158 
THE CULTIVATOR. 
the rind to faciliate its evaporation. In this manner are pre¬ 
pared most of the dried fruits, which form so considerable an 
article of commerce between the south and north. 
Those fruits which contain much sugar, as prunes, figs, 
musk grapes, &e. may be prepared in the above manner, 
and preserve nearly all their qualities, but the acid fruits ac¬ 
quire a disagreeable sharp taste by the concentration of the 
juices; some of them, however, maybe kept advantageously 
in this way. 
In the hottest countries the process of drying is often com¬ 
menced by subjecting the fruits to the heat of an oven, after 
which they are exposed to the sun; some kinds of fruits are 
thrown into a weak ley, till their surface becomes wrinkled, 
when they are taken out, carefully washed in cold water, 
and afterwards dried in the sun: cherries particularly are 
treated in this manner. When the heat of the sun is not suf¬ 
ficiently great to evaporate all the water contained in the 
pulp of large, fleshy fruits, they may be cut in pieces and 
then dried: in this manner apples and pears are prepared for 
keeping.* 
But this method is neither speedy nor economical enough 
for such preparations as have but little value in commerce, 
and which can never supply, for domestic purposes, the 
place of those whole fruits, which may be easily preserved 
from one season to another: it is therefore customary to per¬ 
form the drying either in stove rooms or ovens. In the first 
case, the fruits, after being cut, are placed upon hurdles ar¬ 
ranged in rows in a chamber heated to 112°: in the second, 
the fruits are put into an oven, from which bread has just 
been drawn; this is repeated if the fruits be not sufficiently 
dried the first time. 
Some of the fruits referred to above, may be dried without 
being cut: of this kind are the tender pears, which cannot 
be preserved fresh through the winter; such as the rousselet, 
the butter pear, the doyenne, the messire-jean, the martin- 
sec, &c. These are first peeled, and then thrown into boil¬ 
ing water, after which they are put upon hurdles into an 
oven heated less than is required for bread; after an interval 
of three or four days the pears are again exposed to the same 
degree of heat, having been however first flattened between 
the palms of the hands, whence they have acquired the name 
of pressed pears. 
Fruits prepared in either of the above ways are susceptible 
of fermentation upon being soaked in water, and they thus 
serve to make a cheap and useful drink. 
In those countries where these fruits abound, the drying 
of them is commenced about the first of August, and those 
are made use of, which then fall from the trees; in autumn, 
when the harvest is gathered in, the soundest and finest 
fruits are carefully selected to be used fresh, whilst the rest 
are dried and preserved in a place free from moisture, to be 
employed in making drinks. I shall in another chapter speak 
of the processes by which this is effected. 
The herbage, which serves as food for domestic animals, 
can be preserved only by drying, and this in all countries is 
practised at the time of cutting. Fodder, which is impru¬ 
dently stacked up whilst still damp, ferments, and the heat 
thus produced is sufficient to change the quality, produce 
mouldiness, and is sometimes even great enough to set the 
whole on fire. 
There are some fruits, which may, by a few slight pre¬ 
cautions, be preserved throughout the year. The first of 
these precautions is, that of depriving their surface of all 
moisture before putting them up; and the second consists in 
keeping them in dry places, where the temperature will con¬ 
stantly be between 50° and 54° Fahrenheit: the third, in se¬ 
parating the fruits, so that they shall not come in contact; I 
have seen apples preserved in this manner eighteen months. 
It is necessary to be particular in selecting fruit for preserva¬ 
tion; that only should be taken which is perfectly sound. 
Wood and other portions of vegetables, and various ani¬ 
mal substances are likewise preserved by drying; this pro¬ 
cess increases their hardness and renders them less accessi¬ 
ble to the action of air, insects, and other destructive agents. 
The process of drying is not confined to preserving fruits 
from decomposition: it furnishes the means of securing their 
juices unaltered for the formation of extracts of them. 
When the juices of plants can be extracted by pressure 
alone, it is only necessary to evaporate these juices at a due 
degree of heat and in suitable vessels, till, being deprived of 
all the water which retained them in a liquid state, they are 
reduced to dryness. Evaporation, if continued for a long 
time at the temperature of boiling water, changes these jui¬ 
ces a little; the albumen, which is contained more or less 
abundantly in all sweet fruits, is coagulated, and after this 
they are no longer susceptible of undergoing the vinous fer¬ 
mentation. 
The must of grapes, operated upon in this manner, fur¬ 
nishes an extract called raisine , which is an article of food 
both wholesome and agreeable, and which, when soaked in 
water, decays without producing alcohol. The fermenta¬ 
tive power of this substance may however be restored by 
mixing with it a little of the yeast of beer, as this repairs the 
loss, which the juices had sustained by heat during evapora¬ 
tion. 
All the juices obtained from sweet fruits may be converted 
into extracts and thus furnish agreeable food: the quality of 
the extract varies according to the quantity of sugar contain¬ 
ed in the fruit, and the care taken in the operation: when 
the juices are several times clarified, and evaporation carried 
on in a water bath, care being taken to stir the liquid to pre¬ 
vent its adhering to the sides, the colour and taste of the ex¬ 
tract or jelly obtained is far superior to that procured without 
employing these precautions. 
The sweetest fruits, however, even the well ripened 
grapes of the south, contain a portion of acid, which, when 
concentrated by evaporation, acts upon the copper boilers in 
which the operation is carried on, so as to form an acetate of 
copper: this by producing colics, would render the use of the 
extract dangerous, especially at the south, where the prin¬ 
cipal article of food for children is the raisine. In order to 
obviate this serious evil, an ancient and generally followed 
custom is observed: as soon as the must of the grapes begins 
to boil in the coppers, a bunch of keys is thrown in, and al¬ 
lowed to remain till the operation is completed: these keys 
attract the copper and become covered with the precipitate 
* In this country, apples, pumpkins, squashes, and peaches 
are kept by drying.—T r. 
thus formed; and nothing remains in the extract but the ace¬ 
tate of iron, which is not injurious. 
I have observed that the juices of all succulent fruits might 
be converted into extracts, and thus preserved for use in the 
course of the year; but the greater part of these juices, when 
concentrated by evaporation, are so excessively acid as to be 
totally unfit for food, and they only form, when mixed with 
water, a very sour drink. In order to correct or conceal this 
acidity, these juices are boiled with an equal weight of sugar 
and thus made into sirups and jellies. 
As it is of importance to be able to extract and preserve 
for domestic purposes, for pharmacy, and for the arts, cer¬ 
tain vegetable products, which can be only very imperfectly 
obtained by mechanical pressure, recourse is had to other 
means; those liquids are made use of which will dissolve the 
wished for principles, and the solution is afterwards evapo¬ 
rated to dryness. 
The fluid most generally employed for solutions is water; 
this dissolves the extractive matter; mucilage, sugar, and 
the greater part of the salts, and mixes with the mealy por¬ 
tions of plants; it may be applied cold or hot to the vegeta¬ 
bles, or they may be boiled in it, according to the nature of 
the principle to be extracted; water will dissolve all that is 
soluble in them, and the extracts may be obtained from the 
solution by evaporation. 
The resins, which are found so abundantly in some vege¬ 
tables, are not soluble in water, and the place of this liquid 
must be supplied by alcohol, in which the plant must be di¬ 
gested; evaporation will separate the alcohol from the resin 
which it holds in solution. In order to avoid the accidents 
that might occur from the dispersion in the atmosphere of a 
very inflammable vapor, the evaporation must be so conduct¬ 
ed that the dissolvent may be received into an alembic or 
close vessel. 
In addition to the methods of preserving fruits by drying, 
and by reducing their juices to the state of sirups and jellies 
by natural or artificial heat, M. de Montgolfin has applied the 
action of the air pump with great success. I have tasted jui¬ 
ces prepared and thickened in this manner, and I thought 
they were much superior to those that had been evaporated 
in either of the modes hitherto usually practised. I do not 
doubt that, when this method becomes better known, it will 
be generally adopted. 
[From the Domestic Encyclopedia .] 
Vegetation 
Is the natural process by which plants receive their nou¬ 
rishment. 
Naturalists have formed various conjectures, to account for 
the mysterious phenomena occuring in vegetable nature; and 
though unable to discover the primary source from which 
plants are enlivened, yet it is now agreed, and proved, that 
all vegetables originate from seeds, each of which compre¬ 
hends three parts, namely: 1. The cotyledons, or two porous 
lateral bodies or lobes, that imbibe moisture: 2. The radicle, 
or eye, wffiich appears between the lobes: and, 3. The plu- 
mula, a small round body attached to the radicle, though 
wholly concealed within the cotyledons, forming the part 
that shoots upward. 
If a seed be deposited in the earth, in a favourable situa¬ 
tion, it imbibes moisture, and evolves carbonic acid gas; but 
if any oxygen gas be present, it is gradually absorbed by the 
seed, and the farinaceous matter, contained in the cotyledons, 
acquires a saccharine taste. Numerous vessels then appear 
in the lobes which convey the nutriment to the radicle, that 
progressively increases in size, and at length assumes the 
form of a root; strikes downwards into the earth; and thence 
derives the nourishment necessary for the support of the fu¬ 
ture plant. Now the cotyledons slxoot above the ground, be¬ 
come leaves, and form what botanists have termed the semi¬ 
nal leaves. Thus, the p hum la is gradually enlarged, and 
rises out of the earth, spreading itself into branches, &e. after 
which the seminal leaves wither and decay, while the diffe¬ 
rent processes of vegetation are carried on in the plant, with¬ 
out their assistance. 
Plants are very various, and of course, the structure of each 
species must have many peculiarities. Trees have princi¬ 
pally engaged the attention of anatomists. We shall there¬ 
fore take a tree as an instance of that structure of plants: 
and we shall do it the more readily, as the greater number of 
vegetables are provided with analogous organs dedicated to 
similar uses. 
A tree is composed of a root, a trunk, and branches. Each 
consists of three parts, the bark, the wood, and the pith. 
The bark is the outermost part of the tree. It is usually of 
a green colour. If we inspect a horizontal section, we shall 
perceive that the bark itself is composed of three distinct 
bodies. The outermost of these, is called epidermis , the mid¬ 
dlemost, is called parenchyma, and the innermost, or that next 
the root, is called the cortical layers. 
The epidermis, is a thin transparent membrane, which co¬ 
vers all the outside of the bark. It is pretty tough, is re¬ 
produced when rubbed oft'. In old trees it cracks and decays, 
and a new epidermis is formed. Hence, old trees have a 
rough surface. 
The parenchyma, lies immediately below the epidermis; it is 
of a deep green colour, very tender and succulent. Both in 
it, and the epidermis there are numberless interstices which 
have been compared to so many small bladders. 
The cortical layers, form the innermost part of the bark, or 
that next the wood. They consist of several thin membranes, 
lying the one above the other; and their number appears 
to increase with the age of the plant. 
The wood consists of concentric layers the number of 
which increases with the age of the part. Next the bark, the 
wood is much softer and whiter and more juicy than the rest, 
and is called alburnum or aubier. The perfect wood is 
browner and harder, and the layers increase in density, the 
nearer they are to the centre. 
The pith occupies the centre of the wood. It is a spongy 
body, containing numerous cells. In young shoots it is very 
succulent, but it becomes dry, as the plant advances, and 
finally disappears. 
The leaves are attached to the branches of plants by short 
foot-stalks. The whole leaf is covered with the epidermis 
of the plant; containing many glands. 
Plants are continually increasing in size. New matter 
is continually making its appearance in them, and this 
matter they must receive by some channel or other. Plants 
then require food as well as animals. Now, what is this 
food, and whence do they derive it? These questions can 
only be examined by an attentive survey of the substances 
which are contained in vegetables, and an examination of 
those substances which are necessarv for their vegetation.— 
This subject has already been treated of, under articles, food 
of plants, and manure. Some additional remarks shall now 
be given. 
The analysis of vegetables affords but three essential prin¬ 
ciples, namely, carbon, hydrogen, and oxygen, or charcoal, 
inflammable air, and pure air; and the proportions between 
these principles form all the shades, varieties, modifications, 
which the vegetable creation exhibits. Analysis further 
shews, that vegetable fibre, when cleared of all extraneous 
matter, is scarcely any thing else than a congeries of carbon. 
But how is carbon conveyed into the body of the plant ? It 
is well known, that pure carbon, such as is used for burning 
mixed with pure, dry earth, affords no nourishment to vege¬ 
tables: and it is also known, that when dead plants are so 
far decomposed, that their texture is softened or destroyed, 
living vegetables imbibe all their constituent principles.— 
This difference appears to arise from hence, that in the last 
case, the carbon remaining dissolved in the oily, resinous, or 
alkaline principle, the water, which has the property of dis¬ 
joining these natural combinations, serves as a vehicle to 
convey them into the vegetable system. Air, heat, acids, 
and even rest alone, are sufficient to precipitate the carbon; 
so that, the agents proper to facilitate the concretion of the 
fibre, and to promote nutrition, are every where to be found. 
The principle of life, which governs and animates every or¬ 
gan, suitably divides this nutritive matter. It modifies the 
action of external agents, and presides overall the operations 
of this living laboratory. Hence it is easy to see, that hy¬ 
drogen, carbon, or oxygen, predominates in the plant, accord¬ 
ing to the nature of the soil, exposure and climate, and ac¬ 
cording to the proportions in which these nutritive principles 
are presented. 
Since the only part of plants which is contiguous to the 
soil is the root, and since the plant perishes when the root is 
pulled out of the ground, it is evident, that the food of plants 
must be imbibed by the roots. It is highly probable that the 
great changes, at best, which the food undergoes after ab¬ 
sorption, are produced, not in the roots, but in other parts of 
the plant. The sap, as Dr. Hales has shown us, ascends 
with such impetuosity from the cut end of a vine branch, 
that it supported a column of mercury 32J inches high. It 
is certain that the sap ascends through the wood, and not 
through the bark of the tree; for a plant continues to grow, 
even wflien stripped of a great part of its bark, which could 
not happen, if the sap ascended through the bark. 
It is impossible to account for the motion of the sap in 
plants by capillary attraction, or by any mechanical or che¬ 
mical principles whatever; we know indeed, that heat is an 
agent, but its influence cannot be owing to its dilating powder; 
for unless the sap vessels of plants were furnished with 
valves, (and they have no valves) dilatation would rather 
retard than promote the ascent of the sap. 
We must, therefore, ascribe it to some other cause; the 
vessels themselves must certainly act. Many philosophers 
have seen the necessity of this, and have accordingly as¬ 
cribed the ascent of the sap to irritability. Saussure suppos¬ 
es, that the sap enters the open mouths of the vessels, at the 
extremity of the roots; that these mouths then contract, and 
by that contraction propel the sap upwards; that this con¬ 
traction gradually follows the sap, pushing it up from the 
extremity of the root to the summit of the plant. 
This irritable principle is seen in many plants, particularly 
in the stamina of the barberries, which are thrown into mo¬ 
tion when touched. (To be continued.) 
For Burns and Scalds. —Mix in a bottle three ounces of 
olive oil and four ounces of lime water. Apply the mixture 
to the part burned five or six times a day with a feather.—. 
Linseed oil is equally as good as olive oil. 
Young Men’s Department 
Chemical Catechism—Chapter IX. 
[From Parkes’ Chemical Catechism . j 
OF SIMPLE COMBUSTIBLES. 
What is a simple substance ? 
Those bodies* which have never yet been decomposed, 
nor formed by art, are called simple substances. 
How many simple substances are there ? 
Very lately the simple substances were said to amount to 
more than 50 in number;) but since the truly interesting and 
very important discoveries of Sir Humphrey Davy, it is 
scarcely possible to say what substances are not compound 
bodies. 
Can you enumerate what are now deemed simple substances ? 
All the simple substances that we are acquainted with are 
fifty-two;j viz: electricity, magnetism, light, caloric, chlorine, 
oxygen, nitrogen, iodine,§ the metals, (reckoning as such the 
* The most minute particles into which any compound 
substance can be divided similai to each other, and to the 
substance of which they are parts are termed the integrant 
particles: thus the smallest atom of powdered marble is still 
marble; but if by chemical means the calcium, the carbon, 
and the oxygen of this marble be separated, we shall then 
have the elementary or constituent particles. 
Suppose a little common salt were reduced to pow'der, even 
though it be ground as fine as could be effected by art, still 
every single particle, however minute, would consist of a 
particle of sodium and a particle of chlorine; common salt 
being a compound body incapable of decomposition by me¬ 
chanical means. But if we take a piece of sulphur and pul¬ 
verize that in the same way, every particle will be a homo¬ 
geneous body, sulphur being one of the simple substances. 
t If these substances were all capable of combining, the 
compounds formed by them would amount to many thou¬ 
sands; but several of them cannot be united by any means 
we know of. 
j Of these simple substances it may be remarked that four 
are imponderable; four others exist in a gaseous state; six 
are bases of acids; and thirty-eight are metallic bodies. 
[ § Iodine is a peculiar substance procured from kelp; it poa- 
