164 INOCULATION FOR PLEURO-PNEUMONIA IN CATTLE. 
diseased animals, /^-inoculation, & c. &c., by the Professors. 
I have spoken of the tail as the part selected for the intro- 
duction of the virus ; it is necessary to add that the extre- 
mity of the organ is chosen, so that amputation may be 
resorted to in those cases where mortification supervenes 
upon the inoculation — thus affording the animal a chance of 
recovery at the expense of this member of its body. It is, 
however, by no means unfrequent that amputation fails to 
arrest the progress of mortification, of which one notable ex- 
ception was seen by me among the animals belonging to M. 
Willems’ father. 
The quantity of serous exudation employed never exceeds 
two or three drops, and it certainly is not a little remark- 
able that such serious consequences should so often follow 
its introduction into the system. The material is evidently 
morbific in the extreme, and probably is either dead, or 
possesses so small an amount of vitality when used that 
it soon dies, and as such gives rise to chemical action, ending 
in the speedy destruction of the tissues, more particularly 
in so lowly an organised part as the tail. In very many 
cases, even when ulceration or mortification does not occur, 
the inflammatory action runs so high and the tail enlarges so 
much, that deep incisions, some three or four inches long, 
have to be made to give relief to the engorged tissues. 
These untoward results do not probably occur in more than 
twelve or fifteen cases in every hundred, but they show how 
important it is to adopt means to procure a milder and safer 
material for inoculation than that obtained directly from the 
lungs. Cases of this kind invariably produce great constitu- 
tional disturbance and consequent emaciation, and call for 
long-continued medical treatment. At the commencement 
of these experiments some persons inoculated in the dewlap, 
and the effects were far more destructive than those I have 
described. In one instance in particular, the exudations of a 
gangrenous lung being employed on eighteen animals , twelve out of 
the number died . 
Much stress has been laid on the microscopic appearances 
of the exudations obtained from the inoculated parts, in order 
to show that peculiar corpuscles possessing a tremulous 
motion are therein developed, and that these, most probably, 
are the true agents of the communication of the special 
disease. The instrument used at Hasselt by Dr. Willems 
and myself was very inferior, and no dependence could be 
placed in its defining powers ; and from what I have since 
observed, I believe that none but ordinary inflammatory pro- 
ducts exist, and consequently that no special corpuscles will 
be met with in these exudations. 
