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THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. [January 28,1871. 
SOCIETY OF ARTS. 
On Fermentation. 
BY PROFESSOR A. W. "WILLIAMSON, F.R.S. 
Lecture IV. — concluded. 
M. Pasteur has introduced a process which, I ga¬ 
ther from his statements, has already been adopted 
by a considerable number of wine-growers and mer¬ 
chants, which goes to the root of the matter in such 
-a way as to leave nothing to chance, for he has pro¬ 
ceeded upon the knowledge previously acquired by his 
accurate and masterly experiments, regarding the nature 
of all these little organisms, and the conditions which 
.are favourable to their development, and which are de¬ 
structive of them. He finds that when wine is heated 
to near the boiling-point, in any vessel in which it may 
be enclosed, and left in that vessel to cool, it may then 
be kept (provided the vessel be not opened) for any length 
of time without undergoing any of these deleterious 
changes. He finds also that so high a temperature as 
that I have named is not absolutely necessary, but that 
even if wine, which on keeping would be subject to the 
malady of acetification or ropiness, be heated to a tem¬ 
perature of G0° Centigrade (that is, about 140° in the 
elumsy and inconvenient scale which is still, I am sorry 
to say, in common use in this country), it will kill these 
organisms completely; and the experiment is so easily 
performed that any of you may do it with a very mode- 
pate amount of care. You ought to perform the experi¬ 
ment with several bottles at the same time, and to keep 
some similar bottles in the original state, in order to. 
observe the difference. In the month of September, when 
I last saw M. Pasteur, he gave me several bottles of wine, 
some of which were in their original state, whilst the 
-others had, after bottling, been heated to a temperature 
of 60°, or a little more. I have not yet opened any of 
them, but I have some of each sort here, and we will 
presently see what has been the result of the treatment. 
I ought to say that they have not been kept with proper 
precautions, for, on opening the case, I found that it had 
been left in such a position that the bottles had been 
standing with their necks upwards, which is not very 
favourable to the preservation of the wine. The experi¬ 
ment is so simple, that it is worth while for everybody 
to perform it. You should take some light wine, which 
you have reason to believe will not keep well; the bot¬ 
tles should not be too tightly corked, and there should 
be a little space left below the cork. You put several of 
these bottles into a vessel of water, cautiously if the water 
be warm, to avoid breaking them, and with them 'one 
bottle full of water, uncorked, you then warm the whole 
very gradually, until you find, by inserting a thermo¬ 
meter into the open bottle of water, that the temperature 
is up to 140° Fahrenheit; you then allow the whole to 
cool slowly. The corks are generally lifted a little by 
the expansion of the liquid and air within the bottles, 
and will require to be struck in again to their proper 
place. The same operation is performed on a large scale 
by wine-growers and merchants in France, in casks, and 
.several contrivances have been described for the purpose. 
'The simplest of all is to put a cask, with its bung up¬ 
wards, into any convenient vessel of water, so placing it 
that the top of the cask is just above the water. The 
water surrounding the cask is then warmed gradually until 
it is found, by lifting the bung and inserting a thermo¬ 
meter, that the wine is of a temperature 60° or 70° Centi¬ 
grade. The bung is then closed, and the whole allowed 
to cool. Another form of apparatus has been figured in 
■ft late book of M. Pasteur’s on acetification, which con¬ 
sists of a cask with one of its ends removed, and replaced 
by a sort of double bottom of metal. This cask is then 
put on the fire, so that the water in the false bottom may 
be heated, and raise the temperature of the wine in the 
.cask above, without danger of burning it. M. Pasteur 
recommends that when the wine has reached the right 
temperature it should be allowed to run, while still hot, 
into the cask into which it is to be kept, so that any little 
germs which may be present there may bo as much 
heated as the wine which comes in contact with them. 
He heats the wine in this operation to about 65° or 70 3 , 
but he says there is reason to believe that even 50° is 
sufficient. Upon all occasions on which it has been tested 
it has been found that the little parasites which are pre¬ 
sent, and which are the seeds of the maladies of which 
we have been speaking—and, no doubt, other organisms 
—are changed in such a manner as to be practically dead. 
Whether they are susceptible of being revived is an¬ 
other thing. It is not known, and it is not affirmed that 
there are no germs which might not, by contact with 
oxygen, be afterwards brought into life; but practically 
there are no organisms in the wine, after that tempera¬ 
ture has been applied to it, capable of growing in the 
closed vessel in which it is kept. M. Pasteur says that 
if the wine were, after that treatment, bottled, he would 
expect that some bottles would contain wine which would 
spoil, whereas the greater number probably would not, 
the reason being that the wine, on its passage from the 
cask to the bottle, would be liable to get some little 
germs from the air which possibly might retain some 
vitality, which would be stimulated by the oxygen. 
Therefore, all he affirms is, that when the wine is kept 
in the same vessel in which it was heated, it undergoes 
no further change whatever. 
With regard to the ordinary process of aerating wine 
by keeping it in bottles, 1 should like to show you an 
experiment which illustrates, in a very simple way, what 
is a very familiar well-known fact. Every one who has 
had occasion to keep wine knows what an immense dif¬ 
ference there is if you keep a bottle standing upwards or 
lying down. The difference is of this kind. If it stands 
upwards, the cork is dry, and air has access at a very 
rapid rate to the contents of the bottle, and the wine gets 
oxidized and spoilt; whereas, when the bottle is left 
lying down, the cork is wet, and the air has access much 
less rapidly,—in fact, only at such a low rate as is suit¬ 
able for mellowing and improving the wine. I have hero 
a couple of glass tubes, both open at one end, and closed 
at the upper end by a porous substance, which I may call 
a cork —it is, in fact, a cork made of plaster of Paris, a 
particularly porous substance,—one cork being wetted, 
so that the pores are full of water, whilst the other has 
been carefully kept dry, and this one is covered for the 
present with a little cap to prevent the access of the air. 
Here, in another vessel, is a mixture which is giving off 
hydrogen gas, which is passing upwards into these two 
tubes, one with a wet cork and one with a dry one. After 
a minute or two, both tubes will be full of pretty nearly 
pure hydrogen, and then we will remove them, and put 
the lower ends into this jar containing a coloured liquid. 
Most of you know that this porous substance allows hy¬ 
drogen to pass through it more rapidly even than the air 
which is now outside passes in, and therefore as the hy¬ 
drogen passes out of these tubes more rapidly than the 
air comes in, the liquid will be sucked up in the tubes, 
and we shall have a measure of the rate at which our 
gas passes through the wet cork and the dry cork, by 
noticing the difference in the rise of the liquid in the 
two tubes. If it passes quicker through the dry cork 
than the wet one, we shall find that the liquid will rise 
more rapidly in that tube, and I think you will find that 
the difference will be very great indeed. They aro now 
both standing in the coloured liquid, and already there 
is a perceptible rise in the tube with the dry plug; but 
in the other one I cannot yet see the liquid at all. So it 
is in the simple case of a wine bottle. If the cork of a 
bottle is wetted, so as to allow an exceedingly slow diffu¬ 
sion of air through the contents, the wine gets very slowly 
oxidized, and undergoes only that gradual transformation 
which is wanted; whereas, in the other case, it is turneu 
sour and spoilt by too rapid oxidation. 
I could gladly "have entered upon many other facts and 
