244 Progress of Rational Pathology . 



of inoculation, which afterwards disappeared suddenly, and 

 on the seventh or eighth day after the insertion of the virus, 

 fever came on with the usual premonitory symptoms, and 

 two or three days later the exanthema followed. In scarlet 

 fever and in measles, Helfft declares that he has found the 

 cells of the thrown-off epithelium of the mucous membrane, 

 not only in the urine, but also in the excrement : according 

 to him, the spreading of the exanthema, and the process of 

 desquamation stand in inverse relation to the urinary and 

 to the digestive organs. Sebastian observed the simulta- 

 neous and regular course of measles and vaccine in one 

 individual, while in most cases the vaccine remains quiet till 

 the measles have run their course. 



c. Pemphigus. — Scharlau thinks, that he has proved by in- 

 oculation the contagiousness of this disease among new-born 

 children. 



d. Typhus. — -In the two forms of disease which have been 

 described under the names of typhus (T. contagiosus exanthe- 

 maticus, petechialisj and of typhoid fever, (Fievre typhoide T. 

 abdominalis,) Davidson sees only two varieties of the same 

 species. He endeavours to point out the analogy between 

 typhus and other exanthematous diseases. According to Val- 

 leix, typhus is distinguished from similar and especially from 

 typhoid diseases, by a characteristic eruption (numerous, 

 irregularly grouped, roundish, dark red or violet spots, 

 from the size of a pin head to that of a pea, not projecting, 

 and not disappearing under the pressure of the finger, while 

 in typhoid fever only a few, rare, coloured spots, slightly pro- 

 jecting, and readily yielding to the pressure of the finger ap- 

 pear in small number and only on the belly, — by the almost 

 entire absence of affections of the higher senses — by the com- 

 parative slightness of the cerebral symptoms — by the absence 

 of abdominal complications at the outset (ulcers of the bowels,) 

 and by their small number and slight intensity. According to 

 Valleix, typhus ought for the present to be reckoned among 



