88 
JAMES LAW 
devitalized virus. The presence of the chemical poison in the 
blood and the attendant constitutional distubance invites 
rather than debars the growth of the plague germ ; hence the 
latter must be excluded until the former has been entirely 
eliminated. For the same reason the free use of disinfectants 
in the operating yards and buildings will be of the utmost 
value. So will every conceivable precaution against the in¬ 
troduction of disease germs through accidental channels, as by 
other animals, by the pork, stolen by dogs, as carried by men, 
etc. 
ADVANTAGES PROMISED BY THIS METHOD. 
“ ist. It offers immunity from a fatal disease by a method 
which does not entail the propagation of the living germ in 
the system of the animal to be protected. 
“ 2d. It avoids the risk of the preservation, amplification, 
diffusion or increase of potency of the disease-germ, all of 
which contingencies are possible in inoculation with a mitigat¬ 
ed virus. 
“ 3d. It does away with the necessity for an exhaustive 
disinfection after the animals have been inoculated and have 
recovered from its results. 
“ 4th. The dose of the devitalized chemical products can be 
so graduated to the strength of the animal that there will be 
no risk of a fatal result. When once the mitigated living germ 
is introduced there can no longer be any certainty that it will 
not reproduce itself to a dangerous extent, or that, owing to 
the special condition of the system or of its surroundings, it 
may not suddenly assume its fatal type; but with the devital¬ 
ized chemical products we can graduate the dose so as to se¬ 
cure as great a certainty as in the case of a dose of castor oil 
or epsom salts. 
“ 5th. The system can be habituated to the poison and 
fortified against it by a succession of small doses, no one of 
which is at all dangerous in itself ; whereas if a living germ 
were once introduced, though of mitigated power, it may in¬ 
crease so as to develop a power that is altogether unexpected. 
