Page 40 - Ethel D. Hume - Bešam ili Paster: Izgubljeno poglavlje u istoriji biologije

PASTEUR'S MEMOIRS OF 1857 37
entire Memoir was printed in April, 1858, in the Annales de
1
Chimie et de Physique and from this latter we gain full
details.
The experiment consisted in Pasteur taking the sub-
stance developed in ordinary fermentation, nourished by
sugar, chalk, casein or fibrin, and gluten (an organic
matter occurring in cereals) and placing it in yeast broth
(a complex solution of albuminoid and mineral matters),
in which he had dissolved some sugar and added some chalk.
There was nothing new in the procedure, so Bechamp
points out 2 ; it was only the same experiment that Liebig
had undertaken some sixteen or seventeen years previously.
Unlike Liebig, he did not ignore microscopic examination
and so made observations that had been missed by the
German chemist. Thus Pasteur is able to tell us that a
lactic ferment is obtained, which, under the microscope,
has the appearance of little globules, which he named
"lactic-yeast," no doubt fromTtheir resemblance to yeast,
although in this case the little globules are much smaller,
i In short, he saw the minute organism known today to be
the cause of lactic-acid fermentation.
Now let us go on to his remarkable explanation of the
phenomenon. He tells us that it is not necessary to intro-
duce the lactic ferment in order to prepare it, as "z7 takes
birth spontaneously as easily as beer-yeast every time that the
conditions are favourable." 3 This assertion surely demon-
strates Pasteur's belief in the spontaneous generation both
of beer-yeast and of that which he called "lactic-yeast."
It remains to be seen what "the favourable conditions"
are, according to his teaching. He tells us before long.
"These globules of lactic-yeast take birth spontaneously in
the body of the albuminoid liquid furnished by the soluble
part of the (beer) yeast." 4 There is certainly nothing in
1
A. de Ch. et de Ph., 3e sirie, 52, p. 404.
2
Les Grands Problemes Me'dicaux, p. 56 et suivant.
3
"elle prend naissance spontaniment avec autant de faciliti que la levure de
biere toutes lesfois que les conditions sontfavorables." A. de Ch. et de Ph. je sirie,
52, p. 413-
4
"Les globules prennent naissance spontaniment au sein du liquide albuminoid
fournipar la partie soluble de la levure." A. de Ch. et de Ph. 3c serie, 52, p. 415.