One Doctor’s Experience: Physiological Effects of Coca Leaf

(from) “Erythroxylon Coca” (in) “A New Form Of Nervous Disease” 1881 by W. S. Searle, MD.
Section One:
One Doctor’s Experience: Physiological Effects of Coca Leaf

The author of this paper first became acquainted with the Coca in the year 1865. In May of the following year I obtained my first specimen from Peru. It was a bale of twenty-five pounds in weight, pressed into a solid mass and covered with hide and tarred cloth. It had, however, been six months on the way, had suffered from the curiosity of the custom house, and had thus lost much of its virtue by evaporation of the volatile element. Having at that time no opportunity for exact experiment, I chewed up the majority of the bale without other effect than a lessening of appetite and some increase of physical endurance. Being quite incredulous of the stories told of the effects of the Coca, I addressed a letter of inquiry to Dr. Alexander Stewart, of Arica, Peru, and received from him the following reply:

Dear Doctor Searle: My experience with Coca extends over four years, during which period the native hospital of Arica, having a daily average of thirty-five patients, afforded me ample opportunities for observing its effects. The patients were chiefly Indians from the interior, they being the principal users of the plant. They chew the leaves, and, from their nutritive properties and power to allay hunger, they are enabled to travel day after day for three or four days without food or water. Thus they travel hundreds of miles through this arid country – water not being obtainable unless carried in calabashes. The statements set forth in Johnston’s “Chemistry of Common Life,” to which you refer, are true in almost every particular. The narcotic effect is not so prominent a feature as its power to prevent hunger, thirst, and need for sleep. I have frequently observed patients, when convalescing from fevers, using large quantities of it. It has also the power of mitigating the difficulty of breathing, haemoptysis, and drowsiness incident to traveling among the hills, 4000 feet above the sea. When going to Bolivia it was with difficulty the mule-driver could keep me awake. Only by repeated shaking could he accomplish that object, which was very necessary, as sleep under such circumstances is nearly always fatal.

It is not an astringent. It does not in any way shorten life. With regard to this point I have made every inquiry from gentlemen living in Bolivia for the past twenty years, and who have employed hundreds of these Cholos in their copper mines. They inform me that they have never seen any bad results from its use. On the contrary, natives have been found in the valleys overtaken by fever, and subsisting on it alone for several days. I have never observed that it dilated the pupils. Have given it with marked benefit in phthisis laryngea, and believe that it would prove a valuable addition to the materia medica.

Yours truly, Alexander Stewart, M.R.C.S.

Dr. Stewart also kindly forwarded to me the following letter:

Coro Coro, Peru, May 29, 1866.
Dr. Stewart :

Dear Sir : In answer to your inquiries regarding Coca, I would reply that I have resided in this place for six years. To each of our laborers we give one pound of Coca leaves weekly, and to the boys one half pound. They chew them or drink the infusion. They take away hunger and the need for sleep. A person using them may go forty-eight hours without food or sleep. Though totally unaccustomed to it, I have chewed one-quarter pound in one night, the only effect being to disperse all desire for sleep. Many workers consume two or three pounds weekly.

Yours truly, Geo. Gassett.

The perusal of these letters made it quite evident to my mind that Coca leaves as I had obtained them and Coca leaves in Peru were two quite different things, and I set myself to ascertain why this was so. From a colleague who had been in Peru I learned that my specimen, while undoubtedly genuine, as shown by the taste and smell, had to a very large extent lost its volatile properties, and with them its slightly bitter and strongly aromatic flavor. This I could well believe, since, on opening the bale in order to more carefully inclose its contents, I had noticed that the room was instantly filled with the aroma, and, although great care was taken to encase the leaves as tightly as possible, yet the daily opening of the can in which they had been placed, allowed the escape of the aroma to such an extent that the deterioration of the remainder was very rapid. So that, long before the whole had been used, the flavor was almost lost, and the leaves, from being flexible and somewhat elastic, had become very dry and brittle. I learned, too, that much more of the volatile property of the plant was lost by the very crude manner in which the leaves are cured for the market in Peru. It appears that they are picked by hand, and then spread to dry in the sun, and I am credibly informed that the effluvia which escapes from them during this process is so powerful as to produce headache in those who are exposed to it. It is evident that in this volatile property resides a large, and, perhaps, the greater portion of the especial virtue of the Coca, since specimens which have lost it are inefficient and worthless.