nissr.u TATIOX (>X Till". YAWS. 10f) 



Those who have attempted it have failed of Success, or ;it 

 least their hypotheses are unsatisfactory. For my part I shall 

 he very brief, as the nature of Contagion will probably be 

 ever hid from human sagacity. 



The virus of the vans does not seem to he of an active na- 

 ture. The person who receives the infection perceives no al- 

 teration on the wound, ulcer, or excoriation, for some time, 

 except that it does not heal, and keeps foul on the surface. 

 In a few weeks the neighbouring parts arc inflamed, the edges 

 of the sore arc ragged and painful ; from this we conclude 

 that the ichor secreted is now of an acrid sort, and that part 

 of it is constantly absorbed, and passes through the lymphatics 

 to the subclavian vein, and so is circulated with the blood. 



In the system it occasions but little disturbance, as the in- 

 fected perform all the functions of life as before. We suppose 

 that much of the contagion is carried off' by the cmunetuarics, 

 and particularly by perspiration. 



The quantity and quality of the eruption seems to depend 

 on the state of the patient's health, and the state of the skin. 

 I suppose also, that part of the contagion, in passing through 

 the skin, adheres, and, by irritation, produces pimples. This 

 conjecture is probable ; for a man in full health, and who per- 

 spires freely, will have the yaws large and few in number, 

 whereas a person in ill health and poorly clad, will have a nu- 

 merous crop of small ill-disposed yaws. 



We do not pretend to account for the phenomena in other 

 respects ; as, why the matter of yaws occasions bone-ache, dis- 

 tortions of the limbs, and erosions of the palate, nose, &ic like 

 syphilis. 



We have seen, when the yaws are repelled, that the whole 

 adipose membrane is filled with pus. The poison, in this 

 case, seems to have the power of quickly assimilating the 

 lymph to its own nature, and converting it to pus, without 

 the process of suppuration and abscess. 



