270 Seventeenth Annual Report of the 



texture and finer pores, keeps back the invisible infection-germ, so 

 that the filtered liquid when inoculated no longer produces the 

 disease. This straining out from the liquid contents of the 

 vesicles of the infecting though invisible genu abundantly proves 

 that it is an actual physical body, or organism, which, like all other 

 specific microbes of communicable disease, is self propagating and 

 in favorable media can go on multiplying itself indefinitely. Thus 

 physical research has fully endorsed the long accepted belief that 

 this plague is caused by a specific, living, contagious organism and 

 that a new case can no more be expected to arise spontaneously 

 and without a previous case, than a stalk of wheat can be produced 

 without planting its own particular kind of seed. 



SEAT AND VITALITY OF THE VIKUS 



Some truths bearing on this subject have been settled as the 

 result of experiment, and some assertions are made which still 

 require the support of careful experimental observation to sub- 

 stantiate them. Loeffler and Frosch found that the infection was 

 present in the. liquids of the nose, mouth, pharynx, larynx, 

 bronchia, stomach, and intestines, but all of these would be inevit- 

 ably contaminated from the contents of the vesicles bursting in the 

 mouth. In exceptional cases the characteristic blisters appear on 

 the lining membrane of the bowel, and from the rupture of these 

 the concentrated virus is passed directly into the contents. It has 

 been assumed that the milk is virulent when secreted in the udder, 

 and, while this may be true in certain cases, Galtier and others 

 drawing milk from disinfected teats, through teat tubes, failed to 

 inoculate with it successfully. It is probable that what is drawn 

 from severe cases is infecting and from mild ones much less so. 

 In many epizootics, milk has been used freely without infecting 

 human beings, while in others large numbers have suffered. In 

 cases affecting the teats, however, the milk is usually highly 

 charged with the virus derived from the rupture of blisters formed 

 on the outside of the teats and at times from others formed inside 

 the milk ducts. The infecting quality of the blood has been 

 deduced from the general elevation of body temperature (fever) 

 in the early stages, implying a direct action on the heat-producing 

 and heat-dissipating centers in the brain, on the constancy of the 



