given, on the same subject
by the late Professor Faraday. The Professor, having seen the _resume_ I
had written, warmly commended the execution, and generously accorded me
his sanction to make any use of it, whether for the purpose of a lecture
or otherwise, as might seem good to me. It is on the ground of this
sanction I feel warranted to print it here.

_THE OIL FROM LINSEED_.

Various processes have for a long time been in use for the purpose of
extracting the oils from different species of nuts and seeds, a few of
the more interesting of which are not unworthy of brief notice and
description.

In Ceylon, where cocoa-nuts and oil-producing seeds abound, the means
employed by the natives in the last century for extracting the oils were
of a most primitive character. A few poles were fixed upright in the
ground, two horizontal bars attached to them, between which a bag
containing the pulp of the seed or nut was placed. A lever was then
applied to the horizontal bars, which brought them together, thus
creating a pressure which, by squeezing the bag, gradually expressed the
oil from the pulpy substance. This rude machine was at that time of day
one of the most approved for the purpose.

The system of pestle and mortar was also in use, but as the process was
necessarily very slow, this method was seldom resorted to. An
improvement on this system was invented by a Mr. Herbert, whose design
it had been to construct a powerful and efficient machine which should
combine cheapness and simplicity. It consisted of three pieces of wood,
viz., an upright piece fixed in the ground, from the lower and upper
extremities of which there projected the two other pieces, the top one
attached to the joint of a long horizontal lever, and the lower one to
the joint of a vertical one. The fixed upright post and the horizontal
lever formed the press. The bag of pulp being put between the upright
one and the vertical, the pressure was obtained by suspending a negro or
a weight from the lever.

In another press of the same or a similar kind, the bags were placed in
a horizontal frame, and a loose beam of wood pressed down on it by a
lever.

Another form of press had cambs and wedges; also a modification of it by
Mr. Hall of Dartford, who applied the pressure by means of a
steam-cylinder. The cambs are arranged alternately, so that one is
filled while the other is being pressed. This brief notice will suffice
to give an idea of s