u2 The Lung Plague of Cattle. 



stood in stables as mates with cattle, its constant exten- 

 sion in a stable or in a herd, and finally its sure arrest 

 by the seclusion of stables and localities afford the most 

 conclusive evidence of this." (Bojatrik.) Roll says, 

 "Contamination occurs from the contact of sound animals 

 ■with the sick on roads, pastures, in stables, through the 

 medium of food, of straw that has been breathed upon 

 and soiled by infected beasts, by the utensils that have 

 been used for the latter and by the persons who have 

 attended them." (Pathologie und Therapie.) Fleming 

 says, "Healthy cattle have been contaminated after 

 being lodged in stables that were occupied by diseased 

 ones three or four months previously. Hay soiled by 

 sick cattle has induced the disease after a longer period ; 

 and pastures grazed upon three months before have in- 

 fected healthy stock. The flesh of diseased animals has 

 also conveyed the malady ; and it is recorded that the 

 contagion from cattle buried in the ground infected others 

 fifty or sixty feet distant." (Veterinary Sanitary Sci- 

 ence.) 



Vitality of the Virus. 

 There is much difference of opinion with regard to the 

 power of the virus to resist ordinary destructive influ- 

 ences. In many cases the free exposure of an infected 

 I)lace for three or four months to the action of the air 

 lias purified it so that fresh stock have been introduced 

 Avith impunity. On the other hand, instances can be ad- 

 duced in which cattle have been infected by being placed 

 ill stables in which sick cattle had been kept at least four 

 months previously. Other things being equal, it will be 

 preserved longest where it has been dried up and covered 

 from the free access of the air. Thus, in very dry and 

 close buildings, in those having rotten wood-work, or 

 deep dust-filled cracks in the masonry, and in those with 

 a closed space beneath a wooden floor, it clings with the 



