DISSERTATION ON THE YAWS. 107 



ranthus (caliloo). These vegetables arc made into soups or 

 broths, with the addition of fish, crabs, or pork, and seasoned 

 with salt and capsicum. Instead of bread they have abun- 

 dance of plantains (Musa sapientum), the roots of the Arum 

 colocasia and sagittifolium (cocoes), the sweet and bitter cas- 

 sida (Jatropha), several kinds of yams (Dioscorea), the sweet 

 p statoes (Convolvulus battatas), &c. ; besides many deli- 

 cious fruits which they cultivate in their own gardens and pro- 

 vision-grounds. A simple diet of this kind makes them strong, 

 active, and able to perform their work with ease in their na- 

 tive climate, whilst white people, and their pampered domes- 

 tics, arc unable to stand fatigue or labour in the heat of the 

 sun. 



The diseases of field Negroes, as fevers and pleurisies, are 

 of the inflammatory kind, and they bear repeated bleedings. 

 Those of white people mostly partake of the remitting fever, 

 in which, if the lancet is at all used, it ought to be very spar- 

 ingly. The blood drawn from a Negro is generally firm and 

 often buft'y ; that from a white person, loose, discoloured, and 

 watery. 



Proximate or Exciting Causes. — Having spoken fully of 

 wbat have been deemed the remote causes of the yaws, and re- 

 futed various vulgar errors, and having shewn that no predis- 

 posing causes can exist, cither in the constitution, or from diet 

 or climate, I proceed to the proximate or exciting causes of 

 this disease. 



1st, When the yaws are at the height, the fungi have white 

 sloughs, and discharge a thin ichor ; they are in this state most 

 infectious. 



2fZ/!//, Ulcers from the yaws are at all times foul and offen- 

 sive, and it is by them that the contagion is commonly propa_ 

 gated. 



We know nothing more of the nature of this contagion, 

 than of that of the small-pox or measles. All we can say is, 



