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THE PHARMACEUTICAL JOURNAL AND TRANSACTIONS. [September 3, 1870 . 
samo thing. All the marble and all the hydric chloride 
which takes part in the formation of those three pro¬ 
ducts dis&ppeared as such, and they resolved themselves 
into other compounds possessing different properties; 
but the weight of the products is equal to the weight of 
the materials. That rule holds good throughout all 
ordinary cases of chemical action. 
On the other hand, in fermentation it is not so; one 
of the active substances is formed, and the more active 
the fermentation, the more does it grow. In fact, if you 
want to get yeast, you must go to a place where the 
breaking up of sugar into alcohol and carbonic acid 
is going on ; or if it is in the south, you must go to where 
wine is being made, you go to a wine-maker, and get the 
yeast from him. The only way of getting yeast is from 
that process of fermentation which sets in spontaneously 
under the conditions I named to you. 
I ought, however, in justice to the wonderful process 
which I alluded to, to give you two or three other 
particulars regarding it. I showed that sugar is broken 
up by the ferment into these products, but no case is 
known of pure sugar—and when I say pure sugar, I 
mean sugar in the purest form in which we have it— 
being decomposed by yeast. If you were to put some 
ready-made yeast—thriving, growing, yeast—into a so¬ 
lution of chemically pure sugar, some of your yeast 
would decompose, some of it would resolve itself into 
other products, and other parts of it would be absorb¬ 
ing those products which are present in the liquid, and 
whenever the process is to be carried on advantageously 
and rapidly, it is customary to add some saccharine 
liquid—some other substance capable of nourishing the 
yeast. When I want good fermentation I do not take 
water to dissolve my sugar and put yeast into it, but I 
boil some of this malt, which is one of the best materials 
for the purpose, in water, and take a decoction of malt 
or decoction of yeast and put the sugar into it. In such 
a liquid there are several bodies which we know ; and I 
may safely say that there are a great many others which 
we do not know, and there is no doubt that their pre¬ 
sence is of considerable importance to the chemical 
change which takes place. There are substances which 
I shall presently have occasion to show you and to speak 
of, formed by the germination of the grain, by the for¬ 
mation of the malt, which are related somewhat to this 
body which I have here. This was some pure wheat 
hour—every kind of flour would not do—and it is sup¬ 
posed that some people mix other materials with flour. 
It was kneaded up with water, pressed together, and, 
whilst the pressure was being continued, water was 
allowed to trickle over it. I have in another bottle 
some of the water that flowed over it. There is a 
white substance deposited from this water, which is 
commonly known and much used by the name of starch, 
and starch is, in its chemical composition, first cousin to 
sugar ; it is a substance which passes over very readily 
into a kind of sugar by a process I shall presently have 
occasion to allude to. But the little ball of flour while 
being kneaded had the starch washed away from it, 
and I have left, as the result, a substance which is 
commonly known by the name of gluten. If I were to 
describe it in chemical language, I should say it is some¬ 
thing. like flesh, or the muscular fibre of animals, for, in 
chemical composition, it approaches very nearly to that. 
When , barley is malted, and kept in a warm place for 
some time, the grains begin to germinate and decompose, 
and some bodies are formed from this gluten, which is 
partially broken up. The malt contains also some sugar 
made from that starch—grape sugar, as we usually 
call it. 
If we had only these extreme cases, I really do not 
know what.we should do. If we had in our science one 
set. of bodies which appeared so constantly to act at 
variance with the general laws which the others obey, 
I think we could not call chemistry a science. I have 
taken two or three examples to show you the definite 
proportions which we find to regulate the ordinary 
process of combination. I might have taken thousands, 
but the point is that this law does not appear to apply at 
all to these chemical changes which we call fermentation. 
One of the active substances in fermentation is being- 
formed, it is increasing, not disappearing at all, and the 
contradiction is so strong and manifest that the only way 
out of the difficulty will be to do something of the kind 
which I was speaking of some time ago, that is to say, 
see if we cannot get some intermediate facts which .will 
serve to connect the extreme ones; to see if we cannot 
get at first something between the two classes, and then 
try to get some further links between them. There are 
processes of chemical change—I will not call them pro¬ 
cesses of fermentation, for I do not know whether they 
are, but which are analogous to it, and some of them are 
very interesting and very beautiful. I have here a 
substance called amygdalin, made from bitter almonds. 
It is a bitter-tasting substance and consists of four 
elements -which it is not necessary that I should 
name. In this other bottle I have a paste formed of 
sweet almonds, which have been crushed with a pestle 
and mortar, and I will put some of it into the warm 
distilled water in this flask. Into the mixture I will 
put some of this amygdalin. If I were to leave it with¬ 
out that addition, there would be very little change; the 
substance would gradually subside, but there would be 
no product given off in the way you will presently see. 
After letting it stand for a few minutes, I will pour 
some of the mixture into an open vessel, and we shall 
be able, without difficulty, to perceive a fragrant smell, 
which is due to the presence of a liquid of which I have 
a quantity here, a substance known by the name of oil 
of bitter almonds. If we were to perform the same 
experiment on a large scale, and macerate some of this 
amygdalin with almond paste, put them together with 
warm water, distil the mixture and collect what comes 
over, we should find that water would pass over and 
with it would be a few drops of oil of bitter almonds, 
and the amygdalin would be decomposed in the process. 
There is in the sweet almond paste a substance which I 
cannot describe in better terms than by comparing it to 
that gluten which I showed you just now. It is very 
similar to it in its composition, and by the contact of this, 
the synaptase, as it is called, with the amygdalin, the 
elements of the amygdalin are broken up into several 
products ; one of them is the oil of bitter almonds, an¬ 
other is prussic acid, which generally accompanies the 
oil, the third is a variety of sugar of the kind which is 
called grape-sugar and there is probably also some 
formic acid. Here we have the breaking-up of a com¬ 
plex body—amygdalin—into several simpler bodies by 
the action of the body called synaptase; but there is not 
in the process, as far as I know, any living organism at 
work. There is a substance which is somewhat similar 
to these living organisms, but there is no organized struc¬ 
ture, as far as our knowledge goes at present. 
Take another experiment. I have here something 
which is not a blanc mange, although it looks something 
like it; it was made by boiling potato-starch with water. 
We let it cool, and then turned it out; some was put 
into a flask with two or three ounces of crushed malt. 
It was warmed to a temperature of 60° Centigrade for 
about an hour; there was no boiling. The substance 
was then squeezed through a cloth to keep back the 
husks of the malt, and here is the liquid which ran 
through. It is perfectly liquid, and its consistency 
is entirely different from that of starch, from which 
it was made; it is quite sweet to the taste, and there 
is a large quantity of sugar in it. There is also another 
body which we class with the sugars ; that is, there is in 
this liquid a good deal of a kind of gum, which we call 
dextrine, which would easily pass into sugar. The 
starch, when it was being converted by the action of the 
malt into those soluble bodies, did not, so far as we 
know, break up into simpler substances; the process 
