Angust 13,1870.] THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
123 
influence exercised by a substance in a state of mole¬ 
cular motion upon another highly complex substance 
whose particles are held together feebly and are in a 
state of tension. If the molecular motion in the one 
substance be the consequence of disturbed equili¬ 
brium, some exercise of work may be ascribed to it, 
and this would become sensible in the dislocation or 
severance of the elements of the other substance. 
This view has not been generally accepted, and, 
quite recently, another one has been adopted by 
which the transformation of organic materials into 
inorganic compounds is ascribed to the nutrition and 
growth of inferior organisms. Thus the old idea of 
vital force, belonging to the last century, has again 
become current under a new form in the explanation 
of very simple chemical changes. 
“ Fermentation,” said Mitscherlich,* “ is caused 
by a plant organism, and putrefaction by an animal 
organism.” Then twenty-six years afterwards, Pas¬ 
teur has described certain species of fungi, some of 
which produce acetic fermentation, others lactic fer¬ 
mentation or mucous fermentation, while the butyric 
and tartaric fermentation, that resemble putrefac¬ 
tion, are assumed to be caused by vibrios. 
The characters of these animated ferments are 
very peculiar. 
The acetic acid fungus is, according to Pasteur, 
so much like the lactic acid fungus, that the two are 
frequently undistinguishable by the microscope. 
Moreover, the lactic acid fungus is said to resemble 
beer-yeast, f The action of these ferments is also 
very varied. 
According to Pasteur, acetic acid is the product of 
Mycoderma aceti ; but this plant also produces suc¬ 
cinic acid, l and, in contact with sugar, it gives rise 
to vinous fermentation.§ According to Pasteur, 
phosphates and alkalies are necessary constituents 
of this fungus, while Mulder declares that when burnt 
it does not leave the least trace of ash.|| 
The behaviour of the lactic acid fungus is still 
more remarkable, for its activity is not limited to the 
production of lactic acid only, and it is capable of 
producing butyric acid, mannite, mucus and even 
alcohol.** 
If sugar be fermented with beer-yeast, and the 
fermented liquor be exposed to the air, a layer of 
mould is formed on the surface, while the alcohol is 
converted into acetic acid. A portion of that mould, 
placed in contact until sugar and chalk, causes the 
conversion of the sugar into lactic acid. 
The lactic acid ferment also produces butyric acid 
under certain circumstances, though the proper bu¬ 
tyric ferment is infusorial; it converts sugar, gum 
and lactic acid into butyric acid. Atmospheric air is 
detrimental to it, and it is killed by access of air. How¬ 
ever, Maddrell and Engelhard found that lactate of 
lime, although recrystallized twice and therefore 
containing only a trace of lactic ferment, was re¬ 
markably susceptible of butyric fermentation; while 
in an experiment made specially to determine the 
point they observed, in opposition to Pasteur’s state¬ 
ment, that the butyric fermentation was accelerated 
by access of air.f f 
* Ann. Cliem. Pliarm. xlviii. 126. 
t £ Comptes Rendus,’ xlv. 903. 
X Bull, de la Soc. Chim. 1862, p. 52. 
§ Thomson, Ann. Chem. Pliarm. lxxxiii. 90. 
|| Ann. Chem. Pharm. xlvi. 24. 
** £ Comptes Rendus,’ xlv. 913. 
ft Ann. Chem. Pliarm. lxiii. 86. 
According to Pasteur the butyric ferment can be 
sown like beer-yeast. He states that in suitable media, 
such as solutions of sugar, ammonia, and phosphates, 
it increases, and that butyric acid is formed mean¬ 
while. But if the facts are the same as in the case 
of beer-yeast, there does not appear much hope of 
any particular result. The observations of these 
living ferments are obviously very superficial and 
contradictory, so that it is barely possible to say that 
dining the last twelve years there has been any ad¬ 
vance towards more definite ideas as to their nature 
and mode of action. 
In reference to the part taken by living organisms 
in putrefaction, Van den Broeck* expresses himself 
very clearly as follows:—“ The microscopic exami¬ 
nation of the five animal substances (egg-white, egg- 
yelk, arterial blood, gall and urine of the dog and 
oxen) has taught me that there is no connection 
between their putrefaction and the development or 
growth of vibrios.” 
From the moment a piece of muscle is separated 
from the living body it begins to undergo alteration; 
after some hours it acquires an acid reaction, the 
coagulable substances are coagulated, the contents 
of the muscular tubes become more solid and acquire 
a clouded appearance with a thickish consistence. 
The muscle contracts and thickens, or rigor mortis 
takes place; then, after some time, the stiflhess 
ceases, the acidity augments, and offensive-smelling 
products make their appearance. 
If organized ferments have nothing to do with the 
formation of the first products that appear in the 
muscles up to the occurrence of rigor mortis ,—and I 
believe there is no physiologist who thinks they have, 
—then it is difficult to understand how the further 
alterations can be determined by them. 
Fungi and vibrios are dependent upon organic ma¬ 
terial for their development and nutrition, and the 
cases where they are not met with in putrefying or 
decaying materials under ordinary conditions are 
seldom enough. Accordingly, as one observer finds 
them or not, opinion may shift from one side to the 
other, but it would be hopeless to expect from micro¬ 
scopic observations an elucidation of the part they 
play. 
If acetic fermentation be understood as the pro¬ 
duction of acetic acid from alcohol, it is from a che¬ 
mical point of view the most thoroughly investigated 
and most accurately known of all lands of fermenta¬ 
tion. 
Pasteur has maintained that the production of 
acetic acid is a process of fermentation, and that it is 
determined by the Mycoderma aceti. 
In the cultivation of Mycoderma aceti upon alco¬ 
holic liquids, the alcohol is converted first into 
aldehyde, and then into acetic acid. The vinegar- 
plant acts only when in direct contact with the air, 
not when it is immersed; it also requires as food 
phosphates and albuminous substances.f 
I have hitherto believed that the production of 
acetic acid was well understood, and that it consisted 
simply in the oxidation of alcohol. Finely divided 
platinum converts alcohol into acetic acid by means 
of the oxygen condensed upon it. A number of 
organic substances are known to absorb oxygen from 
the air and to retain for some time the power of oxi¬ 
dizing other substances, as in the case of platinum. 
* Ann. Chem. Pharm. cxv. 79. 
f £ Comptes Rendus,’ lviii. 142. 
