DISEASES OF THE NERVOUS SYSTEM. 519 



from an article entitled " The Seven kinds of Madness." 

 This same article recommends the inoculation with the " matter 

 of the cow pock to prevent distemper and distemper madness." 

 As the date of publication of the work is 1769, it will be ob- 

 served that the virus was thought of in this connection long 

 before the days of Jenner, and vaccination as a prophylactic of 

 small-pox. 



The latest researches on hydrophobia in the human subject, 

 are given by the eminent pathologist, Dr. Felix von Niemeyer, as 

 follows : 



" Most cases of lyssa that have been well observed and described 

 closely resemble each other. As it is universally assumed that 

 morbid processes due to the action of a specific poison run their 

 course with symptoms which only vary through personal idiosyn- 

 crasy and the variable intensity with which the poison has acted, 

 those reports of lyssa humana differing from our description, in 

 which the characteristic symptoms and their peculiar sequence are 

 not mentioned or really did not occur, must arouse the suspicion 

 that they were badly observed, or that there was an error of diag- 

 nosis. 



" Opinions differ as to the length of the period of incubation. 

 The statement that hydrophobia has made its appearance twenty 

 or thirty years after the bite of a rabid animal, as well as those 

 according to which the disease has broken out as early as the 

 second or third day, are probably dependent upon imperfect ob- 

 servation. The shortest term of incubation appears to be about 

 eight or ten days ; the longest twelve or thirteen months. In the 

 majority of instances, the malady breaks out in about forty days 

 after the reception of the bite. The reasons for this inequality of 

 period are obscure. There are numerous instances in which, 

 towards the end of the stage of incubation, and a day or two before 

 the onset of the malady, peculiar alterations have been observed 

 in the wound or its scar, for the wound has generally healed by 

 this time. The bite assumes a livid color, grows painful, and dis- 

 charges a yellow ichor. The scar which has generally soon formed 

 without remarkable symptoms, grows bluish red, swells, and some- 

 times breaks out afresh. The patient also complains of painful 

 sensations, shooting centripetally from the wound or scar, or of a 



