Yeast | Page 5

not know whether it is
common in Lancashire, but it is certainly very common in the Midland
countries), the word "barm," which is derived from a root which
signifies to raise or to bear up. Barm is a something borne up; and thus
there is much more real relation than is commonly supposed by those
who make puns, between the beer which a man takes down his throat
and the bier upon which that process, if carried to excess, generally
lands him, for they are both derived from the root signifying bearing up;
the one thing is borne upon men's shoulders, and the other is the
fermented liquid which was borne up by the fermentation taking place
in itself.
Again, I spoke of the produce of fermentation as "spirit of wine." Now
what a very curious phrase that is, if you come to think of it. The old
alchemists talked of the finest essence of anything as if it had the same
sort of relation to the thing itself as a man's spirit is supposed to have to
his body; and so they spoke of this fine essence of the fermented liquid
as being the spirit of the liquid. Thus came about that extraordinary
ambiguity of language, in virtue of which you apply precisely the same
substantive name to the soul of man and to a glass of gin! And then
there is still yet one other most curious piece of nomenclature
connected with this matter, and that is the word "alcohol" itself, which

is now so familiar to everybody. Alcohol originally meant a very fine
powder. The women of the Arabs and other Eastern people are in the
habit of tinging their eyelashes with a very fine black powder which is
made of antimony, and they call that "kohol;" and the "al" is simply the
article put in front of it, so as to say "the kohol." And up to the 17th
century in this country the word alcohol was employed to signify any
very fine powder; you find it in Robert Boyle's works that he uses
"alcohol" for a very fine subtle powder. But then this name of anything
very fine and very subtle came to be specially connected with the fine
and subtle spirit obtained from the fermentation of sugar; and I believe
that the first person who fairly fixed it as the proper name of what we
now commonly call spirits of wine, was the great French chemist
Lavoisier, so comparatively recent is the use of the word alcohol in this
specialised sense.
So much by way of general introduction to the subject on which I have
to speak to-night. What I have hitherto stated is simply what we may
call common knowledge, which everybody may acquaint himself with.
And you know that what we call scientific knowledge is not any kind
of conjuration, as people sometimes suppose, but it is simply the
application of the same principles of common sense that we apply to
common knowledge, carried out, if I may so speak, to knowledge
which is uncommon. And all that we know now of this substance, yeast,
and all the very strange issues to which that knowledge has led us, have
simply come out of the inveterate habit, and a very fortunate habit for
the human race it is, which scientific men have of not being content
until they have routed out all the different chains and connections of
apparently simple phenomena, until they have taken them to pieces and
understood the conditions upon which they depend. I will try to point
out to you now what has happened in consequence of endeavouring to
apply this process of "analysis," as we call it, this teazing out of an
apparently simple fact into all the little facts of which it is made up, to
the ascertained facts relating to the barm or the yeast; secondly, what
has come of the attempt to ascertain distinctly what is the nature of the
products which are produced by fermentation; then what has come of
the attempt to understand the relation between the yeast and the
products; and lastly, what very curious side issues if I may so call
them--have branched out in the course of this inquiry, which has now

occupied somewhere about two centuries.
The first thing was to make out precisely and clearly what was the
nature of this substance, this apparently mere scum and mud that we
call yeast. And that was first commenced seriously by a wonderful old
Dutchman of the name of Leeuwenhoek, who lived some two hundred
years ago, and who was the first person to invent thoroughly
trustworthy microscopes of high powers. Now, Leeuwenhoek went to
work upon this yeast mud, and by applying to it high powers of the
microscope, he discovered