174 
PLEURO-PNEUMONIA IN AUSTRALIA. 
action lurking fomitic pestilence, or retard its progress, 
together with predispositions or repulsions in the animal 
functions to receive or resist these very potent rudiments of 
disease, often puzzle and perplex, whether in this or in 
some other maladies, by seeming capriciousness. The 
disease is communicated by vitiated saliva of the mouth; 
by gangrenous matter proceeding from ruptured abscesses 
of the lungs; by gaseous expirations from diseased air- 
cells, and inhaled by healthy animals; or by poisonous 
effluvia issuing from bodies labouring under fatal mor¬ 
bific disorders and diffused through the air, fixing on hair, 
fur, cotton, woollen, grass, hay, straw, or mucous mem¬ 
branes of living creatures, as already stated. In proof 
of the contagious character of this disease, we have the 
highest authority in Britain, that of Professor Simonds. 
We have also the evidence of a joint committee from both 
Houses of Legislature in the state of Massachusetts, which, 
after sitting eight days, and instituting a rigorous inquiry, 
made the following report :—“ That the disease was highly 
contagious, and so insidious in its attacks, and so fatal in its 
termination, as to warrant the most stringent measures for 
arresting the progress and protecting the great interests 
exposed to its ravages.” Their opinion was freely expressed, 
that many animals carry about with them the seeds of latent 
disease, which only await conspiring circumstances and con¬ 
ditions for arousing them into fatal activity. A six months* 
lapsus is believed not to be infrequent; but how much longer 
is a term wholly apocryphal. Let the elementary virus be 
what it may, when it enters into the system, it then concen¬ 
trates itself'in some particular organ more susceptible of its 
action than any other, just as parasitic fungi or entozoa will 
only attach themselves to particular plants, or be found on or 
in definite parts of the animal system. The disease, therefore, 
follows the laws of other zymotics, acting from time to time 
with destructive effect when the intensity of its powers is in 
action, and then intermitting, mitigating, or apparently dis¬ 
appearing without any apparent indications that the exciting 
causes had been sensibly changed. We care not whether the 
disease is communicative by morbific germs or mephitic ex¬ 
halations, or whether chemical affinities and chemical action 
are or are not the primary or secondary causes. Men must 
be equally on their guard, in order if possible to avoid the 
fatal consequences. 
The first introduction of this malady into the Australias is 
believed to have been through means of a high bred cow, 
imported from Britain into Victoria. Notwithstanding 
ordinary precautions to destroy all contaminated cattle, the 
