Francis Lieber.

Library of universal knowledge. A reprint of the last (1880) Edinburgh and London edition of Chambers' encyclopaedia, with copious additions by American editors (Volume 13) online

. (page 165 of 203)
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among which are some of the British species, to be found in fields and moors, although
the common house spider (aranea domestica) is of very unattractive appearance.

All spiders kill the insects and other small creatures on which they prey by means oC
their venomous mandibles, and the bite of a house spider is quickly fatal to a house-lly
Hie bite of the lanrer species is dreaded even by man, being very painful, and not only
-oducing much inflammation and swelling, but often much fever. Death has been
l.tiown to ensue.

Spiders' webs have lone been in high repute for stanching wounds. Threads cf tl.i"
material are also employed for the cross-wires of astronomical telescopes. Textile
fabrics .have been made of it, but only ns articles of curiosity.

Spiders have been arranged by Walcknaer in five principal groups, distinguished by
their habits. (1.) Hunting spiders, which incessantly run about in the vicinity of their
abode in quest of prey, some of them weaving silken tubes, in which they dwell, other;?
hiding in fissures; some remarkable for the swiftness with which they run. others fcr
their power of leaping in order to seize their prey. Some of them are of large size.
Livingstone mentions a South African one which can leap a distance of one foot. A
small one is common on windows in Britain in summer, and, when leaping, avoids the



f7-t q Spider.

< 1 Spike.

danger of falling from the window by suspending itself at the same moment by a thread.
(2.) Wandci'iur/ xjiidtrn, which have no tixed residence, have the power of running side-
ways or backwards, and throw out threads to entrap prey, but do not weave them into
regular webs. Some of them live among plants, and place their egg-cases on leaves, the
edges of which they bind together with their silk. (3.) Prowling spider*, which have
nests, hut prowl about in their neighborhood, or in that of the threads which they
spread to catch prey. (4.) Sedentary spider*, such as the common house spider, which
spin large webs, and lie in wait at the middle or at the side. These are .subdivided
according to the fashion and structure of their webs. (5.) Water spiders, which resem-
ble the last group in their habits, except that they live in water, generally among the
stems and leaves of aquatic plants, where they construct their webs. A very interesting
species, one of the most interesting possible inmates of an aquarium, is the common
water spider (aryyroneta aquatica) of Britain, not unfrequently to be found in deep
ditches and ponds in some parts of England. It is of a brownish color, densely covered
with hairs, which are of great importance in its economy, entangling air, which the
animal carries down with it into the water, to supply its pulmonary sacs; for the water
spiders all breathe by the same kind of organs as their terrestrial congeners. The eggs
of the water spider are attached to the leaves or stems of plants under the surface of
the water, and are protected by a dome-shaped web, so close in its structure as to retain
the air which is brought into it, and in which the spider itself lives, bringing down air
on its furred body till the dome is filled. The entrance is from below. The most curi-
ous nests are those of the trap-door spiders, belonging to the group territclarice, or under-
ground weavers. The nest is a tubular burrow, lined with silk, and having the entrance
covered with a circular lid of the same material attached to the edge of the lining by a
kind of hinge. In the most common form of nest, the lid is made thick by having lay-
ers of earth between the layers of silk, and fits like a cork into the mouth of the tube,
which is beveled to receive it. As mosses grow on the lid as well as on the surround-
ing ground, the concealment is complete. In some types of nest, there is a thin external
door, and then one of a more solid kind some inches below, behind which the inmate
can place itself, and resist the intrusion of an enemy. In one kind of these double-door
nests, a side gallery branches off from the main one, and the external door is so placed
at the angle that it can be made to shut either.

SPIDER FLY, OrnitJwmyia, a genus of dipterous insects, closely allied to the forest
fly (q.v.). bat the claws of the tarsi having three instead of two teeth; and the species
are parasitical on birds, never on quadrupeds. 0. aoicularia frequently infests the com-
mon fowl, the blackcock, and other birds in Britain. It is greenish yellow, with smoke- [
colored wings.

SPIDEU-MOHKEY, a name often given to species of the genus ateles, small American
monkeys, on account of their very long, slender, inelegant limbs. The tail is very long,
and not only prehensile in the highest degree, but endowed with a wondrous sensitive-
ness of touch. These monkeys display great intelligence. It is their common practice
to break nuts by means of stones; and a tame one which Dr. Gardner carried with him
iu his travels in Brazil, used to try a larger stone, if the first did not serve its purpose,
and even to take it up in both paws, and dash it upon the nut. jumping quickly out of
the way to avoid injury to its own toes. This animal generally rode on the back of a
large mastiff, and in descending a steep hill, would curl its tail round the root of the
mastiff's tail, to make its seat secure.

SPIEGELEISEN. See BESSEMER PROCESS; also KRUPP'S STEEL.

SPIELHAGEX, FRIEDRICH, b. Magdeburg, 1829; studied philology and philoso-
phy at Berlin, Bonn, and Greifswald; then devoted himself to literature. He wrote
Clara Fere (1837); Auf der Dune (1858); Problematische Naturen (I860); Drch Nacht
zum Licht (1861); In der zwolften Stunde (1862); Die Ton Hohemtein (1863); Roschcn von
/e(1864); In Rcih und Glied (186Q) ; Unter den Tannen (1867); Hammer und Ambos
(1869); Was die Schwalbe sang (1873) ; and Quisisana (1880).

SPIGE LIA, a genus of plants of the natural order loganiacea, having a calyx glandu-
lar inside, a long slender valvate, corolla, long filaments, and a capsule of two cocci,
splitting around at the base. 8. marilandica, often called WORM GRASS and CAROLINA
PINK, is a native of the southern United States, a perennial plant with a simple quad-
rangular stem. The root (?INK ROOT) is purgative, narcotic, and poisonous, but is a
powerful vermifuge, and is very commonly employed in the United States. N. ttnthfi-
mia. an annual native of tropical America with very small purplish flowers, in spike-
like racemes, possesses similar properties. The efficacy of both is, however, unpaired
by keeping; and they are apt to produce unpleasant symptoms when used as medicines.
Other species tire also known as poisons.

SPIKE, in l.oluny, that kind of inflorescence in which pcssile flowers, or flowers having
very short stalks, are arranged around an axis, as in the greater plantain, common ver-
vain, common lavender, and some species of sedge. In rye, wheat, barley, darm-l, and
many other grasses, there is a sort of compound spike, that is, the flowers or fruits are
arranged together in spikelets, upon short stalks, which again surround the top of the



Spikenard. >7 1 A

Spinal.

culm in the form of a spike. The catkin, the spadix, and the cone may be regarded as
varieties of the spike.

SPIKE NARD, or NARD (Gr. Nardos), a perfume highly prized by tho ancients, and
used both hi baths and at feasts. It was brought from India, and was very costly.
The "ointment of spikenard " (John xii. 3) was probably an oil or fat, impregnated
with the perfume. The plant which produces it has been ascertained by the researches
of sir William Jones and Dr. Royle to be thenardostachysjatamaim, the jatamausi of the
Hindus, a small plant of the natural order mlerianacece, a native of the mountains of the
n. of India, and found at least as far s. as the Deccan. It grows on the Himalaya to an
elevation of 18,000 ft. and its roots are a favorite perfume in Tibet and Xepaul. Th
ladies of Nepaul use oil in which the root has been steeped for perfuming their hair.
The odor is not, however, generally agreeable to Europeans. The root, which is from
3 to 12 in. long, sends up many stems, with little spikes of purple flowers, which have
four stamens. The name spikenard was given by the ancients to perfumes used aa
substitutes for the true or Indian spikenard, some of which were derived from the roots
of plants of the same natural order, kind called Gallic or Celtic spikenard from those
of valeriana CeUica and F saliunca, which are still used in the east for perfuming baths;
and that called Cretan spikenard from those of F. Italica, F. tuberona, and V.phu. All of
these grow on the Alps and other mountains of the s. of Europe, and the peasantry of
Styria and Carinthia collect them from rocks an the borders of perpetual snow. They
are tied in bundles, and sold at a very low price to merchants, who .sell them at a great
profit in Turkey and Egypt, from which they are partly transmitted even to India.
About sixty tons are annually exported from Trieste.

SPIKING is the operation of rendering a cannon useless without the expenditure of
much time and labor. It is resorted tq by troops compelled to abandon tlieir own ord-
nance, or unable to remove pieces of the enemy's which they have captured. The
process consists in driving a nail or spike into the vent or touch-hole. To remove it, it
is recommended, if an iron gun, to load with double charge and double balls, and to fire
by a train laid through the muzzle. This is supposed to loosen the spike. If the gun be
of brass, a few drops of sulphuric or nitric acid on the touch-hole will render it practi-
cable to extract the spike. If these methods fail, nothing remains but the tedious
process of drilling out the spike or boring a new vent.

SPI'NA BI FIDA is a congenital malformation, occurring perhaps more frequently
than any other except hare-lip, and arising, like it, from arrest of development. It may
be regarded as a congenital hernia of the membranes of the spinal cord, through a fis-
sure in the wall of the bony canal. A tumor is thus formed, which is usually of a
roundish shape, varying in size from that of an egg to that of an adult head, lying in the
middle line of the back, fluctuating, and adhering to the adjacent vertebra) either directly
or by a pedicle. The usual termination of the disease is death. As the size of the tumor
increases, fatal convulsions ensue; or ths skin investing the tumor may ulcerate, and
the contents escape, in which case palsy or convulsions produce death. Occasional
cases are, however, recorded in which patients with this affection have survived till
middle life. Active surgical treatment" usually hastens death, and should only be
resorted to in the most urgent circumstances. Moderate support by means of a hollow
truss, or a well-padded concave shield, may tend to keep the disease stationary; and any
interference beyond this is, in the great majority of cases, unadvisable.

SPINACH, or SPINAGE (Spinacw), a genus of herbaceous plants, of the natural order
cfanopodiacese; dioacious, the male flowers consisting of a 4 parted perianth and four
stamens; the female of a 3-3 cleft perianth, and a germen with four styles; the perianth
harden ing around the fruit as it ripens; the fruit an acheni urn. COMMON SPINACH, or GAR-
DEN SPINACH (S. oleracea), is in general cultivation for the sake of its youngleaves, which
are a favorite and wholesome vegetable, either prepared by boiling, or by frying with a
little butter. Two very distinct varieties are cultivated : PRICKLY SPINACH", which has the
leaves somewhat triangular and arrow-headed, and the fruit rough with prickle-like pro-
jections; and SMOOTH SPINACH, or ROUND SPINACH, (S. glabra of some botanists), with the
leaves more round and blunt, and the fruit smooth. SPINACH is an annual. Its stem rises
to the height of from 2 to 4 ft. ; the male flowers are in long spikes. the female in clusters
close to the stem. After the stem begins to be developed, tlie leaves become bitter, and
unfit for use. This bitterness appears also at an earlier period in dry weather, or in
poor soil; and the more luxuriantly tliat Spinach grows, the better it is. It is sown
in spring, and is ready for use in a very short time; or it is sown in autumn, thinned out,
and used early in spring. The smooth Spinach is very generally preferred for the
former 'purpose, and the prickly kind for the latter: but a somewhat intermediate
variety, called Flanders Spinach, is now often used for both, being particularly
esteemed for the large size of its leaves. The native country of Spinach is not well
known, but is believed to be some part of AMa, as the plant was introduced by the
Arabs into Spain, and thence diffused over Europe. Another species (S. tetrandra) is
cultivated, and much esteemed, in India. The name of Spinachis also given to a num-
ber of other plants of very different botanical characters, but which have the same
bland and nutritious qualities, and are used in the same way. NEW ZEALAND SPINACH



>71 ?\ Spikenard.

' X J Spiual.

is tetragonia expansa, a plant of the natural order mcwmlryacea}, sub-order telra-
goniat (nat, ord. tctrayoniaceve of Lindley), a trailing, succulent annual, spreading
widely over the snrfaee of the ground, and producing a great abundance of stalked
ovate-rhomboid leaves. The young stems and leaves of Ibis plant are much used in
New Zealand, and have now come into very general use also in oilier parts of the world,



a* a kind of spinach. It is cultivated in the middle and s. of Europe and in Britain,
succeeding well even in Scotland with the slightest aid of a hot-bed in spring.
PATIENCE DOCK, or GARDEN PATIENCE (rumex t>aticutia; see DOCK), is called in Ger-
many ENGLISH SPINACH, and was formerly much cultivated in England, but .is now-




placed one above, or in front, of another, and called vertebra; (q.v.); and hence, these
buimals, having this distinguishing characteristic in common, are all included in the term
Wrtefcrote*. The vertebra; vary greatly in number in different animals, and even in.
members of the same class, and the number have no apparent relation to the other organs
of the animal. Moreover, in their shape, they differ extremely, even in different parts
of the same spine, in accordance with their special functions. In man, the number of
vertebra; which collectively form the spinal column is 1 in the neck (cervical vertebra;),
12 in the back (dorsal vertebra;), 5 in the loins (lumbar vertebra-), all of which are capa-
ble of being detached from one another, and are termed trite vertebra'; and 5 vertebrae
ossified together, and forming the sacrum, and 4 or 5 similarly united forming the termi-
nation of the column, and constituting the bone called the coccyx, which are known as
false vertebra 1 . However long or short the neck may be, every mammal has 7 cervical ver-
tebra;, excepting the three-toed sloth, which has 9, and the sea cow, which lias 6. In
the other regions of the spine no such law exists. Each vertebra is attached to the two
between which it lies by numerous strong and more or less elastic ligaments, and between
ach pair of vertebrae there is interposed a lenticular disk of fibro-cartilage, which acts
as a buffer. By these arrangements the spinal column is rendered highly elastic, the
communication of jars or shocks is prevented, and a very considerable genera! range of




red

the

antero-posterior direction, any well-marked lateral deviation from tiie perpendicular
being abnormal; but a very slight lateral curvature with the convexity to the right may
often be detected in the upper and middle parts of the back, and is supposed to be de-
pendent on the more frequent use and greater strength of the right arm as compared with
the left. From their position they are termed the cervical, dorsal, lumbar, and pelvic
curves. The dorsal and pelvic curves have their concavities in front, and thus enlarge
the spaces in which the thoracic and pelvic viscera are contained; the two other curves
are convex anteriorly, and thus afford support to the parts above them. The upper three
curves are so arranged that their chords are in the same vertical dine in the erect position
of the body, and this vertical line corresponds with the line of gravity of the head. The
cause of these curves is to be sought for partly in the shape of the vertebral bodies, and
partly in that of the intervertebral substance. Among the uses of these curves it may Vie
mentioned (1) that they enable the spine 1o bear a greater vertical weight than it could
otherwise maintain; it is calculated that nine times as great a vertical force is required
to bend it as if it had been straight; (2) that they facilitate the movements of the body,
especially in the <ict of running; and (3) that they are so disposed as to protect Hie chord
In movements cf the spine. Similar curves are seen in the spine of other mammals,
though the degree of flexure is liable to great deviations. The lumbar curve which has
especial reference to the erect position, is always much less marked than in man.

The vertebral canal formed by the .apposition of the spinal foramina, or neural arches
(see SKELETON), and containing and protecting the spinal chord, varies in its size at
different parts of the column. It is largest in its antcm-posterior diameter in the neck
and loins (measuring at the last lumbar vertebra ? of an inch), where the antcro postei ior
movements of the spine are greatest, and where the cord is least closely attached to the
vertebra?; while in its lateral diameter it is greatest at the atlas, where it measures nearly
an inch and a half. A transverse section of the canal is nearly circular through the
greater part of the back. The intervertebral foramina through which the nerves emerge
vary in shape and position in different parts, but are always of snllicient size to prevent
injurious pressure on the nerves during movement of the spine; and in the dorsal region,
which is the ordinary seat of angular curvature, the nerves are so protected by bony
arches that they may escape injury, even when the bodies of several dorsal vertebras
have been destroyed by ulceration.

SPINAL CORD OR MAUUOW, TIIF, STRUCTURE AND FUNCTIONS OF. The spinal cord
is that elongated part of the cerebro-spinal axis (see NERVOUS SYSTEM) which is con-
tained in the spinal canal from the fonnrun n/nf/num, at the base of the skull, superiorly,
to the first or second lumbar vertebra inferior!}', where it merges into the ./////; termi-
nate, which extends to the lower end of the sacral caual, ami in no way diSers atructti-



Spinazzola. h~t (*

Spiue. >

rally from the proper spinal cord, except that no nerve-roots are connected with it. The
membranes by which it is protected from danger, and kept in its proper position, are
described in the article NERVOUS SYSTEM. Its length varies from 15 to 18 in., and it
presents a difference in its diameter in different parts, there being an upper or cervical,
and a lower or lumbar enlargement. In form it is a flattered cylinder. It is almost
completely divided, along the median plane by an anterior and posterior fissure, into two
equal and symmetrical parts. The anterior fissure is more distinct and wider at the sur-
face than the posterior fissure, but it only penetrates to about one-third of the thickness

>f the cord, while the posterior fissure extends to about half the thickness of the cord.

The two halves are hence only united near the center by a commissural band, which ia
traversed by the "spinal canal " extending downward from the fourth ventricle (see
BRAIN), and about one-hundredth of an inch in diameter. A posterior and an interior
lateral furrow (two shallow depressions, the latter being scarcely perceptible) further
divide each half of the cord into a posterior, a lateral, and an anterior column; these
two furrows corresponding with the lines of attachment of the posterior and ante-
rior nerve-roots. The separation of the antero-lateral columns into the " anterior" and
the lateral columns is made more obvious internally by the mode in which the gray or
vesicular nervous matter (described in the article NERVOUS SYSTEM) is arranged ia rela-
tion to the white or fibrous matter. Although the distribution of the gray matter differs
considerably in different parts of the cord, it usually presents in a transverse section the
form of two somewhat crescent-shaped masses, whose convexities are turned toward
each other, and are connected by the gray commissure, while their cornua, are directed
toward the surface of the cord ; the posterior peak on each side nearly reaches the posterior
lateral furrow, while the anterior, though the larger cornu, does not approach quite so
near the surface at the assumed anterior furrow. The enlargement of the cord in the
cervical and lumbar region, where the great nervous plexuses are given off, is chiefly due
to the increase, at those points, of gray matter, whicli is comparatively deficient in the
interval between them. The white substance seems to increase regularly from the lower "
to the upper part of the cord ; and this fact, as Dr. Carpenter remarks, seems to indicate
the probability that the longitudinal columns serve (as formerly supposed) to establish a
direct connection between the encephalic centers and the roots of the spinal nerves.
Careful microscopic investigation has revealed the fact that the root-fibers of the spinal
nerves run two very distinct courses in the substance of the cord; the first transverse, and
the second longitudinal. The transverse fibers traverse the cord horizontally or obliquely,
a:id appear to pass out in the other set of roots connected with the same segment, either
(>a its own or on the opposite side of the median fissure; while the longitudinal fibers in
part connect the posterior roots directly with the posterior column without passing into
the vesicular matter, but for the most part enter the gray matter, and emerge from it into
the posterior column, or into the posterior part of the lateral column of the same or the
opposite side. How far these longitudinal fibers run up or down the cord, is undecided.
It is probable that some of them are longitudinal commissures, serving to connect the
nerve-roots of one segment of the cord with the vesicular matter of another above or
below it, and it is possible that all are of this character, in which case the spinal cord
will be the real center of all the nerve-fibers connected with it.

In considering the functions of the spinal cord, we have to regard it in two distinct
points of view viz., in the first place, as a conductor of nervous force between the
nerve-trunks and the brain; and in the second place, as an independent nervous center.
As a mere conductor of nervous force, its functions and behavior are the same as those
of a nerve-trunk; for, as Dr. Carpenter observes: " If it be divided, all the parts of the
body which are solely supplied by nerves coming off below the point of section are com-
pletely paralyzed, as far as regards sensibility and voluntary movement; no impressions
made upon them having the least power to affect the consciousness, and no exertion of
the will being able to determine contraction of the muscles. This state of para-ple-gitt,
which may be experimentally induced in animals, is frequently exhibited in man, as a
result of injury or of disease that seriously implicates the spinal cord; and as it has been
shown that among the lower animals complete reunion of the cord may take place after
complete division, as indicated by the entire restoration of its functional powers, and the
complete redintegration of its structure, so have we reason to believe that a similar
regeneration may take place, to a considerable extent, in man, this being marked by a
gradual return of sensibility and power of voluntary movement in the lower limbs,
which had been at first completely paralyzed." Human Physiology, 6th ed., pp. 529-30.
There can be little doubt that the gray matter is essentially the conductor of sensory
impressions, for if the anterior, posterior, and antero-lateral columns are divided as com-
pletely as possible, the gray substance remaining uninjured, the sensibility of the parts
below is unaffected; while, conversely, if the gray substance is divided, while the
white columns remain uninjured, sensibility is almost totally extinguished. M.
Brown-Sequard, whose researches on the nervous system are of the highest impor-
tance, has shown that the central portions of the gray substance are the most
effective in the transmission of sensation. He likewise brings forward strong



Online LibraryFrancis LieberLibrary of universal knowledge. A reprint of the last (1880) Edinburgh and London edition of Chambers' encyclopaedia, with copious additions by American editors (Volume 13) → online text (page 165 of 203)