CONSTITUTIONAL SYPHILIS. 755 



By far the most frequent exciting cause of syphilis is coitus with 

 an infected individual ; but there are many well-authenticated cases 

 where infection has been conveyed by the hand of a physician or mid- 

 wife, by using a pipe, or tumbler, or privy, polluted by the venereal 

 virus. There is no doubt, moreover, that the disease has often been 

 propagated by vaccination, and another series of cases is known to 

 have sprung from the use of dirty lancets, and in bleeding and cupping, 

 by careless surgeons. 



SYMPTOMS AND COTTKSE. L The Primary Syphilitic Indura* 

 tion^ and Primary Syphilitic Ulcer. The period of incubation of the 

 syphilitic virus is from three to four weeks. A correct knowledge of 

 this fact is of recent date. Prior to this discovery, which was made 

 by inoculating healthy subjects with syphilitic virus, we were unable 

 to account for the phenomenon that, in a large number of cases, a chan- 

 cre (chancroid), after lasting for some weeks, would become indurated 

 at its base and edges ; and this it was which caused the false impres- 

 sion that a soft chancre could assume a pernicious character, and 

 change into a hard one. Experience has taught that the indurated 

 chancre is almost always tjbe precursor of secondary symptoms. The 

 following is the correct, interpretation of these facts: Both poisons, 

 the chancrous, as well as the syphilitic, act simultaneously upon one 

 and the same point ; in a few days the chancre forms ; the period of 

 incubation of its virus being a very short one. Three or four weeks 

 afterward, the time of incubation of the syphilitic contagion having ex- 

 pired, the syphilitic induration develops at the base and edges of the 

 ulcer. It 'may happen that the chancre has healed before the incuba- 

 tive stage of the syphilis has terminated. In such a case an indura- 

 tion forms in the scar of the chancre. The conversion of a syphilitic 

 induration into a chancre, by the implantation of chancrous virus, may 

 also take place. 



[Some observations seem to indicate that the poison of chancre 

 and chancroid may be present on the same sore, giving a " mixed 

 ulcer ; " so that an apparently soft chancre may become indurated 

 and be followed by constitutional symptoms, and, on the other hand, 

 inoculation from an apparently hard chancre on the bearer of it may 

 induce a chancroid. It has, however, been asserted that inoculation 

 of pus of any kind in a syphilitic patient may induce an ulcer re- 

 sembling a chancre. Even on this point, where so many observa- 

 tions have been made, opinions are not undisputed ; and we may 

 consider that the relation of chancre and chancroid to each other, 

 and to syphilis, is not absolutely determined in all details. 



After exposure to the disease, some time elapses before the de- 

 velopment of the indurated sore, then some weeks longer before the 



