principles, and the formation of real scenery was improved from
what was so prominent in the fictitious. Some painters, even Claude
Lorraine himself, have occasionally erred, from what may be called
_exuberance of design_, in producing extreme effect, by introducing
lights which never can be seen by day or night, at dawn or twilight;
by trees which never existed, and by forms[49] which had only an
imaginary existence. Landscape gardeners, too, in the transition from
the tame to the more natural style, have run into error, by imitating
admirable incidents frequently seen in nature’s works, forgetting
that their value springs entirely from their having happened by
chance, but, as works of art, lose all their interest, and become
insignificant.
We are now arrived on the confines of our own times, of which we will
take a general view, and which will sufficiently show the accumulated
assemblage of horticultural objects, productions, and knowledge; and
which will also give, what was proposed, a comparative survey of the
extent of our improvements.
And first, as to the highest department, Botany. Before the sexual
system of Linnæus was fairly established, (though it spread far
and wide by the literary labours of Hudson, Lee, Curtis, and
several other able contemporary writers, both in England and on
the continent,) defects were found in it, and not only as to the
terms of distinction, but also to its bringing together, in the
classification, plants which appeared, from their [p270] exterior
habit and qualities, to have no natural affinity to each other. This
Linnæus was aware of himself, and left some fragments of a natural
arrangement, but which he did not live to complete. This, or the
idea of it, however, was taken up by Jussieu, a French botanist, and
completed as far, perhaps, as it can be; and though, in our present
botanical publications, both systems are continued, yet it is likely
that Jussieu’s simplified system will, in time, supersede the other,
though the curious fact on which that of Linnæus was founded will
never be forgotten, because of its practical use in the amelioration
of fruits. Botanical publications, under the various names of
Hortuses, Floras, Monographs, and of every country and district
under the skies, and since the promulgation of Jussieu’s system,
monographs, under the titles of Geraniaceæ, Cistineæ, &c., flow in
periodical floods from the press, crowd the bookseller’s shelves, and
thence find their way to every elegant drawing-room in the kingdom.
This additional call on the business of the press, as well as upon
the talent of the artist, arises from the fashionable and refined
bias of the public taste for this rational and delightful study.
To extend botanical collections, and the desire to possess every
vegetable beauty, pervaded the whole community: hence expeditions to
distant lands by collectors; hence the extension and encouragement
of nursery business; hence have sprung up chartered societies and
associations for the encouragement of botany and gardening all over
the realm; so that vegetable beauties and curiosities are now to be
seen in British collections, from every region of the known world.
Neither has the occult subject of botanical physiology been
neglected; many curious facts connected with the organisation,
structure, functions, and qualities of plants, have been ascertained:
but still there remains much for the employment of the naturalist’s
mind on this difficult subject.
Landscape gardening is not so much “the rage” as it was twenty or
thirty years ago: national circumstances, perhaps, may be the cause;
but its principles are much better understood. The errors of Kent
and Brown, and their followers, have been corrected by the works and
writings of Repton, and the critiques of Knight and Price, whose
theories have been [p271] carried into practice by Loudon and
others; and nothing will prevent the universal adoption of their
principles, but the difficulty of giving the foreground from _home
walks_ the extreme degree of ruggedness so much admired, and even
indispensable to the painter. Fern, (unless we can introduce some
uncommon foreign variety,) burdock, kexes, cannot be admitted into
dressed ground; nor have we any plants in cultivation which would
well answer the purpose; true, we have the rhubarb, one or two sorts
of thistles, eryngiums, palma Christi, and gourds with their ample
leaves: but these would only appear intruders, and misplaced: but
much may be done by a judicious disposition of our common shrubs,
so as to conceal the traces of the spade and line, and give all our
combinations of land, wood, and water that flowing character, which
is so true to nature, and so pleasing to the refined eye of taste.
Floriculture, which has been imported from France and Holland, is
also intensely followed about London, as well as in our manufacturing
provinces. Authors have creditably appeared in this line too; and our
annual blows of flowers, both home-cultivated and imported, are at
once rich and costly. Tulips, hyacinths, narcissuses, ranunculuses,
and anemones, are the principal bed flowers: but roses, stocks,
dahlias, chrysanthemums, and even poppies, are out of number.
Flowering shrubs, both within and without doors, are eminently rich
and various, and astonish as much by the splendour of their colours
as by their elegant forms and number.
Orcharding has declined during the last fifty years: first, because
of the gradual deterioration of the trees, and precariousness of the
crops; next, from the improved way of agricultural labourers’ manner
of living. This change renders the use of small cider and perry less
necessary in a farm-house, causing an increased consumption of malt
liquor; and this again, occasioning a greater demand for barley, at
once pleases both the farmer and the Chancellor of the Exchequer.
Thus the cultivation of orchard fruit (except cherries[50]) has
greatly fallen off; and the decayed state of the old, and difficulty
of [p272] raising new orchards, has given a check to such exertion,
except in places at a distance from the metropolis, where orchards
have suffered less from decay, and where the habits of the cider
drinkers are more inveterate. Mr. Knight, the President of the
Horticultural Society, has written copiously on this subject, and
very properly considers the cultivation of orchard fruit as a
national object; and by his example has done as much, nay, much more,
than any other gentleman in the kingdom, to restore our orchards
to what they used to be, and what they may be,—and it is hoped his
excellent instructions will not be thrown away.
Kitchen-gardening, the most important and useful branch of the
subject, next demands attention; and here we are gratified with
a fine display of the efficacy of perseverance, the success of
experience, and the triumphs of skill. In every month of the year, in
spite of the winter’s frost or summer’s sun, our tables are supplied
with wholesome and agreeable vegetables:—of roots we have fourteen
sorts; of stems, shoots, and leaf-stalks, seven; of leaves, eight; of
flowers, four: of culinary fruits we have sixteen; of seeds and pods,
six; of condimental herbs we have twenty-nine; and of herbs and seeds
for confections there are seven, besides various fruit: of roots,
leaves, flowers, and fruit, for salads, there are in cultivation
twenty-two kinds; and various sorts of plants for medicine and
distillation.
Of table-fruit there are above twenty different species, and of
these numberless varieties, extending to several hundreds, or even
thousands, of various excellency and value.
A few tropical and foreign fruits, not included in the above, have
been cultivated in tolerable perfection in Europe within these few
years, viz. the Chinese loquat and litchee, the custard apple,
mangosteen, and mango, &c.; and there is no doubt, if these fruits
could be worked on some hardier kindred stock, and a suitable place
formed for them in a stove, they might be cultivated with the same
success as the anana.
In the forcing department of gardening, wonders have been
accomplished. By this application of art, we appropriate to ourselves
an almost perfect imitation of any of the warmer [p273] climates:
heat, that powerful agent in the development of vegetation, we can
have in any degree, by stoves, by fermenting substances, and from
the steam of boiling water: light, a no less necessary agent in the
maturation of fruits, we combine with the former, by glazed houses
and frames.
The various expedients for obtaining the necessary degree of heat,
are, first, the most simple method of a stove, with its flue passing
through or round the floor of the house, and this for warming the
air within; but in this case, as the roots of the plants do not
sufficiently, it is supposed, receive the proper degree of heat,
various fermenting substances, as recent stable-yard dung, tanners’
bark, oak and other leaves of trees, &c. are formed into beds, on
which the compost of earth is placed, as in hot-bed frames, or in
which the pots containing the plants are placed, or plunged, as in
a hot-house. To obtain the same effect, borders within houses are
formed for the roots, having an excavated heat-chamber beneath,
supplied by simple stove flues, or from the fermenting substances
above named, or from steam admitted for the purpose. This mode of
supplying an equal degree of heat to the roots, as well as to the
leaves and branches of a plant, is plausible, and cannot be far
wrong, because it has been attended with success: but there is,
perhaps, more attributed to it than it deserves, because the region
or stratum of the soil, which is naturally occupied by roots,
differs, in respect of temperature, much less over the whole surface
of our globe, than is commonly imagined. The heat of the air in
different latitudes ranges from several degrees below zero to 110
degrees of Fahrenheit’s scale; but the temperature of the earth
eighteen inches below the surface, it is probable, does not vary
more than ten or fifteen. In England spring water varies only two
degrees, viz. from 42 degrees in summer to 40 degrees in winter; and
the effects of our hardest frosts very rarely penetrate deeper than
nine inches; but it is necessary to observe, that, in such cases,
as well as in hotbeds, we _force_ as well as defend; and probably,
by such mode of applying heat and moisture, nutritious gases may
be communicated, which may be no small advantage. Besides, the
atmosphere of the house can (as is done) be impregnated with the same
qualities and degrees of heat and humidity [p274] (a most necessary
accompaniment[51],) which may be generated below.
Light is a most potent agent in the maturation of vegetables:
united with a moderate degree of cold, it is much more effectual
in progressive vegetation, than the necessary degree of heat with
darkness. Exposure to light is indispensable to plants: and,
therefore, our glass cases are formed to admit as much as possible.
Within these few years, the endeavour to gain an accession of light
by reducing the dimensions of the wooden scantling of hot houses
suggested the idea of metallic frames; and for the concentration of
the sun’s rays, horizontal as well as vertical curvilinear roofs have
been constructed. Lightness to the eye, durability, imperceptible
expansion, and glazed with panes, cut like segments of circles, to
facilitate the passing off of condensed water, with complete command
of ventilation, are an assemblage of properties, always as desirable
as necessary; and as they may be cast in the most elegant forms,
and protected by paint, they add greatly to the ornament of the
garden. Beautiful as these buildings are, some little disappointment
has taken place respecting them: it has been experienced, that the
intensity of the sun’s light, or heat, has been found detrimental
to the tender inmates, and that shading is as necessary in bright,
as light is in cloudy weather. Certain it is, that in the winter
season, when light and heat are most desirable, no fear need be
entertained from this circumstance; and it ought to be considered,
that in our summer, we have at least, daily, _four hours_ more sun
than intertropical plants have at home: of course, they have less
time for their evening’s repose, (which all plants more or less
require); besides, it should be thought of, that all plants are not
equally formed to sustain such a blaze of light; “some affect the sun
and some the shade;” such as the pine-apple[52], and orange, which
require “a warm [p275] shade;” and perhaps all plants which present
a large reflecting surface of foliage to the sun, are content with
a smaller share of his direct rays. These observations attended to,
sun-shades may be applied for occasional use, and with the plants at
a proper distance from the glass, will certainly secure them from all
the inconvenience of such buildings, while none of the advantages are
lost.
The kitchen-garden range of buildings includes pine-stoves, vineries,
houses for peaches, and nectarines, figs, and cherries, hot-walls,
pits for succession pines, melons, cucumbers; besides store pits for
roots, tender vegetables, salading, &c., as well as frames for many
purposes of cultivation. Mushrooms are usually raised in sheds behind
the houses. The hot-houses are also used for growing early culinary
vegetables, and small fruits in pots.
[To be continued.]
FOOTNOTES:
[48] The cocoa palm is rather a gigantic herb than a tree: the stem
rises to a great height, of a strongly tough fibrous substance, but
never so indurated as timber, though it is used in the construction
of houses. It has no branches; but is crowned with from five to
seven ample compound leaves, forming an umbrella-like head. The
spatha issues from the centre, and soon falls pendent between and
below the footstalks of the leaves, where it flowers and ripens the
fruit. The nut is enveloped in a thick brown fibrous husk, which
opens to shed it when fully ripe. The nut, when opened, yields
two liquids, which are nutritious, and accounted delicacies: the
first is the milk which runs out; the next is the cream which is
procured by being scooped off the kernel with a spoon: this is of
thick consistence, and much resembles the cream of milk. After
these remains the perfectly-formed layer of kernel attached to the
shell, and which is used along with the liquids as an article of
food. But another most pleasant beverage, called toddy, is obtained
from this palm, and which constitutes the chief value of the plant.
The fruit is sacrificed to procure this; soon as the frond becomes
pendent, the extremity is cut off, and a narrow-necked vessel is
slung thereto to receive the streaming sap. This, both before and
after being fermented, is an agreeable and refreshing drink. It also
yields an ardent spirit by distillation, but of which the natives
deny themselves the use.
[49] In Martin’s painting of the Paphian Bower, though a fine
composition, the roots of the tree, on the left of the foreground,
are too much out of the ground. The accidental exposure of roots
on the bank of a stream, or high-road, and their buttress-like
departure from the trunk, are legitimate objects for the pencil; but
their ramifications pourtrayed on the surface of the ground, is as
ridiculous as unnatural.
[50] It is said that many of the Caroon cherries brought to
Covent-garden market, are bought up for the purpose of colouring
wine on the Continent.
[51] The admission of humidity into forcing-houses is attended by
the most salutary consequences: it counteracts the bad effects
of fire-heat, and is inimical to many insects. For this purpose,
a steam-supplying apparatus is added to the best-constructed
hot-houses, productive of the greatest advantages.
[52] It has long been observed by gardeners, that the pine-apple
always does best in forcing-pits, merely from the circumstance of
there being more shade.
_Chemical Manipulation, being Instructions to Students in Chemistry,
on the Methods of performing Experiments of Demonstration, or of
Research, with accuracy and success By_ Michael Faraday, F.R.S., &c.
We will not positively assert that no one except Mr. Faraday could
have written this book, but we are of opinion that there are very
few chemists adequate to such a task, which has manifestly required
a considerable share of practical skill, much deep and theoretical
knowledge, and no small degree of patience and perseverance,
more especially shown in the clearness of the details, and the
perspicuous manner in which he has managed to describe prolix and
difficult processes. The work moreover fills up a chasm in chemical
literature, by embodying almost all that is important relating to
chemical manipulation scattered through the writings of others;
while the author’s extensive experience has enabled him to correct
their faults, and to present the student and operator with many new
and important facts and processes, by which the researches of the
laboratory are most essentially facilitated.
Such is our general opinion of the treatise before us, and we are
persuaded that those who are capable of appreciating its merits will
agree in our decision; but it is not so easy to [p276] substantiate
our judgment by quotations, in consequence of the general didactic
character of the book, and the mutual dependence and connexion of
its different parts. We shall attempt, however, to give the general
reader an outline of its contents, and point out such parts to the
chemist as we conceive particularly useful and worthy attention.
The importance of readiness and dexterity in the performance of
experiments has been duly estimated for more than a century. The
writings of Black, Cavendish, Priestley, and especially Scheele, as
opposed to those of their predecessors, show that they had acquired
considerable facility in attaining, by simple and economical means,
those ends which had before consumed much time and much expense
in their accomplishment: but it is only of late years that the
refinements of manipulation have been carried towards perfection;
and the researches carried on in the laboratory of the Royal
Institution have been not a little conducive to this improvement:
to no one, however, is this part of the science more indebted than
to Dr. Wollaston, whose skill in what may be called microscopic
chemistry is consummate, and who has a host of humble but industrious
imitators. So essential, indeed, is the attainment of correct
methods of manipulation to the progress of chemical science, that
many entire trains of research are exclusively dependent upon it for
success. It is true that it must always be subordinate to genius and
invention; yet the person who could only devise, without knowing how
to perform, would comparatively be able to lend little aid to the
extension and usefulness of knowledge: and were it not an invidious
task, we might be able to show that some of the greatest discoveries
and improvements of the science have originated in dexterity of
experiment, rather than in profundity of design. By tact, therefore,
in manipulation, a considerable advantage is gained, independent
of that resulting from an acquaintance with the principles of the
science; and this is so considerable, that, of two persons of
equal talent and information in other respects, he who is the best
manipulator will soon be in advance of the other; the one will draw
just inferences with accuracy and rapidity, while the other will be
lost in doubt, and often led into error. Mr. Faraday has pointed out
several other cases of prominent advantage, arising from skilful
manipulation, especially when very small quantities of matter are to
be operated upon, and where accurate conclusions are of more than
ordinary importance, as in testing for arsenic and other poisons
on judicial occasions. When the substance under examination is
rare, [p277] as often happens, the facility of working with small
quantities is also of much importance, as otherwise the opportunity
of gaining information may be lost, or only retained at great
expense. “There existed,” says our author, “in the British Museum
a small fragment of a black stone, the source and history of which
was unknown: it was unique, no other specimen being in the Museum,
or known to be in existence; yet as it presented some peculiar
characters, Mr. Hatchett was induced to examine it, and, working with
a portion of the stone weighing not more than two hundred grains, he
was enabled to discover in it a new metal, which he distinguished,
by its various characters, from all those previously known, and
which he named Columbium. Ekeberg afterwards discovered a metal,
which he named Tantalium, conceiving it to have been observed and
distinguished for the first time by himself; but Dr. Wollaston, who
examined it, and compared it with columbium, was able to identify it
with that metal, although he had not more than five grains of the
stone from the British Museum upon which to make his experiments.”
In short, there can be but one opinion respecting the first-rate
importance of expertness in manipulation, and neatness, dexterity,
and efficacy of experimenting. These are the subjects to which
the present volume is directed, and which will, therefore, form a
valuable accompaniment to the more general and systematic works. They
are discussed under the following general heads:—
_The conveniences and requisites of a laboratory_.
_Chemical apparatus, and its uses_.
_The methods of performing chemical operations_.
_The facilities acquired by practice; and,_
_The causes which make experiments fail or succeed_.
The description of a laboratory is followed by two long and
well-written sections on the arts of weighing and measuring, in which
the account of the methods of determining specific gravities, and of
the general management of a delicate balance, are well deserving the
student’s attentive perusal: indeed, there are no operations which
are more frequently performed in a slovenly and careless manner, than
those in which scales and weights are concerned; and we should advise
the tyro to sit down with his balance and this book before him, and
practise the manipulations which it explains.
The fourth section, on the sources and management of heat, is devoted
to the construction and management of different kinds of furnaces,
lamps, blowpipes, thermometers, and pyrometers, and abounds in useful
hints, and in the details of [p278] practical information; and
the same remark applies to the succeeding sections on comminution
and solution—indeed, we were surprised at finding so much to be
taught in regard to these very simple operations. The seventh,
eighth, and ninth sections treat of distillation and sublimation,
precipitation, and filtration. Here, and indeed throughout the work,
the wood-cuts are particularly distinct and well executed. In the
section on crystallization, the uses of that process are enumerated;
and to this succeeds an account of evaporation. All these operations
are extremely well investigated and described, both as to their
principles and as to the most proper means of effecting them; a
number of curious circumstances are pointed out, by which their
results are influenced, and by which certainty and success may be
insured.
The uses of coloured tests are explained and illustrated in the
twelfth section. Of coloured liquids the author chiefly recommends
the infusion of red cabbage; and as it is not only a very good test
for private experiments but of excellent service to the public
lecturer in rendering certain changes of composition visible to
an audience, it may be worth while extracting the directions for
preparing it.