246. _The SCOTS FIR_ (Pinus sylvestris), _which has its name from growing
wild in different parts of Scotland, is known from other trees of the
same tribe by having its slender and somewhat needle-shaped leaves in
pairs; its cones or seed-vessels somewhat egg-shaped, mostly in pairs, as
long as the leaves, and the scales blunt._
This useful tree flourishes with greatest luxuriance on the north and
north-east sides of hills, in a poor and sandy soil, especially where this
is mixed with loam. If planted among rocks, or in bogs, it seldom attains a
large size; in black soil it becomes diseased; and in chalky land it
frequently pines away and dies.
Its _timber_, under the name of _deal_, is employed as the wood-work of
houses; for rafters, flooring, doors, the frames of windows, tables, boxes,
and other purposes, infinitely too various to be enumerated. Frigates, and
other ships of large size, have sometimes been constructed of deal but
these are by no means so durable as vessels that are built of oak. Much of
the deal which we use is imported from Norway, and other northern parts of
Europe. That from Christiana, which is called _yellow deal_, or _red deal_,
is frequently brought over in planks, but more commonly in boards, each
about ten inches and half in width. The wood of such trees as are raised in
England is equal to the foreign wood in weight and durability, but its
grain is generally coarser.
The _outer bark_ of the fir-tree may be used in the tanning of leather; and
it is said that, in the northern parts of Europe, the soft, white, and
fibrous _inner bark_ is, in times of scarcity, made into a kind of bread.
For this purpose it is dried over a fire, reduced to powder, kneaded with
water, and a small portion of corn-flour, into cakes, and baked in an oven.
Children in Norway are very fond of the fresh bark, in the spring of the
year, either shaved off with a knife, or grated with a rasp.
_Common Turpentine_ is the resinous juice chiefly of the Scots fir,
obtained by boring holes into the trunks of the trees, early in spring, and
placing vessels beneath for its reception. It is of brown colour; and has a
strong odour, and disagreeable taste. In the distillation of turpentine an
essential oil is produced, called _oil of turpentine_, which is extremely
pungent. When the distillation is continued to dryness, the substance which
remains is known by the name of _common resin_ or _rosin_; but, if water be
mixed with it, while yet fluid, and incorporated by violent agitation, a
substance is formed called _yellow resin_.
Common turpentine is mostly employed as an ingredient in the plasters used
by farriers. The oil is occasionally used in medicine; and, lately, it has
been considered efficacious in cases of worms. It is much employed by
painters for rendering their colours more fluid; as well as in the
composition of different kinds of varnish used in floor-cloth, umbrella,
and other manufactures. The noxious spirit called gin was formerly
flavoured with juniper berries; but as these are now too expensive, oil of
turpentine, the taste of which in a slight degree resembles that of
juniper, is applied to the same purpose; and considerable quantities of
turpentine are thus consumed. The common resin is used in plasters, for
which its great adhesiveness renders it peculiarly applicable. It is also
of considerable importance in the arts; and musicians rub the bows and
strings of violins with it, to take off the greasy particles which are
there collected, as well as to counteract the effects of moisture. Yellow
resin is used in plasters, and for other purposes in medicine.
_Tar_ is obtained from the roots and refuse parts of the fir-tree, by
cutting them into billets, piling these, in a proper manner, in pits or
ovens formed for the purpose, covering them partly over, and setting them
on fire. During the burning, a black and thick matter, which is the tar,
falls to the bottom, and is conducted thence into vessels which are placed
to receive it, and from which it is afterwards poured into barrels for
sale.
Tar is an article of great utility in manufactures, and for various
economical purposes. It is much employed for smearing the rigging, and
other external parts of ships, to prevent their receiving injury from
moisture. It has been used in medicine both internally and externally; and
particularly _tar-water_, or water impregnated with tar, was, some years
ago, a popular remedy in various disorders, but its virtues have been too
much extolled. Although considerable quantities of tar are prepared in this
country, these are insufficient to supply the demand; consequently we,
every year, import great quantities of it from Russia, Sweden, America, and
other countries.
_Pitch_ is usually made by melting together coarse hard resin and an equal
quantity of tar; or, as some writers state, by boiling tar with a certain
portion of water, until it becomes so thick that, on cooling, it forms a
hard black mass.
By the ancients pitch was much employed for giving flavour and fragrance to
their wines. With us it is of extensive use to mechanics, and in numerous
manufactures; but the principal demand for it is in ship-building, to
secure the joints and crevices of the planks and timbers, and for other
purposes. When mixed with a certain quantity of oil and suet, it is made
into _shoe-makers' wax_; and, in conjunction with whale fat, forms
_carriage-grease_, or the substance with which the wheels of carriages are
smeared. The best pitch is imported from Sweden and Norway: and, is of a
glossy black colour, perfectly dry, and very brittle.
_Lamp-black_ is a soot formed by burning the dregs and coarser parts of tar
in furnaces constructed for that purpose. The smoke is conveyed through
tubes into boxes, each covered with linen, in the form of a cone. Upon this
linen the soot is deposited: and it is, from time to time, beaten off into
the boxes, and afterwards packed in barrels for sale. This substance is
employed in printing and dyeing; and has its name from the practice that
was formerly adopted of making it by means of lamps.
247. _The WEYMOUTH PINE is chiefly distinguished by its leaves growing in
fives, and its cones being smooth, cylindrical, and longer than the
leaves._
This species of fir-tree grows wild in North America, and succeeds well in
strong land in England. Its _timber_ is white, of more open grain than
Scots fir, and not so heavy as that. In America it is principally used for
the masts of ships, for which, by its toughness, it is peculiarly
calculated.
248. _The SPRUCE FIR_ (Pinus abies), _a native of Norway, and other
Northern parts of Europe, is known by its short, and four-sided leaves
growing singly, and surrounding the branches; its cones being
cylindrical, the scales somewhat square, flattened, and notched at the
top_
The _wood_ of the spruce fir is what the English carpenters usually
denominate _white deal_. It is considered next in value to that obtained
from the Scots fir; and is remarkable for having few knots. On account of
its lightness it is peculiarly adapted for packing-cases and musical
instruments.
From incisions made into the trunk of the spruce fir-tree, a fine and clear
_turpentine_ oozes, which, after being boiled in water, and strained
through a linen cloth, acquires a somewhat solid consistence, and reddish
brown colour; and is called _Burgundy pitch_. This is employed as an
ingredient in several kinds of ointments and plasters: and is principally
manufactured in Saxony.
The article called _essence of spruce_, which is used in making spruce
beer, is prepared from the branches of this tree, and from those of a
species nearly allied to it which grows in America.
249. _The LARCH_ (Pinus laryx), _a native of the Alps, and the mountains
of Germany, is a species of fir, which has its leaves in tufts, and its
cones oblong, and of somewhat oval shape, the margins of the scales bent
back, and jagged._
The cultivation of larch-trees has of late been much recommended for
adoption in this country, on account of the value of their _timber_, which
for strength and durability, is equal to most kinds of deal. It is well
calculated for masts, and the framework of vessels, being capable of
sustaining much greater pressure even than oak. For wood-work constantly
immersed in water, it is peculiarly calculated, as, in such situations, it
is asserted to become almost as hard as stone. In Petersburg larch timber
is applied to no other use than that of ship-building. Line-of-battle ships
are constructed of it in Archangel, and these generally last about fifteen
years; though, in milder climates, it is imagined that they would last much
longer.
For gates, pales, and similar work, exposed to the vicissitudes of weather,
they are admirably serviceable; and for flooring and other internal
purposes are at least equally durable. Buildings constructed of larch
timber are said to have continued sound for 200 years; and, in some of the
old palaces in Venice, there are beams of larch yet existing that are as
sound as when they were first placed. But the very combustible nature of
this wood renders it objectionable for such uses. No wood with which we are
acquainted affords more durable staves for casks than larch; and, in the
opinion of many persons, it is further valuable by improving the flavour of
the wine contained in them. The wood is of delicate colour, not unlike the
cedar used for black-lead pencils, but is knotty almost throughout.
From the _inner bark_ of the larch the Russians manufacture a soft and fine
kind of white gloves. The trunk, if tapped betwixt the months of March and
September, yields an extremely pure turpentine, which has the name of
_Venice turpentine_; and is of considerable use in medicine. It is usually
thinner than any other kind of turpentine, and of clear, whitish, or
yellowish colour. The drug of this name, which is generally met with in the
shops, is now imported from New England, but was formerly brought from
Venice. A brown gummy substance, known in Russia by the name of _Orenburgh
gum_, is obtained by a curious process from the sap of the tree. On the
large branches of the larch are produced small, sweetish grains, somewhat
resembling sugar; which are frequently substituted for the drug called
manna (275).
The cultivation of the larch was first introduced into Britain towards the
conclusion of the seventeenth century. The trees will grow in almost any
soil; and the proper season for felling them is the month of July. They,
however, seldom attain any large size in this country; and they are said to
decay and become covered with moss, when about forty years old.
250. _The CYPRESS-TREE_ (Cupressus sempervirens) _is a dark-coloured
evergreen, a native of the Levant, the leaves of which are extremely
small, and entirely cover all the slender branches, lying close upon them
so as to give them a somewhat quadrangular shape._
_In some of the trees the branches diminish gradually in length from the
bottom to the top, in such manner as to form a nearly pyramidal shape._
In many of the old gardens in this country cypress-trees are still to be
found, but their generally sombre and gloomy appearance has caused them, of
late years, to be much neglected. They are, however, very valuable on
account of their _wood_, which is hard, compact, and durable, of pale or
reddish colour, with deep veins, and pleasant smell. We are informed by
Pliny that the doors of the famous temple of Diana, at Ephesus, were of
cypress wood, and that, although they were 400 years old at the time when
he wrote, they appeared to be nearly as fresh as new. Indeed this wood was
so much esteemed by the ancients, that the image of Jupiter in the capitol
was made of it. The gates of St. Peter's church at Rome are stated to have
been of cypress, and to have lasted more than 1000 years, from the time of
the Emperor Constantine until that of Pope Eugenius the Fourth, when gates
of brass were erected in their stead. As this wood, in addition to its
other qualities, takes a fine polish, and is not liable to suffer from the
attacks of insects, it was formerly much esteemed for cabinet furniture. By
the Greeks, in the time of Thucydides, it was used for the coffins of
eminent warriors; and many of the chests which enclose Egyptian mummies are
made of it. The latter afford very decisive proof of its almost
incorruptible nature.
The name of this tree is derived from the island of Cyprus, in the
Mediterranean, where it still grows in great luxuriance. Its gloomy hue
caused it to be consecrated by the ancients to Pluto, and to be used at the
funerals of people of eminence. Pliny states that, in his time, it was
customary to place branches of the cypress-tree before the houses in which
persons lay dead.
251. _The CASSAVA, or CASSADA_ (Jatropha manihot) _is a South American
shrub, about three feet in height, with broad, shining, and somewhat
hand-shaped leaves, and beautiful white and rose-coloured flowers._
It is a very remarkable circumstance, that the _roots_ of the cassava, if
eaten raw, are a fatal poison both to man and beast, and that, when
prepared by heat, they yield a safe and valuable food; on which, indeed,
many both of the Indian and European inhabitants of South America almost
wholly subsist. The roots are the only edible parts of the plant. These,
which are white, soft, and farinaceous, from one to two feet in length, and
five or six inches in circumference, are dug out of the earth, at a certain
season of the year, washed, stripped of their rind, and ground to a pulp.
The juice, or poisonous part, is pressed out, and carefully thrown away; as
cattle, and other animals, which have accidentally drunk of it, have almost
instantly died. The flour that remains, after pressure, is formed into thin
round cakes and baked. To an European, accustomed to other bread, these,
though sweetish, and not unpalatable, have an insipid taste. If placed in
close vessels, and preserved from the attacks of insects, cassava bread may
be kept for several months without injury.
With the natives of South America, it is not unusual to throw a great
number of cakes of cassava together to heat, after which they soak them in
water, which causes a rapid fermentation to take place; and from the liquor
thus obtained, they make a very sharp and disagreeable, but intoxicating
beverage, which will not keep longer than twenty-four hours without
spoiling.
From the pure flour of cassava is formed the substance called _tapioca_,
which is frequently imported into this country, and is used for jelly,
puddings, and other culinary purposes. It is prepared from the fibrous part
of the roots by taking a small quantity of the pulp, after the juice is
extracted, and working it in the hand till a thick white cream appears on
the surface. This, being separated, and washed in water, gradually subsides
to the bottom. After the water is poured off, the remaining moisture is
dissipated by a slow fire, the substance being constantly stirred, until at
length it is formed into grains about the size of sago (266). These become
hard by keeping, and are the purest and most wholesome part of the cassava.
The roots of another species of this shrub, called _sweet cassava_, are
usually eaten with butter, and merely after being roasted in hot ashes.
They have much the flavour of chesnuts, and are an agreeable and nutritive
food.
252. _The TALLOW TREE_ (Croton sebiferum) _is a native of China, and in
habit somewhat resembles a cherry-tree, but has shining egg-shaped, and
pointed leaves, that form tufts at the extremity of the branches._
The _fruit_ of this tree, from which the Chinese obtain a kind of tallow
for the manufacture of candles, is enclosed in a husk, not much unlike that
of the chesnut, and consists of three round white kernels. All the
preparation that is requisite is to melt these kernels, adding a little
oil, to render them softer and more pliant than they would otherwise be.
The candles made from this substance are very white, but are sometimes
coloured by adding a little vermilion. They are more firm than those of
tallow, but not equal in quality to candles either of wax or spermaceti.
The wicks that are used are not, like ours, made of cotton, but consist of
little rods of light, dry wood, with the pith of a rush entwined round
them.
253. _INDIAN RUBBER, or CAOUTCHOUC, is the dried juice of a large and
much branched tree_ (Siphonia elastica, Fig. 60), _which grows in Guiana,
and other parts of South America._
_This tree has somewhat oval leaves, entire, veined, and smooth, arranged
in threes, and on long foot-stalks._
_The flowers are small, in bunches, near the ends of the branches, and
the fruit is triangular._
It was not until about the year 1736, that this very extraordinary natural
production was made known in Europe. It is obtained by making incisions
through the bark of the tree, chiefly in wet weather. From the wounds thus
formed the juice flows abundantly. It is of milky-white colour, and is
conducted by a tube or leaf, supported by clay, into a vessel placed to
receive it. Some writers assert that, on mere exposure to the air, it
gradually hardens; and others that, for this purpose, it goes through a
certain process, which the Indians keep a profound secret. It is usually
brought to Europe in the shape of pear-shaped bottles, which are formed by
spreading the juice over a mould of clay. These are exposed to a dense
smoke, or to a fire, till they become so dry as not to stick to the
fingers; and then, by certain instruments of iron or wood, they are
ornamented on the outside with various figures. This done, the clay in the
inside is moistened with water and picked out.
Indian rubber is remarkable for the flexibility and elasticity which it
acquires on attaining a solid state; and also for the numerous useful
purposes to which it is capable of being applied. By the Indians it is
sometimes formed into boots, which are impenetrable by water, and which,
when smoked, have the appearance of leather. Bottles are made of it, to
whose necks are fastened hollow reeds, through which the liquor contained
in them can be squirted at pleasure. One of these, filled with water, is
always presented to each of the guests at their entertainments. Flambeaux
are likewise formed of this substance, which give a very brilliant light;
and it is said that a torch of Indian rubber, an inch and a half in
diameter, and two feet long, will burn twelve hours. The inhabitants of
Quito prepare a species of oil-cloth with the hardened juice of this tree.
The principal uses to which Indian rubber is applied by us are, for the
effacing of black-lead marks; for flexible syringes, tubes, and other
instruments used by surgeons and chemists; and for the formation, by means
of turpentine or linseed oil, of a varnish for air-balloons.
Various experiments have been made to dissolve this substance, so that it
may assume its naturally elastic state, under any figure that may be
required. This has been effected by means of ether, but the process is too
expensive for common use. A simple method of forming tubes of it is to
split a piece of cane and to put between the pieces a slip of whalebone. If
the Indian rubber be cut into slips, and twisted closely round the cane,
and the heat of boiling water be applied, the whole will become united into
one piece or tube, from which the whalebone first, and afterwards the cane,
may easily be separated.
It has been proved that cloth of all kinds may be made impenetrable by
water, if impregnated with the fresh juice of the Indian rubber tree; and
that boots, gloves, and other articles, made of cloth thus prepared, may be
joined without sewing, and only by moistening the edges with the juice.
These are not only more durable, but retain their shape better than such as
are made of the juice without any connecting substance.
It has lately been ascertained that, in Prince of Wales's Island, and also
in Sumatra, there are trees of a class and order totally different from
that above described, which yield a juice similar to this, and applicable
to all the same purposes.
254. _The CASTOR-OIL PLANT_ (Ricinus palma christi) _is a native both of
the East and West Indies, and has a stem from five to fifteen or sixteen
feet in height, and large bluish-green leaves, divided into seven lobes,
serrated and pointed, the footstalks long, and inserted into the disk._
_The flowers are produced in a terminating spike, and the seed-vessels
are covered with spines, and contain each three flattish oblong seeds._
It is to the seeds of this plant that we are indebted for the drug called
_castor-oil_. This is sometimes obtained by pressing the seeds, in the same
way as is practised with respect to oil of almonds (152). But the mode
chiefly adopted in the West Indies, whence we principally import it, is
first to strip the seeds of their husks or pods, and then to bruise them in
a mortar; afterwards they are tied in linen bags, and boiled in water until
the oil which they contain rises to the surface; this is carefully skimmed
off, strained to free it from any accidental impurities, and bottled for
use. The oil which is obtained by boiling is considered more mild than that
obtained by pressure, but it sooner becomes rancid. The mildest and finest
of the Jamaica castor-oil is limpid, nearly colourless, and has scarcely
more taste or smell than good olive-oil.
The uses of castor-oil in medicine are well known.
The plant is sufficiently hardy to grow and ripen its seeds in the open
ground of gardens, in the south of England.
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