from an Agricullural and Veterinarij Point of View. 
75 
a century — of desolating plagues among all kinds of stock, for 
years unchecked and uncontrolled, then encountered with haras- 
sing and sterile legislative measures, until property of the value 
of many millions of pounds was lost, and agriculture was greatly 
crippled. The admission and the continuation of these maladies 
amongst our flocks and herds were due, at first, to the little that 
was known of their history or nature ; and in later years, when 
their communicability was conclusively ascertained, their wide- 
spread ravages were unchecked, partly through indifference, and 
partly through mistaken economical notions. 
It was not until the true nature of fermentation was elucidated, 
thanks to Pasteur, that the cause of communicable disorders 
in man and beast was satisfactorily and firmly established. The 
doctrine of a living infecting agent — a contagium vivum — in these 
maladies had certainly been accepted by physicians for a very 
long time, though it was based only on hypothesis; and even long 
belore then, again, it was imagined, in explanation of the pheno- 
mena of contagion, that in transmissible maladies there was given 
off an imponderable and subtle matter — an aura contagionis— 
which was the active principle operating in their production ; this 
unknown something could originate the disorders in healthy bodies 
into which it had penetrated from those already suffering from 
its effects. Then the chemical notion of the cause of fermenta- 
tion, originated mainly by Liebig, was applied to these diseases, 
which were, and are now, consequently designated zymotic (from 
the Greek word for leaven). Like the ferments, the poisons 
and disease processes were supposed to be the results of atomic 
disturbance peculiar to substances in course of molecular change, 
and capable of communicating themselves to the various con- 
stituents of the living body. As with fermentation, so with 
contagious diseases ; the part played by the microscopic or- 
ganisms, as shown by Pasteur, revolutionised our ideas and 
revived the doctrine of living contagia. And Chauveau, the 
eminent director of the Lyons Veterinary School, was the first to 
demonstrate that the virus of a contagious disease (sheep-pox) was 
particulate, while putrefaction in wounds was due to atmospheric 
germs. In 1862, also, Pasteur had announced in his memoir 
on Spontaneous Generation, and in opposition to the views then 
entertained, that when urine becomes ammoniacal the alteration 
is caused by a microscopical fungus, and not by mucus or 
pus ; at a later period he established the fact, that in affections 
of the bladder ammoniacal urine was always associated with 
the presence of this fungus, to the development of which 
borax, he discovered, was antagonistic. The application of 
this discovery in the treatment of urinary disorders has been 
Jnost beneficial ; as the dangerous fermentation of urine in the 
