|
Main
- books.jibble.org
My Books
- IRC Hacks
Misc. Articles
- Meaning of Jibble
- M4 Su Doku
- Computer Scrapbooking
- Setting up Java
- Bootable Java
- Cookies in Java
- Dynamic Graphs
- Social Shakespeare
External Links
- Paul Mutton
- Jibble Photo Gallery
- Jibble Forums
- Google Landmarks
- Jibble Shop
- Free Books
- Intershot Ltd
|
books.jibble.org
Previous Page
| Next Page
Page 29
By means of electric or magnetic action we can separate bodies
chemically combined, as well as unite them into chemical compounds; as
will appear if we place a piece of blotting paper upon tinfoil, and this
upon wool; if we then spread above these two pieces of test-paper,
litmus and turmeric, the one the test of acids, and the other of
alkalis, and saturate both with Glauber salt (which is by itself neither
an acid nor an alkali, but a combination of the two), and, finally,
connect each by means of a piece of zinc with the poles of a battery,
the test-papers will immediately change colour, as they do the one in
the presence of an acid simply, and the other of an alkali simply, but
never in a compound where these are neutralised; thus proving that the
compound has in this case been decomposed, and its elements
disintegrated one from another.
A very powerful magnet can be produced by coiling a wire round a bar of
soft iron, and attaching its extremities to the poles of a galvanic
battery, when it will be found that its strength will be proportioned to
the strength of the current and the turns of the coil. This is
especially the case when the bar is bent into the form of a horse-shoe,
and the wires are insulated and coiled round its limbs. The force
communicated to a magnet of this kind, which is often immense, is the
product of the chemical action which goes on in the battery, and, in a
certain sense, the measure of it. How great that is we may judge when
we consider that, evanescent as it is in itself, it has imparted a
virtue which is both powerful and constant, and ever at our service.
_Summary_.--Thus, then, on a review of the whole, we find all things are
endowed with attractive power, and that there is no particle which is
not directly or indirectly related, in manifold ways, to the other
particles of the universe. There is, first, the universal attraction of
gravitation, under which every particle is, by a fixed law, drawn to
every other within the sphere of existence. There is, secondly, the
attraction of cohesion or aggregation, which acts at short distances,
and unites the otherwise loose atoms of bodies into coherent masses.
There is, thirdly, the power by which elements of different kinds
combine into compounds with new and useful qualities, known by the name
of chemical affinity. And, lastly, related to the action of affinity,
aiding in it and resulting from it, there are those strange negative and
positive, attractive and repellant polar forces which appear in the
phenomena of electricity and magnetism, agencies of such potency and
universal avail in modern civilisation.
On the permanency of such forces and their mutual play the universe
rests, and its wonderful history. With the collapse of any of them it
would cease to have any more a footing in space, and all its elements
would rush into instant confusion. What a Hand, therefore, that must be
which holds them up, and what a Wisdom which guides their movements!
Verily, He that sends them forth and bids them work His will is greater
than any one--greater than all of them together. How insignificant,
then, should we seem before Him who rules them on the wide scale by
commanding them, while we can only rule them on the small by obeying
them! And yet how benignant must we regard Him to be who both wields
them Himself for our benefit and subjects them to our intelligence and
control!
FOOTNOTES:
[B] This paper on "Attraction" is the substance of a lecture which I
composed on the basis of notes taken by me when. I had the honour of
attending the Prince of Wales at the course given, on the same subject
by the late Professor Faraday. The Professor, having seen the _resum�_ 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.
Previous Page
| Next Page
|
|