In 1850 Niemann discovered the active principle of the leaves of Coca, to which he gave the name of Cocaine, though, in fact, the discovery of this alkaloid should be attributed to Gardeke, who had separated it in 1855 under the name of Erythroxyline.
The work of Demarle appeared in that same year, on "The Coca of Peru"[4], in which he pointed out certain properties attributed by him to the alkaloid that the leaves of the plant contained, and which he studied. He remarked, among other things, the dilatation of the pupils, which he had noticed in his own case after having taken a dose of Coca; the absence of taste for a greater or less length of time after crushing some leaves with his teeth and letting them remain in the mouth.
Mantegazza has studied the effect of Coca and, according to this author, it acts as a stimulant on the nervous system, the respiration, and the circulation.
A dose of fifteen to twenty grammes of Coca produces an increase of the heart-beat, increasing pulse, and finally a rise in temperature. Mantegazza observed on himself that, under the influence of such a dose, his pulse increased from 65 to 124. Moreno, who repeated the same experiment, obtained similar results. The temperature and respiration are increased in the same proportion as the circulation.
The same dose, or even a weaker one, produces a remarkably stimulating effect on the nervous system. It is from this stimulating effect that Coca makes one more active and vigorous and enables those to accomplish more work who, without it, would soon be overcome with more or less fatigue. The use of larger doses (60 grammes for example) has caused intoxication, accompanied by sensation of happiness, which makes everything appear under a favorable aspect. Mantegazza, who experienced this intoxication, describes his sensations in an animated style, which recalls that of the Oriental legends: "Borne on the wings of two Coca leaves, I flew about in the spaces of 77,438 worlds, one more splendid than another. I prefer a life of ten years with Coca to one of a hundred thousand without it. It seemed to me that I was separated from the whole world, and I beheld the strangest images, most beautiful in color and in form that can be imagined."
In 1868, Moreno y Maïz made some researches into the physiological action of Cocaine, and explained them in an interesting thesis which he read before the Faculty of Paris[5].
At about the same time, Lippmann, of Strasbourg, devoted his labors to the same subject, but his investigations did not yield the same results. He says that he could not establish the anæsthetic properties of the plant.[6]
After Moreno y Maïz, Dr. Gazeau[7], in 1870, studied the stimulating effect of Coca on nutrition, and found that it increased the pulse and respiration, assisted digestion, increased urinary excretion, and strengthened the nervous system. This author arrived at the conclusion that Coca prolongs life and promotes muscular energy. He advises its use, locally, for stomatitis, gingivitis, aphthous ulceration, and generally for painful and difficult digestion, gastric disturbance in phthisis, and also for obesity.
It was Charles Fauvel who first described the anæsthetizing effect of Coca on the pharyngeal mucous membrane[8]. Thanks to this circumstance, he has been able to derive much benefit from the use of Coca in granular pharyngitis which is generally unaffected by any other kind of treatment.