F. C. MINETT AND M. R. DHANDA
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The observations set out in this paper do not support the view of those
who believe that the anthrax bacillus may lead a saprophytic mode of exis-
tence. In a sense, therefore, it might be considered erroneous to speak of
anthrax as a soil disease. It is admitted that in most countries soil tempera-
ture and moisture conditions might at times be suitable but there was no sign
of growth in natural soil stored in the laboratory in bottles under favourable
conditions and there seems to be no reason why the result should have been
otherwise in the open. One may put it that the organism has no need to rely
on saprophytism to maintain itself in the world, since in animals dying of
anthrax the disease is septicaemic and hence there is a good chance of the
surroundings becoming heavily contaminated. Considered from this point
of view, the organism is a parasite as obligatory as, say, the tubercle bacillus
both in hot and in temperate countries, but, at the same time, its chance of
survival outside the host are high owing to the resistance of its spores.
We have seen little in the literature which might help one to visualize
quantitatively the possible extent of ground contamination. Szpilman
[1914] refers to an observation where one loopful of blood from a rabbit at the
time of death produced some 4,000 anthrax colonies, or nearly 200 million
bacteria in 100 gm. blood. We have taken the opportunity of making some
further observations of the same nature. In the blood of guinea-pigs freshly
dead of anthrax we have found the numbers of organisms to vary from about
one to 25 millions in each drop. In the blood of 5 goats dying of anthrax in
other experiments, the numbers of anthrax colonies (in millions) developing
from 1.0 c.c. of blood were : 22, 50, 72, 260, 370. From the blood-stained
nasal discharge of dead goats the number of colonies (in thousands) growing
from 1.0 c.c. were : 250, 460, 520, 1000. In 4 goats the nasal discharge
was not visibly blood-stained ; from 3 of these no anthrax colonies were ob-
tained, from the fourth there were 18,000 per c.c. In a hill bull just dead of
anthrax, the organisms in blood-stained nasal discharge numbered 800,000
per c.c. In another hill bull freshly died of anthrax, which we had the oppor-
tunity to examine, there were 2.5 million viable organisms per c.c. haemo¬
lysed blood taken from a peripheral vein and in the blood-stained nasal
discharge there were 8,000 per c.c.
It cannot be said that the failure of the anthrax bacillus to grow in natural
soil or water was entirely unexpected. The organism is known to be suscepti-
ble to the action of bacterial antagonists and these apparently suffice to res-
train multiplication even when, by chance, temperature and other conditions
are favourable. We have, in fact, isolated from Mukteswar soil two bacterial
species which are definitely inhibitory to the anthrax bacillus.
In the case of Cl. chauvœi, the matter is not so straightforward, mainly
owing to technical difficulties, while the literature only contains vague expres-
sions of opinion which are of little value. From the knowledge which has
been gained of mixed infections in the animal body in which anaerobes are
present, we were prepared to find that in unsterilized soil or water aerobes
might assist the multiplication of chauvœi. There has been no satisfactory
evidence of this. It seems that, if the organism multiplies at all it is usually
very restricted, even when extra organic matter is provided. If chauvœi
grows apart from living tissues, it may be that it is in the body after death