290 Seventeenth Annual Report oe the 



strong invulnerability of most human beings to the disease, the 

 variable potency of the germ in different epizootics and cases, and 

 the acquired immunity which so many animals and men attain 

 to in districts in which the malady habitually prevails. Even a 

 large number of negative instances cannot undo the force of a 

 smaller number of positive ones. Veterinary sanitary police must 

 guard against the exceptional cases by which a pestilence is main- 

 tained and propagated, and to forget this and found our sanitary 

 control on negations is but to abandon all prospects of a successful 

 issue. In past times negative results were extensively quoted 

 against contagion in practically every contagious disease of ani- 

 mals, glanders, strangles, influenza, tuberculosis, lung plague, etc., 

 . etc. 



MODES OF INFECTION IN MAN 



The most common cause of infection is the drinking of warm 

 milk. Many, however, drink the uncooked milk, while only a few 

 of these contract the disease. A considerable number of cases 

 are due to accidental inoculation of persons handling the dis- 

 eased animals or their products, the virus entering through chaps, 

 cracks, abrasions, or other wounds of the skin. In the same class 

 come those who milk the cows with sores of any kind on their 

 hands. The lodging, by the soiled fingers, of saliva, virulent 

 lymph, etc., on the lips or other mucous surface is a well-known 

 method (Hildebrandt). A soiled handkerchief, touched to the 

 lips and nose, has been known to infect (Esser). 



Butter has been the bearer of infection in a number of cases. 

 Ebstein and Hildebrandt adduce instances of this, and compara- 

 tively recently a Berlin veterinary student, who had butter made 

 from the infected herd at his home, suffered from vesicular erup- 

 tion on the mouth and a swelling of the ear resembling erysipelas. 

 In a second case, a German clergyman who had eaten butter made 

 from the milk of cows having foot and mouth disease had chill, 

 fever, diarrhoea, itching of the skin and the characteristic eruption 

 of blisters on the mouth. 



Cases of infection by cheese are furnished by Ebstein, Edel- 

 mann, Schneider and others, and this medium appeal's to be a 

 good preservative of the vitality of the virus, especially if kept in 

 cold storage. Cottage cheese, lYeufchalel, and other forms of soft, 

 nnripened cheese are dangerous. 



