February 3,1872.] THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
635 
•Wish a complete theory of acetification which has been 
•carried out practically in a new and successful industry 
in the manufacture of vinegar, he proceeded to state the 
principle upon which that is based. Whenever wine is 
transformed into vinegar it is by the action of My coder ma 
accti developed upon its surface. He did not believe 
that there existed in any country, a single drop of wine, 
acidified spontaneously in contact with air, unless the 
Mycoderma accti had been present previously. This 
microscopic vegetation has the faculty of condensing the 
oxygen of the atmosphere in a similar manner to pla¬ 
tinum black or blood globules, and carrying it to sub¬ 
jacent matter. In what is called the “ German process ” 
the chips of wood or pieces of charcoal that are placed 
in the acetification-casks are but supports of the Myco- 
derma aceti, and do not, by their porosity, intervene in 
the chemical action, as ^as believed previously to the 
publication of his memoir. 
The correctness of this view is formally denied by M. 
Liebig, who says that the elements of nutrition of the 
Mycoderma are excluded from the dilute alcohol used in 
making vinegar, which is produced without its interven¬ 
tion. He also states that he has consulted M. Riemer- 
schmied, the head of one of the largest and best conducted 
manufactories of acetic acid in Germany, who has in¬ 
formed him that the diluted alcohol receives no admix¬ 
ture during its transformation, and that except the air 
and the surfaces of the wood and charcoal nothing can 
act upon the alcohol, and that he does not believe in the 
presence of the Mycoderma accti. Finally, M. Liebig states 
that he himself has been unable to detect any trace of it 
in wood shavings that have been used in the manufacture 
twenty-five years. In answer to this apparently con¬ 
clusive argument, that a plant necessarily containing 
mineral elements could not be developed in a medium 
not containing them, and to another in which it was im¬ 
puted that he had claimed to produce beer-yeast, which 
contained sulphur, in a medium from which that ele¬ 
ment was absent,*—M. Pasteur replied, that in the for¬ 
mer case the alcohol was diluted with ordinary water 
which contained all the mineral elements necessary to 
the life of the Mycoderma accti , and that in the latter the 
yeast-ashes used as a mineral medium contained sul¬ 
phates. 
As a method of testing the truth of the respective 
theories, M. Pasteur proposed that Baron Liebig should 
name one or more members of the Academy, in whose 
presence, and with substances furnished by Baron 
Liebig himself, he would repeat the two chief experi¬ 
ments, the truth of which had been contested. He would 
prepare in a mineral medium as much beer-yeast as 
could reasonably be required, provided M. Liebig bore 
the expense. Upon the same condition he would pre¬ 
pare a few kilograms of vibrion flesh, of which all the 
carbon, nitrogen, sulphur, phosphorus, and cellulose and 
fat matters should be obtained from a medium of crys- 
tallizable mineral substances and fermentable organic 
matter. As to the presence of Mycoderma aceti on the 
beech shavings, if M. Liebig would obtain some from 
the manufactory referred to, dry them quickly in a stove, 
and send them to Paris, he would engage to demonstrate 
the presence of the mycoderm on the surface of the 
shavings. Another suggestion he made was that M. 
Riemerschmied should fill one of his vats which had been 
in use for some time with boiling water for half an hour, 
allow it to cool, run the water off and resume operations. 
According to M. Liebig the fermentation would go on 
just as before; but he (M. Pasteur) affirmed that no 
more vinegar would be produced until, at least, sufficient 
time had elapsed for a fresh growth of mycoderms to 
appear on the shavings, for the boiling water would 
have killed all the old fungus. 
The President (M. Faye) proposed that the Academy 
Pharm. Journ. 3rd Ser. Yol. I. p. 103. 
should engage to bear the expense of the experiments 
necessary for the solution of the questions raised, and the 
proposition was agreed to. 
M. Fremy said that for many years he had studied 
this subject, and that in 1841, a time when M. Pasteur 
had scarcely entered the scientific world, he had, in con¬ 
junction with M. Boutron, published a memoir on 
“ Lactic Fermentation.” They had shown that in this 
fermentation, by which they meant the production of 
lactic acid in soured milk, it is the sugar of milk which is 
the fermentable element; the ferment, which was very 
different from yeast, and which they called the lactic 
ferment, being derived from the caseous matter. They 
had thus clearly distinguished between alcoholic and 
lactic fermentation. They had also established that 
fermentation was not confined to sugar in the presence of 
yeast, but extended to many other organic bodies. The 
same) ferment would not cause different fermentations, 
each fermentable substance requiring a ‘special agent; 
but the same albuminous substance could form, accord¬ 
ing to circumstances, different ferments; thus caseine 
produced equally alcoholic, lactic and butyric ferment. 
Their views were very different to those of M. Pasteur, 
as they considered that yeast had its origin in the de¬ 
composition of albuminous matter, while he maintained 
that it was produced by germs. M. Fremy said that he 
had pointed out to M. Pasteur that the juice of the 
grape, carefully filtered and quite clear, undergoes fer¬ 
mentation when exposed to the air, and produces a con¬ 
siderable quantity of grains of yeast, and had asked him 
to explain the presence of alcoholic fermentation under 
such circumstances. M. Pasteur had replied that it was 
due to the germs of yeast that existed in the air falling 
into the juice. But this presupposed that the air contained 
so large a quantity of yeast germs that, in any locality, 
when the juice was exposed to the air, that moment a 
germ fell into it and caused it to ferment. M. Pasteur 
had stated that germs of yeast could develope in a liquor 
consisting of sugar, phosphates and ammoniacal salts. 
Such a solution, therefore, Jexposed to the air, should 
undergo fermentation by contact with the germs con¬ 
tained in it; but he had not been able to recognize al¬ 
coholic fermentation in such a mixture,—a result that M. 
Pasteur attributed to the formation of some other fer¬ 
mentation which prevented the production of the yeast. 
M. Pasteur replied that the development of beer- 
yeast in a saccharine mineral medium, where it had been 
directly sown, was a very delicate experiment, since such 
a medium was more suitable to the production of various 
other organisms. To repeat the experiment without the 
direct sowing of the yeast-germs he compared to an at¬ 
tempt to grow corn in land covered with other plants, 
the soil of which was favourable to those plants and not 
to corn. M. Fremy demanded the solution of a problem 
that he himself was the first to propose in the following 
terms, “ To find a saccharine mineral medium that would 
be as suitable to the production and development of the 
alcoholic ferment as the natural must of the grape itself.” 
This problem is not insoluble, but it would require long 
research. But one ferment was as good as another to 
prove the truth of the theory, and the results that he had 
obtained with the lactic, butyric and various other fer¬ 
mentations ought to be sufficient evidence of the truth of 
the theory. He denied that he had ever said, as repre¬ 
sented by M. Fremy, that atmospheric air contained so 
great a quantity of yeast-germs; that, in all localities, 
when the juice was exposed to the air, that moment a 
germ fell into it and caused fermentation. On the con¬ 
trary, he had demonstrated with an exactness which had 
not been contested that all the germs—either of yeast or 
of other organisms on the surface of the fruit or wood, 
and those that were floating in the air during the mani¬ 
pulation or were present on the sides of the vessels used 
—were forcibly introduced into the juice in the grape 
vats. He concluded by denying (1) that caseine will 
produce equally alcoholic, lactic and butyric ferment, or 
