_February 1852._
Professor Faraday's lecture, with which, according to use and custom,
the Friday evening course at the Royal Institution was opened, has
been the most noteworthy topic of scientific gossip since my last. The
subject, 'Lines of Magnetic Force,' is one not easily popularised,
otherwise, I should like to give you an abstract of it. One requires
to know so much beforehand, to comprehend the value and significance
of such a lecture. The learned professor's experiments, by which he
demonstrated his reasonings were, however, eminently interesting to
the crowded auditory who had the good-fortune to listen to him. He
promises to give us, before the close of the season, another, wherein
he will make use of that telescope of the mind--speculation, and tell
us much of what his ever-widening researches have led him to conclude
concerning magnetism; a science on which he believes we are shortly to
get large 'increments of knowledge.' Mr Wheatstone, too, having
produced a paper resuming his stereoscopic investigations, had the
honour of reading it before the Royal Society as their Bakerian
Lecture, as I prognosticated a month or two since. Of course in this
practical age the inquiry is put--Of what use is the stereoscope or
pseudoscope? With respect to the former, it is said that artists will
find it very serviceable in copying statuary groups; and a suggestion
has already been made, to adapt it to the purposes of microscopic
observation, as the objects examined will be seen much more accurately
under the extraordinary relief produced by the stereoscope, than by
the ordinary method. And it may interest astronomers to know, that Mr
Wheatstone believes it possible, by means of the same instrument, to
perfect our knowledge of the moon's surface and structure. For
instance: he proposes to take a photographic image of the moon, at one
of the periods of her libration, and a second one about fifteen months
afterwards, at the next libration, which, as you know, would be in the
opposite direction to the first. The two images being then viewed in a
stereoscope, would appear as a solid sphere, in which condition we
should doubtless get such an acquaintance with the surface of our
satellite as can be obtained by no other means. The reason for taking
the images with so long an interval between is, that although each one
represents the same object, each must be taken at a different angle;
and for an object so distant as the moon, the difference caused by the
libration would, it is believed, be sufficient for the desired result.
In the small pictures, however, the difference of angle is so slight,
that to the unpractised observer they appear precisely alike; it is,
nevertheless, essential to the effect that the variation, though
minute, should exist. With respect to the pseudoscope--which makes the
outside of a teacup appear as the inside, and the inside as the
outside; which transforms convexity into concavity, and the reverse;
and a sculptured face into a hollow mask; which makes the tree in your
garden appear inside your room, and the branches farthest off come
nearest to the eye; and which, when you look at your pictures,
represents them as sunk into a deep recess in the wall,--with respect
to this instrument, its practical uses have yet to be discovered. But
as your celebrated countryman, Sir David Brewster, is working at the
subject, as well as Mr Wheatstone, we shall not, so say the initiated,
have to wait long for further results.
Besides these lectures, a course is being delivered at the Museum of
Practical Geology, recently opened in Jermyn Street, by eminent
professors, as you may judge from the fact of De la Beche, Forbes, and
Playfair being among them. Some of the most promising of the pupils at
the School of Design are allowed to attend these lectures gratis. At
the same institution, an attempt is to be made to do what has long
been done in Paris--namely, to admit working-people to the best
scientific lectures free of cost. Now, therefore, is the time for the
working-men of the metropolis to shew whether they wish for knowledge
and enlightenment or not. They have only to present themselves at the
Museum, pay a registration-fee of sixpence, conform to the rules, and
so qualify themselves for the course of six lectures. It is a capital
opportunity; and I, for one, hope that hundreds of the intelligent
working-men of London will avail themselves of it. They, on their
part, may find government education not unacceptable; and government,
on the other hand, encouraged by a successful experiment, may feel
inclined to extend its benefits. If a clear-headed lecturer on
political economy could also be appointed, perhaps in time our
industrial fellow-countrymen might come to understand that strikes are
always a mistake, and the masters, that fair play is a jewel.
Notwithstanding the stir about invasion and amateur rifle-clubs, other
matters do get talked about--as, for instance, the astronomer-royal's
communication to the Society of Antiquaries on the place of Cæsar's
landing at his invasion of Britain. The learned functionary settles it
to his own satisfaction by tide-calculations: he has also been holding
an interesting correspondence with a lady on the geography of Suez, as
bearing on the Exodus of Scripture. And this reminds me that Dr J.
Wilson has written a paper, published in the proceedings of the Bombay
branch of the Royal Asiatic Society, to decide a long debated
question--the identification of the Hazor of Kedar, referred to in
Jeremiah--'Concerning Kedar, and concerning the kingdoms of Hazor,
which Nebuchadrezzar king of Babylon shall smite,' &c. The doctor,
after careful research and reasoning, believes the ruins known as
Hadhar or Hatra, not far distant from Nineveh, to be the remains of
the denounced city. Layard and Ainsworth have both visited and
described the place, as many readers will remember. Those interested
in the progress of research in Biblical countries, will be gratified
to know that Dr Robinson has left the United States for another tour
in the Holy Land. Now that Christians are more tolerated in Turkey
than in some other countries nearer home, travelling in the East will
perhaps be facilitated.
Talking of travel: the Legislative Council at Sydney have granted
L.2000, to fit out an expedition to search for Leichardt; Captain
Beatson, with his steamer, is about to start for Behring's Strait to
look for Franklin; Lieutenant Pim has returned from St Petersburg--the
emperor would not permit him to go to Siberia; and last, supplies of
money and goods have been sent out to Drs Barth and Overweg, in
Central Africa, to enable them to pursue their discoveries; and the
British resident at Zanzibar has been instructed to assist them. We
may thus hope, before long, to add to our knowledge both of the torrid
and frigid zones.
To touch upon a home topic: we are told that government are rather
afraid of their own bill for intermural interments passed last
session, which may account for none of its provisions having yet been
carried out. The project now is to supersede that bill by another,
which is to extend the practice of cemetery interment. This looks like
a want of faith in sanitary principles. On the other hand, the sale of
the lazaretto at Marseilles, with a view to construct docks on its
site, is a proof that the French government can do something in the
way of sanitary reform. It is, in fact, quite time that the
superstitious notions about infection, and the vexations of
quarantine, should give place to sounder views and more rational
methods. Meantime, as meteorologists say, we are coming to the cycle
of hot summers, it behoves us more than ever to bury the dead far from
towns. The Registrar-General tells us that, on the whole, we are
improving, and it is not less an individual than a national duty to
forward the improvement. According to the return just published for
the quarter ending December last, the births in 1851 amounted to
616,251, the largest number ever registered, being an excess of 5 per
cent. over former returns. The deaths were 385,933, leaving a surplus
which increases the population of England and Wales to more than
18,000,000. In the same quarter, 59,200 emigrants, chiefly Irish, left
the kingdom. With respect to marriages, which also exceed in number
those of former years, the Registrar repeats what he has often said
before, that marriages increase 'when the substantial earnings of the
people are above the average; and the experience of a century, during
which the prosperity of the country, though increasing, has been
constantly fluctuating, shews that it is prudent to husband the
resources of good times against future contingencies. Workmen, if they
are wise, will not now squander their savings.' Are we to infer from
this, that a bad time is coming?
I have at times given you some of our post-office statistics, let me
now send you a few from America. The postmaster-general reports to
Congress, that in the year ending last June there were within the
United States 6170 mail-routes, comprising a length in the aggregate
of 196,290 miles; of post-offices, 19,796; of mail-contractors, 5544.
The distance travelled in the year over these routes was 53,272,252
miles, at a cost of 3,421,754 dollars, or rather more than six cents
per mile per annum. On more than 35,000,000 of these miles the service
is performed by coaches, and 'modes not specified;' the remainder by
railway and steam-boat. There were six foreign mail-routes on which
the annual transportation was estimated at 615,206 miles. The gross
receipts of the post-office department for the year amounted to
6,786,493 dollars, being an increase of nearly a million over the
preceding year. If, after this, we can only get Ocean Penny Postage,
we will give the republican postmaster work to do that shall add some
score of pages to his report.
You will perhaps remember my telling you, some time ago, of the
discussion that had been going on in the United States respecting a
prime meridian. Something has now come of it. The committee appointed
by Congress to consider the subject, have recommended 'that the
Greenwich zero of longitude should be preserved for the convenience of
navigators; and that the meridian of the National Observatory--at
Washington--should be adopted by the authority of Congress as its
first meridian on the American continent, for defining accurately and
permanently territorial limits, and for advancing the science of
astronomy in America.' This decision, though it may disappoint those
who consider it derogatory to the national honour to reckon from the
meridian of Greenwich, is nevertheless the true one. In connection
with it, the Americans intend to bring out a nautical almanac.
Another topic from the same quarter is, that Professor Erni of Yale
College has been making an interesting series of experiments on
fermentation--a process of which the original cause has never yet been
satisfactorily explained, and is still a moot-point with chemists.
They tell us it is one by which complex substances are decomposed into
simpler forms, as some suppose, by chemical action; others, by
development of fungi, different in different substances. Among the
experiments, it was observed that the yeast of cane-sugar solution
produced no fermentation whatever when poisoned with a small quantity
of arsenious acid; with oil of turpentine, and creasote, similar
negative results were obtained. The introduction of cream-of-tartar
along with the arsenic neutralised its effect, but not so with the
other two; and, singularly enough, the appearance of the liquor always
shewed when the poisoning was complete; 'the nitrogenous layer on the
cell-membrane seeming to have undergone a change similar to that
produced by boiling.' Judging from the results, Professor Erni
believes 'that alcoholic fermentation is caused by the development of
fungi. He could never trace the process without observing at the very
first evolution of carbonic acid, the formation of yeast-cells,
although it is very difficult to decide certainly which precedes the
other.' His own opinion is in favour of the commencement by the
yeast-cells.
Another noteworthy subject, is Dr W.J. Burnett's paper to the American
Association, 'On the Relation of the Distribution of Lice to the
Different Faunas,' in which he endeavours to demonstrate, that the
creation of animals was a multiplied operation, carried on in several
localities, and that they do not derive from one original parent
stock. Different animals have different parasites; but, as he shews,
the same species of animal has the same parasite, wherever it may be
found. According to Latreille, the _pediculus_ found in the woolly
heads of African negroes 'is sufficiently distinct from that of the
Circassian to entitle it to the rank of a distinct species;' from
which, and similar instances, the doctor concludes: 'Whatever may be
urged in behalf of the hypothesis of the unity of the animal creation,
based upon the alleged metamorphosic changes of types, it is my
opinion that the relations of their parasites, and especially the lice
which are distributed over nearly all of them, must be considered as
fair and full an argument as can be advanced against such hypothesis,
for it is taking up the very premises of the hypothesis in
opposition.' Dr Burnett will perhaps find Sir Charles Lyell ready to
break a lance with him on the point at issue.
Something interesting to workers in metal has been brought before the
Franklin Institute at Philadelphia--it is a method of giving to iron
the appearance of copper, contrived by Mr Pomeroy of Cincinnati, who
thus describes it--rather laboriously, by the way:--
'Immerse the iron in dilute sulphuric acid, for the purpose of
cleansing the surface of the article which is to be coated; and thus
cleansed, submit the iron to a brisk heat to dry it; when dry, immerse
the article in a mixture of clay and water, and again dry it so as to
leave a thin coating of the clay on its surface: it is then to be
immersed in a bath of melted copper, and the length of time requisite
for the iron and copper to form a union, will depend on the thickness
of the article under operation. The object of the clay is to protect
the copper from oxidation during the process of alloying or coating,
and to reduce it to the required thickness it is passed between
rollers. The result of this annealing process will be a smooth
surface, fully equal to the brightness of pure copper.' Let me add to
this, as a finish to transatlantic matters, that a Mr Allan, at St
Louis, having observed that in washing-machines only the linen on the
outside of the heap was perfectly cleansed, has patented a new
machine, which comprises a chamber or tub with a narrowed neck, in
which a plunger is inserted; and this, 'with the clothes wrapped
around it, passes through the narrowed neck of the chamber, and
pressing forcibly on the water confined within, drives it violently
through the body of the clothes, carrying the dirt with it.'
Science is not idle in France, notwithstanding the social
perturbations: some of our engineers are talking about the trials of
electro-magnetic locomotives recently made on one of the railways in
that country, and are rather curious as to what may be the result. To
travel without the whiz and roar of steam would be a consummation
devoutly desired by thousands of travellers. And among the topics from
the Académie, there is one important to the naval service--M.
Normandy's apparatus for converting sea-water into fresh water.
Briefly described, it is a series of disks, placed one above the
other, communicating by concentric galleries, and placed in a
vapour-bath at a pressure a little above that of the atmosphere. 'The
sea-water,' says the inventor, 'circulating in the galleries heated by
the surrounding vapour, gives off a certain quantity of vapour, which,
mingling with the atmospheric air, introduced by a tube from the
outside, finally condenses as perfectly aërated fresh water in a
refrigerator, which is also in communication with the atmosphere. No
other means of agitation or percolation is so efficacious or
economical.' The apparatus, which is free from the defect of
depositing salt while distillation is going on, is rather more than
three feet in height, and eighteen inches diameter. It will yield two
pints of water per minute, at an expenditure of about 2-1/4 lbs. of
coal for each 45 lbs. of water.
Next, Monsieur Rochas proposes a method for preserving limestone
monuments and sculptures for an indefinite period. This material, as
is well known, is very liable to disintegrate, and the remedy is to
silicify it. Specimens of limestone so prepared were exhibited to the
Académie, but without any explanation of the process. We know that
brick and stone have been coated with glass in a few instances, to
insure their preservation; and that at Professor Owen's suggestion,
some decomposing ivory ornaments, sent over by Mr Layard, were
restored by boiling in gelatine; but M. Rochas aims at something still
greater--nothing less than the silicifying of a number of crumbling
limestone statues which have been lately discovered by a Frenchman who
is exploring the temple of Serapis at Memphis. They will then be
strong enough to bear removal.
Naturalists may learn something from Monsieur Falcony, who states that
a solution of sulphate of zinc is an effectual preservative of animals
or animal substances, intended for anatomical examination--it may be
used to inject veins, and the effects last a considerable time.
Another consideration is, that it is harmless: dissecting-instruments
left in the solution for twenty-four hours were not at all injured.