232 
NOCARD AND ROUX. 
udation is sometimes so abundant that several liters of virulent 
serosity can be collected; no matter how extensive, the exudation 
never extends into the connective lamellae of the lungs ; a little 
serous exudate may be observed in the pleural sac, but visceral 
lesions are never found ; consequently death is the result of an 
intoxication. 
Some subjects resist; after several days, the swelling, al¬ 
ways warm, tense and painful, remains stationary, then dimin¬ 
ishes and disappears little by little, without leaving any marks ; 
these subjects are henceforth refractory to the effects of a viru¬ 
lent inoculation and also to those of natural contagion. 
This fortunate occurrence is the rule, when inoculation is 
made far from the trunk, at the end of the tail for instance, 
where the density of the tissues and the low local temperature 
does not permit an active germination of the virus. The swell¬ 
ing following inoculation is always similar to that we have de¬ 
scribed ; but it remains limited and disappears by degrees, leav¬ 
ing the animal refractory to natural or experimental contagion. 
At times, however, the exudation is so abundant, it pro¬ 
motes such tension upon the aponeurosis, that mortification en¬ 
sues with sloughing of pieces of the tail, of varying lengths. At 
others, again, but rarely (once or twice in a hundred), the swell¬ 
ing, instead of remaining confined to the extremity of the tail, 
ascends rapidly along the organ, and invades the cellular tissue 
of the croup and of the pelvis ; death occurs generally, and the 
invaded regions at the post-mortem are found infiltrated with 
large quantities of serosity similar to that of the lung in the 
natural disease. 
Pleuro-pneumonia serosity, so virulent for cattle, is without 
action for other species. Goats, sheep, dogs, swine, rabbits, 
guinea-pigs, fowls, resist without injury the subcutaneous or 
intraperitoneal injections of massive doses of virulent serosity. 
These facts were established by Willems in 1850; from 
these he invented the rules of an efficacious prophylaxy. But 
this inoculation of Willems, which has been so advantageous, 
is not without objections. It necessitates the deposit of a drop 
