Progress of Rational Pathology. 2A5 



essential fevers, since no constant local injury is found. 

 Rochoux observed besides the petechia? in typhus, a measle- 

 like erratic exanthema in the form of scattered points 

 always followed by desquamation : the exanthema of typhoid 

 fever consists of small round elevations, which last for six or 

 eight days. As an essential difference between typhus and 

 typhoid fever he cites the propagation of the former by in- 

 fection, which he positively denies to typhoid, (while Berland 

 accords it.) Those who look on a primary alteration of the 

 blood as the immediate cause of fever and of other exanthema- 

 tous diseases, are supported by the results of the investigations 

 of Andral and Gavarret. Winther deduces all the symptoms 

 of typhus from fluidity and congestion of the blood. According 

 to De Renzi, typhus-blood is very rich in blood corpuscles 

 (generally without a nucleus) the colouring matter dissolved 

 in serum, the placenta incomplete and soft ; there is a deficien- 

 cy of fibrine. Forget concludes from his researches — 1, an 

 appreciable alteration of the blood is not universal : 2, the 

 blood seldom appears to be altered in the earliest stage : 3, 

 the blood is the oftener found altered, the more advanced 

 the disease is : 4, the degree of alteration, if there be any 

 such thing, does not bear any definite relation to the period 

 of the disease : 5, it is not coincident with the putrid and 

 typhous symptoms, which may occur with or without it: 

 6, the different kinds of alteration do not appear to be con- 

 nected with the fixed forms of the disease : 7, the degree of 

 alteration is not in proportion to the intensity of the disease : 

 8, nor to the number of times that bleeding has been em- 

 ployed. As a cause of the slowness of hearing and of the 

 deafness in typhus, Pappenheim discovered inflammation and 

 suppuration in the mucous membrane of the drum of the 

 ear. According to Engel the disappearance of a typhus 

 epidemic may be predicated from the corpses : at the com- 

 mencement, while it prevails strongly, we find the ulcers 



