758 CHRONIC INFECTIOUS DISEASES. 



a scanty thin liquid, in which no pus-cells can be found under the micro- 

 scope, but only a granular detritus. It often heals quickly, but the 

 secondary symptoms follow this form of sore quite as surely and 

 promptly as any other variety. 



The elevated sore (ulcus elevatum) presents an excoriation which 

 is almost void of discharge, seated upon an indurated base of varying 

 thickness and consistence, by which it is elevated above the surround- 

 ing level. From time to time it is coated by a thin layer of epithelium, 

 which generally soon exfoliates in fine scales, leaving a new excoriation. 



The Hunterian chancre (ulcus vallatum) not only has a hard base, 

 but is surrounded by an elevated, hard, callous border, so that it is 

 deeper in the middle than at the periphery. It rarely heals in less 

 than five or six weeks. 



All the different forms of syphilitic sore may become phagedenic, 

 that is, they may be attacked by a rapidly-extending diphtheritic pro- 

 cess. The destruction then often spreads beyond the limit of the in- 

 duration, largely involving the skin or mucous membrane. When the 

 syphilitic induration is associated with the chancre, the operation of 

 both poisons upon the same point results in a modification of the ulcus 

 vallatum, that is, the border of the chancre becomes hard and callous, 

 and surrounds it like a wall. At a later period the induration likewise 

 appears in the bottom of the ulcer. 



The duration of a syphilitic induration or a syphilitic sore varies. 

 Three months, at least, nearly always elapse ere the hardened spoi 

 recovers its normal consistence. The induration often lasts half a year, 

 and even longer. It is remarkable that, as the secondary symptoms 

 begin to appear, the induration begins to dissolve, and then soon sub- 

 sides, leaving behind it a brown pigmented spot. The pigment marks 

 the former site of the disease for a tolerably long time. When it 

 finally disappears, the spot remains whiter than the adjacent parts, 

 like the cicatrix of a neoplastic growth. Unless the indurated spot 

 has also been the seat of a chancre, there is no depression. 



II. The Indolent JBubo and Extended Syphilitic Disease of the 

 Lymphatics. An acute enlargement of the lymphatic glands occurs 

 in many of the acute infectious diseases and in syphilis, the prototype 

 of the chronic infectious maladies, the lymphatic glands always parti 

 cipate in the disorder induced by infection of the system by this per- 

 nicious poison. The changes which take place in the glands consist ic 

 a cellular hyperplasia, and they are but seldom the seat of actual in 

 flammation or suppuration. More frequently, especially when the dis- 

 ease has been of long standing, caseous metamorphosis occurs here and 

 there in them, and this is afterward followed by a calcification. In a 

 few days after its development, the primary syphilitic induration 



