SECTION IL 

 CHRONIC INFECTIOUS DISEASES. 



CHAPTER I. 



SYPHILIS. 



OP late years the study of syphilis has undergone a complete 

 revolution, and the new doctrines have been adopted with remarkable 

 readiness by almost all prominent writers upon the subject, even by 

 those who a few years ago were then* most zealous opponents. In 

 previous editions of this work I have expressed a disbelief in the an- 

 cient views, according to which inoculation by one and the same poison 

 at one time acts locally, and at another induces infection and disorder 

 of the entire system ; and I there declared my preference for the modern 

 theory, according to which there are two poisons, one of which merely 

 induces local disease, namely, an ulcer at the point of inoculation, ac- 

 companied in some instances by inflammation and suppuration of the 

 neighboring lymphatic glands ; while the other always gives rise to 

 constitutional disorder, with extensive derangement of nutrition. At 

 that time, however, I did not declare myself so unreservedly in favor 

 of the doctrine of the duplicity of the virus (or duality, to use another 

 common expression) as I now do. 



I think that it will be to the advantage of my readers if I devote a 

 few lines to a brief analysis of the belief which a short time ago was 

 universally current, regarding the relation of the chancre, or primary 

 syphilitic ulcer, to constitutional syphilis, or lues venerea. It was sup- 

 posed that the secretion of the ulcer possessed virulent properties, 

 whereby, when brought in contact with an excoriated surface, or upon 

 penetrating through a thin coating of epidermis, it induced a specific 

 dermatitis, and a primary syphilitic ulcer. At this stage, it was be- 

 ieved that the noxious power of the virus often became exhausted ; 

 and that, if we could succeed in destroying or in healing the ulcer be- 

 fore the infection from it could involve the constitution, the disease 



