836 
PLEUROPNEUMONIA. 
causes which regulate the outbreak, spread, and cessation of 
epidemic disease. 
44 That inoculation of cattle, as advocated and practised by 
Dr. Willems and others, is not founded on any known basis 
of science or ascertained law with regard to the propagation 
of those diseases commonly called specific. 
“That pleuropneumonia occurs at various periods of time 
after a so-called successful inoculation. 
44 And lastly, that the severity of pleuropneumonia is in no 
way mitigated by previous inoculation, the disease proving 
equally rapid in its progress and fatal in its consequence on 
an inoculated as an uninoculated animal.” 
The French Commission reported in 1854, — 
44 That of 100 bovine animals which were inoculated under 
the most unfavorable circumstances, that is, when the herds of 
which they formed part were threatened, or actually invaded 
by the epizootic, two animals succumbed to the effects of the 
operation. 
44 Two animals contracted the malady in spite of inocula- 
tion. 
44 Ninety-six animals were exposed to the contagion, and 
escaped safe and sound from the results of inoculation, and 
four suffered from gangrene, which materially lessened their 
value. 
44 Inoculation with the fluid obtained from a diseased lung 
has a preservative influence. It imparts to the organism of 
the great majority of animals on which the operation is per- 
formed a power of resisting infection for a period which is 
yet undetermined.” 
Equally conflicting evidence is to be found in reports 
which have been published since 1854 up to the present day ; 
and the testimony of individuals who have tested the system 
of inoculation on their own breeds is not more satisfactory. 
Sometimes inoculation fails to cause any external symptoms 
of disease in the part as in the recent experiments which were 
undertaken in Norfolk ; sometimes very extensive swelling, 
followed by mortification, loss of a large portion of the tail, 
and occasionally death, are the results ; but, in the majority 
of the cases, the introduction of the fluid from a diseased 
lung into an incision in the end of the tail is followed, at an 
interval of ten to fourteen days, by swelling and heat of the 
part, and the effusion into the areolar tissues of a straw- 
coloured fluid which, under the microscope, presents all the 
characters of serous exudation. Occasionally blood is effused 
into the tissues of the inoculated part, and in such a case a 
section of the swollen tissues has a somew hat marbled appear- 
