160 
M. L. PASTEDR. 
bodies of man and of animals, vaccine-viruses of limited development, able to pre¬ 
vent the fatal effects of the first. Therefore did we, with the collaboration of M. 
Chamberlain and Roux, direct all our efforts to the research of the possible 
generation of the oxygen of air in the attenuation of the viruses. 
The virus of anthrax being the most studied, was the first to attract our 
attention. Still we were from the start to meet with a difficulty. Between the 
microb of chicken cholera and that of anthrax, there is an essential difference 
which does not allow a vigorous action in the new research similar to that of the 
old. Indeed, the microb of chicken cholera, does not seem to change in its cul¬ 
tivation into true germs. In those, they are only cells or segments always ready 
to multiply by scission, the peculiar conditions when they give true germs re¬ 
maining unknown. 
The yeast of beer is a striking example of these cellular productions able to 
multiply indefinitely, without appearance of their original spores. There exist 
many amongst the mucedinae with the tubular myceleum which in some conditions 
of cultivation, give chains of cells more or less spheroidal, called conidia. These 
loosened from their branches, may reproduce themselves under the form of cells, 
without ever showing, unless by a change in the conditions of the cultivations, 
the spores of their respective mucedinae. These vegetable organizations could be 
compared to the plants which are multiplied by grafts and whose fruits and seeds 
are not used to serve in the reproduction of the mother plant. 
In its artificial cultivation, the bacteria of anthrax acts very differently. Its 
mycelian threads, so to speak, are scarcely multiplied during twenty-four or forty- 
eight hours that they are seen changing, principally those which have the free 
contact of the air into ovoid, very refringent corpuscles, separating little by little, 
and constituting the true germs of the small organism. Then, observation shows 
that these germs, so rapidly formed in the cultivation, do not alter with time, from 
the action of atmospheric air either in their vitality or their virulency. I could 
show the Academy, a tube containing spores of a bacteria of anthrax formed four 
years ago, the 21st of March, 1877 ; each year, the germination of the little cor¬ 
puscles is tried and it always takes place with the same facility and rapidity as at 
the beginning; each year also the virulency of the new cultivation is tested and 
it shows no apparent loss of power. Consequently, how shall we test the action 
of atmospheric air upon the virus of anthrax with the hope of weakening it ? 
The knot of the difficulty is perhaps altogether in the fact of this rapid pro¬ 
duction of the germs of the bacteridie which we have just mentioned. Under its 
thready form and in its multiplication by scission, is not this organism entirely 
comparable to the microbe of chicken cholera? That a germ properly so called; that 
a seed should undergo no change from the air, this may be easily understood ; but 
it is not so easily conceived that, if change is to take place, it should be in pre¬ 
ference upon a mycelian thread. It is thus that a graft, which would be left alone 
on the ground to the contact of air, should soon lose its vitality while in those 
conditions the seed would preserve its power of reproducing the plant. If these 
views are correct, we are brought to think that to test the action of the oxygen 
of air upon the bacteria of anthrax, it would be necessary to submit to that action 
the mycelian development of the small organism, in circumstances where it could 
not produce the smallest germ corpuscle. Hence, the problem which consists in 
submitting the bacteridies to the action of oxygen, consists in preventing entirely 
