468 INOCULATION FOR PLEURO-PNEUMONIA IN CATTLE. 
issues or setons, it is well known that if these are employed, 
care being taken to prevent their weakening effect on the consti- 
tution by the exhibition of tonic medicine , or the use even of a 
nutritious diet, not only Pleuro-pneumonia but many other 
diseases will be sometimes prevented. 
Further, with regard to protection, we must call attention 
to the present amount of loss in Mr. Paget’s herd. The ino- 
culations were begun at the end of November, and with irre- 
gular intervals carried on so as to be completed by the 
beginning of February. Now, dating from the end of 
November to the end of May, when we have the last report 
of the health of the animals, it will be seen, by reference to 
the particulars contained in this report, that during these six 
months no less than jive inoculated animals have died of Pleuro- 
pneumonia after inoculation. This on the year, at the same 
ratio, would give 10 per cent. — a number equal to the annual 
average loss of M. Willems, sen., and to guard against which 
he adopted inoculation.* It must likewise not be forgotten 
that in many instances on the Continent, the disease, instead 
of decreasing, has progressed much more rapidly after inoculation 
than before , affecting indiscriminately the inoculated and the 
?icw-inoculated animals. A fact of this kind was to be expected 
with a contagious disease like Pleuro-pneumonia, when inocu- 
lation was roughly done on animals already of weak constitution 
and perhaps badly kept, as thereby their susceptibility would 
be further increased to the influence of the contagion. 
To proceed to other matters. It is stated in the fifth con- 
clusion of the Dutch Commission, and admitted by all 
observers, that the lungs are not specially diseased from an 
inoculation, although death may result therefrom. To the 
arguments advanced in our former report on this head, we 
may add that the wo^-production of Pleuro-pneumonia by 
inoculating an animal with the serous exudation from a dis- 
eased lung, must be admitted as one good proof, among many 
others, that such exudation is not a special “ virus.” If the 
exuded serous fluid produced a special and well-marked inflam- 
matory action locally , prior to generating a peculiar condition 
of the constitution, although the evidences of the latter might 
be so slight as to be hardly recognised, as is the case with the 
vaccine lymph ; or if it caused sooner or later the disease 
Pleuro-pneumonia itself, altogether independent of such local 
inflammation , of which we have an example in Rabies, then 
there would be no difficulty in admitting that the inoculation 
of cattle was founded on scientific principles. Neither of 
these properties has, however, as yet been satisfactorily proved 
* See First Report, Journal, vol. xiii, p. 376. 
