SCOTTISH METROPOLITAN VETERINARY MEDICAL SOCIETY. 505 
rom an infectious centre. This is one of the diseases which can be ex¬ 
tinguished, just as noxious plants or animals can be exterminated. 
Contagious pleuro-pneumonia and foot-and-mouth disease belong to 
the same category. They have been extended over the world solely 
through their contagious properties, and they cannot be spontaneously 
generated anywhere. We can trace their existence and diffusion for 
more than a century, and their ravages and extension have been simply 
owing to the fact that they were not looked upon as contagious, but due 
to “something in the air.” For nearly thirty years they were allowed to 
scourge this country unchecked, and we permitted our colonies to be 
invaded by them, because we could not recognise their being purely 
contagious disorders. Within the last few years this recognition has 
taken place, measures have been adopted which should have been taken 
thirty years ago, and now these two maladies are almost unknown 
in the land. Sheep-pox is never seen here, except as an introduced 
disease; and it could be easily extinguished on the Continent if proper 
measures of occision and isolation were enforced. In Denmark it is 
unknown, because diseased sheep are never allowed to enter. 
Rabies is a malady about which doubts might be entertained as to its 
being always due to its contagious properties, but I am now convinced 
that its speed, and indeed its existence, depends solely upon its conta- 
gium. There are several parts of the world in which it has never been 
seen, merely because it has not been carried to them; and the dogs in 
them live, and are subjected to exactly the same external influences as 
in regions where this terrifying and fatal disorder is frequent. The 
irregular, and oftentimes extremely protacted, period of latency, the 
long distances travelled by rabid dogs, the readiness with which bites 
may be inflicted by them on healthy dogs without the wounds being 
detected, and some other circumstances attending the evolution-of this 
disease—all conspire to render its origin sometimes obscure, and make it 
appear as if it could arise spontaneously. 1 feel certain that rabies is 
a contagious malady which could be stamped out by the adoption and 
enforcement of special sanitary measures. 
Tuberculosis is another cruel disorder which the evidence of every 
day goes to prove is contagious and infectious, and that its exist¬ 
ence and spread depend upon its infective principle. It is becoming 
more and more prevalent, simply because its infectiveness is not recog¬ 
nised, and it is all the more serious for the reason that it may be com¬ 
municated from the bovine species to man and other creatures. This 
disease could also be extinguished by proper measures. 
There are several other contagious maladies belonging to this category, 
but I will omit noticing them, and come to one which is at present very 
prevalent in London, and indeed throughout the country, and is causing 
much loss and inconvenience. This is glanders—a notoriously contagious 
disease of solipeds, transmissible to mankind and several other species of 
animals, and nearly always fatal. While many veterinarians would be 
disposed to admit the non-spontaneity of some of the other contagious 
maladies, I feel inclined to believe that there are indeed but few who 
would grant that this disease also belongs to the specific class which 
cannot be developed through aught save its own special contagium. In 
our text-books and in lectures, in our consultations and discussions, it 
is set down as a malady capable of spontaneous origin, though it is also 
admitted that it can be extended by contagion. The causes which are 
supposed to produce it are said to arise—I quote from new edition of 
one of our veterinary text-books—from debilitating influences, “ such as 
old age, bad food, over-work, exhausting diseases, and general bad 
