194 STEPPES AND DESERTS. 



In all tropical countries, human beings shew an extraor- 

 dinary and almost irresistible desire to swallow earth ; and 

 not alkaline earths, which they might be supposed to crave 

 to neutralize acid, but unctuous 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 engaged 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 Gili. (Saggio di 

 Storia Americana, T. ii. p. 311.) Wolves alsa 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 preg- 

 nant women ; while in the tropics it would appear to be 

 indigenous in all quarters of the globe? In Guinea the 

 negroes eat a yellowish earth, whieh they call Caouac. 

 When -brought as slaves to the West Indies, they try to 

 obtain a similar earth, and affirm that in their own country 



