Commissioner of Agriculture 209 



and mouth disease country, and this calf developed aphthous fever. 

 The lesions and their locations were alike unequivocal. 



6. The landing, with some emigrant, of clothing which had 

 been worn while attending infected stock in Europe and which 

 had become saturated with infecting materials. 



Canada was again invaded in 1875 through sheep imported 

 from Britain. They were strictly secluded so that no oilier ani- 

 mals became infected. 



Another invasion of Canada took place in 1884, through a cargo 

 of 199 animals imported from Glasgow on the steamship Missis- 

 sippi. These were slaughtered at Port Lewis quarantine, and the 

 ship disinfected and held for thirty days thereafter. 



On June 4, of the same year, aphthous fever was again found 

 among 106 cattle landed at Port Lewis from the Oxenholme from 

 Glasgow. This also was promptly met by slaughter of the im- 

 ported herd and disinfection of the vessel and station, and the 

 infection did not spread to other animals. 



NATURE OK THE DISEASE 



The disease is a specific eruptive fever like smallpox, cowpox, 

 measles or scarlatina, its distinctive characteristics being mani- 

 fested, among other ways, by its proclivity to attack certain ani- 

 mals, ruminants and swine, by its inoculabilitv to other warm- 

 blooded animals, by the duration of its evolution, by the nature of 

 the eruption, by the favorite seats of the blisters (mouth, teats and 

 feet), by its mild and transient course and prompt recovery, and 

 by its extreme infectiousness. 



Before the microbes of other contagious affections were 

 accepted, or even suspected, foot and mouth disease had been 

 recognized as the very impersonation of contagion, all cases being 

 traceable to preceding ones, and the spread of the malady being- 

 only limited by the absence of susceptible subjects. The presence 

 of a virus or of an organized, self-multiplying, infecting organism 

 was, therefore, assumed, and yet, up to the present time, no one 

 has been able to demonstrate the organism in question under the 

 microscope. It passes through the Berkefeld filter, leaving the 

 liquid as infecting as before (Loeffler and Frosch). The Pasteur 

 filter, however, made of unglazed porcelain, with much closer 



