142 
THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. 
[August 20, 1870. 
more sugar decomposed within sixteen hours than in 
the standard mixture. 
Caustic potash, soda and ammonia, added to the 
mixture in such quantity as to render the liquid 
strongly alkaline, did not hinder fermentation; but 
a much longer time elapsed before the evolution of 
gas became evident, since the carbonic acid was 
taken up by the alkalies until bicarbonates had been 
formed. 
Fermentation is remarkably retarded by chloro¬ 
form. After adding 30 c.c. of a clear, filtered solu¬ 
tion of chloroform in warm water, several mixtures 
were left to ferment for fifteen or eighteen hours, 
with the following results as regards the sugar de¬ 
composed :— 
I. II. III. 
Mixtures with chloroform 0 - 240 1‘240 TOO grm. 
„ without „ P670 2‘230 434 
The mixture I. was tested for sugar eighteen hours 
after fermentation, II. fifteen hours after, and III. 
forty hours after. 
Against 100 parts sugar decomposed in the stand¬ 
ard mixtures, there was in I. only 14 per cent, de¬ 
composed, within the same time, where chloroform 
was present; in II. there was only 55 per cent, de¬ 
composed. 
As chloroform is very sparingly soluble in water, 
if it may be assumed that the solution contained its 
own volume of chloroform vapour, it would only 
amount to one-third of the volume of the mixtures, 
so that the action of chloroform may be regarded as 
very powerful. A few drops of chloroform added to 
one of the mixtures, stopped the fermentation com¬ 
pletely. 
My experiments as to the influence of quinine 
upon fermentation are confirmatory of the results 
obtained by Dr. Kernel’ and others. Small quantities 
retard, while larger quantities entirely stop fermen¬ 
tation. With an addition of 0’2 grm. sulphate of 
quinine, the mixture contained 4 - 75 gim. sugar after 
forty-eight hours, while in the standard mixture the 
whole of the 5 grm. had been decomposed. 
In neutral solutions nicotine appears to accelerate 
fermentation somewhat. With an addition of 0 - 5 
grm. hydrochlorate of nicotine, the sugar decom¬ 
posed after fourteen hours was as 11 : 10 in the 
standard mixture, so that one-tentli of the sugar 
remained in the unmixed solution of sugar; after 
thirty-six hours the quantities of decomposed sugar 
were as 29 5 : 26‘5, or in the same ratio as before. 
Therefore in both instances the acceleration was ap¬ 
parently the same. 
The influence of strychnine is peculiar. On ad¬ 
dition of small quantities, fermentation is at first 
accelerated, then it is retarded. The mixtures con¬ 
taining strychnine evolve much more gas during the 
first six hours than the standard does; they froth 
considerably more and readily rise over the top of 
the vessel. 
In two mixtures, containing respectively 0‘01 grm. 
and 0T grm. hydrochlorate of strychnine, the quan¬ 
tities of sugar decomposed within four hours were 
to the quantity decomposed in the standard as 
15 : 14 : 13; after eighteen hours they were as 
24 : 24 : 25 - 7, so that it would seem there was ac¬ 
celeration during the first four hours and a retarda¬ 
tion subsequently. 
This retardation is more recognizable when the 
addition of strychnine is increased. On adding 0’2 
grm. of the salt, there were decomposed in two mix¬ 
tures— 
With strychnine . . . 3'09 grm. sugar. 
Without ,, ... 368 „ 
Creatin appears to retard fermentation, while crea¬ 
tinine appears to accelerate it, and at the same 
time the creatine is partially converted into creati¬ 
nine. 
An exceedingly minute quantity of prussic acid 
suffices to retard fermentation and to stop it alto¬ 
gether. In a mixture containing O'018 grm. dry 
acid, the quantity of sugar decomposed within six¬ 
teen hours was only 0 6 grm., while on the standard 
there was 3’4 gnu. decomposed, or six times as 
much. With a large quantity of prussic acid there 
was no fermentation. 
The action of the organic substance in yeast-water 
upon cane sugar is not hindered by prussic acid. 
When yeast-water, mixed with a few drops of the 
acid and a solution of cane sugar, is left for some 
hours, a certain quantity of grape sugar is found to 
have been formed. On saturating the liquid with 
oxide of mercury, filtering, and heating the filtered 
liquid after addition of caustic soda, a grey precipi¬ 
tate of metallic mercury is produced. It is only 
grape sugar that has this property of reducing an 
alkaline solution of cyanide of mercury. 
However, prussic acid has a remarkable influence 
upon yeast-water: it has already been mentioned 
that yeast-water left in contact with the air becomes 
turbid and deposits a white sediment. Frequently 
there is also a layer of mould formed on the surface. 
This alteration appears to be entirely prevented by 
prussic acid. Yeast-water mixed with a mere trace 
of prussic acid remains for weeks perfectly clear; 
there is no sediment formed nor any appearance of 
moulding. 
Schonbein has already noticed the retardation 
caused by prussic acid, and one of its most remark¬ 
able features is that the capability of yeast to pro¬ 
duce fermentation is not destroyed. Yeast that has 
been kept for some long time in contact with tole¬ 
rably strong prussic acid was found, after washing 
out the acid, to produce perfectly normal fermenta¬ 
tion in sugar solution. 
It appears, therefore, that prussic acid does not 
effect any decomposition of the cell contents, nor 
enter into any permanent combination with any of 
its constituents, but that its presence suffices to sus¬ 
pend the molecular motion taking place in the cells 
just in the same way that a weak solution of car¬ 
bolic acid or of creasote does. 
When yeast is brought in contact with solution of 
peroxide of hydrogen, a copious evolution of oxygen 
takes place, as pointed out by Sclilossberger; but if 
the yeast be mixed with some prussic acid before¬ 
hand, there is no decomposition of the peroxide of 
hydrogen and no evolution of gas. 
This phenomenon calls to mind the remarkable 
observations of Schonbein as to the action of prussic 
acid on blood-pigment and materials susceptible of 
putrefaction. He found that when fresh blood is 
mixed with a solution of peroxide of hydrogen, the 
equilibrium of this unstable compound is so much 
disturbed that its constituents rapidly break up into 
water and oxygen gas. However, the admixture of 
a very minute quantity of prussic acid entirely neu¬ 
tralized the decomposing influence of the red pig¬ 
ment on the peroxide, and the mixture then became 
dark blackish-brown. 
