598 PLEUKOPNEUMONIA. 



Istly. Is the epizootic pleuro-pneumonia of cattle suscep- 

 tible of being transmitted from diseased to healthy animals 

 by cohabitation. 



2c%, In the event of such contagion existing, would all 

 the animals become affected, or what proportion would resist 

 disease ? 



Sdly, Amongst the animals attacked by the disease, how 

 many recover, and under what circumstances? How many 

 succumb ? 



Mhly, Are there animals of the ox species decidedly free 

 from any susceptibility to be affected from the contagion of 

 pleuro-pneumonia ? 



Sthly, Do the animals which have been once affected by a 

 mild form of the disease enjoy immunity from subsequent 

 attacks ? 



Qthly, Do the animals which have been once affected by 

 the disease in its active form enjoy such immunity ? 



To determine these questions, the Commission submitted 

 at different times to the influence of cohabitation with 

 diseased animals forty-six perfectly healthy ones, chosen from 

 districts where they had never been exposed to a similar in- 

 fluence. 



Of these 46 animals, 20 were experimented on at Pome- 

 raye, 2 at Charentonneau, 13 at Alfort, and 11 in the fourth 

 experiment at Charentonneau. 



Of this number, 21 animals resisted the disease when first 

 submitted to the influence of cohabitation, 10 suffered 

 slightly, and 15 took the disease. Of the 15 affected, four 

 died and 1 1 recovered. Consequently the animals which ap- 

 parently escaped the disease at the first trial, amounted to 

 45'65 per cent., and those affected to 2173 per cent. Of 

 these 23'91 per cent, recovered, and 8 -69 per cent. died. But 

 the external appearances in some instances proved deceptive 



