The erratic Brown-Sequard pounded and hammered away for more than thirty years on the importance to life of the adrenal glands, since death occurred so quickly after their removal.  But it was not until Schaefer, the Scotch physiologist, (who has done more than any other living man to stimulate study of the internal secretions) found that an extract of them, when injected into a vein, produced a remarkable though temporary rise of the blood pressure, that a real enthusiasm for its investigation was generated.  As the upshot, a number of other significant properties besides the first of blood-pressure raising, have been put down to its credit.  Chemical tests demonstrated that it originated in the medulla.  The exact amount of it present in the medulla, in the blood issuing from the adrenals and in the circulation in general have been determined.  The concentration in the blood is about one part in twenty million, while there is about a hundred thousand times as much stored in the gland as reserve.  In infections and intoxications, after muscular exertion, and with profound emotions, there is a decrease of it in the gland and an increase in the blood.  Pain and excitement, especially fear and rage, will bring about its discharge from the gland.  With its entry into the blood, there is a tremendous heightening of the tone, a tensing, of the nervous system.  The nerve cells become more sensitive to stimuli, more sugar is poured into the blood from the liver, more red blood corpuscles are squeezed into the circulation from the blood lakes of the liver and spleen.  There is a redistribution of the whole blood mass, a good deal of it being withdrawn from the internal viscera, and hurried to the skeleton muscles and the brain.  The heart beats more strongly, the eye sees more clearly, the ear hears more distinctly, and the breathing is more rapid.  The temperature rises, the hair of the head and the body becomes erect, the skin gets moist and greasy.  It will help a fatigued muscle to regain its normal tone.  In short, it has a reinforcing action upon the nutritive properties of the blood, the tone of the muscles, and the activity of the brain and the vegetative nerves.

Chemists set themselves the task of discovering just what was the substance possessed of such extraordinary and hitherto unimagined properties.  The pure adrenalin was isolated, capable of evoking all the reactions of the impure adrenal extract mixtures.  The final triumph was the preparation of it artificially in the laboratory, its synthesis.  When a substance can be synthesized in the chemist’s laboratory, it means that its composition has become thoroughly understood.  Here at last was an example of those mysterious internal secretions, the existence of which had indeed been postulated and proven, but which had never actually been inspected by the eye of mortal man.  To have it in a test-tube, indeed to possess it in large quantities in bottles, to be able to manipulate and examine it without fear of the co-action of admixed impurities, to see it with the eye, and to taste it with the tongue, was truly a marvel.  The miracle aroused at once scores of researches.