HISTORY 335 



very unlike those oi la-grippc in man. Its symptoms, lesions 

 and sequelae warrant such a view at least for a working 

 hypothesis. As it is not usually fatal, little progress seems ta 

 be made in acquiring knowledge concerning the nature of its 

 morbid anatomy. There is much need for careful investiga- 

 tion of this very common malady. 



§ 252. History. According to the writings of Falke, 

 influenza was recognized in ver}- early times. There is evi- 

 dence that it was known in the fourth and fifth centuries. It 

 was described by Low in 1729 as an equine epizootic which 

 had spread over Southern Europe. It is also stated that cases 

 of its having been transmitted to man had occurred. Gibson 

 observed it in 1872 in London and in different districts of 

 England. It raged in epizootics in 1760, 1776 and 1803. The 

 disease was widely disseminated during the last century. The 

 more important epizootics are reported in the years from 18 13 

 to 1815, 1825 to 1827, 1836 to 1840, 1846, 1851, 1853, 1862, 

 1870, 1873, 1 88 1 to 1883, and 1890. Anker who described 

 influenza in Switzerland in 1826 laid stress on its contagious 

 nature and stated that in his opinion "a volatile infectious 

 matter was the cause." 



Influenza spread as an epizootic in 1872 to 1873 over the 

 greater part of the United States where it received the name of 

 "pink eye" (French, Fievre typhoidej. It started in Canada 

 and extended south and west reaching into British Columbia 

 to the north and Mexico at the south. The last great epizootic 

 raged in Europe from t88i to 1883 during which time it is said 

 to have spread over nearly the whole continent. In the Prus- 

 sian army, 8,434 horses became infected in 1890; 2,497 io^ 

 1891 ; and 3,645 in 1892. In Copenhagen, 3,000 horses suffered 

 from it in 1890 and 1891. 



§ 253. Geographical distribution. Influenza seems to 

 be known in nearly if not all of the countries of Europe and 

 America. In certain sections of the United States it is almost 

 a constant affection. This is especially true of certain cities 

 owing to the constant introduction of "green" horses. 



§ 254. Etiology. Influenza seems to be produced by a 

 specific infection the nature of which has not yet been deter- 



