PLATE XXXIII.
1. BORO NECKLACE MADE OF MARMOSET TEETH
2. ANDOKE NECKLACE OF HUMAN TEETH
The Indians look upon geophagy as injurious, but it appears to be ineradicable. I cannot help thinking it must be due to some great “want” in Indian diet, a physical craving that the ordinary food of the tribes does not satisfy. It is instinctive. In the manufacture of coca they add clay. This suggests that if taken in small quantities it may have a neutralising and therefore a beneficial effect on some more or less injurious article of daily food. But it rapidly, and invariably, degenerates into a vice; and the habit appears to have a weakening and wasting effect on the whole body.
In some parts of the Amazons, though not with these tribes, the clay is regularly prepared for use,[162] and the vice is shared by other races than the Indian.[163] Children who suffer from this extraordinary craving will swallow anything of a similar character, earth, wax, and Bates even mentions pitch,[164] but they prefer the clay that is scraped from under the spot where the fire has been burning, probably because the chemical processes induced by the heat render it more soluble, easily pulverised, and hence more actually digestive in its action.
It has been suggested that this disease was introduced into America by negro slaves, and is not indigenous. This is a question for the bacteriological expert rather than the traveller to decide, but as it indubitably exists among tribes that have not come in any contact with negroes or negro-influenced natives it would seem to argue on the face of things that the similarity of vicious tastes was due to similarity of causation, rather than to contamination by evil example, unless the ubiquitous microbe is to be held responsible for this ill also.