158 STEPPES AND DESERTS. 



be mixed with it, we heard absolutely nothing during our stay in 

 Uruana. The earth which we brought back with us, and which 

 Vauquelin analyzed, is thoroughly pure and unmixed. May Gumilla ; 

 by a confusion of things wholly distinct, have been alluding to the 

 preparation of bread from the long pod of a kind of Inga, which is 

 previously buried in the earth in order to hasten the commencement 

 of the first stage of decay ? That the health of the Otomacs should 

 not suffer from eating so much earth appears to me' particularly 

 remarkable. Have they become accustomed to it in the course of 

 several generations ? 



In all tropical countries, human beings show an extraordinary and 

 almost irresistible desire to swallow earth ; and not alkaline earths, 

 which they might be supposed to crave to neutralize acid, but unc- 

 tuous and strong-smelling clays. It is often necessary to confine 

 children to prevent them from running out to eat earth immediately 

 after a fall of rain. I have observed with astonishment the Indian 

 women in the village of Banco on the Magdalena River, whilst en- 

 gaged in shaping earthen vessels on the potter's wheel, put great 

 lumps of clay into their mouths. The same thing was remarked at 

 an earlier period by Grili. (Saggio di Storia Americana, t. ii. p. 311.) 

 Wolves also eat earth, and especially clay, in winter. It would be 

 important to examine carefully the excrements" of animals and men 

 that eat earth. With the exception of the Otomacs, individuals of 

 all other races who indulge for any length of time the strange desire 

 of earth-eating have their health injured by it. At the mission of 

 San Borja, we saw the child of an Indian woman, who, his mother 

 said, would hardly eat anything but earth. He* was, however, wasted 

 nearly to a skeleton. 



Why is it that in the temperate and cold zones this morbid craving 

 for eating earth is so much more rare, and is almost entirely confined, 

 when it is met with, to children and pregnant women; while in the 

 tropics it would appear to be indigenous iiv all quarters of the globe ? 

 In G-uinea, the negroes eat a yellowish earth, which they call Caouac. 

 When brought as slaves to the* West Indies, they try to obtain a si- 

 milar earth, and affirm that in their own country the habit never did 

 them any harm. In the American Islands they were made ill by it, 

 and it was forbidden in consequence ; but a kind of earth (un tuf rouge 



