light, and there is a marked distension of the pupil. I
have also observed this peculiarity of the eye in one who had drunk a
strong extract of the infusion of coca leaves. In the effects
consequent on the use of opium and coca there is this distinction,
that coca, when taken even in the utmost excess, never causes a total
alienation of the mental powers or induces sleep; but, like opium, it
excites the sensibility of the brain, and the repeated excitement,
occasioned by its intemperate use after a series of years, wears out
mental vigor and activity.

It is a well known fact, confirmed by long observation and experience,
that the Indians who regularly masticate coca require but little food,
and, nevertheless, go through excessive labor with apparent ease. They,
therefore, ascribe the most extraordinary qualities to the coca, and
even believe that it might be made entirely a substitute for food.
Setting aside all extravagant and visionary notions on the subject, I am
clearly of opinion that the moderate use of coca is not merely
innoxious, but that it may even be very conducive to health. In support
of this conclusion, I may refer to the numerous examples of longevity
among Indians who, almost from the age of boyhood, have been
in the habit of masticating coca three times a day, and who in the
course of their lives have consumed no less than two thousand seven
hundred pounds, yet, nevertheless, enjoy perfect health.[99] The food of
the Indians consists almost exclusively of vegetable substances,
especially roasted maize and barley converted into flour by crushing,
which they eat without the admixture of any other substance. The
continued use of this farinaceous food occasions severe obstructions,
which the well known aperient qualities of the coca counteract, and many
serious diseases are thereby prevented. That the coca is in the highest
degree nutritious, is a fact beyond dispute. The incredible fatigues
endured by the Peruvian infantry, with very spare diet, but with the
regular use of coca; the laborious toil of the Indian miner, kept up,
under similar circumstances, throughout a long series of years;
certainly afford sufficient ground for attributing to the coca leaves,
not a quality of mere temporary stimulus, but a powerful nutritive
principle. Of the great power of the Indians in enduring fatigue with no
other sustenance than coca, I may here mention an example. A Cholo of
Huari, named Hatun Huamang, was employe