RELATION OF BOVINE TO HUMAN TUBERCULOSIS. 5 
At one period it would be considered contagious, at 
another this would be thought improbable, again several of 
the local manifestations of this disease would be looked 
upon as separate and distinct diseases; at other times it has 
been confounded with diseases that had no relation to it 
whatever. It seems strange, but it is nevertheless true, 
that while this disease has been known as affecting the 
lower animals, and a scourg;e in man (now claiming ten per 
cent, of the death rate) during all these centuries compara¬ 
tively nothing was accomplished in working out its etiology 
or pathology until within the last fifty years Villimian and 
Koch have placed the matter on a sound basis. 
IS A GERM DISEASE. 
Long before any suspicion existed as to the relation of 
bacteria to fermentation and disease, various scientists, at 
different times, had suggested that resemblance existed 
between the phenomena of certain diseases and fermenta¬ 
tion, but the idea that a virus or contagium might be some¬ 
thing of the nature of a minute organism, capable of spread¬ 
ing and reproducing itself, had never been thought of. 
The first vague notion in this direction was no doubt the 
ferment theory of Cagniard-Latour in 1828. In 1837, 
Schwann showed that fermentation and putrefaction were 
intimately associated with the presence of organisms derived 
from the air. By 1862 Pasteur had buried forever that 
“ will-o-the-wisp ” spontaneous generation and repeated and 
extended such experiments and proved the way for a com¬ 
plete explanation of the anomalies. 
From 1870 onward the “germ theory of disease” had 
passed into general acceptance and now has become an 
assured fact, and in a sense has revolutionized the theories 
of disease and treatment in that now a persistent war is 
waged on the micro-organisms which excite the disease, and 
is not based altogether upon symptomology. Robert Koch 
first succeeded in demonstrating and isolating the specific 
bacillus of tuberculosis and achieved its artificial cultivation 
by the use of blood-serum. 
TRANSMISSIBILITY. 
The origin of the germ theory of disease and the 
discovery of the specific bacillus of tuberculosis are but 
parts of an old story now relegated to history, but when we 
