The saliva, being alkaline, discourages the growth of germs requiring an acid medium. The normal gastric juice of a healthy stomach is a sure germ-killer. In the early part of digestion, lactic acid is present, and there soon appears the powerful hydrochloric acid, which is a most efficient germicide....
“The living, healthy tissues of the body are all more or less germicidal; that is, they are endowed with certain protective properties against germs and disease. This is true of many of the other special secretions, like those found in the eye and elsewhere in the body, when they are normal. The blood and lymph, the two great circulating fluids of the body, are likewise germicidal. In some conditions of disease, there may be found various substances in the blood which can destroy germs.”
THE WHITE CELLS ON GUARD
And this definitely brings us to the other kind of inhabitants of the human blood, the leucocytes, or white blood corpuscles,—and so to the germ theory of health, which science is showing to be no less true than the germ theory of disease. In their natural state these cells are transparent, spherical forms of the consistency of jelly drops, which float in the bloodstreams or creep along the inner surface of the vessel. Their function was for a long time not understood; the discovery of the real facts, perhaps the most epoch-making discovery ever made concerning the human body, the world owes to the genius of Metchnikoff, the head of the Pasteur Institute of Paris. These cells are the last reserves of the body in its defense against the assault of disease. Whenever, in spite of all opposition, the hostile germs find access either to the blood or to the tissue, the white cells rush to the spot, and fall upon them and devour them.
In their fight against the hordes of evil bacteria that invade the blood, where the battles are waged, the body’s defenders have four main ways of battling. Again we quote from Dr. Ayers: “The blood covers some germs with a sticky paste, and makes them adhere to one another, thereby anchoring them so that they become as helpless as flies on fly paper. The paste comes from the liquid of the blood, the plasma. Another blood-weapon (the ‘lysins’) dissolves the germs as lye does. A third means of defense is the ability of the white blood corpuscles to envelop and digest the living germs. One white cell can digest dozens of germs, but it may mean death to the devouring cells.
The fourth and recently discovered weapon, or ammunition, of the blood is the opsonins. Wright and Douglas in London in 1903 coined the word, which comes from the Latin opsono: “I cook for the table,” “I prepare pabulum for.” This is precisely what the opsonins do in the blood. They manifest this beneficial activity when invading disease germs appear. They attract white blood cells to the germs and make the bacteria more eatable for the cells. They are appetizers for the white blood cells; or sauces, which help the white blood cells to eat more of the bacteria than they could do without this spur to their hunger. Wright and Douglas demonstrated beyond peradventure the ability of the white blood cells to eat a larger number of bacteria when the latter are soaked in opsonins. They also showed that this opsonic sauce, or appetizer, which stimulates the blessed hunger of the white blood cells for disease bacteria, could be artificially produced, and hypodermically introduced into a patient’s blood, thus increasing that blood’s power of defense by raising the quantity of opsonins. They also worked out a practical laboratory technique by means of which the opsonins can be measured, or counted, with a considerable degree of exactitude, thereby making it possible to estimate within limits of accuracy any one’s ability to resist bacterial invasions. If the blood is rich in opsonins, its power to fight disease is strong. Opsonins are now inoculated into the blood at several institutions, notably McGill University in Montreal, and at the Battle Creek Sanitarium.