34 NOTES ON MICRO-ORGANISMS. 
wise existence would be well nigh impossible. Pathogenic 
organisms have not necessarily the same action in men and 
animals, in fact, their action varies much in different individuals ; 
for instance, Anthrax bacilli will produce the disease in human 
beings or herbivorous animals, but not in carnivorous animals or 
the omnivorous pig, but infusions from the blood or tissues of the 
last-named animals will nourish the organism. Death from the 
development of a specific Bacterium, such as in the case of 
Tubercle Bacillus inoculated into guinea pigs, is not always 
attended by the production of large numbers of the organisms, 
that is to say that their number is hardly commensurate with 
the effect. It has been argued from this that Bacteria may 
give rise to specific poisons in the blood, and that these are 
mainly accountable for the symptoms. 
There are two theories connected with non-recurrence of some 
diseases and immunity by inoculation. 
. That the organism uses up substances favourable to its 
grow ee and that a further supply of these matters is not directly 
forthcoming. ‘This is called the Exhaustion Theory. — 
2. That the organisms give rise to substances that act as 
poisons to Bacterial life, these substances remaining in the system 
for a greater or less time. This is known as the Antidote 
Theory, and covers the facts of the case much better than any 
other. 
Amongst antiseptics generally, Sulphurous Acid and Mercuric 
Chloride seem to be the most effectual, but they have very little 
effect on Bacteria in the state of spores. 
It will be fairly evident from what has been said of nourish- 
ment for Bacteria, that a particular food may suit one organism 
much better than another, and that it would be possible in a 
certain plasma to supplant an organism growing indifferently by 
one that could thrive in the same medium. An application of 
this view has recently been made by an Italian doctor, Cantani, 
in the case of consumption, or tubercular disease, by what is 
called Bacterium termo treatment, which consists in supplanting 
the tubercle Bacillus by inoculation of the lung substance with 
