B E P. - • E L E Y

LiC

1 UN1V'
\ CAl

/ OF

NIA

EARTH

Arthur Eaton

DICTIONARY

OF

GEOLOGY AND MINERALOGY,

COMPRISING SUCH TERMS IN

BOTANY, CHEMISTRY, COMPARATIVE ANATOMY,

CONCHOLOGY, ENTOMOLOGY, PALEONTOLOGY,

ZOOLOGY,

AND OTHER BRANCHES OF

NATURAL HISTORY,

AS ARE CONNECTED WITH

THE STUDY OF GEOLOGY,

BY WILLIAM HUMBLE, M.D.

LONDON:

PUBLISHED BY HENRY WASHBOURNE,
SALISBURY SQUARE, FLEET STREET.

MDCCCXL.

SCIENCES

LONDON :

PRINTED BY STEWART AND MURRAY,
OLD BAILEY.

TO

HIS GRACE THE DUKE OF
RICHMOND, LENNOX, AND AUBIGNY, K.G,

LORD LIEUTENANT OF THE COUNTY OF SUSSEX,

ETC. ETC. ETC.

THIS VOLUME

Inscritietr,

AS AN EARNEST OF THE HIGHEST ADMIRATION,

AND MOST PROFOUND RESPECT,

BY HIS GRACE'S

OBEDIENT AND OBLIGED SERVANT,

WILLIAM HUMBLE.

Steyne, Worthing,

February 27, 1840.

690888

PREFACE.

IN submitting the following pages to public approbation, or public censure,
I avail myself of the accustomed privilege to offer a few prefatory obser-
vations ; explanatory, on the one hand, of the motives which led to their
preparation ; and deprecatory, on the other, of severity of criticism.

The labours of the lexicographer greatly differ from those of authors
generally. Dr. Johnson has observed, " every other author may aspire to
praise ; the lexicographer can only hope to escape reproach, and even this
negative recompence has been yet granted to very few. It is the fate of
those, who toil at the lower employments of life, to be rather driven by
the fear of evil, than attracted by the prospect of good ; to be exposed to
censure, without » hope of praise; to be disgraced by miscarriage, or
punished for neglect, where success would have been without applause, and
diligence without reward. Among these unhappy mortals is the writer of
dictionaries; whom mankind have considered, not as the pupil, but the
slave of science, the pioneer of literature, doomed only to remove rubbish
and clear obstructions from the paths through which learning and genius
press forward to conquest and glory, without bestowing a smile on the
humble drudge that facilitates their escape."

When I commenced collecting materials for the present work, I was
induced to undertake the labour from a conviction that something of the
kind was greatly needed. At entering on the study of geology, scarcely
had I read through a single page, ere I found my difficulties much
enhanced by the non-existence of a dictionary containing such technological
terms as are peculiar to this branch of science, and, for a time, I was fre-
quently obliged to pass over words, without any distinct comprehension of
their force or application. Assuredly, some writers on geology have
appended a glossary to their productions ; but, I need scarcely say, these
are, for the most part, necessarily meagre and ineffectual. The very neces-
sity, also, for their insertion, I may, perhaps, claim as one of the strongest
arguments in justification of my present attempt.

It can hardly, however, be adduced as a charge of inattention to the
wants of the student, against the writers on geology, that no dictionary
relating to its nomenclature has already appeared. Geology may still be
regarded as in its infancy ; it is, as it were, almost a creation of the pre-
sent century ; it may, not inaptly, be termed a new science ; for, although

VI PREFACE.

Pythagoras, and Aristotle, and Strabo, were, to a certain extent, geologists ;
although Ovid puts into the mouth of the Saurian philosopher —

" Vidi factas ex sequore terras :

Et procul a pelago conchas jacuere marina? ;

Et vetus inventa est in montibus anchora summis ;

Quodque fuit campus, vallem decursus aquarum

Fecit ; et eluvie mons est deductus in sequor :

Eque paludosa siccis humus aret arenis ;

Quseque sitim tulerant, stagnata paludibus hument."

although, from time to time, theories of the earth have been published,
and hypotheses the most crude, and fanciful, and illusory have been pro-
pounded ; although men have been found so blind as to argue in favour of
a plastic force ; although, almost even in our own days, Vulcanist would
have submerged Neptunist in his own aqueous deposits, and Neptunist
would have torrefied Vulcanist in the igneous causes which he advocated ;
although, for upwards of two thousand years, geology may be said to have
had its students and its advocates ; yet till within the last half century it
has never deserved the name of a science. Mixed up and confounded with
cosmogony, it continued in a state of flux and reflux, at one time making
advances, at another retrograding, till Hutton, in 1795, declared that
"geology was in no ways concerned with questions as to the origin of
things." Nor was it till, throwing aside all preconceived notions, geolo-
gists determined to found, and gradually advance, step by step, their
theories on sound induction, that geology, in the magnitude and sublimity
of the objects of which it treats, second only to astronomy, assumed its
proper position in the order of scientific pursuits.

With the great increase of knowledge in geology, there necessarily
sprang up a new nomenclature, and although this particular branch of
technological lexicography may, and does, admit of much modification, it
appears to me that it has at this time become sufficiently established to
warrant, and call for, the issuing of a dictionary of geological terms.

Nomenclature being in itself an important part of science, I trust I may
be excused for offering hi this place a few observations on the subject. It
is perhaps a very natural weakness that men should desire to distinguish
things by names of their own appointing ; but, inasmuch as a redundancy
of names is prejudicial to the interests of science ; perplexing, and often
disgusting, to the student ; and, in fact, raises an unnecessary obstruction
in the path of knowledge; it becomes a subject of grave consideration
whether the imposition of a new name, in lieu of one already become con-
ventional, though that which has become conventional may, probably, not
be the best or most appropriate that could have been chosen, be not a
hazardous and injudicious course. It has been remarked by one of the

PREFACE. Vll

most scientific men and greatest philosophers of the present day, Sir John
Herschel, " it appears doubtful, whether it is desirable, for the essential
purposes of science, that extreme refinement in systematic nomenclature
should be insisted on. In all subjects where comprehensive heads of clas-
sification do not prominently offer themselves, all nomenclature must be a
balance of difficulties, and a good, short, unmeaning name, which has once
obtained a footing in usage, is preferable almost to any other."

These remarks are the more readily offered, in consequence of a fear,
which I trust is groundless, arising out of, and caused by, the occasional
observations of some of our most able geologists. Thus, I find one author
objecting to the term tertiary, as applied to the supra- cretaceous deposits,
stating it to be exceedingly objectionable : I turn over the pages of another
great luminary, and I find that " the name of tertiary has been given with
much propriety ; that the name of super-cretaceous is peculiarly inappro-
priate, and that if a new name were necessary, post-cretaceous should have
been chosen." Every neophyte in geology now knows that the tertiary
deposits have been divided into eocene, miocene, and pliocene, the last being
subdivided into older and newer pliocene : this also is objected to, and it is
said, " if it be considered convenient to divide the supra-cretaceous rocks
of Europe into three or more sub-groups, names which imply their actual
geological position in the series, such as * superior,' ' medial/ and ' infe-
rior,' 'upper/ 'medial,' and 'lower,' or others of the like kind, would
seem preferable to those derived only from a per-centage of certain organic
contents." To multiply instances of this kind, would, however, be useless,,
and the sole motive for adducing the above, springs from a desire of
restraining, as far as may be, a too natural fondness for innovating on esta-
blished nomenclature.

It is most desirable that geologists should endeavour to avoid a very
great evil which has gradually obtained in, and now sadly clogs, the pursuit
of mineralogy. The redundancy of terms there introduced is most pain-
fully bewildering, as the following instance will illustrate : — " The nomen-
clature of most minerals is at present so incumbered with synonyma, that
it has become exceedingly perplexing to the student. The mineral which
is called epidote by Haiiy, is named pristazit by Werner, thallite by Leme-
therie, akanticone by Dandrada, delphinite by Saussure, glassy actinolite by
Kirwan, arendalit by Karsten, glassiger strahlstein by Emmerling ; la rayon-
nante vitreuse by Brochant, prismatoidischer augit-spath by Mohs, &c. &c."*

To enter, here, on any defence of geology, against the groundless objec-
tions of weak, but amiable opponents, would be to travel out of the record.

* Professor Cleaveland.

Vlll PREFACE.

Happily, the mists of delusion, and the prejudices consequent on long-
cherished and preconceived notions, are rapidly clearing away before the
lucid, and delightful, and unanswerable statements and views of the galaxy
of learned, and scientific, and pious geologists of the present day. I trust
I may be permitted to quote from one of these a most happily conceived
and beautifully expressed passage : — " How then can they, by whom the
magnificent truths of elapsed time and successive generations have been put in
clear and strong evidence — how can they be expected to yield to false notions
of philosophy, and narrow views of religion, the secure conviction that, in the
formation of the crust of the earth, Almighty wisdom was glorified, the per-
mitted laws of nature were in beneficent operation, and thousands of
beautiful and active things enjoyed their appointed life, long before man
was formed of the dust of the ancient earth, and endowed with a divine
power of comprehending the wonders of its construction ? It is something
worse than philosophical prejudice, to close the eyes of reason on the evi-
dence which the earth offers to the eyes of sense ; it is a dangerous theolo-
gical error, to put in unequal conflict a few ill-understood words of the
Pentateuch, and the thousands of facts which the finger of God has plainly
written on the book of nature ; folly, past all excuse, to suppose that the
moral evidence of an eternity of the future should be weakened by admit-
ting the physical evidence for an immensity of the past."*

It remains for me to add a few words only, as deprecatory of severe cri-
ticism. No one can be more aware than myself of the numerous errors
and deficiencies everywhere pervading this small volume : for these I urge
nothing, even in extenuation. For myself, it is sufficient that I have
derived from its preparation much information, great gratification. I
entertain no morbid sensitiveness respecting the fate that awaits it. With
our prince of lexicographers I may say, " I dismiss it with frigid tranquil-
lity, having little to fear or hope from censure or from praise."

The necessity created, by preparing such a book for the press, for care-
fully looking into and examining the opinions of various authors on the
same subject, has made me acquainted with many works which, otherwise,
I never might have perused; and I have, from this circumstance only,
reaped a rich reward of the purest pleasure ; and, though critics may in
unmeasured terms condemn, it is more than probable that

" Seu me tranquilla senectus
Exspectat, seu mors atris circumvolat alls ;
Dives, inops, Romee, seu fors ita, jusserit, exsul ;
Quisquis erit vitse, scribam, color."

* Professor Phillips.

A DICTIONARY.

A. The first letter of the alphabet in all the
known languages except the Ethiopic and
the Runic ; in the former it is the thir-
teenth, and in the latter the tenth.

Among the ancients, A was used as a
numeral, and_signified 500 ; with a line
over the top, I, 5000.

In words of Greek derivation, A is
used privatively, or in a negative sense, as
acephalous, without a head ; acaulous,
having no stem ; apetalous, having no
petals ; acotyledonous, having no coty-
ledons, &c.

ABAI'SIR. A name for spodium, burnt
ivory, or ivory black.

ABARTICULA'TION. (from ab and articu-
latio, Lat.) That kind of articulation
which admits of manifest motion ; it is
also called diarthrosis, from the Greek
word dtap0pw<rt£, and dearticulation.

ABBRE'VIATED. (abbreviatus, Lat.)

1. In botany, an epithet for the perianth.
An abbreviated perianth is shorter than
the tube of the corolla, as in Pulmonaria
maritima.

2. Shorter than a correspondent part.
AB'DITIVE. (from abdo, Lat.) That has

the power of hiding or concealing.

ABDO'MEN. (abdomen, Lat. abdomen, Fr.
addomine, It.) The large cavity com-
monly known as the belly, containing the
organs more immediately concerned in
the process of digestion, as the stomach,
liver, spleen, pancreas, bowels, &c.

ABDO'MINAL. (from abdomen.)

1 . Pertaining to the abdomen or belly.

2. Fishes belonging to the order abdo-
minales, or the fourth order of Lin-
nseus.

ABDOMINA'LES. The fourth order of fishes
in the arrangement of Linnaeus ; they
have ventral fins behind the thoracic, or
fins placed on the belly, and the branchia
ossiculated ; they chiefly inhabit fresh

A B R

water. The salmon, trout, "smelt, &c.,

are examples.
ABDO'MINOUS. Relating to the abdomen

or belly.
ABDU'CENT. (from abduco, Lat.) The name

given to those muscles which serve to

open or draw back parts of the body ;

their opposites, or antagonists, are called

adducent.
ABDUC'TOR. (abducteur,l?r.abduttore, It.)

The same as abducent.
ABERRA'TION. (aberratio, Lat.)

1. A certain deviation in the rays of
light, from the true or geometrical focus
of reflection or refraction, in curved spe-
cula or lenses.

2. A deviation from the ordinary course
of nature.

ABNO'RMAL. ) (aJwonw/svLat.) Irregular;

ABNO'RMOUS. 5 unwonted ; unnatural.

ABNO'RMITY. Departure from natural for-
mation ; irregularity.

ABRA'DE. (abrado, Lat.) To wear away
from the other parts ; to destroy by fric-
tion ; to rub off.

ABRA'SION. (from abrasio, Lat.)

1. The act of wearing or rubbing off.

2. The matter abraded by the friction of
bodies.

ABRA'NCHIA. (from a, priv. and /3p«y%ia,
Gr.) Animals destitute of gills, and hav-
ing no apparent external organs of respi-
ration.

ABRANCHIA'TA. The third order of arti-
culata, having no apparent external organs
of respiration, but seeming to respire,
some, by the entire surface of the skin,
others, by internal cavities. The abran-
chiata are divided into two families ; the
first, Abranchiata setigera, comprising
the Lumbrici and Naides of Linnaeus ; the
second, Abranchiata asetigera, compris-
ing the Hirudo and Gordius of Lin-
naeus.

R '

[2]

A C C

ABRU'PT. (abruptus, Lat.) Broken ;
craggy ; steep ; precipitous. In botany,
applied to leaves ; when the extremity of
the leaf is, as it were, cut off by a trans-
verse line.

ABRTJ'PTLY PIN'NATE. Applied to pinnate
leaves, terminated neither with a leaflet
nor a tendril.

ABRUPTNESS. Cragginess ; steepness ;
roughness ; precipitousness.

A'BSONOUS. (absonus, Lat.) Without
sound ; ill-sounding ; untunable.

ABSO'RBENT. (from absorbeo, Lat.)

1. Any substance possessing the pro-
perty of absorbing, or sucking up, fluids,
or neutralizing acids ; as the earths, alu-
mina, magnesia, &c.

2. In anatomy, the absorbents are small
pellucid tubes, which have been dis-
covered in most parts of the body, and
are supposed to exist in all. The ab-
sorbents begin by numberless open
mouths, too minute to be visible to the
naked eye ; by the assistance, however,
of glasses, the orifices of the lacteals
have been seen in the human body, and
those of the lymphatics in certain fishes.

ABSO'RBENT SYSTEM. This consists of
the absorbent vessels and conglobate
glands ; the former are divided into
lymphatics and lacteals, and the thoracic
duct, or common trunk, in which they
terminate.

ABSTE'RGENT. (from alstergeo, Lat. ab-
stergent, Fr.) Having a cleansing pro-
perty ; which not only wash off adhering
substances, but possess a power of
loosening their cohesion.

ABSTE'RSIVE. (abstersif,¥r. astersivo^t.)
That has the property of cleansing.

ABU'TTAL. A head-land ; a bounding of
land.

ACA'LEPHA. (d/caX^j;, Gr.) A class of
zoophytes found swimming in the waters
of the ocean. The acalepha are divided
into orders, namely, the A. simplicia, and
A. hydrostatica. The latter, or hydro-
statica, are recognized by one or more
bladders commonly filled with air, by the
aid of which they suspend themselves in
their watery element. "In all parts of
the ocean," says Professor Grant, "are
numerous gelatinous animals, for the most
part of a simple and transparent texture,
such as the Medusa and Portuguese man-
of-war, and numerous other genera.
For the most part, those soft gelatinous
animals (which are entirely aquatic, and
all of them marine) possess a property
by which they excite inflammation, when
they touch the surface of the skin, like
nettles. The word whence they derive
their name is a Greek term expressive of
nettles. The Acalepha scarcely possess a
trace of a nervous system, and are all

aquatic. They float, for the most part,
by the action of their own muscular
power, or by air-sacs, or by cilia. They
feed upon animals of extreme minute-
ness— for the most part, on the microscopic
crustaceous animals, which abound in
the ocean as in other waters." Cuvier
places the Acalepha in the third class of
the fourth great division of the animal
kingdom, or Radiata. Linnaeus placed
them in the class Zoophyta, order Gela-
tinous zoophytes.

ACALY'CINOUS. A term applied to plants
which want a calyx.

ACANA'CEOUS. (from UKCIVOG, Gr.) Armed
with spines or prickles.

ACA'NTHA. (dicavQa, Gr.)

1. In botany, the spine or prickle of a
plant.

2. In zoology, a term for the prickly
fins of fishes.

3. In anatomy, the spinous process of a
vertebra.

ACANTHA'CEOUS. (acanthace, Fr.) Pos-
sessing spines or prickles.

ACANTHOPTERY'GIOUS. (from dicavOa and
Trrlpu?, Gr.) A term applied to those
fishes whose back fins arc osseous and
prickly. The acanthoptcrygii form the
first, and by far the most numerous divi-
sion of ordinary fishes.

ACANTHOCE'PHALA. (from aicavQa. and
KtQaXij, Gr.) An intestinal worm, be-
longing to the order Parenchymata, class
Entozoa.

ACAN'TICONE. A sub-species of prismatoi-
dal augite, occurring principally in primi-
tive rocks, such as mica-slate, gneiss, &c.
Known also as pistacite and epidote.

A'CARUS. (aKopi, Gr. animal minutissi-
mum.) The tick or mite. A genus of
insects belonging to the order Aptera.
The Acarus has eight legs, two eyes, and
two jointed tentacula. The female is ovi-
parous, and excessively prolific. Authors
estimate the number of species variously ;
Linnaeus enumerates 35, and Gmelin 82
species. Most of these are very small and
almost microscopical. Some are parasi-
tical, living in the skin of animals : some
of the coleoptera are found covered with
them.

ACAU'LIS. ) (from a, priv. and *arA6c,

ACAU'LOUS. $ Gr.) A term applied to
plants, the flowers of which have no
pedicle or stalk.

ACCENDIBI'LITY. Capability of being kin-
dled or ignited.

ACCI'PITRES. (Lat. from accipiendo.} Ra-
pacious birds ; the first order of birds in
the Linnsean system of ornithology. The
Accipitres are known by their hooked
beak and talons ; they feed upon other
birds, as well as upon the weaker quadru-
peds, and reptiles. They have been di-

A C C

A C I

vided into two families, the diurnal and
the nocturnal.

ACCI'PITRINE. Belonging to the order
Accipitres ; rapacious.

ACCLI'MATED. {acclimate, Fr.) Accus-
tomed to a climate not natural to it.

ACCLIMA'TION. Naturalization to foreign
climate.

ACCLIMATIZE, (acclimater, Fr.) To ac-
custom to foreign climate ; to accustom
to the temperature of a new climate. A
term applied both to persons and things ;
to animals and plants.

ACCRE'TION. (accretio, Lat.) Increase, or
growth, by the accession of new parts.
Bacon says, plants do nourish ; inanimate
bodies do not ; they have an accretion,
but no alimentation.

ACCRE'TIVE. Increasing, or growing, by
the accession of new parts.

ACE'PHALA. (a, priv. and Kt^aX?}, the
head, Gr.)

1. A class of animals not having any head,
but merely a mouth, concealed between
the folds of their mantle ; the mouth is
always edentated: the oyster furnishes an
example. All the acephala are aquatic.

2. In entomology, an order of insects.
ACE'PHALOUS. (acephale, Fr. afce0aXoCj

Gr.) Headless ; this term was given by
Cuvier to animals not having any head.

ACE'RB. (acerbus, Lat. acerbe, Fr. acerbo,
It.) Acid with an addition of roughness :
the taste of an unripe sloe is a familiar
and good illustration.

ACE'RBITY. (acerbitas, Lat. acerbite, Fr.)
Sourness combined with roughness of
taste.

ACERO'SE. ) (acerosus, Lat.)

A'CEROUS. 5 1. Chaffy; branny.

2. In botany, leaves linear, needle-shaped,
every where of an equal breadth, mostly
acute, and rigid.

ACE'SCENT. (ascescens, Lat. acescent, Fr.)
That has a tendency to become sour spon-
taneously, or by spontaneous decomposi-
tion.

ACETA'BDLUM. (Lat.)

1. A cavity in a bone formed for receiving
the head of another bone, and thus named
from its cup-like shape ; it is more parti-
cularly used for expressing the cavity in
the os innominatum, which receives the
head of the femur, or thigh-bone.

2. In botany it is used for the cotyledon.
ACE'TARY. (from acetum, Lat.) An acid

pulpy substance found in some fruits, es-
pecially the pear, surrounding the core ;
it is enclosed in a congeries of small cal-
culous bodies towards the base of the
fruit.

A'CETATE. Any salt formed by the union
of acetic acid with a salifiable base, as
acetate of iron, acetate of potash, &c.
The acetates are all soluble in water ;

many of them are deliquescent, and crys-
tallizable with difficulty: they are de-
composed by the sulphuric acid.

A'CETITE. The old name for what is now
called acetate.

ACHA'TES. (ax«'r»?£> Gr.) The agate.

ACEUS. Terminations in aceus and iciug,
express a resemblance to a material ; those
in eus indicate the material itself; as
membranaceous, resembling skin ; mem-
braneous, skin itself.

ACHA'NIA. (from a^avriQ, Gr. ab a, priv.
et xatvw.) In botany, plants whose co-
rolla does not open. Order Polyandria,
class Monodelphia ; natural order Colum-
niferae.

ACHE'NIUM. (from a^drri, Gr.) A sort
of fruit.

A'CHIRITE. Emerald malachite.

ACI'CULA. (Lat.) A prickle or fine spine.

ACI'CULAR. In the shape of a needle :
rocks of granite having sharp, needle-like,
summits, are thus named.

ACI'CULARLY. Needle-like.

ACID, (acidum, Lat. acide, Fr.) The word
acid, originally synonymous with sour,
and applied only to bodies distinguished
by that taste, has been gradually extended
in its signification, and now comprehends
all substances possessed of the following
properties : —

1 . When applied to the tongue, they ex-
cite that sensation which is called sour-
ness.

2. They change the blue colours of vege-
tables to a red.

3. They unite with water in almost any
proportion, with a condensation of volume,
and evolution of heat.

4. They combine with all the alkalies,
producing effervescence during the com-
bination, and with most of the metallic
oxides and earths, and form with them those
compounds which are called salts.

The acids terminating in ous produce
compounds to which the termination ite
is given, as, e. g. the combination of sul-
phurous acid and potassa is a sulphite of
potassa ; the acids ending in ic form
compounds to which the termination ate
is applied ; the combination of sulphuric
acid and potassa is a sulphate of potassa.

ACIDI'FEROUS. Containing acid.

ACI'DIFIABLE. Any substance capable of
being converted into an acid, by the union
of an acidifying principle, without decom-
position.

ACI'DULOUS. (acidulus, Lat.) Slightly
acid ; sub-acid ; sourish.

ACINA'CIFORM. (from acinaces and forma,
Lat.) Cimeter shaped; a term applied
to leaves, one edge of which is straight
and thick, the other curved and thin.

A'CINI. Granulations ; compound berries.
The plural of acinus.

A C I

A D I

A'CINOSE. Iron ore. A variety of iron ore
found in masses, and commonly lenticu-
lar. Colour, generally, brownish red :
lustre metallic : texture granular : hard-
ness 5 to 9 : brittle.
A'CINUS. (Lat.) Each separate part of a
compound berry containing a seed : com-
pound berries consist of many simple
acini united together, as the raspberry,
blackberry, &c.

ACOTYLE'DON. (from a, priv. and KOTv
£o»v, Gr.) A plant whose seeds have no
cotyledons, or side-lobes.
ACOTYLE'DONOUS. Plants, whose embryos
have no lobes, or seminal leaves; not
having cotyledons, or seed lobes.
ACROCERAU'NIAN. (from dicpoQ and Kfpav-
voc, Gr.) A term given to some moun-
tains, supposed to be especially subject
to the effects of lightning.
A'CROGEN. (from dicpog and •yfvvdo), Gr.)
An acrogen is a cylindrical plant growing
at its point only, and never augmenting
in thickness after once formed.
A'CROMION. (a*C|OOf and w/iof, Gr.) -The
humeral extremity of the spinous process
of the scapula ; situated over the upper
end of the humerus, and contributing to
the protection of the shoulder joint.
A'CROSPIRE. (from dicpog and ffirtlpa, Gr. )
The shoot or sprout of a seed, also called
the plume, or plumule.
ACTI'NIA. The sea-anemony, a genus of
the order Vermes mollusca. The fleshy
body of the actinia is frequently orna-
mented with bright colours, and exhibits
numerous tentacula placed round the
mouth in several ranges, like the ^petals
of a double flower, from which it has
obtained its name of sea-anemony.
ACTINO'COMAX. A genus of fossil shells,

having the form of belemnites.
ACTI'NOCRITE. A fossil crionoidean, found
in the carboniferous limestone near Bristol.
ACTI'NOLITE. (from O.KTIV and Xi9o£, Gr.)
A variety of hornblende. Its con-
stituent parts are silica 46*26, mag-
nesia 19-03, lime 13-96, alumina 14-48,
protoxide of iron 3*43, protoxide of
manganese 0*36, fluoric acid 1-60, water,
&c. 1-04. This variety of hornblende
rarely occurs in the secondary rocks,
being principally confined to those of the
primary class. It is of a green colour.
ACTI'NOLITB-SCHIST. A metamorphicrock,
consisting principally of actinolite, with
an admixture of mica, quartz, or felspar ;
its texture is slaty and foliated.
ACTINOLI'TIC. Containing actinolite ; of

the nature of actinolite.
ACU'ITY. (acuitt, Fr.) Sharpness ; acri-
mony.

ACU'LEATE. > (aculeatus, Lat.) Prickly;

ACU'LIATED. $ having spines or prickles.

Applied to leaves armed with prickles.

Used to denote prickles, fixed in the bark,
in distinction from thorns, which grow
from the wood.

ACU'LEUS. A prickle or spine, arising from
the bark only, and not growing from the
wood.

ACU'MINATED. (acuminates, Lat.) End-
ing in a point ; sharp-pointed, the de-
crease being very gradual.
A'DAMANT. (odajuac, Gr.) A name given to
different stones of excessive hardness, as
to the diamond.

ADAMANTE'AN. (adamanteeus, Lat.) Hard
as adamant ; impenetrable.

ADAMA'NTINE. Of the nature of adamant ;

of excessive hardness.

ADAMA'NTINE SPAR. Imperfect corun-
dum ; a variety of rhombohedral co-
rundum, nearly analogous to perfect
corundum, containing from 3 to 5 per
cent, of silica, and 1 to 2 of oxide of
iron. It occurs massive and in crystals.
The crystals brought from India are the
most pure.

ADA'MIC EARTH. A name given to red
clay.

A'DAPIS. One of the extinct pachyder-
mata, found in the gypsum quarries of
Montmartre. The form of this creature
most nearly resembled that of a hedge-
hog, but it was three times the size of
that animal : it seems to have formed a
link connecting the pachydermata with
the insectivorous carnivora. — Buckland.

ADDU'CENT. (from adduco, Lat.) A
name given to those muscles which bring
forward, close, or draw together, the parts
of the body to which they are attached ;
their antagonists are termed abducent.

ADDU'CTOR. The same as adducent.

ADE'NOID. (from ad^v, a gland, and
6t£o£, form, Gr.) Glandiform; having
the shape of a kernel, almond, or gland ;
glandulous.

ADHE'RENT. (from adheereo, Lat.) Unit-
ed with ; sticking to.

ADHB'SION. (adhaesio, Lat.) The union
of two substances, either similar or dis-
similar. Adhesion is generally used in
the natural, and adherence in the meta-
phorical sense.

ADHE'SIVE. (adh&sivtis, Lat.) Having a
tendency to adhere, or stick to.

ADHE'SIVELY. In an adhesive manner.

ADHE'SIVENESS. Tenacity ; the quality of
sticking to.

ADIPOCERA'TION. The process of being
converted into adipocire.

A'DIPOCERE. ^ (adeps, fat, and cera, wax,

A'DIPOCIRE. $ Lat.) A substance resem-
bling spermaceti, produced by the con-
version of animal matter exposed to
running water ; in this way animal mat-
ter may be converted into a soft, unctu-
ous, or waxy substance in the space of a

A D I

[5 1

A E R

little more than a month ; but adipocire
has also been produced, though not so
rapidly, by the heaping together large
masses of putrefying animal matter, as
was discovered on the removal of a very
great number of bodies from the burial
ground of the Church des Innocens at
Paris, 1787. Adipocire possesses many
of the properties of fat combined with a
portion of ammonia. It was first disco-
vered by Fourcroy.

ADIPOCE'RE MINERAL. A fatty matter
found in the argillaceous iron ore of Mer-
thyr: it is fusible at about 160°, and is
indorous when cold, but when heated it
emits a slightly bituminous odour.

i'mPous: }(^iposuS, Lat.) Fat ; fatty.

A'DIT. (aditus, Lat.) The shaft or en-
trance into a mine, usually made in the
side of a hill, for the conveyance of ore,
and the carrying off the water.

ADJUSTMENT. A rendering fit or com-
formable.

ADMI'XTION. (admisceo, Lat.) The union
of various bodies, or substances, by min-
gling them together. In admixtion each
body retains its own character, and does
not undergo any chemical change, as in
composition.

ADMI'XTURE. The mass of mingled sub-
stances.

ADNA'SCENT. (adnascens, Lat.) Growing
to some other thing.

ADNA'TA. (adnatus, Lat.)

1. Those parts of animal, or vegetable
bodies which are natural, as the nails,
hair, &c.

2. Accidental parts, as fungi, misletoe,
&c.

3. The external coat of the eye.
A'DNATE. Growing to ; adhering. In

botany, it is used when a leaf adheres
to the branch or stem by the surface or
disk itself ; applied to stipules when they
are fixed to the petioles.

ADPRE'SSED. (appressus, Lat.) Appressed,
or pressed close to ; pressed together.

ADSCITI'TIOUS. (Lat.) That is added to
complete something else, though origi-
nally extrinsic.

ADVENTITIOUS, (adventitius, Lat.) Ac-
cidental ; extrinsically added ; that which
does not properly belong to any body, or
substance ; casual.

ADULA'RIA. Moonstone ; a transparent
white-coloured variety of feldspar, with a
silvery, or pearly opalescence.

ADU'NCITY. (aduncitas, Lat.) Crooked-
ness ; hookedness ; flexure inwards.

ADU'ST. (adustus, Lat.) Burnt up ;
scorched.

ADU'STIBLE. That is capable of being
burnt.

A stone found in Sweden, and

thus named by Mr. Kirwan. Its form is
tuberose and knotty. Texture striated;
sometimes resembles quartz. Lustre from
0 to 1. Specific gravity 2 '5 15 after it
has absorbed water. Colour light grey.
Before the blow-pipe it intumesces, and
forms a frothy mass. Acids convert it
into a jelly. "A specimen, analysed by
Bergman, contained 69 silica, 8 lime,
20 alumina, 3 water. — Thomson.

AE'LODON. A fossil saurian of the oolite
and lias.

A'ERATE. To combine with carbonic
acid.

A'ERATED. Combined with carbonic acid,
or fixed air.

A ERA'TION. The combining with fixed air,
or carbonic acid*

AE'RIAL ACID. A name given by Berg-
man to carbonic acid or fixed air ; aerial
acid is of greater specific gravity than
atmospheric air, and extinguishes flame.

AE'RIFORM. Resembling air ; having the
nature and properties of air.

AE'ROLITE. (from arjp and Xi'0o£, Gr.) A
name given to meteoric stones, which, oc-
casionally, fall to the earth. Nothing is
positively known as to the origin of
aerolites : by some authors they have
been supposed to come from the moon,
being projected by volcanic force beyond
the sphere of the moon's attraction ; by
others they have been thought to be
children of the air, created by the union
of simpler forms of matter. They do not
resemble any other substance found on
the earth, and it has been indisputably
proved that they are not of terrestrial
formation. The fall of these bodies has
been well ascertained, and has occurred at
different times, and in various parts,
through many ages. Some of these aero-
lites are immensely large, from 300 Ibs.
downwards. From an analysis of them,
they are all found to agree in their compo-
nent parts. They are covered with a thin
crust of a deep black colour, their ex-
terior is roughened with small projec-
tions, and they are destitute of gloss.
Internally their texture is granulated, and
of a greyish colour. When carefully ex-
amined, they appear composed of a num-
ber of small spherical bodies and metallic
grains imbedded in a softer matter, com-
posed, according to the Hon. Mr. How-
ard, who diligently and carefully studied
them, of silica, magnesia, iron, and
nickel. In addition to these substances,
Vauquelin found chrome, and Stromeyer
discovered cobalt, in aerolites : lime, alu-
mine and manganese have also been de-
tected in them. Meteoric iron has been
imitated by fusing iron with nickel.
When it is considered how many of these
bodies have been seen, or heard, to fall

A E R

A G G

through the air, we must conclude that
they are exceedingly numerous ; more
especially, when we reflect on the small
proportion which must be observed, and
the small comparative portion of the
globe which is inhabited, or habitable, by
man.

AERO'METER. (from arjp and n'trpov, Gr.
acrometre, Fr.) An instrument for ascer-
taining the weight, or density, of the
atmosphere.

AERO'METRY. (ae'rometrie, Fr.) The
science which treats of the properties of
the air ; it comprehends not only the
doctrine of the air itself, considered as a
body, but also its pressure, elasticity,
rarefaction, and condensation.

AERO'SCOPY. (from drjp and (TKOTrsw, Gr.)
The observation of the air.

^RU'GINOUS. (from ceruginosus, Lat.)
Partaking of the nature of the rust of
copper.

,/ERU'GO. Verdigrease, or verdigris ; rust
of copper, formed by the combination of
an acid with copper. Impure subacetate
of copper. Verdigris is inodorous, and
when first applied to the tongue is nearly
insipid, though strongly styptic ; it leaves
a metallic taste in the mouth. It is poi-
sonous ; sugar acts as a specific against
its poisonous effects.

^E'STIVAL. ((Bstivalis, Lat.) Pertaining to
summer.

JE'STIVAL PLANTS. Plants which flower
during the summer.

^ESTIVA'TION. (cestivatio, Lat.)

1. The eifect produced by summer heat.

2. The mode in which the parts of a
flower, taken separately, are arranged in
the bud.

jE'xiTES. (atroc, Gr. aetite, Fr.) Eagle-
stone ; a variety of oxide of iron mixed
with clay. It is found in masses, gene-
rally under the form of a rounded knob,
something resembling a kidney. • It pre-
vails in the coal formations of England,
Wales, and Scotland, has a rough surface,
and is of a brown colour. Specific gra-
vity 4 to 7. Lustre of the exterior
metallic. It frequently contains a sort of
kernel, which rattles on being shaken.
It was formerly in repute for several
extraordinary magical as well as medical
properties, such as preventing abortion,
discovering thieves, &c. It derives its
name from a popular notion that it was
found in eagles' nests, where it was sup-
posed to prevent the eggs from becoming
rotten. See Nodular Iron Ore.

^ETI'TES LAPIS. Eagle-stone. See JEti-
tes.

AFFI'NITY. (affinite, Fr. affinita, It.) The
tendency which bodies, dissimilar in their
composition, have to unite and form new
compounds. Different bodies are pos-

sessed of different attractive powers, and
if several be brought together, those
which have the strongest mutual affini-
ties enter first into union. Affinity, like
sensible attraction, varies with the mass
and the distance of the attracting bodies.
That the force of affinity increases as the
distance diminishes, and the contrary, is
obvious ; for it becomes insensible when
the distance is sensible, and exceedingly
great when the distance is exceedingly
diminished. Affinity agrees with sensible
attraction in every point which it has been
possible to determine.

AGALMA'TOLITE. (from d-ya\p,a and Xi0oc,
Gr.) Figure-stone. A sub-species of
talc-mica, of different colours, as white,
red, brown, green, and grey. It occurs
massive. It feels greasy, is translucent,
and has a conchoidal fracture. The
finest specimens are brought from China.
It does not contain any magnesia, but in
other respects it has the characters of
talc.

A'GARIC. (agaricus, Lat.) The generic
name for the mushroom, a genus of the
order Fungi, class Cryptogamia. Gmelin
enumerates nearly 400 species.

A'GARIC MINERAL. A variety of soft car-
bonate of lime. It is found in the clifts
of rocks, or the bottom of lakes, in pieces
loosely cohering, and it is so light as
nearly to swim upon water. It obtains
its name from its resemblance to a fungus
in colour and texture.

A'GATE. (achates, Lat. d%arrjc, Gr. agate,
Fr. agata, It.) A siliceous, semi-pellucid
gem, of which there are many varieties,
not of great value. Agates are princi-
pally composed of quartz with various
colouring matters. Agates may be arti-
ficially coloured by immersion in metallic
solutions. Amongst the varieties of
agate may be enumerated, calcedony, car-
nelian, onyx, sardonyx and heliotrope.
As precious stones, agates are now less
esteemed than formerly ; the most valua-
ble are the oriental. When cut and
polished, agates present an appearance of
waving lines, sometimes accurately paral-
lel, sometimes varying in breadth, and
sometimes containing a resemblance to
vegetable forms, as mosses, ferns, &c.
Small agates are frequently found in com-
mon gravel.

A'GATY. Of the nature of agate.

AGGELA'TION. Concretion by freezing.

A'GGEROSE. (from agger, Lat.) Full of
heaps.

AGGLU'TINANT. (agglutinant, Fr.) That
which has the power of uniting parts
together.

AGGLU'TINATE. (agglutino, Lat.) To
cause to adhere ; to glue together.

AGGLUTINA'TION. (agglutination, Fr.)

AGO

[7]

ALB

Union ; cohesion ; the state of being
glued, or fastened together by some
viscid matter ; the adhesion of parts by
the effusion of a coagulating medium.

AGGLU'TINATIVE. That which has the
property of causing agglutination.

A'GGREGATE. (aggregat, Fr.)

1. The complex, or collective result of
the conjunction, or acervation, of many
particulars : it differs from a compound
body, inasmuch as the union in the last
is more intimate than between the parts
of an aggregate.

2. In botany, a term used to express
flowers composed of many small florets,
having a common undivided receptacle,
the anthers separate and distant, the
florets commonly standing on stalks, each
having a single or double partial calyx.
They are opposed to simple flowers, and
are usually divided into seven kinds.

A'GGREGATE. (aggrego, Lat.) To collect
together ; to accumulate.

A'GGREGATED. Collected ; accumulated ;
heaped together.

AGGREGATION, (aggregation, Fr. aggr6-
gazione, It.) The collection into one mass
of bodies having no natural connexion,
but, by a species of union, made to con-
stitute one body.

A'GITATE. (agito, Lat.) To put in mo-
tion ; to shake.

AGITA'TION. (agitatio, Lat.) The state
of being moved, or shaken.

AGNO'STUS. (ayvwcrroc, Gr.) A fossil,
genus of trilobites, mentioned by M.
Brongniart.

AGNOTHE'RIUM. An extinct animal of the
miocene period, order Mammalia, allied
to the dog, but of very large size. One
species only has been found, at Epples-
heim, in Germany.

AIGUE MARI'NE. A variety of topaz, of a
bluish or pale green colour.

AIGUILLES, (aiguilles, Fr.) The needle -
like points, or tops, of granitic rocks.

AIGUI'LLE DE DRU. A pyramidal granitic
mountain, according to Bakewell, the
most remarkable at present known ; the
upper part, or spire, rises above its base
nearly to a point, in one solid shaft, more
than 4000 feet ; the summit being 11,000
feet above the level of the sea.

A'LA. (ala, Lat.)

1. In botany, a term used for the hollow,
which either the leaf, or the pedicle of
the leaf, makes with the stalk ; the hol-
low turning, or sinus, placed between
the stalk or branch of a plant and the
leaf, and whence a new offspring generally
rises. Sometimes it is used for those
parts of leaves otherwise called lobes or
wings. Those petals of papilionaceous
flowers placed between those other petals,
distinguished as the vexillum and carina,

and which constitute the top and bottom
of the flower, are also called alae.
2. In anatomy, the lobes of the liver, the
cartilages of the nostrils, and the cartila-
ginous parts of the ears, are called alse.

ALA'TED. (alatm, Lat.) That hath wings ;
winged.

A'LABASTER. (Alabaster, Lat. aXaflaa-
rpov, Gr. ) Granular, or massive sulphate
of lime. Alabaster is found in this coun-
try accompanying the salt deposits in Che-
shire. It is also most abundant at Mont-
martre, in the neighbourhood of Paris.
At Montaiont, in Italy, it is found in
blocks of such magnitude, that statues of
the size of life are occasionally cut from
them. Being semi-transparent, it has
sometimes been employed for windows
instead of glass, and a church at Florence
is still illuminated by alabaster windows.
Instead of panes of glass, there are slabs
of alabaster 15 feet high, each of which
forms a single window, through which the
light is conveyed. Alabaster maybe turned
by the lathe, and is thus formed into a
great variety of ornamental articles.

ALABA'STRITES. (alabastrites, Lat. d\a-
jSaffrpiTrjg, Gr.) Alabaster stone ; a
kind of marble, whereof the ancients
made vessels for ointment ; by Horace
called onyx.

A'LALITE. Called also Diopside, a variety
of augite. It occurs massive, dissemi-
nated, and crystallized, with a vitreous
external, and pearly internal lustre ; it is
translucent, and either white or of a pale
green colour. It was named by Bon-
voisin, from his finding a variety of it
near the village of Ala, in Piedmont.

ALA'SMODON. A species of shells of the
genus Unio, having cardinal, but no la-
teral teeth.

A'LATE. 3 (alatus, Lat.) Winged. In

ALA'TED. $ conchology, applied to shells
having an expanded lip, or when any por-
tion of them is much expanded.

A'LARY. (from ala, Lat.) Of the nature
of wings.

A'LBITE. Tetarto-prismatic felspar ; soda
felspar. A name given to felspar, whose
alkali is soda instead of potash. Colour
generally white, sometimes grey, green,
or red. Lustre upon faces of cleavage
pearly, in other directions vitreous. Al-
bite forms a constituent part of the green-
stone rocks in the neighbourhood of
Edinburgh. It is composed of silica,
alumina, and soda, with a trace of lime.

ALBI'TIC. Of the nature of albite; con-
taining albite.

ALBUGI'NEA. (from albus, Lat.)

1. The fibrous membrane in the eye,
situate immediately under the tunica
conjunctiva.

2. One of the tunics of the testis.

ALB

[8]

A L K

ALBU'GINEOUS. (albuoineus, Lat.)

1. The aqueous humour of the eye.

2. Resembling the white of an egg.
A'LBUM GR.E'CUM. The excrement of

dogs, wolves, hyenas, &c., feeding or liv-
ing on bones. It principally consists of
the earth of bones or lime, in combina-
tion with phosphoric acid.

ALBU'RNUM. (alburnum, Lat.) Called
also sap-wood ; the interior white bark of
trees ; it is this which yearly becomes
new wood ; the last formed wood of the
trunk of trees and woody plants. It
appears probable, that the new layers of
alburnum and liber, which are produced
each year, on the outside of all that pre-
ceded, are formed by the descending
fibres, or roots, of the leaf-buds.

A'LCALI. See Alkali, the more usual way
of writing the word.

ALCYO'NIA. The plural of alcyonium.

ALCYO'NIUM. A genus of zoophytes, the
characters of which are, that the animal
grows in the form of a plant ; the stem,
or root, is fixed, fleshy, gelatinous, spongy,
or coriaceous, with a cellular epidermis,
penetrated with stellated pores, and shoot-
ing out tentaculated oviparous hydrse. —
Encyclop.

From the experiments of Hatchett, it
appears that these animals are composed
principally of carbonate of lime and a
little gelatinous matter. The alcyonium
belongs to the class Vermes, order
Zoophyta. Cuvier places the alcyonium
in the order Coralliferi, class Polypi.

ALCY'ONITE. Alcyonites are fossil alcyonia,
or zoophytes nearly allied to sponges, the
production or habitation of polypi. —
Bakewett.

ALE'MBIC. (alambic, Fr. lambicco, It.
alemlicum, Lat.) A vessel used in the
process of distillation, usually made of
glass or copper. Of alembics there are
two different forms, the beaked and the
blind, the former having communication
with a receiving vessel, the latter being
without such. The use of the alembic
has yielded to that of the retort.

ALE'PIDOTE. (from a, priv. and \ITTIQ,
squama, a scale.) Any fish destitute of
scales, as the eel, cod-fish, &c.

A'LGA. (Lat.) Sea-weed.

A'LG^E. An order, or division, of the
Cryptogamia class of plants. It is one of
the seven families, or natural tribes, into
which Linnaeus distributed the vegetable
kingdom. The whole of the sea- weeds
are comprehended under this division.
The plants belonging to this order are
described as having their leaf, stem, and
root all one. The depths at which, ac-
cording to Lyell, some of the algse live, is
extremely great, being no less than one
thousand feet, " and although in such

situations there must reign darkness
more profound than night, at least to
our organs, many of these vegetables are
highly coloured." — Principles of Geology .

ALGALMA'TOJLITE. Figure-stone. A mi-
neral, the finest varieties of which we
receive from China. A sub-species of
talc-mica. See Ayalmatolite.

A'LGID. (algidus, Lat.) Cold.

ALGI'FICK. That which causes cold.
A'LGOR. (Lat.) Extreme cold.
A'L«OUS. (algosus, Lat.) Having the na-

ture, or characters, of sea-weed.
ALI'FEROUS. (from ala and fero, Lat.)

Having wings ; winged.
ALI'GEROUS. (aliger, Lat.) The same as

alifei-ous.
A'LIMENT. (alimentum, Lat.) Nourish-

ment ; food ; nutriment.
ALIME'NTAL. That has the quality of ali-

ment ; that nourishes.
ALIME'NTALLY. So as to serve for nou-

rishment.
ALIME'NTARINESS. The quality of afford-

ing nourishment.
ALIME'NTARY.

1. That has the property of supplying
nourishment.

2. That relates to nourishment.
ALIMENTA'TION.

1 . The power of affording nutriment.
2. The state of being nourished by assi-
milation of matter received. — Johnson.

A'LITURE. (alitura, Lat.) Nutriment ;
nourishment ; food ; aliment.

ALKALE'SCENCY. A tendency to become
alkaline.

ALK ALE 'SCENT. That has a tendency to
the properties of an alkali.

A'LKALI. (from the Arabic word kali, with
the usual prefix al ; the name given by
the Egyptians to the plant called by us
glasswort.) Any substance which by
uniting with an acid neutralizes, or im-
pairs, its activity, and forms a salt. Al-
kalies possess the property of converting
vegetable blues to green, and yellows to
red. There are three kinds of alkalies :
1. The vegetable alkali, or potash ; 2. The
mineral alkali, or soda ; 3. The animal,
or volatile alkali.

A'LKALINE. Possessing the properties of
alkali ; as baryta, lime, magnesia, stron-
tia, &c.

ALKALI'NITY. The property of changing
vegetable blues into green.

ALKALI'METER. An instrument for ascer-
taining the proportion of alkali contained
in any substance.

A'LKALOID. (from alkali, and eZtfoc, Gr.
likeness.) Bodies possessing some of the
properties of alkalies.

A'LKANET. The name of a plant, the root of

ALL

A L U

which yields a fine red, and is much used
by dyers.

A'LLAGITB. A mineral ; colour brown or
green ; massive ; semi-opaque ; fracture
conchoidal : it is a carbo -silicate of man-
ganese.

A'LLANITE. An orthitic melane-ore. The
cerium oxyde siliceux of Haiiy. A mi-
neral brought from Greenland, and thus
named after Mr. Thomas Allan, of Edin-
burgh, who first distinguished it as a pe-
culiar species. According to the analysis
of Dr. Thomson, allanite was found to
contain silica 35.4, oxide of cerium
33-9, oxide of iron 25-4, lime 9'2,
alumina 4-1, moisture 4'0.

It is of a black colour, inclining to grey
or brown. It is found massive, or in acicu-
lar crystals. External lustre imperfect,
metallic ; internal, shining. Fracture
conchoidal. Opaque. Streak greenish
or brownish-grey. It is a siliceous oxide
of cerium.

A'LLOCHROITE. A mineral variety of the
dodecahedral garnet. It is found mas-
sive, of a green, brown, grey, or yellowish
colour ; lustre glimmering. It consists
of silica, lime, carbonate of lime, oxide of
manganese, oxide of iron, alumina, and
moisture. Before the blow-pipe it melts
into an opaque black enamel.

A'LLOPHANE. A mineral of a blue, green,
or brown colour, occurring massive, or in
imitative shapes. It is rather hard and
brittle. It gelatinizes in acids. Accord-
ing to the analysis of Stromeyer, it con-
sists of alumina, silica, carbonate of cop-
per, lime, iron, sulphuric acid, and
water.

ALLO'Y. To alloy, called also allay, is to
mix one metal with another, in order to
give greater hardness, fusibility, &c. To
diminish the pureness of a metal by mix-
ing with it one of less value.

ALLO'Y.

1. A mixture of different metals : it must,
however, be kept in mind that when
mercury forms one of the metals, the
mixture is called amalgam.

2. The metal of inferior value, which is
used to deteriorate, or give new proper-
ties to, another metal.

ALLU'VIAL. That is carried by water to
another place, and lodged upon something
else.

ALLU'VION. ) (alluvio, Lat. alluvion, Fr.

ALLU'VIUM. $ alluvione, It.) Earth, sand,
gravel, stones, or other transported mat-
ter which has been washed away and de-
posited by water upon land not perma-
nently submerged beneath the waters of
lakes or seas. — Lyell.

Alluvium has been divided into mo-
dern and ancient. The modern, cha-
racterized by the remains of man and

contemporaneous animals and plants ;
the ancient, by an immense propor-
tion of large mammalia and carnivora,
both of extinct and recent genera and
species.

ALLU'VIOUS. See Alluvial.

A'LMANDINE. (almandine, Fr. alabandina,
It.) A precious stone, having some of
the characters of the garnet ; a species of
ruby.

A'LPINE. (alpinus, Lat.) This term is
not confined merely to the Alps, and the
things therewith connected, but is ap-
plied to any lofty or mountainous country,
and to the productions of elevated situ-
ations.

ALTE'RNATE. (alternus, Lat.) Being by
turns ; one after another ; reciprocal. In
botany, applied to leaves when they stand
singly on the stem or branches, alternately
first on one side, then on the other ; to
branches when placed round the stem al-
ternately, one above the other ; to flowers
placed in regular succession, one above
another.

ALTE'RNATE, n. s. That which happens
alternately ; vicissitude.

ALTERNATELY. In reciprocal succession,
so that each shall be succeeded by that
which it succeeds.

ALTE'RNATENESS. The quality of being
alternate, or of happening in reciprocal
succession.

ALTERNATION. Reciprocal succession.

ALTERNATIVELY, (alternativement, Fr.
alternativemente, It.) Reciprocally ; in
alternate manner.

ALTE'RNITY. Reciprocal succession ; vi-
cissitude ; turn.

ALTERNATING. Following, or succeeding,
reciprocally ; happenin^in reciprocal suc-

ALTI'METER. ^(from altus, Lat.

Gr.) An instrument by which the heights
of bodies may be ascertained.

ALTI'METRY. (altimetrie, Fr. altimetria,
It.) The art of measuring altitudes or
heights, whether accessible or other-
wise.

A'LTITUDE. (altitudo, Lat.) Height of
place ; space measured upwards.

A'LTIVOLANT. (altiv&lans, Lat.) High-
flying.

A'LUM. (alumen, Lat. alun, Fr. allume, It.)
A triple sulphate of alumina and potassa.
Alum is both native and factitious. The
common mode of obtaining alum is by
roasting and lixiviating certain clays con-
taining pyrites ; to the leys a certain
quantity of potassa is added, and the tri-
ple salt is obtained by crystallization.
Alum has a sweetish astringent taste. It
dissolves in five parts of water at a tem-
perature of 60°, and the solution reddens
blues.

A L U

C 10 ]

A M B

A'LUM-STONE. The shale from which alum

is extracted.
ALU'MINA. ) Pure argillaceous earth, or alu-
A'LUMINE. ) mina, is a substance which
in a mixed state is well known, but pure
and unmixed, is one of the rarest sub-
stances in the mineral kingdom. This
earth is soft, smooth, and unctuous to the
touch. Combined with other earths, or
rocks, it communicates to them some ol
these properties ; such rocks are termed
argillaceous. Alumina constitutes some
of the hardest gems, such as the ruby and
sapphire, the latter being crystallised alu-
mine. According to the analysis of Kla-
proth the sapphire contains 95 per cent.
of pure clay. Alumina was considered an
elementary substance till Sir Humphry
Davy's electro- chemical researches led to
the opinion of its being a metallic oxide.
Next to silicium, aluminum would ap
pear to be the most important base of the
earths on the face of the globe. Its col-
lective amount is by no means so great as
that of silicium, but it is quite as widely
spread. There is scarcely one among the
mechanical rocks that does not contain
alumina. It constitutes the base of the
various clays, and must be regarded as a
very abundant and important constituent
part of rocks. It contains 46-8 per cent,
of oxygen. — De la Beche.
ALU'MINITE. Sub-sulphate of alumine. A
white mineral, dull, opaque, and having
an earthy fracture. This mineral occurs
massive, in veins, and in tabular and tu-
berose masses ; the former frequently at-
taining a length of several feet, and the
latter a weight equal to three or four
pounds. It appears to have been of sta-
lactitical origin, and is supposed to result
from the decomposition of iron pyrites,
and the reaction of other substances. It
is infusible at 166° of Wedgewood, but
fuses rapidly when exposed to the stream
of the hydro- oxygen blow-pipe. Accord-
ing to the analysis of Stromeyer, it con-
sists of alumine 30, sulphuric acid 25,
water 45.

ALU'MINOUS. Having the properties of
alum; containing alum; resembling
alum.

ALU'MINUM. The metallic base of alumina.
The metal itself has not yet been obtained
in a separate state, but the analyses to
which alumina has been subjected have
clearly shewn that it is a metallic
oxide.
ALVE'OLAR. (alveolus, Lat.) Containing

sockets, pits, hollows or cavities.
ALVE'OLATE. Pitted or honey-combed.
ALVEOH'NA. A genus of microscopic fora-

miniferous shells.

ALVE'OLUS. (alveolus, Lat. alvtole, Fr. al-
veolo, It.) A socket for a tooth ; a small

cavity or cell ; the cell of the honey-
comb.

ALVE'OLUS. > A fossil marine body, large at

ALVE'OLITE. $ one end and tapering to-
wards the other, composed of hemispheric
cells.

AMA'LGAM. (from lipa, together, and ya-
/IEW, to marry.) A compound of any
metal with mercury. When two or more
metals, neither being mercury, are mixed
together, the compound is termed an al-
loy, but when mercury enters into the
composition it is called an amalgam, and
its derivation has been supposed to be
from /Lia\ay/wa, or /iceXdaaw, to soften,
which derivation appears to be more cor-
rect than that of Johnson, and lexicogra-
phers generally.

AMALGAMATE, (amalaamer, Fr. amalga-
mare, It.)

1. To mix mercury with any other metal.

2. To mix any two substances capable of
uniting into one body.

AMALGAMATION. (amalgamation, Fr.
amalgamazione, It.)

1. The act of mixing mercury with other
metals.

2. The act of blending different bodies.
AMA'LTHUS. A species of ammonite.
A'MAZON- STONE. A variety of prismatic

felspar, of a blue or green colour.
A'MBER. (ambar, Arab.) A fossil resin.
For a great length of time, various were
the opinions as to the nature and compo-
sition of amber, but it is now well ascer-
tained to be a fossilized vegetable resin.
It is found in similar localities to coal and
jet. It is brittle, easily cut with a knife,
of various shades of yellow, sometimes
nearly white, and semi-transparent : in-
sects are frequently found enclosed in it, and
Jussieu states that these are not European.
Its constituent parts are carbon 70*68,
hydrogen 11 '62, oxygen 777. Amber is
found in nodular masses, which are some-
times eighteen inches in circumference;
that which is found on the eastern shores
of England, and on the coasts of Prussia,
and Sicily, is derived from beds of lignite in
tertiary strata. Fragments of fossil gum
were found near London in digging the
tunnel through the London clay at High-
gate. In the royal cabinet of Berlin there
is a lump of amber, discovered in Lithua-
nia, weighing eighteen pounds. Amber
is one of the most electric substances
known ; when submitted to distillation, it
yields an acid sublimate, which has re-
ceived the name of succinic acid. Ten
pounds of amber yield about three ounces
of purified succinic acid.
AMBE'RGRIS. ^from amber and ffris, or
grey.) A concretion from the intestines
of the physeter macrocephalus, or sper-
maceti whale. It was long doubted of

AMD

A M M

what ambergris consisted ; and Todd, in
his last edition of Johnson's Dictionary,
retains without any comment, or observa-
tion, the absurd opinions of former days,
stating that ' ' some imagine it to be the
excrement of a bird, which, being melted
by the heat of the sun, and washed off
the shore by the waves, is swallowed by
whales, who return it back in the condi-
tion we find it." Neumann absolutely de-
nies it to be an animal substance, as not
yielding in the analysis any one animal
principle. He concludes it to be a bitu-
men issuing out of the earth into the sea ;
at first [of a viscous consistence, but har-
dening, by its mixture with some liquid
naphtha, into the form in which we find it.
It is stated by Sir E. Home that this sub-
stance is only found in the unhealthy ani-
mal, but whether the cause or the effect
of disease is not well ascertained. When
the pieces of ambergris are large, they are
found to contain beaks of the sepia octo-
pedia, or cuttlefish, the usual food of the
spermaceti whale. Ambergris is a solid,
opaque, ash-coloured, inflammable, sub-
stance, variegated like marble, remarkably
light, its specific gravity ranging from
780 to 926 ; rugged, and, when heated,
emitting a fragrant odour. It is some-
times found in masses of two hundred
pounds weight and upwards. It breaks
easily, but cannot be reduced to powder ;
melts like wax, and is soluble in ether and
the volatile oils, and, assisted by heat, in
alcohol, ammonia, and the fixed oils. It
has been employed in medicine, but is now
quite laid aside. In consequence of its
fragrance it enters into the composition of
many articles of perfumery.

A'MBIENT. (ambiens, Lat. am&iant, Fr.
ambiente, It.) Surrounding ; encompass-
ing ; investing.

A'MBIT. (ambitus, Lat.) The compass or
circuit of any thing ; the line that en-
compasses any thing.

A'MBITUS. In conchology, the circum-
ference or outline of the valves.

AMBLY'PTERUS. A genus of fishes whose
duration was limited to the early periods
of geological formations ; and which are
marked by characters that cease after the
deposition of the magnesian limestone.
This genus occurs only in strata of the
carboniferous order, and presents four
species at Saarbriick, in Lorraine ; it is
found also in Brazil. The character of
the teeth in Amblyterus shews the habit of
this genus to have been to feed on decayed
sea-weed, and soft animal substances at
the bottom of the water; they are all
small and numerous, and set close toge-
ther like a brush. The form of the body,
being not calculated for rapid progression,
accords with this habit. The vertebral

column continues into the upper lobe of
the tail, which is much longer than the
lower lobe, and is thus adapted to sustain
the body in an inclined position, with the
head and mouth nearest to the bottom.
This remarkable elongation of the supe-
rior lobe of the tail is found in every bony
fish of strata anterior to, and including,
the magnesian limestone. — Buckland.

AMBLYRHY'NCHUS CRISTATUS. The only
existing marine lizard now known. — Lyell.

AME'NT. } (amentum, Lat.) A catkin, one

AMF/NTUM. S .kind of inflorescence. When
the bractese on the principal stalk are close,
and overlap one another, or are imbri-
cated with the flowers sessile in their
axillae, the spike is termed an amentum,
or catkin, and the peduncle is always
articulated with the main stem of the
plant. Aments, or catkins, are generally
pendent, while spikes are for the most
part erect.

A'METHYST. (d/ueOvoroc, Gr. contrary to
wine, or drunkenness, so called from a
supposed virtue it possessed of prevent-
ing inebriation.) Quartz, coloured by a
minute portion of iron and manganese.
The finest specimens come from India,
Spain, and Siberia, but the amethyst is
commonly found in most countries. The
amethyst is a transparent gem of a purple
or violet-blue colour ; it is sometimes
found naturally colourless, and may at
any time be made so by putting it into
the fire. When deprived of its colour it
greatly resembles the diamond. Some
derive the name amethyst from its colour,
which resembles wine mixed with water ;
whilst others, with more probability,
think it obtained its name from its sup-
posed virtue of preventing drunkenness ;
an opinion which, however imaginary,
prevailed to that degree among the
ancients, that it was usual for great
drinkers to wear it about their necks.

AMETHY'STINE. Possessing the properties
of an amethyst ; of the colour of an
amethyst.

A'MIANTH. 1 (amiante, Fr. amianto, It.)

AMIA'NTHUS. $ A variety of asbestos,
or flexible asbestus ; an incombustible
mineral composed of very delicate and
minute fibres, which were, sometimes,
according to Dioscorides, worked into a
cloth capable of resisting the action of
fire.

AMIA'NTHIFORM. Having the form or
likeness of Amianthus.

AMMONA'CEA. According to the arrange-
ment of De Blainville, a family of the order
Polythalamacea. It embraces the genera
Discorbis, Scaphites, Ammonites, and
Simplegas. In the Lamarckian system
the ammonacea is a family of the order
Polythalamous cephalopoda, embracing
c 2

A M M

[12 ]

AMP

the genera Ammonites, Ammonoceras,
Baculites, Turrilites.

A'MMONITE. (from Jupiter Ammon.) An
extinct and very numerous genus of the
order of molluscous animals called Cepha-
lopoda, allied to the modern genus Nau-
tilus, which inhabited a chambered shell,
curved like a coiled snake. Species of it
are found in all geological periods of the
secondary strata ; but they have not been
seen in the tertiary beds. They are
named from their resemblance to the
horns on the statues of Jupiter Ammon.
—Lyell.

The ammonite differs greatly from the
chambered nautilus, the whorls, or turns,
being all distinct, and in the same plane,
and the cells very small. The family of
ammonites extends through the entire
series of the fossiliferous formations, from
the transition strata to the chalk inclu-
sive. M. Brochant, in his translation of
De la Beche's Manual of Geology, enu-
merates 270 species ; these species differ
according to the age of the strata in
which they are found, and vary in size
from a line to more than four feet in dia-
meter. The geographical distribution of
ammonites in the ancient world, seems
to have partaken of that universality, we
find so common in the animals and vege-
tables of a former condition of our globe,
and which differs so remarkably from the
varied distribution that prevails among
existing forms of organic life. We find
the same genera, and, in a few cases, the
same species of ammonites, in strata, appa-
rently of the same age, not only through-
out Europe, but also in distant regions of
Asia, and of North and South America.
Dr. Gerard has found at the elevation of
16,OCO feet in the Himalaya Mountains,
species of ammonites, identical with those
of the lias at Whitby and Lyme Regis.
The ammonite, like the nautilus, is com-
posed of three essential parts : — 1st. An
external shell, usually of a flat discoidal
form, and having its surface strengthened
and ornamented with ribs. 2nd. A series
of internal air chambers, formed by trans-
verse plates, intersecting the inner por-
tion of the shell. 3rd. A siphuncle, or
pipe, commencing at the bottom of the
outer chamber, and thence passing through
the entire series of air chambers to the
innermost extremity of the shell. The
most decided distinction between ammo-
nites and nautili is founded on the situa-
tion of the siphon. In the ammonite
this organ is always on the back of the
shell, but never so in the nautilus. —
Buckland.

The opinions of geologists and concho-
logists have greatly varied as to the
situation and use of the shell of the am-

monite ; Cuvier, Lamarck, Bakewell, and
others, have supposed that the shell was
an internal one, but the reasoning of
Buckland on this subject, seems conclu-
sively and indisputably to prove, that the
shell was external.

AMMONITI'FEROUS. Containing the re-
mains of ammonites.

AMMONO'CERAS. } (from ammon, and

AMMONOCE'RATITES. $ Kfpag, Gr.) The
shells of this genus resemble ammonites
in their internal structure, but that they
are only curved instead of being spirally
convolute.

AMO'RPHOUS. (from a, priv. and i*op<pjj,
form, Gr.) Bodies devoid of shape or form.

A'MPELITE. (from a/tTreXof, Gr. a vine.)
A kind of aluminous slate, belonging to
both the fossiliferous and metamorphic
series of rocks.

AMPHI'BIA. (from o/i$t and /3<Y,c, Gr.)
A class of animals possessing the property
of living either in the water or on dry
land. In the Linnaean system the am-
phibia form the third class of animals.
The lungs of the amphibia differ greatly
from those of animals of the classes aves
and mammalia. Their body 4s covered
with a shell, or with scales, or is quite
naked. They have neither hair, mam-
mae, feathers, nor radiated fins : they are
oviparous or viviparous, and are divided
into reptiles and serpents ; or reptilia
pedata, and serpentes apodes, the former
being furnished with teeth, and the latter
being destitute of them. The class Am-
phibia, according to Gmelin, consists of
two orders ; the first, or Reptilia pedata,
being divided into four genera, having
generally four, seldom two feet, namely,
Testudo, Draco, Rana, and Lacerta.
2nd, Serpentia, or serpentes apodes, hav-
ing no feet. Some are ovo- viviparous,
having the egg hatched in the oviduct.
This order is divided into six genera,
namely, Crotalus, or Rattle-snake, Boa,
huge serpents of Asia and Africa, Coluber
or viper, Anguis or blind worm, Am-
phisbsena, and Csecilia. Many of the
amphibia possess the extraordinary pro-
perty of reproducing parts, such as their
legs, tails, &c., if destroyed.

AMPHIBIO'LITHI. (from afi^ifSioQ and
XiQog, Gr.) Fossil amphibise. The am-
phibiolithi form a very large and important
class of fossils.

AMPHI'BIOUS. (n/i0i'/3io£, Gr. amphibie,
Fr. anfibo, It.) That partakes of two
natures, being able to live either in the
air or in the water.

AMPHI'BIOUSNESS. The quality of being
able to live in two elements, air and
water.

A'MPHIBOLE. (a/j0i'/3o\oc, Gr.) The
name given by Haiiy, and the French, to

AMP

ANA

hornblende : for particulars see Horn-
blende.
AMPHI'BOLITE. Any rock whose basis is

amphibole or hornblende.
A'MPHIGENE. (from a/w0i and ysvo£, Gr.)
Trapezoidal zeolite, or leucite. This
mineral, also called Vesuvian, occurs in
imbedded grains or crystals, in the more
ancient lavas, and is found mixed with
garnet, hornblende, quartz, &c. in the
ejected masses of old volcanoes.
A'MPHISB^ENA. (from ap,<piQ and (3aiva>,
Gr. to walk both ways.) The name given
to a genus of serpents, natives of South
America.
AMPHITRI'TE. A genus of Tubicola, of the

division Articulata.

A'MPHORA. A vessel used by the ancients,
containing about seven gallons, and thus
named from its having two handles.
AMPLEXICAU'LENT. (from amplexus and
caulis, Lat.) Stem clasping ; embracing
the stem.

AMPLE'XUS. A singularly formed fossil,
resembling a coral or madrepore, found
in the Dublin limestone : it is described
as being nearly cylindrical, divided into
chambers by numerous transverse septa,
which embrace each other with reflected
margins. — Sowerly.

AMPULLA'RIA. (from ampulla, Lat.) A
ventricose, subglobose, univalve, with an
umbilicated base ; the opening oblong
and entire, with no thickening on the left
lip. The ampullaria is a river shell of
warm climates. Its spire, which always
slightly projects, distinguishes this genus
from Planorbis ; and there being no
thickening on the left lip marks it from
Natica. — Parkinson. Lamarck places
the genus in the family Peristomata
order Trachellipoda. There are many
species, as the Ampullaria patula, Ampul-
laria Sigaretina, &c.

AMY'GDALOID. (afivyddXr], an almond
Gr. amygdala ide, Fr.) A volcanic, or
igneous, rock of any composition, con-
taining nodules of minerals, scatterec
through its base, of a roundish shape
cellular volcanic rock, having its cells, 01
cavities, occupied with nodules of a dis
similar substance.

AMYGDALOI'DAL. Containing rounded, o
kernel-shaped, cavities, filled with mi
neral matter of a different character fron
the substance generally.
AMY'GDALYTE. Almond-stone.
A'NAL. Pertaining to the anus ; the fin

between the vent and the tail.
ANA'LCIME. A simple mineral, a variet
of zeolite, with which it was formerl
confounded ; it is also called eubizite
It occurs regularly crystallised ; in an
gulo -granular concretions, and massive
Specific gravity above 2. When rubbee

it acquires only a small degree of electri-
city, and with difficulty. It is composed
of silica 55-07, alumina 20-22, soda
14 71, moisture 8'28. It is found, in
secondary greenstone rocks, in various
parts of Scotland, more especially near
Edinburgh. This mineral, also called
Cubizite, has been regarded by mineralo-
gists as having the cube for its primitive
form. Analcime has certainly no cleav-
age planes, and it must be regarded at
present as forming in this respect as
great an anomaly in crystallography as it
does in optics by its extraordinary optical
phenomena. The most common form of
analcime is the solid, called the icositetra-
hedron. which is bounded by twenty-four
equal and similar trapezia ; and we may
regard it as derived from the cube, by
cutting off each of its angles by three
planes equally inclined to the three faces
which contain the solid angle. The Abbe
Haiiy first observed in this mineral its
property of yielding no electricity by fric-
tion, and derived the name of analcime
from its want of this property.
ANA'LOGOUS. (from ava and Xoyo£, Gr.
analogue, Fr. analogo, It.) Having ana-
logy ; bearing some resemblance.
A'NALOGUE. (analogue, Fr. On le fait
quelquefois substantif. Ce sont deux
analogues.) Any body which corresponds
with, or bears great resemblance to, some
other body. A recent shell of the same
species with a fossil shell, is an Analogue
of the latter. — Lyell.

ANANCHY'TES. A helmet -shaped echinus,
a fossil of the chalk formation. — Bake-
welL It approaches near to the form of
Spatangus globosus.

ANASTOMO'SIS. (anastomose, Fr. anasto-
mbso, It. from ava and errojua, Gr. ) The
running of vessels one into another, or
communication by inosculation, as of the
arteries into the veins.
ANASTOMO'SING. Communicating by anas-
tomosis. Applied to vessels, threads or
fibres, which by meeting or touching in
separate points only, form a sort of net-
work, or reticulation.

ANATA'SE. (avardaiQ, Gr. extension.)
Pyramidal titanium ; this mineral is
nearly of the same nature as titanite. It
is found in Dauphiny, Bavaria, Norway,
Switzerland, Spain, and Brazil. It is a
pure octahedral oxyde of titanium. Its
colours are brown and blue ; structure
lamellar; lustre splendent and adaman-
tine ; it scratches glass. Specific gravity
3-80.

ANA'TIFA. A cuneiform multi valve, com-
posed of several unequal valves, five or
more, united together at the extremity of
a cartilaginous tube, fixed at its base.
The opening without an operculum. —

ANA

A N I

Parkinson. The genus comprises several
species. It belongs to the class Cirrho-
poda. The anatifse are often found ad-
hering to rocks, pieces of wood, the
bottoms of ships, &c.

ANA'TIFER. (from anas, a duck, Siudfero,
to bear, Lat.) A name given to the bar-
nacle, or pentelasmis. The same as Ana-
tifa.

ANCI'LLA. ) An oblong subcylindrical

ANCILLA'RIA. $ univale, with a short spire,
not channelled : the aperture effused, and
its base slightly notched. — Parkinson.
The eburna glabrata, or ivory shell, be-
longs to the genus Ancilla.

ANDALU'SITE. A massive mineral of a red
or grey colour ; it occurs also crystallised.
Lustre shining, glistening, and vitreous.
Fracture uneven ; is easily broken.
Feebly translucent. Specific gravity 3-160.
Constituent parts, alumina 52, silica 32,
potash 8, oxide of iron 2. It was first
found in Spain ; it occurs in gneiss in
England, Ireland, and Scotland.

ANDRE'OLITE. Thus named from its hav-
ing been first found at Andreasberg, in
the Hartz ; called also Harmotome, and,
sometimes, from the form of its crystals,
cross-stone. Its crystals are two four-
sided flattened prisms, terminated by
four-sided pyramids, intersecting each
other at right angles ; the plane of inter-
section passing longitudinally through
the prisms. Texture foliated. Colour
milk-white. Constituent parts, silica 44,
alumina 20, barytes 20, water 16. It
effervesces with borax and microcosmic
salt, and is reduced to a greenish opaque
mass. With soda it melts into a frothy
white enamel. When its powder is
thrown on a hot coal, it emits a greenish
yellow light. — Thomson.

ANDRO'GYNAL. J (from avtjp, and -yvvn,

ANDRO'GYNOUS. $ Gr.) Having two sexes ;
being both male and female ; hermaphro-
ditical. Plants bearing male and female
flowers on the same root are thus called.

ANEMO'METER. (from dvsfiog and psTpov,
Gr. ane'mometre, Fr. anemometro, It.)
An instrument for measuring the strength
or velocity of the wind.

ANGIOSPE'RMIA. (from ayyttor, a recepta-
cle, and airkpfia, seed, Gr.) In the arti-
ficial system of Linnaeus, an order of
plants of the class Didynamia. It con-
sists of plants having numerous seeds con-
tained in a seed vessel. The class Didy-
namia is divided into two orders, Gym-
nospermia and Angiospermia. In the
first order, or those having naked seeds,
the plants are mostly wholesome and aro-
matic. In the second, where the seeds
are enclosed in a seed-vessel, we find the
Digitalis, and other poisonous plants.

ANGIOSPE'RMOUS. (angiosperme, Fr.) Be-

longing to the order Angiospermia ; hav-
ing the seeds enclosed in a seed-vessel.

ANGIO'STOMA. } A family of univalve shells,

ANGYO'STOMA. \ in the order of Siphono-
branchiata. It includes many genera,
as the Conus, Cyprsea, Terebellum, &c.

A'NGLE. (angulus, Lat. angle, Fr. angolo,
It.) The point at which two lines meet.

ANGUI'LLIFORM. (from anguilla, an eel,
and forma, Lat.) A term given to fishes
having the form of an eel.

A'NGULAR. Having angles or corners.

ANGULA'RITY. The quality of being an-
gular.

A'NGULARLY. With angles or corners ;
in the direction of the angles.

A'NGULARNESS. The quality of being an-
gular.

A'NGULATED. Formed with angles or cor-
ners.

ANGULI'TES. A species of fossil nautilus.

ANGULO'SITY. Angulated ; cornered form.

A'NGULOUS. Angular ; hooked.

ANGU'STATE. (angustatus, Lat.) Begin-
ning with a narrow base, which base then
dilates and thickens.

ANHY'DRITE. Anhydrous gypsum. A
variety of sulphate of lime, called anhy-
drous gypsum, or anhydrite, in conse-
quence of its being quite free from water.
It is harder than selenite, and sometimes
contains chloride of sodium, when it is
called muriacite. Its colours are white,
blue, red, and grey. It occurs both mas-
sive and crystallised. Lustre alternates
from splendent to glistening-, and is pearly.
Fracture splintery and conchoidal. Spe-
cific gravity 2-850. There are six va-
rieties of this mineral.

ANHY'DROUS. (from «, priv. and vSwp,
water.) Without water in its compo-
sition.

ANIMA'LCULAR. Belonging to animalculee,
or animalcules.

ANIMA'LCULE. (animalculum, Lat. ani-
malcule, Fr. animaletto, It.) An exceed-
ingly small animal, scarcely discoverable
by unaided vision, but which, by the help
of the microscope, is found both in solids
and fluids.

A'NKERITE. Paratomous limestone, a spe-
cies of limestone thus named after Prof.
Anker. It is found in the mines of
Styria.

A'NIMAL KINGDOM. The animal kingdom
comprehends beings the most diversified
as to form, structure, and the media in
which they live ; for in it are found some
organised to fly through the air, others to
creep on the earth or burrow under its
surface, and others to descend into, and
inhabit the depths of the sea. Natural-
ists, taking the structure of animals for
their basis, have arranged the whole ani-
mal kingdom under four great divisions,

A N I

A N O

namely, Vertebrata, Mollusca, Articulata,
and Radiata.

In the first of these divisions is in-
cluded man, and all those animals having
the brain and principal trunk of the ner-
vous system enclosed in a bony case, or
envelope, formed by the skull and ver-
tebrae. The division Vertebrata, or as it
has been also termed Spini-Cerebrata,
comprises Mammalia, Aves, Reptilia,
Amphibia, Pisces. All these have red
blood, a muscular heart, a mouth with
two jaws, placed one above the other ;
organs of taste, smell, sight and hearing,
placed in the cavities of the face ; never
more than four limbs, and the sexes
always separated.

The second division, Mollusca, or Cy-
clo-gangliata, comprises Cephalopoda,
Pteropoda, Gasteropoda, Conchifera, Tu-
nicata. These all possess no skeleton,
and from that circumstance have been
called soft animals, or Mollusca. The
muscles are attached to the skin ; they
have no articulated members ; they pos-
sess a heart and blood-vessels, and their
circulation is double. Some are destitute
of an external covering, and are called
Mollusca nuda ; others are enclosed in a
shell, and these are termed Mollusca
testacea. When the shell consists of one
piece only, it is called univalvular ; if of
two pieces, bi valvular ; and when it con-
sists of a greater number, multivalvular.

The third division, Articulata, or Dip-
lo-Neura, comprises Crustacea, Arach-
nida, Insecta, Myriapoda, Annelida, Cir-
rhopoda, Rotifera, Entozoa. In the Ar-
ticulata may be observed the transition
from circulation in closed vessels to nu-
trition by imbibition, and the correspond-
ing transition from respiration in circum-
scribed organs to that effected by tracheae,
or air vessels, distributed throughout the
body. In the Crustacea, the nervous sys-
tem is disposed in the form of two abdo-
minal chords, and this form can be traced
through the whole of the third division,
from Crustacea to Entozoa.

The fourth division, Radiata, or Cyclo-
neura, includes Echinoderma, Acalepha,
Polypiphera, Poriphera, and Polygastrica.
These animals, forming the lowest in the
scale of creation, have been also called
Zoophytes. Many of them bear a great
resemblance to plants.
ANNE'LIDANS. ) (from annellus, a small
ANNELI'DES. $ ring, Lat.) Worms with
red blood, whose bodies are composed of
rings. Professor Buckland observes,
" We have abundant evidence of the early
and continued prevalence of that order
of Annelidans, which formed shelly cal-
careous tubes, in the occurrence of fossil
serpulee, in nearly all formations, from the

transition periods to the present time.';
The shores of the sea, the moist sands of
coasts, as well as the soils of all countries,
are inhabited by myriads of worms, which
are found to contain a red-coloux-ed fluid,
circulating in veins and arteries. These
constitute the red bloody worms of na-
turalists, the lt vers a sang rouge" of Cu-
vier. The term annelida is most fre-
quently applied to them, from their being
surrounded by rings, extending from the
anterior to the posterior part of the
body.— Prof. Grant.

A'NNOLIS. An American animal, resem-
bling a lizard.

A'NNUAL. (from annus, Lat. annuel, Fr.
annuale, It.)

1. That which comes yearly.

2. That which lasts only a year.
A'NNULAR. (from annulus, Lat. annulaire,

Fr. annulario, It.) In the form of a
ring.

ANNULA'RIA. A species of phalsena, of
the geometra section.

A'NNULATE. (annulatus, Lat.) Formed or
divided into distinct rings, or marked with
differently-coloured annulations ; sur-
rounded by rings.

ANNULA'TION. Circular, or ring-like for-
mations.

A'NNULOSE. Furnished with rings ; com-
posed of rings. The annulose animals
form two great series ; those without
jointed feet, viz. vermes, annulosa, cirri-
peda ; and those with jointed feet, name-
ly, insecta, myriapoda, arachnida, crus-
tacea.

ANOCY'STI. The incongruous assemblage
of fossil substances, termed echinites, have
been arranged by Leske into two classes :
the first class is that of the anocysti, the
vent of which is in the vertex. This class
is arranged under two divisions, Cidaris
and Clypeus.

ANODO'NTA. A form of bivalvular mol-
lusc, with a transverse shell, having three
muscular impressions : the hinge plain,
having no appearance of a tooth.

ANO'MIA. A genus of molluscous multi-
valve. The anomise are inhabitants of
every sea, and are found adhering to fo-
reign bodies by means of an operculum,
or valve.

ANO'MITE. A fossil shell of the genus
Anomia.

ANOMORHOMBOI'DA. ) (from avojwoioc, ir-

ANOMORHO'MBOID. $ regular, and pofi-
fioetdris, of a rhomboidal figure.) A genus
of pellucid, crystalline spars, of no de-
terminate, regular, external form, but al-
ways fracturing into regularly rhomboidal
masses. Of this genus there are five
known species, all possessing, in some
degree, the double refraction of the island
crystal.

A N O

ANT

ANOPLOTHE'RE.' ) (from avoxXoc, un-

ANOPLOTHE'RIUM. f armed, and Stipivv,
a wild beast. ) A fossil extinct quadruped,
belonging to the order Pachydermata, re-
sembling a pig. Five species of Anoplo-
therium have been found iu the gypsum
of the neighbourhood of Paris. The
largest (Anaplotherium commune) being
of the size of a dwarf ass, with a thick
tail, equal in length to its body, and re-
sembling that of an otter ; its probable
use was to assist the animal in swimming.
The posterior molar teeth in the genus
Anoplotherium resemble those of the
rhinoceros ; their feet are terminated by
two large toes, like the ruminating ani-
mals, whilst the composition of their
tarsus is like that of the camel. The
place of this genus stands, in one respect,
between the rhinoceros and the horse ;
and in another, between the hippopota-
mus, the hog, and the camel. — Buckland.
Cuvier has shown that the structure of
the hind-foot alone, is sufficient to prove
that the Anoplotherium was of a species
at present unknown.

ANO'RMAL. (anormis, Lat.) Irregular ;
deformed.

ANO'RTHITE. The mineral to which this
name is given is thus called from the ab-
sence of right angles in its fracture, which
circumstance serves to distinguish it. It
is a variety of felspar, and has been de-
scribed by Rose. Its specific gravity is
763. Its constituent parts are silica 44'49,
alumina 34-40, lime 15*68, magnesia 5'30,
oxide of iron, under 1.

ANORTHI'TIC MELANE-ORE. A species of
mellane-ore, called also Allanite, which
see.

ANTA'CID, (from avrl and acid.} Op-
posed to sourness ; of an alkaline quality ;
a remedy for acidity.

ANTAGONIST. (antagonista, Lat. anta-
goniste, Fr. antagonista, It.) A term
applied to such muscles as oppose, or
counteract, others.

ANTARCTIC. (from avrl, against, and
dpKTog, the bear, or northern constella-
tion. )

1. The southern pole, so called, as oppo-
site to the northern.

2. One of the lesser circles, drawn on
the globe, at the distance of twenty-three
degrees and a half from the antarctic, or
south pole.

ANTE'CIAN. (from O.VTOIKOQ, Gr. living
opposite.) Those who live under the
same meridian east or west, but under
opposite parallels of latitude north and
south. The word is also written Antoe-
cian.

ANTEDILU'VIAL. > (from ante, before, and
ANTEDILU'VIAN. \ diluvium, a deluge.)
1. Existing before the deluge.

2. Relating to things existing before the
deluge.

ANTBDILU'VIAN. One that lived before
the deluge.

ANTEMU'NDANE. (from ante, before, and
mundus, the world. ) That existed before
the creation of the world.

AMTK'NJCB. (antenna, Lat. antennes, Fr.
This word appears by all lexicographers
to be given in the plural only.) Those
delicate moveable horns with which the
anterior part of the heads of insects are
furnished. These are peculiar to this
order of beings, and are easily distin-
guished from the tentaculse of vermes, in
being crustaceous ; and from the palpi of
insects, by their situation being nearer
the mouth. The antenna rarely exceed
two in number, though in some insects
of the apterous kind they amount to four,
or even six. Of the uses of the antennas
we are still ignorant.

The antennge are jointed organs, placed
one on either side of the head between
the angle of the mouth and the eyes ; the
variations in their structure are very
great. Those which consist of equal
joints are called equal ; those whose
joints are dissimilar are called unequal.
The inequality of antennae proceeds
chiefly from the differing form of their
second and last joint. Antennie which
consist of but one joint are called exarti-
culate ; those with two joints, biarticu-
late ; with three, triarticulate ; while
those whose joints are numerous are
called multiarticulate. The great ma-
jority of antennae are completely naked ;
others have a clothing consisting of
shorter or longer hair.

ANTE'RIOR. In conchology, the anterior of
bivalves is the side opposite to the
hinge ; of a spiral univalve, that part of
the aperture most distant from its apex ;
of a symmetrical conical univalve, that
part where the head of its inhabitant lies.

A'NTHER. (anthera, Lat. dvOnpa, Gr.)
That part of the flower which contains
the fertilizing dust, pollen, or farina,
which, when mature, it scatters. The
anther forms the essential part of the
stamen. Anthers differ greatly as re-
gards their figure, number, and situation.
The most common form of the anther is
that of a grain of corn, only smaller ; it
has a crease, or line, down it, as the
grain has, at which it opens when burst-
ing ; this is generally turned inwards to-
wards the axis of the flower ; but in
some plants, as the cucumber, iris, ranun-
culus, &c., it is turned outwards. The
anther is generally fixed immoveably to
the filament in various ways ; but in
most of the grasses, and many other
plants, it is attached by its middle, and

ANT

C 17 ]

ANT

the filament being very thin, it is moved
by the slightest air. The plural of anther j
is anthera.

ANTHOPHY'LLITE. (from civBog, a flower,
and (pvXXov, a leaf, Gr.) A mineral oc-
curring both crystallized and massive, of
a yellowish grey, or brownish colour. Its
constituent parts are, silica 56*0 ; alu-
mina 3-0 ; magnesia 23'0 ; lime 2'0 ;
oxide of iron 13'0 ; oxide of manganese
4-0. — Gmelin. Specific gravity 3 '2.
Alone, infusible before the blow-pipe ;
but with borax it yields a grass-green
transparent bead. It is the prismatic
schiller-spar of Mohs. It is found in
Inverness-shire and in Norway.
A'NTHRACITE. (from civQpaZ, Gr. anthrax,
Lat.) A shining substance like black-
lead ; a species of mineral charcoal ; a
mineral approaching to the state of plum-
bago ; it consists nearly of pure carbon,
is hard to ignite, and has frequently a
semi-metallic lustre. The coal in the
extensive coal-formation in Pennsylvania
is called anthracite, because it emits but
little smoke in burning ; but it is only a
variety of common coal, containing but
little bitumen, and is not the true anthra-
cite of mineralogists. From the same
circumstance, also, it has become a com-
mon thing to call the Welsh coal anthra-
cite. Some anthracite contains 97 per
cent, of carbon. Hardness from 2-0 to
2-5. Specific gravity from 1-3 to 1-6.
AN'THRACITIC. Partaking of the nature of

anthracite.

ANTHRA'COLITE. The same as anthracite.
ANTHRA'CONITE. A variety of calcareous
spar, of a black colour, with a compact
fracture, of a glimmering lustre, and
which, on rubbing, yields a sulphureo-
bituminous odour.

ANTHRACOTHE'RIUM. (from avBpaKiog,
and Orjpiov, wild beast, Gr. ) A name given
to an extinct mammifer, thus named by
Cuvier, supposed to belong to the Pachy-
dermata, the bones of which, changed
into a kind of coal, have been found in
the lignite and coal of the tertiary strata.
This genus was first discovered in the
lignite of Cadibona, in Liguria : seven
species are known, some approximating
to the size and appearance of the hog ;
others approaching that of the hippopo-
tamus.

ANTHRO'POLITE. (from avflpwTroc., a man
and \LOoQ, a stone, Gr.) A petrifaction
of the human body ; a fossil human
skeleton. Several skeletons of men,
more or less mutilated, have been found
in the West Indies ; these still retain
some of their animal matter, and all their
phosphate of lime. One of them may be
seen in the British Museum, and another
in the Royal Cabinet at Paris.

A.NTHROPOMO'RPHOUS.
from av0po*7TOC., a man, and ^iop0?}, form,
Gr.) Having a form resembling the hu-
man.

ANTIA'CID. Contrary to sourness ; of an
alkaline quality ; remedial of acidity.
More generally written antacid.

A'NTICHRONISM. (from O.VTI, against, and
Xpovof, time.) Deviation from the right
order, or account, of time.

ANTICLI'NAL. If a range of hills, or a val-
ley, be composed of strata, which on the
two sides dip in opposite directions, the
imaginary line that lies between them,
towards which the strata on each side
rise, is called the anticlinal axis. In a
row of houses, with steep roofs facing
the south, the slates represent inclined
strata dipping north and south, and the
ridge is an east and west anticlinal axis. —
LyelL

In most cases an anticlinal axis forms
a ridge, and a synclinal axis a valley.

ANTIMO'NIAL. Made of antimony ; having
the properties of antimony.

ANTIMO'NIATE. ^ A salt formed by the com-

ANTI'MONITE. $ bination of antimonic
acid with a salifiable base.

A'NTIMONY. (antimoine, Fr. antimonio, It.
The derivation of this word is not agreed
on, some lexicographers stating it to be
from avri and (J.OVOQ, two Greek words,
signifying that it is never found alone :
Dr. Johnson, however, on the authority
of Furetiere, refers it to a ludicrous story
related of Basil Valentine, a German, who
appears to have been the discoverer of
the metal in 1620 ; it is stated that he
was a monk, and practised as a physician,
and having thrown some of it to the hogs,
he observed that after it had purged
them, they immediately fattened ; ima-
gining that the effect on bipeds would be
similar, he administered a like dose to his
fellow monks. The experiment, how-
ever, proved rather an unfortunate one,
for, in consequence of the dose being too
large, they all died of it, and the sub-
stance thenceforth obtained the name of
Antimoine, i. e. Antimonk.) A metallic
ore, consisting of sulphur combined with
the metal which is properly called anti-
mony. This metal is of a bluish-white
colour, and considerable brilliancy, with
a specific gravity of 6' 712. It fuses at a
temperature of 9 00, but requires a greatly
increased heat to volatilize it. It is not
malleable, being so brittle as to be easily
reduced to powder by trituration, and its
ductility is inconsiderable. The most
abundant ore of antimony is that in which
it is found combined with sulphur, and
called sulphuret of antimony. Antimony
combines with chlorine so rapidly as to
produce a shower of fire, if it be poured,

ANT

A P H

finely powdered, into a glass jar, filled
with that gas. It unites with many
metals, some of the alloys being useful.
That with lead is used for the plates on
which music is engraved. With tin it
forms a kind of pewter, and with lead and
copper it forms printer's type metal.
Native, or rhombohedral antimony, occurs
in metalliferous veins in primitive rocks
in Sweden, and in the mountains of Ha-
nover, Dauphiny, Hungary, Brazil, and
Mexico.

ANTIPA'RALLEL. Lines which make equal
angles with other lines, but in a contrary
order ; running in a contrary direction.

ANTI'PATHES. The name given by Lin-
neeus to black coral, a genus of Cera-
tophyta.

ANTI'PODAL. (from antipodes.) Relating
to the countries inhabited by the anti-
podes ; opposed.

ANTI'PODE. (dvriTrofce, Gr. antipode, Fr.
antipodi, It.) Although this word is
occasionally, and with propriety, used in
the singular, yet it is more commonly
used in the plural number ; antipodes.

Those people who, from their situa-
tion on the globe, have their feet opposed
directly to each other.

AN'TIQUATED. In conchology, longitudi-
nally furrowed, but interrupted by trans-
verse furrows, as if the shell had acquired
new growth at each furrow.

ANTISE'PTIC. (from ai/rt, against, and
arj-n-ui, to putrefy, Gr.) Substances which
prevent putrefaction.

A'NTLER. The horn of the stag, or elk.

A'NTLERED. Having antlers, as the an-
tlered elk of Ireland ; now extinct.

A'NTRUM. (antrum, Lat. antre, Fr.
antro, It.)

1. A cavern ; a cave ; a den.

2. The maxillary sinus, situate above the
molar teeth of the upper jaw.

A'NUS. (anus, Lat. anus, Fr. ano, It.)

1. The termination downwards of the
intestinal canal.

2. In conchology, a depression on the
posterior side near the hinge of bivalves.

AO'RTA. (dopr/), Gr. aorte, Fr. aorta, It.)
The principal artery of the body, which
arises from the left ventricle of the heart.

A'PATITE. A genus of calcareous and
brittle earths, composed of lime 55*75
and phosphoric acid 44*25. Apatites are
white, green, blue, red, brown, and yel-
low ; they occur both crystallized and
massive. Fracture conchoidal and un-
even ; lustre resinous. Specific gravity
3*1. The crystals are six-sided prisms,
low, and sometimes passing into the six-
sided table. One set of varieties, in
which the cleavage is very distinct, is

named foliated apatite ; another, in which
the fracture is conchoidal, is called con-
choidal apatite ; and such varieties as
display an uneven fracture have obtained
the name of phosphorite. The crystal-
lized variety is found, extremely beautiful,
in Devon and Cornwall.

A'PENNINE. Relating to the chain of moun-
tains called the Apennines.

A'PENNINES. (apenninus, Lat.) A chain
of mountains extending through Italy.
What now constitutes the central calca-
reous chain of the Apennines must for a
long time have been a narrow ridgy pen-
insula, branching off, at its northern ex-
tremity, from the Alps near Savona. This
peninsula was afterwards raised from one
to two thousand feet, by which movement
the ancient shores, and, for a certain
extent, the bed of the contiguous sea,
were laid dry, both on the side of the
Mediterranean, and the Adriatic. —
Lyell.

A'PERTURE. (from apertus, open.) An
opening ; a chasm ; a mouth, or entrance.

APE'TALOUS. (from a, priv. and irsraXov, a
flower-leaf, or petal, Gr. ) Without flower-
leaves, or petals ; not having petals.

APE'TALOUSNESS. The state of being
without flower-leaves, or petals.

A'PEX. (Lat.) The tip or point of any
thing; the highest point of a hill or
mountain. This word makes apices in
the plural, and not apexes.

A'PHANITE. (from a, priv. and^aifw, Gr.
luceo.) A mineral, a variety of amphi-
bole.

APHE'LION. (from airb, from, and ?/\tof ,
the sun, Gr.) That point of any planet
which is most distant from the sun ; the
point of an orbit farthest from the sun.

A'PHIS. Plural aphides. The puceron,
or plant-louse. Class Insecta, order
Hemiptera. The numerous tribes of this
family of insects are most annoying to
the florist, and most destructive to the
plants. The best means of destroying
them is either by fumigations of tobacco,
or by watering the plants with a weak so-
lution of the chloride of lime. They are
astonishingly prolific ; they live in society
on trees and plants, of which they suck
the juices with their trunk.

A'PHRITE. (from d0poc, spuma, Gr.) A
species of stone composed of carbonate
of lime, and thus named from its frothy,
silver-white, appearance.

A'PHRIZITE. A variety of black tourma-
line.

APHYLLA'NTES. (from a, priv. QvXXov,
a leaf, and dvQog, a flower. ) An apeta-
lous flower ; a genus of plants, class
Hexandria, order Monogynia.

APHY'LLOUS. (from a, priv. and QvXXov,
a leaf.) Without leaves ; leafless.

A P I

[19 ]

A P Y

APIOCRI'NITE. } The pear

APIOCRI'NITES ROTUNDUS. $ encrinite,
so named from the remains of the animal
possessing a pear-like form. The Apio-
crinites rotundas, or Pear encrinite has
been plentifully found in the neighbour-
hood of Bradford, near Bath, and at
Pfeffingen, in Germany. In reference to
this species of encrinite, Professor Buck-
land thus writes : " When living, their
roots were confluent, and formed a thin
pavement at this place, over the bottom
of the sea, from which their stems and
branches rose into a thick submarine
forest, composed of these beautiful zoo-
phytes. The stems and bodies are occa-
sionally found united, as in their living
state ; the arms and fingers have almost
always been separated, but their dislo-
cated fragments still remain, covering
the pavement of roots that overspreads
the surface of the subjacent oolitic lime-
stone rock.

APO'DA. An order of animals belonging
to the class Echinodermata ; division
Radiata. They are distinguished from
Pedicellata by the absence of the vesicu-
lar feet, which peculiarly belong to animals
of that order.

A'POGEE. (apogee, Fr. apogeo, It. apo-
ffteum, Lat. from airb and yaia, Gr.)
That point of an orbit furthest from the
earth. The apogee of the sun is that
part of the earth's orbit which is at the
greatest distance from the sun.

APOPHY'LHTE. A mineral whose consti-
tuent parts are silica 50-76, lime 22'39,
potash 4-18, water 17-36, and a trace of
fluoric acid. This substance is called
also Ichthyophthalmite, and Fish-eye
stone. It occurs both massive and re-
gularly crystallized. It is found in
Sweden, in secondary traprocks in Scot-
land and the Hebrides, and in Iceland,
whence the finest specimens are ob-
tained.

APO'PHYSIS. (a7r60u<ri£, Gr. apophyse,
Fr.) A process of a bone, and part of
the same bone ; herein differing from
epiphysis, which is a process attached to
a bone, and not a part of the same bone ;
an excrescence.

APPE'NDAGE. Something added to another
thing, without being necessary to its
essence. In botany, applied to additional
organs of plants, which are not universal
or essential ; neither is any one plant fur-
nished with them all. Botanists distin-
guish seven kinds of appendages, namely,
stipules, floral leaves, thorns, prickles,
tendrils, glands, and hairs.

APPE'NDANT. (from appendo, Lat.) Hang-
ing to something else, but not forming an
integral part.

APPE'NDANT. That which belongs to

another thing, as an accidental, or ad-
ventitious, part.

APPE'NDICLE. (appendicula,Ija.t.) A small
appendage.

APPENDI'CULATE. Appendicled, or ap-
pended. Applied to flowers furnished
with some addition distinct from the
tube ; to petioles with leafy films at the
base; to seeds furnished with hooks,
scales, &c.

A'PPETENCY. (appetentia, Lat. appetence,
Fr.) The disposition of organized bodies
to select and imbibe such portions of
matter as serve to support and nourish
them. — Webster.

APPOSI'TION. (appositio, Lat. apposition,
Fr. addizione, It. ) The addition of new
matter.

APPRE'SSED. (appressus, Lat.) In bo-
tany, applied to leaves pressed to the
stem ; also to peduncles.

A'PPULSE. (appulsus, Lat. appulse, Fr.
appulso, It.)

1. The act of striking against anything.

2. The approach of any planet to a con-
junction.

A'PSIDES. (apsides, Fr. from a^t'g, Gr.)
The plural of apsis.) Those two points
in the orbit of a planet, one of which is
the farthest from, and the other the
nearest to the sun. The motion of the
apsides may be represented, by supposing
a planet to move in an ellipse, while the
ellipse itself is slowly revolving about
the sun in the same plane. This motion
of the major axis, which is direct in all
the orbits except that of the planet
Venus, is irregular, and so slow, that it
requires more than 109,830 years for the
major axis of the earth's orbit to accom-
plish a sidereal revolution.

A'PSIS. (ai|/''c.» Gr. apsis, Lat.) A term
used indifferently for either of the two
points of a planet's orbit, where it is at
the greatest or least distance from the sun
or earth ; and hence the line connecting
those points is called the line of the
apsides. The apsis at the greatest dis-
tance from the sun is called the aphelion,
and at the greatest distance from the
earth is called the apogee ; while that at
the least distance from the sun is termed
the perihelion, and at the least distance
from the earth, theperigee.

A'PTER. > (from a, priv. and Trrtpov, a

A'PTERA. $ wing.) Insects which have
no wings, forming, according to the Lin-
nsean system, the seventh order of in-
sects.

A'PTEROUS. Destitute of wings ; wingless.

A'PULUM. The name of a metallic substance
obtained from alumina.

APY'ROUS. (from a, priv. and irvp, Gr.
apyre, Fr.J Capable of resisting the
action of fire.

A Q U

[20 ]

A R G

ACIUA'RIUS. The water-bearer, or eleventh
sign in the zodiac. A constellation which
is supposed to have obtained this name
from the opinion that its rising brings
with it an abundance of rain. It rises in
January and sets in February. This
constellation contains, according to Pto-
lemy and Kepler 45 stars, but according
to Flamsted 108.

ACIUA'TIC. "1 (aquaticus, Lat. aquatique,

AQUA'TICAL. \ Fr. aquatico, It.) Relat-

ACIUA'TICK. j ing to the water ; that in-
habits, or frequents, the water ; that grows
in the water.

A'QUATILE. (aquatilis, Lat. aquatile, Fr.
aquatile, It.) See Aquatic.

A'auEous. (aqueus, Lat. aqueux, Fr.
acquoso, It.) Watery.

A'QUEOUSNESS. Waterishness.

ARA'CHNIDA. } (from apd^vrj and t iSog ,

ARA'CHNIDAN. 5 Gr. resembling a spider.)
The arachnida are members of that series
of aunulose animals possessing jointed
feet, and belong to the third class of arti-
culated animals. The two great families
in the higher order of living arachnidans
are spiders and scorpions. — Buckland.
In the arrangement of Cuvier, the ara-
chnidans compose the second class of
articulated animals provided with move-
able feet. They have no wings, and do
not undergo any metamorphosis, merely
casting their skin. The majority of the
arachnidans feed on insects ; some are
parasitical, living on vertebrated animals ;
others are found in flour, in cheese, and
on vegetables. Cuvier has divided the
arachnidans into two orders, Pulmonarise
and Tracheariffi ; the former he subdi-
vided into families, Araneides and Pedi-
palpi ; the latter into three families,
Pseudo-Scorpiones, Pycnogonides, and
Holetra.

ARACHNOI'D.

ARACHNOI'DES.

1. A cobweb-like membrane, forming one
of the tunics or coats of the brain.

2. One of the tunics, or coats, of the eye.

3. A species of fossil madrepore.
ARBORE'OUS. (arloreus, Lat.)

1. Belonging to trees ; resembling trees.

2. A term used to distinguish such
mosses, or funguses, as grow upon trees,
from those that grow on the ground.

ARBORE'SCENCE. (from arboresco, Lat.)
The likeness of a tree, frequently ob-
served in crystallizations and in mineral
productions.

ARBORE'SCENT. Resembling a tree ; grow-
ing like a tree ; becoming woody.

ARC OF A CIRCLE. An arc of a circle is
any part of its circumference ; and the
chord, or subtense of an arc, is a straight
line joining the two extremities of that
arc.

A'RCHED. (arcuatus, Lat.) In the form

of a bow.
A'RCA. A transverse inequilateral shell :

the beaks distant ; the hinge with many

teeth disposed in a straight line. These

are marine shells. Lamarck particularizes

seven species.

ARCH^EOLO'GICAL. ) Relating to a discourse
ARCHEOLO'GICAL. $ on antiquity.
ARCH^O'LOGY. ) from dp^atoc, ancient, and
ARCHEO'LOGY. $ Xoyog, discourse, Gr.) A

discourse on subjects connected with anti-

quity ; the science which treats of anti-

quities.
A'RCHETYPK. (archetype, Fr.) The ori-

ginal of which any resemblance is made.
A'RCTIC. ) (from a/o/crog, ursus ; arctique,
A'RCTICK. $ Fr. artico, It.) Northern;

lying under the arctos, or bear.
A'RCTIC CIRCLE. One of the lesser circles

of the sphere, twenty-three degrees and

twenty-eight minutes from the north pole.

The circle at which the northern frigid

zone begins. This and its opposite, the

antarctic, are called the two polar circles.
A'RCUATE. (arcuatus, Lat.) Bent like a

bow ; in the form of an arch ; incurvated.
A'RCUATILE. (arcuatilis, Lat.) Bent in

the form of an arch ; crooked like a bow ;

bowed.
ARCUA'TION. The act of bending anything ;

the state of being bent in the form of an

arch ; curving ; bending.
A'RCUATURE. The curvature of an arch.
A'REA. (area, Lat.) The surface con-

tained between lines and boundaries.
AREFA'CTION. (from arefacio, Lat.) The

state of growing day ; the act of drying.
A'REFY. To dry ; to free from moisture.
ARENA'CEOUS. (arenaceus, Lat.) Sandy;

having the properties, or appearance, of

sand.
ARENILI'TIC. Resembling sandstone ; hav-

ing the quality of sandstone ; composed

of sandstone.

ARE'N ALDUS. Full of sand ; sandy ; gra-

velly.
AREO'METER. (fromapaiog, and/urpsw, Gr.

areometre, Fr.) An instrument for mea-

suring the density or weight of any liquid.
AREO'METRY. The art of measuring the

density or gravity of fluids.
A'RGAL. Crude tartar, as deposited by

vinous fermentation.
ARGE'NTAL. (from argentum, Lat.) Con-

taining silver ; combined with silver.)
ARGENTIFEROUS. (from argentum and

fero, Lat.) Producing silver.
ARGENTINA. A genus of fishes of the

order of abdominales.
ARGE'NTINE. (aroentin, Fr.) Appearing

like silver ; resembling silver.
ARGE'NTINE. Slate-spar ; a mineral of

A R G

[21 J

A R S

a lamellated, or slaty structure ; a nearly
pure sub-species of carbonate of lime.

A'RGIL. ") (argrilla, Lat. apyiXXog, or ap-

A'RGILL. $ yiXo£, Gr. argille, Fr. argilla,
It.) In 1754, Margraff showed that the
basis of alum is an earth of a peculiar
nature different from every other ; an
earth which is an essential ingredient in
clays, and gives them their peculiar pro-
perties. Hence this earth was called
argill ; Morveau afterwards gave it the
name of alumina, because it is obtained
in the state of greatest purity from
alum.

ARGI'LLA. A genus of argillaceous earths.

ARGILLA'CEOUS. (argillaceous, Latin.)
Clayey ; of the nature of argil ; contain-
ing argil.

ARGILLACEOUS- SCHIST. Clay slate. An
indurated clay, or shale, common to the
fossiliferous and metamorphic series.

ARGILLIFEROUS, (from argilla andfero,
Lat.) Producing or yielding clay.

A'RGILLITE. Argillaceous-schist, or clay-
slate. Slate is a very extensive forma-
tion, composing entire mountains in
many alpine districts. The prevailing
colours are bluish, or greenish grey : it
has a silky lustre.

ARGILLI'TIC. Containing argillite ; of the
quality of argillite ; resembling argillite.

ARGI'LLOUS. (argillosus, Lat. argilleux,
Fr. argilloso, It.) Containing clay; of
the nature or quality of clay.

ARGONA'UTA. The Paper Sailor ; a genus
of animals ; class Vermes, order Tes-
tacea. There are several species, but the
most remarkable one is the Argonauta
Argo, or Paper Nautilus. " Doubts still
exist whether the Sepia found within this
shell be really the constructor of it, or a
parasitic intruder into a shell formed by
some other animal not yet discovered.
Broderip, Gray, and Sowerby, are of
opinion, that this shell is constructed by
an animal allied to Carinaria." — Buck-
land.

Cuvier placed argonauta among the
subgenera of Sepia, and Dr. M'Murtrie,
in his translation, says, " These mol-
lusca are always found in a very thin
shell, symmetrically fluted and spirally
convoluted, the last whorl so large that it
bears some resemblance to a galley of
which the spine is the poop. The ani-
mal makes a consequent use of it, and in
calm weather whole fleets of them may
be observed navigating the surface of the
ocean, employing six of their tentacula
as oars, and elevating the two mem-
branous ones by way of a sail. If the sea
become rough, or they perceive any dan-
ger, the argonaut withdraws all its arms,
concentrates itself in its shell, and de-
scends to the bottom."

A'RID. (aridus, Lat. aride, Fr. arido, It.)
Dry ; parched up ; devoid of moisture.

ARI'DITV. ) ariditas, Lat. ariditt, Fr.

A'RIDNESS. ] ariditcl, It.) Dryness ; the
state of being without moisture.

ARMADI'LLO. (armadille, Fr.) The Dasy-
pus of Linnseus, and placed by him in
the order Bradypoda, class Mammalia.
Cuvier has placed the armadillo in the
order Edentata, or quadrupeds having no
front teeth, class Mammalia. The arma-
dillo is constructed with unusual adapta-
tions to the habit of burrowing in search
of its food, and shelter in the sand ; its
fore feet forming instruments of peculiar
power for the purpose of digging; and
presenting an extraordinary enlargement
and elongation of the extreme bones of
the toes, for the support of long and
massive claws. The armadillo and chlamy-
phorus are the only known animals that
have a compact coat of plated armour.
There are several subgenera.

ARI'LLUS. ) (arillus, Lat.) A substance

A'RIL. ) enclosing the seed in some
plants : it is either a complete or
partial covering of a seed, fixed to its
base only, and more or less loosely or
closely enveloping its other parts. Mace
is the arillus of the nutmeg: the red aril-
lus of the seed of the common spindle-
tree is well known, and is very ornamen-
tal in our hedges in the autumn.

A'RMATURE. (armatura. Lat. armature,
Fr.)

1. That by which the body is protected
from injury.

2. Weapons of attack.

ARME'NIAN STONE. A blue mineral, or
earth, variously spotted. It much re-
sembles Lapis lazuli.

ARRA'GONITE. A variety of carbonate of
lime, found originally in Arragon, in
Spain, from which circumstance it has
obtained its name. Its colours are white,
grey, green, and blue ; it is found both
crystallized and massive. It is fre-
quently combined with a small propor-
tion, about four per cent, of carbonate of
strontites.

ARSE'NIATE. A compound of arsenical
acid with a metallic oxide ; many arse-
niates are found native ; when heated
along with charcoal powder, they are de-
composed, and arsenic sublimes.

A'RSENIC. (apfftvticbv, Gr. arsenic, Fr.
arsenico, It.) Native arsenic is a mineral
found in Germany, France, and England.
It occurs generally in masses of various
shapes ; its colour is that of blue steel ;
it is brittle : its surface readily tarnishes
on exposure to the atmosphere. When
struck it gives a smell resembling garlic ;
before the blow-pipe it emits a white
smoke, burns with a bluish flame, gives a

A R S

[ 22 ]

ART

strong garlicky smell, and deposits a white
powder. This metal and all its com-
pounds are virulent poisons. Combined
with sulphur it forms orpiment or realgar,
or the yellow and red sulphurets of ar-
senic. The term apviviKov, from which
the word arsenic is derived, was an an-
cient epithet, applied to those natural
substances which possessed strong and
acrimonious qualities, and as the poison-
ous quality of arsenic was found to be re-
markably powerful, the term was espe-
cially applied to orpiment, the form in
which this metal more usually occurred.
Dr. Paris, from whose work the above is
quoted, states that in the celebrated plague
of London, amulets of arsenic were worn,
suspended over the region of the heart, as
a preservative against infection ; on the
principle, so prevalent at one period, that
all poisonous substances possess a pow-
erful and mutual elective attraction for
each other.

ARSE'NICAL. Containing arsenic.

A'RSENITE. A name given by Fourcroy to
the combinations formed between oxide
of arsenic, or arsenious acid, and the
earths and alkalies. Arsenite of potassa is
the active ingredient in Fowler's Ague
Drop, and in the Liquor Potassse Ar-
senitis of the Pharmacopoeia.

ARTE'RIAL. (arterialis, Lat. arterial, Fr.
arteriale, It.) Pertaining to an artery;
that is contained in an artery.

A'RTERY. (from arjp, and TTJ/OSW, Gr.
artere, Fr. arterio, It. Thus called be-
cause the ancients thought that only air
was contained in the arteries.) The ar-
teries are strong elastic canals, which
convey the blood from the heart to the
different parts of the body, and, during
life, are distinguished from the veins by
their pulsation. The original trunks of
the arteries are two in number, and from
these all the other arteries are derived.

ARTE'SIAN WELLS. Springs of water, or
fountains, obtained by boring through
strata destitute of water into lower strata
loaded with this fluid, to sometimes great
depths ; thus named from its having been
first practised at Artois, the ancient Ar-
tesium, in France. In forming an Ar-
tesian well, if the boring penetrate a bed
containing impure water, it should be
continued deeper until it arrives at ano-
ther stratum containing pure water ; the
bottom of the pipe being plunged into
this pure water, it ascends within it, and
is conducted to the surface through what-
ever impurities may exist in the superior
strata. The impure water, through which
the boring may pass in its descent, being
excluded by the pipe from mixing with
the pure water ascending from below.
The height to which these springs will

rise above the surface must depend on
the quantum of hydrostatic pressure from
below ; this is sometimes very great. The
water of an Artesian well in Rousillon
rises from thirty to fifty feet above the
surface. At Perpignan and Tours, M.
Arago states that the water rushes up
with such extreme force as violently to
eject a cannon ball placed in the pipe.
An economical and easy method of sink-
ing Artesian wells has recently been prac-
tised. Instead of the tardy and costly
process of boring with a number of iron
rods screwed to each other, one heavy
bar of cast iron, about six feet long, and
four inches in diameter, armed at its
lower end with a cutting chisel, and sur-
rounded by a hollow chamber, to receive
through valves, and bring up the detritus
of the perforated stratum, is suspended
from the end of a strong rope, which
passes over a wheel or pully fixed above
the spot in which the hole is made. As
this rope is moved up and down over the
wheel, its tortion gives to the bar of iron
a circular motion, sufficient to vary the
place of the cutting chisel at each descent.
When the chamber is full, the whole
apparatus is raised quickly to the surface
to be unloaded, and is again let down by
the action of the wheel. — Buckland.

ARTI'CULAR. (articularis, Lat. articu-
laire, Fr. articolare, It.) Belonging to
the joints.

ARTICULA'TA. One of the four great ex-
isting divisions of the animal kingdom ;
the third in Cuvier's arrangement, the
other three being the Vertebrata, the Mol-
lusca, and the Radiata. The earliest
examples furnished by geological research,
of articulated animals, or such as belong
to the division Articulata, are those af-
forded by the extinct family of Tri-
lobites. This division of the animal
kingdom comprehends four classes : 1.
The Annelidans, or worms with red blood ;
2. The Crustaceans, as the lobster,
shrimp, &c.; 3. The Arachnidans ; 4. In-
sects. In the Articulata is observed the
transition from circulation in closed ves-
sels to nutrition by imbibition, and the
corresponding transition from respi-
ration in circumscribed organs to that
effected by tracheae, or air vessels, dis-
tributed through the body. This third
division of the animal kingdom has been
named by Professor Grant, Diplo-Neura.
It comprises Crustacea, Arachnida, In-
secta, Myriapoda, Annelida, Cirrhopoda,
Rotifera, and Entozoa. In the Crus-
tacea, the nervous system is disposed in
the form of two abdominal chords, and
this form can be traced through the whole
of the third division, from Crustacea to
Entozoa inclusive.

ART

C 23]

ASP

ARTI'CULATED. Jointed ; having joints ;
united by joints. In botany, the term
articulated is applied to leaves, when one
leaflet, or pair of leaflets, grow out of the
summit of another, with a sort of joint ;
to stems divided by joints or knots, or
divided from space to space by contrac-
tions ; to culm with joints.

ARTI'CULATING. Fitting by means of joints.

ARTICULA'TION. (articulatio, Lat. articu-
lation, Fr. articolazione, It.) The junc-
ture or joint of bones. There are three
kinds of articulation, 1. Immoveable,
called Synarthrosis ; 2. Moveable, or
Diarthrosis ; 3. Mixed, or Amphi-ar-
throsis.

ARTICULO'SA. See Articulata.

ARUNDINA'CEOUS. (Lat.) Resembling
reeds.

ARUNDI'NEOUS. ^ (arundineus, Latin)

ARU'NDINOSE. $ Reedy ; abounding with
reeds.

ARYTJE'NOID. (from apvTaiva, a ewer,
and tldog, resemblance, Gr.) A name
given to some of the cartilages, glands,
and muscles of the larynx.

A'SAPHUS. (a<ra0?}c, Gr. obscurus.) A
genus of Trilobites. Professor Buck-
land observes, in writing of Trilobites,
" Fossils of this family were long con-
founded with insects, under the name of
Entomolithus paradoxus ; after many dis-
putes respecting their true nature, their
place has now been fixed in a separate
section of the class Crustaceans, and al-
though the entire family appears to have
been annihilated at so early a period as
the termination of the carboniferous
strata, they nevertheless present analo-
gies of structure, which place them in
near approximation to the inhabitants
of the existing seas.

ASBE'STINE. Incombustible ; partaking
of the properties of asbestos.

ASBE'STINITE. A species of asbestos.
This mineral is amorphous. Texture fo-
liated. Lustre silky, 3. Specific gra-
vity 2'8SO. Colour white, with shades
of red, yellow, blue, and green. At 150°
Wedgewood, it melts into a green glass.

ASBE'STOID. A mineral, thus called from
its resemblance to Asbestos. It is amor-
phous. Texture foliated or striated.
Specific gravity from '3 to 3*30. Colour
olive or green. It consists of silica 46,
oxide of iron 25, lime 11, oxide of
manganese 10, magnesia 8.

ASBE'STOS. ) (dafiearoQ, Gr. nomen lapidis,

ASBE'STUS. $ unde telse fiunt, quse non
comburuntur in igni ; asbeste, Fr. asbeste,
It.) A mineral of which there are several
varieties, all marked by their fibrous flexi-
ble quality. Asbestos is itself a variety of
hornblende. It was well known to the
ancients, by whom a kind of cloth was

made of one of its varieties, which was
esteemed to be incombustible. It is
found abundantly in most mountainous
countries, and in the isle of Anglesea it
lies in considerable quantities between the
beds of serpentine. Although fire acts
slowly on its fibres, yet it will, in the
course of time, consume them. It is
commonly amorphous. Texture fibrous.
Lustre from 0 to 2. Hardness from 3 to
7. It absorbs water. Colours white,
green, blue, yelloAV, and brown. Its
constituent parts are, silica CO, magnesia
30, lime 6, alumina 4. It feels soapy
or greasy. For one of its varieties,
flexible asbestos, see Amianthus. Another
variety has obtained the name of moun-
tain cork, from its swimming when thrown
into water. This variety has a strong
resemblance to common cork. Its fibres
are interwoven. Specific gravity from
0-6806 to 0-9933. It feels meagre ;
yields to the fingers like cork, and is
somewhat elastic. Colour white or grey.
Its constituent parts are, silica 62, car-
bonate of magnesia 23, carbonate of
lime 12, alumina 2-7, oxide of iron 2*3,
One variety is called rigid or common
asbestos. Of this the colours are usually
green, and disposed in straight, pearly,
rigid fibrous concretions. Soapy or unc-
tuous to the feel. Another variety is
known by the names of rockwood, moun-
tainwood, or ligneous asbestos. The
colour of this variety is brown, and its
general appearance greatly resembles fos-
sil wood.

A'SCARIS. (ao-fcapif, Gr.) Cuvier placed
the ascaris in the order Nematoidea, class
Entozoa. The thread- worm.

ASCI'DIA. A genus of animals found in the
sea, adhering to the rocks. Class Vermes,
order Mollusca.

ASCITI'TIOUS. (ascititius, Lat.) Supple-
mental ; additional ; not originally form-
ing part of.

ASH-COLOURED. Coloured between brown
and grey.

A'SHLAR. A name given to freestone as it
is taken from the quarry.

ASIPHONIBRANCHIA'TA. In De Blainville's
system, the second order of the class
Paracepholophora Dioica, comprising the
genera Goniostomata, Cricostomata, He-
micyclostomata, Ellipsostomata, and Oxy-
stomata.

ASLA'NT. Obliquely ; not perpendicularly.

A'SPHALT. "^ (a<T0crArof,Gr. bitumen, as-

ASPHA'LTOS. }• phalte, Fr.) A bituminous

ASPH A'LTUM. ) substance,found abundant-
ly on the shores of the Dead Sea, in the
island of Trinidad, in China, America, and
various parts of Europe. Its colour is
brown or black ; it is lighter than water,
and easily soluble in naphtha, but quite

ASP

[ 24]

A U G

insoluble in water. Fracture conchoidal.
Brittle. Feels smooth, but not unctuous.
Does not stain the fingers. On the sur-
face of the Dead Sea it is found floating
in a state of liquidity, but exposure to the
air soon renders it hard. It melts easily
when heated, and, if pure, burns without
leaving any ashes.

A'SPEROUS. Rough ; uneven.

ASPIDORHY'NCHUS. The name given to a
fossil Sauroid fish from the lime stone
of Solenhofen. An example of this is
given by Professor Buckland in his Bridge-
water Treatise, pi. 27 a, fig. 5.

ASSA'Y. The operation of determining
the proportion of precious metal con-
tained in any mineral or metallic com-
pound, by analyzing a portion thereof.

A'STACID. )The craw-fish, or lobster; a

A'STACITE. S genus of the family Ma-
croura ; it is divided into four sections
each consisting of many subgenera. The
lobster, crab, craw-fish, prawn, ,and
shrimp are included.

A'STACUS. (from doraieog, Gr. astacus,
Lat.) The lobster or craw-fish.

ASTA'COLITE. (from aoraKOQ and XlBoq,
Gr.) Fossil or petrified craw-fish, or
lobster.

ASTE'RIA. (asterias, Lat. asterie, Fr.) A
variety of sapphire, or bastard opal.

ASTE'RIA. (from affrrjp, Gr. a star.) The
star-fish, or sea-star, a genus of animals,
class Vermes, order Mollusca. These
animals have their mouth in the centre,
and placed downwards ; from their bodies
five or more rays, or arms, are given off,
furnished with numerous retractile tenta-
cula. They have the power of repro-
ducing their rays if destroyed. They are
all inhabitants of the sea, and they are
frequently found fossil, in great perfection,
in the chalk. Some remarkably fine
impressions have been discovered in flint.
The whetstone of Devonshire affords
similar remains. Linnaeus has placed
them in the order Pedicellata, class Echi-
nodermata.

ASTE'RIATED. Radiated.

ASTE'RIALITE. (from aarfiQ and XiOoQ, Gr.)
Fossilized, petrified, or silicified asterias,
or star-fish.

A'STERITE.^ (astroite, Fr. Espece de ma-

A'STRITE. Y drepore ou de corps marin,

A'STROITE.J sur lequel on voit repre-
sentee la figure d'une etoile.) Star
stone. This name is given to certain
varieties of the perfect corundum.

A'STEROID. (from acrr)p and fldog, Gr.*)
The name assigned by Herschel to some
newly discovered planets.

ASTERO'IDAL. Resembling a star-fish.

ASTEROPHY'.LLITE. (from aarfip and 0uX-
Xov, Gr.) A plant discovered in the coal j
formation, and thus named from the stel- |

lated disposition of the leaves around the
branches.

ASTRE'A. A species of madrepore. The
appearance of groups of astrea, and other
corals, is described as being most beauti-
ful when viewed with the animals alive
and in activity ; looking down through
the clear sea-water, the surface of the
rocks appears one living mass, and the
polypi present the most vivid hues.

ASTRI'FEROUS. > Bearing stars ; having

ASTRI'GEROUS. 5 stars ; carrying stars.

A'STRITE. See Asterite.

A'STROITE. See Asterite.

ATA'CAMITE. Prismatoidal green mala-
chite. Native muriate of copper, of a
green colour, occurring both massive and
crystallized. It consists of oxide of cop-
per 76*6, muriatic acid 12 -4, water 11. It
has obtained its name from having been
found in alluvial sand in the river Lipas,
in the desert of Atacama in Peru. It has
also been found in some of the Vesuvian
lavas. The primitive form is an octoe-
dron. It is the Cuivre muriate of Haiiy.

ATMO'METER. (from drfibg, vapour, and
/*erpsw, to measure, Gr.) An instrument
contrived by Professor Leslie, for ascer-
taining the quantity of moisture exhaled
from a damp surface in a given period.

ATRAME'NTAL. } (from atr amentum, Lat.)

ATRAME'NTOUS. 5 Black ; ink - coloured ;
dark.

A'TROUS. (from ater, Lat.) Intensely
black.

ATTENUATED, (attenuatus, Lat. attenue,
Fr.) Thin; slender; tapering. An epi-
thet for a leaf tapering at one or both
extremities.

ATTI'GUOUS. (attiguus, Lat.) Adjoining;
hard by.

ATTRI'TE. (attritus, Lat.) Worn by fric-
tion, or rubbing.

ATTRI'TENESS. The state of being much
worn.

ATTRITION, (attritio, Lat. attrition, Fr.
attrizione, It.)

1. The act of wearing by friction ; abra-
sion.

2. The state of being worn.

A'TUS. Terminations in atus and itus, show
merely the existence of something in ge-
neral ; for example, antennatus, provided
with antennae ; alatus, winged ; sulcatus,
furrowed ; auritus, furnished with ears, or
appendages.

AU'DITORY. (from audio, Lat.) Belong-
ing to the parts connected with the sense
of hearing, as the auditory canal, the au-
ditory nerves, &c.

ATJ'GITE. (auy»), Gr. splendour.) A mi-
neral of a dark green, brown, or black
colour, found in volcanic rocks. It is the
Pyroxene of Haiiy, the Puratoma augit of
Mohs, and the augit of Werner. Its frac-

A U G

A X I

ture is conchoidal and uneven. It gene-
rally crystallizes in six or eight-sided
prisms, terminated by dihedral summits.
It is commonly attracted by the magnet.
Scarcely fusible by the blow-pipe. With
borax it melts into a yellowish glass, which
while hot appears red. There are many
varieties of augite, as the Diopside, Mu-
site, Alalite, Sahlite, Pyrogome, Fassaite,
Malacolite, Common Augite, Conchoidal
Augite, Granular Augite, Coccolite and
Amianthus. Augite consists of silica 52,
lime 13, protoxide of iron and manga-
nese 16, magnesia 10, alumina 9.

AUGI'TIC. Resembling augite ; containing
augite.

AUGI'TIC PORPHY'RY. A rock with a dark
grey, or greenish, base, containing cry-
stals of augite and Labrador felspar.

AU'RATED.

1. Resembling gold.

2. Eared ; having ears, as in the scallop-
shell.

AURE'LIA. The first change of the eruca,
or maggot, of any kind of insect ; a chry-
salis, having a golden hue, previous to its
becoming the perfect insect.

AU'RICLE. (auricula, Lat.)

1. That part of the ear which is prominent
from the head.

2. A cavity of the heart. The heart is
divided into four cavities, or chambers,
namely, two auricles and two ventricles.

AU'RICLEU. Having ears ; having appen-
dages resembling ears : applied to leaves
when they are furnished with a pair of
leaflets, generally distinct, but sometimes
joined with them.

AURI'CULA. An ovate or oblong pyra-
midal univalve, with the spire extruded :
the opening entire, oblong, and narrowed
upwards ; the columella plicated, with
different plicae in the opposite lip. La-
marck has placed those shells whose open-
ings are entire, but whose columellse are
plicated, under this genus, Auricula. —
Parkinson.

AURI'CULATE. Ear-shaped.
ATJRI'FEROUS. That which yields gold ;

containing gold.

AU'RIFORM. (from auris and forma, Lat.)
Having the form of an ear ; in the shape
of an ear ; the haliotis is an example.
AUSTE'RE. (austerus, Lat.) Sour or harsh

to the taste ; acrid.
AUSTE'RENESS. Roughness or harshness

in taste.

AU'STRAL. ) (australis, Lat. austral, Fr.
AU'STRINE. J australe, It.) Southern;

southward.

AUTO'MALITE. Octahedral corundum. Spi-
nelle zincifere of Haiiy. A variety of co-
rundum containing oxide of zinc. It oc-
curs imbedded in talc and associated with
lead-glance. It is crystallized in regular

octahedrons, or in tetrahedrons with trun-
cated angles. Its constituent parts are
alumina, the oxides of zinc and iron, and
silica. It has been found in America and
in Sweden.

AUTO'MOLITE. See Automalite.

AVALANCHE, (avalange, ou avalanche, Fr.)
A mass of snow which, detached from any
mountainous height, by rolling onwards
accumulates frequently prodigious bulk
and acquires great momentum. Ava-
lanches are in mountainous countries pro-
ductive of the direst misfortunes, sweep-
ing before them in their irresistible and
destructive progress every impeding ob-
ject ; breaking off large masses of rocks,
uprooting, or tearing away, the noblest
trees, damming up river courses, and
burying beneath their volumes villages,
with their whole population.

AVI'CULA. (from avis, Lat.) A free shell,
a little gaping near the beaks, fixing itself
by a byssus, and having its valves of un-
equal size; the hinge without a tooth, and
rather callous. The cartilaginal pit ob-
long, marginal, and parallel to the edge
by which it is sustained. — Parkinson.

AXE-STONE. A mineral found in New Zea-
land and the islands of the Pacific, and by
the inhabitants made into axes and other
cutting instruments, from which circum-
stance it has obtained its name. It is a
sub-species of jade, and in many respects
resembles nephrite, or nephritic stone.
See Jade.

AXI'JLLA. (axilla, Lat.)

1. In anatomy, the arm-pit.

2. In botany, the angle formed by the
stalk of a leaf with the stem.

AXI'LLARY. (axillaris, Lat. axillaire, Fr.)

1. In botany, applied to peduncles when
proceeding from the angle made by the
leaf and stem, or branch and stem ; also
to flowers, and to spikes of flowers, pro-
ceeding from either of the above situa-
tions.

2. In anatomy, pertaining to the axilla, or
arm -pit.

3. In entomology, applied to parts which
spring from the point of union of two
other parts.

AXI'NITE. The thumerstein or thumerstone
of Werner. It has obtained the name of
axinite in consequence of the axe-like
shape of its crystals. Its colours are
brown, grey, black, and blue. The name
of thumerstein was given to it by Werner,
from its having been found near Thum,
in Saxony. Texture foliated. Fracture
conchoidal. Before the blow-pipe it froths
like zeolite, and melts into a hard black
enamel. It has been found sparingly in
Cornwall, but in no other part of Great
Britain. A specimen analysed by Vau-
quelin was found to consist of silica 44,

A X I

[26]

BAR

alumina 18, lime 19, oxide of iron 14,
oxide of manganese 4.
A'xis. (axis, Lat.)

1. The line, real or imaginary, that passes
through anything on which it may re-
volve.

2. In botany, the imaginary central line
of different parts of a plant, round which
leaves, or modified leaves, are produced.
The stem is also so called, for this reason.

AXO'TOMOUS. (from a£<*>v, and re/ttvw, Gr.)

A mineralogical term, signifying cleavable

in one particular direction.
A'ZOTE. (from a, priv. and £w?}, life, Gr.)

A constituent part of the atmosphere,

receiving its name from its fatal effects

on animal life. It is now usually called

Nitrogen, which see.
A'zoxic. Consisting of azote ; resembling

azote in its properties ; destructive of life.
A'ZURE-STONE. > Names given to the lapis
A'ZURITE. 5 lazuli, or lazulite.

B

BA'CCA. (bacca, Lat.) A fruit ; a berry.

BACCI'FEROUS. (from bacca, a berry, and
fero, to bear, baccifere, Fr.) Berry-
bearing ; that produces berries.

BA'CULITE. (from baculus, Lat. So named
from its resemblance to a straight staff.)
A fossil, straight chambered, conical,
elongated and symmetrical shell, de-
pressed laterally, and divided into nu-
merous chambers by transverse, sinuous,
and imperfect septa ; the articulations, or
sutures, being indented in. the manner of
the battlements of a tower. The external
chamber is considerably larger than the
rest, and capable of containing a con-
siderable portion of the animal. The
remains of baculites have been hitherto
found in the chalk formation only, and
the bacuiite appears to have become ex-
tinct simultaneously with the last of the
ammonites, at the termination of the
chalk formation. This fossil may be seen
beautifully figured in Professor Buck-
land's Bridgewater Treatise,

BAI'KALITE. A variety of augite, of a
whitish, or yellowish white, and pale
green colour.

BA'LANITE. (balanites, Lat.) A fossil
belonging to the genus balanus.

BA'LANUS. (balanus, Lat. /3d\avo£, Gr.)
A conical multivalve, fixed by its base,
and composed of six articulated valves ;
the opening being closed by an oper-
culum, formed of four valves. The
balani are not to be considered among
those fossils which are frequently found. —
Parkinson.

The recent balanus is observed on
rocks and shells at a depth ranging to ten
fathoms ; and affixed to bottoms of ships
and other floating bodies. — De La Beche.
Balanus is the only genus of sessile
cirrhipedes, the shells of which consist of
six principal valves, except Coronula. —
Sowerby.

-BA'LASS. > (Called also Spinel and Zeilanit

BA'LLASS. $ by Werner.) A sub-species of
corundum; it is found in crystals of a
regular octahedron, composed of two

four-sided pyramids applied base to base.
Colour red. Balass is chiefly found in
Ceylon, and the dark and black varieties
have obtained the name Ceylanite. It
ranks among the precious stones, and
when of a certain size is deemed very
valuable.

BALI'STES. The file-fish ; a cartilaginous
fish belonging to the fourth class. Pro-
fessor Buckland, in his chapter on Ich-
thyodorulites, or fossil spines, states that
the spines of balistes have not their base,
like that of the spines of sharks, simply
imbedded in the flesh, and attached to
strong muscles ; but articulate with a
bone beneath them. The spine of balistes
is also kept erect by a second spine be-
hind its base, acting like a bolt or wedge,
which is simultaneously inserted or with-
drawn by the same muscular motion that
raises or depresses the spine.

BA'LKSTONE. A provincial name given
to an impure stratified limestone.

BA'NNER. The upper large petal of a papil-
lionaceous flower.

BA'OBAL. A stone which has obtained its
name from its resemblance to the fruit of
the baobal tree. -

BARB.

1. That which grows in place of a beard.

2. A sort of pubescence in plants.
BA'RBATE. } (from barbatus, Lat.)
BA'RBATED. $ Bearded ; awned.
BA'RBED. Bearded ; awned.
BA'RIUM. The metallic basis of baryta,

discovered by Sir H. Davy.

BARK. In botany, the covering of plants,
composed of woody fibres, situated above
the wood and under the cellular integu-
ment, consisting of from one to many
layers, according to the age of the plant
or branch, an additional layer being pro-
duced every year.

BA'RNACLE. (The Lepas balanus of Lin-
naeus. Barnacle, Fr. barnacla, It.) A
species of shell-fish, a pedunculated cir-
rhipede, frequently found adhering to the
bottoms of ships in such prodigious num-
bers, and of so great a length, as to ma-

BAR

[27]

B A S

terially impede their progress through
the water. Some very fine specimens
may be seen of them in the British
Museum. The barnacle is known by the
names Anatifer, and Pentelasmis. In
the arrangement of Cuvier the barnacle
is placed in the sixth class, namely,
Cirrhopoda, of Mollusca. Linnaeus com-
prised them all in one genus, Lepas,
which Brugieres divided into two. The
name anatifer, from the two Latin words
anas and fero, signifying duck-bearing,
was given to the barnacle from a ridicu-
lous notion, formerly entertained, that
they enclosed in an embryo state the
young of the barnacle duck. Sowerby
states that fossil specimens of this marine
genus are found in the calcaire-grossier,
of Paris, and in other similar beds.
Parkinson observes that anatifa Isevis
and anatifa striata are both said by Bosc
to be found fossil ; the latter is also said
by Gmelin to be sometimes found fossil,
but that he believes neither of these
statements to be supported by sufficient
authority. He, however, gives a re-
presentation of what he believes to be
a fossil barnacle in a flint stone which he
found in the gravel pits near Hackney-
road, and the opinion he first formed, not
only of its having derived its figure from
animal organization, but of its affinity
to the barnacle, received corroboration
from different specimens which he subse-
quently met with. Large bunches of
barnacles attached to pieces of wood are
frequently thrown up by the waves upon
our coasts.

BA'ROLITE. (from (3api>£, heavy, and
Xi#of, a stone, Gr.) Carbonate of
barytes. The Baryte carbonatee of Haiiy.
Barolite is found native, or it may be
artificially prepared. It was first dis-
covered native by Dr. Withering, from
whom it was named Witherite. Accord-
ing to the analysis of Dr. Withering,
carbonate of barytes consists of barytes
80, and carbonic acid 20. It is soluble
in dilute nitric acid. It is poisonous. It
occurs abundantly in lead veins, that
traverse a secondary limestone in Cum-
berland and Durham, and at Anglesark,
in Lancashire.

BAROSE'LENITE. (from (3api>£, heavy, and
selenite.) Heavy spar ; native sulphate
of barytes, or boroselenite. The Baryte
sulphatee of Haiiy. A mineral, found
abundantly in this and other countries.
It occurs both massive and crystallised.
The varieties of its crystals are very
numerous. It is of various colours,
white, grey, yellow, brown, red, green,
blue, and black. It consists of 66 per
cent, of barytes and 34 per cent, of
sulphuric acid. Its texture is generally

foliated. When heated it decrepitates-
It is soluble in dilute sulphuric acid. It
is found in veins, in primary, transition ,
and secondary rocks.

BA'ROTE. A name given to barytes by
Morveau. See Barytes.

BARYSTRO'NTIANITE. (from fiapvG, heavy,
and strontian.) This mineral has also
obtained the name of Stromnite, from its
being found at Stromness, in the island
of Pomona. Its principal constituent is
carbonate of strontia, of which it contains
nearly 70 per cent., combined with sul-
phate of baryta and a small proportion
of carbonate of lime and oxide of iron. It
occurs massive, of a greyish colour exter-
nally, and of a yellowish white internally.

BARY'TA. ^ from flapvg, heavy, Gr.)

BA'RYTE. }> Barytes has been also called

BARY'TES. j ponderous spar, heavy spar,
and barote. The first account of the
properties, &c. of barytes, was published
by Scheele in his dissertation on Man-
ganese. It has obtained its name from
its great specific gravity, which is about
4, being the heaviest of all the known
earths. It was called barote by Morveau,
and barytes by Kirwaii. Barytes con-
verts vegetable blues to green. When
exposed to the atmosphere it attracts
moisture, and when water is 'poured
upon it the same appearances present
themselves as in the slacking of lime,
with the evolution of great heat, the pro-
cess being more rapid, and the evolution
of heat greater. Barytes is found in two
natural combinations only, with the sul-
phuric and carbonic acids, forming sul-
phate and carbonate of barytes. Nearly
all the compounds of barytes are poison-
ous, the best antidotes being dilute sul-
phuric acid, or sulphate of soda in solution.

BARY'TIC. Containing barytes ; resem-
bling barytes ; having the properties of
barytes.

BA'SAL. Arising from the base of some
other part.

BA'SALT. (Said to be derived from an
Ethiopian word, basal, signifying iron.)
A variety of trap-rock of a dark green or
brownish black colour, composed of au-
gite and felspar with some iron and
olivine, the predominant mineral being
felspar. Basalt occurs, sometimes, in
veins or dykes, which traverse rocks of
all ages, filling up fissures or crevices,
and at others, in layers spread over the
surface of the strata, or interposed be-
tween them. Many modern lavas differ
so little from basalt, that it is unneces-
sary to adduce proof of the volcanic na-
ture of this rock. It often occurs in the
form of regular pillars, or columns, clus-
tered together ; or, in scientific language,
has a columnar structure, a character

B A S

BAT

also observable in some recent lavas.
This structure is found by some highly
interesting and philosophical experiments,
to have originated from the manner in
which refrigeration took place. Mr.
Gregory Watt melted seven hundred
weight of basalt, and kept it in the fur-
nace several days after the fire was re-
duced. It fused into a dark-coloured
vitreous mass, with less heat than was
required to melt pig-iron ; as refrigera-
tion proceeded, the mass changed into a
stony substance, and globules appeared ;
these enlarged till they pressed laterally
against each other, and became converted
into polygonal prisms. The articulated
structure and regular forms of basaltic
columns have, therefore, resulted from
the crystalline arrangements of the par-
ticles in cooling ; and the concavities,
or sockets, have been formed by one set
of prisms pressing upon others, and oc-
casioning the upper spheres to sink into
those beneath. — Mantell.

On examination with a lens, even the
more compact varieties of basalt are
seen to be composed of minute crystalline
grains. Basalt, in enormous masses,
often covers the primary mountain in the
Andes, and arranged in regular columns,
which to the eye of the traveller appear
like immense castles lifted into the sky.
Basaltic dykes intersect both primary and
secondary rocks. Few countries in the
world present more magnificent basaltic
columnar ranges than the north part of
Ireland, and some of the Hebrides. The
Giant's Causeway constitutes a small
part of a vast basaltic range, along the
north coast of Ireland, in the county of
Antrim. The promontories of Fairhead
and Borgue, in the same range, are situ-
ated eight miles from each other : these
capes consist of various ranges of pillars
and horizontal strata, which rise from the
sea to the height of five hundred feet. —
Bakewell.

BASA'LTIC. Composed of basalt ; resem-
bling basalt ; containing basalt.

BASA'LTIFORM. Resembling basalt in its
columnar form, or structure.

BASA'LTIC HORNBLENDE. \ Two names

BASA'LTINE. \ given to the

same mineral. A variety of common
hornblende to which these names have
been given from its having been found
commonly in basaltic rocks. The primi-
tive form of its crystals is a rhomboidal
prism. It has by analysis been found
to consist of silica 58, alumina 27, iron
9, lime 4, and magnesia 1. Its colour is
black, dark-green, or yellowish-green.
Texture foliated.

BA'SANITE. (from ftdaavog, Gr. lapis quo
probatur aurum, lapis Lydius.) Lydian

stone, a variety of schistose hornstone.
This stone acquired its name from its
having been formerly used as a touch-
stone in trying the purity of metals : it
also was called Lydian stone, from its
being found abundantly in Lydia. Ac-
cording to an analysis of it, its constituents
are, silica 75 per cent., lime, magnesia,
carbon, and iron.

BASILOSAU'RUS. The name of an enormous
fossil reptile, described by Dr. Harlan
of Philadelphia. Neither the relation of
the basilosaurus to other species, nor its
geological position, has been accurately
determined — Mantell.

BASE, (from basis, Lat.j3a<«c. , Gr. base, Fr.
basa, It.)

1. The bottom, or lowest part, of any
thing.

2. In conchology, that part of the shell
in univalves by which they are attached
to rocks, or other substances : in multi-
valves, the opposite extremity to the
apex.

BA'SIN. (bassin, Fr. bacino, It.) In geo-
logy, large concavities filled with deposits,
as the London basin, the Paris basin, &c.
are called basins. The surface of the earth
is covered with a series of irregular de-
pressions or basins, divided from one
another, and sometimes wholly surrounded
by projecting portions of subjacent strata,
or by unstratified crystalline rocks, which
have been raised into hills and mountains
of various degrees of height, direction,
and continuity. This disposition in the
form of basins, which is common to all
formations, has been more particularly
observed in the carboniferous series, from
the beds of coal contained therein having
been wrought thi'oughout their whole
extent. In consequence of this basin-
shaped disposition of the carboniferous
strata a most beneficial result obtains,
namely, that these strata, which an un-
interrupted inclination in one direction
only would soon have plunged into depths
inaccessible to man's greatest efforts, are,
by their being placed around the circumfer-
ence of the basin, all brought sufficiently
near the surface to be attainable, and are
thus made subservient to his benefit and
comfort.

BA'SSET. A term, used by miners, to ex-
press an upward slanting direction of a
vein, from below to the surface.

BA'SSETING. Slanting upwards.

BA'STAKD. (batard, Fr. bastardo, It.)
Spurious ; not genuine.

BATH-STONE. A species of limestone,
called also Bath-oolite. This member of
the oolite formation has been called
the great oolite ; it is of considerable
thickness, and yields an abundant supply
of freestone for building. It has ob-

BAT

C 29 ]

BEL

tained the name of oolite from its being
composed of small rounded grains, or
particles, supposed to resemble the roe
of a fish. Bath-stone consists of minute
globules, cemented together by yellowish
earthy calcareous matter, and contains a
considerable portion of broken shells.
When first quarried, Bath-stone is soft,
but it soon becomes hard by exposure to
the atmosphere.

BATH-OOLITE. See Bath-stone.

BATIIA'CHIA. (from /3arpa%o£, a frog,
Gr.) The fourth order in Cuvier's ar-
rangement of the class Reptilia ; it com-
prises frogs, toads, salamanders, and
sirens.

BA'TRACHITE. (from /3arp«'%£toe, Gr.
latrachites, Lat ) A fossil of the colour
of a frog ; a fossil frog ; a fossil resem-
bling a frog, either in form or colour.

BEACH. The shore of the sea ; the
strand.

BE'ACHY. Having beaches.

BEAK.

1 . In conchology, the continuation of the
body of univalves in which the canal is
situate.

2. In ornithology, the bill, or horny
mouth of a bird.

3. In botany, applied to an elongation of
the seed-vessel ; proceeding also from
the permanent style ; also to naked
seeds.

BE'AKED. Pointed ; terminating in a bill-
like point or process ; having the form of
a bill.

BEARD. (from barla, Lat. larle, Fr.
bar&a, It.)

1. The hair which grows on the lower
lip and chin.

2. In botany, a bristle-shaped projection,
growing out from the glume or chaff, in
corn and grasses ; called also the awn.

3. In conchology, the process by which
some univalves adhere to rocks, &c.

BE'ARDED. Having a beard ; awned.

BED. A stratum of considerable thickness.
It is desirable that the geological student
should draw a distinct line between the
words bed and stratum. Whenever a
layer, or stratum, is of the thickness of
two yards, or more, it should be denomi-
nated a bed, but otherwise a stratum.
There are sometimes found many dis-
tinct strata in the thickness of an inch ; to
denominate these as beds would be ab-
surd. Let it therefore be kept in mind
that the words bed and stratum are not
synonymous.

BE'ETLE. A coleopterous insect, the sca-
rabseus of Linnaeus. Remains of beetles
have been found in the oolite : wing
covers of beetles occur in the shale of the
Danby coal-pits, in the eastern moorlands

. of Yorkshire.

BE'ETLE. To jut out ; to hang over : thus
rocks are said to beetle.

BE'ETLE-STONE. A name given to coprol-
ites, from their falsely imagined insect
origin.

BEHE'MOTH. A huge animal spoken of in
Scripture, supposed by some to mean the
elephant, by others the ox, and by Bo-
chart the hippopotamus.

BE'LEMNITE. (from fltXtfivov, Gr. a
dart.) An extinct genus of chambered
molluscous animals, having a straight ta-
pering shell. Belemnites are found in
the secondary formation only, the lowest
stratum containing their remains being
the muschel-kalk, and the highest the
upper chalk of Maestricht. M. De Blain-
ville has given a list of ninety-one au-
thors, from Theophrastus downwards,
who have written on the subject of belem-
nites. The most intelligent of these
agree in supposing these bodies to have
been formed by cephalopods allied to the
modern sepia. That fossil which is
called a belemnite was a compound in-
ternal shell, made up of three essential
parts, which are rarely found together in
perfect preservation. The belemnite is
one of the most common fossils of the
chalk, it resembles an elongated conical
stone, of a crystalline, radiated struc-
ture, and is generally of a brown colour :
some limestones on the continent of Eu-
rope are almost wholly composed of
them. Ink-bags, resembling those of the
Loligo have been found in connection with
belemnites in the lias at Lyme Regis ;
these, in some instances, are nearly a
foot long, and prove that the animal to
which they belonged must have been of
great size. The fact of these animals
having been provided with a reservoir of
ink, affords an a priori probability that
they had no external shell, but recent
discoveries decide the question ; two
specimens having been found each con-
taining an ink-bag within the anterior
portion of the sheath, and, consequently,
all the species of belemnites may hence-
forth with certainty be referred to a
family in the class of Cephalopods.
Eighty-eight species of belemnites have
already been discovered ; and the vast
numerical amount to which individuals of
these species were extended, is proved by
the myriads of their fossil remains that
fill the oolitic and cretaceous formations.
— BucJcland. BaJcewell. Mantell.

BELE'MNO-SE'PIA. The name proposed to
be given by Professor Bucklaud, in con-
currence with M. Agassiz, to a new fa-
mily of cephalopods, to which family may
be referred every species of belemnites.

BELLE'ROPHON. An extinct cephalopod,
found in the mountain limestone, the

B E R

B I P

shell of which was without chambers.
Montfort placed the bellerophon among
chambered shells ; De Blainville assigned
their position next to Bulla.

BE'RYL. (beryllus, Lat. beryl, Fr.) A
crystallised compound of the earth glu-
cina with silica, alumina, lime, and oxide
of iron. The beryl is a gem, or precious
stone, of the genus emerald, but less va-
luable than the emerald. It differs from
the precious emerald in not possessing any
of the oxide of chrome, from the presence
of which the emerald obtains its splen-
did green colour. The aqua-marine is a
variety of the beryl, having a more
transparent texture. The beryl is of a
greyish-green colour, blue, yellow, and
sometimes nearly white ; occasionally
different colours appear in the same stone.
Beryl is found in many parts of the world,
but the finest specimens are brought from
Siberia. Vauquelin first discovered the
earth glucina from analyzing the beryl.

BE'RYX LEWESIE'NSIS. A fossil fish dis-
covered in the Lewes chalk quarries, of
the length of twelve inches, greatly re-
sembling the dory, and, by the workmen,
called the Johnny Dory. This is the most
abundant of the Sussex ichthyolites ; its
scales are very frequent in all the pits of
the South Downs, as well as in those of
Surrey and Kent. — Mantell. Cuvier
places the beryx in the family Percoides,
order Acanthopterygii.

BE'RYX RA'DIANS. A fossil fish from the
chalk-marl, of the length of seven inches.
This, like the Beryx Lewesiensis, last de-
scribed, belongs to the family Percoides,
order Acanthopterygii.

BIA'NGULAR. ) (from bis and angulus,

BIA'NGULOUS. $ Lat.) Having two angles.

BIA'NGULATED. Having two angles or
corners.

BICA'PSULAR. Having two capsules, or
seed-vessels.

BICI'PITAL. } (from biceps, Lat.) Having

BICI'PETOUS. $ two heads. It is a term
applied to muscles, which have two dis-
tinct origins.

BICO'RNOUS. (bicornis, Lat.) Having two
horns.

BICO'RPORAL. Having two bodies.

BICC'SPID. (from bis and cu?pis, a spear,
Lat. ) Two-pointed ; two-fanged.

BI'DENTATED. teeth'

BIE'NNIAL. (biennis, Lat.) Enduring

throughout two years and then perishing ;

plants which do not bear flowers and seed

till the second year, and then die.
BI'FID. } (from bifidis, Lat.) Cleft,

BI'FIDATED. $ or cloven, into two ; open-

ing with a cleft ; two-cleft, but not very

deeply divided.

BIFA'RIOUS. (bifarius, Lat.) Parting in
opposite directions.

BI'FURCATED. (from bis and/wrea, Lat.)
Divided into two heads or branches ;
forked.

BIFURCATION Division into two parts,
as in a fork.

BIGE'MINATE. In botany, applied to a
compound leaf, having a forked petiole,
with several petioles, or leaflets, at the
end of each division.

BILA'BIATE. (from bis and labium, a lip,
Lat.) Two-lipped ; furnished both with
an outer and inner lip.

BILA'TERAL. (from bis and latus, side,
Lat.) Two-sided; having two sides.

BI'LDSTEIN. (from bild, shape, and stein,
stone, German.) A massive mineral with,
sometimes, an imperfect slaty structure.
It is also called agalmatolite. By M.
Brongniart it has been named steatite
pagodite, but it is wanting in magnesia,
which is present in all steatites.

BILL. The beak of a bird.

BI'LOBED. \ (from bis and lobus, Lat.)

BILO'BATE. S Divided into two lobes.

BILO'CULAR. (from bis and loculus, Lat.)
Two-celled ; divided into two cells.

BIMA'RGINATE. In conchology, furnished
with a double margin as far as the
lip.

BI'MANOUS. (from bis and manus, Lat.)
Two-handed ; having two hands.

BI'NARY. (binarius, Lat.) Arranged by
twos.

BI'NATE. (from binus, Lat.) Two and
two ; by couples ; growing in pairs ; a
fingered leaf of two leaflets, inserted at
the same point, precisely on the summit
of the petiole.

BIND. Called also clunch ; a name given
to the soil on which the coal strata rest.
An argillaceous shale, more or less indu-
rated, sometimes coloured black by bitu-
men, and sometimes intermixed with
sand resembling sandstone, but generally
decomposing into a clayey soil on expo-
sure to the atmosphere. — Bakewell.

BINO'CULAR. (from binus and oculus, Lat )
Having two eyes.

BI'PAROUS. (from bis and pario, Lat.)
Bringing forth two at one birth.

BIPARTITE, (from bis and partitus, Lat.)
Having two correspondent parts ; an epi-
thet for the corolla, leaf, and other parts
of plants, when divided into two cor-
respondent parts at the base.

BI'PED. (from bipes, Lat. bipede, Fr.
bipede, che ha due piedi, It.) Any animal
having two feet only.

BI'PEDAL. (bipedal, Fr.) Having two
feet.

BIPE'NNATE. ) (bipennis, Lat.) Having

BIPE'NNATED. $ two wings.

BIPE'TALOUS. (from bis, Lat. and

B I P

B I T

Gr.) Consisting of two flower leaves;
having two petals.

BIPI'NNATE. (bipinnatum, Lat.) Doubly
pinnate ; applied to a compound leaf,
having a common petiole, which produces
two partial ones, upon which the leaflets
are inserted.

BIPINNA'TIFID. Having pinnatifid leaves
on each side the petoile.

BIRA'DIATE. 1 (from bis and radiatus,

BIRA'DIATED. ) Lat.) Consisting of two
rays.

BIRHOMBO'IDAL. Having a surface of
twelve rhombic faces.

BIRO'STRATE. (from linus and rostrum,
Lat.) Having a two-beaked prominence ;
two beaked.

BIROSTRI'TES. A fossil bivalve with coni-
cal umbones.

BI'SMUTH. (bismut, German, bismuth and
bismut, Fr.) A metal of a reddish -white,
or cream colour. It is neither malleable
nor ductile, its specific gravity is 98, it
fuses at a temperature of 476 Fahrenheit.
In hardness it is intermediate between
gold and silver. Bismuth unites with
most metals, rendering them generally
more fusible, and in some cases remark-
ably so. Eight parts of bismuth, five of
lead, and three of tin, constitute what has
been calle'd Sir I. Newton's fusible metal,
which liquefies at the temperature of boil-
ing water, 212°, and may be fused over
the flame of a candle in a piece of stiff
paper. Bismuth was discovered in the
early part of the sixteenth century, and is
mentioned by Bermannus. It occurs in
veins in primitive rocks, as gneiss, granite,
mica-slate, and clay-slate, in Saxony, Bo-
hemia, France, Sweden, and Cornwall.
One part of bismuth with five of lead and
three of tin form the soft solder used by
pewterers ; it is also used in the manu-
facture of printer's types. It is with a
compound of two parts of bismuth, one of
lead, one of tin, and four of mercury, the
whole being fusible at a temperature
under that of boiling water, that glass
globes are silvered on the inside ; a piece
of this compound being placed within
the globe, the latter is plunged into ho
water, the metallic compound readily
melts, and the globe being turned round"
the fluid metal is spread over the intern a
surface.
BISMU'THAL. Resembling bismuth ; con.

taining bismuth.

BISMU'THIC. Containing bismuth.
BI'SON. (bison, Fr. bison, Lat.) A largi
wild untameable herbivorous and grega
rious animal, often confounded with th
buffalo. The bison has a large flesh;
protuberance, or hunch, growing upor
the top and between the shoulders ; it
horns are short, black, and bent forwards

its back gibbous ; mane long ; tail about
a foot in length, and naked, except some
hairs at the end. Immense herds of bi-
sons are often seen in South America, and
Mr. James states that in one place on the
banks of the Plata, he saw ten thousand
bisons at once.

SISU'LCOUS. (bisulcus, Lat.) Cloven-
footed, as the ox, or the pig.
JITE'RNATE. (biternatum, Lat.) A term
given to compound leaves when the com-
mon petiole divides into two, each of
which bears three leaflets.
SITU'ME, } (bitumen, Lat. bitume, It.
h'lUMEN, 5 bitume, Fr. matiere liquide,
epaisse, noire et inflammable, qui se truuve
dans le sein de la terre, et dont on pretend
qu'on se. servoit autrefois au lieu de ci-
ment. ) The term bitumen is applied to
a number of inflammable substances found
in the earth, or issuing from the earth's
surface, and these are known under their
names of naphtha, petroleum, mineral tar,
mineral pitch or maltha, asphalt, elastic
bitumen, jet, mineral coal, amber, and
mineral tallow. These, however, may
perhaps be more correctly called bitumi-
nous varieties. Bitumen is a substance
of a peculiar kind, seeming to partake
both of an oily and resinous nature, and
is found either buried in, or proceeding
from, different parts of the earth, in dif-
ferent states of consistence. Bitumen is
composed of carbon and hydrogen. It
appears that formerly bitumen was gene-
rally used instead of mortar, and authors
suppose that the tower of Babel, the walls
of Babylon, of Sodom, and other places,
were built of bricks cemented together by
bitumen, and that the ark of Noah, and
the vessel of bull-rushes in which Moses
was exposed, were coated with this sub-
stance. Bitumen, when fluid, has been
called by some Latin writers, oleum vi-
vum. Lyell says that the tar-like sub-
stance, which is often seen to ooze out of
the Newcastle coal when on fire, and
which makes it cake, is a good example
of bitumen. The varieties of bitumen
will be separately described under their
different names. — Parkinson. Lyell.
Bakewell.

BITU'MINATED. (bituminatus, Lat.) Pre-
pared with bitumen ; impregnated with
bitumen.
BITUMINI'FEROUS. Yielding bitumen;

containing bitumen.
BITU'MINISE. To prepare with, or coat

with, bitumen.

BITUMINISA'TION, The preparing, or im-
pregnating, with bitumen.
BITU'MINOUS. (bituminosus, Lat.) Con-
taining bitumen ; having the nature and
qualities of bitumen.
BITU'MINOUS SHALE. An argillaceous shale,

B I T

C 32 ]

BOG

much impregnated with bitumen, which
is very common in the coal measures. —
LyelL

BITU'MINOUS SPRINGS. We are informed
by Mr. Lyell that springs impregnated
with petroleum, and the various minerals
allied to it, are very numerous, and are,
in many cases, undoubtedly connected
with subterranean fires. The most pow-
erful yet known, are those on the Irawadi,
in the Burman empire, which, from one
locality, are said to yield 400,000 hogs-
heads of petrdleum annually.

BI'VALVE. (bivalvis, Lat. bivalve, Fr.)
An animal having two valves, shells, or
shutters, as the oyster, muscle, &c.

BI'VALVE. "^ Consisting of two valves

BIVA'LVULAR. > or divisions ; having two

BIVA'LVOUS. J valves, or shells.

BLACK CHALK. A clay of a bluish black
colour, extremely soft, a quality which it
owes to the presence of about twelve per
cent, of carbon. That most esteemed is
found in Italy and Germany, and takes its
name from those countries respectively.

BLACK-JACK. A name given by miners to
a sulphuret of zinc. See Blende.

BLACK-LEAD. The substance about to be
described has been thus named from its
leaden appearance, or general resemblance
to lead, but it does not in fact contain a
single particle of lead in its composition.
It is the same as plumbago and graphite.
Black-lead is a compound of carbon, with
a small portion of iron, and some earthy
matters. It is of a dark steel-grey co-
lour, inclining to iron-black ; it occurs
regularly crystallised ; in granular con-
cretions ; massive and disseminated ;
it has a greasy feel, and blackens the fin-
gers, or any other substance to which it is
applied ; it is infusible, and burns with
much difficulty. According to Vauquelin
its constituent parts are carbon 92*0,
iron 8'0 ; but according to Allen and
Others, it contains only five parts per
centum of iron. Its nature was first in-
vestigated by Scheele, who, by combus-
tion, converted nearly the whole into car-
bonic acid gas, the residuum being oxide
of iron. Black-lead, or carburet of iron,
is used for many domestic purposes, but
its principal use is in its manufacture into
black-lead pencils. It is found in the
primitive, transition, and secondary rocks.
Anthracite resembles and appears to pass
into plumbago, or black-lead ; common
coal, also, according to Bakewell, some-
times graduates into plumbago.

BLACK-WADD. An ore of manganese, used
as a drying ingredient in paints.

BLA'TTA. (blatta, Lat.) The cockroach,
placed by Linnseus in the second order,
Hemiptera, of the seventh class, In-
sects.

BLENDE, (from blenden, Germ, to dazzle,
or blind.) Sulphuret of zinc ; a metallic
ore whose constituent parts are zinc, iron,
sulphur, and a trace of quartz- Blende
is called by the English miners black-
jack. The primitive form of its crystals
is a rhomboidal dodecahedron ; there are
several varieties known, as -brown blende,
yellow blende, black blende.
j BLOOD-STONE. Hematites ; a variety of
agate to which the name blood-stone
has been applied from some absurd
notion of its efficacy in restraining he-
morrhage.

BLUE-JOHN. A name given by the miners
to fluor spar ;- called also Derbyshire
spar, in which county it occurs in great
abundance. It is manufactured into
vases and ornamental figures, being ca-
pable of being turned by the lathe. Bake-
well, in describing the blue-John, or
fluor spar mine near Castleton, in Der-
byshire, observes, " the crystallisations
and mineral incrustations on the roof and
sides of the natural caverns which are
passed through in this mine, far exceed
in beauty those of any other cavern in
England ; and were the descriptions of
the grotto of Antiparos translated into
the simple language of truth, I am in-
clined to believe it would be found in-
ferior in magnificence and splendour of
mineral decoration, to the natural caverns
of the fluor mine.

BLUE VITRIOL. Sulphate of copper.

BLUFF. Any high head-land, or bank,
presenting a precipitous front.

BOG. (log, Irish, soft.) A kind of mo-
rass, too soft to bear a man's weight, and
partly composed of decayed vegetable
matter.

BOG-IRON-ORE. } Iron ore peculiar to bog-

BOG-ORE. S gyland. Mr. Lyell ob-

serves, " at the bottom of peat mosses
there is sometimes found a cake, or pan,
of oxide of iron, and the frequency of
bog-iron ore is familiar to the mineral-
ogist. From what source the iron is de-
rived is by no means obvious, since we
cannot in all cases suppose that it has
been precipitated from the waters of mi-
neral springs. It has been suggested that
iron, being soluble in acids, may be dif-
fused through the whole mass of vege-
tables, when they decay in a bog, and
may, by its superior gravity, sink to the
bottom, and be there precipitated so as to
form bog-iron ore. Dr. Mantell ob-
serves, " the formation of what is termed
bog-iron ore, found in marshes and peat
bogs, is supposed to have been derived
from the decomposition of rocks over
which water has flowed ; but the observ-
ations of Ehrenbergh, seem to indicate
a different origin."

B O L

[ 33 ]

BRA

BOLE. (from/3w\o£, Gr.) A friable clay,
or earth, often highly coloured with
iron.

BOLE'TUS. A genus of mushrooms, of the
order Fungi.

BOLO'GNA STONE. ) A variety of sulphate

BOLO'GNIAN STONE. 3 of barytes, pos-
sessing phosphoric properties. These
properties were first discovered accident-
ally by Vicenzo Casciarolo, an Italian
shoemaker.

BORA'CIC. Pertaining to borax ; containing
borax.

BORA'CIC ACID. A compound of boron
and oxygen, containing about 26 per cent,
of boron and 74 of oxygen. It is found
native on the edges of certain hot mineral
springs in Italy. It occurs in scaly
^rusts, or small pearly scales, and mas-
sive. Homberg was the discoverer of
boracic acid. Boracic acid may be ob-
tained by adding to a solution of borax
half its weight of sulphuric acid. The
term Sassolin has been applied to boracic
acid from its presence in the hot springs
of Sasso.

BO'RACITE. Borate of magnesia ; a com-
bination of boracic acid with magnesian
earth. Boracite is found imbedded in
gypsum, in Hanover and Holstein ; its
colours are white and greyish ; it is gene-
rally of a cubic form, and possesses, when
heated, strong electrical properties. Bo-
rate of magnesia may be artificially ob-
tained. Before the blow-pipe boracite
froths, emits a greenish light, and is con-
verted into a yellowish enamel.

Bo' RATE. A combination of boracic acid
with any saturated base ; a salt formed
by the combination of any base with the
acid of borax. — Parkes.

BO'RAX. (borax, Lat. borax, Fr. borace, It.)
Subborate or borate of soda ; a salt of soda
formed of the alkali with boracic acid.
It is prepared artificially by purifying the
natural borate of soda, a mineral found in
Thibet, where it is held in solution in the
waters of a lake, which also contains com-
mon salt. Borax in its impure state is
called tincal, and is purified by calci-
nation, solution, and crystallization after
its importation. Borax is an important
article in the arts, as a flux in the reduc-
tion of many metals, especially in assay-
ing ; it is also used in medicine. Accord-
ing to Berzelius, borax consists of soda
16-31, boracic acid 36'59, water 47'10.
Bergman states the proportions to be
boracic acid 34, soda 17, water 49 ; and
Kirwan gives, as his analysis, boracic
acid 34, soda 17, water 47.
BORE. A violent rush of tidal water.
BO'RON. The undecomposable base of bo-
racic acid ; this may be obtained by
heating in a copper tube two parts of

potassium with one of boracic acid pre-
viously powdered and fused.

Boss, (bosse, Fr.) A protuberance or
swelling ; a kind of knob or stud.

BOSSED. Knobbed or studded.

BOTHRODE'NDRON. (from fioOpoQ and
dzvdpov, Gr.) An extinct genus of coni-
feree belonging to the coal formation.
The bothrodendron has a stem not fur-
rowed, covered with dots. Scars of cones,
obliquely oval. The stems are marked
with deep oval or circular concavities,
which appear to have been made up by
the bases of large cones. These cavities
are ranged in two vertical rows, on
opposite sides of the trunk, and in some
species are nearly five inches in diameter.
— Prof. Buckland.

BO'TRYOID. ) (from /3orpv£, a bunch of

BOTRYOI'DAL. $ grapes, and Htioc, form.)
Resembling a bunch of grapes ; clustered
like grapes.

BOTRY'OLITE. (from ftorpvg, a cluster of
grapes, and Xi'0oe, Gr.) Grape-stone ;
a variety of prismatic datolite, occurring
in mamillary concretions.

BO'VEY-COAL, A name given to wood-coal
from its having been found in abundance
at Bovey Heathfield near Exeter ; called
also brown -coal. In wood-coal we may
almost seize nature in the act of making
coal, before the process is completed.
These formations of coal are far more
recent than those of common coal, and
have been referred to the first, or Eocene
period of the tertiary formations. Heat
and pressure appear to be required to
convert wood-coal into mineral coal.
Bovey-coal contains carbon 77'10, oxy-
gen 19'35, hydrogen 2-54, earthy parts
1-00.

BOU'LDER. ^ Large fragments, or rounded

BO'WLDER. { masses of any rock found
lying on the surface, or, sometimes, im-
bedded in soil, and differing from the
rocks where they are found ; these frag-
ments or outlying boulders, are of no
determinate size, they are supposed to
have been transported by the force of
water, and are occasionally found at very
great distances from their parent rocks.
The mass of rock on which is placed the
statue of Peter the Great at St. Peters-
burgh, is a detached block of granite, or
a boulder, forty-two feet in length, twen-
ty-seven feet broad, and twenty-one feet
high, and was removed from the Gulf of
Finland.

BRACHELY'TRA. A family of coleopterous
insects, having but one palpus to the
maxillae. It comprises only one genus,
namely Staphylinus.

BRA'CTEA. (bractea, Lat.) In botany, a
leafy appendage to the flower or stalk,
differing from the other leaves of the

BRA

13 R O

plant in form or colour ; the floral leaf.
Bracteee vary greatly in appearance ; most
commonly they are green and herbaceous.
The leaf, in the axilla of which a flower-
bud is produced, is called a bractea. The
most remarkable sort of bractea is that
called spathe ; the spathe or bractea of
many flowers is membranous. When two
or more bractese, instead of appearing
singly on the principal flower-stalk, are
opposite, or verticillate, they form an
involucrum.

BRA'CHIAL. (from brachium, an arm, Lat.
brachial, Fr. del braccio, It.) Belonging
to the arm.

BRA'CHIATE. (brachiatus, Lat.) Four-
ranked ; applied to stems, when they
divide and spread in four directions,
crossing each other.

BRANCHI'FERA. In the conchological sys-
tem of De Blainville, we find branchifera
placed in the order Cervicobranchiata, and
it comprises three genera, namely, Fis-
surella, Emarginula, and Parmophorus.

BRACHIO'PODA. (from jSpa^iW, an arm,
and TTO£;£, afoot, Gr.) Animals having
arms instead of feet. The brachiopoda
are all bivlaves. The brachiopoda, as
placed by Cuvier, form his fifth class of
Mollusca ; like the acephala, they have
an open bilobcd mantle. Instead of feet,
the brachiopoda have two fleshy arms,
which are furnished with numerous fila-
ments, which they have the power of
thrusting out of or drawing into their shell
at pleasure. This class, or family, com-
prises three genera, Orbicula, Terebra-
tula, and Lingula. Lamarck places bra-
chiopoda in the order Monomyaria.

BRACHIO'PODOUS. Having arms in the
place of feet and legs ; belonging to the
class Brachiopoda.

BRADY'PODA. Slow-moving animals, with
their bodies generally covered by a hard
crust. Some want the incisor teeth ;
others want the incisors and cuspidati ;
in others, the jaws are destitute of teeth.
Placed by Linnaeus in the class Mam-
malia, and composing the third order.
The order Bradypoda includes the genera
Bradypus, or Sloth, Mermecophaga,
Ant-eaters, Manis, Scaly Lizard or Ban -
golin, Dasypus, Armadillo, Ornithorrhyn-
chus. Duck-billed animal.

BRA'DYPUS. (ppadvirovg, Gr.) The sloth,
a genus of the order Bradypoda, class
Mammalia. These animals have no fore-
teeth ; they have six grinders in either
jaw ; and their bodies are covered with
hair. There are several species.

BRA'NCHIA. (from /3payxta> Gr.) This
word is rarely used substantively ; it
makes branchiae in the plural. Branchiae
are filamentous organs for breathing in
water ; gills.

BRANCHIO'PODA. (from /3pay%ta, and
TTOVQ, Gr. ) An order of crustaceans,
mostly microscopic, and many monocu-
lous. The order contains only one genus,
monoculus, having either but one eye, or
two so closely placed as to appear but
one.

BRANCHIO'PODOUS. Gill-footed ; belonging
to the order Branchiopoda.

BRAXCHIO'STEGI. (from /3oa'yx<a, gills,
and oreyoc, or oreyjj, a covering) A
term used to express one of the orders of
fishes, the characters of which are, that
the rays of the fins are of a bony sub-
stance.

BRANCHIO'STEGOUS. Having the charac-
ters of the branchiostegi ; belonging to
the order Branchiostegi ; having the gills
covered.

BRA'NCHIPUS. The cancer stagnalis of
Linnaeus ; an animal belonging to the
crustaceans, having the legs reduced to
soft paddles, and combining the func-
tions of respiration with those of locomo-
tion. In the branchipus, we find at-
tennse, but no crustaceous legs. The
soft branchiae of branchipus perform the
double office of lungs and feet.

BRAU'NITE. (The Brachytypes mangan-
erz of Mohs.) A mineral of a brownish
black colour, occurring massive and crys-
tallized, consisting of protoxide of man-
ganese 87 per cent. ; oxygen 10 per
cent. ; baryta 2'26 per cent ; and water
nearly 1. It has been thus named after
Mr. Braun of Gotha.

BRE'CCIA. (Ital.) Any rock composed of
angular fragments cemented together.

BRE'CCIATED. Composed of angular frag-
ments united into a mass by cement.

BREI'SLAKITE. A Vesuvian mineral, thus
named after Breislak.

BRILLIANT, (brillant, Fr. brillante, It.)
A diamond cut into angles, by which the
rays of light are refracted, and a greater
brilliancy is obtained.

BRI'MSTONE. A name for sulphur, which
see.

BRI'NDED. In conchology, streaked.

BRI'NDLED. Spotted ; variegated ; streaked.

BRI'STOL-STONE. ) Rock-crystal, or crys-

BRI'STOL-DIAMOND. 5 tallized quartz. Very
fine specimens are found in the rocks
near Bristol, and these have thence ob-
tained the name of Bristol diamonds.
They are pure silica, crystallized in six-
sided prisms, terminated by six-sided
pyramids.

BRO'ME. \ (from /3poytoc., Gr.) A simple,

BRO'MINE. \ or elementary substance, being
non-metallic. Bromine has obtained its
name from its powerful and unpleasant
smell.

BRO'NTIA. (from flpovTi), Gr. thunder ;
from its being supposed that these fossils

B R O

[35 ]

B Y S

were thrown to the earth by thun-
der.) A fossil echinite of the family
Cidaris.

BRO'NZITE. A mineral called by Werner
Bliittriger anthophyllite, and by Haiiy
Diallage metalloide. It has a yellowish
brown colour, with a semi-metallic lustre.
It is found in serpentine in Shetland and
in Upper Stiria, and in greenstone in
many other places. According to Klap-
roth, it consists of, silica 60 ; mag-
nesia 27-5 ; oxide of iron 10'5 ; wa-
ter 0-5.

BROWN-COAL. A fresh-water formation of
the tertiary series, but to which sub-
division of the tertiary period it may
belong is considered uncertain by Mr.
Lyell, from the extreme rarity of shells
found in it. Professor Buckland states,
" In some parts of Germany this brown -
coal occurs in strata of more than thirty
feet in thickness, chiefly composed of
trees which have been drifted, apparently
by fresh water, from their place of
growth, and spread forth in beds, usually
alternating with sand and clay, at the
bottom of then existing lakes or es-
tuaries."

BRU'CITE. Called also Chondrodite and
Hemiprismatic Chrysolite. This mineral
was named Brucite, after Bruce, an
American mineralogist ; it occurs massive
and in small grains ; colours from a pale
yellow to a brownish red ; it possesses a
vitreous lustre, is translucent, with a
fracture imperfectly conchoidal. It con-
tains a small portion of fluoric acid, and
scratches glass. It is found in America,
Scotland, and Finland. It consists of
magnesia, silica, fluoric acid, about four
per cent, oxide of iron, potash, and
water.

BUCA'RDIUM. An acephalous bivalve, hav-
ing powers of locomotion.

BU'CCINUM. (buccinum, Lat.) The whelk.
An ovate elongated univalve ; opening
oblong, notched in the lower part, and
with no canal ; columella convex, full
and naked. — Parkinson.

Linnaeus places this genus, the Bucci-
num, or Whelk, in the order Gastero-
poda, class Mollusca : it comprises all the
shells furnished with an emargination
inflected to the left, and in which the
columella is destitute of plicae. Many
fossil species have been discovered, the
greater number in the crag ; some in the
London-clay ; six species have been

found in the environs of Paris. De
Blainville places the buccinum in the
family Entomostomata.

BU'CCINITE. The fossil remains of the
buccinum. The greater part of the
genus buccinum is littoral.

BUCCINOI'DA. The third family in the
order Pectinibranchiata, division Mol-
lusca.

BU'FONITE. (from bufo, Lat.) Fossil
teeth of fishes belonging to the family of
Pycnodonts ; they occur in great abun-
dance throughout the oolite formation.
These bufonites have been also called
Serpent's-eyes, Batrachites, and Crapau-
dines, from the notion of their having
been formed in the heads of serpents,
toads, and frogs ; and, from presumed
virtues which it was thought they pos-
sessed, they were worn in rings and as
amulets.

BU'LLA. An ovate, gibbous, and cylindri-
cal univalve : the fossil occurring in ter-
tiary formations : the spire not standing
out, but concealed : the opening the
length of the shell : the lip acute. The
recent bulla is marine, and found in sands
and sandy mud, at depths varying to
twelve fathoms. — Parkinson. De la
Beche.

BU'LLITE. The fossil remains of the
bulla.

BU'LLATE. Of a blistered appearance.

BU'LIMUS. A fossil ovate or oblong sub-
turreted shell : the opening entire, ob-
long, and longitudinal, and this is the
chief characteristic of this genus. The
bulimus is a land shell. — Parkinson.

BUNT. In conchology, an increasing
cavity ; a tunnel.

BURRH-STONE. This word is sometimes
written buhr-stone. Mill-stone. The
substance of burrh-stone, or mill-stone,
when unmixed is pure silex ; it has gene-
rally a reddish or yellowish colour, but
that of the best quality is nearly white ;
it is full of pores and cavities, which
give it a corroded and cellular appear-
ance.

BY'SSUS. (from fivaffbs, Gr.) A beard,
as in the mytilus and pinna. The byssus
is peculiar to bivalves.

BY'SSOLITE. (from (Swabs, flax, and
\i0of, a stone.) A rare mineral, occur-
ring massive, in short, delicate, and sJtif-
fish filaments, of an olive-green, pr
brownish colour, with a silky lustre.

C A C

[ 36 ]

C A L

C

CACHO'LONG. A milk-white variety of
quartz, having a pearly, or glistening
lustre, a flat conchoidal fracture, and per-
fect opacity. It is found on the river
Cach, in Bucharia, and obtains its name
from that river and choloug, the Calmuc
word for stone. It is said by Brougniart
that the cacholong has been found in
calcareous breccia in France.
CA'DMIUM. A metal of a bluish-white
colour, with a specific gravity of 86. It
is the least malleable and ductile of all
metals which possess those properties. It
was discovered by Professor Stromeyer,
of Gottingen, in 1817, in some oxide, or
carbonate, of zinc ; it has subsequently
been found in the silicates of zinc of Der-
byshire, and in ores of that metal found
in other situations. The equivalent num-
ber of cadmium is 52-5. Cadmium has not
as yet been usefully employed in the arts.
CADU'COUS. (caducus, Lat.) In botany,
applied to leaves falling before the end of
summer ; to corollas falling off before the
dropping of the stamens ; to perianths
falling before the corolla is well un-
folded.
CAIRN. (Gael.) A name given to a heap

of stones covering a dead body.
CA'LAITE. Mineral turquois.
CA'LAMAR. A name given to the cuttle-fish.
CA'LAMINE. (calamine, Fr. giallamina,
It.) Carbonate of zinc. Calamine is
found either loose, or in masses, or crys-
tallized ; colour white, grey, or yellow.
Before the blow-pipe it decrepitates, but
does not melt. It is used in the manu
facture of brass. It consists of oxide of
zinc 65, and carbonic acid 34. It con-
tains also some sesquioxide of iron.
CA'LAMITB. (from calamus, Lat.
Gr.)

1. A genus of fossil equisetacese. Cala-
mites abound universally in the most
ancient coal formations, occur but spar-
ingly in the lower strata of the secondary
series, and are entirely wanting in the
tertiary formations, and also on the actua
surface of the earth. Brongniart enume-
rates twelve species of calamites. Cala-
mites are characterized by large and sim-
ple cylindrical stems, articulated at in
tervals, but either without sheaths, or
presenting them under forms unknown
among existing equiseta; they however
most differ from equiseta in their heigh
and bulk, sometimes exceeding seven
inches in diameter, whilst that of a living
equiseta rarely exceeds half an inch. A
calamite fourteen inches in diameter has
lately been placed in the museum at Leeds

2. A mineral variety of hornblende, called
also Actynolite, or Actinolite. See Acti-
nolite.

}ALC-SINTER. Stalactitical or stalagmiti-
cal carbonate of lime. This is so called
from the German kalk, lime, and sintern,
to drop. It is deposited from thermal
springs holding carbonate of lime in so-
lution.

CALCAI'RE GRO'SSIER. (Fr.) A coarse
limestone, often passing into sand, and
abounding in marine shells. According
to Lyell, it belongs to the eocene tertiary
period, and is found in the Paris basin.
ALCAI'RE SILI'CIEUX. (Fr.) A compact
silicious limestone, occupying, according
to the early opinion of Brongniart, the
place of the calcaire grossier where that
is wanting, who discovered in it the sili-
cate of magnesia. Like the calcaire gros-
sier, the calcaire silicieux belongs to the
eocene tertiary period ; it has been found
in the Paris basin, in the Isle of Wight,
and in several parts of France.
CALCA'REOUS. ) (calcarms, Lat. calcaire,
CALCA'RIOUS. $ Fr. I do not remember
to have met with this word as here given,
spelt with an i, except in Webster, and I
believe, in this instance, his orthography
to be incorrect.) Partaking of the pro-
perties of lime ; containing lime in com-
position ; of a limy nature.
CALCA'REOUS ROCK. Limestone.
CALCA'REOUS SPAR. Crystallized carbon-
ate of lime. Calcareous spar occurs
crystallized in a vast variety of forms, but
its primitive form is invariably a rhom-
boid with obtuse angles of 105° 5', and
74° 55', the crystals break easily with the
stroke of a hammer. It consists of nearly
57 parts of lime and 43 parts and a frac-
tion of carbonic acid. The finest speci-
mens are brought from Derbyshire, but
it is found almost in all parts of the
globe. Calcareous spar is often as trans-
parent as rock-crystal, but it is usually
coloured of various tints by the presence
of oxide of iron. All its forms, which
amount to nearly 500, are derived from
the rhomb. When in irregular forms, it
may always be distinguished from quartz
by its admitting of being scratched with a
knife, and by its effervescing when weak
nitrous acid is applied to it. Iceland
spar is this mineral in its purest form,
and affords the readiest means of obser-
ving the optical phenomenon of double
refraction. Its almost universal diffusion
is probably owing to its partial solubility
in water; in this condition it filters
through the crevices abounding in all

e A L

[37 ]

C A L

strata, and recrystallizes as the water eva-
porates. When this nitration continues
so uninterruptedly as to prevent by its
mechanical action crystallization from
taking place, and yet so gradually as to
admit of the solid mineral being deposited
from the water, those curious and beau-
tiful concretions called stalactites are pro-
duced, which ornament, in so singular a
manner, most caverns in rocks or moun-
tains formed principally of limestone.
CALCA'REOUS TUFA. Beds of calcareous
tufa are sometimes formed in valleys, and
at the bottom of lakes, by a process which
bears some resemblance to chemical for-
mations. Springs containing carbonic
acid, that issue from limestone strata,
contain particles of carbonate of lime che-
mically dissolved in water ; but on ex-
posure to air and light, the carbonic acid,
which had but a slight affinity for the
particles of limestone, separates, and the
particles of lime are precipitated, and
form calcareous incrustations: these, in
the course of time, form beds, and occa-
sionally are of sufficient hardness to be
used for architectural purposes. Ther-
mal springs holding in solution calcareous
earth, rapidly deposit beds of calcare-
ous tufa.

CALCEDO'NIC. Containing calcedony ; re-
sembling calcedony.

CALCE'DONY. (calcedonius, Lat. calce-
doine, Fr. calcedonia, It. Sometimes
spelt chalcedony.) A semi-transparent
and translucent variety of quartz, to which
this name has been applied, from its hav-
ing been formerly found at Calcedon. It
is a simple, siliceous, uncrystallized mine-
ral. Flint nodules are frequently calce-
donic. When flints contain calcedony,
there may generally be perceived some
small bubbles, or a mammillated appear-
ance, in some part of the exterior of the
flint ; between calcedony and flint there
is a near resemblance, being only differ-
ent modes of the same substance. Spe-
cific gravity 2*56. There are several sub-
species ; the beautiful apple-green is
called chrysoprase ; the grass-green va
rieties, plasma ; those with red, brown
yellow, and green tints, carnelian ; others
are known as heliotrope, jasper, &c. these
will all be described under their severa
names, and in their proper order.
CALCI'FEROUS. (from calx and fero, Lat.
Producing lime ; containing lime ; yield
ing lime.
CA'LCINABLE. That is capable of behij

calcined.

CA'LCINATE. (calciner, Fr. calcinare, It.
To calcine ; to burn by fire to a calx, o
friable substance.

CALCINA'TION. (calcination, Fr. calc
nazione, It.) The reduction by th

action of fire of any substance to a con-
dition that it may be converted into a
state of powder.

A'LCINE. (calciner, Fr. calcinare, It.)
To burn by fire to a calx, or friable sub-
stance.

A'LCIUM. The metallic base of lime ; this
metal was obtained by Sir H. Davy from
lime by means of galvanic agency. Being
received during the process into a vessel
filled with naphtha, it was excluded from
oxygen, and consequently retained its
metallic appearance, which resembles that
of silver. But no further investigations
can be made in the present state of sci-
ence, regarding its properties as a metal,
for the instant atmospheric air is ad-
mitted to it, it absorbs oxygen rapidly,
burns with an intense white light, and re-
produces lime, which is an oxide of cal-
cium.

^ALC-TUFF. A deposit of carbonate of
lime from calcareous springs. See Cal-
careous Tufa.

}A'LIX. ) (/cvXt?, Gr. calix, Lat. ca/ice,
HA'LYX. \ Fr. calice, It. ) The calyx, or
flower-cup, is the outer expanded part,
or external covering of a flower, generally
resembling the leaves in colour and tex-
ture ; there are seven kinds of calyxes,
or calyces, namely, periantheum, amen-
tum, spatha, gluma, involucrum, volva,
pericha5tium.

The calyx is the outer set of the floral
envelopes, when there are more than one
verticil of these. It is composed of two
at least, but generally more leaves, called
sepals. When the sepals are distinct, or
separate from each other, the calyx is
said to be polysepalous. In many plants
the sepals are joined together, more or
less, by their edges, so as to form one
piece in appearance ; in this case the
calyx is said to be monosepalous. When
all the sepals are alike in size and form,
the calyx is said to be regular. When
the sepals vary in size or form, the calyx
is said to be irregular. When the calyx
has one of its sepals hollowed out into a
long thin tube, as in the larkspur, gera-
nium, &c. it is said to be spurred. When
the calyx dies off soon after or immedi-
ately on its expanding, it is termed de-
ciduous ; this is commonly the case with
polysepalous calyces. When the calyx
survives the rest of the flower, either en-
closing or forming part of the fruit, it is
said to be persistent : most monosepalous
calyces are persistent.
CALP. A subspecies of carbonate of lime ;

an argillo-ferruginous limestone.
CALY'MENE. (from KeKa\vmj.tvn, Gr. con-
cealed.) A genus of trilobites, which
appears to have been annihilated at the
termination of the carboniferous strata.

C A L

[381

CAR

Fossils of this family were long con-
founded with insects under the name of
Entomolithus paradoxus.

CALY'PTRA. (icaXv-Tpa, Gr. calyptra,
Lat.) The calyx of mosses, according
to some writers. In the mosses, the
organs of reproduction consist of sporules,
contained vrithin an urn, or theca, placed
at the top of a thin stalk : this is closed
with a lid, called an operculum, and that
again is covered with a hood, termed a
calyptra.

CALYPTRE'A. A fossil conoidal univalve,
with the apex entire, erect, and some-
what pointed, the cavity furnished with a
spirally convoluted lip. — Parkinson.

CA'MBIUM. (cambium, Lat.) In botany,
a juice exuded between the bark and the
alburnum, supposed to serve the purpose
of nourishing the fibres of the leaf-
buds.

CA'MBRIAN. (from Cambria, a name for
the principality of Wales.) A name
given by Professor Sedgwick to a group
of rocks, placed below the Silurian, from
their being largely developed in North
Wales ; they principally consist of slaty
sandstone and conglomerate.

CAMPA'NULATE. (from campanula, Lat.)
Bell- shaped ; in the form of a bell. A
term applied to the calyx or corolla.

CAMPA'NIFORM. The same as campanu-
late.

CAMPANULA'RIA. A zoophyte, found abun-
dantly on our shores, and thus named
from its bell-shaped cells placed on foot-
stalks.

CANALI'CULATED. (from canaliculatus,
Lat.) Channelled ; furrowed ; made like
a pipe or gutter. Applied to any distinct
groove or furrow in shells.

CANCELLA'RIA. A genus of shell com-
prising many species. It is an ovate, or
subturrated univalve, with the lip inter-
nally sulcated ; the base of the opening
slightly channelled. The columella hav-
ing sharp, but compressed, plicae. Fos-
sils of this genus have been found in the
Londay clay and calc-grossier of Paris.
The recent cancellaria is found in sandy
mud at depths varying from 5 to 15 fa-
thoms.

CANCELLATED, (from cancelli, lattice-
work, Lat.) Cross-barred ; marked with
lines crossing each other. In concho-
logy, surrounded with arched longitudinal
ribs.

CA'NCER.

1. One of the twelve signs of the zodiac,
being the sign of the summer solstice,
and represented by the figure of a
crab.

2. The crab-fish.

CA'NDENT. (candens, Lat.) Hot in the
highest degree, to a white heat.

CA'NDLE-COAL. ) (This substance has pro-
CA'NNEL-COAL. $ bably obtained its name
from the bright flame, unmixed with
smoke, which it yields during combus-
tion, lighting a room as with candles,
candle being provincially pronounced
cannel.) Candle, or cannel, coal is a
bituminous substance next in purity to
jet. It is black, opaque, compact, and
brittle ; breaking with a conchoidal frac-
ture. Cannel-coal does not soil the
fingers when handled, is susceptible of
polish, and is capable, like jet, of being
worked into trinkets and ornaments. The
difference between jet and cannel-coal
appears to consist entirely in the presence
or absence of foreign earthy matters.
When these are absent, or exist in minute
proportion only, the bituminous mass is
so light as to float on water, and then
the term jet is properly applicable ; but
when the presence of foreign earthy mat-
ters is considerable, and the mass is
specifically heavier than water, and does
not readily manifest electric properties, it
is with more propriety termed cannel-coal.
— Parkinson.

CA'PSTONE. The name for a fossil echi-
nite, or that genus of echinite known as
conulus.

The capstone, thus called from its sup-
posed resemblance to a cap, rises from a
circular base into a cone, with an acute or
obtuse vertex, from which five pairs of
punctuated or crenulated lines pass, divid-
ing the shell into five large and five small
areae, that in which the anal aperture is
placed being rather the largest. — Par-

CA'PSULE. (capsula, Lat. capsule, Fr.)

1. In botany, a membranous or woody
seed vessel, internally consisting of one
or more cells, splitting into several valves,
and sometimes discharging its contents
through pores or orifices, or falling off
entire with the seed.

2. A membranous or ligamentous bag.
CAOU'TCHOUC.

1. Vegetable caoutchouc, called also
elastic-gum, and India-rubber, is the
milky exudation from certain trees, more
especially the Haevea caoutchouc and the
latropha elastica, but it is obtained from
several others.

2. Mineral caoutchouc. A bituminous
fossil, elastic when soft, but brittle when
hard. It was discovered in 1786 near
Castletown in Derbyshire. In its appear-
ance it much resembles India-rubber,
whence it has obtained its name.

CA'RAPACE. The upper shell of reptiles.

CA'RBON. (car bo, Lat. carbon, Sp. car-
bone, It. charbon, Fr.) The pure in-
flammable principle of charcoal. If a
piece of wood, or any vegetable matter,

CAR

[39 ]

C A II

be placed in a closed vessel, and kept red-
hot for some time, it is converted into a
shining black brittle substance, possessing
neither smell nor taste, commonly known
as charcoal. Charcoal is infusible, insol-
uble in water, is capable of combining
both with hydrogen and sulphur, is a
conductor of electricity, and has a power-
ful affinity for oxygen. Carbon is ob-
tained nearly pure in charcoal ; but, what
is astonishing, the diamond appears to
be this elementary substance in its purest
known form. Why it is, or how it is,
that the same elementary substance can,
with little or no addition, form two
bodies so dissimilar in every respect as
charcoal and diamond, the one a soft,
black, brittle mass, the other the clearest
and hardest body we know of, is a mys-
tery beyond our weak comprehensions to
understand. Carbon enters as a con-
stituent part into many of the slate rocks,
to which it generally communicates a dark
colour : it forms also regular beds of con-
siderable thickness, being the principal
constituent part of coal. Combined with
oxygen, carbon forms carbonic acid or
fixed air.

CARBONA'CEOUS. (from carbon.) Con-
taining carbon ; pertaining to carbon.

CA'RBONATE. A combination of carbonic
acid with a base. Carbonic acid is capable
of combining with earths, oxides, and al-
kalies, and to these combinations the term
carbonate has been applied ; thus we
have the carbonate of lime, carbonate of
magnesia, carbonate of lead, carbonate
of iron, carbonate of ammonia, &c. &c.&c.

CA'RBONATED. Combined with carbon.

CA'RBONATE OF LIME. A union of car-
bonic acid and lime, consisting of 57
parts of lime and 43 of carbonic acid.
Carbonate of lime, under the several
names of chalk, lime-stone, marble, &c.
is found most abundantly throughout na-
ture. All limestones effervesce when a
drop of strong acid is thrown on them,
and they entirely dissolve in nitric or
muriatic acid.

CARBO'NIC ACID. A compound of carbon
and oxygen ; it has been called aerial
acid, fixed air, cretaceous acid, and me-
phitic gas. Carbonic acid is very plenti-
fully disengaged from springs in almost
all countries, but especially near active
or extinct volcanoes. This elastic fluid
has the property of decomposing many of
the hardest rocks with which it comes in
contact, particularly that numerous class
in whose composition felspar is an in-
gredient. In volcanic countries these
gaseous emanations are not confined to
springs, but rise up in the state of pure
gas from the soil in various places. The
Grotto del Cane, near Naples, affords an

excellent example. The acid is invisible,
is specifically heavier than atmospheric
air, and on this account it accumulates
in any cavities on the surface of the
ground. It may be dipped out of any
excavations in which it has accumulated,
poured into a bottle, like water, corked,
and carried to any distance. It is fatal
to human life when breathed undiluted,
and by the miners it is called choke-
damp.

CARBONIFEROUS, (from carlo and fero,
Lat.) Containing carbon ; yielding car-
bon.

CA'RBONISED. Converted into charcoal, or
carbon.

CARBONIZA'TION. The converting into
carbon.

CA'RBURET. A compound formed by the
combination of carbon with any metal,
alkali, or earth.

CA'RBURETTED HYDROGEN GAS. The fire-
damp of miners.

CA'RBUNCLE. (carbuncuhis, Lat.) A
precious stone, supposed by some authors
to be the ruby, by others the garnet ;
called by the Greeks anthrax.

CA'RDIAC. } (from icap£ia,the heart, Gr.

CARDI'ACAL. \ cardiaque, Fr.) Relating
to the heart, as the cardiac nerves, &c.

CARDIA'CEA. In Cuvier's arrangement a
family of bivalves of the class Testacea,
comprising Cardium, Donax, Cyclades,
Corbis, Tellina, Lucina, and Venus.

CA'RDITA. An inequilateral bivalve, found
at various depths to thirteen fathoms, in
mud and sands ; sometimes attached to
stones. The hinge with two unequal
teeth ; the hinge tooth the shortest, be-
neath the beak ; the other longitudinal,
beneath the insertion of the cartilage.
Lamarck places Cardium in the family
Cardiacea.

CA'RDIUM. The cockle ; animal a tethys.
A genus of bivalves, the shells of which
are characterized by the teeth of their
hinge, and by the projection of their
beaks ; the latter giving them a cordiform
appearance. They are generally orna-
mented with longitudinal ridges, and
frequently with strise, scales or spines.
The different species are found at depths
varying to thirteen fathoms, in mud,
sands, and gravel. This genus belongs
to the class Vermes, order Testacea.
Many of the species, as the C. aculea-
tum, arcuatum, ciliare, discors, edule,
elongatum, Isevigatum, nodosum, spi-
nosum, &c. &c. are found on our coasts.
The cardium, with the exception of one
species, cardium fiuviatile, has only
been found to inhabit the ocean ; gene-
rally they live just under the surface of
the sand. Fifty-two species have been
described.

CAR

[40 ]

CAT

CARI'NA. (Lat.) The keel ; a term ap-
plied to two of the petals in papiliona-
ceous flowers. The carina is composed
of two petals, separate or united, and
encloses the internal organs of fructifica-
tion.

CARINA'RIA. A very thin univalve, in
the form of a cone flattened on its sides,
the apex terminating in a very small con-
voluted spire, and the back having a
dentated keel. De Blaiuville places Ca-
rinaria in the family Nectopoda. It de-
rives its name from its dorsal keel.
Parkinson states that it has not been
found fossil, nor is its inhabitant known.
Sowerby mentions that this beautiful
shell was once so rare, that a specimen
would fetch one hundred guineas.

CA'RINATED. (carinatus, Lat.) Keel-
shaped; in conchology, having a longi-
tudinal prominence like the keel of a
vessel.

CARI'NTHINE. A variety of augite, of a
dark green or black colour. It obtains
its name from being found in Carinthia.

CARNA'RIA. (carnarius, Lat.) Flesh-
eating animals. In Cuvier's arrange-
ment, the third order of Mammalia.

CARNE'LIAN. > (cornaline, FT. comalina,

CARNE'LION. $ It.) A precious stone of
various colours, as red, brown, yellow,
and white. It is a variety of rhombohe-
dral quartz. The finest specimens are
brought from India. Carnelian is com-
posed of 94 parts silica, 3'50 alumina,
and a trace of oxide of iron. Carnelian
differs from calcedony only in being more
or less transparent. It varies in its con-
stituents from being nearly pure silex, to a
mixture of this earth with alumine and
iron, in small quantities.

CA'RNEOUS. See Carnous.

CARNI'VORA. (from camis, and voro, Lat.)

1. Animals which subsist solely on flesh.
They belong to the order Mammalia.
Fossil remains of carnivora are abundant
in the pliocene strata. Cuvier placed the
carnivora as a family in the order Carna-
ria, class Mammalia.

2. In entomology, a family of coleopterous
insects. These insects pursue and devour
others.

CARNI'VOROUS. (carnivorus, Lat. carni-
vore, Fr.) Living on flesh ; devouring
flesh.

CA'ROTID. (from icapwri&c, Gr. carotides,
Lat. carotides, Fr.) The name given to
certain arteries of the neck.

CA'RPAL. (from carpus. Lat. Kapirbg, Gr.)
Relating to the wrist.

CARPE'LLUM. (from Kapirb£, Gr.) In
botany, a leaf in a particular state of mo-
dification. Each modified leaf which

forms the pistil, is called a carpellum, and
has its under side turned outwards, and
its upper inwards, or towards the centre
of the flower. The carpella are folded so
that the margins of the leaf are next to
the axis, or centre : from these a kind of
bud is produced, which is the seed. On
the form of the carpella, on their number,
and on their arrangement around the
centre, depends, necessarily, the form of
the pistil.

CA'RPOLITE. ^(from Kapirbg, fructus,

CA'RPOLITH. > and XiOog, lapis.) Any

CARPOLI'THUS. 3 fruit which by silifica-
tion has been converted into stone.

CARPO'LOGY. (from KapTrb^ and Xoyoe, Gr.)
That branch of the science of botany
which treats of fruits.

CA'RTILAGE. (cartilago, Lat. cartilage, Fr.
cartilagine, It.) Smooth, solid, animal
matter, softer than bone, and harder than
ligament ; gristle.

CARTILA'GINOUS. (cartilagineux, Fr. car-
tilayinoso, It.) Consisting of cartilage ;
resembling cartilage ; gristly.

CARTILA'GINOUS.

1. A name given to all fish whose mus-
cles are supported by cartilages instead of
bones.

2. A term applied to leaves, the borders
of which are hard and horny.

CARYOPHI'LLIA. A coral zoophyte. In
the caryophillise possessing more than one
cell, each receptacle contains a polypus.
A branched madrepore with a star at the
end of each branch ; each star having a
mouth and tentacula. — Bake well.

CASSIDA'RIA. A genus of univalve molluscs
found both recent and fossil. The recent
species are found near the shore, and at
small depths from the surface. The fossil
specimens occur in the tertiary strata.

CA'SSIS.

1. The helmet-stone. An echinite, a sec-
tion of the class of Catocysti.

2. A. gibbose ventricose univalve ; the
aperture longitudinal and sub-dentated,
and terminating in a short reflected canal.
The columella plicated in its lower part ;
the left lip flattened, and forming a ridge
on the body of the shell. — Parkinson.

This genus of shells is found both recent
and fossil : the recent is an inhabitant of
tropical seas ; the fossil occurs in the ter-
tiary deposits. Some species are figured
in Parkinson's Organic Remains.

CA'SSIDITE. A fossil shell of the genus
cassidaria. The hills of Tuscany yield
these fossils.

CA'TACLYSM. (from KaraK\v<r/t6c, Gr.
cataclysme, Fr.) A great inundation or
deluge : used generally to describe the
Noachian deluge.

CAT'S-EYE. A beautiful mineral, a variety
of rhombohedral quartz, having an opal-

CAT

C E N

escence resembling the light from the eye
of the cat ; whence its name. The pecu-
liar play of light arising from the struc-
ture of this stone, is better known than
susceptible of description. The finest
specimens are brought from Ceylon.
Cat's-eye is harder than quartz, and con-
sists of silex 95, alumine 1*75, lime 1'25,
oxide of iron 0'25.

CATO'DON. A name given to the sperma-
ceti whale. Of the genus Catodon, Ray
mentions a large one stranded on the
coast of Holland.

CATOCY'STI. The second great division, or
family, of Echini. The catocysti have
the opening for the vent in some part of
the base of the shell ; they are divided
into fibulse, cassides, scuta, and placenta?.

CAU'DA. (Lat.) In conchology, the elon-
gated base of the ventre, lip, and colu-
mella.

CAI/DAL. (from cauda, Lat.) Relating
'to the tail ; as the caudal fin of a fish.

CAU'DATE. } (caudatus, Lat.) That hath

CAU'DATED. $ a tail; tailed; having a
long termination like a tail.

CAU'DEX. (Lat.) The stock or trunk, the
stem or body of a tree.

CA'VERNOUS. (cavernosus, Lat. caverneux,
Fr. cavernoso, It.) Full of caverns or
hollows.

CAWK. A name for sulphate of barytes.

CELE'STINE. Sulphate of strontia, or sul-
phate of strontites. It has obtained the
name of celestine from being frequently
found possessing a blue colour, but as it
does not invariably possess that colour,
and is often found either colourless or
red, the name appears to be inappropriate.
It occurs both massive and crystallized.
It is composed of 58 parts of strontia, and
42 of sulphuric acid. It is found in Scot-
land, in Yorkshire, and in Somersetshire,
near Bristol ; also in the neighbourhood of
Paris, and in Sicily, from which last place
we obtain the finest specimens.

CELLEPO'RA. Animals belonging to the
class Vermes, order Zoophytes. Generic
characters : — Animal an hydra or polype ;
coral somewhat membranaceous, com-
posed of cells. Species : — The principal
species are the Cellepora pumicosa, an-
nulata, spongites, &c. — Crabb.

CELL, (cella, Lat. cellule, Fr. cella, It.)
A cavity or hollow.

CELLI'FEROUS. (from cella and/ero, Lat.)
Producing cells ; containing cells.

CE'LLULAR. Having small cavities, hol-
lows, or cells. In botany, containing cells,
opposed to vascular.

CE'LLULAR MEMBRANE. In anatomy, that
tissue of filmy meshes which connects the
minute component parts of most of the
structures of the body.

CE'LLULAR INTEGUMENT. In botany, the

succulent pulpy substance, situated im-
mediately under the cuticle ; the seat of
colour, mostly green, particularly in the
leaves or branches. Leaves consist al-
most entirely of this substance, covered
on each side by the cuticle ; the stems
and branches of both annual and peren-
nial plants are invested with it. This
tissue is membranous and transparent: in
its simplest state, it appears like a mass
of globules or vesicles, crowded together ;
these, by pressing against each other, as-
sume a six-sided, or hexagonal form. This
cellular tissue allows of the passage of
fluids, and is, consequently, porous, but
no pores or openings have been discovered
in it. Cellular integument is in itself
colourless, but its vesicles contain that
colouring matter which gives to the co-
rolla its brilliant colours, and to the her-
baceous parts of plants their green.

CE'LLULE. (from cellula, Lat.) This may
be considered as the diminutive of cell,
and though, probably, frequently used
synonymously with cell, yet is strictly not
so : a small cell or hollow.

CELLULI'FEROUS. Bearing, or producing,
cellules.

CEME'NT. (ciment, Fr. cimento, It.) The
matter with which any two, or more, bo-
dies are made to cohere.

CEMENTA'TION. (cementation, Fr.)

1. The act of uniting by means of cement.

2. A chemical process by which iron is
converted into steel ; glass into porcelain,
&c. This process is effected by sur-
rounding the body to be acted on with
some other substance, as iron with char-
coal, and subjecting it to the action of fire
in a closed vessel.

CEMENTI'TIOUS. Having the property or
quality of uniting.

CENTIFO'LIOUS. (from centum and fo-
lium, Lat.) Having a hundred leaves.

CENTRI'FUGAL. (centrifugo, It. centri-
fuge, Fr. Terme de Physique. Un
corps qui se meut en rond, a une force
centrifuge.) That power which bodies
in rapid rotatory motion acquire of flying
off from the centre. The force with which
a revolving body tends to fly from the
centre of motion : a sling tends to fly
from the hand in consequence of the cen-
trifugal force. The centrifugal force
arising from the velocity of the moon in
her orbit, balances the attraction of the
earth. The dimensions of the earth being
known, as well as the time of its rota-
tion, it is easy thence to calculate the
exact amount of the centrifugal force,
which, at the equator, appears to be 5|gth
part of the force or weight by which all
btrdies, whether solid or liquid, tend to -#-
fall towards the earth.

CENTRI'PETAL. (centripete, Fr. Qui tende

CEP

[42]

C E T

a approcher d'-un centre. Leu planetes
ont une force centripete vers le soleil.)
The contrary power to centrifugal, for
while the one drives, as it were, the sur-
rounding bodies from the centre, the
other, the centripetal, attracts and holds
them to it.

CEPHALA'SPIS. A fossil fish of the carbo-
niferous series. It has received its name
from its head being covered by a sort of
shield, having the bones united into one
osseous case. In form, this fish bears a
resemblance to the elongated trilobites of
the transition rocks. — Mantell.

CEPHA'LOPOD. ^ (from K£0aX?}, head,

CEPHALO'PODA. V and TTO^O, feet, Gr.)

CEPHALO'PODES. J A term applied by Cu-
vier to a large family of molluscous ani-
mals, from their having the feet placed
around their heads, and walking with
their heads downwards. The feet are
lined internally with ranges of horny
cups, or suckers, by which the animal
seizes on its prey, and adheres to extra-
neous bodies. The mouth, both in form
and substance, resembles a parrot's beak,
and is surrounded by the feet. It is now
well established that the living species of
cephalopods which possess no external
shell, are protected from their enemies by
a peculiar internal provision, consisting
of a bladder-shaped sac, containing a black
and viscid fluid, or ink, the ejection of
which, by rendering the surrounding water
opaque, conceals and defends them. The
sepia vulgaris and loligo afford us familiar
exam pies . — Buckland.

According to Prof. Phillips, the following
are the genera of Cephalopoda : Bellero-
phon, Orthoceras, Belemnite, Nautilus,
Ammonite, Hamite, Scaphite, Baculite,
Nummulite. The only living species
belong to the genus Nautilus, of which
there are two.

The Cephalopoda, in the arrangement
of Cuvier, form the first class of mollusca,
aad comprise the following genera, which
he divided according to the nature of the
shell, Sepia, Nautilus, Belemnites, Am-
monites, and Nummulites.

CERAU'NII LA'PIDES. (from Ktpawbc.,
Gr.) A name formerly given to fossil
echinites, from a supposition that they
were formed in the air.

CERATOPHY'TA. In Linnseusrs arrange-
ment, an order, the 6th, of the class Zoo-
phytes, or animal plants, comprising
Gorgonia, Corallium, Pennatula, &c.
They have a horny axis, covered with a
fleshy substance, from the cavities of
which polypi occasionally appear.

CEREBE'LLUM. (Lat.) Dim. of cerebrum ;
the little brain, situate behind the brain,
or cerebrum.

CF/REBRUM. (Lat.) The brain.

CE'REBRAL. } (cerebral, Fr. cerebrate, It.)

CE'REBRINE. S Belonging to the brain ;
relating to the brain.

CE'RITHIUM. A turreted or turriculated
univalve, with an oblique opening. La-
marck has discovered sixty fossil species
of the germs Cerithium in the neighbour-
hood of Paris. The recent cerithium i&
found at depths varying to seventeen
fathoms, and it is stated that so tena-
cious of life is at least one species, the
cerithium telescopium, that a specimen
sent from Calcutta in sea water, lived out
of water in a tin-box for more than a
week. The recent cerithium has a veil
on its head, with two separated tentacula.

CE'RITHITE. The fossil cerithium.

CE'RITE. The siliceous oxide of cerium.

CE'RIUM. A metallic substance discovered
by Berzelius and Kissinger in 1804. It
was obtained from a mineral called cerite,
which was formerly supposed to be an
ore of tungsten ; it is also found in allanite.

CERU'LEAN. ^(cceruleus, Lat.) Blue ;

CERU'LEOUS. $ sky-coloured.

CE'RVIX. (Lat.) The neck.

CERVI'CAL. (cervicalis, Lat. cervical, Fr.
cervicale, It.) Belonging to the neck,
as the cervical vertebrae, the cervical
muscles, the cervical arteries.

CERVI'COBRANCHIATA. In the concholo-
gical system of De Blainville, the name
given to an order of shells, comprising
the two families Retifera and Branchifera,
and the genera Patella, Fissurella, Emar-
ginula, and Parmophorus.

CESTRA'CIONTS. The first and oldest sub-
family of sharks. The cestracionts begin
with the transition strata, appear in every
subsequent formation, and have only one
living representative, the Cestracion Phi-
lippi, or Port Jackson Shark. The cha-
racter of this sub-family of sharks is
marked by the presence of large polygonal
obtuse enamelled teeth, covering the inte-
rior of the mouth with a kind of tesselated
pavement. In some species not fewer
than sixty of these teeth occupied each
jaw. They are rarely found connected
together in a fossil state, in consequence
of the perishable nature of the cartila-
ginous bones to which they are attached.
They are found abundantly dispersed
throughout all the strata, from the carbo-
niferous to the most recent chalk series. —
Buckland.

CETA'CEA. Vertebral, warm-blooded ani-
mals living in the sea ; they have no gills ;
there is an orifice on the top of the head
through which they breathe, and eject
water ; and they have a flat horizontal
tail. The cetacea breathe by means of
lungs, and this compels them to rise fre-
quently to the surface of the water for
the purpose of respiration ; they also

C E T

[43 ]

C H A

sleep on the surface. The cetacea both
bring forth their young alive, and suckle
them. In the order Cetacea are found
the narwal, or sea-unicorn, the proper
whale or balsena, the physeter or sperma-
ceti whale, the dolphin, porpoise, &c.

Cetaceous animals being incapable of
coming upon shore to rear their young,
we find the form and structure of their
arms remarkably approaching to those of
the extinct aquatic saurians, and to those
of fishes, and this resemblance is seen
also in the general form of the trunk, and
in the lengthened tapering form of the
muzzle, and of the whole head of these
animals. This lengthened, fish-like, taper-
ing form is especially marked in the hori-
zontal head of such cetaceous animals as
the dolphins and porpoises, the food of
which consists of living prey, which they
find swimming before them in the water.
But there are some cetaceous animals, as
the dugong and the lamantine, that are
not piscivorous, feeding only on marine
plants ; these have the face bent down-
wards, instead of projecting forwards.
That bent form, which is so remarkable
in the lamantine and the dugong, is the
best position for enabling them to take
the marine plants from the rocks below
them, and they have the neck long and
flexible, so that they can with facility
bend down the whole head. Breathing
atmospheric air, like other mammalia,
they require to have the nostrils elevated ;
the shortness of the neck, however, and
the magnitude of the head, render it
almost impossible for them every time
they wish to breathe to raise it to the
surface of the water, so that we find the
nostrils raised to the vertex of the head ;
these are the blowing-holes of the cetacea.
In consequence of the extension of the
intermaxillary bones, the exterior open-
ings of the nostrils are raised thus high
upon the head, and frequently also the
cartilages of the nose are directed up-
wards so as to reach above the level of
the highest part of the head, so that
gliding along the ocean, immediately be-
neath the surface of the water, they can
breathe, having only their lengthened and
elevated nostrils in contact with the
atmosphere. The tail of cetacea is their
organ of progressive motion ; it is sup-
ported by cylindrical vertebrae, almost
without processes, to admit of the freest
motion, and it is directed horizontally ;
that of a fish is directed perpendicularly.
This horizontal direction of the tail of
cetacea is necessary, in consequence of
their breathing atmospheric air, to arrive
at which they must ascend in the water,
and again descend when seeking their
food,— Prof, Grant.

In Cuvier's arrangement we find the
cetacea forming the ninth order of Mam-
malia, and comprising two families,
namely, Cetacea herbivora, which in-
cludes Manatus or Lamantin, Halicore
or Dugong, and Stellerus, and Cetacea
ordinaria, which includes Delphinus, or
Dolphin, Phocoena or Porpoise, Monodon
or Narwhal, Physeter or Cachalot, and
Baloena, or Whale. The seas of the
Miocene and Pliocene periods were
inhabited by marine mammalia, but no
traces of them have been discovered in
the secondary deposits.

CETA'CEOUS. (cetace, Fr. cetaceo, It.
cetaceous, Lat) Belonging to the order
Cetacea.

CE'YLANITE. A dark-green or black va-
riety of dodecahedral corundum. It oc-
curs in the sand of the rivers of Ceylon,
from which island it obtains its name.

CHA'BASITE. Rhombohedral zeolite. The
chabasie of Haiiy, and schabasit of Wer-
ner. A mineral of a white colour, with
sometimes a rosy tinge. It occurs crys-
tallized and massive. It is composed of
silica, alumina, lime, potass, soda, and
water, silica forming about fifty per cent,
of the whole.

CHALA'ZA. (xa\cr£a, Gr.) In botany, a
small swelling on the outside of the seeds
of some plants, it is sometimes coloured :
the lemon and orange afford examples of
the chalaza.

CHALCE'DONY. See Calcedony.

CHALK. (Jcalk, Germ.) A white earthy
limestone, composed of lime and car-
bonic acid ; a carbonate of lime. It has
an earthy fracture, is meagre to the touch,
and adheres to the tongue ; it is dull,
opaque, soft, and light ; its specific gra-
vity being 2'3. It contains an inconsi-
derable proportion of silex and iron. The
harder varieties of this substance were
formerly used for building, and, when
protected from the influence of the atmo-
sphere by a thin casing of limestone or
flint, proved very durable. The ruins of
the Priory of St. Pancras, near Lewes,
which have stood nearly 800 years, prove
this. — Dr. Mantell.

CHALK FORMATION. This term is applied
in the nomenclature of geology to a group
of deposites very dissimilar in their litho-
logical compositions, but agreeing in the
character of the organic remains which
they contain, and referrible to the same
epoch of formation. The chalk, with its
subjacent beds of green sand, comprises
a formation, or series of strata, of great
depth, which are spread over a large
portion of the eastern and south-eastern
counties of England. Scarcely a trace
of chalk can be found in Scotland or
Wales, but it occurs in Ireland on the

C H A

[44]

CHE

north coast. The chalk formation is
composed of six divisions, namely, 1. The
Maestricht beds ; 2. The upper chalk
with flints ; 3. The lower chalk without
flints ; 4. The Upper green sand ; 5. The
gault; 6. The lower green sand. The
whole of these are marine deposits. It
must however be kept in mind that this
order is far from constant. The mem-
bers of the cretaceous group are ranked
as the last of the secondary period ; and,
in the order of superposition, are placed
above the wealden, and below the earliest
of the tertiary period, or eocene. The
greatest thickness of the chalk strata in
England may be estimated at from 600
to 1000 feet. The organic remains in
the chalk formation are exclusively ma-
rine. The nodules and veins of flint
which occur in the chalk, show ,#rat
water holding silex in solution must have
been very abundant at the cretaceous
period, although we are ignorant by what
means silex may be dissolved in water.
Mammalia are not known in the creta-
ceous rocks.

The chalk hills of England are bounded
by a line which stretches from south-west
to north-east, and they form three prin-
cipal mountain ranges. The first, leaving
Berkshire, runs north through Bucks,
Bedfordshire, and Hertfordshire, to Gog-
magog hills, near Cambridge. The se-
cond, passing from Bei'kshire eastward,
stretches through Surrey, where it forms
the Hog's Back, a beautiful ridge extend-
ing from Farnham to Guildford, and
then appears at Boxhill. This branch
forms the hilly country and the Downs
north of Reigate, Bletchingly, and God-
stone. It enters Kent to the north of
Westerham, and extends to Folkstone
and Dover. One division of this ridge
is continued to the north coast of Kent,
and terminates at the North Foreland.
The third range, leaving Wilts and Berks,
enters Hants, and to the south passes
round Petersfield, then stretching to the
east, forms a barrier against the sea along
the coast from Chichester, constituting
the South Downs, ranging from Maple-
durham to Beach-head.
CHA'LICO-THERIUM. An extinct animal,
belonging to the order of Mammalia
allied to the tapir, and referrible to the
miocene period.
CHALY'BEATE. (from chalybeus, Lat. cha~
liMe, Fr.) Impregnated with iron or
steel ; holding iron in solution, as cha-
lybeate springs.

CHAM A. {animal a chiton.} A genus o
inequivalved adhering bivalves, with un-
equal incurvated beaks. It is placed both
by De Blainville and Lamarck in the fa-
mily Chamacea, together with Diceras

Etheria, &c. Bruguiere limits this genus
to those shells possessing a single hinge-
tooth only. Many species have been
found fossil, more particularly in the
neighbourhood of Paris. The shells of
this genus are inhabitants of the ocean,
and live in deep water. Twenty-five
species have been described ; one only
of these has been discovered in our seas,
namely, the Chama Cor.

HAMA'CEA. A family of bivalves, placed
by Lamarck in the order Dimyaria, and
by De Blainville in the order Lamelli-
branchiata. It comprises the genera
chama, diceras, etheria, isocardium, tri-
gonia, &c.

CHA'MA GIGAS. A species of chama in-
habiting the Indian ocean ; it is the
largest and heaviest shell yet discovered,
being sometimes of the enormous weight
of 530 pounds, and its occupant so large
as to furnish one hundred and twenty
men with a meal ; it is said to be very
palateable.

CHA'MBERED. (chambre, Fr.) Divided
into compartments by septa : The cham-
bered shells have also been called multi-
locular. The fossil chambered shells are
exceedingly numerous, and afford proofs
of not only having performed the office of
ordinary shells, as a defence for the body
of their inhabitants, but, also, of having
been hydraulic instruments of nice ope-
ration, and delicate adjustment, con-
structed to act in subordination to those
universal and unchanging laws, which
appear to have ever regulated the move-
ment of fluids. The history of chambered
shells illustrates also some of those phe-
nomena of fossil conchology, which re-
late to the limitation of species to parti-
cular geological formations ; and affords
striking proofs of the curious fact, that
many genera, and even whole families,
have been called into existence, and again
totally annihilated, at various and suc-
cessive periods, during the progress of the
construction of the crust of our globe. —
Prof. EucUand.

CHA'OS. (Lat. chaos, Fr.) A matter
without form ; the first matter of which
poets supposed all things to have been
made in the beginning.

CHA'OTIC. Confused ; thrown together in
one vast heap, without any order or re-
gularity.

CHEIRO'PTER. (from x£'i°» manus, and
Trrtpoi/, ala.) An animal having the fin-
gers elongated, for the expansion of
membranes which act as wings, as in the
Vespertib'o or bat. The Cheiroptera,
according to the arrangement of Cuvier,
form the first family of Carnaria.

CHEIRO'PTEROUS. Furnished with elon-
gated fingers, or toes, for the expansion

CHE

[45]

C H L

of membranes which serve as wings ; be-
longing to the family Chieroptera.
CHEI/IFEROUS. (from %>jX.^, Gr. a claw,
and fero, Lat.) Furnished with claws ;
armed with claws.

CHELO'NIA. (from xeXwi/j/, testudo.) The
tortoise tribe. In the arrangement of
Cuvier, chelonia forms the first order of
Reptilia. Linneeus includes chelonia in
the genus testudo, but the order has
been, by subsequent writers, divided into
five genera, namely, testudo, or land-
lortoise ; emys, or fresh-water tortoise ;
chelonia, or sea- tortoise ; chelys ; and
tryonyx, or soft- shelled tortoise.
CHELO'NIAN. Having the form or charac-
ters of the tortoise.

CHE'LONITE. A name given to some fossil
echinites, from their resemblance, in
their sutures, to the shells of the tor-
toise. The chelonite belongs to the
family Cidaris, class Anocysti.
CHEROPO'TAMUS. An extinct genus in
the order Pachydermata ; or animals
having thick skins. The cheropotamus
was an animal most nearly allied to the
hog; forming a link between the Ana-
plotherium and the Peccary. — Buckland.
CHERT. (Dr. Johnson deduces chert from
quartz.) A kind of flint. Chert is also,
by some, called horn-stone. A siliceous
stone, resembling flint, but less splintery
in the fracture, and fusible ; which latter
property is probably owing to some
admixture of calcareous matter. A gra-
dual passage from chert to limestone is
not uncommon.
CHE'RTY. Containing chert ; resembling

chert.

CHIA'STOLITE. (from ^la^rdc, decussa-
tionis formam habens, and Ai0of.) A
mineral whose crystals are arranged in
four-sided nearly rectangular prisms. Its
constituent parts are, silica 68'49, alu-
mina 30' 17, magnesia 4' 12, oxide of iron
2-7, water 0-27. It is the Holspath of
Werner, and the Made of Haiiy. It is
found in Cumberland and Argyleshire,
occurring in clay -slate.
CHIASTOLI'TIC. Composed of chiastolite
containing chiastolite. A mass of chias-
tolitic and hornblendic slates forms the
base of the clay- slate system of Cumber-
land,

CHIMJS'RA. (from %i^aipa,Gr.) A genus
of animals, placed in Cuvier 's arrange-
ment in the order Sturiones, or Chon-
dropterygii Branchiis Liberis, class Pisces
Professor Buckland observes, "The Chi-
msera is one of the most remarkabh
among living fishes, as a link in the
family of Choridropterygians ; and thi
discovery of a similar link, in the geolo
gical epochs of the oolitic and creta
ceous formations, shows that the dura

tion of this curious genus has extended
through a greater range of geological
epochs, than that of any other genus of
fishes yet ascertained by Professor Agas-
siz. The jaws of four extinct species
of fossil fishes of the genus Chimaera have
been discovered, and Dr. Mantell states
that the jaw, or mandible of a Chimsera,
has been found in the Kentish Rag. The
only known species is the Chimsera mon-
strosa, or Arctic chimsera, two or three feet
in length, of a silvery colour, and spotted
with brown. This species has the first
ray of the dorsal fin enlarged into a
strong bony spine, armed with sharp
hooks, and placed over the pectorals ; like
the Ichthyodorulite of the earliest fossil
sharks. It produces large coriaceous eggs
with flattened and hairy borders.

CHINE. A narrow ravine with vertical
sides. These are numerous in the Isle of
Wight, and are objects of curiosity and
admiration, being sometimes of great
depth.

CHIROTHE'RIUM. A name proposed to be
given by Professor Kaup to the great
unknown animal whose footsteps have
been discovered in beds of red sandstone.
These footsteps are beautifully figured
in Professor Buckland' s Bridgewater
Treatise. The name proposed by Kaup
is on account of a distant resemblance,
both of the fore and hind feet, to the im-
pression of a human hand.

These impressions of feet are partly
hollow, and partly in relief ; all the de-
pressions are upon the upper surfaces of
slabs or sandstone, while the reliefs are
only upon the lower surfaces, covering-
those which bear the depressions. These
footsteps follow one another in pairs, at
intervals of fourteen inches, from pair to
pair, each pair being in the same line.
Both large and small steps have the
great-toes alternately on the left and
right side ; each has the print of five
toes, and the first, or great-toe, is bent
inwards like a thumb. The fore and hind
foot resemble each other in form, though
they differ greatly in size.

CHI'TON. (from %<rwv, Gr.) An oval,
convex, multivalved shell, having eight
arcuated valves, partly lying over each
other, in a row across the back of the
animal. The chiton is found both fossil
and recent ; recent, attached to rocks in
the southern seas ; fossil, at Grignon.
The animal inhabiting the shell, a Doris.
In Turton's Linne, twenty-eight species
of chitons are described, seven of which
have been found in the seas of our
coasts.

CHLAMY'PHORUS. (from chlamys, Lat. %\a-
jwuc, Gr. andy<?ro.) The name it possesses
has been given to this animal from its

C H L

[46]

C H R

being cased in a coat of armour. The
chlamyphorus and armadillo are th
only known animals that have a compact
coat of plated armour. The chlamy-
phorus lives almost entirely in burrows
beneath the surface of sandy plains ; its
scales are of a dense substance, resem-
bling hard leather.

CHLO'RITE. (from Y,Xo>p6g, Gr.) A mi-
neral, consisting of silica 27-43, alumina
17'9, lime 0'50, oxide of iron 30'63,
magnesia 14'56, potash 1'56, water
6'92. It is a dark green variety of talc ;
has a glistening lustre ; minutely foliated
structure ; is soft and unctuous to the
feel ; and has obtained its name from its
colour. There are several varieties of
talc having a dark green colour, and
these are known as compact chlorite,
earthy chlorite, chlorite slate, foliated
chlorite, &c. Chlorite and talc pass by
insensible gradations into each other,
and in this state they supply the place of
mica, in most of the granitic rocks in the
vicinity of Mont Blanc.
CHLO'RITE-SCHIST. A metamorphic rock,
of a green slaty character, abounding with
chlorite.
CHLORI'TIC-SAND. Sand, coloured green

by an admixture of chlorite. — Lyell.
CHLORI'TIC. Resembling chlorite ; con-
taining chlorite.

CHLORI'TIC GRANITE. Granite contain-
ing particles of chlorite.
CHO'ANITE. A zoophyte of the chalk for-
mation, intermediate between Alcyonia
and Ventriculites. Dr. Mantell, in his
" Wonders of Geology," states, " the
choanite, called petrified sea-anemone
by lapidaries, bears a close resemblance
to the recent Alcyonia. In the choanite,
crucial spines, resembling those in the
recent Alcyonia, may be detected. The
choanite is of a sub-cylindrical form,
with root-like processes, and having a
cavity or sac, which is deep and small
in comparison to the bulk of the animal.
The inner surface is studded with pores,
which are the terminal openings of tubes,
disposed in a radiating manner, and
ramifying through the mass." The beau-
tiful pebbles found on the shores of Bog-
nor and Worthing owe their markings to
the internal structure of the choanite,
and these are worked into a variety of
ornaments, as brooches, buckles, ear-
rings, &c. &c. Some lately found at
Worthing have been sold, when cut and
polished, at high prices. One of the
finest collections has been made by
Captain Tompkins, of that town.
CHOAN'ITES KONIGI. A species of choa-
nite to which this name has been given,
by Dr. Mantell, " in honour to Charles
Konig of the British Museum." This

fossil is figured in Dr. Mantell's Geology
of the south-east of England, who therein
states that it is inversely conical ; exter-
nally marked with irregular fibres, some
of which penetrate the substance, and
terminate in openings on the inner sur-
face ; central cavity, cylindrical, deep,
narrow ; base fixed by radical processes.
This species is for the most part en-
veloped in large irregular flints, which
exhibit but slight traces externally of the
body they enclose.— Dr. Mantell.

CHOKE-DAMP. A name given by miners
to carbonic acid.

CHO'NDRODITE. Hemiprismatic chrysolite.
Another name for brucite ; a mineral
composed of magnesia 54, silica 32,
fluoric acid 4, oxide of iron 2, potass 1,
and water 1.

CHROME. > (from %pw^ta, colour, Gr.)

CHRO'MIUM. $ This mineral is said to
have obtained its name from the property
it possesses of imparting colour to other
bodies in a very remarkable degree.
Chromium was first discovered by Vau-
quelin in 1797, after a variety of discor-
dant analyses made by Macquart, Bind-
heim and others. Its principal ore is
found in Siberia, and is a salt of lead,
formed by an acid oxide of chromium.
To the presence of chrome the emerald
and the ruby owe their hues. It is used
in tinting glass of an emerald green.

CHRY'SALIS. (from xpvtroc, gold, because
of the golden colour in the nymphae of
some insects.) A state of rest and seem-
ing insensibility, which butterflies, moths,
and several other kinds of insects, pass
through before they arrive at their winged
or most perfect state. It is also called
aurelia. The figure of the aurelia or
chrysalis generally approaches to that of
a cone, and in this state it appears to
have neither legs nor wings, nor any

Swer of locomotion ; it seems indeed to
ve hardly so much as life. The time
the duration of the animal in its chry-
salis state is different in different species,
for while some remain a few days only,
others continue eight months.

CHRYSOBE'RYL. (from xpv^oc, gold, and
(3rjpv\\iov, gemma.) The cymophane
of Haiiy. Chrysopal of Delametherie.
Werner first made the chrysoberyl a dis-
tinct species, and gave it the name which
it now bears. Colour, a light yellowish
or asparagus green. This gem is found
in the Brazils, in Ceylon, in America, and
in Siberia. It consists of alumina 76'75,
glucina 17'79, and protoxide of iron 4-50.

CHRY'SOLITE. (from xpvtroc, gold, and
\i9oQ, a stone, chrysolite, Fr.) The
Peridot of Haiiy, and Krisolith and Olivin
of Werner. The term chrysolite was
applied, without any regard to distinction,

C II R

C I R

or any discrimination, to a great variety
of precious stones, till Werner defined it
accurately, and confined it to that stone
which the French mineralogists distin-
guish by the appellation of Peridot (sorte
de pierre precieuse, peu recherchee, qui
tire un peu sur le vert.) Chrysolite
contains a very large proportion of mag-
nesia, according to some authorities more
than half its weight, but agreeably to the
analysis of others from forty to fifty per
cent. Chrysolite is of a green colour,
inclining to yellow ; its texture is foli-
ated ; fracture conchoidal. It causes
double refraction. It is infusible at 150°,
but at that temperatue loses its transpa-
rency, and becomes of a dark grey. With
borax it melts, without effervescence, into
a transparent glass of a light green
colour. The chrysolites of commerce^
come from Upper Egypt and the Brazils ;
they are also found in Ceylon, in South
America, and in Bohemia. The variety
called Olivine is met with in Scotland ;
of this the colour is olive-green. Accord-
ing to the analysis of Klaproth, chrysolite
consists of magnesia 43.5, silica 38'5,
oxide of iron 19.

CHRY'SOPRASE. (from xpvaoQ, gold, and
prasinus, green ; ckrysoprase, Fr. Pierre
precieuse d'un vert clair mele d'ttne
nuance de jaune.} A precious stone of
an apple-green colour. It is a variety of
quartz, or of calcedony. It owes its
colour to the presence of the metals
nickel and iron, in small quantities. It
is found in different parts of Germany,
particularly in Silesia. It is always amor-
phous, and possesses but little lustre. It
consists of 96 per cent, silica, 1 per cent,
oxide of nickel, with a trace of iron,
alumina, and lime.

CI'CATRICE. i (cicatrix, Lat. cicatrix, Fr.

CICA'TRIX. ) cicatrice, It.)

1. The scar remaining after a wound.

2. In conchology, the glossy impression
in the inside of the valves, to which the
muscles of the animal have been affixed.

CI'DARIS. (cidaris, Lat.) A family of
echini tes, characterised by being hemi-
spherical, globular, or sub-oval ; with
porous ambulacra, diverging equally on
all sides, from the vent to the mouth ;
vent vertical ; mouth beneath, and central.
The name cidaris has been given to them
from their supposed resemblance to tur-
bans. From other characters, derived
from their spines, they have obtained the
names of sea-urchins, sea-hedgehogs, sea-
thistles, &c., and those in a petrified
state, have obtained various names, ac-
cording to the particular, fanciful, and
erroneous notions which have been enter-
tained respecting their origin. Thus,
they were called ombria, fromo/i/Spcc, Gr.

signifying the heavy rain, in which it was
supposed they fell ; brontia, from fipovrr),
from an idea that they were thrown to
the earth by thunder ; ceraunii lapides,
from KtpavvoQ, under an impression that
they were formed in the air and generated
by lightning ; chelonites, from their re-
semblance to the shells of the tortoise ;
and ova anguina, from their being sup-
posed to be the eggs of serpents.— Par-
kinson.

The species are numerous.
CI'LIA. (from cilium, Lat.)

1. The eye-lashes.

2. Hair-like vibratile organs. The organs
of motion in the radiated animals. The
cilia resemble very minute hairs, and are
only visible with the microscope. In the
simpler forms of animals, the cilia are
the organs for motion, respiration, and
the obtaining of food. Dr. Grant ha&
calculated four hundred millions of them
on a single flustra foliacea.

CI'LIATED. Fringed, or edged, with paral-
lel hair, bristles, or appendages ; occupied
with short stiff hairs.

CINE'REOUS. (cinereus, Lat.) Of a dark
grey, with a prevalence of black ; of the
colour of wood-ashes.

CINERI'TIOUS. (cinericius, Lat.) Ash-
coloured ; resembling ashes.

CI'NNABAR. (from icivvaflapi, Gr. cinabrer
Fr. cinabro, It.) The mercure sulphure
of Haiiy. Native cinnabar is a red, heavy,
sulphureous ore of quicksilver, the prin-
cipal mines of which are at Idria ir»
Carinthia, and at Almaden in Spain.
Cinnabar is called " ore of mercury,"
since from it mercury is obtained.

CI'NNAMON-STONE. A blood-red, or hya-
cinth-red, variety of the dodecahedral
garnet. It consists of silica, alumina,
lime, and oxide of iron. The finest spe-
cimens are brought from Ceylon, where
it is found in the sand of the rivers. It
is also called Essonite.

CI'RCULAR. A round surface with its dia-
meter equal on all sides.

CI'RRIPEDE. An annulose, articulated,
animal without jointed feet. Cirripedes are
not plentiful, and are found only in the
upper secondary, and in tertiary deposits.

CI'RRHOPOD. (from cirrus, Lat. and
TTowg, Gr.) The cirrhopods, or cirrho-
poda, like the entomostraceous Crustacea,
are articulated animals, enclosed in shells
like those of mollusca, so that they pre-
sent both forms of the skeleton. The
cirrhopods are almost always inclosed in
multivalve shells, secreted from the outer
surface of a fleshy, thin, enveloping, man-
tle, and are attached to submarine bodies
either directly, by their base, or by
means of a fleshy tubular peduncle. The
barnacle is an example of the cirrhopoda.

C I R

[48 ]

C L I

In Cuvier's arrangement the cirrhopoda
form the sixth class of Mollusca. Lin-
nseus comprised them all in one genus
Lepas ; they have since been divided into
two, and again, by others, subdivided.
CI'RRUS. (cirrus, Lat. ) A genus of
fossil spiral shells of the chalk deposit.
This genus bears great resemblance to
trochus, from which, however, it may be
distinguished by its deep funnel-shaped
umbilicus. Two species of cirrus,
namely, cirrus depressus and cirrus per-
spectivus, are figured in Dr. Man tell 's
" Geology of the South-east of Eng-
land."

CLATHRA'RIA LYE'LLII. A fossil plant
discovered by Dr. Mantell, and thus
named by him in honour of Charles Lyell,
Esq. The following description is ex-
tracted from Dr. Mantell's works. The
Clathraria Lyellii bears an analogy to the
yucca, and dracsena or dragon-blood
plant. Stems, with the markings of the
bases of the leaves, point out the relation
of this vegetable to the arborescent
ferns, while its internal structure is
essentially different. The clathraria has
only been found in the quarries in Fel-
gate Forest. This vegetable appears to
have possessed a thick epidermis, or false
bark, formed by the union of the bases of
the leaves, and covered externally with
distinct rhomboidal scales, each scale
being surrounded by an elevated ridge.
The form of the leaves is not positively
known, although, from some imperfect
traces on the stone in a specimen bear-
ing the impressions of the cicatrices of
the bases of the leaves, there is reason to
conclude that they were of a lineari -lance-
olate form. The axis, or interior part of
the trunk, originally enclosed by the
bark, occurs in the state of solid subcy-
lindrical blocks of sandstone, attenuated
at their base, the surfaces of which are
marked with longitudinal interrupted
ridges, and, in some instances, are deeply
imbricated ; they are generally of a dark-
brown colour.

CLAVAGE'LLA. A genus of bivalves, of
which only one species has been found
recent in the Sicilian seas. It has two
irregular, flattish valves, one of which is
clasped by the tube, the other being left
free. Mr. Sowerby observes, " The shells
composing this genus are found in stones,
madrepores, &c. and appear to form the
connecting link between Aspergillum,
which has both valves cemented into the
tube, and Fistulana which has both
free."

CLA'VICLE. (clavicula, Lat. clavicule, Fr.
clavicula, It.) The collar-bone.

CLAY. When clay is quite pure and un-
mixed (and in this state it is one of the

rarest substances in the mineral king-
dom) it is termed alumina, but under the
term clay is comprehended an extensive
class of compounds, of which silex is a
principal constituent. Clay, then, may be
denned an unctuous and tenacious earth,
capable of being moulded into form.
Clays are firmly coherent, weighty, com-
pact and hard when dry, but stiff, viscid,
and ductile when moist ; being smooth
also and unctuous to the touch. Besides
alumina and silica, clays often contain
carbonate of lime, magnesia, barytes,
oxide of iron, &c. When clay is breathed
on, it yields a peculiar smell"; it has also
a strong affinity for moisture, which is
shewn by its sticking to the tongue,
when applied to it.

CLAY-SLATE. (The argillite of Kirwan.)
An indurated clay or shale, common to
the fossiliferous and metamorphic series.
Clay- slate is opaque, of various shades
of colour, and of different degrees of
hardness, but easily scratched by iron.
It is composed of about fifty per cent, of
silex, twenty-five of alumine, and ten or
twelve of oxide of iron. Some varieties
are used as whetstones. The common
hone is a variety of slate containing a
smaller proportion of alumine and some
lime.

CLA'YSTONE. An earthy stone resembling
indurated clay, and generally of a colour
approaching to purple ; it is a variety of
prismatic felspar.

CLEA'VAGE. A peculiar fracture, im-
pressed by nature, which is sometimes
mistaken for stratification. This is pret-
tily described by Dr. Mantell: "If I
take a flint and break it at random, it
still preserves a conchoidal fracture, a
sharp cutting edge ; and subdivide it as
I may, it still retains the same character.
If I shiver to pieces calcareous spar,
every fragment presents, more or less dis-
tinctly, a rhomboidal form ; so true is
the remark, that we cannot break a stone
but in one of nature's joinings."

The regular partings or cleavages in
many slate rocks which intersect the beds,
nearly at right angles to their dip or in-
clination, have often been mistaken for
strata seams, and have led geologists of
some eminence to draw very erroneous
inferences.

CLEA'VELAXDITE. A mineral, to which
this name has been given after Professor
Cleaveland ; it has been also called
albite.

CLEFT. A space made by the separation
of parts ; in rocks, a crack or crevice.
LEFT. Divided ; cloven.

CLI'MBING. In botany, plants are called
climbing, when they mount up other
bodies (namely, walls, trees, &c.), and

C L I

[49

0 O A

support themselves by means of their
tendrils, or adhesive fibres.

CLI'NKSTONE. (So named from its yield-
ing a metallic sound when struck.)
Called also phonolite, a felspathic rock of
the trap family. In basalt or wacke,
when the felspar greatly prevails, and the
texture becomes nearly compact, basalt
passes into clinkstone ; again, when clink-
stone has a more earthy texture, it passes
into claystone. Clinkstone often contains
imbedded crystals of felspar, and then
becomes a trap-porphyry, varying in
colour according to the prevailing ingre-
dients of its base. The colour of clink-
stone is grey, of various shades.

CLINO'METER. (from K\iva> and /jgrpov,
Gr.) An instrument, invented by R.
Griffith, Esq., for measuring the dip of
mineral strata.

CLO'VEN. In botany, leaves are called clo-
ven, when the margins of the segments
and fissures are straight.

CLO'VATE. In corichology, thicker towards
the top, elongated towards the base.

CLUNCH. A provincial term for a sort of
indurated clay which is found dividing the
coal seams.

CLY'PEUS. (Lat.) A division of the first
class of echinites. The fossil echinites of
the second division of anocysti are distin-
guished as clypei, from their similitude in
form to the round bucklers of the ancient
foot-soldiers.

COAL, (col, Sax. kol, Germ, kole, Dutch.)
Coal is composed of charcoal, bitumen,
and earthy matter ; the latter forms the
ashes which remain after combustion.
Common coal is a black, solid, and com-
pact substance, generally of a foliated, or
rather laminated, structure, which neces-
sarily directs its fracture. Its specific gra-
vity is T25 to 1'37. It cakes into cinders
during combustion in proportion to its
degree of purity, and the nature of the
earths which enter into its composition.
Coal has obtained various names from va-
rieties of appearance, hardness, situation
whence obtained, &c. &c.

COAL FORMATION. The carboniferous group
succeeds the grauwacke in the ascending
series of Europe, and is so called because
the great mass of European coal is in-
cluded among the rocks of which it is
composed. Considered in its greatest
generality, and with reference to where
the masses appear in the greatest simpli-
city, the carboniferous system consists of
three formations, namely, the coal forma-
tion, a mass 1000 yards or more in thick-
ness, consisting of indefinite alternations
of shales and sandstones of different kinds,
with about fifty feet of coal in many beds,
some ironstone layers, and (very rarely)
thin layers of limestone ; mountain lime-

stone, a mass of calcareous rocks, from
500 to 1500 feet in thickness ; and old
red sandstone, a mass of arenaceous and
argillaceous rocks, varying in thickness
from 100 to 10,000 feet. The total thick-
ness of coal existing in the English and
Scotch fields is generally about 50 or 60
feet, divided into 20 or more beds, of a
thickness of from six feet to a few inches,
alternating with from twenty to fifty or
one hundred times as great a thickness of
shales and sandstones. Every coal dis-
trict has its peculiar series of strata, un-
connected with any other. A district
with its peculiar series of strata is called
a coal-field. Coal-fields are of limited
extent, and the strata frequently dip to a
common centre, being often arranged in
basin-shaped concavities, which appear to
have been originally detached lakes, that
were gradually filled up by repeated depo-
sitions of carbonaceous and mineral mat-
ter. In some of the larger coal-fields, the
original form of the lake cannot be traced,
but in the smaller ones it is distinctly
preserved. The stratum lying over a bed
of coal is called its roof, and the stratum
under it, the floor. On the eastern side
of England, the coal strata generally dip
to the south-east point : on the western
side the strata are more frequently thrown
into different and opposite directions, by,
what are termed, faults and dykes. A
fault is a break or intersection of strata,
by which they are commonly either sud-
denly raised or depressed, so that in
working a coal-mine, the miners come
suddenly to its apparent termination. A
dyke is a wall of mineral matter which
from igneous or volcanic action has forced
upwards through the strata, cutting them
in a direction nearly vertical. In these
cases sometimes the coal is reduced to a
cinder for some distance on either side of
the wall or dyke. One of the green-stone
dykes of Ireland, passing through a bed of
coal, has reduced it to a cinder for the
space of nine feet on each side. Our an-
cient coal formation has not been found
in Italy, Spain, Sicily, or in any of the
more southern countries in Europe. Coal
is now universally admitted to be of ve-
getable origin, a question which was long
disputed. It is not uncommon to find
among the cinders beneath our grates,
traces of fossil plants, whose cavities
having been filled with silt, at the time of
their deposition in the vegetable mass,
that gave origin to the coal, have left the
impression of their forms upon clay and
sand enclosed within them, sharp as those
received by a cast from the interior of a
mould. Mr. Hutton has recently disco-
vered the most decisive and indisputable
proof of the vegetable origin even of the

C O A

[50]

C O A

most bituminous coal ; he has ascertained
that if any of the three varieties of coal
found near Newcastle be cut into very
thin slices and submitted to the micro-
scope, more or less of vegetable structure
can be recognised. He says, " each of
these three kinds of coal, besides the fine
distinct reticulation of the original vege-
table texture, exhibits other cells, which
are filled with a light wine-yellow-coloured
matter, apparently of a bituminous nature,
and which is so volatile as to be entirely
expelled by heat, before any change is
effected in the other constituents of the
coal." The plants of the carboniferous
group are by no means confined to the
simplest forms of vegetation, as to crypto-
gamic plants ; but, on the contrary, be-
long to all the leading divisions of the
vegetable kingdom ; some of the more
fully developed forms, both of the dicoty-
ledonous and monocotyledonous class, ha-
ving been already discovered, in the first
three or four hundred species brought to
light. If violence had attended the trans-
port of the plants now converted into
coal, or discovered fossil in the associated
beds, the appearance of those in the latter
would not be as we now find them : in-
stead of appearing as if spread out by the
botanist for examination, we should have
had them crushed and disfigured. More-
over, tranquillity seems requisite to ex-
plain the condition of those vertical, or
nearly vertical , stems of plants discovered
in the coal measures of different situations,
where they have been gradually enveloped
by different beds of sandstone or shale
through which they appear to pierce. The
alternations of limestones containing ma-
rine remains, and of sandstones, shales,
and coal-beds, with no trace of a marine
animal in them, are exceedingly remark-
able, and seem difficult of explanation,
•without calling in the aid of oscillations
of the solid surface of the earth, by which
very gradual risings and depressions are
effected.

The study of the more ancient coal
deposits has yielded the most extraordi-
nary evidence of an extremely hot climate ;
for it appears from the fossils of that pe-
riod that the flora consisted almost exclu-
sively of large vascular cryptogamic plants.
M. Ad. Brongniart states that there ex-
isted at that epoch equiseta upwards of
ten feet high, and from five to six inches
in diameter ; tree-ferns, or plants allied
to them, of from forty to fifty feet in
height, and arborescent lycopodiacese, of
from sixty to seventy feet high, exceeding
in their development those now found in
the hottest parts of the globe. The New-
castle coal-field is supplying rich mate-
rials to the fossil flora of Great Britain.

The finest example of distinctly preserved
vegetable remains is that witnessed in the
coal-mines of Bohemia. " The most ela-
borate imitations," says Prof. Buckland,
" of living foliage upon the painted ceil-
ings of Italian palaces, bear no comparison
with the beauteous profusion of extinct
vegetable forms, with which the galleries
of these instructive coal-mines are over-
hung. The roof is covered as with a ca-
nopy of gorgeous tapestry, enriched with
festoons of most graceful foliage, flung in
wild, irregular profusion over every por-
tion of its surface. The spectator feels
himself transported, as if by enchantment,
into the forests of another world ; he be-
holds trees, of forms and characters now
unknown upon the surface of the earth,
presented to his senses almost in the
beauty and vigour of their primeval life ;
their scaly stems, and bending branches,
with their delicate apparatus of foliage,
are all spread forth before him ; little
impaired by the lapse of countless
ages, and bearing faithful records of ex-
tinct systems of vegetation, which began
and terminated in times of which these
relics are the infallible historians." I can
hardly conclude this article better, than
by again drawing on the composition of
the above quoted elegant and eloquent
author, in transferring to my page from
his delightful work on Geology and Mi-
neralogy the following beautiful passage.
" The important uses of coal and iron in
administering to the supply of our daily
wants, give to every individual amongst
us, in almost every moment of our lives,
a personal concern in the geological events
of these very distant eras. We are all
brought into immediate connexion with
the vegetation that filothed the ancient
earth, before one-half of its actual surface
had yet been formed. The trees of the
primeval forests have not, like modern
trees, undergone decay, yielding back their
elements to the soil and atmosphere by
which they had been nourished ; but
treasured up in subterranean storehouses,
have been transformed into enduring beds
of coal, which in these later ages have be-
come to man the sources of heat, and Light,
and wealth. My fire now burns with fuel,
and my lamp is shining with the light of
gas, derived from coal which has been
buried for countless ages in the deep and
dark recesses of the earth. We prepare
our food, and maintain our forges and
furnaces, and the power of our steam-en-
gines, with the remains of plants of ancient
forms and extinct species, which were
swept from the earth ere the formation of
the transition series was completed. Thus,
from the wreck of forests that waved upon
the surface of the primeval lands, and

C O A

[51 ]

COL

from ferruginous mud that was lodged at
the bottom of the primeval waters, we
derive our chief supplies of coal and iron ;
those two fundamental elements of art and
industry, which contribute more than any
other mineral productions of the earth, to
increase the riches, and multiply the com-
forts, and ameliorate the condition of
mankind."

COA'RCTATE. (coarctatus, Lat.) Pressed
together. A term used in entomology, to
express that state wherein the larva is.
CO'BALT. (The word cobalt seems to be
derived from cobalus, or kobold, the name
of a spirit, or goblin, that, according to
the superstitious notions of the times,
haunted mines, destroyed the works of
the miners, and often gave them much
unnecessary trouble. It was once cus-
tomary in Germany to introduce into the
church service a prayer that God would
preserve miners and their works from
kobalts and spirits.)

This metal is of a gray colour, with a
shade of red, with but little lustre ; its
texture is fibrous ; specific gravity 8*6.
Fusible only at a temperature of 16-677
of Fahrenheit. When heated, cobalt is
partly malleable ; it is permanently mag-
netic. The fine blue mineral called zaffre
is an impure oxide of this metal. The
colour of this oxide is so intense that a
single grain of it will impart a full blue to
240 grains of glass. An oxide of cobalt,
dissolved in muriatic acid, forms a sym-
pathetic ink ; the characters written with
it being invisible when cold, but on expo-
sure to heat assuming a bright green co-
lour, which on cooling they again lose
The principal use of cobalt is to give to
glass and porcelain a beautiful blue colour,
CO'BBLE. 1 A pebble. This word is

CO'BBLE-STONE. $ given by Ray as be-
longing to the northern counties. Cob-
ble has the same signification as boulder.
COCCI'FEROUS. (from KOKKOQ, a berry, anc
fero, to bear.) Any plant or tree bearing
berries.

CO'CCOLITE. (from KOKKOQ and Xi'0oc., Gr.}
A mineral of a green colour, a variety o
augite : called also Granular Augite.
CO'CHLE^S. (cochlea, Lat.) Univalves

shells of one piece.

CO'CHLEATE. i Twisted like a screw, or the
CO'CHLEATED $ shell of a snail ; of i

screwed or turbinated form.
CO'CKLE. See Cardium.
Co'cos. Petrifactions resembling nuts o

that genus.
COETA'NEOUS. (from con and atas, Lat.

Of the same age with another.
COE'VAL. \ (coavus, Lat.) Of the sam
COE'VOUS. 5 age. The word coeval re
quires to be followed by with, coetaneou
by to.

COS'J.IAC. Relating or pertaining to the
abdominal cavity, or belly.
OHE'RE. (cohcereo, Lat.) To stick to-
gether ; to hold fast one to another, as
parts of the same mass. Particles of clay
are said to cohere.

OHE'RENCE. } That state of bodies in which,
^OHE'RENCY. $ their parts are joined to-
gether, so that they resist divulsion or
separation.

^OHE'SION. (cohesion, Fr. coesione, It.)
The act of sticking together, or being
united, by natural attraction ; one of the
different kinds of attraction.
?OHE'SIVE. That has the property of uni-
ting in a mass so as to resist separation.
>OHE'SIVENESS. The quality of being
cohesive ; the property of resisting sepa-
ration.

HOLEO'PTERA. (from fcoXsoc, a sheath,
and TTTtpbv, Gr. awing.) An order of
insects, according to the arrangement of
Linnaeus, having four wings, the two
upper being crustaceous, and forming a
shield. In this order are included Sea-
rabseus, Lucanus, Dermestes, Coccinella,
Curculio, Lampyris, Meloe, Staphylinus,
Forficula, &c. In Cuvier's arrangement
coleoptera forms the fifth order, class
Insecta, and it comprises four sections,
divided according to the number of joints
in the tarsi. The first, Pentamera, com-
prises those in which all the tarsi consist
of five joints ; these are Carnivora, Bra-
chelytra, Serricornes, Clavicornes, and
Palpicornes. The second, Heteromera, in
which the four first tarsi have five joints,
and the two last four each ; this section
comprises Melasoma, Taxicornes, Ste-
nelytra, and Trachelides. The third sec-
tion includes those in which all the tarsi
have four joints ; these are Rhyncophora,
Xylophagi, Platysoma, Longicornes, Eu-
poda, Cyclica, and Vivalpi. The fourth
section, Trimera, consists of such as have
only three joints to each tarsus, and com-
prises Fungicolse, Aphidiphagi, and
Pselaphii. Nearly all these families of
the four sections are subdivided into ge-
nera, but some consist of a single genus.
COLEO'PTEROUS. Belonging to the order
Coleoptera ; having a horny hollow case
under which the wings are folded. Cole-
opterous insects have four wings, the two
superior resembling horizontal scales, and
joining in a straight line along the inner
margin ; the inferior wings are merely
folded transversely, and covered with,
cases, commonly called elytra.
CO'LOLITE. (from KW\OJ/, and \i9og, Gr.)
The name given to the fossil intestines of
fishes by M. Agassiz.

CO'LON. (K&\OV, Gr. colon, Lat. colon,
Fr.) One of the large intestines, and
by much the longest. The colon com-

COL

CON

mences at the coecurn, and terminates in
the rectum.

COLO'PHONITE. A brown or red variety of
dodecahedral garnet, having a resino-ada-
mantine lustre ; it is chiefly found at
Arendal, in Norway. It consists of si-
lica 37-0, alumina 13-6, lime 29 0, oxide
of iron 7*4, magnesia 6'5, oxide of man-
ganese 4-0, water I'D.

COLU'MBITE. A mineral ore, the ore of
columbium.

COLU'MBIUM. A metal first discovered in
1801 in a mineral brought from North
America, from which it received its name.
It is of a dark grey colour, very dense,
and difficult of fusion.

COLOME'LLA. (Lat.) In conchology, the
upright pillar in the centre of most of the
univalve shells.

CO'LUMN. In botany the central point of
union of the partitions of the seed-vessel,
(that is in a capsule containing many
cells) to which the seeds are usually at-
tached.

COLU'MNAR. Formed in columns ; having
the form of columns ; having the circum-
ference always circular, but the thickness
indeterminate.

CO'MATE. (comatus, Lat.) Hairy. In
entomology, having the upper part of the
head, or vertex, alone covered with long
hairs.

COMA'TULA. An existing species of the
family of Crinoidea. The comatula pre-
sents a conformity of structure with that
of the pentacrinite, almost perfect in
every essential part, except that the co-
lumn is either wanting, or at least re-
duced to a single plate. Peron states
that the comatula suspends itself by its
side arms fromfuci, and in this position
watches for its prey, and obtains it by
its spreading arms and fingers. — Miller.

COMB. ^ These words, thus differently writ-

COMBE. > ten, appear to be of Saxon ori-

COOMB. J gin. Ray gives the second as
a south and east country word, and de-
fines it to be a valley, " vallis utrinque
collibus msita." Lyell states it to be a
provincial name for a valley on the de-
clivity of a hill, and which is generally
without water. Buckland says, " the
term Combe is usually applied to that un-
watered portion of a valley, which forms
its continuation beyond, and above the
most elevated spring that issues into it ;
at this point, or spring-head, the valley
ends and the combe begins." A narrow
undulating ravine.

COMBU'STIBLE. (Fr.) Having the qua-
lity of catching fire ; susceptible of fire.

COMBU'STION. (combustion, Fr. combus*
Hone, It.) Consumption by fire; the
disengagement of light and heat which
accompanies chemical combination.

CO'MMINUTE. (from comminuo, Lat.) To

pulverise; to break into small portions;

to grind.
COMMINU'TION. The act of pulverising,

or breaking into small parts.
CO'MMISSURE. (commissure, Lat.) A

joint, seam, or suture.
COMPA'CTED. (compactus, Lat.) Firmly

pressed together ; closely pressed.
COMPA'CTLY. Closely; densely.
COMPRE'SSED. (compressus, Lat.)

1. In botany, leaves are so termed when
flattened laterally.

2. In conchology, having one valve flatter
than the other.

COMPRESSIBILITY. The quality of being
brought into a smaller compass ; thus
air is compressible, water is not.

COMPRE'SSIBLE. (compressible, Fr. che
pub essere compresso, It.) That may be
forced by pressure into a smaller space.

COMPRE'SSURE. The force of one body
pressing against or upon another.

CO'MPTONITE. A mineral thus named after
Lord Compton, who first brought it to
England, found in the erupted matter of
Vesuvius.

CONCA'MERATED. (from concamero, Lat.)
Arched over ; vaulted.

CONCAMERA'TION. (concameratio, Lat.)
An arched chamber. In conchology con-
camerations are those small chambers
into which multilocular shells are divided
by transverse septa, as in the nautilus,
ammonite, &c.

CO'NCAVE. (concjavus, Lat. concave, Fr.
concavo, It.) Hollow, as the inner sur-
face of an egg-shell : opposed to convex ;
when the surface gradually declines to-
wards its centre, the centre being the
deepest point.

CON'CAVENESS. Hollowness.

CONCA'VITY. (concavite, Fr. concavila, It.)
The internal surface of a hollow spheri-
cal or spheroidal body.

CONCA'VO-CO'NCAVE. Concave, or hollow,
on both sides.

CONCA'VO-CO'NVEX. Having one side con-
cave, the other convex.

CONCE'NTRIC. (concentrique, Fr. con-
centrico, It.) Having one common cen-
tre, as the coats of the onion ; running
to a centre. A term applied to the di-
rection taken by the lines of growth in
spiral bodies.

CONCH, (concha, Lat. Koyxn> Gr.) A
marine shell.

CONCHA. Shells consisting of two or more
pieces or valves, as bivalves, and multi-
valves.

CO'NCHIFER. A class of mollusca, the con-
structors and inhabitants of bivalves.
All turbinated and simple shells are con-
structed by molluscs of a higher order
than the conchifers, which construct bi-

CON

[53 ]

CON

valves ; the former have heads and eyes ;
conchifers are without either, and possess
but a low degree of any other sense than
touch and taste. Thus the whelk is an
animal of a higher order than the muscle
or oyster. — Buckland. Lamark divides
Conchifera,which includes all the bivalves,
into two orders, Dimyaria and Mono-
myaria.

CONCHI'FEROUS. (from concha, andyero,
Lat.) Animals having shelly coverings ;
producing shells.

CONCHI'PHERA. A class of mollusca,
inhabiting bivalve shells. See Conchifer.

CO'NCHITE. (conchytes, Fr. coquilles pe-
trifiees.) Petrified, or fossil, shells.

CO'NCHOID. In geometry, the name given
to the curve invented by Nicomedes.

CONCHOI'DAL. Shelly ; shell-like. The
fracture of flint is said to be conchoidal,
that is to resemble a shell, having convex
elevations and concave depressions.

CONCHO'LEPAS. A genus of oval vaulted
univalvular molluscs ; one species only is
known, the conch olepas peruviana,
brought from Peru.

CONCHOLO'GICAL. Relating to the science
of conchology.

CONCHOLO'GIST. (from conchology.} One
versed in the science of conchology.

CONCHO'LOGY. (from Koy^rj, concha, and
Xoyoc, Gr. conchyliogogie, Fr.) That
branch of natural history which treats
of testaceous animals, or animals having
a testaceous covering, whether they in-
habit the ocean, or fresh water, or the
land.

It is upon the exclusive shape of the
shell, and not the animal inhabitant, that
the arrangement of conchology is founded.
In early periods, naturalists hesitated
whether to construct the arrangement
from the animal or the shell; it was,
however, very wisely determined that it
should be from the latter. The greater
part of shells are found without the ani-
mal in them, and all fossil shells can only
be determined by their form. The Lin-
nsean arrangement of shells consists of
three orders, namely, Univalves, Bivalves,
and Multivalves. Univalves consist of
shells complete in one piece, as the
cyprea, bulla, buccinum, &c. Bivalves
are shells of two parts, or valves, gene-
rally connected by a cartilage or liga-
ment, as the oyster, muscle, cockle, &c.
Multivalves are shells consisting of more
parts than two, as chiton, lepas, and
pholas. Every part of a shell which is
connected by a cartilage, ligament, hinge,
or teeth, is called a valve of such shell.
Of the three orders of shells, the uni-
valves are the most numerous, both in
genera and species.

CONCRE'SCENCE. (from concresco, Lat.)

The act or quality of growing by the
union of separate particles.

CONCHYLIO'LITHUS. > (from /coyv^, and

CONCHY'LIOLITE. 5 \i0og.) A fossil
shell.

CONCRE'TE. (from concresco, Lat.) To
coalesce into one mass ; to grow by the
union and cohesion of particles.

CONCRE'TE. (concrete, Fr. concrete, It.
concretum, Lat.) A mass formed by
the union and cohesion of various par-
ticles.

CONCRE'TION. (concretion, Fr. concre-
zione, It.) A coalition, union, or cohe-
sion of separate particles.

CONDE'NSABLE. That which is capable
of being drawn or pressed into a narrower
space or compass.

CONDENSA'TION. (condensation, Fr. con-
densazione, It.) The act of forcing
bodies into a smaller space.

CONDE'NSE. (from condenso, Lat. con-
denser, Fr. condensare. It.) To force
into smaller compass.

CONDE'NSITY. The state of being con-
densed.

CONDU'CTOR. (from conduco, Lat. con-
ducteur, Fr. conduttore,\t.} Any sub-
stance capable of receiving and trans-
mitting electricity, or the electric virtue,
or fluid, or spark.

CO'NDUIT. (conduite, Fr. condotto, It.)
Any hollow vessel for the conveyance of
water, or any other fluid, from one place
to another.

CO'NDYLE. (ic6vSv\o£, Gr. condylus, Lat.
condyle, Fr.) The condyles are bony
projections, or eminences, at the ends of
bones, as the condyles of the shoulder-
bone at the elbow ; the condyles of the
thigh-bone at the knee.

CO'NDYLOID. (from Kovdv\o<; and tWog,
form, Gr.) Anapophysis of a bone.

CONE. (K&VOQ, Gr. conus, Lat. c6ne, Fr.
cono, It.)

1. A solid figure having a circle for its
base, and terminating in a point ; a figure
resembling a sugar-loaf.

2. The fruit of the fir-tree ; a catkin
hardened, and enlarged into a seed-

Co NFE'RVA. A genus of plants, class
Cryptogama, order Algae.

CONFIGURATION. (Fr. Forme exterieure,
ou surface qui borne les corps, et leur
donne une figure particuliere.)

1. The form of a body in relation to its
various parts, and their mutual adap-
tation.

2. The conjunction, or mutual aspect of
the planets.

CONFLA'TION. (conftatio, Lat.) The cast-
ing or melting of metal.

CONFLUENCE, (from confluo, Lat. to flow
or run together.)

CON

[54 ]

CON

1. The junction, or flowing together, of
two or more streams.

2. The point of junction between two
or more bodies of water ; thus, we speak
of a river at its confluence with the
sea.

CO'NFLUENT. (confluent, Fr. confluente,
It.) Running into one another ; running
into one channel.

CO'NFLUX. (confluxio, Lat.) A flowing
together by the union of two or more
currents or streams.

CONFO'RMABLE. (conforme, Fr. conforms,
It.) A term used in geology to express
parallel strata lying upon each other ;
thus, when several horizontal strata are
deposited one upon another, they are
said to be in a conformable position, but
when horizontal are placed over vertical
strata, they are said to be uncomformable,
so far as regards the horizontal in relation
to the vertical strata.

CONFO'RMABLY. In agreement with one
another. Horizontal strata placed on
parallel strata lie conformably ; when
placed on vertical strata, or strata having
an inclination, or dip, they rest uncom-
formably.

CONFORMATION, (conformatio , Lat. con-
formation, Fr. conformazione, It.) The
form, shape, or structure of a body, as
regards the disposition of the various
parts, and their relation to each other.

CONFO'RMITY. (conformite, Fr. confor-
mita, It.) Similitude ; resemblance.

CONFRICA'TION. (from con and frico,
Lat.) The act of nibbing against ano-
ther body.

CONGE'NER. (Lat.) A thing of the same
kind or nature ; species of the same
genus.

CONGE'NEROUS. (congenereux, Fr.) Of
the same kind or nature.

1. In anatomy, muscles which act to-
gether to produce the same movement are
called congenerous.

2. In botany, plants of the same genera.
CONGE'NERACY. Similarity of origin.
CONGENE'RIC. Of the same nature or

kind ; belonging to the same genus.

CONGE'RIES. (Lat.) A collection of many
particles into one mass ; an aggregate, or
mass, of particles.

CONGLACIA'TION. (from conglacio, Lat.)
The state of being converted into ice ; the
act of changing into ice.

CONGLO'BATE. (conglobatus, Lat.) Ga-
thered together in a round ball ; conglo-
bate glands are such as are smooth in
their surface, and seem to be made up of
one continued surface.

CONGLO'BATELY. In a spherical form or
shape.

CONGLO'BULATE. To gather into a round
mass.

ONGLO'MERATE. (conglomtratus, Lat.)
This in geology has the same meaning
as breccia, and pudding-stone. A mass
of fragments united by some cement. Geo-
logical writers have chosen to define the
term variously, and oppositely, to one ano-
ther ; thus Lyell states a conglomerate to
be "rounded water- worn fragments of
rock or pebbles, cemented together by
another mineral substance." Mantell
defines it " fragments cemented toge-
ther." Bakewell " large fragments of
stone, whether rounded or angular, and
imbedded in clay or sandstone." Ure
" a compound mineral mass, in which
angular fragments of rock are imbedded.
The Italian word breccia has the same
meaning." Mantell, in his " Wonders
of Geology," p. 417, has " the most
interesting beds of these conglomerates,
or breccias, in this country."
CONGLOMERATE GLAND. A gland com-
posed of several glomerate glands, whose
excretory ducts unite in one common
duct : the liver, kidneys, pancreas, &c.
are all conglomerate glands.
CONGLOMERATION. Accumulation into a

ball, or mass.

CONGLU'TINATE. (conglutino, Lat. con-
glutiner, Fr. conglutinare, It.) To glue
together ; to cement, or unite, by some
viscid or glutinous medium.
CONGLU'TINATED. Cemented ; glued ;
united by some glutinous matter.
CONGLUTINA'TION. (conglutination, Fr.
conglutinazione, It.) The act of gluing
together ; of healing by the first in-
tention.

CONGLU'TINATIVE. Having the property
of uniting.

Having
a round
base up-
wards ; rounded, and having a flat circle
for its base, and a point for its apex.
CO'NIC SECTIONS. Lines formed by any
plane cutting a cone. If a right cone with
a circular base be cut at right angles to
the base by a plane passing through the
apex, the section will be a triangle. If the
cone be cut through both sides by a plane
parallel to the base, the section will be a
circle. If the cone be cut slanting quite
through both sides, the section will be an
ellipse. If the cone be cut parallel to
one of the sloping sides, the section will
be a parabola. And if the plain cut only
one side of the cone, and be not parallel
to the other, the section will be a hy-
perbola.

CO'NICALLY. In the form of a cone.
CO'NICALNESS. The state or quality of

being conical.

CONI'FER^E. (from conus and fero, Lat.)
An order of trees bearing cones or tops,

CON

CON

containing the seeds • the fifteenth order in
Linnreus's Fragmenta Methodi Naturalis,
and the fifty-first of his natural orders.
The Coniferse are plants whose female
flowers, placed at a distance from the
male, either on the same or distinct roots,
are formed into a cone.

" The Coniferse/' says Professor Buck-
land, " form a large and very important
tribe among living plants, which are cha-
racterised not only by peculiarities in
their fructification, (having their seeds
originally naked, and not enclosed within
an ovary ; for which reason they have
been arranged in a distinct order, as
Gymnospermous Phanegoramise,) but
also by certain remarkable arrange-
ments in the structure af their wood,
whereby the smallest fragment may be
identified. The recognition of these pecu-
liar characters in the structure of the
stem, is especially important to the geo-
logical botanist, because the stems of
plants are often the only parts which are
found preserved in a fossil state. A
transverse section of any coniferous
wood, in addition to the radiating and
concentric lines, exhibits under the mi-
croscope a system of reticulations by
which coniferae are distinguishable from
other plants. It appears that the coni-
ferse are common to fossiliferous strata of
all periods ; they are least abundant in
the transition series, more numerous in
the secondai'y, and most frequent in the
tertiary series. All the trees of this
order secrete resin, have branched trunks,
and linear, rigid, entire leaves : species
are found in the coldest as well as in the
hottest regions."

CONI'FEROUS. (conifere, Fr.) Bearing
fruit in the form of a pine-apple, or cone.

CO'NIFORM. Conical ; in the form of a
cone.

CO'NILITE. A genus of molluscous uni-
valves, placed both by Lamarck and De
Blainville in the family Orthocerata. It
is conical, straight, or slightly curved.

" The difference between conilites and
baculites, is that the external sheath of
the latter is thin, and not filled up with
solid matter, from the point of the alveole
to the apex, as in the former." — Sowerby.

CO'NITE. An ash- coloured mineral, be-
coming brown by exposure to the atmo-
sphere.

CO'NJUGATE. (conjugatus, Lat.) A pin-
nate leaf having only one pair of leaflets ;
leaves that consist of one pair of pinnae
or leaflets.

CO'NNATE. (connatum, Lat.) Applied to
leaves, when two leaves are so united at
their base as to have the appearance of
one leaf.

CO'NOID. (from K&VOQ and tldoe, Gr.)

Resembling a cone in form ; sugar-loaf
shaped.

CONSOLIDATE, (from consolider, Fr. ren-
dreferme.} To form into a compact and
solid body ; to unite into a solid mass.

CONSOLIDATED, (consolidatus, Lat. cow
solide, Fr.) Made firm, solid, compact.

CONSOLIDATION, (consolidation, Fr. con-
solidazione, It.) The act of making into
a compact and solid mass.

CONSTRINGENT. (constringens, Lat.)
Having the power or quality of compress-
ing, binding, or contracting into a smaller
compass.

CONTEMPORANEITY. (contemporaneity,
Fr.) The state of being contemporary
with. This word is used by J. Phillips :
" it becomes a very curious problem to
determine what are the lines of contem-
poraneity in the oolitic system."

CONTEMPORANEOUS. ) (contemporain, Fr.

CONTE'MPORARY. $ coetaneo, It.)
Existing at the same period.

CONTE'MPORARY. One who lives at the
same time with another.

CONTE'RMINOUS. (conterminus, Lat.)
Bordering upon ; contiguous ; touching
at the boundaries.

CONTERRA'NEOUS. (conterraneus, Lat.)
Of the same country.

CONTIGU'ITY. (contiauite, Fr. contiguita,
It.) Actual contact.

CONTINI/ITY. (continuitas, Lat. continuite,
Fr. continuita, It.) Uninterrupted con-
nection, without the intervention of any
space.

CONTINUOUS, (continu, Fr.) Joined to-
gether, without interruption or inter-
vention.

CONTO'RSION. ) (contorsion, Fr. contorsio,

CONTO'RTION. $ Lat. contorsione, It.) A
twisting, or writhing ; wry motion ;
flexure.

CONTO'RTED. (contortus, Lat.) Twisted ;
ravelled ; wound. In conchology, twisted
on each other in an oblique direction.

CONTRA'CTILE. Having the power of con-
tracting itself ; having the power of con-
traction.

CONTRA'CTIBLE. Capable of contraction.

CONTRA'CTIBLENESS. The quality of un-
dergoing contraction.

CONTRACTILITY. The inherent property
by which bodies contract.

CONVE'RGE. (convergo, Lat. converger,
Fr.) To tend to one point from different
quarters.

CONVERGENT. J T di Qne int<

CONVERGING. $

CO'NVEX. (convextis, Lat. convene, Fr.
convesso, It.) Rising on the exterior
into a circular or spherical form ; the
opposite to concave.

CO'NVEXED. Protuberant in a spherical
form.

CON

[ 56]

COP

CONVE'XEDLT. In a convex form.

CONVE'XITY. (convexite, Fr. convessita,
It.) Protuberance in a circular or spheri-
cal form.

CO'NVEXLY. In a convex form.

CO'NVEXNESS. Convexity.

CONVE'XO-CONCAVE. Convex on one side,
and concave on the other, but having the
convexity on the inside.

CO'NVEXO-CO'NVEX. Convex, or protu-
berant, on both sides.

CO'N VOLUTE. > (convolutus, from con-

CO'NVOLUTED. $ ro/#o,Lat. ) Rolled up;
twisted spirally ; rolled upon itself.

CONVOLUTION. (convolutio, Lat.) The
state of being rolled upon itself ; the act
of twisting anything spirally, or of rolling
it upon itself.

CONVO'LVE. (convolve, Lat.) To roll up ;
to roll together ; to roll upon itself.

CONULA'RIA. A genus of orthocerata, of a
conical shape, and polythalamous, the
transverse septa being imperforate. The
conularia has no siphon, and in this
character differs from orthoceras.

CO'NULUS. A genus of echinites ; in it are
contained those which rise from a cir-
cular base into a cone, (from which form
they obtain their name,) with an acute
or obtuse vertex, from which five pairs of
punctated or crenulated lines, or am-
bulacra, pass ; dividing the shell into five
large and five small arese, that in which
the anus is placed being rather the
largest. All the species which constitute
the genus are known only as fossils, and
are distinguished by the modification of
their form.

CO'NUS. (icutvog, Gr. conus, Lat.) Ani-
mal, a Limax ; shell univalve, convolute,
turbinate ; aperture effuse, longitudinal,
linear, without teeth, entire at the base ;
pillar smooth. This genus is divided by
some into five families. The recent conus
is an inhabitant of the ocean, and is ge-
nerally found on rocky shores. Some of
the shells are very beautiful, and are both
rare and valuable ; one species, the cedo
nulli, is valued at one hundred guineas.
The conus does not inhabit our seas.

*•<*-»•

CO'PPER. (cuprum, Lat. kupfer, Germ.
koper, Dutch. The word is derived
from the island of Cyprus, where it was
first wrought.) When pure, copper is of
a red colour ; its specific gravity is from
8'6 to 8'9, or nearly nine times as heavy
as water. Copper is found in primary
and secondary rocks, and is often native,
i. e. in a pure metallic state ; it is also
found crystallized. In smell and taste
copper is excessively nauseous. It is
very malleable, next so in degree after
gold and silver, and can be hammered

out into extremely thin leaves, so thin as
to be blown about by the slightest breeze.
In ductility it ranks after gold, silver,
platinum, and iron ; while in tenacity it
yields only to iron. A copper wire one-
tenth of an inch in diameter will sustain a
weight of 385 Ibs. Copper is the most
sonorous of all metals : its fusing point
is 1450 Fah., and it can be volatilized by
an increased temperature ; when allowed
to cool slowly, it assumes a crystalline
form. At common temperatures, copper
is not acted on by water, but, if long ex-
posed to the action of the atmosphere
and moisture, it oxidizes ; as it does in
the air alone, if heated to redness. It
combines with oxygen in two proportions.
Copper admits of a greater degree of
condensation by hammering than any
other metal. Copper has been known
from the earliest ages. As stated before,
it occurs frequently in the native state,
either in masses, grains, or crystallized
in cubes and octohedrons. The most
abundant, and most generally diffused
ore, and that from which the metal is
chiefly obtained, is the sulphuret of cop-
per, termed copper pyrites, composed of
copper, sulphur, and a small portion of
iron. Copper has never been combined
with carbon, hydrogen, or azote ; but it
combines readily with sulphur and phos-
phorus, forming with them compounds
called sulphuret and phosphuret of cop-
per. Copper, having the property of in-
creasing the hardness of gold without in-
juring its colour, is used in the making
of gold coin ; that of Great Britain is an
alloy of 11 parts of gold and 1 of
copper.

CO'PPERAS. (copparosa, It. couperose,
Fr. kupferwasser, Germ.) Sulphate of
iron ; green vitriol. Sulphate of iron
has a fine green colour ; its crystals are
transparent rhomboidal prisms, the faces
of which are rhombs with angles of
79° 50' and 100° 10' inclined to each
other at angles of 98° 37' and 81° 23'.
It has a strong styptic taste, and reddens
vegetable blues. It is prepared by moist-
ening the sulphurets of iron, which are
found native in abundance, and exposing
them to the open air. These are slowly
covered with a crust of sulphate of iron,
which is first dissolved in water and sub-
sequently, by means of evaporation, ob-
tained in crystals.

CO'PPLE-STONES. Boulders ; cobble-stones,
which see.

CO'PROLITE. The petrified faecal matter
of carnivorous reptiles. The following
description of coprolites is taken from a
memoir on the subject, by Professor
Buckland, published in the transactions
of the Geological Society, as well as from

COP

[57 ]

COR

his splendid Bridgewater Treatise : — " In
variety of size and external form, the
coprolites resemble oblong pebbles or
kidney potatoes. They, for the most
part, vary from two to four inches in
length, and from one to two inches in
diameter. Some few are much larger,
and bear a due proportion to the gigantic
calibre of the largest ichthyosauri ; some
are flat and amorphous, as if the sub-
stance had been voided in a semifluid
state ; others are flattened by pressure
of the shale. Their usual colour is ash-
grey, sometimes interspersed with black,
and sometimes wholly black. Their sub-
stance is of a compact earthy texture, re-
sembling indurated clay, and having a
conchoidal and glassy fracture. Their
structure is in most cases tortuous, but
the number of coils is very unequal ; the
most common number is three. Some
coprolites, especially the small ones,
shew no traces of contortion. The
sections of these fsecal balls, show their
interior to be arranged in a folded plate,
wrapped spirally round from the centre
outwards, like the whorls of a turbinated
shell ; their exterior also retains the
corrugations and minute impressions,
which, in their plastic state, they may
have received from the intestines of the
living animals. Dispersed irregularly
throughout the petrified fseces, are the
scales, and occasionally the teeth and
bones of fishes, that seem to have passed
undigested through the bodies of the sau-
rians ; just as the enamel of teeth, and
sometimes fragments of bones are found
undigested both in the recent and fossil
album grsecum of hysenas." On the
shore at Lyme Regis, in Dorsetshire,
coprolites are found in great abundance,
lying scattered in the ground like potatoes.
The true character and real nature of the
coprolite was long misunderstood, having
formerly been called Juli, and believed to
be fossil fir cones. Coprolites are found
in all strata which contain the remains of
carnivorous reptiles. The real origin of
these coprolites is placed beyond all
doubt by their being found frequently
within the intestinal canal of fossil ske-
letons of ichthyosauri. The preservation
of such fsecal matter, and its lapidifica-
tion, result from the imperishable nature
of the phosphate of lime, one of the con-
stituents of bony matter.

COPROM'TIC. Composed of coprolites ; re-
sembling coprolites ; containing copro-
lites.

CO'RACOID. (from Kop«£, and tidoc, Gr.)
Resembling the beak of a crow. A name
given to the upper anterior point or pro-
cess of the scapula.

CO'RAL. (xropaXXtov, Gr. corallium, Lat.

corail, Fr. coralla, It. It is somewhat
marvellous to find Todd following John-
son in his description of coral, and stat-
ing it to be a plant.) The red coral is a
branched zoophyte, somewhat resembling
in miniature a tree deprived of its leaves
and twigs. It seldom exceeds one foot
in height, and is attached to the rocks by
a broad expansion or base. It consists
of a bright red, stony axis, invested with
a fleshy, or gelatinous substance of a pale
blue colour, which is studded over with
stellular polypi. Coral is composed of
carbonate of lime and animal matter.
The powers of the organic creation,
says Lyell, in modifying the form and
structure of the earth's crust, which
may be said to be undergoing repair, or
where new rock formations are continually
in progress, are most conspicuously dis-
played in the labours of the coral animals.
We may compare the operation of these
zoophytes in the sea to the effects pro-
duced on a smaller scale upon the land,
by the plants which generate peat. In
corals, the more durable materials of the
generation that has passed away serve as
the foundation on which living animals
are continuing to rear a similar structure.
Of the numerous species of zoophytes
which are engaged in the production of
coral banks, some of the most common
belong to the genera meandrina, caryo-
phyllia, millepora, and astrea, but espe-
cially the latter. It has been asked,
" From whence do these innumerable zoo-
phytes and molluscous animals procure
the lime, which, mixed with a small
quantity of animal matter, forms the
solid covering by which they are pro-
tected ? Have they the power of separat-
ing it from other substances, or the still
more extraordinary faculty of producing
it from simple elements ? The latter I
consider the more probable ; for the
polypi which accumulate rocks of coral
have no power of locomotion ; their
growth is rapid, and the quantity of cal-
careous matter they produce, in a short
space of time, can scarcely be supposed
to exist in the waters of the ocean to
which they have access, as sea-water con-
tains but a minute portion of lime." Le
Sueur, who observed them in the West
Indies, describes these polypes, when ex-
panded in calm weather at the bottom of
the sea, as covering their stony receptacles
with a continuous sheet of most brilliant
colours. Ehrenberg, the distinguished
German naturalist, was so struck with
the splendid spectacle presented by living
polyparia covering every portion of the
bottom of the Red Sea, that he is said to
have exclaimed, " Where is the paradise
of flowers that can rival in variety and
i

COR

[58]

COR

beauty these living wonders of the ocean ! ' '
— LyelL Mantell. Buckland. Bakcwell.

CORALLI'FERI. An order of polypi, em-
bracing those species which were so long
considered to be marine plants.

CO'RALLINE. Belonging to the class Zoo-
phyta, order Eschara, each polypus being
contained in a calcareous or horny shell,
without any central axis. The animal
which secretes and inhabits coral.

CO'RALLINE. (corallin, Fr. corallino, It.)
Composed of coral ; resembling coral ; of
the colour of coral.

CO'RAL-RAG. A member of the middle di-
vision of oolite, of the thickness of about
forty feet in the Bath district.

CO'RAL REEF. ) It is a curious, but in-

CO'RAL ISLAND. \ disputable fact, that a
considerable portion of the earth's surface
is the result of organic secretion, and the
same process is still going on extensively
in the Pacific and Indian seas, where in-
numerable coral islands rise above and
innumerable reefs and shoals lie just be-
low the surface of the waves. The ob-
servations of modern voyagers have thrown
much light on the formation of coral is-
lands and reefs ; they concur in the opi-
nion that these reefs and islands do not
rise from the depth even of many hundred
yards, but commence on the summit of
some volcanic elevations, or other sub-
marine ridges and rocks, not far below
the surface of the sea. The calcareous
masses usually termed coral reefs are by
no means exclusively composed of zoo-
phytes ; a great variety of shells, and
among them some of the largest and hea-
viest of known species, contributing to
augment the mass. The reefs, which just
raise themselves above the level of the
sea, are usually of a circular or oval form,
and surrounded by a deep, and often un-
fathomable ocean. In the centre of each,
there is usually a comparatively shallow
lagoon, where there is still water, and
where the smaller and more delicate kind
of zoophytes find a tranquil abode, while
the stronger species live on the exterior
margin of the isle. When the reef is of
such a height that it remains almost dry
at low water, the corals leave off building.
Fragments of coral limestone are thrown
up by the waves, unlil the ridge becomes
so high, that it is covered only during
some seasons of the year by the high tides.
The heat of the sun often penetrates the
mass when it is dry, and splits it. The
force of the waves subsequently separates
blocks of the coral and throws them upon
the reef. Afterwards the calcareous sand,
removed from the action of the waves, lies
undisturbed, and offers to the seeds of
trees and plants, cast upon it by the waves,
a soil upon which they rapidly vegetate.

Entire trunks of trees, carried by the
rivers from other countries, find here a
resting-place : with these come small ani-
mals, such as insects, lizards, &c. , as the
first inhabitants. Even before the trees
form a wood, the sea-birds nestle here ;
strayed land-birds take refuge in the
bushes : and at a much later period, man
appears, and builds his hut on the fruitful
soil. — Phillips. LyelL Kotzelue. Bake-
well.

CORALLI'GENOUS. Producing coral. The
depth at which the coralligenous zoophyta
commence their labours is said not to
exceed fifteen or twenty fathoms.

CO'RALLOID. } (from coral and tldog,

CORALLOI'DAL. $ Gr.) Resembling co-
ral ; having the form of coral.

CORALLOI'DES. (coralloides, Fr. seme del
corallo bianco, It.) Coral -wort ; the
clavaria coralloides of Linnaeus.

CO'RBULA. (corlula, Lat.) A genus of
bivalves belonging to the family Corbu-
lacea in Lamarck's arrangement, and to
that of Conchacea in De Blainville's.
The corbula is a marine animal, found at
depths varying to thirteen fathoms, in
sandy mud. Some authors place the
genus corbula in Solen, others in Mya.
Corbulse are found both fossil and recent.
Fossil corbulae occur in the London clay,
calcaire grossier, and Norfolk crag.
They are also found in the Shanklin sand,
at Parham, and elsewhere.

CORBULA'CEA. A family of bivalves in
Lamarck's system, belonging to the order
Dimyaria, and comprising the two genera
Pandora and Corbula.

CO'RDATED. 1 (status.) Heart-shaped.

CO'RDIFORM. (from cor and forma, Lat.)
Resembling the form of a heart ; heart-
shaped.

CORIA'CEOUS. (coriaceus, Lat. coriacce,
Fr.) Resembling leather ; consisting of
leather ; of a leather-like consistence.

COR-MARINUM. A genus of echmites,
characterized by the bilabiated mouth
being in the third region of the axis of
the base, and the anus in the side of the
truncated extremity. In this genus, or,
as he terms it, family, Leske, with Mul-
ler, includes spatangus, spatagoides, bris-
sus, and brissoides, not considering the
absence of the groove to be a generic dis-
tinction. — Parkinson .

CORDI'ERITE. Another name for iolite, or
prismatic quartz.

CO'RINDON. Another name for corundum
or spinel.

CO'RNEA. (from cornu, Lat. corw^e, Fr.
cornea dell'occhio, It.) The anterior
transparent portion of the ball of the eye,
or that portion of the front of the eye
which allows the rays of light to pass

COR

[59 ]

COR

through, and permits objects to be re-
flected on the retina at the back.

CO'RNEAN. A variety of clay-stone.

CO'RNEOUS. (corneus, Lat.) Horny; of
a substance resembling horn ; of a horn-
colour.

CORNE'HAN. For an account of this sub-
species of calcedony, see Carnelian.

CO'RNBRASH. A coarse shelly limestone ;
a provincial term. Cornbrash is a ma-
rine deposit, a member of the oolite ; it
occurs in Wiltshire.

CO'RNSTONE. A red limestone, occurring
in the old red sandstone. The name of
this and of the preceding word may be
considered as provincial, and given to
them from their presumed utility in pro-
ducing fertile corn-land.

CORNU'TED. (cornutus, Lat.) Horned.

CORO'LLA. (Lat.) The corolla consists of
the delicate petal, or petals, forming
what, in common language, are termed
the blossoms ; and in polypetalous flow-
ers, the petals are usually called the
leaves of the flower. The corolla consti-
tutes the beauty of the flower, and the
odour and fragancy of the plant fre-
quently reside therein, as in the rose, jes-
samine, violet, &c. The cerolla has a
diversity of forms, as well as of colour,
being found of every shade and variety
except black. It includes two parts, the
petals and the nectary : the latter is some-
times a part of the former, and some-
times separate from it. The leaves of the
corolla are called petals, and these are
either distinct, when the corolla is termed
polypetalous, as in the rose, ranunculus,
&c. or they are united by their edges, in
which case the corolla is said to be mono-
petalous, as in the honey-suckle, convol-
vulus, &c. The corolla is either regular
or irregular : when the petals are all alike
in size and form, the corolla having a
symmetrical appearance, it is called regu-
lar ; but when the petals are unequal, or
unlike each other, it is termed irregular,
as in the geranium, violet, &c. A papili-
onaceous corolla consists of five petals of
particular forms, of which the uppermost
is turned back, and is called the vexillum
or standard ; the two next resemble each
other, but differ from the first ; they
have their faces towards each other ; they
are called the alae, or wings; the remain-
ing two, which are placed below the
others, also resemble each other, but dif-
fer from the three already mentioned ;
they are usually united by their lower
edge, and form a figure resembling the
keel of a boat, whence they obtain the
name of carina, or keel. This corolla is
the characteristic of the leguminosse, a very
large order of plants, of which the broom,
lupin, sweet-pea, vetch, £c. are examples.

In some plants the corolla has one or
more of its petals spurred, as in the
violet.

In the orchidese, the corolla consists of
three pieces, one differing very greatly in
form and size from the other two ; it is
called the labcllum, or little lip, and is
often spurred. In many species, this re-
sembles an insect.

The lower part of the single petal of a
corolla, by which it is fixed to the recep-
tacle, is named the claw.

The cruciferous plants have four petals,
and these are so arranged as to resemble
a cross, from which circumstance they
have been named Cruciferse. The stock,
radish, cabbage, mustard, &c. are exam-
ples.

The outer part of the heads of many
composite flowers is formed of the ligu-
late corollas of the exterior florets, and
these are commonly white, blue, or yel-
low, as in the aster, daisy, &c. ; this part
of the head is termed the ray, the cen-
tral part being called the disk, which
disk is composed of florets, with regular
corollas.

A corolla with two lips is called bilabi-
ate: when the two lips present an ap-
pearance resembling the mouth of an
animal, the corolla is called ringent.

The petals of all corollas are placed
alternately with the sepals of the calyx.

CORO'NA. (Lat.) In botany, an appen-
dage of the corolla or perianth.

CO'RONOID. See Coracoid.

CORO'NULA. A regular subrotund, or sub-
conical shell, divided into twelve arese,
with an opening both in the superior and
inferior part ; that in the superior closed
by a four-valved operculum.

CO'RONATED. (coronatus, Lat.) In con-
chology, crowned, or girt towards the
apex with a single row of eminences.

CO'RPUSCLE. \ (corpusculum, Lat. cor-

CORPU'SCULE. $ puscule, Fr. corpuscolo,
It.) A minute particle of a body ; an
atom.

CORRO'DED. (from corrodo, Lat. corrode,
Fr.) Eaten away by degrees ; consumed ;
worn away.

CORRO'DENT. (from corrodo, Lat.) Hav-
ing the power of wasting, of wearing any-
thing away by degrees.

CORRODIBI'LITY. The quality of being
corrosible.

CORRO'DIBLE. } That may be worn away,

CORRO'SIBLE. $ consumed, or corroded.

CORRO'SION. (Fr. Faction ou Veffet de
ce qui est corrosif; corrosione, It.) A
dissolution of bodies by means of acids
or corrosive menstrua.

CORRO'SIVE. (corrosif, Fr. corrosivo, It.)
Having the power of dissolving or gradu-
ally wearing away.

COR

C O V

CO'RRUGATED. (from corrugo, Lat.) Con-
tracted ; wrinkled ; as the skin by cold.

CORRUGA'TIOX. Contraction into wrinkles.

CO'RTEX. (Lat.) The exterior skin, or
epidermis ; the bark or rind.

CO'RTICAL. (from cortex, Lat. cortical, Fr.
corticate, It.) Belonging to the bark or
rind ; resembling the bark or rind.

CO'RTICATED. (corticatus, Lat.) That
hath a rind or bark.

CO'RTICOSE. (from corticosus, Lat.) Full
of bark ; abounding in rind.

CORTICI'FEROUS. (from cortex and fero,
Lat.) Producing bark.

CORU'NDUM. A genus of gems comprising
four species.

1. Spinel, or dodecahedral corundum.

2. Automolite, or octahedral corundum.

3. Sapphire, or rhombohedral corundum.

4. Chrysoberyl, or prismatic corundum.
These will all be described under their

several names.

CO'RYMB. (corymbe, Fr. corymlus, Lat.)
A kind of efflorescence. A raceme. A
spike of flowers, whose partial peduncles
take their rise from different heights
upon the common stalk, but the lower
peduncles being longer than the upper
ones, they all form nearly a level surface
at the top.

CORY'MBIATED. Garnished with bunches
of berries or blossoms in the form of
corymbs.

CORYMBI'FEROUS. (from corymlus and
fero, Lat.) Bearing berries or blossoms
in the form of corymbs.

CO'SMICAL. (from Ko<r/uic6c, Gr.)

1. Relating to the world.

2. Rising or setting with the sun : thus a
star is said to rise cosmically, when it
rises together with the sun ; and to set
cosmically when it sets at the same
instant that the sun rises : but to rise and
set cosmically, according to Kepler, is
to ascend above, or descend below the
horizon.

CO'SMICALLY. With the sun.

COSMO'GONIST. One who makes a study of
the origin and creation of the world.

COSMO'GONY. (Koapoyivtia, Gr. cosmo-
gonie, Fr.) The science of the formation
of the universe.

COSMO'GRAPHER. (from cosmographe, Fr.
cosmografo, It. KoGfJtog and ypd^w,
KO(T/ioypa0oc, Gr.) One who describes
the several parts of the creation by writing.

COSMO' GRAPH Y. (cosmoyraphie, Fr. cos-
mografia, It. K0<r/ioypa0ia, Gr.) The
science which describes the several parts
of the creation, delineating them accord-
ing to their number, positions, motions,
magnitudes, figures, &c.

COSMOLO'GICAL. (cosmologique, Fr. Ko<r/to-
XoycKoc., Gr.) Pertaining to the science
of cosmology.

COSMO'LOGIST. A pursuer of the science
of cosmology ; who describes the several
parts of creation.

COSMO'LOGY. (cosmologie, Fr. *co<r^o-
Xoyta, Gr.) The science which treats of
the general laws by which the physical
world is governed ; the study of the
world in general.

CO'STA. (costa, Lat.) A rib.

CO'STAL. (costal, costale, Fr.) Belong-
ing to the ribs.

CO'STATE. )(from costatus, Lat.) Rib-

CO'STATED. S bed, or having ribs.

COTEMPORA'NEOUS. ^ (contemporain, Fr.

COTE'MPORARY. $ coetaneo, It.) Liv-
ing at the same time ; coetaneous.

COTE'MPORARY. One living atthesame time.

CO'TTOXOUS. )(cotonneux, Fr.) Resem-

CO'TTONY. ( bling cotton, either in its
feel or appearance ; downy.

CO'TYLE. (from KOTV\T], Gr. cotyle, Fr.
cavite d'un os dans laquelle un autre os
s'articule.) The cavity or socket of a
bone which receives another bone in ar-
ticulation, as the socket of the hip which
receives the head of the femur, or thigh-
bone.

COTYLE'DON. (KOTv\r)£wv, Gr. cotyledon,
Fr.) The side lobe, or seed-lobe of seeds,
furnishing nourishment and protection to
the corculum, and forming the chief bulk
of the seeds : these lobes swell and ex-
pand in the ground, and as the stem as-
cends they are usually raised out of the
ground, assume a green colour, and per-
form the functions of leaves until the
young leaves unfold, when they generally
wither. The cotyledon is found at the
point of union of the radicle and plu-
mule. The most essential difference in
the structure, mode of growth, and cha-
racter of the plants growing from the
seeds, is found connected with the num-
ber or position of the cotyledons. Those
plants, the seeds of which have only one
cotyledon, or if more, these alternate on
the embryo, are called monocotyledonous.
All monocotyledonous plants can be re-
cognised without any difficulty, by a cha-
racteristic feature of the leaf, the veins of
the leaf being parallel, and not reticu-
lated ; all the palms, the tulip, lily, aloe,
&c. are instances. Those plants which
have two cotyledons, and those opposite,
are called dicotyledonous ; all dicotyle-
donous plants have the veins of their
leaves reticulated.

COTYLE'DONOUS. Having cotyledons.

CO'UNTER- CURRENT. A stream, or current,
which runs in an opposite direction to
another.

CO'UNTER-CURRENT. Running in an op-
posite direction.

COVE. (covum, Lat.) A small bay,
creek, or inlet.

cow

[61 ]

C R I

CO'WRY. The common or familiar name
for shells belonging to the genus Cyprsea.

CRAG. A tertiary deposit of the older
pliocene period, which has obtained this
name from a provincial term signifying
gravel. The crag is chiefly developed in
the eastern parts of Norfolk and Suffolk,
extending thence into Essex : it is seen
to rest on the chalk and on the London
clay, but generally on the chalk. By
some the crag has been divided into two
groups, the lower, or coralline, which is,
in some places, fifty feet or more in thick-
ness, and the upper, or red crag, thus
named from its ferruginous colour. . The
fossils of the crag are very numerous.

CRA'NIA. (from cranium, Lat. a skull,
in consequence of a supposed resemblance
of the interior of the shells to a skull,
arising from some deep muscular impres-
sions.) A regular inequivalved bivalve ;
the upper valve very convex, patelliform,
with the umbo near the centre, the lower
valve flat, and nearly round, and pierced
internally with three unequal and oblique
holes. The arms of the animal are cili-
ated. Cuvier places crania in the class
Brachiopoda, division Mollusca. By La-
marck this genus is placed in the family
Rudistes, order Monomyaria ; and by De
Blainville in the order Palliobranchiata.
Cranise are found attached to stones and
shells, and are brought up, probably from

freat depths, by cod-lines off the coast of
hetland, and with corals in the Mediter
ranean. Several species of fossil crania
are found in the chalk formation.
CRA/NIUM. The skull.

CRASSATE'LLA. (from crassus, Lat.) A
genus of equivalved inequilateral close
bivalves. The hinge teeth two, with an
adjoining fossa ; the lateral teeth obso-
lete. The cartilage inserted in a pit
formed in the hinge.

As the crassatella advances in age the
valves become very greatly thickened,
from which circumstance it obtains its
name. Cuvier places this genus in
the family Mytilacia, order Acephala ;
Lamarck in the family Mactracea ; and
De Blainville in the family Conchacea.
Recent crassatellse inhabit sandy mud at
depths varying from eight to twelve fa-
thoms. Some species of fossil crassa-
tellee have been found in the tertiary for-
mations.

CRA'TER. (cratere, Fr. KpctTrip, Gr
KpciTrjpeQ, montip foramina, quibus igni
cinisgue evomitur.~) The basin-shapec
hollow in volcanic mountains whence
issue the flames and erupted matter.

CRATE'RIFORM. (from crater and forma
Lat.) Hollowed out like a crater; o
the form of a crater ; bowl-shaped.

CREMA'TION. (crematio, Lat.) A burning

RE'NATE. ^(crenatus, Lat.) Notched
/RE'NATED. } at the margin ; scolloped ;
indented.

1 . It is applied to leaves when the notches
or teeth on the borders are rounded, and
the notches not directed to either end of
the leaf.

2. In entomology, a margin with inden-
tations, not sufficient to be called teeth,
the exterior whereof is rounded.

RE'NATURE. The notch or indentation of
a leaf.

CRENA'TULA. (from crenatus, Lat.) This
name has been given to this genus of bi-
valves from the hinge showing a row of
roundish or oval pits, making it appear as
if crenulated. An irregularly formed flat
bivalve ; closed, not giving passage to any
byssus ; the hinge linear, excavated, and
crenulated ; umbones terminal. It is
found in sponges, and moored to coral-
lines, &c. Parkinson, in describing the
crenatula, says, "there are very few
among the fossil shells of this or of any
other country, which, at first sight, are
more dissimilar from any of the recent
shells than the fossil crenatula. It is
very rarely found.

CRE'NTILATE. ^ (crenels', Fr.) Indented

CRE'NULATED. $ round the margin with

small notches. The fine saw-like edge of

the shell of the cockle, which so nicely

fits into the opposite shells, is a familiar

example of a crenulated margin.

CRE'PITATE. (crepito, Lat.) To crackle.

CREPITA'TION. (crepitation, Fr.) A low

crackling noise.
CRE'SCIVE. (from cresco, Lat.) Grow-
ing ; increasing.
CRE'TA. (Lat.) Chalk ; carbonate of

lime.
CRETA'CEOUS. Having the qualities of

chalk ; containing chalk ; chalky.
CRETA'CEOUS GROUP. This group com-
prises the different strata from the chalk
of Maestricht to the lower green-sand
inclusive. In Lyell's Principles, they are
thus arranged: 1. Maestricht beds; 2.
Chalk with flints; 3. Chalk without
flints ; 4. Upper green-sand ; 5. Gault ;
6. Lower green-sand. The whole of these
formations are marine.
CRI'CHTONITE. The name given to a
black, opaque, shining mineral, after Dr.
Crichton.
CRIO'CERATES. A genus of ammonites,

having the whorls disconnected.
CRINI'GEROUS. (from criniger, Lat.)
That hath much hair ; hairy ; overgrown
with hair.

CRI'NITE. (crinitus, Lat.) Having tufts
of hair ; having the hair long, slender,
and dispersed.

CRINO'IDAL. Containing fossil crinoidean
remains. The Derbyshire encrinital

C R I

[62 ]

C R O

marble is composed principally of the fos-
silized remains of crinoidea, cemented to-
gether by carbonate of lime.

CRINOIDE'AN. Belonging to the order
of Crinoidea.

Although the representatives of crinoi-
deans in our modern seas are of rare oc-
currence, this family was of vast numeri-
cal importance among the earliest inha-
bitants of the ancient deep. The exten-
sive range which it formerly occupied
among the earliest inhabitants of our
planet, may be estimated from the fact,
that the crinoi'deans already discovered
have been arranged in four divisions,
comprising nine genera, most of them
containing several species, and each indi-
vidual exhibiting, in every one of its many
thousand component little bones, or ossi-
cula, a mechanism which shows them all
to have formed parts of a well-contrived
and delicate mechanical instrument. —
Prof. Buckland.

CRINOIDE'A. (from Kpivov and «7£oc, Gr.)
Lily-shaped zoophytes. A name given
to the whole class of encrinites and pen-
tacrinites, from their resemblance to the
head of the lily.

The fossil remains of this order have
been long known by the name of stone
lilies, or encrinites, and have lately been
classed under a separate order by the
name of Crinoidea. This order compre-
hends many genera and species, and is
ranged by Cuvier after the asteriae, in the
division of zoophytes. The skeleton of
the crinoidea is composed of numerous
ossicula, the number of bones in one ske-
leton being computed at upwards of thirty
thousand. Mr. Miller, in his work, en-
titled " a Natural History of the Cri-
noidea," thus defines them: " An animal
with a round, oval, or angular column,
composed of numerous articulating joints,
supporting at its summit a series of plates,
or joints, which form a cup-like body,
containing the viscera, from whose upper
rim proceed five articulated arms, divided
into tentaculated fingers, more or less
numerous, surrounding the aperture of the
mouth, situated in the centre of a plated
integument, which extends over the abdo-
minal cavity, and is capable of being con-
tracted into a conical or proboscal shape."
The detached ossicula of the crinoidea
occur in myriads in the mountain lime-
stone and transition rocks, forming suc-
cessions of strata, each many feet in
thickness, and miles in extent ; showing
how largely the bodies of animals have
contributed by their remains, to increase
the mass of materials which compose the
mineral world. If we imagine a star-
fish to possess a long flexible column, the
base of which is attached to a rock, we

shall have a correct idea of the general
character of the crinoidea, or lily-shaped
animals ; which are so called from their
fancied resemblance, when in a state of
repose, to a closed lily. — Buckland.
Mantell.
CRISP, (crispus, Lat.)

1 . Curled ; crisped ; wrinkled ; veined or
grained.

2. Indented.

3. Brittle ; friable.

CRISPA'TION. (crispation, Fr.) The act
of curling ; the state of being curled.

CRI'SPATED. (crispe, Fr.) Rough with
waving lines.

CRISPISU'LCANT. (crispisulcans , Lat.)
Waved, or undulating.

CRI'STATE. \(cristatus, Lat.) Crested;

CRI'STATED. \ tufted ; plumed ; combed.

CRO'CODILE. (icpoKodtiXoQ, Gr. crocodilus,
Lat. coccodrillo, It. crocodile, Fr.) An
amphibious voracious animal of the genus
Lacerta, or lizard. It is covered with
very hard scales, which can be pierced
with great difficulty, except under the belly.
It has four feet, and a tail, with five toes
on each of the fore, and four toes on each
of the hind feet, of which only the three
internal ones on each foot are armed with
nails. It has a wide throat, with several
rows of teeth. The fossil remains of cro-
codiles are common and abundant. Cro-
codiles are omnivorous. The living spe-
cies of the crocodile family are twelve,
one Gavial, three Alligators, and eight true
Crocodiles. Crocodiles, it is said, con-
tinue to grow throughout the whole of
their existence, and Buckland states their
increase to be no less than four hundred
times their original bulk, between the
period at which they leave the egg and
their full maturity. Crocodiles are fur-
nished with a frequent succession of teeth,
in order to maintain a duly proportioned
supply during every period of their life.
The vertebrae of the neck rest on each
other through the medium of small false
ribs, whereby all lateral motion is rendered
difficult, and the crocodile is unable to
deviate suddenly from his course ; this
renders escape from them facile, by either
running round them, or pursuing a zigzag
course. The eggs of the crocodile are as
large as those of the goose. They inhabit
fresh water, but they cannot swallow their
food under water.

CROCODI'LEAN. > T, , .. .* Vi

CROCODILIAN. \ RelatinS to the crocodlle-

CROP-OUT. A term used by miners to ex-
press the rising up at the surface of one
or more strata. A stratum rising to the
surface is said to crop out.

CROSS-STONE. Called also Staurolite, and
Harmotome ; it is the Paratomer Kuphon-
spath of Mohs, and the Kreutzstein of

C R O

C R U

Werner. Colours white and grey ; occa-
sionally it is found with a reddish and
yellowish cast. It is composed of 47 parts
silica, 21 baryta, 15 alumina, 0'88 potash,
0-10 lime, 15 water. It occurs in small
quadrangular prisms terminated by four
rhombic planes, crossing each other. The
surface of the smaller lateral planes is
double plumosely streaked. It is found
in galena veins and agate balls in the
mines of Strontian, in Argyleshire, and
in other parts of Scotland ; also at An-
dreasburg, in the Hartz, and in Norway.

CROY'LSTONE. Crystallized cauk. In this
the crystals are small.

CRU'CIAL. (from crux, Lat. crucial, Fr.)
Transverse ; intersecting one another ; in
form of a cross.

CRUCIFEROUS, (from crux andfero, Lat.)
The name given to a large order of plants,
whose petals, four in number, are so
arranged as to resemble a cross. The
radish, cabbage, stock, &c., are crucife-
rous plants.

CRU'CIFORM. (from crux and forma, Lat.)
Cross-shaped ; in the form of a cross. In
botany, polypetalous flowers are so called,
when the petals are placed in the form of
a cross ; this is particularly the case in a
very large order of plants, which have
four petals, so arranged as to resemble a
cross.

CRU'CIBLE. (crucibulum, Lat.) A vessel,
or melting-pot, made of earth, so named,
according to some, from its having been
formerly made in the shape of a cross ;
but, according to others, from the metals
being tortured in it by fire to compel them
to become gold.

CRU'RA. (The plural of crus, Lat.) Ap-
plied to parts from their resemblance to
legs ; the legs.

CRU'RAL. (crural, Fr. cruralis, Lat.) Be-
longing to the leg.

CRUST, (kruste, Germ, crusta, Lat. croute,
Fr. crosta, It.) Any shell, hard coat, or
external covering. That portion of our
globe which is accessible to our inspection
and observation is called by geologists,
the earth's crust. It is this crust which
offers proper occupation to the geologist.
The greatest depth to which he has been
hitherto able to extend his observations,
from the uppermost strata to the lowest
beds, is from eight to ten miles ; a thick-
ness which, compared with the bulk of
the earth, does not exceed that of the
thickness of the paper which covers a
globe a foot in diameter. The inequalities
and crevices in the varnish applied over
the surface of such a globe would fairly
represent, and be in proportion to, the
highest mountains and deepest valleys of
the world. The mean density of the
earth's mineral crust has generally been

taken at 2 '5 : according to De la Beche
2'6 would be a nearer approxima-
tion.

CRUSTA'CEA. ) (from crusta, Lat.) The
CRUSTA'CEANS. $ Crustacea possess a hard
external covering, and numerous articu-
lated limbs ; antennae, and palpi. A
heart, with circulating vessels and gills,
and a nervous system. The crab, lobster,
sea-urchin, shrimp, &c., are examples.
Crustaceous animals possess the most
solid form of the skeleton met with in the
articulated classes. It is found in the
larger decopods to contain nearly half its
weight of carbonate of lime, and there is
also a considerable proportion of phos-
phate of lime, with traces of magnesia,
iron, and soda. These substances are
exuded from the surface of the true skin,
along with a tough coagulable animal
gluten, which connects all their particles,
and forms a thin varnish on the surface.
The colouring matter is generally beneath
this varnish, and on the exterior surface
of the calcareous deposit, but sometimes
it pervades the whole substance of the
shell. The history of fossil crustaceans
has been hitherto almost untouched by
palaeontologists, and their relations to the
existing genera of this great class of the
animal kingdom are but little known.
Some idea may be formed of their extent
in certain formations, from the fact, that
in the cabinet of Count Munster, there
are nearly sixty species collected from a
single stratum of the Jurassic Limestone
of Solenhofen. — Dr. Rob. Grant. Pro-
fessors Buckland andFyfe.

The Crustacea respire by means of
branchiae ; these branchiae, sometimes si-
tuated at the bottom of the feet, at others
on the inferior abdominal appendages,
either form pyramids composed of laminae
in piles, or bristled with setae ; and in
some cases consist seemingly wholly of
hairs. The Crustacea differ from the tes-
tacea in one most striking point of view :
lobsters, crabs, &c., cast their shell or
covering every year, whereas the testa-
ceous animals retain theirs as long as
they exist. The shells of crustaceous
animals appear to grow all at once, where-
as those of testaceous animals are evi-
dently formed by the animal adding gra-
dually to them, either annually or period-
ically, and they are all composed of
layers.

CRUSTA'CEAN. } (crustacee, Fr. crust aceo,
CRUSTA'CEOUS. $ It.) Shelly, with joints.
The crustaceous animals possess a hard
shelly covering divided into parts by joints,
while the testaceous have a continued un-
interrupted shell. The crustaceous ani-
mals are the spiders of the sea.
CRUSTA'CEOUSNESS. The quality of having

e R u

[64]

CRY

a jointed, hard, external covering, or
shell.

CRU'STATED. (crustatus, Lat.) Covered
with a crust, or shell.

CRUSTA'TION. A hard shelly covering ;
incrustation.

CRY'OLITE. (from KpvoQ and X/0oc, Gr.)
Ice-stone. A rare mineral of a white,
brown, or red colour, hitherto found only
in Greenland, at the arm of the sea named
Arksut, where it occurs in gneiss, asso-
ciated with iron-pyrites and galena. It
consists of fluoric acid 44, soda 32, alu-
mina 24.

CRYPTOGA'MIA. (from icpuTrroc, concealed,
and ydfioc, nuptials, Gr.) The 24th class
of plants in the Linnsean artificial system,
comprehending those whose fructifications
are concealed, either through minuteness,
or within the fruit. The carboniferous
era abounded in the vascular cryptogamia
to a degree unexampled at the present
time ; the plants belong to species and
genera now extinct, but allied to existing
types by common principles of organiza-
tion. The numerical preponderance of
the cryptogamia in the coal is such, that
while in the present order of nature, they
are to the whole number of known plants
as one to thirty, at that epoch they were
in the proportion of twenty-five to thirty.
In the saliferous system, about fifty spe-
cies have been ascertained, some of which
differ from any observed in the coal mea-
sures. The class Cryptogamia contains
the ferns, mosses, funguses, and sea-
weeds : in all of which the parts of the
flowers are either little known, or too
minute to be evident.

CRYPTOGA'MIC. A term applied to plants
not bearing flowers with stamens and ova-
rium visible. Belonging to the class
Cryptogamia. Ferns, mosses, fungi, &c.,
are cryptogamic plants. In the transition
rocks, about thirteen species of crypto-
gamic plants, four of which are algse, and
the remainder ferns, comprise all that is
known of the vegetable kingdom, anterior
to the carboniferous system.

CRYPTOGA'MOUS. See Cryptogamic. The
family of ferns, both in the living and
fossil flora, is the most numerous of vas-
cular cryptogamous plants.

CRY'STALS. (from /cpvoraXXoe, Gr. crys-
tallus, Lat. crystal, Fr. cristallo, It.
krystall, Germ.) There are many mineral,
or inorganic, substances, which assume
certain regular forms when becoming solid
from a fluid state, or when, after being
dissolved in a fluid, this fluid is evapo-
rated. These regular figures are termed
crystals. The cause of a body's possess-
ing this power, or property, is unknown,
but it is supposed to be connected with
the form of the molecules of which it is

composed. Crystals are symmetrical
forms. There are six primitive forms of
crystals.

1. The regular tetrahedron, having four
equilateral triangles for its faces.

2. The regular cube of six squares for its
faces.

3. A dodecahedron, or solid of twelve
faces, each being a rhombus.

4. The octohedron, having eight triangles
for its faces.

5. A six-sided prism.

6. A parallelepiped, or a solid of six faces,
each two of which are parallel and equal,
as a cube, a rhomboid, &c. From these
six primitive forms of crystals, every va-
riety may be supposed to be produced by
cutting away its angles or edges in various
manners ; or by additions supposed to be
made on its faces. The regularity of the
figure will be influenced by the rapidity of
the evaporation, as when the evaporation
is hurried the crystals will be confused,
and wanting in regularity ; sometimes the
evaporation must be spontaneous, or not
assisted by the addition of heat, for pro-
curing regular and large crystals. It must
not be supposed that every mineral crys-
tallizes naturally in, or can be cut into,
all the forms, which might be deduced
from its primitive form ; but it never
occurs that the same mineral is found as-
suming a form, which cannot be shown on
these principles to be related to its primi-
tive, or in which primitive it either is
occasionally found, or to which the other
forms in which it occurs may not be re-
duced.— Min. and Metals.

When bodies dissolved in any fluid are
separated by crystallization, they are al-
ways found to retain a part of the fluid.
The water thus retained by saline crystals
is called the water of crystallization. This
water appears to be essential to the trans-
parent crystalline form of salts. Most
salts may be deprived of their water of
crystallization by heat ; some lose it in
the common temperature of the atmo-
sphere, and fall into a pulverulent mass ;
others attract moisture so strongly that
they, from exposure to the atmosphere,
deliquesce.

CRY'STAL. Resembling crystal ; bright ;
clear ; transparent.

CRY'STALLINE. (krystallen, Germ, crys-
tallin, Fr. cristallino, It.) Resembling
crystals ; bright ; clear ; transparent.

CRY STALLINE HUMOUR. } (icpvardXivot;,

CRY'STALLINE LENS. $ Gr. crystal-

linus, Lat.) A solid body of a lenticular
form, being a part of the eye. It appears
most absurd ever to have given to this
solid body the name of humour. The
crystalline lens is situated behind the
aqueous humour, opposite to the pupil,

CRY

C U N

and its posterior portion is received into
a depression on the fore part of the vi-
treous humour. It has two convex sur-
faces, like a common lens, the anterior
being the less convex ; the two being
formed of segments of spheres of unequal
size.

CRYSTALI'ZABLE. JThat is capable of

CRYSTALLI'ZABLE, $ being crystallized.

CRYSTALIZA'TION. ) (crystallisation, Fr.

CRYSTALLIZA'TION. $ cristallisazione, It.)
A methodical arrangement of the particles
of matter according to fixed laws ; conge-
lation into crystals.

CRY'STALLIZED. Formed into crystals.

CRYSTALLO'GRAPHER. } (from KpvoraXXoc

CRYSTALO'GRAPHER. $ and -ypa'^w, Gr.)
One who describes crystals. The crystal-
lographer has shewn that the several in-
gredients of all kinds of crystalline rocks
are composed of molecules which are
invisibly minute.

CRYSTALLO'GRAPHY. The science of crys-
tallization.

CTENOI'DEAN. Belonging to the third
order of fishes, according to the arrange-
ment of M. Agassiz.

CTENOI'DIAN. (from KTSIQ, pecten, a comb ;
and tides, Gr.) The third order of fishes
in the arrangement of M. Agassiz. The
cteno'idians have their scales jagged on
the posterior margin, resembling the teeth
of a comb, from which circumstance they
derive their name ; the perch is an ex-
ample. The cteno'idians first appear at
the commencement of the cretaceous for-
mations, succeeding the placoidean and
ganoidian orders. — Prof. Buckland.

CU'BATURE. The finding exactly the solid
content of any proposed body.

CUBE, (from Kvj3og, Gr. cubus, Lat. cube,
Fr. cubo, It.) A regular solid body con-
sisting of six square and equal faces, with
right, and therefore equal, angles : a die
is a small cube ; a prism contained by six
equal squares.

CUBE-ORE. A name given to the mineral
hexahedral olivenite.

CU'BIC. ) (cubisch, Germ.) Having the

CU'BICAL. $ form or properties of a cube.

CU'BICALNESS. The state of being cubical.

CU'BIFORM. Of the form, or shape, of a
cube.

CU'BIT.

1. A measure, according to Dr. Arbuth-
not, equal to one foot nine inches, and
888 decimal parts. — Home.

2. That part of the arm which extends
from the elbow to the wrist.

CU'BITAL. (cubital, Fr.) Relating to the

fore arm, or cubit.
CU'BIZITE. A name given by Wenrer to

analcime.

CUBOI'D. > Having the form of a cube;
CUBOI'DAL. \ cubiform.

CUBOI'DBS. A bone of the foot, in shape
somewhat resembling a cube ; it is placed
at the fore and outer part of the tarsus.

CU'BO-OCTAHE'DRAL. A combination of
a cube and an octahedron.

CUCU'LLATE. > (cucullatus^i.} Hooded ;

CUCU'LLATED. $ having the shape of a
hood. Applied to leaves when their
edges meet in the lower and expand to-
wards the upper part.

CUCUMERI'NA. (from cucumer, Lat.) A
species of fossil spine belonging to the
echinus, and possessing something of the
form of a cucumber, whence its name is
derived. There are several varieties.

CUCU'MERINE. Fossil spines of the species
cucumerina. Several varieties of cucu-
merine spines are figured in Parkinson's
Organic Remains.

CUI'RASS. (cuirasse, Fr. corazza, It.) A
defensive armour which protects the body
from the shoulders to the waist.

CULM. (Welsh.)

1. A kind of fossil coal, of indifferent
quality, burning with little flame, and
emitting a disagreeable smell.

2. An herbaceous stem peculiar to grasses,
rushes, and some other plants allied to
them. Culms are either hollow or solid,
jointed or without joints, round or trian-
gular, rough or smooth, hairy or downy,
and bear both leaves and flowers.

CU'LTRATED. (cultratus, Lat.) Sharp-
edged.

CU'MBRIAN SYSTEM. The Cumbrian or
slate system, as described by Professor
Sedgwick, extends over a large portion of
Cumberland, Lancashire, and Westmore-
land, attaining an elevation in some places
of upwards of three thousand feet, and
affording the splendid scenery of North
Wales and of the lakes. The strata are
of great, but unknown, thickness, possess-
ing a slaty character, and nearly destitute
of organic remains. The Cumbrian, or,
as it has been also called, Grauwacke
system, includes the Plynlymmon rocks,
the Bala limestone, and the Snowdon
rocks.

CU'MULATE. (from cumulo, Lat.) To
heap together.

CUMULATION. A heap ; the act of heap-
ing together.

CUMULATIVE. (cumulatif, Fr.) Com-
posed of parts heaped together.

CU'NEAL. (cuneus, Lat.) Having the form
of a wedge.

CU'NEIFORM. ) Having the form of a wedge.

CU'NIFORM. $ Three bones of the foot
have obtained the name of cuneiform
bones from their wedge-like shape ; they
are situated at the fore part of the tarsus
and inner side of the os cuboides, and are
K

C U P

C Y A

applied to each other like the stones of an

arch.
CU'PREOUS. (ciipreits, Lat.) Coppery ;

consisting of copper.
CUPRI'FEROUS. (from cuprum and fero,

Lat.) Yielding copper ; containing

copper.
CU'PULE. (cupula, Lat.) The cup of the

acorn and of similar fruits.
CU'RVATE. } (curvatus, Lat.) Crooked;
CU'RVATEP. $ bent.
CURVA'TION. (curvo, Lat.) The act of

bending or making crooked.
CU'RVATURE. (curvatura, Lat.) Flexure;

crookedness; inflexion.
CURVE. A flexure, or bending, in a regular

form ; a portion of a circle.
CU'RVED. Bent ; flexed.
CURVILI'NEAR. (from curvus and linea,

Lat.) Consisting of curved or crooked

lines.

CU'RVITY. Crookedness.
CU'SPATED. (from cuspis, Lat.) Pointed ;

terminating in a point, as the leaves of

the thistle.

CU'SPIDAL. Ending in a point,
CU'SPIDATED.

1. A botanical term, applied to leaves ter-
minating in sharp rigid spines.

2. In entomology, having a pointed pro-
cess much extended, and nearly setiform.

CUTA'NEOUS. (cutanee, Fr. cutaneo, It.)

Pertaining to the skin.
CU'TICLE. (cuticula, Lat. cuticule, Fr.)

1. The scarf-skin; the outermost skin.
The cuticle is a thin, greyish, semi-trans-
parent, insensible membrane, which covers
the skin, and adheres to it by small vas-
cular filaments. It is this which is sepa-
rated by the application of blisters.

2. In botany, the outward covering of
plants. Every plant is covered by a cuti-
cular expansion, analogous to the scarf-
skin that covers animal bodies. The
cuticle, or epidermis, of plants varies in
thickness, being extremely delicate on
some parts of a flower, and very thick,
hard, and coarse on the trunks of many

CUTI'CULAR. Pertaining to the cuticle, or
external covering of the body.

CU'TIS. (Lat.) The skin, dermis, or true
skin, as distinguished from the cuticle or
scarf-skin. It lies immediately under the
corpus mucosum, and gives a covering to
the whole body. It is formed of fibres
intimately interwoven, and running in
every direction, like the hairs in the felt
of a hat, and is so plentifully supplied
with nerves and blood-vessels, that the
smallest puncture cannot be made in any
part of it, without occasioning pain and a
discharge of blood. It is that part of
quadrupeds of which leather is made.
The cutia can be entirely dissolved by the

action of boiling water, and consists
chiefly of gelatin, from which circum-
stance it is a principal article in the
manufacture of glue.

CU'TTLE. i The sepia of Linnseus. A

CU'TTLE FISH. } species of Cephalopoda,
genus Mollusca. The bone of the sepia
(which is an internal bone, flat and broad,
somewhat resembling a sole in its appear-
ance,) is found, commonly, washed up on
our coasts, and when ground into fine
powder is used as pounce, and is some-
times employed in the making of tooth-
powder. The sepia attains to an immense
size in the seas of India and China, and
it is said that its arms, which are eight in
number, are sometimes several fathoms
long, so that it will, by throwing them
around a boat, endanger the safety of the
boat's crew, and that it is usual to keep
on board a hatchet for the purpose of
severing them on such occasions. The
cuttle-fish having no external shell, is
protected from its enemies by a peculiar
internal provision, consisting of a bladder-
shaped sac, containing a black and viscid
ink, soluble in water, the ejection of
which, by rendering the surrounding
water opaque, conceals and defends the
animal. The sepia has its feet around its
head, and walks along the bottom of the
sea with its head downwards. The feet
are lined internally with little round
serrated cups, or suckers, by which the
animal both seizes its prey and adheres
to other bodies. The mouth, which re-
sembles a parrot's beak, or the bill of a
hawk, is placed in the centre of the arms.
The ink of the cuttle-fish is said to form
an ingredient in the composition of Indian
ink.

Professor Buckland states, in describing
the ink found in a fossil ink-bag of the
cuttle-fish, " So completely are the cha-
racters and qualities of the ink retained
in its fossil state, that when, in 1826, I
submitted a portion of it to my friend
Sir Francis Chantrey, requesting him to
try its power as a pigment, and he had
prepared a drawing with a triturated por-
tion of this fossil substance ; the drawing
was shown to a celebrated painter, without
any information as to its origin, and he
immediately pronounced it to be tinted
with sepia of excellent quality."

The common sepia used in drawing is
from the ink-bag of an oriental species of
cuttle-fish.

CY'ANITE. (from KVO.VOQ, Gr. color cce-
rultus, or sky-coloured.) Called also
Kyanite, and by Saussure, Sappare, is a
mineral of a grey, blue, and blueish-green
colour. It occurs regularly crystallized,
as well as massive and disseminated. Its
texture is foliated ; laminae long ; frag-

C Y A

[ 67]

C Y M

ments splintery. It feels somewhat
greasy. Before the blow-pipe it becomes
almost perfectly white, but it does not
melt. Its constituent parts are, alumina
64-30, silica 34'33, with a trace of oxide
of iron and a very small portion of lime.

CYA'THIFORM. (from cyathus and forma^
Lat.) In the form of a cup, or drinking-
vessel ; cup-shaped.

CYATHOPHY'LLOUS. (from KVO.BOQ, and
$vX\ov, Gr.) Having cup-shaped leaves.

CYCA'DEA. (from KVKU^, cycas, Gr.) A
genus of plants. The cycadeae hold an
intermediate place between the palms,
ferns, and coniferse. Some species are
very short, as the zamia ; others attain a
height of thirty feet and upwards. This
beautiful family of plants in their exter-
nal habit resemble that of palms, whilst
their internal structure approximates to
that of coniferse. The cycadese are na-
tives of warm climates, mostly tropical,
though some are found at the Cape of
Good Hope. Leaves of cycadese are of
frequent occurrence in the shale of the
oolitic formation near Scarborough, and
they have been found in the Stonesneld
slate. Cycadese have been found in the
coal formation of Bohemia. The trunk
of the cycadea has no true bark, but it is
surrounded by a dense case, composed of
persistent scales, which have formed the
bases of fallen leaves ; these, together with
other abortive scales, constitute a com-
pact covering that supplies the place of
bark. The prevalence of cycadese gives
a distinctive character to the flora of the
upper secondary formations. The stems
found in the Isle of Portland, and the
leaves and fruits in the oolitic formations
of Yorkshire, show considerable analogy
to the existing forms of the tribe at the
Cape of Good Hope, in India, and Aus-
tralia.

CYCA'DEOUS. Possessing the characters
of cycadese ; belonging to the genus cy-
cadea.

CYCA'DITES. A name applied to some
fossil species of cycas. Our fossil cyca-
dites are closely allied by many remark-
able characters of structure to existing
cycadese. — BucJcland.

CY'CAS. (KVKCIQ, Gr.) A genus of plants,
belonging to the first natural order Palmse,
according to the first arrangement of
Linnseus, but subsequently placed among
the ferns.

CY'CLAS. (pi. cyclades.) A genus of
lacustrines, or fresh- water bivalves. The
calciferous grit near Hastings is full of
cyclades, and several species of cyclas
occur, in myriads, in the shales and
clays of the Wealden formation. — Mantell.
The cyclas is an ovato- transverse bi-
valve, not inflected on the fore part ; the

hinge with three hinge -teeth and two
lateral teeth, compressed and rather re-
mote.— Parkinson.

While the cyclas of Europe is de-
scribed as small, thin, and horny, abound-
ing in ditches, ponds, and slow streams,
that of Asia is stated to be very large.
The cyclas is viviparous.

CY'CLE. (from KVK\OQ, Gr. cycle, Fr. ciclo,
It. ) A round of years which go on from
first to last, and then return to the same
order as before ; a space in which the
same revolutions begin again.

CY'CLOID. (from KVK\OC,, and eidoc., Gr.
cyclo'ide, Fr.) A geometrical curve ;
a figure made by the upper end of the
diameter of a circle, turning about a
right line.

CYCLO'IDAL. Relating to a cycloid.

CYCLOI'DIANS. (from /cw/cXoc, Gr.) The
fourth order of fishes according to the
arrangement of M. Agassiz. Families of
this order have their scales smooth and
simple at their margin, and often orna-
mented with various figures at the upper
surface. The salmon and herring are
examples.

CYCLOI'DEAN. Belonging to the fourth
order of fishes, according to the arrange-
ment of M. Agassiz. The cycloidean and
ctenoidean orders succeeded the placoi-
dean and ganoidean.

CY'CLOLITE. (from KVK\OQ and \i9og, Gr.)
Another name for madrepore.

CYG'NET. (from cycnus, Lat.) A young
swan.

CY'LINDER. (icvXivdpoc,, Gr. cylindrus,
Lat. cylindre, Fr. cilindro, It.) A solid,
formed by the revolution of a rectangular
parallelogram about one of its sides, so
that it is extended in length equally round,
and its ends or extremities are equal
circles.

CYLI'NDRIC. ) Partaking of the nature of

CYLINDRICAL. $ a cylinder ; having the
form of a cylinder ; having its circum-
ference round, of indeterminate length,
but of equal thickness throughout.

CYLI'NDRIFORM. Of the form of a cylin
der ; round like a roller.

CYLI'NDROID. A solid, in many respects
resembling a cylinder, but having ellipti-
cal instead of circular extremities, yet
parallel and equal.

CYLINDRICO'DON. The name given to a
genus of oviparous quadrupeds.

CYME, (cyma, Lat. KVjita, Gr.)

1. A form of inflorescence, the general
appearance of which resembles an umbel,
and agrees with it in this respect, that its
common stalks all spring from one centre ;
but differs in having those stalks alter-
nately and variously divided. The olean-
der and elder are examples.

2. A sprout, as of a cabbage.

C Y M

[ 68]

DEC

CYMO'PHANE. A name given by Haiiy to
the chrysoberyl, which see.

CYMO'S^E. Plants whose inflorescence is
disposed in the form of a cyme ; the
sixty-third natural order of Linnaeus.

CYPERA'CE^. A tribe of plants answering
to the English sedges ; they are distin-
guished from grasses by their stems being
solid and generally triangular, instead of
being hollow and round. Together with
gramineae, they constitute what writers
on botanical geography often call glu-
maceae. — Lyell, Principles of Geology.

CYPR^E'A. (The cowry.) Animal a slug ;
shell univalve, oval, or oblong, involute,
smooth, obtuse at each end ; aperture
long, narrow, extending the whole length
of the shell, and dentated on each side.
The mantle sufficiently ample to fold
over and envelope the shell, which at
a certain age it covers with a layer of
another colour. The genus cypraea con-
sists of beautifully coloured shells very
highly polished. They live in sand at
the bottom of the ocean ; the animal is
provided with a membrane, which it
throws over its shell, which not only
preserves the fine polish, but prevents
testacese from fixing on it. One hundred
and twenty species have been described,
one only of which belongs to our seas ; the
rest are all tropical. In some parts the
shell of this animal is used in the place of
money, and passes current. By some it
is thought that the cyprsea casts its shell
annually.

CYPRI'FEROUS. Containing shells of the
genus Cypris. Entire layers of stone
are sometimes composed of the consoli-
dated remains of the cypris ; these shells
occur in the Hastings sand and sand-
stone, in the Sussex marble, and in the
Purbeck limestone.

CY'PRIS. A genus of animals, enclosed
within two flat valves, like those of a
bivalve shell, inhabiting the waters of
lakes and marshes. The cypris throws
off its integuments every year. The
cypris is a microscopic crustacean, with
which certain clay beds of the Wealden
are so abundantly charged, that the sur-
faces of many laminae into which this
clay is easily divided, are often entirely
covered with them as with small seeds.
The Sussex marble abounds in the shells
of the cypris.

CY'PRINA. An equivalve, inequilateral,
sub-orbicular, marine bivalve ; living in
sandy mud. Fossil species occur in the
tertiary deposits.

CYTHER^E'A. A marine bivalve ; equivalve,
lenticular, oval ; hinge with two cardinal
teeth ; one anterior lateral tooth in each
valve, which distinguishes this genus from
Venus. It is found in depths of the
ocean varying to fifty fathoms, in mud
and coarse sands. Several species have
been found fossil in the tertiary deposits.
Cytheraea nitidula is mentioned by Dr.
Mantell as occurring in the London clay,
and cytheraea convexa in the Plactic clay.

D

DA'OURITE. The siberite of Lermina. A
variety of the red schorl of Siberia, called
also rubellite. This stone is found in
Siberia mixed with white quartz. It is
composed of silica 56, alumina 36, with
some oxide of manganese, and oxide of
iron.

DASY'PUS. (daavTTovs, from SO.CTVG and
TTOVC, Gr.) The armadillo, which see.

DASYU'RUS. An animal of the marsupial
order. The dasyurus is said to be the
largest of the carnivorous marsupial ani-
mals. The head of a species of dasyurus
has been discovered in the Eocene fresh-
water limestone of Auvergne.

DA'THOLITE. ) The Dystom-spath of Mohs.

DA'TOLITE. > A. sort of spar- stone ; the
siliceous borate of lime. According to
Menil, it is a combination of silica 38-50,
lime 35-60, boracic acid 21-30, water
4-60. Its varieties are named Botryolite,
Earthy Botryoidal Datolite, and Com-
mon Datolite. It has been found prin-

cipally in Norway, in beds of magnetic
iron-ore.

DEBA'CLE. (Debacle, Fr. Amas de gla^ons
qui arrivent avec impetuosite, dans un
degel subit, apres qu'une riviere a ete
prise long-temps.) A violent torrent or
rush of waters, which, overcoming all
opposing barriers, carries with it stones,
rocks, and other fragments, spreading
them in all directions.

DEBOU'CHE. (debouche, Fr. Uextremite
d'un defile, d'un col de montagnes.} The
outlet of a narrow pass.

DEBRI'S. (debris, Fr.) The fragments of
rocks ; the ruins of strata ; the rubbish,
sand, grit, &c., brought down by tor-
rents.

DECAHE'DRAL. (from <S!ica, and efya, Gr.)
Having ten sides.

DECAHE'DRON. A figure which hath ten
sides.

DECA'NDRIA. (from <fg»ca, and avrjp, Gr.)
A class of plants characterized by having

DEC

[ 69]

DBF

ten stamens ; it includes cassia, ruta,
saxifraga, &c.

DECA'NDRIAN. Belonging to the class
Decandria ; having ten stamens.

DECAPHY'LLOUS. (from deica, and QvXXov,
Gr.) A calyx which hath ten leaves.

DECA'PODA. (from dsica, ten, and TTOVQ,
foot.) The first order of Crustacea. This
order includes the lobster, crab, craw-
fish, shrimp, &c.

DECA'PODAL. Belonging to the order De-
capoda ; having ten feet. Synonymous
with decempedal.

DECE'MFID. (from decem andjissus, Lat.)
Ten-cleft ; in botany, a term for a calyx,
cleft, or divided, into ten parts.

DECEMLO'CULAR. (from decem and locu-
lus, Lat.) Ten-celled ; in botany, an epi-
thet for a pericarp divided into ten loculi
or cells.

DECI'DUOUS. (deciduus, Lat.)

1. In botany, falling off; plants which
lose their leaves in autumn are called
deciduous ; applied also to stipules falling
in the autumn ; to calyces falling soon
after the expansion of the corolla ; and to
the corolla when falling with the sta-
mens.

2. In conchology, to shells having a ten-
dency in the apex of the spire to fall off ;
to crustaceans, annually casting their
shells.

DECLE'NSION. (from declinatio, Lat.)
Declination ; descent ; slope from or
downwards.

DECLINA'TION. (declinatio, Lat.) Devia-
tion from a right line.

DECLI'VITY. (declivitas, Lat. declivitt,
Fr.) Gradual descent of land, as distin-
guished from precipitous or perpendi-
cular.

DECLI'VOUS. ) (declivis, Lat.) Gradually
DECLI'VITOUS. $ descending, as distin-
guished from sudden and precipitous
descent.

DECOMPOSABLE. That may be resolved
into its constituent elements ; capable ol
being decomposed.
DE'COMPOSE. (decomposer, Fr. R6duire
un corps a ses principes, ou stparer les
parties dont il est compost. ) To resolve a
body into its constituent elements ; to
overcome the power of affinity, anc
thereby to separate elementary particles.
DECOMPOSITION. (decomposition, Fr."
Separation of parts previously united
Decomposition may be effected by vari-
ous methods ; it is of two kinds, simple
or single, and complex, or double.
DE'COMPOUND. Doubly compound. Leaves
are so called when the petioles, instead o
bearing leaflets, branch out into othei
petioles to which the leaflets are at
tached.
DECO'KTICATE. (decortico, Lat.) To de

prive of the bark or husk ; to peel ; to
strip off.

DECO'RTICATED. (decorticatus,~L*.t.} Worn
or divested of the epidermis, bark, husk,
or skin.

DECORTICA'TION. The stripping off the
bark or peel.

DECREMENT, (decrementum, Lat.) Gra-
dual waste, or wearing away, as of rocks
by the action of water ; gradual diminu-
tion.

DECRE'PITATE. (from decrepo, Lat.) To
fall into pieces with a crackling noise.

DECREPITA'TION. (dtcr£pitation,~Fr.) The
crackling noise made by certain sub-
stances in falling to pieces when heated.

DECRE'SCENT. (decrescent, Lat.) Gra-
dually becoming less.

DECU'RRENT. (from decurro, Lat.) Run-
ning downwards. Applied to sessile
leaves when the base runs down the
stem and forms a border or wing ; applied
also to stipules when extending down-
wards along the stem. In some plants,
as in some of the thistles, the margins of
sessile leaves run down on each side of
the stem, so as to appear to be of one
piece with it ; these leaves are called
decurrent.

DECU'RSION. The act of running down, as
of a stream of water.

DECU'RSIVE. Running down.

DECU'RSIVELY PINNATE. Applied to leaves
having their leaflets decurrent, or run-
ning along the petiole.

DECU'SSATE. (decusso, Lat.) To inter-
sect at acute angles ; to cross each other
at right angles. Applied to branches
growing in pairs, and alternately crossing
each other at right angles ; applied also
to leaves alternately opposite. In con-
chology, applied to striae, crossing or in-
tersecting each other at acute angles.

DECUSSA'TION. The act of crossing at
unequal angles ; the crossing of two lines,
rays, or threads, when they meet in a
point, and then proceed separately.

DEDENTI'TION. (from de and dentitio,
Lat.) The loss or shedding of the teeth,
as distinguished from dentition or the
appearing of the teeth.

DEFLAGRABI'LITY. (from deflagro, Lat.)
Combustibility ; the property of igniting,
and entirely consuming away.

DEFLA'GRABLE. That may be entirely
consumed by fire.

DE'FLAGRATE. To entirely consume by
fire.

DEFLAGRA'TION. (deflagratio, Lat. defla-
gration, Fr.) The operation by which a
body is wholly consumed by fire.

DEFLE'CT. (deflccto, Lat.) To turn

aside.

DEFLE'CTED. Turned aside ; bent aside
from its straight course.

DBF

[ 70 ]

DEN

DEFLE'CTION. The act of turning aside
from its straight course ; deviation.

DEFLE'XED. (deflexus, Lat.) In ento-
mology, having the sharp edge bent
downwards.

DEFLE'XURE. A turning aside from a
straight course.

DEGRADA'TION. (degradation, }?Y. II sig-
nifie deptrissement, etat de decadence, de
mine.} This term is used by geologists
to signify the lessening or wearing away
of rocks, strata, &c., by the action of
water, or other causes.

DEGRA'DE. (degrader.fr.) To diminish;
to wear away ; to reduce in size.

DEGRA'DED. Worn away ; reduced in size
by attrition, &c,

DEHI'SCENT. (dehiscens, Lat.) In bo-
tany, fruits which open when ripe, so as
to enable the seeds to escape, are termed
dehiscent. Gaping ; opening.

DEI'NTE GRATE. To diminish ; to separate
the integrant parts of.

DELICIU'ESCE. (deliquesce, Lat.) To be-
come fluid by the attraction of water from
the atmosphere.

DELIQUE'SCENT. That which by exposure
to the atmosphere attracts moisture, and
becomes from a solid a fluid body.

DELL. A narrow opening between hills ; a
small valley.

DELPHI'NULA. (from delpMnus, Lat.) A
turbinated, subdiscoidal, umbilicated uni-
valve. The aperture round and pearly ;
operculum horny. The delphinula creeps
on rocks and sea- weeds. This genus is
formed of shells formerly included by
Linnaeus in his genus Turbo. Lamarck
places delphinula in the family Scalariana.
The fossil delphinula occurs in the ter-
tiary deposits.

DE'LTA. A term applied by geologists to
the alluvial deposits formed at the
mouths of rivers. It has obtained its
name from a supposed resemblance to
the Greek letter A. Deltas are occa-
sionally of immense size, and they are
divided into lacustrine, mediterranean,
and oceanic, the first being those formed
in lakes, as the delta at the mouth of the
Rhone, at the upper end of the lake of
Geneva ; the second, or mediterranean,
are those formed in inland seas, as that
at the mouth of the Rhone, where it
enters the Mediterranean ; the third, or
oceanic, are those formed on the bor-
ders of the ocean, as the delta of the
Ganges.

DE'LTOID. (from delta, the fourth letter of
the Greek alphabet.) The name of a
muscle of the shoulder, from its supposed
resemblance to the Greek letter A ; tri-
angular.

DE'NDRACHATE. (from Skvfipov and a%a-
r»/f , Gr.) An agate with delineations of

trees, ferns, moss, &c. Some of these
are exceedingly beautiful, and are so
elegantly depicted that they have been
erroneously taken for real plants, whence
their name. These pebbles are found
abundantly on the shore from Bognor to
Brighton, and when cut and polished, are
made into very beautiful necklaces,
brooches, snuff-boxes, &c. &c.

DE'NDRITE. (dtvdpiTi£, Gr.) The same
as dendrachate.

DENDRI'TICAL. Containing the resem-
blance of trees, ferns, or mosses.

DE'NDROITE. A fossil resembling the branch
of a tree.

DE'NDROLITE. (from devdpov and X<0oe,
Gr.) Fossil wood ; the fossil branch of a
tree.

DE'NSITY. (densitas, Lat. densite, Fr. den-
sita, It.) Closeness ; compactness ; that
property directly opposite to rarity, where-
by bodies contain such a quantity of
matter in such a bulk. The densities of
bodies are proportional to their masses,
divided by their volumes. Hence if the
sun and planets be assumed to be spheres,
their volumes will be as the cubes of their
diameters. The strata of the terrestrial
spheroid are not only concentric and
elliptical, but the lunar inequalities show
that they increase in density from the
surface of the earth to its centre.

The absolute density of, or the quan-
tity of matter contained in, the earth,
compared with an equal bulk of any
known substance, may be nearly deter-
mined by the attractive force which any
given mass of matter exerts upon a plum-
met, when suspended in its vicinity, to
draw it from a vertical line. By this me-
thod it has been found that the mean
density of the earth is about five times
greater than that of water, or nearly
twice the average density of the rocks and
stones on the surface. The mean den-
sity of the ocean is only about one-fifth
part of the mean density of the earth.

DE'NTAL. (dentalis, Lat. dentate, Fr.
dentale, It.) Relating to the teeth; re-
sembling a tooth, as a dental process.

DE'NTAL. ) (from dens, Lat.) A shell-

DENTA'LIUM. $ fish belonging, according
to Linnaeus, to the class Vermes, order
Testacea. The shell consists of one tu-
bulous arcuated cone, open at both ends.
There are many species, distinguished by
the angles, striae, &c. of their shells.

The observations of Deshayes lead to
the conclusion that the genus Dentalium
approaches very closely to the molluscs,
if, indeed, it does not belong to them.
The dentalia are found in deep water,
frequently near the shore, inhabiting the
ocean only ; they are solitary. The ani-
mal is a terebella. The shells are known

DEN

D E R

commonly by the name of tooth-shells,
or sea teeth. Twenty-two species have
been described, seven of which inhabit
our coasts.

DE'NTALITE.' } (from dens, a tooth, and

DE'NTALITHE. $ \iQoQ, a stone.) A fossil
dentalium found in the tertiary formations,
in the gait and in the lower green sand.
Of these there are many species ; as the
Dentalium planum, D. striatum, D. ellip-
ticum, D. decussatum, &c.

DENTA'TA. A name given to the second
vertebra of the spinal column, from a
tooth-like process which it possesses.

DE'NTATE. > (dentatus, Lat.) Indented;

DE'NTATED. 5 jagged ; notched ; toothed.
In botany, leaves are called dentated,
when the border is beset with horizontal
projecting points or teeth, with rather a
distant space between each, and of the
same consistence as the substance of the
leaf itself: applied also to stipules hav-
ing spreading teeth about the margin,
remote from each other.

DE'NTED. (dente, Fr. decoupt en point es
serr6es les unes contre les autres.)
Notched; indented.

DE'NTILE. A small tooth, as that of a
saw : a term used in conchology.

DENTI'CULATED. (denticulatus, Lat.) Set
with small teeth, as in the area.

DENTICULA'TION. The state of being set
with small teeth.

DE'NTIFORM. (from dens and forma, Lat.)
Tooth-shaped.

DENTI'TION. (dentition, Fr.) The period
at which the teeth are being formed within
the jaws, and protruded through the
gums.

DE'NTOID. (from dens and tldog, Gr.) Of
the shape, or form, of a tooth.

DE'NUDATE. (denudo, Lat.) To lay bare ;
to strip ; to divest of its covering.

DENUDA'TION. (denudatio, Lat. denuda-
tion, Fr.) The laying bare ; the act of
divesting of its covering ; the uncovering
of strata by the washing away of their
covering.

DENU'DE. (denudo, Lat. dtnuer, Fr. de-
nudare, It.) To lay bare ; to divest of
its covering ; to strip.

DENU'DED. Laid bare ; exposed ; divested
of its covering ; stripped.

DEOBSTRU'CT. (from deobstruo, Lat.) To
free from impediments.

DEO'XYDATE. ) To reduce from the state of

DEO'XYDIZE. 5 an oxyd by depriving it
of its oxygen.

DEO'XIDIZED. "I Deprived of oxygen ; dis-

DEO'XYDIZED. { united, or separated

DEO'XIDATED. f from the oxygen with

DEO'XYDATED. J which it was previously
joined.

DE'PILATE. (depilo, Lat. depiler, Fr.
depilare, It. ) To deprive of hair.

DE'PILOUS. (from de and pilus, Lat.)
Having no hair.

DEPLUMA'TION. (deplumatio, Lat.) The
plucking off the feathers.

DEPLU'ME. (dtplumer, Fr.) To pluck, or
strip, of its feathers.

DEPLU'MED. (deplume, Fr.) Stripped of
its feathers.

DEPO'SIT. Matter laid or thrown down ;
that which having been suspended or
carried along in a medium lighter than
itself at length subsides, as mud, gravel,
stones, detritus, organic remains, &c.

DEPOSITION. That which is deposited or
thrown down.

DEPRE'SSED. (depressus, Lat.) Pressed
down ; low ; shallow ; flat. In botany,
leaves are called depressed when flattened
vertically : radical leaves are thus called
when they are pressed close to the ground.

DEPRESSION, (depressio, Lat. depression,
Fr. depressione, It.) The sinking, or
falling in, of a surface.

DEPRE'SSOR. The name given to such
muscles as have the power of depressing,
as the depressor anguli oris, &c.

DE'PURATE. > (dtpurer, Fr. rendre plus

DEPU'RE. $ pur: depurare, It.) To
free from impurities ; to cleanse.

DE'PURATE. \ (dtpurt, Fr.) Cleansed;

DE'PURATED. $ freed from impurities.

DEPURATION. (depuration, Fr. depura-
zione, It. depuratio, Lat.) The action
of freeing from impurities, of cleansing.

DERA'CINATE. (de'raciner, Fr. tirer de
terre, arracher de terre un arbre.) To
tear up by the roots ; to extirpate.

DERACINATING. Tearing up by the roots ;
violently extirpating.

DERBYSHIRE SPAR. This beautiful sub-
stance is fluate of lime, a combination of
calcareous earth with fluoric acid ; it oc-
curs in nodular masses, and in crystals.
It is found in great beauty and abun-
dance in Derbyshire, whence it has ob-
tained its name, but it is also plentiful in
other parts of England. It is also called
flour-spar and blue-John, which latter
see.

DERIVA'TION. (derivatio, Lat. derivation,
Fr. detour qu1 on fait prendre aux eaux.}
The turning of water from its usual
course ; the drawing off of water from its
regular channel.

DERI'VE. (from derivo, Lat. dMver, Fr.)
To turn the current of water from its
course.

DE'RMAL. (from dep/ja, Gr. ) Belonging
to the skin ; composed of skin. Thus
we read of the dermal fringe of the
iguana ; the dermal bones of the hylseo •
saurus.

DE'RMA. ) (depict, Gr.) The true skin,

DE'RMIS. $ as distinguished from the
cuticle, epidermis, or scarf-skin.

D E R

C 72]

D E X

DE'RMOID. (from deppa, and tl^oQ Gr.)
Belonging to the skin ; resembling the
skin.
DESI'CCATE. (from desicco, Lat.) To

dry up ; to exhaust of moisture.
DESI'CCATE. To grow dry ; to be freed

of moisture.

DESI'CCATED. Dried ; exhausted of mois-
ture.

DESICCA'TION. (desiccatio, Lat.) The
state of being dried ; the act of making
dry.
DESI'CCATIVE. That has the quality of

making dry.

DE'SMINE. A mineral found in the lava of
extinct volcanoes accompanying spinel-
lane ; its form of crystallization is in
small silken tufts.

DE'SPUMATE. (despumo, Lat.) To throw
off in froth or foam ; to discharge impu-
rities, or excrementitious matter in foam
or scum.

DESPUMA'TION. (despumatio, Lat.) The
throwing off of excrementitious matter
and impurities in froth, foam, or scum.
DESQ,UAMA'TION. (desquamatio, from de
and squama, Lat.) The falling off of the
cuticle in the form of scales.
DE'SQUAMATE. (desquamo, Lat.) To

scale off ; to fall off in small scales.
DETRI'TION. The act of wearing away.
DETRI'TAL. Composed of detritus ; con-
sisting of the disintegrated materials of
rocks.

DETRI'TUS. (Lat.) The worn off, or
rubbed off, materials of rocks. " Beneath
the whole series of stratified rocks," says
Professor Buckland, " that appear on the
surface of the globe, there probably exists
a foundation of un stratified crystalline
rocks, bearing an irregular surface, from
the detritus of which the materials of
stratified rocks have in great measure
been derived."

DEUTO'XIDE. > (from StvTepos and oxyd.*)
DEUTO'XYDE. $ A substance in the se-
cond degree of oxidation, or containing two
prime proportions of oxygen : a protoxide
is in the first or smallest degree ; a trit-
oxide denotes a third proportion, and a
peroxide has the greatest degree of oxida-
tion.

DEVE'LOPE. (dtvelopper, Fr.) To un-
fold ; to disclose ; to clear from its cover-
ing ; to unravel.

DEVE'LOPEMENT. (dlveloppement, Fr.)
In this word and that which precedes it,
the French derivation is incorrectly spelt,
in the former by Johnson, in the latter
by Todd, who introduces it.) The act
of unfolding ; the discovering of something
hidden.

DE'VEX. (<7e0e.rttS,.Lat.) Inclining down-
wards ; declivous ; bending down-
wards.

DEVE'XITY. (devexita*, Lat.) Declivity ;
a bending downwards.

DKVOLTJ'TJON. (devolutio, Lat. devolution,
Fr. devoluzione, It.) The act of rolling
down, as the removal of earth or strata into
a valley.

DEVO'LVE. (devolvo, Lat.) To roll down,
as "every headlong stream devolves its
winding waters to the main." In this
sense, however, the word is not modern-
ly used : in its common acceptation,
at the present day, it signifies to pass by
succession from one person to another.

DEW. The following account of dew is
extracted from " Mrs. Somerville's Con-
nexion of the Physical Sciences:" —
" Our sensations only measure compara-
tive degrees of heat : when a body, such
as ice, appears to be cold, it imparts
fewer calorific rays than it receives ; and
when a substance seems to be warm, for
example, a fire, it gives more caloric than
it receives. The phenomena of dew and
hoar-frost are owing to this inequality of
exchange ; the caloric radiated during
the night by substances on the surface of
the earth into a clear expanse of sky is
lost, and no return is made from the blue
vault, so that their temperature sinks be-
low that of the air, whence they abstract
a part of that caloric which holds the at-
mospheric humidity in solution, and a
deposition of dew takes place. If the
radiation be great, the dew is frozen and
becomes hoar-frost, which is the ice of
dew. Cloudy weather is unfavourable to
the formation of dew, by preventing the
free radiation of caloric ; and actual con-
tact is requisite for its deposition, since
it is never suspended in the air like fog.
Plants derive a great part of their nou-
rishment from this source ; and as each
possesses a power of radiation peculiar
to itself, they are capable of procuring a
sufficient supply for their wants."

DEW-LA.P. The loose skin which hangs
down under the throat of the cow and
other animals, and thus called from its
licking or lapping the dew when grazing.

DEX'TER. )(Lat.) The right, as op-

DE'XTRAL. 5 posed to the left. In con-
chology, shells are divided into dextral
and sinistral. The more common turn of
shells is with the apparent motion of the
sun, or as the index or hand of a clock
moves. On the contrary, a reversed, or
sinistral, shell, when placed in a perpen-
dicular position has its spiral volutions in
an opposite direction to the motion of the
index of a clock, and resembles what is
called a sinistral, or left-handed, screw.
The sinistral shells are sometimes termed
heteroclitical, and heterostrophe shells.
There has been considerable confusion
amongst conchological writers in describ-

D I A

C 73]

D I C

ing the position in which shells should be
held to ascertain the right from the left side,
&c. Perhaps, the most simple plan is, to
place the apex of any spiral shell towards
the eye with the mouth downwards ; dextral
shells will then be found to have their
aperture on the right side of the axis;
sinistral shells, on the contrary, will have
theirs on the left of the axis.

DI'ABASE. The French name for green-
stone ; a trap- rock, composed of horn-
blende and feldspar.

DIADE'LPHIA. (from dig and adeXtyog,
Gr.) The seventeenth class of plants in
the artificial system of Linnseus. The
stamens are united into two parcels at
the base. This class has papilionaceous
flowers and leguminous fruits. Familiar
specimens will be found in the garden
pea, bean, &c. &c.

DIADE'LPHOUS. Having its stamens united
into two parcels at the base ; belonging to
the class Diadelphia.

DIA'GONAL. (diaywviog, Gr. db angulo ad
angulum perductus : diagonius, Lat. dia-
gonal, Fr. diagonale, It.) A line reach-
ing from one angle to another, so as
to divide a parallelogram into equal parts.
Diagonals principally belong to quadrila-
teral figures.

DIA'GONALLY. (diagonalement ', Fr. dia-
gonalemente, It.) In a diagonal direc-
tion.

DI'ALLAGE. Schiller-spar ; a variety of
serpentine, or crystallized serpentine.
The colour of diallage is dark-green.

DIA'METER. (^ta/zerpoe,Gr. diameter lineam
dimentiens, per medium secans: diame-
ter, Lat. diametre, Fr. diametro, It.)
A straight line passing through a centre,
and terminated both ways by the sides or
surface of a figure.

DIAME'TRAL. ) (diametral, Fr. diame-

DIAME'TRICAL. $ trale, It.) Describing
a diameter ; relating to the diameter.

DIA'METRALLY. } (diametralement :, Fr.

DIAMETRICALLY. { diametralmente, It.)
In a diametrical direction ; in direct oppo-
sition ; directly.

DI'AMOND. (diamant, Fr. diamante, It.
d£a/i«c, Gr. adamas, Lat.) The hardest
and most valuable of all the precious
stones. Strange as it may appear, dia-
mond consists of pure carbon. If the
best charcoal be burnt in oxygen, carbonic
acid gas is formed, the weight of which
is nearly equal to that of the charcoal
and the oxygen, there being a small re-
siduum of earthy ashes left after the com-
bustion ; but if, in like manner, a diamond
be burnt in oxygen, carbonic acid gas is
equally the result, though, in the latter
case, there is no residuum, and the car-
bonic acid gas obtained is precisely equal
in weight to the two elements, the oxygen

and the diamond. Why, or how, it is
that the same elementary substance can,
with little or no addition, form two such
excessively dissimilar bodies as diamond
and charcoal, — the former the hardest and
clearest body in nature, the latter a mere
black, soft, brittle mass, — is a mystery be-
yond our finite powers to comprehend.
The primitive crystal of the diamond
is the regular octohedron, each triangular
facet of which is sometimes replaced by
six secondary triangles bounded by curved
lines ; so that the crystal becomes sphe-
roidal, with 48 facets. When rubbed,
the diamond shews positive electricity.
It reflects all the light falling on its pos-
terior surface at an angle of incidence
greater than 24° 13', whence its great
brilliancy is derived. It is the natural
edge of the diamond only that has the
property of cutting glass, all artificially
formed edges will only tear or scratch it.
Diamonds are found of nearly every
shade of colour, those which are colourless
are deemed the most valuable. The largest
diamond known is said to be that which
belonged to the late Emperor of the Bra-
zils ; it is uncut, and weighs 1680 carats,
or 11 ounces 96 grains. This magnificent
gem would be worth, supposing the table
of rates to be applicable to stones above
a certain size, 5,6'45,000/., but the highest
price that has ever been given for a single
diamond is 150,000/. A diamond in the
possession of the Great Mogul is of the
size of half a hen's egg. The Pitt dia-
mond, now the property of the king of
the French, was sold for 100, OOO/. ; it
weighs 136 carats, or nearly 1 ounce.

DI'AMOND-SHAPED. Leaves are so called
when approaching to a square, having
four sides, of which those opposite are
equal : the four angles are generally, two
obtuse, and two acute.

DIA'NDRIA. (from dig, and «v/)p, Gr.)
The second class of plants in Linnaeus'
artificial arrangement ; they have two
stamens. This is a very numerous class,
consisting of three orders, and compre-
hends all hermaphrodite flowers having
two stamens.

DIA'NDRIAN. Having two stamens ; be-
longing to the class Diandria.

DIAPHANE'ITY. (diaphaneite, Fr.) Trans-
parency.

DIA'PHANOUS. (SiaQavrig, from SiatyaivM,
Gr. diaphane, Fr.) Which may be seen
through ; transparent ; pellucid.

DI'APHRAGM. (Sia(ppayfia, Gr. dia-
phragma, Lat. diaphragms, Fr. dia-
fragma, It. ) A large transverse muscle,
which separates the chest from the belly ;
the midriff.

DI'CERAS. (from Sig and Kepag, Gr.)
A genus of fossil shells discovered in

L

D I C

[ 74 ]

I G

granular limestone, and thus named from
possessing two prominent spiral umbones,
which resemble two twisted horns.
DICHO'TOMOUS. (from ^t'xaandrl/ivw. Gr.
dichotome, Fr. dicotomo, It.) Forked ;
regularly and continually divided by
pairs from the top to the bottom : ap-
plied to stems dividing into two parts ;
example, the misletoe.

DI'CHROIT. ) A mineral, called also io-
DI'CHROITE. ) lite. The prismatic quartz
of Mohs ; iolithe of Haiiy. Dichroite is
of a blue colour, shining lustre, and con-
choidal fracture. It consists of nearly
50 per cent, of silica, alumina 30, magne-
sia 11, oxide of iron 5, with a trace of
oxide of manganese. It occurs in granite
and gneiss.

Dico'ccous. (from die and KOKKOZ, Gr.)
A capsule which consists of two cohering
grains, or cells, with one seed in each.
DJCOTYLE'DON. (from dig andjcoruX/;£o*»'.)
A plant which has two cotyledons or se-
minal leaves.

DICOTYLE'DONOUS. Every plant the em-
bryo of whose seed is made up of two lobes,
or which possesses two cotyledons, or semi-
nal leaves, is included in this great division
of the vegetable kingdom ; or is a dico-
tyledonous plant. The stems of dico-
tyledonous plants are all exogenous, that
is, they increase externally by the addi-
tion of concentric layers from without ;
these concentric additions being made
annually, a vertical section of a tree of
this division will shew, at once, its age ;
the number of rings or circles marking
its number of years. Dicotyledonous
plants may always be distinguished from
monocotyledonous by their leaves : mo-
nocotyledonous plants have the veins of
their leaves parallel and not reticulated,
while all dicotyledonous plants have the
veins of their leaves reticulated.
DIDA'CTYLE. (diSuKTvXog, Gr.) An ani-
mal having two toes only.
DIDA'CTYLOUS. Two-toed ; having two

toes only.

DIDE'LPHIS. > (from dig and Setyvg, Gr.
DIDE'LPHYS. $ having two wombs.) A
genus of animals, belonging to the class
Mammalia, order Ferae. All the animals
of this genus are marsupial, that is, pos-
sess an external abdominal pouch, mar-
supium, or sac, in which the foetus is
placed after a very short period of uter-
ine gestation, and where it remains sus-
pended to the nipple by its mouth, until
sufficiently matured to come forth to the
external air. The opossum and kangaroo
are examples. The didelphys affords the
only known example of mammalian re-
mains in the secondary formations.
DIPE'LPHOID. Belonging to the genus di-
delphys.

DIDYNA'MIA. (from cJeand dvvafiig, Gr.)
The name given to the 14th class in Lin-
nseus's artificial arrangement : it has four
stamens, two long and two short. This class
is easily distinguishable from the 4th class,
Tetrandria, which has also four stamens.
The flowers of this class are generally la-
biate ; corolla monopetalous. It is di-
vided into two orders: Gymnospermia,
with four naked seeds in the bottom of
the calyx, and Augiospermia, the seeds
numerous and contained in a seed-vessel.
In the first order, with the naked seeds,
the plants are mostly aromatic and whole-
some, including the mint, lavender, &c.
In the second, where the seeds are con-
tained in a seed-vessel, we find digitalis,
and other poisonous plants.
DIDYNA'MIC. ) Belonging to the class
DIDYNA'MOUS. ) Didynamia. Plants hav-
ing four stamens, two of which are
shorter than the others, are called didy-
namous.

DI'FFLUENT. } (diffluens, Lat.) The
DI'FFLUENCY. \ quality of flowing
away on all sides, as does water; the
effect of fluidity.

DI'FFLUENT. Flowing every way ; not fixed.
Water is diffluent, but if it be converted into
ice it ceases to be so, becoming fixed.
DIFFU'SE. (from diffundo, Lat.) To

pour out ; to spread ; to disperse.
DIFFU'SE. ( (diffus, Fr. diffuso, It.)
DIFFU'SED. S Poured out ; scattered ;
spread. Widely spread out ; scattered ;
dispersed.

DIFFU'SEDLY. (diffustment , Fr. diffusa-
mente, It. diffuse, Lat.,) In a scattered
manner.
DIFFU'SEDNESS. The state of being widely

spread out, of being scattered.
DIFFU'SIVE. Having the quality of spread-
ing in all directions, as water.
DIGA'STRIC. (from dig and yaor?}p, Gr.)

Having two bellies.

DI'GITAGRADA. In Cuvier's arrangement,
the second tribe of carnivora. The name
digitagrada has been applied to them
from the circumstance of the animals
which compose this tribe walking on the
ends of their toes.

DI'GITATE. ) (digitatus, Lat.) A sort of
DI'GITATED. $ compound leaf, composed
of two or more leaflets. Botanists in-
clude under the name digitate, binate and
ternate leaves, as well as those having
more than five leaflets, as the horse-ches-
nut, which has seven leaflets.
DIGY'JSIA. (from £jg and yvvfj, Gr.) The
second order in Linnseus's artificial sys-
tem, comprehending such plants as have
two styles, or pistils.

DIGY'NIAN. ) Having two styles, or pis-
DJGY'NIOUS. $ tils; belonging to the
order Digynia.

D I K

[ 75]

D I P

DIKE. (Sax.)

1. A ditch ; a channel to receive water.

2. A mound ; defence ; wall; fortification.

3. Geologists use the word dike to express
a wall of mineral matter, cutting through
strata in nearly a vertical direction.
Lyell observes, " That it is not easy to
draw the line between dikes and veins ;
the former are generally of larger dimen-
sions, and have their sides parallel for
considerable distances ; while veins have
generally many ramifications, and these
often thin away into slender threads."

DILU'VIAL. (dihivialis, Lat.) Relating
to the deluge. A term introduced by
Professor Buckland to distinguish accu-
mulations consequent on the deluge.
"It is always," says Dr. Mantell, "in
diluvial beds spread over the surface of
plains, or accumulated in the bottoms of
valleys, that the teeth and bones of mam-
malia have been discovered in various
parts of England."

DILU'VIALIST. One who attributes cer-
tain effects, denied by others, as conse-
quent on the Noachian deluge.

DILU'VIAN. (Lat.) A name applied by
Professor Buckland to the superficial beds
of gravel, clay, and sand which he consi-
ders to have been produced by the No-
achian deluge : loose and water-worn
strata not at all consolidated, and depo-
sited by an inundation of water.

DI'NGLE. A dale ; a narrow valley between
hills ; a hollow.

DINOTHE'RIUM. (from <5Tvo£, and 6ij-
piov, Gr.) An extinct genus of terres-
trial mammalia. There are two known
species of dinotherium. The dinotherium
may be considered to have been the
largest of terrestrial mammalia. The
most abundant fossil remains of this
genus have been found at Epplesheim, in
Germany. In various parts of the south
of France, large molar teeth and osseous
fragments of dinotheria have been found
occasionally, and these were referred by
Cuvier to a gigantic species of tapir, and
named by him Tapir giganteus.

Subsequent discoveries have enabled
Prof. Kaup to place the dinotherium in a
new genus, and to establish the fact that
it was an herbivorous aquatic animal, in-
habiting marshes and lakes, and that it
sometimes attained the length of eighteen
feet. The dinotherium holds an inter-
mediate place between the tapir and the
mastodon, supplying a link between the
cetacea and pachydermata. The scapula,
or shoulder-blade, is the most remarkable
bone hitherto discovered, belonging to
this animal ; it resembles that of the
mole, and seems to indicate that the fore-
leg was adapted for digging up the earth.
It appears also certain that this huge

creature was furnished with a proboscis.
The dinotherium may be found figured in
Prof. Buckland's Bridgewater Treatise,
and in Mantell's Wonders of Geology,
from which works much of the preceding
account has been extracted. The dino-
therium is referrible to the miocene
period.

DI'ODON. In Cuvier's arrangement, a genus
of fishes belonging to the family Gymno-
dontes, and thus named in consequence of
their jaws being undivided, and forming
one piece only above and one below.
Their skin is in all parts so armed with
spines, that they resemble the case of the
fruit of the horse-chesnut. Teeth sup-
posed to belong to diodon histrix have
been found in the chalk.

DIO/CIA. (from t>i£ and ol/coc, Gr.) The
twenty-second class of plants in Lin-
nseus's artificial system. The stamens
and pistils are in separate flowers, and
situated on two separate plants. The
orders in this class depend on the cir-
cumstances of their male flowers.

Diffi'cious. Belonging to the class Dicecia ;
plants which have the barren and fertile
flowers growing from the two separate
roots.

DIO'PSIDE. (from Sio^iQ, Gr. transpectus.)
A mineral known also as alalite, baikalite,
and musite. It is a white or pale green
variety of augite. It occurs massive, dis-
seminated, and crystallized. It is found,
generally imbedded in Serpentine, in
Piedmont. It consists of more than half
silica, one fourth lime, about eighteen
per cent, magnesia, with a trace of alu-
mina and protoxide of iron.

DIO'PTASE. The Cuivre Dioptase of Haiiy.
Emerald copper-ore, a very rare mineral
of an emerald-green colour, consisting of
oxide of copper and silica in nearly equal
proportions, with about eleven per cent,
of water.

DI'ORITE. A variety of greenstone.

DIORI'TIC. Resembling diorite ; contain-
ing diorite ; of the nature of diorite.

DIP. To incline downwards ; to sink ; to
immerge.

DIP. In geology, the downward inclina-
tion of strata. The point of the com-
pass towards which strata incline is called
their dip, and the angle of such inclina-
tion with the horizon is termed the dip,
or angle, of inclination. It sometimes
happens that a stratum, without varying
its direction, may be so bent as to dip two
ways in the same mountain, like the
sloping sides of the roof of a house, or
the letter V reversed A •

DIPE'TALOUS. (from dig and TrsraXoi/,
Gr.) Having two flower-leaves or petals.

DI'PTERA. (from SIQ and Trrtpbv, Gr.)
The sixth order of insects in the Lin-

D I P

r 76]

D I S

nsean system, or insects having two
wings. The musca, or common fly ; the
culex, or gnat ; and the oestrus, or gad-fly,
are familiar examples. In Cuvier's ar-
rangement diptera forms the twelfth class
of insecta, and their distinguishing cha-
racters are said to be the possessing six
feet, and two membranous extended wings,
accompanied generally by two moveable
bodies, called halteres, which are placed
behind the wings ; the organs of mandu-
cation are a sucker composed of squa-
tnous, sectaceous pieces, varying in num-
ber from two to six, enclosed in an inar-
ticulated sheath, most frequently in the
form of a proboscis. In these divisions
almost every entomologist is disposed to
make alterations, and the systems pro-
posed are far too numerous to be re-
counted.

DI'PTEROUS, Two -winged insects ; belong-
ing to the order Diptera.

DIPY'RE. A mineral, a variety of scapolite
found in the Pyrenees, thus named by
Haiiy. It consists of silica 60'0, alumina
20'0, lime lO'O, and some water or
loss.

DIRU'PTION. (diruptio, Lat.) A forcible
rending asunder ; a breaking, or tearing
away.

DIRU'PTED. (diruptus, Lat.) Rent asun-
der ; broken away.

Disc. > (discus, Lat.)

DISK. J 1. Inconchology,the middle part
of the valves, or that which lies between
the umbo and the margin; the convex
centre of a valve, or most prominent part
of the valve, supposing it to lie with its
inside undermost.

2. In botany, the central florets of a com-
pound flower ; the whole surface of a
leaf.

DISCO'BOLI. The name given to a family
of fishes, in Cuvier's arrangement, from
the disk formed by their ventrals. The
fishes of this family form two genera.

DI'SCOID. ) 1. In the form of a disc. In

DISCOI'DAL. $ botany, plants, the petals
of whose flowers are set so closely and
evenly as to make the surface plain and
flat like a dish.

2. In conchology, when the whorls are so
horizontal as to form a flattened spire.

DISCOI'DES. A genus of fossil echinus,
one species only of which has been found,
namely, discoides subuculus.

DISCO'RBIS. A genus of microscopic spiral
discoidal univalves.

These have been thought by some au-
thors, and the number includes Lamarck,
to be found in a fossil state only; but
Parkinson states that they are found
recent on our coasts.

DISCORBI'TES. Fossil shells of the genus
discorbis.

Di'scous. Broad ; flat ; wide, but of a
rounded form.

DISCONTINUITY. Disunity of parts ; ab-
sence of cohesion.

DISCONTINUOUS. Separated ; interrupted.

DISEMBO'GUE. (Bailey and Johnson give
the etymology of this word from desem-
boucher, Fr. ; but I do not find any such
word as desemloucher in the Dictionnaire
de L' Academic ; indeed, the word itself
is rarely modernly used.) To roll or dis-
charge itself into the sea, as a large river
does ; to gain a vent ; to flow.

DISGO'RGE. (d6gorger, Fr.) To vomit
forth ; to eject with violence.

DISGO'RGED. Vomited out ; ejected with
violence.

DISINTEGRATED. Separated into its inte-
grant parts by mechanical division.

DISINTEGRATION. The separation of a
body into its integrant parts by mecha-
nical division ; the wearing down of rocks.

DISK. See Disc.

DI'SLOCATE. (disloquer,J?r. dislogare,It.)
To put out of its proper place.

DISLOCATION. (dislocation, Fr. dislo-
ffazione, It.) The state of being dis-
placed ; displacement of portions of the
earth's crust. According to the theory of
M. De Beaumont, the principal dislo-
cations of the earth's crust of the same
geological age range in lines parallel to
one and the same great circle of the
sphere ; those of different ages are parallel
to different circles. The geological era,
consequently, of the elevation of moun-
tains, may be ascertained from the direc-
tion of their axes of movement.

DISPE'RMOUS. (from Sic,, and (nrspfia, Gr.)
Two- seeded ; an epithet for fruit contain-
ing two seeds only ; stellate and umbel-
late plants are thus termed.

DISROO'T. To tear away by the roots ; to
tear from its foundation.

DISROO'TED. Torn up with its roots ; torn
from its foundation.

DISRU'PTED. Rent asunder ; broken for-
cibly away.

DISRUPTION. A forcible rending asunder ;
a tearing away.

DISSE'PIMENT. (dissepimentum, Lat.) In
botany, the partition which divides a
capsule into cells. In many plants the
dissepiments do not reach to the axis or
centre, in some plants the dissepiments
are not formed, or subsequently disappear,
and leave the placenta in the centre of
the ovarium, like a column, with the
seeds adhering to it.

DI'STHENE. ) Disthene is the name

DI'STHEN-SPATH. $ given by Haiiy, and
Disthen-spath by Mohs, to the mineral
Kyanite or Cyanite, which last, see.

DI'STICHOUS. (Siffnxof, Gr. distichum,
Lat.) Two-ranked ; applied to leaves

D I S

[77]

D O D

occupying two sides of a branch, but not
regularly opposite at their insertion, as
the fir, yew, &c. ; applied also to branches
when they spread into two horizontal
directions ; and to flowers, placed in two
opposite ranks.

DISTO'RT. ( distortus from distorqueo, Lat.)
To twist from its usual, or natural,
shape ; to turn away.

DISTORTED, (distortus, Lat.) Twisted from
its usual or natural form ; turned away.

DISTORTION. (distortio, Lat.) Unna-
tural crookedness ; the turning awry ;
the act of twisting from its natural
form.

DIVA'RICATE. (divarico, Lat.) To sepa-
rate into two ; to divide into two.

DIVARICA'TION. (divaricatio, Lat.) Sepa-
ration into two.

DIVE'LLENT. (divellens, Lat.) Separating ;
drawing apart, in different directions.

DIVE'RGE. (divergo, Lat.) To tend from
one point in various directions.

DIVERGENCE. A tending from one point,
as a centre, in various directions.

DIVE'RGENT. (divergent, Fr. divergente,
It.) Radiating from a centre in different
directions ; tending to various parts from
one point.

DIVE'RGING. In botany, applied to the
position of leaves during sleep, signifying
that the leaflets approach at their base,
and are open at their summits.

DIVE'RSIFORM. Of forms differing from
one another.

DIVE'RSITY. (diversitas, Lat. diversity Fr.
diversita, It.) Dissimilarity ; variety.

DIVE'RT. (diverto, Lat. divertir, Fr. diver-
tire, It.) To turn aside from its course.

DIVU'LSION. (divulsio, Lat.) A pulling
in pieces ; a forcible tearing asunder.

DIVU'LSIVE. That rends asunder.

DODE'CAGON. (from dwdsica and ywv/a,
Gr. dodecagone, Fr. dodecagono, It.) A
regular polygon having twelve equal sides
and angles.

DODECAHE'DRON. (from ^wfo/ca and idpa,
Gr.) A geometrical solid, comprehended
under twelve equal sides, each whereof is
a pentagon. It is one of the regular or
plutonic bodies.

DODECAHE'DRAL. Having twelve equal
sides ; relating to a dodecahedron.

DODECAHE'DRAL CORUNDUM. Called also
Spinel ; the Spinelle and Pleonaste of
Hau'y. There are two varieties, the Cey-
lanite and Spinel Ruby. Colours red,
blue, brown, black, green and white. It
consists of alumina 74, silica 16, magnesia
8, oxide of iron one and a half, and lime
0*75 per cent.

DODECAHE'DRAL GARNET. A species of
garnet containing ten subspecies or va-
rieties ; these are the Grossullaire, or
asparagus-green variety ; the Pyrenaite,

or greyish black variety ; the Colopho-
nite, or red variety in granular concre-
tions ; the Precious Garnet, or highly
crystallized and transparent red variety ;
the Topazolite, or yellow variety; the
Melanite, or velvet-black opaque variety ;
the Allochroite, or brown, green, and
grey massive variety ; the Pyrope, or
deep blood-red variety ; the Essonite, or
hyacinthine and orange-yellow variety ;
the Common Garnet, or brown and green
variety in granular concretions and trans-
lucent.

DODECAHE'DRAL MERCURY. Called also
native amalgam, the Mercur Argental of
Haiiy. A mixture of mercury and silver
in the proportions of nearly three-fourths
of the former, and rather more than one-
fourth of the latter. It is found in quick-
silver mines together with cinnabar. It is
of the colour of silver, and regularly crys-
tallized.

DODECA'NDRIA. (from dwctica and avi}p,
Gr.) The eleventh class of plants in
Linnseus's artificial system. The plants
in this class have from twelve to nineteen
stamens : the common houseleek will
illustrate it.

DODECA'NDRIAN. Belonging to the class
Dodecandria ; having from twelve to
nineteen stamens.

DO'DO. A genus of birds belonging to the
order of gallinae. The bill is contracted
in the middle by two transverse rugae ;
each mandible is inflected at the point ;
and the face is bare behind the eyes.
The dodo is a case in point serving
strongly to illustrate the views and
opinions of those who argue for the ex-
tinction of species, even in the present
day. Lyell says, " The most striking
example of the loss, even within the last
two centuries, of a remarkable species, is
that of the dodo, a bird first seen by the
Dutch, when they landed on the isle of
France, at that time uninhabited, imme-
diately after the discovery of the passage
to the East Indies by the Cape of Good
Hope. It was of a large size, and sin-
gular form ; its wings short like those of
an ostrich, and wholly incapable of sus-
taining its heavy body, even for a short
flight. In its general appearance it dif-
fered from the ostrich, cassowary, or any
known bird. Many naturalists gave fi-
gures of the dodo after the commence-
ment of the seventeenth century ; and
there is a painting of it in the British
Museum, which is said to have been
taken from a living individual. Beneath
the painting is a leg, in a fine state of
preservation, which ornithologists are
agreed cannot have belonged to any other
known bird. In the museum at Oxford,
also, there is a foot and a head." " The

D O L

DOW

dodo," as Dr.Mantell observes, "has been
annihilated, and become a denizen of the
fossil kingdom, almost before our eyes.
The bones of the dodo have been found in
a tufaceous deposit, beneath a bed of
lava, in the Isle of France ; so that if the
very few remains of the recent bird,
above alluded to, had not been preserved,
these fossil relics would have constituted
the only record that such a creature had
ever existed on our planet.'' Neverthe-
less, two centuries since, the dodo formed
the principal food of the inhabitants of
the isle of France.

DOLABE'LLA. A genus of univalvular mol-
luscs the known species of which are
found in the Indian ocean and in the
Mediterranean. They differ from Aply-
siae only in the position of their branchiae
and their surrounding envelope.

DOLA'BRIFORM. (from dolabra and forma,
Lat.) Hatchet-shaped ; a term more
commonly applied to leaves, cylindrical
at the base and having the upper part
dilated, thick on one edge and cutting on
the other.

DO'LERITE. A variety of trap-rock, or
greenstone, composed of augite and La-
brador-felspar.

DO'LIUM. (dolium, Lat. a tub, a tun.) A
subglobular ventrose univalve, spirally
ribbed in the direction of the whorls ;
the inferior whorl ample and ventricose ;
outer lip crenated, or dentated, through-
out its whole length. Aperture oblong,
ample, and notched ; epidermis light and
horny. Parkinson states that the dolium
has not been found fossil : this is not the
case ; one species, Dolium nodosum, has
been found at Clayton, near Hurst, in
Sussex, by R. Weekes, Esq. of Hurst.

DO'LOMITE. A variety, or modification, of
limestone, consisting of magnesian earth
48 parts, and calcareous earth 52 parts.
It derives its name from Dolomieu, a
French geologist. There are three sub-
species. Von Buch maintains that lime-
stone has been converted into dolomite
by its proximity to porphyry in fusion,
and that the magnesia has been trans-
ferred from magnesian minerals in the
porphyry to the limestone ; the magnesia
being reduced to vapour or gas. — Bake-
well.

The name Zechstein (from zeche and
stein, Germ.) has also been given to dolo-
mite or magnesian limestone. This is a
calcareous deposit, of a somewhat variable
aspect ; it is fossiliferous. The zechstein
has not yet afforded any remains of trilo-
bites. It does not appear to be a deposit
widely spread over the European area.
As yet, it is principally known in Ger-
many and England. Dolomite is gene-
rally of a light fawn or yellow colour, and

in some parts of a crystalline, in others of
a concretionary, character. It is included
in the new red sandstone group, its posi-
tion being immediately above the coal
measures. It is frequently traversed by
veins of carbonate of lime, and there are
sometimes met with enclosed in it hollow
geodes of calcareous spar, with sulphate
of strontian and sulphate of barytes.

DO'LOMITE MA'RBLE. A variety of dolo-
mite of a white colour, occurring in small
granular concretions ; these concretions
are frequently so loosely united as to fall
apart by the slightest pressure.

DOLOMI'TIC. Containing dolomite ; of the
nature of dolomite.

DO'MITE. A variety of trachyte, and thus
named from being found in the Puy de
Dome, in Auvergne, in France. It has
the appearance and gritty feel of sandy
chalk.

DO'NAX. (donax, Lat. S6va%, Gr.) Ani-
mal a tethys ; an equivalved inequilateral
bivalve, with a crenulate margin, the
frontal margin obtuse ; hinge with two
cardinal teeth in one valve, one in the
other ; the lateral teeth one or two, rather
distant. The shells of this genus are in
general triangular, inequilateral, flattened,
truncated before, and wedge-shaped. It
is found in sands and sandy mud, at
depths varying to ten fathoms. Nine-
teen species have been described, six of
which have been found in our seas. Se-
veral fossil species occur in the neigh-
bourhood of Paris.

DO'RIS. In the Linnsean arrangement, a
genus of gasteropoda, belonging to the
class Mollusca. An animal inhabiting a
shell ; body, creeping, oblong, and flat
beneath ; mouth below, on the fore part ;
vent behind, on the dorsum, surrounded
by a fringe ; feelers two and four, retrac-
tile, and placed on the front of the upper
part of the body. They are all marine,
and are found in every sea. In Cuvier's
arrangement doris is placed in the order
Nudibranchiata.

DO'RSAL. (dorsal, Fr. dorsale, It. from
dorsum, Lat.) Appertaining to the back,
as the dorsal fin, the dorsal ligaments, &c.

DO'RSUM. (dorsum,Ltat.) The back : the
ridge of a hill is sometimes called the
dorsum. In conchology, it generally
means the upper surface of the body of
the shell, when laid upon the aperture or
opening. In the genera of patella and
haliotis, the dorsum means the upper con-
vex surface.

DOWN.

1. The fine soft under feathers of many
birds, as the swan, goose, Sac.

2. The pubescence of plants, or very
soft, short hairs, covering various parts
of plants.

DOW

E B O

3. A considerable tract of elevated land,
generally covered with short grass.

DO'WNY. Soft ; cottony ; nappy ; covered
with soft hairs.

DRUPE, (drupes, Lat, (?pi>7rf7r?}c, Gr.) A
pulpy pericarp, or seed-vessel, containing
a single hard and bony nut, to which it is
attached : the epicarp and sarcocarp se-
parable from each other, and from the
endocarp, which is stony ; the nectarine,
peach, apricot, &c., furnish, us with fami-
liar examples.

DRUPA'CEOUS.

1. Having the characters of a drupe, as
drupaceous fruit.

2. Bearing drupes, as drupaceous trees.
DRUSE. A hollow space in veins of ore,

generally lined with crystals.
DUCT, (diictus, Lat.) A tube, canal, or
passage through which anything is con-
veyed.

1. In anatomy the ducts are very nu-
merous ; thus we have the cystic duct,
the hepatic duct, the nasal duct, &c. &c.

2. In botany, ducts are membranous
tubes, having their sides dotted or barred ;
they are large enough to be visible to
the naked eye, and are plainly seen
when a cane, or oak, or vine-branch, is
cut across.

DU'CTILE. (ductilis, Lat. ductile, Fr. dut-
tile, It.) That may be drawn out into
greater length without breaking. The
term is applied to metals only, and is
sometimes confounded with malleable,
whereas the two have very different sig-
nifications ; thus copper is both malleable
and ductile, but lead is only malleable
and not ductile ; some metals are neither
malleable nor ductile, but brittle, as anti-
mony, manganese, tellurium, &c. &c.

DUCTI'LITY. (ductilite, Fr. dutiilita, It.)
That property which metals possess of
being drawn out into greater length with
diminished thickness, without separation
of parts. The French used the word
ductilite to express malleability ; but we
do not. " La ductilite est un synonyme
de malleabilite." — Diet. De L'Acad.
Franfoise.

DUG. The teat or nipple.

DU'GONG. A species of phytophagous, or
herbivorous, cetacea.

DUNE. By geological writers, this word is
used to signify a low hill, or bank, of
drifted sand, and in no respect is synony-
mous with down, as might be inferred
from Todd and Webster. The downs,
both north and south, are very extensive
ranges of chalk hills, principally covered
with short grass, affording excellent herb-
age for sheep, whereas dunes are banks
of drifted sand, scarcely of sufficient
heights to be ranked as hills.

DUODE'NUM. (duodenum, Lat. duodenum,
Fr.) The first of the small intestines,
immediately adjoining the stomach, and
called duodenum from its length, sup-
posed to be twelve inches.

DUPLICATION, (duplicatio^ Lat. duplica-
tion, Fr. duplicazione, It.) A doubling,
or folding, of any part.

DU'PLICATURE. Duplication.

DUST. In botany, the pollen of the anther.
The pollen or dust is contained in the
anther. In dry and warm weather the
anther contracts and bursts, when the
pollen is thrown out. It is found, from
microscopic examination, that each par-
ticle of dust is generally a membranous
bag, either round or angular, smooth or
rough, which on meeting with any mois-
ture instantly bursts and discharges a
subtile vapour. To the perfecting the
seeds of plants, it is necessary that the
pistil, or female organ, be impregnated
by the pollen of the anther ; the fluid
contained in the pollen, when the anther
bursts, penetrates the stigma, and is con-
veyed to the seeds, whereby they are
rendered fertile, or endued with the pro-
perty of growing, and producing a plant
resembling the parent one.

DYKE. See Dike.

DY'NAMICS GEOLOGICAL. These include
the nature and mode of operation of all
kinds of physical agents, that have at any
time, and in any manner, affected the
surface and interior of the earth. — Buck-
land's Bridgew. Treatise.

DYSO'DILE. (from Svaw$riG,graviterolenSj
fcetidus, Gr.) A mineral of a greenish
colour found near Syracuse, which burns
like coal, but gives out during its com-
bustion a most intolerable odour.

E

EA'GLE-STONE. Called also cetites. A
variety of argillaceous iron ore, of a no-
dular form, something resembling a kid-
ney in shape, and containing a sort of
loose kernel. It obtained its nsme from
a supposition that it was either found in,
or had dropped from, the nests of eagles.

EARTH'S CRUST. That portion of our
planet which is accessible to our observa-
tion and inspection.

EBOU'LEMENT. (Fr.) Fall of any de-
tached rock. The fall of parts of moun-
tains is so common an occurrence in the
Alps, that it is expressively called an

E B U

[80 ]

E C H

eboulement, from the verb ebouler. —
Bakewell.

EBULLI'TION. (ebullitio, Lat. ebullition,
Fr. ebollizione, It.) Intestine motion or
agitation, occasioned by the struggling of
particles of different properties ; boiling
or bubbling.

EBU'RNA. (from eburmis, Lat. ivory.)
An oval or elongated univalve with a
deeply umbilicated columella ; the aper-
ture oblong, and notched at the bottom.
The recent eburna lives in sandy mud. Fos-
sil eburnse are rarely met with. Parkinson
states that Lamarck does not notice them
among the Paris fossils, but that a shell
exists among the Essex fossils which he
names Eburna glabrata. Dr. Mantell
gives eburna as a fossil of the chalk mark,
but affixes a note of interrogation to it, as
though doubtful.

ECCE'NTRIC. See Excentric.

ECCENTRI'CITY. See Excentricity.

ECCHYMO'SIS. (gKxv/iwo-ic, Gr. sanguinis
subcutem per grumos effusio.) A dark
spot on the skin, caused by an extravasa-
tion of blood.

ECHI'DNA. (txtfiva, Gr.) A genus of
quadrupeds belonging to the order Mono-
trema, an order comprising only two
genera, the Ornithorhynchus and Echidna.
The spiny ant-eater of New Holland, a
land quadruped, with a peculiar construc-
tion of clavicles and furcula. There are
two species, echidna hystrix, or spiny
echidna, and echidna setosa, or bristly
echidna.

ECHI'NATE. ) (echinatw, Lat.) Bristled

E'CHINATED. S like a hedge-hog ; set
with spines ; having sharp points or
spines.

ECHI'NIDAN. A fossil belonging to the
class Echinoderms. Prof. Buckland states
that the family of Echinidans appears to
have extended through all formations,
from the epoch of the transition series to
the present time.

ECHI'NITE. The fossil echinus, or sea-
urchin. Echinites vary greatly both in
form and structure, and are arranged
accordingly into many sub-genera ; they
are all marine. The chalk formation
abounds with these fossil shells, some of
which are exceedingly beautiful from
their elegant and minute decorations.
The Ananchytes cretosus, a sub-genus,
is found in some places in shoals, and in
every condition from the youngest to the
oldest age. The Spatangus cor-marinum,
another sub-genus, silicified, is frequently
found on our shores and in our gravel-
pits, and the spines of the different sub-
genera, detached from the shells, are
very numerously dispersed throughout
the chalk.

ECHI'NUS. (echinus, Lat. i\ivoG, Gr.)

The sea-urchin, or egg. The echinus
is included in the order Echinodermata,
being covered by a hard and coriaceous
skin. The shell is spherical, and com-
posed of polygonal plates, closely fitted
to each other, and has attached to it
many spines or prickles, which serve as
instruments of motion. Some species of
the echinus are edible, more especially
the E. Esculentus. The echinus feeds
principally on small shell-fish, which it
seizes with its feet.

ECHINODER'MATA. } (from iylvoQ, and
ECHI'NODERMS. $ fo'pjua, Gr.) An
order of radiated animals, including the
Echinus, or sea-urchin ; the Asterias, or
star-fish ; the Holothuria, and the Si-
phunculus. The skeletons of the animals
of this class are generally in the form of
extemal crusts, or shells, covered with
projecting spines. Echinoderms extend
through all the formations, from the
epoch of the transition series to the pre-
sent time. They are composed of the
carbonate, mixed with a small, but va-
riable, proportion of the phosphate of
lime, and are hardened by animal matter.
Of the radiated animals, Cuvier states that
the Echinodermata are the most compli-
cated. He divides them into two orders :

1. The Pedicellata, or those furnished
with feet, or with vesicular organs ful-
filling the functions of feet.

2. The Apoda, or those destitute of the
vesicular organs of progressive motion
which the Pedicellata possess.

In the first order he places the Asterias,
Encrinus, Echinus, and Holothuria ; in the
second, or Apoda, the Molpadia, Minyas,
Priapulus, Lithodermis, Siphunculus, Bo-
nellia, and Thalassema. Agassiz has re-
cently shown, contrary to the opinion
always previously entertained, that the
rays of Echinoderms are dissimilar, and
not always connected with a uniform
centre ; and that a bilateral symmetry,
analogous to that of the more perfect
classes of animals, exists throughout the
different families.

ECHINA'NTHUS. The name given to a
section of Catocysti by Leske. The
genus echinanthus comprises all the
echinites of this section. Of this genus
there are many species, namely, Echinan-
thus humilis, Ech. altus, Ech. ovatus,
Ech. orbicularis. The echinanthus was
named Scutum by Klein. The shells are
of an irregular figure, resembling a buck-
ler. On the base, which is concave, five
grooves pass from the margin, and ter-
minate at the mouth iu the centre. Five
rays ornament the upper part. The
mouth is placed in the centre of the base,
and is of a pentagonal form. The whole
of the surface is marked with very small

E C H

[81 ]

E L E

depressions, of a circular form, with cen-
tral tubercles. — Parkinson.

ECHINARA'CHNIUS. (from e%u>o£ and
apaxvij, Gr.) A genus of echini be-
longing to the class Pleurocysti. To this
genus Klein gave the name Arachnoides.

ECHINOCO'RYS. A genus of fossil echinites,
thus named by Leske, belonging to the
class of Catocysti. This genus com-
prises all those echinites which Klein di-
vided into Galeae and Galeolse. There
are several species.

ECHINODI'SCUS. The name given by Brey-
nius to a section of echini belonging to
the class Catocysti. The echinodiscus
is of a depressed discoidal figure, whence
it has its name, nearly flat on both sides.
Echinodisci are found both recent and
fossil. There are many species.

EDA'CIOUS. (from edax, Lat.) Predaci-
ous ; voracious ; rapacious.

EDENTA'TA. The sixth order of Mamma-
lia, in Cuvier's arrangement, or quadru-
peds without front teeth. This order
comprises three tribes, Targigrada, Eden-
tata ordinaria, and Monotremata.

EDENTA'TED. (edentatus, Lat. edente, Fr.
edentato, It.) Without teeth.

E'DIBLE. (from edo, Lat.) That may be
eaten ; fit for food.

EDI'NGTONITE. A mineral, resembling
some varieties of felspar and prehnite.

EFFERVESCE, (ejfervesco, Lat.) To be
in a state of intestine motion from the
generation of gas, which is continually
rushing to the surface and making its
escape.

EFFERVE'SCENCE. (effervescentia, Lat.
effervescence, Fr. effervescenza, It.) That
commotion which takes place in fluids
when gas is generated, rises to the sur-
face in small bubbles, and escapes ; it is
accompanied by a kind of hissing noise.

EFFLORE'SCENCE. (effloresco, Lat. efflo-
rescence, Fr. efflorescenza, It.)

1. Prodiiction of flowers.

2. Excrescences in the form of flowers.

3. The pulverescence of crystals on expo-
sure to the atmosphere.

EFFLORESCENT.

1. Shooting out in the form of flowers.

2. Becoming pulverulent on exposure to
the atmosphere ; the reverse of deliques-
cent.

E'FF;LUX. )(effluxio, Lat) The act of

EFFH/XION. 5 flowing out ; as the efflux
of a river or tide.

EFFO'SSION. (from effodio, Lat.) The
digging out of the earth, as of fossils, &c.

EFFU'SE. In conchology, a term applied
to shells where the aperture is not whole
behind, but the lips are separated by a
gap.

EGE'RIA. A genus of fossil bivalves belong-
ing to the tertiary formation.

ELA'OLITE. (from eXat'a, an olive, and
Xi'flof, a stone.) A sub-species of pyra-
midal felspar, known also as fettstein, or
fatstone, a name given to it from its
greasy feel.

ELA'STIC MINERAL PITCH. Called also
elaterite and mineral caoutchouc ; a brown,
massive, elastic variety of bitumen : it
consists of about 52 per cent, of carbon,
40 percent, of oxygen, 0'15 of nitrogen,
and 8 per cent, of hydrogen.

ELA'TERITE. Another name for elastic
mineral pitch.

ELE'CTRUM. Argentiferous gold ore, a
variety of hexahedral gold, of a pale brass-
yellow colour. Pliny informs us that it
was a mixture of gold and silver, and thus
writes, " Omni auro inest argentum vario
pondere. Ubicunque quinta argenti por-
tio est, electrum vocatur." It has been
attempted to prove that platinum is the
electrum of the ancients, but such is not
the case.

ELEME'NTARY. (element arius, Lat. ele-
mentaire, Fr. elementario, It.) Uncom-
pounded; uncombined; simple; primary.

ELEME'NTARY SUBSTANCES. There are
fifty -five simple, or elementary substances
at present known, that is, substances
which, under the conditions yet applied
to them, are found to be incapable of fur-
ther analysis, and are therefore called
simple, or elementary, substances. Five
of these exist in a separate state as gases,
namely, oxygen, hydrogen, chlorine, azote,
and fluorine ; the last, however, of these
has not yet been obtained in a separate
state, and is only known to be a distinct
substance from the qualities of the com-
pounds it forms with other matter. Seven
are non-metallic solids and liquids, name-
ly, sulphur, phosphorus, selenium, boron,
carbon, bromine, and iodine ; of these,
the two last, bromine and iodine, are
either gaseous, liquid, or solid, according
to the temperature. Sulphur, phospho-
rus, selenium, boron, and carbon, are
solids, but differ from the remaining forty-
one in being non-conductors of electricity.
Of the remainder, thirteen are metallic or
metalloid bodies, uniting with oxygen to
form the earths and alkalies ; namely,
sodium, aluminum, magnesium, calcium,
lithium, potassium, glucinum, barium,
silicium, thorinum, strontium, yttrium,
zirconium. Twenty-nine are what are
commonly called metals; of these, five,
namely, iron, tin, cadmium, zinc, and
manganese, decompose water at a red
heat ; the others do not decompose water,
namely, arsenic, antimony, copper, mo-
lybdenum, uranium, tellurium, chromium,
cerium, nickel, vanadium, cobalt, lead,
tungstenum, titanium, mercury, colum-
bium, bismuth, osmium, silver, palla-

E L E

[82 ]

E L E

dium, rhodium, platinum, gold, iri-
dium.

To the class of metals an addition lias
recently been made by the discovery of
Lantane, which makes the 55th element-
ary body. " L' oxide de cerium, extrait
de la cerite par le procede ordinaire, con-
tient a peu pres les deux cinquiemes de
son poids de 1'oxide du nouveau metal,
qui ne change que peu les proprietes du
cerium, et qui s'y tient pour ainsi dire
cache. Cette raison a engager M. Mo-
sander a donner au nouveau metal le nom
de Lantane. L' oxide de lantane a une
couleur rouge de brique, qui ne parait
pas etre due a la presence de 1'oxide ce-
rique." — Annales de Chimie.
ELEVA'TION. The question of the elevation
and subsidence of the earth's surface is
one which long gave rise to controversy,
and various were the arguments adduced
in support of, and in opposition to, opi-
nions which now are unhesitatingly and
universally received, and on which the
vitality, as it were, of geology depends.
It may not, however, be amiss to quote
here some of the views of our best and
soundest geologists, on a point of so great
importance, and one which, to the Neo-
phyte, seems often so startling. The fact
of great and frequent alteration in the re-
lative level of the sea and land is so well
established, that the only remaining ques-
tions regard the mode in which these
alterations have been effected. The evi-
dence in proof of great and frequent
movements of the land itself, both by
protrusion and subsidence, and of the
connection of these movements with the
operations of volcanoes, is so various and
so strong, derived from so many different
quarters on the surface of the globe, and
every day so much extended by recent in-
quiry, as almost to demonstrate that these
have been the causes by which those great
revolutions were effected ; and that al-
though the action of the inward forces
which protrude the land has varied greatly
in different countries, and at different
periods, they are now, and ever have been,
incessantly at work in operating present
change, and preparing the way for future
alteration in the exterior of our globe. —
Dr. Fitton.

Mr. Lyell says, " We may regard the
doctrine of the sudden elevation of whole
continents by paroxysmal eruptions as
invalidated. In 1822, the coast of Chili
was visited by a most destructive earth-
quake ; when the district round Valpa-
raiso was examined on the following day,
the whole line of coast, for the distance of
above 100 miles was found raised above
its former level. The area over which
this permanent alteration of level extended

was estimated at 100,000 square miles;
the rise upon the coast was from two to
four feet, inland it was from five to seven
feet." The following extracts are from
Mr. Bake' well's Introduction to Geology.
" The granite-beds in the Alps were not
elevated till a late geological epoch, after
the deposition of the oolites and chalk.
M. Elie de Beaumont has proved, that
whole mountain-chains have been elevated
at one geological period, that great phy-
sical regions have partaken of the same
movement at the same time, and that
these paroxysms of elevatory force have
come into action at many successive pe-
riods. I agree with Professor Sedgwick,
and M. Elie de Beaumont, that the ele-
vation of mountain-ranges, where the beds
are nearly vertical, was effected by a sud-
den and violent upheaving, yet I am per-
suaded that the elevation of continents,
or extensive tracts of country, was (as
Mr. Lyell observes) a long continued
process, and that these operations were
distinct from each other. The elevation
of large continents and islands, was not
effected by the same operation, which up-
raised the primary rocks. I consider it
probable, that all large tracts of country
or continents emerged slowly from the
ocean, forming at first mountainous is-
lands, before the lower countries were
raised above the level of the sea. In the
Wealden beds the strata have been up-
heaved and submerged more than once.
All the coal-basins were either formed in
inland marshes or lakes, or were sur-
rounded by dry land ; but a great sub-
mergence of the land took place, and they
were covered in many parts by thick de-
positions of marine limestone. At a sub-
sequent period they again emerged from
the ocean with a covering of marine se-
condary strata. The elevations of limited
portions of the earth' s surface, at a dis-
tance from any known volcanic agency,
are not uncommon. Loose stones, or
shingles of an ancient sea-beach, are
found at heights considerably above the
present level of the sea in many parts of
England. The elevation of extensive is-
lands or continents was probably always
accompanied by the depression of other
portions of the earth's crust." M. Elie
de Beaumont has discovered probable evi-
dence of no less than twelve periods of
elevation, affecting the strata of Europe.
The Isle of Portland affords us an admir-
able example of alternate elevations and
submersions of strata.

1 . We have evidence of the rise of Port-
land stone, till it reached the surface of
the sea, wherein it was formed.

2. This surface became, for a time, dry
land, covered by a temporary forest, dur-

ELL

E N C

ing an interval which is indicated by the
thickness of a bed of black mould, called
the dirt-bed, and by the rings of annual
growth in large petrified trunks of pros-
trate trees, whose roots had grown in this
mould.

3. We find this forest to have been gra-
dually submerged, first beneath the waters
of a fresh water lake, next of an estuary,
and afterwards beneath those of a deep
sea, in which cretaceous and tertiary strata
were deposited.

4. The whole of these have been elevated
by subterranean violence. — Prof. Buck-
land.

It is now clearly ascertained that the
whole country from Frederickshall, in
Sweden, to Abo, in Finland, is slowly and
visibly rising, while the coast of Green-
land is being gradually depressed. Certain
parts of Sweden are being gradually ele-
vated at the rate of two or three feet in a
century.

ELLI'PTICAL. (elliptique, Fr. ellittico, It.)
Having the form of an ellipsis ; oval.

ELY'TRA. (from tXvrpov, Gr. ) The hard
cases which cover the wings of coleopte-
rous insects ; the wing-sheaths, or upper
crustaceous membranes, which cover the
true membranous wings of insects of the
beetle tribe.

EMA'RGINATE.

EMA'RGINATED.

1. In botany, applied to leaves terminating
in a small acute notch at the summit.

2. In conchology, to shells having no
margin ; or when the edges, instead of
being level, are hollowed out.

3. In mineralogy, to minerals having all
the edges of the primitive form truncated,
each by one face.

EMBE'DOED. Sunk in, and surrounded by,

another substance.
E'MBRYO. (tpflpvov, Gr. embryon, Lat.)

1. In botany, the germ, or most essential
part of a seed, and without which no seed
is perfect, or capable of re-production.
The embryo is usually placed within the
substance of the seed, either central, ex
central out of the centre, or external ; its
direction is curved or straight, and in
some instances spiral. — Flora Medica.

2. The offspring yet enclosed in the ute-
rus, and in the early stage only of utero-
gestation ; afterwards called the foetus

EMBOUCHU'RE. (Fr.) The mouth of a
river, or that part where it enters the
sea.

E'MERALD. (emeraude, Fr. emeraldo, It.
p,apaySoe, Gr. smaragdus, Lat.) A pre-
cious stone of a green colour, found crys-
tallized. Under the genus emerald are
comprised two species, the first, the pris-
matic emerald, or euclase of Werner and
Haiiy, and prismatischer smaragd o

Mohs ; the second, the rhombohedral
emerald, or rhomboedrischer smaragd of
Mohs. This last species contains two
varieties, the precious emerald and the
beryl, or common emerald. The emerald
and beryl are crystallized compounds of
an earth called glycina, with silex, alu-
mine, lime, and oxide of iron ; the splen-
did green of the emerald is attributed to
the presence of oxide of chromium. The
finest emeralds are brought from Peru.
Vauquelin, in analysing the emerald, first
discovered the earth which he called gly-
cina, or glucina.
EME'RGE. (emeryo, Lat.) To rise out of

any thing by which it is covered.
EME'RGENCE. The act of rising out of

that by which it has been covered.
EME'RGENT. Rising out of that by which

it was covered.
EME'RSION. (emersion, Fr. emersione, It.)

Emergence.

E'MERY. (emeri, Fr. pierre ferrugineuse
fort dure, dont on se sert pour polir les
mitaux et lespierres. ) A massive, nearly
opaque, greyish-black variety of rhom-
bohedral corundum, consisting of alumina
86-0, silica 3'0, oxide of iron 4-0. Emery
powder is used for the purpose of polish-
ing metals and hard stones, and also for
domestic purposes, sprinkled upon, and
fastened to, brown paper ; then called
emery-paper.

E'MYS. (from *)/*vw, Gr.) Emydes, pi.
The fresh-Water turtle or tortoise. This
has five nails to the fore feet, and four to
the hind ones. Most of them feed on
insects, small fishes, &c. Their envelope
is generally more flattened than that of
the land tortoises. In fresh-water tor-
toises all the toes are nearly equal, and of
moderate length ; in land tortoises the
toes are also nearly equal, but they are
short ; in the marine tortoise, or turtle,
the toes are all long, and the middle toe
of the fore paddle is considerably longer
than the rest. Fossil species of the
emys have been discovered in the Weal-
den, as well as in lacustrine deposits of
the tertiary period.
ENCE'PHALON. (eyictyaXoQ, Gr.) The

brain.

ENCRI'NAL. Pertaining to encrinites ;
composed of encrinites ; containing en-
crinites.

ENCRI'NITE. (from Kpivov, Gr. lilium.)
A fossil encrinus. A genus of the order
Crinoidea, known by the name of stone -
lily. Dr. Mantell observes, " there are
some kinds of star-fish which, instead of
the five flat rays of the common species,
have jointed arms, which surround the
body and mouth, like the tentacula of the
polypus. These arms are composed of
thousands of little bones, or ossicula, and

E N C

E N T

the whole are inclosed in the common
integument or skin. The asterias is a free
animal, floating at liberty in the water.
Now, if we imagine a star-fish, like that
which I have described, to possess a long
flexible column, the base of which is at-
tached to a rock, we shall have a correct
idea of the general character of the cri-
no'idea, or lily-shaped animals." Prof.
Buckland states, " successions of strata,
each many feet in thickness. and many miles
in extent, are often half made up of the cal-
careous skeletons of encrinites." The en-
crinite differs from the pentacrinite, ano-
ther genus of the same order, in having the
bones of its column circular, or elliptical,
whereas those of the pentacrinite are an-
gular or pentagonal. Two existing spe-
cies, the pentacrinus caput medusae and
the comatula fimbriatae, afford us consi-
derable insight of the nature of these fos-
sil remains. In the encrinites monili-
formis, a species of encrinite, Mr. Par-
kinson states the upper part of the ske-
leton to consist of nearly 27,000 ossicula,
or small bones. Fossil encriuites are so
various that they have been divided into
several subgenera, according to the forma-
tion of the central body.

ENCRINI'TAL. Containing the remains of
encrinites. The Derbyshire encrinital
marble is formed of the fossilized remains
of the crinoidea, cemented together by
carbonate of lime.

ENCRI'NUS. A genus of the order Pedi-
cellata, class Echinodermata, in Cuvier's
arrangement. For a description, see
Encrinite.

ENCY'STED. (from ev and Kvarig, Gr.)
Contained in a cyst or sac.

E'NDOCARP. (from tvdov, within, and
Kapirbq, fruit, Gr.) The stone or shell
of certain fruits is called the endocarp, as
in the peach, cherry, &c. ; the outer skin
the epicarp ,• the fleshy substance, the
sarcocarp.

ENDOGENOUS. Plants are called endoge-
nous (from two Greek words, tvdov and
yivojucu) the growth of whose stems takes
place by addition from within, while
those whose growth takes place by addi-
tion from without are named exogenous.
The ferns and equisetacese are endogenous
plants.

ENDOGENI'TES ECHINA'TUS. The name as-
signed by M. Brongniart to the fossil
trunk of a tree, nearly four feet in diame-
ter, obtained from the calcaire grossier
at Vaillet, near Soissons.

ENDOGENI'TES ERO'SA. A fossil plant dis-
covered by Dr. Fitton at Hastings, im-
bedded in clay. The stems, when cut
and polished, exhibit the monocotyledo-
nous structure, and were considered re-
lated to the palms. It occurs in the

strata of Tilgate forest. A small speci-
men exhibiting that very peculiar eroded
appearance of the exterior, which its spe-
cific name denotes, is beautifully figured
in Dr. MantelPs Geology of the South-
East of England.

ENDOSI'PHONITE. (from ivSov and (n'0wi>,
Gr.) A cephalopod, found in the Cam-
brian rocks. The siphuncle is ventral,
differing therein from the ammonite, in
which it is dorsal, and from the nautilus,
in which it is central.

E'NNEAGON. (from tvvea, nine, and ywWa,
angle, Gr.) A polygon with nine faces.

ENNEAPE'TALOUS. (from tvvia, nine, and
irtraXov, a petal, Gr.) In botany, a co-
rolla having nine petals.

E'NSIFORM. (ensiformis, Lat.) Sword-
shaped ; two-edged ; tapering towards the
point like a sabre. In botany, applied
to two-edged leaves, slightly convex on
both surfaces, and gradually tapering to a
point from the base to the apex.

ENTI'RE. (entier, Fr. intero, It.) Whole;
undivided ; complete in all its parts. In
botany, a term applied to leaves when the
margins are devoid of notches, serrations,
or incisions. In conchology, when a shell
is whole and undivided, neither interrupt-
ed nor intermarginated, it is termed en-
tire.

ENTO'MOHTE. (from tvro/ia, an insect,
and Xi0oc, a stone, Gr.) A fossil insect ;
a petrified insect.

ENTOMOLI'THUS PARADOXUS. The name
given, erroneously, at one time to fossil
trilobites. Fossil trilobites were long
confounded with insects, under the name
of entomolithus paradoxus ; after many
disputes, their place is now established in
a separate section of the class Crustacea.

ENTOMOLO'GICAL. Relating to the science
of entomology, or that part of the science
of zoology which treats exclusively of
insects.

ENTOMO'LOGIST. A person skilled in the
science of entomology ; one who studies
entomology.

ENTOMO'LOGY. (from IVTO\ICL and Xoyoc,
Gr.) That part of the science of zoology
which treats exclusively of insects, of
their history and habits ; that branch of
natural history which treats of insects.
The object of entomology is, to investigate
the nature of insects ; its design is to
show how the insect is organised and
formed, and why it was obliged to adopt
this particular conformation and internal
structure ; and, when this is accomplished,
it proceeds to the generalisation and de-
velopment of the various vital phenomena
observable in the class. Its view, how-
ever, is not limited to show the mere ge-
neral form of the body of the insect, but
it also displays how this general form va-

E N T

E O C

ries in the several orders of insects, and
how far this general transformation and
change may extend, without destruction,
to its identification.

ENTOMOSTO'MATA. In the conchological
system of De Blainville, the entomosto-
mata form the second family of Sipho-
branchiata, and include many genera, as
the buccinum, dolium, cerithiuna, eburna,
and other univalves.

ENTOMO'STRACA. (from IVTO\HOL, an insect,
and offrpaKov, a shell, Gr.) Shelled in-
sects. In Cuvier's arrangement the en-
tomostraca form the second section of
Crustacea. Entomostraca are both den-
tated and edentated ; they are mostly mi-
croscopic, they are without exception
aquatic, and they mostly, though not
without exceptions, inhabit fresh water.
The entomostracans appear to have been
the only representatives of the class Crus-
taceans until after the deposition of the
carboniferous strata.

ENTOMO'STRACOUS. Belonging to the fa-
mily of Entomostracans.

ENTOMO'TOMY. (from cvrojua, an insect,
and re/ii/w, to cut, Gr.) The dissection
of insects, by which we learn their inter-
nal construction, and become acquainted
with the form and texture of their organs.

ENTOZO'A. (from IVTOQ and £wj), Gr.)
Intestinal worms.

E'NTROCHAL. (from entrochite.) Re-
sembling an entrochite ; containing en-
trochites.

E'NTROCHITE. (from iv and Tpo^og, Gr.)
Wheel-stone ; a name given to the broken
stems of fossil encrinites. Some beds of
mountain limestone are almost entirely
composed of broken stems and branches
of encrinites, frequently called entro-
chites. The detached vertebrae of the
radiaria are known by the name of tro-
chitse ; and when several are united toge-
ther, so as to form part of a column, the
series is termed an entrochite. The per-
forations in the centre of the vertebrae
afford a facility for stringing them as
beads, from which, in ancient times, they
were used as rosaries, and in the northern
parts of England they still continue to be
known under the name of St. Cuthbert's
beads.

ENVE'LOPE. (envelopper, Fr. invilup-
pdre, It.) To enclose on all sides ; to
invest with some covering.

E'NVELOPE. (enveloppe, Fr. involto, It.)
A wrapper ; a cover ; an investing inte-
gument.

ENVI'RON. (environner, Fr.) To encom-
pass ; to surround ; to enclose on every
side ; to encircle.

E'OCENE. (from ?}w£, aurora, and fcaivoc,
recens, because, as Mr. Lyell observes,
the very small proportion of living spe-

cies contained in these strata indicates
what may be considered the dawn, or
first commencement, of the existing state
of the animate creation.) M. Deshayes
and Mr. Lyell have proposed a fourfold
division of the marine formations of the
tertiary series, founded on the propor-
tions which their fossil shells bear to
marine shells of existing species. To
these divisions Mr. Lyell has, with the
soundest judgment, applied the terms
Eocene, Miocene, Older Pliocene, and
Newer Pliocene, and well would it be for
the advancement of geology, if its nomen-
clature were, in all instances, derived
from some universal language. In fully
explaining the meaning of these terms, I
shall borrow largely from Mr. Lyell's
Principles of Geology. In proportion as
geological investigations have been ex-
tended over a larger area, it has become
necessary to intercalate new groups of an
age intermediate between those first ex-
amined; and we have every reason to
believe that, as the science advances, new
links in the chain will be supplied, and
that the passage from one period to
another will become less abrupt. All
those geological monuments are by Mr.
Lyell called tertiary, which are newer
than the secondary formations, and which,
on the other hand, cannot be proved to
have originated since the earth was inha-
bited by man. All formations, whether
igneous or aqueous, which can be shewn
by any proofs to be of a date posterior to
the introduction of man will be called
recent. The European strata may be
referred to four successive periods, each
characterised by containing a very dif-
ferent proportion of fossil shells of recent
species. These four periods will be
called, Newer Pliocene, Older Pliocene,
Miocene, and Eocene. In the older
groups we find an extremely small number
of fossils identifiable with species now
living ; but as we approach the superior
and newer sets, we find the traces of recent
testacea in abundance. The latest of the
four periods before alluded to, is that
which immediately preceded the recent
era. To this more modern period may
be referred a portion of the strata of
Sicily, the district round Naples, and
several others. They are characterised
by a great preponderance of fossil shells
referable to species still living, and may
be called the Newer Pliocene strata.

Out of 226 fossil species brought from
beds belonging to this division, M. Des-
hayes found that no less than 216 were
of species still living, ten only being of
extinct or unknown species. Neverthe-
less, the antiquity of some Newer Pliocene
strata of Sicily, as contrasted with our

E O C

E P I

most remote historical eras, must be very
great, embracing perhaps myriads of
years. There are no data for supposing
that there is any break, or strongly
marked line of demarcation, between the
strata of this and the recent epoch ; but,
on the contrary, the monuments of the
one seem to pass insensibly into those of
the other.

The Older Pliocene strata contain
among their fossil shells a large propor-
tion of recent species, amounting to
nearly one-half. Thus out of 569 species
examined from Older Pliocene strata in
Italy, 238 were found to be still belonging
to living, and 331 to extinct, or unknown,
species.

The next division of the marine for-
mations of the tertiary period is the
Miocene, from /weiwv, minor, and KCUVOG,
recens. In this division a small minority,
less than eighteen per centum, of fossil
shells being referable to living species.
From an examination of 1021 shells of
the Miocene period, M. Deshayes found
176 only to be recent. As there are
some fossil species which are exclusively
confined to the Pliocene, so are there
many shells equally characteristic of the
Miocene period. The Miocene strata are
largely developed in Touraine, and in the
South of France, near Bourdeaux ; in
Piedmont ; in the basin of Vienna, and
other localities.

The oldest division of the marine for-
mations of the tertiary period is the
Eocene, the derivation of which term is
given at the commencement of this ar-
ticle. To this era the formations, first
called tertiary, of the Paris and London
basins, are referable. The total number
of fossil shells of this period known when
the tables of M. Deshayes were con-
structed, was 1238, of which number 42
only are living species, being at the rate
of three and a half per centum. Of fossil
species, not known as recent, forty-two
were found to be common to the Eocene
and Miocene epochs. Of the present
geographical distribution of those recent
species which are found fossil, in forma-
tions of such high antiquity as those of
the London and Paris basins, there is
much of great interest and importance.
Of the forty-two Eocene species, which
occur fossil in England, France, and Bel-
gium, and which are still living, about
one -half now inhabit the seas within, or
near the tropics, and almost all the rest
are inhabitants of the more Southern parts
of Europe.

As a summary of the preceding, the
numerical proportion of recent to extinct
species of fossil shells, in the four dif-
ferent tertiary periods, is as follows : —

Newer Pliocene period 90 to 95^ percen-
Older Pliocene period 35 to 50 I turn of
Miocene period .18 [ recent

Eocene period . 3£ J fossils.

EPHE'MERA. (t^TjjUfpta, ex tiri et >;/i£pa,
Gr.) Insects, so called from their short
term of life in their perfect state. Their
body is extremely soft, long, tapering,
and terminated posteriorly by two or
three long and articulated setse. The
antennae are very small and composed of
three joints, the last of which is very
long, and in the form of a conical thread.
The ephemera usually appear at sun-set,
in fine weather, in summer and autumn,
along the banks of rivers and lakes. The
continuation of their species is the only
function these animals have to perform,
for they take no food, and frequently die
on the day of their metamorphosis. In
another condition, as larvae, their exis-
tence is much longer, extending from two
to three years. In this first state they
live in water.

EPHE'MERAL. ^ (c^T^uepoe, Gr. ephemere,

EPHK'MERICK. $ Fr. effimero, It.) Of
transitory duration ; short-lived ; exist-
ing only one day.

EPHE'MERON. (ifrmtpov, Gr. ephemeron,
Lat.) A creature whose existence lasts
but a day.

E'PICARP. (from STH, upon, and Kap-rrbz,
fruit, Gr.) In botany, the outer skin of
fruits is called the epicarp, the fleshy sub-
stance, or edible portion, is termed the
sarcocarp, and the stone is called the
endocarp.

EPIDE'RMAL. ) Composed of epidermis ; re-

EPIDE'RMIC. $ lating to the epidermis ;
resembling the epidermis.

EPIDE'RMIS. («7rifop/tu£, Gr. epidermis,
Lat. epiderme, Fr. epidermide, It.) The
scarf-skin, or cuticle of animals. In
conchology, the outer skin or cuticle,
with which the exterior surface of many
of the univalve and bivalve shells is
covered. It is membranaceous, and re-
sembles the periosteum which covers the
bones of animals. This skin seems to be
formed entirely by the animal, and is
always met with in some species, and
never in others ; those shells with a
ragged surface have almost always an
epidermis. In some it is laminated, vel-
vety, fibrous, or rough ; in others it is
thin and pellucid, allowing the colours of
the shell to show through it. It often
falls off of its own accord, and without
any injury to the surface of the shell :
the beauty of many shells is hidden by
this outer coat. — In botany, the outward
covering of plants : every plant is covered
by a skin, or membrane, analogous to the
scarf-skin that covers animal bodies ;
this epidermis varies in thickness, being

E P I

E Q U

extremely delicate and diaphanous on
some parts of a flower, and very thick,
hard, and coarse, on the trunks of many
trees.

EPIDI'DYMIS. (etrididvplG, from STTI, and
SiSv/jiog, Gr.) A body principally com-
posed of minute, tender, elastic tubes,
intricately convoluted, termed tubuli
seminiferi, and placed at the outer and
back part of the testis.

E'PIDOTE. The Prismatoidischer Augit-
spath of Mohs, and Pistazit or Pistacite
of Werner. A mineral of a green or grey
colour ; a subspecies of prismatoidal au-
gite. It occurs regularly crystallized, in
granular, prismatic, and fibrous concre-
tions, and is said to derive its name from
the Greek word £7rt'<5(.$ai/ii, from an en-
largement of the base of the prism in one
direction. It is brittle and easily broken.
It is found, principally, in primary
rocks, and in many parts of Scotland, as
well as in England, Norway, France,
&c. It consists of silica 37'0, alumina
27*0, lime 14-0, oxide of iron 17'0, oxide
of manganese 1'5. There are many va-
rieties.

EPIGA'STRIC. (from i-rri, above, and
•yaffTrjp, the belly, Gr. epigastrique, Fr.)
Belonging to the upper part of the abdo-
men, or epigastric region.

EPIGA'STRIUM. (tTrtyairrpiov, Gr. epigas-
trium, Lat. epigastre, Fr.) The upper
part of the abdomen or belly.

EPIGLO'TTIS. (epiglottis, Lat. cpiglotte,
Fr. STriyXwffo-tc, vel iTrtyXwrric, Gr.
membrana cartilaginosa rotunditatis ob-
longse gutturi claudendo et reserando.)
One of the five cartilages of the larynx,
situated above the glottis, whose use is to
close the glottis during the act of swal-
lowing and thereby to prevent the pas-
sage of food into the trachea, or windpipe.

EPIPHYLLOSPE'RMOUS. (from STTI, QvXXov,
and <77T£p/*a, Gr.) A term in botany,
applied to plants bearing their seed on
the back part of their leaves.

EPI'PHYSIS. (£7ri0w<7ic, from £7ri0i5o>,
Gr.) A process of bone attached to a
bone, but not being a part of the same
bone, as is the case of apophysis.

EPI'PLOON. (fc7rt7rXoor,from tTrtTrXew, Gr.
epiploon, Fr.) The omentum, or caul;
that membranous expansion which hangs
from the bottom of the stomach and co-
vers the intestines.

EPIZOO'TIC. (from STU and %u>ov, Gr.)
Containing animal remains, as epizootic
hills, or epizootic strata.

E'POCH. (ITTOX?/, Gr. epocha, Lat. epoque,
Fr. epoco, It.) A term literally signify-
ing a stop, a fixed point of time, from
which succeeding years are numbered ;
the period at which a new computation,
or reckoning, is begun.

EPO'CHA. (Lat.) The same as epoch.

ECIUA'NGULAR. (from cequus and angulus,
Lat.) The harshness of this word has
caused it to be supplanted by equiangu-
lar, one far more euphonic. Consisting
of equal angles ; having equal angles.

EQUA'TOR. (equateur, Fr. (equator, Lat.
equatore, It.) A great circle of the
sphere, equally distant from the two
poles of the world, or having the same
poles with those of the world. It is
called the equator, because when the sun
is in it, the days and nights are equal ;
whence also it is called the equinoctial.
Every point of the equator is a quad-
rant's distance from the poles of the
world ; whence it follows, that the equa-
tor divides the sphere into two hemi-
spheres, in one of which is the northern,
and in the other the southern pole.

EftUAxo'RiAL. Pertaining to the equa-
tor : the equatorial diameter of our
planet exceeds its polar diameter by
about 27 miles ; the length of the equa-
torial diameter being 7927 miles, that of
the polar 7900.

EauiA^NGULAR. (from cequus and angu-
lus, Lat. tquiangule, Fr. equiangolo, It.)
A figure whose angles are all equal ; con-
sisting of equal angles ; having equal
angles.

EQUICRU'RAL. (from cequus and crus,
Lat.) Having all its legs of equal
length.

EQUIDI'FFERENT. Arithmetically propor-
tional ; having equal differences.

EQUIDI'STANT. (Equidistant, Fr. equidis-
tante, It.) Being at equal distance
from some one point.

E'CIUIFORM. (cequiformis, Lat.) Having
the same shape, form, or make.

EQUIFO'RMITY. Likeness, or resemblance,
in form ; uniform equality.

EQUILA'TERAL. (cequilatus and cequila-
terus, Lat. equilateral^ Fr. equilatero,
It.) Having all the sides equal. In
conchology, shells whose sides are alike,,
as in those of ostrsea ; or when a line
drawn perpendicularly from the apex of
a bivalve would cut it into equal parts.

EQ,UI'NAL. > (equinus, Lat.) Pertaining

E'QUINE. 5 to a horse ; relating to a
horse.

EQUISETA'CE^E. (from equisetum, horse-
tail.) The plants are known in this
country as the horse-tail of our ditches.
Equisetacese are found both fossil and
recent. M. Ad. Brongniart has, in
his "Histoiredes Vegetaux Fossiles,'r
divided fossil equisetacese into two ge-
nera ; the one exhibits the characters of
living equiseta, and as a fossil is rare ;
the other differs greatly in its form, fre-
quently attaining an immense magnitude ;
these last have been arranged under the

E Q U

ERR

distinct genus Calamites. Equisetacoce
are found from Lapland to the Torrid
Zone ; its species are most abundant in
the temperate zone : as we approach a
more frigid temperature they diminish in
size and abundance, and in the warm and
humid regions of the tropics they acquire
their greatest magnitude.

ECIUISE'TUM. (Lat. A genus of the or-
der Filices, belonging to the Cryptogamia
class of plants.) Horse-tail. Of this
genus there are numerous species. The
equisetum fluviatile of our marshes is the
largest of all the species, growing some-
times to the height of three feet, and
nearly an inch in diameter. It has a suc-
culent, erect, jointed stem, with attenuated
foliage surrounding the joints in whorls.
In the coal measures, remains of equiseta
are in great abundance, and occur of a
magnitude quite unknown at the present
day, some of the stems being fourteen in-
ches in diameter. M. Ad. Brongniart
enumerates twelve species of calamites
and two of equiseta found in strata of
the carboniferous series. Equiseta occa-
sionally occur in the Wealden strata, and
where they are found they are abun-
dant.

ECIUISE'TUM LYELLII. The name given
by Dr. Mantell to a distinct species of
equisetum, found in the grey and blue
grit and limestone at Pounceford, in ho-
nour of Professor Lyell. When perfect,
it probably attained a height of two feet
or more. This plant is beautifully fi-
gured in Dr. Mantell' s " Geology of the
South-east of England."

ECIUISE'TIFORM. (from equisetum and
forma, Lat.) Having the shape of
equisetum, or horse-tail ; resembling equi-
setum.

EQUIVALENT, (from eequus and valens,
Lat.) In geology, where one bed sup-
plies the place of another which, in that
situation, is wanting, such bed is called
the equivalent of the wanting bed. When
a stratum suddenly terminates, and its
place is supplied by a stratum of a dif-
ferent character, the latter is called the
equivalent of the former. In the beds
of transition limestone at Llanymynah,
says Mr. Bakewell, which are very re-
gularly stratified, one stratum of the best
limestone suddenly terminates, and its
place is supplied by a bed of marie of
equal thickness ; in this case the marie is
the equivalent of the absent limestone.

E'auiVALVE. (fromaquus and valva, Lat.)
In conchology, when the shells of bivalves
are formed exactly alike, as regards their
length, width, depth, &c. The shells of
mya, solen, tellina, &c., are generally of
the kind called equivalve, while those of
ostrea, pinna, &c., are inequivalve.

E'RA. (cera, Lat. Written frequently <z>ra.)
A particular account and reckoning of
time and years, from some remarkable
event. Webster, quoting from some
encyclopaedia, says, " it differs from
epoch in this ; era is a point of time fixed
by some nation or denomination of men ;
epoch is a point fixed by historians and
chronologists. The Christian era began
at the epoch of the birth of Christ."

ERADIA'TION. (from e and radiatio, Lat.)
Emission of rays.

ERE'CTILE. (from erigo, Lat.) A tissue
peculiar to certain parts of the body, as
the nipple, &c.

ERE'CT. (emtfw*, Lat.) In botany, leaves
are so called when they form a very acute
angle with the stem. The term also is
applied to branches rising in an upright
direction ; to petioles rising nearly per-
pendicularly ; and to flowers and pedicles
rising perpendicularly.

E'RINITE. A name given to a species of
native arseniate of copper, from its hav-
ing been discovered in Ireland. It is of
an emerald-green colour ; its constituent
parts are oxide of copper, arsenic acid,
alumina, and water.

ERO'DED. (erodo, Lat.) Eaten away:
corroded.

ERO'SION. (erosio, Lat.)

1. The act of gradually wearing away.

2. The state of being gradually eaten away
or corroded.

ERO'SIVE. That has the property of gra-
dually eating away.

ERO'SE. ) (erosus, Lat.) Jagged ; applied

ERO'SUS. 5 to leaves very irregularly
cut or notched, and having the appear-
ance of being gnawed or eaten by in-
sects.

ERO'TYLUS. A genus of insects, belong-
ing to the Vivalpi, or the seventh family
of the Tetramera. In the erotyli the
intermediate joints of the antennae are
almost cylindrical, and the club, formed
by the last ones, is oblong ; the interior
and corneous division of their maxillae is
terminated by two teeth. They are pe-
culiar to South America.

ERINA'CEUS. (Lat.) The hedgehog.

ERPETO'LOGIST. (from erpetology.} One
who studies, or is skilled in, that branch
of natural history, which relates to rep-
tiles.

ERPETO'LOGY. (from tpTrt roc and Xoyoc,
Gr.) That branch of natural history
which treats of the structure, habits, &c.
of reptiles.

ERRA'TIC. (erraticus, from erro, Lat.
erratique, Fr. erratico, It.) Wandering ;
not fixed ; irregular.

ERRA'TIC BLOCK GROUP. One of the sub-
divisions of detrital deposits. Professor
Phillips observes, " In the British islands,

ERR

[89]

E T H

very considerable tracts of country have
been traversed, since the land had its
present general aspect of hill and dale,
and was inhabited by large quadrupeds,
by currents of water due to some un-
known cause, which transported rock
masses with so great a degree of force, to
points so elevated, in such directions,
and at such distances, that we cannot
avoid feeling extreme astonishment, and
look around in disappointment on the
physical processes now at work on the
earth, for anything similar. But it is
only in particular tracts that the magni-
tude of the transported rocks is such as
to deserve the name of erratic blocks.
It appears to be certain that, in the dis-
persion of boulders, the present physical
configuration of the neighbouring regions
had great influence ; they are found to
descend from the Cumbrian mountains
northward in the vale of Eden to Carlisle,
eastward to the foot of the Penine chain,
southward by the Lune and the Kent
to the narrow tract between Bolland Fo-
rest and the bay of Morecambe ; and
from the vicinity of Lancaster they are
traced at intervals through the compara-
tively low country of Preston and Man-
chester, lying between the sea and the
Yorkshire and Derbyshire hills, to the
valley of the Trent, the plains of Che-
shire and Staffordshire, and the vale of
the Severn, where they occur of great
magnitude." — Phillips' Treatise on Geo-
logy.

ERRA'TICALLY. Irregularly ; without order
or method.

ERUBE'SCENCE. ) (from erubesco, Lat.)

ERUBE'SCENCY. 5 Redness; the act of
growing red.

ERUBE'SCENT. Inclining to redness ; red-
dish ; blushing.

ERUCTA'TION. (eructatio, Lat. Eructation,
Fr.) A violent belching forth of wind
or other matter, as from a volcano or
geyser.

ERU'GINOUS. (from csrugo, Lat. eru-
gineux, Fr. ruginoso, It.) Of the nature
of copper.

ERU'PTED. (from erumpo, Lat.) Forcibly
thrown out, as from a volcano.

ERU'PTION. (eruptio, Lat. Eruption, Fr.
eruzione. It.) A violent bursting forth
of contained matters.

ERY'CINA. An equivalved, inequilateral,
transverse bivalve. The hinge-teeth, two,
diverging upwards, with a small inter-
mediate pit ; the lateral teeth compressed
and oblong. The cartilage inserted in
the hinge-pit. Lamarck is of opinion
that the shells of this genus exist only
fossil, and enumerates eleven species
found in the environs of Paris. He
places them in the family Mactracea.

ESCA'LOP. ) Commonly called scollop. A

ESCA'LLOP. \ bivalve, whose shell is regu-
larly indented.

ESCA'RPMENT. (escarpement, Fr.) The
steep face of a ridge of high land ; the
escarpment of a mountain range is gene-
rally on that side which is nearest to
the sea.

ES'CHARA. (eschara, Lat.)

1. Fishes which are said to chew the cud.

2. In Linnceus* arrangement, eschara
forms the fifth order of Zoophytes, each
polypus being contained in a calcareous
or horny shell, without any central axis.

ES'CULENT. (esculentus, Lat.) Fit for
food ; that may be eaten.

ESO'PHAGUS. (from otw and <payt~iv, Gr.
esophage, Fr. esofago, It.) The canal,
or passage, leading from the pharynx to
the stomach, and through which the food
passes from the mouth to the stomach.
It is also written oesophagus.

E'sox. (Lat.) The pike, a genus of
fishes of the order Abdominales. The
esox has small intermaxillaries furnished
with little pointed teeth in the middle of
the upper jaw, of which they form the
two-thirds, those on the sides of the jaw
being edentated. The vomer, palatines,
tongue, pharyngeals> and rays of the
branchiae, bristled with teeth resembling
those of a carp.

E'sox LEWESIENSIS. The name given to
a species of fossil pike, by Dr. Mantell,
found in the chalk, the jaws of which are
beautifully figured in his Geology of the
South-east of England. He states that
its recent prototype is unknown.

ESSE'NTIAL CHARACTER. That single
circumstance which serves to distinguish
a genus from every other genus.

E'SSONITE. Another name for cinnamon-
stone. A variety of dodecahedral garnet,
of an orange-yellow or hyacinth colour.
The finest are brought from Ceylon. See
Cinnamon-stone.

E'STIVAL. (eestivus, Lat.) Pertaining to
the summer.

E'STUARY. (testuarium, Lat.) An inlet
of the land entered by the tide of the sea,
and by fresh water from a river ; the
mouth of a river or lake where the salt and
fresh water alternately prevail.

E'SURINE. (from esurio, Lat.) Corrod-
ing ; eating.

ETHE'RIA. A genus of large inequivalve
molluscs belonging to the family Ostracea.
They differ from the ostreee in having two
elongated muscular impressions in each
valve, which are united by a slender pal-
leal impression. The animal is not
known to produce a byssus.

E'THMOID. (from 770/ioc;, a sieve, and
eWoQ, like, Gr.) A bone of the nose to
which the name ethmoid has been given

N

E T I

[90]

E X O

from its being cribriform, or perforated
like a sieve, for the passage of the olfac-
tory nerves.

E'TIOLATE. (ttioler, Fr.) To blanch by
concealing from the light.

ETIOLA'TION. The becoming white or
blanched by concealment from light.
Thus the inner leaves of lettuces and en-
dive are made white by being tied up,
and celery is blanched by being earthed
up.

E'TITE. See JEtites.

E'TYUS. A genus of crustaceans, some
species of which have been discovered in
the gait.

EU'CLASB. (from tv and «\aw, Gr.) The
Prismatischer Smaragd of Mohs. Prisma-
tic Emerald. This stone has obtained
its name from the ease with which it is
broken. It is a rare and beautiful mi-
neral, and was brought first from Peru
by Dombey ; it was at first confounded
with the emerald, in consequence of its
green colour. The primitive form of its
crystals is a rectangular prism, whose
bases are squares. It is of sufficient hard-
ness to scratch quartz. Its constituents
are silica, alumina, glucina, and the ox-
ides of iron and tin.

EUDI'ALITE. A mineral of a brownish-red
colour, having an octohedral cleavage.

EUKAI'RITE. Cupreous seleniuret of sil-
ver, consisting of silver 39, selenium 26,
copper 23, alumina 8.

EUO'MPHALUS. A univalve unchambered
fossil shell, found in the mountain lime-
stone.

EU'PHOTIDE. ) Names given by the French

EU'PHOTITE. ) mineralogists to Saussu-
rite.

EU'PODA. The name given in Cuvier's
" Regne Animale " to the fifth family of
Tetramerous Coleoptera ; Eupoda com-
prises two tribes, Sagrides and Crioce-
rides.

EU'RITE. White-stone, the weiss-stein of
Werner. A variety of granite in which
felspar predominates, and named Eurite
by the French mineralogists. It occurs
in beds, in common granite, in Cornwall.
In its most compact form, it becomes a
porphyry, and is closely allied to volcanic
rocks in Auvergne ; felspathic granite. —
Bakewell.

EURI'TIC. Containing eurite ; composed
of eurite ; resembling eurite.

EXCANDE'SCENCE. (excandescentia, ex-
candesco, Lat.) White heat; extreme
heat.

E'XCAVATE. (excavo, Lat. excaver, Fr.)
To hollow out; to dig out; to make
hollow.

EXCAVATION. (excavatio, Lat. excavation,
Fr.) A cavity ; a hollow formed by the
removal of a portion of the interior.

E'XCBNTRICITY. (excentricitt , Fr. eccen-
tricita, It.) Deviation from circular
form.

EXCE'RN. (excerno, Lat.) To excrete;
to separate and emit through the
pores.

EXCE'RNED. Excreted.

EXCO'RIATED. (from excorio, Lat. exco-
rite, Fr.) Abraded ; deprived of its cuti-
cle or external covering.

EXCORIA'TION. (excoriation, Fr. exoria-
zione, It.) The state of being deprived
of its cuticle, or external natural cover-
ing.

EXCO'RTICATED. Deprived of its bark.

EX'CREMENT. (cxcrementum, Lat. excri-
ment, Fr. escremento, It.) That which
is separated from the aliment after diges-
tion and is to be ejected downwards from
the intestinal canal ; faecal matter ; ex-
creted matter.

EXCREMKNTI'TIOUS. (excrtmenteux, Fr.
escrementoso, It.) Containing excre-
ments ; consisting of excreted matter.

EXCRESCENCES (from excresco, Lat. ex-
croissance, Fr. escrescenzo, It.) A pre-
ternatural growth of any substance ; a
body growing upon, or out of, another
in an unnatural manner ; a deformity.

EXCRE'SCENT. Growing out of another
body preternaturally.

EXCRE'TE. (from excerno, Lat.) To
throw off by excretion.

EXCRE'TION. (excretio, Lat. excretion,
Fr. escrezione, It.)

1. The act of separating and voiding ex-
crementitious matter from the blood and
food.

2. The substance excreted.
EXCRE'TORY. (excrttoire, Fr. escretorio,

It.) Organs which have the power of
excreting.

EXFO'LIATE. (exfolier, Fr.) To separate
in laminae or scales.

EXFOLIA'TION. (exfoliation, Fr.) The
process of separation of dead bone.

EXHALA'TION. (exhalatio, Lat. exhalai-
son, Fr. esalazione, It.) A vapour from
animal or vegetable substances.

EXHA'LE. (exhalo, Lat, exhaler, Fr. esa-
lare, It.) To breathe out in vapours or
fumes ; to emit odours ; to give out
effluvia.

EXHUMA'TION. (exhumation, Fr. esuma-
zione, It.) The digging out of the ground
what has been buried therein.

EXHU'ME. (exhumer, Fr.) To dig out of
the earth what has been buried.

EXHU'MED. Disinterred.

E'XOGEN. Exogens are plants which have
a pith in the centre of their stems, not
descending into the roots ; or having
their woody system separated from the
cellular, and arranged in concentric
zones. They increase by additions to the

E X O

[91

F A L

outside of their wood, as the name
implies. See the etymology of Exo-
genous.

EXO'GENOUS. (from t'£w and yevvaw, Gr.)
Plants in which the growth takes place by
additions from without, or by external
increase.

E'XOLETE. (exoletus, Lat.) Worn ; faded.

EXO'SSATED. (exossatus, Lat.) Deprived
of bones.

EXO'SSEOUS. (from ex and ossa, Lat.)
Destitute of bones ; animals not possess-
ing bones.

EXOSTO'SIS. (from t% and 6oreov, Gr.) A
diseased growth of bone.

EXO'TIC. (exoticus, Lat. £ga»rtKO£, Gr.
exotique, Fr. esotico, It.) In botany,

plants not natives of the countries in
which they are cultivated.

EXSANGUINE'OUS. ) (fromexet sanguineus,

EXSA'NGUINOUS. $ Lat.) Bloodless ;
without red blood.

EXTE'NSOR. (from extendo, Lat. extenseur,
Fr.) The name of such muscles as ex-
tend or straighten the parts, and serve as
antagonist muscles to the flexors.

E'XTIRPATE. (extirpo, Lat. extirper, Fr.
esterpare, It.) To entirely destroy ; to
root up ; to eradicate.

EXU'VI^E. (Lat.) Cast shells ; cast skins ;
organic remains.

Exu' VIABLE, That may be cast or thrown
off, as the skeletons of articulated ani-
mals.

FABA'CEOUS. (fabaceus, Lat.) Of the
nature of a bean ; resembling a bean.

FACE, (face, Fr. facda, It. fades, Lat.)
One of the figures which compose the su-
perficies of a body ; the surface which
presents itself to the sight. Polyhedrons
have several faces ; a cube has six faces.

FA'CET. (facetta, It.facette, Fr. run des
c6t£s d'un corps qui a pltisieurs petits
cot6s.) A superficies cut into several
angles.

FA'CIAL. (from fades, Lat. facial, Fr.)
Belonging to the face, as the facial nerves,
&c.

F'ACIAL ANGLE. An angle composed of
two lines, one drawn in the direction of
the base of the skull, from the ear to the
roots of the superior incisores, the other
from that point to the superciliary ridge
of the frontal bone.

FACTITIOUS, (factitius, Lat.) Made by
art as contrary to that formed by nature :
thus we have factitious waters and facti-
tious stones.

F^E'CAL. (from faces, Lat.) Containing

F^E'CES. (f<RXt Lat. used plurally only.)
Excrement ; sediment. The fossil faeces
of certain fishes are called coprolites ; the
excrement of dogs and wolves, album grse-
cum ; of mice, album nigrum.

FA'HLUNITE. (from Fahlun, in Sweden,
where it is found.) Automolite, or oc-
tahedral corundum. See Automolite.

FAIRY-RING. In meadows and grass-lands,
circles of a different hue from the sur-
rounding grass are often seen ; these are
commonly called fairy-rings, from a vul-
gar saying that at night fairies dance there-
on. The true cause of these appearances,
which have excited the astonishment of
many, is as follows; they are external

indications of the centrifugal growth of
the subterranean stems of certain agarics,
which, originally springing from a com-
mon point, continually spread out-
wards upon the same plane, the centres, or
first formed parts, perishing as the cir-
cumference, or last formed parts, develope
themselves.

FAIRY-STONE. A. name sometimes given
to the echinite.

FA'LCATE. A figure formed by two curves
bending the same way, and meeting in a
point at the apex, the base terminating
in a straight margin, resembling a sickle.

FA'LCATED. (falcatus, Lat.) Hooked;
crooked like a reaping-hook.

FALCA'TION. Crookedness.

FA'LCIFORM. (fromfalx and forma, Lat.)
Shaped like a scythe or reaping-hook.

FALLING-STONE. A meteoric body, com-
monly called an aerolite.

FA'LUN. (Fr. assemblage de coquilles
brisdes, qu'on trouve en mass a une cer-
taine profondeur de terre.) A provin-
cial name given to some shelly strata in
the neighbourhood of the Loire, and
which resemble, in their lithological cha-
racters, what is denominated the crag.
The faluns, or marls of Tourraine and the
Loire, constitute an extensive formation
of marl beds, which are now admitted to
be of later date than the most recent of
the fresh-water beds in the Paris basin.
They are regular depositions, formed du-
ring an epoch of tranquillity, and sub-
jected to laws of which the action is con-
tinued on the present shores. The great
mass of fossil shells which these beds con-
tain, differ from those of the Paris basin :
in nearly 400 species, there are only
about 20 identical with the Paris fossils.
The terrestrial and river shells are in the

FAR

F A U

same state of mineralization as the marine
shells. The bones of the mastodon, rhi-
noceros, and hippopotamus, are in the
same state of preservation as those o
whales, and other cetaceous animals, with
which they are intermixed. They are coat-
ed with marine polypi and serpulae, which
proves that they were long covered by a
tranquil and stationary sea. These faluns
are distinct from the tertiary beds of the
Seine, and more recent than any of them ;
but they are themselves the lowest term
of a new system, more important, and
more extensive, than the formations of the
Paris or London basins, and which has
been continued to the present epoch,
during all the numerous up-heavings of
the ground, the changes in the relative
level of seas and continents, and the suc-
cessive modifications of organic beings.
FARI'NA (Lat.) Meal; flour: in bo-
tany, the pollen, or dust of the anther.
The pollen, or farina, is contained in the
anther. In dry and warm weather the
anther contracts and bursts, when the
pollen is thrown out. From microscopic
observation we find each particle of dust
to be generally a membranous bag, either
round or angular, smooth or rough, which
on meeting with any moisture instantly
bursts with great force, and discharges a
subtile vapour.

FARINA'CEOUS. Containing meal or flour.
In botany, applied to those parts of vege-
tables which yield starch.
FA'RINOSE. In entomology, having the sur-
face covered with dust, resembling flour,
which the slightest touch will remove.
FARRA'GINOUS. (farrago, Lat.) Com-
posed of many materials ; thus Kirwan
writes " a farraginous mountain." The
word is rarely used by geologists.
FA'SCIA. (Lat.) The tendinous expansion
of a muscle, inclosing others like a band.
FA'SCIATED. Filleted, or enclosed with a

band.

FA'SCICLE. (fasciculus, Lat.) A bundle,
or little bundle : applied to flowers on
small stalks, when many spring from one
point, and are collected into a close and
level bundle at the top ; as the sweet-
william.
FA'SCICLED. Clustered together as in a

bundle.

FASCI'CULAR. (fascicularis, Lat.) United,
or growing together, in a bundle , applied
to leaves growing in a cluster, or tuft, as
the larch, and some species of pine ; ap-
plied also to roots, when many tubes pro-
ceed from the same centre, shooting forth
in an elongated form.

FASCIO'LA. The fluke-worm. A genus of
internal worm belonging to the order Pa-
renchymata, family Tremadotea. There
are many species ; they are furnished

underneath the body, or at its extremity,
with organs resembling cupping-glasses,
by which they adhere to the viscera. In
this genus is included the Distoma hepa-
tica, or Fasciola Hepatica of Linnreus,
which so infests, and is so common in,
the hepatic vessels of sheep.
FASCIOLA'RIA. A subfusiform univalve,
channelled at its base, without any pro-
jecting sutures, and having two or three
very oblique folds on the columella. —
Parkinson.

FASCIOLI'TES. A subcylindrical, shelly, or
bony body, about half an inch in length,
rather tapering at the ends, and formed
by the spiral arrangement of perpendicu-
lar, concamerated tubes, the tapering end
of which is obliquely and transversely
folded on that of the preceding one. The
tubes are seen to be distinct ; and, where
the outer surface has been removed, the
concamerations are perceived, resulting
from the interposition of very numerous
and minute septa, transversely disposed.
The tubes are placed perpendicularly
round the centre, and it appears that
round the first formed tube, or chamber,
successive increasing columnar tubes were
disposed, folding over each other at their
ends. Whether these several tubes were
internally connected with each other, or
not, or whether the chambers communi-
cated, or not, with each other, by a si-
phuncle, are questions not yet clearly as-
certained. Like some of the nummulites,
this body, when polished, has more the
appearance of bone than of shell, and from
this and other circumstances, it seems to
approximate nearer to the nummulite than
to any other fossil. — 16.

FA'SSAITE. (from Fassa in the Tyrol.) A
mineral, a dark-green variety of augite ;
it is also found in Scotland and Ireland,
in beds of primitive trap, limestone, and
magnetic ore.

FASTI'GIATE. ) (fastiaiatus, Lat.) Point-

FASTI'GIATED. $ ed ; a term applied to a
stem, peduncles, umbel, &c.

FA'THOM. A measure of length equal to
six feet, or two yards.

FA'THOMLESS. A depth which cannot be
ascertained by sounding ; a depth to
which no bottom can be found.

FAULT. (faule,~Fr.) A break or intersec-
tion of strata ; interruption of the conti-
nuity of strata, with displacement ; the
sudden interruption of the continuity
of strata, in the same plane, accom-
panied by a crack or fissure, varying in
width from a mere line to several feet ;
such fissure being generally filled with
fragments, &c. When a fault occurs in
strata they are generally either derated or
depressed, so that in working a bed or
vein there appears to be a sudden termi-

F A U

F E L

nation of it. Faults consist of fissures
traversing the strata, extending often for
several miles, and penetrating to a depth,
in very few instances ascertained ; they
are accompanied by a subsidence of the
strata on one side of their line, or, which
amounts to the same thing, an elevation
of them on the other ; so that it appears,
that the same force which has rent the
rocks thus asunder, has caused one side
of the fractured mass to rise, or the other
to sink. If we suppose a thick sheet of
ice to be broken into fragments of irregu-
lar area, and these fragments again united,
after receiving a slight degree of irregular
inclination to the plane of the original
sheet, the re-united fragments of ice will
represent the appearance of the compo-
nent portions of the broken masses, while
the intervening portion of more recent ice
represents the clay and rubbish that fill
the faults. In the coal-fields, these
faults operate as coffer-dams, and are of
the greatest possible advantage.

FA'UNA. (fauni, Lat.) As the plants
peculiar to a country constitute its flora,
so do the animals constitute its fauna ,-
the zoology of a country.

FAUX. (Fr.) That portion of the cavity
of the first chamber of a shell which may
be seen by looking in at the aperture.

FAVULA'RIA. A genus of fossil plants.
Stem-furrowed. Scars of leaves small,
square, and of a breadth with the ridges
of the stem. In the favularia, the trunk
was entirely covered with a mass of dense-
ly imbricated foliage, the bases of the
leaves are nearly square, and the rows of
leaves separated by intermediate grooves.
The genus is believed to be extinct, but is
found fossil in the coal-formation.

FEA'THERY. Plumose ; applied to plants
furnished with lateral hairs.

FE'CAL. See F&cal.

FE'CES. See Faeces,

FECU'LA. (from fax, Lat. ftcule, Fr.)

1. The sediment or grounds of any liquid.
The word fecula, says Dr. Paris, origin-
ally meant to imply any substance which
was derived by spontaneous subsidence
from a liquid.

2. The green matter of plants.
FE'CUND. (facundus, Lat. ft cond, ~Fr.fe-

condo,It.) Prolific; fruitful.

FECUNDA'TION. (fecondation, Fr. fecon-
dazione, It.) Impregnation.

FECU'NDATE. (fecondare, It. feconder,
Fr.) To impregnate ; to render fruitful.

FECU'NDITY. (facunditas, 'La.t.ftconditt,
Fr. feconodita, It.) Fruitfulness ; pro-
ductiveness ; fertility ; capability of pro-
ducing.

FEE'LERS. In conchology, those crenated
arms, evolved from the side of the Lepas
anatifera, and other shells of the second

division of Lepas. While the animal is in
the water it continually moves its feelers,
evidently for the purpose of entangling
minute marine insects as food. — Brown.
FE'LDSPAR. ) A mineral which enters into
FE'LSPAR. 5 the composition of, and,
next to quartz, constitutes the chief ma-
terial of, many rocks. There are many
species and subspecies, or varieties, of
this mineral, though all agree nearly in
their chemical composition, and all are
found both crystallized and massive.
Feldspar is lamellar in its structure, but
not in so great a degree as mica ; it
scratches glass, and is nearly opaque. It is
composed of silex 64, alumina 18, potash
13, lime 3, and some oxide of iron.
Common feldspar is perhaps the most
generally diffused mineral next to quartz
and iron. It is one of the components
of granite, gneiss, and some other pri-
mary rocks, and granite owes its variety
of appearance and colour principally to
the abundance, or otherwise, of the feld-
spar it contains. In some kinds of gra-
nite the feldspar is in large whitish crys-
tals of irregular forms, occasionally of
one or two inches in length. From the
liability of feldspar to be decomposed by
atmospheric action, granite containing
large crystals of it is less durable than
that which is finer grained, and it is said
that Waterloo-bridge, being unfortu-
nately built of granite containing large
crystals of feldspar, will be less durable
than could be wished for. Professor
Jameson divides feldspar into five species,
namely, 1. Rhombohedral Feldspar, or
Nepheline. 2. Prismatic Feldspar, or
Common Feldspar. 3. Tetarto-prismatic
Feldspar, or Scapolite. 4. Polychromatic
or Labrador Feldspar. 5. Pyramidal Feld-
spar, or Scapolite.

1. Therhombohedral feldspar, or nephe-
line of Haiiy and Werner, is of a white or
grey colour, and occurs both massive and
crystallized; it is externally splendent,
internally vitreous and shining. Cleav-
age fourfold. Fracture conchoidal, melts
with difficulty before the blow-pipe. Its
crystals form druses. It occurs in drusy
cavities. Its constituent parts are, ac-
cording to Gmelin, silica 43-36, alumina
33-49, soda 13'36, potass 7'13. Other
authors, however, give a different analy-
sis, stating lime and oxide of iron to form
a portion of its constituents.

2. Prismatic feldspar, or common feld-
spar. The prismatischer feldspath of
Mohs. Potash feldspar. Of this there
are many varieties, namely, adularia, or
moonstone, a transparent variety with a
silvery or pearly opalescence ; glassy
feldspar, a grey variety ; common feld-
spar, a translucent variety, with various

F E L

F E T

shades of colour, such as white and red,
which from its abundance has obtained
its name ; amazon-stone, a blue or green
variety ; Norwegian Labrador feldspar, a
dark-green variety with a beautiful
changeableness of colour, obtained from
Frederickswarn, in Norway ; compact
feldspar, a feebly translucent variety,
with a splintery fracture ; slaty feldspar,
or clinkstone, a slaty variety; porcelain
earth, earthy feldspar, and claystone, va-
rieties, in a comparatively loose state of
aggregation, without lustre or transpa-
rency, and varying in their degree of com-
pactness.

3. Tetarto-prismatic feldspar, or albite.
See Albite.

4. Polychromatic or Labrador feldspar.
Lime feldspar. The polychromatischer
feldspath of Mohs. This beautiful mi-
neral was first discovered on the coast of
Labrador as a constituent part of syenite.
When light falls on it in certain direc-
tions it exhibits the most beautiful change-
ability of colour. It occurs massive and
disseminated. Cleavage splendent. Frac-
ture glistening. It has been subse-
quently found in different parts of Europe.
It contains about eleven per cent, of
lime and four of soda. It breaks into
rhomboidal fragments. In its changea-
bility of colour, it exhibits patches of
blue, green, yellow, red, and grey colour.

5. Pyramidal feldspar, or scapolite.
Meionite. Pyramidaler feldspath of
Mohs. Of this species of feldspar there
are many varieties, namely, Weionite,
Scapolite, Paranthine, Wernerite, Di-
pyre, and Schmelzstein. These will be
all described under their several heads.

FELSPA'THIC. > Any mineral in which

FELSPA'THOSE. $ feldspar greatly predo-
dominates ; of the nature of feldspar.

FE'LIS. (Lat.) A genus of quadrupeds
belonging to the order of Ferse, the cha-
racters of which are these : — The fore-
teeth are equal ; the molares, or grinders,
have three points ; the tongue is fur-
nished with rough sharp prickles, point-
ing backward ; the claws are sheathed
and retractile, and being raised perpen-
dicularly, and hidden between the toes
when at rest, by the action of an elastic
ligament, lose neither point nor edge.
The species of this genus are very numer-
ous, and various with regard to size and
colour, though they are all similar with
respect to form.

FE'LINE. Belonging to the genus Felis.

FE'MORAL. (femoralis, Lat.) Belonging
to the thigh.

FE'MUR. (Lat.) The thigh bone ; the
thigh.

FB'RGUSONITK. A brownish-black ore,
occurring in quartz ; thus named after
Mr. Ferguson of Raith.

FERN. (Sax. fearn.} Ferns are distin-
guishable from all other vegetables by
the peculiar division and distribution of
the veins of the leaves; and in arbore-
scent species by their cylindrical stems
without branches, and by the regular dis-
position and shape of the scars left upon
the stem, at the point from which the pe-
tioles, or leaf -stalks, have fallen off. The
brake, or fern, of our commons and waste
lands, is a familiar example of this re-
markable and numerous family of plants,
distinguished by the peculiar distribution
of the seed-vessels. The family of ferns,
both in the living and fossil flora, is the
most numerous of vascular cryptogamous
plants. The total number of living spe-
cies of ferns is about 1500. The large
tree ferns are confined almost exclusively
to the tropics ; an elevated and uniform
temperature and great humidity being the
conditions most favourable to their deve-
lopement. The existence of immense
fossil arborescent ferns from thirty to
forty feet in height in the coal formation,
is one of the strongest possible evidences
of the great diminution of temperature
and change of climate which the earth
has undergone. In the coal formation,
there are not fewer than 130 known spe-
cies of ferns, nearly all of which belong
to the tribe of Polypodiacese. An arbor-
escent fern, forty-five feet high, from
Silhet in Bengal, may be seen in the stair-
case of the British Museum. In the
strata of the secondary series there is a
considerable diminution in the absolute
and relative number of ferns ; and in
the strata of the tertiary series the
ferns seem to bear nearly the same
proportion to other vegetables as in
the temperate regions of the earth at
the present day. — Buckland. Lyell. Man-
tell.

FE'RREOUS. (ferreus, Lat.) Irony ; con-
taining iron ; resembling iron.

FERRI'FEROUS. (from ferrum and fero,
Lat.) Producing iron ; yielding iron.

FERRUGI'NEOUS. > (ferrugineus, Lat./cr-

FERRU'GINOUS. $ rugineux,-euse, Fr.
ferruginoso, It.) Containing particles of
iron ; resembling iron ore ; rust-coloured ;
impregnated with iron ; anything con-
taining iron.

FE'TID. (foetidus, Lat. fttide, Fr. fetido,
It.) Having a strong and disagreeable
smell.

FE'TIDNESS. The quality of smelling
offensively.

FE'TOR. (foetor, Lat. feteur, Fr. fetore,
It.) A strong offensive smell.

FE'TUS. (ftetus, Lat.) Commonly writ-

F 1 B

[95 ]

FIR

ten foetus. Of viviparous animals, the
young in utero ; of oviparous, the young
in the shell : in the earliest stages of
utero-gestation,the young is usually called
the embryo, and when fully formed, or
after a certain period, the fetus.

FI'BER. )(fibra, Lat. fibre, Fr. fibra, It.)

FI'BRE. S A filament or thread, whether
of animal, vegetable, or mineral struc-
ture.

FI'BRIL. (fibrille, Fr. petite fibre, fibrilla,
It.) A small fibre; the diminutive of
fibre.

FI'BROUS. (fibreaux, ~Fr.fibroso, It.) Com-
posed of fibres ; containing fibres.

In botany, a fibrous root consists of nu-
merous fibres, either simple or branched ;
these are the most simple of all roots,
conveying nourishment directly to the
stem, or leaves.

FI'BROLITE. (from fibra, Lat. and \idog,
Gr.) A mineral of a white or grey
colour, occurring with corundum. Cleav-
age imperfect. Hardness more consi-
derable than that of quartz. Consists of
alumina 46, silica 33, oxide of iron 13.
It is composed of minute fibres, from
which circumstance it obtains its name,
some of which appear to be rhomboidal
prisms. It is found in China and in the
Carnatic.

FI'BULA. (Lat.)

1. The small bone of the leg, thus named,
according to some authors, from being
placed opposite to the part where the
knee-buckle, or clasp, was formerly
used.

2. A fossil echinite, resembling, not a
buckle, but a button. By some oryctolo-
gists these have been termed Bufonitse
and Scolopendritse, and by others Pilei ;
and, by the English, Capstones. — Parkin-
son.

FI'GURE-STONE. Agalmatolite, a variety
of talc-mica, of a grey, green, white, red,
or brown colour. The finest are brought
from China.

FI'LAMENT. (filamenta, Lat. filament, Fr.
filament o, It.)

1. A long thread or fibre ; a slender
thread-like process.

2. In botany, the long thread-like part
that supports the anther ; the filament is
not essential, being sometimes wanting ;
the form is various, being sometimes
short and thick, or long and slender, or
forked, one point only supporting the
anther ; generally smooth, sometimes
hairy ; the number varies from one to
many. Most filaments are simple, some
are bifid ; others tricuspidate or broad,
and trifid at the extremity.

FILAMK'NTOUS. (filamenteux, Fr. fila
mentoso, It.) Composed of fine threads
or fibres.

FILA'RIA. A genus of nematoidea, belong-
ing to the class Entozoa.

FILE. A name given by the chalk-diggers
to the striated and prolonged cucurmerine
claviculse of echinites.

FILI'CES. (filix, Lat.) Ferns, the first
order of Cryptogamia/in Linnseus' artifi-
cial system ; the first tribe of acotyle-
donous plants.

FILICOIDE'^E. (from filix, Lat. and eldog,
' Gr.) Fern -like plants.

FI'LIFORM. (from filum and forma, Lat.)
Thread-like ; thread-shaped ; slender and
of equal thickness. In botany, applied
to peduncles when very fine, resembling
threads ; applied also to the tube of
monopetalous flowers when of a thread-
like form ; and also to aments.

FIN. (Sax. ) The organ in fishes by which
they steady and keep upright their bo-
dies in the water : the caudal fin alone
assists in progressive motion. The fin
consists of a membrane supported by
rays, or little bony or cartilaginous os-
sicles.

FIN-FOOTED. Palmipedous ; having pal-
mated feet, or feet with membranes be-
tween the toes, connecting them with
each other.

FI'NLESS. Wanting fins ; destitute of fins.

FI'NNY. Having fins.

FIN-TOED. Palmipedous ; having mem-
branes between the toes.

FI'ORITE. A siliceous incrustation depo-
sited by the thermal waters of Ischia,
first noticed by Dr. Thompson.

FIRE-DAMP. Choke-damp. Carburetted hy-
drogen gas. This is sometimes very abun-
dantly evolved in coal mines, and is pro-
ductive of the most dreadful results, occa-
sionally nearly all employed in the mines
perishing from its combustion. When
carburetted hydrogen gas constitutes more
than one-thirteenth of the volume of the
atmosphere of pits and mines, the whole
become explosive whenever a flame is
brought into contact with it ; to prevent
the disastrous consequences which were
so frequently resulting, Sir H. Davy in-
vented a safety-lamp, which being formed
of wire-gauze, in the form of a cylinder,
consumes, but does not explode, the ex-
plosive mixture. Fire-damp, or car-
buretted hydrogen gas, appears to be
generated by the decomposition of iron
pyrites in coal, and may often be heard
issuing from the fissures in coal-beds
with a bubbling noise, as it forces the
water out along with it.

FIRE-STONE. An arenaceo - argillaceous
deposit of a greyish green colour, com-
posed of marl and grains of silicate of
iron ; in some places, in a state of sand ;

F I S

[ 96]

F L I

in others, forming a Stone sufficiently
hard for building. The transition from
the marl to the fire-stone is in many
localities so gradual, and the sandy par-
ticles are so sparingly distributed, that
the chalk-marl may be said to repose
immediately on the gait ; in others, how-
ever, the characters of the fire-stone are
very peculiar, and some geologists have
deemed them of sufficient importance to
rank this deposit as an independent for-
mation. The fire-stone contains the same
fossils as the grey marl, and a few species
not found in any other bed. — Dr. Man-
tell.

FI'SSILE. (fissilis,Lait.) Capable of being
split, or divided, in the direction of the
grain or cleavage.

FISSI'LITY. The quality of admitting to
be split, or divided in the line of its
cleavage.

FISSIRO'STRES. A family of aves, numeri-
cally small, but very distinct from all
others in the beak, which is short, broad,
horizontally flattened, slightly hooked,
unemarginate, and with an extended com-
missure, so that the opening of the mouth
is very large, which enables them to
swallow with ease the insects they cap-
ture while on the wing : the swallow be-
longs to this family, and is an example.

FI'SSURE. (fissura,fromfindo, Lat. fissure,
Fr. fessura, It.) A cleft; a narrow
chasm.

FI'SSURED. Cracked ; separated by narrow
chasms ; divided by clefts.

FISSURE'LLA. A gasteropod ; a genus of
the order Scutibranchiata. A buckler-
formed univalve, without spire : the ver-
tex perforated by a small ovate or oblong
orifice, which affords a passage to the
water required for respiration ; this orifice
penetrates into the cavity of the branchiae,
which are situated on the fore part of the
back. The fissurella has been found in
the Essex cliffs.

FISTULA'NA. A genus of the family Inclusa,
class Acephala, division Mollusca. Nearly
all of the family inclusa live buried in sand,
stones, ooze, or wood. The external tube
of fistulana is entirely closed at its larger
end, and is more or less like a bottle or
club. The fistulanae are sometimes found
buried in submerged fragments of wood,
or in fruits, and the animal, like the
teredo, has two small valves, and as many
palettes. Recent specimens are only ob-
tained from the Indian Ocean, but fis-
tulana are found fossil in the Shanklin
sand, where, in some instances, the wood
is studded with the remains of a small
species of fistulana, of a pyriform shape,
about one-third of an inch long, to which
the name of Fistulana pyriformis has been
given. Fistulanse personate are found in

the chalk formation, and in the arenaceous
limestone, or sandstone of Bognor ; and
Fistulana pyriformis, at the junction of
the Gait and Shanklin Sand, imbedded in
wood.

FI'STULAR. (fromfistularis, Lat.) Hollow
like a pipe.

FI'STULIFORM. (from fistula and forma,
Lat.) In round hollow columns.

FI'STULOUS. (fistuleux, Fr. infistolito, It.)
Hollow; tube-like.

FIXA'TION. (fixation, Fr. fissazione, It.)
Want of volatility ; that condition which
resists evaporation, or volatilization by
heat.

FI'XITY. (fixitt, Fr. propriety qu'ont quel-
ques corps de rfetre point dissipte par
Faction du feu.} Coherence of parts:
that property which some bodies possess
of resisting dissipation by heat.

FLABE'LLIFORM. (from fiabellum and
forma, Lat.) Fan-shaped.

FLAKE, (floccus, Lat. flake, Sw.) Astra-
turn or layer ; a sort of scale.

FLA'KY. Composed of small strata or
layers ; having scales or laminae.

FLAMMABI'LITY. The quality of being ig-
nited so as to burn with a flame.

FLA'MMABLE. That may be set on fire so
as to blaze.

FLAMMI'VOMOUS. (fromflamma and vomo,
Lat.) That vomits forth flames ; volca-
noes areflammivomous.

FLA'VOUS. (flavus, Lat.) Yellow; of a
yellow colour.

FLAW, (from 0\ao>, Gr., to break.) A
crack ; a break or split ; a defect.

FLAWED. Cracked.

FLEXIBILITY, (flexibility, Fr. fiessibilita,
Fr.flexibilitas, Lat.) Pliancy ; the qua-
lity of admitting to be bent.

FLE'XIBLE. (ftexibilis, Lat. flexibile, Fr.
fiessibile, It.) That can be bent ; not
brittle: pliable; possessing elastic pro-
perties.

FLE'XIBLENESS. Pliancy ; pliantness ; the
opposite to brittleness.

FLE'XUOUS. Winding ; tortuous ; bending
in different directions ; zigzag ; with an-
gles gently winding.

FLE'XURE. (flexura, Lat.) The direction
in which anything is bent.

FLINT. (Sax.) Siliceous earth, nearly
pure. Flint is the commonest form in
which quartz exhibits itself; it is rather
harder than quartz, and contains a minute
portion of alumine and of oxide of iron ; 98
per cent, being pure silex. A remarkable
circumstance attending flint is, that it is
found in masses, dispersed in regular
parallel beds, in chalk-rocks. This is
elucidated, and partly explained, in a
beautiful manner in the manufacturing of
porcelain. Porcelain is made of flint and
clay, pounded extremely fine, and mingled

F L I

together with water so perfectly, as to form
a smooth fluid, of the consistence and co-
lour of cream ; if this fluid be left a long
time quite tranquil, the flint separates from
the cky, and collects in small masses, in
a manner analagous to that in which the
natu'-al masses occur in the chalk. When
flint is first extracted from the quarry it
is brittle, has a conchoidal fracture, and
feeble lustre ; thin fragments are trans--
lucent. Specific gravity 2*594. According
to Klaproth's analysis, it consists of silex
98, lime 0'5, alumine 0'25, oxide of iron
0'25, water 1. The constant occurrence
of flint in the upper chalk, and the ap-
parent conversion of animal remains into
flint, has given rise to much speculation
respecting its origin ; and it was at one
time maintained, that flint and chalk were
convertible, or capable of undergoing
a mutual transmutation. I propose to
submit a few observations from the pens
of our first writers on this interesting and
intricate subject, for after having con-
sidered the matter in every point of view ;
after having carefully read the opinions of
others, and again and again examined
strata of flint nodules and tabular flints,
flints horizontally and diagonally distri-
buted throughout the numerous chalk-
pits in the neighbourhood ; after having
observed their crushed but not disordered
condition, and having commonly found
flints imbedded in flints, I am totally
unable to arrive at anything approaching
to a legitimate deduction.

" That the beds of chalk and flint were
deposited periodically," says Dr. Mantell,
"cannot admit of the slightest doubt. Spe-
cimens are not unusual, in which angular
fragments of black flint, that could not
possibly have been originally formed in
their present state, are imbedded in chalk.
Sir Henry Englefield was the first who
directed the attention of geologists to the
subject of the shattered condition of the
flints found in certain strata. In a paper
read before the Linnsean Society, he
notices several beds of shattered flints,
which occur in a chalk-pit at Carisbrook,
in the Isle of Wight ; and, after describing
their situation and appearance, proceeds
to offer some conjectures upon the pro-
bable cause of their destruction. This he
supposed might have been occasioned by
some sudden shock or convulsion, which
in an instant shivered the flints, though
their resistance stopped the incipient mo-
tion ; for the flints, though crushed, are
not displaced, which must have been the
case, had the beds slid sensibly. Chal-
cedony is often found occupying the
hollows of flints, and on this subject it
has been remarked that although hi the
present compact state of the matter oi

[ i)7 ] F L I

flint, it is not easy, though possible, to
force a fluid slowly through its pores, yet
it is probable that before its consolidation
was complete, it was permeable to a fluid
whose particles were finer than its own ;
and that the particles of chalcedony,
whilst yet in a fluid state, being finer than
those of common flint, did thus pass
through the outer crust to the inner sta-
tion they now occupy ; where they also
allowed a passage through their own in-
terstices to the still purer siliceous matter,
which is often crystallized, in the form of
quartz, in the centre of the chalcedony,
and is so entirely surrounded by it, that
it could have no access to its present
place, except through the substance of
the chalcedony, and the flint enclosing it."
In Professor Buckland's Bridgewater
Treatise we find the following : — " We may
in like manner refer the origin of those
large quantities of silex, which constitute
the chert and flint beds of stratified forma-
tions, to the waters of hot springs, holding
siliceous earth in solution, and depositing
it on exposure to reduced degrees of tem-
perature and pressure, as silex is deposited
by the hot waters that issue from the
geysers of Iceland." Again Dr. Mantell,
" the nodular masses of flint are very ir-
regular in form, and variable in magni-
tude ; some of them scarcely exceeding
the size of a bullet, while others are se-
veral feet in circumference. Although
thickly distributed in horizontal beds and
layers, they are never in contact with each
other, but every nodule is completely sur-
rounded by chalk. Flints so commonly
enclose the remains of sponges, alcyonia,
and other zoophytes, that some geologists
are of opinion that the nucleus of every
nodule was originally an organic body,
and Townsend states, ' so far as my ob-
servation goes, zoophytes appear univer-
sally to have formed the nuclei of nodu-
lated and coated flints.' The nodules of
flint frequently exhibit the internal struc-
ture of the enclosed zoophyte most beau-
tifully and delicately preserved/' A theory
offered by Professor Buckland is to this
effect : " It does not appear possible that
flints could have been formed by infil-
tration into pre-existing cavities, like the
regularly disseminated geodes of the trap
rocks. Assuming that the mass which is
now separated into beds of chalk and flint,
was, previously to its consolidation, a
compound pulpy fluid, and that the or-
ganic bodies now enveloped in the strata
were lodged in the matter of the rock,
before the separation of its calcareous
from its siliceous ingredients, the bodies
thus dispersed throughout the mass would
afford nuclei, to which the flint, in sepa-
rating from the chalk, would, upon the
o

F L I

[ 98]

FLU

principle of chemical affinity, have a ten-
dency to attach itself. The chalk and
flint proceeded through a contemporaneous
process of consolidation ; the separation
of the siliceous from the calcareous in-
gredients having been modified by at-
tractions, which drew to certain centres
the particles of the siliceous nodules, as
they were in the act of separation from
the original compound mass. The dis-
tances of the siliceous strata must have
been regulated by the intervals of pre-
cipitation of the matter from which they
are derived ; each new mass, as it was
discharged, forming a bed of pulpy fluid
at the bottom of their existing ocean,
which, being more recent than the bed
produced by the last preceding precipitate,
would rest upon it as a foundation similar
in substance to itself, but of which the
consolidation was sufficiently advanced to
prevent the ingredients of the last de-
posit, from penetrating or disturbing the
productions of that which preceded it."
Sir. H. Davy found pure flint in the
cuticle of many grasses ; it is also found
in the hollow stems of bamboo ; the ashes
of wheat straw also are found to contain it.

FLI'NTY SLATE. Flinty slate differs from
common slate, in containing a larger pro-
portion of siliceous earth. Slate and
flinty slate not only pass into each other,
but frequently alternate. When flinty
slate ceases to have the slaty structure, it
becomes hornstone, or, what the French
geologists term petrosilex. If it contains
crystals of felspar, it becomes hornstone
porphyry. — Bakewell.

FLO'ATSTONE. The white and grey porous
varieties of rhombohedral quartz. In
consequence of their extreme porousness
they swim on the surface of water, and
have therefrom been named floatstone, or
spongiform quartz.

FLOETZ. (flotz, Germ.) The name given
by Werner to certain rocks which were
flat, horizontal, and parallel to each
other.

FLO'RA. (Lat.) As the animals peculiar
to any country constitute its fauna, so
do the trees and plants its flora ; the
botany of a country.

FLO'RAL. (floralis, Lat.) An epithet for
a bud or leaf; pertaining to flowers ; be-
longing to the flower. The calyx is the
outer set of the floral envelopes.

FLO'RET. (jleurette, petite fleur, Fr.) A
floret is a small monopetalous flower,
many of which, enclosed in one calyx or
perianthium, and placed sessile on a com-
mon undivided receptacle, form a species
of compound flower.

FLORI'FEROUS. (florifer, Lat.) Bearing
flowers ; producing flowers.

FLO'RIFORM. (from flos and forma, Lat.)

Having the form, or appearance, of a
flower.

FLO'SCULOUS. (flosculus, Lat.) A little
flower ; a floret.

FJLU'ATE. A compound of fluoric acid
with a salifiable base.

FLU'CAN. A provincial name for a fault or
dam ; particularly used by the Cornish
miners.

FLU'OR. ) (Lat.) Octahedral fluor.

FLU'OR SPAR. $ Octaedrisches Flus-Ha-
loide of Mohs. Chaux Fluate of Haiiy.
Fluate of lime ; consisting of 67' 75 lime
and 32-25 fluoric acid. If a cube of fluor
spar be split with a knife and a hammer,
it will yield only in the direction of the
solid angles, and if the division be pur-
sued the result will be an octohedron.
There are three varieties of fluor spar ;
the first, with even fracture and feeble
lustre, is called compact fluor ; the second,
in which the cleavage is distinct, foliated
fluor ; the third, which occurs incrusting
other minerals, earthy fluor. See also
Blue-John and Derbyshire spar.

FLUO'RIC ACID. An acid first procured by
Gay Lussac, or by Margraff, and called
fluorine by Sir H. Davy. It may.be ob-
tained by putting a quantity of fluor-spar
in powder into a leaden retort, pouring
over it an equal quantity of sulphuric
acid, and then applying a very gentle
heat. From its exceedingly destructive
properties it has been called phtore, from
00optoc, Gr., by M. Ampere. It destroys
the skin, almost immediately, if applied
to it, producing very painful wounds.
The most singular property- which it pos-
sesses is that of corroding glass and
siliceous bodies, especially when hot, and
the thickest glass vessel can only with-
stand its action for a short time.

Fluorine enters into the composition of
some minerals which form constituent
portions of great masses of rocks. Fluoric
acid is found in mica and hornblende,
two minerals of very great importance, as
component parts of many rocks. Fifteen
analyses of mica, from various parts of
the world, by Klaproth, Vauquelin, Rose,
and Bendant, afford as a mean, T09 per
cent, of fluoric acid ; and Bousdorf's
analysis of hornblende, gives 1*5 per cent,
of the same substance. Calculation af-
fords us 0'36 of fluoric acid in gneiss with
mica, 0'54 in mica slate, 0'75 per cent,
in hornblende rock and greenstone, 0-18
in granite with mica, 0*5 of the same
substance in sienite, 0'65 in granite com-
posed of quartz, felspar, mica, and horn-
blende, and 0'5 per cent, in porphyritic
greenstone. Fluor spar is, however, the
mineral in which the greatest relative
amount of fluorine is detected. — De la
Beche.

FLU

FOR

FLU'STRA. A genus of polyparia, class
Vermes, order Zoophyta. If we carefully
observe the patches of white calcareous
matter, called flustroe, that may be seen
on every sea-weed or shell on the shore,
appearing like delicate lace, we shall dis-
cover that these apparently mere specks
of earthy substance belong to the Emhnal
kingdom. The fluslra, when taken fresh
and alive out of the water, presents to
the naked eye the appearance of fine net-
work, coated over with a glossy varnish.
With a glass of moderate powers, it is
discovered to be full of pores, disposed
with much regularity. If a powerful lens
be employed, while the flustra is immersed
in sea-water, very different phenomena
appear ; the surface is seen to be invested
with a fleshy, or gelatinous, substance,
and every pore to be the opening of a cell
or cavity, whence issues a tube with
several long feelers or tentacula ; these
expand, then suddenly close, withdraw
into the cells, and again issue forth ; and
thejvhole surface of the flustra is studded
with these hydra-like forms, sporting
about iu all the energy and activity of
life. For a more full account, see Dr.
Mantell's Wonders of Geology, whence
the above is taken.

FLU'TKD. Grooved ; channelled ; furrowed.

FLUVIA'TIC. ^fi-uvialis, fluviaticus, Lat.

FLU'VIAL. ^ ftuviatile, Fr.) Belong-

FLV'VIATILE.J ing to a river ; growing, or
living, in the fresh water of rivers.

FLUX, (fluxus, Lat. flux, Fr. mouvement
regie de la mer vers le rivage & certaines
heures dujour.)

1. The flow of the tidal wave : the flux is
the rise ; the reflux, the ebb of the tide.

2. Any substance added to facilitate the
fusion of metals or minerals.

FOE'CAL. See Fecal.
F(E'CES. See Feces.
FOLIA'CEOUS. (foliaceus, Lat.) Leafy ;

consisting of leaves or lamina.
FO'LIAGE. (folium, Lat.) The leaves of

plants or trees.
FO'LTATED. (foliatus, Lat.)

1. In botany, leaved or having leaves.

2. In conchology, in laminae or leaves, as
when the edges of the shelly layers are not
compact, but seem to separate from each
other. This may easily be seen in the
large coarse oyster shell.

FDLIA'TION.

1 . In botany, vernation or leafing of trees,
&c.

2. In mineralogy, the act of beating into
thin leaves.

FOLI'FEROUS. (horn folium and fero, Lat.)
Bearing leaves.

FO'LKSTONE MARL. A stiff marl, varying
in colour from a light grey to a dark
blue, more generally known under the

provincial term Gait. The thickness of
this bed is in some places in the South of
Sussex not less than between two and
three hundred feet. It is a member of
the cretaceous groupe, lying between the
upper and lower green-sand. Where the
Folkstone mari is exposed, and forms the
surface of the country, the soil is exceed-
ingly tenacious, and ranks amongst the
finest aud most productive. The Folk-
stone marl abounds in fossils.
FO'LLICLE. (folliculus, Lat. follicule, Fr.
follicolo, It.)

1. In botany, a univalvular pericarp, open-
ing on one side longitudinally, and having
the seeds loose in it ; a membranous seed-
vessel of one valve and one cell, bursting
lengthwise, and having no apparent su-
ture to which the seeds are attached.

2. In anatomy, a small secreting cavity.
FONTANE'L. (fontanelle, Fr. fontanella,

It.) An opening left in the skull at birth,
which is subsequently closed by osseous
deposit ; there are two.

FORA'MEN. (Lat.) A hole ; an opening ;
generally by which nerves or blood ves-
sels obtain a passage through bones. In
botany, the opening in the ovulum. When
the foramen is visible on the seed, as is
the case in the bean and pea, it is called
the micropyle.

FORA'MINATED. > (from foramino, Lat.)

FORA'MINOUS. $ Pierced with small open-
ings ; full of small holes ; porous.

FORAMI'NIFER. A genus of microscopic
shells. Mr. Lonsdale has discovered six-
teen species of foraminifers in the Eng-
lish chalk, and Mr. Searles Wood has
discovered fifty species of foraminifers in
the lower crag formation of Suffolk.

FORAMINI'FEROUS. Belonging to the genus
foraminifer. Some recent observations
have induced M. Dugardin to refer the

, animals which construct the Miliola and
some other microscopic foraminiferous
shells to a new class of animals of lower
degree than the radiata, and possessing a
locomotive power by means of minute
tentacular filaments. — Prof. BucJ.land.

FO'RCIPATED. (forcipatus, Lat.) Hooked,
or furnished with pincers, as the claws of
a lobster, crab, &c.

FO'RELAND. A promontory : a jutting of
high land into the sea, as the North-
Foreland, in the Isle of Thanet, and the
South-Foreland, near Dover.

FO'RKED. Opening into two or more parts ;
furcated.

FORMA'TION. (formatio, Lat. formation,
Fr. formazione, It.) Any assemblage of
rocks possessing some character in com-
mon, either as regards their age, oi'igin,
or composition. When a series of strata
of a similar rock are arranged with occa-
sional strata intervening, of rocks of ano^

FOR

[ 100 ]

F U L

ther kind, which recur in different parts
of the series, they are regarded as having
been all formed nearly at the same epoch,
and under similar circumstances ; and
such series are called by geologists /or-
mations. Thus, the strata of shale, sand-
stone, and iron-stone, that accompany
beds of coal, are called the conformation.
Strata of different kinds, in which a gra-
dation is observed into each other, and
which contain similar species of organic
remains, constitute a geological forma-
tion. The chalk with flints above, the
lower chalk without flints, the chalk-
marl, and the green-sand under the chalk,
are all regarded as members of the chalk
formation. — Bakewell.

FO'RNI GATED, (fornicatus, Lat.) Concave
within, and convex without ; vaulted ;
arched.

FO'RNIX. (Lat.) In conchology, the ex-
cavated part under the umbo. It like-
wise signifies the upper, or convex shell
in the ostea.

FO'SSIL. l(fossilis,fromfodio, Lat. fos-

FO'SSILE. 5 sile, Fr.fossile, It.) Dugout
of the earth, as fossil shells, fossil bones,
fossil coal, &c. The adjective is fre-
quently spelt fossile.

Fo SSIL. A substance dug out of the earth.
At the present day, the word fossil is used
by geologists to express only the remains
of animal, or vegetable, substances found
buried in the earth's crust.

FOSSILI'FEROUS. (from fossilis and fero,
Lat.) Producing fossils ; containing fos-
sil remains ; yielding fossils.

FO'SSILIST. One who collects fossils ; who
studies the nature and history of fossil
remains.

FOSSILIZA'TION. The conversion of ani-
mal or vegetable substances into fossils.

FO'SSILIZED. Become fossil; converted
into a fossil body.

FRA'GILE. (fragilis, Lat. fragile, Fr.
fragile, It.) Brittle ; easily broken ;
weak.

FRAGILITY, (fragilite, fv.fragilita, It.)
Brittleness ; weakness.

FRA'GMENT. (fragmentum, Lat. frag-
ment, Fr. frammento, It.) A part broken
from the whole ; an imperfect piece.

FRAGMENTARY. Composed of fragments.
Dr. Johnson says, a word not elegant,
nor in use : in elegance or euphony it may
or may not be, deficient, but, at the pre-
sent day, it is in use by geologists.

FREE-STONE. Any kind of stone, the tex-
ture of which is so free or loose that it
may be easily worked.

FRIABI'LITY. (friabilite, Fr. friabilita,
It.) The property of being easily crum-
bled, broken small, and reduced to
powder.

FRI'ABLE. (friabilis, Lat. friable, Fr.

friabile, It.) Easily broken into small

pieces ; easily crumbled, or reduced to

powder.
FRITH. An arm of the sea, as the Frith

of Tay, the Frith of Forth.
FROND, (frons, Lat.)

1. In botany, implies peculiar union of
the fructification with the leaf and stem,
namely, the flowers and fruit are pro-
duced from the leaf itself.

2. The herbaceous parts of flowerless
plants, resembling leaves, are called
fronds ; they differ from true leaves in
their structure in many respects.

FRONDI'FEROUS. (frondifer, from frons,
smdfero, Lat.) Producing fronds.

FRONT, (front, Fr. fronte, It.) In con-
chology, when the aperture in univalves
is turned towards the observer.

FRO'NTAL. (frontale, Lat. frontal, Fr.
frontale, It.) Appertaining to the fore-
head.

FRUCTIFEROUS . (fruciifer, Lat.) Bear-
ing fruit.

FRUCTIFICATION. (fructification, Fr.
frutiificazione, It.)

1. The temporary part of a -vegetable ap-
propriated to generation, terminating the
old vegetable, and beginning the new. It
consists of the following parts ; namely,
the calyx, corolla, stamen, pistillum, pe-
ricarpium, semen, and receptaculum.

2. The act of bearing fruit ; fertility ;
fecundation.

FRU'CTUOUS. (fructueux,-euse, Fr. frut-
tuoso, It.) Fruitful.

FRUGI'FEROUS. (frvffifer, Lat.) Pro-
ducing fruit or corn ; fruitful.

FRUGI'VOROUS. (frugivorus, Lat.) fru-
ffivore, Fr.) Animals which live on fruits
and seeds.

FU'COID. (from tyvKog and tlSoQ, Gr.) A
species of fucus. Fucoids are very abund-
ant in many of the strata, occurring in
the transition strata of North America in
numerous thin layers. An account of
these has been published by Dr. Harlan,
of America, and by Mr. R. C. Taylor, in
Loudon's Magazine of Natural History.
Fucoids are found in great abundance in
the grauwacke slate of the maritime Alps,
in the lias, and in the chalk. There is
one species, the Fucoides targionii, that
abounds in the upper green-sand. To a
fine species, discovered in the chalk by
Dr. Mantell, he has given the name Fu-
coides Brongniarti.

Fu'cus. (fucus, Lat. 0v*coc, Gr. pi. fuel.)
A genus of the order of Algse, belonging
to the class Cryptogamia. This genus
comprehends most of those plants com-
monly called sea-weed.

FU'LGORITE. (fulguritus, Lat. ) Any-
thing struck by lightning. Rocks, and
the tops of mountains, often bear the

F U L

GAL

marks of fusion from the action of light-
ning ; and occasionally vitreous tubes,
descending many feet into banks of sand,
mark the path of the electric fluid. Some
years ago, Dr. Fiedler exhibited several
of the fulgorites in London, which had
been dug out of the sandy plains of Si-
lesia and Eastern Prussia. — Mrs. Somer-
ville.

FULI'GINOUS. (fuliginosus, Lat. fuliyi-
neu#,-euse, Fr. fulliginoso, It.) Sooty;
dark ; smoky ; dusky ; of the colour of soot.

FU'LLERS'-EARTH. A marl of a close tex-
ture, soft and unctuous, containing about
25 per cent, of alumina. It derives its
name from its being used by fullers to
take the grease out of cloth before they
apply soap. Any clay having its parti-
cles of silica very fine, may be considered
as fullers' earth ; for it is the alumina
alone which acts upon the cloth, on ac-
count of its strong affinity for greasy sub-
stances.

FU'LVOUS. (fulvuSj Lat.) Of a light
brown, with much yellow.

FU'NGUS. (Lat. pi. fungi.} One of the
orders of the class Cryptogamia, according
to the artificial system of Linnaeus. A
mushroom ; an excrescence from trees
or plants not naturally belonging to
them ; any morbid sponge-like excre-
scence.

FU'NNEL-SHAPED. In botany, applied to
a monopetalous corolla, having a conical
border placed upon a tube.

FU'RCATED. (furca, Lat.) Forked ;
branched.

FU'RCULA. (Lat.) A fork. A peculiar
formation of bone in birds, of a fork-like
shape. The furcula, commonly known
as the merry-thought-bone, is seldom
wanting in birds. It is in form like
a V, common to both shoulders, and
joined by its point to the most prominent
part of the crista of the sternum, while
the other extremities are connected to
the humeral end of the clavicles, and the
point of the scapulae, where these two
bones are articulated with each other, and

with the os humeri. The furcula serves
to keep the wings at a proper distance in
flying, and is strong and expanded in
birds which fly with great force and ra-
pidity. In the ostrich and cassowary, it
is imperfect, the lateral branches not
uniting together.

The ornithorhynchus and ichthyosau-
rus both possess a peculiar form of ster-
num, resembling the furcula of birds.
The echidna is the only known land qua-
druped that has a similar furcula and
clavicles. A cartilaginous rudiment of a
furcula occurs also in the dasypus.

FURFURA'CEOUS. ( furfuraceus, from
furfur, Lat,) Branny ; scaly.

FU'SCITE. An opaque mineral of a greyish
or greenish-black colour, found in Nor-
way, in masses of granular quartz.

Fu'scous. (fuscus, Lat.) Brown ; tawny ;
dusky.

FUSIBI'LITY. (fusilibilite, Fr. qualita di
do che e fusibile, It.) The quality of
being rendered fluid by a heat attainable
by artificial means, and of again becom-
ing solid on cooling.

FU'SIBLE. (fusus, from fundo, Lat. fu-
sibile, Fr. fusibile, It.) Capable of being
melted by the application of heat, and of
again becoming solid when cooled.

FU'SION. (fusio, ~La.t.fusion,l?r.fusione, It.)

1. The action of melting by heat.

2. The state of being melted by heat.
Applied to minerals and metals.

FU'SIFORM. Spindle-shaped, swelling in
the centre with the ends tapering ; inter-
mediate between the conical and the oval.

Fu'sus. A subfusiform univalve, ventricose
in its middle or lower part, with a canali-
culated base, and no varicose sutures ; an
elongated spire, a smooth columella, and
the lip not slit. The genus comprises
many species. The genus fusus com-
prises all shells with a salient and straight
canal, which are destitute of varices. Fusi
are found at depths varying to eleven
fathoms, in mud, sandy mud, and sand.

Fu'sus CONTRA'RIUS. A species of fusus
found in the crag of Suffolk, a sinister shell.

G

GA'BBRO. A synonymous name with Dial-
lage.

GADO'LINITE. A mineral thus named after
Gadolin, who first ascertained its compo-
sition. Its colour is greenish-black ; that
of its powder greenish-grey. Occurs
massive ; in granular and prismatic con-
cretions. Fracture conchoidal and glassy.
According to Berzelius its constituent
parts are yttria 45-93, silica 24-16, pro-
toxide of cerium 16-90, protoxide of iron

11-34. It was first discovered at Ytterby,
in Sweden, by Capt. Arhenius, in white
felspar ; it is found also in Ceylon, in
granite.

GA'HNITE. Thus named from Gahn ; an-
other name for automalite.

GALA'CTITE. (yaXeiKTiTrjc., Gr.) Milk-
stone.

GA'LEA. (Lat.) A genus of echini,
found fossil only. They are distin-
guished by an oval base, from which

GAL

C 102 ]

GAS

the shell rises in a vaulted, helmet-like,
form.

GALEO'LA. A genus of echinites possess-
ing the same characters as the galea, but
differing in size. This circumstance in-
duced Klein to divide them into two
genera, but Leske deeming a mere dif-
ference of size as insufficient to affect the
genus, included them both under the
genus echinocorys. — Parkinson.

GA'LEATED. (galealus, Lat.) Helmet-
shaped ; covered as with a helmet. In
botany, plants beai'ing flowers of a helmet
shape, as the monk's-hood.

GALE'NA. (galena, Lat.) A shining me-
tallic ore composed of sulphur and lead ;
sulphuret of lead ; lead-glance. Its colour
is bluish-grey, resembling lead. Occurs
regularly crystallized, frequently in cubes
and cubo-octahedrons. Before the blow-
pipe it decrepitates and melts, emitting a
sulphureous smell. It is found in every
lead-mine. There are two varieties,
common galena and compact galena.

GALLINA'CE^E. Gallinee of Linngeus. The
fourth order of the second class, Aves.
So called from their affinity with the do-
mestic cock.

GALLINA'CEOUS. (yallinaceus, Lat.) Be-
longing to the order Gallinaceae.

GALT. } A provincial name for a stiff marl,

GAULT. $ varying in colour from a light
grey to a dark blue. The upper and
lower beds of the green-sand are in many
places separated by the gait ; it has been
also called Folkstone Marl. The gait
abounds in fossil remains, remarkable for
their beauty, the pearly covering of the
shells being in many instances preserved.
The gault is a member of the cretaceous
group, passing, in its lower parts, into
calcareous marl. The fossils hitherto
found in the gait belong to forty-three
species, among which are several species
of ammonites and hamites ; nautili and
belemnites ; nucula? and inocerami ; cary-
ophillea, &c. The gait rarely exceeds
100 feet in thickness ; although in some
parts of Sussex it is not less than 250.
It is a soil that must rank, says Mr.
Young, among the finest in this or any
other country, being pure clay and calca-
reous earth.

GAMOPE'TALOUS. Another term for mo-
nopetalous. Having the petals united by
their edges ; a corolla, the petals of which
are all united by their edges.

GAMOSE'PALOUS. In botany, a term used
for a calyx when the sepals of which it is
composed are all united.

GA'NOID. Belonging to the order Ganoi-
dian.

GANOI'DIANS. (from ydvog, Gr. splendour,
from the brightness of their enamel.)
The second order of fishes according to

the arrangement of M. Agassiz. The
families of this order are characterized by
angular scales, composed of horny or
bony plates, covered with a thick plate of
enamel. The bony pike and sturgeons
are of this order. It contains more than
sixty genera, of which fifty are extinct. —
Prof. Bucldand.

GANOI'DIAN. Belonging to the order Ga-
noidia. The ganoidian order of fishes
with the placoidean prevailed, exclusively,
in all formations till the termination of
the oolitic series, when they ceased sud-
denly and were replaced by genera of new
orders, the Ctenoidean and Cycloidean,
then for the first time introduced. — Ib.

GAP. In conchology, an opening, in mul-
tivalves and bivalves, when the valves are
shut, as in the pholades, myse, &c.

GA'RNET. (grenat, sorte de pierre preci-
euse, d'un rouge f once, comme le gros vin,
Fr. granato, It. pietra preziosa. ) There
are eleven species of garnet, all of them
crystals. The precious garnet is found in
dodecahedrons, in mica-slate, amongst
the oldest, or primary, rocks, in many
parts of the world. It is of a beautiful-
red colour, sometimes with shades of yel-
low or blue. Those from the kingdom of
Pegu are most esteemed, and it is sup-
posed that this was the carbuncle of the
ancients. It is harder than quartz, and
consists of nearly equal parts of silex,
alumine, and oxide of iron, with traces of
manganese. Common garnets are more
opaque, of a duller colour, and less hard
than the precious garnet, though harder
than quartz. They are abundant in simi-
lar localities in all countries, sometimes
constituting nearly the whole mass of a
rock.

GAS. The name given to all permanently
elastic, or aeriform, fluids, except the
atmosphere. The term was first used by
Van Helmont, who appears to have in-
tended to denote by it every thing which
is driven off from bodies in the state of
vapour by heat.

GA'SEOUS. (from gas.) In the form
of gas.

GASTE'ROPOD. Belonging to the order
Gasteropoda.

GASTERO'PODA. (from yaarrip, the belly,
and TTOVQ, the foot, Gr. ) The third
class of Mollusca ; they have the head
free, they crawl upon the belly, or upon
a fleshy disk, situated under the belly,
which serves them as feet. They are
univalvular or multivalvular, but in no
case bivalvular. The back is furnished
with a mantle which is more or less ex-
tended, takes various forms, and in the
greater number of genera, produces a
shell. The tentacula are very small, si-
tuated above the mouth, and do not sur-

GAS

C 103 ]

G E O

round it, varying in number from two to
six ; sometimes they are wanting alto-
gether. The eyes are very small, and
sometimes wanting. Several are entirely
naked ; others have merely a concealed
shell, but most of them are furnished
with one that is large enough to receive
and shelter them. Most of the aquatic
gasteropoda, with a spiral shell, have an
operculum, a part sometimes horny, some-
times calcareous, attached to the pos-
terior part of the foot, which closes the
shell when its occupant is withdrawn into
it and folded up. The Umax or slug is
an example of the class. Cuvier divides
this class of Mollusca into nine orders,
namely, 1. the Pulmonea ; 2. the Nudi-
branchiata ; 3. the Inferobranchiata ; 4.
the Tectibranchiata ; 5. the Heteropoda ;
6. the Pectinibranchiata ; 7. the Tubuli-
branchiatse ; 8. the Scutibranchiata ; 9.
the Cyclobranchiata.

GA'STRIC. (from ya<rr?}|0, Gr. yastrique,
Fr. yastrico, It.) Belonging to the sto-
mach or belly.

GAULT. See Gait.

GA'VIAL. A subdivision of the genus
crocodile, characterized by the narrow,
elongated, almost cylindrical jaws, which
form an extremely lengthened muzzle. —
Dr. Mantcll.

The living species of the crocodile
family are twelve in number, namely,
one gavial, eight crocodiles, and three
alligators. Teeth of the fossil gavial
have been found in the Tilgate strata,
and one of these is figured in Dr. Man-
tell' s Geology of the South-east of Eng-
land, who observes, " it appears that the
strata of Tilgate Forest contain the re-
mains of at least two, if not four, species
of crocodiles: that one of these (that
with slender curved teeth) resembles the
gavial of Caen, and probably was about
twenty-five feet in length.

GE'HLINITE. A mineral allied to Vesu-
vian, and named after Gehlin. Colours,
various shades of green and brown.
Authors are not yet agreed as to its con-
stituents, &c.

GE'LATINE \(gelee, Fr. gelatina, It.) A

GE'LATIN. £ concrete animal substance ;
the principle of jelly. If a piece of the
fresh skin of an animal, after every im-
purity is carefully separated, be put into
a quantity of cold water, and boiled for
some time, part of it will be dissolved.
Let the decoction be slowly evaporated
till it is reduced to a small quantity, and
then put aside to cool. When cold, it
will have assumed a solid form, and pre-
cisely resemble that tremulous substance
known as jelly. This is, what is called
by chemists, gelatin. If the evaporation
be carried farther, the substance becomes

hard, semitransparent, breaks with a
glassy fracture, and is, in short, that
substance known under the name of glue.
Gelatine therefore is the same with glue,
only that it is free from those impurities
with which glue is so often contaminated.
Gelatine is colourless and transparent;
when thrown into water it soon swells,
and assumes a gelatinous appearance, and
gradually dissolves away. By evaporat-
ing the water it may again be obtained
unaltered in the form of jelly. Cold
water dissolves it slowly, but water at a
temperature of 90° rapidly. Gelatin is
insoluble in alcohol.

GELA'TINOUS. (gelatineux, -euse, Fr. qui
resemble a de la gelee.) Of the nature
of gelatine ; containing gelatine ; jelly-
like ; viscous.

GELA'TINATE. To assume the appearance
of jelly.

GELATINA'TION. The process of being
converted into a jelly-like substance.

GEM. (gemma, Lat.)

1. In mineralogy, any precious stone.
Gems may be divided into natural and
artificial ; the latter are made of what is
termed paste, coloured with different me-
tallic oxides.

2. In botany, the bud, a small conoid
body, covered with scales, formed during
summer on the branches of trees, con-
taining the rudiments of a future plant,
or part of a plant : some plants produce
flowers and leaves, others leaves only, and
some flowers only.

GEMELLI'PAROUS. (from gemelli and pario,

Lat. ) Producing twins.
GE'MTNATED. In conchology, marked with

a double elevated striae connecting the

wreaths.
GE'MINOUS. (geminus, Lat.) Double ;

in pairs.

GE'MMULE. A little bud.
GE'NERA. The plural of genus.
GENE'RIC. } (generique, Fr. generico, It.)
GENE'RICAL. $ That which comprehends

the genus, or distinguishes from another

genus ; but does not distinguish the spe-
cies.
GENE'RIC ALLY. With regard to the genus,

though not to the species.
GENI'CULATE. > (geniculat us, Lat. ) Knot-
GENI'CULATED. $ ted ; jointed ; applied

to culms bent like the knee ; also to

peduncles bent at the joints.
GE'NUS. (Lat.)

1. That which is predicated of many
things, as the material or common part
of their essence.

2. A subdivision of any class or order of
natural beings, whether of the animal,
vegetable, or mineral kingdoms, all agree-
ing in certain common characters.

GE'ODE. (yew^K, from yea, Gr.) A

G E O

[ 104 ]

G E O

roundish piece of mineral matter, some-
times only an incrustation, generally
more or less hollow, usually lined with
crystals, or in some cases loose earthy
matter. The geodes found in the green-
sand near Sidmouth, says Mr. Bakewell,
in his valuable Introduction to Botany,
are composed of opaque chert on the
outside, and contain within, mammil-
lated concretions of beautiful chalcedony,
and occasionally perfect minute rock-
crystals.

GEO'GNOSY. (from ytj and yi/w<nc, Gr.)
That branch of natural history which
treats of the structure of the earth.
Werner and his disciples, as well as some
of the French geologists, have substituted
geognosy for geology, the former derived
from y>) and yvaxri^, the latter from yrj
and Xoyoc: Mr. Bakewell has justly ob-
served, for this change no sufficient reason
can be assigned, and it is contrary to
established analogies of language. No-
thing can be more unmeaning than the
apologies that have been offered for sub-
stituting yvuxriQ, knowledge, for Xoyoc,
reason. By the same rule we ought to
change meteorology, physiology, &c. into
meteorognosy, physiognosy, &c. — Sake-
well, Introduction to Geology.

GEOLO'GICAL. Pertaining to the science
of geology.

GEO'LOGIST. One versed in that branch of
natural history which treats of the struc-
ture of the earth.

GEO'LOGY. (from -yij and \oyoc, Gr.) Geo-
logy may be defined to be that branch of
natural history which investigates the
successive changes that have taken place
in the organic and inorganic kingdoms of
nature. It is a science founded in exact
observation and careful induction ; it
may be termed the physical history of
our globe ; it investigates the structure
of the planet on which we live, and ex-
plains the character and causes of the
various changes in the organic and inor-
ganic kingdoms of nature. It has been
emphatically termed the sister science of
astronomy, ranking, undoubtedly, in the
scale of sciences, next to astronomy, from
the sublimity of the objects of which it
treats.

Geology is as intimately related to al-
most all the physical sciences, as is his-
tory to the moral. As the historian
should, if possible, be at once profound-
edly acquainted with ethics, politics, juris-
prudence, the military art, theology ; in
short, with all those branches of know-
ledge, whereby any insight into human
affairs, or into the moral and intellectual
nature of man can be obtained ; so is it
desirable that the geologist should be
well versed in chemistry, mineralogy,

zoology, botany, comparative anatomy ;
in short, in every branch of science
relating to organic and inorganic nature.
" It was long," says Prof. Lyell, " ere
the distinct nature and legitimate objects
of geology were fully recognised, and it
was at first confounded with many other
branches of inquiry, just as the limits of
history, poetry and mythology, were ill
defined in the infancy of civilization."

Werner appears to ha\e regarded geo-
logy as little other than a subordinate
department of mineralogy, and Desmarest
included it under the head of physical
geography. Dr. Button, in his treatise,
published in 1795, first endeavoured to
draw a positive line of demarcation be-
tween geology and cosmogony, declaring
that geology was in no ways concerned
with questions as to the origin of things ;
and, in fact, geology differs as widely
from cosmogony, as hypothesis concern-
ing the mode of man's first creation differs
from history. Philosophers for some
ages past neglected the examination of
the earth, contenting themselves with
vain speculations respecting its forma-
tion ; and to Strabo, who flourished under
Augustus, and died under Tiberius, about
the year 25, and to the old philosophers,
who studied the local phenomena of their
countries, would the title of geologists
with more propriety be given than to
Burnet and Buffon, whose systems of
cosmogony have more the air of a system
of romance, than of a serious generaliza-
tion of facts. In tracing the history of
geology from the close of the seventeenth
to the end of the eighteenth century, we
find the science retarded by the wild and
visionary speculations of a host of writers ;
to enter on these would, however, far
exceed the limits of a work of this kind,
and those desirous of so doing, I would
refer to Mr. Ly ell's admirable work,
Principles of Geology.

Hutton, following the example of New-
ton in astronomy, endeavoured to give
fixed principles to geology ; but, at that
time, too little progress had been made
in the science, to enable him to realize so
noble a project. A brighter period has
now dawned, and the following out the
only true method, namely, that of keep-
ing within the boundary of inductive
philosophy, has led to the most important
results.

One of the greatest difficulties with
which geology has had to contend, is the
false notion entertained by many well-
meaning but weak persons, that geology
was opposed to Scripture revelation, and
that geological researches might prove
injurious to religion. Unfortunately,
prejudice and ignorance have too fre-

G E O

[ 105 ]

G E R

quently called in the aid of religious
feeling to thwart and oppose the progress
of scientific knowledge ; and it is too
much to be feared that did the same
power now exist, the geologists of the
present day might suffer the same perse-
cutions that Gallileo Gallilei did, and
that the works of Lyell, Buckland, De la
Beche, Conybeare, Murchison, Phillips,
Sedgwick, Mantell, and a host of others,
would swell the catalogue of the forbidden
list.

Why, it may be asked, should persons
whose religious opinions are founded on
the basis of immutable truth fear the
elicitation of truth ? or what has religion
to fear from the minutest, the most
searching, investigation ? Let it ever be
borne in mind that, on the one hand,
truth can never be opposed to truth, and,
on the other, that error is only to be effec-
tually confounded by searching deep and
tracing it to its source.

Nothing can be more unfounded than
the objection which has been taken
against the study of natural philosophy,
and, indeed, against all science, that it
fosters in its cultivators an undue and
overweening self-conceit, leads them to
doubt the immortality of the soul, and
to scoff at revealed religion. Its natural
effect on every well regulated mind is,
and must be, directly the reverse. Minds
which have long been accustomed to date
the origin of the universe, as well as that
of the human race, from an era of about
six thousand years back, receive reluc-
tantly any information, which, if true,
demands some new modification of their
present ideas of cosmogony, and, as in
this respect, geology has shared the fate
of other infant sciences, in being for a
while considered hostile to revealed reli-
gion; so, like them, when fully under-
stood, it will be found a potent and con-
sistent auxiliary to it, exalting our con-
viction of the power, wisdom, and good-
ness of the Creator.

" It may fairly be asked," says Chalmers,
" of those persons who consider, physical
science a fit subject for revelation, what
point they can imagine short of a commu-
nication of omniscience, at which such a
revelation might have stopped, without
imperfection or omission, less in degree,
but similar in kind, to that which they
impute to the existing narrative of Moses.
A revelation of so much only of astro-
nomy as was known to Copernicus, would
have seemed imperfect after the disco-
veries of Newton ; and a revelation of the
science of Newton would have appeared
defective to Laplace. And unless hu-
man nature had been constituted other-
wise than it is, the above supposed com-

munication of omniscience would have
been imparted to creatures, utterly inca-
pable of receiving it, under any past or
present moral or physical condition of
the human race. Does Moses even say,
that when God created the heavens and
the earth he did more, at the time alluded
to, than transform them out of previously
existing materials ? Or does he ever say
that there was not an interval of many
ages between the first act of creation, de-
scribed in the first book of Genesis, and
said to have been performed l in the be-
ginning,' and those more detailed ope-
rations, the account of which commences
at the second verse, and which are de-
scribed as having been performed in so
many clays ?

"Let no one, therefore, be checked in
his enquiries into the history of the globe
by anything but the good rules of philo-
sophical induction, which are essential to
the right use of the intellectual strength
which God has conferred upon man, to be
exercised on the mighty works of nature ;
arid least of all let him be deterred from
the pursuit of truth by the vain and im-
pious dread that he may go too far, and
penetrate too deeply into those mysteries,
which, among their other uses have this
one, namely, that they continually excite
to activity the soul of man ; and, the more
they are studied, lead to deeper delight,
and more awful contemplation of their
glorious and beneficent Author."

Geology, aided not only by the higher
branches of physics, but by recent disco-
veries in mineralogy and chemistry, in
botany, zoology, and comparative ana-
tomy, is enabled to extract from the ar-
chives of the interior of the earth, intelli-
gible records of former conditions of our
planets, and to decipher documents, which
were a sealed book to our predecessors.
Thus enlarged in its views, and provided
with fit means for pursuing them, geology
extends its researches into regions more
vast and remote, than come within the
scope of any other physical science, ex-
cept astronomy. — Davy. Buckland.

Herschell. Chalmers. Lyell. Phillips.

Mantell. Bakewell.
GEOSAU'RTJS. A fossil saurian of the oolite

and lias formations.
GERM, (oerme, Fr.germe, It.grermen, Lat.)

1. In botany, the swollen base of the
pistil, forming the rudiment of the fruit
and seed.

2. The embryo ; origin. So long as the
offspring has no independent existence,
but participates in that of its parent, it is
called a germ. The separation of the
germ is called generation.

GE'RMINANT. (germinans, Lat.) Sprout-
ing ; beginning to grow.

G E R

[ 106

GIL

GE'RMINATE. (germino, Lat. germcr, Fr.
germinare, It.) To sprout; to bud; to
shoot forth.

GERMINA'TION. (germination, Fr. germi-
nazione, It. germinatio, Lat.) The act
of sprouting or shooting forth.

GE'YSER. The name given to certain
boiling springs or fountains in Iceland.
The water of these geysers holds a consi-
derable proportion of silex in solution.
The following account of the geysers of
Iceland is extracted from Mr. Lyell's
Principles of Geology. «' These inter-
mittent hot springs occur in a district
situated in the south-western division of
Iceland, where nearly one hundred of
them are said to break out within a cir-
cle of two miles. They rise through a
thick current of lava which may, per-
haps, have flowed from Mount Hecla, the
summit of that volcano being seen from
the spot at a distance of more than thirty
miles. Few of the geysers play longer
than five or six minutes at a time, and the
intervals between their eruptions are, for
the most part, very irregular. The great
geyser rises out of a spacious basin at the
summit of a circular mound composed
of siliceous incrustations deposited from
the spray of its waters. The diameter of
this basin is fifty-six feet in one direction
by forty-six in another. In the centre
is a pipe seventy-eight feet in perpen-
dicular depth, and from eight to ten feet
in diameter, but gradually widening as it
rises into the basin. The circular basin
is sometimes empty, but is usually filled
with beautifully transparent water in a
state of ebullition. During the rise of the
boiling water in the pipe, especially when
the ebullition is most violent, and when
the water is thrown up in jets, subterra-
nean noises are heard, like the distant
firing of cannon, and the earth is slightly
shaken. The sound then increases, and
the motion becomes more violent, till at
length a column of water is thrown up,
with loud explosions, to the height of one
or two hundred feet. After playing for
a time like an artificial fountain, and
giving off clouds of vapour, the pipe or
tube is emptied, and a column of steam
rushing up with amazing force and a
thundering noise, terminates the erup-
tion. If stones are thrown into the cra-
ter, they are instantly ejected, and such
is the explosive force, that very hard
rocks are sometimes shivered by it into
small pieces.

GI'BBOUS. (gibbus, Lat. gilbeaux, Fr. gib-
boso, It.) Bossed ; convex ; bunched.
In botany, applied to fleshy leaves having
one or both sides convex, arising from the
great abundance of pulp.
GI'BBSITE. A mineral of a dirty white j

colour, found in America, and named
after Mr. Gibbs.

GILL. The lung, or respiratory orgr.n of
the fish. The gills, or branchiae, lie in
openings on each side of the head ; their
form is semicircular ; they have a vast
number of fibrillse standing out on each
side of them like a fringe, and very much
resemble the vane of a feather. There
are, in most fishes, four gills on each side,
resting on an equal number of arched
portions of cartilage or bone, connected
with the os hyoides. In some cartila-
ginous fishes there are five gills on each
side ; in the lamprey there are seven.
The larger Crustacea have their branchiae
situated on the under side of their body,
not only in order to obtain protection
from the carapace, which is folded over
them, but also for the sake of being
attached to the haunches of the feet,
jaws, and thoracic feet, and thus partici-
pating in the movements of those organs.
They may be seen in the lobster and in
the crab, by raising the lower edge of the
carapace.

In the greater number of mollusca
these important organs, although external
with respect to the viscera, are within the
shell, and are generally situated near its
outer margin. They are composed of
parallel filaments, arranged like the teeth
of a fine comb ; and an opening exists
in the mouth for admitting the water
which is to act upon them. These fila-
ments appear, in many instances, to have
the power of producing currents of water
in their vicinity by the action of minute
cilia, similar to those belonging to the
tentacula of many polypi, where the same
phenomenon is observable. In the Ace-
phala, or bivalve mollusca, the gills are
spread out, in the form of laminae, round
the margin of the shell, as is exemplified
in the oyster when it is commonly known
by the name of beard. The aerated
water is admitted through a fissure in the
mouth, and when it has performed its
office in respiration, is usually expelled
by a separate opening.

All the sepise have their gills enclosed
in two lateral cavities, which communi-
cate with a funnel-shaped opening in the
middle of- the neck, alternately receiving
and expelling the water by the muscular
action of its sides. The forms assumed
by the respiratory organs in this class are
almost infinitely diversified. In fishes
the gills form large organs, and the con-
tinuance of their action is more essential
to life than it appears to be in any of the
inferior classes. When their surfaces
are minutely examined, they are found to
be covered with innumerable minute pro-
cesses, crowded together like the pile of

GIN

C 107 ]

G L A

velvet ; and on these are distributed
myriads of blood-vessels, spread like a
delicate net work, over every part of their
surface. A large flap, termed the oper-
culum, extends over the whole organ,
defending it from injury, and leaving
below a wide fissure for the escape of the
water which has performed its office in
respiration. For this purpose the water
is taken in by the rnouth, and forced by
the muscles of the throat through the
apertures which lead to the branchial
cavities ; in this action the branchial
arteries are brought forward and sepa-
rated to a certain distance from each
other, and the rush of water through
them unfolds, and separates, each of the
thousand minute filaments of the bran-
chioe, so that they all receive the full
action of that fluid as it passes by them.
When a fish is taken out of the water, the
animal vainly reiterates its utmost efforts
to raise the branchiae, and relieve the sense
of suffocation it experiences in conse-
quence of the general collapse of the fila-
ments of those organs, which adhere
together in a mass, and can no longer
receive the vivifying influence of oxygen.
" It has been generally stated," says Dr.
Roget, "by physiologists, even of the
highest authority, that the principal rea-
son why fishes cannot maintain life, when
surrounded by air instead of water, is
that the branchiee become dry, and lose
the power of acting when thus deprived
of their natural moisture. The rectifica-
tion of this error is due to Flourens, who
pointed out the true cause."

GI'NGLYMOID. (from ytyyXv/zos and tldoQ,
Gr.) Resembling a hinge ; pertaining
to that species of hinge-like joint which
admits of flexion and extension.

GI'NGLYMUS. (ytyyX^juof, Gr.) Articu-
lation admitting flexion and extension.

GI'RASOLE. (from gyro, to turn, and sol,
the sun, Lat.) The name given to a
variety of opal. The silex girasol of
Brongniart, and quartz resinite girasol of
Haiiy. The girasole is of a milk white
colour, but it possesses a remarkable
property of reflecting a red colour
when turned towards the sun, or any
bright light. From this peculiar property
it obtains its name. Girasole is some-
times strongly translucent, and the finest
specimens resemble translucid jelly.

GLA'BROUS. (glaber, Lat.) Smooth ; the
opposite to hairy ; downy.

GLA'CIAL. (glacialis, Lat. glacial, Fr.)
Icy ; frozen.

GLA'CIER. (glacier, Fr. Amos de mon-
tagnes de glace, qui se trouvent en quel-
ques endroits de la Suisse de la Saroie et
du Dauphint, au sommet des montagnes.}
Great accumulations or extensive fields

of ice, common in mountainous coun-
tries.

GLA'CIS. (glacis, F.) A sloping bank.

GLANCE, (glantz, Germ.)

1 . A name given to some minerals which
possess a metallic, or pseudo-metallic
lustre.

2. An order of minerals, containing eight
genera. — 1. Copper glance ; 2. Silver-
glance ; 3. Lead-glance ; 4. Tellurium-
glance; 5. Molybdena-glance ; 6. Bis-
muth-glance ; 7. Antimony-glance ; 8.
Melane-glance.

GLANCE -COAL, (glanzkohle, Germ.) A
variety of coal, known also as anthracite.
This is the glanzkohle of Werner,; the
glance-coal of Jameson, the native mine-
ral carbon of Kirwan, and the blind-
coal of some authors. There are several
varieties of the glance-coal, namely, con-
choidal glance-coal, or that having a
conchoidal fracture and splendent lustre ;
slaty glance-coal, or that with a slaty
structure ; columnar glance-coal, and
fibroifs glance-coal. This combustible,
at first view, strongly resembles coal,
from which, however, it materially differs.
Its colour is black, or rather grayish and
iron-black, sometimes tinged with blue
or brown. It, perhaps, never possesses
the pure deep black of coal. Glance-
coal, like the diamond, appears to be
essentially composed of pure carbon, but
in a very different state of aggregation.
The glance-coal of Kilkenny contains
about 97 per cent, of carbon ; that of
Rhode Island about 94 or 95. It occurs
in beds in the coal formation, in the
secondary class of rocks ; it is occasion-
ally found among rocks of the primary
and transition series. It is sometimes
nearly allied to graphite. It may be dis-
tinguished from coal by the difficulty
with which it burns, by its greater spe-
cific gravity, and by its composition : it
differs from graphite in being less heavy ;
its trace on paper is dull and blackish,
whereas that of graphite is a shining
metallic gray ; and graphite is unctuous
to the feel, whereas glance-coal is not.

GLAND, (glande, Fr. glandula, It.)

1. Bodies employed to form or alter the
different liquids in the animal body.
There are two distinct sets of glands, the
conglobate, and the conglomerate. Great
variety is observable both in the form
and structure of different glands, and in

- the mode in which their blood-vessels
are distributed. In some glands, the
minute arteries suddenly divide into a
great number of smaller branches, like
the fibres of a camel-hair pencil ; this
is called the pencillated structure. Some-
times, the minute branches, instead of
proceeding parallel to each other, after

G L A

[ 108 ]

ONE

their division, separate like rays from a
centre, presenting a stellated arrange-
ment. In the greater number of in-
stances, the smaller arteries take a tor-
tuous course, and are sometimes coiled
into spirals. It is only by means of
microscopic aid that these minute struc-
tures can be rendered visible.
2. In botany, a small transparent tumour
or vesicle, discharging a fluid, either oily
or watery, and situated on various parts
of plants, as the stalk, calyx, leaves, &c.
These glands are composed of closely
compacted cells, which perform the func-
tions of secretion, or the conversion of
the nutritious juices into particular pro-
ducts required for various purposes in
the economy of the plant. The perfume
of the flowers and leaves of plants arises
from secretions from glands.

GLANDI'FEROUS. (from glandifer, Lat.)
Bearing acorns, or fruit resembling
acorns.

GLA'NDIFORM. Of the form or shape of a
gland.

GLA'NDULAR. } (glanduleux, Fr. glandulo-

GLA'NDULOUS. $ so, It.glandulosus, Lat.)

1. Pertaining to glands ; containing
glands ; full of glands.

2. In botany, applied to the margins of
leaves having glands.

GLAU'BERITE. An hydrous sulphate of
soda and lime. A mineral of a white or
yellow colour ; crystallized in oblique
four-sided prisms ; consisting of 51 parts
sulphate of soda, and 49 parts sulphate
of lime. It is less hard than carbonate of
lime, but scratches sulphate of lime. It
is found in New Castile, in Spain, dis-
seminated in muriate of soda.

GLAU'COUS. (glaucus, Lat azure, yXavKot;,
Gr.)

1 . Of a sea-green colour ; grey or blue ;
azure.

2. In botany, applied to the leaves or
stems of plants, when covered with a fine
mealiness of a sea-green colour.

GLE'NOID. (from yXrfvri and eZ<5of, Gr.)

A part having a shallow cavity.
GLI'MMER. (Germ.) The name given by

Werner to mica.
GLO'BOSE. (globosus, Lat.) Round ;

spherical.
GLOBO'SITY. (globesita, It.) Roundness ;

sphericity ; sphericalness.
GLO'BOUS. Spherical; round.
GLO'BULAR. Round; spherical.
GLO'BULE. (globule, Fr. globetto, It.) A

small particle of matter having a round

or spherical form.
GLO'BULOUS. (globuleux, Fr. globuloso,

It.) Round; spherical.
GLO'MERATE. \(glomeratu8, Lat.) Ga-
GLO'MERATED. $ thered into a mass of a

globular form.

GLO'MERIS. (from glomero, Lat. to gather
into a round heap. ) A myriapod, resem-
bling a wood-louse, which, like the arma-
dillo, when alarmed, rolls itself up into a
spherical ball.

GLO'MEROUS. (glomerosus, Lat.) The
same as glomerate.

GLO'TTIS. (from yXwrra, Gr.) The up-
per opening of the larynx, at the root of
the tongue.

GLUCI'NA. (from yXvicic, Gr. sweet.)
An earth obtainable from the emerald,
beryl, and euclase, of all which it forms
a constituent part. Sir H. Davy disco-
vered that glucina consisted of three
parts glucinum and one part oxygen.
Glucina is soluble in the liquid fixed
alkalies, in which respect it agrees with
alumina. It is insoluble in ammonia,
but soluble in carbonate of ammonia. It
combines with all the acids, and forms
with them sweetish salts, from which
circumstance it obtained its name. It
was first discovered by Vauquelin in
1798.

GLUCI'NUM. The metal which is the base
of the earth glucina ; it has not yet been
obtained in a separate state.

GLUMA'CEOUS. Having glumes.

GLUME, (gluma, Lat.) The husk of corn ;
the chaff; the outer husk of corn and
grasses ; the calyx of corn and grasses.
In the grasses, and plants resembling
them, the floral envelopes are not called
calyx and corolla, but bracteae. The two
outer bractese are termed glumes.

GLU'TINOUS. (glutineux, Fr. glutinoso,
It. glutinosus, Lat.) Viscid ; tenacious ;
gluey.

GLU'TINOUSNESS. Viscosity ; tenacity ;
viscidity.

GLYCE'MERIS. > A transverse shell, gaping

GLYCI'MERIS. $ at both extremities ; hinge
callous, without tooth.

GNARLED. Having hard knots.

GNEISS. The name given by the German
mineralogists to a schistose or slaty gra-
nite, abounding in mica. It is a member
of the metamorphic rocks. By some
geologists, gneiss has been called se-
condary granite. Granite frequently may
be observed passing by scarcely per-
ceptible gradations into gneiss : when
granite contains but little felspar, and
the proportion of mica is increased, the
mica being arranged in layers, it becomes
schistose, and we find a true gneiss.
Again, when the mica becomes very
abundant, gneiss passes into mica-slate.
Gneiss occurs in Ireland and Scotland ;
but it is rarely found in England or
Wales. It is most abundant in Sweden.
Gneiss is composed of the same ingre-
dients with granite, namely, felspar,
quartz, and mica, its texture being equally

G L A

[ 10!) ]

G R E

crystalline. According to the Huttonian
theory, the materials composing gneiss
were originally deposited from water ; but
from the influence of subterranean heat,
became altered so as to assume a new
texture. The structure of gneiss is always
more or less distinctly slaty, when viewed
in the mass ; although individual layers
may possess a granular structure. When
this mineral is broken perpendicularly to
the direction of its strata, its fracture has
commonly a striped aspect. This rock,
though slaty in its structure, is rarely
perfectly fissile. Gneiss, like granite,
never contains any fossil remains ; when
it occurs with granite, it usually lies im-
mediately over the granite j or, if the
strata be highly inclined, it appears rather
to rest against the granite than to be
incumbent upon it. Gneiss is more or
less distinctly stratified, and the strata
are often inclined to the horizon at a
very great angle ; indeed, they are some-
times nearly, or quite, vertical. Moun-
tains composed of gneiss are seldom so
steep as those of granite, and their sum~
mits, instead of presenting those needle-
like points, or aiguilles, which charac-
terize granitic mountains, are usually
rounded. Few of the primary rocks are
so metalliferous as gneiss. Its ores oc-
cur both in beds and veins : more fre-
quently in the latter.

GLA'NDULOUS GNEISS. A variety of gneiss,
(in which the mica is sometimes ar-
ranged in undulated layers,) presenting
numerous small masses of felspar or
quartz, of a globular or ellipitical form,
interspersed like glands through the
mass. From this circumstance it has
obtained its name.

GOLD. (Sax.) A metal, when pure, of a
rich yellow colour : specific gravity 19 '3.
It does not readily combine with oxygen ;
hence it does not rust when exposed to
the air, and it may be melted and re-
melted frequently with scarcely any dimi-
nution of its quantity. It is said to have
been kept in a state of fusion for nearly
eight months without undergoing any
perceptible change. In ductility and
malleability it surpasses all other metals,
and it may be beaten into leaves so ex-
ceedingly thin, that one grain of gold
shall cover fifty-six square inches, such
leaves having the thickness only of one
282,000th part of an inch. Its tenacity
is inferior to that of iron, copper, pla-
tinum, and silver. Gold is soluble in
nitro-muriatic acid, and in a solution of
chlorine. The gold coins of this country
contain one-twelfth part of copper alloy :
jewellers' gold is a mixture of gold and
copper in the proportions of three-fourths
of pure gold and one-fourth of copper.

GOLT. See Gault,

GONI'ATITES. A sub-genus of ammonites,
in which the last whorl covers the spire.
Seven species have been found in the
carboniferous system, and seventeen in
the primary strata.

GONIO'METER. (from yom'a, an angle,
and fjLkrpov, a measure, Gr.) An instru-
ment invented by M. Carangeau, for the
accurate measurement of crystals. Dr.
Wollaston also invented a goniometer.

GONYLE'PTES. A genus of the second order
of Pseudarachnidans, the posterior legs
exhibiting a raptorious character.

GORGO'NIA. A genus of Ceratophyta, of
the family Corticati, class Polypi. These
animals have a horny skeleton, are car-
nivorous, feeding upon living animalcules.
The polypi of several species have been
observed, and they are found to possess
eight denticulated arms, a stomach, &c.

GRA'LL^E. An order of aquatic birds. Wa-
ders ; frequenting marshes and streams ;
having long naked legs ; long neck ;
cylindrical bills. In this order are in-
cluded the crane, stork, heron, bittern,
&c. &c.

GRA'MINA. (gramen, Lat.) The fourth
order in Linnseus's division ; the grasses.

GRAMINEOUS. (gramineus,~Lat.) Grassy;
resembling grass. Gramineous plants are
such as have a long narrow leaf, and no
foot-stalk.

GRAMINIVOROUS, (from gramen, grass,
and voro, to devour, Lat.) Subsisting
wholly on grass or vegetable food. Ani-
mals which subsist wholly on vegetable
food are called graminivorous, while those
which live on flesh alone are called car-
nivorous ; those feeding on both are
called omnivorous ; while those feeding
solely on fishes are denominated pisci-
vorous.

GRA'MMATITE. (The name given by
Brongniart to Tremolin.) A mineral, a
variety of hornblende, confined almost
entirely to primary rocks. Colours white
and blue. Disposed in fibrous, radiated,
and granular concretions.

GRA'NATINE. A name given by Mr. Kir-
wan to a granular aggregate containing
three ingredients, but those differing from
the ingredients of granite. A compound
embracing two ingredients only, he
termed agranitell; when three ingredi-
ents are present, but not the three form-
ing granite, he called it a granatine ;
when more than three ingredients form
the compound, he termed it a granilite.

GRA'NATITE. > The Prismatoidischer gra-

GRE'NATITE. $ nat of Mohs, Granatit of
Werner, Staurotide of Haiiy. A reddish-
brown mineral, occurring in primary
rocks in the Shetland Isles, and in many
parts of Scotland, and in America. Ac-

G R A

G R A

cording to Vauquelin, it consists of alu-
mina 45, silica 33, oxide of iron 13,
oxide of manganese 4, and lime 4. Its
form and infusibility distinguish it from
the garnet.

GRANI'FEROUS. (from yranum and fero,
Lat.) Pods which bear seeds like
grains.

GRANILI'TE. An aggregate containing
more than three constituent parts ; thus
named by Mr. Kirwan.

GRA'NITE. (granito, It. granit, ou granite,
Fr. Pierre fort dure, qui est composte
d'un assemblage d'autres pierres de dif-
ftrentes couleurs.) An aggregate of
felspar, quartz, and mica, whatever may
be the size or figure of the several ingre-
dients, or their relative proportions, is
denominated granite. There are many
varieties of granite ; as porphyritic granite,
in which large crystals of felspar occur ;
sienitic granite, in which hornblende
supplies the place of mica ; chloritic, or
talcy granite, composed of quartz, fel-
spar, and talc or chlorite, instead of
mica ; felspathic granite, &c. &c. Gra-
nite is a compound plutonic or igneous
rock, unstratified and crystalline, of a
granular structure, whence its name.
From its great relative depth, granite is
rarely met with but in mountainous situ-
ations, where it appears to have been
forced through the more superficial co-
vering. " It was at one time supposed
that granite was peculiar to the lowest
portions of the rocks composing the crust
of the earth, and that, in fact, it consti-
tuted the fundamental rock upon which
all others had been formed, and was not
discovered higher in the series. This
opinion has given way before facts, for
we find granitic rocks in situations where
they must have been ejected subsequent-
ly to the period during which the creta-
ceous group was deposited, as also in
other places, into which they must have
been thrust at intermediate periods down
to the oldest rocks inclusive. Granite
is said to contain forty-eight per cent, of
oxygen. Granite being an igneous rock,
no organic fossil remains could be ex-
pected to be found therein, nor have any
ever been discovered ; nevertheless gra-
nite is occasionally found overlying strata
containing fossil organic remains, as in
Norway ; a mass of granite has been dis-
covered superincumbent on secondary
limestone, which contains orthocerata,
&c. From these circumstances there can
no longer exist a doubt but that granite
has been formed at different periods, and
is of various ages. A comparatively mo-
dern granite may be observed in the Alps
penetrating secondary strata, such se-
condary strata containing fossils, such as

belemnites, referrible to the age of the
English lias. Felspar is by far the largest
constituent of granite, and in some kinds
it is found in large whitish crystals of
irregular forms, occasionally of one or two
inches in length. Granite of this kind,
however beautiful it may be to the eye,
is not well adapted for buildings, the fel-
spar being subject to decomposition from
the continued action of the atmosphere.
Waterloo-bridge is unfortunately built of
this perishable kind of granite. It may
be considered as a general law, that
wherever granite rises to any height above
the surface of the earth, the strata of
other surrounding rocks rise towards it.
The highest point at which granite has
been discovered in any part of the world
is Mont Blanc, 15,683 feet above the
level of the ocean. Saussure, who has
published an account of his ascent of
Mont Blanc, infers from his observations
that the vertical beds of granite were
originally horizontal and have been up-
heaved by some violent convulsions of
nature, and he states that what now
forms the summit of the mountain must
at some former period have been more
than two leagues below the surface.
GRA'NITEL. > A name given by Kirwan to
GRA'NITELL. 5 a binary aggregate com-
posed of any two of the following ingre-
dients : felspar, mica, shorl, quartz, gar-
net, steatites, hornblende, jade.
GRANI'TIC. Composed of grains or crys-
tals united without a cement, as in gra-
nites and some sandstones.
GRANI'TICAL. Consisting of granite ; com-
posed of granite.

GRANI'TIC AGGREGATE. A granular com-
pound, consisting of two, three, or four
simple minerals, among which only one
of the essential ingredients of granite is
present. Among the granitic aggregates,
which contain only one of the essential
ingredients of granite, may be enumerated
combinations of quartz and hornblende,
— quartz and actinolite, — felspar and
schorl, — mica and hornblende, — quartz,
hornblende, and garnet, — quartz, horn-
blende, and epidote, &c. &c.
GRANITIFICA'TION. The act of being

formed into granite.
GRANI'TIFORM. Resembling granite in

structure or shape.

GRA'NITINE. An aggregate of three mi-
neral constituents, one or more differing
from those which compose granite. For
example, an aggregate of quartz, fel-
spar, and shorl is a granitine, as is one of
quartz, mica, and shorl; or quartz, horn-
blende and garnet ; and many others.
GRANI'TOID. (from granite and tiBoc, Gr.)

Resembling granite.
GRANI'VOROUS. (from yranum and voro,

G R A

£

G R A

Lat.) Eating grain ; subsisting on
grain.

GRA'NULAR. } Bodies containing, or com-

GRA'NULARY. J posed of, small grains.

GRA'NULAR LIMESTONE. A subspecies of
carbonate of lime, the result of a con-
fused or irregular crystallization. Struc-
ture foliated and granular. The grains
are of various sizes, from coarse to very
fine, sometimes, indeed, so fine that the
mass appears almost compact. W7hen
these grains are white and of a moderate
size, this mineral strongly resembles
white sugar in solid masses. Its fracture
is foliated, and when the structure is very
finely granular, the fracture often be-
comes a little splintery. It is more or
less translucent, but in the dark-coloured
varieties, at the edges only. Its colour
is most commonly white or gray, often
snow-white, and sometimes grayish black.
Some varieties are flexible when sawn into
thin slabs. Granular limestone is some-
times a pure carbonate of lime. It occurs
in very large masses, and is almost exclu-
sively found in primary rocks ; some-
times it occurs among secondary, but
then its relative age is easily determined
by the shells it contains, or the accom-
panying minerals. In the Pyrennees
vertical beds of granular limestone alter-
nate with granite, and trap, or the limestone
is sometimes intermixed with those rocks.
There are few countries in which gra-
nular limestone is not found. Italy and
Greece furnished the ancients with valu-
able quarries. Both granular and com-
pact limestone furnish numerous varieties
of marbles, but those which belong to
the former exhibit a more uniform colour,
are generally susceptible of a higher po-
lish, and are consequently most esteemed
for statuary and some other purposes. —
Cleaveland.

GRA'NULATE. (granuler, Fr.) To be
formed into small grains.

GRA'NULATED. Having a structure resem-
bling grains ; formed into grains ; bead-
ed ; having small roundish elevations,
placed in rows.

GRANULA'TION. (granulation, Fr.)

1. The operation by which metals are
reduced into small grains.

2. The act of forming into bodies resem-
bling aggregates of grains.

GRA'NULE. (diminutive of grain.) A small
grain.

GRA'NULOUS. Composed of grains; full of
small grains.

GRA'PHIC GRA'NITE. A variety of granite,
composed of felspar and quartz, so ar-
ranged as to produce an imperfect laminar
structure. When a section of graphic
granite is made at right angles to the alter-
nations of the constituent minerals, bro-

ken lines, resembling Hebrew characters,
present themselves ; hence its derivation.

GRA'PHITE. Another name for black-lead,
or plumbago ; carburet of iron. Graphite
is of a dark steel-gray, or nearly iron-
black. It leaves on paper a well defined,
shining trace, which has very nearly the
colour of the mass, and consists of minute
grains. It is perfectly opaque, easily
scraped by a knife, and soils the fingers.
It is a conductor of electricity, and when
rubbed on sealing-wax till a metallic trace
appears, communicates no electricity to
the wax. Specific gravity from 1'98 to
2-26. Constituent 'parts, carbon 92'0,
iron 8'0. — Cleaveland.

GRA'PTOLITE. A fossil zoophyte, found in
the Silurian shales.

GRA'VEL. Fragments of stones and flints ;
small pebbles.

GRAVITA'TION. (gravitation, Fr. gravita*
zione, It.) The difference between gra-
vity and the centrifugal force induced by
the velocity of rotation or revolution : the
force which causes substances to fall to
the surface of the earth, and which retains
the celestial bodies in their orbits ; its
intensity increases as the squares of the
distance decrease.

GRA'VITY. (gravite, Fr. gravita, It.) The
reciprocal attraction of matter on matter.
The force of gravity is every where per-
pendicular to the surface, and in direct
proportion to the quantity of matter.

GRA'YWACKE. ^ (from grauwacke, Germ.

GRAU'WACKE. ! a compound of grau,

GRAUWACKE'. \ grey, and wacke, a

GRE'YWACKE. J provincial term used by
miners.) The name given to a group of
rocks, being the lowest members of the
secondary strata. Mr. Lyell comprises in
this group the Ludlow, Wenlock and
Dudley, Horderly and May Hill rocks,
the Builth and Llandeilo flags, and the
Longmynd rocks. The French have
changed the name grauwacJce for trau-
mate, a word as little euphonic as the
one repudiated. Mr. Bakewell observes,
" Graywacke, in its most common form,
may be described as a coarse slate con-
taining particles or fragments of other
rocks or minerals, varying in size from
two or more inches to the smallest grain."
When the imbedded particles become ex-
tremely minute, graywacke passes into
common slate. When the particles and
fragments are numerous, and the slate in
which they are cemented can scarcely be
perceived, graywacke becomes coarse
sandstone, or gritstone. When the frag-
ments are larger and angular, graywacke
might be described as a breccia with a
paste of slate. When the fragments are
rounded it might not improperly be called
an ancient conglomerate. The old red

G R A

[ 112 ]

G R E

sandstone is a graywacke, coloured red
by the accidental admixture of oxide of
iron ; it possesses all the mineral charac-
ters, and occupies the geological position
of, graywacke. The rock, though com-
posed of substances of various colours,
usually exhibits some shade of gray or
brown ; it is sometimes of considerable
hai-dness, and susceptible of a high polish.
Graywacke is often distinctly stratified,
but the strata are not usually parallel to
those of the subjacent rocks. The com-
mon and slaty varieties often alternate
with each other, and both are traversed
by veins of quartz. This rock is remark-
ably metalliferous ; and its ores occur
both in beds and veins. Most of the
mines of the Hartz are contained in gray-
wacke.

Graywacke abounds in Germany and
in Scotland ; indeed, nearly all the moun-
tains of Scotland north of the Frith of
Forth are chiefly composed of it. In the
neighbourhood of Mont Blanc, and in
other parts of the Alps, it occurs at a
great elevation, forming large masses in
vertical beds.

GRA'YWACKE SLATE. A variety of gray-
wacke, in which the grains are so minute
as to be scarcely perceptible by the naked
eye.

GREEN-EARTH. The Griin Erde of Werner ;
the Talc Zographique of Haiiy ; the
Chlorite Baldogee of Brongniart. A va-
riety of talc, occurring in vesicular cavi-
ties in amygdaloid. Its colour is a plea-
sant green, more or less deep, sometimes
bluish or grayish-green, and passing to
olive and blackish -green. Its fracture is
dull, and fine-grained earthy, or slightly
conchoidal. It is somewhat unctuous to
the touch, and adheres to the tongue.
Easily reducible to powder. Specific
gravity 2*63. — Kirwan.

According to Vauquelin it consists of
silex 52'0, magnesia 6'0, oxide of iron
23-4, alumina 7'0, potash 7'4, water 4'0.
It is met with in the mountainous districts
of England and Scotland. It is the moun-
tain-green of artists ; and, when ground
with oil, is employed as a paint.

GREEN-SAND. A member of the chalk
formation, called also Shanklin sand. The
beds of sand, sandstone, and limestone,
which form the lowermost strata of the
chalk formation, have obtained the name
of green-sand, from the circumstance of
their containing a considerable quantity
of chlorite, or green earth, scattered
throughout their substance. In describ-
ing the group of deposits to which the
name of green-sand, or Shanklin-sand, is
appropriated, geologists state that they
admit of a triple division ; the first, or
uppermost, consists of sand, with irregular

concretions of limestone and chert, some-
times disposed in courses oblique to the
general direction of the strata. The se-
cond consists chiefly of sand, but in some
places is so mixed with clay, or with oxide
of iron, as to retain water. The third,
and lowest group, abounds much more in
stone ; the concretional beds being closer
together and more nearly continuous.
The total thickness of the green-sand,
where it is fully developed, is more than
400 feet. The animal remains of the
green-sand are exclusively marine. The
French have denominated this formation
glauconie crayeuse, and craie chloritee.
It is very common to divide the green-
sand into the upper green-sand and the
lower green-sand, the two being separated
by the gault.

GREE'NSTONE. The Griinstein of Werner ;
Roche Amphibolique of Haiiy ; the dia-
base of the French geologists. A granular
rock composed of hornblende and felspar,
in the state of grains, or sometimes of
small crystals. Greenstone contains a
larger quantity of felspar than basalt, and
the grains both of hornblende and felspar
are less amalgamated. It is a variety of
trap rock. The hornblende usually pre-
dominates, and frequently gives to this
aggregate a greenish hue, from which cir-
cumstance it obtains its name. Green-
stone occurs in beds of considerable mag-
nitude, and sometimes forms whole moun-
tains. It often appears in conical hills,
or presents high, mural precipices, whose
fronts are frequently composed of nume-
rous columns of various sizes, resembling
basalt. Sometimes it forms only the
summits of mountains. Small veins of
actinolite, epidote, felspar, prehuite,
quartz, &c., &c., frequently are found
traversing greenstone.

GREGA'RIOUS. (gregarfas, Lat.) Living
in flocks or herds ; animals whose habits
lead them to assemble in numbers.

GRE'NATITE. Prismatoidal garnet. See
Granatite.

GRE'YSTONE. A rock of greyish or green-
ish colour, composed of felspar and au-
gite, the former being more than 75 per
cent, of the whole.

GRE'YWACKE. For a full description of
this, see Graywacke.

GREY-WEATHERS. The name given to
large boulders of siliceous sandstone.
There is a singular assemblage of these
erratic blocks in a field on the borders of
Wiltshire, not far from Marlboro ugh.
The immense blocks forming, as is sup-
posed, the druidical temple at Stonehenge,
are composed of this siliceous sandstone.
tf Boulders of druid sandstone," observes
Dr. Mantell, " also occur in the shingle
bed, and calcareous deposit, at Brighton,

G R I

[ us 1

GYP

and may be observed lying on the sea-
shore in considerable numbers, after a
recent fall of the cliff. Upon comparing
the sandstone of Stonehenge with that of
Sussex, no perceptible difference can be
detected.

GRI'SEOUS. (from yriser, Fr.) A mix-
ture of black and white.

GRIT. The provincial term for a coarse
siliceous sandstone. Some of the strata
of this description have been worked for
mill-stones, from which circumstance
they have been called mill-stone grit.
The mill-stone grit is an important depo-
sit in the north of England, from the
Coquet to the Tyne, and on the hills be-
tween the dales of Durham and York,
from the Tyne to the Kibble.

GROSSULA'RE. The asparagus-green va-
riety of dodecahedral garnet. It is found
in Siberia. Its constituents are, silica
40-50, alumina 20'10, lime 33-80, oxide
of iron 5'00, oxide of managanese 0'50.

GRYPH^'A. (from gryps, Lat. a griffin.)
A fossil inequivalved bivalve ; the lower
valve concave, terminated by a beak, and
curving upwards and inwards ; the upper
valve much smaller, like an operculum ;
the hinge toothless, the pit oblong and
arched : one impression in each valve.
Fossil shells of this genus are found in
considerable numbers in different parts
of England. From the curved beak of
the shell, Linnaeus placed it among the
anomise ; but Lamarck placed it under a
distinct genus. He notices nine dif-
ferent species. Parkinson observes, " on
viewing the different specimens of ostra-
cites and gryphites, I cannot help doubt-
ing as to the propriety of the formation
of a distinct genus for this shell. T find
specimens in which the beak and the
body of the valve possess various degrees
of curvature, from the complete curve of
the gryphites to the slight turn of the
edible oyster. The recent gryphsea is
found at a shallow depth, in estuaries, on
gravel and sand.

GRYPHI'TE. (gryphites, Lat.) Belonging
to the genus gryphsea. This deeply-
incurved bivalve is so abundant in some
of the beds of lias in France, as to have
occasioned them to be called Galcaire a
gryphites. These shells are known in
this country by the provincial term of
" miller's thumbs."

GYMNOSPE'RMIA. (from yv^ivog, nudus,
naked, and (TTrlp^a, semen, seed.) The
first order in the fourteenth class, Didy-
namia, in Linnseus's artificial system ;
having four naked seeds in the bottom of
the calyx, with the exception of one
genus, Phryma, which is monosper-
mous.

GYMNOSPE'RMOUS. Having naked seeds

in the bottom of the calyx ; belonging to
the order Gymnospermia.

GYNA'NDRIA. (from yvvri, a woman, and
avrjp, Gr. a man.) The name of the 20th
class in Linnseus's sexual system, con-
sisting of plants with hermaphrodite
flowers, having the stamens growing upon
the style, or having the stamina united
with, or growing out of the pistil, and
either proceeding from the germen or the
style. The orders of this class are taken
from the number of the pistils, but bo-
tanists are not agreed as to the admission
of some of them into the class.

GYNA'NDRIAN. Belonging to the class
Gynandria.

GYNA'NDROUS. A term applied to a par-
ticular class of plants, in which the sta-
mens and pistils are united. The orders
of this class depend on the number of the
anthers.

GY'PSEOUS. (gypseux, Fr.) Resembling
gypsum ; containing gypsum ; of the na-
ture of gypsum.

GY'PSUM. ( yttyoff, Gr. gypsum, Lat. gypse,
Fr. gesso, It.) The chaux sulfatee of
Brongniart and Haiiy. Sulphate of lime ;
it is composed of sulphuric acid 46'0,
lime 33'0, water 21 . It possesses double
refraction. There is one variety known
by the name of anhydrite, or anhydrous
gypsum, which contains no water. Sul-
phate of lime is an abundant mineral
salt, presenting itself under various forms,
crystallized or otherwise. From gypsum
is obtained plaster of Paris, the gypsum
being burnt in a kiln, and the water
thereby driven off. The varieties of
gypsum are numerous ; the crystallized
transparent varieties are known as se-
lenite ; the fibrous and earthy as gypsum ;
and the granular and massive as alabas-
ter. The salt mines of this country
afford examples of nearly all the varieties.
The white powder obtained by exposing
gypsum to a strong heat has obtained the
name of plaster of Paris, from the ex-
treme abundance of this mineral in the
neighbourhood of that capital. Its infe-
rior hardness, together with its chemical
characters, will serve to distinguish it
from the carbonate, fluate, and phos-
phate of lime. " The gypsum formation
consists of alternating beds of gypsum
and argillaceous and calcareous marl,
which are regularly arranged, and pre-
serve the same order of succession where-
ever they have been examined. The
gypsum forms three distinct masses. The
lowest consists of thin strata of gypsum
containing crystals of selenite, which al-
ternate with strata of solid calcareous
marl, and with argillaceous shale. The
middle is like the lowest mass, except
that the strata of gypsum are thicker,
Q

G Y R

HAM

and the beds of marl are not -so uu-
merous ; it is chiefly in this mass that
fossil fish are found. The uppermost
mass is the most remarkable and impor-
tant of all ; it is in some parts more than
seventy feet thick ; there are but few beds
of marl in it ; the lower strata of gypsum
in this mass have a columnar structure.
In this upper mass of gypsum the skele-
tons and scattered bones of birds and
unknown quadrupeds are discovered.
Remains of turtles and crocodiles have
been also found in the same strata." For
a further and more interesting detail,
see Bakewell's Introduction to Geology.
GY'RODUS. A fossil fish of the family of

Pycnodonts, or thick-toothed fishes, found
in the oolite of Durrheim, in Baden.
GYRO'GONITE. (from yvpog, curvus, and
ysvog, genus.) Petrified seed-vessels of
the Chara hispida. These bodies are
found in fresh-water deposits, and were,
not very long since, supposed to be mi-
croscopic shells, indeed they are thus
described by Parkinson, who concludes
his notice of them by stating, " Lamarck
observes, that it has the form of a very
small seed of some species of lucern ;
and hesitating at determining it to be
really a multilocular shell, only assumes
it as such for the present."

H

HA'BITAT. Habitation ; place of abode.

HA'BITUDE. (habitude, lint, habitude, Fr.
abitudine, It.) Customary manner or
mode of life.

HADE. A term used by miners; to dip.

HA'DING. The dip from the perpendicular
line of descent ; the dipping of a vein.

HJE'MATITE. («i/tarir»;c., Gr. haematites
lapis, Lat.) Blood-stone, an iron ore ;
it occurs in masses of various shapes,
both globular and stalactitic.

HAJLIO'TIS. (from aXor, mare, and OJTOQ,
auris, Gr.) The sea-ear. A shell, both
fossil and recent, obtaining its name from
the excessive amplitude of its aperture,
and the flatness and smallness of its
spire, whence it has been likened to an
ear. The shells of this genus are said,
by Mr. Parkinson, to be among the
rarest fossils. The recent shells are
littoral, and found adhering to rocks ;
they are very beautiful, and are remarka-
ble for the pearly irridescence of the
inner surface, and for the shell being
perforated along the side of the columella
by a series of holes ; they are amongst
the most highly ornamented of all the
gasteropoda. The sea-ears protect their
open side by fixing themselves to the
rocks, and preserve a communication
with the atmosphere, or water, without
elevating their shells, by means of a line
of apertures, under the thickest margin,
near the apex : these apertures begin,
when the animal is young, near the spire,
and as it grows it stops up one and opens
another, as its occasions require. " I
have," says the Rev. W. Kirby, " a very
large specimen, in which there are traces
of eighteen apertures, and all but six are
stopped up." The soft parts of the in-
habitant of this shell are eaten in some
places, and are esteemed as being deli-
cious.

HA'LOIDE. (from a\f , salt, and ei^oc, Gr.
form or appearance.) An order of
earthy and metalliferous minerals ; taste-
less ; specific gravity from 2-2 to 3' 3.

HALTE'RES. (aXriJpff, Gr. halteres, Lat)
The poisers, so named from their sup-
posed use in balancing the body, or ad-
justing with exactness the centre of gra-
vity when the insect is flying. In those
insects which compose the order Diptera,
we meet with two organs, consisting of
cylindrical filaments, terminated in a
clubbed extremity ; one arising from
each side of the thorax, in the situation
in which the second pair of wings origi-
nate in those insects that have four wings ;
these are called halteres. Whatever
may be their real utility, they may still
be regarded as rudiments of a second
pair of wings.

HA'MITE. (from hamus, Lat. a hook.) Agenus
of fossil multilocular hook-formed shells.
Parkinson states that the hamite has
no evident siphunculus, but this is a mis-
take ; the siphuncle of the hamite, like
that of the ammonite, is placed on the
back, or outer margin of the shell, and in
some species this marginal siphuncle has
a keel-shaped pipe raised over it. The ex-
ternal shell is fortified by transverse folds
or ribs, which serve to strengthen both
the outer and the air chambers. The
hamite is sometimes found of large size,
more especially that species known as
Karaites grandis ; some of them are of
the diameter of a man's wrist. Nine spe-
cies are stated to have been discovered
in the gault or Speeton clay immediately
below the chalk in Yorkshire. Dr. Man-
tell gives the following as found in Sus-
sex:— In the chalk one species, Hamites
armatus. In the chalk mark five species,
H. armatus, H. plicatilis, H. alternatus,
H. ejlipticus, H. attenuatus. In the gait six

H A M

C "5 ]

H E L

species, H.maximus, H. attenuatus, H.
intermedius, H. tenuis, H. rotundus, H.
compressus.

HA'MOUS. (hamus, Lat.) Hooked.

HAR'MOTOME. (from ap/iog, a joint, and
TSftvu, to divide.) The Kreutzstein of
Werner; Cross-stone of Jameson; Pierre
cruciforme of Brochant ; Staurolite of
Kirwan. For a description of harmo-
tome, see Cross-stone.

HA'RPA. A genus of shells placed by
Cuvier in the family Buccinoida, order
Pectinibranchiata, class Gasteropoda. A
beautiful genus of shells, distinguisha-
ble from all others by the regular Ion •
gitudinal ribs that mark the external sur-
face, in some degree resembling a stringed
instrument, from which the name is de-
rived. The genus is both fossil and re-
cent ; the shells are marine, and are in-
habitants of warm climates ; they are
easily recognized by the projecting trans-
verse ribs on the whorls ; the last of
which forms a lip on the margin.

HA'RPAX. A genus of fossil shells de-
scribed by Parkinson. They are of an
oblong, and somewhat of a triangular,
form. The hinge is formed by two long
projecting teeth, transversely crenulated
on both sides, and diverging in the form
of the letter V on the flat valve.

HA'STATE. (hastatus, Lat.) Spear-
shaped.

HA'TCHETINE. A variety of bitumen,
known also as mineral adipocere, found
in the iron ore of Merthyr Tydfil in
Glamorganshire. It is insoluble in
water, but soluble in alcohol and ether.
It fuses at 160°. It is of the hardness of
soft tallow.

HAUSMA'NNITE. } Pyramidal manganese-

HAUSSMA'NNITE. $ ore. The Manganese
oxyde hydrate of Haiiy. It occurs in
porphyry, in veins, in America and Ger-
many. It is of a brownish-black colour.
It consists, according to Turner, of
98'10 of red oxide of manganese, silica
0-34, oxygen 0 21, baryta, O'll, water
0-43.

HAUYNE. Dodecahedral Zeolite, or Lapis
Lazuli.

HEART-SHAPED. A triangular figure, hav-
ing its base emarginate, lateral angles
rounded, and lateral margin slightly
swoln.

HEA'VY SPAR. Sulphate of barytes, baro-
selenite, or prismatic heavy spar. The
Baryte sulphatee of Haiiy ; the Schwer
spath of Werner ; and Prismatischer hal-
baryte of Mohs. There are several va-
rieties of this genus, namely, the compact
heavy spar, having a splintery and uneven
fracture ; the fibrous heavy spar ; the
straight and curved lamellar heavy spar ;
the radiated heavy spar ; the fetid heavy

spar, giving out, on friction a hepatic
odour, whence it is also called hepatite ;
the earthy heavy spar ; the prismatic
heavy spar.

Heavy spar consists of baryta 66 parts
and sulphuric acid 34 parts. It fre-
quently contains a trace of silex, alumine,
oxide of iron, and sometimes of sulphate
of strontian. It occurs in veins, both
massive and crystallized, in many parts
of England, Ireland, Scotland, and Ger-
many, being found in primary, transition,
and secondary rocks. It is of different
colours. It strongly decrepitates when
heated, and fuses into a white enamel,
which in the course of some hours falls
into powder. One of the most striking cha-
racters of this mineral is its great specific
gravity, which varies from 4'29 to 4'50.
It is from this circumstance it has ob-
tained its name. It is harder than crys-
tallized carbonate of lime, but may be
scratched by fluate of lime. Heavy
spar may be confounded with sulphate
of strontian, but its specific gravity is
greater. After fusion, the enamel pro-
duced from heavy spar, if applied to the
tongue, produces a taste similar to that
of rotten eggs, this does not occur in the
enamel of sulphate of strontian. Heavy
spar is seldom found in large masses.
It is sometimes employed as a flux in
metallurgic operations, and is said to be
a good base for water colours.

HE'LICAL. (helice, Fr. t'Xi£, Gr.) Spiral ;
winding.

HE'LIOTROPE. (heliotrope, Fr. eliotropia,
It. heliotropium, Lat. rjXioTpojriov, Gr.
from 77\io£ and TJOETTW.)

1. A plant, the turnsole.

2. A variety of rhombohedral quartz, of a
deep green colour, with disseminated
spots of yellow and red jasper. It is
more or less translucent. Fracture im-
perfectly conchoidai. Specific gravity
about 2-63. The finest specimens are
brought from Siberia and Bucharia. Like
agate, it is employed in forming orna-
mental articles.

HE'LIX. (s'Xil, Gr.)

1. The outer bar, or margin, of the exter-
nal ear.

2. The snail. A globular or orbicular
shell ; spire short, convex or conoidal,
last whorl ventricose ; opening entire,
being wider than long ; no operculum.
The helix aspera, or common snail, is a
well-known illustration. Parkinson ob-
serves of the fossil helix, " Shells of this
genus are rarely found in a state of petri-
faction. The circumstances of conserva-
tion in which they are found are, gene-
rally, such as are explicable on the sup-
position of their having become involved
in the gradually accreting tufaceous mat-

H E L

H E T

ter, which is deposited by certain streams
and rivers ; or in the stalactitic concre-
tions forming in the cavities of limestone
rocks, of comparatively modern forma-
tion." It is observed that the terrestrial
univalves are never armed with spines,
tubercles, or other elevations, but exhibit
generally a levigated shell.

HE'LVINE. Tetrahedral garnet.

HE'MATITE. (a</tan'r?;£> Gr.) Iron ore.
There are two kinds of hematite, the red
hematite, or rhombohedral iron-ore, and
the brown hematite, or prismatic iron-ore.
Also written Haematite.

HEMATI'TIC. Composed of hematite; con-
taining hematite ; resembling hematite.

HEMI'PTERA. (from ijfj.i<rv and Trrtpov,
Gr. So called, because their wing-covers
at the base are of a substance resembling
horn or leather, and at the tip are mem-
branous.) An order of insects, compris-
ing two families, Geocorisse and Hydro-
corisse. TheSe insects have four wings,
either stretched straight out, or resting
across each other; the superior are co-
riaceous at their base, with a membranous
apex. The mouth of hemipterous insects
is adapted for extracting fluids by suction
only. They are carnivorous, or, more
properly, animal- suckers. The cockroach,
locust, grasshopper, bug, lantern-fly, &c.,
belong to this order.

HEMI'PTERAL. ) Belonging to the order

HEMI'PTEROUS. $ Hemiptera ; insects
which have one-half of their wings coria-
ceous, and the other half membranous.

HE'MISPHERE. (hemisphere, Fr. emisfero,
It. hemispheerium, Lat. jjfiiatyaipiov, Gr.)
The half of a globe when it is supposed to
be cut through its centre, in the plane of
one of its greatest circles ; one-half of the
globe, or sphere, when divided into two
by a plane passing through its centre.
The equator divides the sphere into two
equal parts, called the northern and
southern hemispheres. The horizon also
divides the sphere into two parts, the
upper and the lower hemispheres.

.«-**•

HEMISPHERIC*. half a globe.

HENDE'CAGON. (from IVOCME and ywj/t'a,
Gr.) A figure of eleven faces or angles.

HEPA'TIC. ) (hepaticus, Lat. hepatigue,

HEPA'TICAL. $ Fr. epatico, It.) Belong-
ing to the liver ; pertaining to the liver.

HEPA'TIC CINNABAR. A dark-coloured,
steel-grey variety of the mercure sulphure
of Haiiy, or cinnabar.

HEPA'TIC PYRI'TES. Hepatic sulphuret of
iron. A variety of prismatic iron-pyrites,
of a yellow colour, which, on exposure to
the atmosphere, acquires a brown tarnish.
This embraces those varieties of sulphuret
of iron, which are susceptible of a pecu-

liar decomposition, by which the sulphur
is more or less disengaged. During this
process the pyrites is converted, wholly or
in part, into a compact oxide of iron of a
liver-brown colour, from which circum-
stance it obtains its name. In conse-
quence of this decomposition, the mass
does not lose its original form, but its
hardness and specific gravity are somewhat
diminished, and its lustre disappears.
The decomposition begins at the surface,
and gradually passes into the centre.

HE'PATITE. A mineral ; a variety of heavy
spar, or sulphate of barytes. This variety
is distinguished by its emitting a fetid
smell when rubbed, resembling that of
sulphuretted hydrogen, arising from its
containing a portion of sulphur.

HE'PATULE. A name given by Kirwan to
certain combinations called by others hy-
drosulphurets.

HEPTACA'PSULAR. (from sVrd, Gr. and
capsula, Lat.) Having seven cells.

HE'PTAGON. (heptagone et eptagone, Fr.
ettagono, It. STTTU and ywria, Gr.) A
figure having seven sides and as many
angles.

HEPTA'GONAL. Having seven sides and as
many angles.

HERBA'CEOUS. (herbaceus, Lat.) Plants
that perish annually down to the roots,
having succulent stems, or stalks. Of
herbaceous plants, some are annual, these
perish, stem and root, every year ; some
are biennial, the roots subsisting two
years ; others are perennial, being perpe-
tuated for many years by their roots, a
new stem springing up every year.

HERBA'RIUM. (herbarius, Lat.) A col-
lection of dried plants ; a place set apart
for growing herbs in.

HERBI'VOROUS. (from herba and voro,
Lat. to devour.) Subsisting on vegeta-
bles.

HERMA'PHRODITE. (from 'Epfjirjz, Mer-
cury, and 'AtypodiTT), Venus, htrmapho-
dite, Fr. ermaphrodito, It. A fabulous
name, compounded of those of Mercury
and Venus, Hermes and Aphrodite.)

1. Having both the male and female parts
of generation.

2. In botany, plants are so called which
contain both stamens and ovarium, in
distinction to monoecious and dioecious
plants.

HERPETO'LOGIST. One skilled in the na-
tural history of insects.

HERPETO'LOGY. (tpirfTog and \6yo£, Gr. )
That branch of natural history which
treats of reptiles, their habits, &c.

HERSCHELI'TE. A mineral of a white co-
lour, found by Herschel in olivine, and
named after its discoverer.

HETEROCLI'TICAL. In conchology, revers-
ed ; a term applied to shells whose spires

H E T

HIP

turn in a contrary direction to the usual
way ; sinistral. In shells, the axis of
revolution is termed the columella, and
the turns of the spiral are denominated
whorls. In consequence of the situation
of the heart and great blood-vessels rela-
tively to the shell, the left side of the
mantle is more active than the right side,
so that the lateral turns are made in the
contrary direction. Sometimes, in con-
sequence of the heart being placed on the
right side the turns of the spiral are made
to the left : this left-handed convolution
seldom occurs among the shells of land or
fresh -water mollusca.

HETERO'STROPHE. (trtpoarpo^a, Gr. ex
*T£po£ et crr)0o^j}.) A term applied to
reversed shells, or shells whose spires
turn in a contrary direction to the usual
way ; sinistral shells. Synonymous with
Heterocrital.

HEU'LANDITE. Hemi-prismatic zeolite or
foliated zeolite. The Stilbite of Haiiy. A
mineral, thus named after Heuland. It
occurs in drusy cavities, in secondary trap
rocks, in the Hartz mountains, in Ireland,
and in Scotland. It is of different colours,
white, grey, brown, and red. Its consti-
tuent parts are silica 59, alumina 16'87,
potash 8, (or, according to others, lime
9,) water 16'5.

HE'XAGON. (Jiexagone, Fr. esayono, It.)
f£dyo»vo£, Gr. from t'4, six, and ywvia,
angle.) A figure of six sides or angles ;
the most capacious of all the figures that
can be added to each other without any
interstice. The cells of the honeycomb
are hexagons.

HEXA'GONAL. Six-sided.

HE'XAGYN. (from ?£, rx, and yvvfi, Gr.
a woman.) A plant h- nng six pistils.

HEXAGY'NIAN. Having six pistils.

HEXAHE'DRAL. Having six sides equal to
one another ; cubi-i.!.

HEXAHE'DRON. (from t£ and tdpa, Gr.
hexaedre, Fr. esaedra, It.) A cube ; a
solid body having six equal faces.

HEXA'NDER. (from !£, six, and avrjp, Gr.
a man.) As plants which have six pistils
are denominated hexagyns, so those with
six stamens are termed hexanders.

HEX'ANDRIAN. Having six stamens ; be-
longing to the sixth class in Linnaeus' s
sexual method.

HEXA'NGULAR. (from t£ and angulus.)
Having six angles.

HE'XAPED. ) (iZo-jrodrjg, from «f and TTQVQ,

HE'XAPOD. ) Gr.) An animal with six
feet.

HEXAPE'TALOUS. (from t£, six, and TrlraXov,
Gr. a leaf.) A plant having six petals ;
a corolla consisting of six petals.

HEXAPHY'LLOUS. (from t'f and <pv\\ov,
Gr.) Six- leaved.

HI'LUM. (hilum, Lat.) In botany, the

small mark on seeds showing the spot
where they were joined to the fruit.

HINGE. In conchology, the point by which
bivalve shells are united : it is formed by
the teeth of the one valve inserting them-
selves between those of the other, or by
the teeth of one valve fitting into the
cavities or sockets of the opposite valve.

It is on the peculiar construction of
the hinge that the generic character of
bivalve shells is mainly founded, in con-
nection with the general form of the
shell.

Some hinges have no visible teeth, and
are termed inarticulate; hinges with few
teeth are termed articulate ; those having
many teeth are called multiarticulate.

HIPPOPO'TAMUS. (iTTTroTrorctjuoc, Gr. hip-
popotame, Fr. ippopotamo, It.) The
hippopotamus, or river-horse, belongs to
the order Pachydermata, or thick-skinned
animals, class Mammalia. This genus of
quadrupeds has four fore-teeth in the
upper jaw, disposed in pairs at a distance
from each other ; and four prominent
fore-teeth in the under jaw, the inter-
mediate ones being longest. There are
two tusks in each jaw, those of the under
being long, and obliquely truncated ; in
both they stand solitary, and are recur-
vated. The feet are hoofed on the edges.
The head is of an enormous size, and the
mouth vastly wide. The ears are small
and pointed. The eyes arid nostrils are
small. The body is naked. The tail is
about a foot long, taper, compressed, and
naked. The legs are short and thick ;
the belly reaching to the ground. One
species only is known, the hippopotamus
amphibius, confined to the rivers of
Africa.

Fossil bones and teeth of the hippopo-
tamus are abundantly found in England,
France, Germany, and Italy ; several ex-
tinct species have been determined by
Cuvier. The head of a hippopotamus
was found in Lancashire, under the peat ;
bones and teeth are found in large quan-
tities in the Val d'Arno, in Italy, and in
alluvial deposites in the neighbourhood of
Rome.

HI'PPOPUS. (from 'ITTTTOQ, a horse, and
TTO ug, a foot. ) A subtransverse, equivalve,
inequilateral shell ; lunule closed with
crenulated edges ; the hinge formed of
two long compressed entering teeth in one
valve and three in the other ; the cres-
cent closed. Parkinson states that he
does not know of any fossil shells of this
genus having been found, but Sowerby
mentions fossil species.

HIPPOTHE'RIUM. (from ITTTTOC, and $r]-
plov, Gr.) An extinct animal, allied to
the horse, belonging to the miocene
period.

H I P

[ 118 ]

H O R

HI'PPURITE. A fossil bivalve, having an
under shell of great depth, and of a coni-
cal form, with a flat lid, or operculum.
This genus is believed to be wholly ex-
tinct. The operculum is sometimes con-
vex, but generally it is concave. The
particular economy of the inhabitant of
this shell is not known. Lamarck has
placed the hippurite among his chambered
cephalopoda. Specimens of the upper
chamber of hippurites have lately been
found in the chalk, near Lewes. Dr.
Mantell has named a species there dis-
covered Hippurites Mortoni, after Dr.
Morton, Secretary to the Academy of
Natural Sciences of Philadelphia.

HIRSU'TE. (hirsutus, Lat.) Hairy ; rough ;
shaggy ; beset with strong hairs.

HIRSU'TENESS. Hairiness ; shagginess.

HISI'NGERTTE. A mineral of a dark co-
lour, occurring massive, found in the
cavities of calcareous spar.

HI'SPED. ) (hispidus, Lat.) Hairy ; beset

HI'SPID. $ with strong bristles.

HOG-TOOTH SPAR. A dodecahedral variety
of calcareous spar. The Matastatique of
Hatiy.

HOLOPTY'CHUS. A genus of fossil sauroid
fishes, discovered in the coal formation.

HOLOPTY'CHUS HIBBERTI. A species of
holoptychus named after Dr. Hibbert,
and found by him in the limestone of
Burdie House.

HOLOTHU'RIA. A zoophyte belonging to
the order Pedicellata, class Echinoder-
mata. The holothuria is covered with a
thick coriaceous skin, which, by means of
longitudinal and circular bands of mus-
cular fibres, the animal can shorten or
lengthen at pleasure. The body is ob-
long, and open at each end ; numerous
tentacula surround the mouth. There are
many species.

HO'LMITE. A mineral, a variety of car-
bonate of lime, named after Mr. Holme,
who analysed it. Its constituents are
lime, carbonic acid, oxide of iron, silica,
alumina, and water.

HOMOGENEITY, (homogeneite, Fr. omo-
ffeneita, It.) Of the same nature ; having
the same nature throughout.

HOMOGE'NEAL. ^ (ofjLoytvrjQ, Gr. homo-

HOMOGE'NEOUS. $ gene, Fr. omogeneo,
It.) Similitude of kind ; sameness of
nature.

HOMO'LOGOUS. (fiomologue,Yr. omologo,lt.
o/i6Xoyoc, Gr. ) Having the same manner
or proportions.

HONE, (keen, Sax.) Whetstone slate.
A variety of talcy slate, containing parti-
cles of quartz : when these particles are
exceedingly minute, and the slate pos-
sesses a certain degree of hardness with a
uniform consistence, it yields hones of the
best quality. Kirwan gave to this mine-

ral the name novaculite, from novacula,
the Latin for a razor.

HO'NEY -STONE. Pyramidal mellite. The
Honigstein of Werner ; Mellite of Haiiy
and Brongniart ; and Mellilite of Kirwan.
It is pyramidal, its primitive form being
a pyramid of 118° 4' and 93° 22'. It was
first discovered in Thuringia, between
the layers of wood-coal. It is of a honey-
yellow colour, sometimes a little tinged
with brown. Transparency considerable.
When heated it whitens, and in the open
air burns without being sensibly charred.
It yields neither flame, smoke, nor odour.
It is composed of alumina, water, and an
acid to which Klaproth gave the name of
mellitic acid : the latter constitutes 46 per
cent, of the whole. It differs from amber
in its weak electricity, double refraction,
and chemical character.

HORIZO'NTAL. (horizontal, Fr. orizzon-
tale, It.) Parallel to the horizon ; flat.

HORIZONTA'LITY. Flatness ; the state of
being horizontal.

HORIZO'NTALLY. In a direction parallel to
the horizon.

HO'RNBLENDE. The amphibole of Haiiy.
A mineral of a black or dark green
colour, often intermixed ; heavier than
either quartz or felspar, but less hard,
its specific gravity being between 3 '15
to 3*38. It enters largely into the com-
position, and forms a constituent part of
several of the trap rocks, and appears to
connect the primary with the volcanic.
When breathed on, it yields a peculiar
bitter smell. Before the blow-pipe it
melts easily into a black or grayish-
black, glass. There are many varieties
of hornblende, known as carinthine, tre-
molite, actynolite, calamite, amianthus,
&c. &c. The constituents of horn-
blende are, silica 45*60, magnesia 18*50,
lime 14, alumina 1'18, protoxide of iron
7'50, fluoric acid 1*50. Its colours are
produced by the oxides of chrome and
iron. Massive hornblende is generally
coarsely granular and lamellar ; when
intermixed with felspar in large lamellar
grains, it forms sienite. This very com-
mon mineral may, generally, be easily
recognized. Though sometimes in regu-
lar and distinct crystals, it is more com-
monly the result of a confused crystal-
lization, and appears in masses composed
of laminae, acicular crystals, or fibres
variously aggregated. Though inferior
to schorl in hardness, hornblende usually
will scratch glass, and, though with diffi-
culty, will yield sparks with steel. Its
laminated structure, its inferior hardness,
and its inability of becoming electric by
heat, distinguish it from schorl. It is
less hard and more easily fusible than
augite. It differs from epidote in hard-

H O R

H Y A

ness, and the results of fusion. Its pow-
der is not soft to the touch like that of
asbestus. — Cleaveland.
HO'RNBLENDE SCHIST. One of the me-
tamorphic rocks, composed principally
of hornblende, with an uncertain pro-
portion of felspar, and sometimes grains
of quartz : its colour is usually black,
Dr. M'Culloch observes, " hornblende
schist may at first have been mere clay,
for clay or shale is found changed by trap
into Lydian stone, a substance differing
from hornblende schist almost solely in
its compactness and in the uniformity of
its texture. Argillaceous schist, when in
contact with granite, is sometimes con-
verted into hornblende schist, the schist
becoming first siliceous, and, at the con-
tact, hornblende schist."
HORNBLE'NDIC. Containing hornblende ;
resembling hornblende. A mass of chi-
astolitic and hornblendic slates forms the
base of the clay-slate system of Cumber-
land.

HO'RNSTONE. A siliceous mineral ; a sub-
species of quartz. It has usually a dull
and splintery fracture, but sometimes it
is conchoidal. It differs from felspar in
being infusible without the addition of
an alkali. It occurs massive, and in ex-
traneous external shapes ; lustre dull or
glimmering, opaque or translucent on the
edges ; sometimes the whole mass, if
thin, has the strong translucency of cer-
tain horns. According to Kirwan, its
constituents are, silica 72, alumina 22,
carbonate of lime 6. Its colours are nu-
merous, and commonly dull. Its infusi-
bility by the blow-pipe distinguishes it
from petrosilex and jade. Its translu-
cency serves to render it distinct from
jasper. It is generally more dull than
flint, and emits sparks more feebly with
steel. It is deficient in lustre in com-
parison with quartz.

Professor Cleaveland observes, " so
much ambiguity of meaning is attached
to the word hornstone, that it would be
favourable to the interests of mineralogy
if this term could be banished from its
nomenclature. It has by some been
confounded with hornblende : by others
it has been applied to two minerals en-
tirely distinct. This confusion and ob-
scurity in the use of the word hornstone,
appear to have arisen in part from acci-
dental circumstances. It is asserted by
Kirwan, on the authority of Henckel,
that this word was originally employed
by miners to designate a certain stone,
which they found difficult to be cul
through in consequence of its tenacity
But a certain degree of translucency is
also a character of horn. Hence, as
mineralogists did not observe both these

properties to unite in the same mineral,
they subsequently applied the term horn-
stone, to two distinct minerals, one of
which possessed tenacity only, while
the other was translucent, but not re-
markably tenacious. Hence the applica-
tion of the term hornstone to the mineral
now called hornblende."
HO'RNSTONE PORPHYRY. The Hornstein
porphir of Werner. A variety of por-
phyry of a red, brown, purple, or black-
ish colour. Fracture splintery and con-
choidal. Emits sparks when struck with
steel. Is susceptible of a fine polish.
HO'RTUS siccus. (Lat.) A collection of

dried plants.
HU'MBOLDITE. A rare mineral, thus named

after Humboldt.

HU'MERAL. (from humerus, Lat.) Be-
longing to the shoulder.
HU'MERUS. (Lat.) The shoulder.
HU'MID. (humidus, Lat. humide, ¥r.umido,

It.) Moist ; wet ; damp ; watery.
HUMI'DITY. (humidite, Fr. umidita, It.)

Moisture ; dampness.

HU'MITE. A reddish-brown mineral, found
at Somma, thus named after Sir A.
Hume.

HU'MMOCK. A mound of land.
HY'ACINTH. (vdicivQoQ, Gr. hyacinthus,
Lat. hyacinthe, Fr.) The Hiazinth of
Werner ; Zircon hyacinthe of Brong-
niart. A mineral ; a variety of pyrami-
dal zircon, of a hyacinth-red colour. It
is crystallized, and when in distinct cry-
stals its ordinary form is a four-sided
prism, terminated by four rhombic planes.
Each plane angle at the summit is 73°
44'. It is found in beds of streams and
rivers along with rubies, sapphires, &c.,
but sometimes it occurs in the primary
rocks. It consists of, zirconia 70, silica
25, oxide of iron 0'5. It is considered a
gem, but is little used as such. Before
the blow-pipe it loses its colour, but re-
tains its transparency. With borax it
melts into a transparent glass.
HYACI'NTHINE. A mineral of a brown or
greenish colour, usually crystallized in
rectangular eight-sided prisms. Frac-
ture imperfectly conchoidal. Transparent.
Causes double refraction.
HYACI'NTHINE. Of the colour of hya-
cinth ; resembling hyacinth ; containing
hyacinth.

HYALVE'A. (So named from its semi-
transparent shell.) A genus of Ptero-
pods, or animals furnished with organs
only for swimming and sailing. The
Hyalcsa has the appearance of a bivalve
with soldered valves, the upper one being
the largest ; this difference of size of the
seeming valves causes an aperture through
which the animal sends forth two large
yellow and violet wings, or sails, rounded

H Y A

[ 120 ]

H Y D

and divided at their summit into three
lobes. When its wings, or sails, are
unfolded, it moves with great velocity on
the surface of the sea. The Pteropods,
both from the beautiful colouring of their
filmy wings, and from their number and
symmetry, are better entitled to the ap-
pellation of the butterflies of the ocean,
than the escalop shells, which have
sometimes been so called. — Rev. W.
Kirby.

HY'ALINE. (from hyalus, Lat. VCL\QQ , Gr.)
Transparent.

HY'ALITE. (waXoc, Gr.) A yellowish or
greyish variety of uncleavable quartz or
opal. It exhibits the usual appearance
of a concretion, and differs but little
from calcedony, except in possessing a
vitreous lustre, and sometimes a loose
texture. It is found in secondary trap j
rocks ; it occurs ingrains, filaments, and
rhomboidal masses. It is infusible before
the blow-pipe. It is nearly all silica, its
component parts being silica 92'00, wa-
ter 6-33.

HYBER'NACLE. (hibernacula, Lat.)

1. The winter dwelling or residence of
animals.

2. That part of the plant which defends
the embryo from injuries arising from
frost.

HYBE'RNAL. (hibernus, Lat.) Belonging

to the winter.
HY'BERNATE. To pass the winter in places

protected from the cold, as some animals

burrow in the 'earth, others in the trunks

of trees, &c. &c.
HYBERNA'TION.

1. The passing of the winter season in a
situation protected from cold.

2. In many animals a general suspension
of the actions of life, extending even to
the vital functions of respiration and cir-
culation, takes place during the winter
months, constituting what is termed hy-
bernation.

HY'B-RID. (v/3pie, Gr. hybrida, Lat. hy-
bride, Fr. ) Mongrel ; a term applied
both to plants and animals, when of a
cross-breed.

HY'BODONT. (from w/36f, and dens, Lat.)
A sub-family of sharks, according to the
arrangement of M. Agassiz. They seem
to have begun with the coal formation,
to have continued throughout the oolitic
deposition, and to have ceased at the
beginning of the chalk formation. The
teeth of this sub-family possess characters
intermediate between the blunt crushing
teeth of cestracionts, and the sharp cut-
ting teeth of squaloids.

HY'BODUS. A genus of fishes that pre-
vailed throughout the oolitic period. It
is well remarked by Prof. Buckland, "not
a single genus of all that are found in

the oolitic series exist at the present
time."

HYDA'TID. (vSarlg, Gr. hydatide, Fr.)
An order of internal worms. In hydatids
there has not been discovered any vascular
system. Hydatids, so frequently found
in the liver and other parts of the body
in mammalia, have been considered by
some as animals, consisting merely of a
stomach ; by others, as a matrix, or
womb, from something like young hyda-
tids being frequently found adhering to
their inner side. Hydatids immersed in
warm water, immediately after being ob-
tained from a living animal, are observed
to have a contractile power, but they
have no external opening ; they are pel-
lucid spherical bodies, of different sizes
and kinds. Each consists of two coats,
the inner of which is extremely delicate.
They do not possess any visible blood-
vessels, though the sac containing them
has abundance of vessels, nerves, &c.
derived from those of the organ with
which it is connected. Hydatids ought
not to be confounded with watery vesi-
cles, connected occasionally with the
kidney, &c. which are not enclosed in
cysts, have no small hydatids adhering to
their inner surface, and want contrac-
tility. There are many genera.

HY'DRATE. (from i'£wp, Gr.) A chemi-
cal compound in definite proportions of
a solid body with water, still retaining a
solid form. It must, however, be borne
in mind that when water in combination
with other bodies contributes (as in crys-
tallized bodies) to their regular form and
transparency, it is then termed water of
crystallization. The hydrates are nume-
rous, as hydrate of alumine, baryta, co-
balt, copper, lime, magnesia, potassa,
soda, &c. &c.

HY'DRATED. Mixed with water, but re-
taining its solid form.

HYDRAU'IIC. "^ (vdpavXlg, Gr. hydrauli-

HYDRAU'LICAL. S> cus, Lat. hydraulique,

HYDRAU'LICK. J Fr. idraulico, It.) Re-
lating to the conveyance of water through
pipes. The siphuncle of the nautilus,
ammonite, belemnite, &c. forms a very
beautiful and complete hydraulic appa-
ratus.

HY'DRAULICS. The science of the motion
of fluids, and the construction of all kinds
of instruments and machines relating
thereto.

HY'DROGEN. (from v£o>p and ysvi'aw, Gr.)
One of the fifty-five simple, or elementary
bodies. Inflammable air, proved by Ca-
vendish to be the basis of water, from
which circumstance it has obtained its
name. It can be obtained only from
water. Hydrogen is colourless, and has
commonly a slight odour of garlic ; it is

H Y D

II Y M

not absorbable by water ; it is devoid of
taste, and is destructive of life when re-
spired for any time. It is the lightest
body known, 100 cubic inches weighing
only 2*25 grains, or being nearly thirteen
times lighter than atmospheric air. It is
combustible, and, when pure, burns with a
yellowish-white flame. Hydrogen enters
into the composition of all waters, and is
evolved in a compound state from vol-
canos, from certain fissures in the earth,
and in districts where coal is found.
Two volumes of hydrogen unite with one
of oxygen in the production of water.
As far as the superficies of our planet is
concerned, water so predominates, that, at
first sight, hydrogen might be considered
as constituting a substance of more rela-
tive abundance than it really does. The
quantity of hydrogen locked up in coal is
considerable. According to Dr. Thom-
son, cannel coal contains 21 per cent, of
it, although in the Newcastle caking coal
the proportion is but a trifle more than
4 per cent. Hydrogen may be considered
as the most important substance of its
class next to oxygen, which enters into
the composition of the earth's crust.

HYDRO'GENATED. Combined with hydro-
gen.

HYDRO'GRAPHER. (from u£wp and ypa0w,
Gr. hydro graphe, Fr. idrografo,It.) One
who draws maps of the sea-coast, rocks,
islands, shoals, &c.

HYDROGRA'PHIC. ) Relating to a descrip-

HYDROGRA'PHICAL. $ tion of the sea-
coast, rocks, islands, &c. &c.

HYDRO'GRAPHY. (from vSup and yp«0w,
Gr. idrografia, It. hydrographie, Fr.)
Description of the watery part of the
globe ; the art of measuring and de-
scribing the sea, rivers, canals, lakes, &c.
With regard to the sea, it gives an ac-
count of its tides, counter-tides, sound-
ings, bays, gulfs, creeks, &c. as also of
the rocks, shelves, sands, shallows, pro-
montories, harbours ; the distance and
bearing of one point from another ; with
every thing that is remarkable either at
sea or on the coast.

HYDRO'METER. (from vSwp and juerpoj',
Gr. hydrometre, Fr. idrometro, It.) An
instrument for measuring the extent or
depth, gravity, density, and velocity of
liquids.

HY'DROPHANE. (from u^wp and ^euvw,
Gr. ) A variety of opal which is opaque
and white when dry, but by immersion in
water becomes transparent.

HY'DROPHYTE. (from vSwp and <j>vrbv,
Gr.) A plant which lives and grows in
water. Mr. Lyell observes, " the num-
ber of hydrophytes is very considerable,
and their stations more varied than could
have been anticipated j for while some

plants are covered and uncovered daily
by the tide, others live in abysses of the
ocean, at the extraordinary depth of one
thousand feet : and although in such
situations there must reign darkness more
profound than night, at least to our
organs, many of these vegetables are
highly coloured." — Principles of Geology.

HYDROSTA'TIC. ^ (from i)£wp and trra-

HYDROSTA"'TICK. \- T-IKOC, Gr.) Relat-

HYDROSTA'TICAL. j ing to that branch of
science termed hydrostatics.

HY'DROSTATICS. (from inTwp and (TTciTiicbg,
Gr. hydrostatique, Fr. i'drostatica, It.)
The science which treats of the nature,
gravity, pressure, and equilibrium of
fluids, and of the weighing of solids in
them.

HY'DRURET. A compound of hydrogen
with a metal.

HYGRO'METER. (from vypoe and fji'tTpov,
Gr. hygrometre, Fr. igrometro, It.) An
instrument for measuring the degree of
moisture of the atmosphere. There are
various kinds of hygrometers ; for what-
ever either swells by moisture, or shrinks
by dryness, is capable of being formed
into an hygrometer.

HYGROME'TRICAL. Relating to hygro-
metry.

HYGRO'METRY. The art of measuring the
degree of moisture in the atmosphere.

HYL^EOSAU'RUS. A fossil lizard discovered
in the wealden formation of Tilgate
forest by Dr. Mantell, and fully described
by him in his Geology of the South-East
of England. The Hylseosaurus, or Lizard
of the Weald, was discovered in 1832.
Its probable length was about twenty-five
feet. It is characterised by a series of
long, flat, and pointed bones, which ap-
pear to have formed a large dermal
fringe, resembling the bones on the back
of the modern iguana. In this reptile the
osteology of the lizard seems blended with
that of the crocodile. Dr. Mantell ob-
serves, " the most extraordinary parts are
many enormous, angular spinous bones,
which lie in the direction of the vertebral
column, and evidently extended originally,
like a serrated fringe, along the back of
the animal/'

HYMENO'PTERA. (from v/rn'OTrrepoc., Gr.
alas membranaceas habens : membrane-
winged.) Cuvier makes Hymenoptera
the ninth order of the class Insecta.
They have four membranous wings, and
the tail of the female is usually armed
with a sting. Though the insects of this
order are included in the mandibulate
section, for their mouth is furnished with
mandibles and rnaxillee, yet they do not
generally use them to masticate their
food, but for purposes usually connected
with their sequence of instincts, as the

II Y M

[ 122 ]

JAN

bees in building their cells ; the wasps in
scraping particles of wood from posts and
rails for a similar purpose, and likewise
to seize their prey ; but the great instru-
ment by which they collect their food is
their tongue; this the bees particularly
have the power of inflating, and can wipe
with it both convex and concave surfaces ;
and with it they lick, but not suck, the
honey from the blossoms, for Reaumur
lias proved that this organ acts as a
tongue and not as a pump. Some of
the Hymenoptera prefer a vegetable
diet.

HYMENO'PTEROUS. Belonging to the order
Hymenoptera ; having tour membranous
wings

HY'PERSTHENE. ) (from v-n-ep and

HY'PERSTENE. j Gr. ) Prismatoidal
Schiller-spar. Labrador Schiller-spar. A
mineral of a greenish-black colour, but
on the cleavage of a copper-red. Occurs
in granular and lamellar concretions,
and massive. It is found in Labrador,
in the Isle of Skye, in Banffshire, and in
the Shetland Isles. It is composed of
silica, magnesia, alumina, lime, and oxide
of iron, the last of which is said to form
one-fourth of the whole.

HYPERSTHE'NIC. Containing hypersthene ;
resembling hypersthene.

HYPOCRATE'RIFORM. Salver-shaped : a
term applied to a monopetalous corolla,

the limb of which being placed on a tube,
spreads out horizontally.

HYPOGA'STRIC. (from VTTO and •yctoTJ/jO,

. Gr.) Belonging to that region of the
abdomen which is called the hypogas-
trium.

HYPOGA/STRIUM. The lower anterior re-
gion of the abdomen, from a little below
the umbilicus to the pubes.

HY'POGE^E. (from VTTO and yivo^ai, Gr.)
A term applied to rocks, expressing that
they have assumed their form, or struc-
ture, at a depth from the surface.

Mr. Lyell, who proposes to give this
term to certain rocks, observes, " It will
appear that the popular nomenclature of
geology, in reference to the so called
' primary' rocks, is not only imperfect,
but in a great degree founded on a false
theory ; inasmuch as some granites and
granitic schists are of origin posterior to
many secondary rocks. In other words,
some primary formations can already be
shown to be newer than many secondary
groups, a manifest contradiction in terms."
To obviate this difficulty, Mr. Lyell pre-
fers the terra hypogene, as one not of
chronological import, but implying the
theory that such rocks are netherformed,
and have not assumed their form and
structure at the surface. — Principles of
Geology.

HY'STRIX. (varpiZ, Gr.) The porcupine.

I J

JA'DE. The Nephrit of Werner ; Neph-
rite of Jameson ; called also nephritic
stone, nephrite, and axe-stone. It was
formerly much celebrated for its supposed
medicinal properties in nephritic affec-
tions, or diseases of the kidneys. It is
found in Hungary and Siberia, America,
Egypt, and China. The inhabitants of
New Zealand form it into axes, and other
cutting instruments, from which circum-
stance it has obtained the name of axe-
stone. Its surface is smooth ; fracture
splintery. It has a greasy feel. Colour
dark leek-green. In hardness, jade is, at
least, equal to quartz ; it possesses a
peculiar tenacity which renders it difficult
either to break, cut, or polish. Brochant
states its fresh fracture to present a
paler green than that of its surface. Be-
fore the blow-pipe it fuses easily, and with
a slight ebullition, into a bead of white
semi-transparent glass. Its analysis is
very variously given by different authors ;
its constituents are according to some,
silica, carbonate of magnesia, iron, alu-
mina, carbonate of lime ; others add

chrome, oxide of manganese, soda, and
potassa. In consequence of its tenacity
it has been wrought into chains and other
delicate works.

JA'GGED. Irregularly cut or notched, and
with the appearance of having been
knawed ; denticulated ; uneven ; toothed
like a saw.

JAMB. A term used by miners for a thick
bed of stone which prevents their pur-
suing a vein.

JA'MESONITE. A mineral, thus named after
Prof. Jameson by Haidinger ; axotomous
antimony-glance. It was first discovered
in Cornwall, in clay-slate, and it has been
since found in Germany and Siberia. Its
colour is steel-grey. It consists of lead,
antimony, sulphur, and iron.

JA'NTHINA. (from ianthum, Lat. a violet.)
The violet snail. A purple-coloured uni-
valve shell, nearly resembling a snail in
its form: it is recent, and commonly
found in the Mediterranean. The inha"-
bitaiits of this shell is said, when irri-
tated, to discharge a purple secretion.

JA'NTHINA FRAGILIS. A species of jan-

JAN

t 123 ]

I C H

thina. Mr. Lyell remarks " the janthina
fragilis has wandered into almost every
sea, both tropical and temperate. This
common oceanic shell derives its buoy-
ancy from an admirably contrived float,
which has enabled it not only to disperse
itself so universally, but to become an
active agent in disseminating other spe-
cies, which attach themselves, or their
ova, to its shell. — Principles of Geology.
According to the account given by Bosc,
the janthina exhibits many remarkable pe-
culiarities. When the sea is calm, these
animals may be seen collected often in
large bands, swimming over the surface
by means of a floating apparatus consist-
ing of aerial vesicles produced by their
foot. During this action their head is
very prominent, and the foot is so ex-
tended that the float or line of vesicles
forms an angle with the middle of the
shell. When the sea is rough, the animal
absorbs the air from its vesicles, changes
the direction of its foot, contracts its body,
and lets itself sink. It does the same
when in danger from any enemy, and
like the cuttle-fish, has the power of
emitting a coloured fluid, which, by
darkening the surrounding water, serves
to conceal it from view. If the floating
apparatus be injured or destroyed, there
exists a reproductive power in the foot,
by which it can be restored.

JA'RGON. The zircon jargon of Brong-
niart. A mineral, a variety of zircon.

JA'SPER. (jaspe, Fr. pierre dure et opaque,
de la nature de V agate; jaspide, It.)
A sub-species, a variety of rhombohedral
quartz. It is an ingredient in the com-
position of many mountains. It occurs
usually in large amorphous masses, and
sometimes also crystallized in six-sided
prisms. Fracture conchoidal. It is said
to compose the substance of entire ranges
of the Asiatic mountains. When quartz
is combined with a considerable propor-
tion of iron and alumine, it loses its trans-
lucency and becomes jasper. There are
many varieties of jasper, distinguished
principally by their different colours, and
the arrangement of their colours. Mr.
Bake well states, " there can be little
doubt that jasper has been, in many in-
stances, formed by subterranean heat,
acting with great intensity on beds of ar-
gillaceous shale, containing iron."

JASPI'DEAN. ^ Resembling jasper ; contain-

JASPI'DIOUS. $ ing jasper.

ICE/BERG. (from ice and berg, Germ.)
A large mass of ice, met with in cold re-
gions, floating upon the sea, sometimes of
enormous magnitude and great height.
Icebergs have been seen of the great height
of 300 feet, and as it has been ascertained
that for every foot above the surface of

the sea-water there are eight feet below,
the whole thickness must be immense. In
a geological point of view, icebergs are to
be viewed as very important and power-
ful agents, inasmuch as they are the
means of transporting to great distances,
animals, plants, and rocks.

ICHTHYODO'RULITE. The fossil dorsal
spine of certain fishes, armed with tooth-
like hooks, or prickles. These were long
supposed, says Prof. Buckland, to be
jaws, and true teeth ; more recently they
have been ascertained to be dorsal spines
of fishes, and, from their supposed defen-
sive office, have been named ichthyodo-
rulites, from the Greek words ixOi'c, a
fish, dopv, a spear, and Ai'0of , a stone.

I'CHTHYOUTE. (from ix®vQ, and Xi'0oe,
Gr. ichtyolite, Fr.) Fossil fish; a pe-
trified fish. Fossil fishes occur in all the
English formations, from the old red
sandstone to the tertiary deposits inclu-
sive.

ICHTHYOLO'GICAL. Relating to ichthyo-
logy* or that branch of zoology which
treats of the structure, habits, &c. of
fishes.

ICHTHYO'LOGIST. One who pursues the
study of ichthyology.

ICHTHYOLOGY, (from i%0vc, a fish, and
Xoyoc, Gr. discourse ; ichtyologie, Fr.
ictologia, It.) That branch of zoology
which treats of the structure, classifica-
tion, habits, and history of fishes.

ICHTHYO'PHAGOUS. (from ty^c, a fish,
and 0a'yw, Gr. to eat ; ichthyophage, Fr.
colui che non si ciba d"1 altro fuorche di
pesci, It.) Feeding on fish.

ICHTHYO'PHAGY. The practice of feed-
ing on fish.

ICHTHYOSAU'RUS. (from t-x^vg, a fish,
and iravpoG, Gr. a lizard ) A fish-like
lizard ; an immense fossil marine -saurian
or reptile, having an intermediate orga-
nization between that of a lizard and a
fish. The name appears to have been given
to it by Mr. Konig. The genus comprises
many species ; some of these attain a
magnitude not inferior to that of young
whales. The head of the ichthyosaurus
resembled that of a dolphin, its teeth were
conical, sharp, and striated, and exceed-
ingly numerous, in some cases amounting
to nearly two hundred, not enclosed in
separate sockets, but as in the crocodile,
ranged in one continuous groove, or fur-
row, of the maxillary bone ; as also in
the crocodile, abundant provision was
made for replacing the old teeth, as they
were lost, by a supply of new ones. The
eye was of enormous magnitude, the
orbit in some instances measuring four-
teen inches in its longer diameter, and
Professor Buckland states, " We have
evidence that it possessed both micro-

I C H

[ 124 ]

ICO

scopic and telescopic properties/' The
beak was that of the porpoise ; the teeth,
as before mentioned, those of the croco-
dile ; the vertebrae nearly resembled those
of the shark, being hour-glass shaped ;
the vertebral column was composed of
more than one hundred pieces; the ribs
were slender, and the majority of them
bifurcated, or forked, at the top ; the
boner, of the sternum were strong and
largely developed, and combined nearly
in the same manner as in the ornithoryn-
chus or platypus. The ichthyosaurus
had four paddles, the form of its ex-
tremities deviating from the saurians and
approaching the mammalians, being con-
verted from feet into fins ; these fins, or
paddles, were composed of numerous
bones enclosed in one fold of integument ;
the fore-paddle was composed of nearly
one hundred bones, and like the mam-
malians it possessed a humerus, or
shoulder bone, a radius and ulna, or the
bones of the fore arm, and phalanges ; the
bones of the phalanges were polygonal
and exceedingly numerous, as before
stated. The hind-paddles were very
much smaller, containing only from thirty
to forty bones. The general conforma-
tion of the ichthyosaurus must have
greatly resembled that of the porpoise or
grampus. Its teeth would have suffici-
ently proved it to have been carnivorous,
but the subsequent discovery of its faecal
remains, now called coprolites, and the
finding within the intestinal canal the
half-digested remains of fishes and rep-
tiles, render this point quite certain ;
like the crocodile, it must have gorged its
prey entire ; its stomach was exceedingly
capacious, forming a sort of pouch, or
sac, and extending through nearly the
whole body. The fossil remains of the
ichthyosaurus have been discovered in
the lias formation, and it appears to have
become extinct at the termination of the
secondary series of geological formations.
It is however 'the opinion of Mr. Bake-
well that the ichthyosaurus, or some spe-
cies of a similar genus, is still existing in
the present seas, and with his remarks
the description of the fish-like lizard will
be concluded. "About sixteen years since,
a large animal was seen for several sum-
mers in the Atlantic, near the coast of
the United States, and was called the
great sea-serpent. I am informed by
Professor Silliman, that many persons
who attested the existence of the sea ser-
pent from their own observations, were so
highly respectable, both for intelligence
and veracity, that their evidence could
not be disputed. I remember one of the
most particular descriptions of the sea-
serpent was given by an American cap-

tain, who saw the animal raise a large
portion of its body from the water : he
represented it as of great length, and
about the bulk of a large water cask ; it
had paddles somewhat like a turtle, and
enormous jaws like the crocodile. This
desci'iption certainly approaches to, or
may be said to correspond with, the ich-
thyosaurus, of which animal the captain
had probably never heard." — BakeweW*
Introduction to Geology.

ICHTHYOPHTHA'LMITE. (from t%^£> anc*
600a\/zoc., Gr.) Fish-eye stone ; apo-
phyllite ; pyramidal zeolite ; the fischau-
genstein of Werner ; mesotype epointee
of Hauy. It is of a white colour, and
semi-transparent, or translucent. Occurs
both crystallized, and massive. The
primitive form of its crystals is a four-
sided prism, with rectangular bases. It
is easily divisible by percussion into la-
minae, whose broader surfaces are splen-
dent and somewhat pearly. It scarcely
scratches glass, and does not yield sparks
when struck with steel. Specific gravity
2 '4 6. Before the blow-pipe it exfoliates,
froths, and eventually melts into an
opaque bead. It is composed of silica
50, lime 23, potash 4, water 18, with a
trace of fluoric acid. It is found in
secondary trap -rocks in the Hebrides and
other parts of Scotland, in Sweden, and
Iceland.

I'cius. The terminations of adjectives in
icius and aceus express a resemblance to
a material ; those in eus indicate the ma-
terial itself: thus, membranaceus, resem-
bling skin ; membraneus, skin itself ; co-
riaceous, leathery ; latericius, resembling
bricks.

ICOSAHE'DRAL. (from icosahedrsn.) Hav-
ing twenty equal sides or faces.

ICOSAHE'DRON. (eiKoaafdpog, Gr. icosae-
dre, FT. isosaedro, It.) A regular solid,
consisting of twenty triangular pyramids,
whose vertices meet in the centre of a
sphere supposed to circumscribe it ; and
therefore have their height and bases
equal : wherefore the solidity of one of
these pyramids multiplied by twenty, the
number of bases, gives the solid contents
of the icosahedron.

ICOSA'NBRIAN. (from eicoo'i and ai'rjp,
Gr.) The twelfth class in Linnaeus'
sexual method, consisting of plants with
hermaphrodite flowers, furnished with
twenty or more stamens, inserted into the
calyx. The first order of this class con-
sists of trees bearing for the most part
stone fruits, surrounded by a pulp, as the
plum, peach, cherry, &c. ; in the second
order we find the apple, pear, &c. ; in the
third order, the genus rosae. In this class
the stamens grow out of the sides of the
calyx, as in the strawberry, and it is im-

I C O

[ 125]

I G U

portant to observe, that such a mode of
insertion indicates the wholesomeness of
the fruit ; we are not aware that there is
a single exception to this rule, so that a
traveller, who might meet with an un-
known fruit, need not scruple to eat it if
he find the stamens thus inserted. This
character of the insertion of the stamens
into the calyx holds good in other classes,
as well as in the class Icosandria ; thus,
in the genus Ribes, including the goose-
berry and currant, which belong to the
class Pentandria, the stamens grow out of
the calyx, and these fruits are well known
to be wholesome, while many of the ber-
ries of the same class, whose stamens
have not a like insertion, are often very
deleterious.

ICOSA'NDRIAN. Belonging to the class
Icosandria ; having twenty or more sta-
mens, inserted into the calyx.

I'DOCRASE. (from idia and Kpaoif, Gr.)
A mineral found in lava, and formerly
mistaken for the hyacinth ; it is the Ve-
suvian of Werner.

JE'FFERSONITE. A mineral found in New
Jersey ; colour olive-green passing into
brown. It is named after Mr. Jeffer-
son.

JET. (from Gaga, a river of Asia; jayet,
Fr.) The Jayet of Haiiy ; Lignite Jayet
of Brongniart ; Pech Kohle of Werner.
A mineral substance, found in detached
kidney-formed masses in many countries.
It is of a firm and very even structure,
harder than asphaltum, and susceptible of
a good polish. It becomes electrical by
rubbing, attracting light bodies, like am-
ber. In many respects it resembles can-
nel-coal, its colour is full-black, and it
does not soil the fingers. It is, however,
easily distinguished from cannel-coal, in
being specifically lighter than water, which
cannel-coal is not, and in possessing elec-
trical properties which cannel-coal does
not. Some persons have supposed that
jet is a true amber, differing only in the
mere circumstance of colour. During
combustion it emits a bituminous smell.
It is never found in strata or continued
masses, but always in separate and un-
connected heaps.

It is formed into various trinkets, and
is particularly used for making mourning
ornaments, such as ear-rings, brooches,
bracelets, buttons, &c.

JEWS- STONE. An extraneous fossil, being
the elevated spine of a very large egg-
shaped sea-urchin, or echinus.

I'GNEOUS. (igneus, Lat. ignte, Fr. igneo,
It.) Fiery ; containing fire ; produced
by the action of fire. In this last sense
it is commonly used by geologists when
speaking of igneous rocks, or igneous pro-
ductions.

IGNE'SCENT. (ignescens, Lat.) Giving
out sparks of fire when struck.

IGNI'FLUOUS. (ignifluus, Lat.) Flowing
with fire.

IGNI'VOMOUS. (ignivomus, Lat.) That
vomits fire. Volcanoes are ignivomous
mountains.

IGUA'NA. A species of lizard, a native of
many parts of America and the West In-
dies, is rarely met with any where north
or south of the tropics. It is from three
to five feet long, from the end of the
snout to the tip of the tail. It inhabits
rocky and woody places, and feeds on in-
sects and vegetables. Cuvier states that
the iguana subsists upon fruit, grain, and
leaves : Bosc, that it lives principally
upon insects. It nestles in hollow rocks
and trees. The female lays its eggs,
which have a thin skin like those of the
turtle, and are about the size of those of
a pigeon, in the sand. Though not am-
phibious, they are said to be able to re-
main under water an hour. When they
swim, they do not use their feet, but place
them close to their body, and guide them-
selves with their tails. Captain Belcher
found, in the island of Isabella, swarms
of iguanas, that appeared omnivorous.
This statement proves both Cuvier and
Bosc to be correct. The teeth of the
iguana are not fitted for comminuting its
food, and it is said to swallow it whole.

IGUA'NODON. An extinctfossil colossal lizard,
discovered in the strata of Tilgate Forest by
that indefatigable historian of the chalk and
Wealden formation, Dr. Mantell, to whose
profound and scientific researches the
world is indebted for a knowledge of this
genus, and whose splendid museum has
lately, to the disgrace of the county of
Sussex, been removed from Brighton to
the British Museum. The following de-
scription of this huge animal is almost
entirely taken from Dr. Mantell' s Geology
of the South-East of England. He ob-
serves, " the discovery of the teeth and
other remains of a nondescript herbivorous
reptile in the strata of Tilgate Forest, a
reptile pronounced by Cuvier to be ' en-
core plus extraordinaire que tous ceux
dont nous avons connoissance,' is one of
the most gratifying results of my labours."
The remains of one of these immense ani-
mals have lately been found in the Kent-
ish Rag, near Maidstone. The Kentish
rag is a grey arenaceous limestone, be-
longing to the Shanklin sands. From the
great resemblance in the dentature, as
well as in many other extraordinary cha-
racteristics, of this immense reptile to
that of the iguana, Dr. Mantell determined
on naming it the Iguanodon, signifying an
animal having teeth like the iguana. In
the perfect teeth, and in those which have

I M B

[ 126 ]

I N C

been but little worn, the crown is some-
what of a prismatic form ; widest, and
most depressed, in front ; convex poste-
riorly, and rather flattened at the sides.
As soon as the tooth emerges from the
gum it gradually enlarges, and its edges
approach each other and terminate in a
point, making the upper part of the crown
angular ; the edges forming the side of
this angle are deeply serrated, or den-
tated ; and the teeth exhibit two kinds of
provisions to maintain sharp edges along
the cutting surface : the first the serrated
edge already described ; the second, a
provision of compensation for the gradual
destruction of this edge, by substituting
a plate of thin enamel, to maintain a cut-
ting power in the anterior portion of the
tooth, until its entire substance was con-
sumed. These teeth were sometimes two
inches and a half in length. While the
crown of the tooth was diminishing above,
an absorption of the fang was proceeding
below, caused by the pressure of a new
tooth rising to replace the old one, until
by continual consumption, both above and
below, the middle portion of the older
tooth was reduced to a hollow stump,
which fell from the jaw to make room for
its more efficient successor. The size at-
tained by the iguanodon appears to have
been enormous, the average length from
the snout to the tip of the tail being esti-
mated by Dr. Mantell at seventy feet,
while, he considers, some may have been
one hundred feet in length. This last
calculation Prof. Buckland deems impro-
bable, but he gives a length of seventy
feet to the iguanodon. A thigh-bone in
the possession of Dr. Mantell is three
feet eight inches long, and thirty-five
inches round, at its largest extremity.
The length of the hind foot is supposed to
have been six feet and a-half ; the cir-
cumference of the body, fourteen feet and
a-half. A most remarkable appendage
possessed by the iguanodon was a horn of
bone, placed upon the nose, equal in size,
and resembling in form, the lesser horn
of the rhinoceros ; here was a further
analogy between the extinct fossil igua-
nodon and the recent iguana. The base
of this nasal horn was of an irregular oval
form, and slightly concave. It possessed
an osseous structure, and appears to have
had no internal cavity. It is evident that
it was not attached to the skull by a bony
union, as are the horns of the mammalia.

IMBE'DDED. Inclosed by surrounding mat-
ter.

I'MBIUCATED. (imbricatus, Lat.) Laid
one over the other at the edges, like the
tiles of a house. In botany, applied to
leaves, when lying one over the other like
tiles upon a house ; applied also to the

leaves of the calyx when lying one over
the other.

IMMA'LLEABLE. Incapable of being ex-
tended by hammering or beating.

IMPA'LPABLE. (impalpable, Fr. impalpa-
bile, It.) That cannot be felt ; not per-
ceptible to the touch ; not gritty.

IMPE'NNOUS. Wanting wings.

IMPE'RFORATE. ^ (from in and perforatus,

IMPE'RFORATED. $ Lat.) Not perforate ;
having no opening ; not pierced.

IMPERMEABILITY. The state of being
impermeable.

IMPE'RMEABLE. Not admitting the passage
of fluids through its pores or interstices.

IMPE'RVIOUS, Impenetrable ; un passable.

FMPETUS. (impetus, Lat.) Force; vio-
lence ; the force with which one body
dashes against another.

IMPI'NGE. (impwi^O, Lat.) To fall against ;
to strike against.

IMPLU'MED. ) (implumis, Lat.) Without

IMPLU'MOUS. > feathers ; without hair ;
callow.

IMPORO'SITY. Absence of interstices ;
closeness of texture to the exclusion of
pores.

IMPO'ROUS. Devoid of pores, of inter-
stices.

INCANDE'SCENCE. (from incandesce, Lat.)
White heat.

INCANDESCENT. White-hot; white from
intense heat, far exceeding red-hot.

INCA'RNADINE. (incarnadin,Fr. incarna-
tivo, It.) Bright carnation colour ; of a
flesh colour.

I'NCAVATED. (incavatus, Lat.) Hol-
lowed ; scooped out ; made hollow.

INCAVA'TION. A hollow place.

INCI'NERATE. To burn to ashes.

INCINERA'TION. The act of burning to
ashes.

INCI'SOR. (from incisores, Lat.) A fore
or cutting tooth.

INCOHERENCE. } Want of cohesion ; want

INCOHE'RENCY. \ of adherence.

INCOHERENT. Wanting cohesion ; un-
connected ; loose.

INCOMBUSTIBLE. (incombustible, Fr.)
That will not burn ; that is not consumed
by the action of fire.

INCOMBU'STIBLENESS. The property of
resisting the action of fire.

INCONDE'NSABLE. That cannot be forced
into a smaller compass.

INCO'NGRUOUS. (incongruus, Lat. incon-
gru, Fr. inconffruo, It.) Unsuitable ;
not fitting.

INCORPORATE. (incorporo, Lat. incor-
porer, Fr. incorporare, It.) To mingle
different substances so as to reduce them,
to one mass.

INCRA'SSATE. (incrasso, Lat.) To
thicken.

INCRA'SSATE. (incrassatum, Lat.) Much

I N C

C 127 ]

I N F

swollen at one portion of its length ;
rounded and somewhat swollen.
INCRASSA'TION. The act of thickening ;

the state of growing thick.
INCREMENT, (incrementum, Lat.) In-
crease ; matter added.
INCRESCENT, (increscens, Lat.) Increas-
ing ; growing larger.

INCRUSTA'TION. (incrustafio, Lat. in-
crustation, Fr. incrostatura, It.) An
adherent covering ; something superin-
duced ; a coating of siliceous matter.
INCUBA'TION. (incubatio, Lat. incubation,
Fr.) The act of sitting upon eggs for
the purpose of hatching them.
INCU'RVATE. (incurvo, Lat.) To bend;

to make crooked.
INCURVA'TION. A state of bending or

crookedness.

INDECI'DUOUS. (from in and deciduus,
Lat.) Not falling off; not shed, as the
leaves of trees, but evergreen.
INDECOMPO'SABLE. That cannot be de-
composed, or resolved, into its primary
elements or constituent parts.
I'NDIANITE. A whitish or grey mineral,
brought from the Carnatic, found in
masses, of a foliated structure, and hav-
ing a shining lustre.

I'NDICOLITE. (from indigo, and \iQoc,,
Gr.) An indigo-coloured mineral found
in Sweden. It occurs crystallized, and
is considered a variety of shorl.
INDI'GENOUS. (indigena, Lat. indigene,
Fr.) Native to a country ; originally
born, or produced, in a particular coun
try. The term is more usually applied
to plants than animals ; thus plants, the
natural produce of any particular coun-
try, are said to be indigenous to that
country.

INDU'CTION. (inductio, Lat. induction
Fr. induzione, It.) A consequence drawn
from several propositions or principles
first laid down ; reasoning from particu-
lars to generals, as when from severa
particular propositions we infer one ge-
neral. The process by which a new
principle is collected from an assemblage
of facts, has been termed induction.
INDU'CTIVE PHILOSOPHY. A science which
ascends from particular facts to genera
principles, and then descends again from
these general principles to particular ap-
plications and exemplifications.
INDU'CTIVE REASONING. That kind o
philosophic reasoning which ascends from
particular facts to general principles, an
then descends again from these genera
principles to particular applications an
exemplifications.
I'NDURATED. (induratus, from induro

Lat.) Hardened.
INDURA'TION. (induratio, Lat.) The stat
of growing hard ; the act of hardening

NDU'SIA. (indusia, Lat.) The case or
covering of certain larvae ; generally used
plurally, indusia.

NDU'SIAL. Composed of indusise ; con-
taining indusise. Mr. Lyell states,
"there is another remarkable form of
fresh-water limestone in Auvergne, called
indusial, from the cases, or indusise, of
the larvse of Phrygania, great heaps of
which have been encrusted, as they lay,
by hard travertin, and formed into a
rock."

NDU'SIAL LIMESTONE. A fresh-water
limestone to which the name indusial has
been given, from its containing the in-
dusise, or cases, of the larvse of Phrygania.
— Lyell.

N^ECIUILA'TERAL. ^ Having unequal sides;
NEGIUILA'TERAL. $ in conchology, when
the anterior and posterior sides make dif-
ferent angles with the hin'ge.
'NE'QUIVALVE. i Where one valve is
^NEQUJLVA'LVULAR. 5 more convex than
the other, or dissimilar in any respect, as
in the common oyster.
^NE'RMOUS. (inermus, Lat.) Unarmed ;

devoid of spines, or thorns.
INFI'LTRATE. (infiltrer, Fr.) To enter
by percolation ; to enter a body through
its pores or interstices.
INFILTRA'TION. The diffusion of fluids

through the interstices or pores.
INFINITESIMAL. (adj.) Infinitely di-
vided.
[NFINITE'SIMAL. (subst.) An infinitely

small quantity.
[NFLAMMABI'LITY. The property of ig-
niting ; the quality of taking fire.
INFLA'MMABLE. (inflammable, Fr. che pub
inflammarsi,It.) Combustible; that may
easily be set on fire ; capable of burning
INFLAMMATION, (inflammatio, Lat. in-
flammation, Fr. inftammagione, It.) The
act of setting on flame.
INFLA'TED. (inflatus, Lat.) Blown or

puffed up ; swoln ; distended with air.
INFLATION, (inflatio, Lat.) A puffing

up ; distention with wind.
INFLE'CTED. Bent ; bowed ; turned ; bent

inwards.

INFLECTION, (inflectio, Lat.) The act of
bending or turning; the state of being
curved.

INFLE'XED. (inflexus, Lat.) Curved in-
wards ; bent towards each other.
INFLORESCENCE, (inflorescentia, Lat.) A
word used to express the particular man-
ner in which flowers are placed upon a
plant ; this by older writers was denomi-
nated the modus florendi, or manner of
flowering. Botanists distinguish many
kinds of inflorescence, under the names
whorl, cluster or raceme, spike, corymb,
fascicle, tuft, umbel, cyme, panicle, bunch,
&c.

INF

[ 128]

I N K

I'NFLUX. (influxus, Lat.) The act of
flowing into any thing or place.

INFO'RMOUS. (informis, Lat. informe, Fr.
informe, It.) Without shape ; of no
regular figure ; mis-shapen ; ill-fashioned.

INFRANGIBLE, (infrangibilis, Lat.) That
cannot be broken.

INFUNDIBU'LIFORM. (from infundibulum
and forma, Lat.) Funnel-shaped : in
botany, applied to a monopetalous corolla,
having a conical border placed upon a
tube.

INFUSCA'TION. (infuscatio, Lat.) The
act of darkening, or making blackish.

INFU'SIBLE. That cannot be melted by the
application of heat.

INFUSO'RIA. ) Beings so ex-

INFU'SORY ANIMA'LCULES. 5 tremely mi-
nute as to be invisible to the naked eye,
and which have only been discovered since
the invention of the microscope. The
infusoria have been divided into two or-
ders, the Rotifera and Homogenea. The
order of Rotifera comprises many genera,
Brachiouus, Furcularia, Tubicolaria, and
Vaginicola : the Homogenea comprises
Ureolaria, Trichoda, Leucophra, Kerona,
Himantopes, &c., &c. The most extra-
ordinary genus of all is the Proteus. It
is not possible to assign to them any de-
terminate form ; their figure changes
momentarily ; sometimes rounded, some-
times divided. The bodies of the infuso-
ria are, for the most past, gelatinous.
>. When we place a drop of any decayed
infusion of animal or vegetable matter
under a powerful microscope, and throw
a light through that drop, and through
the microscope to the eye, we discover in
the drop of water various forms of living
beings, some of a rounded, some of a
lengthened form, and some exhibiting
ramifications shooting in all directions,
but all apparently of a soft, transparent,
gelatinous, and almost homogeneous tex-
ture. These beings constitute the lowest
form of animals with which we are at
present acquainted, and they were at first
considered astomatous, that is, without
any mouth, and agastric, or possessing no
stomach, and were called infusoria, a de-
nomination explanatory merely of their
habitat, but not of their structure. Upon
further examination, it was discovered
that there existed animalculse of a higher
denomination ; these exist in every stag-
nant pool of water, iu every river, and in
the ocean. Upon examining with great
care many years since the effects of co-
loured infusions upon these minute ani-
malculse, it was found that they devoured
great quantities of the coloured matter in
which they were placed, and that they
conveyed it into internal cavities or sto-
machs, which are sometimes extremely

numerous in them. Those cavities exist
in almost every known genus. Sometimes
there are nearly 200 stomachs in a single
animalcule. Animalcules are found so
exceedingly minute that nearly five hun-
dred millions are contained in a single
drop of water, that is, as many as there
are individuals of our own race on the
face of the earth. In those minute beings
which constitute the simplest forms of
animals, there are numerous stomachs,
the lowest class is therefore called Poly-
gastrica. They are the food of higher
classes, particularly of zoophytes. There
is no proper skeleton in the entire class
of animalcules called Polygastrica. Some
of the polygastrica exude on their surface
a secretion which agglutinates, and lays
hold of, foreign particles floating in the
waters which surround them, and thus
form for themselves a partial covering.
The earthy matter, however, is not their
own produce. — Prof. Grant.

Prof. Buckland observes, " We are
more perplexed in attempting to compre-
hend the organization of the minutest in-
fusoria, than that of a whale ; and one of
the last conclusions at which we arrive, is
a conviction that the greatest and most
important operations of nature are con-
ducted by the agency of atoms too minute
to be either perceptible by the human eye,
or comprehensible by the human under-
standing."

Ehrenberg has ascertained that the in-
fusoria, which have heretofore been con-
sidered as scarcely organized, have an in-
ternal structure resembling that of the
higher animals. He has discovered in
them muscles, intestines, teeth, different
kinds of glands, eyes, nerves, and male
and female organs of reproduction. He
finds that some are born alive, others
produced by eggs, and some multiplied
by spontaneous divisions of their bodies
into two or more distinct animals. Their
powers of reproduction are so great, that
from one individual a million were pro-
duced in ten days ; on the eleventh day
four millions, and on the twelfth sixteen
millions. Ehrenberg has described and
figured more than 500 species of animal-
cules ; he has found them in fog, in rain,
and in snow.

I'NGUINAL. (from inauen, Lat.) Pertain-
ing to the groin.

INHUMA'TION. (inhumatio, Lat. inhuma-
tion, Fr.) A burying ; interment.

INHU'ME. (inhumo, Lat. inhumer, Fr.)
To bury ; to cover over with earth.

INK-BAG. A bladder-shaped sac found in
some species of cephalopods, containing a
black arid viscid fluid resembling ink, by
ejecting which, in case of danger from
enemies, they are enabled t« render the

I N O

L 129]

I N S

surrounding water opaque, and thus to
conceal themselves. Examples of this
contrivance may be seen in the Sepia vul-
garis and Loligo of our seas. To Miss
Mary Anning we owe the discovery of
numerous fossil ink-bags, found in the
lias of Lyme Regis, still distended, as
when they formed parts of the living ani-
mals. The contents of the ink-bags of
cephalopods is used in drawing, the sort
preferred is from an oriental species of
sepia ; some of that extracted from a fossil
ink-bag found in the lias was used by Sir
Francis Chantrey, on the request of Prof.
Buckland, and was by a celebrated painter,
who was ignorant of the particulars, pro-
nounced to be sepia of excellent quality.
This extreme indestructibleness of sepia
arises from its being chiefly composed of
carbon.

INOCERA'MUS. A genus of fossil bivalvular
shells of the chalk series, with an oblique
beak. Dr. Mantell, in his geology of the
South' East of England, states, " The
shells of the genus inoceramus are very
remarkable, and ten species occur in the
chalk of the South of England. These
shells are more or less gibbous, and are
commonly marked with transverse con-
centric ridges, and strise ; their consti-
tuent substance is invariably composed of
crystallized carbonate of lime, of a radiated
or fibrous structure. The hinge is a lon-
gitudinal furrow, transversely crenulated,
extending on one side of the beaks only.
One species, the Inoceramus Cuvieri, at-
tains a large size ; a length of three feet,
by two in width.

INORGA'NIC. ) Devoid of the organs of

INORGA'NICAL. $ vitality.

INO'RGANISKD. Void of organic structure.

INO'SCULATE. (from in and oscular, Lat.)
To unite by apposition.

INOSCULATION. Union by junction of the
extremities ; the union, or junction, of the
mouths of vessels, as arteries with veins.

I'NSECT. (insecta, Lat. insecte, Fr. inset-
to, It.) The third class of articulated
animals provided with articulated legs ;
they possess a dorsal vessel analogous to
the vestige of a heart, but are wholly des-
titute of any branch for the circulation.
Insects breathe atmospheric air by means
of trachese, which are most freely ramified
through all parts of the body ; they pos-
sess compound eyes. All insects, which
possess wings, metamorphose, or pass
through certain changes, before they ar-
rive at their perfect form. In their first
state, after leaving the egg, they form
larvse, or caterpillars. The bodies of in-
sects are divided into head, corslet, pec-
tus, abdomen, and members. The head
is joined to the body, in some, by ball
and socket ; in others, by plain surfaces ;

in others, after the manner of a hinge.
In some, the connection is entirely liga-
mentous, the different motions correspond-
ing with the nature of the joint. The
corslet, or thorax, is situated between the
pectus and head. The first pair of feet
are joined to this, and it contains the
muscles for moving those and the head.
To the upper and lateral part of the pec-
tus, the wings, when present, are fixed,
and the four posterior feet to its under
part. To the upper part a horny process
is frequently fixed, termed scutellum, or
escutcheon. The pectus contains the mus-
cles which move the wings and four pair
of the feet.— Fyfe.

Cuvier divided insects into twelve or-
ders:— 1. Myriapoda, or insects having
more than six feet, to twenty-four and up-
wards ; the insects of this order are apte-
rous, that is, destitute of wings. The
myriapoda are also called centipedes. 2.
Thysanoura ; this order possesses six legs
and no wings, and is characterized by the
abdomen being furnished with lateral
moveable parts, resembling false feet, or
appendages fitted for leaping. This order
has also been called aptera. 3. Parasita,
having six legs, no wings, and ocelli ; the
mouth consists of a sort of snout contain-
ing a retractile sucker. 4. Suctoria, hav-
ing six legs, but not supplied with wings.
5. Coleoptera, having six legs and four
wings, with a horny case, under which
the wings are folded. 6. Orthoptera,
having six legs and four wings, the two
superior wings in the form of cases, and
mandibles and jaws for mastication, co-
vered at the extremity by a galea. 7.
Hemiptera, having four wings, either
stretched straight out, or resting across
each other : the blatta, gryllus, fulgora,
cymen, &c., are examples. 8. Neurop-
tera, having four reticulated wings, the
inferior being usually of equal size with
the superior ; the libellula, ephemera, &c.
are examples. 9. Hymenoptera, having
four wings, naked and membranous, and
six feet ; these generally possess a sting ;
the vespa, apis, formica, termes, &c., are
examples. 10. The Lepidoptera, pos-
sessing a soft hairy body, and four ex-
panded wings, membranous, and covered
with small coloured scales resembling
dust: the papilio, or butterfly, sphinx,
and phalsena, are examples. 11. The
Rhipiptera, having two membranous wings,
folded like a fan, six legs, and two crus-
taceous moveable bodies. This order was
established by Mr. Kirby, under the name
of Stresiptera, or twisted wings ; two ge-
nera are included in it, Stylops and Xe-
nos. 12. Diptera, having two membra-
nous extended wings and six legs, with,
generally, two moveable bodies placed
s

I N S

[ 130 ]

I N T

over the wings, called halteres, the use of
which is not clearly understood : the
oestrus, or gad-fly, the musca, or common
fly, the culex, or gnat, &c., are exam-
ples.

INSECTI'VORA. (from insect and voro,
Lat.) In Cuvier's arrangement, a family
of animals which lead a subterraneous
life, and having grinders studded with
conical points. They live principally on
insects, and many of them, in cold cli-
mates, pass the winter season in a state
of torpidity. The hedgehog and mole
are examples.

INSECTI'VOROUS. (from insectivora.) Ani-
mals subsisting wholly, or in part, on in-
sects.

INSPI'SSATED. (from in and spissatus,
Lat.) Thickened ; made thick by eva-
poration. A term applicable only to
fluids whose consistence has been in-
creased.
INSPISSA'TION. The act of making any

liquid of a thick consistence.
INSTAURA'TION. (instauratio, Lat. in-
stauration, Fr. restaurazione, It.) Re-
storation to its former condition after
decay ; renewal ; reparation.
INSTAU'RATOR. He who restores that
which is decayed to its former condition.
INSTRA'TIFIED. Stratified within some

other body.
I'NSULAR. (insularis, Lat. insulaire, Fr.

isolano, It.) Belonging to an inland.
I'NSULATED. (from insula, Lat.) De-
tached from all surrounding objects ;
standing by itself ; not contiguous.
I'NTEGRAL. (integral, Fr. integrate, It.
integer, Lat.) .A portion of a whole,
being similar to the whole and not an
elementary portion. Thus the smallest
portion of carbonate of lime is still car-
bonate of lime, but if by any means we
separate the carbonic acid from the lime,
we no longer have in these, separately,
integral portions but the elementary parts.
INTE'GUMENT. (integumentum, Lat.) That
which covers or envelopes anything ;
commonly applied to the natural cover-
ings of the body, as the cuticle, corpus
mucosum, cutis, &c.

INTERCO'STAL. (from inter and costa, Lat
intercostal, Fr. ) Anything between the
ribs, as the intercostal muscles, intercos-
tal arteries, nerves, or veins.
INTERJA'CENT. (interjacens, Lat.) Lying

between ; intervening.
INTERJE'CTED. (interjectus, Lat.) Thrown

between other bodies.
INTERLA'MINATED. Placed between la-
minae of plates ; enclosed by laminae.
INTERMEDIATE, (intermediare, and in-
termediat, Fr. from inter and medius
Lat.) Intervening ; interposed ; betweei
the extremes.

NTERMO'NTANE. (from inter and montfl-
nus, Lat.) Placed between mountains ;
lying among mountains.
NTERMU'NDANE. (from inter and mundus,
Lat. ) Subsisting between orb and orb ;
relating or belonging to the space between
worlds.

[NTERNO'DAL. (from inter andnodus, Lat.)
Applied to flower-stalks proceeding from
the intermediate space of a branch be-
tween two leaves.

['NTERNODE. The space between one knot
or joint and another ; a term used both
in conchology and botany.
INTERO'SSEAL. ) (from inter and os, Lat.)
INTERO'SSEOUS. $ Placed between bones,
as interosseous muscles, arteries, veins,
&c.

INTERRUPTED. Divided ; separated.
INTERRU'PTEDLY. In botany, applied to
compound leaves when the principal
leaflets are divided by intervals of smaller
ones ; applied also to spikes of flowers,
when the larger spikes are divided by a
series of smaller ones.

INTERSTE'LLAR. (from inter and stella,
Lat.) Placed between the stars ; situ-
ated amongst the stars ; a term used to
express those parts of the universe which
are without and beyond our solar system.
INTE'RSTICE. (inter stitium, Lat. inter-
. stice, Fr. interstizio, It.) The space
between one thing and another ; time be-
tween one act and another. Neither of
the above definitions of Dr. Johnson's
can be considered to elucidate the word
interstice in its common and usual signi-
fication. A small hollow space between
the parts of a body ; the space between
one part of a body and another. II se dit
des petits intervalles que laissent entre
eux plusieurs corpuscules contigus ou
voisins.

INTERSTI'TIAL. Containing interstices.
INTERSTRA'TIFIED. Stratified between bo-
dies of a different character.
INTERTRO'PICAL. (from inter and tropical.}
Those parts which are situated between
the tropics.

INTESTI'NA. Linnaeus divided the class
Vermes, or worms, into five orders, the
first of which he named intestina ; these
mostly inhabit the bodies of other ani-
mals ; they are denominated the most
simple animals, being perfectly naked,
and without limbs of any kind. Cuvier
has divided them into cavitaria, or nema-
toidea, and parenchymata. The cavita-
ria or nematoidea are worms having ca-
vities or stomachs, or an intestinal canal
floating in a distinct abdominal cavity,
such canal extending from the mouth to
the anus. The parenchymata comprises
those species in which the body is filled
with a cellular substance, or with a con-

I N f

[ 131 ]

I O D

tirmous parenchyma ; the only alimentary
organ it contains being ramified canals.

INTESTI'NAL. (intestinal, Fr. intestinale,
It. ) Belonging to the intestines.

INTE'STINE. (intestin, Fr. intestino, It.
intestinus, Lat.) Internal ; inward.

INTE'STINES. (This word is generally used
in the plural.) All that portion of the
alimentary canal which extends from the
pyloric extremity of the stomach to the
anus ; comprehending, in man, the duo-
denum, jejunum, and ilium, or small in-
testines, and the coecum, colon, and rec-
tum, or large intestines.

INTO'RSION. ^ (from intorqueo, intorsum et

INTO'RTION. S intortum, Lat.) A twist-
ing or turning in any particular direction.
A term used in botany and conchology.

INTRAFOLIA'CEOUS. Growing on the in-
side of a leaf.

INTRANSMU'TABLE. (from in and trans-
mutable.) Unchangeable into any other
substance ; not capable of being trans-
muted.

INTUME'SCENCE. (intumescence, Fr. intu-
mesco, Lat.) A swelling or rising up ;
an expansion in the form of bubbles ; a
puffing.

I'NULIN. (from inula.) A vegetable pro-
duct, resembling starch, obtained from
the roots of the Inula Hellenium, or ela-
campane, by boiling them in water. It
was thus named by Mr. Rose.

INVE'RSION. (inversio, Lat. inversion, Fr.
inversione, It. ) Change of order or po-
sition so that the upper may be lower, or
the lower upper ; the first last, or the
last first. In the order of superposition
of the different stratified rocks, some
strata may be wanting altogether, but
there will not be found an inversion of
the regular order of superposition.

INVE'RTEBRAL. (from in and vertebral.)
Not possessing any vertebral column, or
hard bony tube for the spinal cord, or
medulla spinalis ; not having a back-
bone.

INVE'RTEBRATE. )A11 those animals are

INVE'RTEBRATED. $ invertebrated which
are included in the three great divisions,
mollusca, or cyclo-gangliata ; articulata,
or diplo-neura ; and radiata, or cyclo-
neura. The other great division includes
the vertebrata, or spini-cerebrata. In
the cephalopodes, the invertebrate form
of the lower divisions is beginning to be
lost, and the vertebrate form of that divi-
sion, to which man belongs,- to appear.
The first of the true vertebrated animals,
is the class of fishes ; from this class
upwards, including pisces, amphibia, rep-
tilia, aves, and mammalia, all are verte-
brated. From the class Pisces down-
wards, including cephalopoda, pteropoda,
gasteropoda, conchiphera, tunicata, of the

division mollusca; Crustacea, arachnida,
insecta, myriapoda, annelida, cirrhopoda,
rotifera, entozoa, of the division articu-
lata ; echinoderma, acalepha, polypiphera,
poriphera, polygastrica, of the division
radiata, all are invertebrated. There is
one remarkable distinction which sepa-
rates the vertebrated from the inverte-
brated animals, namely, that in the
former, the muscles have no external
points of attachment ; and in the latter,
with a few partial exceptions, no internal
ones.

INVE'RTED. (from inverto, inversus, Lat.)
Turned upside down ; turned inwards ;
placed in contrary order to that which
was before, or which is usual.

INVE'RTEDLY. In contrary or reversed
order.

INVO'LUCEL. A small or partial involucre.

INVOLU'CRE. ) (involucrum, Lat. cui ali-

INVOLU'CRUM. $ quidinvolvitur.)

1. Any membranous covering.

2. In botany, a species of calyx, remote
from the flower, and bearing a great re-
semblance to bractea; : the involucre is
composed of many small leaves placed at
the foot of the general umbel ; in umbel-
liferous plants, the involucre, accompany-
ing the partial umbels, is called the in-
volucella.

INVOLU'CRET. A small, imperfect, or par-
tial involucre, an involucel.

FN VOLUTE. } (from involvo, Lat.)

I'NVOLUTED. \ 1. In botany, applied to
leaves, when the margins are rolled in-
wards upon each other.
2. In conchology, where the exterior lip
is turned inwards, at the margin, as in all
the cyprese.

INVOLUTION, (involutio, Lat. involution,
Fr.)

1. The act of in wrapping or involving.

2. The state of being involved or en-
tangled.

3. That which infolds or inwraps any-
thing ; that part which inwraps another.

I'ODATE. A compound salt formed by the
combination of iodine, ozygen, and a
salifiable base ; as the iodates of ammo-
nia, soda, &c.

I'ODIDE. A compound of iodine and some
metallic substance ; as iodide of iron,
iodide of lead, &c. Also a compound of
iodine with a simple non-metallic sub-
stance. When iodine combines with
metals in more than one proportion, it
forms a protiodide, or a periodide.

FODIN. ^ (from ioeidrjg, ex lov and tlSoe,

FODINE. $ Gr.) This substance, which
was discovered by Courtois, a manufac-
turer of salt-petre, at Paris, in 1812,
obtained its name from the colour of its
vapour, which is a beautiful violet.
Iodine is procured from sea-water and

1 O L

[ 132 ]

I R O

from marine vegetables. It is of a grey-
ish-black colour and shining metallic
lustre.

I'OLITE. (from lov and \i9og, Gr.) A
stone, as its name implies, of a violet
colour. It is the prismatischer quartz of
Mohs, the lolith of Werner, and the lolithe
of Haiiy. It is found massive and dis-
seminated, and crystallized, in Finland,
Norway, Greenland, Switzerland, and
Spain ; in gneiss and granite. It occurs
in regular six and twelve-sided prisms.
Its fracture is conchoidal and uneven.
It is of a deep blue colour when seen
along the axis, and of a brownish yellow
when seen in a direction perpendicular to
the axis of the prism. When we look
alongthe resultant axes, which are inclined
62° 50' to one another, we see a system
of rings which are pretty distinct when
the plate is thin ; but when it is thick,
and when the plane passing through the
axis is in the plane of primitive polarisa-
tion, branches of blue and white light are
seen to diverge in the form of a cross
from the centre of the system of rings.
It consists of silica, nearly 50 per cent,
alumina, magnesia, oxide of iron, and
oxide of manganese.

IRIDE'SCENCE. (from iris, Lat. the rain-
bow.) The quality of shining with many
colours, resembling those of the rainbow.

IRIDE'SCENT. Shining with the colours of
the rainbow. Many membranous shells
exhibit, on several parts of their internal
surface, a glistening, silvery, or iridescent
appearance. This appearance is caused
by the peculiar thinness, transparency,
and regularity of arrangement, of the
outer layers of the membrane, which, in
conjunction with the particles of carbo-
nate of lime, enter into the formation of
that part of the surface of the shell. The
surface, which has thus acquired a pearly
lustre, was formerly believed to be a
peculiar substance, and was termed mo-
ther-of-pearl ; Sir David Brewster has,
however, satisfactorily proved in the Phi-
losophical Transactions, that the iride-
scent colours exhibited by these surfaces
are wholly the effect of the parallel
grooves, consequent upon the regularity of
arrangement in the successive deposites
of shell. This iridescent property may
be communicated to shell-lac, sealing-
wax, gum Arabic, balsam of Tolu, or
fusible metal, by taking an accurate cast
or impression of the surface of mother-of-
pearl with any one of these substances. —
Dr. Roget.

IRI'DIUM. (from iris, Lat.) An exces-
sively infusible metal to which this name
has been given from some of its salts
having varied tints like those of the rain-
bow, and from the variety of colours ex-

hibited by its solution. It was discovered,
by Mr. Tennant, in 1803, who, in ex-
amining the black powder left after dis-
solving platina, found that it contained
two distinct metals, which he named
iridium and osmium. It is of a pale
steel-grey colour. It occurs in grains, in
alluvium, in South America.
I'RIS. (iris, Lat. iris, Fr. iride, It. "ipig,
Gr.)

1. The rainbow.

2. The membrane round the pupil of the
eye, deriving its name from its various
colours. The colour of the iris corre-
sponds in general with that of the hair,
being blue or grey where the hair is
light, and brown or black where the hair
and complexion are of a dark colour. It
floats in the aqueous humour, and serves
to regulate the quantity of light sent to
the bottom of the eye.

3. A genus of plants ; order Monogynia,
class Triandria ; the flag-flower.

IRON. One of the most generally diffused
of all solid minerals. Of all the metals
the oxides of which are neither alkalies
nor earths, iron, geologically considered,
is the most important. " Calculating the
mean," says Mr. De La Beche, '• of
thirty kinds of rocks, and neglecting iron
ores, properly so called, of every kind,
iron constitutes, as an oxide, 5'5 of the
lowest stratified rocks, amounting to
14-72 per cent, in mica slate with gar-
nets, and 15*31 per cent, in chlorite slate.
It forms 12'62 per cent, in hypersthene
rock, and about 20 per cent, in basalts.
Oxide of iron constitutes about two and
three per cent, of the mass of granites and
gneiss, and between three and four per
cent, of the mass of greenstone and the
more common trappean rocks. When
we consider the large amount of iron
which exists either in the state of an
oxide, a carbonate, a carburet, a silicate,
or a sulphuret, therefore including all
iron ores of importance, we shall probably
not err greatly if we estimate iron as
constituting about 2 per cent, of the
whole mineral crust of our globe. There
is scarcely a rock without iron. — Geolo-
gical Researches.

It is to the presence of iron that rocks
and stones most frequently owe their
colour, earths when pure being white.
The specific gravity of all stones or earthy
minerals if it much exceed 2'5 may be
attributed to the presence of iron.

In its natural state iron is very unlike
what we are hourly accustomed to see it.
It presents itself every where only as an
earthy mass, a dirty impure rust ; and
even when found in the mine with a me-
tallic lustre, it is still far from possessing
those qualities which are necessary to fit

I R O

C 133 ]

I R O

it for the endless uses to which it is
applied. Man has only to purify gold,
silver, &c. but he has, as it were, to
create iron. It does not appear to have
been known so early, or wrought so easily,
as gold., silver, and copper. For its dis-
covery we must have recourse to the
nations of the East. The writings of
Moses furnish us with the most ample
proof at how early a period it was known
in Egypt and Phoenicia. He mentions
furnaces for working iron, " and brought
you out of the iron furnace ;" the ores
from which iron was extracted, " a land
whose stones are iron ;" and he states
that swords, knives, axes, and tools for
cutting stones, were at that time made of
iron, " and if he smite him with an in-
strument of iron, so that he die, he is a
murderer," "and his hand fetcheth a
stroke with the axe to cut down the
tree," " thou shalt not lift up any iron
tool upon them." The knowledge of
iron was brought over from Phrygia to
Greece by the Dactyli, according to He-
siod, as quoted by Pliny, who settled in
Crete during the reign of Minos I. about
1431 years before Christ. It would ap-
pear that a knowledge of iron obtained
even before the deluge, for in Genesis we
read " And Zillah, she also bare Tubal-
Cain, an instructor of every artificer in
brass and iron."

Iron forms a constituent part of many
animal and vegetable substances ; it enters
into the composition of the blood ; and
the various shades of hue of some of the
most delicate flowers are more or less
owing to its presence.

Iron is of a bluish-white colour, and
when polished, has a considerable degree
of brilliancy. It has a styptic taste, and
emits a smell when rubbed. Its specific
gravity is 7' 7 7.

Iron is placed the eighth in order, as
regards its malleability, possessing this
quality in a less degree than gold, silver,
copper, tin, platinum, lead, and zinc. In
ductility it ranks fourth, being inferior
only to gold, silver, and platinum, and it
may be drawn out into wire as fine as a
human hair. In tenacity it ranks first,
an iron wire one-twelfth of an inch in
diameter being capable of supporting 995
pounds without breaking. Iron is fusible
at a temperature of 1797 Fahr.

Iron is found native, and is generally
considered to be of meteoric origin, being
alloyed with nickel and other metals ;
these masses are called meteoric iron,
and it certainly appears that they have
fallen from the atmosphere. A mass was
discovered in Siberia by Prof. Pallas, weigh-
ing 1680 Ibs. A mass discovered in Bahia,
in Brazil, is estimated to weigh 14,000 Ibs.

A singular structure is frequently ob-
served in the argillaceous iron ores of
coal districts. The substance of the iron
ore is formed into conical sheaths, in-
volving one another, and marked by con-
centric undulations and radiating stria?.
Large spheroidal masses of iron ore,
weighing at least a ton, are thus found,
in connexion with the coal, at Ingleton,
in Yorkshire ; and in the coal fields of
Staffordshire and South Wales, it is a
well known form of aggregation.

The quantity of iron manufactured in
Great Britain is enormous ; in the year
1827 it was calculated at 690,000 tons ;
nearly one-half of which, or 296,000
tons, was manufactured in Wales, and
upwards of 200,000 in Staffordshire.
For the manufacturing of this immense
quantity, three millions seven hundred
and ninety-five thousand tons of coals
would be required.

In a supplementary note to Professor
Buckland's Bridgewater Treatise, it is
stated, " Ehrenberg has ascertained that
a soft yellow ochreous substance, called
Raseneisen, which is found in large
quantities every spring in marshes about
Berlin, covering the bottom of ditches,
and in the footsteps of animals, is com-
posed of iron secreted by infusorial ani-
malcules of the genus Gaillonella. This
iron may be separated from the siliceous
shields of these animals, which retain
their form after the extraction of the iron.
I'RONSTONE. A heavy mineral, possessing
sometimes a specific gravity of 3*6, and
composed chiefly of iron combined with
oxygen, carbonic acid, silex, and water,
with, in some instances, calcareous earth.
When of a superior quality, it will yield
upwards of 36 per cent, of iron. Mr.
Bakewell observes, "We know nothing,
however, certain, respecting the forma-
tion of ironstone ; but it appears to have
been deposited in fresh water, as it oc-
curs in fresh-water strata in the regular
coal formation, and in the coal strata
of the oolites of Yorkshire, and among
the clay and sandstone strata in the
wealds of Kent. Few geologists have
attempted to explain the formation of
ironstone. It may have been a deposi-
tion from chalybeate waters, or wasr
perhaps, the produce of decomposed ve-
getation, as bog or peat iron is supposed
to have been. If ever we arrive at just
conclusions respecting the origin of iron-
stone, it must be by an accurate exami-
nation of the strata in which it occurs,
and the relation of these strata to each
other. In the Missouri there is a mass
of iron ore 300 feet in height, and five
miles in extent, which yields 75 per cent,
of fine malleable iron.

I R O

[ 134]

I S O

I'RON-GLANCE. Rhombohedral iron-ore;
the Fero ligiste of Haiiy ; the Roth eisen-
stein of Werner. A peroxide of iron, of
a dark steel-gray colour. There are
several varieties ; the red varieties are
called red iron ore, and the fibrous, hema-
tite.

I'RON PY'RITES. See Pyrites.

I'RON SAND. A variety of octahedral iron-
ore, in grains.

IRRU'PTED. (from irrumpo, Lat.) Broken
violently, and with great force.

IRRU'PTION. (irruptio, Lat. irruption,
Fr.) A violent breaking in; a bursting
in ; a violent rushing into.

ISCHIA'TIC. (ischiadicus, Lat. trr%ia£iK:6c,
Gr.) Pertaining to the ischium, as the
ischiatic notch, &c.

I'SCHIUM. (ischium, Lat. la^ibv, Gr.)
One of the bones of the pelvis, situated
in the lowest part thereof, and being that
bone upon which we sit. It forms the
under, and largest portion of the aceta-
bulum, or cup which receives the head of
the thigh bone.

I'SERIN. (from eisen, Germ.) A mineral
of an iron-black colour, from which it
derives its name. It consists of 48 per
cent, of oxide of titanium, an equal pro-
portion of oxide of iron, and four per
cent, of uranium. It occurs in small
obtuse angular grains.

ISOCA'RDIA. A heart-shaped shell, with
separated involuted and diverging beaks.
The hinge formed by two flattened car-
dinal inserted teeth, and an isolated
lateral tooth under the cartilage slope.
This genus includes the Chama cor.
Some authors divide the genus Chama
into five, of which Isocardia is one.

ISOCHEI'MAL. (from i<n>£, equal, and
XeT/ia, winter, Gr.) Of the same winter
temperature : lines drawn through places
having the same winter temperature are
denominated isocheimal lines.

ISO'CHRONAL. (isochrone, Fr. from IrroQ,
and xpovoe, Gr.) Having equal times ;
uniform in time. The isochronal vibra-
tions of a pendulum are such as are per-
formed in the same space of time ; as all
the swings or vibrations of the same pen-
dulum are, whether the arches it describes
are longer or shorter.

ISO'CHRONAL LINE. That in which a
heavy body is supposed to descend with-
out any acceleration.

ISO'CHRONOUS. The same as isochronal.

I'SOGEOTHE'RMAL LINES, (from i<roc, yrj,
and Qepfjibc, Gr.) Certain lines or divi-
sions in the earth's crust possessing an
equal degree of mean annual tempera-
ture. This word is not very common, and
I have met with it only in Mrs. Somer-
ville's Connexion of the Physical Sciences.
It is, however, more definite than iso-

thermal, inasmuch as it applies solely to
divisions of the land, whereas isother-
mal applies equally to air, land, and
water.

ISOMORPHISM, (from tcrog and //op0/},
Gr.) That quality which a substance
possesses of replacing some other sub-
stance in a compound body, without any
alteration of its primitive form.

ISOMO'RPHOUS. That has the property of
retaining its primitive form when united
with other substances in a compound
body.

ISOPERIME'TRICAL. (from Iffog, Trtpi, and
H'trpov, Gr. isoperimetro, It.) Such
figures as have equal perimeters or cir-
cumferences, of which the circle is the
greatest.

ISO'PODA. (from loog and TTOVQ, Gr. ) An
order of crustaceans, thus named from
the formation of their feet, which are
fourteen in number. This order em-
braces the genus Oniscus.

ISO'SCELES. (laoaiceXriQ, Gr. isocele, Fr.)
That which hath only two sides equal.

I'SOPYRE. A mineral of a greyish or
black colour. Occurs massive. Found
in Cornwall, imbedded in granite.

ISO'THERAL. (from IGOQ and Oepoc, sum-
mer, Gr.) Of the same summer tem-
perature : lines drawn through places
having the same summer temperature are
denominated isotheral lines.

LSOTHE'RMAL. (from itroc. and Ospfjirj, Gr.)
Possessing equal temperature. Lines
drawn upon a map through a series of
places having the same annual mean tem-
perature are termed isothermal lines, or
lines of equal temperature. Mr. Lyell
observes, " it is now well ascertained that
zones of equal warmth, both in the
atmosphere and in the waters of the
ocean, are neither parallel to the equator
nor to each other. It is also discovered
that the same mean annual temperature
may exist in two places which enjoy very
different climates, for the seasons may
be nearly equalized or violently con-
trasted. Thus the lines of equal winter
temperature do not coincide with the
lines of equal annual heat, or isothermal
lines. If lines be drawn round the globe
through all those places which have the
same winter temperature, they are found
to deviate from the terrestrial parallels
much farther than the lines of equal
mean annual heat. The lines, for in-
stance, of equal winter in Europe,, are
often curved so as to reach parallels of
latitude 9° or 10° distant from each other,
whereas the isothermal lines only differ
from 4° to 5°." — Principles of Geology.

ISOTHE'RMAL ZONES. As the isothermal
lines are as numerous as the places, and
as diversified as numerous, geographers

I S T

[ 135 ]

K A R

have grouped them into bands or zones.
Humboldt has divided the northern
hemisphere into six isothermal zones or
bands.

ISTIU'RUS. A genus of that family of
saurian s called iguanida, and thus named
by Cuvier. The distinguishing character
of the genus Istiurus is an elevated and
trenchant crest, extending along a por-
tion of the tail, and supported by spinous
apophyses of the vertebrae.

FT us. The termination of adjectives in
itus shows merely the existence of some-
thing in general, as, for example, aitritus,
furnished with ears.

JU'GULAR. (from jugulum, It&t.jugulaire,
Fr. giugtdare, It.) Pertaining to the
throat ; belonging to the neck.

1. In botany, a catkin ; a species of in-
florescence consisting of chaffy scales
arranged along a stalk ; they are worm-
like tufts, which at the beginning of the
year grow out, and hang pendular down
from the hazle, walnut, filberd, &c.

2. In zoology, a genus of insects of the
order Aptera. The feet are very nu-
merous, being on each side twice as many
as the segments of the body ; the an-
tennae are moniliform ; there are two
articulated palpi ; and the body is of a
semicylindrical form. There are many
species.

I'VORY. (ebur, Lat. ivoire, Fr. avorio, It.)
A hard, solid, and firm substance, of a
white colour, and capable of a very good
polish. It is the tusk of the elephant.
The ivory from Ceylon is more valuable
than any other, from its not becoming
yellow in the wearing, as nearly all other
ivory does.

JU'RA LIMESTONE, (calcaire de Jura, Jura
kalJc.) The name given by some con-
tinental geologists to that group of rocks
comprised in the oolite. The Jura lime-
stone group is composed of limestones of
various qualities, clays, sands, and sand-
stone, and contains the same fossils as
those found in the oolitic group of Eng-
land. In the range of the Jura and the
outer ranges of the Alps, the calcareous
formations are of such immense magni-
tude, and the beds are often so highly
indurated and crystalline, that it is only
from their relative position and imbedded
fossils, that we can trace their analogy to
the English strata.

I/us. The termination of adjectives in ius
expresses the uses or aptness of an
organ ; for example, raptorius, adapted
to seize prey ; fossorius, fitted for digging ;
nutatorius, suited to swim, &c.

JU'XTA-POSI'TION. (juxta- position, Fr.
juxta and positio, Lat.) The state of
being placed in nearness or contiguity ;
apposition.

K

KANGAROO'. An animal of the genus di-
delphys, the Didelphys gigantea of Lin-
nseus. It is a native of New Holland.
When of full growth it attains the size of
a large sheep. The fore-legs are short,
the hind legs of considerable length, so
that it advances by leaping rather than
walking or running.

KA'OLIN. (The Porzellan Erde of Werner ;
the Argile Kaolin of Brongniart ; and
Feldspath decompose of Haiiy.) Porce-
lain clay. The name of an earth which
is used as one of the two ingredients in
the manufacture of oriental porcelain.
Mr. Bakewell observes, " I believe it is
the soft earthy granite from the moun-
tains of Auvergne which supplies the
kaolin used in the porcelain manufacture
at Sevres. Mons. Brongniart shewed me
a specimen of their best kaolin : it con-
tained crystals of pinite." M. Bromare
says that by analysing some Chinese
kaolin, he found it was a compound earth,
consisting of clay, to which it owed its
tenacity ; of calcareous earth ; of spark-

ling crystals of mica ; and of small quartz
crystals. He says that he has found a
similar earth upon a stratum of granite.,
and conjectures that it may be a decom-
posed granite. The kaolin used in most
countries for the manufacture of fine por-
celain or china, is generally produced
from the felspar of decomposing granite,
in which the cause of decay is the disso-
lution and separation of the alkaline in-
gredients. Cleveland says, " Kaolin is
essentially composed of silex and alu-
mine ; the proportions are variable, but
the silex usually predominates. When
pure kaolin is employed in the manu-
facture of porcelain, some ingredient must
be added as a flux, as, when pure, it is in-
fusible. There is satisfactory evidence
that kaolin has in most cases, if not in all,
originated from the decomposition of
rocks abounding in felspar, more par-
ticularly from graphic granite, which
consists almost entirely of quartz and
felspar.
KA'RPHOLITE. (from fcap^og and Xi'0o£,

K E E

C 136 ]

LAB

Gr.) A straw-coloured mineral not long
discovered, occurring in thin prismatic
concretions, and of a fibrous structure.
KEEL. (Kiel, Germ, quille, Fr.)

1. In conchology, the longitudinal pro-
minence in the Argonautse.

2. In botany, the term keel is applied to
two of the petals in papilionaceous flow-
ers : the keel is composed of two petals,
separate or united, and encloses the in-
ternal organs of fructification.

3. In entomology, a sharp, longitudinal,
gradually rising elevation upon the in-
ferior surface.

KEE'LED. Applied to leaves when the back
is very prominent longitudinally.

KERA'TOPHYTE. A name given to the
horny zoophyte.

KE'RATE. (from Kspag, Gr. a horn ; from
the minerals placed in this order having a
resemblance to horn in their outward
aspect.) The name of the third order of
earthy and metalliferous minerals. The
characters of the genera of this order are
as follows : they are not metallic ; have a
white streak ; no single distinct cleavage ;
hardness = I'O — 2'0 ; specific gravity
5-5 to 6-5.

KI'LLAS. A provincial name for a coarse
argillaceous schist ; a variety of slate.
Mr. Bakewell, in mentioning the killas of
Cornwall, says, " perhaps the best desig-
nation of the killas rock on this situation
is, that of a minutely grained and highly
indurated gneiss that had lost its schis-
toze character."

KI'LLINITE. (Thus named from its having
been discovered at Killiney, in Ireland,
by Dr. Taylor.) A mineral of a pale
green colour, occurring in veins of granite
at Killiney, near Dublin.

KI'MMERIDGE CLAY. A blue and greyish-
yellow slaty clay of the oolite formation ;
a member of the oolite group, thus called
from its being found abundantly at Kim-
meridge, in the Isle of Purbeck. It is
also found at Sunning, near Oxford. It
contains gypsum and bituminous slate.
It is a marine deposit. Kimmeridge clay
forms the base of the Isle of Portland.

KING-CRAB, (an entomostracan, or shelled
insect.) The Limulus polyphemus, known
also as the horse-shoe. It is very com-

mon on the coast of New Jersey. The
king-crab is placed by Cuvier amongst
the poecilopods.

KNOB, (knobel, knopf, Germ.) A hard
protuberance. In conchology, any part
of a shell bluntly rising above the rest.

KNO'BBED. Containing protuberances or
knobs ; set with knobs.

KOA'LA. An extraordinary quadruped in-
habiting the continent of Australia. Cu-
vier places the koala in marsupialia, or
the fourth order of Mammalia. This ani-
mal has a short stout body, short legs,
and no tail : it has the five toes, or fin-
gers, of the fore-feet divided into two
groups, the thumb and index forming one
group, and the three remaining toes or
fingers the other. On the hind feet the
thumb is altogether wanting. Carrying
its young for a long period on its back,
this separation of the toes of the fore-
feet enables it to take firmer hold of the
branches of the trees, on which it passes a
portion of its time.

KOTH. A name given by the Spaniards to
an earthy slimy substance ejected from the
volcanoes of South America. It is of a
blackish brown colour, an earthy texture,
and is but slightly coherent. The na-
tives call it Moya.

KOU'PHOLITE. (from Kovtyog, light, and
Xi9oQ, a stone, Gr.) The prehnite kou-
pholite of Brongniart. A mineral, a va-
riety of prehnite. It occurs in minute,
rhomboidal plates, is of a greenish or pale
yellow colour, glistening, and slightly
pearly. It has been found in the Py-
renees.

KY'ANITE. (from KVO.VOQ, blue colour, Gr.
This is frequently written Cyanite.) The
Cyanit of Werner ; the Disthene of Haiiy,
and the Sappare of Kirwan. Kyanite
occurs both massive and crystallized, the
crystals, often very long, are frequently
grouped. Its colour, as its name imports,
is blue, varying from an intense to a light
sky-blue. It is infusible, except under
the compound blow-pipe. It consists of
alumina 64, silica 34, with a small quan-
tity of oxide of iron and a trace of lime.
It is found in primary rocks in Scotland
and in America.

LABE'LLUM. (labellum, Lat. a little lip.)
A term applied, in botany, to one of the
three pieces forming the corolla in orchi-
deous plants. The calyx and corolla
consist of three pieces each, and one of
those forming the latter, differs very much

in size and form from the other two ; it is
called the labellum, and is often spurred.
LA'BIAL. (from labium, a lip, Lat. labial,

Fr. labbiale, It.) Pertaining to the lips.
LA'BIATE. > In botany, plants are so called
LA'BIATED. $ which have the segments or

LAB

137 ]

LAC

divisions of their corollas resembling the
form of lips.

LABIA'T^E. There is a large class of plants
called labiates, which have irregular mo-
nopetalous corollas, and these, generally,
bilabiate and ringent; the mint, nettle,
&c. are examples.

LA'BIUM. (labium, Lat.)

1. In entomology, the lower lip of insects
is called the labium; the upper, the la-
drum. The lower pair of jaws are behind
the mandibles, and between them is situ-
ated the labium, or lower lip, which closes
the mouth below, as the labrum does
above. The labium of insects consists of
two chief parts, each of which may be
considered as a separate organ ; namely,
the chin and the tongue.

2. In conchology, the inner lip of the
shell.

LA'BRUM. {labrum, Lat.)

1. In entomology, the upper lip of insects.
The labrum is situated above, or rather
in front of, the mandibles, it is generally
of the form of the segment of a circle, or
a triangular, or quadrangular, somewhat
convex, corneous plate, which is united
posteriorly by a membranous hinge with
the clypeus.

2. In conchology, the outer lip ; that
edge of the aperture which is placed at
the greatest distance from the axis of the
shell.

LA'BRADOR FELSPAR. } So named from

LA'BRADOR STONE. $ having been
found on the coast of Labrador, more
particularly on the Island of St. Paul.

This mineral was at one time
called Labrador Hornblende, but its
present name has very properly been
substituted for what was incorrect.
Labrador felspar has been found
massive and disseminated only. Its
laminae are slightly curved ; lustre
nearly metallic, and pearly on the per-
fect cleavage faces. It is distinguished
by its splendent changeability of colour,
reflecting very beautiful colours when the
light falls upon it in certain directions.
Although principally occurring on the
coast of Labrador, yet this mineral has
been found in different parts of Europe.

LA'BRADORITE. A name for Labrador fel-
spar.

LABYRINTH. (labyrinthus, Lat. Xa/3v-
pivOog, Gr. labyrinthe, Fr. laberinto, It.)
The name given to several cavities of the
ear, from their flexuous position. The
internal parts of the ear compose what is
designated, from the intricacy of its
winding passages, the labyrinth. It con-
sists of a middle portion, termed the ves-
tibule, from which, on its upper and
posterior side, proceed three tubes, called
from their shape, semicircular canals ; to

the lower anterior side of the vestibule
there is attached a spiral canal, resem-
bling the shell of snail, and termed the
cochlea.

LACE'RTA. (lacerta, Lat.) A lizard. In
Cuvier's arrangement, lacerta constitutes
the second genus of Lacertiuida, or lacer-
tians.

LACE'RTIAN. Belonging to the family La-
certinida ; order Sauria.

LACE'RTINE. Resembling a lizard.

LACI'NIATE. i (laciniatus , Lat. lacinie,

LACI'NIATED. $ Fr.) Ragged at the
edges ; jagged. In botany, applied to
leaves cut into numerous irregular por-
tions.

LA'CRYMAL. (from lachryma, vel lacryma,
Lat. lacrymale. Fr.) Certain parts
about the eye, connected with the secre-
tion and passage of the tears, as the
lacrymal glands, the lacrymal ducts, &c.
This word is also written lachrymal.

LACTA'TION. (from lac, milk, Lat.) The
act of suckling ; the period of suck-
ling.

LA'CTEAL. (from lac, Lat.) The lacteals
are numerous minute tubes commencing,
by open and very minute orifices, from
the inner surface of the intestines, and
uniting successively into larger vessels,
till they form trunks of considerable
magnitude. The office of the lacteals is,
to take up the chyle and transmit it to
the heart. It is only among the verte-
brata that lacteals are met with ; in in-
vertebrated animals, the absorption of
the chyle is performed by veins instead
of lacteal vessels. The chyle of the
higher orders of animals often contains a
multitude of globules, which give to it
a milky appearance, from which circum-
stance the vessels containing it have ob-
tained their name.

LA'CTEOUS. (lacteus, Lat.) Milky; of a
white colour, resembling milk.

LACTI'FEROUS. (from lac, milk, and/ero,
to bear, Lat.) Conveying milk ; yielding
a white juice, or milky liquor.

LACU'NJE. (lacuna, Lat.) PI. Small ex-
cretory ducts.

LACU'NOSE. ) (from lacunosus, Lat.) Hav-

LACU'NOUS. $ ing the surface -covered
with small furrows, pits, or depressions.

LACU'STRAL. } (from lacm, Lat.) Per-

LACU'STRINE. $ taining to a lake.

LACU'STRINE DEPOSITS. Purely lacustrine
deposits are almost unknown among any
of the stratified rocks of a date earlier
than the tertiary period, and it was not
until the publication of Cuvier and Brong-
niart, on the environs of Paris, that the
attention of geologists was much directed
to the study of those numerous fresh*
water deposits from which we may obtain
a knowledge of the ancient condition of

LAG

[ 138 ]

LAM

the land. "If we drain a lake," says
Mr. Lyell, u we frequently find at the
bottom a series of deposits, disposed with
great regularity one above the other ; the
uppermost, perhaps, may be a stratum of
peat, next below a more compact variety
of the same, still lower a bed of lami-
nated marl, alternating with peat, and
then other beds of marl, alternating with
clay. Now if we sink a second pit
through the same continuous lacustrine
deposit, at some distance from the first,
we commonly meet with nearly the same
series of beds, yet with slight variations ;
some, for example, of the layers of sand,
clay, or marl may be wanting, one or
more of them having thinned out, and
given place to others, or sometimes one
of the masses, first examined, is observed
to increase in thickness to the exclusion
of other beds. At length we arrive at a
point where the whole assemblage of la-
custrine strata terminate, as, for example,
when we arrive at the borders of the
original lake-basin." Prof. J. Philips
observes, "lacustrine deposits of un-
doubtedly meiocene age are scarcely
known. On the coasts of Yorkshire and
Lancashire, lacustrine deposits occur at
many points, and present a considerable
variety of circumstances as to level, above
or below the sea, sandy, marly, or peaty
composition ; but are always governed by
the general condition, that they occupy
small hollows on the surface of the diluvial
accumulations .

LAGA'NUM. A fossil echinite thus named
by Klein, called also pancake.

LAGO'MYS. (from Xdyoc, a hare, and
fivg, a rat, Gr.) A rat hare. A genus of
animals forming a link between the hare
and the rat. The lagomys is placed by
Cuvier in the order rodentia. They have
been found in Siberia only, and are de-
scribed by Pallas. There are several
species ; One has been found fossil in the
osseous breccia of Corsica. The lagomys
has ears of a moderate size ; legs nearly
alike ; clavicles almost perfect ; and no
tail. The Rev. W. Kirby observes of the
lagomys, "it ought rather to have been
called the hay-maker, since man may, or
might, have learned that part of the busi-
ness of the agriculturist, which consists
in providing a store of winter provender
for his cattle, from this industrious ani-
mal. The Tungusians, who inhabit the
country beyond the lake of Baikal, call it
Pika, which has been adopted as its
trivial name. These animals make their
abode between the rocks, and during the
summer employ themselves in making hay
for a winter store. About the middle of
August these little animals collect with
admirable precaution their winter's pro-

vender, which is formed of the choicest
grasses and the sweetest herbs, which
they bring near their habitations and
spread out to dry like hay. In Septem-
ber, they form heaps or stacks of the
fodder they have collected under the rocks,
• or in other places sheltered from the rain
or snow. Where many of them have
laboured together, their stacks are some-
times as high as a man, and more than
eight feet in diameter. A subterranean
gallery leads from the burrow, below the
mass of hay, so that neither frost nor
snow can intercept their communication
with it. — Bridgewater Treatise.

LAGOO'N. } (laguna, It.) A salt-water

LAGU'NE. \ lake.

LAKE. (lacus, Lat. lache, Germ, lac or
laque, Fr. lago, It.) A large collection of
inland water. Some of the lakes of
America are upwards of 1500 miles in
circuit. The filling up of lakes, and the
formation of deltas at their mouths, form
subjects of great importance to the geo-
logical student. In lakes, the diminu-
tion of the surface, by the gradual in-
crease of land at the mouths of rivers
which flow into them, is remarkable. The
mud and debris brought by the Rhone
into the lake of Geneva, and deposited near
its entrance, has caused an advance of the
land to the extent of two miles within
1700 years, the Roman harbour Portus
Valesise, now called Port Vallais, being
at this time two miles distant from the
lake.

LAMA'NTIN. ) The manatus of Cuvier. A

LAMA'NTINE. $ species of herbivorous
cetacea, living upon the plants which
grow at the bottom of the sea. The
lamantin appears to have existed during
the miocene and pliocene periods. Fossil
remains have been discovered in France.
The existing species of the lamantine are
found near the mouths of rivers in the
hottest parts of the Atlantic ocean and in
the torrid zone, and the discovery of their
fossil remains in Europe adds another
link to the long chain of evidence of a
diminished temperature of the climate of
Europe.

LAMBDOI'DAL. (from the Greek letter
XctfiSa, and dSos, form.) The name
given to one of the sutures of the cra-
nium, from its supposed resemblance in
form to the Greek letter A.

LAME'LLA. (lamella, Lat.) A thin plate
or scale. This word is generally used in
the plural, lamellae.

LA'MELLATED. Composed of thin plates,
layers, or scales. In conchology, when a
shell is divided into thin and distinct
plates or layers, overlying each other with
the edges produced.

LAME'LLAR. Composed of minute plates

LAM

[ 139 ]

LAP

or layers placed one over the other ;
foliated.

LAME'LLI BRANCHIA'TA. In De Blain-
ville's conchological arrangement, the
third order of Acephalophora, containing
ten families of bivalves.

LAMELLICO'RNES. In Cuvier's arrange-
ment, the sixth family of pentamerous
coleoptera ; they have foliated horns,
from which circumstance they obtain their
name.

LAMELLI'FEROUS. (from lamella, a small
plate, and/ero, to bear, Lat.) Having a
structure composed of thin layers ; having
a foliated structure.

LAMELLIRO'STRES. In Cuvier's arrange-
ment, the fourth family of the order of
Palmipedes. The lamellirostres have a
thick bill, the edges of which are furnished
with laminae, from which circumstance
they have obtained their name.

LA'MINA. (lamina, Lat.) A thin plate or
scale ; a thin layer of a stratum. This
word is generally used in the plural,
laminae.

LA'MINATED. (laming Fr.) Disposed in
layers, placed one over another.

LAMINA'TION. Arrangement in layers.
Lamination prevails amongst all the va-
rieties of gneiss, mica schist, chlorite
schist, hornblende schist, &c. It is often
observable in primary limestone, and
sometimes in quartz rock. All the mem-
bers of the carboniferous series display
lamination, though in unequal degrees.
" The coarse sandstones frequently," says
Prof. Phillips, "present oblique lamina-
tion, which, added to the irregularity of
'the beds, renders it often embarrassing to
say what is the true dip of such rocks.

LAMINI'FEROUS. (from lamina and fero,
Lat.) Having a structure consisting of
laminae or layers.

LA'NATE. ) (from lanatus, Lat.) Woolly;

LA'NATED. $ covered with a sort of pube-
scence resembling short woolly hairs.

LA'NCEOLATE. Lance-shaped; narrow and
tapering.

1. In conchology, applied to a shell of an
oblong shape, and gradually tapering to
each end.

2. In entomology, in describing the figure
of the superficies, when the base is not so
broad as the centre, and the lateral mar-
gins slightly, but equally, swollen, gradu-
ally tapering towards the apex, where if
terminates in a point, and the longitudina
diameter more than three times the length
of the transverse. — Burmeister.

3. In botany, applied to leaves of a nar-
row oblong form, gradually tapering to-
wards each end.

LA'NCIFORM. (from lancea and forma

Lat.) Spear-shaped ; lance- shaped.
LA'NDSLIP. A portion of land that has

separated from the main body, in conse-
quence of long-continued rains, or the
expansive powers of severe frosts, and has
fallen to a lower situation. Landslips are
not uncommon on our coasts ; one of
great extent occurred some years since at
the back of the Isle of Wight, and another
is announced, though not of such magni-
tude, at Alum Bay, while I am writing
the present account. Landslips must
necessarily be often attended by fatal
consequences, as in the falls of avalanches.
We are informed that when the mountain
of Piz fell, in 1772, three villages, with
their entire population, were covered ;
and that when part of Mount Grenier, in
Savoy, fell, in 1248, five parishes were
buried, the ruins occupying an extent of
nine square miles.

A'NGOUSTE. (Fr. sorte d'ecrevisse de
mer.) The name given by the French to
the Palinurus vulgaris of Leach ; the
cray-fish or thorny lobster.
IANI'FEROUS. (from lana, wool, and/ero,
to produce, Lat.) Bearing or producing
wool.

IANI'GEROUS. (from lana, wool, and gero,
to bear, Lat.) Bearing wool.
LA'NTANE. (from XavQdvu, to conceal,
Gr.) A new elementary body, lately dis-
covered, making the fifty-fifth. See Ele-
mentary body.

LANU'GINOSE. ) (from lanuginosus, Lat.)
LANU'GINOUS. $ In entomology, when
longish curled hair is spread over the sur-
face; covered with soft hair resembling
wool.

LA'PIDES JUDA'ICI. A name given to cer-
tain fossil spines of echinites, formerly
supposed to be petrified olives.
LAPIDE'SCENCE. (from lapidesco, Lat. to
become stone.) Stony concretion ; the
process of being converted into stone.
LAPIDE'SCEMT. Growing or turning into

stone.

LAPIDIFICA'TION. (lapidification, Fr. from
lapis, a stone, and fio, to make or be-
come, Lat.) The conversion into stone
of some other substance ; the act of form-
ing stone.
LAPI'DIFY. (lapidifier, Fr.) To convert

into stone ; to form stone.
LAPI'DIFIED. Converted into stone ; form-
ed into stone.

LAPI'LLI. (lapillus, Lat.) Volcanic cin-
ders, abounding in minute globular con-
cretions.

LA'PIS LA'ZULI. The Lazur stein of Werner;
Azure-stone of Jameson ; Lazulite of
Haiiy ; Dodecaedrischer Kuphon-spath
of Mohs. When lapis lazuli is pure, it is
a mineral of a fine azure-blue colour ; it
occurs in rhombohedral dodecahedrons,
massiver and disseminated. Structure
finely granular, almost compact ; fracture

LAP

LAV

uneven or conchoidal ; lustre feeble ; a '
little translucent at its edges. It scratches j
glass, but gives sparks with steel with dif- \
ficulty. Specific gravity about 2 '30. Its |
analysis is very differently given by differ- •
ent authors. It contains silica, nearly
fifty per cent, carbonate of lime, alumina,
potash, soda, oxide of iron, and sulphuric
acid. It occurs associated with primary j
rocks, especially granite. It is accompa- |
nied by garnets, quartz, felspar, &c., with j
some of which it is often intermixed. It I
is found chiefly in China, Persia, and
Russia. It is capable of a high polish,
and is much esteemed. Its chief use,
however, is to furnish the ultra -marine
blue, used by painters, a pigment remark-
able for the durability of its colour.

LA'PIS (ETI'TES. Eagle-stone. A mineral
which derives its name from the ancient
belief that it was found in the nests of the
eagle. It is a variety of iron ore, com-
monly met with in the argillaceous mines
of this country. Its supposed virtues are
described by Dioscorides, CEtius, and
Pliny, who assert that if tied to the arm it
will prevent abortion ; if fixed to the thigh
it will facilitate delivery.

LA'RYNX. (XdpuyC, Gr.) The upper part
of the wind-pipe or trachea ; that cartila-
ginous projection in the throat known as
the pomum Adami, which strictly is formed
by one of the cartilages of the larynx only,
namely, the thyroid. The larynx consists
of five cartilages, the cricoid, thyroid, two
arytsenoid, and the epiglottis.

_,A'TERAL. (lateralis, Lat. lateral, Fr. la-
terale, It.) Pertaining to the side ; ex-
tending to one side from the centre.

LATERI'TIOUS. (lateritius, Lat.) Of the
colour of brick- dust; applied generally to
sediment.

LATIRO'STROUS. (from latus, broad, and
rostrum, a beak, Lat.) Broad beaked.

LA'TITUDE. (latitudo, Lat. latitude, Fr.
latitudine, It.) The latitude of a place
on the earth's surface is its angular dis-
tance from the equator, measured on its
own terrestrial meridian : it is reckoned
in degrees, minutes, and seconds, from 0
up to 90°, and northwards or southwards
according to the hemisphere the plane
lies in. Thus the observatory at Green-
wich is situated in 51° 28' 40" north lati-
tude. Latitude may also be thus defined,
the angular distance between the direction
of a plumb-line at any place and the plane
of the equator.

LA'TROBITE. A mineral, thus named after
Latrobe, having been found by him on
the coast of Labrador. Colour, pale
pink; specific gravity 2 '8. Occurs mas-
sive and crystallized.

LA'TTICED. In conchology, shells having
longitudinal lines or furrows decussated

by transverse ones, resembling lattice-
work.

LA'RVA. (larva, a mask, Lat.) An insect
in its caterpillar state, before it has at-
tained its winged or perfect state. Some
insects, as the butterfly, moth of the silk-
worm, &c., pass through four distinct
states, namely, the egg; the larva, or
caterpillar ; the pupa, or chrysalis ; and
the imago, or perfect insect. The egg,
which is deposited by the perfect insect,
gives birth to a caterpillar, or larva •, an
animal, which, in outward shape, bears
not the slightest resemblance to its parent,
or to the form it is itself afterwards to
assume. It has, in fact, both the external
resemblance, and the mechanical struc-
ture, of a worm. The same elongated
cylindric shape, the same annular struc-
ture of the denser parts of the integument,
the same arrangements of longitudinal
and oblique muscles connecting these
rings, the same apparatus of short feet,
with claws, or bristles, or tufts of hair,
for facilitating progression ; in short, all
the circumstances most characteristic of
the vermiform type are equally exempli-
fied in the different tribes of caterpillars,
as in the proper annelida. These exter-
nal investments, which hide the real form
of the future animal, have been compared
to a mask ; so that the insect, while wear-
ing this disguise, has been termed larva,
the Latin name for a mask. — Roget.

We have in the larvae of insects a kind
of intermediate animal, in some degree
expansile.

LA'VA. (This word, according to Kirwan,
is derived from the Gothic, lopa or lauffen,
to run, and is applied to the melted or li-
quified matter, discharged from the mouths
of volcanoes.) The matter which flows
in a fused, or melted, state from a vol-
cano.

Lava, whatever be its chemical compo-
sition, puts on very different appearances,
according to the circumstances which ac-
company its consolidation, hence by some
authors it has been divided into compact
lava, cellular lava, and cavernous lava.
The mineral called felspar forms, in gene-
ral, more than half of the mass of modern
lavas. When this is in great excess, lavas
are called trachytic ; when, on the other
hand, augite prevails, they are called ba-
saltic. When lava is observed as near as
possible to the point whence it issues, it
is found to be, for the most part, a semi-
fluid mass of the consistence of honey,
but occasionally so liquid as to penetrate
the fibre of wood. It soon cools exter-
nally, arid consequently exhibits a rough
uneven surface ; but, from its being a bad
conductor of heat, the internal mass re-
mains liquid long after that portion which

LAV

[ 141 ]

LEA

is exposed to the air has become solid.
That of 1822, some days after it had been
ejected, raised the thermometer from 59°
to 95°, at a distance of twelve feet ; at a
distance of three feet the temperature
greatly exceeded that of boiling water.
The temperature at which lava continues
in a state of fluidity is sufficiently great to
melt glass and silver ; even stones are
said to have been fused when thrown into
the lava of Etna and Vesuvius. The
length of time during which streams of
lava retain their heat is quite astonishing :
the current of lava which flowed from
Etna in 1669 retains a portion of it to the
present time. That which was poured
from Jorullo, in Mexico, in the year 1759,
was found to retain a high temperature
half a century afterwards. Sir W. Ha-
milton lighted small pieces of wood in the
fissures of a current of Vesuvian lava four
years after it had been ejected. The
streams of lava often become solid exter-
nally, even while yet in motion, and their
sides may be compared to two rocky walls,
which are sometimes inclined at an angle
of 45°. Of the immense bodies of lava
thrown out during volcanic eruptions, few
persons entertain a just idea. Etna,
which rises upwards of 10,000 feet in
height, and embraces a circumference of
180 miles, is composed entirely of lavas.
" In the structure of this mountain," says
Dr. Daubeny, " every thing wears alike
the character of vastness." The products
of the eruptions of Vesuvius may be said
almost to sink into insignificance, when
compared with these coulees, some of
which are four or five miles in breadth,
fifteen in length, and from fifty to one
hundred feet in thickness. Still the erup-
tions of Etna are nothing when compared
with that of Skaptar Jokul, the following
account of which is extracted from Mr.
Lyell's Principles of Geology. " On the
llth of June Skaptar Jokul threw out a
torrent of lava which flowed down into
the river Skapta, and completely dried it
up. The channel of the river was be-
tween high rocks, in many places from
four hundred to six hundred feet in depth,
and near two hundred in breadth. Not
only did the lava fill up these great defiles
to the brink, but it overflowed the adja-
cent fields to a considerable extent. The
burning flood, on issuing from the con-
fined rocky gorge, was then arrested for
some time by a deep lake, which it en-
tirely filled. The current then again pro-
ceeded, and reaching some ancient lava
full of subterraneous caverns, penetrated
and melted down part of it. On the 18th
of June, another ejection of liquid lava
rushed from the volcano, which flowed
down with amazing velocity over the sur-

face of the first stream. After flowing
for several days, it was precipitated down
a tremendous cataract called Stapafoss,
where it filled a profound abyss, which
that great waterfall had been hollowing
out for ages, and again the fiery current
pursued its onward course. On the 3d of
August, fresh floods of lava still pouring
from the volcano, a new branch was sent
off in a different direction. "When the
fiery lake which filled up the lower por-
tion of the valley of the Skapta had been
augmented with new supplies, the lava
flowed up the course of the river to the
foot of the hills whence the Skapta takes
its rise. This eruption did not entirely
cease till the end of two years, and al-
though the population of Iceland did not
exceed fifty thousand, not fewer than
twenty villages were overwhelmed, besides
those inundated by water, and more than
nine thousand human beings perished, to-
gether with an immense number of cattle.
Of the two branches of liquid lava, which
flowed in nearly opposite directions, the
greater was fifty, and the lesser forty
miles in length. The extreme breadth
which the Skapta branch attained in the
low countries was from twelve to fifteen
miles, that of the other about seven. The
ordinary height of both currents was one
hundred feet, but in narrow defiles it
sometimes amounted to six hundred."

LAU'MONITE. Diatomous zeolite. A mine-
ral thus named after its discoverer, Gillet
Laumont. It is of a white, or grayish-
white colour, sometimes tinged with red.
It occurs regularly crystallized, and in
distinct granular concretions. Its crystals
are four-sided prisms, slightly oblique,
sometimes terminated by diedral summits,
sometimes truncated on their lateral edges.
By exposure to the air, Laumonite disin-
tegrates, and is at length reduced to a
white powder. If, however, recent spe-
cimens be immersed for two or three hours
in a strong mucilage of gum, the action of
the atmosphere upon them, and their
efflorescence, will be prevented. Laumo-
nite consists of silica 52*0, alumina 21*20,
lime 10-50, and water about 14. It occurs
in secondary trap-rocks in France, Scot-
land, Iceland, and America.

LA'ZULI. See Lapis lazuli.

LA'ZULITE. A mineral of a light blue co-
lour, supposed by some mineralogists to
be a sub-species of lapis lazuli.

LEAD. (Iced, Sax.) Lead is of a bluish-
grey colour, with considerable lustre, but
soon tarnishes by exposure to the atmo-
sphere. By friction this metal exhales a
peculiar, and somewhat disagreeable,
odour. Its specific gravity is 11 '35, or
nearly eleven and a-half times heavier
than water. It is soft and easily melted,

LEA

C 142 ]

L E N

being fusible at about 600° Fahrenheit.
It is the softest of all the durable metals ;
it can be scratched by the nail, and is
easily cut by a knife. Its elasticity, duc-
tility, and tenacity, are comparatively low ;
it cannot be drawn into wire thinner than
a line in diameter. Lead is very mallea-
ble, and can be beaten into thin leaves,
but these, from its imperfect tenacity, are
easily torn. All the salts of this metal
are highly poisonous ; they are, however,
most shamefully employed by unprincipled
persons to correct or conceal the acidity
of cider and wines. The presence of lead
in these liquors may be detected by the
following means. Dissolve 120 grains of
sulphuret of lime and 180 grains of super-
tartrate of potash in 16 ounces of distilled
water, by repeated shaking the mixture ;
when perfectly dissolved, leave the mix-
ture to settle, and pour off the clear liquid
into clean phials, adding about twenty
drops of hydrochloric acid to each. A
small quantity of this poured into a wine-
glass of the suspected wine, will detect
the smallest quantity of lead, if any be
present, by producing a black precipi-
tate.

Several instances of the occurrence of
native lead have been mentioned, though
in few of them does the fact appear to be
well established. In the island of Ma-
deira, it is found in small masses, in lava,
and hai undoubtedly been reduced to its
present state by volcanic fire. Next to
iron, lead may be considered the most
abundantly diffused of all the metals ; it
has been known from the earliest ages
The lead of our mines is in a state of
combination with sulphur, forming a sul-
phuret of lead ; this is called galena, or
lead-glance. By exposure to a strong
heat the sulphur is driven off and pure
lead is obtained : the average produce of
metal from the Derbyshire ore is about
66 per cent.

LEGU'ME. (legumen, Lat. legume, Fr. le-
gume, It.) A species of fruit ; apod; a
seed vessel peculiar to leguminous plants,
formed of two oblong valves having no
longitudinal partition ; the seeds are at-
tached to one of its margins only ; the
bean, pea, vetch, and all the natural order
of leguminosae, furnish examples.

LEGUMINO'S^E. An order of plants, calyx
five-toothed, inferior, the odd segment
anterior, or farthest from the axis ; corolla
papilionaceous, rarely regular; stamens
definite or indefinite, perigynous, either
distinct, monadelphous, or diadelphous ;
ovarium superior, one-celled, many seed-
ed, style and stigma simple ; fruit a le-
gume, or, rarely, a drupe ; seeds occa-
sionally with an arillus ; embryo, ex albu-
minous, cotyledons, either remaining under

ground, or appearing above, in germina-
tion ; leaves oompound, stipulate, alter-
nate ; leaflets stipulate ; inflorescence
usually axillary, but various.

One genus of this order, Detarium, has
a drupe for its fruit, and Mimosa has a
perfectly regular corolla.

The order Leguminosse is most impor-
tant to man both for its beauty and utility.
The pea, bean, harico, vetch, liquorice,
clover, sainfoin, lucerne, tamarind, indigo,
gum arabic, &c. &c., belong to it. Ge-
nerally, the order is innocent, if not
wholesome ; but some few genera are
poisonous.

LEGU'MINOUS. Belonging to the order
Leguminosse ; bearing pods ; having a
legume for a pericarp. Linnseus stated
that among all the leguminous or papi-
lionaceous tribe, no deleterious plant is
to be found ; this, however, is not strictly
true.

LE'MMING. The Lapland marmot. The
lemming has short ears and a tail, with
the toes of its fore-feet peculiarly adapted
for digging. Cuvier places the lemming
in the order Rodentia, class Mammalia.
Bones of the lemming have been found
fossil in a breccia at Cette.

LE'MNIAN EARTH. A mineral found in the
island of Lemnos, in the Egean Sea,
whence its name. It is also called sphra-
gide, from o^payic, sigillum, a seal. It
is of a reddish colour and has a soapy
feel.

LENS, (lens, a lentil, Lat. lentille, Fr.
lente, It.) So named from its resem-
blance to a seed of the lentil. A trans-
parent substance having its two surfaces
so formed that the rays of light, in passing
through it, have their direction changed.
Of lenses there are various sorts ; a
spherical lens, is a sphere, all the points
in its surface being equally distant from
the centre. A double convex lens, is a
solid formed by two convex spherical
surfaces, having their surfaces on opposite
sides of the lens. When the radii of its
two surfaces are equal, it is said to be
equally convex; when the radii are un-
equal, it is said to be unequally convex, A
plano-convex lens, is a lens having one of
its surfaces convex and the other plane.
A double concave lens, is a solid, bounded
by two concave spherical surfaces, and
may be either equally or unequally con-
cave. A plano-concave lens, is a lens
one of whose surfaces is concave and the
other plane. A meniscus, is a lens one of
whose surfaces is convex and the other
concave, and in which the two surfaces
meet if continued. A concavo-convex lens,
is a lens one of whose surfaces is concave
and the other convex, and in which the
two surfaces will not meet if continued.

L E N

C 143 ]

L E P

Convex lenses possess peculiar advan-
tages for concentrating the sun's rays,
and for conveying to an immense distance
a condensed and parallel beam of light.
The most perfect burning lens ever con-
structed was executed by Mr. Parker, of
Fleet Street, at an expense of 7001. It
\tas made of flint-glass, was three feet in
diameter, and weighed 212 pounds. By
means of this powerful burning lens,
platina, gold, silver, copper, tin, quartz,
agate, jasper, flint, topaz, garnet, &c.,
were melted in a few seconds. — Brew-
ster.

LENTICE'LL^E. The name given by De
Candolle to certain points, which appear
as dark spots, on the surface of the bark
of plants.

LENTI'CULAR. (lenticularis, resembling a
lentil, Lat. lenticulaire, Fr.) Having
the form of a lens.

In entomology, a round body, with its
opposite sides convex, meeting in a sharp
edge. In conchology, doubly convex
shells.

LENTI'CULAR ORE. The name given by
Jameson to obtuse octahedral arseniate of
copper, a variety of arseniate of copper ;
called also lenticular arseniate of copper.

LENTICULI'NA. A sublenticular, multilo-
cular, spiral univalve ; a genus of micro-
scopic foraminifera. Distinguished from
Nautilus by having no syphon. Three
species have been found fossil in the
neighbourhood of Paris.

LENTI'CULITE. A fossil shell of a lenticular
form.

LE'NTIFORM. (from lens and/brma, Lat.)
Of the form of a lens.

LB'NZINITE. A mineral found in Germany,
and thus named after Lenzius, a German
mineralogist. There are two kinds of
lenzinite, the opaline and the argillaceous ;
the former of a milk-white, the latter of a
snow-white colour.

LE'PADITES. The goose-barnacle. An
order of Cirripedes, the species of which
are distinguished by a tendinous, con-
tractile, and often long tube, fixed by its
base to some solid marine substance,
supporting a compressed shell, consisting
of valves united to each other by mem-
brane ; and by having six pairs of tenta-
culated arms. They are usually found in
places exposed to the fluctuations of the
waves.— Rev. W. Kirby.

LE'PAS. (\£7rac, Gr. lepas, Lat. lepas,
Fr.) Linnaeus included under the name
lepas all the cirripedes or multivalves.
These animals are known in this country
by the name of Barnacles. The lepas, or
barnacle, constitutes a connecting link
between molluscous and articulated ani-
mals ; the gills are attached to the bases
of the cirrhi, or jointed tentacula. In

the Linnsean system, the lepas constitutes
the second genus of multivalve shells.
The animal a triton ; shell affixed at the
base, and consisting of many unequal
erect valves. They are without eyes, or
any distinct head ; have no powers of
locomotion, but are fixed to various bo-
dies. Their body, which has no articula-
tions, is enveloped in a mantle : their
mouth is armed with transverse toothed
jaws in pairs, and furnished with a feeler.
This genus consists of two families, or
divisions, very different in their form, the
first of which is the Balanites, or Acorn-
barnacles, having a shelly instead of a
tendinous tube, with an operculum or lid,
consisting generally of four, but some-
times of six valves, and being of a sub-
conic form. The second family consists
of the Lepadites, or Goose-barnacles, the
specks of which are distinguished by a
tendinous, contractile, and often long
tube or pedicle, which, being of a flexible
nature, allows the animal, fixed by its
base to some solid marine substance, to
writhe about in quest of food. The ani-
mals of this genus have only been found
in the ocean. In Turton's Linne thirty-
two species of lepas are described ; fifteen
of these have been discovered in our seas.
LEPIDODE'NDRON. (from Xeirlg and dsv-
dpov, Gr.) An extinct genus of fossil
plants, of very frequent occurrence in the
coal formation. It is stated by Lindley
and Hutton that plants of this genus are,
next to the calamites, the most abundant
of the fossils in the coal formation of the
north of England. Thirty-four species
are enumerated by M. Ad. Brongniart.
Lepidodendra are sometimes found of
enormous size, fragments of stems occur-
ring upwards of forty feet in length.
Their internal structure has been ascer-
tained to be intermediate between coni-
ferae and lycopodiacese. In some points
of their structure they resemble coniferse,
but in other respects, setting aside their
great magnitude, they may be compared
to lycopodiacese. To botanists, this dis-
covery is of very high interest, as it proves
that those systematists are right, who
contend for the possibility of certain
chasms now existing between the grada-
tions of organization, being caused by the
extinction of genera, or even of whole
orders, the existence of which was neces-
sary to complete the harmony which it is
believed originally existed in the structure
of all parts of the vegetable kingdom.
By means of Lepidodendron, a better
passage is established from flowering to
flowerless plants, than by either equise-
tum or cycas, or any other known genus.
— Lindley and Hutton.

Count Sternberg remarks, that we are

L E P

C 144 ]

L I A

unacquainted with any existing species of
plant, which, like the lepidodendron, pre-
serves at all ages, and throughout the
whole extent of the trunk, the scars
formed by the attachment of the petioles,
or leaf-stalks, or the markings of the ad-
hesion of the leaves themselves.

LE'PIDOIDS. A family of extinct fossil
fishes, found in the oolitic series : they
were remarkable for their large rhomboidal
bony scales, which were of great thick-
ness, and covered with enamel. The
scales of lepidoids had a remarkable struc-
ture in being furnished on their upper
margin with a hook-like process, placed
like the hook or peg near the upper mar-
gin of a roofing tile ; this hook fitted into
a depression on the lower margin of the
scale placed immediately above it. In
order to obtain a correct notion of the
form and appearance of the scales, the
reader is referred to Prof. Buckland's
Bridgewater Treatise, in which they are
very accurately figured.

LEPI'DOLITE. (from XETTIC, a scale, and
Xi'0oc, a stone, Gr.) The Lepidolith of
Werner ; Hemiprismatischer Talk-glim-
mer of Mohs. Lepidolite Mica. A mi-
neral of a peach-blossom, red, and some-
times grey colour, occurring massive and
in small concretions. This mineral, at
first view, appears to be composed of
small grains, sometimes extremely minute ;
but these grains, among which little pearly
scales are often interspersed, are them-
selves composed of a great number of mi-
nute foliae or spangles, like those of mica,
from which circumstance it has obtained
its name. Its constituents have been
variously stated. According to some au-
thors, it contains silica 50'36, alumina
28'32, potash 9'0, oxide of manganese
1*25, fluoric acid and water 5'40, lithion
5'50. It exhibits two axes of double re-
fraction, from which circumstance it has
been called Di-axial mica. From the
beauty of its colour it has been cut into
snuff- boxes.

LEPIDO'PTERA. (from XCTTIC, a scale, and
•n-Tfpbv, a wing, Gr.) Scaly-winged in-
sects. Lepidoptera form the tenth order
of insects in Cuvier's arrangement ; they
have four wings, both sides of which are
covered with small, coloured scales, re-
sembling farinaceous dust. This order
comprises butterflies, moths, and sphinxes.
The scales are attached so slightly to the
membrane of the wing as to come off
when touched with the fingers, to which
they adhere like fine dust. When ex-
amined with the microscope, their con-
struction and arrangement appear to be
exceedingly beautiful, being marked with
parallel and equidistant strive, often
crossed by still finer lines. The former

of these scales are exceedingly diversified,
not only in different species, but also in
different parts of the same insect. The
proboscis of the Lepidoptera is a double
tube.

LEPIDO'PTERAL. ) Belonging to the order

LEPIDO'PTEROUS. { Lepidoptera ; having
wings covered with scales. The progress
of the metamorphoses of insects is most
strikingly displayed in the history of the
Lepidopterous, or butterfly and moth
tribe.

LEPIDO'STEUS. ) (The Lepisosteus of La-

LEPISO'STEUS. $ cepede. ) A genus of
fishes inhabiting the rivers of North Ame-
rica, one of the two living representative
genera of Sauroid fishes. Teeth of a fish
related to Lepidosteus, or Lepisosteus,
have been found in the Tilgate beds and
in those of Stonesfield.

LEPISO'STEUS FITTONI. A species of fossil
Lepisosteus, thus named after Dr. Fit-
ton. Scales with bifurcating processes,
belonging to the Lepisosteus Fittoni, are
very abundantly found in the Tilgate
strata.

LEPIDO'TUS. An extinct genus of fishes
belonging to the oolite series.

LEU'CIN. > (from Xei»Koc, white, Gr.) The

LEU'CINE. \ name given by M. Bracounot
to a white substance obtained from mus-
cular fibre, by treating it with sulphuric
acid, and subjecting it to a peculiar pro-
cess.

LEU'CITE. (from Xev/coc, Gr.) A mineral
of a white colour, found in volcanic rocks.
The Leuzit of Werner ; Amphigene of
Haiiy ; Vesuvian of Kirwan ; Trapezoi-
daler Kuphon-spath of Mohs. Before
the blow-pipe it is infusible, a circum-
stance which serves to distinguish leucite
from the garnet and analcime. Its consti-
tuents are silex 53'75, alumine 24-62,
potash 21 '35. It occurs regularly crys-
tallized ; in granular concretions, and in
roundish grains. It is often embedded
in lava and in basalt. All lavas do not
contain crystals of leucite. In the lava
of Vesuvius they are abundant, but in
that of Etna they are rarely found. Some
authors have supposed that the crystals
of leucite found in lava pre-existed in the
mineral fused by volcanic heat, but that
in consequence of their infusibility these
crystals were not acted on ; others main-
tain that the Leucite has crystallized
within the lava.

LEUCI'TIC. Containing leucite ; resem-
bling leucite.

LEU'TTRITE. A mineral found in Leuttra,
in Saxony, and thus named from that
circumstance. Colour, grayish-white,
tinged in places with an ochreous brown .

LI'AS. A provincial name, now become
conventional amongst geologists, for a

L I B

C H5 ]

L I L

kind of limestone, which, with its asso-
ciated beds, form a particular group of
the secondary series. Mr. Bakewell con-
siders that the name lias was probably
given to this formation by the provincial
pronunciation of the word layers, as the
strata of lias limestone are generally very
regular and flat, and can easily be raised
in slabs from the quarry. " The great
bed of dark argillaceous limestone, di-
vided into thin strata, called lias, is the
best characterized of all the secondary
strata, (except chalk) both by its mineral
characters and the fossil remains im-
bedded in it. The lias cannot be mis-
taken for any of the lower strata ; it
serves as a key to the geology of the
secondary formations in England ; and
the first enquiry which the student should
make, when he is in doubt respecting the
position of any of the secondary beds,
should be, does it occur above or below
the lias ?

When the lias beds are fully developed
with their associated beds of clay, they
form a mass of stratified limestone and
clay, several hundred feet in thickness,
which rests upon the red marl. — Bakewell
Introd. to Geology.

The lias group is placed below the
oolite, and above the variegated sandstone,
in this country ; in France and Germany,
below the oolite and above the Muschel-
kalk. The Muschelkalk has not been
discovered hitherto in England. It is in
the lias that the petrified ink-bags of
Loligo have been found. Proofs are not
wanting of intervals between the depo-
sitions of the component strata of the
lias. Twenty different kinds of ammo-
nites have been discovered in the lias.
Gryphites are so abundant in it, that in
France it has obtained the name of Cal-
caire a Gryphites ; and, indeed, the Gry-
phite appears peculiar to, and character-
istic of, the lias formation.

LI'BER. In botany, a layer on the inner
surface, or that which is contiguous to
the wood, or the bark of trees ; the
innermost layer of the bark. The liber
appears to be formed from the cambium.

LI'GAMENT. (ligamentum, Lat. ligament,
Fr. ligamento, It.) A strong, flexible,
tough, compact, membrane, serving to
keep together certain parts.

" Nothing," says Dr. Roget, " can be
more artificially contrived than the inter-
weaving of the fibres of ligaments ; for
they are not only disposed, as in a rope,
in bundles placed side by side, and appa-
rently parallel, to each other ; but, on
careful examination, they are found to be
tied together by oblique fibres curiously
interlaced in a way that no art can imi-
tate. It is only after long maceration in

water, that this complicated and beautiful
structure can be unravelled."

In conchology, the membranaceous
substance which connects the valves
together ; the true ligament is always
external.

LIGAME'NTAL. ) Composed of ligament ;

LIGAME'NTOUS. $ resembling ligament.

LI'GNEOUS. (ligneus, Lat. ligneux, Fr.
lianeo, It.) Made of wood; resembling
wood ; containing wood.

LIGNI'FEROUS. (from lignum, wood, and
fero, to produce, Lat.) Producing wood ;
yielding wood.

LIGNIFICA'TION. The process of being
converted into wood.

LI'GNIN. ^ From an analysis of lignin by

LI'GNINE. \ Dr. Prout it is found to con-
sist of equal parts of water and carbon.
Lignin is deposited, during the growth of
the plant, with the intention of forming a
permanent part of the vegetable structure
constituting the basis of the woody fibre,
and giving mechanical support and
strength to the whole fabric of the plant.

LIGNIPE'RDOUS. (from lignum, wood, and
perdo, to destroy, Lat.) A term applied
to insects which destroy wood.

LI'GNITE. (from lignum, Lat.) Wood-
coal. Lignite is brown or black. Some
lignite has the appearance of jet, is of a
velvet-black, does not soil the fingers, is
very brittle, and burns with a bright
flame. Lignite is a much more recent
formation than that of common coal. By
some, lignite is considered to be an im-
perfect coal, as wood not yet mineralized,
or passed into a state of coal ; while
others doubt whether lignite ever becomes
true coal. Lignite, like coal, is of vege-
table origin, but it differs in many re-
spects from common coal. There are several
varieties of lignite; these mostly burn
with flame, but they neither swell nor
cake like coal.

LIGNI'TIC. Containing lignite ; resembling
lignite.

LI'GULATE. > (from ligula, a strap, Lat.)

LI'GTJLATED. ] Strap-shaped. A term
applied to the radical florets of compound
flowers, when shaped like a strap or rib-
bon. The projecting parts of the limb of
an irregular corolla are called lips ; when
one lip is very long and narrow, compared
to the length of the tube, the corolla is
called ligulate, or strap-shaped.

LI'GURITE. (from liguria,} A mineral
of an apple-green colour, occasionally
speckled. It ranks as a gem.

LI'LALITE. Another name for the mineral
lepidolite, which see.

LILIA'CEOUS. (liliaceus, Lat.) Resem-
bling a lily ; lily-like. A corolla having
six regular petals is termed a liliaceous
corolla.

L I L

[ 146]

L I M

LI'LY E'NCRINITE. (The encrinites monili-
formis.) So called, because the arms,
when folded, resemble the head of the
lily. This is one of the most beautiful
of the fossil crinnoidea, hitherto found
only in the muschelkalk of the new red
sandstone group. Mr. Parkinson states
that, independently of the number of
pieces which may be contained in the
vertebral column, and which, from its
probable length, may be very numerous,
the fossil skeleton of the superior part of
the lily encrinite consists of at least
twenty-six thousand six hundred pieces.
The body is supported by a long verte-
bral column attached to the ground by
an enlargement of its base. It is com-
posed of many cylindrical thick joints,
articulating firmly with each other, and
having a central aperture, like the spinal
canal in the vertebra of a quadruped,
through which a small alimentary cavity
descends from the stomach to the base of
the column. From one extremity of the
vertebral column to the other, and
throughout the hands and fingers, the
surface of each bone articulates with that
adjacent to it, with the most perfect
regularity and nicety of adjustment.
" So exact and methodical is this arrange-
ment," says Prof. Buckland, in his
Bridgewater Treatise, " even to the ex-
tremity of its minutest tentacula, that it
is just as improbable, that the metals
which compose the wheels of a chronometer
should for themselves have calculated
and arranged the form and number of the
teeth of each respective wheel, and that
these wheels should have placed them-
selves in the precise position, fitted to
attain the end resulting from the com-
bined action of them all, as for the suc-
cessive hundreds and thousands of little
bones that compose an encrinite, to have
arranged themselves, in a position subor-
dinate to the end produced by the com-
bined effect of their united mechanism ;
each acting its peculiar part in harmo-
nious subordination to the rest, and all
conjointly producing a result which no
single series of them acting separately,
could possibly have effected." The pelvis
of the lily encrinite resembles in shape a
depressed vase, and, by some, it is sup-
posed that its upper part was closed by
an integument, in the centre of which
was placed the mouth. The encrinite
differs from the pentacrinite in having its
plates, or vertebrae, rounded, whereas in
the pentacrinite they are pentagonal.

LI'MA. (lima, Lat. a file.) A genus of
shells, placed by Cuvier in the family
Ostracea, order Acephala testacea ; and
by Lamarck in the family Pectenides.
Lima differ from pectens in the greater

length of their shell in a direction per-
pendicular to the hinge ; they have also a
wide opening for the passage of a byssus,
by which they are attached. The lima is
a longitudinal, neaiiy equivalved, eared
bivalve, with "m the beaks separated by a
cavity. Hinge toothless. The hinge-
pit, which receives the ligament, partly
internal and partly external. The lima is
a marine shell, found at depths varying
to thirty fathoms, moored by a byssus.
Lamarck describes five fossil species of
lima found in the neighbourhood of Paris,
namely, L. spathulata, L. balloides, L.
obliqua, L. dilatata, L. fragilis.

LI'MAX. (Umax, Lat. a snail.) The
cochlea terrestris, or snail, so called from
its sliminess.

LIMB, (from limbus, Lat.)

1. An edge or border, as the sun's limb,
the moon's limb, &c.

2. An extremity of the body, as the arm
or leg.

3. In botany, the outer spreading portion
of a monopetalous corolla.

LI'MBILITE. (from Limbourg, in Swabia.)
A compact mineral of a honey-yellow
colour, supposed to be a decomposed
olivine. On exposure to the action of
the blow-pipe, it fuses into a compact,
shining, black enamel.

LIME. The oxide of calcium, one hundred
parts consisting of 72 of calcium, its me-
tallic basis, and 28 of oxygen. Lime does
not exist in a pure state in nature, it has
so strong an affinity for carbonic acid as
to absorb it from the atmosphere, when
it becomes converted into carbonate of
lime, constituting the different kinds of
marble, chalk, and limestone, and form-
ing extensive strata, and the largest
mountain ranges. Lime is a white or
light grey earth, fusible only by the heat
of a galvanic battery, or of a gas blow-
pipe ; it is exceedingly caustic, and if
water be sprinkled upon it, great heat is
produced, the water unites with the lime,
forming a hydrate of lime. Lime is
partially soluble in water, and there is a
singular circumstance connected with
this, namely, that cold water dissolves a
larger proportion than hot water.

LI'MESTONE. A genus of minerals com-
prising many species. Mr. Bakewell ob-
serves, "however various in external
appearance limestone may be, it is, if
pure, essentially composed of 57 parts of
lime and 43 carbonic acid ; but in some
rocks the limestone is intermixed with
magnesia, alumine, silex, or iron. The
specific gravity of limestone varies from
2-50 to 2-80. All limestones may be
scraped with a knife. They are infusible ;
but when impure, by an intermixture
with a portion of other earths, they vi-

L I M

[147]

L I N

trify in burning. All limestones effervesce
when a drop of strong acid is applied on
the surface ; and they dissolve entirely
in nitric or muriatic acid. The specific
gravity, hardness, and effervescence with
acids, taken collectively, distinguish lime-
stone from all other minerals."

Limestone is found in the three great
classes of rocks, primary, transition, and
secondary ; but most abundantly in the
last. It is also not uncommon in alluvial
deposites, and is known by the name of
calcareous tufa.

Mr. Macculloch has attempted to re-
vive the theory of some of the earlier
geologists, that all limestones have ori-
ginated in organized substances. He
says, "if we examine the quantity of
limestone in the primary strata, it will be
found to bear a much smaller proportion
to the siliceous and argillaceous rocks
than in the secondary ; and this may
have some connexion with the rarity of
testaceous animals in the ancient ocean."
He further infers, that, in consequence of
the operations of animals, the quantity of
calcareous earth deposited in the form of
mud or stone is always increasing ; and
that, as the secondary series far exceeds
the primary in this respect, so a third
series may hereafter arise from the depths
of the sea, which may exceed the last in
the proportion of its calcareous strata.
To this Mr. Lyell observes, if these
propositions went no farther than to sug-
gest that every particle of lime that now
enters into the crust of the globe may
possibly in its turn have been subservient
to the purposes of life, by entering into
the composition of organized bodies, I
should not deem the speculation impro-
bable ; but when it is hinted that lime
may be an animal product combined by
the powers of vitality from some simple
elements, I can discover no sufficient
grounds for such an hypothesis, and many
facts which militate against it.

Primary limestone has always a granu-
lar structure ; but the size of the grains is
variable, and seems, in some degree, to
correspond with the relative age of the
mineral. Thus the limestone, which oc-
curs in beds in gneiss, and which is
supposed to belong to the older forma-
tions, has usually a coarse texture, and
large granular concretions. But when
its beds exist in mica slate, or argillite,
its texture, becomes more finely grained,
and its colour less uniform. Transition
limestone has a texture more or less
compact ; its colours are much varie-
gated ; and it often contains petrifac-
tions. Secondary limestone has a com-
pact texture, a dull fracture, and usually
contains shells, and sometimes other or-

ganic remains. It is always stratified ;
but the strata are sometimes inclined,
sometimes horizontal.

Mr. De La Beche states the quantity
of lime in granite composed of two-fifths
quartz, two-fifths felspar, and one-fifth
mica, to be 0'37 ; and in greenstone,
composed of equal parts of felspar and
hornblende, to be 7'29.

LIMN^E'A. } (from Xijw^df , Gr.) A genus of

LIMNE'A. $ fresh-water univalves, placed
by Cuvier in the order Pulmonea, class
Gasteropoda ; and by Lamarck in the
family Limnacea. The Limnea is an
ovato-conical, or turretted univalve. Like
the bulinij it has an oblong spire, and
the aperture higher than it is wide ; but
it may be distinguished from the bulini
by the very oblique fold on the columella.
The Limnea has been found fossil in the
neighbourhood of Paris. The recent Lim-
nea inhabits our lakes and pools ; its
shell is of a light amber colour.

LIM'NITE. A fossil limnea.

LI'MOUS. (from limosus, Lat. slimy.)
Muddy ; slimy.

LI'MPID. (limpidus, Lat. limpide, Fr. lim-
pido, It.) Clear; pure; transparent.

LIMPI'PITY. (limpidite, Fr. limpidezza,
It.) Clearness; pureness ; brightness;
transparency.

LI'MULUS. The Molucca crab. A genus
of crustaceans, or entomostracans, having
a distinct carapace, or buckler, with two
eyes in front of the shield. The limulus
appears to approximate towards the trilo-
bite, and Professor Buckland says, «' the
history of this genus is important, on
account of its relations both to the exist-
ing and extinct forms of crustaceans ;
it has been found fossil in the coal forma-
tions of Staffordshire and Derbyshire ;
and in the Jurassic limestone of Aich-
stadt, near Pappenheim ; a small fossil
species is found in the iron-stone nodules
of Coalbrook Dale. In the genus Limu-
lus there are but faint traces of antennae,
and the shield, which covers the anterior
portion of the body, is expanded entirely
over a series of small crustaceous legs.
Of the tail of the recent limulus, savages
form a point to their arrows ; and when
thus armed, they are much dreaded. The
eggs of the limulus are eaten by the Chi-
nese.

LINE OF BEARING. See Line of Dip.

LINE OF DIP. Strata almost always de-
cline, or dip down to some point of the
horizon, and, of course, rise towards the
opposite point. A line drawn through
these points is called the line of their
dip. If a book be raised in an inclined
position, with the back resting lengthwise
upon the table, the leaves may be sup-
posed to represent different strata, then a

L I N

[148]

L I T

line descending from the upper edges to
the table, will be the line of dip, and their
direction lengthwise will be their line of
bearing.

LINES OF GROWTH. In conchology, those
concentric lines or markings in a shell,
formed by successive layers of shelly
matter, which mark its growth. The
external layer is always the most recent.

LI'NEAR. (linearis, Lat.)

1. In entomology, a figure having the
lateral margins very close together, and
parallel throughout.

2. In conchology, composed of lines ;
being marked with lines.

3. In botany, a term applied to narrow
leaves, when they are of equal breadth
throughout, the two edges being straight,
and equi-distant from each other.

LI'NEATE. (lineatus, Lat.) Marked with
lines ; marked with longitudinal depres-
sions.

LI'NGUAFORM. ) (from lingua, the tongue,

LI'NGUIFORM. ) and forma, shape, Lat.)
Tongue-shaped.

LI'NGUAL. (linguale, Fr. from lingua, a
tongue, Lat.) Pertaining to the tongue,
as the lingual arteries, lingual veins, &c.

LI'NGULA. A genus of bivalves, shells
composed of two valves, nearly equal,
truncated anteriorly ; the hinge having
no teeth : the beak of the valves pointed,
and united to a tendinous tube, serving
for a ligament of attachment. . This is
the only bivalve shell which is pedun-
culated. The recent lingula inhabits the
Indian ocean ; it has thin, horny, and
greenish valves. Linnaeus, who had seen
but one valve of this shell, named it
Patella unguis. Parkinson says it has
not been found fossil, but Mr. Sowerby
mentions that some have been found
fossil in sandy indurated marl, in Dur-
ham limestone, and in alluvium of Suf-
folk.

LI'NGULATE. (lingulatus,'Lat.') Tongue-
shaped ; an epithet for leaves shaped like
a tongue.

LIP. (lippe, Germ.) In conchology, the
outer edge of the aperture of univales.

LI'PPED. Having lips.

LIQ,UEFA'CTION. (iiquefactio, a melting,
Lat. liquefaction, Fr. liquefazione, It.)
The act of melting ; the state of being
melted. This word is sometimes used
synonymously with fusion, sometimes with
deliquescence, and at others with solu-
tion.

LIQ,UEFI'ABLE. That is capable of being
changed from a solid to a fluid state.

LI'CIUEFY. (from liquefio, Lat. liquffier,
Fr. liquefare, It.) To dissolve ; to melt ;
to convert from a solid to a fluid state.

LIQUE'SCENCY. (liquescentia,ljii.t.) Apt-
ness to melt,

LI'RICONITE. (from Xeipog, pale, and
Kovia, sand or dust, Gr.) A name given
to arseniate of copper. It is of a blue
or green colour, and occurs in copper
mines.

LI'THIA. A new alkaline substance, disco-
vered by M. Arfwedson, a Swedish chemist,
in 1818, in the mineral called Petalite.

LI'THIUM. The metallic base of Lithia,
discovered by Sir H. Davy.

LI'THOCARP. (from XiOoQ, a stone, and
KapTrog, fruit, Gr.) Petrified, or fossil
fruit.

LITHO'DENDRON. (from Xi9og, a stone,
and Stvdpov, a tree, Gr.) A name given
to coral, from its likeness to petrified
wood.

LITHO'DOMUS. (from \iOoc, a stone, and
(tejuw, to build, Gr.) A transverse, elon-
gated, cylindrical, marine equivalve. Af-
fixed at first by byssus to rocks, which it
subsequently penetrates, and remains ever
after in the cavity. It is a littoral shell,
found at depths varying to ten fathoms.
A mollusc, which forms holes in stones
and solid rocks, which it effects, not me-
chanically, by boring, but chemically, by
dissolving the rock. Generally used plu-
rally, lithodomi.

LITHO'DOMOUS. Belonging to the genus
Lithodomus.

LITHO'GENOUS. (from \iQog, stone, and
yevvdn), to produce, Gr.) Belonging to
the class of animals which form coral.

LITHOI'DAL. (from XiOoQ, a stone, and
tlSog, resemblance, Gr.) Resembling
stone ; of a stony structure.

LITHOLO'GICAL. (from \i9og, and Xoyi/e6f ,
Gr.) Relating to the science of stones ;
in geology, a term used to express the
stony character or structure of a mineral
mass.

LITHO'LOGY. (from Xi0o£, a stone, and
Xoyof, discourse, Gr. litholooie, Fr. )
That branch of natural history which
treats of stones.

LITHO'LOGIST. (from \i9og and Xoyiort-
Kog, Gr. litholooue, Fr.) One skilled in
that branch of natural history which treats
of stones.

LI'THOMARGE. Called also stone-marrow;
a variety of talc. It has commonly a
fine grain, of a white, gray, yellow, red,
or brown colour, these colours being
sometimes disposed in spots, clouds,
veins, or stripes ; unctuous or greasy to
the touch, and adheres to the tongue. In
water it falls to powder, and does not
form a paste. Specific gravity 2'4. It is
infusible before the blow-pipe. It differs
from potters' clay in not forming a paste
with water. It occurs massive, dissemi-
nated, globular, and in irregular lumps, in
gneiss, porphyry, serpentine, &c.

LITHO'PHAGI. (from XiOo£ and fyayliv, to

L I T

[ 149 ]

L O L

eat, Gr. lithophaye, Fr.) Molluscs which
eat holes in stones and rocks. While the
lithodomi penetrate rocks by chemical ac-
tion, dissolving the stony matter.lithophagi
mechanically perforate, or bore into them.
They belong to Lamarck's family of Li-
thophagidge.

LITHOPHA'GID^. A family of terebrating
bivalves.

LI'THOPHYTE. (from \i9og, a stone, and
0yrov, a plant, Gr. lithopkyte, Fr.)

1 . A stony plant ; a coral.

2. The animal which secretes coral.
LITHO'XYLE. (from \iQoQ, stone, and

%v\ov, wood, Gr.) Silicified wood.
LI'TTORAL. (littoralis, Lat.) Pertaining
to the shore.

LI'TUITE. A fossil shell found in the tran-
sition limestone together with the Ortho-
ceratite. The lituite is a chambered shell,
partially coiled up into a spiral form at
its smaller extremity, its larger end being
continued into a straight cube of con-
siderable length, separated by transverse
plates, outwardly concave, and sepa-
rated by a siphuncle. — Professor Buck-
land.

LITU'OLA. A multilocular univalve ; a ge-
nus of microscopic foraminifera, partly
spiral, the last turn being straight at the
end. They are found both recent and
fossil ; of the latter, Lamarck describes
two species.

LITU'OLITE. A fossil lituola.

LI'ZARD. (lezard, Fr. lucertola, It. la-
certus, Lat.) In Cuvier's arrangement
the lizards form the second genus of La-
certinida. They are distinguished by the
tongue, which is thin, extensible, and ter-
minating in two threads. The extremity
of the palate is armed with two rows of
teeth, which are generally either recur-
vated or conical. Lizards have usually a
single perforated eye-lid, which, when
closed by its orbicular muscle, exhibits
merely a horizontal slit. The body is
naked, with four feet and a tail ; and they
possess the property of reproducing the
tail should it be lost.

LOAM, (lehm, Germ.) An earthy mix-
ture, in which sand and clay form large
proportions: when the compound con-
tains much calcareous matter it is usually
called marl ; a mixture of sand and clay.
Any soil which does not cohere so strongly
as clay, but more strongly than chalk, is
designated loam.

LOA'MY. Containing loam ; of the nature
of loam.

LO'BATE. ^ 1. In entomology, when the

LO'BATED. >• margin is divided by deep,

LO'BED. J undulating, and successive
incisions.

2. In botany, applied to leaves, when the
margins of the segments are rounded ;

according to the number of lobes, the leaf
is termed bilobate, trilobate, &c.
LOBE, (lobus, Lat. lobe,Fr. Joio, It.)

1. A rounded portion of certain bodies,
as the lobes of the brain, the lobe of the
ear, the lobes of the lungs, liver, &c.

2. In botany, the cotyledon of the seed is
also called the lobe.

LO'BULE. The diminutive of lobe; a little
lobe.

LOCOMO'TION. (from /ocwsand motio, Lat.)
The power of moving at will from one
place to another ; of transferring the
whole body from one place to another.
The power of locomotion constitutes the
most general and palpable feature of dis-
tinction between animals and vegetables.
Excepting a few among the lower orders
of the creation, such as molluscs and zoo-
phytes, all animals are gifted with the
power of spontaneously changing their
situation.

LOCOMO'TIVE. Having the power of trans-
ferring itself from one place to another.

LOCUH'CIDAL. In botany, a particular
kind of dehiscence. Some fruits open
by the dividing of each carpellum at its
midrib, so that the dissepiments stick to-
gether, and to two halves of contiguous
carpella ; this is called loculicidal dehis-

LODE, (a mining term.) A word used to
signify a regular vein or course, whether
metallic or not ; but most commonly it
signifies a metallic vein. When the sub-
stances forming the lodes are reducible to
metal, the lodes are said to be alive ;
otherwise, they are termed dead lodes.

Loess. (Germ.) An alluvial tertiary de-
posit, consisting of calcareous loam, oc-
curring in patches between Cologne and
Basle. It encloses freshwater and land
shells, as well as some few mammiferous
remains. Mr. Lyell observes, " the loess
is found reposing on every rock, from the
granite near Heidelberg to the gravel of
the plains of the Rhine. It overlies al-
most all the volcanic products, even those
which have the most modern aspect ; and
it has filled up, in part, the crater of the
Rodenberg; at the bottom of which a
well was sunk in 1833, through seventy
feet of loess. Here, as elsewhere, it is a
yellow loam, with calcareous concretions,
and has not the character of a local al-
luvium.

LOLI'GO. (loliffo, Lat.) A genus of the
family of Sepiae. In the loligo is found
that peculiar provision for defence, the
ink-bag, a bladder- shaped sac, containing
a black and viscid ink, the ejection of
which, by rendering the surrounding
water dark and opaque, defends the ani-
mal from the attacks of its enemies. In
the lias of Lime Regis, ink-bags of the

L O M

[150 ]

LOW

fossil loligo are preserved, still distended,
as when they formed parts of the organi-
zation of living bodies, and retaining the
same juxta-position to an internal rudi-
mentary shell resembling a horny pen,
which the ink-bag of the existing loligo
bears to the pen within the body of that
animal.

LO'MONITE. Diatomous Geolite. Named
after its discoverer, Gillet Laumont. For
a description of this mineral, see Lau-
monite.

LONCHO'PTERIS MANTfi'LLI. A SpCClBS of

fossil fern found in the shales and clays of
Tilgate Forest, and thus named after Dr.
Mantell. It is characterized, says Dr.
Mantell, by the distribution of the ner-
vures of the leaves. This fern probably
did not exceed a few feet in height. The
Lonchopteris Mantelli is very beautifully
figured in Dr. Mantell's Geology of the
South-East of England, and in his Won-
ders of Geology.

LONDON BASIN. The deposits of the Lon-
don basin belong to the eocene period ;
they are aqueous.

LONDON CLAY. This formation consists
of a bluish or blackish clay, lying imme-
diately over the plastic clay and sand,
and is an upper member of the arena-
ceous and argillaceous formation that
covers the chalk. Its thickness is very
considerable, sometimes exceeding 500
feet, but varying from one to five hundred
feet. It contains layers of ovate, or
flattish masses of argillaceous limestone.
These masses, called septaria, are some-
times continued through a thickness of
two hundred feet ; of these Parker's
cement is made. From the London clay
three or four hundred species of testacea

i have been procured, but the only bones of
vertebrated animals are those of reptiles
and fish. Remains of turtles have been
dug out of this deposit at Highgate and
Islington, and some bones of a crocodile
were discovered by Mr. Parkinson ; nau-
tilites also are found in it. The shells of
the London clay mostly belong to genera
inhabiting onr present seas. The Lon-
don clay belongs to the eocene period.

LONGICO'RNES. (from longusand corwM,Lat.
long-horned.) A family of insects in Cu-
vier's arrangement, and so named from the
length of their antennae, which are filiform
and cetaceous, and usually as long, often
longer, than the body of the insect.

LONGIPE'NNES. (from longus and penna,
Lat. long wings.) A family of birds in
Cuvier's arrangement, including those
birds, which, from the great strength of
their wings, are to be met with in all lati-
tudes. They are recognised by the great
length of their wings, whence they de-
rive their name, and by their bill, which

in some genera is hooked at the end, in
others simply pointed.

LONGIRO'STRES. (from longus and ros-
trum, a beak, or bill, Lat.) A family of
birds comprising the waders, or birds with
long bills.

LO'NGITUDE. (longitudo, Lat. longitude,
Fr. longitudine, It.) The distance of any
part of the earth to the east or west of
any place. The meridian passing through
the observatory at Greenwich is as-
sumed by the British as a fixed origin,
from whence terrestrial longitudes are
measured. And as each point on the
surface of the earth passes through 360°,
or a complete circle, in twenty-four hours,
at the rate of 15° in an hour, time be-
comes a representative of angular motion.
Hence, if the eclipse of a satellite happens
at any place at eight o'clock in the even-
ing, and the nautical almanack shows that
the same phenomenon will take place at
Greenwich at nine, the place of observa-
tion will be 15° of west longitude. In
the case of stations differing only in lati-
tude, the same star comes to the meridian
at the same time, but at different altitudes.
In that of stations differing only in longi-
tude, it comes to the meridian at the
same altitude, but at different times.
Supposing, then, that an observer is in
possession of any means by which he can
certainly ascertain the time of a known
star's transit across his meridian, he
knows his longitude; or if he knows the
difference between its time of transit
across his meridian and across that of any
other station, he knows the difference of
longitudes between those two places.

LONGITU'DINAL. (longitudinaire, Fr. lon-
gitudinale, It.) Pertaining to longitude
or length.

In conchology, the length of the shell
from the apex to the base ; thus, longi-
tudinal strise, &c., are those which radiate
from the apex to the base.

LOPHI'ODON. (from Xo<pig and oSovQ, Gr.)
A fossil genus of animals, now entirely
extinct, allied to the tapir, rhinoceros,
and hippopotamus, and connected with
the Anoplotherium and Palseotherium ;
so named from certain points, or emi-
nences, on the teeth. Fifteen species
have beeu discovered in the same fresh-
water formations as contain remains of
the palseotherium.

LOWER CHALK. The chalk formation or
series is generally divided into six distinct
members, namely, the lower green-sand ;
the gault ; the upper green -sand ; the
chalk without flints, or the lower chalk ;
the chalk with flints, or the upper chalk,
and the Maestricht beds. This arrange-
ment is, however, altered by some writers,
inasmuch as a more minute subdivision

LOW

L Y C

of some of the members is concerned, de-
pending on local appearances. Generally
speaking, the lower chalk may be distin-
guished from the upper by the absence of
flints, and by the superior hardness of the
chalk, which is sometimes used for build-
ing-stone. The lower is regularly strati-
fied. In the north of England, Professor
Phillips states, " The lower chalk is of a
red colour, and flints are found in it. The
only mineral found in the lower chalk is
sulphuret of iron. The fossil remains
are very numerous and all of them ma-
rine."

LOWER GREEN-SAND. The lowest member
of the chalk series ; called also Shanklin
sand, from Shanklin, in the Isle of Wight,
and iron-sand. A considerable mass of
green, or ferruginous sands, with layers
of chert, local beds of gault, rocks of
cherty or chalky limestone, and deposits
of ochre and fuller's-earth. In York-
shire, this member of the series is wholly
wanting, but in Lincolnshire it is fully
developed. The lower green- sand is a
marine deposit. In some situations, the
beds of Shanklin, or lower green-sand
admit of a triple division ; the first, or
uppermost, consists of sand, with irregu-
lar concretions of limestone and chert,
sometimes disposed in courses oblique to
the general direction of the strata. The
second consists chiefly of sand, but in
some places is so mixed with clay, or with
oxide of iron, as to retain water ; it is
remarkable for its great variation in its
colour and consistency. The third, and
lowest division abounds much more in
stone ; the concretional beds being closer
together and more continuous. The fos-
sils of the lower green- sand are not so
numerous as those of the lower chalk. It
contains upwards of thirty genera belong-
ing to different classes ; among these may
be enumerated ammonites, nautilus, pa-
tella, turbo, natica auricula, rostellaria,
pileopsis, &c., of the class Mollusca;
corbula, cucullea, gervillia, inoceramus,
lenia, modiola, mytilus, mya, nucula, or-
bicula, pecten, pholadomya, pinna, tellina
thetis, terebratula, trigonia, venus, &c.
of the class Conchifera; dentalium and
vermicularia of Anuelides ; spatangus, of
the class Radiaria, &c., &c.

LO'ZENGED. In entomology, of a quadran-
gular shape, with two opposite angles
acute, and two obtuse.

LUBRI'CITY. (lubricite, Fr.) Smoothness
of surface ; slipperiness. More particu-
larly applied to shells.

LUCU'LLITE. (from Lucius Lucullus, a
celebrated Roman, who is said greatly to
have admired it.) A black variety of
transition limestone, a black marble.

LU'CID. (from lucidus, Lat. lucide, Fr.

lucido, It.) Bright; shining; clear;
pellucid ; transparent.

LUCI'DITY. (lucidite, Fr.) Splendour;
brightness ; transparency.

LU'MBAR. (from lumbus, Lat.) Pertain-
ing to the loins, as the lumbar region,
the lumbar muscles, &c.

LUMINI'FEROUS. (from lumen, light, and
fero, to produce, Lat.) Producing light ;
yielding light.

LU'MINOUS. (luminosus, Lat. lummeux^.
luminoso, It.) Shining; bright; emit-
ting light.

LU'MINOUSNESS. Brightness ; the quality
of shining so as to emit light, or to ap-
pear to do so, as the luminousness of the
sea ; the luminousness of phosphoric bo-
dies.

LU'NATED. (lunatus, Lat.) Crescent-
shaped ; formed like a half-moon.

LU'NULATED. Crescent-shaped ; shaped
like a half-moon ; semilunar.

LU'NULE. In conchology, a crescent-like
mark or spot, situated near the anterior
and posterior slopes in bivalve shells. In
different species of Venus they are pro-
minent ; they are frequently very useful
in assisting to ascertain the species.

LU'NULET. In entomology, a half-moon
shaped spot in insects, of a different
colour from the rest of the body.

LU'TEOUS. (luteus, Lat.) A brownish
yellow, something of a clay colour.

LTJ'TOSE. (lutosus, Lat.) Miry ; covered
with clay.

LUTRA'RIA. A genus of bivalves, placed
by Lamarck in the family Mactracea. A
thin, transverse, inequilateral shell, gap-
ing at the extremities ; two oblique and
diverging hinge-teeth accompanying a
large pit for the cartilage. No lateral
teeth, in which feature it differs from
Mactra. One species, Lutraria com-
pressa, has been found fossil in alluvial
deposits, and another, Lutraria oblata, in
the sandstone of Bognor.

LYCOPODIA'CEA. The club-mosses ; or
club-moss tribe. Plants of an inferior
degree of organization to coniferse, some
of which they greatly resemble in their
foliage. This tribe, at the present day,
contains no species more than three feet
high, while many of the fossil species are
as large as recent coniferse, having at-
tained to the size of forest trees. Their
mode of reproduction is similar to that of
ferns. The affinities of existing lycopo-
diacecs are intermediate between ferns
and coniferse on the one hand, and ferns
and mosses on the other. They are
related to ferns in the want of sexual
apparatus, and in the abundance of annu-
lar ducts contained in their axis ; to coni-
ferae in the aspect of their stems ; and to
mosses in their general appearance. The

L Y C

[ 152 ]

MAC

leaves of existing lycopodiacese are simple,
and arranged in spiral lines around the
stem, and impress on its surface scars of
rhomboidal, or lanceolate form, marked
with prints of the insertions of vessels. —
Buckland. Lindley. Lyell.

LYCOPODI'TES. Fossil plants of the genus
Lycopodium.

LYCOPO'DIUM. A genus of plants of the
club-moss tribe.

LY'DIAN STONE. The Lydischer stein of
Werner ; La pierre de Lydie of Brochant ;
Basanite of Kirwan ; Lydian stone of
Jameson. A variety of siliceous slate ; a
black siliceous flint-slate, called by some
black jasper. It differs but little from
the common variety of siliceous slate.
Colour grayish or bluish-black, some-
times quite black.

LYMN^E'A. See Limneea.

LYMPH. (lympha, Lat. water.) A co-
lourless liquid, found in the lymphatics.

LYMPH OF PLANTS. During the vegeta-
tion of plants, there is a juice continually
ascending from their roots. This is
called the sap, or lymph of plants. From
experiments made by Vauquelin, it was
ascertained that the lymph of the com-
mon elm consisted as follows : — Of 1039
parts, 1027-904 water and volatile matter,
9-240 acetite of potash, 1-060 vegetable
matter, 0-796 carbonate of lime.

LYMPHA'TICS. Minute vessels pervading
every part of the body, absorbing and
conveying the absorbed matter into the
thoracic duct, to be afterwards conveyed
into the blood. The lymphatics are sup-
plied within with valves, and without with
glands.

LY'RATE. (from lyra, a harp, Lat.) Lyre-
shaped ; a term applied to leaves divided
transversely into several segments, the
segments gradually increasing in size as
they approach the extremity of the leaf.

M

MACHAI'RODUS. An extinct animal of the
order Mammalia, referrible to the Mio-
cene period, and allied to the bear.

MACI'GNO. The Italian word for a kind of
stone, a siliceous sandstone sometimes
containing calcareous grains, &c. Macigna
pietra, a very hard stone.

MA'CLE. The Hohl spath of Werner;
Hollow spar of Jameson. Made occurs
only in crystals, the form of which is a
four-sided prism. But each crystal, when
viewed at its extremities, or on a trans-
verse section, is obviously composed of
two very different substances ; and its
general appearance is that of a black
prism, passing longitudinally through the
axis of another prism, which is whitish.
These crystals, often long, are sometimes
very minute ; in some instances their
edges are rounded. The crystals of
Macle present a considerable number of
natural joints, which lead to an octohe-
dron for their primitive form. Macle
scratches glass ; its powder is soft and
unctuous. It is opaque, or sometimes
translucent. Colour white or gray, often
shaded with yellow, green, or red. Spe-
cific gravity 2'94. It is found, generally,
imbedded in black argillaceous slate. —
Cleaveland.

MACLU'REITE. Called also Brucite and
Chondrodite. A mineral occurring in
imbedded grains in small massive pieces,
and in longish granular concretions. Co-
lours yellow, straw-colour, orange, red,
and brown ; translucent ; scratches glass ;
fracture imperfectly conchoidal. Specific

gravity 3'15 to 3'50. It consists of mag-
nesia 54-0, silica 36-60, fluoric acid 4'0,
oxide of iron 2-30, potash 2'0, manganese
a trace.

MACROPO'MA. The name given by M.
Agassiz to a genus of sauroid fishes, the
fossil remains of which have been disco-
vered in the chalk formation. The scales
of the Macropoma are studded with hol-
low tubes, through which, it is stated,
there flowed a fluid which served to lubri-
cate the surface of the body.

MACROPO'MA MANTELLI. A species of
fossil fishes belonging to the genus Ma-
cropoma, found in the chalk near Lewes,
and named after Dr. Mantell. The
length of a specimen figured in Dr. Man-
tell' s Wonders of Geology is twenty-four
inches.

MACRODA'CTYLI. (from /waicpoc, long, and
SctKTvXoG, finger, Gr.) The name given
to a family of birds in Cuvier's arrange-
ment, having very long toes. The coot,
rail, &c. are examples.

MACROSPO'NDYLUS. A fossil saurian found
in the oolite and lias formations.

MACROSTO'MATA. (from juaiepof, long,
and (rro/ia, mouth, Gr.) A family of
univalves, belonging to the order Tra-
chellipoda, comprising the genera Sto-
mata, Stomatella, and Haliotis.

MACROU'RA. (from paKpoQ, long, and
ovpa, a tail.) A family of crustaceans,
including the lobster, prawn, shrimp, &c.
They are so named from their having
a long tail, which is, at least, as long as
the body, and provided at its termination

MAC

C 153]

M A G

with appendages which most frequently
form a fin on each side. This tail is
always composed of seven distinct seg-
ments. Fossil genera of the family Ma
croura have been found in the Muschel-
kalk and in the lias.

MACROU'ROUS. Belonging to the family
Macroura. Five or six genera of Ma-
crourous decapods have been recently ob-
served in the muschel-kalk.

MA'CTRA. (juajcrpa, Gr. mactra, Lat. a
kneading-trough.) Animal a tethys. A
genus of equivalve, inequilateral, trans-
verse bivalves, slightly gaping at the
extremities; the hinge, or middle tooth,
complicated ; lateral teeth rather remote,
compressed, and inserted. Shells of this
genus have only been found to inhabit
the ocean, at depths varying from 0
to twelve fathoms, in sands and sandy
mud. The French naturalists divide
Mactra into two genera, Mactra and Lu-
traria. In Turton's Linne twenty-seven
species are described ; twelve are inhabi-
tants of our seas. The fossil species
belong to the tertiary formations. La-
marck describes one species, Mactra
semisulcata, found in the neighbourhood
of Paris ; and Parkinson mentions one,
found in Essex.

MA-CULA. (macula, Lat. macule, Fr. ma
cula, It.) A spot, generally of a dark
colour.

MA'CULATED. Spotted ; marked with small
spots.

MA'DREPORE. (madrepore, Fr. corps marin
pierreux qui resemble a des rameaux, d.
une vegetation.} Madrepores are stony
polypi, with concentric laminae, resem-
bling stars. In a living state, the stony
matter is covered with a skin of living
gelatinous matter, fringed with little
bunches of tentacula ; these are the po-
lypi : the skin and the polypi contract
on the slightest touch. Madrepores are
sometimes united and sometimes de-
tached ; where the laminae take a serpen-
tine direction they are called meandrina,
or brain-stone.— BaJcewelVs Introduction
to Geology.

The term Madrepore is generally ap-
plied to all those corals which have super-
ficial star-shaped cavities. In the water,
madrepores are invested with a fleshy
covering of various colours ; when the
animal dies this fleshy gelatinous covering
becomes decomposed, and the axis ap-
pears studded over with lamellated cells,
or stars. Madrepores raise up walls and
reefs of coral rocks with astonishing rapi-
dity, in tropical climates.

MA'DREPORITE.

1. Fossil madrepore.

2. A variety of limestone, found in large
rounded fragments, composed of numerous ,

small prisms, nearly cylindrical. Opaque ;
surface dark brown ; fracture conchoidal
and black. Constituent parts, carbonate
of lime 63, silex 13, alumine 10, oxide of
iron 11.

MAE'STRICHT BEDS. The name given to
the uppermost member of the cretaceous
group, from Maestricht, a town of the
Netherlands. The Maestricht beds are
marine, and composed of a soft yellowish-
white limestone, resembling chalk, and
containing siliceous masses, ammonites,
hamites, hippurites, baculites, &c. The
siliceous masses found in these beds are
not composed of black flint, but of chert
arid calcedony. The Maestricht beds re-
pose on the upper chalk with flints. M.
Deshayes has been unable to identify any
of the shells of the Maestricht beds with
those of the tertiary deposites.

MAGI'LUS. A genus of univalve shells be-
longing to the family Cricostomata, ac-
cording to the arrangement of De Blain-
ville, and to the order Tubulibranchiata
of Cuvier. The shell is thick, tubular,
and irregularly contorted, having a longi-
tudinally carinated tube, at first regularly
spiral, and then extending itself in a line
more or less straight. The young of the
genus Magilus has a very thin shell of a
crystalline texture, but, when it has at-
tained its full size, and has formed for
itself a lodgment in a coral, it fills up
the cavity of the shell with a glassy de-
posite, leaving only a small conical space
for its body ; it continues to accumu-
late layers of this material, so as to main-
tain its body at a level with the top of the
coral to which it is attached, until the
original shell is quite buried in this vi-
treous substance. — Roget. Cuvier. Sow-
er by.

MAGNE'SIA. (magnesie, Fr.) An earth
with a metallic basis called magnesium.
Magnesia consists of magnesium 61'4,
oxygen, 38*6. Magnesia is rarely found
pure in a native state. It enters into the
composition of some of the primary rocks,
to which it usually imparts a saponaceous
feel, producing also a striated texture,
and frequently a greenish shade. Mag-
nesia first became known about the be-
ginning of the eighteenth century. Little,
however, was known concerning its na-
ture, till Dr. Black published his cele-
brated experiments on it in 1755. Mag-
nesia may be thus prepared : sulphate of
magnesia, a salt, composed of magnesia
and sulphuric acid, is to be dissolved in
water, and half its weight of potass added.
The potass having a stronger affinity for
the sulphuric acid than the magnesia has,
seizes the sulphuric acid, and the mag-
nesia is precipitated. Magnesia is often
present in the chalk ; some of the strata
x

MAG

[ 154

M A L

in France are said to contain ten per cent,
of magnesia. Magnesia is present in all
the inferior stratified rocks, with the ex-
ception of quartz rock, (without mica,)
and certain eurites, or compact felspars.
In the detrital rocks it is also common,
particularly when mica forms any consi-
derable portion of them. There are few
limestones which do not contain mag-
nesia. It is an essential ingredient of
dolomite, carbonate of magnesia consti-
tuting more than forty per cent, of that
rock. Magnesia is also disseminated
through the waters of the ocean, muriate
of magnesia forming from '004 to '005 of
their mass.

MAGNE'SIAN. Containing magnesia ; re-
sembling magnesia.

MAGNE'SIAN LI'MESTONE. A marine de-
posit, belonging to the new red sandstone
group. It lies above the red conglome-
rate and below the variegated sandstone.
It is composed of carbonate of lime and
carbonate of magnesia. The magnesian
limestone of this country is a dolomite of
a yellow or yellowish-brown colour ; it is
distinctly stratified, the strata varying
from a few inches to several feet in thick-
ness. This deposit is fossiliferous, and
certain shells, products, appear for the
first time in the magnesian limestone.
Magnesian limestone forms the most du-
rable building-stone, and it is of this that
the two new houses of parliament are to
be built. It is to be lamented that Wa-
terloo Bridge was not built of magnesian
limestone instead of felspathic granit,e, a
very perishable kind of stone. Magnesian
limestone is also called zechstein. Where
the magnesia is in excess the land is ste-
rile, but when it is not in excess, the soil
is fruitful, and, as a subsoil, healthful.

MA'GNESITE. A mineral of a white or yel-
lowish-white colour. It occurs massive,
tuberose, reniform, and vesicular. Its
fracture is conchoidal. Opaque. Speci-
fic gravity 2'881 . It is infusible, and be-
fore the blow-pipe becomes so hard as to
scratch glass. It occurs in serpentine.

MAGNE'SIUM. The metallic basis of mag-
nesia, magnesia consisting of magnesium
61-4, oxygen 38-6.

MAGNE'TIC IRON ORE. The Fer oxydule
of Haiiy ; Magnet eisenstein of Werner.
A black ore, possessing a slight metallic
lustre. Occurs regularly crystallized ; in
granular concretions ; massive and disse-
minated. It is magnetic, sometimes suf-
ficiently so to take up a needle. It oc-
curs in beds in primary and transition
rocks. This ore is very common in
Sweden.

MA'GNETISM. (magne'tisme, Fr.) The
tendency of the iron towards the magnet,
and the power of the magnet to produce

that tendency ; the power of attraction.
Very delicate experiments have shewn
that all bodies are more or less susceptible
of magnetism. Many of the gems give
signs of it ; titanium and nickel always
possess the properties of attraction and
repulsion. But the magnetic agency is
most powerfully developed in iron, and in
that particular ore of iron called the load-
stone, which consists of the protoxide
and peroxide of iron, together with small
portions of alumina and silica. A metal
is often susceptible of magnetism if it
contain only the 130,000th part of its
weight of iron, a quantity too small to be
detected by any chemical test. One of
the most distinguishing tests of magnet-
ism is polarity, or the property a magnet
possesses when freely suspended, of spon-
taneously pointing nearly north and south,
and always returning to that position
when disturbed. Induction is the power
which a magnet possesses of exciting
temporary or permanent magnetism in
such bodies in its vicinity as are capable
of receiving it. By this property the
mere approach of a magnet renders iron
or steel magnetic, the more powerfully
the less the distance. Iron acquires
magnetism more rapidly than steel, yet it
loses it as quickly on the removal of the
magnet, whereas the steel is impressed
•with a lasting polarity. There can hardly
be a doubt but that all the phenomena of
magnetism, like those of electricity, may
be explained on the hypothesis of one
ethereal fluid, which is condensed or re-
dundant in the positive pole, and deficient
in the negative. — Mrs. Somerville.

MAIL, (maille, Fr. maglio, It.) Armour
for the defence of the body.

MAI'LED. Protected by an external coat or
covering, of scales or hard substances,
which protects the body.

MA'LACHITE. (malachite, Fr. malachite,
It.) An oxide of copper combined with
carbonic acid. It is of a blue colour, and
occurs in mineral veins and in beds of
gneiss, mica-slate, limestone, red-sand-
stone, &c.

MA'LACOLITE. A variety of augite of a
darkish green colour.

MALACO'STRACAN. Certain orders of
Crustaceans, distinguished by having ses-
sile eyes, imbedded in the substance of
the head.

MALLEABILITY, (malleabilite, Fr.) The
property or capability of being hammered
into different forms without breaking.

MA'LLEABLE. (malleable, Fr. malleabile,
It.) That may be spread out by ham-
mering. Of all the metals, the most
malleable is gold, five grains of which
may be hammered out so as to cover a
surface of 273 square inches, the thick-

M A L

C 155 ]

MAM

ness of the leaf not exceeding s^gth of an
inch.
MA'LLEUS. (malleus, Lat. a hammer.)

1. One of the bones of the ear, thus named
from its supposed resemblance to a ham-
mer.

2. A bivalve shell of the family Malleacea.
MALM ROCK. The name given to a variety

of firestone, a member of the chalk series.

MA'LTHA. A variety of bitumen ; called
also mineral pitch. This substance bears
a considerable resemblance to pitch. Co-
lour black or dark brown. Specific gra-
vity from 1-45 to 2-07.

MA'MMA. (mamma, Lat.) The breast.

MAMMA'LIA. (frommamma, Lat. the breast.
A name given to that class of animals
which suckle their young by teats or nip-
ples.) The highest class of animals is
that which comprehends man, and all
animals which, like man, possess a vivi-
parous mode of generation. These ani-
mals have a heart consisting of four cavi-
ties ; they have hot and red blood. Their
most essential character is that of their
being viviparous, and suckling their young
by teats, and they are thence called Mam-
malia. The mammalia are placed at the
head of the animal kingdom, not only be-
cause it is the class to which man himself
belongs, but also because it is that which
enjoys the most numerous faculties, the
most delicate sensations, the most varied
powers of motion, and in which all the
different qualities seem combined in order
to produce a more perfect degree of intel-
ligence— the one most fertile in resources,
most susceptible of perfection, and least
the slave of instinct. The muscular sys-
tem and the living movements of mam-
malia are more varied than in any other
vertebrated class, for some are organized
to plough the deep or to clamber on the
rocky coasts ; some to burrow in the earth
or to bound over the plains ; some to
gamble on lofty trees or cliffs, or to wing
their way through the air, and these dif-
ferent conditions affect more especially
the organs of motion. The bones of all
the mammalia are nearly of the same
colour and general appearance as those of
man ; they are covered with a periosteum,
and contain marrow, which in the whale
tribe is fluid. The skeleton of mammalia
is divided into head, trunk, and extremi-
ties. Next to man, the ape tribe is found
to have the largest skull in proportion to
the face, but, even in the ape, it is found
to be small when compared with that of
man. The facial angle, which in the adult
European is about 85°, is in the ourang
outang 67°, gradually descending in some
of the monkeys as low as 30°, till among
the other genera of quadrupeds it does
not sometimes exceed 20°. The young

of mammalia are nourished for some time
after birth by milk, a fluid peculiar to
animals of this class, which is produced
by the mammae at the time of parturition,
and remains as long as it is necessary.
Mammalia constitutes the first class of
Spini-Cerebrata or Vertebrata, and this
class has been divided by some into ten
orders.

1. Bimanum, or two-handed ; the
thumbs separate on the superior extremi-
ties only.

2. Quadrumana, or four-handed ; the
thumb, or great toe, capable of being op-
posed to the other fingers or toes on each
of the four extremities. The ape is an
example.

3. Bradypoda, or slow moving animals,
with their bodies generally covered by a
hard crust. The armadillo is an example.

4. Cheiroptera, or animals having their
fingers elongated for the expansion of
membranes, which serve as wings. This
membrane commences at the side of the
neck, extends between the feet and toes,
serves to support them in the air, and
enables such of them to fly as have their
hands sufficiently developed for that pur-
pose. The bat is an example.

5. Glires, or Rodentia. Gnawing ani-
mals, having large incisors in each jaw,
separated from the molars by an empty
space, by which they divide hard sub-
stances. They have no canine teeth ;
they cannot seize living prey nor tear
flesh ; they cannot even, with their teeth,
cut their food, but they gnuw or file it,
hence their name. The squirrel, mouse,
hare, &c., are familiar examples.

6. Ferse, or predaceous and carnivorous
animals. They have large canine teeth,
the molares forming pointed prominences
for tearing and cutting the food. The
bear, hedge-hog, &c., are examples.

7. Solidungula, or Solipeda. Animals
having a single toe, or hoof, on each foot.
These have six incisor teeth in each jaw,
and are all of them herbivorous. The
horse is an example.

8. Ruminantia, or Pecora. The term
ruminantia indicates the peculiar property
possessed by these animals of chewing the
cud, that is, of masticating their food a
second time, by bringing it back to the
mouth after having swallowed it. This
property depends upon the structure of
their stomachs, of which they have four,
the three first being so disposed that the
food may enter into either of them, the
sesophagus, or gullet, terminating at the
point of communication. They have two
toes on each foot, and no incisors in the
upper jaw. The sheep, goat, ox, &c., are
familiar examples.

9. Pachydermata, or Belluae. Thick-

MAM

[ 156]

MAM

skinned animals. Animals of unshapely
form and thick tough hide. They have
more than two toes on each foot, some
having three, four, or five ; some of them
have large tusks, and a proboscis. The
elephant, rhinoceros, hippopotamus, &c.,
are placed in this order.

10. Cetacea. These are mammiferous
animals, destitute of hind feet ; their
trunk terminates in a thick horizontal tail
with a cartilaginous fin. They live in the
sea, and their external form is that of
fishes, the fin of the tail excepted, which
in cetacea is horizontal, while in fishes it
is always vertical. Their respiring by
lungs, instead of gills ; their possessing
warm blood ; their viviparous production ;
and their having mammae with which they
suckle their young, all entitle them to be
placed in the class to which they belong.
The arrangement of mammalia by Cuvier
somewhat differs from the above, and is
as follows : — 1 . Bimana ; 2. Quadrumana ;
3. Carnaria; 4. Marsupialia ; 5. Roden-
tia; G.Edentata; 7. Pachydermata ; 8.
Ruminantia; 9. Cetacea.

As regards the fossil remains of mam-
malia, the only terrestrial mammalia yet
discovered in any secondary stratum, are
the small marsupial quadrupeds allied to
the opossum, which occur in the oolite
formation, at Stonesfieid, near Oxford.
Prof. Buckland observes, in reference to
the secondary series, " With respect to
the state of animal life, during the depo-
sition of the secondary strata, although
the petrified remains of zoophytes, crus-
tacea, testacea, and fishes, show that the
seas in which these strata were formed
abounded with creatures referrible to the
four existing divisions of the animal king-
dom ; still the condition of the globe
seems not yet to have been sufficiently
advanced in tranquillity, to admit of ge-
neral occupation by warm-blooded terres-
trial mammalia." The opinion formerly
entertained was, that during the whole of
the primary and secondary periods, at
least, the class of Mammalia had no ex-
istence, and only came into being during
the tertiary period. But this conclusion,
founded upon the mere want of such re-
mains, was easily seen to be insecure,
and at length proved to be erroneous by
the decision of Cuvier, that certain small
jaw-bones, with teeth, found in the oolitic
system, belonged to viviparous quadru-
peds.

MAMMA'LIAN. Belonging to the class
Mammalia.

MAMMA'LOGIST. (from mamma, Lat. and
Xoyoe, Gr.) One skilled in the study of
mammiferous animals.

MAMM ALI'FEROUS. (from mammalia and
fero, to produce, Lat.) A term applied

to strata containing mammiferous remains.
As the mammaliferous crag of Norfolk,
&c.

MA'MMARY. Pertaining to the mammse, as
the mammary glands, the mammary ar-
teries, &c.

MA'MMIFER. (from mamma, a breast, and
fero, to bear.) All animals having breasts
and suckling their young are included
amongst the mammifers. To these Lin-
naeus assigned the name Mammalia. Cu-
vier, however, called them Mammifera ;
but, as has been observed, there appears
no good reason for altering the original
term.

MAMMI'FEROUS. Having breasts where-
with to suckle their young ; belonging to
the order Mammalia.

MA'MMILLARY. Having small rounded
prominences, or projections something
resembling teats or nipples ; studded with
rounded projections.

MA'MMILLATED. A term, like the one im-
mediately preceding it, applied to certain
appearances observed in minerals, which
have the appearance of small bubbles, or
rounded protuberances. Flint contain-
ing calcedony, is generally mammillated.
In conchology, the apex of a shell
when rounded like a teat, is termed mam-
millated.

MA'MMOTH. (The etymology of this word
does not appear quite agreed on ; some
state it to be from a Russian word, ma-
mant ; some, that it is of Tartar origin ;
others, that it is derived from Behemoth,
an Arabic word, signifying elephant.
Mammut, Germ.) The mammoth ap-
pears to be quite extinct ; from the fossil
remains of it which have been disco-
vered, it appears to have had the feet,
tusks, trunk, and many other particulars
of conformation in common with the
elephant ; but it differed from the elephant
in its grinders. Two species have been
distinguished. The bones of the mam-
moth are found in great abundance in
Siberia, and not only the bones, but por-
tions of the flesh and the skin, and even
whole animals have been found in ice-
bergs and in frozen gravel. Towards the
close of the last century, the entire car-
case of a mammoth was exposed, and at
length fell to the ground from a cliff of
ice and gravel, on the banks of the river
Lena. This animal was nine feet high,
and about sixteen feet in length ; the
tusks were nine feet long. The skin was
covered with hair, and it had a mane
upon the neck.

The mammoth appears to have sur-
vived in England when the temperature
of our latitudes could not have been very
different from what it now is ; for re-
mains of this animal have been found in a

MAM

[ 157]

MAR

lacustrine formation, at North Cliff, in
Yorkshire, in which all the land and
fresh-water shells can be identified with
species now existing in that county. It
is supposed, from the prodigious number
of bones found in certain places, that the
mammoth must have existed in herds of
hundreds, or even thousands. According
to Pallas, there is scarcely a river, from
the Don, or the Tanais, to the extremity
of the promontory Tchuskoinosa, in the
banks of which the bones of the mam-
moth are not most abundant. There are
two large islands near the mouth of the
river Indigerska, which are said to be
entirely composed of bones of the mam-
moth, intermixed with ice and sand.

The grinders of the mammoth are
formed of two substances only ; an inter-
nal bony substance, and a thick covering
of enamel. The form of their crown is
generally rectangular, the crown being
divided by spreading grooves into a cer-
tain number of transverse risings, each of
which is divided, in the contrary direc-
tion, into two large obtuse, and some-
what quadrangular and pyramidical points ;
the whole crown, when not worn, being
beset with large points, arranged in pairs.
In consequence of several of these teeth
being much worn down, not only to the
base of the pyramids, but even so low as
only to leave one square surface edged
with enamel, it has been concluded that
they were used in the trituration of ve-
getable food. M. Cuvier particularizes
three sorts of these grinders ; nearly
square, with three pairs of points, gene-
rally much worn ; rectangular, with eight
points, less worn ; and others with five
pairs of points, and a single smaller one,
scarcely the least worn. Cuvier consi-
dered he had distinguished five different
species.

MANA'TUS. A genus of herbivorous ceta-
cea, placed by Cuvier in the family Ceta-
cea herbivora. The manatus appears to
have inhabited the seas of our latitude
during the Miocene and Pliocene periods.
The recent species are now found near the
coasts and mouths of rivers, in the torrid
zone. They have an oblong body, termi-
mated by an elongated oval fin : the
grinders have a square crown, marked
with two transverse elevations ; they are
eight in number throughout. Lamantin,
a name often given to manatus, is said to
be merely a corruption of Manatus.

MA'NDIBLE. (mandibulum, Lat. a jaw.)
In insects, the upper jaws are called
mandibles ; the under jaws, maxillse. The
mandibles of insects are two strong, cor-
neous, somewhat bent hooks, their inner
margin being more or less dentate ; they
articulate with the cheeks at their broad

basis, move by ginglymus, and are opposed
to each other like the blades of scissors.

MANDI'BULAR. Pertaining to the jaw.

MANGANE'SE. (manganese, Fr. maganese,
It.) A metal but little known in its pure
or metallic state, to which it is reduced
with much difficulty, in consequence of
its great affinity for oxygen. When pure,
it has a grayish -white colour, with some
lustre. Its texture is granular ; hardness,
nearly that of iron. Specific gravity
from 7-0 to 8'0. It has little or no
malleability. It absorbs oxygen by ex-
posure to the atmosphere ; and its melt-
ing point is about 160° W.

In its metallic state, manganese is not
applied to any use. It is obtainable in
small quantities from the black oxide by
heating it in an intense furnace, with char-
coal and a little oil.

The common ore of manganese is the
black, or peroxide, a valuable substance
to chemists, as that from which oxygen is
most easily obtained. When added in
small quantities to glass, it removes the
greenish or yellowish tinge which arises
from iron or other impurities ; but if
added in considerable quantity, it com-
municates to glass or enamel a violet or
purple colour. The ores of manganese
present much diversity in their exter-
nal characters. All minerals containing
any considerable quantity of this metal,
when melted with borax and a little nitre,
yield a violet glass. One of the ores of
manganese, known by the name of Black
Waddj is remarkable for its spontaneous
inflammation when mixed with oil ; the
reason of this does not appear to be un-
derstood.

Oxids of manganese occurs principally,
though not exclusively, in primary and
transition rocks, in nodules or irregular
masses, in veins, and in beds.

Of all the metals, the oxides of which
are neither alkalies nor earths, iron and
manganese are the most important, geolo-
gically considered. It is remarkable that
manganese is almost, though not quite,
as widely disseminated through rocks as
is iron, the proportions, however, being
much smaller. There is scarcely a rock
without iron, and there are very few which
do not afford some trace of manganese : ex-
cept, however, in the places where its
ores are worked, the latter exists only in
minute quantities. Its calculated amount
is greatest in mica slate with garnets,
where, as an oxide, it forms 1*23 per cent,
of the constituent parts of the rocks. —
De La Beche. Cleaveland. Ure.

MANGANE'SIAN. Containing manganese ;
resembling manganese ; having the pro-
perties of manganese.

MA'RBLE. (marbre, Fr. marmo, It. mar-

MAR

[ 158]

MAR

mor, Germ, warmer, Lat.) Any lime-
stone possessing sufficient hardness to
take a polish may be called marble.

MA'RGARATE. A compound of margaric
acid with potash, soda, or some other base,
and so named from its pearly lustre. —
LyelVs Elements.

MARGA'RIC ACID. An oleaginous acid,
formed from different animal and vegetable
fatty substances. — Ib.

MA'RGARITE. A mineral, of a grayish-
white colour, occurring massive and in
thin crystalline laminae, intersecting each
other in all directions. It bears some
resemblance to silvery mica.

MA'RGIN. (marge, Fr. margine, It.) The
border or edge. In conchology, the
whole circumference or outline of the
shell in bivalves.

MA'RGINATE. ) T ,

MA'RGINATED. \™arffznatus, Lat.

1. In conchology^ having a prominent
margin or border.

2. In entomology, when the sharp edge is
margined, and surrounds the surface with
a narrow border.

MARGINE'LLA. An ovato-oblong, smooth,
univalve, with a short spire. The lip
thickly marginated on the outside. The
base of the aperture slightly notched ; the
columella plicated. Marginella differs
from Voluta in the reflection of its outer
lip. Recent marginellse are found in sand
and sandy mud. Several fossil species

• have been discovered in the calcaire gros-
sier.

MARI'GENOUS. (from mare, the sea, and
ffiffno, to produce, Lat.) Produced by or
in the sea.

MARI'NE. (marinus, Lat. marin, Fr. ma-
rino, It.), Belonging to the sea ; relating
to the sea.

MA'RINE ALLU'VIUM. Shingle thrown up
by the sea ; materials cast upon the land
by a wave of the sea, or those which
a submarine current has left in its
track.

MARI'NE VEGETA'TION. The marine ve-
getation, says Mr. Lyell, is less known ;
but we learn from Lamouroux, that it is
divisible into different systems, appa-
rently as distinct as those on the land,
notwithstanding that the uniformity of
temperature is so much greater in the
ocean. The number of hydrophytes, or
plants growing in water, is very consi-
derable, and their stations are found to be
infinitely more varied than could have
been anticipated ; for while some plants
are covered and uncovered daily by the
tide, others live in abysses of the ocean,
at the extraordinary depth of one thou-
sand feet ; and although in such situa-
tions there must reign darkness more
profound than night, at least to our

organs, many of these vegetables are
highly coloured. — Principles of Geology.

MARL, (mergel, margel, Germ.) A com-
bination of common clay and calcareous
earth ; a mixture of clay and lime.

MA'RLY. Composed of marl ; containing
marl ; resembling marl.

MA'RMORATE. } (marmoratus, Lat.) When

MA'RMORATED. $ the markings or lines
are variegated like marble.

MARMORA'TION. Incrustation with marble.

MARSU'PIAL. (from marsupium, a pouch,
Lat.) Having a pouch; belonging to
the order Marsupialia. New Holland is
known to contain a most singular assem-
blage of mammiferous animals, consisting
of more than forty species of the marsu-
pial family.

MARSUPIA'LIA. Animals possessing abdo-
minal pouches. The marsupialia form
the fourth order of Mammalia, in Cu-
vier's arrangement. The economy of
marsupialia is in many respects most sin-
gular. One most striking peculiarity is
the premature production of the foetus,
whose state of ^development at birth is
extremely small. Immediately on their
birth they pass into a sort of second
matrix. Incapable of motion, and scarcely
displaying any germs of limbs or external
organs, these diminutive beings attach
themselves to the mammae of the mother,
where they remain fixed by the mouth,
until they have acquired a growth and
development, resembling that of other
newly-born animals. The skin of the
animal is so arranged round the mammae
as to form a pouch in which not only the
imperfect foetus, attached to the nipple by
its mouth, remains till fully developed,
but into which, long after it is able to run
about, it leaps when alarmed, or when
wishing to conceal itself. The order
Marsupiala holds an intermediate place
between viviparous and oviparous ani-
mals, forming a link, as it were, be-
tween Mammalia and Reptiles. The
order Marsupialia contains many genera,
both herbivorous and carnivorous. The
kangaroo and opossum are familiar ex-
amples. Another peculiarity in these
animals consists in this ; that the mem-
bers of two litters are sometimes sucking
at the same time. The New Holland
opossums are very voracious, and devour
carcasses as well as insects ; they enter
into the houses, where their voracity is
very troublesome. That most common,
the Didelphys Virginiana, attacks poultry
in the night, and sucks their eggs. It is
said to produce sixteen young ones in
one litter, which, when first born, do not
weigh more than one grain each ; though
blind, and almost shapeless, when placed
in the pouch tlx>,y instinctively find the

MAR

[ 159 ]

MED

nipple, and adhere to it till they attain
the size of a mouse, which does not take
place till they are fifty days old, at which
period they begin to see. The discovery
of marsupials, both in tb.3 secondary and
tertiary formations, shows that, so far
from being of more recent introduction
than other orders of Mammalia, this
order is in reality the first and most
ancient condition, xinder which animals
of this class appeared upon our pla-
net.

MA/RSUPITE. (from marsupium, a purse,
Lat.) The name given by Dr. Mantell,
from their resemblance to a purse, to a
genus of Crino'idea found in the chalk. A
specimen of one species, named by him
Marsupites Milleri, found near Brighton,
is beautifully figured in his Geology of
the South-East of England, and in his
Wonders of Geology. The following de-
scription of the marsupite I have ex-
tracted from the. above two works of Dr.
Mantell's : — " The marsupite was a mol-
luscous animal, of a sub-ovate form, hav-
ing the mouth in the centre, and sur-
rounded by arms, or tentacula. The
skeleton was composed of crustaceous,
hexagonal plates ; the arms, which are
subdivided into numerous branches, of
ossicula, or little bones : the whole was
invested with a muscular tissue, or mem-
brane. When floating, the creature could
spread out its tentacula like a net, and by
closing them, seize its prey, and convey
it to its mouth. The fossil remains of
this zoophyte, of which one species only
is known, have hitherto been found in
the upper chalk of Sussex, Wiltshire, and
Yorkshire only. The name of ' cluster-
stones,1 given to them by the quarry-
men of Sussex, conveys an idea of their
general appearance. They may, how-
ever, so far as their body is concerned, be
compared to the fruit of the pine. The
body is orbicular, contained in a pelvis
composed of sixteen convex, radiated,
angular, crustaceous plates."

MARSU'PIUM. The name given to a dark-
coloured membrane situated in the vitre-
ous humour of the eye of birds. The
use of the marsupium is not ascertained,
but it is present in almost every bird hav-
ing extensive powers of vision.

MA'SCAGNINE. A native sulphate of am-
monia, found, by Mr. Mascagni, near the
warm spring of Sasso, in Tuscany, and
named after its discoverer. It has also
been called Sassolin, from the place near
which it was found.

MA'SSETER. (from /^ao-ffaojucu, Gr. to
chew.) A muscle connected with the
under jaw of insects, and which assists in
masticating.

MA'STODON. (from naorbq, a breast, and

6£ou£ , a tooth, Gr.) For a full descrip-
tion of the Mastodon, see Mammoth.

MA'STOID. (from juaoro^, the breast, and
£i£oc, likeness, Gr.) Shaped like the
breast, or like a nipple. Applied to
some prominences of bones ; to a fora-
men ; to a muscle ; and to cells in the
ear.

MA'TRIX. (matrix, Lat. matrices, pi.)
The earthy or stony matter in which a
fossil is imbedded.

MAXI'LLA. (maxilla, Lat.) The jaw.
The lower jaws of insects are called
maxillae ; they are placed behind the
mandibles, and between is situated the
labium, or lower lip. The maxillae are
employed principally for holding the sub-
stanCes on which the grinding apparatus
of the mandible is exerted.

MA'XILLARY. Belonging to the maxilla, or
attached to it.

MAW. (magen, Germ*) The craw of
fowls ; the stomach of brutes.

MEANDRI'NA. Brain-stone ; brain-coral.
Madrepores in which the laminae assume
a meandering direction are called mean-
drinse. Meandrinse are large hemis-
pherical corals, having their surface co-
vered with serpentine ridges and depres-
sions, resembling the convolutions of the
cerebrum, or brain, from which circum-
stance they have been called brain-stone.
A very fine specimen, four feet in -cir-
cumference, may be seen in the British
Museum, presented by the late Dr. Jar-
vis, of Margate.

MEA'TUS. (meatus, Lat. from meo, to
flow.) A passage, as that leading to the
ear, called the meatus auditorius, &c.

MECHA'NICAL ORIGIN. A term used, says
Mr. Lyell, to distinguish rocks of sand,
pebbles, or fragments, from those of
chemical origin ; or such rocks as are of a
uniform crystalline texture.

MEDU'LLA. (medulla, the marrow, Lat)

1. In botany, the pith of plants.

2. The marrow in the cavities of bones.
MEDU'LLARY. (medullaris, Lat.)

1. Relating to the brain, or to the marrow.
The medullary substance composes the
greater part of the brain, spinal marrow,
and nerves.

2. In botany, relating to the pith of
plants .

MEDU'LLIN. A name given by Dr. John to
the porous pith of the sun-flower.

MEDU'SA. A genus of marine molluscous
animals belonging to the class Acalepha.
The medusa approach nearly to the fluid
state, appearing like a soft and trans-
parent jelly, which by spontaneous de-
composition after death, or by the appli-
cation of heat, is resolved almost into a
limpid watery fluid. The usual form of
a medusa is that of a hemisphere, with a

MED

[ 160 ]

MEL

marginal membrane, like the fold of a
mantle, extending loosely downwards from
the circumference.

Medusae are met with of very various
sizes ; the larger abound in the seas around
our coasts, but immense numbers of the
more minute, and often microscopic, species
occur in every part of the ocean. In some
parts of the Greenland seas the number of
Medusae is so great, that in a cubic inch,
taken up at random, there are not fewer
than 64. In a cubic foot this will amount
to 110,592 ; and in a cubic mile, the num-
ber is such, that allowing one person
to count a million in a week, it would
have required 80,000 persons from the
creation of the world, to complete the
enumeration. — Dr. Roget. Dr. Kidd.

MEGALO'NYX. (from p-eyag, great, and
ovvZ,, a claw, Gr.) A huge fossil mam-
malian, of the order Edentata, and thus
named from the great size of its unguical,
or claw, bones. The remains of the
Megalonyx were discovered in the floor of
a cavern, in the limestone of Virginia, in
America.

MEGAH'CHTHYS. (from /i£ycrc> great, and
t%0iic., a fish, Gr.) The name given to a
fossil sauroid fish, first discovered, by Dr.
Hibbert, in the limestone near the bottom
of the coal formation, near Edinburgh.
Specimens of Megalichthys have since
been obtained by Sir P. Grey Egerton,
Mr. Austin, and Mr. Murchison, in the
coal formation.

MEGALOSAU'RUS. (from /jsyac;, great, and
ffavpog, a lizard, Gr. ) A genus of fossil
amphibious animals, of great size, belong-
ing to the saurian tribe. This genus was
established by Professor Buckland. Cu-
vier concludes, from a comparison of the
fossil bones with those of existing lizards,
the megalosaurus to have been an enor-
mous reptile measuring from forty to
fifty, or even seventy, feet in length, and
partaking of the structure of the croco-
dile and monitor. Remains of the mega-
losaurus have been found in the Oolite
and in the Wealden. This huge creature
appears to have been carnivorous, from
the form of its teeth, and its head termi-
nated in a straight and narrow snout.

MEGAPHY'TON. (from ftsyac., great, and
0vroj/, a plant.) An extinct genus of
plants belonging to the order Conifera.
In the genus Megaphyton the stem is not
furrowed, and the leaf scars are very
large, resembling the shape of horse-
shoes, and arranged on each side of the
stem in two vertical rows. It is found in
the coal strata.

MEGATHE'RIUM. (from [isyag, great, and
Oijplov, a beast, Gr.) An extinct animal,
of great size, belonging to the order Eden-
tata. Fossil remains of the Megatherium

have been discovered in South America,
in the alluvial deposites of the Pampas.
The Megatherium was about eight feet
high, and its body twelve feet long ; it
united part of the structure of the arma-
dillo with that of the sloth. The relative
proportions of the extremities of the me-
gatherium differ greatly from those of
the sloth, and indeed from those of any
known animal. Its teeth prove that it
lived on vegetables, and its fore-feet,
robust, and armed with sharp claws,
show that roots were its chief objects of
search. Its hide appears to have been
covered with a bony coat of armour of
considerable thickness, the use of which
was probably defensive, not only against
the sharp claws of beasts of prey, but
also against the myriads of insects that
surrounded it. " Secure within the pano-
ply of his defensive armour," says Pro-
fessor Buckland, " where was the enemy
that would dare encounter this behemoth
of the Pampas ? a creature whose giant
carcase was encased in an impenetrable
cuirass, and who, by a single pat of his
paw, or lash of his tail, could in an instant
have annihilated the couguar or the cro-
codile."

MEI'ONITE. (from ptiuv, less, Gr.) The
Meionit of Werner. A mineral, thus
named from its terminating pyramids
being lower than those of similar forms in
the other minerals. Meionite much re-
sembles Wernerite in the measures of its
angles, but the terminating faces of Wer-
nerite stand on the lateral faces of the
primitive form, whereas in the meionite
they correspond to the truncated lateral
edges of the primitive form. Meionite is
a prismato -pyramidal felspar. It occurs
in grains, or small crystals, whose more
common form is an eight-sided prism,
truncated on its lateral edges, and termi-
nated by four low-sided pyramids. It is
of a greyish-white colour ; translucent
and sometimes transparent. It scratches
glass, and before the blow-pipe readily
melts into a white spongy glass. It is
found at Mount Somma, near Vesuvius.

MELA'NIA. (from fttXag, black, Gr.) A
genus of univalve fresh-water shells be-
longing to the order Pectinibranchiata,
class Mollusca. The melania is a tur-
reted univalve ; the aperture entire, ovate,
or oblong, and spread out at the base of
the columella, which is smooth. Recent
melanise are found in rivers and estuaries.
Fossil melaniae are found in the environs
of Paris. Lamarck describes twelve spe-
cies.

ME'LANITE. (from jutXerf, black, Gr.)
The Melanit of Werner ; Grenat noir of
Haiiy ; Grenat melanit of Brongniart. A
velvet-black, opaque, dodecahedral variety

MEL

[ 161 ]

M E N

of garnet. It occurs in crystals, which
are dodecaedrons, with truncated edges.
Fracture conchoidal. Specific gravity
3' 73. Its constituents are silex 35 -5,
lime 32-5, oxide of iron 25*25, alumine
6-0, oxide of manganese 0'4. It is found
at Frascati, near Mount Vesuvius, in Bo-
hemia, and in North America.

MELANO'PSIS. A genus of oval or oblong,
fusiform, univalves, belonging to the fa-
mily Melaniana, in Lamarck's arrange-
ment. Melanopsides are found both re-
cent and fossil ; they are distinguished
from Melanise by a notch in the aperture.
Fossil melanopsides are found in the shale
of the Wealden, at Pounceford.

ME'LAPHYRE. A variety of black or py-
roxenic porphyry.

MELASTO'MA. (from /*£\ae, black, and
orojita, mouth, Gr.) A name given to a
genus of plants, belonging to the order
Melastomacea, from the fruit staining the
lips of a black colour.

MELEAGRI'NA. A genus of bivalve mol-
luscans, known as the pearl-oyster. Me-
leagrina inhabit the Persian Gulf, the
coasts of Ceylon, the sea of New Hol-
land, the Gulf of Mexico, and the coasts
of Japan. It attains perfection nowhere
but in the equatorial seas, but in the pearl
fishery of the island of Ceylon it is the
most celebrated and productive. The
pearls are situated in the fleshy part of
the oyster, near the hinge. For one
pearl that is found perfectly round and
detached between the membranes of the
mantle, hundreds of irregular ones occur
attached to the interior of the shell, like
so many warts : they are sometimes so
numerous, that the animal cannot shut
its shell, and so perishes.

ME'LITA. (from mel, honey, Lat.) Honey-
cake. A genus of echinites, belonging to
Catocysti.

ME'LLATE. The name given to a salt, in
which the mellitic acid is combined with
any salifiable base.

ME'LILITE. (from jus'Xt, honey, and Ai'0o£,
a stone, Gr.) The name given to a rare
mineral from its honey colour. It occurs
only in very minute crystals, perfectly
regular and well-defined, but not larger
than a grain of millet- seed. These grains
are of a cubic or prismatic form ; their
surface is often coated with an oxide of
iron. They are glistening, semitranspa-
rent, and will scratch glass. Before the
blow-pipe, melilite fuses into a compact,
greenish, transparent glass. It occurs in
the fissures and cavities of lava.

ME'LLITE. (from mel, honey, and XiQog, a
stone.) Honey-stone. The Honigstein
of Werner ; La Pierre de mi el of Bro-
chant ; Pyramidales Melichron-Hartz of
Mohs. This mineral was first observed

in Tlmringia, where it occurs associated
with brown coal. It is of a honey-yellow
colour, whence its name, and is usually
crystallized in small octahedrons, whose
angles are often truncated. Fracture
conchoidal. Lustre shining or splendent.
By friction the crystals acquire a weak ne-
gative electricity. They are more or less
translucent, or even transparent, and ex-
hibit double refraction. Mellite may be
distinguished from amber by its weak elec-
tricity, and double refraction. It consists
of mellitic acid 41 -0, alumina 14 '10,
water 44*8.

MEMBRANA'CEOUS. (membranaceus, Lat.)
Resembling membrane. In botany, a
membranaceous leaf has no distinguish-
able pulp between the two surfaces.

MEMBRA'NEOUS. (membraneux, Fr. mem-
branoso, It. membraneus, Lat.) Con-
sisting of membrane. In this and the
preceding word may be observed the dif-
ference between words ending in aceus
and eous : those ending in aceous express
a resemblance to a material, those ending
in eous indicate the material itself.

ME'MBRANE. (membrana, Lat. membrane,
Fr. membrana, It.) The membranes of
animals are thin semitransparent bodies,
which envelope certain parts of the body,
to which they furnish a covering for their
support and protection. Membranes are
modifications of cellular texture, the sur-
faces of the plates cohering so as to obli-
terate all the cellular interstices, and
being impervious to fluids. Membranes
also line the interior of all the large cavi-
ties of the body ; these membranes, after
lining the sides of their respective cavi-
ties, are reflected back upon the organs
which are enclosed in those cavities, so
as to furnish them with an external co-
vering. Thus the bowels are covered by
the peritoneum, the lungs by the pleurae ;
nevertheless, in consequence of these
membranes being reflected, the lungs and
bowels may be said to be external to their
investing membranes.

ME'MBRANOUS. Consisting of membrane ;
resembling membrane. In botany, ap-
plied to leaves of an extremely thin and
pliable texture ; also to stems of a delicate
substance, composed of several thin mem-
branes laid one over the other ; opposed
to herbaceous.

ME'NACHINE. (from Menachan, a valley
in Cornwall.) The name given to a new
metal, discovered by Mr. Gregor, to
which the name titanium is now more ge-
nerally applied. The menacMne of Gregor
and the titanium of Klaproth are the
same substance, and to Gregor is owing
the merit of the discovery. See Tita-
nium.

ME'NACHANITE. (from Menachan, in

Y

MEN

[ 162 ]

M E R

Cornwall.) An oxide of titanium, or
menachine, combined with iron. This
substance is found abundantly in the val-
ley of Menachan, in Cornwall, and was
thus named by its discoverer, Mr. Gregor.
It is of a greyish-black colour, and occurs
in small grains resembling gunpowder, ol
no determinate shape, and mixed with a
fine grey sand. Specific gravity 4'4.
Before the blow-pipe it neither decrepi
tates nor melts. According to the analy
sis of Klaproth it consists of oxide of iron
51-00, oxide of titanium 45'25, silica
3-50, oxide of manganese 0'25.

ME'NILITE. (from Menil-montant, near
Paris, where it is found.) The Menilit
of Werner ; Silex menilite of Brongniart ;
Quartz resinite subluisant of Haiiy. A
brown or yellowish-grey tuberose variety
of uncleavable quartz. Menilite occurs
in small irregular or roundish masses,
often tuberose, or marked with little
ridges on its surface. It is translucent,
often only at its edges. Structure rather
slaty ; fracture conchoidal or splintery.
It scratches glass. Specific gravity 2' 18.
Infusible before the blow-pipe. Con-
stituents, silica 85'5, alumine 1"0, lime
0*5, oxide of iron 0*5, water and carbona-
ceous matter ll'O.

MENI'NGES. (from prjviyZ, Gr. a mem-
brane.) A name given to the membranes
which cover the brain.

MENI'SCUS. (from fjuqviaicog, Gr.) A lens,
one of whose surfaces is convex and the
other concave, and in which the two sur-
faces meet if continued. As the convexity
exceeds the concavity, a meniscus may be
regarded as a convex lens.

ME'NSTRUUM. A solvent.

MEPHI'TIC. (mephitis, Lat.) Offensive
to the smell ; noxious ; pestilential.

MEPHI'TIC A'CID. Another name for car-
bonic acid.

MEPHI'TIC AIR. Another name for nitro-
gen gas.

ME'RCURY. (mercure, Fr. mercurio, It.)
One of the fifty-five simple or elementary
bodies. This metal is of the same colour
as burnished silver ; when pure and fluid,
it is still opaque, and nearly silver-white,
with a strong lustre. Its specific gravity
is 13-56, or thirteen times and a-half
heavier than water, its density being next
to those of platinum and gold. Mercury
fuses at a temperature of 39° or 40° below
the zero of Fahrenheit, that is, at a tem-
perature of 71° below the freezing point
of water Mercury, which when exposed
to a lower temperature is a solid body,
becomes fluid : consequently under com-
mon circumstances we always find it fluid,
and in this respect it remarkably differs
from all the other metals. It has obtained |
its name from its fluidity and colour. The !

boiling point of mercury is somewhere
about 680°, at which temperature it is con-
verted into vapour of a highly expansive
power ; this vapour may be again con-
densed into the fluid metal, by being re-
ceived into cold vessels. Geoffrey in-
closed a quantity of mercury in an iron
globe, strongly secured by iron hoops, and
put the whole into a furnace ; soon after
the globe became red-hot it burst with
the violence of a bomb, and all the mer-
cury was dissipated.

Mercury has less affinity for oxygen
than most other metals ; it may be dis-
tilled over five hundred times, without
loss of quantity. It combines, however,
with oxygen in two proportions, forming
a red and a black oxide. By merely
heating these in a retort the oxygen may
be driven off, and the metal once more
obtained in its pure state.

The existence of mercury, even in small
quantities, in any of its ores, may be as-
certained by mingling the ore with iron
filings, and heating this mixture to red-
ness under any cold body, as a plate of
polished copper ; the mercury is vola-
tilized, and condensed in minute globules
on the plate. In consequence of the vo-
latility of mercury, it is usually purified
by distillation.

Two of the combinations of mercury
with chlorine form most valuable and
important medicines ; the one called
chloride of mercury, or calomel, the other
bichloride of mercury, or corrosive subli-
mate. From the fluid state in which
mercury exists, it readily combines with
most of the metals, to which, if in suffi-
cient quantity, it imparts a degree of
fusibility or softness : these compounds
are termed amalgams. An amalgam of
mercury and tin is employed for silvering
the backs of looking-glasses, and an
amalgam of four parts of mercury, two
of bismuth, one of lead, and one of tin, is
used for silvering the inside of glass
globes, the amalgam fusing on the globe
being placed in hot water. The ready
combination of mercury with gold or sil-
ver, and the facility with which it may be
again separated from them by heat, ren-
ders it of great value in the obtaining
those metals from their ores and alloys in
the operations of mining.

Mercury is also most useful in the con-
struction of barometers and thermome-
ters. It was known in the remotest ages,
and seems to have been employed by
the ancients in gilding, and in separating
gold from other bodies, as in the present
day. It possesses neither taste nor smell.
Native mercury occurs in small globules,
disseminated in other metals. These
globules are but feebly united to their

M E R

C

gangue, and may be liberated by striking
or heating the substance which embraces
them. It is from the sulphuret of mer-
cury that the metal is principally ob-
tained. Sulphuret of mercury occurs in
beds, or large irregular masses, and some-
times in veins. The mines which fur-
nish the ore, sulphuret of mercury, are
by no means common ; Spain, Germany,
and Peru possess the most important.
In Spain, at Almaden, these mines are in
a mountain of argillaceous slate or shale.
The most celebrated, however, are at
Idria ; these are situated partly in gray
compact limestone, and partly in shale.
The working these mines is exceedingly
injurious to the health and life of those
employed. Criminals, and those con-
victed of political offences, are sent hither
to eke out a miserable existence. They
soon lose their teeth, and are subject to
paralysis, convulsions, and premature old
age. It is said that the surrounding dis-
trict is so affected by the noxious vapours,
that cattle cannot be reared there, and that
fruit and grain do^not come to maturity.

ME'SENTERY. (ntvivrkpiov, Gr. from
/igoroc, middle, and tvrfpov, bowel.) A
fatty membrane formed of folds of the
peritoneum. This is a fine and delicate
membrane which connects the intestines
to the spine, and which appears to be
interposed in order to allow to the intes-
tines that freedom of motion which is so
necessary to the proper performance of
their functions.

MESENTE'RIC. Pertaining to the mesentery,
as the mesenteric glands, &c.

MESOTHO'RAX. (from /^e<roc, middle, and
9d)pa%, chest.) In entomology, the meso-
thorax gives origin to the second pair of
legs, and also the first pair of wings, or to
the elytra, of insects.

ME'SOTYPE. (from ^sdoc, middle, and
rwTroc, form.) Prismatic zeolite ; a simple
mineral of the zeolite family, occurring
in drusy cavities, or in veins in secondary
trap rocks. The Prismatischer Kuphon-
spath of Mohs. Mesotype is of a white,
red, yellow, or yellowish-brown colour.
It occurs regularly crystallized. It con-
sists of silica 54'40, alumina 19'75, soda
15-05, lime 1*60, water 9*80. Specific
gravity 2*3.

METACA'RPAL. (from /utrd, with, and
KapTrbQ, the wrist.) Belonging to the
metacarpus; as the metacarpal bones, &c.

METACA'RPUS. (from fierd, Yfith, and
KapTTog, the wrist.) That part of the
superior extremity which connects the
•wrist with the fingers ; what is commonly
known as the hand, but not including
either the wrist or the fingers.

METABO'LIANS. (from /isra/SaXXw, Gr. to
change.) That sub-class of insects which

I] MET

undergo a metamorphosis, and are usually
fitted with wings in their final state. The
insects of the class Condylopes may be
divided into two sub-classes, namely,
Ametabolians, or those that do not un-
dergo any metamorphosis, and have no
wings ; and Metabolians.
ME'TAL. (fj,kra\\ov, Gr. metallum, Lat.
mttal, Fr. metallo, It. metall, Germ.)
Metals, as presented by nature, are some-
times pure, or combined with each other
only, and are said to exist in a metallic
state. But more frequently they are
combined with oxygen, sulphur, &c., by
which their peculiar metallic properties
are more or less disguised ; in this case
the metal is said to be mineralized, and
the oxygen, or sulphur, is called the mi-
neralizer. All the individuals of the class
of metals, with the exception perhaps of
iron, are perfectly inert and harmless ;
even arsenic, lead, copper, and mercury,
which in certain states of combination
constitute some of the most virulent of
known substances, exert no action upon
the living system, unless they be in union
with some other body ; but when so
united, how valuable do they become, and
what various medicinal effects may they
not be made to produce ! The metals at
present known are forty-three in number.
Of these, seven were known in the earliest
ages, and, in consequence of a supersti-
tious belief in the influence of the stars
over human affairs, were first distinguished
by the names and signs of the planets ;
and as the latter were supposed to hold
dominion over time, so were astrologers
led to believe that some, more than others,
had an influence on certain days of the
week ; and, moreover, that they could
impart to the corresponding metals con-
siderable efficacy upon the particular days
which were devoted to them. As regards
the ages of metals, tin, molybdena, tung-
sten, and wolfram, are ranked as the most
ancient ; uranium and bismuth succeed.
Gold and copper are deemed relatively
and comparatively as new metals. Iron
is of all ages. The specific gravity of
metals, if we exclude those recently dis-
covered by Sir H. Davy, is always greater
than that of minerals ; tellurium, the
lightest metal, being above 6*0, while the
heaviest earthy body is less than 5'0.
Metals are opaque ; they possess a pecu-
liar lustre, which has been termed metallic
lustre, retaining it even when reduced to
powder. They are mostly malleable, or
capable of being hammered into various
orders and thin leaves ; and ductile, or
capable of being drawn into wires of
greater or less fineness. They are not
soluble in water. They all unite with
oxygen, and, probably, all with chlorine.

MET

[ 164 ]

MET

They are fusible, or capable of being ren-
dered fluid by a heat attainable by artifi-
cial means ; becoming again solid on cool-
ing. They are elastic, hard, heavy, and,
generally, sonorous. Some of the metals
possess a degree of taste and smell. All
the metals are expansible by heat, and
their degree of expansibility appears to
bear a relation to their fusibility.

META'LLIC. ^ (metallicus, Lat. metal-

META'LLICAL. S lique, Fr. metallico, It.)
Partaking of metal ; consisting of metal ;
containing metal ; resembling metal.

META'LLIC BEDS. Some metallic ores oc-
cur in the form of beds in primary and
transition rocks. Iron ore often forms
beds of considerable thickness, interposed
between rocks of gneiss, slate, and mica
slate. The difference of external character
is so great between a pure metal and an
earth, that it is difficult to conceive, at
first, how metallic matter can form beds
interstratified with earthy rocks ; the dis-
coveries, however, of modern chemistry
have shown, that metallic and earthy mi-
nerals are closely allied. — BakewelL

META'LLIC LU'STRE. One of the most
conspicuous properties of metals is a par-
ticular brilliancy which they possess, and
which has been called the metallic lustre.
There are other bodies which apparently
possess this peculiar lustre, as, for exam-
ple, mica, but in them it is confined to
the surface, and accordingly disappears
when they are scratched, whereas it per-
vades every part of metals.

META'LLIC ORE. Metals existing in the
state of an oxide, or a salt, or united with
a combustible, are called ores / and this
term is, by analogy, extended to the na-
tive metals and alloys.

The earthy, stony, saline, or combusti-
ble substance, which contains the ore, or
is only mingled with it, without being
chemically combined, is called the gangue,

. or matrix, of the ore.

Metals and their ores, are sometimes
disseminated in other rocks; sometimes
they form irregular masses of various
sizes, and sometimes they constitute beds ;
but more frequently they are found in
veins, either filling the whole vein, or
mixed with various saline and earthy mi-
nerals. They appear to be the production
of every period, but more frequently exist
in primary and transition, than in secon-
dary rocks, or than in alluvial earths.

META'LLIC O'XIDE. A metal combined with
any proportion of oxygen, is called a
metallic oxide, provided it do not possess
the properties of an acid. Hence the
same metal, by uniting with different
quantities of oxygen, often furnishes two
or more oxides, which differ in colour and
in other properties. All metals must be

converted into oxides, before they can
combine with acids to form metallic salts.
— Cleaveland.

META'LLIC SALTS. Those salts which have
a metallic oxide for their base ; carbonate
of lead is an example.

METALLIC VEINS. " Perhaps," says Mr.
Bake well, " the reader may obtain a clearer
notion of a metallic vein, by first imagin-
ing a crack or fissure in the earth, a foot
or more in width, and extending east and
west on the surface, many hundred yards.
Suppose the crack, or fissure, to descend
to an unknown depth, not in a perpendi-
cular direction, but sloping a little to the
north or south. Now, let us suppose each
side of the fissure to become coated with
mineral matter, of a different kind from
the rocks in which the fissure is made,
and then the whole fissure to be filled by
successive layers of various metallic and
mineral substances ; we shall thus have a
type of a metallic vein. Its course from
east to west is called its direction, and
the dip from the perpendicular line of
descent, is called its hading." — Introduc-
tion to Geology.

While plain countries are utterly desti-
tute of all indications of metallic veins,
there are few mountainous countries ia
which they do not occur in abundance.

" There is a remarkable circumstance,"
says Prof. Phillips, " in the distribution of
metallic veins in the same class of strati-
fied rocks, — a peculiarity depending on
local influences ; such, that while the
slates of Cornwall near the granitic erup-
tions, yield tin and copper, and the Snow-
donian slates, and those of Coniston
Water Head yield copper ; those of
Loweswater, Borrowdale, Patterdale, and
Caldbeck fells yield lead, or lead and
copper."

METALLI'FEROUS. (from metallum, metal,
and fero, to produce.) Yielding metal,
as metalliferous deposits, metalliferous
districts, metalliferous veins, metalliferous
dykes, &c.

METALLIZA'TION. The act, or process, of
forming into a metal.

METALLO'GRAPHY. (from ftsraXXov, a
metal, and ypaQfj, a description.) A
treatise on metals, or metallic substances.

META'LLURGY. (from ^eraXXov, a metal,
and Ipyov, a work, Gr. metallurgie, Fr.)
Some authors comprehend under this
term, the whole art of working metals,
from the glebe, or ore, to the utensil ; in
which sense assaying, smelting, refining,
parting, smithery, gilding, &c., are only
branches of metallurgy. Others restrain
metallurgy to those operations required
to separate metals from their ores.

METAMO'RPHIC. (from fierd, trans, and
p,op<j>r}, form, Gr.) A term proposed for

MET

C 165]

MET

such hypogene rocks as are stratified, or
altered by stratification ; any stratified
primary rock may be termed metamorphic.
By some authors the metamorphic rocks
have been divided into two groups ;
namely, those which present traces of
stratification, and, secondly, those which
present no appearance of regular arrange-
ment, but occur in amorphous or shape-
less masses.

METAMO'RPHOSIS. (jufra/jojo^wcric., Gr.
change into another form, metamorphose,
Fr. metamorfosi, It.) Transformations
which insects undergo previously to their
arriving at their state of perfection. The
progress of metamorphosis of insects is
most strikingly displayed in the history
of the Lepidopterous, or butterfly and
moth tribe. The egg, which is de-
posited by the butterfly, gives birth to a
caterpillar ; an animal which, in outward
shape, bears not the slightest resemblance
to its parent, or to the form it is itself
afterwards to assume. It has, in fact,
both the external appearance, and the
mechanical structure, of a worm. But
these vermiform insects contain in their
interior the rudiments of all the organs
of the perfect insect. These organs are,
however, concealed from view by a great
number of membranous coverings, which
successively invest one another, like the
coats of an onion, and are thrown off,
one after another, as the internal parts
are gradually developed. These succes-
sive peelings of the skin are but so many
steps in preparation for a more impor-
tant change. A time comes when the
whole of the coverings of the body are at
once cast off, and the insect assumes the
form of a pupa or chrysalis ; being wrapt
as in a shroud, presenting no appearance
of external members, and retaining but
feeble indications of life. In this condi-
tion it remains for a certain period : its
internal system continuing in secret the
farther consolidation of the organs ; until
the period arrives when it is qualified to
emerge into the world, by bursting asun-
der the fetters which had confined it, and
to commence a new career of existence.
The worm, which so lately crawled with a
slow and tedious pace along the surface
of the ground, now ranks among the
sportive inhabitants of the air ; and ex-
panding its newly acquired wings, launches
forward into the element on which its
powers can be freely exerted, and which
is to waft it to the object of its gratifica-
tion, and to new scenes of pleasure and
delight. Dr. Roget, Bridgewater Trea-
tise.

Transformations quite as remarkable
occur in several tribes of animals belong-
ing to other classes : such as those of the

frog among reptiles, and of the lernsea
among parasitic worms. Whether the
higher order of crustaceans undergo a
real metamorphosis, has not been satis-
factorily proved. They are known to
change their shells annually ; but it has
not been observed that this moult has
been attended by any change of form, or
by the acquisition of any new locomotive
or other organs.

METATA'RSAL. (from fierci and rapabg,
Gr.) Belonging to the metatarsus, as the
metatarsal bones, &c.

METATA'RSUS. (from /tsrd and rapo-df,
Gr. metatarse, Fr.) That part of the
foot which lies between the ankle and the
toes, corresponding to the metacarpus of
the superior extremities. The bones of
the metatarsus in the most complete
forms of development are always five in
number, in each limb.

METATHO'RAX. (from yuerd, beyond, and
Owpak, the chest.) In entomology, the
third and last segment of the thorax, re-
sembling the second in being of a more
united structure than the first. The
second and third segments are closely
united together, but the original distinc-
tion into two portions is marked by a
transverse line. To the second and third
segments are attached both wings and
legs, whereas the first segment has legs
alone. The third segment consists of
seven pieces, which are similar to those
of the second. The posterior wings are
placed at the anterior angles, and often
occupy the whole sides of the meta-
thorax. A pergamenteous partition at
the posterior margin, which descends in
a perpendicular direction, bowing in its
middle towards the abdomen, separates
the metathorax from the abdomen.

METEO'RIC IRON. The Octaedrisches eisen
of Mohs ; Fer natif of Haiiy. Colour
pale steel-grey ; occurs ramose, and dis-
seminated in meteoric stones. Native,
or meteoric iron, is composed of iron
and nickel, the proportion of nickel vary-
ing from one to nearly ten per cent. In
some specimens a trace of cobalt has been
discovered.

Pallas found a mass of native iron
1680 Ibs. in weight, in Siberia, which tra-
dition stated to have fallen from the air.
Meteoric iron is assuredly unlike any
iron of earthly origin, but it has been
imitated by fusing iron with nickel.

METEORO'LOGY. (from /wsrswpa, meteors,
and \6yoc, a description, Gr.) The
study of the phenomena of the atmo-
sphere. It was not till the 17th century
that any considerable progress was made
in investigating the laws of meteorology.

M I C

[ 166 ]

M I E

Previously to that period, the want of
proper instruments precluded the culti-
vation of this science ; but the discovery
of the barometer and thermometer in
the 17th, and the invention of accurate
hygrometers in the 18th century, sup-
plied the pre-existing defects, and ena-
bled philosophers to enter on meteorologi-
cal observations with accuracy and facility.

MI'CA. (from mico, to glisten.) This
mineral appears to be always the result
of crystallization, but is rarely found in
regular, well-defined crystals. Most com-
monly it appears in thin, flexible, elastic
laminae, which exhibit a high polish and
strong lustre. These laminae have some-
times an extent of many square inches,
and, from this, gradually diminish till
they become mere spangles, discoverable,
indeed, by their lustre, but whose area is
scarcely perceptible by the naked eye.
Mica is said to contain forty-four per
cent, of oxygen. The laminae of mica
are easily separated, and may be reduced
to a thickness not much exceeding the
millionth part of an inch. Mica is easily
scratched with a knife, and, commonly,
even by the finger-nail. Its surface is
smooth to the touch ; its powder is dull,
usually grayish, and feels soft. Its co-
lours are silver-white, gray, green, brown,
reddish, and black, or nearly black. Spe-
cific gravity from 2'50 to 2'90. When
rubbed on sealing-wax, it communicates
to the wax negative electricity. Before
the blow-pipe, it fuses into a grey or
black enamel. Its constituent parts are,
according to Klaproth, silex 48'0, alu-
mine 34'20, potash 8 75, oxide of iron
4'5, oxide of manganese 0'5. According
to others, it is a compound of silicium,
potassium, magnesium, calcium, &c.,
combined with oxygen. Mica is one of
the component parts of granite, gneiss,
and mica-slate ; it occurs also in syenite,
porphyry, and other primary rocks. To
quartz and limestone it frequently com-
municates a slaty texture. It may always
be distinguished from talc by the elas-
ticity of its plates, in its want of unctuo-
sity, and by its communicating negative
electricity to sealing-wax. There are
several varieties, or sub-species ; Jame-
son enumerates ten. Mica has been em-
ployed, instead of glass, in the windows
of dwelling-houses. In lanterns it is su-
perior to horn, being more transparent,
and not so easily injured by the flame.
Mica is a doubly refracting substance,
with two optic axes ; along which, light is
refracted in one pencil.

MICA'CEOUS. Containing mica ; resem-
bling mica.

MICA'CEOUS IRON ORE. A variety of
oxide of iron. This occurs generally in

amorphous masses, composed of thin six.
sided laminae. Colour iron-black, or
steel-grey. Lustre metallic. Opaque.
Feel greasy. Hardness 5 to 7. Specific
gravity from 4'5 to 5'7. It is said to
yield nearly 70 per cent, of iron.

MI'CA SCHIST. > A metamorphic rock, com-

MI'CA SLATE. $ posed of mica and quartz ;
it passes by insensible gradations into
clay-slate, and its texture is slaty. Some-
times the mica and quartz alternate,
though commonly they are more or less
intimately mingled ; the mica usually
predominating.

MI'CARELLE. The Finite of Kirwan. See
Finite.

MI'CROPYLE. (from /ziKpoc, small, and
TruXoc, gate, Gr. ) A term for the fora-
men in the perfect seed ; this foramen is
often visible, as in the pea and bean.

MI'CROSCOPE. (from /tuKpoe, small, and
OTKOTTHO, to behold, Gr. microscope, Fr.
microscopio, It.) A microscope is an
optical instrument for examining and
magnifying minute objects. Jansen and
Drebell are supposed to have separately
invented the single microscope, and Fon-
tana and Galileo seem to have been the
first who constructed the instrument in
its compound form. The single micro-
scope is nothing more than a lens or
sphere of any transparent substance, in
the focus of which minute objects are
placed. The best single microscopes are
minute lenses ground and polished on a
concave tool ; but as the perfect execu-
tion of these requires considerable skill,
small spheres have often been constructed
as a substitute. The most perfect single
microscopes ever executed, of solid sub-
stances, are those made of the gems, such
as garnet, ruby, diamond, &c. Garnet is
the best material, as it has no double re-
fraction, and may be procured perfectly
pure and homogenous. When a single
microscope is used for opaque objects,
the lens is placed within a concave silver
speculum, which concentrates parallel or
converging rays upon the face of the ob-
ject next the eye.

When a microscope consists of two or
more lenses or specula, one of which
forms an enlarged image of objects, while
the rest magnify that image, it is called a
compound microscope. The ingenuity of
philosophers and of artists p has been
nearly exhausted in devising the best
forms of object-glasses and of eye-glasses
for the compound microscope. — Dr.
Brewster.

MICROSCO'PIC. That may be seen only by
the aid of a microscope.

MI'EMITE. A mineral, thus named from
having been found at Miemo, in Tuscany.
A green variety of Dolomite, occurring in

M I L

[ 167 ]

M I N

crystals, and in masses with a radiated
structure.

MI'LLEPEDE. > (millepeda, Lat. from mille,
MI'LLIPEDE. $ a thousand, and pes, a
foot.) Insects whose body is generally
cylindrical ; segments half membrana-
ceous and half crustaceous, each half
bearing a pair of legs ; antennae seven-
jointed, filiform, often a little thicker
towards the end. These are called milli-
pedes. The millipedes belong to the
necrophagous tribe, or those which de-
vour dead animals, or any other pu-
trescent substances. — Rev. W. Kirby.
MI'LLEPORE. (from mille, a thousand, and
porus, a pore.) A genus of lithophytes
of various forms, having the surface per-
forated with numerous small pores or
holes. In millepores the cells are more
minute and closer than in madrepores,
and do not exhibit any star-like radia-
tions.

MILLE'PORITE. A fossil millepore.
MI'LIOLA. ) A genus of microscopic mul-
MI'LLIOLA. $ tilocular univalves, not larger
than a millet seed, with transverse cham-
bers, involving the axis alternately, and
in three directions ; the opening small
and circular, or oblong, at the base of the
last chamber. Several species are found
to exist on our shores, and many recent
specimens have been obtained, on fucus,
near the island of Corsica.
MI'LIOLITE. }The fossil Miliola. So nu-
MILLI'OLITE. $ merous are these minute
fossils in the neighbourhood of Paris,
that some species of them form the prin-
cipal part of the masses of stone in some
of the quarries. The remains of such
minute animals as the milliola, have
added much more to the mass of ma-
terials forming the earth's crust than the
bones of the mammoths, whales, and
hippopotami.

MI'LLSTONE. Called also Burrhstone. The
Quartz agathe molaire of Haiiy ; Silex
meuliere of Brongniart. The exterior
aspect of this mineral is somewhat pecu-
liar, being full of pores and cavities,
which give it a corroded and cellular
appearance. It occurs in amorphous
masses, above the marine sand and sand-
stone. Sometimes the mass is compara-
tively compact, and the cavities small
and not numerous ; but in all specimens
these cavities or cells are to be found.
Millstone is of a white or greyish colour ;
sometimes with a tinge of blue or yellow ;
when unmixed it is pure silex. It con-
tains no organic remains, and in the
order of superposition of the formations
in the neighbourhood of Paris, it consti-
tutes the ninth horizontal bed, counting
from the chalk upwards. In is of great
use for making into millstones, from

which circumstance it has obtained its
name.

MI'LLSTONE GRIT. The name given to a
siliceous conglomerate, composed of the
detritus of primary rocks. It has been
thus named from some of the strata hav-
ing been worked for millstones. It con-
stitutes one of the members of the car-
boniferous, or mountain limestone group.
The millstone grit forms a bed of consi-
derable thickness in some situations,
amounting to three or four hundred feet ;
in others it is of very limited extent ;
and sometimes it is wholly wanting.

MINERAL ADIPOCI'RE. A fatty bitumi-
nous substance occurring in the argilla-
ceous iron ore of Merthyr, in Wales. It
is insoluble in water, and fuses at a tern-
perature of 160°. When cold it is in-
odorous, but on being heated gives out a
bituminous odour.

MI'NERAL CAOU'TCHOUC. A variety of bi-
tumen, intermediate between the harder
and softer kinds. It sometimes much
resembles India rubber in its softness
and elasticity, from whence it derives its
name, and like that removes the traces of
the pencil, but, at the same time, it soils
slightly the paper. Colour brown, red-
dish-brown, or hyacinth-red. Specific
gravity from 0'90 to 1-23. It burns with
a bright flame, emitting during its com-
bustion, a bituminous odour. It occurs
near Castleton, in Derbyshire.

MI'NERAL CHA'RCOAL. A fibrous variety
of non-bituminous mineral coal.

MI'NERAL WA'TERS. Waters impregnated
with mineral substances.

MINERALIZA'TION. The process of con-
verting into a mineral some body not
previously such.

MI'NERALIZE. To convert into a mineral.

MI'NERALIZER. That which converts a
substance into a mineral. Metals are
combined with oxygen, sulphur, &c. by
which their peculiar metallic properties
are more or less disguised ; in this case
the metal is said to be mineralized, and
the oxygen or sulphur is termed the mi-
neralizer.

MI'NERALS. (minerale, Lat. mineral, FT.
minerale, It.) Those bodies which are
destitute of organization, and which na-
turally exist within the earth or at its
surface. The term fossil is usually ap-
propriated to those organic substances
which have become penetrated by earthy
or metallic particles.

Minerals have been divided into two
kinds ; simple, or homogeneous, and com-
pound, or heterogeneous. Simple minerals
appear uniform and homogeneous in all
their parts. They do, in fact, usually con-
tain several different elementary systems ;
but these are so intimately combined, and

M I N

[ 168 ]

M I N

similarly blended, in every part, as to
exhibit a uniformity of appearance.

Compound minerals more or less evi-
dently discover to the eye, that they are
composed of two or more simple mine-
rals, which either merely adhere to each
other, or, as is sometimes the case, appear
imbedded one in the other. Compound mi-
nerals are frequently aggregates or rocks.

The description of minerals, and their
arrangement in systematic order, must
result from an investigation of their pro-
perties. These properties consist in cer-
tain relations which minerals bear to our
senses, or to other objects. Some of
them are discoverable by mere inspection,
or, at most, require some simple experi-
ment to be made upon the mineral to as-
certain its hardness, structure, gravity,
&c. while others cannot be observed
without a decomposition of the mineral.
All these properties are usually called
characters. We hence have a twofold
division of the properties or characters of
minerals into chemical and physical. —
Cleaveland.

MI'NERALOGY. That science, says Cleave-
land, which has for its object a knowledge
of the properties and relations of mine-
rals, and enables us to distinguish, ar-
range, and describe them.

Jameson defines mineralogy to be that
part of natural history which makes us ac-
quainted with all the properties and rela-
tions of minerals. It is divided, accord-
ing to that professor, into two grand
branches, namely, mineralogy properly so
called, and geology. Mineralogy treats
of the properties and relations of simple
minerals / while geology considers the
various properties and relations of the
atmosphere, the waters of the globe, the
mountain rocks, or those mineral masses
of which the earth is principally com-
posed, and the form, density, heat, elec-
tricity, and magnetism of the earth.

The history of the materials of the
crust of the globe, their properties as
objects of philosophical enquiry, and their
application to the useful arts and the
embellishments of life, with the charac-
ters by which they can be certainly dis-
tinguished one from another, form the
object of mineralogy, taken in its most
extended sense.

There is no branch of science which
presents so many points of contact with
other departments of physical research,
and serves as a connecting link between
so many distant points of philosophical
speculation as this. Nor, with the ex-
ception of chemistry, is there any which
has undergone more revolutions, or been
exhibited in a greater variety of forms.
To the ancients it could scarcely be said

to be known at all, and up to a com-
paratively recent period, nothing could
be more imperfect than its descriptions,
or more inartificial or unnatural than its
classification. It was only, however,
whSn chemical analysis had acquired a
certain degree of precision and universal
applicability, that the importance of mi-
neralogy as a science began to be recog-
nized, and the connection between a
stone and its ingredient constituents
brought into distinct notice. The ar-
rangement of simple minerals has always
been a subject of controversy with miner-
alogists ; and the discussions to which
it has given rise have materially contri.-
buted to the advancement of our know-
ledge of the natural and chemical history
of minerals. Berzelius contends for the
chemical arrangement, according to which
the species are grouped in conformity
with their chemical composition and
characters. Werner rejects the pure che-
mical, and adopts the mixed method, in
which the species are arranged and de-
termined according to the conjoined ex-
ternal and chemical characters. The
writers of the WTernerian school usually
divide mineralogy into the five following
branches ; namely, oryctognosy, chemi-
cal mineralogy, geognosy, geographical
mineralogy, and economical mineralogy.
Of late years, the arrangement according
to external characters alone (named the
natural history system) has been advo-
cated by Mohs. Among the external
characters of a stone, none were, how-
ever, found to possess that eminent dis-
tinctness which the crystalline form
offers ; a character in the highest degree
geometrical, and affording the strongest
evidence of its necessary connection with
the intimate constitution of the sub-
stance. The full importance of this cha-
racter was, however, not felt until its
connection with the texture or cleavage
of a mineral was pointed out, and even
then it required numerous and striking
instances of the critical discernment of
Haiiy, and other eminent mineralogists
in predicting from the measurements of
the angles of crystals which had been
confounded together, that differences
would be found to exist in their chemical
composition, all which proved fully jus-
tified in their result before the essential
value of this character was acknowledged.
A simple and elegant invention of Dr.
Wollaston, the reflecting goniometer, gave
a fresh impulse to that view of miner-
alogy which makes the crystalline form
the essential or leading character, by
putting it in the power of every one, by
the examination of even the smallest
portion of a broken crystal, to ascertain

M I N

[ 169 ]

M O L

the character on which the identity of
mineral in the system of Haiiy was mad
to depend. Mineralogy, however, as a
branch of natural history, remains stil
distinct from either optics or crystallo-
graphy. But whatever progress may have
hitherto been made in mineralogica]
pursuits, every new advance has opened a
wider and more interesting prospect.
The science is still in its infancy, and in
many of its paths can proceed only with
a faultering and uncertain step. — Hers-
chell. Jameson. Cleaveland.

MI'NIUM. (minium, Lat.) A red oxide
of lead. Minium is of a bright scarlet ;
it occurs in a loose state, or in masses,
composed of flakes with a crystalline
texture. It is found in the lead mines of
Westphalia. It is used in glass-making,
enamelling, and some other arts.

MI'OCENE. (from /mW, less, and Kaivbg,
recent, Gr.) The name given by Mr.
Lyell to a subdivision of the tertiary
strata. He says, the European tertiary
strata may be referred to four successive
periods, each characterized by containing
a very different proportion of fossil shells
of recent species. These four periods he
names, Newer Pliocene, Older Pliocene,
Miocene, and Eocene. The Miocene
period has been found to yield eighteen
per cent, of recent fossils. This was the
result of an examination of 1021 fossil
species by M. Deshayes. Many shells
belong exclusively to the Miocene period.
The Miocene strata are largely developed
in Touraine, and in the South of France
near Bourdeaux, in the basin of Vienna,
and other localities. The miocene strata
contain an admixture of the extinct genera
of lacustrine mammalia of the Eocene
series, with the earliest forms of genera
which exist at the present time.

MI'TRA. A genus of shells belonging to
the Columellaria in Lamarck's arrange-
ment. It is a subfusiform univalve, with
a long pointed turreted apex, a notched
base, and no canal. Covered with an
epidermis of a light brown colour. The
columella is plicated ; the inferior plicae
being the smallest. Mitres are found
both fossil and recent. The recent are
found at depths varying to seventeen
fathoms, on reefs, in sands, and in sandy
mud. Of the fossil mitres, Lamarck de-
scribes thirteen species as having been
found in the neighbourhood of Paris.

MO'CHA STONE, (from Mocha, in Arabia.)
The quartz agathe arborise of Haiiy.
Called also dendritic agate. A mineral,
containing in its interior very beautiful
delineations of leafless shrubs, trees, &c.,
of a brown or dark colour. Mocha stones
resemble those agates which are found on
the Sussex coast called dendrachates.

MODI'OLA. (from modiolm, Lat. a little
measure.) A genus of shells belonging
to the family Mytilacea. A transverse
inequilateral bivalve. Parkinson states
that modiolae do not attach themselves
by a byssus, but this is incorrect. The
modiola is a littoral shell, moored to
rocks, stones, and shells. One species,
modiola discors, floats free, enveloped in
its own silky byssus. One modiola lives
in the ascidias, and another floats among
the Gulf or Sargasso weed. The fossil
species have been found in the neigh-
bourhood of Paris, and some in this
country.

MO'LAR (from mola, a mill, Lat. molaire,
Fr.) A grinder-tooth. The large double
teeth are called molar teeth, or grinders ;
these are, however, subdivided according
to their different forms ; thus those with
two fangs are called bicuspid, or false
molar teeth. The posterior molar teeth
are differently shaped in carnivorous ani-
mals, for they are raised into sharp, and
often serrated, edges, having many of the
properties of cutting teeth. In insecti-
vorous and frugivorous animals, their
surface presents prominent tubercles,
either pointed or round, for pounding the
food ; while in graminivorous quadrupeds
they are fiat and rough, for the purpose
simply of grinding.

MOLA'SSE. (from mollis, soft, Lat.) The
name given to a soft green sandstone
found in Switzerland ; one of the most
recent of the tertiary deposites. — Lyell.
In the Molasse of Switzerland there are
many deposites affording sometimes coal
of considerable purity. — Prof. Buckland.
Mr. Bakewell observes, " By many
geologists it is maintained that the beds
of soft sandstone, called molasse, belong
to the London clay division of the ter-
tiary formations. That some of these
beds may be tertiary, I do not deny ; but
I am fully convinced, that many beds
called molasse, in Savoy, are covered by
the Jura limestone and oolites, having re-
peatedly seen them in contact, and got
specimens from each bed at the line of
junction."

WO'LECULE. (molecule, Fr. petite partie
d'un corps.} A minute particle of a mass
or body, differing from atom, inasmuch as
it is always a portion of some aggregate.
All substances consist of an assemblage
of material particles, which are far too
small to be visible by any means human
ingenuity has yet been able to devise,
and which are much beyond the limits of
our perceptions. The size of the ulti-
mate particles of matter must be small in
the extreme. Organised beings, possess-
ing life and all its functions, have been
discovered so small that a million of them

M O L

[ 170 ]

M O L

would occupy less space than a grain of
sand. The ingredients of granite, and
of all other kinds of crystalline rocks, are
composed of molecules which are invisibly
minute, and each of these molecules is
made up of still smaller and more minute
molecules, every one of them combined in
fixed and definite proportions, and afford-
ing, at all the successive stages of their
analysis, presumptive proof that they
possess determinate geometrical figures.
MOLLU'SCA. (mollusca, a nut with a soft
shell, Lat.) According to the arrange-
ment of Cuvier, the second great division
of the animal kingdom. This he subdi-
vided into six classes, namely, Cephalo-
poda, Pteropoda, Gasteropoda, Acephala,
Brachiopoda, and Cirrhopoda. A vast
multitude of species, possessing in com-
mon many remarkable physiological cha-
racters, are comprehended in this great
division. In all, as their name imports,
the body is of soft consistence ; and it is
enclosed, more or less completely, in a
muscular envelope, called the mantle,
composed of a layer of contractile fibres,
which are interwoven with the soft and
elastic integument. Openings are left in
this mantle for the admission of the
external fluid to the mouth and to the
respiratory organs, and also protrusion
of the head and the foot, when these
organs exist. But a larger proportion of
this class are acephalous, that is, destitute
of a head, and the mantle is then often
elongated to form tubes, occasionally of
considerable length, for the purpose of
conducting water into the interior of the
body.

The general form of the body, and the
kind of motions it performs, vary more in
the molluscous than in the articulated
classes of animals, and we observe a cor-
responding diversity in their active organs
of motion. In the molluscous classes
there appear much greater variety, diver-
sity, and want of symmetry in the whole
muscular system. Many of the lower
mollusca are fixed by long peduncles at
the bottom of the sea ; some, as the
limaces, creep on the surface of the dry
land ; the pteropods swim at the surface
of the ocean, where the janthinse hang
suspended by floats ; the naked cepha-
lopoda bound from the surface, and the
pholades are fixed deep in cavities of
rocks at the bottom ; the oyster is fixed
to the rock, while the clam skips to and
fro by the flapping of its shells ; the
pinna is anchored to the bottom by its
strong byssus, while the cardium swims
along the still surface, suspended by its
concave expanded foot. So that although
none of these animals have wings to fly
through the air, or jointed legs to creep

upon the earth, or spines to oar them
through the sea, they possess the means
of almost every kind of motion, from the
vibratile cilia of the fixed corals to the
hands and feet of the finny tribe.

The circulation of the mollusca is al-
ways double ; that is, their pulmonary
circulation describes a separate and dis-
tinct circle. Their alimentary canal hardly
ever passes straight through their body :
nor is the anus terminal, as in most of
the articulata. Their digestive cavities
are more numerous and capacious, the
intestine is more lengthened and convo-
luted, and all the assistant glandular
organs are developed on a higher plan,
and more constant throughout the classes.
The lowest of the molluscous classes,
the tunicated animals, shut up in the
interior of a cartilaginous, more or less
elastic, and biforate tunic, have no pre-
hensile or masticating organs connected
with their mouth. The mouth, in fact,
is placed at the bottom of the respiratory
sac, and appears to be destitute even of
those tentacula, appendices, or lips, which
are so much developed, and so various in
their forms, in the conchiferous animals.
Many of the mollusca are formed for
an existence as completely stationary as
the zoophytes attached to a fixed base.
This permanent attachment does not,
however, take place till they have arrived
at a certain period of their growth.

The mollusca are the only instance of
a unipede structure in creation, but this
one foot answers every purpose of a hand
or leg ; it spins for the bivalves their
byssus, is used by others as a trowel, by
others as an augur, and by others for
other manipulations, and is generally
their sole organ of locomotion ; from its
soft and flexible substance it can adapt
itself to the surfaces on which it moves,
and by the slime that it copiously secretes
lubricates them to facilitate its progress.
It is probable that the foot may be also
employed by these animals as an organ of
touch. In the nervous system of mol-
lusca, the ganglia have a circular arrange-
ment.— Cuvier. Grant. Kirly. Roget.
MOLLU'SCOUS. Animals belonging to the
division mollusca, or soft, invertebral,
inarticulate animals ; often protected by
a shell. The external skeleton of the
molluscous animals is consolidated by
carbonate of lime, without the phosphate
of lime which is common to the other
great divisions of the animal kingdom.
This earthy matter is secreted from the
skin in successive layers, mixed with a
glutinous coagulable animal matter, which
gives firmness and tenacity to the whole
mass, and the skeletons are not exuviable
as in the articulated classes.

M O L

[ 171 ]

M O N

MOJLY'BDATE or LEAD. The plomb molyb-
date of Haiiy ; pyramidaler blaibaryt of
Mohs. Yellow lead ore. It is of a yel-
low colour, varying from lemon yellow to
yellowish brown. Occurs crystallized and
massive. Its specific gravity from 6'5 to
6*9. Fracture uneven, or imperfectly
conchoidal. Slightly translucent, espe-
cially at the edges. Before the blow-pipe
it decrepitates, and fuses into a dark
coloured mass. It consits of oxide of
lead 58, molybdic acid 38, oxide of iron
2. It is found at Bleyberg, in Carinthia,
and in Mexico, in compact limestone. It
is sometimes associated with sulphuret of
molybdena.

MOLYBDE'NA. A mineral of a lead-grey
colour, occurring in thin flexible leaves.

MOLYBDE'NUM. (from po\v@t)aiva, Gr.)
This metal was discovered by Hielm in
1782. Molybdenum is externally of a
whitish yellow colour, but its fracture is
a whitish grey. Its specific gravity about
8-6. It is nearly infusible. It has not
been applied to any use. It is obtained
from the mineral molybdena in small
grains, agglutinated together in brittle
masses.

MO'NAD. (from juomc, Gr. an atom, mo-
nade, Fr.) The recent observations of
Professor Ehrenberg have brought to light
the existence of monads, which are not
larger than the 24,000th of an inch, and
which are so thickly crowded in the fluid
as to leave intervals not greater than their
own diameter. Hence he has made the
computation that each cubic line, which is
nearly the bulk of a single drop, contains
500,000,000 of these monads ; a number
which equals that of all the human beings
on the surface of the globe in one drop of
fluid. Monads, which are the smallest of
all visible animalcules, have been spoken
of as constituting " the ultimate term of
animality."

MO'NAS. A genus of animalcules, the
smallest visible.

MONA'NDRIA. (from (JLOVOQ, one, and avfjp,
a man, Gr.) The first class of plants in
Linnaeus' s artificial system. The plants
of this class have only one stamen ; it is
a small class, and contains only two
orders.

MONA'NDRIAN. Belonging to the class
Monandria ; having only one stamen.

MONI'LIFORM. (from monile, a necklace,
and forma, form, Lat.) Resembling a
necklace.

MO'NITOR. (monitor, an admonisher, Lat.)
A genus of lizards or saurians, species of
which are found both fossil and recent ;
the recent inhabit the tropics. Cuvier
places this genus in the family Lacerti
nida. The monitors frequent marshes
and the banks of rivers in hot climates ;

they have received their name from a
common but silly notion that they give
warning of the approach of crocodiles and
caymans by a whistling noise. One spe-
cies, the Lacerta nilotica, devours the
eggs of crocodiles. Fossil remains of the
monitor have been discovered in the
strata of Tilgate Forest, in Sussex.

MONO'CEROS. (from /iovof, one, and fclpag,
a horn, Gr.) A name given to the unicorn.

MONOCOTYLE'DON. (from povoQ, one, and
fcoruXj/dwv, aseed lobe, Gr.) Aplantwhich
has only one cotyledon or seed-lobe.

MONOCOTYLE'DONOUS. Those plants, the
seeds of which have either only one coty-
ledon, or if more, those alternate on the
embryo, are called monocotyledonous ;
grasses, lilies, aloes, and palms, are ex-
amples. Monocotyledonous plants may
be at all times recognised, from the cir-
cumstance of the veins of their leaves
being parallel, while those of dicotyledo-
nous plants are reticulated.

MoNOi/ciA. (from fiovog, one, and ot/eia,
a house, Gr.) The twenty-first class of
plants in the artificial system of Linnseus.
In this class the stamina and pistils are
in separate flowers, but growing on the
same individual plant. The orders in this
class depend upon the circumstances of
their male flowers, and are nine or ten in
number.

MONOS'CIOUS. Plants belonging to the
class Monoecia, or such as have male
flowers, or flowers with stamens, only,
and female flowers, or flowers with an
ovarium, only, on the same individual
plant.

MO'NODON. (from ^ovodovg, Gr. having
one tooth.) The sea unicora, or narwhal,
distinguished by its long tusk, or tusks,
for there are sometimes two, extended in
a horizontal direction. Only one species
is known, namely, the Monodon monoce-
ros. The monodon belongs to the order
Cetacea, class Mammalia.

MONOPE'TALOUS. (from povoQ, one, and
TrsraXov, a petal, Gr.) Flowers are so
called which consist of only one leaf or
petal ; or when the leaves which compose
the corolla are united by their edges ; the
convolvulus, honeysuckle, &c. are exam-
ples.

MONOPHY'LLOUS. (from HOVOQ, sole, and
QvXkov, a leaf, Gr.) Having one leaf
only, or formed of one leaf; applied to
calices consisting of not more than one leaf.

MONOSE'PALOUS. (from /i6vo£, sole, and
sepal, a word without any derivation, but
invented by botanists to distinguish the
parts of the calyx from those of the co-
rolla.) A term applied to the calyx of a
flower, when the sepals which compose it
are united by their edges : the pink, con-
volvulus, henbane, &c. are examples.

M O N

[ 172]

M O U

MONOTHA'LAMOUS. (from ^dvoc, single,
and OdXctfiog, a chamber, Gr.) Shells
whose chamber is undivided by partitions ;
these are termed unilocular, or mono-
thalamous : the argonaut is an example.

MO'NOTREME. The Monotremes form Cu-
vier's third tribe of Edentata, comprising
two genera, namely, Echidna and Orni-
thorhynchus. They are found only in
New Holland. The Monotremes seem
connected with the birds ; one genus, the
ornithorhyiichus, having a mouth resem-
bling the bill of a duck, and being almost
web-footed ; it has also been stated to be
oviparous. The Monotremes have no
marsupial pouch. They suckle their
young from a mammary orifice.

MONOTRE'MATOUS. Belonging to the tribe
Monotremata.

MOO'NSTONE. A variety of felspar, called
also adularia, possessing a silvery or
pearly opalescence. Moonstone is trans-
parent and translucent. Its colour is
white, with sometimes a tinge of yellow,
green, or red. When held in certain po-
sitions, its surface is iridescent. It occurs
massive, and in crystals. It is found in
the fissures and cavities of granite, gneiss,
&c.

MORA'INE. An accumulation of sand,
stones, or debris, found upon icebergs,
glaciers, &c.

MO'RDANT. (from mordeo, to bite, Lat.
mordant, Fr.) A substance, employed in
the process of dying, which has an affinity
both for the colouring matter and the
material to be dyed. It is also termed a
basis. Sulphate of iron and acetate of
alumina are commonly employed as mor-
dants.

MORO'XITE. A sub-species of apatite, oc-
curring in crystals, of a brownish or
greenish-blue colour. It is found in
Norway, in primary rocks.

MOSASAU'RUS. "| " The Mosasaurus," says

MOSASAU'RUS. > Prof. Buckland, " has

MOSOSAU'RUS. J been long known by the
name of the Great Animal of Maestricht,
occurring near that city, in the calcareous
freestone, which forms the most recent
deposit of the cretaceous formation. A
nearly perfect head of this animal was
discovered in 1780, and is now in the
museum at Paris. This celebrated head,
during many years, puzzled the most skil-
ful naturalists ; some considered it to be
that of a whale, others of a crocodile ;
,but its true place, in the animal kingdom,
was first suggested by Adrian Camper,
and, at length, confirmed by Cuvier. By
their investigations, it is proved to have
been a gigantic marine reptile, most nearly
allied to the monitor. Some vertebrae of
the mososaurus have been discovered in
the upper chalk near Lewes, in Sussex :

these have the body convex posteriorly,
and concave anteriorly. Teeth of the
mososaurus have been discovered, by Dr.
Morton, in the green- sand of Virginia.
Portions of jaws, with teeth of the mosse-
saurus, may be seen in the British Mu-
seum. Dr. Man tell observes, " The mo-
sosaurus was a reptile, holding an inter-
mediate place between the monitor and
iguana, about twenty-five feet long, and
furnished with a tail of such construction
as must have rendered it a powerful oar,
enabling the animal to stem the waves of
the ocean, of which Cuvier supposes it to
have been an inhabitant."

" From the lias upwards," says Dr.
Buckland, " to the commencement of the
chalk formation, the ichthyosauri and
plesiosaui'i were the tyrants of the ocean ;
and just at the point of time when their
existence terminated, during the deposi-
tion of the chalk, the new genus mosa-
saurus appears to have been introduced,
to supply for a while their place and of-
fice, being itself destined, in its turn, to
give place to the cetacea of the tertiary
periods."

MOU'NTAIN CORK. The Berg kork of
Werner ; Suber montanum of Kirwan ;
Asbeste suberiforme of Brongniart. A
white or grey variety of asbestos, to which
the name of mountain cork has been
given from its extreme lightness, its
specific gravity being from 0'68 to 0'99,
consequently so light as to swim in water.
Its structure is fibrous ; the fibres pro-
miscuous and interwoven. Its consti-
tuents are silex 56'2, magnesia 26*1, lime
12'7, iron 3'0, alumine 2'0. It occurs in
France and Saxony.

MOU'NTAIN BLUE. A species of blue ma-
lachite or blue copper. The Cuivre car-
bonate bleu of Haiiy ; Kupfer lazur of
Werner. Carbonate of copper. The
characteristic colour of mountain blue is
azure-blue, often exceedingly beautiful
and splendent. Occurs regularly crystal-
lized in scopiform and stellular concre-
tions, radiated, and also curved lamellar.
When rubbed on paper it leaves a light
blue streak. Specific gravity from 3'20
to 3 '60. It dissolves with effervescence
in nitric acid. It is scarcely fusible alone,
but with borax, to which it communicates
a fine green, it yields a globule of copper.
Its constituents are copper 66'0, carbonic
acid 18-0, oxygen 8'0, water 2-0.

MOU'NTAIN LI'MESTONE. A series of ma-
rine limestone strata, whose geological
position is immediately below the coal
measures and above the old red-sandstone.
To this formation the French have given
the name of Calcaire de transition. Moun-
tain limestone is one of the most impor-
tant calcareous rocks in England and

M O U

[ 173 ]

M U S

Wales, both from its "extent, the thickness
and number of its beds, the quantity and
variety of its organic remains, and its
richness in metallic ores, particularly of
lead. In Derbyshire, where the different
beds of limestone have been pierced
through by the miners, the average thick-
ness of the three uppermost is about 160
yards ; the beds are separated by beds of
trap or basalt, resembling ancient lavas.
The limestone is generally sufficiently
hard to bear a polish, and forms what
is denominated marble, of considerable
beauty. The mountain limestone forma-
tion occupies an immense tract in North-
umberland, Durham, and Yorkshire, from
which country it runs out in a curve to
encircle on the north, and partially on
the south, the group of Cumbrian slate
mountains. It also appears in great force
in Derbyshire, ranges through Flint and
Denbigh, to St. Orme's head and Angle-
sea ; shows slightly round the Glee hills
in Shropshire ; and presents picturesque
cliffs on the Wye, near Monmouth. The
prevailing characteristic organic fossils
are madrepores and encrinites ; of the
latter some of the upper beds appear to
be almost entirely composed. Mountain
limestone is generally almost a pure car-
bonate of lime, but sometimes it contains
a considerable proportion of magnesia.

MOU'NTAIN SOAP. A mineral, a variety of
green earth, of a brown or blackish-brown
colour. It is massive, dull, smooth and
soapy to the touch, and adheres strongly
to the tongue. It writes on paper. Its
constituents are silex 44-0, alumine 26%
oxide of iron 8'0, lime 0-5, water 2(HO.
It occurs in secondary rocks of the trap
formation, in the Isle of Skye and in
Poland.

MU'CRONATE. (mucronatus, Lat. pointed.)

1. In entomology, when from an obtuse
end a fine point suddenly proceeds.

2. In botany, when a small point termi-
nates an entire leaf, as in the vetch,
house-leek, &c.

3. In conchology, when a shell terminates
in a sharp rigid point.

MO'YA. The name given by the natives of
South America to the mud and slime
ejected from volcanos during the erup-
tions.

MULTISPI'RAL. (from multus, many, and
spira, a spire, Lat.) In conchology, a
term for a shell whose spire consists of
many whorls ; also to an operculuin of
many volutions.

MULTILO'CULAR. (from multus, many,
and loculus, a chamber or shell, Lat.) A
term applied to shells containing parti-
tions, which divide them into several
chambers. Orthoceratites, baculites, ha-
mites, scaphites, belemnites, &c., are all

multilocular shells ; the argonaut, or
paper nautilus, is a unilocular shell.

MU'LTI VALVE, (from multus, many, and
valves, valves, Lat.) Some of the mol-
lusca have, in addition to the two princi-
pal valves, small supplementary pieces of
shell ; these have been comprised in the
order of multivalves.

MU'RCHISONITE. A new mineral, thus
named in honour of Mr. Murchison. Its
constituents are silica 68*10, alumina 16'6,
potash 14'8. It occurs near Dawlish.

MU'REX. (murex, Lat. murex, Fr.) A
genus of shells. Animal a Umax : shell
univalve, spiral, rough, with membraneous
sutures ; aperture oval, ending in an en-

• tire straight, or slightly ascending canal.
The murex is an inhabitant of the ocean,
found at depths varying from five to
twenty-five fathoms, on different bottoms.
These shells, besides their long channelled
beaks, are remarkable for the beauty and
variety of their spines. Murices, or rock-
shells, were in high esteem from the ear-
liest ages, on account of the dye that
some of them yielded ; cloths died with it
bearing a higher price than others. More
than one species yielded a dye ; one, ac-
cording to Bochart, a glaucous or azure
colour ; the other, a purple. Different
species of fossil murex are found in the
London clay and in Bognor sandstone,
and Lamarck describes upwards of seven-
teen species found in the neighbourhood
of Paris.

MU'RICATED. (muricatus, Lat. full of
sharp points and prickles.) Clothed with
sharp rigid points ; beset with short erect
spines.

MU'RICITE. The fossil murex.

MUSA'CEA. A family of tropical monoco-
tyledonous plants, including the banana
and plaintains. — Lyell, Principles of
Geology.

MU'SCHEL KALK. (from muschel, shell,
and kalk, lime or chalk, Germ.) A
compact hard limestone, of a greyish co-
lour, found in Germany. It belongs to
the red sandstone group. The muschel
kalk has not yet been discovered in Eng-
land, but the upper part of the mountain
limestone of the north of England is in
some respects similar in mineral proper-
ties. In Bavaria and Wurtemburg the
muschel kalk is interposed between the
red sandstone, on which it rests, and the
variegated marls which lie over it, and
with which, at the junction, it alternates.
The muschel kalk abounds in organic
remains ; its chief fossils are the lily
encrinite, ammonite, and terebratula. Re-
mains of ichthyosauri, plesiosauri, cro-
codiles, and turtles, are also found in it.
The salt mines of Wurtemburg are also
in this formation.

M U S

[ 174 ]

M Y T

MU'SCLE-BIND. The name given to a stra-
tum of imperfect ironstone and indu-
rated shell, found in the Derbyshire and
Yorkshire coal fields. The shells re-
semble fresh-water muscles, and they are
most abundant.

MU'SITE. )A mineral, thus named from

MU'SSITE. ) Mussa, in Piedmont, where
it occurs. It is a white, or pale green,
variety of augite.

MY'A. (from pvwv, a muscle, Gr.) A
genus of bivalves belonging to the family
Myaria. Animal an ascidia. Shell
transverse, oval, thick, gaping at both
ends ; ligament internal. Hinge with
broad, thick, strong, patulous tooth, sel-
dom more than one, perpendicular to the
valve, and giving attachment to the liga-
ments. The My a is found on beaches, in
which it often lies buried, with its tube
just projecting. It is found in the sea
and in rivers ; principally in the silt of
estuaries. It belongs to the northern
hemisphere. Whether any shells of this
genus have been found fossil appears
problematical. Lamarck states that he
has not met with any ; Parkinson men-
tions that a shell resembling Mya is
found in the cliffs at Bognor, but that he
is not able to speak decidedly with re-
spect to it ; and Dr. Mantell places it
among the fossils of the Shanklin sand,
but with a note of interrogation.

MY'LIOBATES. A genus of fossil Rays.
They are abundant in the London clay
and in the crag.

MYRIA'METER. (from pvpia, ten thou-
sand, and /Lttrpov, measure, Gr.) A
French measure, the length of ten thou-
sand meters, equivalent to two mean
leagues of the old measure. Brongniart
has expressed, in strong terms, his im-
pression on the subject of the distur-
bance of the strata composing the earth's
crust, by saying that there is hardly a
square myriameter which is left in its
original position.

MYRIA'PODA. ) (from /iwpicr, ten thousand,

MY'RIAPODS. \ and TTOVQ, Tro^og , a foot,
Gr.) A class of insects, commonly called
Centipedes, possessing a number of feet,
from six to some hundreds. The Myria-
poda, in general, resemble little serpents,
or Nereides, their feet being closely ap-
proximated to each other throughout the
whole extent of the body. Myriapods
exhibit the following general characters.
Animal undergoing a metamorphosis by

acquiring in its progress from the egg to
the adult state several additional seg-
ments and legs. Body without wings,
divided into numerous pedigerous seg-
ments, with no distinction of trunk and
abdomen. Head with a pair of an-
tennae ; two compound eyes ; a pair of
mandibles ; under-lip connate with the
maxillae.

This class is divided into two orders,
the Chilognathans and the Chilopodans.
The julus terrestris, belonging to the
first of these two orders, has, at its
entrance into the world, only eight seg-
ments and six feet ; but acquires, in the
course of its development, fifty segments
and about two hundred feet. The an-
terior legs are directed obliquely for-
wards, and the rest more or less back-
wards. The Myriapoda possess in their
internal structure an organization closely
allied to the larva of insects.

MYTILA'CEA. In Cuvier's arrangement,
the second family of the order Acephala
Testacea. All belonging to this family
are bivalves, having a foot which they
use in crawling. Mytilacea comprises, in
Lamarck's system, Modiola, Mytilus, and
Pinna.

MY'TILUS. (mytilus, Lat.) A genus of
the family Mytilacea. The muscle. A
rough, longitudinal, bivalve ; with equal,
convex, and triangular valves ; the an-
terior, and longest side of the shell,
allowing passage of the byssus. The
Mytilus is a littoral shell, moored to
rocks, stones, crustaceans, &c. The foot
of the Mytilus edulis, or common muscle,
can be advanced to the distance of two
inches from the shell, and applied to any
fixed body within that range. By attach-
ing the point to such body, and retract-
ing the foot, this animal drags its shell
towards it ; and by repeating the opera-
tion successively on other points of the
fixed object, continues slowly to advance.
Some Mytili produce pearls.

Lamarck describes two species of fos-
sil Mytili, found at Grignon and Long-
jumeau. Dr. Woodward mentions se-
veral shells of this genus found fossil in
different parts of England ; and Dr. Man-
tell states that they are found in the
Ashburnham beds ; in the lower green
sand ; and in the diluvium of Sussex.
Dr. Mantell also states that shells of this
genus were found by himself and Mr.
Lyell in a bed of shale.

N A C

C 175 ]

NAT

N

NA'CRE. (nacre, Fr. ndcchera, It.) A
sort of mother-of-pearl. The fossil ink-
bags of belemnites found in the lias are
surrounded by nacre.

NA'CREOUS. Glistening ; silvery ; irri-
descent. Having the appearance of mo-
ther-of-pearl. Many membranous shells
exhibit a necreous appearance on their
internal surface, as the Halioti?., or sea-
ear ; Anodon, or fresh-water muscle, &c.

NA'CRITE. (from nacre.) A mineral so
called in consequence of its pearly lustre.
The Talcite of Kirwan. Nacrite occurs
in reniform masses, composed of extremely
minute spangles, or glittering scales. Co-
lour pearly grey, with a tinge of red or
green. It fuses easily before the blow-
pipe. When rubbed between the fingers
it leaves a pearly gloss. Unctuous to
the touch. Its constituents are, silex
56*0, alumine 18-25, potash 8-50, lime
3-10, iron 4-20, water 6-0.

NA'KED. (nackt, Germ.)

1. In botany, applied to flowers having no
calices ; to stems without leaves ; also to
leaves when perfectly smooth, and quite
destitute of hairs.

2. In zoology, applied to molluscs, when
the body is not defended by a calcareous
shell.

NA'NDIT. An ostrich of America ; the Rhea
Americana.

NA'PHTHA. (vd<p9a, Gr. naptha, Lat.
naphte, Fr.) A variety of bitumen,
thin, volatile, fluid, and inflammable ;
unctuous to the touch, and constantly
emitting a strong odour. Colours yel-
lowish-white and yellowish-grey ; trans-
parent. Specific gravity from 0'70 to
0"85. It is highly combustible, igniting
even on the approach of a lighted taper.
It burns with a white or bluish flame,
yields a dense smoke, and yields no resi-
duum. It is insoluble in alcohol. When
long exposed to the air, it becomes yellow
and then brown ; its consistence is in-
creased, and it passes into petroleum.
Naphtha consists of carbon 82-2, hydro-
gen 14 '8. Springs of it exist in many
countries, particularly in the neighbour-
hood of volcanoes. The finest varieties
of naphtha are found on the shores of
the Caspian. The soil is sandy and
marly, and the surrounding minerals are
calcareous. The naphtha is constantly
rising in the state of an odorous inflam-
mable vapour. Naphtha is burnt in lamps
instead of oil.

NA'RWAL. } (narkwal, narwall, Germ, the

NA'RWHAL. $ sea unicorns.) The Mo-

nodon monoceros of Linnaeus. Placed
by Cuvier in the family Cetacea ordi-
naria, order Cetacea. The tusk of this
animal is sometimes ten feet long, and
spirally furrowed. Portions of the skull
of the narwhal have been found in the
Lewes levels, in Sussex.

NA'RES. (from naris, Lat.) The nos-
trils,

NA'SAL. (from nasus, a nose, Lat. nasal,
Fr. nasale, It.) Pertaining to the nose.

NA'SCENT. (nascens, Lat. from nascor, to
be born.) Beginning to exist ; growing.

NA'TANT. (from nato, Lat. to swim.) Swim-
ming in the water ; floating on the sur-
face of the water.

NA'TATORY. (from natator, Lat. a swim-
mer.) Enabling to swim. Certain or-
gans possessed by many animals are
natatory organs. Several of the cephal-
pods and pteropods, and other mollus-
cans, have natatory appendages.

NA'TICA. A genus of nearly globose, um-
bilicated, univalves, belonging to the fa-
mily Neritacea. Aperture entire and
semicircular ; columella transverse, with-
out teeth, and callous externally. These
shells, though strongly resembling Ne-
ritse, may be distinguished from those of
that genus by their being always umbili-
cated, and the columella never dentated.
The recent Natica is found in estuaries and
tidal rivers, in mud and sandy mud, at
depths varying to forty fathoms.

Several species of fossil Natica are
found in the London clay ; Bognor sand-
stone ; Gait ; and in the Shanklin sand.

NA'TROLITE. The Natrolith of Werner;
Natrolithe of Haiiy. Considered by some
mineralogists to be a variety of prismatic
zeolite. Occurs in small, reniform,
rounded, or irregular masses, composed
of very minute fibres. The fibres are
divergent, or even radiate from a centre,
and are sometimes extremely minute and
close. Colours yellow, yellowish brown,
and brown, with striped-colour delinea-
tions* Translucent at the edges. Spe-
cific gravity 2-16 to 2'20. Before the
blow-pipe it fuses readily into a white
glass. In nitric acid it is reduced, with-
out any effervescence, into a thick jelly.
It derives its name from containing soda.
Its constituents are silex 48-20, alumine
24-50, soda 16-10, oxide of iron 1'75, wa-
ter 9-0. It occurs principally at Roegau,
in Suabia, imbedded in amygdaloid.

NA'TRON. (natron, Fr.) The Soude car-
bonatee of Haiiy ; L' alkali mineral natif
of Brochant ; the Natron of Kirwan ,. A

NAT

[ 176 ]

N A U

carbonate of soda occurring massive and
crystallized, the principal supplies com
•ing from lakes in Egypt and Hungary.
Native specimens of Natron are always
mixed with other salts. In Egypt, the
lakes which yield Natron abundantly are
called the lakes of Natron. These are
six in number, to the westward of the
Nile, not far from Terrana, in a valley,
surrounded by limestone.
NA'TURAL HISTORY. This extensive science
has for its object the enquiry into the
being of natural bodies, and their thorough
investigation in reference to their various
qualities, and the relative functions of
their component parts. Understood in
this extent, it presents us with a distinct
unique entirety, which treats the natural
body as complete, but gradually perfected ;
and at the same time seeks to discover
the means whereby it attained its com-
pletion and perfection. Natural history,
therefore, is no mere description of form,
— no description of nature, as it has been,
latterly, very incorrectly considered, but
a true and pragmatical history, developed
from its own fundamental principles. —
Burmeister.

Most unjustly has natural history been
accused of favouring merely minute and
curious enquiries into the small parts of
creation, and of neglecting the larger
views and contemplations which delight
the man of taste and refined feeling.
Whoever reads the works of Pallas, Hum-
boldt, White, Sedgwick, or Lyell, will
acknowledge the error of this misrepre-
sentation.

NAVICULA'RE. (from navicula, dim. of
navis, Lat.) The name given to one of
the bones of the wrist, and of the ankle.
NAUTILA'CEA. A family of Polythalamous
cephalapods, in the arrangement of La-
marck. This family comprises Discor-
bites, Nautilus, Nummilites, Polysto-
mella, Siderolites, and Verticialis.
NAU'TILITE. A fossil nautilus.
NAU'TILUS. A genus of shells belonging to
the family Nautilacea. A spiral, poly-
thalamous, discoidal univalve with smooth
sides. The turns contiguous, the outer
side covering the inner. The chambers
separated by transverse septa, which are
concave outwards, and perforated by a
tube passing through the disk. Three or
four recent species are known. "It is a
curious fact," says Prof. Buckland, "that
although the shells of the nautilus have
been familiar to naturalists, from the days
of Aristotle, and abound in every col-
lection, the only authentic account of the
animals inhabiting them, is that by Rum-
phius, in his history of Amboyna."
Lately Mr. R. Owen has published a
most admirable memoir on this subject.

At the present day the nautilus is an in-
habitant of tropical seas, but its fossil
remains are found in formations of every
age. From Mr. Owen's memoir we learn,
that the animals by which all fossil nau-
tili were constructed, belong to the ex-
isting family of Cephalopodous molluscs,
allied to the common cuttle-fish. The
organ of locomotion in the nautilus ap-
pears to be a foot, resembling that of the
snail. This organ is expansive, and sur-
mounts the head. The oral organs are
much more complicated and numerous
than those of the cuttle-fish, and are fur-
nished with no suckers. Its tentacles are
retractile within four processes, each
pierced by twelve canals protruding an
equal number of these organs, so that, in
all, there are forty-eight. In fact, the
whole oral apparatus, except the mandi-
bles and the lip, is formed upon a plan
different from that of the cuttle-fish, as
likewise from that of the carnivorous tra-
chelipod molluscans, and indicate very
different modes of entrapping and catch-
ing their prey : being deprived of suck-
ers, they seem destitute of any powerful
means of prehension and detention. The
eye, also, is reduced to the simplest con-
dition that the organ of vision can as-
sume, without departing altogether from
the type of the higher classes, so that it
appears not far removed from that of the
proper molluscs. The nautilus has only
a single heart, the branchial one being
absent. The nautilus resides in the ca-
pacious cavity of its first, or external,
chamber ; and it is now well ascertained
that this animal is not a piratical parasite,
occupying the shell of another animal,
which it has murdered, but that it lives,
and sails in a skiff of its own building.
A siphuncle connects the body of the
nautilus with the air chambers, passing
through an aperture and short projecting
tube in each transverse septum, till it
terminates in the smallest chamber at the
inner extremity of the shell. These in-
ternal chambers contain only air, and have
no communication with the outer cham-
ber but by one small aperture in each
septum through which the siphuncle
passes. No water can by any possibility
pass into these chambers, between the
exterior of the siphuncle and the siphonic
apertures of the transverse plates, because
the entire circumference of the mantle in
which the siphuncle originates, is firmly
attached to the shell by a horny girdle,
impenetrable by any fluid. The number
of chambers varies greatly, according to
the age of the animal. Dr. Hook states
that he has found in some shells as many
as forty. The ascent and descent of the
nautilus by means of its siphuncle is very

N A U

[ 177]

NEC

ingeniously and beautifully explained by
Prof. Buckland. The siphuncle, as ap-
pears from Mr. Owen's statement, ter-
minates in a large sac surrounding the
heart of the animal ; if we suppose this
sac to contain a pericardial fluid, the
place of which is alternately changed from
the pericardium to the siphuncle, we shall
find in these organs an hydraulic appa-
ratus for varying the specific gravity of
the shell ; so that it sinks when the peri-
cardial fluid is forced into the siphuncle,
and becomes buoyant, when the same
fluid returns to the pericardium. The
substance of the siphuncle is a thin and
strong membrane, surrounded by a coat
of muscular fibres, by which it could con-
tract or expand itself, in the process of
admitting or ejecting any fluid to or from
its interior. When the arms and body
are expanded, the fluid remains in the
pericardium, and the siphuncle is empty,
and collapsed, and surrounded by the
portions of air that are permanently con-
fined within each chamber ; in this state
the specific gravity of the body and shell
together is such as to cause the animal to
rise, and be sustained floating at the sur-
face. When, on any alarm, the arms and
body are contracted, and withdrawn into
the shell, the retraction of these parts,
causing pressure on the pericardium,
forces its fluid contents into the siphun-
cle ; and as the quantity of matter within
the shell is thus increased, without any
increase of magnitude, the specific gra-
vity of the entire animal is increased,
and it begins to sink. Rumphius states
that, at the bottom of the sea, the nautilus
creeps with his boat above him.

Fossil remains of the nautilus are found
in strata from the mountain limestone
upwards. In some of these the siphun-
culus is beautifully preserved. But while,
as a genus, the nautilus occurs in forma-
tions of every age, from the transition
series upwards, yet certain species appear
limited to particular geological formations :
thus the nautilus multicarinatus is limited
to strata of the transition formation ; the
nautilus bidorsatus, to the muschelkalk ;
the nautilus obesus, and nautilus lineatus,
to the oolite ; the nautilus elegans, and
nautilus undulatus, to the chalk forma-
tion. The eocene, miocene, and pliocene
has each its particular nautili. — Buck-
land. Kir by. Owen. Parkinson.
Sowerby .

NAU'TILUS SY'PHO. The name given to a
very beautiful, camerated, siphuncled fos-
sil shell found in the tertiary strata at
Dax, near Bourdeaux. This fossil pre-
sents deviations from the usual characters
of the nautilus, whereby it approximates
to the ammonite.

NAU'TILUS zic ZAC. A fossil, camerated,
siphuncled shell, found in the London
clay. This and the nautilus sypho ap.-
pear to form connecting links between
the genera Nautilus and Ammonite.

NE'BULA. (nebula, Lat.) A cloud ; a
cluster of stars. It is to Sir Wm. Her-
schel that we owe the most complete
analysis of the great variety of those
objects which are generally classed under
the common head of Nebulae, but which
have been separated by him into, — 1st,
clusters of stars, in which the stars are
clearly distinguishable ; and these, again,
into globular and irregular clusters ; 2nd ,
resolvable nebula, or such as excite a
suspicion that they consist of stars, and
which any increase of the optical power
of the telescope may be expected to re-
solve into distinct stars ; 3d, nebulae,
properly so called, in which there is no
appearance whatever of stars ; which,
again, have been subdivided into subor-
dinate classes, according to their bright-
ness and size ; 4th, planetary nebulae ; 5th,
stellar nebulae ; and, 6th, nebulous stars.
Not fewer than 2000 nebulae, and clus-
ters of stars, were observed by Sir Wm.
Herschel, whose places have been com-
puted from his observations, reduced to a
common epoch, and arranged into a cata-
logue, in order of right ascension. In a
paper read before the Royal Society, Sir
John Herschel gives the places of 2,500
nebulae and clusters of stars ; of these 500
are new. Nebulae have great variety of
forms. The distribution of the nebulae
over the heavens is even more irregular
than that of the stars. In some places
they are so crowded together as scarcely
to allow one to pass through the field of
the telescope before another appears, while
in other parts, hours elapse without a
single nebula appearing. — Sir J. Her-
schel. Mrs. Somerville.

NE'BULAR. Pertaining to nebulae.

NE'BULOUS. Cloudy ; hazy.

NEBULO'SITY. The state of being cloudy.

NECRO'PHAGOUS. (from vtKpbg, dead, and
0ayau, to eat, Gr.) Animals which de-
vour dead substances. The unclean
animals, with respect to their habits and
food, were divided into two classes ;
namely, zoophagous animals, or those
which attack ami devour living animals ;
and necrophagous animals, or those which
devour dead ones, or any other putres-
cent substances.

NE'CROMITE. (from veicpog, dead, Gr.)
A mineral occurring in small masses in
limestone ; found near Baltimore. When
struck it exhales a fetid odour, resem-
bling that of putrid flesh ; from this
quality it obtained its name.

NE'CTARY. That part of a flower which

NEE

[ 178

NEW

secretes and contains the honey, (an al-
most universal fluid in flowers) and is
either a part of the corolla, or an organ
distinct from it, and variously formed, as
the monks'-hood, black hellebore, &c. ;
or it is a tubular elongation of the calyx,
or of a petal ; or, an assemblage of
glands. In monopetalous flowers, the
honey is contained in the tube which,
probably, secretes it. The secretion of
honey is not exclusively confined to the
flower ; in some of the liliaceous tribe
it exudes from the flower- stalk, and in
the passion- flower it is secreted by glands
situated in the peduncle.

NEE'DLE ORE. The Nadelerz of Werner.
Colour steel-grey. Amorphous, or in
acicular hexaedral prisms, which are oc-
casionally invested with a yellowish or
greenish crust. Fracture uneven and
metallic. Specific gravity 6'8. Consti-
tuents, bismuth 43*6, lead 24*50, copper
12-12, sulphur 11-60, nickel 1'58, tellu-
rium 1-32. It occurs in a gold-mine near
Schlangenberg, in Siberia.

NEE'DLE STONE. A variety of zoolite, of a
yellowish-white colour, found in Ice-
land.

NEMATU'RA. A genus of shells belonging
to the family Turbinacea. Two species
are known as recent, and one has been
found fossil.

NE'PHELINE. (from vetyiXr), a cloud, Gr.)
The Sommite of Jameson ; Nephelin of
Werner. A mineral found only in the
cavities of lava at Mount Somma, from
which circumstance it has been called
Sommite. Occurs generally in small,
regular, six-sided prisms, associated with
mica, hornblende, and idiocrase. Specific
gravity 3-27. Colour greyish-white, or
greenish-grey. It is translucent, and
sometimes transparent. Before the blow-
pipe it fuses, with difficulty, into a trans-
parent glass. Its constituents are silex
46, alumine 49, lime 2, oxide of iron 1.

NE'PHRITE. (from veQpiTrjQ, ab vtQpog, a
kidney, Gr.) A mineral, formerly worn
from an absurd notion that diseases of the
kidney were relieved by so doing. It is
a subspecies of jade, possessing the hard-
ness of quartz, combined with a peculiar
tenacity which renders it difficult either
to break, cut, or polish. It is unctuous
to the touch ; fracture splintery and dull ;
translucent. Colours green, grey, and
white. Specific gravity from 2'9 to 3'1.
Constituents, silex 53*80, lime 12-75,
soda 10-80, potash 8'50, alumine 1-55,
oxide of iron 5-0, oxide of manganese 2-0,
water 2'30. Nephrite is brought from
India, China, and Persia ; it is found
also, in primary rocks, in Germany and
Egypt. It is worked into handles for
sabres, knives, daggers, &c.

NEPTU'NIAN. (from Neptunus, the fabled
deity of the ocean.) Pertaining to the
ocean.

NEPTU'NIAN THE'ORY. That theory which
attempted to prove that all the formations
have been precipitated from water, or
from a chaotic fluid.

NE'PTUNISTS. The supporters of the Nep-
tunian theory ; they were opposed by the
Vulcanists.

NERITA'CEA. A family of Trachelipods,
including the genera Natica, Nerita, Ne-
ritina, Navicella, and Janthina.

NERITI'NA. A genus of fresh-water uni-
valves, belonging to the family Neritacea.
Shell thin, semiglobose, obliquely oval,
smooth, flattish in front ; spire short ;
aperture semicircular ; outer lip thin ;
columellar lip broad, flat, denticulated.
Differs from Nerita in the minuteness of
the denticulation of the columella. —
Sowerby.

Dr. Mantell describes a species, found,
in the state of casts, in the Tilgate grit,
which he has named Neritina Fittoni, in
honour of Dr. Fitton.

NERI'TA. A genus of marine univalves
included in the family Neritacea. The
Nerita is a littoral shell, creeping on rocks
and sea-weeds. A semi-globose univalve,
depressed beneath, and having no umbi-
licus ; aperture entire and semicircular.
The aperture is generally large in compa-
rison with the shell, but it is furnished
with an operculum which completely
closes it.

Of the fossil species, one, Nerita Conoi-
dea, is remarkable, both on account of its
form and the magnitude which it some-
times possesses. Parkinson states that
he is not acquainted with any shells of
this genus among our English fossils ;
Dr. Mantell mentions one species from
the diluvium of Sussex. Lamarck par-
ticularizes three species as being found in
France.

NEURO'PTERA. (from vtvpov, a nerve, and
Trrt/oov, a wing, Gr.) Nerve-winged in-
sects. Neuroptera, in Cuvier's arrange-
ment, constitutes the eighth order of In-
secta. The Neuroptera have four mem-
branous wings, usually reticulated by
numerous nervures, but having no sting,
or ovipositor. The Neuroptera are mostly
bold, rapacious, and sanguinary ; perpe-
tually chasing and devouring other insects.
The libellula, or dragon-fly, is a familiar
example.

NEURO'PTEROUS. Belonging to the order
of Neuroptera.

NEW RED SANDSTONE. A series of brick-
red strata lying immediately above the
coal measures ; sometimes called varie-
gated sandstone, in consequence of the
occurrence of spots and stripes of a

NEW

[ 179 ]

N I T

greenish -grey colour. It is a conglome-
rate, its prevailing character being sili-
ceous, but comprising calcareous beds of
considerable magnitude and extent. By
some, the new red sandstone has been
divided into three series ; the upper, the
middle, and the lower beds. Over a
large part of England the new red sand-
stone rests unconforrnably upon the car-
boniferous group, showing that the latter
was disturbed, dislocated, and partially
removed, before the former was accumu-
lated upon it ; there is, however, reason
to believe that in other parts of the Euro-
pean area deposits still continued quietly
to be thrown down upon undisturbed
parts of the carboniferous series, so that
no real line of separation can be well
established between them. It is almost
needless to observe when we contemplate
the red sandstone series as a whole, and
consider that it is in great measure com-
posed of matter which must have been
deposited from water where it was, for
the time, mechanically suspended, that
great variations should be expected at the
same geological levels ; here clay or marl
being found, there sandstone or conglo-
merate, while, occasionally, calcareous
matter should be dispersed among it,
under favourable circumstances, in suffi-
cient abundance to constitute numerous
beds of limestone.

A very remarkable discovery was made
in 1828 of the foot-marks of some un-
known quadruped in strata of new red
sandstone, three miles from Lochmaben
in Dumfries-shire. They were found
forty-five feet under the present surface ;
the strata are inclined thirty- seven de-
grees.— Bakewell. Phillips.

NEWER PLIOCENE PERIOD. Mr. Lyell re-
fers the European tertiary strata to four
successive periods, each characterised by
containing a very different proportion of
fossil shells of recent species. These
four periods he termed Newer Pliocene,
Older Pliocene, Miocene and Eocene ;
the etymology of these terms will be fully
explained under the several words. The
Newer Pliocene period is the latest of the
four periods, and immediately precedes
the recent era. Nevertheless, the anti-
quity of some Newer Pliocene strata, as
contrasted with our most remote his-
torical eras, must be very great, em-
bracing perhaps myriads of years. Out
of 226 fossil species brought from the
Sicilian beds, M. Deshayes found that no
fewer than 216 were of species still living.
The newer pliocene formation is deve-
loped in Sicily and Tuscany ; its character
is marine, fresh water, and volcanic.

NI'CKEL. (nickel, Germ.) A metal of
considerable hardness, nearly equal to

that of iron, of a colour intermediate be-
tween silver and platina. When polished,
it has a high lustre. Specific gravity
8-93. It is both ductile and malleable,
and may be hammered into very thin
plates. It is difficult to be purified. In
common with iron, it is magnetic, capable
of acquiring polarity, and may be formed
into permanent magnetic needles ; this
property is destroyed by an alloy with
arsenic. Nickel unites in alloys with
gold, copper, tin, and arsenic, which
metals it renders brittle. With silver and
iron its alloys are ductile.

Nickel was discovered as a distinct
metal by Cronstadt, in 1751. Its solu-
tion in nitric acid is nearly grass green.
Nickel is found in all meteoric stones.

NI'GRINE. (from nig/er, Lat. black.) A
variety of ferruginous oxide of titanium,
occurring in grains, or rolled pieces.
Colour black, or brownish- black. It
consists of titanium 84*0, oxide of iron
14'0, oxide of manganese 2'0.

NI'TRATE. A compound of nitric acid with
a salifiable base.

NI'TRE. (virpov, Gr. nitrum, Lat. nitre,
Fr. nitro, It.) Nitrate of potash ; salt-
petre. The potasse nitratee of Haiiy ;
natiirlicher salpeter, of Werner. Nitre,
or nitrate of potash, is found native in
all countries, where there are circum-
stances favourable to its production. It
frequently effloresces on the soil ; but
never exists at a greater depth, than that
of a few yards beneath the surface. It
occurs, naturally, either in masses, or in
thin irregular crystals ; it is white, semi-
transparent, and brittle ; salt and cold in
taste. When thrown on hot coals, it
burns with a sparkling bright light, and
with a crackling noise. It crystallizes in
six-sided prisms, terminated by a dihedral
summit, and retains no water of crystalli-
zation. The crystals are permanent, and
soluble in seven parts of water at 60°,
and in less than their own weight at 212°.
The principal supply of nitre is from
India. One of the most remarkable lo-
calities of nitre in Europe, is in the Pula,
or cavity of Molfetta, in the kingdom of
Naples. This cavity, which is about one
hundred feet deep, contains several grot-
tos or caverns, in the interior of which is
found nitre in crusts, attached to compact
limestone. When these crusts are re-
moved, others appear in about a month.
The various sources of native nitre not
being sufficient to supply the great de-
mand there exists for it, it is manufac-
tured wholesale, in the following manner.
Rubbish, consisting of lime, mortar,
plaster, and earth, is mixed up in heaps,
under sheds, with decaying vegetables
and refuse matter, and left to rot; the

N I T

[ 130]

NOD

masses being occasionally moistened wkh
animal fluids, as urine, blood, &c. The
nitrogen, disengaged from the corrupting
mass, unites with the oxygen of the at-
mosphere, and forms nitric acid ; this,
combining with the potash furnished by
the vegetable substances, produces an
impure nitre. The salt is collected, and
afterwards washed and purified.
NI'TROGEN. (from virpov, nitre, and
ytvvdb}, to produce, Gr. ) Called also
azote. Nitrogen constitutes about four-
fifths, or eighty per cent, of common air ;
the rest being principally oxygen. In its
pure state, nitrogen is remarkable for its
negative qualities ; that is to say, for the
difficulty with which it enters into combi-
nation with other matters. Thus, it is
neither combustible, nor a supporter of
combustion ; it is neither acid, nor alka-
line ; possesses neither taste nor smell ;
nor does it directly combine with any
known substance. Yet when made by
peculiar management to unite with oxygen,
hydrogen, or carbon, nitrogen forms some
of the most energetic compounds we pos-
sess ; thus, mixed with oxygen, it forms
atmospheric air ; united with oxygen, it
forms aquafortis, the most corrosive of
liquids ; united with hydrogen, it forms
the volatile alkali, or ammonia, likewise
an energetic compound, but of an oppo-
site nature ; while united with carbon and
hydrogen, it forms prussic acid, the most
virulent poison in existence.

The existence of nitrogen in animal and
vegetable life may be considered as se-
condary, that is, derived from the atmo-
sphere in the first instance. There is
also every reason to suppose that it can-
not be absent from numerous rocks which
contain the organic remains of animals
that have been entombed living, or at
least with their flesh upon them. We
have direct evidence in coal that nitrogen
forms a portion of what may be con-
sidered solid rock. Dr. Thomson found
it to constitute 15-96 per cent, of the
Newcastle caking coal, and there is good
reason for supposing that this is rather an
tinder-estimate of the amount of nitrogen
contained in some coal, judging from the
abundance of ammoniacal products given
out during the distillation of coal in gas-
works.

The absorption of nitrogen during re-
spiration, was one of the results Dr.
Priestley had deduced from his experi-
ments ; and this fact, though often
doubted, appears, on the whole, to be
tolerably well ascertained by the inquiries
of Davy, Pfaff, and Henderson. With
regard to the respiration of cold-blooded
animals, it has been satisfactorily esta-
blished by the researches of Spallanzani,

and more especially by those of Hum-
boldt and Provencal, on fishes, that ni-
trogen is actually absorbed. A confirma-
tion of this result has been obtained by
Macaire and Marcet, who have found
that the blood contains a larger propor-
tion of nitrogen than the chyle, from
which it is formed.

Nitrogen has been recently found, by
Dr. Daubeny, to be contained very gene-
rally in the waters of mineral springs.
The king's bath, at Bath, evolves 96'5 per
cent, of nitrogen, 3'5 oxygen, and some
carbonic acid. The hot-well at Bristol
evolves 92 per cent, nitrogen, and 8 oxy-
gen. The springs at Buxton, Bakewell,
and Stony Middleton, Derbyshire, evolve
nitrogen only. Those of the Spas, in
Germany, yield various proportions, as
do the other thermal springs in other
parts of the globe.

The easiest mode of procuring nitrogen
is to abstract from atmospheric air, by
the combustion of phosphorus or hydro-
gen, the oxygen with which it is asso-
ciated. Its specific gravity is 0*9722. It
forms one of the fifty-five simple, or
elementary bodies. — Prout. De la Heche.
Roget. Phillips.

NI'VEOTJS. (niveus, Lat.) Snowy ; resem-
bling snow ; of a snow-white colour.

NOA'CHIAN. Pertaining to the great deluge
related by Moses, from which Noah and
his family were saved, and thus called
after Noah.

NODE, (nodus, a knot, Lat. nodus, Fr.
nado, It.) A hard knot or swelling, a
bump, or rising.

In astronomy, the nodes of a satellite's
orbit are the points in which it intersects
the plane of the orbit of a planet. The
ascending node is the point through which
the body passes in rising above the plane
of the ecliptic, and the descending node
is the point through which the body
passes in sinking below the plane of the
ecliptic.

NOCTI'VAGANT. } (from nox, the night, and

NOCTI'VAGOUS. $ vagor, to wander, Lat.)
A name given to such animals as wander,
in search of prey, during the night.

NODOSA'RIA. A genus of orthocerata, found
only fossil. They are polythalamous
univalves.

NO'DOUS. Knotty ; full of knots.

NO'DCLAR. In the form of a nodule or
small lump.

NO'DULAR IRON ORE. A variety of argil-
laceous oxide of iron ; occurring in masses,
varying from the size of a walnut to that
of a man's head. Their form is spheri-
cal, oval, or nearly reniform, or sometimes
like a parallelepiped with rounded edges
and angles. They have a rough surface,
and are essentially composed of concentric

NOD

C 181 ]

NOR

layers. These nodules often contain, at
the centre, a kernel or nucleus, which is
sometimes moveable, and always differing
from the exterior in colour, density, and
fracture. The texture of the exterior is
compact and solid ; but the density gra-
dually diminishes to the centre, which has
an earthy texture. Specific gravity, about
2*57. Its constituents are oxide of iron
77'0, silex 6-0, oxide of manganese I'O,
alumine 0'5, water 13-5. These nodules
have also been called CEtites and Eagle-
stones, from an opinion that they were
found in eagles' nests, where, it was sup-
posed, they prevented the eggs from be-
coming rotten.

Nodular iron ore is found disseminated
in beds of ferruginous clay in secondary
earths, and sometimes in alluvial deposites
of clay, loam, or sand. This ore is fre-
quently worked, and yields very good
iron. Nothing very satisfactory can be
said concerning the manner in which these
nodules have been formed. — Cleaveland.

NO'DULE. (from nodulus, a little knot,
Lat.) A rounded, irregular shaped, mi-
neral mass.

NO'GROBS. A fossil resembling a belem-
nite.

NOMENCLATURE, (nomenclatura, Lat. no-
menclature, Fr. collection des mots qui
sont propres auoc difftrentes parties d'une
science ou d'un art.) The names of
things in any art or science, or the whole
vocabulary of technical terms which are
appropriated to any particular branch of
art or science.

The imposition of a name on any sub-
ject of contemplation is an epoch in its
history of great importance. It not only
enables us readily to refer to it in conver-
sation or writing, without circumlocution,
but, what is of more consequence, it gives
it a recognized existence in our own
minds, as a matter for separate and pe-
culiar consideration. How important a
good system of nomenclature is, may at
once be seen, by considering the immense
number of species presented by almost
every branch of science of any extent,
which absolutely require to be distin-
guished by names. Thus, the botanist
is conversant with from 80, 000 to 100,000
species of plants; the entomologist with,
perhaps, as many, of insects. And the
same as regards chemistry, astronomy, &c.
Nomenclature, then, is, in itself, an
important part of science, as it prevents
our being lost in a wilderness of parti-
culars, and involved in inextricable con-
fusion. Happily, in those great branches
of science, where the objects of classi-
fication are more numerous, and the ne-
cessity for a clear and convenient nomen-
clature most pressing, no very great diffi-

culty in its establishment is felt. The
facility with which the chemist, the bo-
tanist, or the entomologist, refers by name
to any individual object in his science,
shows what may be effected in this way
when characters are themselves distinct.

Nomenclature, in a systematic point of
view, is as much, perhaps more, a con-
sequence than a cause x>f extended know-
ledge. Any one may give an arbitrary
name to a thing, merely to be able to talk
of it ; but to give a name which shall at
once refer it to a place in a system, we
must know its properties ; and we must
have a system, large enough, and regular
enough, to receive it in a place which be-
longs to it and to no other.

There is no science in which the evils
resulting from a rage for nomenclature have
been felt to such an extent as in mineralogy.
The nomenclature of most minerals is at
present so encumbered with synonyma,
that it has become extremely perplexing
to the student. This may be illustrated
by the example of Epidote. This mineral,
which is called epidote by Haiiy, is named
pistazit by Werner, thallite by Leme-
therie, akanticone by Dandrada, delphi-
nite by Saussure, glassy actinolite by
Werner, arendalit by Karsten, glassiger
strahlstein by Emm^rling, la rayonnante
vitreuse by Brochant, prismatoidischer
augit-spath by Mohs, &c. &c.

In all subjects where comprehensive
heads of classification do not promi-
nently offer themselves, all nomenclature
must be a balance of difficulties, and a
good, short, unmeaning name, which has
once obtained a footing in usage, is pre-
ferable to almost any other. When the
composition is unknown, those names,
which are altogether unmeaning in re-
gard to any property of the thing, are,
perhaps, the least objectionable; at all
events, they cannot lead to error.

Linnaeus was the first to introduce
systematic names into natural history.
By the introduction of these scientific,
fixed, and universally valid names, Lin-
naeus has undoubtedly acquired his great-
est merit in science, and if every thing
else which he has done should be for-
gotten, this, which is wholly his work,
will secure his name from forgetfulness. —
Herschel. Cleaveland. Burmeister.
NO'RKA. The name given by Cronstadt to
an aggregate of quartz, mica, and garnet.
This aggregate is included by Kirwan in
the granatines.

NO'RFOLK CRAG. An English tertiary for-
mation belonging to the older pliocene.
It is observed to rest on the chalk and on
the London clay. It consists of irregular
beds of ferruginous sand clay, mixed with
marine shells. According to an account

N O V

[ 182 ]

NUT

of Mr. S. Woodward, if a line be drawn
from Cromer, on the northern coast of
Norfolk, to Wayburn, about six miles
west, and from thence extending in a
southerly direction towards Norwich,
about 18 miles, it will comprise all the
regular beds of Norfolk crag.

NOVA'CULITE. (from novacula, a razor,
Lat.) The Wetz schiefer of Werner ; ar-
gile schisteuse novaculaire of Haiiy. Hone-
stone. See Hone.

NU'CLEUS. (nucletis, a kernel, Lat.) A
solid centre or point, round which matter
is collected.

NU'CULA. A genus of marine bivalve shells
belonging to the family Arcacea. An
inequilateral, equivalved, transverse, sub-
trigonal bivalve ; covered with an epi-
dermis. The hinge linear, bent at an
angle formed by numerous, alternately
inserted teeth ; muscular impressions,
two, simple ; beaks approximating, and
turned backwards. The recent species of
this genus are found in estuaries, and in
the ocean, at depths varying to sixty fa-
thoms, in mud and sand.

Of fossil species, one is mentioned by
Dr. Mantell, as found in the upper green -
sand, and one in the lower green- sand.
Mr. Parkinson states that he has found
shells of the Nucula inargaritaeea, with
their fine comb-like teeth, and their pearly
coat, quite perfect, in the Essex bank of
shells ; and in a perfect state, and of a
microscopic size, at Plumsted ; also some
minute calcedonvc specimens, in a perfect
state, from the Devonshire whetstone.
Several species are described by La-
marck.

NU'DIBRANCHIATA. The second order of
the class Gasteropoda. The nudibran-
cliiata have no shell whatever ; neither
are they furnished with any pulmonary
cavity, their branchiae being exposed on
some part of their back, from which cir-
cumstance they have obtained their name.
The triton, doris, &c. are examples.

NU'MMULITE. (from nummus, money, Lat.
and Xi0oc, a stone, Gr.) The nummu-
lites compose a fossil extinct genus of mul-
tilocular cephalopods, presenting, exter-
nally, a lenticular figure, without any
apparent opening, and, internally, a
spiral cavity, divided by septa into nu-
merous chambers ; they do not possess a
siphuncle, but their chambers communi-
cate by means of small foramina with each
other. They have obtained their name
from their supposed resemblance to pieces
of money. It is of stone composed of
Nummulites that the pyramids of Egypt
are constructed. The extreme obscurity
in which the nature of nummulites has
been involved, almost to the present day,
has occasioned the adoption of various

vague and absurd notions respecting their
origin, and a variety of names have been
assigned to them. Thus, they have been
named Helicites, from their spiral struc-
ture ; Phacites, from their resemblance
to a lentil ; and Salicites, from the sup-
posed resemblance of their sections to
the leaf of the willow. Pliny is supposed
to refer to them, under the name of Daph-
nias. when he mentions that Zoroaster em-
ployed these substances for the cure of
epilepsy. They have been also termed
Lentes lapidea?, Lapides cumini, circu-
lares, numismales, &c.

Scheuchzer was the first who concluded
that these bodies ought to be ranked
among the mineralized remains of animals
which had lived before the flood.

Nummulites vary in size from less than
an eighth of an inch, or even microscopic
minuteness, to an inch and a half in dia-
meter. Their surface is in some nearly
smooth, in others rough and scabrous,
•with numerous small projecting knobs, or
undulating lines. Their colour varies
from nearly white to brown and red, and
sometimes nearly blue. The number of
spiral turns seems to depend on the age
and size of the animal : in those of a
quarter of an inch in diameter, being
three or four, while in those of the largest
size the number of whorls is frequently
upwards of twenty. Lamarck divides the
genus into four species.

Nummulites occupy an important place
in the history of fossil shells, on account
of the prodigious extent to which they are
accumulated in the later members of the
secondary, and in many of the tertiary
strata.' They are often piled on each other
nearly in as close contact as the grains in
a heap of corn. Entire calcareous hills
are composed of fossil nummulites.

NUMMULI'TIC. Containing nummulites ;
composed of nummulites.

NU'TANT. (from nutans, nodding, Lat.)
A perpendicular part, the apex of which
bends over.

NUTA'TION. (from nutatio, a nodding, Lat.
nutation, Fr.) A tremulous or vibratory
motion of the earth's axis, by which its
inclination to the plane of the ecliptic is
continually varying, being, in its annual
revolution, twice inclined to the ecliptic,
and as often returning to its former po-
sition. Both the celestial latitudes and
longitudes are altered to a small degree by
nutation. In consequence of this real
motion in the earth's axis, the pole-star,
forming part of the constellation of the
Little Bear, which was formerly 12° from
the celestial pole, is now within 1° 24' of
it, and will continue to approach it till it
is within i°, after which it will retreat
from the pole for ages ; and 12,934 years

NUT

[ 183]

O C E

hence, the star a Lyrse will come within
5° of the celestial pole, and become the
polar star of the northern hemisphere.
NUT-GALL. An excrescence which grows
on some species of oaks. These excres-
cences are produced by the Cynip quercus
folii, of Linnaeus, a small insect which
deposits its egg in the tender shoots of

the quercus infectoria, a species of oak
abundant in Asia Minor. When the
maggot is hatched, it produces a morbid
excrescence of the surrounding parts, and
it ultimately eats its way out of the nidus
thus formed, and makes its escape. The
best galls are imported from Smyrna and
Aleppo. — Brande, Man. of Pharmacy.

O

OBCO'RDATE. In botany, an epithet for an
inversely heart-shaped leaf, petal, or le-
gume.

OBLA'TE. (oblatus, Lat.) Flattened or
depressed at the poles ; generally applied
to spherical bodies, flattened at the poles ;
of the shape of an orange.

OBLA'TE SPHE'ROID. A spheroid flattened
at the poles is called an oblate spheroid :
such is the form of the earth and planets.
When, on the contrary, a spheroid is
drawn out at the poles instead of
being flattened, it is called a prolate
spheroid.

OBLI'QUE. (obliquus, Lat. oblique, Fr.
oblico, It.) Not direct ; not perpendi-
cular ; not parallel.

In botany, applied to the position of
leaves, and implies that one part of the
leaf is horizontal and the other ver-
tical.

In conchology, applied to the whorls of
spiral univalves, which commonly 'are in
an oblique direction in reference to the
axis of the shell. The term is also ap-
plied to bivalves when they slant off from
the umbones.

OBLI'Q,UITY. (from obliquitas, Lat. obli-
quite, Fr. obliquita, It.) Deviation from
parallelism or perpendicularity.

O'BLONG. (oblongus, Lat. oblong, Fr.)
Having greater length than breadth ;
longer than broad.

In botany, applied to leaves several
times longer than broad. The term is
chiefly used to discriminate a leaf whose
form does not accurately come under
the denominations oval, linear, or
round.

O'BLONG O'VATE. Oblong egg-shaped ;
between oblong and egg-shaped.

OBO'VATE. In botany, applied to leaves
having the form of an egg, with the broad
end forming the base, and the pointed the
apex of the leaf.

OBSI'DIAN. Vitreous lava, a volcanic pro-
duction, of a dark green colour approach-
ing to black. An analysis of obsidian
from Mount Hecla, by Vauquelin, gives
the constituents as follows, silica 78'0,
alumina lO'O, potash 6'0, lime TO, soda

1*6, oxides of iron and manganese
1-0.

Obsidian has been divided into two
kinds, the vitreous and pearly ; these
may be distinguished by their fracture,
which is either vitreous or pearly.

Vitreous obsidian bears a strong re-
semblance to the glass of wine-bottles.
Its fracture is conchoidal, showing fre-
quently large cavities. Lustre vitreous.
Specific gravity from 2'34 to 2'90. It
generally occurs in large amorphous
masses, when it appears almost black; it
is sometimes found in rounded grains.

Pearlstone, the Obsidienne perlee of
Brongniart ; this variety has a granular
structure, and is traversed by fissures in
all directions. It is consequently very
brittle. Its fracture is uneven or granu-
lar, and, as before mentioned, pearly.
When moistened by the breath it fre-
quently returns an argillaceous odour. It
occurs amorphous only.

Before the blow-pipe both varieties in-
tumesce, but the vitreous alone fuses into
a globule. Obsidian bears indisputable
characters of having once been in a state
of fusion.

OBTU'SE. (obtusus, Lat. obtus, Fr.) An
angle which is more than ninety degrees,
or that of a right angle.

O'B VOLUTE. In botany, applied to leaves,
when their margins alternately embrace
the straight margin of the opposite leaf.

OCCIDENTAL, (occidentalis, Lat. occiden-
tal, Fr. occidentale, It.) Western, as
opposed to oriental.

OCCIPITAL, (from occiput, the hind part
of the head, Lat. occipital, Fr.) Per-
taining to the back part of the head.

O'CCIPUT. (occiput, Lat. from ob and
caput, occiput, Fr.) The back part of
the head : the fore part is called sinciput.

O'CEAN. (uKtavoQ, Gr. oceanus, Lat.
ocean, Fr. oceano, It.) That vast body of
water which covers more than three-fifths
of the earth's surface. The average depth
of the ocean has been very variously esti-
mated. Laplace considered, in order to
account for the height of the tides ac-
cording to the laws of gravitation, the

O C E

[ 184 ]

O E S

depth to average ten miles ; others rate
it at five miles. The present cannot be
considered as having always been the bed
of the ocean ; on the contrary, what are
now the most elevated portions of the
earth's crust were once submerged, and
over them the ocean for ages rolled its
majestic waves. This is not an invention
of modern geologists, Ovid declares the
same : —

Vidi factas ex sequore terras ;
Et procul a pelago conchse j acuere marinee ;
Et vetus inventa est in montibus anchora summis;
Quodque fuit campus, vallem decursus aquarum
Fecit ; et eluvie mons est deductus in sequor :
Eque paludosa siccis humus aret arenis ;
Quaeque sitim tulerant, stagnata paludibus hument.
Metamorph. lib. xv.

OCEA'NIC. Pertaining to the ocean ; in-
habiting the ocean.

OCEA'NIC DE'LTA. A delta formed at the
mouth of rivers where they enter the
ocean, as distinguished from either lacus-
trine or mediterranean deltas. Mr. Lyell
observes, " whenever the volume of fresh
water is so great as to counteract and
almost neutralize the force of tides and
currents, and in all cases where these
agents have not sufficient power to remove
to a distance the whole of the sediment
periodically brought down by rivers,
oceanic deltas are produced.

O'CELLATED. (ocellatus, Lat.) In con-
chology, applied to shells, when marked
with little eye-like spots.

O'CHRE. (u»xpa> Gr. ochra, Lat. ocre, Fr.)
Red iron ore ; it yields good malleable
iron. Colours red, yellow, and brown.
It occurs in dull earthy masses, nearly or
quite friable, which soil the fingers. Its
constituents are oxide of iron 83'0, silex
5-0, water 12 0.

O'CHREOUS. Containing ochre ; resembling
ochre.

OcxAe'DRAL. ^ Having eight sides all

OCTAHE'DRAL. $ equal.

OCTAC'DRITE. Octaedral oxide of titanium ;
the Titane anatase of Brongniart ; Octae-
drit of Werner ; Octaedrite of Jameson ;
the Oisanite of Lameth. A pure oxide of
titanium, crystallized in acute, elongated
octacdrons, consisting of two pyramids,
whose faces are isosceles triangles, and
whose bases are squares. Colours blue,
blackish- blue, and brown. Lustre splen-
dent and adamantine. Fracture foliated ;
easily broken. It scratches glass. Spe-
cific gravity 3'8. Before the blow-pipe it
is infusible by itself, but with borax it
fuses into a glass. It occurs in veins in
Dauphiny, Norway, Spain, and Brazil.

OCTAC'DRON. ) (oKTaidpog, from OKTCJ,

OCTAHE'DRON. $ eight, and tdpa, a side,
Gr. octaedre, Fr.) The solid angles of
an octaedron are formed by four equal

and equilateral plane triangles ; conse-
quently it is formed by two equal spare
pyramids joined together at their bases,
the sides whereof are equilateral triangles.
The octahedron (unlike some forms which
are not susceptible of variation, as the die
or cube, a solid invariably bounded by six
square surfaces or planes) is susceptible
of variation ; it is sometimes flat and low,
and, at others, acute and high.

Ocxoe'jDRiTE. See Octaedrite.

O'CTOPUS. (from oicrtu, eight, and TTOVC, a
foot, Gr.) A genus of sepise. The octo-
pus was the animal denominated polypus
by Aristotle. It has eight arms, all of
equal length, and contains in its interior
two very small rudimental shells, formed
by the inner surface of the mantle. This
shell becomes much more distinct in the
loligo. — Roget.

O'CTODENTATE. (from octo, eight, and
dentatus, toothed, Lat.) Having eight
teeth, and no more.

O'CTOFID. (from octo, eight, andfindo, to
cleave, Lat.) Eight-cleft. In botany,
an epithet for a calyx divided into eight
segments.

OCTOLO'CULAR. (from octo, eight, and
loculus, a cell or pocket, Lat.) Eight-
celled.

OCTONO'CULAR. (from octo, eight, and
oculus, an eye, Lat.) Having eight
eyes.

OCTOPE'TALOUS. (from o/crw, eight, and
irtToXbv, a petal, Gr.) Having eight
petals or flower-leaves.

OCTO%PE'RMOUS. (from OKT-W, eight, and
(TTrgpjua, seed, Gr.) Eight-seeded; hav-
ing^ eight seeds.

O'CULATE. (oculatus, Lat.) Having
eyes.

O'CULIFORM. (from ocvJus, an eye, and
forma, shape, Lat.) Resembling an eye
in its form ; eye- shaped.

ODORI'FEROUS. (from odor, scent, and
fero, to give, Lat. odoriferant, Fr. odori-
fico, It.) Yielding scent ; giving out
perfume. Generally, but not always, used
to denote sweet scent.

O'DOROUS. (odorant, Fr. odorifero, It.)
Fragrant ; sweet of scent.

(ESO'PHAGUS. (asophage, Fr.) The gul-
let, or passage leading from the mouth to
the stomach, through which the food
passes. In the structure of the oesopha-
gus, we may trace an adaptation to the
particular kind of food taken in by the
animal. When it is swallowed entire, or
but little changed, the oesophagus is a
very wide canal, capable of being greatly
dilated. Serpents, which swallow animals
of greater circumference than themselves,
have an oesophagus admitting of great di-
latation ; the food in such cases remaining
a long time in the canal, before it reaches

O G Y

[185 ]

OMB

the stomach. Grazing animals, who
carry their heads close to the ground
while feeding, have the oesophagus
strengthened by thick muscular coats,
whereby the food is propelled towards
the stomach, the direction being contrary
to that of gravity.

OGY'GIAN. (from Ogyges, a celebrated
monarch, the most ancient of those that
reigned in Greece.) His origin, the age
in which he lived, and the duration of his
reign are so obscure and unknown, that
the epithet of Ogygian is often applied to
every thing of dark antiquity.
OGY'GIAN DE'LUGE. The name given to a
deluge which happened in the reign of
Ogyges, which so inundated the territories
of Attica, that they remained waste for
nearly 200 years. This is supposed to
have happened about 1764 years before
the Christian sera.

OGY'GES. The name given by Guettard to

a species of trilobite, from its being found

among the most ancient rock formations,

containing vestiges of organic life.

OI'SANITE. The name given by Lameth to

pyramidal titanium or anatase.
OLD RED SANDSTONE. The lowest member
of the carboniferous group, extensively
developed in the counties of Shropshire
and Herefordshire, in England ; Breck-
nockshire, in Wales ; and Dumfriesshire
and Forfarshire, in Scotland. The old
red sandstone strata lie between the car-
boniferous series and the silurian rocks.
It consists of many varieties and alter-
nations of silicious sandstones and conglo-
merates of various colours, red predomi-
nating. Mr. Bakewell says, " the old
red sandstone, about which so much has
been written, and so little understood, is
a greywacke, coloured red by the acci-
dental admixture of oxide of iron. It
possesses all the mineral characters of
greywacke, except the colour, which is a
quality that never can be considered of
importance, being chiefly derived from
local or accidental causes. The old red
sandstone also occupies the geological
position of greywacke, and greywacke
slate, into which it passes merely by a
change of colour. Until English geolo-
gists shall renounce their prejudices, and
place the old red sandstone and mountain
limestone in the transition class, as grey-
wacke, and transition limestone, every
attempt will be vain to identify this part
of the geology of England with that ol
the continent."
OLDER PLIOCENE. Mr. Lyeli has sub-di-
vided the tertiary epoch into four periods ;
namely, the newer pliocene, the older
pliocene, the miocene, and the eocene.
The term pliocene he derived from the
two Greek words TrXawv, more, anc

Kaii'oc, recent. The older pliocene for*
mations lie between the miocene and the
newer pliocene. Of fossil shells examined
by M. Deshayes, the older pliocene con-
tained from thirty-five to fifty per cent, of
recent fossils.
^LEA'GINOUS. (oleaginus, Lat. oleagi-

neux, Fr. olioso, It.) Oily ; unctuous.
DLE'CRANON. (oXeKoavov, Gr. from ojXevri, 4
the ulna, and icdprjvov, the head.) A
process of one of the bones of the fore
arm, the ulna, forming part of the elbow-
joint.

DLFA'CTORY. (from olfacio, to smell, to
give a scent to, Lat. olfactoire, Fr. ol-
fattore, It. ) Having the sense of smell-
ing ; pertaining to smelling : as the ol-
factory nerves, &c.

D'LIVA. (oliva, an olive, Lat.) So named
from the oblong and elliptical shape of the
shell. A marine subcylindrical univalve ;
aperture narrow, long, and emarginated
opposite to the spire, which is short ; the
plicae of the columella are numerous, and
resemble striae ; whorls sulciform. Mr.
Gray has ascertained that , in the olivee,
shell is deposited, and most probably
secreted, by the upper surface of the foot,
which is very large, and not by the
mantle, which is small, and does not ex-
tend beyond the edge of the mouth. The
shells of this genus are very beautiful,
and display a great variety of rich mark-
ings and splendid colours. Recent olivae
are found at depths varying to twelve
fathoms, in mud, sandy mud, coarse
sand, &c. They are also caught by
fishing lines. Fossil olivse are found in
the calcaire grossier, and London clay.
Several species have beefr described.
OLIVA'CEOUS. Of an oiive colour, a green

with an admixture of brown.
OLI'VENITE. An ore of copper of an olive-
green colour. It consists of oxide of
copper 63P0, phosphoric acid 28'6, water
8 '4. Occurs with quartz in micaceous
clay-slate, in drusy cavities.
O'LIVINE. The prismatischer chrysolithe
of Mohs ; peridot of Hau'y ; olivin of
Werner. A mineral, generally of an
olive-green colour, from which circum-
stance it obtains its name : it is sometimes
of an asparagus green, or yellowish green.
Occurs in distinct granular concretions,
or in rounded masses. Structure foliated.
Fracture imperfectly conchoidal. Lustre
shining, translucent, and, sometimes,
transparent. Its constituents are, silex
50'0, magnesia 37'5, oxide of iron 12*0,
lime 0*5. It is found in basalt, and is a
constituent of many lavas.
O'MBRIA. (from ofjflpiog, rain, Gr.) Fos-
sil echini, to which the name of ombria
has been given, from a supposition that
they fell from heaven in the midst of

B B

O M E

C 186 ]

O O L

heavy rain ; they are of a rounded form,
and have been compared to turbans.

OME'NTUM. (omentitm, Lat.) The caul.

OMNI'VOROUS. (from omnis, all, and voro,
to devour, Lat.) Animals which eat food
of all kinds.

O'MOPLATE. (from w/*og, the shoulder,
and TrXarrg, broad, Gr.) The scapula,
or shoulder-blade.

O'NCHUS. A genus of sharks, belonging to
the sub-family of Hybodonts, teeth of
which have been found in the lias, at
Lyme Regis.

O'OLITE. (from MOV, an egg, and XiOog, a
stone, Gr. oolites, Fr.) A group of
strata, whose order of superposition is
below the Purbeck and above the lias :
called also the Jura limestone. The two
lowest members of this group, or those
immediately above the lias, are called the
great oolite, and the inferior oolite. All
the members of the group are marine
deposites. The oolite has been thus named
from its being composed of spherical gra-
nular concretions, supposed to resemble
the roe, or eggs, of a fish : it is a mere
term of convenience, like those of carbo-
niferous, red-sandstone, &c., for many
limestones in other groups are oolitic.
The oolite is an accumulation of sands,
sandstones, marls, clays, and limestones.
A very striking zoological feature of this
group is the immense abundance of am-
monites and belemnites which must have
existed previous to, and during, its de-
posit ; for, notwithstanding the usual
chances of destruction to which we may
suppose they were exposed, myriads of
their shells have been found entombed
entire, and not unfrequently the animal
must have been in them. One hundred
and seventy-three species of ammonites,
and sixty-five species of belemnites have
been enumerated as discovered in the
oolite. There can be little doubt that
this group, greatly expanded in thickness,
and mixed with sandstones, marls, and
slates, possessing a very different aspect
from the equivalent rocks in a large por-
tion of Western Europe, extends over
various parts of Eastern Europe. At
present it seems to be considered that
rocks equivalent to the oolitic group have
not been detected in North America.
The aggregate average thickness of the
oolite may be estimated at 1200 feet. In
some instances the spherical granular
concretions, which are imbedded in many
of the strata, attain the size of a pea, and
this variety has obtained the name of
pisiform oolite. Some oolites have been
used for building-stone, but they are said
not to be durable. Somerset House is
built of oolite. The vertebrated animals,
whose remains are found in oolite, are

fishes and reptiles of the same genera as
those discovered in the lias. Some strata
of this group are composed, almost en-
tirely, of madreporites, and these have
been called " coral ragg." Other strata
abound in the remains of fossil alcyonia
and sponges, and with congeries of minute
millepores and madrepores. In England,
the limestone of the oolite has a yellow-
ish brown, or ochreous colour, by which
it may at once be distinguished from the
lias ; and the fossils partaking of the
colour of the limestone, renders it easy
to separate them from the fossils of the
lias. The oolite has been divided into
three formations, the upper, the middle,
and the lower. Between the lower and
the middle division of oolites, there oc-
curs a bed of dark blue clay, called Ox-
ford, or clunch, clay, the thickness of
which has been stated to be 200 feet.
Between the middle and upper also, there
is found a thick bed of clay, called Kim-
meridge clay, of a thickness exceeding,
in some parts, 100 feet. The uppermost
members of the oolite group are the
Portland beds, lying immediately under
the Purbeck beds.

Ooolite has been also called roe-stone,
from a supposition of the older geologists,
that the globules contained in it were the
petrified roes of fishes. In the litho-
graphic limestone of Solenhofen, belong-
ing to one of the upper members of the
oolite, a great variety of organic remains
is found ; and in the museum of Count
Munster, there are not fewer than seven
species of flying lizards, six saurians,
three tortoises, sixty species of fishes,
forty-six species of Crustacea, and twenty-
six species of insects, taken from that
deposit.

The lower division of the oolite in York-
shire, and in Scotland, contains coal for-
mations. In the district north of the
river Humber, the lower oolite assumes a
new character : instead of finding beneath
the cornbrash the forest marble and great
oolitic beds of sandstone, shale and car-
bonaceous matter are interpolated above
the sand which covers the lias. Proceed-
ing northwards, these strata rapidly in-
crease in thickness, and the carbonaceous
layers gradually become concentrated
into a stratum of coal, which, though
never exceeding sixteen inches in thick-
ness, is, from local circumstances, of con-
siderable value.

The oolitic tracts of England present a
broad band of dry limestone surface,
rising westward to elevations of from 800
to 1,400 feet, with escarpments com-
manding very extensive prospects over
the undulating plains of lias and red
marl. The whole tortuous line of oolitic

O O L

[ 187 J

O P H

escarpment from the Humber to the Avon ,
may be regarded as the wasting effects of
water on the subjacent red marls and lias
clays. — Bakewell. De La Beche. LyelL
Cleaveland. MantelL Phillips.

OOLI'TIC. Composed of oolite ; resembling
oolite. The name of a large group of
strata commencing with the Portland beds
above, and terminating in the inferior
oolite below.

OOLITI'FEROUS. Producing oolite, or roe-
stone.

OPA'CITY. (opacitas, darkness, Lat. opa-
cite, Fr. opacita, It.) Opaqueness ;
darkness. The quality of opacity is not
a contrary or antagonist quality to that of
transparency, but only its extreme lowest
degree.

OPAL. The quartz resinite of Werner ;
untheilbarer quartz of Mohs. A sub-
species of indivisible quartz. Of this
there are many varieties, the principal of
which are, — 1. The precious opal, a milk-
white variety, with a beautiful play of
various rich colours. 2. Fire-opal ; a
transparent variety, brought from Mexico,
with a carmine-red and apple-green iri-
descence of great beauty. 3. Common
opal ; a variety differing but little from
the precious opal in many of its charac-
ters, but not presenting that effulgence,
or play of colours, by which the precious
opal is distinguished. Its colour is
white, shaded with grey, green, or yellow,
sometimes milk-white. When viewed
by transmitted light, the milk-white and
greenish varieties often change their
colours. 4. Semi-opal ; a feebly trans-
lucent variety, having a conchoidal frac-
ture ; colours white, grey, and brown.
Prof. Ehrenberg states that nodules of
semi-opal, which occur in the Poliers-
chiefer, are composed of silex derived
from infusorial remains that have been
dissolved and formed into siliceous con-
cretions, having dispersed through them
numbers of infusorial shields, partially
dissolved, together with others that are
unaltered. Ehrenberg also thinks that
he has found indications of microscopic
organic bodies of a spherical form in
semi-opal from Champigny, and also
in semi- opal from the dolerite of Stein -
heim, and in precious opal from the
porphyry of Kaschan. 5. Menilite ; a
variety occurring in small, irregular,
roundish masses, often tuberose, or
marked with little edges on the surface.
The exterior is often bluish or striped,
but the interior has a brown or dark

ry appearance. Fracture conchoidal.
is translucent. These varieties con-
sist of silex in various proportion, from
86 to 95 per cent., combined with
oxide of iron and water. The semi-

opal contains about 3 per cent, of
alumina.

OPALE'SCENT. Resembling opal ; exhibit-
ing a play of various colours ; displaying
iridescence.

O'PALIZED. Converted into a substance
resembling opal.

O'PALIZED WOOD. This has the form and
texture of wood ; the vegetable matter
having gradually given place to a siliceous
deposite possessing the characters of
semi-opal. Its texture is fibrous ; frac-
ture conchoidal, with a moderate lustre.
It does not strike fire with steel. Spe-
cific gravity between 2'0 and 2'6. Co-
lours white and grey, often shaded with
yellow or red, and passing into yellow or
brown. Translucent at the edges. It
has been found in Hungary, near Schem-
nitz . — Cleaveland.

OPE'RCULAR. Having a lid, or cover, or
operculum.

OPE'RCULUM. (operculum, Lat. from
operio, to close or shmt.)

1. A lid, by means of which many of the
molluscous animals close the aperture of
their shells. It is in some animals tes-
taceous; in others, homy or cartilaginous.
It is affixed to the animal. The oper-
culum of multivalves is composed of two
or four pieces. The operculum is cal-
culated for the protection of the animal
when it retires within its dwelling, of
which it may be termed the door ; it is
adapted to the shape of the aperture,
which it closes completely. The carti-
laginous operculum of the common peri-
winkle is a familiar example.

2. The flap which covers the gill, or organ
of respiration, in fishes. " A large flap,
termed the operculum," says Dr. Roget,
" extends over the whole gill, defending it
from injury, and leaving below a wide
fissure for the escape of the water, which
has performed its office in respiration."

OPHI'DIA. (from o^if, a serpent, Gr.)
The third order in the class Reptilia, in
Cuvier's arrangement, comprising three
families, Anguina, Serpentia. and Nuda.
In the structure of the skeleton of the
serpents, the first of the true reptiles, we
may observe a beautiful illustration of
the simple means employed in organic
structures to accomplish the most numer-
ous and diversified ends, and of the re-
sources of nature in adapting the forms of
bones, in all their essential and common
parts, to the various uses the animal is to
make of them in the living state. We
have here animals destitute of anterior
and posterior extremities, destitute of
arms and legs, of hands and feet, yet ca-
pable of a great variety of those active

, movements which we see in animals the
most gifted with those parts. We see

O P H

[ 188]

ORB

them as if running on all fours, pursuing
their prey, rapidly winding through the
turf, and through the low vegetables tha
cover extensive plains. If the prey, t<
escape from danger, betake itself to thi
trees, imagining there to be in safety, w<
find these serpents winding round the
tree, and almost without any apparen
motion of any portion of their trunk
gliding, as if they were sticking by suck-
ers to the trunks of the trees they climb
till within reach, and then with a velo-
city, like an elastic spring let loose
they dart forward and twine rounc
their prey. If their prey should even rise
from the ground into the air, we see these
serpents, as if they were gifted with wings
spring with velocity from the ground, dart
upon the bird and seize it, or if the ani-
mal be a quadruped, and plunge for
safety into the water, the serpents still
pursue them in that element, swimming
like fishes. Yet, when we examine the
condition of the skeleton, we find it
simply to consist of a vertebral column
and ribs ; and with that simple condition
of the solid internal frame-work, we see
all those varied movements effected. The
spine of serpents is formed of a great
number of vertebrae ; in the rattle-snake
there are about two hundred, and in the
coluber natrix above three hundred have
been counted. These vertebras are all
united by ball and socket joints, the pos-
terior rounded eminence of each vertebra
being received into the anterior surface of
the next. Serpents swallow their prey
entire ; and it is well ascertained that
they will swallow animals having ten times
the diameter of that of their own neck.
The loose connexion of all the bones
surrounding the mouth of serpents, en-
ables them to distend their jaws and
mouth to receive undivided prey, and
thus, so far as food is concerned, to dis-
pense with arms to grasp it, and assist in
its sub-divisiou. Neither are their teeth
suited for mastication, being conical,
slender, sharp, osseous, and recurved.

Venomous serpents, or those with iso-
lated fangs, have their organs of mandu-
cation constructed on a very peculiar plan.
Their superior maxillary bones are very
small, attached to a long pedicle, and are
very moveable ; in them is fixed a sharp -
pointed pervious tooth, through which
flows a liquor which, poured into the
wound made by the tooth, produces
effects according to the species of the
reptile secreting it. This tooth, when
the animal does not wish to use it, is con-
cealed in a fold of the gum, and behind it
are several germs destined to replace it,
in the event of its being broken.

All those venomous serpents, whose

mode of production is well ascertained,
bring forth living young ones, as their
eggs are hatched without being laid. —
Grant. M'Murtrie. Royet.
OPHI'DIOUS. Belonging to the order

Ophidia. .

OPHI'OLITE. (from o<pig, a serpent, and
\<0o£, a stone, Gr.) Another name for
the mineral serpentine.
O'PHITE. (O^J'TTJC, lapis in modum serpen-
tis maculosus, ab o$>i£, a serpent, Gr.)
Green porphyry, or serpentine. A green-
stone, varying from blackish-green to
pistachio-green. It contains greenish-
white crystals of felspar, which on the
polished surface often shew themselves in
parallelograms, and are sometimes cru-
ciform. It occurs massive and disse-
minated. Lustre glistening and resinous.
Fracture conchoidal, and often splin-
tery.

OPO'SSUM. A genus of quadrupeds belong-
ing to the order Marsupialia. The opos-
sums are peculiar to America, and are
remarkable for having a greater number
of teeth than any other animal, amounting
in all to fifty. These teeth are thus di-
vided : ten incisors above and eight below,
three anterior compressed grinders, and
four posterior bristled ones, which with
the four canine make the fifty. They
approach the quadrumanes, by having the
thumb of their hind foot opposed to the
fingers, whence they have been called
pedimanes : the thumb is not armed with
a nail.

The small opossums, in the oolite for-
mation at Stonesfield, are the only land
mammalia whose bones have yet been
discovered in any strata more ancient
than the tertiary.

O'PPOSITE. (oppositus, Lat.) In botany,
applied to the position of leaves placed
exactly opposite each other on the stem ;
also to b'ranches growing in pairs ; and to
peduncles placed opposite to a leaf. —
Flora Medica.

O'PTICS. (from oTrrojuai, to see, Gr.)

That branch of science which treats of

the properties of light and of vision, as

performed by the human eye.

O'RBED. Round ; circular ; formed in a

circle.

ORBI'CULA. (from orbis, an orb, Lat.) A
genus of bivalve shells belonging to the
family Brachiopoda. The orbicula is a
very small inequivalved flat bivalve ; the
lower valve very thin and adherent to
other bodies. It is a marine shell, found
at depths varying to sixteen fathoms,
attached to stones, shells, sunken wrecks,
&c. Orbicula? have not been found
fossil.

ORBI'CULAR. (orbiculaire, Fr. orbicolare,
It.) Spherical; circular; roundish and

ORB

[ 189]

O R N

flat. In botany, leaves are so called when
their length and breadth are equal, and
their form nearly circular.

O'RBIT. (orbita, Lat. orbite, Fr. orbita, It.)
The line described by the revolution of a
planet ; the path of a planet, or of a
comet. The mean distance of a planet
from the sun is equal to half the major
axis of its orbit. A planet moves in its
elliptical orbit with a velocity varying
every instant, in consequence of two
forces, one tending to the centre of the
sun, and the other in the direction of a
tangent to its orbit, arising from the
primitive impulse, given at the time when
it was launched. into space.

ORCHI'DE^E. (from bp\tQ, Gr. orchis, Lat.)
An order of monocotyledonous plants.
Perianth superior, sepals three, usually
coloured, the odd one uppermost, from
the twisting of the ovarium ; petals three,
usually coloured, of which two are the
uppermost, while the third, called the
labellum, is usually lobed, and differs in
figure, colour, or size, from the other
two, and is often spurred ; stamens three,
united in a central column, the two lateral
generally abortive, the central one per-
fect ; anther either persistent or decidu-
ous ; pollen either powdery or cohering
in granular or waxy masses ; ovarium
one-celled, with three parietal placentae ;
style forming part of the column of the
stamens ; stigma a viscid space in front
of the column ; fruit usually a capsule,
dehiscing by three valves, sometimes bac-
cate ; seeds numerous, testa loose and
reticulated, no albumen, embryo a solid
undivided fleshy mass ; herbaceous plants,
either stemless, or forming a kind of
tuber above ground ; or sometimes with
a true stem ; leaves simple and entire,
sometimes articulated with the stem ; in-
florescence terminal or radical^ spikes,
racemes or panicles, occasionally solitary.
Natives of all countries, except very
cold or very dry. There are thirty-seven
British species ; and, probably, altogether
not fewer than fifteen hundred species.

The flower of the orchidise is very pe-
culiar ; the calyx and corolla consist of
three pieces each, and one of those form-
ing the latter, differs very greatly in size
and form from the other two ; it is called
the labellum, or little lip, and is often
spurred. In many species, this resembles
an insect, and hence they have received
the name of bee, fly, spider, £c. &c.

ORCHI'DEOUS. Belonging to the order
Orchidese ; parasitical plants.

O'RDER OF SUPERPOSI'TION. That ar-
rangement of strata in which they are
invariably found. The order of superpo-
sition is never inverted. Strata are fre-
quently absent, but the order of superpo-

sition of such as are present is invariably
the same.

ORE. (erz, Germ.) A metallic compound.
Metals are found usually combined with
other substances : the compounds they
thus form are called Ores, when the metal
exists in them in sufficient quantities to
form a considerable portion of the mass.

ORGA'NIC. (bpyaviKOQ, Gr. organicus, Lat.
organique, Fr. organico, It.) Consisting
of various parts co-operating with each
other ; consisting of natural instruments
of action or operation.

ORGA'NIC BO'DIES. Such as possess na-
tural instruments of action ; on the action
of each, arid their co-operation together,
depend the growth and perfection of the
body.

ORGA'NIC REMAI'NS. The relics of what
were once living bodies : generally applied
to the fossil remains of animals or plants.

ORISMO'LOGY. (from opto-juof, definition,
and Xoyo£, discourse, Gr.) Called also
terminology. In entomology, orismology
contains the various technical terms used
in explaining the perceptible differences
in the body of an insect, and at the same
time acquaints us with its exterior visible
parts in the several periods of its exist-
ence, until its full and perfect develop-
ment. Mr. Kirby introduced the term
orismology. — Shuckard.

ORISMOLO'GICAL. Relating to orismology.

ORNITHI'CKNITES. (from oyvig, a bird,
and 0iyw, to touch, Gr.) The footmarks
of birds found in different formations.
Some recent discoveries of ornithicknites
are very remarkable ; the footsteps appear
in regular succession, on the continuous
track of an animal in the act of running
or walking, with the right and left foot
always in their relative places. An ac-
count of these has been published by
Prof. Hitchcock, in the American Journal
of Arts and Sciences : they were disco-
vered in the new red sandstone of the
valley of Connecticut. The most remark-
able were those of a gigantic bird, twice
the size of an ostrich, whose foot measured
fifteen inches in length, exclusive of the
largest claw, which measured two inches.
The discovery of these ornithicknites is
exceedingly interesting to the palaeonto-
logist, as proving the existence of birds at
the early epoch of the new red sandstone
formation.

ORNI'THOLITE. (from opiate, a bird, and
XiOoe, a stone, Gr.) A fossil bird. Stones
of various colours and forms, bearing the
figures of birds. Specimens of this kind
may be obtained at Matlock, in Derby-
shire, arid at other places where the water
is surcharged with lime.

ORNITHO'J-OGY. (from opvig, a bird, and
, discourse, Gr.) That department

O R N

[ 190 ]

O S M

of natural history which treats of birds ;
describes their structure, external and
internal ; and teaches their economy and
their uses.

ORNITHO'LOGIST. One versed in that
branch of natural history which treats
of the habits, structure and uses of
birds.

ORNITHORHY'NCHUS. (from opr/tg, a bird,
and puyxoc., a beak, Gr.) The platypus
of Shaw. The duck-bill ; an animal in-
digenous to New Holland, and found in
no other country. In this anomalous
animal, we have a quadruped clothed with
fur, having a bill like a duck, with four
webbed feet, suckling its young, and most
probably ovo-viviparous : the male is
furnished with spurs. The mouth of the
ornithorhynchus has a form of construc-
tion between that of quadrupeds and birds,
being furnished, like the former, with
grinding teeth at the posterior part of
both the upper and lower jaws, but they
are of a horny substance ; the mouth
is terminated in front by a horny bill,
greatly resembling that of che duck, or the
spoon-bill. It has also small cheek-
pouches. Membranes unite the toes of
the fore and hind-feet ; in the fore-feet it
extends beyond the nails, in the hind-feet
it terminates at the root of the nails. It
has also a flattened tail. It inhabits the
rivers and marshes.

O'RPIMENT. (from auripigmmtum, Lat.
orpiment, Fr. orpimento, It.) The Arse-
nic sulfure jaune of Haiiy ; Arsenic sulfure
orpiment of Brongniart. Yellow sul-
phuret of arsenic, an ore of arsenic com-
bined with sulphur. Its colour is usually
lemon-yellow, which is often shining and
beautiful. It occurs in laminated or
lamellar masses ; in concretions ; and
sometimes in minute crystals. It is
principally volatilized before the blow-
pipe, with a white smoke, and with the
odour of both sulphur and arsenic, leaving
a small earthy residue. According to
Thenard it is composed of arsenic 57,
sulphur 43. Klaproth states his analysis
to be arsenic 52, sulphur 38.

The foliated structure of orpiment, and
its arsenical odour, when exposed to heat,
distinguish it from native sulphur. It
occurs in veins, in various metalliferous
formations, in Hungary and Germany,
India and America.

O'RTHITE. (from 6p0o£, straight, Gr.) A
mineral found in the mine of Finbo, in
Sweden, and thus named from its being
always found in straight layers.

ORTHOCE'RATA. 1 (from 6pOo£, straight,

ORTHOCE'RATITE. $ and Kt/oac, a horn,
Gr.) An extinct genus of polythalamous,
or many chambered, cephalapods, which
inhabited straight shells. The orthocera-

tite resembles an ammonite unrolled,
having its chambers separated by trans-
verse septa, concave externally, and con-
vex internally ; the septa being pierced
by a siphuncle. There are many varie-
ties ; some upwards of two feet in length.
Orthoceratites are abundantly found in
the transition strata, appearing to have
been early called into existence, and at an
early period to have been consigned to
almost total destruction. Part of the
pavement of the palace at Hampton Court,
and that of the hall of University College,
Oxford, are composed of marble contain-
ing remains of Orthoceratites. Some
species, found in the carboniferous lime-
stone of Closeburn,in Dumfries-shire, are
nearly of the size of a man's thigh.

ORTHO'PTERA. (from 6y9o£, straight, and
TTTtpbv, a wing, Gr.) An order of in-
sects, the sixth in Cuvier's arrangement.
The coverings of the wings, instead of
being of a horny texture, are soft and
flexible. The wings themselves, being
broader than their coverings, are, when
not in use, folded longitudinally like a
fan.

ORYCTOLO'GICAL. (from bpvKrbg, a fossil,
and Xoyog, discourse, Gr. ) Pertaining to
that part of physics which treats of
fossils.

ORYCTO'LOGIST. One who studies, or is
versed in, that part of physics which
treats of fossils.

ORYCTO'LOGY. (from opvicroc., a fossil, and
Xoyog, discourse, Gr.) By some persons
oryctognosy has been substituted for
oryctology, and geognosy for geology ;
for this there appears no valid reason,
and if followed, we ought, by the same
rule, to change metereology into metere-
ognosy, physiology into physiognosy, &c.
Oryctology is that branch of mineralogy
which has for its object the classification
of minerals ; or, in other words, it con-
sists in the description of minerals, the
determination of their nomenclature, and
the systematic arrangement of their dif-
ferent species. — Cleaveland.

OSCILLA'TION. (oscillatio, Lat. oscillation,
Fr. oscillazione, It.) Vibration ; the act
of swinging to and fro ; a movement to
and fro, like the swinging of the pendu-
lum of a clock, or waves in water. The
tides are oscillations of the sea.

OSMERO'IDES MANTE'LLII. The name
given by Dr. Mantell to an ichthyolite of
the chalk formation discovered in the
Lewes chalk-pits. It is closely related
to the smelt.

O'SMIUM. (from ocrfir], odour, Gr.) A
metal discovered by Tennant in crude
platinum, and deriving its name from the
strong odour emitted by some of its com-
pounds.

OSS

C

O V U

O'SSEOUS. (osseous, Lat.) Bony; con-
taining bone ; resembling bone.

O'SSEOUS BRE'CCIA. A mass of fragments
of the bones of animals cemented toge-
ther by a calcareous gangue, and com-
monly found in fissures and caves.

O'SSICLE. (ossiculum, a little bone, Lat.)
A small bone : some of the small bones
which enter into the formation of the ear
are termed the ossicula auditus.

OSSI'FEROUS. (from os, a bone, and/ere,
to produce, to bear, or contain, Lat.)
Yielding bones or fragments of bones ;
containing bones. Thus we have ossi-
ferous gravel, ossiferous clay, ossiferous
strata, ossiferous caves, &c. &c. Large
portions of this kingdom are covered by
irregular aggregations of gravelly sands
and pebbly clays, locally stored with the
bones of various land quadrupeds. It is
a remarkable fact that the ossiferous caves
and fissures are situated almost every
where in limestone.

OSTEOCO'LLA. (from oorsov, a bone, and
KoXXa, glue, Gr.) Vegetables of the
most delicate texture, when immersed in
waters containing carbonate of lime, be-
come incrusted, still preserving their form
even to their most delicate ramifications.
These incrustations somewhat resemble
the bone of an animal, and the property
has been absurdly attributed to them of
facilitating the union of fractured bones.

OSTEO'LOGY. (from oartbv, a bone, and
Xoyoc, discourse, Gr. osteologie, Fr. osteo-
logia, It.) A description of the bones ;
that part of anatomy which treats of the
bones.

OS'TRACITE. A fossil oyster.

OSTRJE'A. ) The oyster. A rough, adherent,

OSTRE'A. $ inequivalved bivalve ; the
hinge without a tooth. One muscular
impression in each valve. The oyster is
found both fossil and recent. Of this
genus one hundred and thirty-seven spe-
cies have been described in Turton's
Linne. Lamarck describes eighteen
species as found fossil in the neighbour-
hood of Paris. The most extraordinary
shell of this genus for size, says Mr.
Parkinson, is the large fossil oyster, the
recent analogue of which, from Virginia,
appears to be depicted by Lister. Some
attain to the length of twenty inches.
An under valve in Mr. Parkinson's pos-
session weighed four pounds, being thir-
teen inches in length and three in thick-
ness. The recent oyster is found at
depths varying to seventeen fathoms, in
the ocean and in estuaries. Sometimes
attached to rocks and other substances.

Osus. The termination of words in osus
expresses fulness, or the abundant pre-
sence of a quality : examples, pilosus,
covered with much hair ; setosus, covered

with thick bristles ; squamosus, covered
with scales.

OU'TCROP. A term used by miners, to ex-
press the exposure at the surface of a
stratum or strata.

OU'TLIER. A portion of a stratum de-
tached from the principal mass, and lying
detached at some distance from it.

O'VA ANGUI'NA. A species of fossil ci-
daris or echinus.

O'VAL. (from ovum, an egg, Lat. ovale,
Fr. ovale, It.) A rounded surface, its
two right-angular diameters being of an
unequal length, so that its longest trans-
verse diameter does not pass through the
centre of its longitudinal diameter, but
lies nearer to one end. — Skuckard.

OVA'RIUM. } (ovaire, Fr. ovaja, It.) That

O'VARY. $ part of the body which con-
tains the ova, and in which impregnation
is performed. In animals, it is only in
the organs termed ovaries, that ova are
formed.

In botany, that part of the flower which
ripens into the fruit, and contains the
seed.

O'VATE. (ovatus, made like an egg, from
ovum, Lat.) Of the shape of an egg ;
egg-shaped.

O'VIDUCT. (from ovum, an egg, and duc-
tus, a passage, Lat.) A canal, or duct,
through which the ova pass, after impreg-
nation, from the ovary to the uterus. In
the human subject the oviducts are called
the Fallopian tubes.

O'VIFORM. (from ovum, an egg, and forma,
shape, Lat.) Of the form or shape of an

O'VIFORM LI'MESTONE. Oolite, or roe-
stone.

OVI'PAROUS. (from ovum, an egg, and
pario, to produce, Lat. ovipare, Fr. ovi-
paro, It.) All animals which lay eggs,
enclosed in a calcareous shell, are called
oviparous. Oviparous production is thus
characterized : the young animal is not
attached to the parieties of the oviduct,
but remains separated from it by its ex-
ternal envelope ; its aliment being en-
closed in a sac, which is attached to its
intestinal canal.

OVO'-VIVIPAROUS. Some animals, such as
the salamander and the viper, never lay,
their eggs, but these are hatched within
the body of the parent ; so that although
originally contained in eggs, the offspring
are brought forth in a living state. Such
animals are termed ovo-viviparous.

OVIPO'SITING. The laying of eggs.

OVIPO'SITOR. A name given to the ter-
minal apex of the abdomen of insects.

O'VULE. } (dim. of ovum, an egg, Lat.)

O'VULUM. $ In botany, the seed before it
is perfected. The small bodies produced
on the margins of the carpel la in the

O X F

C 192 ]

PAL

pistil, are called ovula, or ovules ; when ;
perfected they become the seeds of the
plant. The ovule is generally attached
to the placenta of the ovarium by a very
small stalk.

O'xFORn CLAY. Called also clunch clay.
A bed of dark blue clay, sometimes
nearly two hundred feet in thickness, in-
terposed between the lower and the mid-
dle oolites. One species of ichthyosau-
rus, distinct from the species occurring in
the lias, has been found in this deposit.

OXIDA'TION. That process by which me-
tals, and other substances, are converted
into oxides by their combination, with
oxygen.

O'XIDE. A substance combined with oxy-
gen, without being in the state of an
acid.

O'XIDIZED. Converted into an oxide, by
combination with oxygen.

O'XYGEN. (from o£t>c, acid, and ytwdb),
to produce, Gr.) So called from its
property of forming acids. One of the
fifty-five simple or elementary substances,
and one of the five which exist as gas.
So generally does oxygen enter into com.
bination with metallic and non-metallic

bodies, and in such large proportions,
that it has been computed that one-half of
the ponderable matter of the globe is
composed of oxygen gas. Oxygen con-
stitutes about one-20th per cent, of the
volume of the atmosphere ; it forms a
third part, by measure, of the gases com-
posing pure water ; and is locked up to
an immense amount in the various rocks,
which are little else than a mass of oxi-
dized substances. Plants give out oxy-
gen, animals absorb it. It is to Dr.
Priestley we owe the knowledge of the
former of these two facts ; and he it was
who first discovered oxygen, in 1774.
Oxygen has neither taste nor smell. It
is a trifle heavier than atmospheric air,
100 inches weighing 33'88 grains.

OXYGENA'TION. "This word," says Dr.
Ure, (t is often used for oxidation, and
frequently confounded with it : but it
differs, in being of more general import,
as every union with oxygen, whatever the
product may be, is an oxygenation ; but
oxidation takes place only when an oxide
is formed." — Diet, of Chem.

O'YSANITE. A name given by Lameth to
pyramidal titanium, or anatase.

PACHYDE'RMATA. (from Trn\vQ, thick,
and Bepua, skin, Gr.) Thick-skinned
animals. The seventh order of the class
Mammalia, in Cuvier's arrangement. This
order Cuvier divided into two families,
namely, Proboscidiana, or those pachy-
dermatous animals which have tusks and
a proboscis, as the elephant and masto-
don ; and pachydermata ordinaria, in
which are included the hippopotamus,
anoplotherium, palseotherium, tapir, &c.

Several genera of the order Pachyder-
mata have become extinct, their fossil
remains alone proving that such ever
existed. Amongst these are the masto-
don, the anoplotherium, the palaeothe-
rium, and the lophiodon. Of the exist-
ing genera of pachydermata, many species
which existed during the older and newer
pliocene periods also seem to have be-
come extinct.

The pachydermata appear to be, as it
were, only the remnants of a very exten-
sive order, which formerly inhabited the
earth, but have now almost entirely dis-
appeared. They feed upon grass, but
they do not ruminate. They are, for the
most part, huge and unwieldy animals,
with thick integuments ; solidity and
strength appearing to be the objects
chiefly regarded in their construction.

PACHYDE'RMATOUS. Thick-skinned ; be-
longing to the order Pachydermata.

PA'DDLE. The swimming apparatus of the
chelonian reptiles, and of the marine sau-
rians, has obtained the name of paddles.

PJSCILO'PODA. (from TTOIKJAOC, and Trove,
Gr. various footed.) The second order
of the class Crustacea ; it comprises two
families, Xysophura and Siphonostoma.

PA'LATAL. Pertaining to the palate, or
roof of the mouth.

PA'LATE. (palatum, Lat. palais, Fr. pa-
lato, It.) The roof, or upper part of the
mouth.

PAL^EO'LOGY. (from TraXatoc, ancient, and
Xoyoc, discourse, Gr.) The study of
ancient things. This word is commonly
written paleology.

PAL^EONTO'LOGIST. (from palaeontology.}
One who studies, or is versed in, the
history of fossil plants and animals.

PAL^EONTO'LOGY. (from TraXaioe, ancient,
oj/ra, beings, and Xoyoc, discourse, Gr. )
The history of fossil plants and animals ;
that branch of natural history which treats
of fossil and extinct animals and plants.

PAL^JOSAU'RUS. (from TraXntoc, ancient,
and cravpog, a lizard, Gr.) A genus of
fossil saurians, now extinct, found in the
magnesian limestone.

PAL^EOTHE'RIUM. (from TraXatoe, ancient,

PAL

[ 193 ]

PAL

and flr/pt'ov, a wild beast, Gr.) An ex-
tiuct genus of fossil quadrupeds, belong-
ing to the order Pachydermata, having
twenty-eight molar teeth, or grinders, six
incisors, and two canine teeth in each
jaw. It possessed three toes to each foot,
and had a short fleshy proboscis. Eleven
or twelve species of the genus have been
discovered. " The place of the genus Pa-
Iseotherium," says Prof. Buckland, "is
intermediate between the rhinoceros, the
horse, and the tapir. Some of the dis-
covered species were as large as a rhi-
noceros, others were from the size of a
horse to that of a hog. These animals
probably lived upon the margins of the
then existing lakes and rivers.
PAL^EOTHE'RIAN. Belonging to the genus
Palseotherium, as palseotherian remains,
&c.

PA'LEA. (palea, chaff, Lat.) In botany,
a term applied to the two inner bractese of
grasses : the palese are membranous or
chaffy in texture.

PALLA'DIUM. (from the planet Pallas.) A
metal of a greyish or bluish-white colour,
discovered by Dr. Wollaston in 1803, in
platinum. It is malleable, ductile, and
flexible, but does not possess much elas-
ticity. In hardness it surpasses all other
metals, with the exception of tungsten,
which it equals. Specific gravity 11 '5.
It is not oxidated by the action of the
atmosphere. It is fusible only at a very
high temperature.

PA'LLEAL. (from pallium, a mantle, Lat.)
In conchology, the name given to the
mark or impression observed in bivalves,
formed by the muscular attachment of the
mantle.

PA'LMATE. } (palmatus, Lat.) Webbed,
PA'LM ATED. S like the feet of some water-
birds ; deeply divided into lobes like the
fingers on the hand ; resembling a hand ;
palmed or hand-like. Applied to leaves
which are divided, half, or more than half-
way, down the middle, into several nearly
equal segments, having a space between
each.

PA'LMIPEDES. (from palmipes, that hath
its feet closed with a film or web, Lat.
The sixth order of birds in Cuvier's ar-
rangement. The goose and duck are
familiar examples.
PALM, (from palma, Lat.) The palms
constitute a natural order of monocotyle-
donous, or endogenous, plants. The
flowers are hermaphrodite, or polyga-
mous. Perianth six-parted, persistent
Stamens inserted into the base of th
perianth, definite or indefinite. Ovary
three-celled, or deeply three-lobed, witi
an erect ovule. Fruit baccate or dru
paceous, with fibrous flesh. Albumen
cartilaginous ; embryo in a cavity at

distance from the hilum. Leaves ter-
minal, large, pinnate, or flabelliform,
plaited in vernation. Spadix enclosed
in a valved spatha. Flowers small.

A palm tree affords an example of the
mode of growth in endogenous plants.
The stem of this tree is usually perfectly
cylindrical, attains a great height, and
bears on its summit a tuft of leaves. It
is composed of an extremely dense ex-
ternal cylindric layer of wood ; but the
texture of the interior becomes gradually
softer and more porous as it approaches
the centre. It has neither medullary
rays, nor central pith, nor true outward
bark. The first stage of its growth con-
sists in the appearance of a circle of
leaves, which shoot upwards from the
neck of the plant, and attain, during the
first year, a certain size. The following
year another circle of leaves arises ; but
they grow from the interior of the former
circle, which they force outwards as their
vegetation advances, and as ligneous
matter is deposited within them. As
soon as the outer layer has become too
hard to yield to the pressure from within,
the growth of the inner layers is imme-
diately directed upwards ; so that they
rise in succession by distinct stages, al-
ways proceeding from the interior ; a
mode of development which has been
compared by De Candolle to the draw-
ing out of the sliding tubes of a telescope.
The whole stem, whatever height it may
attain, never increases in diameter after
its outer layer has been consolidated. A
circle of leaves annually sprouts from the
margin of the new layer of wood ; these,
when they fall off, leave traces, consisting
of a circular impression, round the stem.
By the number of these circles the age of
the tree may be ascertained. The ex-
isting family of palms is supposed to con-
sist of nearly a thousand species, of
which the greater number are limited to
peculiar regions of the torrid zone. It is
not surprising to find the remains of
palms in warm latitudes, where plants of
this family are now indigenous ; beau-
tifully silicified stems of palm trees
abound in Antigua, and in India ; but
their occurrence in the tertiary forma-
tions of Europe, associated with the re-
mains of crocodiles and tortoises, and with
marine shells, nearly allied to forms now
found in seas of a warmer temperature,
seems to indicate that the climate of
Europe, during the tertiary period, was
warmer than at the present time. The
palms have pervaded all the series of for-
mations, though in small proportions.
PA'LPI. In entomology, the palpi, or
feelers, are the auxiliary organs of a mas-
ticating mouth. Those upon the max-
c c

PAL

[ 194 ]

PAP

illse are termed the palpi maxillares, or
maxillary feelers; those placed laterally
upon the labium, are designated the palpi
labiales, or labial feelers.
PALUDI'NA. A genus of fresh- water uni-
valves, belonging to the family Peristo-
mata. Several species, Paludina elon-
gata, Paludina fluviorum, Paludina cari-
nifera, &c. have been found in the Weal-
den formation.

PA'NCAKE. The name given by Klein to
the Echinodiscus laganum, a species of
fossil echinus, belonging to the division
Catocysti.

PANDA'NEA. } (from pandust Lat. crooked.)

PANDA'NUS. $ The screw-pine, so named
from the spiral arrangement of its leaves,
is a monocotyledonous tree, growing
only in the warmer zones, and princi-
pally near the sea. The pandanea, like
the cocoa-nut palm, is generally the first
vegetable colonist of the newly-raised
coral islands. Its appearance is that of a
gigantic pine-apple plant with arbores-
cent stems. The pandanus bears a large,
spherical, drupaceous fruit : the seed
within each drupe being enclosed within
a hard nut. From the pandanus growing
near to the sea, its fruit frequently drops
into the water, and is drifted by the
waves and winds to distant shores : thus
the elements of vegetation are transported
to the emerging coral islands, where it
vegetates. A fossil* fruit of the pan-
danus was found by Mr. Page in the in-
ferior oolite, and is in the Oxford mu-
seum. It is of the size of a large orange,
and is covered by a stellated rind, or epi-
carpium, composed of hexagonal tuber-
cles, forming the summits of cells which
occupy the entire surface of the fruit.
Fruits of a genus, to which M. Adam
Brongniart has given the name of Pan-
danocarpum, occur, together with cocoa-
nut fruit, at an early period of the ter-
tiary formations, in the London clay of
the Isle of Sheppey.

PA'NGOLIN. A species of manis, or scaly
lizard ; called also the scaly ant-eater. Its
armature is composed of separate, horny,
moveable scales. It is destitute of teeth,
has a very extensile tongue, and lives on
ants and termites.

PA'NICLE. (panicula, Lat. a bunch or
cluster.) A species of inflorescence, in
which the flowers are scattered on pedun-
cles, variously subdivided without any
order, and more or less close. The oat
affords a familar example. When the
middle branches of a panicle are longer
than the others, it is termed a thyrsus.

PANNI'CULUS CARNO'SUS. (from panni-
culus, a cloth, and carnosus, fleshy, Lat.)
A peculiar set of sub-cutaneous mus-
cular bands which serve to erect the bris-

tles, or armour, of certain animals ; as
the hedge-hog, porcupine, &c.

PANOP^E'A. A genus of bivalve shells of
the faaiily Solenacea. The panopsea is a
transverse inequilateral bivalve, gaping
at both extremities. The hinge similar
in both valves, with an acute cardinal
tooth in each, and, on the right valve, a
little pit, which receives the tooth of the
opposite valve.

This shell appears to be of a mixed
genus between mya and solen. It is
found both recent and fossil, but no great
deal appears to be known of the recent
species.

PA'PER COAL. A bituminous shale, to
which the name has been given from its
divisibility into extremely thin leaves. In
the brown coal formation, and in the
surturbrand, are found beds that divide
into laminae, as thin as paper, and are
composed entirely of a congeries of many
kinds of leaves.

PA'PER NAU'TILUS. Called also the Paper
Sailor. See Argonauta.

PAPI'LIO. (papilio, Lat. a butterfly.) A
genus of the family Diurna, belonging to
the order Lepidoptera. The butterfly.
The species are numerous. It has been
weU observed that the chrysalis is the
tomb of the caterpillar, and the cradle of
the butterfly.

PAPILIONA'CEOUS. Resembling a butterfly.
In botany, the corolla is called papiliona-
ceous when it consists of five petals of
particular forms, of which the uppermost
is generally the largest, and turned back ;
the two next resemble each other, but
differ from the first ; they have their
faces turned towards each other, and are
called the alee ; the two lowermost are
generally united by their lower edge, and
form a keel-like figure, and are, from that
circumstance, called the carina or keel ;
the two last, so united, contain, and pro-
tect, the internal organs.

PAPI'LLA. (papilla, Lat.) This word is
generally used in the plural, papillae.
Malpighi first discovered this structure
in the foot of the pig, and gave to it its
name. The external surface of the skin
presents a great number of minute pro-
jecting filaments ; these are the papillae.
" It is probable," says Dr. Roget, "that
each of these papillae contains a separate
branch of the nerves of touch, so that
we may consider these papillae as the
principal and immediate organs of touch.
The papillae are much more easily per-
ceived on some parts than others, but no
where are they more perceptible than on
the tongue, where, more especially in a
morbid condition of the body, they are
frequently much elevated.

PAPI'LLOUS. (from papilla, Lat. a pimple.)

PAP

[

PAR

Having the surface covered with pimples
or dots.

PAPI'LLOSE. In botany, a term applied to
stems covered with soft tubercles ; also
to leaves covered with fleshy dots or
points.

PA'PULOUS. (from papula, Lat. a kind of
pimple.) Full of pimples ; pimply ;
blistered.

PA'PPUS. (pappus, Lat. thistle-down.
TraTrTroe, Gr.) The feathery appendage
that crowns many seeds which have no
pericarpium ; a particular form of calyx
of which we have a familiar example in
the dandelion.

PARA'BOLA. (parabola, Lat. TrapafioXfj,
Gr. parabole, Fr. parabola, It.) One of
the five conic sections : thus, if a cone be
cut by a plane parallel to one of its
sloping sides, the section will be a para-
bola.

PARABO'LICK. (parabolique, Fr. parabolico,
It.) Having the nature or form of a
parabola.

PARALLE'LOGRAM. (from TrapaXX^Xoc and
•ypa/jjua, Gr. parallelograme, Fr. paral-
lelogrammo, It.) In geometry, a right-
lined quadrilateral figure, whose opposite
sides are parallel and equal.

PARALLELOPI'PED. (parallelipipede, Fr.
terme de geometric. Corps solide termine
par six parallelogrammes dont les opposes
sont paralleles entre eux.*) A solid figure
contained under six parallelograms, the
opposites of which are parallel and equal ;
or it is a prism whose base is a parallelo-
gram : it is always triple to a pyramid of
the same base and height.

PARA'NTHINE. A rare mineral, thus named
by Hauy, more commonly known as Sea-
polite, which see.

PARASI'TA. (parasita, Lat. 7rapa<rtroc?
Gr.) In Cuvier's arrangement, the third
order of Insecta ; they have six legs and
are apterous. Mr. Kirby observes, " the
order of parasites, consisting of the most
unclean and disgusting animals of the
whole class, infest both man, beast, and
bird, no less than four species being
attached to man, may be divided into two
sections, namely, those that live by suc-
tion, and those that masticate their food.
To the first of these belong the human
and the dog-louse, and to the other the
various lice that inhabit the birds, of which
almost every species has a peculiar one.

PARASI'TIC. )1. In botany, applied to

PARASI'TICAL. $ plants which fix their
roots into other plants, and from them,
instead of from the earth, derive their
nourishment : the mistletoe is a familiar
example.

2. In zoology, a name given to certain
insects which live upon the animals they
infest.

PARENCHY'MA. (rrapt-yx^fjia, Gr. paren-
chyme, Fr.)

1 . A spongy or porous substance forming
the bulk of some of the viscera, as the
parenchyma of the liver, &c.

2. In botany, a fine, transparent, mem-
branous tissue, lying immediately beneath
the epidermis of plants ; it is of a deep
green colour, very tender, and succulent.
When viewed with a microscope, it seems
to be composed of fibres which cross each
other in every direction. In its simplest
state, it appears like a mass of globules or
vesicles, crowded together ; these, from
pressure, assume a six-sided, or hexagonal
figure.

PARENCHY'MATOUS. Consisting of paren-
chyma ; spongy ; porous.

PA'RGASITE. The name given to a variety
of actinolite, from its being found in the
Isle of Pargas, in Finland.

PARIE'TAL. (from paries, a wall, Lat.)

1 . The name given to certain bones of the
skull, from their serving as walls to the brain.

2. In botany, a term used to express an
adhesion of some part to the inner side of
an organ ; as when the seeds are attached
to the placentae, the latter are termed
parietal.

PA'RIS BA'SIN. A large area, to which the
name of Paris Basin has been given, about
180 miles in length, from north-east to
south-west, and about ninety miles wide,
from east to west. The country in which
the capital of France is situated, is per-
haps the most remarkable that has yet
been observed, both from the succession
of different soils of which it is formed,
and from the extraordinary organic re-
mains which it contains. Bones of land
animals, of which the genera are entirely
unknown, are found in certain parts ;
other bones remarkable for their vast
size, and of which some of similar genera
exist only in distant countries, are found
scattered in the upper beds. Millions of
marine shells, which alternate regularly
with fresh-water shells, compose the
principal mass. The strata composing
the Paris basin rest upon chalk, lying, as
it were, in a depression of the chalk.
The depth of these strata varies from one
to five hundred feet. MM. Brongniart
and Cuvier divided the strata into the
five following formations, commencing
with the undermost. 1. First fresh- water
formation ; consisting of plastic clay, lig-
nite, and first sandstone. 2. First marine
formation ; comprising the calcaire gros-
sier. 3. Second fresh-water formation ;
containing siliceous limestone, gypsum,
with bones of animals, and fresh-water
marls. 4. Second marine formation ;
consisting of gypseous marine marls,
upper marine sands and sandstones, and

PAR

PEA

upper marine marls and limestones. 5.
Third fresh-water formation ; containing
siliceous millstone without shells, siliceous
millstone with shells, and upper fresh-
water marls. Subsequent observations
have proved that this division, as well as
many of the views entertained by MM.
Brongniart and Cuvier, is not in accord-
ance with facts with which they were un-
acquainted, and much modification of the
above arrangement has been the conse-
quence. The siliceous limestone, with
fresh-water and terrestrial shells and
plants, and the calcaire grossier, or first
marine formation, often alternate, and
are deemed by M. Constant. Prevost to
be contemporaneous formations ; and it
is not improbable that while the waters
in one lake or basin might be marine,
those in another might be fresh, and thus
two formations containing different or-
ganic remains might be deposited con-
temporaneously.— LyelL Bakewell.

PA'RTICLES ELEME'NTARY. The final re-
sults of chemical analysis. Elementary
particles are those of which integrant
particles are composed ; thus, while the
latter remain invariable in the same body,
the former must vary with the progress
of chemistry. In bodies really simple,
the integrant and elementary particles
must be the same. — Cleaveland.

PA'RTICLES I'NTEGRANT. These are the
smallest particles into which a body can
be reduced without destroying its nature,
or, in other words, without decomposing
it. Only three forms of integrant par-
ticles have hitherto been discovered.
They are the three most simple, geome-
trical solids ; namely, a tetraedron ; a tri-
angular prism ; and a parallelepiped, in-
cluding all solids of six sides, parallel
two and two.

PA'RTITE. (partitus, Lat. from partior, to
divide.) Divided. In botany, a partite
leaf is one separated to the base.

PATE'LLA. (j9atfe?Za, Lat. a little deep dish
with a broad brim.) That bone of the
leg commonly known as the knee-pan.

PATE'LLA. In conchology, the limpet shell.
Animal a limax. A marine shell, uni-
valve, subconic, shaped like a basin ;
without a spire. In Turton's Linne two
hundred and forty species of patella, or
limpets, are described : fourteen of these
are inhabitants of our coasts. The patella
is found both recent and fossil. Recent
patellae are found at depths varying to
thirty fathoms, on rocky coasts, stones,
and sea- weeds. Many species have been
found" fossil in the neighbourhood of
Paris. Patellae have also been obtained
from the Shanklin sand, and from the
Harwich cliffs. Mr. Parkinson mentions
that he possesses a fossil patella of the

species P. ungarica, of the size of two
inches and a-half in its longest diameter.

PATE'LLIFORM. (from patella, a dish, and
forma, form, Lat.) Of the form of a
small dish.

PATE'LLITE. A fossil patella.

PA'TULOUS. (patulus, from pateo, Lat. to
be open.) In botany, spreading, as a
patulous calyx. In conchology, gaping ;
with a spreading aperture.

PAVO'NIA. (from pavo, Lat. a peacock.)
A coral with a deep and isolated cell,
such cell containing a large depressed
polypus, very similar to the actinia as
regards both its structure and appearance.
In Dr. Mantell's Wonders of Geology a
species of pavouia, the P. lactuca, is beau-
tifully figured. He states that the polypi
are of a deep green colour, and that there
is a connecting, transparent, fleshy sub-
stance, which extends over the extreme
edges of the foliated expansion of this
elegant coral.

PEA ORE. The name given to granular
argillaceous oxide of iron, from its occur-
ring in small masses or grains, nearly or
quite spherical, and of the size of a pea.
It is the pisiform iron-stone of Kirwan.

PEAR E'NCRINITE. The Apiocrinites ro-
tundus, or Bradford ecrinite. A species
of crinoidea abounding in the oolitic lime-
stone in the neighbourhood of Bradford,
near Bath. When living, their roots were
confluent, and formed a thick pavement
over the bottom of the sea, from which
their stems and branches rose into a
thick submarine forest, composed of these
splendid zoophytes. This bed of beauti-
ful remains has been buried by a thick
stratum of clay. The body of the pear
ecrinite was of a pyriform shape, from
which circumstance it has been thus
named. The pear ecrinite is confined to
the middle oolite.

PEARL, (perle, Germ, perle, Fr. perla, It.)
A spherical concretion consisting of con-
centric coats of the same substance as that
which forms the mother-of-pearl of the
shell. It is produced by the extravasation
of a lapidifying fluid, secreted in the
organs of the animal, the pearl oyster,
and filtered by its glands. The animal
that produces pearls in the greatest abun-
dance, of the purest nature, and of the
highest value, has been formed by Lamarck
into a genus named Meleagrina ; Linne
classed it with the muscles. It inhabits
the Persian gulf, the coasts of Ceylon, &c.
It attains perfection no where but in the
equatorial seas. The pearl fishery off the
island of Ceylon is the most productive
of any ; the oyster-beds extending over a
space thirty miles long by twenty-four
broad. The oysters at the greatest depths
yield the largest pearls, which are situated

PEA

197 ]

PEC

in the fleshy part, near the hinge. For
one pearl that is found perfectly round
and detached between the membranes of
the mantle, hundreds of irregular ones
occur attached to the mother-of-pearl;
these are sometimes in such numbers as
to prevent the animal from closing its
valves, and thereby cause its destruction.
The pearl is supposed by some writers
to be the effect of disease ; it is a forma-
tion forced upon the oyster by some ex-
traneous substance within the shell, which
it covers with mother-of-pearl. Sir
Everard Home considered that the abor-
tive eggs of the animal were the nuclei
upon which the pearls were formed.

To collect the pearl oysters, divers are
employed ; these men, provided with
baskets, descend to the bed at the bottom
of the sea, and during their stay there,
which does not exceed two minutes, ge-
nerally a minute and a-half, collect into
their baskets every thing they can grasp,
when they are rapidly, at a signal given,
hauled up to the surface. When the bed
is richly stored, a diver will collect 150
oysters at one dip, and a single diver will,
in one day, bring up from 1000 to 4000
oysters. — Rev. W. Kirly. Bridgewater
Treatise.

PEARL SI'NTER. Called also fiorite. A
variety of siliceous sinter of a white or
grey colour, found in volcanic tuff.

PEARLA'CEOUS. Resembling mother-of-
pearl.

PEA'RLSTONE. An igneous or volcanic
rock with a mother-of pearl lustre. The
Perlstein of Werner ; Obsidienne perlee
of Brongniart; Lave vitreuse perlee of
Haiiy. Pearlstone is a variety of obsidian
occurring in globular and concentric la-
mellar, iridescent, translucent concre-
tion. It scratches glass. Specific gra-
vity from 2-20 to 2-55. When breathed
upon, it frequently gives out an argilla-
ceous odour. Tts constituents are silica
77'0, alumina 13'0, lime and natron 2'6,
potash 1*4, oxides of manganese and iron
2-0, water 4-0.

PEA STONE. A variety of limestone, called
also pisolite. It occurs in globular or
spheroidal concretions of the size of a pea.
See Pisolite.

PEAT, (derived by some from the German
word pfutze, a pool, or standing water.)
An intermediate substance between simple
vegetable matter and lignite, the conver-
sion of peat into lignite being gradual,
and brought about by the action of water.
Peat is composed of the remains of many
different plants, but probably & great
portion is derived from the Sphagnum
palustre, and the process by which these
vegetables are thus converted is clearly
seen in the sphagnum palustre. As the

lower extremity of the plant dies, the
upper sends forth fresh roots, thus fur-
nishing a perpetual supply of decomposing
vegetable matter. Dr. Maculloch states,
" where the living plant is still in contact
with the peat, the roots of the rushes,
and ligneous vegetables, are found vacil-
lating between life and death, in a spongy
half decomposed mass. Lower down,
the pulverized carbonaceous matter is
soon mixed with similar fibres, still re-
sisting decomposition. These gradually
disappear, and at length a finely-powdered
substance alone is found, the process
being completed by the total destruction
of all the organised bodies. The genera-
tion of peat, when not completely under
water, is confined to moist situations,
where the temperature is low, and where
vegetables may decompose without putri-
fying.'1

Sir H. Davy states that one hundred
parts of dry peat contain from sixty to
ninety-nine parts of matter destructible
by fire. One-tenth of the whole of the
surface of Ireland is stated to be peat.
At the bottom of peat-mosses there is
occasionally found a cake or pan of oxide
of iron ; whence this is derived does not
appear to be clearly understood. The
preservative property of peat is very re-
markable ; bodies of persons who have
perished in peat-bogs have been kept free
from putrefaction for many years.
PE'CTEN. (pecten, Lat. a comb.) A genus
of marine bivalves, belonging to the family
Ostracea, or, according to Lamarck's
arrangement, to the family Pectenides.
The pecten is a fossil as well as a recent
shell, many species being found in our
seas. Pecten s are found at depths vary-
ing to twenty fathoms, in mud, sandy
mud, and sand. It is a regular, eared,
longitudinally ribbed, inequivalved bi-
valve, with contiguous beaks, having a
triangular auricle on each side of the um-
bones. Hinge toothless ; pit trigonal.
One muscular impression. Fossil pectens
are found in the neighbourhood of Paris,
and in many parts of England ; in the
Harwich cliff; in the green-sand of Wilt-
shire ; near Thame in Oxfordshire ; in
Gloucestershire ; and in Sussex. Amongst
the fossils of Sussex one species of pecten
is found in the chalk ; four species in the
chalk marl ; one species in the gait ; and
three species in the Shanklin sand.

1. In conchology, resembling a comb ;
cut into regular, straight, segments like a
comb.

2. In botany, applied to a pinnatifid leaf,
whose segments are extremely narrow,
resembling the teeth of a comb.

PEC

[ 198 1

PEN

PECTINIBRANCHIA'TA. The sixth order of
mollusca, in Cuvier's arrangement.

PECTU'NCULUS. A genus of orbicular sub-
equilateral marine bivalves, with an arched
hinge ; numerous teeth, alternately in-
serted in a single row. Pectunculi are
easily recognized by their rounded or len-
ticular form. Muscular impressions two,
and strongly marked. Recent pectunculi
are found at depths varying from five to
seventeen fathoms in sandy mud and
sands. Fossil pectunculi are met with in
the London clay and calcaire grossier, and
in the Bognor sandstone.

PE'DATE. (pedatus, Lat. from pes, afoot.)
In botany, applied to leaves in which a
bifid petiole connects several leaflets on
the inside only ; also to a peculiar kind of
ternate leaf, its lateral leaflet being com-
pounded in the fore part : the black helle-
bore is an example.

PE'DICLE. (pediculus, Lat. a little foot.)
The support of the Lepas anatifera, and
its corresponding species, by which they
are attached to wood, &c.

PE'DICEL. In botany, a partial flower-
stalk, or a subdivision of the general
one, each subdivision being termed a
pedicel.

PEDI'GEROUS. (from pes, a foot, and gero,
to bear, Lat.) Having legs; thus the
body of the myriapod is divided into nu-
merous pedigerous segments.

PEDIPA'LPI. The second family of Arach-
nidans. They have very large palpi ter-
minated by a forceps or claw. The prin-
cipal animals among the pedipalps are the
scorpions, possessing powerful organs for
seizing their prey, and having a tail ter-
minating in a deadly sting. The other
pedipalps are not armed with a sting.

PE'DUM. (pedum, Lat. a shepherd's
crook.) A genus of marine bivalvular
shells found attached by a byssus to
rocks. It is an eared inequivalved bi-
valve, gaping at the lower valve, and
having its beaks separated : hinge tooth-
less ; ligament exterior ; inferior notch
grooved. This genus does not appear to
have been found fossil.

PE'DUNCLE. (pedunculus, Lat. from pedof
a splay foot.)

1. In botany, the stalk that bears the
flower and fruit.

2. In conchology, a sort of stem by which
the shells of the second division of lepas
are attached to wood, &c.

PEDU'NCULATE. ) Attached to obj ects su ch
PEDU'NCULATED. \ as wood, rocks, &c.,

by a peduncle ; having a peduncle.
PEGMATI'TE. A name given by the French
mineralogists to a variety of granite com-
posed of granular quartz and felspar.
PELA'GIAN. } (pelagus, Lat. the sea.) Be-
PELA'GIC. $ longing to the sea. Mr.

Lyell says, " belonging to the deep
sea."

PELA'GIAN FORMATIONS. Oceanic accu-
mulations ; deposites by currents, or
from other causes, at the bottom of the
sea.

PE'LIOM. (from TrtX/w/za, Gr. blueness,
or of a lead colour.) A blue coloured
mineral resembling iolite, of which it is
a variety. It is found in Bavaria.

PE'JLLICLE. (from pellicula, Lat. dim. of
pellis, a little skin, pellicule, Fr. pelli-
cella, It.) A film ; a thin crust or co-
vering.

In botany, a membranous or mucila-
ginous covering, closely adhering to the
outside of some seeds, so as to conceal
their proper surface and colour.

PELTA'TE. (from pelta, Lat. a target.)
In botany, a term applied to leaves which
have their footstalk inserted in the middle
of the leaf, and not joined to the edge ;
the nasturtium is a familiar example.

PE'LVIS. (pelvis, Lat. from Tri\vq, Gr. a
basin.) The lower part of the trunk of
vertebrated animals.

PE'NCIL. A name given to the belemnite.

PE'NNATE. ) (pennatus, Lat. from penna, a

PE'NNATED. $ wing.) Winged ; feathered.

PENNA'TULA. Called, commonly, the sea-
pen. A polypus with a calcareous axis
or stem, having a double set of branches
extending in the same plane from both
sides, like the vane of a quill. Penna-
tulse are not fixed by any attachment to
the ground, but float about in the waters
of the ocean, carried hither and thither as
the current may direct them.

PE'NNIFORM. (from penna, a feather, and
form.) Having the form of a feather or

r'll. In anatomy, muscles in which
muscular fibres pass obliquely out-
wards on either side from a tendinous
centre, are termed penniform. The rec-
tus femoris affords an illustration of a
penniform muscle.

PENTACA'PSULAR. (from Trevre, Gr. five,
and capsula, Lat. a cell or capsule.)
Having five cavities, capsules, or cells.

PENTA'CEROS RETICULA'TUS. A fossil
species of asteria, or stella marina.

PENTA'CEROS DENTIGINO'SUS. A fossil
species of asteria or stella marina, found
in the chalk and in the London clay.

PENTA'CRINITE. (from TreVrt, five, and
encrinite.) So called from the penta-
gonal formation of its vertebral column.
The fossil pentacrinus. Pentacrinites
abound in the lower strata of the oolite
formation, and especially in the lias ; but
disappear entirely in the uppermost for-
mations. From this circumstance geolo-
gists were disposed to limit their exis-
tence to certain periods, and to conclude
that the pentacrinite furnished the re-

PEN

[ 199]

PER

mains of an extinct genus. Subsequent
discoveries, however, prove that the pen-
tacrinus does still exist ; two species, the
Pentacrinus caput medusae, and the Pen-
tacrinus europseus, having been lately
discovered. Thus, probably, it may be
with many genera which, in ignorance,
geologists describe to be extinct, merely
because they have not met with living or
recent specimens.

PENTA'CRINUS. This animal consists of
an angular flexible column, composed of
numerous joints, articulating by means
of cartilage, and perforated for the trans-
mission of a siphon, or intestinal canal,
and sending forth at intervals, in whoi'ls,
several articulated cylindrical branches,
curving into a hook at their summit ;
fixed at its base, and supporting at its
free extremity a cup-like body, contain-
ing the mouth and larger viscera, con-
sisting of several pieces, terminating
above in five or six dichotomizing, arti-
culated, semi-cylindrical arms, fringed
with a double series of tentacular jointed
digitations, furnished below on each side
with a series of minute suckers. These
arms, when expanded, resemble a star of
five (or six) rays ; and when they con-
verge, a pentapetalous or hexapetalous
flower. The whole animal, when alive,
is supposed to be invested with a gelati-
nous muscular integument. — Rev. W.
Kirby, Bridg. Treatise.

Two species of the genus pentacrinus
have been lately obtained ; one, the Pen-
tacrinus caput medusae, from the bottom
of deep" seas in the West Indies ; the
other, Pentacrinus europseus, has been
found on the coast of Ireland, attached
to different kinds of Sertularia and Flus-
tracea. The calcareous joints which
compose the fingers of the pentacrinus
europseus, are capable of expansion and
contraction in all directions ; now spread-
ing outwards, like the petals of an ex-
panded flower, and again rolled inwards
towards the mouth in the form of a closed
bud. These organs serve to seize, and
convey to the mouth, the food of the
animal. The number of bones in each
animal is computed at thirty thousand.
Dr. Buckland says that the number of
bones in the Briarean Pentacrinite, a
species beautifully described in his admi-
rable Bridgewater Treatise, exceeded a
hundred and fifty thousand. The num-
ber of bones in the fingers and tentacula
amount at least to a hundred thousand,
and fifty thousand more, which is consi-
derably under the real number, may be
added for the ossicula of the side arms.
Each bone requiring at least two fasciculi
of fibres, one for expansion, the other for
contraction, the Briarean Pentacrinus

must have had three hundred thousand
fasciculi of fibres equivalent to muscles.

PENTADA'CTYJ,. (from Trevre, five, and
daKTV\o£, a finger, Gr.) Having five
fingers. Applied also to leaves.

PE'NTAGON. (from Trevre, five, and ywvi'a,
an angle, Gr. pentagone, Fr. pentayono,
It.) A figure having five sides and five
angles.

PENTA'GONAL. (pentagone, Fr. penta-
gonale, It.) Having five angles and five
sides; quinquangular.

PENTAGONA'STER SE'MILUNATUS. A fos-
sil species of the Stella marina, found in
the chalk pits of Kent.

PENTAGONA'STER REGULA'RIS. A fossil
asterite, or species of stella marina, found
in the chalk pits of Kent.

PE'NTAGYN, from Trkvre, five, and yvvrj, a
woman, Gr.) A plant which has five
pistils.

PENTAHE'DRAL. Having five equal sides.

PENTAHE'DRON. (from TrkvTt, five, and
tdpa, a base, Gr.) A figure of five equal
sides.

PENTA'NDER. (from Trkvrt, five, and
art]?, a man, Gr.) A plant having five
stamens.

PENTA'NDRIAN. Five stamens ; having
five stamens.

PENTAPHYLLOI'DAL. (from irdvre, five,
(pvXXovy a leaf, and tidoc, resemblance,
Gr.) Appearing to have five leaves ;
resembling five leaves. The Placentae
are all ornamented with a pentaphylloidal
flower.

PENTELA'SMIS. (from irevTs, five, and
IXaoyia, a plate, or layer, Gr.) A spe-
cies of Anatifa, or of the Lepas of Lin-
nseus.

PEPERI'NO. The name given by Italian
geologists to a particular form of volcanic
tuff, composed of basaltic scoriae .

PERA'MELES. A genus of marsupialia.
The following description is from Major
Mitchell's Australia. " The most re-
markable incident of this day's journey
was the discovery of an animal, of which
I had seen only the head amongst the
fossil specimens of Wellington valley.
This animal was of the size of a wild
young rabbit, and of nearly the same
colour, having a broad head, terminating
in a long very slender snout, like the
narrow neck of a wide bottle ; and no
tail. The feet, and especially the fore
legs, were singularly formed ; the latter
resembling those of a hog, and the mar-
supial opening was downwards, and not
upwards, as in the kangaroo and others
of that class of animals. This animal
was discovered by our natives on the
ground, but when pursued it took refuge
in a hollow tree, from which they took it
alive ; all of them declaring that they had

PER

[ 200 ]

PET

never before seen an animal of that kind.
The original has been deposited in the
Sydney Museum ; but having shown to
my friend Mr. Ogilvy a drawing of it, he
has noticed the discovery in the Pro-
ceedings of the Geological Society for
1838, describing the animal as belonging
to a new genus closely allied to Pera-
meles, but differing in the form of the
fore feet, which have only two middle
toes resembling those of a hog, and in
the total absence of tail. This genus re-
quires to be verified by an examination
of the specimens at Sydney. It may
eventually turn out to be a real Perameles,
and in that case be called Perameles
Ecaudatus, or, if generally distinct, Chae-
ropus Ecaudatus."

PE'RCOLATE. (from per, through, and colo,
to strain, or filter. ) To filter through ;
to strain through ; to run through the
pores, as through a filter.
PERCOLA'TION. Filtration ; the act of run-
ning through the interstices of a stratum,
as the percolation of water.
PERE'NNIAL. (perennis, Lat. perenne,
It.) In botany, applied to plants that
live many years, bearing flowers and fruit
frequently.

PERBO'LIATE. In botany, applied to leaves
when the stem appears to pass through
their substance. The common hare's-ear
is an example.

PE'RIANTH. (from TrjpJ, about, and avBog,
a flower, Gr.) The calyx is so called
when it is united with the corolla, so as
to form only one floral envelope.
PERICA'RDIUM. (from Trtpi, round, and
Kapdia, the heart, Gr. pericarde, Fr.
pericardia, It.) The membrane which
envelopes the heart.

PE'RICARP. (from Trtpi, round, and KapTroe,
fruit, Gr. pericarpe, Fr.) The ovarium,
when ripened into fruit, is called the
pericarp; this consists of three parts,
which in some fruits, as the peach and
plum, are easily separable. The outer
skin is called epicarp ; the fleshy part,
the sarcocarp ; the stone, or shell, the
endocarp. There are ten different kinds
of pericarps, namely, drupe, pome, berry,
follicle, silique, silicic, legume, capsule,
nut, and strobile.

PERICLI'NIUM. The name given by foreign
botanists to a kind of involucre. See
Periphoranthium.
PE'RIDOT. The name given by Haiiy to

prismatic chrysolite.

PERIGE'E. (from Trepl, round, and yr), the
earth, Gr. perigee, Fr.) A term used
to denote that point where the sun is
nearest to the earth. The perigee of the
lunar orbit is the point where the moon
is nearest to the earth.
PERI'GYNOUS. (from irtpit about, and

yvvi}, a woman, Gr.) Inserted around
the pistil. When the stamens grow out
of the corolla, calyx, or perianth, or are
not in any way joined to the seed-vessel,
they are said to be perigynous.
PERIO'STETJM. (from Trtp/, around, and
dffTtbv, a bone, Gr. perioste, Fr.) The
membrane which covers all the bones ;
that, however, which covers the bones of
the skull is called the pericranium.
PERIPHORA'NTHIUM. When bracts are
collected into a whorl, as in umbelli-
ferous plants, they are said to form an
involucre, which, if very small, receives
the diminutive name of involucel. This
kind of organ is very remarkable in
compound - flowered plants, appearing
as if it constituted a calyx common to
many flowers ; and hence it used to be
called a common calyx. It, however,
does not differ from the involucre in any
thing more than its bracts being more
numerous, more closely packed, and pa-
rallel with each other, instead of diverging.
Foreign botanists have given the names
Periphoranthium and Periclinium to this
kind of involucre.

PE'RNA. A genus established by Bru-
guieres. A flat, irregular, subequivalve,
compressed, foliaceous, marine, bivalve.
Several parallel cavities across the hinge
opposed to each other in the two valves,
and lodging as many elastic ligaments :
anterior margin with a passage for a
byssus. Recent Pernae are found at
depths varying to ten fathoms ; they are
littoral shells ; moored by their byssus
to mangrove trees and corals. Fossil
Pernse have been found on the borders of
the Rhine.

PERSI'STENT. (from persisto, Lat. to
abide. ) In botany, opposed to deciduous.
Not withering and falling ; remaining.
PE'RSOXATE. A term applied to a mono-
petalous flower of an irregular form, the
border of the corolla having an oral ap-
pearance with the labia closed.
PE'RVIOUS. (pervius, Lat.) Admitting

passage ; capable of being penetrated.
PK'TAL. (TrkraXov, Gr. petale, Fr.) The
name given to each leaf of the corolla, or
flower of a plant.

PE'TALITE. A mineral, of a reddish, or
greyish-white colour, which has only been
found in Sweden. It consists of silica 77'0,
alumina 17*0, lithia 6*0 ; or according to
others, of silica 76-21, alumina 17'22,
lithia 5' 76. It occurs in a mine of black
iron-ore, associated with spodumene, fel-
spar, tourmaline, mica, and quartz. Its
fracture is foliated ; scratches glass ;
brittle, and translucent at the edges.
Specific gravity 2 -62.

PE'TIOLE. (from petiolus, Lat. the stalk of
fruits.) In botany, a foot-stalk ; the

PET

[201 ]

P H O

stalk, or stem, which connects the leaf
with the branch.

PETRI'COLA. (from Trerpoc, a stone, Gr.
and cplo, to inhabit, Lat.) A genus of
transverse, inequilateral, bivalve, marine
shells, belonging to the family Lithophagi.
Two muscular impressions ; two hinge-
teeth on one valve, and a bifid one on the
other ; anterior side rounded, posterior
side more or less slightly gaping ; liga-
ment external. Petricolse are found at
depths varying to ten fathoms ; they
inhabit cavities, of their own working, in
rocks and shells. They may be distin-
guished from saxicava by the regularity
of their form, and by the teeth on the
hinge, which in saxicava become obsolete
when the animal is full grown.

PETRIFA'CTION. (petrifaction, Fr.) A
substance converted into stone. Sub-
stances, either animal or vegetable, con-
verted into stone by the infiltration, or
incrustation, of siliceous matter.

PETRE'SCENT. (from petrescens, Lat.)
Becoming stone ; growing into stony
matter.

PETRO'LEUM. (petrole, Fr.) A mineral
oil, rather thicker than tar, and of a
reddish-brown colour ; it has obtained its
name from the circumstance of its oozing
out of rocks like oil. In the East it is
burnt as oil. It is unctuous to the
touch, and exhales a strong and unplea-
sant odour. It is lighter than water, its
specific gravity being 0 87. In the island
of Zante, petroleum is at the present
time obtained from the same spot, and in
the same manner, as in the days of Hero-
dotus. The most powerful springs pro-
ducing petroleum are on the Irawaddi, in
the Burman empire. In one locality
there are said to be 520 wells, yielding
annually 400,000 hogsheads of petroleum.
It occurs in most countries where coal is
found.

PETROSI'LEX. A fusible variety of horn-
stone ; according to some authors, the
same as clinkstone ; to others, compact
felspar.

PETUN'TZE. The felspathe petuntze of
Brongniart. A variety of felspar, used
in the manufacture of porcelain. It is
called Petuntze by the Chinese.

PE'TWORTH MA'RBLE. Called also Sussex
marble, occurs in layers varying from a
few inches to a foot and upwards in
thickness, separated from each other by
seams of clay. The Petworth or Sussex
marble is a limestone of various shades of
colour, occurring in the Weald clay ; it is
composed of the remains of fresh-water
univalves, shells of the paludina, and
crusts of the cypris faba, united into a
compact marble by a gangue of calcareous
cement. The more compact varieties

bear a beautiful polish, and are elegantly
marked, when cut into slabs, by the sec-
tions of the contained shells.

PHJENOGA'MOUS. (frpm 0aivw, to shew,
and y«/iO£, marriage, Gr.) The name
given to such plants as have the stamens
and ovarium distinctly visible.

PHA'LANX. PI. Phalanges. (0o\ay£, Gr.
phalange, Fr. falange, It.) The bones
composing the fingers and toes are termed
the phalanges.

PHANEROGA'MIC. \ (from 0«vEpo£, mani-

PHANEROGA'MOUS. $ fest, and ydfiog,
marriage, Gr.) Plants in which the sta-
mens and ovarium are distinctly visible ;
plants having the reproductive organs
visible. In all the phanerogamous plants
the whole of the double apparatus re-
quired for reproduction is contained in
the flower. The term is used in contra-
distinction to cryptogamous.

PHARMA'COLITE. The name given by Bro-
chant to arseniate of lime.

PHASIANF/LLA. (from phasianus, Lat. a
pheasant.) A genus of shells belonging
to the family Trochoida ; or, according
to Lamarck's arrangement, Turbinacea.
It is a solid ovate or conical univalve ;
opening longitudinal, ovate, and entire ;
lip thin ; columella smooth, with an at-
tenuated base. Recent phasianella? are
inhabitants of the Indian ocean, they are
found on the coasts and in estuaries, at
small depths only. These shells are
marked with beautiful lines of various
colours, and are much esteemed and
sought after for their beauty.

Two species of Phasianella have been
found fossil at Grignon, P. turbinoides,
and P. semistriata.

PHI'LLIPSITE. A mineral, found accom-
panying Herschelite. It is a species of
Harmotome or cross-stone, containing
lime and potash instead of baryta.

PHO'LAS. (c&oAdg, from 0w\sw, Gr. to lie
concealed.) A genus of marine bivalves,
belonging to the family Inclusa ; or, ac-
cording to Lamarck's arrangement, the
family Pholadaria. A transverse gaping
shell, composed of two principal valves,
with several small accessory pieces placed
on the ligament or at the hinge. A long
curved tooth protrudes in each valve from
beneath the umbones. Pholades are
found at depths varying to nine fathoms ;
they pierce wood, rocks, indurated clay,
&c. They are much sought for in con-
sequence of their delicious flavour. The
history of none of the boring bivalves,
says Mr. Kirby, is more interesting than
that of the Pholads, or stone-borers.
These animals are defended by two very
fragile shells, strengthened indeed by sup-
plementary pieces, and rough like a file,
inhabited by a very soft animal which

P H O

[ 202 ]

PHY

appears to be furnished with no organs
adapted to boring so hard a substance as
a rock. When the young are disclosed
from the egg, being cast upon the rock in
which their mother resides, they bore a
hole in it which they enlarge daily, and
which they never leave, unless compelled
by force. This hole always communi-
cates with the water, and is the orifice
through which the animal exerts its
double siphons. One of these siphons is
its mouth, and the other its anal orifice.
Poli says they use their foot as an augur in
excavating their crypts, the shell revolv-
ing upon it as upon an axis. Pholades
possess a remarkable degree of phospho-
rescent property.

Fragments of fossils belonging to this
genus are found in Essex.

PHO'LADITE. A fossil or petrified pholas.

PHOLIDO'PHORUS. A genus of fishes of
the Wealden formation that prevailed
during the oolitic period, but believed to
be now quite extinct.

PHO'NOLITE. (from <f>ovrj, sound, and
XiOoQ, a stone, Gr.) Another name for
clinkstone. A felspathic rock, sonorous
when struck with a hammer, from which
circumstance it derives its name. When
the texture of basalt is compact, and its
felspar greatly prevails, it passes into pho-
lonite ; its colour is generally grey, or
greenish-grey. Again, when phonolite
has a more earthy texture it passes into
claystone.

PHO'SPHATE. A salt formed by the union
of phosphoric acid with a salifiable
base.

PHO'SPHATE OF LIMB. This is found in
the bones of animals, and constitutes
their base, as well as in the mineral king-
dom. It consists of lime 59-0, phospho-
ric acid 41-0. It is destitute of taste,
insoluble in water, and not affected by
exposure to the atmosphere. Exposed to
a very high temperature it becomes soft,
and is converted into a white semitrans-
parent enamel, or rather porcelain. Hu-
man bones, according to Berzelius, con-
tain 51-04 of phosphate of lime, and the
enamel of teeth, according to Mr. Pepys,
is composed of 78 per cent, of it. Sul-
phuric, nitric, muriatic, fluoric, aad
several vegetable acids are capable of
more or less decomposing phosphate of
lime. Mineral phosphate of lime contains
several species, namely apatite, asparagus
stone, &c., which are described under
their several names.

PHOSPHORESCENCE OF THE SEA. This
luminous appearance of sea-water arises
from the presence of immense numbers
of microscopic medusae which people
every region of the ocean, and, being
specifically lighter than the sea-water,

float in incalculable multitudes on its
surface.

PHOSPHORESCENT. Emitting light in the
dark without sensible heat.

PHO'SPHORITE. Amorphous phospate of
lime. The chaux phosphatee terreuse of
Haiiy ; phosphorit of Werner ; phospho-
rite of Jameson. A variety of apatite,
with commonly an earthy aspect : it
occurs in masses whose surface often dis-
plays mamillary projections. Fracture
dull and earthy. Colour white or grey,
often marked with spots or zones of a
brownish tinge. Specific gravity from
2-8 to 3-2. Before the blow-pipe it is
infusible, but its powder thrown upon
live coals emits a yellowish-green phos-
phorescent light. In Spain it forms
whole mountains ; it is also met with in
Germany. According to Pelletier, it con-
tains lime 59'0, phosphoric acid 34'0, and
the remainder consists of the carbonic,
fluoric, and muriatic acids, with a trifling
portion of silex and oxide of iron.

PHO'SPHORUS. (0wo-06pvc;, Gr. phosphorus,
Lat. phosphore, Fr.) One of the fifty-
five simple or elementary substances, and
belonging to that sub-division termed
non-metallic. Phosphorus is principally
known as entering into the chemical com-
position of animals. As a component
part of minerals, phosphorus is rare ;
but there must be some amount of it
entombed in fossiliferous rocks. Phos-
phorus is never found pure in nature,
and is only to be obtained from organic
matter by elaborate chemical processes.
It is yellow, and semi-transparent ; re-
sembling wax in softness, but more cohe-
sive and ductile. Specific gravity 1'77.
Its affinity for oxygen is so great that it
burns spontaneously in the atmosphere.
It should always be kept in bottles filled
with water, and well corked.

PHYLLA'DE. The name given by D'Au-
buisson, and the French geologists, to
clay-slate.

PHY'SALITE. A variety of prismatic to-
paz, of a greenish-white colour. It occurs
in coarse granular concretions, having a
low degree of lustre. Edges feebly trans-
lucent. It consists of alumina 57-75,
silica 34-30, fluoric acid 7'82. It is
found at Finbo, in Sweden, and at Alten-
berg, in Saxony.

PHY'LLITE. (from $v\\ov, a leaf, and
XiOoe, a stone, Gr.) A petrified leaf.

PHYSICAL, (physique, Tfr.fisico, It.) Re-
lating to nature or to natural philosophy ;
not moral ; pertaining to material things.

PHYSICS, (from ^ixrig, nature, Gr.) Taken
in its most enlarged sense, comprehends
the whole study of nature ; but in the
usual acceptation of the word, that branch
of science which treats of the properties

PHY

[ 203 ]

P I S

of natural bodies, and it includes natural
history and philosophy.

PHYTI'VOROUS. (from 0wrov, Gr. a plant,
and voro, Lat. to devour.) Feeding on
plants.

PHY'TOLITK. (from QVTOV, a plant, and
XiOoQ, a stone, Gr.) A petrified or fos-
silized plant.

PHYTO'LOGIST. (from phytology.} One
skilled in the structure, &c. of plants.

PHYTO'LOGY. (from tyvTov, a plant, and
X6yo£, discourse, Gr.) That department
of science which treats of the nature,
habits, qualities, &c. of plants.

PHYTO'PHAGOUS. (from 0wrov, a plant,
and Qaytlv, to eat, Gr.) Feeding on
plants ; devouring plants ; feeding upon
vegetable substances.

PHYTOSAU'RUS. A fossil saurian disco-
vered in the saliferous formation.

PHYTOZO'A. (from Qvrbv, a plant, and
Ztiov, an animal, Gr.) Plant-like animals.
Another, and more modern, as well as
appropriate, name for zoophytes.

PIGME'NTUM NI'GRUM. A dark brown, or
nearly black substance, which covers the
surfaces of the choroid membrane of the
eye, and gives to it its colour.

PI'LEUS. The name given to a genus of
fossil echini ; pileus is another name for
conulus.

PI'LLAR. In conchology, the columella, or
perpendicular centre, which extends from
the base to the apex, in most of the
spiral shells.

PI'LLAR-LIP. In conchology, a continua-
tion of the glossy process with which the
aperture of shells is lined, expanded on
the columella.

PI'LOSE. (pilosus, Lat.) In entomology,
covered with dispersed, long, and bent
hairs.

PI'MELITE. A variety of steatite, coloured
by chrome or nickel.

PI'NEAL GLAND, (from pineus, Lat. a
pine.) The name given to a gland of the
brain from its supposed resemblance to a
pine. This gland was at one time sup-
posed to be the seat of the soul.

PI'NNA. (pinna, Lat. the fin of a fish.) A
genus of marine bivalves belonging to
the family Mytalacea. A cuneiform, lon-
gitudinal bivalve, with an acute base, the
upper part gaping ; hinge without a
tooth, lateral, and very long ; valves
coalescent. Recent pinnse are found in
the ocean at depths varying to seventeen
fathoms ; they are moored by a long
silky byssus, which has been manufac-
tured into stockings and gloves. Pinnse
have been found fossil at Grignon, and in
the limestone of Gloucestershire, Wilt-
shire, and Somersetshire.

PI'NNITE. A fossil pinna.

PI'NNATE. (pinnatus, Lat. winged.) In

botany, applied to compound leaves, com-
posed of many leaflets, placed on each
side of the petiole ; these are placed in
pairs opposite to each other, and, in some
cases, an odd leaflet at the termination,
or, in others, a tendril : of the former the
rose furnishes an example ; of the latter,
the vetch.

PINNA'TIFID. In botany, applied to leaves
cut transversely into several deep, oblong,
parallel segments, the incisions reaching
nearly to the midrib, and dividing the
leaf into irregular forms, termed lobes.
The groundsel affords a familiar illus-
tration.

PIPE-CLAY. The Pfeifenthon of Werner.
This is the purest kind of potter's clay,
and is called pipe-clay, from its being
manufactured into tobacco-pipes. It is
of a grey or greyish white colour ; is
infusible ; and on exposure to a strong
heat it becomes white. It is abundant
in Devonshire and Staffordshire.

PISCI'VOROUS. (from piscis, a fish, and
voro, to devour, Lat.) Feeding on
fishes ; devouring fishes ; subsisting on
fishes.

PI'SIFORM. (frompisum, a pea, and forma,
form, Lat.) Of the form of a pea ; hav-
ing a structure resembling peas. Gra-
nular iron ore is called pisiform iron ore,
from its containing small rounded masses
of the size of a pea.

PI'SIFORM IRON ORE. )The pea ore of

PI'SIFORM IRON STONE. $ Jameson ; pi-
siform iron stone of Kirwan. A variety
of argillaceous oxide of iron, occurring in
small masses or grains, nearly or quite
spherical, and often equal in size to a
pea, or even larger. These globules are
composed of thin, concentric layers,
which decrease in density as they ap-
proach the centre. The exterior layers
are compact, and present an even, glis-
tening fracture with a resinous lustre,
whereas the centre of the grain is almost
always friable, and has a dull earthy
fracture. They are easily broken, and
may be cut by a knife. Specific gravity
3'40. These grains, sometimes solitary,
are generally united by a ferruginous
cement, either calcareous or argillaceous,
which adheres to their surface. This
variety is composed of oxide of iron 71'5,
water 14-5, silex 7'5, alumine 3'5, oxide
of manganese 0'5. It is abundant in
France, Switzerland, and Germany ; oc-
curring in secondary rocks. It some-
times contains fossil shells, which become
penetrated with oxide of iron. — Cleave-
land.

PI'SOLITE. (from Triffov, a pea, and \lOoQ,
a stone.) So called from its resembling
an agglutination of pease. The pisolithe
of Brongniart ; the peastone of Jameson.

P I S

C 204 ]

P L A

Pisolite is nearly or quite opaque, a»d
consists of small rounded masses, coin-
posed of concentric layers, each concre-
tion having a grain of sand for its nu-
cleus, or centre. These concretions, ag-
glutinated by a calcareous cement, form
masses of considerable magnitude, and
sometimes continuous beds.

PISOLI'TIC. Composed of pisolite ; con
taining pisolite ; resembling pisolite.

PI'STACITE. Another name for epidote.
See Epidote.

PI'STAZITE. See Epidote.

PI'STIL. (from pintillum, Lat. pistil, Fr.)
In botany, the female organ of the plant ;
situated in the centre of the flower, and
forming the rudiments of the fruit. A
perfect pistil is composed of three parts,
the ovarium, the style, and the stigma.
Each modified leaf which forms the pis-
til, is called a carpellum : the carpella
are so folded that the margins of the leaf
are next to the axis, or centre ; and from
these a species of bud is produced, which
is the seed. The form of the pistil must
depend on that of the carpella, on their
number, and on their arrangement.

PITCH -STONE. A vitreous lava, of a black-
ish-green, or a nearly black colour ; a
semi-vitreous substance having the lustre
and appearance of pitch, and containing
a portion of bitumen. Specific gravity
from 2-29 to 2-64. Before the blow-pipe
it whitens, tumesces, and fuses into a
porous, whitish enamel. It consists of
silex 73*0, alumine 14'5, soda 1'75, lime
I'O, oxides of iron and manganese 1*1,
water 8 '.50. Pitch-stone occurs in veins
and in beds ; sometimes forming whole
mountains.

PIT COAL. The coal usually consumed in
our houses, and thus called from its
being dug out of pits. See Coal.

PLACE'NTA. (placenta, Lat. a cake, pla-
centa, Fr.)

1. In anatomy, the medium of commu-
nication between the mother and the
foetus.

2. In botany, that part of the ovarium
to which the seeds are attached.

3. In fossilogy, the name given by Klein
to a section of catocysti, from the shells
being flat, like a cake. They are all or-
namented with a pentaphylloid flower.
The mouth is in the middle of the base,
and the anal orifice near the margin.
Placenta are divided by Klein into three
genera, mellita, laganum, and rotula.

PLACOI'DIAN. (from 7r\d£, a broad plate,
and tt^oc, form, Gr.) One of the orders
into which M. Agassiz divides the class
of fishes. The placoidians are distin-
guished by their skin being irregularly
covered with plates of enamel. In this
order are comprised all the cartilaginous

fishes of Cuvier, the sturgeon only ex-
cepted.

PLACOI'DIAN. Belonging to the order of
Placoidians.

PLAGIO'STOMA. (from TrXayiof, oblique,
and ffrofjia, mouth, Gr.) A genus of
sub - equivalve, inequilateral, oblique
shells, known only in a fossil state. The
plagiostoma is one of the most charac-
teristic shells of the chalk formation.
Several species are known, namely, P.
spinosum, P. Hoperi, P. elongatum, P.
asper, &c. The Plagiostoma spinosum
for the long slender spines attached to
its upper valve. The spines arise from
costae, which radiate from the beaks to
the margin, but without any regularity :
they vary in number from fifteen to
twenty, and some of them are two inches
and upwards in length. They are very
numerous in the chalk pits between
Shoreham and Bramber, but there is
great difficulty in extricating them from
the surrounding chalk without breaking
the spines.

PLANO'RBIS. (from planus, flat, and orbis,
an orb, Lat.) A genus of discoidal,
fresh-water univalves, resembling the am-
monite, but not chambered. Planorbis
belongs to the family Pulmonea in Cu-
vier's arrangement, and to Lymnacea in
Lamarck's and Blainville's. Planorbes
may be distinguished from helices by the
slight increase of the whorls of their
shell, by the convolutions being nearly in
one plane, and by the aperture being
wider than it is high. All the shells of
this genus are reversed : they abound in
pools and ditches.

From the delicacy of their structure,
as well as the slight degree of mineraliza-
tion they have undergone, planorbes are
rarely obtained as fossils in a perfect
state. Three species have been found in
the neighbourhood of Paris. Two spe-
cies are mentioned as found in the allu-
vial deposites of Sussex ; and planorbes
are also found in the fresh-water strata
of the Isle of Wight.

PLA'SMA. A grass-green variety of rhom-
bohedral quartz. Fracture conchoidal ;
lustre feeble and resinous. It occurs in
beds associated with common chalcedony.
It is brought from Italy and the Levant :
it was worn by the Romans, and formed
into ornamental articles of dress.

PLA'STER OF PA'RIS. A sub-species of
gypsum. See Gypsum.

PLA'STER STONE. Another name for plaster
of Paris.

PLA'STIC CLAY, (from TrXaoriKoc, Gr. fit
for the art of fashioning, plastiquc, Fr.)
A name given to one of the beds of the
eocene period, from its being used in the
manufacture of pottery. The plastic clay

P L A

[ 205 ]

P L U

and the London clay are deemed by some
geologists as one formation, and, although
separated by others, the line of separation
appears to be quite arbitrary. The plas-
tic clay is in some places of great thick-
ness, amounting to four or five hundred
feet ; in other parts, where present, it is
very thin. It is a marine deposit, oysters
and other marine shells being found
in it.

PLA'STRON. (plastron, Fr.) A name given
to the sternum of reptiles.

PLATI'NA. } (platina, Spanish, from plata,

PLATI'NUM. $ silver.) A metal, consti-
tuting one of the fifty-five simple or ele-
mentary bodies. Platinum was not known
in Europe till Mr. Wood brought some of
it from America in 1741. When pure, it
is of a white colour, like silver, but not so'
bright. It has neither taste nor smell.
It is exceedingly malleable and ductile ;
it may be hammered into plates of ex-
treme thinness, and Dr. Wollaston suc-
ceeded in drawing out a wire of this metal
to the fineness of 1- 10,000dth of an inch.
Platinum is one of the most infusible of
metals, not yielding before the utmost
heat of the furnace ; it is soluble in chlo-
rine and nitro-muriatic acid. It was first
obtained from Choco and Santa Fe, in
South America ; it has since been dis-
covered in the Brazils, Spain, and in the
Ural mountains, in Siberia. In the ore
of platinum four new metals have been
discovered, namely iridium, palladium,
osmium, and rhodium,

PLEROSA'URUS. A fossil saurian of the lias
and oolite.

PLESIOSAU'RUS. (from 7rXr/<7«W, near to,
and vavpa, a lizard, Gr.) A genus of
extinct amphibious animals, nearly allied
to the Ichthyosaurus. Cuvier says
this inhabitant of the ancient world, is
perhaps the most heterogeneous, and ap-
•pears to merit the name of monster above
all others. It united the teeth of a cro-
codile to the head of a lizard ; its neck
was of enormous length, exceeding that of
its body, and resembling the body of a
serpent ; it possessed a trunk and tail
of the proportions of an ordinary qua-
druped ; to all these were added the pad-
dles of a whale. The teeth were conical,
very slender, curved inwards, finely stri-
ated on the enamelled surface, and hollow
throughout the interior. Five or six
species of the plesiosauri are known ;
they appear to have lived in shallow seas
and estuaries, and, in the opinion of
some, they swam upon or near the sur-
face, having the neck arched, like the
swan, and darting it down at the prey
within reach. Prodigious numbers of
remains are found in the lias. Ver-
tebree and teeth are found in the Hastings

beds. Some of the plesiosauri were up-
wards of twenty feet long.

PLEUROCY'STI. The third class of echini.

PLEUROTOMA'RIA. A fossil genus of tur-
binated, spiral, univalve shells belonging
to the family Turbinacea, They are
found only fossil, and occur in the in-
ferior oolite.

PLI'CATED. (from plico, Lat. to fold.)
Plaited ; folded.

PU'OCENE. (from TrXeiuv, more, and
icaivoQ, recent, Gr.) The name given by
Mr. Lyell to a division of the supracre-
taceous group, or tertiary strata. The
tertiary series Mr. Lyell divided into four
principal groups, namely, the eocene, the
miocene, the older pliocene, and the
newer pliocene, each characterized by
containing a very different proportion of
fossil recent species. The newer pliocene,
the latest of the four, contains from
ninety to ninety-five per cent, of recent
fossils ; the older pliocene contains from
thirty-five to fifty per cent, of recent
fossils ; the miocene contains eighteen
per cent, of recent fossils ; the eocene
contains only three and a half per cent, of
recent fossils. In the newer pliocene de-
posites of the valley of Elsa, in Tuscany,
six living species of testacea were recog-
nized by M. Deshayes. The newer plio-
cene period is that which immediately
preceded the recent era ; the older plio-
cene period is that which intervened be-
tween the miocene and the newer plio-
cene. The newer pliocene formations
occur in Sicily and Tuscany ; the older
pliocene at Nice, Perpignan, Norfolk,
Suffolk, and near Sienna. Both the
newer pliocene and the older pliocene
exhibit marine as well as fresh-water
deposites.

PLUMBA'GO. (plumbago, Lat.) Graphite.
Commonly called black-lead. See Black
Lead.

PLU'MOSE. ) (plumosus, Lat. full of fea-

PLU'MOUS. ) thers.) Feathery ; downy.

PLTJ'MULE. (from plumula, Lat. a little
feather.) In botany, that part of the
seed which grows into the stem and axis
of the future plant. In the bean, horse-
chesnut, &c. the plumule is distinctly
visible, but in plants generally, it is
scarcely perceptible without the aid of a
magnifying glass ; and in many it does
not appear till the seed begins to ger-
minate. The first indication of develop-
ment, whenever the seed begins to ger-
minate, is the appearance of the plu-
mule, which is a collection of feathery
fibres, bursting from the enveloping cap-
sule of the germ, and which proceeds im-
mediately to extend itself vertically up-
wards.

PLUTO'NIC. (from Pluto, one of the hea-

P L U

[ 206 ]

POL

then deities.) A name given to certain
rocks elaborated in the deep recesses of
the earth.

PLUTO'NIC ROCKS. Unstratified crystal-
line rocks, such as granites, greenstones,
and others, of igneous origin formed at
great depths from the surface. Plutonic
rocks are distinguished from those which
are called volcanic, although they are
both igneous ; plutonic rocks having
been elaborated in the deep recesses of
the earth, while the volcanic are solidified
at or near the surface.

PNEUMA'TICS. (from Trvtv/taruc/}, Gr.)
That branch of science which relates to
the equilibrium or movements of aerial j
fluids under all circumstances of pressure,
density, and elasticity. The weight of
the air, and its pressure on all the bodies
on the earth's surface, were quite un-
known to the ancients, and only first
perceived by Galileo, on the occasion of
a sucking-pump refusing to draw water
above a certain height. The manner in
which the observed law of equilibrium of
an elastic fluid, like air, may be consider-
ed to originate in the mutual repulsion of
its particles, has been investigated by
Newton, and the actual statement of the
law itself, as announced by Mariotte,
" that the density of the air, or the
quantity of it contained in the same space,
is, cseteris paribus, proportional to the
pressure it supports," has recently been
verified by direct experiment. This law
contains the principle of solution of every
dynamical question that can occur re-
lative to the equilibrium of elastic fluids,
and is therefore to be regarded a* one of
the highest axioms in the science of pneu-
matics.— Herschel.

POIKILI'TIC. (from TrouaXoc, Gr. various,
variegated.) To the new red sandstone
group, M. Brongniart has applied the
name of Terrain Poecilien. Mr. Cony-
beare has proposed to extend the term
Pcecilitic to the entire group of strata
between the coal formation and the lias,
comprising the new red conglomerate,
the magnesian limestone, the variegated
sandstone, the shell limestone, and the
variegated marl. Some common appel-
lative, says Dr. Buckland, for all these
formations has been long a desideratum
in geology; but the word poecilitic is, in
sound, so like pisolite, that it may be
better to adhere more literally to the
Greek root, and apply the common name
of Poikilitic group to the strata in ques-
tion.

PO'LLEN. (pollen, Lat. fine flour.) In
botany, the fecundating powder or dust
contained in the anther. In dry and
warm weather the anther bursts, and the
pollen is thrown out.

POLYGA'STRICA. (from TroXvc, many, and
yaor^p, a stomach, Gr.) The lowest
class of animals, belonging to Cyclo-
neura, or Radiata.

When we place, says Professor Grant,
a drop of any decayed infusion of animal
or vegetable matter under a powerful
microscope, and throw a light through
that drop, and through the microscope
to the eye, we discover in the drop of
water various forms of living beings ;
some of a rounded, some of a lengthened
form, and some exhibiting ramifications
shooting in all directions but all appa-
rently of a soft, transparent, gelatinous,
and almost homogeneous texture. In
these minute animals there are numerous
cavities or stomachs, in some of them being
two hundred in number. There is every
reason to believe that polygastrica exist
in every drop of water. They form the
food of other classes, more especially the
zoophytes. Almost all the known genera
of polygastric animalcules possess eyes :
they are also found to possess an acute
sense of taste ; they distinguish, pursue,
and seize their prey, and, although so
excessively minute that five millions
have been calculated as being contained
in one drop of water, they avoid in-
fringing on one another while swimming.
All their movements appear to be as well
directed, regular, methodical, and spon-
taneous, as those of the higher classes of
swimming animals. These movements
are effected by means of very minute,
hair-like, tapering, transparent, vibratile
filaments disposed frequently around the
mouth, where they are generally largest
and longest. There is no proper skeleton
in the whole order polygastrica, nor any
secretion of shell on the surface, yet
there are parts destined to give support.
Some of the polygastric animals exude
on their surface a secretion which agglu-
tinates foreign particles floating in the
waters which surround them, and thus
form for themselves a partial covering.
In the majority of polygastric animals
there is an alimentary canal, with an
oral and an anal orifice, which traverses
the body. No teeth for mastication, nor
any glandular organs to assist in diges-
tion, have been discovered in them.
Notwithstanding their extreme minute-
ness, they appear to be the most nu-
merous, the most prolific, the most active,
and the most voracious of all living
beings. — Lectures on Comp. Anatomy,
passim.

PO'LYGON. (from TTO\VC, many, and yow'a,
angle, Gr.) A geometrical figure of many
angles.

POLY'GONAL. (polygone, Fr.) Having many
angles and sides.

POL

[ 207]

FOR

POLYHA'LLITE. A mineral found at Ischel,
in Austria. It occurs in masses of a
fibrous texture. Lustre pearly. Specific
gravity 2 '76.

POLYHE'DRON. (from TroXvc, many, and
(Spa, side, Gr.) A solid contained under
many planes or sides.

POLYHE'DRAL. } Having many sides or

POLYHE'DROUS. $ planes.

POLYMI'GNITE. (from TTO\VG, many, and
fjiiyvv/jLi, to mix, Gr.) A newly disco-
vered mineral, which has been thus named
in consequence of the variety of its con-
stituent parts. It consists of titanic
acid, zirconia, lime, yttria, the oxides
of iron, cerium, and manganese, with
minute portions of magnesia, potash,
silica, and oxide of tin. It is of a black
colour ; crystallized in small prisms ;
scratches glass ; specific gravity 4 '8.
Fracture conchoidal. Lustre almost me-
tallic.

PO'LYPE. The name given to each tube,
surrounded with its tentacula, of the
Polypus ; Polypus designating the entire
animal mass, composed of an aggregation
of Polypes.

POLYPA'RIA. ) The fourth class of Radiata

PO'LYPI. $ or Zoophytes ; thus named
from a supposed resemblance to an Oc-
topus, called Polypus by the ancients,
this resemblance arising from the ar-
rangement of the tentacula around the
mouth.

These animals are commonly known
as Corals. From an idea which long
prevailed that these animals are allied to
marine plants, they obtained the name of
Zoophytes. The body is cylindrical or
conical, sometimes possessing no viscus
but its cavity ; at others possessing a
stomach, which is visible, and other or-
gans. The greater number of Polyparia
are inhabitants of the ocean, and from
the ocean's depths they raise those im-
mense reefs that at some future period
may form a communication between the
inhabitants of the temperate zones. Al-
though Polypi abound in every part of
the ocean, still it is in the warmer re-
gions that they grow in greatest luxuri-
ance. The tentacula of Polypi are ex-
quisitely sensible, and are frequently
seen, either singly or altogether, bending
their extremities towards the mouth
when any minute floating body comes in
contact with them. A question arises,
says Dr. Roget, with regard to the con-
stitution of these Zoophytes, similar to
that which has been proposed with regard
to trees, namely, what limit should be
assigned to their individuality ? Is the
whole mass, which appears to grow from
one root, and which consists of multi-
tudes of branches, proceeding from a

common stem, to be considered as one
individual animal, or is it an assemblage,
or aggregation of smaller individuals ;
each individual being characterized by
having a single mouth, with its accom-
panying tentacula, and yet the whole
being animated by a common principle
of life and growth ? The greater number
of naturalists have adopted this latter
view, regarding each portion as provided
with a distinct circle of tentacula, as a
separate animal, associated with its neigh-
bours in the construction of a common
habitation, and contributing its quota to
the general nourishment of this animal
republic.

POLYPI'FERA. ) That class of animals com-

POLYPI'PHERA. $ monly known by the
name of Zoophytes. They are carni-
vorous, feeding upon living animalcules.
These animals precipitate immense quan-
tities of carbonate of lime, especially in
tropical seas.

POLYPI'FEROUS. Animals which have po-
lypi ; zoophytes.

POLYPE'TALOUS. (from 7ro\t»f, many, and
TTtTaXov, a leaf of the corolla, Gr.) In
botany, a term applied to a corolla which
has the petals separate.

POLYSE'PALOUS. (from TroXic, many, and
sepal, the name given to the parts of
which the calyx is composed.) In bo-
tany, a term given to a calyx which has
its sepals separate from each other.

POLYPOTHE'CIA. A genus of spongeous
zoophytes found in flints. Miss Bennett,
in her catalogue of the organic remains of
Wiltshire, has described seven species.

POLY'PTERUS. A genus of fishes found in
the Nile and in the rivers of Senegal.
M. Agassiz has described two species.
The Polypterus and Lepidosteus are the
only known genera of living representa-
tives of the sauroid fishes.

POLYSPE'RMOUS. (from TTO\UC, many, and
GirkpfjLa, seed, Gr.) In botany, a term
applied to the ovarium and fruit when
they contain many seeds.

POLYTHA'LAMOUS. (from TroXvg, many, and
OaXanoQ, a chamber, Gr. ) Having many
cells or chambers, as potythalamous
shells ; multilocular ; camerated.

PORCELANA'CEOUS. > Resembling porce-

PORCELA'NEOUS. $ lain. Shells have
been divided into two classes. The first
are of a compact texture, have an ena-
melled surface, and are generally beauti-
fully variegated. The shells of this class
have been termed porcelanaceous, or por-
celaneous shells ; they contain but a
small proportion of soft animal matter.

PORCE'LLANITE. A mineral of various co-
lours, from grey to nearly black, occur-
ring in amorphous masses or fragments,
which are often rifted. Porcellanite

FOR

[ 208 ]

FOR

sometimes resembles a brick which has
undergone a slight vitrification. Its
fracture is imperfectly conchoidal or
uneven, more or less glistening, and
often has the aspect of certain porce-
lains. It is opaque, very brittle, and less
hard than quartz. Before the blow-pipe
it melts into a black scoria. An analysis
of it yielded silex 60'75, alumine 27'25,
potash 3-66, magnesia 3'00, oxide of
iron 2-50. It is most likely an alteration
of some variety of argillaceous slate by
pseudo-volcanic fires : it does not consti-
tute a distinct species. It is found in
large masses near the pitch-lake in Trini-
dad, and occurs usually in the vicinity of
coal mines. — Cleaveland.
PORI'FERA. )from porus, a pore, and
PORI'PHERA. $ fero, to bear.) A class
of animals belonging to Cyclo-Neura,
or Radiata. Poriphera constitute the
second lowest class of animals, com-
ing between Polypiphera and Polygas-
trica. They form the various species
of sponge which are met with in such
multitudes on every rocky coast of the
ocean, from the shores of Greenland to
those of Australia. On the shores of
the sea, says Professor Grant, when the
tide has retired, rocks and other marine
substances may be seen covered with
a layer of a soft spongy substance, of va-
rious forms, colours, and consistence,
sometimes hanging in branches from the
cliffs which are covered by the sea,
sometimes covering the surface of marine
animals. This layer consists of beings
which possess an organization extremely
simple. Their surface is porous ; those
pores lead to canals which ramify through
all parts of their texture ; and those
canals anastomosing into larger and
larger trunks, lead, again, to orifices on
the surface, from which there issue con-
stant streams of water. The poriferous
animals present various and remarkable
forms in the skeleton ; and the simple
gelatinous body of the animal is sup-
ported by a skeleton composed of dif-
ferent kinds of earth : in one group the
earth is silica ; in another it is the car-
bonate of lime ; in another it is a horny
substance. The skeleton, thus composed,
has been called the axis of the animal.
The material of which the fleshy portion
is composed is of so tender and gelatinous
a nature, that the slightest pressure is
sufficient to tear it asunder, and allow
the fluid parts to escape ; and the whole
soon melts away into a thin oily liquid.

The surface of a living sponge presents
two kinds of orifices ; the larger of a
rounded shape with raised margins, which
form projecting papillae ; the smaller, mi-
nute and numerous, constituting the pores

of the sponge. It was long the received
opinion that the superficial layer of gela-
tinous substance possessed a considerable
degree of contractile power, nor was it till
Prof. Grant clearly demonstrated that the
sponge does not possess any such property
that the illusion was dissipated. The
porifera present a digestive system, which,
"by its form and simplicity, approaches the
nearest to that of plants. The cellular
tissue of their body is permeated in all
directions by anastomozing and ramifying
canals, which begin by minute superficial
pores closely distributed over every part,
and terminate in larger orifices variously
placed according to the form of the entire
animal. The pores are provided with a
gelatinousjnetwork and projecting spicula,
to protect them from the larger animal-
cules and floating particles The internal
canals, like the venous system, leading
from capillaries to trunks, are bounded
by a more condensed portion of the general
cellular substance of the body, and are
incessantly traversed by streams of water,
passing inwards through the minute pores,
and discharged through the larger orifices
or vents, but|no polypi or cilia have been
discovered in those parts, although from
analogy we might consider them neces-
sary. From the incessant streams that
are conveyed through the bodies of these
animals, it appears that all parts of these
interior perforations, as well as the general
external surface of this cellular structure,
serve for the conveyance of nutritious
matter into the interior substance of the
body. On watching the streams of water
which issue from the foecal orifices, there
may be seen minute flocculent particles
that are incessantly detached and thrown
out, which appear as if they were the
residue of digestion, or pellicles excreted
from the bodv, and thrown off from the
surface of internal canals.

No nervous filaments have been de-
tected in the soft gelatinous bodies of
poriphera. Their ciliated gemmules,
however, are endowed with remarkable
living properties, and powers of sponta-
neous motion. They have an evident
object in their motions ; they can accele-
rate, retard, or cease, at pleasure, the
vibrations of their cilia ; they can change
the direction of their course in ifoe water,
perceive each other's vicinity, revolve
round each other, distinguish the most
suitable place for the fixing of each spe-
cies, or bound forward suddenly from a
state of rest. They appear in this state
of freedom to be sensible to light, and to
shun it.

Although sponges, or poriferous ani-
mals, are permanently attached to rocks,
and other solid bodies in the ocean, and

P O R

[209 ]

POT

are consequently destined to an existence
as completely stationary as that of plants,
yet such is not the condition of the earlier,
and more transitory stages of their deve-
lopment. On the gemmule the power of
locomotion is conferred, until it has found
for itself a proper habitation ; this chosen,
it there fixes itself and there continues
for the remaining period of its existence.

PORO'SITY. (porosite, Fr. porosita, It.)
The quality of having pores ; of being
porous.

PO'ROUS. (poreux, ~Fr.poroso, It.) Hav-
ing small spiracles, interstices, or pas-

PO'ROUSNESS. The quality of being porous.

PO'RPHYRY. (from iroptyvpa, purple, Gr.
porphyrites, Lat. porphyre, Fr. porfiro,
It. porphyr, Germ.) Porphyry has been
so called in reference to the purple, or
reddish, colour so commonly perceptible
in it. Generally, any form of rock in
which one or more minerals are scat-
tered through an earthy or compact base.
Porphyry has generally a compact texture.
Sometimes it is composed of tabular,
columnar, or globular distinct concre-
tions ; and not unfrequently it is tra-
versed by numerous seams and rents.
There are many varieties of porphyry,
named according to the base of each, as
Petrosiliceous Porphyry, Felspar Por-
phyry, Clinkstone Porphyry, Argillaceous
Porphyry, &c. Geologists have described
four formations of porphyry ; but it is
generally agreed that there is much un-
certainty with respect to the situation of
these formations. The porphyry which
occurs regularly imbedded in granite, or
which appears to be formed by a mere
change of structure in that rock, may
properly be classed with primary rocks ;
it is not considered to be an extensive
formation. Porphyry also occurs in enor-
mous masses ; at the head of Glen
Ptarmagan, a cliff of porphyry fifteen
hundred feet in height, in shape resem-
bling an oblique truncated pyramid, passes
through granite. In some instances por-
phyry is, beyond all question, a volcanic
formation. Near Christiana, in Norway,
an immense mass of porphyry, from
1600 to 2000 feet in thickness, covers
beds of gneiss, limestone, and grey-
wacke. Dykes of porphyry cutting
through the subjacent rocks indisputably
prove the volcanic character of this im-
mense mass. Porphyry and basalt often
cover the primary mountains in the
Andes ; resembling immense castles lifted
into the sky.

PORPHYRI'TIC. > Resembling porphyry ;

PORPHYRA'CEOUS. J containing porphyry ;
composed of a compact homogeneous
rock, in which distinct crystals or grains

are imbedded : the compact stone is called
the base, and sometimes the paste. The
base, or paste, is generally felspar.

PO'RTLAND BEDS. A marine formation,
occurring in the Isle of Portland and in
Wiltshire. These beds consist of coarse
shelly limestone, fine grained white lime-
stone, and compact limestone, all pos-
sessing an oolitic structure ; and beds of
chert. The Portland beds lie imme-
diately under the Purbeck beds, and
above the Kimmeridge clay. They con-
stitute the uppermost members of the
oolite group, and abound in ammonites,
trigonise, &c.

PO'RTLAND LI'MESTONE. ^ One of the mem-

PO'RTLAND STONE. $ bers of the

Portland beds ; a marine oolitic forma-
tion, obtained principally from Portland,
whence the name, and used in building.
This limestone is soft when quarried,
but hardens on exposure to the at-
mosphere.

PO'TASH. An alkali obtained by the inci-
neration of vegetables, or the woody parts
of plants that do not grow near the sea.
The water in which the ashes are washed
is evaporated in iron pots, from which
circumstance it was called potash. Al j
though potash is very widely dissemi-
nated in the earth's crust, its amount,
collectively considered, is greatly inferior
to that of silex and alumine. There are
few, if any, of the inferior stratified rocks
without potash; and, viewing them in
the mass, potash may be considered as
constituting five or six per cent, of the
whole. Potash may be regarded as con-
stituting between six and seven per cent,
of granites, greenstones, and rocks of
that class.

POTA'SSIUM. A metal discovered by Sir
H. Davy in 1808. At a temperature of
32° potassium is hard and brittle, with a
crystalline texture; at 50° it becomes
malleable, with a lustre like that of po-
lished silver; and at 150° it fuses. Po-
tassium is lighter than water, its specific
gravity being 0'85 : to preserve it un-
changed, it should be kept in a phial
with pure naphtha. Sir H. Davy ob-
tained potassium by submitting solid
hydrate of potash to the action of vol-
taic electricity ; it has, however, subse-
quently been procured by other means,
particularly by those described by Gay
Lussac and Thenard.

PO'TSTONE. The Lapis ollaris of Pliny ;
Toftstein of Werner ; Talcollaire of Haiiy.
A variety of steatite, nearly equal in
hardness to common steatite ; it is, how-
ever, more tenacious, and though it may
be turned with the lathe, it breaks with
difficulty. It is smooth and unctuous to
the touch. It is usually of a greenish-

O T

[ 210 ]

P R I

grey colour, with various shades, and
often spotted. Its fracture curved, and,
sometimes, almost foliated. Specific gra-
vity from 2-8 to 3'2. It emits an argil-
laceous odour when breathed on. From
its being formed into culinary vessels it
has obtained its name. From an analysis
by Wiegleb, the potstone of Corno, in
Lombardy, where it occurs in great abun-
dance, consists of magnesia 38*0, silica
38'0, alumina 7'0, iron 15 0, carbonate of
lime I'O, fluoric acid 1*0.

PO'TTERS' CLAY. A variety of clay, of a
reddish or grey colour, which becomes
red when heated. That used in our pot-
teries for making coarse red ware comes
chiefly from Devonshire. It is exceed-
ingly infusible, and contains a large pro-
portion of alumine.

POZZUOLA'NA. Scoriae or volcanic ashes,
brought from Pozzuoli, a town in the bay
of Naples, and named therefrom. Poz-
zuolana is used, mixed with lime, for
making a Roman, or water-setting, ce-
ment.

PRASE. The Prasem of Werner ; Quartz
hyalin vert obscur of Haiiy ; Quartz
prase of Brongniart. A leek- green trans-
lucent variety of rhombohedral quartz ;
lustre vitreous ; fracture splintery. Spe-
cific gravity 2*5. Prase appears to be
common quartz, coloured by actynolite or
epidote.

PRA'SINOUS. (prasinus, Lat.) Of a light
green colour, inclining to yellow.

PRECI'PITATE. A deposit, in a solid form,
of a body previously held in solution.

PRECI'PITATE. (precipiter, Fr. precipi-
tare, It.) To throw down a substance
that had previously been held in solu-
tion.

PRECIPITOUS, (from preeceps, Lat. pre-
cipitoso, It.) Steep ; headlong.

PREDA'CEOUS. (from prada, Lat. booty.)
Living upon prey.

PREHE'NSILE. (from prehendo, Lat. to
lay hold of.) That can lay hold of. The
prehensile portion of the tails of monkeys
is naked beneath.

PRE'HNITE. A mineral thus named after
Colonel Prehn, who brought it from the
Cape of Good Hope. Prehnite is of a
green, grey, or white colour. It occurs
crystallized ; in granular, scopiform, and
stellular fibrous distinct concretions ;
massive and reniform. Its texture is fo-
liated. Fracture uneven. Internal lustre
pearly. It scratches glass, though feebly,
and gives sparks with steel. Specific
gravity from 2'60 to 2'94. Mr. Bake-
well was the first person who discovered
prehnite in England; he found it in 1816,
in amygdaloidal wacke, in Gloucester-
shire. It has since been found in the
basalt of Staffordshire.

PRI'MARV. A term applied to rocks or
strata, because it was supposed, from the
absence of fossil remains, that they were
formed before animals and vegetables ; as
well as that they were the first rocks
formed. Mr. Lyell, with his wonted
acumen, proposes to substitute the word
hypogene for primary. It would ap-
pear, says Mr. Lyell, that the popular
nomenclature of geology, in reference to
the so called "primary'' rocks, is not
only imperfect, but in a great degree
founded on a false theory ; inasmuch as
some granites and granitic schists are of
origin posterior to many secondary rocks.
In other words, some primary forma-
tions can already be shown to be newer
than many secondary groups, — a mani-
fest contradiction in terms. See Hypo-
gene.

PRI'MARY ROCKS. These rocks were for-
merly called primitive, and will, in all
probability, hereafter be called hypo-
gene. They are of crystalline structure,
and manifestly owe their present state to
igneous agency. The primary rocks are
those which are older than the most
ancient European group, (grey wacke,)
in which distinct fossils have as yet been
discovered. Primary rocks are divisible
into two groups, the stratified and the
unstratified. The stratified group con-
sists of the rocks called gneiss, mica
schist, argillaceous schist, hornblende
schist, primary limestone, and some
others. The unstratified, or Plutonic,
is composed in a great measure of gra-
nite, and rocks closely allied to granite. —
LyeWs Principles of Geology.

PRI'MARY STRA'TA. The primary strata
are defined above by the old red sand-
stone ; and when that is absent, by the
carboniferous limestone ; below, they
usually rest, but sometimes unconforma-
bly, upon granite. They consist, in a
great measure, of mechanical aggregates,
comparable with sandstones and clays,
but yet generally distinguishable by su-
perior hardness, and somewhat of a crys-
talline structure in mass, or texture in
detail, from the secondary rocks. In the
secondary rocks there is more variety of
arenaceous and calcareous members. In
the tertiary strata loose sands, marls, and
clays abound, while these scarcely occur
at all among the primary rocks. — Prof.
Phillips.

PRIMITIVE. A term applied to certain
rocks, from the circumstance of no fossil
remains of animals or vegetables, nor
any fragments of other rocks, being found
in them. The term has given way to
what is considered a more appropriate
one, namely, primary. With the con-
tinued advance of geological knowledge,

P R I

[ 211 ]

PRO

the term primary will, in all probability,
yield to that proposed by Mr. Lyell,
namely, hypogene.

PRIMO'RDIAL. (from primordium, Lat
primordial, Fr.) Original ; existing from
the beginning ; first in order.

PRISM, (arpio-jwa, Gr. prisme, Fr. prisma,
It.) A solid figure, the ends whereof
are parallel, equal, and similar plane
figures, and the sides which connect the
ends are parallelograms. Prisms take
particular names from the figure of their
bases or ends, namely, triangular, square,
rectangular, pentagonal, hexagonal, &c.

PROBOSCIDIA'NA. A family of quadrupeds
belonging to the order Pachydermata.
The proboscideans have five toes to each ;
foot ; they possess no canine teeth, but
two tusks, which project from the mouth,
and frequently attain to an immense size.
The nostrils are continued out into a
proboscis, which is exceedingly flexible,
possesses great flexibility, and terminates
in a finger-like appendage. The pro-
boscis may be considered as the hand of
the elephant. One living genus only of
this family is known, namely, the ele-
phant ; the other genus, the mastodon, is
believed to be extinct.

PROBO'SCIS. (Trpo/Scxriaf, Gr. from /36<r/ew,
to feed, and vrpo, before, proboscis, Lat.
proboscide, Fr. proboscide, It.) A
lengthened tube, snout, or trunk belong-
ing to certain animals. The proboscis of
the elephant is of great length, serving
the purposes of a hand, conveying to the
mouth anything it desires to swallow.
It is an instrument of most delicate
touch, of scent, and breathing, and of
prehension as adroit as that of a hand.
By the extraordinary flexibility with
which it is endowed, it can not only be
inflected inwards to carry things to the
mouth, but be bent upwards, downwards, or
laterally, to lay hold of things above, below,
or on either side ; and, by the assistance
of its finger-like termination, it can grasp
anything, even the most minute, as
readily as we can with our four fingers
and thumb. In insects, when the in-
strument for suction extends for some
length from the mouth, it is called a pro-
boscis ; such is the apparatus of the butter-
fly, the moth, the gnat, the house-fly, and
other insects that subsist on fluid aliment.

PROCU'MBENT. (procumbens, Lat.) Lying
down ; prone. In botany, a term applied
to plants, the stems of which lie or fall
upon the ground through weakness.

PRODU'CTA. An extinct genus of equila-
teral inequivalve, striated bivalves. It is
found in the mountain limestone and
older secondary rocks only ; it is allied to
the existing genus Terebratula.

PRO'LEGS. The name given to what are

termed the spurious legs of insects. While
the number of the true legs is limited
to six, the prolegs are often very nu-
merous ; they consist of fleshy and re-
tractile tubercles. The true legs are
generally protracted by horny scales ; but
the coverings of the prolegs are wholly
membranous. The office of the prolegs
appears to be merely to serve as props to
support the body while the insect is
walking, and to prevent its hinder part
from treading on the ground. They are
frequently terminated by single or double
hooks ; and also by a marginal coronet of
recurved spines. — Dr. Rogret, Bridg.
Treatise.

PRO'TEUS. (7rpwr£V£, proteus, Lat.) The
name given to a genus of the order Ba-
trachia. One species only has been
hitherto discovered, namely, the Proteus
Anguinus. A subterranean saurian,
which never makes its appearance on
the earth's surface, but is always con-
cealed at a considerable depth below it,
being found in subterraneous lakes and
caves two or three hundred feet below
the surface of the ground. The following
particulars are extracted from Sir H.
Davy's Consolations in Travel : — " Inde-
pendently of the natural beauties found
in Illyria, and the various sources of
amusement which a traveller fond of
natural history may find in this region, it
has a peculiar object of interest in the
extraordinary animals which are found in
the bottom of its subterraneous cavities,
namely, the Proteus anguinus, a far
greater wonder of nature than any of
those which the Baron Valvasor detailed
to the Royal Society a century and a half
ago, as belonging to Carniola.

At first view, you might suppose this
animal to be a lizard, but it has the mo-
tions of a fish. Its head, and the lower
parts of its body, and its tail, bear a
strong resemblance to those of the eel ;
but it has no fins ; and its curious bron-
chial organs are not like the gills of
fishes ; they form a singular vascular
structure, almost like a crest, round the
throat, which may be removed without
occasioning the death of the animal, who
is likewise furnished with lungs. With
this double apparatus for supplying air to
the blood, it can either live below or
above the water. Its fore feet resemble
hands, but they have only three claws or
fingers, and are too feeble to be of use in
grasping or supporting the weight of the
animal ; the hinder feet have only two
claws or toes, and in the larger specimens
are found so imperfect as to be almost
obliterated. It has small points instead
of eyes, as if to preserve the analogy of
nature. It is of a fleshy whiteness or

PRO

C 212 ]

P T E

transparency in its natural state, but
when exposed to light, its skin gradually
becomes darker, and at last gains an olive
tint. Its nasal organs appear large ; and
it is abundantly furnished with teeth,
from which it may be concluded that it is
an animal of prey ; yet in its confined
state it has never been known to eat, and
it has been kept alive for many years by
occasionally changing the water in which
it was placed. The proteus was first
discovered in Illyria by the late Baron
Zois ; but it has been reported that some
individuals of the same species have been
recognized in the calcareous strata in
Sicily."

The proteus has been found of various
sizes, from that of the thickness of a
quill to that of the thumb, but its form
of organs has always been the same. It
is a perfect animal of a peculiar species,
and it adds one instance more to the
number already known, of the wonderful
manner in which life is produced and
perpetuated in every part of our globe,
even in places which seem the least suited
to organized existences. And the same
Infinite Power and Wisdom which has
fitted the camel and the ostrich for the
deserts of Africa, the whale for the Polar
seas, and the morse and the white bear
for the Arctic ice, has given the proteus
to the deep and dark subterraneous lakes
of Illyrica, — an animal to whom the pre-
sence of light is not essential, and who
can live indifferently in air and in water,
on the surface of the rock, or in the
mud. The organization of the spine of
the proteus is analogous to that of one of
the sauri, the remains of which are found
in the older secondary strata. The pro-
blem of the reproduction of the proteus,
like that of the eel, is not yet solved, but
ovaria have been discovered in animals
of both species.

This name is also given to a species of
infusoria. Of these, the most singular,
says Dr. Roget, is the proteus, which
cannot, indeed, be said to have any de-
terminate shape ; for it seldom remains
the same for two minutes together. It
looks like a mass of soft jelly, highly
irritable and contractile in every part ;
at one time wholly shrunk into a ball, at
another stretched out into a lengthened
riband ; and again, at another moment,
perhaps, we find it doubled upon itself
like a leech. If we watch its motions for
any time, we see some parts shooting
out, as if suddenly inflated, and branch
ing forth into star-like radiations, or
assuming various grotesque shapes, while
other parts will, in like manner, be as
quickly contracted. Thus the whole
figure may, in an instant, be completely

changed, by metamorphoses as rapid as
they are irregular and capricious.
PROTHE'EITE. A mineral species, recently
discovered, occurring in the valley of the
Zillerthal, in the Tyrol.
PRO'TOGINE. The name given to a granite
composed of felspar, quartz, and talc or
chlorite ; the talc supplying the place of
mica. Mr. Bakewell observes that this
name has been improperly given, whereas
talcy or chloritic granite would at once
convey a distinct idea of its nature.
PRUI'NOSE. (from pmina, Lat. a frost, or
rime.) In entomology, applied to the
clothing of insects when covered with a
minute dust, scarely discoverable by the
lens.
PSAMMO'BIA. A small bivalve found in the

cyclas limestone of Burwash.
PSEU'DO. (\frfvdoe, Gr. false.) A term
generally used as a prefix to, and in com-
position with, other words ; it implies a
sense of spuriousness, as, for example, a
pseudo-tuber is a false tuber ; pseudo-
galena is false galena ; a pseudo-volcano
is a coal mine in a state of combustion.
PSILOME'LLANE. Another name for un-

cleavable manganese ore.
PTERODA'CTYLE. } (from Trrepbv, a wing,
PTERODA'CTYLUS. $ and ^aKrvXoc, a
finger, Gr.) An extinct genus of winged
reptiles, belonging to the family Iguanida.
It is found fossil in the' Jura limestone
formation, in the lias at Lyme Regis, and
in the oolitic slate of Stonesfield. " The
structure of these animals," says Prof.
Buckland, " is so exceedingly anomalous,
that the first discovered pterodactyle was
considered by one naturalist to be a bird ;
by another, a species of bat ; and by a
third, as a flying reptile. The form of its
head and length of neck, resembled that
of birds, its wings approached to the pro-
portion and form of those of bats, and its
body and tail approximated to those of
ordinary mammalia. The pterodactylus
forms an extinct genus of the order Sau-
rians, in the class of reptiles ; adapted by
a peculiarity of structure to fly in the air.
The pterodactyles are considered by Cu-
vier to rank among the most extraordinary
of all the extinct animals that have come
under his consideration. Eight species
have been discovered, of sizes varying
from that of a snipe to that of a cormo-
rant. They had a short tail, an extreme-
ly long neck, and a very large head ; their
eyes were of enormous size, apparently
enabling them to fly by night ; the beaks
were long, like those of a crocodile, and
furnished with sixty sharp-pointed teeth.
Their most remarkable character con-
sisted in the excessive elongation of the
second toe of the fore-foot, which was
more than double the length of the trunk,

P T E

C 213 }

PUR

and, in all probability, served the purpose
of supporting some membrane which en-
abled the animal to fly. The fingers ter-
minated in long hooks, like the curved
claws of the bat. The form and size of
the foot, leg, and thigh, show that this
extraordinary animal was capable either
of standing firmly on the ground, or of
perching upon the branches of trees. It
is deemed probable that the pterodactyle
had the power of swimming.
PTE'ROPODS. ) (from Trrepov, a wing, and
PTERO'PODA. S Trovf, a foot, Gr.) A
class of molluses possessing organs adapt-
ed for either swimming or sailing. The
genera belonging to this class have the
sac formed by the mantle closed on every
side ; a structure rendering it necessary
that the gills should be placed externally,
as regards the sac; and they are found
spreading out like a pair of wings on each
side of the neck. This position of the
gills, causing them to resemble the wings
of an insect, suggested to Cuvier the name
which he assigned to the class. Four ge-
nera only are known, namely, Clio, Cym-
bulia, Pneumodermon, and Limacina.
These molluscs abound in the colder re-
gions of the ocean, and the clio borealis
is considered to form the chief source of
food for the whale.
PTERO'PODOUS. Belonging to the class

Pteropoda ; wing-footed.
PUBE'SCENCE. (from pubesco, Lat. to grow
mossy, or hairy. ) The downy substance
on plants, resembling fine silken short
hairs.
PUBE'SCENT. Clothed with fine hairs or

down.

PU'DDING-STONE. A conglomerate com-
posed of rounded stones imbedded in a
paste. Pudding-stone is distinguished
from breccia by the form of the contained
pebbles : in the latter they are sharp an-
gular fragments ; in the former they are
rounded nodules.

PULVINI'TES. (from pulvinus, Lat. a
cushion.) A fossil bivalve found in the
baculite limestone of Normandy.
PU'MICE. ^ (pumex, ~L&t.pomice, It.)

PU'MICE STONE. \ A light, spongy, fibrous
lava, produced by the action of gases on
trachytic and other lavas. The island of
Lipari contains a mountain entirely form-
ed of white pumice : when viewed from a
distance, the appearance is that of a moun-
tain completely covered with snow. Pumice
is supposed to have been produced from a
considerable disengagement of gas, while
the lava was in a plastic, but not in a fluid
state ; the escape of the gas producing the
porous structure which characterizes pu-
mice stone. Pumice is very light, and swims
upon water, its specific gravity being
about 9*0. It is fusible before the blow-

pipe, melting into a whitish enamel or
glass. Klaproth gives the analysis of a
specimen from Lipari as follows : silex
76*5, alumine 17*5, soda and potash 5-0,
iron 1'75. Immense quantities of pumice
are sometimes ejected from volcanoes.

PUMI'CEOUS. Having the characters of
pumice ; resembling pumice ; containing
pumice.

PU'NCTATED. (from jtmw^o, Lat. to prick.)
Marked with small dots or punctures ;
full of small holes.

PU'PA. (pupa, Lat.)

1. In conchology, a genus of cylindrical
univalve land shells, belonging to the
family Colimacea.

2. In entomology, the chrysalis ; one of the
states of existence of such insects as un-
dergo metamorphoses. The insect in its
pupa state of existence appears as if wrapt
in a shroud, presenting no appearance of
external members, and retaining but
feeble indications of life. In this con-
dition it remains for a certain period,
until the time arrives when it is quali-
fied to emerge into the world, by bursting
asunder the fetters which had confined it,
and to commence a new existence.

PU'RBECK BEDS. A fresh-water deposit,
consisting of various kinds of limestones
and marls. The Purbeck beds constitute
the lowest members of the Wealden
group, lying below the Hastings sands,
and immediately above the Portland beds.
The Purbeck limestone abounds in or-
ganic remains, and the marble is a con-
geries of small fresh-water snail-shells
(paludina), intermixed with the minute
crustaceous coverings of a species of
cypris. — Dr. Mantell.

PU'RBECK STRATA. The lowest deposits
of the Wealden group.

PU'RPLE CO'PPER ORE. The Cuivre py-
riteux hepatique of Haiiy ; the buntkup-
fererz of Werner. A species of sulphuret
of copper. This ore occurs in masses, or
plates, or disseminated; it is characterized
by its lively and variegated colours, from
which circumstance it is frequently called
variegated pyritous copper. It has a
metallic lustre ; fracture conchoidal, with
small cavities. Specific gravity from
4'95 to 5-46. It effervesces with nitric
acid, imparting to it a green tinge. Be-
fore the blow-pipe, on charcoal, it melts,
yielding a metallic globule. According
to Klaproth, its constituents are, copper
58, iron 18, sulphur 19, oxygen 5. It
occurs in metallic veins, and in beds, most
commonly in primary rocks.

PU'RPURA. (purpura, Lat. the shell-fish
from which purple cometh.) A genus of
marine univalves belonging to the family
Purpurifera. The shells of this genus are
found at depths varying to twenty-five

PUR

[ 214 ]

P Y R

fathoms, and the greater number of the
species are littoral. The Purpura is an
ovate univalve, its surface being rather
rough with spines or tubercles ; aperture
notched, and slightly channelled in the
lower part ; the columella naked, flat,
depressed, and terminating in a point at
the base. The animal resembles that of a
true buccinum. The species are very nume-
rous ; the animal secretes a purple liquor,
which was formerly used in dyeing. Only
one species is described as having been
found fossil, namely, the purpura lapillus.

PURPURI'FERA. A family of Trachelipoda
in Lamarck's system, comprising the
genera Buccinum, Cassidarea, Cassis,
Concholesas, Dolium, Eburna, Harpa,
Monoceros, Purpura, Ricinula, Terebra.

PUTA'MEN. (put amen, Lat. a shell of a
nut.) In botany, another name for the
endocarp, stone, or shell of certain
fruits.

PY'CNODONTS. (from TTVKVOQ, thick, and
odovQ, a tooth, Gr.) Thick-toothed
fishes. An extinct family of fishes
which prevailed extensively during the
middle ages of geological history. " Of
this extinct family," says Prof. Buck-
land, " there are five genera. Their
leading character consists in a peculiar
armature of all parts of the mouth with a
pavement of thick, round, and flat teeth,
the remains of which, under the name of
bufonites, occur most abundantly through-
out the oolite formation.

PYCNO'DUS TRIGONUS. A genus of thick-
toothed fishes, belonging to the family of
Pycnodonts.

PYCNI'TE. A mineral of a yellowish -white
colour, found principally at Altenberg, in
Saxony.

PYRA'LLOLIT. A newly-discovered mine-
ral found in the lime quarries of Finland.

PY'RAMID. (Trvpctfiig, Gr. from -n-vp, fire.
pyramide,¥r. pyramide, It.) The name
given to a certain figure, from its re-
sembling the shape of flame. A solid
figure, whose base is a polygon, and whose
sides are plain triangles, their several
points meeting in one.

PYRA'MIDAL. ) Having the form of a py-

PYRAMI'DICAL. 5 ramid.

PYRAMIDE'LLA. A genus of marine uni-
valves, belonging to the family Plicacea.
It is found on coral reefs, sands, and
sandy mud, at depths varying to twelve
fathoms. The pyramidella is a turri-
culated univalve ; opening entire and
semi-oval ; columella projecting, with
three transverse folds, and perforated at
its end.

PY'RENAITE. ) A greyish-black, dodecahe-

PY'RENEITE. $ dral, opaque variety of
dodecahedral garnet. It consists of si-
lica 43, alumina 16, lime 20, oxide of

iron 16, water 4. It is found in the
French Pyrenees, from which circum-
stance it has obtained its name, in lime-
stone.

PY'RIFORM. (from pyrum, a pear, and
forma, form, Lat.) Pear-shaped; of the
form of a pear.

PYRI'TES. (Trupi'rj/c, Gr. pyrites, Lat.
pyrite, Fr.) Sulphuret of iron. The fer-
sulfure of Haiiy, who has described six-
teen modifications of the primitive form
of its crystals. The colour of pyrites is
usually bronze yellow, passing to pale
brass yellow, and sometimes to brown.
It possesses the hardness of quartz,
striking fire with steel, and emitting an
odour of sulphur. Specific gravity from
4-10 to 4-80. Before the blow-pipe it
exhales a strong odour of sulphur, and
yields a brownish globule. It is com-
posed of sulphur and iron ; iron 47'85,
sulphur 52'15. It occurs in almost every
rock, stratified or unstratified. The
shining yellow streaks so common in our
coals afford familiar examples of pyrites.
It is a well-known property of iron py-
rites to decompose rapidly when laid in
heaps and moistened with water. There
are many varieties of pyrites, namely,
capillary, cellular, hepatic, radiated, &c.
&c.

Mr. Webster gives the word pyrite,
making pyrites the plural, and he adduces
an authority in a quotation from Darwin ;
but it is most unusual to write pyrite,
and pyrites is used in the singular.

PYRI'TOUS. Containing pyrites.

PY'ROCHLORE. The pyrochlor of Werner.
Another name for octahedral titanium ore.

PYRO'GENOUS. (from Trvp, fire, and ytwdu),
to produce, Gr.) Produced by fire, as
rocks of igneous origin.

PYROLU'SITE. Another name for the com-
mon ore of manganese, as prismatic man-
ganese ore.

PYRO'METER. (from Trvp, fire, and /zerpov,
measure, Gr.) An instrument for mea-
suring intense degrees of heat. The most
celebrated pyrometer is that invented by
Mr. Wedgewood, the extremity of his
scale reaching to 240° Wedgewood, or
32277° Fahrenheit.

PYRO'METRY. The dilatation of bodies by
heat forms the subject of that branch of
science called pyrometry. There is no
body but is capable of being penetrated
by heat, though some with greater, others
with less rapidity ; and, being so pene-
trated, all bodies (with a very few ex-
ceptions, and those depending on very
peculiar circumstances), are dilated by it
in bulk, though with a great diversity in
the amount of dilatation produced by the
same degree of heat.

PYRO'PE. (from Trvpo/Troc, Gr. pyropvs,

P Y R

[ 215 ]

QUA,

Lat.) A deep blood-red variety of dode-
cahedral garnet. It consists of silica 40*0,
alumina 27'6, oxide of iron 16'0, mag-
nesia 1OO, lime 3*5, chromic acid 2'6,
oxide of manganese 0'3. It occurs in
small masses or grains. It is generally
transparent, with a splendent, vitreous,
conchoidal fracture. As a gem it is
highly prized.

PYROPHO'RUS. (from TrDp, fire, and 0opoc,
bearing, Gr. pyrophore, Fr.) A sub-
stance which has the property of igniting
merely on exposure to the air. It is an
artificial production, and may be vari-
ously prepared. M. Gay Lussac formed
a pyrophorus of one part of lamp-black
and two parts of sulphate of potash.

PYROPHY'SALITE. A variety of topaz.

PYROSO'MA. (from TTVO, fire, and crwjua,
a body, Gr.) The pyrosomse unite in
great numbers, forming a large hollow
cylinder, open at one end and closed at
the other, which swims in the ocean by
the alternate contraction and dilatation
of the individual animals which compose
it. A pyrosoma may thus be compared to
a great number of stars of botrylli strung
together; the whole being moveable.

From the phosphorescent character which
they possess they have obtained their
name. It is a floating polyp, differing
from the coral in being locomotive. Pe-
ron observed that when irritated its phos-
phorescence was augmented.

PYROXE'NE. (from 7n~p, fire, and £tVoc,
a stranger, Gr.) The name given by
Haiiy and Brongniart to augite. See
Auffite.

PYROXE'NIC. Composed of pyroxene or
augite ; containing augite ; resembling
augite.

PYROXE'NIC PORPHYRY. Augitic por-
phyry.

PY'RULA. (from pyrum, a pear, Lat.) A
genus of marine univalves, belonging to
the family Canalifera. Recent pyrulse are
found at depths varying to nine fathoms,
in mud and sand. The pyrula is a some-
what pyriform univalve, swelling in the
upper part, with no variciform sutures,
caudated, canaliculated, spire short,
aperture wide, outer lip thin, and not
slit, columella smooth. Six species have
been found fossil by Lamarck. Pyrulse
are also found in the London clay, and in
the Bognor sandstone.

Q

QUA'DRANGLE. A square ; a surface with

four right angles.
QUADRA'NGULAR. (quadrangularis, Lat.

quadrangulaire, Fr.) Four cornered;

square ; having four right angles.
QUA'DRATE. (quadratus, Lat.) Square ;

having four equal and parallel sides.
QUADRICA'PSULAR. In botany, having

four capsules to a flower.
QUADRIDE'NTATE. Four-toothed.
QUADRILO'BATE. (from quatuor, four,

and lobus, a lobe, Lat.) A term applied

in botany to a part having four lobes ; as

a quadrilobate leaf.
QUADRILO'CULAR. (from quatuor, four,

and loculus, a cell, Lat.) Four-celled ;

having four cells.
QUADRIPHY'LLOUS. (from quatuor, four,

Lat. and QvXXov, a leaf, Gr.) In botany,

having four leaves ; four-leaved.
QUADRIPLI'CATED. (from quatuor, four,

and plica, a fold, Lat.) A term in con-

chology ; having four plaits or folds,
QUADRIVA'LVULAR. (from quatuor, four,

and valva, a valve, Lat.) A term in

botany ; having four valves.
QUADRU'MANA. (from quatuor, four, and

manus, a hand, Lat.) The second order

of Mammalia, including the monkeys,

lemurs, and onistites. All the animals of

this order have the toes of the hind feet
free and opposable to the others, and all
the toes are as long and flexible as the
fingers. The great character which dis-
tinguishes the members of this order is
the possessing a moveable thumb on their
lower extremities opposed to the fingers.

QUADRU'M ANGUS. Having four hands;
four-handed.

QUA'DRUPED. (quadrupes, Lat. quadru-
pede, Fr. quadrnpede. It.) An animal
that goes on four legs ; that has four legs
and feet.

QUA-QUA-VE'RSAL. (quaqua, Lat. on
every side, and versus, inclined, Lat.)
Inclined towards every side ; facing all
ways.

QUAQUAVE'RSAL DIP. A term applied to
the dip of a bed which is inclined, facing
all sides.

QUA'RRY. (carriere, Fr. le lieu d'ou Von
tire de la pierre.) A place whence are
obtained stones for building and other
purposes

QUARTZ, (quarz, Germ, quartz, Fr. mot
emprunte de VAllemand.) Silex in its
purest form. Quartz is a hydrate of sili-
con, or silex with some water of crystalli-
zation ; it is a compound of a metallic
basis, silicium, and oxygen. Quartz is

QUA

21fi

RAD

found in every variety of form, although
in its composition it varies but slightly.
When crystallized, it usually occurs in
six-sided prisms, terminated by pyramidal
points ; but it also occurs in many deriva-
tive forms, its primitive being a rhom-
boid. It scratches glass, of which it is
an essential ingredient ; it gives sparks
with steel in great abundance. Hardness
= 7-0. Specific gravity = 2-5, to 2'7.
Its lustre ranges from splendent to glim-
mering, and is vitreous. Fracture con-
choidal. Brittle and easily frangible. It
exhibits double refraction, which must be
observed by viewing an object through
one face of the pyramid and the opposite
side of the prism. It is infusible before
the blow-pipe, even when the flame is
excited by oxygen. Before the compound
blow-pipe a fragment of rock crystal
fuses instantly into a white glass. Quartz
is very generally distributed, and, as far
as our knowledge extends at present, ap-
pears to be the most abundant mineral in
nature. It occurs in every rock, from
granite to the newest secondary forma-
tion ; it is found in every district of the
globe. When mixed with alkalies quartz
melts easily, and forms glass. It is not
acted upon by any acid but the fluoric.
Quartz often encloses, or is mixed up
with foreign substances, from which cir-
cumstance it assumes great varieties of
colour. Many of the precious stones
consist of simple quartz combined with
some colouring matter. Among these
we may place the amethyst, cats' -eye,
opal, Bristol diamond, Scotch topaz, &c.
Quartz exists in veins intersecting moun-
tains, and it sometimes forms large beds,
and even entire mountains, which are
composed of this mineral in grains united
without a cement, called granular quartz.
Combined with alumine and iron, quartz
loses its translucency and passes into
jasper. When rubbed, quartz yields a
peculiar odour, and a phosphorescent
light. Quartz is a constituent of granite.

Qu A' RTZOS E. ) Containing quartz; com-

QUA'RTZY. $ posed of quartz ; resem-
bling quartz ; having the properties of
quartz.

QUATERNARY. (quaternarius, Lat. the
number of four ; quaternaire, Fr.) Con-
sisting of four. In geology, a term ap-
plied to the upper tertiary strata, or those
which are supposed to be of later forma-
tion than any of the strata in the Paris or
London basins. The faluns, or marls of
Tourraine and the Loire, are quaternary
formations.

QUI'CKLIME. This may be obtained by
exposing chalk, limestone, or any calca-
reous substance, for a length of time, to
full red heat, whereby the carbonic acid
and the water which were previously in
combination are expelled.

QUI'CKSILVER. See Mercury.

QUI'NARY. (quinarius, Lat. quinaire, Fr.)
Containing five ; applied to things ar-
ranged in "order by fives.

QUI'NATK. In botany, applied to com-
pound leaves when composed of five
leaflets.

QuiNdUA'NGULAR. (from quinque, five,
and angulus, an angle, Lat.) Having
five corners or angles.

QUINQUECA'PSULAR. (from quinque, five,
and capsula, a capsule, Lat.) In botany,
applied to a flower having five capsules.

QUINQUEDE'NTATE. (from quinque, five,
and dens, a tooth, Lat.) Five-toothed.

QUINCIUEFO'LIATED. (from quinque, five,
and folium, a leaf, Lat.) Having five
leaves.

QUINQUELO'BATE. } (from quinque, five,

QUINQUELO'BED. 5 an<i lobus, a lobe,
Lat.) In botany, applied to parts which
are divided to the middle into five distinct
parts or lobes.

QUINQUELO'CULAR. (from quinque, five,
and loculus, a cell, Lat.) Five celled ;
having five cells.

QUINCIUEVA'LVULAR. (from quinque, five,
and valves, doors or valves, Lat.) Having
five valves.

R

RACE'ME. (racemus, Lat. a bunch of ber-
ries.) A term used in botany to express
a kind of inflorescence, when all the buds
of a newly-formed axis unfold into flow-
ers, each having a stalk ; a raceme con-
sists of numerous flowers, rather distant,
each on its own proper stalk, and all
connected together by one common pe-
duncle.

RADIA'TA, The name given to the fourth
great division of the animal kingdom, in

consequence of the radiated form of the
body which is so apparent in some of the
classes which compose it. This division
comprises five classes, namely, Echi-
noderma, Acalepha, Polypiphera, Pori-
phera, and Polygastrica. The radiata are
amongst the most frequent organic re-
mains in the transition strata, and they
present numerous forms of great beauty.
Radiata have also been called zoophyta.
They form the lowest division of the

RAD

[ 217 ]

11 A P

animal kingdom, having skeletons as
various as the forms of the animals.
These skeletons are sometimes external,
most frequently internal, often composed
of minute pieces symmetrically arranged,
or of one solid mass ; often of a thin
diaphanous horny consistence, or com-
posed of dense siliceous or calcareous
spicula, or of masses of carbonate with a
little phosphate of lime. The osseous
parts in these classes appear to be extra
vascular, and to grow by the juxta-position
of new portions, and from the simplicity
of the general structure and functions of
these animals, and from the internal situa-
tion of their solid parts, they are not
exuviable.

RA'DIATE. In botany, a corolla consisting
of a disk, in which the corollets are tubu-
lar and regular, and of a ray, in which
the florets are irregular.

RA'DIATED. (radiatus, Lat.)

1. Adorned with rays.

2. Belonging to the division Radiata.
The radiated animals are among the most
frequent organic remains in the transition
strata ; many of the strata appear almost
entirely composed of their mineralized
exuviae ; but generally in a fractured
condition. Radiated animals comprise all
those which were formerly called zoo-
phytes, or animal plants, as the corallines,
&c. ; which were long mistaken for ma-
rine vegetables.

3. In mineralogy, when the fibres are
broad and fl«at, and diverging as from a
centre.

RA'DIATED IRON PYRI'TES. A variety of
sulphuret of iron of a pale bronze yellow,
more or less inclining to steel-grey, or to
brass-yellow. It occurs regularly crys-
tallized ; in radiated, granular, and
lamellar concretions. But more fre-
quently its form is globular, botryoidal,
reniform, tuberose, &c. Its surface is
often rough, and sometimes presents the
solid angles of octahedral crystals. Lustre
varies from glistening to glimmering, and
is metallic. It is easily frangible. When
its form is spherical, the fibres diverge
from the centre ; when nearly cylindrical,
from the axis. Its constituents are iron
46-03, sulphur 53'97. It occurs more
particularly in the chalk deposit.

RADIA'TION. (radiation, Lat. radiation,
Fr.)

1. Beamy lustre ; emission of rays.

2. Divergence from a centre.
RADIA'TION OF HEAT. It is a general law,

that all hot bodies throw out or radiate
heat in all directions, and that other
colder bodies placed in their neighbour-
hood become hot, as if they received the
heat so radiated. There are two modes
of communicating heat, — by radiation,

and by conduction ; and both these have
their peculiar, and, to all appearance,
very different laws.

RA'DICATED. (radicatus, Lat.) In coii-
chology, when the shell is fixed by the
base, or by a byssus, to some other body.

RA'DICAL. (from radix, Lat. a root, radi-
cal, Fr.) Primitive; original. In bota-
ny, radical leaves are such as spring from
the root : the dandelion is a familiar
example.

RA'DICLE. (radicula, a little root, from
radix, Lat. radicitle, Fr.) In botany,
that part of the embryo which grows
downwards and becomes the root. The
primary object of vegetable structures
appears to be the establishment of the
functions of nutrition ; and we find that
while the plumule, bursting from its en-
veloping capsule, proceeds to extend itself
vertically upwards, at the same time,
slender filaments, or radicles, shoot out
below to form the roots.

RA'DII VECTO'RES. Imaginary lines joining
the centre of the sun and the centre of a
planet or comet, or the centres of a planet
and its satellite,

RA'DIOLITES. A genus of irregular inequi-
valved fossil shells obtained from that
part of the Pyrenees which is named
Les Corbieres. They are striated exter-
nally. The inferior valve is in the form
of a reversed cone ; the superior valve
convex. They have neither hinge nor
cartilage. The shell is beautifully figured
in Parkinson's Organic Remains.

RA'DIUS. (radius, Lat. radius, Fr.)

1. The semi-diameter of a circle. The
mean radius of the earth is intermediate
between the distances of the centre of the
earth from the pole and from the equator.

2. One of the bones of the fore-arm, or
that part of the upper extremity which
extends from the elbow to the wrist. The
fore-arm contains two bones, the radius
and the ulna ; the radius is the smaller of
the two.

RAGG. ) Called also Rowley ragg, or

RA'GSTONE. $ Dudley basalt. A fusible

siliceous stone, of a dark grey colour,

occurring near Dudley.

RA'MOSE. > (from ramus, a branch, Lat.)

RA'MOUS. $ Branched , full of branches.

Applied also to flowers growing on the

branches ; to peduncles proceeding from

a branch ; and also to leaves growing on

branches when they differ from those on

the stems.

RANE'LLA. A genus of marine univalves,
belonging to the family Canalifera. Recent
ranellse are found principally in the Indian
seas at depths varying to eleven fathoms.
Some fossil species have been discovered
in the London clay.
RAPTO'RIOUS. (from rapio, Lat. to snatch.)

P F

RAP

[ 218 ]

REG

1. The name given to animals which dart
upon and seize their prey.

2. The name given to certain parts of
insects. The legs are called pedes ; when
adapted to the seizing of prey, they are
suitably called pedes raptorii, not arms.
The idea of arms presents a certain or-
ganization not found in insects, although
the raptorious legs of insects may possibly
be analogous in their functions. — Shuck-
ard.

RA'TIO. (ratio, from reor, Lat.) The
relation which one quantity bears to an-
other.

RA'VIN. ) (ravin, Fr.) A deep, hollow,

RA'VINE. 5 narrow excavation formed by
the force of running water. The French
use the two words ravin and ravine in
different significations. The word ravin,
a substantive masculine, is used to express
a place which has been hollowed out by
a stream of running water, as "passer un
ravin profond." Ravine is employed to
denote a torrent of water, " espece de
torrent forme d'eaux qui tombent subite-
ment et impetueusement des montagnes,
ou d'autres lieux eleves, apres quelque
grande pluie." Sometimes, however,
ravine is used also to signify the place
worn by the torrent.

RAY. (from raja, Lat. raie, Fr.) A fish
of the sea. The rays form a genus of
fishes of the order Chondropterygii ; they
may be known by their flattened body,
which is in the form of a disk, from the
union of the body with the very broad
and fleshy pectorals, which are joined to
each other before or to the snout, and
which extend behind the two sides of the
abdomen as far as the base of the ventrals.
The rays have no ribs. The phalanges of
the carpus are very numerous, and each
is subdivided into several pieces by regu-
lar articulations ; they are arranged close
to one another in one plane, and form an
effectual base of support to the integu-
ment which covers them. Both the an-
terior and posterior extremities are sup-
ported by arches of bones, forming a sort
of belt. In this genus are included the
skate, torpedo, and sting-ray. The di-
rection of the eyes is oblique. Rays are
sometimes called sea-eagles, because, in
their rage and fury, they occasionally
raise themselves out of the water, and
fall again with such force as to make the
sea foam. Mr. Kirby, quoting from La-
cepede, says, an individual of a species of
this tribe, called by the sailors the sea-
devil, taken at Barbadoes, was so large,
as to require seven pairs of oxen to draw
it on shore ; he very judiciously, how-
ever, adds two notes of admiration to this
marvellous story. Fossil rays are abun-
dant throughout the tertiary formation ;

they occur also in the Jurassic limestone ;
not any have been found in any stratum
older than the lias.

RAYS OF FISHES. A name given to the
fins of certain fishes. Dr. Roget says,
the dorsal fins are supported by a series
of slender bones which are joined to the
spinous processes of the vertebrae, and
are formed from distinct centres of ossifi-
cation. These rays, as they are called,
are sometimes destined to grow to so
considerable a length, as to require being
subdivided into many pieces, in order to
lessen the danger of fracture, and also to
allow of a greater degree of flexibility.
These rays assume branched forms from
the farther subdivision of their parts. —
Bridg. Treatise.

RAY. In botany, the florets composing the
margin of a compound flower form the ray.

REA'GENT. A term used in chemistry for
a certain body employed to ascertain the
component parts of other bodies, either
as regards the quantity or quality of such
component parts.

RE'ALGAR. (realgar, Fr. arsenic rouge.)
The Hemiprismatischer Schwefel of Mohs ;
Rothes-rausch gelb of Werner ; Arsenic
sulfure rouge of Haiiy. Red sulphuret
of arsenic. Arsenic combined with sul-
phur forms realgar and orpiment, which
are found as natural ores ; the realgar is
of a beautiful and variable red. Realgar
is a bi- sulphuret of arsenic, consisting of
arsenic 69 '0, sulphur 31 "0. Specific
gravity 3'27. It occurs iji regular crys-
tals, in compact masses, in concretions,
or in crusts, which are sometimes earthy.
Before the blow-pipe it melts easily,
burns with a blue flame and garlic smell,
and soon evaporates. Nitric acid de-
prives it of its colour. It occurs in veins
in primary, transition, secondary, and
volcanic rocks ; in Sicily, Germany, Ame-
rica, and other parts.

RE'CENT FORMA'TION. Any formation,
whether igneous or aqueous, which can
be proved to be of a date posterior to the
introduction of man is called recent. Re-
cent formations are marine, fresh-water,
and volcanic. Of recent marine formations,
we may instance the coral formations of the
Pacific ocean ; the deltas of the Ganges,
Po, &c. Of recent fresh-water forma-
tions, the deposits in many lakes ; Italian
travertin, &c. Of recent volcanic forma-
tions, the lavas of the different volcanoes,
which have been in action since man was
introduced. A fine specimen of recent
limestone from Gaudaloupe, containing a
fossil human skeleton, may be seen in the
British Museum.

RE'CENT PE'RIOD. That period of time
commencing with the introduction of man
upon this earth.

R E C

C 219 ]

R E F

RECE'PTACLE. (receptaculum, Lat. recep-
tacle, Fr. ricettacolo, It.) In botany, the
basis or point, upon which all the parts
of the fructification rest ; the receptacle
has not always any particular figure to
distinguish it, except in compound flowers,
when the surface, which is either convex,
concave, conical, scaly, cellular, hairy, or
naked, forms the distinguishing character
of the genus or family. The receptacle
is distinguished into receptaculum pro-
prium, or receptacle appertaining to one
fructification only ; and receptaculum
commune, or common receptacle, con-
necting several distinct fructifications.

RECLI'NED. In botany, applied to leaves
when the point is lower than the base ;
also to stems when curved towards the
ground.

RECTA'NGLE. (rectangulus, Lat. rectangle,
Fr.) Every right-angled parallelogram
is called a rectangle, and is said to be
contained by any two of the straight
lines which contain one of the right
angles.

RECTA'NGLED. Having a right angle, or an
angle of ninety degrees.

RECTA'NGULAR. (rectangulaire,¥r.') Right
angled ; having one or more angles of
ninety degrees.

RECTILI'NEAL. ^ (from rectilineus, Lat.

RECTILINEAR. )> made of straight lines,

RECTILI'NEOUS.J rectiligne, Fr.) Con-
sisting of right lines ; right lined ; in a
straight line.

RECU'RVATED. ^ (from re, back, and curvo,

RECI/RVED. $ to bend, Lat.) Bent
backwards ; turned backwards.

RED CO'RAL. (the corallium rubrum.} A
branched zoophyte, somewhat resembling
in miniature a tree deprived of its leaves
and twigs. It seldom exceeds one foot
in height, and is attached to the rocks by
a broad expansion or base. It consists of
a bright red, stony axis, invested with a
fleshy, or gelatinous substance of a pale
blue colour, which is studded over with
stellular polypi. — Dr. Mantell, Wonders
of Geology.

RED CHALK. See Reddle.

RED MARL. Another name for the new red
sandstone.

RE'DDLE. The roethel of Werner ; the
crayon rouge of Brochant ; the argile
ocreuse rouge graphique of Haiiy. Red
chalk ; a species of argillaceous iron-stone
ore. The best specimens are brought
from Germany. It occurs in opaque
masses, having a compact texture. In
hardness, it differs but little from chalk.
It is dry, and rough to the touch, ad-
hering to the tongue, and yielding an
argillaceous odour. Specific gravity from
3-10 to 3-90.

REEF, (riff, Germ.) A range of rocks

lying generally near the surface of the
water.

REFLE'CT. (reflecto, Lat. rejlfo/tir, Fr.
riflettere, It.) To throw back ; to return.

REFLECTED, (refiechi, Fr.) Folded back-
wards ; thrown back.

REFLECTION. The act of throwing back ;
the act of bending back ; that which is
reflected. By the laws of optics, the
angle of reflection is equal to that of inci-
dence, whatever the reflecting surface
may be, and however obliquely the light
may fall upon it.

REFLE'XED. Recurvated ; bent backwards.

REFRA'CTED.

1. In conchology, abruptly bent, as if
broken.

2. In botany, bent back at an acute angle.
REFRA'CTION. (refraction, Fr. refrazione,

It.) The incurvation, or change of deter-
mination in the body moved, which hap-
pens to it whilst it enters or penetrates
any medium ; in dioptricks, it is the
variation of a ray of light from that right
line, which it would have passed on in,
had not the density of the medium turned
it aside. When light passes through a
drop of water or a piece of glass, it ob-
viously suffers some change in its direc-
tion. These bodies have therefore exer-
cised some action, or produced some
change upon the light, during its progress
through them. The power which thus
bends or changes the direction of a ray of
light is called refraction, and the amount
of this refraction varies with the nature
of the body. All the celestial bodies ap-
pear to be more elevated than they really
are ; because the rays of light moving
through the atmosphere in straight lines,
are continually inflected towards the
earth. Light passing obliquely out of a
rare into a denser medium, as from va-
cuum into air, or from air into water, is
bent or refracted from its course towards
a perpendicular to that point of the
denser surface where the light enters it.
The denser the medium the more the
ray is bent. — Mrs. Somerville. Brewster.
Herschel.

REFRA'CTION DOUBLE. When a ray of
light passes obliquely from one medium
to another of a different density, it is re-
fracted, or bent from its original direc-
tion. Still, the image of any object, seen
through a refracting medium, usually ap-
pears single. There are, however, some
transparent minerals, which have the
remarkable property of causing objects to
appear double ; that is, they present two
images of any object seen through them.
In this case it is evident, that the ray
must be divided into two portions after
entering the refracting medium, and that
each portion presents an image of the

R E F

[ 220 ]

RES

object. This is a distinctive character of
very considerable value in some minerals,
not depending on any accidental circum-
stances, but on the nature of the mine-
ral. Double refraction is exhibited most
strikingly in Iceland spar.

REFRIGERATED. (from refrigero, Lat.)
Cooled.

REFRIGERA'TION. (refrigeration, Fr.) The
act of cooling down ; the state of being
cooled.

It is the opinion of some geologists
that the whole of this planet was formerly
in an incandescent state, and that the
process of gradual refrigeration has been
constantly proceeding; that the crust of
the earth has cooled down to its present
temperature, but that the centre of the
earth is still a molten mass. Professor
Whewel, speaking of Fourier's arguments
on the subject, says, " it results from
Fourier's analysis that at a depth of
twelve or eighteen miles the earth may
be actually incandescent, and yet that the
effect of this fervent mass upon the tem-
perature at the surface may be a scarcely
perceptible fraction of a degree. The
slowness with which any heating or cool-
frg effect would take place through a
solid crust is much greater than might be
supposed. If the earth below twelve
leagues depth were replaced by a globe
of a temperature five hundred times
greater than that of boiling water, 200,000
years would be required to increase the
temperature of the surface one degree."

REGENERATION, (regeneration, Fr. rige-
nerazione, It. regeneratio, Lat.) Repro-
duction. The property which some ani-
mals possess of reproducing parts which
have been destroyed.

RELi'ciuLdB. (Lat.) Remnants ; remains of
the dead. To understand rightly, says
Prof. Phillips, the daily accumulating
stores of organic reliquiae, requires more
than a slight knowledge of existing na-
ture,— more even than an acquaintance
with the animal and vegetable forms.

RE'NAL. (renalis, Lat, from ren, a kid-
ney.) Pertaining to the kidneys.

RE'NIFORM. (from ren, a kidney, and/br-
ma, form, Lat.) Kidney- shaped.

RENU'LINA. A genus of flat, sulcated,
reniform, many-chambered, microscopic
foraminiferous shells, with linear cham-
bers adapted to the curves of the shells ;
the last being the longest.

RE'PTILE. (reptilis, Lat. reptile, Fr. rettile,
It.) A vertebrated, cold-blooded, animal.
The body covered with a shell, or with
scales, or entirely naked. Possessing
neither hair, mammae, feathers, nor ra-
diated fins ; breathing through the mouth
and nose by means of lungs ; oviparous,
but never hatching its eggs, and amphi-

bious. The oldest formations in which*
any reptiles have been found are those
connected with the magnesian limestone
formation.

REPTI'LIA. Reptiles form the third class
of vertebrated animals, and it is sub-
divided into four orders, namely, Chelo-
nia, or tortoises, Sauria, or lizards, Ophi-
dia, or serpents, and Batrachia, or frogs.
Of these four orders, the Chelonians and
Batrachians are partly aquatic, partly
terrestrial ; the Saurians and Ophidians
are principally tenants of the land.

REPU'LSION. (repulsion, Fr.) That pro-
perty possessed by bodies which causes
their particles to recede from one another,
or to avoid coming in contact. In air
and in liquids, the most perfect freedom
of motion of the parts among each other
subsists, and from this, and other consi-
derations, it has been concluded that the
several parts do not touch, but are kept
asunder at determinate distances from
each other, by the constant action of the
two forces of attraction and repulsion,
which are supposed to balance and coun-
teract each other. — Herschel.

RE'SIN. (resina, Lat. resine, Fr.) Called
also rosin. A yellowish-white coloured
substance, which exudes from many trees,
more particularly the different species of
fir. It is somewhat transparent, is hard
and brittle, of a disagreeable taste, and
may be collected in considerable quanti-
ties. Resin may be distinguished from
other substances by the following pro-
perties. It is more or less concrete, and
possesses a certain degree of transparency.
Its taste is sometimes hot and disagree-
able, but not unfrequently it is tasteless,
or nearly so. Colour generally between
pale yellow and brown. Specific gravity
from 1-0 to 1'3. It is electric and a non-
conductor of electricity. When heated it
readily melts ; and if the heat be much
increased it is volatilized, and burns with
a white flame and strong odour, producing
a great quantity of smoke. It is insoluble
in water, and by this may be distinguished
as well as separated from gum. It is
soluble in alcohol, ether, and in the vola-
tile oils. The number of resins is very
great, as there is scarcely a plant which
does not contain some kind of resin.

RESINI'FEROUS. (from resina, resin, and
fero, to produce, Lat.) Yielding resin.

RE'SINOUS. Resembling resin ; containing
resin ; possessing the properties of resin.

RESPIRA'TION. (respiratio, Lat. respira-
tion, Fr. respirazione, It.) The function
of breathing ; the act of inhaling air into
and exhaling it from the lungs. Respi-
ration consists of two parts, inspiration,
which, in a healthy condition, takes place
about twenty-six times in a minute, thir-

RES

[ 221 ]

REV

teen cubic inches of air being the average
quantity taken in at each inspiration ;
and expiration, which alternates with
inspiration. It is by respiration that the
blood becomes freed of its carbon and, at
the same time, obtains fresh supplies of
oxygen.

RE'SPIRATORY. Serving for the function
of breathing ; connected with the function
of respiration.

RESU'PINATE. (resupinatus, Lat.) In
botany, a term applied to leaves, when
the under surface is turned upwards.

RESPLE'NDENT FE'LSPAR. Another name
for Adularia, or moon-stone.

RE'TE MUCO'SUM. (from rete, a net, and
mucosum, mucous, Lat.) A tissue lying
immediately under the epidermis, or
scarfskin, and the cutis vera, or true
skin. The black colour of negroes de-
pends upon a black pigment, situated in
this substance.

RETI'CULAR. (reticulaire, Fr.) Having
the form of net- work, as a reticular mem-
brane, reticular tissue, &c.

RETI'CULATE. } (reticulatus, Lat. from

RETI'CULATED. \ rete, a net ; reticule,
r£ticul6e, Fr.) Made of net-work ;
formed of interstitial vacuities. — Johnson.

RE'TICULE. (reticulum, dimin. of rete,
Lat. a small net.) A name given to
the second stomach of ruminant animals.

RK'TINA. (from rete, a net, Lat. retine,
Fr.) The net-like expansion of the optic
nerve placed at the back of the eye, and
which has been called one of the mem-
branes of that organ. The retina is an
exceedingly thin and delicate layer of
nervous matter, supported by a fine mem-
brane. No nerve but the optic nerve,
and no part of that nerve but the retina,
is capable of giving rise to the sensation
of light.

RE'TINASPHALTUM. The name given by
Mr. Hatchett to a sub-species of bitumen.
It is an opaque, ochre-yellow, and brittle
substance found in Bovey coal and fossil
wood. Fracture vitreous, and imperfectly
conchoidal. Specific gravity 1*13. Ac-
cording to its analysis by Mr. Hatchett,
who deems this substance to be an im-
perfectly mineralized resin, it consists of
resin 55, asphaltum 41, earthy matter
3 ; = 99.

RE'TINITE. Another name for Retinas-
phaltum.

RE'TORT. A globular vessel with a long
neck, sufficiently bent as to make with
the belly of the vessel an angle of sixty
degrees. Retorts are used for distil-
lation, and some other chemical pro-

RETRA'CTILE. Capable of being drawn

back ; as the organs of certain animals.
RETROFLE'CTED. (from retro, back, and

fiecto, to bend, Lat.) Bent in different
directions, usually in a distorted manner.

RETROMI'NGENT. (from retro, backwards,
and mingo, to stale, Lat.) Passing the
urine backwards ; belonging to the class
of retromingents.

RETROMI'NGENTS. In zoology, a class of
animals, whose characteristic is, that,
both male and female, they void their
urine backwards.

RETU'NDATED. (from retundo, Lat. to
blunt.) Blunted, or turned at the edge.

RETU'SE. (retusus, Lat. blunted.)

1 . In conchology , a shell ending in an
obtuse sinus is termed a refuse shell ;
bluntly notched.

2. In botany, leaves are called refuse,
when ending in a broad shallow notch, or
sinus.

REVE'RSKD. (reversus, from re and verto,
to turn, Lat.) Turned upside down ;
turned side for side.

1. In conchology, a reversed shell is one,
the volutions of which are the reverse
way of the common corkscrew.

2. In botany, when the upper lip of the
corolla is larger and more expanded than
the lower.

REVIVIFICA'TION. (revivification, Fr. from
re and vivifico, Lat.) Renewal of life ;
restoration to life. A dormant vitality
may exist in a system of organs which
have been brought into a perfectly dry
state ; and this is the case not with vege-
tables only, but with many species of ani-
malcules, and even with some of the more
highly developed worms. These may be
kept in a dry state for an indefinite length
of time, and when moistened with water,
shall resume their activity, as if restored
to life. The revivification of animalcules
is a curious phenomenon. The Rotofer
redivivus, or wheat animalcule, can live
only in water, and is commonly found in
that which has remained stagnant for
some time in the gutters of houses. But
it may be deprived of this fluid, and re-
duced to perfect dryness, so that all the
functions of life shall be completely sus-
pended, yet without the destruction of the
vital principle ; for this atom of dust,
after remaining for years in a dry state,
may be revived in a few minutes by being
again supplied with water. This alter-
nate suspension and restoration of life
may be repeated, without apparent in-
jury to the animalcule, for a great num-
ber of times. — Dr. Roget, Bridgewater
Treat.

REVIV'ISCENCE. Revivification ; renewal
of life.

RE'VOLUTE. (revolutus, Lat. rolled back-
wards.) In botany, applied to leaves,
when the margins are rolled backwards
towards the under surface.

R H A

[ 222 ]

ROC

RHACHEOSAO'RUS. A fossil saurian of the
lias and oolite.

RHA'TIZIT. The name given by Werner to
prismatic kyanite.

RHINO'CEROS. (pivoKepotg, Gr. from piv,
a nose, and ictpas, a horn : rhinoceros,
tat. rhinoceros, Fr. rinoceronte, It.) A
genus of thick-skinned mammalia, in-
cluded by Cuvier in the family Pachyder-
rnata Ordinaria. The rhinoceros is found
at the present day, in India, Java, Africa,
and Sumatra. It is a large animal, hav-
ing three toes, but the feet not cloven.
The bones of the nose support a solid horn
in two species of this genus ; but the other
species possess two horns. Burchel and
Campbell met with more than one new
species of rhinoceros in their journey from
the Cape of Good Hope into the interior.
Campbell's had a straight horn projecting
three feet from the forehead, different from
any he had before seen, its horn resem-
bling that of the supposed unicorn. — Rev.
W. Kirby.

Fossil remains of the rhinoceros are
found in Siberia and Germany. The en-
tire carcass of a fossil rhinoceros was
discovered, in frozen sand, on the banks
of the Wilaji, in Siberia. Bones and
teeth of the rhinoceros are found in this
country in superficial gravel and loam.

RHIPI'PTERA. A new order of insects,
established by Mr. Kirby under the name
of Strepsiptera (twisted wings), named
Rhipiptera by Latreille, includes only
two genera, namely, stylops and xenos.
These insects are remarkable for their
anomalous form, and the irregularity of
their habits. The tegmina are fixed at the
base of the anterior legs ; they are both
long and narrow, and appear to be in-
capable of protecting the wings. The wings
are large, membranous, divided by longi-
tudinal and radiating nervures, and fold
longitudinally, after the manner of a fan.

RHIZO'MA. (piZwfta, a root, Gr.) A
species of creeping stem which grows
under-ground.

RHIZO'PODES. The name proposed, by M.
Dujardin, to a new class of animals of
lower degree than the radiata, possessing
a power of locomotion by means of minute
tentacular filaments. This new class
would comprise the animals which con-
struct the miliola, and some microscopic
foraminiferous shells.

RHOMB. (po/z/3oc, Gr. rhombus, Lat.
rhombe, Fr. rombo, It.) In geometry,
an oblique angled parallelogram, or qua-
drilateral figure, whose sides are equal
and parallel, but the angles unequal, two
of the opposite sides being obtuse, and
two acute.

RHO'MBIC. Having the figure of a i*homb.

RHO'MBOID. (from popflog, a rhomb, and

e7^oc, form, Gr.) Is a figure which has
its opposite sides equal to one another,
but all its sides are not equal, nor are its
angles right angles.

RHOMBO'IDAL. Having the form of a
rhomboid.

RHO'MBUS. A rhomb ; that which has its
sides equal, but its angles are not right
angles.

RHOMB SPAR. Called also bitter spar, a
variety of magnesian carbonate of lime.
This variety occurs crystallized, most of
its crystals being rhombs, sometimes
truncated, and sometimes with rounded
edges. Fracture foliated, the foliae having
a shining or splendent lustre, more pearly
than that of calcareous spar. Specific
gravity from 2*48 to 3'00. It is gene-
rally of a greyish colour to pale yellow, or
yellowish brown. It appears to pass by
imperceptible shades into dolomite.

RI'BBED.

1. Having bones communicating with and
attached to the vertebrae, and serving to
protect the organs contained within the
chest.

2. In botany, a term applied to leaves
when they possess large raised vessels on
the under side.

3. In conchology, when shells have ridges,
or ribs, either longitudinal or transverse.

RI'MA. In conchology, the interstice be-
tween the valves, when the hymen is
removed.

RI'NGENT. (from ringo, to grin, Lat.)
In botany, applied to a monopetalous co-
rolla, the border of which is usually
divided into two lips, which gape like the
mouth of an animal. A corolla with two
lips is called bilabiate ; when these pre-
sent an appearance like the mouth of
an animal, the corolla is called ringent.

ROCK, (roc and roche, Fr. rocca, It.)
Rocks, and the substances they enclose,
lie beneath the superficial accumulations,
and constitute the crust of the earth.
The term "rocks" is apt to mislead
beginners ; for under this title geologists
rank clay, sand, coal, and chalk, as well
as limestone, granite, slate, and basalt,
and other hard and solid masses, to which
the use of the term is generally restricted.
-Prof. Phillips.

The rocks of which the mineral crust
of the globe is composed are divided into
those of aqueous and igneous origin,
from the two agents known to us as
capable of their production. Rocks are
also divided into primary, transition, se-
condary and tertiary. These, and many
other divisions, such as crystalline, fos-
siliferous, &c. &c. are described in the
various works on geology.

ROCK BU'TTER. Native alum. It occurs
in the cavities or fissures of argillaceous

ROC

[ 223 ]

R O S

slate in soft masses ; it is of a yel-
lowish-white colour ; a little unctuous to
the touch ; massive, tuberose, or stalac-
tical. It is mingled with clay and oxide
of iron.

ROCK CRY'STAL. This, which is only the
most perfect variety of quartz, has, when
crystallized, received the name of rock
crystal: the same name has been ex-
tended to coloured crystals, when trans-
parent. The finest specimens of rock
crystal are found in Dauphine, in the
Alps, in Madagascar, &c. ; but it abounds
in every country, in all parts of the
world, in chasms or clefts of the oldest
rocks. The primitive form is a rhom-
boid of 94° 15' and 85° 45' ; the secon-
dary forms are an equiangular six-sided
prism, rather acutely acuminated on both
extremities by six planes which are set
on the lateral planes, a double six-sided
pyramid, an acute simple six-sided pyra-
mid, and acute double three-sided pyra-
mid. Splendent ; fracture perfect con-
choidal ; gives double refraction feebly.
Its specific gravity is from 2*5 to 2*8.
By friction it exhales a peculiar odour,
and some varieties also phosphoresce in
the dark. An analysis by Bergman gave
silex 93, alumine 6, lime 1.

ROCK WOOD. A variety of asbestos of a
brown colour ; in its general appearance
greatly resembling fossil wood.

ROCK CORK. The Bei-g kork of Werner ;
Suber montanum of Kirwan ; Asbeste
suberiform of Brongniart. Called also
Mountain cork ; a white or grey-coloured
variety of asbestus. Its specific gravity
varies from 0'68 to 0'99 : this, and its
fibrous structure, have obtained for it the
name of cork. Its constituents are silex
56-3, magnesia 26'2, lime 12-4, alumine
2*0, iron 3*1. It occurs in France, Ger-
many, and some other countries. Near
Alais, in France, it is met with on the
surface of the ground, in long white
masses, having a resemblance to human
bones.

ROCK SALT. Common salt. This is found
in vast solid masses or beds, in different
formations, extensively in the new red
sandstone formation. The saliferous strata
of Northwich, form two beds of great thick-
ness, one being 120, the other 110 feet
in thickness. The origin of these beds
does not appear, to the present time,
to be satisfactorily understood or ex-
plained.

RODE'NTIA. (from rodo, Lat. to gnaw.)
The fifth order of Mammalia. Called
also Gnawers. The order contains many
genera, some of which are familiar to us,
namely, the squirrel, the rat, the mouse,
the hare, the rabbit, &c. &c. From
the characters of their teeth, which are

adapted neither for seizing nor tearing
their food, but merely to nibble and
gnaw it, they have received their name of
Roclents, or gnawers. The great ma-
jority of this order are gregarious, living
in burrows, in common habitations which
they excavate or fabricate themselves."

ROE STONE. The roogenstein of Werner ;
oviform limestone of Kirwan. A name
given to the oolite, a variety of lime-
stone, from its being composed of small
rounded particles, resembling the roe or
eggs of a fish. See Oolite.

ROSA'CE^E. An order of plants, including
the genera potentilla, fragaria, rosa, ru-
bus, spirasa, brayera, dryas, &c. &c.
The following is a description of this
order ; calyx with four or five teeth, the
odd one posterior or next the axis, with a
disk lining the tube, or surrounding the
orifice ; petals five, equal, perigynous ;
stamens indefinite in number, inserted
into the calyx within the petals ; ovaria
superior, sometimes solitary, one-celled,
either distinct, or, in some genera, co-
hering into a many-celled pistil, styles
lateral, and stigmata simple ; fruit either
a cynarrhodum, an etserio, or follicular ;
seeds suspended, embryo pointing to the
hilum, hardly any albumen ; herbaceous
plants or shrubs, leaves alternate, com-
pound, with two stipulae.

Chiefly found in temperate or cold
northerly climates ; very few within the
tropics ; fourteen British genera. The
whole order is innocent. — Prof. Lindley.

ROSA'CEOUS. Belonging to the order Ro-
sacese. Applied to polypetalous corollas,
consisting of four or more petals, spread-
ing like a rose.

ROMA'NZOVITE. A mineral recently dis-
covered in Finland. It is of a brown,
brownish yellow, and blackish- brown co-
lour. It has been named after Count
Romaiizoff. According to the analysis
of M. Julin, it consists of silica 41 '22.
lime 24-78, alumine 24-08, oxide of
iron 7-02, magnesia and oxide of man-
ganese 0-92.

RO'SIN. See Resin.

ROSTELLA'RIA. A genus of marine uni-
valves, found both recent and fossil. A
slightly turreted or fusiform univalve,
terminating at its base in a lengthened
canal, similar to a sharp beak. The lip
whole or dentated, and dilated with
age ; with a groove contiguous to the
canal.

The most remarkable fossil shell of this
genus is Rostellaria macroptera, found
in Hampshire, and in France. This large
and handsome fossil is remarkable for
the size of its right lip, which is formed
into a wide, round, and rather thin wing,
extending from the canal at the base,

R O S

[ 224 ]

RUG

dver the body of the shell and a great
part of the spire. The most common
species is Rostellaria fissurella. — Par-
kinson.

Five species are enumerated by Dr.
Mantell as occurring in. the strata of
Sussex, above the Wealden, namely, R.
Sowerbii, R. Parkinson, R. carinata,
and R. calcarata : one species is found
with two processes, closely resembling
R. Pes Pelicani. Recent Rostellarije
are found in the Indian seas.
RO'STRATED. (rostratiis, Lat. beaked.)

1. In botany, a term applied to plants
when the fruit has a beak-like process.

2. In conchology, applied to shells having
a beak-like extension of the shell, in
which the canal is situated.

RO'STRUM. (Lat.) A beak or bill; the
beak or bill of a bird.

RO'TALITES. A genus of shells existing
only in a fossil state, and found at Grig-
non. Four species are described by La-
marck, namely, R. trochidiformis, R.
lenticulina, R. depressa, and R. discor-
bula. The shells of this genus are con-
vex, conical, spiral, multilocular, uni-
valves, slightly radiated beneath ; aperture
marginal, trigonal, and inclined down-
wards.

ROTHE TODTE LiEGENDE. The name given
by the Germans to the lower beds of new
red sandstone.

ROTI'FERA. The first order of the class
Infusoria. The researches of Ehrenberg
show that a group, formerly believed to
belong to the class of the most minute
animalcules, possess an organization ex-
tremely complex. They were charac-
terized as rotiferous animalcules, because
they have circles of vibratile cilia, which
appear like revolving wheels when they
are in rapid action, and by these hair-
like processes they were enabled to swim.
They float, attract their prey with these,
and thus get their food. They possess
an alimentary canal passing through the
body. They possess also muscular fas-
ciculi ; nervous ganglia ; and even a cere-
bral or supra-aesophageal ganglion. They
possess a vascular system pretty highly
developed, so that they are far removed
from the polygastrica, -Ehrenberg has
called them "rotatoria," but the term
rotifera is more generally used. They
are distinguished by their circles of cilia,
sometimes single, sometimes double,
which, through the microscope, appear
like revolving wheels.

Lamarck is of opinion, from the obser-
tions of Du Trochet, that what are taken
for two or more wheels, are only one, bent
so as to form partial ones ; but in some
they certainly are distinct organs. The
object of the rapid gyration of this wheel

or wheels is to create a vortex in the
water, whose centre is the mouth of the
animal ; a little charybdis bearing with it
all the animalcules or molecules that come
within its sphere of action. — Prof. Grant.
Rev. W. Kirby.

RO'TTEN STONE. Another name for Tri-
poli, in Barbary, whence it was formerly
brought. Although the name has been
applied to all the species of Tripoli, yet,
strictly, it ought to be confined to those
varieties only which are most light and
friable, and have a very fine grain. Rot-
ten stone occurs near Bakewell, in Der-
byshire, resting on compact limestone.
It is used in polishing metals, stones,
and glass, as well as for many other pur-
poses.

ROTU'ND. (rotundus, Lat. ) Round; circu-
lar; spherical. Applied to leaves and shells.

RU'BELITE. > The Tourmaline rubellite of

RU'BELLITE. S Brongniart ; Tourmaline
apyre of Haiiy. Red tourmaline. This
mineral is of a red colour, of various
shades ; in the form of its crystals it re-
sembles schorl, as well as in its power of
acquiring opposite electricities by heat.
It is translucent, sometimes transparent.
Specific gravity 3-07. Its crystals are
cylindrical or acicular, and aggregated in
groups. Before the blowpipe this mi-
neral becomes white, but does not fuse,
a circumstance, considering its composi-
tion, not easily explained. Its consti-
tuents are silex 42'0, alumine 40'0, soda
lO'O, oxides of manganese and iron 7'0.
In the British Museum there is a speci-
men of Rubellite, from the kingdom of
Ava, valued at 1000J. Some specimens
of Rubellite afford from five to six per
cent, of boracic acid, and from two to
three of lithion.

RU'BBLE STONE. The name given by Kir-
wan to Greywacke.

RU'BY. (from rubeo, Lat. to be red, rubis,
Fr. rubino, It. rubin, Germ.) The Spi-
nell of Werner ; Spinelle rubis of Brong-
niart. A transparent red variety of
rhombohedral corundum. The ruby is a
variety of the same mineral genus as the
sapphire, but differs from it in containing
rather more silex, and in being less hard.
Rubies are found in alluvial soil in Cey-
lon, Pegu, and other countries in the
East. The ruby ranks next to the dia-
mond in value. When a specimen is
fine, and free from flaws, a ruby of large
size will sell for from ten to fifteen thou-
sand pounds. It is composed principally
of alumine, containing not less than ninety
per cent.

RU'GGED. (from ruga, Lat. a wrinkle.)
Rough ; uneven. In botany, applied to
leaves when the surface rises into little
inequalities above the veins.

RUG

[ 225 ]

SAL

1. In conchology, applied to shells which
are rugged and full of wrinkles.

2. In botany, applied to leaves when the
veins are more contracted than the disc,
so that the disc rises into little inequali-
ties : the primrose and sage afford ex-
amples.

3. In entomology, when longitudinal ele-
vations are placed irregularly on the sur-
face, resembling coarse wrinkles.

RU'MINANTS. (from rumino, to chew over
again, Lat. ruminant, Fr. ruminante, It.)
Chewing the cud.

RUMINA'NTIA. > The eighth order of Mam-
RU'MINANTS. J malia, or those animals
that chew the cud. These animals pos-
sess the singular property of returning
the food to the mouth after it has been
swallowed, that it may undergo the pro-
cess of a second mastication. This pro-
perty depends upon the structure of the
four stomachs which these animals pos-
sess, the three first being so arranged
that the food may pass from the oesopha-
gus into either of them. Cuvier divides
this great order into those that have
horns, and those that have none.

RU'NCINATIT. (from runcina, a saw, Lat.)
In botany, a term applied to leaves whose
edges are cut into teeth turning back-
wards like a scythe.

RUST, (rout, Germ.) If iron be exposed
to the air, more especially if the at-
mosphere be moist, its surface is soon
tarnished, and it is gradually changed
into a brown or yellow! powder, well
known by the name of rust. Rust
is an oxide of iron, or of some other
metal.

RU'TILE. Red oxide of titanium. The
titane oxyde of Haiiy ; titane ruthil of
Brongniart ; rutil of Werner ; peritomes
titan-erz of Mohs. A brown, red, yel-
low, and sometimes nearly velvet-black
ore. Occurs regularly crystallized, mas-
sive, disseminated, in angular grains and
in flakes. External lustre considerable,
and sometimes metallic. Opaque or
translucent. Scratches glass. Specific
gravity = 4'2 to 4'4. It is infusible
before the blow-pipe unless a flux be em-
ployed. It is found in Scotland, in the
granite of Cairngorm.

RYA'KOLITE. A name lately given to
glassy felspar.

SA'CCHAROID. (from ffaicxap, sugar, and
fidof, form, Gr.) A term applied to
rocks which have a texture resembling
that of loaf-sugar.

SA'CRAL. Pertaining to the sacrum.

SA'CRUM. (Lat.) The bone which forms
the basis of the vertebral column.

SADDLE-SHAPED STRATA. When strata
are bent on each side of a mountain,
without being broken at the top, they are
called saddle- shaped. — BakewelL

SA'GENITE. Another name for rutile, or
red oxide of titanium. See Rutile.

SAGI'TTA. An obsolete name for belemnite.

SAGI'TTATE. (from sayittatus, Lat.) Ar-
row-shaped.

SA'HLITE. The sahlit of Werner ; the
malacolith of Brongniart. A variety of
augite, discovered in a silver mine at
Sahla, in Sweden, from which it takes its
name. It is of a green colour of various
shades. It occurs in straight, lamellar,
and granular concretions, sometimes crys-
tallized, with a shining, vitreous, or
pearly lustre ; translucent at the edges.
It is soft to the touch, scarcely scratches
glass, and is easily scratched by a knife.
Specific gravity 3'2. Before the blow-
pipe it melts, with some ebullition, into a
porous glass. It consists of silica 53,

magnesia 19, lime 20, alumina 3, iron and
manganese 4.

SA'LAMANDER. (craXapavdpa, Gr. sala-
mandra, Lat. salamandre, Fr. salaman-
dra, It. salamander, Germ.) A genus of
reptiles belonging to the order Batrachia.
The salamander possesses the general
form of the lizard, and is placed by Lin-
naeus among the lizards ; but its charac-
ters are those of the Batrachians. Its
body is elongated ; it has four feet, and a
long tail. When arrived at an adult
state, its respiration is performed in the
same manner as in frogs and tortoises.
Aristotle and Pliny state that if the sala-
mander passes through fire, the fire is
immediately extinguished, and that it
emits a milky saliva, which is depilatory.
Bosc says that it emits from its skin a
milky fluid when annoyed, and when put
into the fire, it sometimes happens that
this fluid sufficiently extinguishes it to
permit the animal to escape. This se-
cretion of a milky fluid appears to be
exceedingly acrid ; produces, if applied to
the tongue, a very painful sensation ; is
an excellent depilatory, and destroys
small animals. Spallanzani has disco-
vered that the salamander has the power
of reproducing lost or mutilated organs,

G 6

SAL

[ 226 ]

SAL

so that if its legs or tail be cut off, or its
eyes plucked out, these organs will, in
the course of a few months, be repro-
duced.

From the strata at CEningen has been
extracted a gigantic fossil salamander up-
wards of three feet in length, the Homo
diluvii testis of Scheuchzeru

SA'LIENT. (saliens, from salio, Lat. to
leap.) Leaping ; moving by leaps.

SA'LIENT A'NGLE. A projecting angle. In
a zig-zag line the upper are the salient,
the lower the re-entering angles.

SALI'KEROUS. (from sal, salt, and/ero, to
bear, or produce, Lat.) Containing salt ;
yielding salt. Thus, in geology, we
have saliferous deposites ; saliferous
rocks ; saliferous strata ; saliferous sys-
tem, &c. &c.

SALI'FEROUS SYSTEM. This ris the new
red sandstone system of some authors ;
the Poikilitic system of Mr. Conybeare.
Of above two hundred species of fossils
found in the rocks of the saliferous sys-
tem, not more than fifty have been disco -
vered.in England. The saliferous system
comprises the new red sandstone and the
magnesian limestone formations ; in the
former of these two formations no organic
remains have been discovered in Eng-
land. In Germany and France there is
added to the series of strata which we
possess in this country, a member which
is called muschel-kalk ; this, though ex-
tensively developed in Germany, has
never been discovered in England. The
organic remains of this system, says
Prof. Phillips, though few in number,
are exceedingly interesting to the na-
turalist and geologist, from the strong
testimony they offer of the successive
changes of the living creation, according
to the new circumstances of the land and
sea. The fossil plants, shells, fishes,
and reptiles of the saliferous system, ap-
pear to partake both of the character of
those in the older carboniferous, and the
newer oolitic, deposites. Calamites, re-
sembling those of the coal formation, are
mingled with cycadese, like those of the
oolites. Fishes of the genus palaeoniscus
are here found for the last time ; while
the remains of oviparous quadrupeds, the
phytosaurus and protorosaurus, are first
discovered. If the saliferous system
were arranged only in accordance with
its organic remains, the lower half, or
magnesian limestone formation, might be
ranked with the carboniferous rocks ; the
upper half, or new red sandstone forma-
tion with the oolitic rocks ; but regarding
it according to its mineral characters, it
forms one great series of deposites, which
were thrown down at a period when a
decided change in the conditions of the

globe was taking place. The manner in
which the group rests upon the carboni-
ferous group in England is such as to
show that the latter was disturbed, dislo-
cated, and partially removed before the
former was accumulated upon it ; never-
theless, in other parts of the European
area, there is reason for supposing that
the new red sandstone was quietly depo-
sited upon the carboniferous series, no
real line of separation being established
between them. Mr. De La Beche ob-
serves, " it is worthy of remark, that, as
far as the European area is concerned,
rock-salt is very frequently distributed
among the higher parts of the new red
sandstone series, from which circum-
stance it has sometimes been named sali-
ferous t by way of distinction ; a term
exceedingly objectionable, as it would
imply either that at this geological period
salt was more abundantly deposited than
at any other, or that it was confined to
it." The saliferous system, commencing
with the keuper, or variegated marls, lies
immediately under the lias, and, termi-
nating in the reg conglomerate, rests upon
the carboniferous series. Its depth in
some parts has been estimated at eight or
nine hundred feet.

SALIFI'ABLE. That may become a salt by
combination with some other body.

SALI'NE. (salin, Fr.) Containing salt ;
consisting of salt.

SALI'VA. (saliva, Lat. salive, Fr.) A
fluid secreted by the salivary glands, which
serves to lubricate the tongue and fauces,
to facilitate deglutition, and is supposed
greatly to assist the function of digestion.
Its principal saline constituent appears,
from analysis, to be muriate of potash.

SA'LIVARY GLANDS. Organs which secrete
the saliva. All animals that masticate
their food are provided with salivary
glands, which pour the saliva into the
mouth as near as possible to the grinding
surfaces of the teeth. In animals sub-
sisting on vegetable food, which requires
much maceration, the salivary glands are
of large size. Fishes and the cetacea,
performing no mastication, have no sali-
vary glands.

SALT, (sal, Lat. salz, Germ, sel, Fr. sale,
It.) Formerly called muriate of soda,
now known as chloride of sodium. In an
impure state, this is one of the most
abundant productions of nature. It occurs
in two forms, either as a solid mineral, or
in solution, in the waters of the ocean,
and of lakes and springs in inland dis-
tricts. The waters of the ocean contain
about one-thirtieth of their bulk in solu-
tion. The uses of salt are numerous,
putting aside its great importance, or ab-
solute necessity, as a matter of food. It

SAL

[227 ]

S A S

is employed in glass-making, enamelling,
glazing, and bleaching. It is a valuable
manure ; and it is used in the making of
bread. On an average, an adult may be
considered to consume from five to six
ounces of salt a-week. About a million
of tons is supposed to be annually con-
sumed.

SALT MINES. Although the most frequent
position of rock-salt is in strata of the
new red sandstone formation, yet it is not
exclusively confined to them. The salt
mines of Wieliezka and Sicily are in ter-
tiary formations ; those of Cardona in
cretaceous ; some are found in the oolite ;
while others occur in the coal formation.
There are salt-mines in Mexico which
furnish annually one million eight hun-
dred thousand bushels. The salt-mine of
Wieliezka, already mentioned as existing
in the tertiary formation, is very cele-
brated. It is entered by six shafts of
four or five yards in diameter, and from
sixty to seventy yards deep. It is worked
to a depth of upwards of nine hundred
feet. The works in the mine are most
surprising ; there is a stable, apartments,
a chapel, &c., all the furniture of which
is made of salt.

SALT SPRINGS. The salt-springs generally,
but not invariably, rise from strata of
the new red sandstone formation. The
strongest yield about one-fourth of their
weight in salt. Those at Droitwich, in
Cheshire, are remarkably abundant, fur-
nishing upwards of sixteen thousand tons
of salt annually. The salt is obtained
merely by evaporation.

SALTPE'TRE. Nitrate of potash, or nitre.
See Nitre.

SAND. (sand, Germ.) Flint or quartz
broken fine by the action of water, but
not reduced to powder. Very small par-
ticles of siliceous matter not cohering to-
gether, nor softened by water.

SA'NDSTONE. An aggregate of siliceous
grains. Any stone composed of grains
of sand agglutinated together. The grains
of sandstone are sometimes so fine as
scarcely to be distinguished by the un-
aided eye; at others their magnitude is
equal to that of a walnut or an egg, as in
the coarse sandstones known as conglo-
merates, pudding-stones, breccias, &c.
The cement which agglutinates the sili-
ceous particles of sandstones may be cal-
careous, argillaceous, or siliceous : when
siliceous the sandstone sometimes resem-
bles quartz. Sandstones are close, porous,
and vesicular. They vary in colour, from
white to red or brown, but their most
common colour is grey or greyish white :
sometimes their colour is uniform, at
others it is variegated. Sandstone is in
general distinctly stratified, and the beds

horizontally arranged ; this, however, is
not invariably the case, as they are some-
times much inclined, or even vertical.

SAPONA'CEOUS. (from sapo, soap, Lat.)
Soapy to the touch ; resembling soap ;
having a soapy feel.

SA'PPARE. A mineral first described by
Saussure, who gave it the name of sap-
pare. It is the Cyanit of Werner, and
the Disthene of Haiiy. For its descrip-
tion see Cyanite.

SA'PPHIRE. (from <ra7T0apoc, Gr. sapplti-
rus, Lat. sapMr, Fr. zaffiro, It. saphir,
Germ.) A precious stone, exceeding all
others in hardness except the diamond.
It consists of nearly pure alumina, with a
little oxide of iron, and some silex or
lime ; but the sapphire contains upwards
of ninety-eight per cent, of alumina. Its
specific gravity is from 3' 70 to 4-30. It
possesses double refraction, and varies
from opaque to transparent. Its colours
are blue, red, green, white, grey, yellow,
brown, and black. There are several
varieties of the sapphire, as the white,
blue, or oriental sapphire, the oriental
amethyst, the oriental topaz, and the
oriental emerald. The finest sapphires
are found in alluvial soil in Ceylon and
Pegu. Lately the sapphire has been em-
ployed in the formation of small lenses
for microscopes. The red sapphire is the
most highly esteemed, its value being
sometimes equal to that of a diamond of
the same size : a single stone has been
estimated at the value of one thousand
guineas.

SA'RCOCARP. The fleshy part of certain
fruits, placed between the epicarp and
the endocarp. That part of fleshy fruits
which is usually eaten. -__

SA'RCOLITE. (from crapZ, flesh, and \iQo£,
stone, Gr.) A variety of analcirne, found
at Mount Somma, and obtaining its name
from the flesh colour of its crystals, which
are cubo-octahedral.

SA'RDONYX. (aap86vv%, Gr. sardonyx,
Lat. sardoine, Fr. sardonico, It. sardonyx,
Germ.) The Quartz agate sardoine of
Haiiy ; Silex sardoine of Brongniart. A
variety of calcedony differing from carne-
lian only in its colour, which is reddish
yellow, or nearly orange, with occasion-
ally a tinge of brown.

SARMENTO'SE. ) (sarmenteux, euse, Fr. sar-

SARME'NTOUS. \ mentosus, Lat. full of
twigs.) In botany, applied to stems that
are thrown out from the roots for the
purpose of increase, being barren of
flowers, and creep along, putting forth
roots from various points.

SA'SSOLIN. ) So called from its having

SA'SSOLINE. ] been found near the warm
spring of Sasso, in Tuscany. Native
boracic acid.

SAT

[ 228 ]

S C A

SATELLITE, (satellite, Fr. sattellite, It.)
A small body revolving about a planet.
The moon is a satellite to the earth. The
moon is so near the earth, that the reci-
procal attraction between each of her
particles, and each of the particles in the
prominent mass at the terrestrial equator,
occasions considerable disturbances in
the motions of both bodies ; for the action
of the moon on the matter at the earth's
equator, produces a nutation in the axis
of rotation, and the re-action of that
matter on the moon, is the cause of a
corresponding nutation in the lunar orbit.
— Mrs. Somerville.

SA'TIN SPAR. A fibrous variety of calca-
reous spar. It is susceptible of a fine
polish, and exhibits the lustre of satin,
from which circumstance it has obtained
its name. Its colours are grey and pale
rose-red. Very fine specimens are met
with in Cumberland.

SAU'RIA. (from travpoc, a lizard, Gr.)
The second order in the class Reptilia.
This order, according to Cuvier's ar-
rangement, includes six families, name-
ly, Crocodilida, Lacertinida, Iguanida,
Geckotida, Chamseleonida, and Scin-
coide.

SAU'RIAN. A reptile belonging to the
order Sauria.

SAU'RIAN REMAINS. The oldest strata in
which any remains of saurians have been
found, are those connected with the mag-
nesian limestone formation. The bones
and entire skeletons of reptiles allied to
the class Reptilia occur in the lower part
of the secondary strata, and are very
abundant in the lias. Many of these
animals were different from any known
existing genera. " The species of fossil
saurians are exceedingly numerous, at-
taining in many instances a magnitude
unknown among the living orders of that
class, and which seem to have been
peculiar to those middle ages of geologi-
cal chronology that were intermediate
between the transition and tertiary for-
mations. During these ages of reptiles,
neither the carnivorous nor the lacus-
trine mammalia of the tertiary periods
had begun to appear ; but the most for-
midable occupants both of land and wa-
ter, were crocodiles, and lizards ; of
various forms, and often of gigantic sta-
ture, fitted to endure the turbulence, and
continual convulsions of the unquiet sur-
face of our infant world." Upon the
whole, it is in the oolitic period, between
the eras of the red sandstones and the
greensands, that the gigantic saurians
existed in greatest abundance about the
shores, in the rivers, and on the land, in
these now cold regions of the globe.
Some of the saurians were exclusively

marine ; others amphibious ; others were
terrestrial, ranging in marshes and jungles,
clothed with a tropical vegetation, or
basking on the margins of estuaries,
lakes, and rivers. Even the air was
tenanted by flying lizards, under the dra-
gon form of pterodactyles.— Professors
BucJcland and Phillips.

SAUROCE'PHALOUS. A fossil saurian, found
in the oolite, and by M. Agassiz ranked
among fishes. Its form was adapted for
swimming.

SAU'ROID. (from aavpa, a lizard, and
tlSoz, form, Gr.) The name given to a
group of fishes found in great abundance
in the carboniferous and secondary for-
mations. The sauroid fishes, says Prof.
Buckland, occupy a higher place in the
scale of organization, than the ordinary
forms of bony fishes. In the tertiary
strata the sauroids almost disappear, and
are replaced by less complex forms, and
present only two genera among existing
fishes.

SAU'SSURITE. A combination of crys-
tallized serpentine with jade or felspar.
It is thus named after Saussure, who first
described it. It is the jade de Saussure
of Brongniart. In its external characters
it differs but little from nephrite, but in
its composition it by no means resembles
it. It was first noticed by Saussure near
the lake of Geneva, scattered about in
rounded pieces and loose blocks. Its
colours are green, greenish grey, or white
with a slight tinge of green or blue. Its
specific gravity is about 3'35. Before
the blow-pipe it fuses. It consists of
silex 49-0, alumine 24'0, lime 10'5,
soda 5'5, magnesia 3'75, oxide of iron
6'5. By many mineralogists, saussurite
is included under nephrite.

SAXICA'VA. A genus of bivalves, belonging
to the family Lithophagi, or stone-eaters.

SAXICA'VOUS. Animals which make holes
in the rocks, either by boring them, by
means of some auger-like process they
possess ; or by dissolving the rock, by
some acid which it secretes.

SCA'BROUS. (from scabrosus, Lat. rough ;
scabreux, Fr.)

1 . In entomology, applied to the surface
of an insect when covered with small and
slight elevations.

2. Applied to shells, when rough, rugged,
harsh, or like a file.

3. In botany, applied to the stems that
are rough, from any little inequalities or
tubercles.

SCA'GLIA. (Ital.) A mode of chalk, of a
red colour. In an interesting paper, by
Prof. Sedgwick and R. J. Murchison,
Esq. published in the Philosophical Ma-
gazine for June 1829, on the relations of
the secondary and tertiary strata on the

S C A

[ 229 J

S C H

southern flanks of the Tyrolese Alps, the
tertiary strata are described as forming a
vast series of beds resting on scaglia or
chalk. The scaglia occurs in beds nearly
vertical ; the upper ones contain nodules
and layers of flints ; their colour is red,
and their structure fissile. The scaglia
contains in some parts ammonites and
belemnites. — Mr. Bakewell, Introd. to
Geology.

SCALA'RIA. A genus of marine turreted
univalves, with acute longitudinal raised
ribs. The aperture nearly circular ; the
margins uninterrupted, bordered, and re-
flected. Scalarise are found in sandy
mud at depths varying from seven to
thirteen fathoms. Lamarck has described
five species of this genus as found among
the fossils of Grignon and Femes.

SCALA'RIFORM. (from scalaris, a ladder,
and forma, form, Lat.) Mr. Robert
Brown has ascertained by examination of
a trunk of Cycadites mycrophyllus, from
Portland, the existence of scalariform
vessels without discs, in the mature
trunk.

SCA'LLOPED. Indented at the edges.

SCA'NDENT. (from scandens, climbing,
Lat.) A term applied to plants which
climb upon some support, attaching them-
selves by fibres or tendrils.

SCAPE, (from scapus, Lat.) In botany,
an herbaceous stalk springing from the
root, and bearing the flower and fruit,
but not the leaves. The hyacinth, cow-
slip, and dandelion, are examples.

SCA'PHITE. (from scapha, a boat.) So
named from its supposed resemblance to
a boat. The scaphite resembles an am-
monite partly unrolled. Scaphites are
found in the chalk and in the greensand.
They are believed to be altogether ex-
tinct ; but the Rev. W. Kirby most justly
remarks, " who shall say what species
lurk in those unapproachable recesses
never to be revealed to human eye, but
in a fossil state. The baculites, hamites,
scaphites, and numerous others, there
have space sufficient to live unknown to
fame, while they are reckoned by the
geologist as expunged from the list of
living animals."

SCA'POLITE. Pyramidal felspar. The sca-
polith of Werner ; scapolithe of Bro-
chant ; paranthine of Haiiy. A rare mi-
neral, occurring massive and in long
prismatic crystals. It consists of silica
43-83, alumina 35-43, lime 18-96. It is
of a grey, yellowish, greenish-white, or
silver-white colour. Specific gravity from
3'68 to 3-71. Before the blow-pipe it
intumesces, and fuses into a shining,
white enamel. It is found in beds of
magnetic ironstone and iron pyrites, at
Arendal, in Norway.

SCA'PULA. The shoulder-blade.

SCA'PULAR. Pertaining Jto the shoulder-
blade or scapula.

SCARF-SKIN. The cuticle or external co-
vering of the body ; called also the epider-
mis.

SCHAA'LSTEIN. Shell-stone. The schaal-
stone of Jameson ; pierre calcaire tes-
tacee of Brochant ; spath en table of
Haiiy. Called also tabular spar or table
spar. A substance of a grey or pearly-
white colour, usually occurring in masses,
composed of thin laminae, collected into
large prismatic concretions. It is very
rare, and has been found chiefly at Dog-
natska, in the Bannat.

SCHEE'LIUM. Another name for Tung-
sten.

SCHI'LLER SPAR, (from schillerm, Germ.
to vary colours, to play from one colour
to another.) The schiller spath of Mohs.
A genus of spars comprising four varie-
ties, namely, common schiller spar ;
bronzite, or hemiprismatic schiller spar ;
hypersthene, or prismatoidal schiller
spar ; and anthophyllite, or prismatic
schiller spar. The characters of the
genus are, the cleavage monotomous, per-
fect. Metallic pearly lustre. Hardness
=3-5 to 6-0. Specific gravity = 2-6 to
3.4.

SCHIST. (rrxiffroQ, Gr. schistus, "Lat.schiste,
Fr.) A term synonymous with slate. A
rock, of a fissile character, which may
easily be split.

.

SCHISTO'SE MI'CA. The name given by
Kirwan to mica slate.

SCHNEIDE'RIAN MEMBRANE. Thus named
from Schneider, who first described it.
The lining membrance of the nostrils.

SCHORL. A dark-coloured, opaque, variety
of tourmaline. It occurs crystallized ;
in prismatic and granular concretions,
massive and disseminated. The electric
powers of schorl constitute one of its
most striking characters. By friction it
becomes positively electric ; but by ex-
posure to heat, it acquires positive elec-
tricity at one end, and negative at the
other. Schorl is brittle ; it scratches
glass ; is harder than hornblende, but
less hard than quartz. Fracture vitreous
and conchoidal. Specific gravity from
3-05 to 3-36. It fuses easily before the-
blow-pipe, and is converted into a grey-
ish-white or brownish enamel, sometimes
nearly compact at others vesicular. Its
constituents are, silex 36-75, alumina
34-50, potash 6-0, magnesia 0'25, oxide
of iron 21'0. It occurs imbedded in
granite, gneiss, &c. in Scotland and in
Cornwall.

SCHO'RLITE, The Pycnite of Haiiy and

SCI

[ 230 ]

SEC

Brongniart ; the Schorlous beryll of Jame-
son. A mineral of a straw colour, occur-
ing at Altenburg, in Saxony, in a rock of
quartz and mica.

SCI'ENCE. (from scientia, knowledge, Lat.
science, Fr. sienza, It.) The knowledge
of many, orderly and methodically ar-
ranged and digested, so as to become
attainable by one. The knowledge of
reasons and their conclusions constitutes
abstract, that of causes and their effects,
and of the laws of nature ; natural science.

SCITAMI'NE^E. One of Linnseus's natural
orders of plants ; they are all natives of
warm climates : the ginger, plantain, &c.
are examples.

SCITAMI'NEOUS. Belonging to the order
Scitaininese. Scitamineous plants have
been found fossil in the strata of the Isle
of Sheppey.

SCLERO'TICA. ) (from <TK\rjpoG, hard, Gr.)

SCLERO'TIC. $ The outermost coat, tunic,
or membrane of the eye. It is exceed-
ingly dense and firm, and does not pass
over more than about four-fifths of the
ball of the eye, its place in front being
supplied by a transparent membrane, the
cornea, to permit the passage of light.

SCO'PIFORM. (from scopa, a besom, and
forma, form, Lat.) Of the form of a
besom or broom.

SCORBI'CULATE. In conchology, pitted ;
having the surface covered with hollows.

SCORBI'CULUS. A depression or cavity.

SCO'RIA. (ffKwpia, Gr. scoria, Lat.) The
dross or scum of metals ; the cinders of
volcanic eruptions (then used plurally,
scoriae) ; the recrementitious matter of
metals in a state of fusion.

SCORIA'CEOUS. Resembling scoria ; con-
taining scoria.

SCO'RIFIED. Reduced to scoria or dross.

SCO'RIFORM. Having the form, shape, or
external appearance of scoria.

SCO'RIOUS. Drossy ; cindery ; excremen-
titious.

SCORPION. (<TKop7r/o£, Gr. scorpius, Lat.
scorpion, Fr. scorpio, It. scorpion, Germ.)
A genus of arachnidans, belonging to the
family Pedipalpi, order Pulmonariae. The
scorpion is remarkable, not only for the
powerful organs by the aid of which it
is able to seize its prey, but also for its
jointed tail, terminating in a deadly sting.
The palpi are very large, with a forceps
at the extremity resembling a hand ; the
tail is composed of six joints, the last
joint terminating in an arcuated and ex-
ceedingly acute point or sting, which
allows the exit of a poisonous fluid con-
tained in an internal reservoir. The
scorpion is provided, on each side of the
thorax, with four pulmonary cavities, into
each of which air is admitted by a sepa-
rate external opening. The eyes are

compound, accompanied by stemmata.
A fossil scorpion has been discovered by
Count Sternberg in the ancient coal for-
mation at Chorale, near Radnitz.

SCROBI'CULATED. (scrobiculus, fromttcrobs,
a furrow, Lat. ) Furrowed ; having small
ridges and furrows.

SCRU'BSTONE. A provincial term for a
species of calciferous sandstone.

SCU'TUM. (scutum, Lat. a shield or buck-
ler.) A species of Echinite. The name
given by Klein to the third section of the
class of Catocysti ; the scutum of Klein
is the Echinanthus of Leske.

SE'CONDARY. (from secundus, Lat. secon-
daire, Fr.) Succeeding to the first.

SE'CONDARY FORMA'TIONS.^ Bysecondary

SE'CONDARY STRATA. }> are meant

SE'CONDARY ROCKS. ) those stra-

tified rocks older than the tertiary, which
contain distinct organic remains, and
which sometimes pass into the strata
commonly called primary. The principal
groups of the secondary formations, be-
ginning with the uppermost and descend-
ing, are as follows: — 1. The cretaceous
group, beginning with the Maestricht
beds, and terminating in the lower green
sand. 2. The wealden group, commenc-
ing with the weald clay, and closing with
the Purbeck beds ; this group is a fresh-
water deposit. 3. The oolite, or Jura
limestone group, beginning with the Port-
land beds and ending with the inferior
oolite. 3. The lias group. 4. The new
red sandstone group, commencing with
the Keaper and ending in the red con-
glomerate. 5. The carboniferous group,
comprising the coal measures, the moun-
tain limestone, and the old red sandstone.
6. The graywacke group.

Some authors, however, subdivide the
secondary formations as thus described,
separating the transition rocks and coal
measures, and making the secondary rocks
terminate with those formations that
cover the transition rocks and the coal
measures. The secondary strata cover a
large portion of the habitable globe, and
are the immediate subsoil of the most
fertile districts in Europe. The secondary
strata are composed of extensive beds of
sand and sandstone, mixed occasionally
with pebbles, and alternating with de-
posits of clay, and marl, and limestone.
Six substances are interstratified in this
system : arenaceous, argillaceous, and
calcareous rocks form the principal
masses, and are associated with beds of
chert, iron-stone, and coal. In colour,
these rocks are white, brown, grey, green,
yellow, or red. It is no small proof of
design, says Prof. Buckland, in the ar-
rangement of the materials that compose
the surface of our globe, that whereas

SEC

[ 231 ]

SEC

the primary and granitic rocks are least
calculated to afford a fertile soil, they are
for the most part made to constitute the
mountain districts of the world, which
from their elevation and irregularities,
would otherwise be but ill adapted for
human habitation ; while the lower and
more temperate regions are usually com-
posed of derivative, or secondary strata,
in which the compound nature of their
ingredients qualifies them to be of the
greatest utility to mankind, by their sub-
serviency to the purposes of luxuriant
vegetation.

It is in the strata belonging to the se-
condary formations that the bones of
enormous reptiles are first discovered ;
but throughout the whole series no bones
of mammiferous land quadrupeds have
been discovered, with the single exception
of marsupial remains which occur in the
oolite, at Stonesfield, near Oxford. The
peculiar feature in the population of the
whole series of secondary strata, was the
prevalence of numerous and gigantic
forms of Saurian reptiles. The earth
was, probably, at that time too much
covered with water, and those portions of
the land which had emerged above the
surface, were too frequently agitated by
earthquakes, inundations, and atmo-
spheric irregularities, to be extensively
occupied by any higher orders of qua-
drupeds than reptiles.

The order of succession of the upper
strata of the secondary series may be more
accurately ascertained in England than in
any other country already examined.

" From the examination," says Dr.
Mantell, " of the organic remains of the
secondary formations, we arrive at the
following results ; that the seas, lakes,
and rivers, during the geological epoch
termed secondary, were peopled by fishes,
mollusca, Crustacea, radiaria, polyparia,
and other zoophites ; all of extinct spe-
cies, and presenting as a whole, a greater
discrepancy with existing forms, than
those of the tertiary ; the most remark-
able feature being the absence of cetacea,
and the presence of several genera of ex-
tinct marine reptiles. On the land we
find no analogy to the tertiary or present
seras ; throughout the vast accumulation
of the spoils of the ancient islands and
continents, although the remains of fresh-
water turtles, insects, and terrestrial
plants abound, no indications are afforded
of the existence of mammalia, one in-
stance only excepted, that of the didel-
phis, discovered at Stonesfield. In vain
we search for the bones of man, or the
remains of works of art — for the skeletons
of the mastodon or the elk — of the palse-
otheria, or of other mammalia that were

their ootemporaries : the osseous remains
of reptiles, terrestrial or fluviatile, alone
appear."

With the cretaceous system ends the
long series of deposits which are, by ge-
neral consent, ranked as strata of the se-
condary periods of geology. Prof. Phil-
lips says, " turning to the organic remains
of the several secondary systems, it is ap-
parent that, within the period of time
which elapsed between the deposition of
the primary and tertiary strata, two very
distinct assemblages of terrestrial plants
had flourished, and become extinct. The
ancient and abundant flora of the carbo-
niferous era, with its lepidodendra, si-
gillariae, and calamites, had been replaced
by new races of zamiae and cycadse,
which, in their turn, vanished from the
northern zones of the globe before the
cretaceous system. The marine zoo-
phyta were changed. One total change
had come over the Crustacea, — not a sin-
gle trilobite being known in the strata
more recent than coal : the brachopodous
conchifera, the gasteropodous and cepha-
lopous mollusca were equally altered.
Two large assemblages of fishes had va-
nished before the deposition of the chalk ;
and both on the land, and in the sea,
gigantic reptile forms had come into
being, reproduced themselves to a mar-
vellous extent, and then all perished with
the close of the secondary period."

Long as the above extract has been, it
is scarcely possible to refrain from quoting
the following splendid passage from the
same eloquent author :

" How, then, can they, by whom the
: magnificent truths of elapsed time and
successive creations have been put in
clear and strong evidence, — how can they
be expected to yield to false notions of
philosophy, and narrow views of religion,
the secure conviction that, in the forma-
tion of the crust of the earth, Almighty
Wisdom was glorified, the permitted laws
of nature were in beneficent operation,
and thousands of beautiful and active
things enjoyed their appointed life, long
before man was formed of the dust of the
ancient earth, and endowed with a divine
power of comprehending the wonders of
its construction? It is something worse
than philosophical prejudice, to close the
eyes of reason on the evidence which the
earth offers to the eyes of sense ; it is a
dangerous theological error to put in un-
equal conflict a few ill-understood words
of the Pentateuch, and the thousands of
facts which the finger of God has plainly
written in the book of nature ; folly, past
all excuse, to suppose that the moral evi-
dence of an eternity of the future shall be
weakened by admitting the physical evi-

SEC

[232 ]

S E 11

dence for an immensity of the past." —
Phillips. Buckland. Mantell. Bake-
well.

SE'CTILE. (from sectilis, that may be easily
cut, Lat.) A term in mineralogy, applied
to minerals, when, being cut with a knife,
the separated particles do not fly away,
but remain on the mass.

SE'CULAR REFRJGERA'TION. The periodi-
cal cooling and consolidation of the globe
from a supposed original state of fluidity
from heat. — LyelVs Principles of Geology.

SECU'RIFORM. (from securis, a hatchet,
Lat. and form.} Hatchet-shaped : a term
applied to shells and to leaves.

SE'DIMENT. (sedimentum, Lat. sediment,
Fr.) That which subsides, or settles at
the bottom.

SEDIMENTARY ROCKS. Rocks which have
been deposited by water.

SEED VE'SSEL. In botany, the pericarp.

SE'J.ENITE. (o-tXj/rtTT/g, Gr. selenite, Fr.)
Sulphate of lime, or crystallized gypsum.
A transparent and highly crystallized va-
riety of gypsum. The crystals of selenite
are frequently united, or collected into
groups of various forms. Selenite con-
sists of lime 33-0, sulphuric acid 44-8,
water 21 '0. It is found abundantly in
the gypsum and salt formations of Eng-
land, France, Germany, &c., &c. The
primitive form of its crystals is a dodeca-
hedron, which may be conceived as two
four- sided pyramids, applied base to base,
and which, instead of terminating in
pointed summits, are truncated near the
bases ; so that the sides of the pyramids
are trapeziums, each terminating in a
rhomb. It causes double refraction.
Before the blow-pipe it melts into a white
enamel. It does not effervesce with mu-
riatic acid, unless it be impure.

SELE'NIUM. (from GtXrjvrj, the moon, Gr.)
One of the fifty-five simple or elementary
bodies, and a non-conductor of electricity.
It was extracted by Berzelius from the
pyrites of Fahlun. According to Dr.
Prout, it appears to constitute the con-
necting link between sulphur and the
metals.

SELF-LU'M INDUS BO'DIES. All visible bo-
dies may be divided into self-luminous
and non-luminous. Self-luminous bodies,
such as the stars, flames of all kinds, and
bodies which shine by being heated or
rubbed, are those which possess in them-
selves the property of discharging light. —
Dr. Brewster.

SE'MI. (semi, Lat.) In composition with
other words, implies half; as semi-sphe-
rical ; semi-transparent, &c. , &c.

SE'MINAL LEAVES. The first leaves of a
plant.

SB'MI-O'PAL. A variety of opal. The
Halbopal of Werner ; La demi-opale of

Brochant ; Quartz resinite commune of
Haiiy. The colours of semi-opal are
white, grey, green, red, brown, and blue.
Fracture imperfectly conchoidal. Specific
gravity 2'0 to 2P5. It is infusible before
the blow-pipe. It consists of silica 85 -0,
alumina 3*0, oxide of iron T74, carbon
5-0, amrnoniacal water 8-0, with a fraction
of bituminous oil : or, according to an-
other analysis, of silica 82'7, water lO'O,
oxide of iron 3'0, alumina 3'5.

SENSO'RIUM. (sensorium, Lat. sensorium,
Fr.) That particular part of the brain
in which sensation produces percep-
tion.

SE'PAL. This word has no derivation, but
was invented by botanists to distinguish
the several parts of the calyx from those
of the corolla.

SE'PIA.

1. The name given by Linnaeus to the
cuttle-fish. A genus of cephalopods com-
prising several subgenera, the two most
interesting of which are the Argonauta of
Linnaeus and the Sepia of Lamarck. For
a description of sepia the reader is referred
to the article Cuttle-fish.

2. The ink of the cuttle-fish. This has
been found in a beautiful state of pre-
servation in fossil ink -bags of sepise in the
lias at Lyme Regis. The common sepia,
used in drawing, is from the ink-bag of an
oriental species of cuttle-fish.

SE'PIOSTAIRE. The name given, by Blain-
ville, to the internal bone of the sepia or
cuttle-fish. The absence of a siphuncle
renders the sepiostaire an organ of more
simple structure, and of lower office, than
the more compound shell of the belem-
nite.

SEPTA'RIA. (from septa, inclosures, Lat )
Spheroidal concretions, varying from a
few inches to a foot in diameter, and
divided into cells or chambers of irregular
form ; sometimes they are nodules of
clay, having the chambers filled with
spar ; they are usually found in argilla-
ceous strata. Masses of argillaceous
limestone, traversed interiorly by cracks
passing in different directions, and con-
taining calcareous spar.

SE'PTUM. (septum, Lat.) A partition.
The plates dividing the chambers of mul-
tilocular shells are termed septa ; a par-
tition separating certain portions of the
brain is called the septum ; and the car-
tilaginous partition of the nostrils is called
the septum of the nose.

SE'ROLIS. A genus of crustaceans, afford-
ing the nearest approach among living
animals to the external form of the trilo-
bite. This genus was first established by
Dr. Leach. The greatest difference be-
tween the serolis and trilobite consists in
the former possessing a fully developed

S E R

[ 233 ]

S II A

series of crustaceous legs and antennse,
whilst the trilobite does not display any
traces of either of these organs. Captain
King has lately collected many specimens
of scrolls on the east coast of Patagonia,
and in the Straits of Magelhaens he saw
the beach covered with them dead. — Prof.
Buckland.

SE'RPENTINE. A mineral substance de-
riving its name from its spots and varie-
gated colours, supposed to resemble the
skin of the serpent ; its colours and their
peculiar arrangement, are in great measure,
characteristic. It sometimes forms whole
rocks. It differs from hornblende in con-
taining a larger"" portion of magnesia and
a smaller quantity of iron. There is,
however, an intimate connection between
serpentine and hornblende, as the latter
is observed, in some situations, to be
changed into serpentine by contact with
limestone. The grain of serpentine is

• fine, and its texture compact : it may be
cut or scraped with a knife, but it does
not yield to the finger-nail. When broken,
it possesses some lustre and a slightly
unctuous feel. Its surface, which is
sometimes glossy, is soft to the touch.
Specific gravity from 2-5 to 2*7. Before
the blow-pipe it hardens but does not
fuse. Its constituents are magnesia 34-5,
silex 28-0, alumine 23'0, lime 0-5, water
10-5, oxide of iron 4-5 = 101. There are
two varieties, the precious and the com-
mon serpentine. When serpentine is
found intermixed with patches of crystal-
line white marble, it constitutes a stone
denominated verde-antique. Some crys-
tallized varieties have obtained the name
of diallage, or schillar spar. Many of the
Alpine districts of Europe contain beds
and rocks of serpentine ; but Patrin states
that there is no serpentine in Northern
Asia, neither was any seen in the Andes
of South America, by Humboldt. In the
United States it is met with abundantly.
Brongniart has given to serpentine the
name of Ophiolite. In the Apennines, the
serpentine rests upon saussurite, the
saussurite upon jasper, and the jasper
upon limestone. Its degree of hardness,
and the peculiar arrangement of its co-
lours form the distinctive characters of
serpentine. — BaJcewell. Cleaveland.

SE'RPULA. A genus of the order Tubicola,
class Annulata. The animal a terebella ;
shell univalve, tubular, generally adher-
ing to other substances ; often separated
internally by septa at uncertain dis-
tances. Serpulse have only been found
to inhabit the ocean. They are generally
littoral, attached to rocks, stones, shells,
crustaceans, corals, and other marine bo-
dies ; sometimes several species are found
on one stone or shell. In Turton's Linne

forty-eight species of serpula are de-
scribed, twenty-seven of which inhabit
the seas of our coasts. Serpulse may
commonly be seen upon the shells of
lobsters, crabs, oysters, &c., to which
they adhere by the lower surface, looking
like small worms creeping upon them.
Wherever the sea is or has been, they
abound either in a recent or fossil
state.

SE'RRATE. } (serratus, Lat. from serro, to
SE'RRATED. ji saw.) Jagged; notched.

1. In botany, applied to leaves, the mar-
gins of which resemble a saw, the teeth
pointing towards the extremity of the
leaf.

2. In entomology, applied to the bodies
of insects, the margins having jagged in-
cisions, like the teeth of a saw.

SE'RRULATE. } (from serrula, a little saw,

SE'RRULATED. $ Lat.) When the edges
of leaves or margins of shells are very
finely jagged or notched, they are said
to be serrulated, and not serrated.

SERTULA'RIA. A genus of ai'borescent
corals belonging to the family Tubu-
larii.

SE'RUM. (serum, Lat , serum, Fr.) The
thin, watery, transparent part of the
blood.

SE'SAMOID. (from (reader], an Indian
grain, and dSog, resemblance, Gr. sesa-
mo'ide, Fr.) The name of some exceed-
ingly small bones found at the root of the
thumb or great-toe.

Sfi'saui. (A contraction of semisque, Lat.
signifying and a half. ) A prefix to many
words, signifying the quantity and a half
more.

SE'SSILE. (from sessilis, seated, Lat.) In
botany, applied to flowers when placed
directly on the branch or stem ; also to
leaves when they grow directly from the
stem, branch or root, without any foot-
stalk : any part of a plant which com-
monly is borne on a stalk, is said to be
sessile when it has none.

SETA'CEOUS. (from seta, a bristle, Lat.)
Bristle-shaped ; bristly.

SHALE, (schale, Germ.) Slate clay ; in-
durated slaty clay.

SHA'NKLIN SAND. Called also lower
green sand. A marine deposit of sili-
ceous sands and sandstone of various
shades of green, red, brown, yellow, feru-
ginous, grey, and white, with subordi-
nate beds of cherts and siliceous lime-
stones, constitute the formation called
the Shanklin sand, or lower green
sand. It is the lowest member of the
cretaceous group, intervening between the
gault above and the weald clay below.
The beds consist of an aggregation of
sand, with comminuted shells and frag-
ments of corals, impregnated with iron,

H H

S H A

[ 234 ]

SHE

and containing the remains of myriads of |
shells, polyparia, &c.

SHARK. (from icapxapiaQ, Gr.) The
squalus of Linnaeus. A genus of fishes
belonging to the family Selachii, order
Chondropterygii Branchiis Fixis. The
shark is a phosphoric fish. That tribe of
sharks, called by the French Regains,
which is thought to be synonymous with
the carcharias of the Greeks, and one of
which was probably the monster that
swallowed Jonah, are stated to exceed
thirty feet in length. The genus of sharks
may be considered as one of the most
universally diffused, and most voracious
of modern fishes. Several rows of teeth
are lodged in each jaw, but one only of
these rows projects, and is in use at the
same time ; the rest lying flat, but ready
to rise in order to replace those that have
been broken off, or worn down. The
shark is oviparous or ovo-viviparous, ac-
cording to circumstances. The vertebral
column is prolonged into the upper lobe
of the tail, and the tail is of great service
in enabling the shark to turn its body
so as to bring the mouth, which is placed
downwards beneath the head, into con-
tact with its prey. Sharks appear to
have existed throughout every period of
geological history. M. Agassiz has se-
parated the sharks into three sub-fami-
lies, each containing forms peculiar to
certain geological epochs, and which
change simultaneously with the other great
changes in fossil remains. The first of
these sub-families, or the Cestracionts,
commences with the transition strata, ap-
pearing in every subsequent formation
till the commencement of the tertiary.
Of the Cestracionts, one representative
only now remains, namely, the Cestra-
cion Philippi, or Port Jackson shark.
The Cestracionts possessed large poly-
gonal, obtuse, enamelled teeth, covering
the interior of the mouth with a kind of
tesselated pavement. The second sub-
family, or Hybodonts, commenced with
the muschel-kalk, is found throughout
the whole of the oolitic deposits, and dis-
appears at the commencement of the
cretaceous group. The teeth of the Hy-
bodonts were intermediate between the
blunt polygonal teeth of the Cestracionts
and the sharp-edged cutting teeth of the
Squaloids. The third sub-family, termed
Squaloids, appeared at the commence-
ment of the chalk deposits, and conti-
nues downwards to the present period.
In the Squaloids, the teeth are smooth
on the outer side, and plicated on the
inner ; sometimes the edge is serrated.

SHELL, (schale, Germ.) The hard cover-
ing of anything ; the covering of a testa-
ceous or crustaceous animal. The crus-

taceous coverings of animals, as of echini,
crabs, lobsters, cray-fish, &c., are com-
posed of the game ingredients as bones ;
but the proportion of carbonate of lime
far exceeds that of the phosphate in
shells. The following are the propor-
tions contained in the" shell of the lob-
ster : — Carbonate of lime 60'0, phosphate
of lime 14-0, cartilage 26-0. The shells
of marine animals may be divided into
two classes, namely, porcellaneous and
mother-of-pearl, or membranous, shells ;
the porcellaneous shells have the appear-
ance of porcelain ; their surface is ena-
melled, and their texture often slightly
fibrous : the mother-of-pearl, or mem-
branous shells, are covered with a strong
epidermis, below which lies the shelly
matter in layers. Porcellaneous shells
are composed of carbonate of lime, ce-
mented together by a small portion of
gelatine ; most of the univalve shells, and
many of the convoluted beautiful shells
of the tropics, belong to this division.
Mother-of-pearl, or membranous shells,
are composed of alternate layers of car-
bonate of lime and a thin membranaceous
substance, which resembles coagulated
albumen in its properties. This mem-
brane still retains the figure of the shell
after all the carbonate of lime has been
separated by acids. Many membranous,
or mother-of-pearl shells, exhibit, on se-
veral parts of their internal surface, a
glistening, silvery, or iridescent appear-
ance ; to this structure the term nacreous
has been applied.

This appearance is caused by the pecu-
liar thinness, transparency, and regularity
of arrangement of the outer layers of the
membrane, which enter into the formation
of that part of the surface of the shell. The
surface, which has thus acquired a pearly
lustre, was formerly believed to be a pe-
culiar substance, and was termed mother-
of-pearl, from a supposition that of it
pearls were formed. Assuredly, pearls
are composed of the same materials, and
have the same laminated structure as the
membranous shells ; but Sir D. Brewster
has satisfactorily demonstrated that the
iridescent colours exhibited by these sur-
faces are wholly the effect of the parallel
grooves, consequent upon the regularity of
arrangement in the successive deposites of
shell.

The process employed by nature for the
formation and enlargement of the shells
of the mollusca was very imperfectly un-
derstood prior to the investigations of
Reaumur. His experimental enquiries
have established these two general facts ;
first, that the growth of a shell is simply
the result of successive additions made to
its surface, and, secondly, that the ma-

SHE

[235 ]

SHE

terials constituting each successive layer
are supplied by the organized fleshy sub-
stance called the mantle, and not by any
vessels belonging to the shell itself. The
connexion between the animal and the
shell may be regarded as mechanical
rather than vital ; for whatever portion of
vitality it might have possessed when first
deposited, all trace of that property soon
disappears. It is found that shells may
be impregnated with poisonous metallic
salts, and yet the animal suffer no in-
convenience.

It is upon the exclusive shape of the
shell, and not the animal inhabiting it,
that the arrangement of conchology is
formed. Most shells are very different in
their young and adult state, both as
regards their form and colour. The Lin-
nsean arrangement of shells consists of
three orders, namely, multivalve, bivalve,
and univalve.

Shells are found fossil in the most
ancient strata of the transition period
that contain any traces of organic life,
and many of these agree so closely with
the existing species, that we infer their
functions to have been the same, and that
they were inhabited by animals of form
and habits similar to those which fabri-
cate the living shells most nearly resem-
bling them. The most prolific source of
organic remains has been the accumula-
tion of the shelly coverings of animals
which occupied the bottom of the sea
during a long series of consecutive gene-
rations. A large proportion of the en-
tire substance of many strata is com-
posed of myriads of these shells, reduced
to a comminuted state by the long-con-
tinued movements of water. Minute
examination discloses occasionally pro-
digious accumulations of microscopic
shells, no less surprising by their abund-
ance, than their extreme minuteness ; the
mode in which they are sometimes crowd-
ed together, may be estimated from the
fact, that Soldani collected from less than
an ounce and a half of stone, found in the
hills of Tuscany, ten thousand four hun-
dred and fifty-four microscopic cham-
bered shells. Of several species of these
shells, four or five hundred weigh but a
single grain ; of one species, a thousand
individuals would scarcely weigh one
grain ; and great numbers of them could
pass through a paper in which holes have
been pricked with a needle of the smallest
size.

The phenomenon of shells found in
rocks, at a great height above the sea,
has been attributed to several causes. By
some, it has been ascribed to a plastic
virtue in the soil ; by some, to fermen-
tation ; by some, to the influence of the

celestial bodies ; by some, to the casual
passage of pilgrims with their scallops ;
by some, to birds feeding on shell-fish ;
but by all modern geologists, with one
consent, to the life and death of real mol-
lusca at the bottom of the sea, and a sub-
sequent alteration of the relative level of
the land and sea.

The specific gravities of many shells have
been lately ascertained by Mr. De La
Beche. Those of land-shells ranged from
2-82 to 2-87 ; of fresh-water shells, from
279 to 2-82 ; those of marine shells, from
2-43 to 2-85. He adds, while the spe-
cific gravities of the land shells enu-
merated is generally greatest, the den-
sities of {he, floating marine shells is much
the smallest. The greatest observed den-
sity was that of a Jtelix, the smallest that
of an argonaut. The specific gravity of
all the land shells examined was greater
than that of Carrara marble ; in general
more approaching that of Arragonite.
The fresh- water and marine shells, with
the exception of the argonaut, nautilus,
ianthina, lithodomus, heliotis, and great
radiated crystalline teredo, exceeded Car-
rara marble in density. This marble and
the haliotis are of equal specific gravities.
The testacea, says Mr. Lyell, are by
far the most important class of organic
beings which have left their spoils in the
subaqueous deposites. There is scarcely
any great series of strata that does not
contain some marine or fresh-water
shells, and these fossils are often found
so entire, especially in the tertiary forma-
tions, that when disengaged from the
gangue, or matrix, they have all the ap-
pearance of having been just procured
from the sea. Their colour, indeed, is
usually gone, but the parts whereon spe-
cific characters are founded, remain un-
impaired ; and though the animals them-
selves have disappeared, their form and
habits can generally be inferred from the
shell which covered them.

From the proportions which fossil shells
bear to marine shells of existing species,
M. Deshayes and Mr. Lyell have proposed
a fourfold division of the marine forma-
tions of the tertiary series. The total
number of known fossil shells, at the time
Mr. Lyell wrote his fourth edition of
Principles of Geology, in the tertiary
series was 3,036. Of these 1,238 are
found in the eocene; 1,021 in the mio-
cene ; and 777 in the older, and newer
pliocene divisions. The numerical pro-
portions of recent to extinct species may
be thus expressed. In the newer pliocene
period 90 to 95 per cent, are of recent
species ; in the older pliocene, 35 to 50 ;
in the miocene period 1 8 ; in the eocene
period 3£ per cent, only are of recent

SHE

[236 ]

S I L

species. — Buckland. DeLaBeche. Lyell.
Thomsom. Brown. Brewster.

SHELL MARL. A deposite of calcareous
earth and clay containing shells.

SHI'NGLE. (schindel, Germ.) The loose,
water-worn, pebbles on the sea-shore.

SHIST. See Schist.

SHO'OTING STARS. Shooting stars and me-
teors differ from aerolites in several re-
spects. They burst from the clear azure
sky, and darting along the heavens are
extinguished without leaving any resi-
duum, except a vapour-like smoke, and
generally without noise. Their parallax
shows them to be very high in the atmo-
sphere, sometimes even beyond its sup-
posed limit, and the direction of their
motion is, for the most part diametrically
opposite to the motion of the earth in its
planet. The astonishing multitudes of
shooting stars that have appeared within
these few years at stated periods, over the
American continent, and other parts of
the globe, warrant the conclusion that
there is either a nebula, or that there are
myriads of bodies revolving in groups
around the sun, which only become visi-
ble when inflamed by entering our at-
mosphere.

SHORL. See Schorl.

SHO'RLITE. See Schorlite.

SIBE'RITE. Another name for Rubellite,
or red tourmaline.

SI'DERO-CA'LCITE. The name given by
Kirwan to brown spar ; the braun spath
of Werner.

SIDE'RUM. The name given by Bergman,
who took it for a new metal, to phosphu-
ret of iron.

SI'ENITE. ) (from Siena, a city of Egypt,

SY'ENITE. $ where this rock occurs in
abundance, and whence the Romans ob-
tained it for architectural and other pur-
poses.) Werner gave the name of
sienite to aggregates composed of felspar,
hornblende, and quartz ; or of felspar,
hornblende, quartz, and mica. Sienite is
the roche feldspathique of Haiiy. It often
bears the general aspect of a granite.
Felspar and hornblende may be deemed
its two constant and essential ingredients,
but it frequently contains quartz and
mica, and occasionally talc and epidote.
It is the presence of hornblende, as a
constituent part, which distinguishes this
rock from certain granites, that acci-
dentally contain hornblende. The struc-
ture of sienite is commonly granular ;
but the grains are sometimes coarse, and
sometimes very fine. In some instances
the structure of sienite is slaty. Green-
stone and sienite are essentially composed
of the same ingredients, namely, felspar
and hornblende ; from granitic green-
stone there is a transition to sienite, and

from sienite to true granite. The colour
of sienite is usually grey, but this is
affected by the ingredients entering into
its composition. — Cleaveland.

SIENI'TIC. Containing sienite ; resembling
sienite ; possessing some of the characters
of sienite. Sienitic granite contains
hornblende. Sienitic porphyry is fine-
grained sienite containing large crystals
of felspar.

SIGARE'TUS. A genus of marine univalve
shells belonging to the family Macrosto-
mata. It is a depressed, oval, nearly
auriform shell, with a short spiral colu-
mella : the aperture entire, wide, spread
out towards the summit of the right lip,
and longer than wide. It is a Tuscan
fossil, and exceedingly rare. The living
sigaretus is found in sand at depths vary-
ing from five to fifteen fathoms.

SIGILLA'RIA. (from sigillum, Lat.) The
name given by M. Ad. Brongniart, to-
certain large, and, in modern vegetation,
unknown forms of plants discovered in
the coal formation : the name has been
assigned from the peculiar impressions
on the stems. The stems are of various
sizes from a few inches to upwards of
three feet in circumference, and of great
length. They are scattered throughout
the sandstones and shales that accompany
the coal, and may occasionally be seen in
the coal itself. These stems are inclined
in all directions, and some of them are
nearly vertical : they are supposed to
have been hollow, like the reed, and with
but little substance. M. Ad. Brongniart
has enumerated nearly fifty species.

SI'LEX. (silex, Lat. flint.) An oxide of
silicon, constituting the greater part of
all the rocks of which the crust of the
earth is composed.

SI'LICA. The same as silex. One hundred
parts of silica contain 48-4 of silicium, and
51*6 of oxygen. It is white ; its specific
gravity is 2*6 ; it is fusible.

SILICICA'LCE, The quartz agathe calcifere
of Haiiy : silex silicicalce of Brongniart.
A substance occurring in amorphous
masses, in thin beds, under strata of
compact limestone, in Provence. It is of
a grey or brown colour, sometimes nearly
black. It effervesces with nitric acid ;
and before the blow-pipe fuses into a
white scoria. It is a mixture of flint and
carbonate of lime.

SILI'CEOUS. Containing silex ; flinty ;
having the appearance or properties of
flint. Thus we have siliceous limestone ;
siliceous slate ; siliceous nodules, &c.

SILI'CIFY. To convert into flint ; to petrify.

SILICIFICA'TION. Called also petrifaction.
The conversion of any substance into
stone by the infiltration of siliceous
matter.

S I L

[ 237 ]

S I M

SILI'CIUM. iThe hitherto undecomposed
SILICON. ) base of silica or silex. Of
the metallic bases of the alkalies and
earths, silicium is the most abundant on
the surface of our planet, silica entering
so largely into the composition of both
chemical and mechanical rocks. Accord-
ing to a table of Mr. De La Beche's,
gneiss contains 71 per cent, of silica ;
mica slate 73 per cent. : talcose slate 78 ;
granite 74 ; basalt 59, &c. &c. In pure
quartz rock, silica would be the only in-
gredient. Flint, quartz or rock-crystal,
&c., are hydrates of silicon, or silex with
some water of crystallization.
SILI'CULA. (Lat. a little husk or pod.)

In botany, a species of fruit.
SILI'CTJLOTJS. Having small pods or husks.
SI'LIGIUA. (Lat.) A pod ; a long seed
vessel of two valves, separated by a linear
receptacle, on whose edges the seeds are
ranged alternately.

SILIQ,UA'RIA. A genus of marine univalves,
found both fossil and recent. It is a
tubular shell, spiral at its beginning, con-
tinued in an irregular form ; divided
laterally, through its whole length, by a
narrow slit, and formed into chambers by
entire septa. Recent siliquarise have been
found in sponges ; they may be distin-
guished from serpulse by the longitudinal
slit. Cuvier places the genus in the order
Tubulibranchiata. Fossil siliquarise occur
at Grignon.

Si'LiauosE. } Bearing pods. A term ap-
SI'LICIUOUS. S plied to plants having that
sort of pericarp denominated a pod or
legume.

SI'LLIMANITE. A dark grey or brown mi-
neral, composed of silica 42-6, alumina
54'1, oxide of iron 1/9, water 0'5, dis-
covered at Saybrook, in Connecticut, and
named after Prof. Silliman.
SILT. The deposit of running water ; mud.
SI'LVAN. The name given by Werner to

the metal tellurium.

SI'LVER. (silber, Ger.) One of the fifty -five
simple or elementary bodies, and included
in the subdivision termed metals. When
pure, it is nearly white. It is superior to
gold in lustre, and inferior to it in malle-
ability ; it is however so malleable that
it may be beaten into leaves not ex-
ceeding 100,000th of an inch in thick-
ness. It is very ductile, surpassing gold
in tenacity, but inferior to iron, copper,
and platinum. It may be drawn out into
wire of greater fineness than human hair.
It is harder than gold, but softer than
copper, and may be easily cut by a knife.
Its specific gravity is 10-47. Silver fuses
at a temperature of about 1,000 degrees
Fahr. It is not oxidated by exposure to
the atmosphere, but becomes tarnished
by sulphureous vapours. It is tasteless,

and free from smell. It is soluble in
nitric acid. Silver for domestic purposes,
as well as that made into coin, is rendered
harder by an alloy of copper. The
standard silver of this country consists of
eleven ounces two pennyweights of pure
silver and eighteen pennyweights of cop-
per. Silver has been known from the
earliest ages. It is found native and in
ores of several kinds. The ores of silver
occur in metallic veins, traversing primary
rocks. There are many ores which yield
silver that are not, strictly speaking, ores
of silver. Although the mines of Europe
yield considerable quantities of silver,
yet it is to Mexico and Peru that we are
indebted for the main supplies. The
mines of Potosi have paid a royal duty
on silver valued at 234,700,000/. ster-
ling.

SILU'RIAN. The name given by Mr. Mur-
chison to an upper subdivision of the
sedimentary strata found below the old
red sandstone. Mr. Murchison assigned
this name to these strata from their being
best developed in that portion of England
and Wales formerly included in the an-
cient British kingdom of the Silures.
The Silurian rocks are divided into up-
per and lower : the upper Silurian rocks
comprise the Ludlow formation and the
Wenlock formation ; the Ludlow forma-
tion consisting of the upper Ludlow rock,
the Aymestry limestone, and the lower
Ludlow rock ; the Wenlock formation
consisting of the Wenlock limestone and
the Wenlock shale : the lower Silurian
rocks are subdivided into the Caradoc
formation and the Llandeilo formation ;
the Caradoc formation consisting of flags,
sandstones, grits, and limestones ; the
Llandeilo formation, of calcareous, dark-
coloured flags, with sandstone and schist.
The whole of the Silurian rocks attain a
thickness in some parts of seven thou-
sand five hundred feet. They are all
marine deposites. Upwards of five hun-
dred and fifty species of organic beings
have been discovered in the Silurian
rocks. The name Greywacke has been
also given to this group.

SI'MIA. (simia, an ape, Lat.) A genus of
Quadrumana. The ape. The lower jaw
of an ape has been discovered in the
miocene strata, in the department of
Gers, in France.

SI'MPLE. (simplex, Lat. simple, Fr. sem-
plice, It.)

1. In botany, applied to roots, when
undivided ; to a leaf, when consisting
of only one leaf, and not divided into
leaflets, &c. &c.

2. In mineralogy, a term applied to ele-
mentary, or undecomposed substances :
these are fifty-five in number, and are

S I N

[ 238 ]

SOD

described under the article " elementary
substances." The mineralogist and the
geologist consider those minerals as simple
and homogeneous, which present no dif-
ference of qualities to our senses through-
out the mass, although the chemist may
discover that such minerals are composed
of two or more elementary substances.
The difference between a simple mineral
and a simple substance may be illus-
trated by the case of calcareous spar, or
crystallized carbonate of lime. The ulti-
mate elements, calcium, oxygen, and car-
bon, are simple substances ,• the crystal-
line compound resulting from the union
of these elements, forms a simple mineral,
called carbonate of lime. — Bakewell.
Buckland.

SINI'STRAL. A term applied to shells,
where, in consequence of the heart
being placed on the right side, the turns
of the spiral are made to the left.
These shells are termed sinistral, or re-
versed.

SI'NTER. (sinter, Germ, a mineral sub-
stance ; scale which flies from the iron
while it is under the hammer.) Cal-
careous sinter is a variety of carbonate of
lime, and may be either stalactical, tu-
berose, reniform, globular, cylindrical,
tubular, branched, or in large, undulated,
masses. It is composed, whatever may
be its form, of a series of successive
layers, concentric, plane, or undulated,
and nearly or quite parallel. Quartzy
sinter, or pearl sinter, is a variety of
opal.

SI'NUATE. > (sinuatus, Lat.) In botany,

SI'NUATED. $ applied to leaves when the
margins are cut into wide rounded open-
ings, as in the leaf of the oak.

SI'NUOUS. (sinuev,x, Fr. sinuoso, It.)
Bending in and out ; winding ; crooked ;
tortuous.

SI'NUS. (sinus, Lat. a bag, sinus, Fr.)
] . In anatomy, a cavity or cell ; a narrow

2. In conchology, a groove or cavity.

SI'PHON. ) (siphon and siphunculus,

SI'PHUNCLE. \ Lat. siphon, Fr. sifone,
It.) An hydraulic apparatus belonging
to chambered, or polythalamous, shells,
passing through the several chambers,
and terminating in a large sac, which
surrounds the heart of the animal. The
use of the siphunculus appears to be the
enabling the animal to rise to the surface,
or descend to the bottom, of the water, by
increasing its specific gravity.

SI'PHUNCLED. Possessing a siphuncle ;
formed with a siphuncle.

SKO'RODITE. (from ffKopodov, gaiiick, Gr.)
A mineral of a leek-green or brown co-
lour ; an arseniate of iron. Before the
blow-pipe it fuses, giving out a smell of

garlick, from which circumstance it has
obtained its name.

SKO'RZA. The epidote skorza of Brong-
niart ; epidote arenace of Hatty. A va-
riety of epidote.
SLAG, (schlacke, Germ, slagg, Dan.) The

drop or recrement of metal.
SLATE. A kind of clay, of a structure
termed schistose, which admits of being
split into thin layers of considerable ex-
tent. Slate is commonly of a bluish or
greenish colour, with a silky lustre. It
consists of silex 50'0, alumina 25'0,
oxide of iron ITS, manganese 1'6, potash
4*8, carbon 0'3, water 75. It is opaque ;
may be scratched by the knife ; and fuses
into a blackish slag.

SLA'TY. Resembling slate ; containing
slate ; composed of parallel thin plates
which admit of being separated by split-
ting.

SLATE SYSTEM. This group is sub-divided
into, 1st, the Plynlymmon rocks, con-
sisting of grauwacke and grauwacke slate,
with beds of conglomerates, the thick-
ness of the whole being estimated at
several thousand yards. 2nd, The Bala
limestone, a dark limestone associated
with slate, containing shells and corals.
3rd, The Snowdon rocks, consisting of
fine-grained slates, of various shades of
colour, and of fine and coarse grauwacke
and conglomerate. In the strata of the
slate system are found the most ancient
organic remains.

SLI'CKENSIDES. A provincial name for a
variety of galena,

SLOTH. The Bradypus of Linnaeus, the
only existing genus of Tardigrada.

SMALT, (smalto, It. schmalte, Germ.)
Powder-blue, a vitreous substance ob-
tained by melting zaffre, silex, and potash
together.

SMARA'GDITE. The name given by Saus-
sure to diallage.

SMA'RAGD. ) (from oyxapay^oc, Gr. sma-

SMARA'GDUS. $ ragdus, Lat. smeraldo,
It. smaragd, Germ.) The emerald. See
Emerald.

SOA'PSTONE. A name given to steatite, in
consequence of its soapy feel. Its de-
scription will be found under the word
Steatite.

SO'DA. (soda, sode, soude, Germ.) Mi-
neral fixed alkali, found native in some
situations, but generally obtained from
the combustion of marine plants, more
particularly of the salsola soda. Com-
mon salt, so universally employed as a
condiment and as an article of food, so
absolutely necessary to the preservation
of health, is a chloride of sodium, con-
sisting of 52'26 parts of soda, and 45 -74
parts of hydrochloric acid. Soda, says
Mr. De La Beche, is found in schorl, and

SOD

[ 239 ]

SPA

certain hypersthene rocks, in some eurites,
in trachytes, pitchstones, basalts, and
some diallage rocks. There can be little
doubt that a large amount of soda is
thus locked up in rocks, particularly if
we include the masses of rock-salt disco-
vered in different parts of the world. It
is, however, found in greatest abundance
diffused through the waters of the ocean.

SO'DA FE'LSPAR. Another name for albite,
or tetarto-prismatic felspar. See Albite.

SO'DALITE. (from soda, and Xi'0oe, Gr. a
stone.) A sub-species of lapis lazuli.
The name sodalite has been given to this
mineral from the large proportion of soda
which it contains, being 25 per cent. Its
constituents are silex 36''0, alumine 32'0,
soda 25-0, muriatic acid 6'7, oxide of
iron 0-2. It is found in Greenland and
Vesuvius. It occurs massive, and in do-
decahedrons with rhombic faces. Colour
green, of different shades. Structure fo-
liated ; fracture conchoidal. Specific gra-
vity 2-37. It is infusible.

SO'DIUM. One of the fifty-five simple or
elementary bodies. Sodium is the metallic
basis of soda, and, like potassium, was
discovered by Sir H. Davy in 1807. It
has the appearance of silver, or of lead,
and is both ductile and malleable. Its
specific gravity is 0-97, consequently it is
lighter than water.

SOIL, (sol, Fr. soulo, It.) The name given
to that superficial accumulation of various
substances which lies upon the surface of
the globe, and covers the rocks below ; it
is also called earth, mould, loam, &c. Its
depth is irregular, from a few inches to
several feet.

SOLA'RIUM. A genus of depressed, coni-
cal, nearly discoidal, umbilicated, marine,
univalve shells, belonging to the family
Turbinacea. Recent solaria are littoral
shells, found on rocks and weeds, and be-
long to tropical seas. One species, sola-
rium canaliculatum , has been found in the
London clay of Hampshire : Lamarck
describes nine species.

SO'LEN. A genus of marine bivalves, found
on sandy beaches, wherein it burrows ver-
tically, and lies concealed at a depth of
about six inches, when the tide leaves
the beach dry. The shell is bivalve, ob-
long, equivalve, inequilateral, open at
both ends ; hinge with a subulate reflected
tooth, often double, and not inserted in
the opposite valve. It is included in the
family Solenacea.

SO'LENITE. A fossil solen. Lamarck de-
scribes five species, as found in the neigh-
bourhood of Paris. Fragments of sole-
nites are found in the Essex cliffs.

SOLFATA'RA. The name of an extinct vol.
cano near Puzzuoli, which constantly
emits aqueous vapour, and sulphureous

and muriatic exhalations. The word sol-

fatara is now applied to any volcanic

vent emitting sulphureous, muriatic, and

acid vapours or gases.
SO'LID. A solid is that which has length,

breadth, and thickness.
SOLIDU'NGULOUS. (from solidus, solid, and

unyula, a hoof, Lat.) Having the hoof

whole and undivided.
SO'HTARY. (solitarius, Lat. solitaire, Fr.

solitario, It.)

1. In botany, applied to peduncles when
there is only one on the same plant, or
when they stand singly in the same place ;
to seeds, when there is only one in a peri-
carp.

2. In conchology, applied to a single tooth.
SO'MMITE. The name given by Jameson to

the mineral called by Haiiy nepheline. For
a description of sommite, see Nepheline.

SPAR, (spath, Germ, spath, Fr. terme de
miner aloffie, emprunte de VAllemand.
Quelques uns disent, spar.) In miner-
alogy, a name given to those earths which
easily break into rhomboidal, cubical, or
laminated fragments with polished sur-
faces. Spar constitutes the sixth order
of the second class in the natural history
system of mineralogy. Spar is not me-
tallic ; its streak is white, grey, brown, or
blue. Hardness from 3-5 to 7'0. Spe-
cific gravity from 2'0 to 3'7. As the
term spar is applied to stones of different
kinds, without any regard to the ingre-
dients of which they are composed, an
additional term must necessarily be em-
ployed to express the constituent parts as
well as the figure ; for instance, calca-
reous spar, gypseous spar, adamantine
spar, cubic spar, brown spar, &c. &c.

SPA'RRY I'RON. The fei* oxide carbonate
of Haiiy ; spath eisenstein of Werner ;
fer spathique of Brongniart ; sparry iron-
stone of Jameson ; sparry iron-ore of
Kirwan. Carbonate of iron. It is of a
yellow, grey, brown, or black colour ;
occurring crystallized in rhombohedrons,
or in laminated and lamellar masses. It is
found in metalliferous veins, as well as in
common veins, in primary, transition, and
secondary rocks. It consists principally
of protoxide of iron and carbonic acid ;
some specimens yielding manganese and
lime ; others, magnesia, oxide of manga-
nese,andlime,but in very small proportions.
Sparry iron is a valuable ore, from the fa-
cility with which it may be converted into
excellent steel. It is, from the last cir-
cumstance, sometimes called steel ore.

SPA'DIX. (spadix, Lat.) In botany, an
elongated receptacle : a spike, the sessile
flowers of which are very crowded, the
principal axis thick and fleshy, and en-
veloped in a large, coloured, bractea, is
termed a spadix.

SPA

[ 240

S P I

SPATA'NGUS. A genus of echini, of the
section Cor marinum, belonging to the
class Pleurocysti. It is characterized by
the bilabiated mouth being in the third
region of the axis of the base, and the
anus in the side of the truncated ex-
tremity. There are a great many species
of the genus. The shell of the spatangus
is oval, possessing a great number of
spines, by the action of which it buries
itself in the sand. Fossil spatangi are
very abundant in the chalk formation.
Dr. Mantell enumerates four species
found in the chalk, one species found in
thfr chalk marl, and one iu the upper
green-sand.

SPATHE. (spatha, Lat.) In botany, a kind
of bractea ; a large coloured bractea
which envelopes the principal axis of
sessile flowers ; it forms a sort of hood or
sheath, opening longitudinally, at some
distance from the flower ; the arum,
calla, &c. are examples.

SPA'THIC. In mineralogy, lamellar; fo-
liated.

SPA'TULATE. (from spathula, Lat.)

1. In botany, applied to leaves shaped
like a spatula or battledore, having the
upper part of a roundish figure, the base
tapering and linear.

2. In conchology, applied to shells which
are rounded and broad at the top, and
becoming narrower below.

3. In entomology, applied to the figure
of insects, when commencing with a nar-
row base, gradually widening by the la-
teral margins sloping out, and terminated
at the extremity by a sudden straight
line.

SPE'CIES. (species, Lat.)
. 1. That which is predicated of many
things as the whole of their essence.

2. In mineralogy, a species may be de-
fined, a collection of minerals, which are
composed of the same ingredients, and
combined in the same proportions.

3. In entomology, a group of natural bo-
dies which agree together in all their
essential, unchangeable characters. The
idea of species comprises in it a congru-
ency, that is to say, not a mere conform-
ity, but also a resemblance of its indivi-
duals. Species is the lowest of all the
systematic groups, and, consequently, the
most fixed and conformable.

4. In botany, according to Jussieu and
others, a species is a combination of indi-
viduals alike in all their parts. De Can-
dolle makes it " a collection of all the in-
dividuals which resemble each other more
than they resemble any thing else ; which
can by mutual fecundation produce other
individuals ; and which reproduce them-
selves, by generation, in such a manner
that we may from analogy suppose them

all sprung originally from one single indi-
vidual."

The physiological definition of a species
is, that all the individuals that belong to
it will breed together and produce suc-
cessors, having the same power of repro-
duction by seed.

SPHA'GNOUS. Mossy ; containing peat-
moss.

SPHA'GNUM PALU'STRE. A kind of moss,
generally constituting a large portion of
the entire mass of peat-bogs. The
sphagnum palustre has the property of
throwing up new shoots in its upper part,
while its lower part decays, and from this
circumstance it mainly contributes to the
formation of beds of peat. ,

SPHERE, (sphcera, Lat. crpatpa, Gr. sphere,
Fr. sfera, It.) A solid, generated by the
revolution of a semicircle about its dia-
meter, which remains fixed ; a globe ; an
orbicular body ; a body of which the
centre is at the same distance from every
point of the circumference ; such a solid
body that all lines drawn from its centre
to its surface are equal. The lines are
called radii.

SPHE'RICAL. (spherique, Fr. sferico, It.)
Round ; orbicular ; globular.

SPHERI'CITY. Roundness ; globosity.

SPHE'ROID. (from atyaipa, a sphere, and
eldog, likeness, Gr. sferoide, It. spheroide,
Fr. corps solide, dont la figure approche
de celle de la sphere.) A solid body ap-
proaching to the form of a sphere. A
spheroid may be either oblate or prolate ;
an oblate spheroid resembles an orange,
having its poles flattened, such is the
form of the earth and planets ; a prolate
spheroid has its poles drawn out, and its
form somewhat resembles an egg.

SPHEROI'DAL. Having the form of a sphe-
roid, whether oblate or prolate.

SPHENO'-PTERIS. A very beautiful and
delicate genus of fossil ferns described by
M. Ad. Brongniart. Three species are
figured in Dr. Mantell's Geology of the
South- East of England, namely, Sphe-
nopteris Sillimani, named after Prof.
Silliman ; Sphenopteris Phillipsii, named
after Prof. Phillips ; and Sphenopteris
Mantelli, named, by M. Adolphe Brong-
niart, in honour of Dr. Mantell.

SPHE'RULE. (spharula, Lat.) A little
globe ; a globule.

SPHI'NCTER. (from tr^tyyo), Gr. to con-
tract ; sphincter, Fr.) The name given
to certain muscles whose office it is to
contract the part in all directions, draw-
ing it together as the mouth of a purse is
contracted by a circular string.

SPI'CATE. (from spicatus, Lat.) Having
a spike or ear.

SPI'DER. The different species of spiders
compose the genus named Aranea by

S P 1

[ 241 ]

S P I

Linnaeus, order Pulmonariae, class Araeh-
nides. The male spider possesses four
pairs of legs, the female live, the addi-
tional pair enabling her to carry her eggs.
The legs are composed of seven joints,
the two first forming the hip, the third
the thigh, the fourth and fifth the tibia,
the sixth and seventh the tarsus. The
feet are spread out in diverging rays, so
as to include a wide circle, and afford an
extensive base of support ; they terminate
in two, or, sometimes, in three hooks. In
front of the head are placed members
resembling feet, having affixed to them,
or terminating in, a moveable hook, or
pincers, flexed inferiorly, underneath
which is a minute opening that permits
exit to a venomous fluid contained in an
adjoining gland. By the injection of this
poisonous fluid the common spider of this
country is able to kill a fly in a few mi-
nutes, and the large spider of South
America can, by the same means, destroy
the smaller vertebrated animals, and pro-
duce even in man severe constitutional
disturbance. The greater number of
species possess a curious apparatus for
spinning threads, and for constructing
nets, for the entanglement of flies and
small insects. This net or web is as
various as the species, each species con-
structing its own peculiar form of net : in
addition to the principal web, which is
spun out for the capture of small insects,
the spider frequently constructs a smaller
one, both as a residence and a place of
ambush. Between these two constructions
there is placed a thread of communication,
and no sooner is the struggling insect
involved in the meshes of the larger net
than the vibrations of this communicating
thread afford information to the concealed
spider, who instantly rushes towards his
victim and endeavours to destroy it by
piercing it with his dart and infusing into
the wound his poisonous fluid. The web
is produced by a double series of spines,
opposed to each other, and planted on a
prominent ridge of the upper side of the
metatarsal joint, or that usually regarded
as the first joint of the foot of the pos-
terior legs next the abdomen. These
spines are employed as a carding appara-
tus, the low series combing, or extracting
the ravelled web from the spinneret, and
the upper series, by the insertion of its
spines between those of the other, disen-
gaging the web from them.

Fossil remains of spiders exist in strata
of very high antiquity. Prof. Buckland
is of opinion that, although spiders have
not yet been discovered in the carbonife-
rous series, the probability is they did
exist at that period. Count Munster has
established the existence of spiders in the

Jurassic portion of the secondary forma-
tions.

SPIKE, (spica, Lat.) In botany, a species
of inflorescence, in which the flowers
stand sessile along a common peduncle,
and are either placed alternately and
crowded together, or in separate groups.
When the flowers are sessile they form a
spike: the plantain, lavender, corn, &c.,
afford examples.

SPI'KELET. In botany, the term applied to
a subdivision of a spike, forming, as it
were, a small spike : by some authors
this word is applied exclusively to the
spike of grasses.

SPI'NAL. (spinalis, Lat. spinal, Fr. spinale,
It.) Relating to the spine ; belonging to
the spine.

SPINE, (spina, Lat. epine, Fr. spina, It.)

1. In anatomy, the vertebral column or
back-bone of vertebrated animals.

2. In botany, a sharp point, or thorn ;
the spines of plants differ from prickles,
inasmuch as they proceed from the wood
of the plant, whereas a prickle comes from
the bark only.

3. In zoology, a thin pointed spike. Some
of the spines of fishes are simply imbed-
ded in the flesh of the animal, and attached
to muscles ; others are articulated with
bones which lie beneath them.

4. The word spine is occasionally used to
signify a ridge.

The fossil spines of various fishes are
found in strata from the greywacke series
to the chalk inclusive ; they have obtained
the name of ichthyodorulites.
SPI'NEL,. > (spinelle, Fr. spinella, It.) A
SPI'NELLE. $ species of corundum both of
an octahedral and a dodecahedral form.
Its colours are red, black, blue, brown,
yellow, and white. It occurs in regular
crystals, and, occasionally, in rounded
grains. It scratches quartz, its hardness
being == 8'0. Its structure is usually
foliated, with laminse parallel to the faces
of the octahedron. Specific gravity from
3-5 to 3-8. It is infusible before the
blow-pipe, and intense heat does not even
deprive it of its colour. It consists of
alumina 82'47, magnesia 8'78, chromic
acid 6*18, loss 2'57. Sometimes its co-
louring matter is oxide of iron instead of
chrome. The spinelle ruby is a sub-
species.

SPINE'LLANE. A variety of dodecahedral
zeolite. A mineral of a plum-blue or
blackish-brown colour, found on the
banks of the river Laach, near Ander*
nach. It occurs in hexahedral prisms,
terminated by three-sided summits, whose
faces stand on alternate, but different,
lateral edges at each extremity. It fuses
easily before the blow-pipe, becoming
white, and is converted into a porous

4 I

S P I

[ 242 ]

S P O

enamel. It consists, according to the
analysis of Klaproth, of silica 43*0, alu-
mina 29-5, soda 19'0, lime 1'4, oxide of
iron 2'0, sulphuric acid I'O, water 2'6.

SPI'NTHERE. The name given by Haiiy to
a mineral of a greenish-grey colour found
in the department of the Isere, in France.

SPI'NY. ^ Having spines, thorns, or

SPI'NOUS. $ points.

1. In botany, applied to plants possessing
thorns or spines ; also to leaves, the
margins of which are beset with thorns.

2. In anatomy, applied to certain pro-
cesses of bones.

SPI'RACLE. (spiraculum, a breathing-hole,
Lat. spiraglio, It.) The spiracles are
the external orifices from which the air
tubes of insects commence : they are also
called stigmata.

SPI'RAL. (from spira, a spire, Lat. spiral,
Fr. spirale, It.) Winding in a cir-
cular form, and, at the same time, rising :
a corkscrew is an example of spiral form.

SPIRE. (from <T7mpa, Gr, spira, Lat.
spire, Fr. spiro, It.) That part of a
body which shoots up to a point.

In conchology, the spire of univalve shells
consists of all the whorls except the lower
one, which is termed the body. The spire
is a prominent feature in univalve shells,
and upon its being elevated, depressed,
&c., depends much of the generic and spe-
cific definition. There are several kinds
of spire ; the depressed spire, when the
spire is very flat ; the involuted spire,
when the whorls are concealed in the in-
side of the first whorl, as in the nautilus ;
the reversed spire, when the whorls turn
in the contrary direction to a right-hand-
ed screw, &c.

SPI'RIFER. (from spira, a spire, and/ero,
to bear, Lat.) A genus of bivalve shells,
distinguished from terebratula by its very
extraordinary internal spiral processes or
cones, from which it obtains its name.

SPIROLI'NA. A genus of microscopic forami-
niferous multilocular univalves, described
by Lamarck, who discovered several spe-
cies of them in the fossils of Grignon.

SPIRO'RBIS. A genus of shells belonging
to the family of the Serpulacea. A fa-
miliar example of spirorbis is afforded in
the common, small, white, coiled shell so
frequently seen upon the shell of the lob-
ster. The spirorbis is found on sea-weed,
shells, &c.

SPI'RULA. (from spira, Lat.) Both a
recent and a fossil shell. A genus of
multilocular shells, partly spiral and partly
straight, the whorls being arranged in a
discoidal form, and separate from each
other ; the last turn being elongated, and
continued in a straight line. The siphun-
culus, instead of being membranous, is
formed by one continuous shelly tube.

It appears that the spirula, notwithstand-
ing it possessed a siphuncle, was, alto-
gether or in part, an internal shell. The
living spirula is an inhabitant of tropical
seas ; it floats on the surface of the ocean.

SPI'RULITE. A fossil spirula. Spirulites
are sometimes termed litnites, from their
supposed resemblance to a bishop's pas-
toral staff. They are found principally in
Normandy, Mecklenberg, and, as is
stated, in Switzerland.

SPLE'NDENT. (splendens, shining, Lat.
splendente, It.) In mineralogy, a term
applied to metals as regards their degree
of lustre. A mineral is splendent when
perceptible in full day-light at a great
distance, as in highly polished metals.

SPLENT COAL. An impure variety of can-
nel coal, occurring in Scotland.

SPLI'NTERY. In mineralogy, a term applied
to a particular fracture of minerals. The
fracture is called splintery, when the sur-
face, produced by breaking a mineral, is
nearly even, but exhibits little splinters
or scales, somewhat thicker at one extre-
mity than the other, and still adhering to
the surface by their thicker extremities. —
Cleaveland.

SPO'DUMENE. (from O-TTO^OW, Gr. in cine-
rem redigo.} The Triphane of Haiiy ;
Spodumene of Jameson. A rare mineral
of a greenish white or gray colour ; oc-
curring massive, and in large granular
concretions. Spodumene has been found
in the iron-mine of Uton, in Sweden, and
in primary rocks in Ireland. According
to the analysis of Vauquelin, it consists of
silica 64*4, alumina 24*4, potash 5'0, lime
3'0, oxide of iron 2-2. Arfwedson dis-
covered in a specimen of spodumene
nearly toine per cent, of lithion.

SPO'NDYLUS. A genus of rough, slightly-
eared, inequivalved, marine, bivalves, with
unequal beaks ; hinge with two recurved
teeth, separated by a small hollow. Spon-
dyli are found only in the ocean, attached
to rocks, corals, &c. : they are remarkable
for their spines, and the richness of colour-
ing of the shells. No species have been
found in the seas of our coasts. They
are eaten like oysters.

Lamarck has described one species as
occurring fossil in the neighbourhood of
Paris, and very fine fossils are found in
Tuscany.

SPONGE. (o-Troyyia, Gr. spongia, Lat.
eponge, Fr. spugna, It.) This word is
pronounced, and frequently written,
spunge. A porous marine substance
found adhering to rocks, formerly sup-
posed to be a vegetable production, but
now classed among the zoophytes : it is
soft, light, porous, and easily compressi-
ble, readily imbibing fluids, and thereby
distending.

S P O

[ 243 ]

S T A

Sponges assume a great variety of
shapes, each according to its species, and
resemble shrubs, globes, tubes, fans,
vases, &c., &c. For a description of
living sponges, the reader is referred to
the article Porifera.

SPO'NGEOUS. (spongieux, Fr.) Of the
nature of sponge ; full of small pores.

SPO'NGIFORM Q.UARTZ. The name given
to a white or grey, porous, variety of
quartz, so light as to swim on water, and
also called Floatstone.

SPO'NGIOLE. In botany, an organ situated
at the extremity of the root, and thus
named from its peculiar texture. It is
by the spongioles, thus situated, that
plants are enabled to absorb. They are
constructed of common cellular spongy
tissue, and they imbibe the fluids which
are in contact with them, partly by capil-
lary action, and partly, also, by a hygro-
scopic power.

SPO'RULE. (from ffiropa, a seed, Gr.) The
organ of reproduction in cryptogamic
plants. Ferns are increased by minute
bodies, called sporules ; these are pro-
duced either on the backs, or in the axillse
of the fronds, and on other parts. The or-
gans of reproduction in mosses consist of
sporules, contained within an urn or theca,
placed at the top of a thin stalk. In lichens,
the organs of reproduction are sporules.

SPRINGS OF WA'TER. " All permeable
strata," says Prof. Buckland, " receive
rain-water at their surface, whence it de-
scends until it is arrested by an imperme-
able subjacent bed of clay, causing it to
accumulate throughout the lower region
of each porous stratum, and to form ex-
tensive reservoirs, the overflowings of
which on the sides of valleys constitute
the ordinary supply of springs and rivers.
The water, however, which descended
from the atmosphere in the form of rain,
having passed through the various strata,
does not re-issue in the same condition.
Rain-water contains carbonic acid ; in
passing through the strata it absorbs
oxide of iron, lime, &c., and on issuing
in the form of springs it loses its excess
of carbonic acid, and again deposits car-
bonate of iron, &c. Springs usually pos-
sess one particular average temperature,
generally identical with that of the ground
through which the particular spring
passes. That the generality of springs
owe their supply to the atmosphere is
evident from this, that they become lan-
guid, or entirely cease to flow, after long
droughts, and are again replenished by
copious showers of rain. For the con-
stancy and uniformity of their volume
they are most probably indebted to the
large extent of those subterranean reser-
voirs with which they communicate.

SPUNGE. See Sponge.

SHUA'LOID. (from squalus, a shark, Lat.
and tWoQ, resemblance, Gr.) The squa-
loid, or third division of fossils of the
family of sharks, appears for the first
time in the chalk formations, and ex-
tends through all the tertiary deposits to
the present period. Species of the squa-
loid division only, abound in all the strata
of the tertiary period.

SQUA'LUS. The name given by Linnaeus to
the true shark.

SCIUA'MOSE. } (squamosus, Lat.) Scaly;

SQUA'MOUS. $ covered with scales.

SQ,UA'RROUS. (from squarra, roughness of
skin, Lat. str^dpa, Gr.)

1. In conchology, consisting of scales
spreading every way, or standing upright,
and not parallel with the plane.

2. In botany, applied to parts with scales
widely divaricating.

STALA'CTIC. ^ Resembling stalactite ; of
STALA'CTICAL. $ the character and ap-
pearance of stalactite.

STALA'CTITE. ((rraXa/crig, from 0ra\a£w,
Gr. to drop or distil ; stalactite, Fr.) A
concretion of carbonate of lime pendent
from the roof of a cavern, and produced by
the percolation and dripping of water,
holding in solution, or super-saturated
with, carbonate of lime. The mode of
formation of a stalactite resembles that
of an icicle ; the water, as it slowly drips
from the roof, continually deposits upon
the pendent stalactite a small quantity of
its carbonate of lime, and thus the stalac-
tite increases in length and bulk.
STALACTI'TIC. ) Synonymous with sta-
STALACTI'TICAL. $ lactic and stalactical.
STALA'GMITE. (from 0ra\ay|u6f, Gr. sta-
lagmite, Fr.) A concretion of carbonate
of lime produced by the dripping of water
holding in solution carbonate of lime.
The difference between a stalactite and a
stalagmite is this : the former is attached
to, suspended from, and formed at, the
roof of a cave or grotto, ; the latter is
formed upon the floor : the stalactite
generally resembles a large icicle ; the
stalagmite is an unshapen mass upon the
floor. It sometimes happens that from
the stalactite lengthening downwards, and
the stalagmite increasing upwards, the two
become united, and thus form a column
extending from the roof to the floor.
STALAGMI'TIC. ) (from stalagmite. ) Re-
STALAGMI'TICAL. $ sembling stalagmite ;

containing stalagmite.

STA'MEN. (stamen, Lat.) A constituent
part of a flower, situated within the
corolla, consisting of two parts, the fila-
ment and the anther. The stamens are
the male organs of the plant. In the
plural the word is written either stamens
or stamina.

S T A

C 2-14 ]

S T E

STA'NDARD. In botany, the upper large
petal of a papilionaceous flower ; also
called the banner.

STAU'ROLITE. (There appears to be some
incorrect arrangement, or confused mixing
together, by some authors, of the words
staurolite and staurotide. Dr. Ure, in his
explanation of staurolite, gives merely
" grenatite, or prismatic garnet ;" then,
immediately after, in his dictionary of mi-
neralogy, comes staurotide, which he states
to be ' ' grenatite, prismatic garnet, or stau-
rolite. Dr. Webster, in his dictionary,
brackets staurolite and staurotide, as
meaning the same mineral. I believe
both these gentlemen to be wrong, and ]
imagine staurolite and staurotide to be
two distinct minerals.) Staurolite is the
name given by Kirwan to the harmo-
tome of Haiiy, the cross-stone of Jame-
son ; kreutzstein of Werner. The com-
position of staurolite differs entirely from
that of staurotide. Staurolite contains,
according to some analyses, upwards of
twenty per cent, of baryta, and no oxide
of manganese ; whereas staurotide con-
tains no baryta, but four per cent, of
oxide of manganese. For a description
of staurolite, see Cross-stone.

STAU'ROTIDE. The name given by Haiiy
to prismatoidal garnet or grenatite. The
prismatoidischer garnet of Mohs ; the
granatit of Werner ; the grenatite of
Jameson and Brochant. This mineral
occurs crystallized in four and six-sided
prisms, sometimes intersecting each other
at right angles. Its primitive form, un-
der which it sometimes appears, is a
four-sided prism, whose bases are rhombs
with angles of 1 29° 30' and 50° 30'. Its in-
tegrant particles are triangular prisms.
Its colours are reddish-brown to black-
ish-brown. Specific gravity from 3'3 to
3-9. Hardness from 7-0* to 7'5. It
feebly scratchesquartz, but does not yield
sparks with steel. Fracture uneven or
imperfectly conchoidal. It does not fuse
before the blow-pipe, but its surface is
converted into a kind of black frit. It
consists of silica, alumina, lime, and the
oxides of iron and manganese. It is
found in primary rocks only. It may be
distinguished from garnet by its form and
infusibility.-Cleaveland. Jameson. Brande.

STEA'RTN. } (from arkaD, Gr.) The name

STEARI'NE. } given by Chevreuil to the
solid part of oil and fatty matter. Fat is
composed of two constituent principles,
which Chevreuil distinguished by the
terms stearine and elaine.

STE'ATITE. (from orcap, gen. ortarof,
Gr. steatite, Fr.) Called also soap-stone.
See Soap-stone.

STEATI'TIC. Containing steatite ; resem-
bling steatite.

STEEL, (stahl, Germ.) Iron combined
with carbon. The proportion of carbon
has, perhaps, never been accurately as-
certained ; but steel containing one-six-
tieth of its mass of carbon is said to have
the maximum degree of hardness. The
following are some of the properties of
steel : — It is so hard as to be unmalleable
when cold ; it is brittle, resists the file,
cuts glass, affords sparks with flint, and
retains the magnetic virtue for an inde-
finite length of time. By being ignited,
and afterwards slowly cooled, it loses its
hardness. It fuses at 130° Wedgewood.
When red-hot it is malleable. It is more
sonorous than iron, and may be ham-
mered out into much thinner plates.
The conversion of iron into steel is
effected by combining it with carbon.
This combination is performed in three
ways, by three different processes, and
the products are distinguished by the
names of natural steel, steel of cementa-
tion, and cast-steel. Of these, the most
valuable is cast-steel, its texture being
the most compact, and it admitting of
the finest polish. The manufacture of
articles of steel, says Mr. Babbage, af-
fords a most striking example of the
value conferred by human labour on the
raw produce of nature. The value of a
pound of crude iron is twopence. This
pound of iron, after having been con-
verted into steel, is manufactured into
balance-springs for watches. One of
these springs weighs -^j of a grain, and
sells for twopence. After deducting for
waste, a pound of iron will make fifty
thousand springs, and the twopenny-
worth of iron becomes worth 416/.
13*. The value of the charcoal is too
minute to be taken into the calcula-
tion.

STEI'NHEILITE. A variety of iolite, a mi-
neral of a blue colour.
STE'LLA MARI'NA. The name employed by
Linck, on the authority of Pliny, to sig-
nify the asteria or star- fish.
STE'LLITE. A fossil asteria or star-fish.
STELLE'RIDAN. An animal resembling an
asteria. Fossil stelleridans have not been
discovered in strata more ancient than
the muschel-kalk, a member of the new
red sandstone group.

STELLI'FEROUS. (from stella, a star, and
fero, to bear, Lat.) Having stars, as
some of the corallines.
STE'LLIFORM. In the form of a star ; ra-
diated.

STE'LLULAR. Having markings resembling
stars. The surface of the tubipora, or
organ-pipe coral, is covered with a green
fleshy substance, studded with stellular
polypi. — Mantell.
STENEOSAU'RUS. A genus of fossil sau-

S T E

C 245 ]

S T R

rians, with long and~narrow beaks ; thus
named by M. Geoffrey St. Hilaire.

STE'RNAL. (from sternum, the breast-
bone.) Pertaining to the sternum or
breast-bone.

STE'RNUM. (orspvov, Gr. sternum, Lat.)
The breast-bone. In the human subject the
sternum is divided into three parts ; in
some vertebrated animals it is formed of
nine elementary species, each proceeding
from a separate centre of ossification.
Few subjects in comparative osteology,
says Dr. Roget, are more curious and in-
structive than to trace the development of
these several elementary parts in the dif-
ferent classes of animals, from the rudimen-
tal states of this bone as it occurs in fishes,
to its greatly expanded conditions in the
tortoise and the bird, which severally
exhibit the most opposite proportions of
these animals. — Bridgewater Treatise.

STI'GMA. (orty/za, Gr. stigma, Lat.) In
botany, the apex of the pistil ; the stigma
is variously formed, being either a fine
point, a round head, or lobed ; generally
downy, often hollow and gaping, and
more or less moist. Sometimes, though
there is only one style, there are two or
more stigmas : when there is no style, the
stigma is sessile on the ovarium.

STIGMA'RIA. A family of extinct fossil
plants of the coal formations. Professor
Buckland says, " the centre of the plant
presents a dome -shaped trunk or stem,
three or four feet in diameter, the sub-
stance of which was probably yielding
and fleshy ; both its surfaces were slightly
corrugated, and covered with indistinct
circular spots." The stigmaria was an
aquatic plant, inhabiting swamps or lakes,
and, as regards its external structure,
resembled the euphorbiacese. Fragments
of stigmarise occur abundantly in the coal
shales. It appears to have been dicotyle-
donous.

STI'GMATA. Spiracles from which the
tracheae of insects commence. See Spi-
racle.

STI'LBITE. (from ori'X/3w, to shine, Gr.)
The name given to this mineral from the
degree of lustre which it possesses. The
radiated zeolite of Jameson ; strahl-
zeolith of Werner ; prismatoidischer ku-
phon-spath of Mohs. Stilbite is of a
white colour generally, sometimes pure,
at others shaded with grey, yellow, or
red. It occurs both crystallized and
massive. It is splendent externally ; in-
ternally shining and pearly. Translu-
cent, and sometimes transparent. Spe-
cific gravity 2'2. It does not scratch
glass. It consists of 52*5, alumine
17-5, lime 11'5, water 18-5 It occurs in
secondary trap rocks, in Scotland, Nor-
way, and in the Faroe islands.

STINK STONE. The name given to a variety
of limestone, from the fetid odour which
it gives out on friction ; a smell resem-
bling rotten eggs. It is the chaux car-
bonatee fetide of Hatty ; the stinkstein
of Werner. It occurs in masses, either
compact, or having a granular or foliated
structure, frequently forming large beds,
or even whole mountains.

STIPE, (stipes, Lat.) In botany, the stem
or base of a frond ; a species of stem
passing into a leaf, or not distinct from
the leaf : the name given to the stem of
palm trees ; it differs essentially in form,
structure, and mode of growth, from the
trunk, increasing in length only, and not
in thickness. The stem of a fungus is
also called a stipe, as is the thread, or
slender stalk, which supports the down,
and connects it with the seed.

STI'PULA. ^ (from stipula, Lat.) In bo-

STI'PULE. S tany, a membranous leafy
appendage, placed at the part of the stem
whence the leaf or footstalk arises. Sti-
pules vary in number, being solitary or
in pairs ; in situation, being either exter-
nal with regard to the leaf or footstalk,
or internal, the internal sometimes em-
bracing the stem in an undivided tube ;
in form, linear at the base, or crescentic ;
in attachment, connected directly with
the stem, or with the petal ; in direction,
erect, or variously reflected. Stipulae
serve to protect the nascent leaves.

STIPULATE. Having stipules ; producing
stipulse.

STONE GALL. The name given by the
workmen to an oval or round mass of
clay, occurring in variegated sandstone.
These stone galls often fall out of the
sand-stone, when it is exposed to the
weather, and diminish the value of the
stone for architectural purposes.

STONE-BORER. The name for a mollus-
cous bivalve which mechanically per-
forates, or bores into, rocks. These
stone-borers are also called lithophagi :
they effect their purpose by means of a
fleshy foot, upon which they turn as upon
a pivot.

STRA'TA. The plural of stratum. See
Stratum.

STRATIFICATION. The arrangement of
substances in strata or layers, like the
leaves of a book, one upon another.

STRA'TIFIED. Arranged in layers or strata,
one upon another, like the leaves of a
book.

STRA'TUM. (stratum, Lat. from sterna, to
lay out, to spread.) A layer of any
deposited substance. The term stratum,
says Professor Phillips, is of general sig-
nification, and independent of the abso-
lute thickness of the mass : it need never
be used as a special term of definition,

S T R

[ 246 ]

S T R

but reserved for general reasoning. Mr.
Bakewell observes, " though the word
stratum, in its original language, and by
general acceptation in speaking of rocks,
denotes a bed, it is convenient to restrict
the term bed to a stratum of considerable
thickness ; for such beds are often sub-
divided into several distinct minor strata,
and we cannot well describe a stratified
stratum." The true thickness of a stra-
tum is measured by a line perpendicular
to the upper and under surface, let its
inclination be whatever it may.

STREAK, (strich, Germ.) In mineralogy,
the appearance of a mineral which arises
from its being scratched by a hard sharp
instrument. The streak is said to be
similar, when the colour of the powder
produced by scratching the mineral is the
same with the colour of the mineral itself ;
when the colour varies, the streak is said
to be dissimilar.

STREPSI'PTEBA. An order of insects, pa-
rasitic animals, that have two ample
wings, forming the quadrant of a circle,
and of a substance between coriaceous
and membranous ; and two elytriform
sub-spiral organs, appendages of the base
of the anterior legs. The above is Mr.
Kirby's description of the order he has
named Strepsiptera ; Latreille has given
to this order the name Rhipiptera.

STRIDE, (stria, a streak, Lat. stries, Fr.
This word is used in the plural only. )

1. In conchology, striae are fine thread-
like lines, generally on the exterior sur-
face of shells, longitudinal, transverse, or
oblique.

2. In botany, fine thread-like lines run-
ning in parallel directions.

STRI'ATED. (strie, Fr.) Arranged in fine
lines running parallel to each other, let
the direction of the lines be what it may.
Marked with fine thread-like lines run-
ning parallel to each other.

STRIKE, (stretch, Germ, stroke, stripe.)
The line of bearing of strata. The strike
or direction of strata is always at right
angles to their dip.

STRO'BIL. } (from stroMlus, Lat.) In bo-

STRO'BILE. $ tany, a pericarp formed from
an ament by the hardening of the scales ;
a catkin hardened and enlarged into a
seed-vessel; a seed-vessel composed of
ligneous scales.

STRO'MBITE. A fossil strombus ; a petri-
fied strombus. Strombites are very rare :
Lamarck describes one shell only of the
genus strombus, as found in the environs
of Paris. In the mountains of Arragon,
and in the Veronese, some specimens
beautifully preserved have been disco-
vered.

STRO'MBUS. The name given by Linnaeus
to a genus of univalve, spiral, marine,

shells ; aperture jnuch dilated : lip ex-
panding and produced into a groove.
Lamarck has divided this genus into two
subgenera, Strombus and Pteroceras. In
some of the shells of this genus the spines
are of great length, and are arranged
round the circumference of the base,
being at first tubular, and afterwards solid,
according to the period of growth. In
Turton'sLinne fifty-five species of strombi
are described ; of these, two only have
been found in the seas of this country.
STRO'NTIA. } A mineral was brought to
STRO'NTIAN. \ Edinburgh about the year
1787, from the lead-mine of Strontian in
Argyleshire, from which was obtained the
earth thus named by Klaproth. It has
subsequently been found in England,
America, and France. It is sometimes
transparent and colourless, but generally
has a tinge of yellow or green. Its hard-
ness is 5. Specific gravity from 3*4 to
3*9. Its texture is generally fibrous ;
sometimes it occurs crystallized in slender
prismatic columns of various lengths.
The mineral is composed of carbonic acid
and a peculiar earth, to which Dr. Hope
gave the name of Strontites, and Klaproth
that of Strontian. The carbonic acid
may be expelled from the carbonate, and
the strontian obtained pure, by mixing
the mineral with powdered charcoal, and
exposing it to a heat of 140° Wedgewood.
When strontian is combined with sul-
phuric acid, forming a sulphate of stron-
tian, it may be separated from the sul-
phuric acid by mixing the mineral with
the eighth part of its weight of charcoal-
powder, and keeping it for some hours
red-hot in a crucible ; it will then be
reduced to a sulphuret of strontian. Dis-
solve the sulphuret in water, and pour
nitric acid into the solution, the sulphur
will then be precipitated. This solution,
which consists of nitric acid combined
with strontian, is to be filtered and eva-
porated slowly till it crystallizes. The
crystals are then to be put into a crucible,
and subjected to a strong heat, the nitric
acid will be driven off and pure strontian
remains.

Strontian is of a greyish-white colour ;
its taste is acrid and alkaline ; it converts
vegetable blues to green. The principal
use of strontian is to communicate a
beautiful red colour.

STRO'NTIANITE. Carbonate of strontian.
The Strontian carbonatee of Haiiy ;
Strontianit of Werner ; Strontiane of
Jameson ; Stronthianite of Kirwan. A
mineral first brought to Edinburgh from
the lead-mines of Strontian, in Argyle-
shire, in the year 1787. It greatly re-
sembles carbonate of barytes, but it is not
poisonous.

S T R

[ 247 ]

SUB

STRO'NTITES. The name given by Dr.
Hope to the earth obtained from strontia-
nite ; it has been named strontian by
Klaproth, and is more usually known
under that designation.

STRO'NTIOM. The metallic base of strontia.
Strontium greatly resembles barium in its
appearance, although it is indeed, a very
different substance. Strontium is harm-
less, but barium and all its salts are poi-
sonous. The salts of strontium commu-
nicate to flame a fine red tinge ; those of
barium, a yellow.

STRU'CTURE. (structura, Lat. structure,
Fr. struttura, It.)

1. A term used in mineralogy, to denote
one of the characters of minerals. The
structure of a mineral depends on the
shape, size, and arrangement of the mi-
nute parts of which it is composed. It is
sometimes used synonymously with frac-
ture, but it is not correct so to do, there
existing a considerable difference between
the two terms.

2. The manner of organization of animals
and vegetables. The manner in which
the parts of an organized body are ar-
ranged among themselves.

STU'FA. (stufa, It. ) A jet of steam issu-
ing from a fissure of the earth. In vol-
canic regions stufas are by no means
uncommon. The name is taken from the
Italians, who thus apply it.

STYLE, (stylus, Lat.) In botany, that
part of the pistil which elevates the stigma
above the germen. The style is not ab-
solutely essential, and is sometimes want-
ing. The style is a continuation of the
midrib, and constitutes a portion of the
pistil.

SUB-A'PENNINE. " This term," says Mr.
Lyell, " is applied geologically to a series
of strata of the older pliocene period.
The beds which have been termed sub-
apennine are composed of sand, clay,
marl, and calcareous tufa ; they are all
tertiary deposites, and abound in marine
shells of genera and species which prove
some of them to be contemporaneous with
the crag deposit, and others of a more
ancient epoch : they rest unconformably
upon the inclined beds of the Apennine
range. Brodchi, an Italian geologist,
gave to this group the name it bears.

SUB-A'PENNINES. The name given to cer-
tain ranges of hills, rising at the height of
from one to two thousand feet, which
flank or skirt the great chain of the
Apennines.

SUBA'QJJEOUS. (from sub, under, and
aqua, water.) Being under the water ;
formed under water ; deposited under
water.

SUBDIVISION. A more minute division of
something already divided.

SUBGLO'BULAR. In botany, approaching
to, but not completely globular.

SUBJA'CENT. (from sub, under, and ja-
cens, lying, Lat.) Lying beneath or
below. A term applied to rocks, beds,
or strata which lie under, or are covered
by others.

SUBLIMA'TION. (sublimation, Fr. subli-
mamento, It.) That operation by which
solids are, by the aid of heat, brought
into a state of vapour, and again con-
densed into a solid form. One of the
hypotheses proposed to explain the fill-
ing of chasms in solid rocks with metal-
lic ores, is by a process of sublimation
from subjacent masses of intensely heated
mineral matter.

SU'BMARINE. Under the sea, as submarine
forests, submarine volcanoes, &c. Grow-
ing under the sea, as submarine plants ;
formed under the sea, as submarine lava,
submarine strata, &c.

SUBORBI'CULAR. ) Approaching to a cir-

SUBORBI'CULATE. $ cular form, but not
quite circular.

SUBORDINATE. Inferior in the order of
superposition.

SUBO'VATE. Not perfectly ovate.

SUBRO'TUND. Nearly globular ; almost
round.

SUBSE'SSILE. In botany, applied to leaves
having very short footstalks.

SUBSIDENCE. The act of sinking ; ten-
dency downwards. The subsidence of
large tracts of country, or of volcanic
hills, may be either gradual or sudden,
according to the circumstances of weak-
ness, &c. in the earth's crust.

SU'BSOIL. That portion of the earth's
covering which intervenes between the
surface soil and the rocks on which it
rests.

SUBSPE'CIES. A division of a species :
used plurally for the more minute divi-
sion of a species into several subspe-
cies.

SU'BSTANCES, SIMPLE. See Elementary
substances.

SU'BSTANTIVE CO'LOURS. Dr. Bancrot di-
vided colours into substantive and adjec-
tive : those which he termed substantive
colours, communicate their colour with-
out the intervention of some other sub-
stance ; those which he called adjective,
require the aid of a mordant or basis.

SUBSTRA'TUM. A stratum lying under
another stratum.

SUBTE'ND. (from sub, under, and tendo,
to stretch, Lat.) To extend under.

SUBTE'NSE. The chord of an arch.

SUBTERRA'NEA.N. ^ (from sub, under, and

SUBTERRA'NEOUS. \ terra, the earth, Lat.
souterrain, Fr. sotteraneo, It.) Lying
under the earth ; placed below the sur-
face of the earth.

SUB

248 ]

SUP

SU'BULATE. (from subula, an awl, Lat.)
Awl-shaped.

1 . In botany, applied to leaves, when
thickest at the base, and gradually taper-
ing towards the point.

2. In conchology, applied to shells taper-
ing gradually to a point.

3. In entomology, a long thin cone softly
bent throughout its whole course.

SU'CCINITE. (from succinum, amber, Lat.)
A mineral of an amber-yellow colour,
thus named by Bonvoisin. It occurs in
small rounded masses about the size of a
pea. Some mineralogists refer succinite
to the idocrase ; others, to the garnet.

SU'CCULENT. (succulentus, Lat. succulent,
Fr. sugoso, It.) Juicy; full of juice. A
term applied to plants with a soft and
juicy stem, as distinguished from those
called ligneous.

SU'DES. (sudes, Lat. a spear.) A class
of spines comprising several genera,
as Sudes villarum, Sudes fortalitiorum,
&c.

SU'FFOLK CRAG. A marine deposit of the
older pliocene period. It consists of
beds of sand and gravel, abounding in
shells and corals.

SU'LCATED. (from sulcus, a furrow, Lat.)
Furrowed ; grooved.

1. In botany, applied to stems marked
with broad deep lines ; also to leaves
having broad, deep, parallel lines.

2. In conchology, applied to shells that
are deeply furrowed, or marked with
ridges or broad furrows.

SU'LCUS. Plural sulci. A broad furrow or
groove.

SU'LPHATE. (from sulphur.) A combi-
nation of sulphuric acid with any sali-
fiable base.

SU'LPHITE. A combination of sulphurous
acid with any salifiable base.

SU'LPHUR. (sulphur, Lat. soufre, Fr.
zolfo, It.) One of the fifty-five simple or
elementary substances, and a non-con-
ductor of electricity. It is of different
shades of yellow, and occurs either in
masses or crystallized. Mr. De La Beche
says, " sulphur must be a more abundant
substance in rocks, than, at first sight,
we might suppose. We are in the habit
of associating our ideas of the connexion
of sulphur and rocks more especially
with volcanic rocks. When so estimated,
the amount, though often locally great,
is, taken generally, not considerable.
Sulphur is, however, widely dissemi-
nated among many rocks. As a sul-
phuret of iron, it is distributed over the
surface of the earth to a great extent,
more particularly in those rocks which
I have elsewhere termed the superior
stratified or fossiliferous rocks, and in
those usually known as trappean. In

many clays sulphuret of iron prevails to a
great extent. Iron pyrites is a neces-
sary and abundant substance in the alum-
shales. By far the larger portion of the
ores of copper and lead are sulphurets.
In the state also of sulphate of lime, sul-
phur is widely spread. Not only does
sulphur thus occur among rocks, but it is
also disseminated throughout the ocean,
sulphate of soda being one of the salts
constantly present in sea-water. We
may therefore consider that sulphur is
far from being a. rare substance on the
face of the earth." The specific gravity
of sulphur is from 1 9 to 2* 1. By fric-
tion it acquires negative electricity. It
is very brittle and friable. When its
combustion is slow, it burns with a bluish
flame and with a suffocating vapour,
which is sulphurous acid ; but when its
combustion is rapid, the flame is white,
the vapour less suffocating, and the pro-
duct is sulphuric acid.

SU'LPHURET. A combination of sulphur
with a metallic base ; as sulphuret of
iron.

SU'LPHURET OF IRON. Iron pyrites. This
is very commonly found in irregular and
subglobular nodules and masses in the
chalk formation.

SU'MMIT. (summit as, Lat. sommet, Fr.)
In conchology, the most elevated point of
the shell in which the hinge is placed.

SUPERFI'CIES. (superficies, Lat. super-
fide, Fr. c'e*/ longeur et largeur sans
profondeur.} The surface only of a
body ; the exterior part.

SUPERIMPO'SED. Laid upon something
else ; as one stratum is superimposed on
a stratum below.

SUPERINCU'MBENT. (from super, above,
and incumbens, lying, Lat.) Lying above
or upon something else.

SUPERPO'SED. Placed upon or above some
other matter or substance, as superposed
structures.

SUPERPOSI'TION. The order in which bo-
dies are placed upon or above other
bodies, as more recent strata upon those
that are older ; secondary rocks upon
primary ; tertiary upon secondary, &c.
&c. The order of superposition of rocks
is never reversed, unless it be by volcanic
agency, when rocks may be forced from
below and thrown, as it were, upon those
which in the usual order of superposition
would be above them. Beds, or strata,
may be altogether wanting, but where-
ever similar beds occur together, the order
of superposition is never inverted. Thus
the Wealden deposites are never found
above the chalk ; the chalk is never found
above the London clay ; the London clay
is never found above the crag : nor do we
meet with the chalk under oolite ; the lias

SUP

[ .249 ]

S Y N

under the red sandstone, or the coal
under the greywacke.

SUPRA-CRETA'CEOUS. (from supra, above,
and cretaceus, chalky, Lat.) Above the
chalk ; formations more recent than those
of the chalk. The supra-cretaceous de-
posites, says Mr. De La Beche, are very
commonly termed tertiary. This is, how-
ever, a name exceedingly objectionable,
as it would imply that there were three
great classes of rocks possessing marked
characteristic distinctions, and that the
deposites above the chalk -constituted the
third of such classes. The supra-creta-
ceous rocks constitute a large portion of
the dry land of Europe, among the lowest
of which in Western Europe are those of
the London and Paris basins. The su-
pra-cretaceous group passes so insensibly,
apparently, into the present order of
things, viewing the subject on a large
scale, that probably no line of demarca-
tion will ever be drawn between them.
Still, even during the time that the upper
portion of the series was being deposited,
great changes must have been produced
in animal life over a considerable part of
the earth's surface. Mr. Bakewell con-
siders the term supra-cretaceous, or, as
he writes it, super-cretaceous, to be pe-
culiarly inappropriate, and adds, " if a
new name were necessary, jsostf-cretaceous
should have been chosen."

SURBE'D. To set stone edgewise, contrary
to the posture it had in the quarry.

SU'RTURBRAND. A name given to Bovey
coal, or brown coal. See Brown Coal.

SU'SSEX MA'RBLE. A member of the Weal-
den group : this occurs in layers varying
from a few inches to upwards of a foot in
thickness, the layers being separated by
seams of clay, or loose friable limestone.
It is a fresh-water deposit, and contains
in great abundance shells of paludinse, a
genus of fresh-water univalves.

This limestone has obtained the name
of Sussex marble from its great abund-
ance throughout the Weald of that county.
It is of various shades of grey and bluish-
grey, mottled with green and yellow ; it
bears a high polish, and is used exten-
sively for architectural and ornamental
purposes.

SU'TURE. (sutura, a seam, Lat. from suo,
to sew, suture, Fr. cucitura, It.) A
seam ; the junction of the bones of the
head by an irregularly jagged zig-zag line.

SWI'LLEY. A provincial term for a coal-
field of very limited extent.

.SWINE-STONE. The name given by Kir-
wan to fetid carbonate of lime or stink-
stone. See Stink-stone.

SY'ENITE. See Sienite.

SY'LVANITE. Native tellurium. A re-
. cently discovered metallic substance.

SY'MPHYSIS. (cv^vaiq, Gr. from (rvpQvu
to grow together; symphyse, Fr.) A
term used in anatomy to denote a parti-
cular form of union of two bones. Bones
united by symphysis have no manifest
motion.

SY'NCHRONAL. ) (from GVV, the same, and

SYNCHRONOUS. $ XQOVOQ, ti™6 or a§e>
Gr. synchrone, Fr. ) Occurring at the
same period of time ; simultaneous ; of
the same age.

SY'NCLINAL LINES. " A term," says Mr.
Lyell, "first used, I believe, by Prof.Sedg-
wick : lines which form ridges and
troughs running nearly parallel to each
other."

SYNGENE'SIA.' (from GVV, with, and ylvf-
<TIQ, generation, Gr.) In botany, the
nineteenth class of plants in Linnseus's
artificial system. This class contains
plants with syngenesious anthers : the
orders of this large class, five in number,
are founded on the circumstance of the
florets of the capitule being hermaphro-
dite and unisexual, variously combined in
the disk and ray. The anthers are united
into a tube, and the flowers are com-
pound. The following are the five orders
composing the class Syngenesia ; they are
determined by the arrangement of their
flowers, and by the sex of their florets.

1. Polygamia sequalis, where each floret
is perfect, being furnished with stamens
and pistils, and capable of bringing its
seed to maturity : the leontodon tarax-
acum, or dandelion, is a familiar ex-
ample. 2. Polygamea superflua. The
florets of the disk perfect, those of the
margin having pistils only : the anthemis
nobilis, or chamomile, is an example.
3. Polygamia frustranea. Florets of the
disk perfect or united, those of the margin
neuter, or destitute of pistils as well as of
stamens. 4. Polygamia necessaria. The
florets of the disc are male, of the ray
female : the garden marygold affords an
illustration. 5. Polygamia segregate.
Several florets, either simple or com-
pound, but with a proper calyx, included
within one common calyx : the globe-
thistle is an example. To these five
orders, some authors add a sixth, namely,
Monogamia, which has the flowers se-
parate, and not crowded in heads.

SYNGENE'SIAN. > Belonging to the class

SYNGENE'SIOUS. ) Syngenesia.

SYNO'VIA. (from <rvv, with, like, and
MOV, an egg, Gr. synovie, Fr.) A glairy
lubricating fluid contained within the cap-
sular ligament of joints, serving the pur-
pose of preventing friction, and resem-
bling the white of an egg, whence its
name.

SYNO'VIAL. Pertaining to synovia ; resem-
bling synovia ; secreting synovia.
K K

S Y N

[250 ]

T A L

SY'NTHESIS. (avvOtvig, Gr. from avvri-
0t/jui, to join together ; synthese, Fr.)
The act of joining ; opposed to analysis.
Water is proved to consist of oxygen and
hydrogen by analysis, that is, by decom-
posing water and ascertaining its constitu-
ents ; it may however be proved to consist
of oxygen and hydrogen by synthesis,
that is, by uniting the relative proportions
of oxygen and hydrogen.

SY'PHON. ) See Siphon and Siphun-

SY'PHUNCLE. $ cle.

SYRI'NGODENDRON. The name given by
Count Sternberg to many species of sigil-
laria, from the parallel pipe - shaped
flutings that extend from the top to the
bottom of their trunks. These trunks
are without joints, and many of them
attain the size of forest trees. — Prof.
Buckland. Bridgewater Treatise.

SYSTE'MIC CIRCULATION. The circulation

of the blood through the body generally,
as distinguished from that other circula-
tion which is confined to the respiratory
organs and the heart, or the respiratory
circulation.

SY'STOLE. ((rvoroXr), Gr. contraction,
systole, Fr.) A term used to signify the
heart's contraction. The two movements
of the heart are its systole and diastole ;
by the systole of the heart, or its contrac-
tion, the blood is pressed out of the heart
and forced into the arteries ; by its dias-
tole, the blood is received from the veins
into the heart.

SY'ZIGY. (from (rv^vyia, Gr. conjunction;
syzygie, Fr. ) A term applied to the con-
junction or opposition of a planet with the
sun. The syzygies of the sun and moon
occur at the time of full and new moon ;
the tides are much increased, and are
called spring tides, in the syzygies.

TABASHEE'R. A siliceous concretion found
in the joints of the bamboo : by some it
has been supposed to be the juice of the
plant inspissated and hardened. It is
remarkable on account of its peculiar
optical properties ; its refractive power is
between air and water, namely 1-111.
The finest varieties reflect a delicate azure
colour, and transmit a straw-yellow tint,
which is complementary to the azure.
When it is wetted slightly with a wet
needle or pin, the wet spot instantly be-
comes milk-white and opaque. The appli-
cation of a larger quantity of water re-
stores its transparency. The word is
from the Persian. — Dr. Brewster.

TA'BULAR. (from tabularis, Lat.) Formed
in laminae or plates ; having a flat or
square surface ; in large plates.

TA'BULAR STRU'CTURE. This.form of struc-
ture consists of parallel plates, separated
by regular seams ; it is the consequence
of crystallization, and though closely allied
to the columnar structure, is not uncom-
monly confounded with stratification. —
Mr. Bakewell.

TA'BULAR SPAR. The schaalstein of Wer-
ner ; spath en tables of Haiiy ; prismati-
scher augit-spath of Mohs. A greyish-
white mineral, occurring massive and in
granular concretions. Lustre' pearly ;
fracture splintery; translucent. Specific
gravity 2- 7 to 3*2. Its constituents are
silica 51-40, lime 45-0, oxide of iron a
trace, water 4'0. It occurs in primary
rocks in Norway and other places.
TA'BULATED. (from tabula, a table, Lat.)
Having a flat surface.

TALC. ) (talk, Germ, talc, Fr.) A some-

TALCK. $ what fibrous and very commonly
foliated mineral, resembling mica in its
lamellar structure, but its laminae not
being elastic as are those of mica. Its
colours are white, pale yellow, or greenish.
Both its surface and powder are unctuous
to the touch. It is so soft as to be easily
scratched with the finger-nail. Its lustre
is often pearly, or inclined to metallic.
It is translucent, and, when divided into
thin laminae, transparent. Specific gravity
from 2-58 to 2*90. Before the blow-pipe
it whitens, its laminae separate, and their
extremities fuse into a white enamel. Its
constituents are principally silex and
magnesia, with small quantities of potash,
alumine, oxide of iron, and water. Talc
and chlorite are nearly allied, and pass
by insensible gradations, into each other.
Talc is sometimes used as a substitute for
glass, and windows are formed of its
laminae, which are sometimes obtained of
the size of twelve inches square. There
are two varieties of talc, namely, fibrous
talc and indurated talc.

TA'LCITE. The nacrite of Brongniart ; talc
granuleux of Haiiy ; erdiger talc of Wer-
ner. A rare mineral, occurring in coats
or reniform masses, composed of very
minute shining spangles or scales. The
French have given to it the name of na-
crite in consequence of its pearly lustre.
When rubbed between the fingers, it leaves
a pearly gloss. For its constituents and
other particulars, see Nacrite.

TA'LCOUS. ) Resembling talc ; containing

TA'LCY. ( talc.

T A L

[251 ]

TEL

TA'LUS. (talus, Lat. talus, Fr. inclinaison
que Von donne a la surface laterals et
exterieure d*un mur, de telle sorte que de
haut en has il aille toujours en *' fyaissis-
sent. Jl se dit aussi d'une terrasse san#
murs, lorsque ses faces lattrales s'elargis-
sent de haut en bos.)

1. A sloping heap. When, from disinte-
gration, the fragments of a face of rock
accumulate at its base and form a sloping
heap, the heap is called a talus.

2. In anatomy, a name sometimes given to
one of the bones of the tarsus, the astra-
galus.

TA'NGENT. (from tango, to touch, Lat.
tang eiite, Fr. tangente, It.) A straight
line which touches a curved line in one
point without cutting it.

TA'NTAHTE. The name given by some
mineralogists, and in the first instance by
Ekeberg, to the ferruginous oxide of co-
lumbium. The tantale oxide ferro-
manganesifere of Haiiy ; the tantale tan-
talite of Brongniart. Called also colum-
bite. The ore of tantalum or columbium.
When recently broken, tantalite is of a
dark bluish-gray or nearly iron-black
colour. It occurs in octohedral crystals,
and in small masses. Its specific gravity
is from 5 '9 to 7' 9. It consists of oxide
of columbium 80'0, oxide of iron 12*0,
oxide of manganese 8'0. It has been
found in Finland, and in the United
States of America.

TA'NTALUM. A metal extracted from tan-
talite ; it appears to be the same sub-
stance as columbium, and identical with
it.

TA'PIR. A genus of mammalia, belonging
to the family Pachydermata Ordinaria.
The nose of the tapir may be compared
to a small fleshy proboscis, the snout
being lengthened and moveable. There
are several species of this genus still sur-
viving, but they are all natives of tropical
climates. The general appearance of the
tapir is that of a pig, but some of the
species are as large as the ass. The fore
feet have four toes each, all of equal size ;
the hind feet have only three each. The
skin is of a dark colour, nearly black,
with but few hairs.

Fossil tapirs are found in different parts
of Europe.

TAP-ROOT. In botany, the main root of a
plant, which passes directly downwards.

TARDIGRA'DA. ) (from tardigradus, slow-

TA'RDIGRADE. $ paced, Lat.) A family
of quadrupeds of the order Edentata.
These animals have obtained their name
from the extreme slowness of their mo-
tions. The only existing genus is the
Bradypus or sloth. Their nails are enor-
mously long, compressed, and crooked.
The molars are cylindrical ; the canini

sharp, and longer than the molars. They
live in trees, and so great is their indis-
position to locomotion, that they continue
on the same tree till they have devoured
every leaf to be found thereon. Some
authors state that, to avoid the trouble of
a regular descent, they tumble themselves
down from the branch they happen to be
on. When they have eaten their full,
they can roll themselves into a ball, and
take a long and reckless sleep.

TAR MI'NERAL. A variety of bitumen,
bearing a great resemblance to petroleum,
but more viscid, and of a darker colour.

TARN. A bog ; a fen ; a marsh ; a pool.
This word appears to be of Icelandic
origin.

TA'RSAL. Pertaining to the tarsus or in-
step, as the tarsal bones, &c.

TA'RSUS. (rapaoQ, Gr. tarse, Fr.)

1. The instep, or that part of the foot
situated between the bones of the leg and
the metatarsus.

2. In entomology, the tarsus, or foot, of
insects is the last division of the limb : it
is divided into several joints, which have
been supposed to represent the toes of
quadrupeds. The last joint of the tarsus
is generally terminated by a claw, which
is sometimes single and sometimes double,
and which contributes to fasten the foot,
under a variety of circumstances both of
action and repose. The hooks of the
anterior tarsi are directed backwards,
those of the middle pair inwards, of the
hindermost pair forwards. Many insects
are provided with cushions at the ex-
tremity of the feet, which break the force
of falls, and prevent the jar which the
frame would otherwise have to sustain.
These cushions are formed of dense vel-
vety tufts of hair, lining the underside of
the tarsi, but leaving the claw uncovered.
— Rev. W. Kirby.

TA'RTARIN. ) Vegetable alkali, or potash :

TA'RTARINE. 5 a name assigned to it by
Kirwan.

TAXO'NOMY. (from ra£tc., order, and
VO^OQ, law, Gr.) The classification or
arrangement of animals or plants, accord-
ing to certain principles, in divisions and
groups.

TE'GMEN. (tegmen, any sort of covering,
Lat.) A covering of the body, as the
cuticle, &c. ; used in botany to denote one
of the coats of the seed ; in entomology,
applied to the coverings of the wings of
the order Orthoptera, or straight-winged
insects.

TE'GUMENT. The same as teamen.

TELEOSA'URUS. A new genus of fossil
saurians, thus named and arranged by M.
Geoffroy St. Hilaire. The teleosauri have
long and narrow beaks, the nostrils form-
ing almost a vertical section of the an-

TEL

[ 252 ]

T E M

terior extremity of the beak. — Professor
Buckland.

TKLLI'NA. (tellina, Lat. a limpin.) A
genus of orbicular or ovate transverse
equivalved, marine bivalves, with a fold
on the anterior part, and short beaks,
found in sands, at depths varying to
fifteen fathoms. Hinge with usually three
teeth, the lateral ones smooth on one
side. The shells of this genus are chiefly
known by the inflection, or irregular fold,
on the fore part ; in the one valve the
fold is convex, in the other, concave.
There are three families of tellinse : ovate
and thickish, ovate and compressed, sub-
orbicular. Some conchologists have di-
vided tellina into three genera ; Tellina,
Cyclas, and Pandora. Ninety-four spe-
cies are described in Turton's Linne,
twenty-two of which have been found in
the seas of our coasts. The tellina is
remarkable for the quickness and agility
with which it can spring to considerable
distances, by first folding the foot into a
small compass, and theu suddenly ex-
tending it ; while the shell is at the same
time closed with a loud snap.

Many species of this genus are found
fossil ; Lamarck enumerates ten, as hav-
ing been found in the neighbourhood of
Paris. Dr. Man tell gives three species
as occurring in Sussex ; two in the lower
green sand, Tellina sequalis and Tellina
inaequalis, and one in the alluvial depo-
sites, Tellina solidula.

TELLI'NIDES. A genus of sub-equivalve,
inequilateral, transverse, marine bivalves,
found in sandy mud at depths varying
from five to fifteen fathoms.

TE'LLINITE. A fossil tellina. See Tellina.

TELLU'RIUM. The name given by Klap-
roth to a metal first discovered by him or
by Miiller in 1782, from an ore of gold,
•with which metal it is found combined
in the Transylvanian mines. Its colour
is nearly a tin white, with a shade of
blue. Structure foliated. Specific gra-
vity 6-1. Before the blow- pipe it fuses
easily, and is very volatile, giving out a
pungent odour, compared by some to that
of a radish. Tellurium is not used in
any form.

NA'TIVE TELLD'RIUM. Rhombohedral Tel-
lurium. The tellure natif auro-ferrifere
of Hau'y ; gediegen silvan of Werner ;
tellure natif ferrifere of Brongniart. This
ore is never perfectly pure. It always
contains a greater or less quantity of gold,
and sometimes silver, lead, copper, and
sulphur. It is found in Transylvania
only, in veins, traversing greywacke. It
is of a white colour ; of a shining and me-
tallic lustre ; brittle and frangible. Its
constituents are tellurium 92'6, iron 7-2,
gold 0-2.

TE'MPERATURE. (temperatura, Lat. tem-
ptrature, Fr. tempra, It.) Constitution of
nature ; the constitution or state of the at-
mosphere, whether it be hot or cold, humid

• or dry ; the condition of a body, as mani-
fested by its influence on the thermometer.
A question of great importance, in the
study of geology, arises as regards the
existing and the former temperature of
this planet. Whether the nebular hypo-
thesis be correct, (and assuredly, if we
dispassionately examine the question with
our minds divested of prejudices and pre-
conceived notions, there are many very
powerful arguments in its favour,) or
otherwise, it certainly does appear
that a very high temperature did once
exist on this planet ; and that such tem-
perature has been gradually diminishing.
Whether also the nucleus of the globe be
in a state of incandescence or fusion is a
question which probably never will be
solved, till the heavens shall be rolled
away as a curtain, and the elements shall
melt with fervent heat. Still we well
know that the temperature of the earth
does increase in a fixed and certain ratio
as we descend into its depths. The fol-
lowing observations on this interesting
subject are extracted from some of our
most able geologists and greatest autho-
rities. There is so much grandeur and
simplicity in the idea of the condensation
of gaseous matter into those spheres and
spheroids which exist, not only in our
solar system, but also by myriads through-
out the universe, that we are irresistibly
led to adopt some view of this kind, more
particularly as it would accord with the
unity of design so evident throughout
creation. There is no argument, a priori,
against the hypothesis that the matter
composing our globe may once have
existed in a gaseous state, and in that
state have revolved round the sun. If it
be highly probable that heat to a certain
extent resists the action of gravitation in
the sun, Jupiter, and Saturn, there is
nothing unphilosophical in the inference
that heat has resisted, and may continue
to resist, in a minor degree, the action of
gravitation in our planet. The following
are general results from the various facts
observable on the earth's surface, and
such depths thereof as man has hitherto
been able to penetrate. 1. Numerous
experiments in mines show an increase of
temperature from the surface downwards,
that is, from those depths where the
action of the solar rays ceases to produce
a Variable heat. 2. Thermal springs
occur in all parts of the world, and among
all varieties of rock. 3. The temperature
of the water in Artesian wells is found to
increase with the depth. 4. Terrestrial

T E M

[ 253 ]

T E M

temperature, at small depths, does not
coincide with the mean temperature of
the atmosphere above it. 5. Igneous
matter has been ejected at all periods
from the interior of the earth. 6. Active
volcanoes occur widely spread over the
surface of the world, and so closely re-
semble each other, that they may be con-
sidered as produced by a common cause,
and that cause deep-seated. 7. Geologi-
cal phenomena attest a great decrease of
temperature on the surface of the globe.
8. A decreased temperature of the earth
would, by radiation, produce the various
mountain ranges and fractured strata found
on the surface of our planet. " When all
these circumstances," says the able and
learned author, H. T. De la Beche, Esq.,
from whose work, Researches on Theo-
retical Geology, I have extracted the pre-
ceding observations, " are taken into con-
sideration, and we add the probability
that heat counteracts the effects of gravity
in the sun and certain planets, and that
the free passage of the particles of terres-
trial matter among each other was neces-
sary to produce the figure of the earth, the
evidence in favour not only of a central
heat at present, but also of a heat of far
greater intensity at remote geological
epochs, becomes exceedingly strong ; so
strong, indeed, that there is some diffi-
culty in resisting the impression that we
have, by various means, made as fair an
approximation to the truth, as the nature
of the subject will admit. If the theory
of central heat be founded on probability,
the very general occurrence of tilted and
fractured rocks is of easy explanation."

M. Adolphe Brongniart has shewn,
says Professor Buckland, "that the exist-
ing submarine vegetation seems to admit
of three great divisions which charac-
terize, to a certain degree, the plants of
the frigid, temperate, and torrid zones.
If we take a general review of the remains
of terrestrial vegetables, that are distri-
buted through the three great periods of
geological history, we find a similar di-
vision of them into groups, each re-
spectively indicating the same successive
diminutions of temperature upon the land,
which have been inferred from the re-
mains of submarine vegetation. Thus,
in strata of the transition series, we have
an association of a few existing families of
endogenous plants, chiefly ferns and equi-
setacese, with extinct families both endo-
genous and exogenous, which some mo-
dern botanists have considered to indicate
a climate hotter than that of the tropics
of the present day. In the secondary
formations, the species of these most
early families become less numerous, and
many genera and families entirely cease;

while a large increase takes place in
Cycadese and Coniferse, two families com-
prehending many existing forms of vege-
tables. The united character of the
groups thus associated, indicate a climate,
whose temperature was nearly similar to
that which prevails within the present
tropics. In the tertiary deposites, the
greater number of the families of the first
series, and many of those of the second
disappear, and a more complicated dicoty-
ledonous vegetation takes place of the
simpler forms, and the general character
marks a climate nearly approaching to
that of the Mediterranean. This third
great change in the vegetable kingdom is
considered to supply another argument in
favour of the opinion, that the temper-
ature of the atmosphere has gone on con-
tinually diminishing from the first com-
mencement of life upon our globe."

" To know the temperature of the in-
terior parts of the globe at the present
period," says Professor Phillips, " and the
effects depending on its condition in this
respect, is important, as furnishing one,
and that, perhaps, the most instructive,
of the elements for computing the changes
which have, in earlier times, affected its
structure and configuration, and varied
its adaptations for organic life. That
the earth has below its surface a source
of great heat, independent of solar in-
fluence, is perfectly ascertained by vol-
canic phenomena ; that this heat is very
generally diffused, is equally certain, from
the extent of country in which thermal
springs are found ; that it is universally
spread below our feet, becomes conti-
nually more and more probable from ex-
perimental researches."

From a series of experiments, it ap-
pears that the temperature of the earth's
crust increases at the rate of 1° Fahren-
heit for every forty-five feet of perpendi-
cular descent.

The uninjured corals and chambered
univalves of Iglulic, Melville Island, and
other high latitudes, sufficiently prove
that during the carboniferous period
there was an elevated temperature even
in the northern regions bordering on the
Arctic circle. The heat and the humidity of
the air, and the uniformity of climate, ap-
pear to have been most remarkable when
the oldest strata hitherto discovered were
formed. The approximation to a climate
similar to that now enjoyed in these la-
titudes does not commence till the era of
the formations termed tertiary ; and while
the different tertiary rocks were depo-
sited in succession, the temperature seems
to have been still further lowered, and to
have continued to diminish gradually,
even after the appearance upon the earth

TEN

[254]

T E R

of a great portion of the existing species.
—Mr. Lyell.

TENA'CITY. (tenacitas, Lat. tenacite, Fr.)
Viscocity ; adhesiveness ; glutinousness ;
cohesiveness. The degree of force with
which the particles of bodies cohere.- It
is in consequence of possessing the pro-
perty of tenacity, that certain substances
permit themselves to be drawn out into
wire or flattened under the blows of the
hammer.

TE'NDON. (tendo, Lat. from rtiva), to
stretch, Gr. tendon, Fr.) The fibrous
cord-like extremity of a muscle.

TE'NDINOUS. (tendineux, Fr. tendinoso,
It.) Composed of tendons ; resembling
tendon.

TE'NDRIL. (tendron, Fr.) In botany, a
spiral appendage to certain plants, its
use being to clasp and wind round other
bodies, by which means weak and climb-
ing stems support themselves, and rise to
a great height.

TE'NNANTITE. A variety of sulphuret of
copper of a lead-grey or blackish colour.
It has been thus named by Mr. R.
Phillips. It occurs in copper veins in
some of the mines of Cornwall. Its
constituents are, according to the analysis
of Mr. Phillips, copper 45'32, arsenic
11-84, iron 9'26, sulphur 28'74, silica
5'00. Hardness 4*0. Specific gravity
from 4'3 to 4-4. It occurs massive, and
crystallized in rhomboidal dodecahedrons,
cubes, and octohedrons.

TE'NTACLES. ) Feelers ; exploring organs.

TENTA'CULA. ) In its most restricted
sense, says the Rev. W. Kirby, this term is
understood to signify organs, appendages
of the mouth, which have no articula-
tions, but, in a larger sense, the term has
been applied also to all jointed organs in
its vicinity, and used for a similar pur-
pose, which indeed are the precursors of
feelers and antennae. It is to these or-
gans, as well as for their food, that
polypes are indebted for what consti-
tutes their principal ornament, that re-
semblance of a plant or shrub in full
blossom adorned with crimson or orange-
coloured flowers. In the fixed polypes,
the tentacles are the only motive organs.
The tentacles of the fresh-water polypes,
forming the locomotive genus hydra, are
not, as those of the fixed marine ones,
shaped like the petals of a blossom, but
are long hair-like flexile arms, somewhat
resembling the branches of a chandelier.
Amongst the Radiaries, tentacles exist in
some genera, and not in others. In the
Stelleridans and Echinidans, there are
no tentacles, but the Fistulidans present
a floriform coronet of tentacles. Ten-
tacles as exploratory, prehensory, and
locomotive organs, exist in several other

classes of animals. In none, however,
are they more remarkable than in the
Cephalopoda : in these animals they are
used as arms for prehension, as legs for
locomotion, as sails for wafting their pos-
sessors over the boundless deep, as oars
for passing through its waves, as a rudder
for directing their course, and as an an-
chor for fixing themselves. The tenta-
cula of the various tribes of Polypi, of
Actiniae, and of Annelida, are organs both
of prehension and of touch.

TEREBE'LLA. A genus of Annelidans, or
annulose animals, placed by Cuvier in
the order Tubicola. They are inhabi-
tants of the sea, and are met with
generally in shallow water, on the coasts,
and on shells, &c. The body is oblong,
creeping, naked, often enclosed in a tube,
furnished with lateral fascicles, or tufts,
and small branchiae ; mouth placed be-
fore, furnished with lips without teeth,
and protruding a clavate proboscis ;
feelers numerous, ciliate, capillary, seated
round the mouth. Terebellae not being
provided by nature with any external
shell, endeavour to furnish themselves
with an armature. For this purpose they
collect grains of sand, or fragments of
decayed shells, or other substances, which
they agglutinate together by means of a
viscid exudation, so as to form a firm
defensive covering, like a coat of mail.
These coverings, however, composed as
they are of extraneous materials, and
not being organic productions of the ani-
mals themselves, are structures wholly
foreign to their systems. Terebellae are
provided with tentacles, issuing from the
head, which, when the rest of the body
has retired within the tube, is the only
part exposed.

TE'REBRA. A genus of turreted subulated
marine univalves : the opening short, and
notched in the lower part. The basis of
the columella twisted. Two species are
found fossil in the environs of Paris,
namely, Terebra plicatula, and Terebra
scalarina.

TE'REBRATING. A term applied to shells
which form holes in rocks, wood, &c.,
and reside therein.

TEREBRA'TULA. A genus of the class
Brachiopoda. Terebratulse are marine
bivalves found moored to rocks, shells,
&c., at depths varying from ten to ninety
fathoms. The valves are unequal and
united with a hinge, but having no liga-
ment : the summit of one, more salient
than the other, is perforated to permit
the passage of a fleshy pedicle, by means
of which the animal attaches itself to
rocks, shells, &c. The recent species are
few, but the fossil are very numerous. In
the fossil shell, the operculum which

T E R

[ 255 ]

T E R

serves for the attachment of the animal to
the object to which it is moored, can
rarely be traced. The casts of some spe-
cies of fossil Terebratulse are of a most
extraordinary form. These casts are said
to have been first noticed by Pliny, who
describes certain stones, some of which
were white and others brown. Agricola
next noticed these bodies, as having been
found whilst digging near the fortress of
Ehrenbreitstein, in Treves. After various
opinions had been offered respecting the
true origin and nature of these fossils,
Wolfart advanced the opinion that they
were the casts of marine shells. Tere-
bratulae are found most abundantly in the
secondary and tertiary formations. Dr.
Mantell enumerates the following species
as occurring among the organic remains
of Sussex. In the chalk formation Tere-
bratula subrotunda, very common, T.
carnea, T. ovata, T. nudata, T. subplicata,
T. elongata, and T. plicatilis. In the two
last species, namely, T. elongata and T.
plicatilis are included as varieties T. un-
dulata, T. subundata, T. intermedia, T.
semiglobosa, T. octoplicata, and T. con-
cinna. In the chalk marl are found Te-
rebratula subrotunda, T. undulata, T.
striatula, T. Mantelliana, T. Martini, T.
rostrata, and T. squamosa. In the upper
green-sand, Terebratula biplicata. In
the Shanklin sand Terebratula ovata, and
T. lata.

TEREDI'NA. (from teredo, a little worm
that eateth wood, Lat.) A genus of
acephalous testacea, belonging to the
family Inclusa, or, according to Lamarck,
Tubicolaria. The valves are equal and
inequilateral, with a little hollow on the
inside of each valve, and a small, free,
shield- shaped piece on the hinge. Tere-
dinse are known only in a fossil state.

TERE'DO. (teredo, Lat. a little worm that
eateth wood ; Teprjdtjjv, from Tepew, to
bore, Gr.) A genus of marine bivalves,
belonging to the family Inclusa, in Cu-
vier's arrangement, and to Tubicolaria, in
Lamarck's. The Teredo is contained in
the lower end of a cylindrical tubular
shell, generally open at both ends, two
opercula being adapted to the upper end :
it is capable of penetrating wood. The
shells of this genus inhabit the bottoms of
ships, and wood under water. One spe-
cies, Teredo gigantea, has been found in
mud at the bottom of the ocean ; it attains
to a great size, one specimen measuring
five feet four inches in length, with a cir-
cumference at the base of nine inches.
The body of the shell had an appearance
resembling stalactites, and was found
filled with a soft gelatinous flesh. When
arrived at its full growth the Teredo gi-
gantea closes up the end of its shell.

TERE'DO NAVA'LIS. The ship-worm. The
name given to a species of Teredo from
the circumstance of its insinuating itself
into the timbers of the bottoms of ships,
even although the oak is perfectly sound :
it very soon completely destroys the tim-
bers it attacks. This destructive creature
was brought originally, by our ships, from
tropical climates, but it has now become
an inhabitant of most of the harbours of
this country. The teredo navalis or ship-
worm, will destroy every thing constructed
of timber that is under the surface of tthe
water. Their object is not to devour the
wood, but to make for themselves a cell
in which they may be safe from their
enemies. They bore in the direction of
the grain of the timber, deviating only to
avoid the track of others. Fortunately
these animals cannot exist in fresh-water.

TE'RMINAL. (from terminalis, Lat.) In
botany, applied to flowers and umbels
proceeding from the extremity of the stem
or branches.

TERMINO'LOGY. For an explanation of
this term, see Orismology.

TE'RNA FO'LIA. In botany, leaves growing
three together in a whorl. This term, it
must be remarked, is very different in its
signification from ternate.

TE'RNARY. (ternarius, Lat. of or belong-
ing to three; ternaire, Fr. ternario, It.)
Proceeding by threes ; consisting of three.
Applied to things arranged in order by
threes : thus, in botany, a flower is said
to have a ternary division of its parts
when it has three sepals, three petals,
three stamens, or twice or thrice as many.

TE'RNATE. (from ternus, Lat.) A term
in botany, applied to compound leaves
that consist of three leaflets on a petiole :
the leaf of the strawberry affords a fami-
liar example of a ternate leaf.

TE'RRA PONDERO'SA. Another name for
barytes. See Barytes.

TE'RRA SIE'NNA. The name given to an
ochreous earth from its being brought
from Sienna : it is a sort of brown bole,
and is used as a pigment.

TE'RRAIN TERTIA'IRE. The name given by
the French geologists to the tertiary
strata. The Germans call these, Tertiar-
gebilde.

TE'RRE VERTE. Green earth. The griin
erde of Werner ; talc zographique of
Haiiy ; chlorite baldogee of Brongniart.
An earth of a green colour, sometimes
passing to olive. It consists, according
to Klaproth, of silex 53, magnesia 2,
potash 10, oxide of iron 28, water 6.
Vauquelin states that it contains 7'00 of
alumine. It is found in Germany, France,
Italy, and North America. It is ground
with oil, and used as a pigment.

TE'RREOUS. (terreus, Lat. terreux, Fr.

T E R

[256 ]

T E R

terroso, It.) Consisting of earth
earthy.

TERRE'STRIAL. (terreslris, Lat. terrestre
Fr. terrestre, It.) Pertaining to the
earth ; consisting of earthy matter.

TERRE'STRIAL REFRA'CTION. It is the
power which air possesses, in common
with all transparent media, of refracting
the rays of light, or bending them out ol
their straight course, which renders a
knowledge of the constitution of the at-
mosphere important to the astronomer.
Whenever a ray of light passes obliquely
from a higher level to a lower one, or
vice versa, its course is not rectilinear,
but concave downwards ; and of course
any object seen by means of such a ray,
must appear deviated from its true course,
whether that object be, like the celestial
bodies, entirely beyond the atmosphere,
or, like the summits of mountains, seen
from the plains, or other terrestrial sta-
tions, at different levels, seen from each
other, immersed in it. Every difference
of level, accompanied, as it must be, with
a difference of density in the aerial strata,
must also have, corresponding to it, a
certain amount of refraction. This re-
fraction between terrestrial stations is
termed terrestrial refraction. The re-
fraction of a terrestrial object is estimated
differently from that of a celestial body.
It is measured by the angle contained
between the tangent to the curvilineal
path of the ray where it meets the eye,
and the straight line joining the eye and
the object The quantity of terrestrial
refraction is obtained, by measuring con-
temporaneously the elevation of the top
of a mountain above a point in the plain
at its base, and the depression of that
point below the top of the mountain.
The distance between these two stations
is the chord of the horizontal angle ; and
it is easy to prove that double the refrac-
tion is equal to the horizontal angle, in-
creased by the difference between the ap-
parent elevation and the apparent de-
pression. Whence it appears that in the
mean state of the atmosphere, the refrac-
tion is about the fourteenth part of the
horizontal angle. — Mrs. Somerville. Sir
John Herschel.

TE'RTIARY. Third. A term applied to
those formations which have been depo-
sited subsequently to the chalk formation.

TE'RTIARY STRA'TA. A division of sedi-
mentary formations called tertiary, as
being of newer origin than the secondary,
and characterized by distinct species of
fossil animals and plants. They present
a most decided contrast with the second-
ary and older strata in most of their es-
sential characters. The most striking
feature of these formations consists in the

repeated alternations of marine deposites
with those of fresh water. We are in-
debted to Cuvier and Brongniart, for the
first detailed account of the nature and
relations of a very important portion of
the tertiary strata, namely, those which
occur in the neighbourhood of Paris.
These were found to fill a depression in
the chalk, and to be composed of different
materials, sometimes including the re-
mains of marine, sometimes of fresh-
water animals. The first discovery of the
tertiary strata in the Isle of Wight and
south-east of England, .we owe to Mr.
Webster. The whole of the tertiary ac-
cumulations are stratiform deposites, ex-
hibiting various kinds of lamination and
bedding. Previously to the commence-
ment of the present century, the true
nature of the tertiary formations was
unknown, the chalk was considered the
highest known rock, and the tertiary de-
posites as mere superficial sands, gravels,
or clays.

The tertiary system may be said to con-
stitute a series of formations which link
together the present and the past ; while
the more ancient tertiary deposites con-
tain organic remains related to the se-
condary formations, the most recent con-
tain many existing species of animals and
plants, associated with forms now ex-
tinct. The English series of marine
tertiary deposites is most distinctly shewn
in the Hampshire basin, and the Isle of
Wight, in the London basin, and on the
eastern coast, from the mouth of the river
Yare to that of the Thames. In France,
however, we find a much more full de-
velopment than in England of the ter-
tiary strata. From the commencement
of the tertiary period, there appears to
have been a constantly increasing pro-
vision for the diffusion of animal life.
The term tertiary has been altogether dis-
approved of by some geological authors.
Mr. De La Beche considers the name
highly objectionable, " inasmuch as it
would imply that there were three great
classes of rocks possessing marked cha-
racteristic distinctions, and that the de-
posites above the chalk constituted the
third of such classes." He proposes
that the term supra-cretaceous be em-
ployed in preference to tertiary. On the
other hand, Mr. Bakewell says, "the
name of tertiary has been given with much
propriety to all the strata that are more
recent than the secondary ; the term is
intelligible, and ought not to be changed
without sufficient reason. The name of
supercretaceous, which has recently been
applied to the tertiary strata, is peculiarly
inappropriate, as these strata may cover
any of the lower rocks, and in Auvergne

T E R

T E S

they may be seen resting on granite. If
a new name were necessary, post-cre-
taceous should have been chosen ; as all
geologists are agreed that the » tertiary
strata were deposited after the chalk."

The tertiary strata have been sub-
divided by Mr. Lyell and M. Deshayes
into four principal groups, to which Mr.
Lyell has assigned the terms eocene, mio-
cene, older pliocene, and newer pliocene ;
each group being characterized by the
relative proportion of recent and extinct
species of shells therein contained. To
this nomenclature of Mr. Lyell's, Mr. De
La Beche urges the following objections.
" Classifications entirely founded on or-
ganic remains are at all times liable to be
erroneous, if contemporaneous deposition
be thence inferred as a necessary conse-
quence ; they therefore may be consi-
dered as doubly liable to error when em-
ployed in proving contemporaneous ori-
gin in such rocks as those of the supra-
cretaceous period, and which may contain
a certain per centage of the remains of
molluscs resembling those of the present
day. When we appropriate names of this
kind to rocks, derived from one character j
alone, and that character one which can- \
not be considered constant, we theoreti-
cally prejudge the place which the rocks |
should occupy in a geological series, where
the comparative date of the deposit itself
is sought, not the particular proportion
of given organic remains detected in it,
which is necessarily a secondary consider-
ation. If it be considered convenient to
divide the supra-cretaceous rocks of Eu-
rope into three or more sub-groups,
names which imply their actual geological
position in the series, such as superior,
medial, and inferior ; upper, medial, and
lower, or others of the like kind, would
be preferable to those derived only from
a per- centage of certain organic con- -
tents."

These little differences of opinion, how-
ever, between our leading geologists will ;
give place to the general advancement of
the science. A multiplied nomenclature
is greatly to be deprecated, leading not
only to much confusion, but being, in
itself, a source of discouragement to the
student, and deterring many from enter-
ing on the study of any branch of
science.

Although the tertiary or supra-creta-
ceous formations may be said to include
all the deposits from the chalk upwards,
yet, by some geologists, those of what is
termed the recent period form a distinct
subdivision, and the tertiary formations
include only the four groups, namely,
the eocene, miocene, older pliocene, and
newer pliocene. Commencing therefore

from below upwards, we find included in
the tertiary series, 1. The eocene, com-
prising marine and fresh-water deposits,
including in the former, the calcaire gros-
sier and the London clay, in the latter, the
calcaire siliceux. 2. The miocene, com-
prising the faluns of the Loire, marine
deposits, and sands, clays, lignites, &c.
&c. ; fresh-water deposits. 3. The older
pliocene, consisting of subapennine marl,
subapennine yellow sand, English crag,
marine deposits ; arid sands, clay&, lig-
nites, &c., fresh- water formations. 4.
Newer pliocene. In this, the most recent
of the tertiary deposits, we have limestone,
sand, clays, conglomerates, marls, &c.
containing marine fossils, being marine
stratifications ; and sands, clays, sand-
stones, lignites, &c., containing fresh-
water fossils, being fresh-water de-
posits.

TE'SSELATED. (tcsselatus, Lat. wrought
in chequer-work.) Chequered, like a chess
board. In oonchology, applied to shells
that are coloured in regular and defined
patches.

TE'SSULAR. A term applied to a system
of crystallization, not susceptible of va-
riation. The cube, tetrahedron, and
several other forms belong to the tessular
system.

TE'STA. (testa, Lat. a shell.)

1. Commonly applied to the shelly co-
vering of testaceous animals.

2. In botany, the outer coat of the seed.
The seed, or ripened ovulum, consists of
coverings called integuments or seed-
coats, the outer of which is called the
testa.

TESTA'CEA. (from testa, Lat. a shell ;
testace', Fr.) In the Linneean system of
natural history, the third order of vermes.
This order comprises all shell-fish, ar-
ranged by Linnseus under thirty-six ge-
nera. The testacea differ from the crus-
tacea in their composition ; the calca-
reous part of the shells of testacea being
carbonate of lime, whereas in the shells
of Crustacea it is phosphate of lime. The
testacea also retain their shells as long as
they live ; the Crustacea cast them an-
nually, or, at least, periodically.

TESTA'CEOUS. (testacms, Lat. testacee,
Fr. testaceo, It.) Belonging to the
order testacea ; having a strong thick
shell, the calcareous portion of which con-
sists of carbonate of lime.

TESTACEO'LOGY. A modern term for the
natural history of shells, and synonymous
with conchology.

TESTU'DINATE. ( testudineatus, Lat.)
Arched ; vaulted ; resembling the back
of a tortoise.

TKSTU'DO. (testudo, Lat.)

1. A genus of the order Chelonia; the

T E T

[ 258 ]

T H U

tortoise. This genus has been divided
into five subgenera.

2. The land tortoise, a sub-genus of the
genus above mentioned.

TETRACAU'LODON. An extinct animal of
the order mammalia ; allied to the masto-
don, and referrible to themiocene period.
One species only has been discovered
hitherto ; at Epplesheim, in Germany.

TETRADA'CTYLOUS. (from rtrpatfa/cruXoc;,
Gr. quatuor digitos habem.} Having
four toes.

TETRADYNA'MIAN. ) A term applied to

TETRADYNA'MOUS. $ plants that have six
stamens, four of which are longer than
the other two : the wall-flower is a fami-
liar example.

TE'TRAGON. (from rerpaywi'oc, Gr. tetra-
gonus, Lat. ) A quadrangle ; a figure that
has four angles, as a square.

TETRA'GONAL. (tetragone, Fr.) Having
four sides and four angles ; four-cor-
nered.

TE'TRAGYN. In botany, a plant that has
four pistils.

TETRAHE'DRAL. Having four triangles,
equal and equilateral.

TETRAHE'DRON. ) (from rsrpn, four, and

TETRAC'DRON. ) tdpa, side, or base, Gr.
tetraedre, Fr.) The solid angles of a tetra-
hedron are formed by three equilateral
plane triangles, and the solid is bounded
by four equal and equilateral plane trian-
gles, therefore it is a pyramid ; a four-
sided solid contained by four equal-sided
triangles ; a solid contained by four tri-
angular surfaces.

THA'LLITE. The name given by Lemethe-
rie to the Epidote of Haiiy, or Pistazit of
Werner.

THA'LLUS. (from 0aXXoe, a green leaf,
Gr.) In botany, a name given to the
frond, or leaf-like part, of certain plants.
Lichens are stemless, leafless, plants,
consisting of a tough wrinkled substance,
called a thallus.

THE'CA. (from 0jjo/, Gr. theca, Lat.) A
case or sheath. The sporules of plants
are contained within thecse.

THECODONTOSAU'RUS. A recently disco-
vered genus of fossil saurians, found in
the magnesian limestone : the vertebrae
are deeply concave at each end.

THE'RMAL. (thermal, Fr. 0ep/ioc, warm,
from 0£/oo>, to make warm, Gr.) A term
applied principally to warm springs and
waters. The temperatures of different
thermal springs vary greatly from each
other, but the same spring is found to be
of a uniform temperature at all seasons of
the year. Thermal waters are found to
be, on the average, neither more nor less
pure than springs of common tempera-
ture. There is no one product of thermal
springs, constantly found in them, which

never occurs in cold waters ; but it ap-
pears, from Dr. Daubeny's researches,
that nitrogen gas is very common in hot
springs, and, perhaps, very rare in cold
waters. Thermal waters prove the exten-
sive effects of subterranean heat, deriving
their temperature from a deep-seated in-
ternal source of heat, and not from any
local cause, or from chemical changes.
Some thermal springs have flowed with-
out any known diminution of temperature
for nearly two thousand years. The
range of temperature of the thermal
springs of Europe is from 66° to 165°
Fahrenheit.

THE'RMO-ELECTRI'CITY. Electricity deve-
loped by heat. — Lyell.

THIN OUT. This is a term used by geolo-
gical writers to express the appearance of
a stratum which gradually becomes thin-
ner, till it wholly disappears.

THO'MSONITE. A mineral, thus named
after Dr. Thomson, a variety of zeolite,
crystallized in rectangular prisms. It is
found near Dumbarton, in Scotland.

THORA'CIC. (thorachique, Fr. from tho-
rax, Lat.) Pertaining to the chest. The
name given to the duct into which the
absorbents empty themselves, namely,
the thoracic duct, and which terminates
in the left subclavian vein.

THO'RAX. (thorax, Lat. Owpo?, Gr. tho-
rax, Fr.) The cavity of the chest, con-
taining the heart, lungs, £c., £c.

THORI'NA. An earth discovered by Berze-
lius, in 1816 or 1817, in gadolinite. It
bears a strong resemblance to zirconia,
but differs from it in many particulars.
After being heated to redness it is soluble
in acids. No precipitate is caused by the
addition of sulphate of potash to a solu-
tion of it. Thorina is colourless and in-
fusible after ignition. Dr. Ure states
that a strong solution of the sulphate
becomes a thick mass by boiling, but
it is soluble in cold water ; a property
which particularly characterizes the new
earth.

THO'RITE. A mineral discovered a few
years since, in Norway, by Esmark, and
named thorite by Berzelius. It is com-
pact ; of a black colour ; brittle. Specific
gravity 4'8. It is rare, and not used.

THORI'NUM. ) The metallic base of the

THORI'UM. $ earth thorina.

THU'LITE. A mineral of a peach-blossom
colour, occurring in Norway ; it is very
rare.

THU'MERSTONE. > A mineral, thus named,

THU'MMERSTONE. \ by Kirwan, from its
being found, in masses, near Thum, in
Saxony. It is the Axinite of Haiiy and
Brongniart ; the Axinit of Werner ; La
pierre de Thum of Brochant. For a de-
scription of this mineral, see Axinite.

T H Y

[ 259 ]

T I N

THYRSE. } (thyrsus, Lat. Bvptrog, Gr.

THY'RSUS. i thyrse, Fr.) In botany, a
kind of inflorescence, as when the middle
branches of a panicle are longer than the
others. The horse-chesnut, lilac, &c.,
afford examples.

TI'BIA. (tibia, Lat. tibia, Fr.) The name
given to the shin-bone, or large bone of
the leg. It is said to have received its
name from a supposed resemblance to a
pipe or flute.

TIDE, (ebbe and fluth, Germ, fiusso del
mare, It.) The flow of the water in the
ocean ; the alternate rise and fall of the
surface of the sea twice in the course of
a lunar day, or in 24h. 50m. 28s. of solar
time. The tides are a subject on which
many persons find a great difficulty of
conception. As the tides depend upon
the action of the sun and moon, their rise
and fall are classed among astronomical
problems, of which they are the most
difficult, and their explanation the least
satisfactory. That the moon, by her at-
traction, should heap up the waters of the
ocean under her, seems to .most persons
very natural, — that the same cause should,
at the same time, heap them up at the
opposite, appears to many a palpable
absurdity. Yet nothing is more true, nor
indeed more evident, when we consider
that it is not by her whole attraction, but
by the differences of her attractions at the
two surfaces and at the centre that the
waters are raised. In the semi-diurnal
tides there are two phenomena particu-
larly to be distinguished, one occurring
twice in a month, and the other twice in
a-year. The first phenomenon is that
the tides are much increased in the syzi-
gies, or at the time of new and full moon.
In both cases the sun and moon are in
the same meridian : for when the moon
is new they are in conjunction ; when she
is full they are in opposition. In each of
these positions, their action is combined
to produce the highest or spring-tides
under that meridian. The neap tides
take place when the moon is in quadra-
ture. The higher the sea rises in full
tide, the lower it is in the ebb. The
second phenomenon is the augmentation
in the tides occurring at the time of the
equinoxes, when the sun's declination is
zero, which happens twice every year.
The greatest tides take place when a new
or full moon happens near the equinoxes,
while the moon is in perigee. The height
to which the tides rise is much greater in
narrow channels than in the open sea, on
account of the obstructions they meet
with. The tides in the British channel
sometimes, in some parts, rise as high as
fifty feet ; whereas on the shores of some
of the islands near the centre of the Pacific

ocean, they do not exceed one or two
feet. One of the most remarkable cir-
cumstances in the theory of the tides is
the assurance, that in consequence of the
density of the sea being only one-fifth of
the mean density of the earth, and the
earth itself increasing in density towards
its centre, the stability of the equilibrium
of the ocean can never be subverted by
any physical cause. A general inundation
arising from the mere instability of the
ocean is therefore impossible. — Mrs. So-
merville. Sir John Herschel.
TIN. (zinn, Germ, etain, Fr. stagno, It.)
A metal of a white brilliant colour, slightly
tinged with grey, being one of the fifty-
five simple or elementary bodies. Its
specific gravity is 7*3. It fuses at a tem-
perature of 442° Fahrenheit. It is of
greater hardness than lead, but not so
hard as gold. It is very malleable, and
may be beaten out into leaves one two-
thousandth of an inch in thickness. It is
more tenacious than lead, and a wire of
tin one-tenth of an inch in diameter will
sustain a weight of forty-seven pounds.
It is very flexible, and, while being bent,
it causes a crackling noise. Tin unites
with many metals, forming valuable alloys.
The bronze of the ancients consisted of
88 or 90 parts of copper, with 10 or 12
parts of tin. Bell-metal consists generally
of one-fifth of tin to four-fifths of copper.
The gongs of the Chinese are formed of
one-fifth of tin and four-fifths of copper.

Tin is mentioned repeatedly in the
Pentateuch. It is generally believed that
the Phoenicians came to Britain for tin,
and, from the importance of the trade,
that they concealed the situation whence
it was obtained ; it is certain that be-
fore the time of Herodotus tin was ob-
tained from Cornwall. The period at
which Cornish tin was first worked and
exported would appear to be lost in the
obscurity of past ages. Mr. Hawkins con-
siders that the Phoenician colony of Gades,
on the western coast of Spain, was the
medium or entrepot of the commercial
intercourse between Phoenicia and Corn-
wall. Diodorus says, " we will now give
an account of the tin which is produced
in Britain." The total value of tin-ores
sold in 1837, according to a statement
in Mr. De La Beche's Geological Report
of Cornwall, &c. amounted to .£363,322
16*. 4d. Mr. W. Phillips states "at
about 80 or 100 feet under the surface,
the first traces of copper or tin are usually
found. If tin be first discovered, even
without a trace of copper, it is not un-
usual that, in the course. of sinking 80 or
100 feet, or more, all trace of it is lost, and
copper only is found ; but if, instead of tin,
copper be first discovered at a depth of 80 or

T I N

[ 2CO ]

T O U

100 feet, it seldom or never happens that
tin is found below it in the same vein."
There are, however, many instances of
tin-ore accompanying copper-ore to great
depths.

Tin occurs in rocks of granite, gneiss,
&C-, in veins or fissures, called lodes ;
also in horizontal beds termed floors ; and
it is also found loosely scattered among
pebbles.

TINSTONE. Oxide of tin ; an ore contain-
ing tin. Tinstone sometimes yields nearly
80 per cent, of its weight in tin.

TITANI'FEROUS. (from titan or titanium,
and fero, Lat. to produce.) Yielding
titanium ; containing titanium.

TI'TANITE. The ore or oxide of titanium ;
it is nearly a pure oxide ; is of a brown co-
lour, and is met with in granite and quartz.

TITA'NIUM. (from riravoc, Gr.) One of
the substances commonly known as me-
tals, forming one of the fifty-five simple or
elementary bodies. Titanium was first
discovered by the Rev. Mr. Gregor in
1789 ; it is of a dark, copper-red colour,
with a strong metallic lustre, which tar-
nishes by exposure to the atmosphere.
Werner gave the name of Menak to tita-
nium, from the circumstance of its having
been first found at Menachan, in Cornwall.

TOAD-STONE. A provincial term for a spe-
cies of wack, or basal tick rock, found in
Derbyshire. Mr. Phillips asks whether
this word is derived from the German
todstein, in which case it would signify,
in mining language, a rock unproductive
of mineral treasures, a character generally
applicable to toadstone. It appears, how-
ever, that writers on mineralogy generally
state the name to be given to toadstone
from a supposed resemblance in its general
aspect to the exterior of a toad. Toad-
stone is a pyrogenous or volcanic produc-
tion that has been erupted in a fluid
state. Its ordinary colours are brownish
grey, purplish brown, bluish, or greenish ;
and its vesicles are either empty, or filled
with carbonate of lime. Toadstone is
found abundantly in Derbyshire, lying
between beds of limestone ; in some in-
stances, beds of toadstone and limestone
are found alternating with each other.

TONGUE-SHAPED. In botany, applied to
leaves of an oblong, blunt, thick form,
being generally of a cartilaginous sub-
stance at the edges.

TOOTHED. See Dentate.

TO'PAZ. (from ro7ra£tov, Gr. topaz, Fr.)
A precious stone or gem, generally of a
yellow colour. It is the silice fluatee
alumineuse of Haiiy ; the topaze of
Brongniart and Brochant. It is harder
than quartz, with a specific gravity of
from 3'4 to 3-6. There are many varie-
ties of topaz, differing greatly in form

and colour. The highly crystallized and
transparent varieties are named precious
topaz. In some places, as in Scotland,
the topaz is found in alluvial earths. The
Scotch pebble, called cairn-gorum, is a
topaz. Generally the topaz occurs in
primary rocks, the finest specimens being
obtained from the mountains of Brazil,
and from the Uralian mountains of
Asiatic Russia. The precious topaz con-
sists of alumina, silica, and fluoric acid,
with, sometimes, a small quantity of iron.

TOPA'ZOLITE. A pale yellow, nearly trans-
parent, subvariety of garnet, found in
Piedmont. Its constituents are, silex
37, alumine 2, lime 29, glucine 4, iron 25,
manganese 2.

TORNATE'LLA. A genus of oval, spirally
grooved, marine, univalves, belonging to
the family Plicacea. Recent tornatellse
are found in shallow water, creeping on
sands, and leaving furrows. Several spe-
cies are found in the oolite and super-
jacent strata.

TORO'SE. ^ (torosus, Lat.) Swelling into

TO'ROUS. $ knobs or protuberances. A
term used both in botany and conchology.

TORPE'DO. (torpedo, Lat. from torpeo, to
benumb.) A subgenus of fishes, be-
longing to the genus Raia. The torpedo
is found fossil in the tertiary formations.
The torpedo is furnished with an elec-
trical apparatus, resembling the voltaic
battery, which it has the power of charg-
ing and discharging at pleasure. The
benumbing effect producible by the tor-
pedo depends on certain singularly con-
structed organs composed of membranous
columns, filled from end to end with la-
minae, separated from each other by a fluid.

TO'RRELITE. A new mineral brought from
the United States, and thus named after
Dr. Torrey.

TO'RTOISE. (tortue, Fr.) An order of the
class Reptilia, or reptiles ; tortoises are
also termed Chelonians. The chelonians,
or tortoises, were all included by Lin-
meus in one genus, namely, testudo ; they
are now divided into five subgenera.
1. Testudo, or land- tortoise ; 2. Emys,
or fresh-water tortoise ; 3. Chelonia, or
sea- tortoise ; 4. Chelys ; 5. Trionyx, or
the tortoise with a soft shell.

This order of reptiles, geologists inform
us, began to exist at about the same
period with the order of Saurians, and
has continued from that time to the pre-
sent. No fossil remains of the tortoise
have been discovered in any strata not
more recent than the coal formations.

TOU'RMALINE. } A mineral which has been

TOU'RMALIN. $ divided by some miner-
alogists into two sub-species, namely,
schorl and tourmaline ; by others, tourma-
line is regarded as a sub-species, or va-

T R A

[ 261 ]

T R A

riety, of schorl. It is the tourmalin of
Werner ; the tourmaline verte of Haiiy ;
the schorl electrique of Brochant. —
It is of various colours, the shades of
some of which are so dark as to approach
nearly to black. Its hardness is about 7'5.
Specific gravity from 3'0 to 3'2. By
friction it yields vitreous electricity; by
heating, vitreous electricity at one extre-
mity and resinous electricity at the other.
It occurs imbedded in granite, gneiss,
mica slate, &c. in Scotland, Sweden,
America, Spain, and other parts. Its
property of polarizing light is thus de-
scribed by Mrs. Somerville. — " If a brown
tourmaline, which is a mineral generally
crystallized in the form of a long prism",
be cut longitudinally, that is, parallel to
the axis of the prism, into plates about
the thirtieth of an inch in thickness, and
the surfaces polished, luminous objects
may be seen through them, as through
plates of coloured glass. If one of these
plates be held perpendicularly between
the eye and a candle, and turned slowly
round in its own plane, no change will
take place in the. image of the candle.
But if the plate be held in a fixed posi-
tion, with its axis or longitudinal section
vertical, when a second plate of tourma-
line is interposed between it and the eye,
parallel to the first, and turned slowly
round in its own plane, a remarkable
change will be found to have taken place
in the nature of the light. For the
image of the candle will vanish and ap-
pear alternately at every quarter revolu-
tion of the plate, varying through all de-
grees of brightness, down to total or
almost total evanescence, and then in-
creasing again by the same degrees as it
had before decreased."
TRA'CHEA. (trachea, Lat. from rpaxvz,
Gr. rough.)

1. The windpipe, or that canal which
leads from the throat to the lungs.

2. In botany, the vessels of plants in
which the internal fibres run in a spiral
direction ; they are also called air-tubes.

TRA'CHEAL. Belonging to the trachea, as
tracheal-vessels.

TRACHE'LIPODS. (from rpa%7;Xoc, the
neck, and TTOVQ, a foot, Gr.) In La-
marck's arrangement, the third order of
Molluscans : they have the greatest part
of the body spirally convolved, always
inhabiting a spiiivalve shell ; the foot
free, attached to the neck, formed for
creeping. Trachelipods may be divided
into .herbivorous and carnivorous, the
latter possessing a respiratory siphon,
which the herbivorous have not. This
order contains fourteen families, and up-
wards of seventy genera.

TRA'CHYTE. (from rpaxvff, Gr. rough.)

A kind of volcanic porphyry, usually
containing crystals of glassy felspar, and
excessively rough to the touch. It is not
found in this country, but is very abun-
dant in the neighbourhood of all volcanic
craters. Trachyte sometimes possesses a
columnar structure ; it is generally of a
coarse grain, and with a degree of po-
rosity. From this latter circumstance it
easily breaks down, and forms frequently
a conglomerate with other substances.
It sometimes is found to contain augite
and horneblende. In some districts tra-
chyte seems little else than granite which
has been again fused, and, having been
exposed to different conditions, no longer
presents the appearance of granite.
TRACHY'TIC. Composed of trachyte ; re-
sembling trachyte ; rough.
TRANSITION ROCKS. ~*j The name

TRANSITION SERIES. )» transition

TRANSITION FORMATIONS. ) has been
applied to certain rocks from an opinion
that they had been formed at a period
when the globe was undergoing a great
change, fitting it for the reception of
organized beings. The term, though no
longer applicable in its original significa-
tion, is still retained. The rocks usually
included in the transition series are the
Dudley limestone, the Caradoc sand-
stones, and the British and Llandilo
rocks ; the whole possessing a thickness
of upwards of two thousand four hundred
yards, and containing, throughout, or-
ganic remains. The transition rocks rest
upon the rocks called primary, and are
themselves covered by the old red sand-
stone formation. Professor Buckland
observes, "it is most convenient to in-
clude within the transition series, all
kinds of stratified rocks, from the earliest
slates, in which we find the first traces of
animal or vegetable remains, to the ter-
mination of the great coal formation.
TRANSLU'CENCY. (from trans, through,
and luceo, to shine, Lat.) A term used
in mineralogy to express the property,
which some minerals possess, of permit-
ting the passage of rays of light, but with-
out sufficient transparency to perceive
objects through the mineral.
TRANSLU'CENT. A mineral is said to be
translucent when light evidently passes,
but objects cannot be distinguished through
the mineral.

TRAP. > (trappa, a stair, Sw. trapp,

TRAP ROCKS. > a step, Germ, probably
from rpaTTf^a, Gr. a table.) Kirwan gave
the name of trap to basalt, which he
divided into two families, namely, Com-
mon Trap, and Figurate Trap. The word
trap is usually employed to designate
certain volcanic rocks, frequently occur-
ring in large tabular masses at different

T R A

[ 262 ]

T R A

heights, and forming a succession of ter-
races or steps. The term is applied to
various igneous rocks, without any re-
gard to their constituent parts, but merely
in reference to their form. Mr. Bake-
well, in his Introduction to Geology,
says, " trap-rocks not only reveal the
secret of their birth, but, from their
close alliance to many of the most an-
cient primary rocks, they disclose the
operations by which a large portion of
the earth's surface was consolidated, in
the most remote geological epochs. Many
of the trap-rocks are so similar in struc-
ture and composition to the products of
active volcanoes, and to the beds of lava
erupted in our own times, that we may
be said to see the very cause in opera-
tion by which they were formed. Many
of the trap-rocks are also so similar in
structure and composition to some of the
most ancient primary rocks, that we can
scarcely doubt respecting their having
had the same origin, though they may
have been consolidated under different
degrees of heat or pressure, and with
different attendant conditions."

TRA'PPEAN ROCKS. Another name for
trap rocks.

TRAPE'ZIUM. (from rpcnrtZiov, a little
table, Gr. trapeze, FT.)

1. In anatomy, the name given to one of
the bones of the carpus, or wrist.

2. In geometry, a quadrilateral figure,
whose four sides are not equal, and none
of its sides parallel.

TRAPEZOI'D. (from rparTrt^ior, a little
table, and dSoc , likeness, Gr. trapezo'ide,
Fr.)

1. In anatomy, a small bone of the wrist,
placed in the same row with the tra-
pezium.

2. An irregular solid figure, whose four
sides are not parallel.

TRAPEZOI'DAL. In mineralogy, when the
surface is composed of twenty-four tra-
peziums, all equal and similar.

TRAU'MATE. (from Qpadff^a, Gr. a frag-
ment. ) The name given by the French geo-
logists to grauwacke, a term about as eupho-
nious as that they have substituted it for.

TRA'VERTIN. An Italian name for a con-
cretionary limestone or calcareous preci-
pitate, deposited by water holding in
solution a considerable quantity of car-
bonate of lime. The water parting with
some of its carbonic acid gas, which rises
in bubbles to the surface, the lime be-
comes deposited. In Italy, immense
masses of travertin are being constantly
formed from waters copiously charged
with carbonate of lime. At the baths of
San Filippo a manufactory of medallions
in basso-relievo is carried on. The water
is first conducted into pits, where it frees

itself from its grosser parts ; it is then
conducted by a tube to the top of a small
chamber, and made to fall through a
space of ten or twelve feet in height.
The stream is broken in its descent by
means of numerous sticks placed across,
by which the spray is dispersed upon
moulds, which are slightly soaped, and
the result is a cast of the figures formed
in the mould, of a solid, marble-like sub-
stance. The waters of the lake of the
Solfatara, between Rome and Tivoli, are
so supersaturated with carbonic acid gas,
that they appear in a constant state of
ebullition, from the extrication of the
gas. The Coliseum, and the majority of
the public buildings of Rome, are com-
posed of travertin.

TRE'MOLITE. (from Tremola, a valley of
St. Gothard, where it was first found.)
A nearly white, grey, or bluish, variety of
horneblende or hemiprismatic augite. It
occurs in crystals, but most commonly in
fibrous or radiated masses, composed of
minute, imperfect prisms or fibres. There
are several subvarieties of tremolite,
namely, common tremolite, glassy tre-
molite, fibrous tremolite, and Baikalite.
Tremolite is found almost exclusively in
primary rocks, but it sometimes occurs
in secondary. Specific gravity from 2 '9
to 3-2. Hardness from 5-0 to 6'0. Be-
fore the blow-pipe, tremolite fuses into a
white glass, full of pores. Its consti-
tuents are silex, lime, magnesia, water
and carbonic acid, and oxide of iron.
Very differing analyses are, however,
given by different chemists and mineralo-
gists ; some describe it as containing fluo-
rid acid and alumina.

TRIA'NDRIA. (from rptiq, three, and
avijp, a male, Gr.) The name of the
third class in Linnaeus' sexual system,
consisting of plants with hermaphrodite
flowers, having three stamens or male
organs. This class is divided into three
orders : — 1. Monogynia. 2. Digynia.
3. Trigynia.

TRICA'PSULAR. A plant that has three
capsules to each flower.

TRICU'SPIDATE. Three-pointed.

TRIDA'CNA. A genus of sub transverse
inequilateral, equivalve, marine, bivalves,
belonging to Lamarck's family of Tri-
dacnacea, and found both recent and
fossil. Recent tridacnse are found at
depths varying to seven fathoms, moored
by a byssus to rocks, and on coral reefs.
The shells of this genus are exceedingly
beautiful, being radiately ribbed, the ribs
adorned with vaulted foliations, and waved
at the margins. The hinge is formed of
two compressed and entering teeth. One
species, the tridacna gigas, is met with of
immense size. Fossil shells of this genus

T R I

[263]

T R I

are very rare ; it is said some large spe-
cimens have been obtained from the neigh-
bourhood of Verona.
TRIDA'CTYLOUS. Having three toes.
TRI'GONAL. (trigonalis, Lat. ) Trian-
gular ; three-cornered ; having three
sides.

TRIGONE'LLITES. A genus of shells de-
scribed, and thus named, by Mr. Parkin-
son. A slightly rounded, trigonal, thick
shell, gaping on each side. The anterior
margin nearly on a straight line ; the
posterior in a gently waving, and the
upper side in nearly a circular direction.
The outer surface of each valve thickly
pierced by foramina, which, passing nearly
through its substance, give it the can-
cellous appearance of bone : the inner
surface smooth, but marked with striae,
concentric with the upper margin. The
hinge completely linear, without teeth ;
there being only an appropriate surface
on the anterior margin of each valve, for
the attachment of the cartilage exter-
nally. Mr. Parkinson also observes,
" this shell, which I have presumed thus
to name and to dispose of, is exceedingly
anomalous in every respect : it is of an
extraordinary degree of thickness, being,
in some specimens, full three-eighths
of an inch thick, and even in young
specimens, full one quarter of an inch
thick."

In the supplementary notes attached
to Prof. Buckland's Bridgewater Trea-
tise it is stated, " it is shown in a notice
read by M. Voltz to the Natural History
Society at Strasbourg, that the problema-
tical fossils known by the name of Apty-
chus, Trigonellites, &c , which are some-
times found lodged in pairs within the
first chamber of the ammonites, were
opercula connected with the foot, or
organ by which the animals inhabiting
these shells moved along the bottom of
the sea."

TRIGO'NIA.^ (from rpiywvor, triangular,
TRI'GON. )> Gr.) A genus of marine bi-
TRY'GON. J valves, found both fossil and
living, belonging to the family Ostracea.
The trigonia is a triangular or suborbicu-
lar, inequilateral, equivalve, transverse
bivalve. One valve has two oblong,
flat, diverging, hinge teeth, transversely
grooved on each side ; the other has four
flat, oblong, diverging, hinge teeth, trans-
versely grooved on one side only, dis-
posed in pairs, receiving between their
grooved sides the two hinge teeth of the
opposite valve. Recent trigonise have
hitherto been discovered near Australia
only, in sandy mud. They are nearly
related to the cardium, or cockle, the
foot of the animal being bent, like that

of tVif> «v^«l.-'~ ««• or> 4r>wf-A apo-lp. SO as.

upon pressure, to form a very elastic
organ. The species found recent has
been named Trigonia Margaritacea, or
pearl trigon, from the pearly lustre of the
inside of its shells.

Fossil trigoniae differ considerably from
the "recent ; nine species have been de-
scribed by Mr. Parkinson. Three spe-
cies are mentioned by Dr. Mantell as
occurring in the Shanklin sand. Tri-
gons are also found in the lias, oolite,
and tertiary formations.

TRILO'BATE. (from tres, three, and lobus,
a lobe, Lat.) Divided into three lobes
having three lobes.

TRI'LOBITE. (So named from its being
divided into three lobes or principal
parts.) A family of fossil crustaceans,
which appear to have become extinct at
the close of the period during which the
carboniferous series were formed, no
traces of their remains having been dis-
covered in strata of a more recent pe-
riod. Twelve genera and fifty-two spe-
cies have been described. For a long
time, fossil trilobites were confounded
with insects, under the name of Entomo-
lithus paradoxus : several names have
also been given to them, derived chiefly
from the three lobular divisions by which
they are so characteristically marked, as
well as from their being found sometimes
in a coiled, sometimes in an extended
state. By Bromel, the trilobite was
named Lapis insectiferus ; by Wolster-
dorf, Conchitus trilobus ; by Hermann,
Pectunculites trilobus imbricatus ; by Da
Costa, Pediculus marinus ; by Linnaeus,
Entomolithes paradoxus ; by Baumur,
Trigonella striata ; and by Wilke, Ento-
molithus cancriformis marini. The tri-
lobite is often called the Dudley fossil,
from its having been first noticed in the
transition limestone near that town. Mr.
Bakewell states that the largest species
are found in the slate quarries at Angers,
in France, and that he possesses a speci-
men from that place which measures
seven inches in length. The following
details are extracted from Prof. Buck-
land's very interesting and copious de-
scription of trilobites : — " The great ex-
tent to which trilobites are distributed
over the surface of the globe, and their
numerical abundance in the places where
they have been discovered, are remarkable
features in their history. They have
been found throughout all northern Eu-
rope, and in numerous localities in North
America, in the Andes, and at the Cape
of Good Hope. The anterior segment of
the trilobites is composed of a large
semi-circular, or crescent- shaped shield,
succeeded by a body composed of nu-
merous segments folding over each other,

T R I

I 264 ]

TUB

like those in the tail of a lobster, and
generally divided by two longitudinal
furrows into three ranges of lobes. The
nearest approach among living animals to
the external form of trilobites is that
afforded by the genus serolis, in the class
Crustacea."

TRILO'CULAR. (from tres, three, and locu-
lus, a partition, Lat. ) A term applied in
botany to seed-vessels divided into three
portions or cells.

TRI'ONYX. (trionices, pi.) A subgenus
of testudo, belonging to the order Che-
Ionia. The soft-shelled tortoise. Two
species are mentioned, namely, ^Egyptia-
cus and ferox : the latter, or Trionyx
ferox, will attack, and master, aquatic
birds. The soft-shelled tortoises have
no scales, the shell and sternum being
merely enveloped in a soft skin ; many
of the pieces that are bony in the tortoise
being replaced by a simple cartilage or
membrane. Fossil remains of trionices
are found in fresh- water Wealden forma-
tions of the secondary series : one spe-
cies, named Trionyx Bakewelli, is de-
scribed by Dr. Mantell, as occurring in
Hastings beds. Remains also are abun-
dantly found in the lacustrine deposits of
the tertiary formations.

TRI'POLI. An admixture of silex and clay.
It has obtained its name from having
been originally brought from Tripoli, in
Barbary. It is a mineral of a dull ar-
gillaceous appearance, occurring usually
in friable or earthy masses. Its powder
is fine, but dry and rough to the touch,
and sufficiently hard to scratch metals,
glass, &c. It is employed for the polish-
ing of metals and stones. Rotten-stone
and polishing-slate, the Polierschiefer of
Werner, appear to be varieties of Tri-
poli.

TRISE'PALOUS. (from tres, three, and
sepal.) A term used in botany for a
calyx that has three sepals.

TRI'TON. A genus of the molluscous order
of Nudibranchiata, inhabiting an oblong,
thick, ribbed, or tuberculated spiral shell.
The body is oblong ; mouth with an in-
volute spiral proboscis ; tentacula twelve,
six on either side, divided nearly to the
base, the hind one cheliferous.

TROCHI'TA. A detached vertebra of a
radiated animal. When several trochitae
are united, so as to form part of a
column, the series is termed an entro-
chite.

TRO'CHUS. (trochus, Lat. a top.) A
genus of conical, spiral, thick, striated,
marine, univalves, found both fossil and
recent. The animal is a Limax ; aperture
transversely depressed, and somewhat
quadrangular ; columella oblique ; oper-
culura horny, with numerous whorls.

Recent trochi are found in the ocean at
depths varying to forty-five fathoms ;
they most commonly, however, are met
with near the shore, creeping on rocks,
sands, and gravel. One hundred and
thirty-three species are described in Tur-
ton's Linne. Lamarck has separated
from the genus trochus of Linnaeus cer-
tain shells possessing peculiar characters,
which he has arranged under two new
genera, namely, Solarium and Mono-
donta. These genera, as well as tro-
chus, are comprised in the family Turbi-
nacea.

Of fossil trochi, Dr. Mantell enu-
merates six species as occurring among
the Sussex fossils. One species in dilu-
vium, one in the London clay, one in the
chalk, two in the chalk-marl, and two in
the upper green-sand. Very large casts
of trochi are found in Oxfordshire, Glou-
cestershire, and Somersetshire.

TRO'PHI. The name given by Kirby and
S pence to the elementary parts which
enter into the composition of the mouth
of an insect.

TRU'NCATED. (truncatus, Lat.) Cutoff;
shortened.

TRUNCATION. A term used in mineralogy,
implying that a segment is cut off or
separated from the predominant form.
The term may be applied either to an
edge, or a solid angle of a crystal, and
will leave a face more or less large in
place of the edge or angle. A truncation
is said to be oblique, when the face does
not make equal angles with all the conti-
guous faces. — Cleaveland.

TUBE, (tubiis, Lat. tube, Fr. tubo, It.)
A pipe ; a siphon. In botany, the round
hollow part of a monopetalous flower.

TU'BER. In botany, a fleshy irregular
stem produced under ground, and distin-
guished from a root by its having eyes
or buds, which the true root never
possesses : the potatoe is a familiar ex-
ample.

TU'BEROUS. (tubereux, Fr. tuberoso, It.)
Having prominent knots or excrescences.

TUBICINE'LLA. (from tubicen, Lat. a trum-
peter.) A genus of multivalve tubular
shells, not spiral. Tubicinella is placed
by Lamarck in the order Sessile cirri-
pedes. The tube is cylindrical, and com-
posed of six elongated valves, laterally
united. The aperture circular, with a
four-valved operculum. Tubicinellse are
not described as occurring fossil ; the
recent are found imbedded in the blubber
of whales.

TUBI'COLA. (from tubus, a tube, and cola,
an inhabitant, Lat.) An order of Arti-
culata, comprising Serpula, Sabella, Te-
rebella, Amphitrite, Syphostoma, and
Dentalium.

TUB

[ 265 ]

TUN

TUBI'PORA. } Organ-pipe coral, consisting

TU'BIPORE. $ of tubes of a stony sub-
stance, each containing a polype. A
genus of corals or zoophytes belonging
to the class Polypifera ; subregnum Cyclo-
neura, or Radiata. There are several
species. In one species, Tubipora mu-
sica, the tubes are placed parallel to
each other, like the pipes of an organ,
with transverse partitions at regular in-
tervals : in another species, Sertularia,
the tubes are joined together endwise,
like the branches of a tree, leaving la-
teral apertures for the protrusion of the
tentacula of each separate polype. Tu-
bipores are found among the earliest
traces of organic bodies in the ancient
strata.

TUBI'PORITE. A fossil tubipore. Many
marbles and,, pebbles are beautifully
marked by the sections of the inclosed
tubipores. One very remarkable form
is found in the Dudley limestone, the
tubes, which are oval, being arranged in
undulating lines ; from its reticulated
appearance it has obtained the name of
chain coral. The pebbles gathered upon
the coast of Sussex frequently display
beautiful specimens of tubiporse : these
are cut, polished, and formed into orna-
mental articles.

TUBTPORI'TIC. Containing tubiporse ; as
tubiporitic marble, &c.

TU'BULAR. In the shape of a hollow tube.
In botany, applied to the florets of a
compound flower, when they form a
cylindrical tube, and are five -cleft.

TUBULA'RIA. (from tululus, a hollow pipe,
Lat.) A genus of corals belonging to
the class Polypifera. Simple or branched
tubes of a horny substance, each tube
containing a polype. Tubularise are both
fresh-water and marine. Some species
of this genus establish themselves in the
fissures of rocks, which serve them in-
stead of a shell to protect the mem-
branous tubes into which they retract
their petaliform tentacles. Of this kind
is theTubularia magnifica of Shaw; found
in the rocks of the coast of Jamaica.

TUBULA'RII. (tulularius, Lat.) A family
of the order Coralliferi, class Polypi.
The tubularii inhabit tubes of which the
common gelatinous body traverses the
axis, like the medulla of a tree, the tubes
being open, either at their sides or sum-
mits, to allow the passage of the polypi. —
Dr. McMurtrie,

TU'FA. (tuf, Fr. tufo, It.) An earthy
precipitate deposited from water. See
Calcareous Tufa.

TUFF. } A name applied to se-

TTJ'FA,VOLCA'NJC. \ veral different sub-
stances the production of volcanic erup-
tions. Generally, an aggregate of sand,

volcanic ashes, and fragments of scoria
and lava, united by an argillaceous or
muddy cement. Sometimes it is com-
posed of volcanic ashes and sand, trans-
ported and deposited by rain water.

Tuff, or volcanic tufa, as distinguished
from calcareous tufa, presents various
shades of grey, brown, red, yellow, &c.
or it is sometimes spotted. Hardness mo-
derate ; fracture dull and earthy.

TUFA'CEOUS. Having the appearance or
texture of tufa.

TU'NGSTEN. (from tung, heavy, and sten,
stone, Dan.)

1. A greyish white metal, brittle, and
very hard. Specific gravity 17*4. Fusible
in the most intense heat only, its infu-
sibility equalling that of platinum. It
has been obtained only in the form of
grains of extreme hardness. It was dis-
covered by Scheele, and by Werner has
been named Scheel ; by Haiiy, Scheelin.

2. A mineral, of a grey or yellowish-
grey colour, occurring in Bohemia,
Sweden, and Cornwall, massive and dis-
seminated. Its external lustre is shining
and splendent ; internal lustre shining
and resinous. Specific gravity from 5P57
to 6*06. It can be scratched with a
knife, and is easily broken. It is infu-
sible, but before the blow-pipe it becomes
opaque, and decrepitates. By digestion
in nitric acid it is converted into a yellow
powder, which is the oxide of tungsten.
It consists of oxide of tungsten 77'75,
lime 17'60, silex 3'00, according to Klap-
roth : Berzelius gives its analysis as con-
sisting of oxide of tungsten 80'24, lime
19-40. It is the Scheelin calcaire of
Haiiy and Brongniart ; the schwerstem
of Werner ; the tungsten of Kirwan.

TU'NICARIES. A class of acephalous mol-
luscs in Lamarck's arrangement. The
Rev. W. Kirby says, " the characters of
the class may be thus stated : animal
either gelatinous or leathery, covered by
a double tunic, or envelope. The ex-
ternal one, analogous to the shell of mol-
luscans, distinctly organized, provided
with two apertures ; the interior envelope,
analogous to their mantle, provided also
with two apertures, the one oral, the
other anal, adhering to those of the outer
one. Body oblong, irregular, divided in-
teriorly into many cavities, without a
head ; gills occupying, entirely or in
part, the surface of a cavity within the
mantle ; mouth placed towards the bot-
tom of the respiratory cavity between the
gills ; alimentary tube, open at both ends ;
a ganglion, sending nerves to the mouth
and anus. These animals are found both
simple and aggregate, fixed or floating."
— Bridgw. Treat.

TUNICA'TA. (tunicatus, coated, Lat.) The

TUN

26'6

U M B

tunicated animals have no external shell
nor internal solid parts, but are covered
with a tough, elastic, homogeneous tunic,
in the form of an enveloping sac, with a
respiratory and an anal orifice. This ex-
terior sac is the analogue of the valves of
conchifera, and has the muscular fibres
of the lining mantle inserted into its
inner surface. The word is synonymous
with tunicaries.

TU'NICATED. Covered with one or more
tunics or membranes.

TU'RBINATED. (turbint, Fr. turbinatus,
from turbo, a top, Lat.) Of a spiral
oblong form ; in conchology, applied to
shells, broad at the base, and becoming
gradually narrower till they are pointed
at the apex.

TU'RBINATED BONES. Two bones of the
nostrils. These are curiously folded, and
often convoluted in a spiral form.

TU'RBO. (turbo, a top, Lat.) Plural,
turbines. A genus of marine univalves,
found on rocks and sea-weeds at depths
varying to ten fathoms. The genus turbo
is placed by Cuvier in the family Tro-
choida, and by Lamarck, in the family
Turbinacea. The turbo of Linnaeus
comprises all the species with a com-
pletely and regularly turbinated shell and
a perfectly round aperture.

The turbo is a conoidal or slightly tur-
reted shell, the aperture complete,
rounded, and not toothed ; the margins
disjoined in the upper part ; the colu-
mella smoothed at the base. In Turton's
Linne one hundred and fifty-one species
of turbines are described, sixty-nine of
which are indigenous to Britain. Four
species of turbines have been described
as found fossil.

TU'RKOIS. ) (turquoise, Fr.) A gem of

TU'RCIUOISE. $ a blue or greenish colour,

and opaque, found in roundish masses,
from the size of a pea to that of an egg.
The finest specimens are brought from
Persia, where they occur in small veins in
slate-clay.

TU'RRILITE. (from turris, a tower, Lat.
and \i9oQ, a stone, Gr.) A spiral, tur-
riculated, multilocular shell ; the turns
contiguous and all visible. The cham-
bers divided by sinuous septa, pierced by
a siphuncle in their disks. The mouth
round. The shells of this genus abound
in the chalk marl, gait, and Shanklin
sand. They are extremely thin, and their
exterior is adorned and strengthened with
ribs and tubercles. The outer chamber,
which contained the animal, is large.
Professor Buckland states that turrilites
do not appear until the commencement
of the cretaceous formations, and that
having thus suddenly appeared, they be-
come as suddenly extinct at the same
period with the ammonites.

TURRITE'LLA. A genus of turreted, elon-
gated, marine univalves, of the family
Turbinacea, found both recent and fossil.
Turritellse are commonly known by the
name of screw-shells. Recent turritellae
are found in sandy mud, at depths vary-
ing from five to twenty fathoms. Fossil
turritellse are found in the tertiary de-
posits. Dr. Mantell enumerates four
species as occurring in the London clay
of Sussex, and Lamarck mentions ten
species as discovered among the fossils of
Grignon, &c.

TY'MPAN. 1 (tympanum, Lat. TV^TTOVOV,

TY'MPANUM. $ Gr. tympan, Fr. timpano,
It.) A cavity or chamber of the ear. It
is sometimes also applied to a membrane
that stretches across the cavity of the
ear, called also the drum of the ear.

U

U'LNA. (ulna, Lat. from w\lvri, Gr.)
The cubit or large bone of the fore-arm.
The two bones that form the fore -arm,
or that portion of the upper extremity
situated between the elbow and the wrist,
are the radius and ulna ; of these the
ulna is the larger.

U'LNAR. Pertaining to the ulna.

ULTRAMARI'NE. Azure stone ; lapis la-
zuli. A pigment remarkable for the
durability of its colour. For a description
see Lapis Lazuli.

U'MBEL. (umbella, Lat.) In botany, a
peculiar form of inflorescence : an umbel
consists of several flower-stalks or rays,
nearly equal in length, which spread from
one common centre, and the summits of

which form a regular surface, either level,
convex, or globular ; sometimes, but
rarely, concave. An umbel is either
simple or compound : a simple umbel has
the stalks springing from the same part
of the principal one, and each bears but
one flower. A compound umbel has each
ray or stalk terminating in another set of
rays ; the carrot, parsnip, parsley, &c. fur-
nish familiar examples ofcompoundumbels.

UMBELLA'TA. (from umbella, Lat.) The
name given to the partial or smaller
umbel of a compound umbel.

U'MBELLATED. Having umbels ; bearing
umbels ; in the form of an umbel.

UMBELLA'T^E. One of Linnaeus' natural
classes or orders of plants. The urn-

U M B

C 267]

U N M

bellatse are plants whose flowers grow in
umbels, with five petals, and two naked
seeds joined at top and separated below.
The parsley, fennel, &c. are examples.

UMBELLI'FER^E. A large order of plants
characterized by their flowers being in
umbels. Calyx entire or five-toothed.
Petals five, usually inflexed at the point.
Stamens five, alternate with the petals.
Ovary two-celled. Fruit consisting of
two carpels, separable from a common
axis. Seed pendulous. Herbaceous
plants with fistular stems.

UMBI'LICATED. (umbilicatus, Lat.) In
conchology, a term applied to such shells
as have a depression in the centre like a
navel. Univalves that have the umbi-
licus covered in a greater or less degree
by a thin process, are termed sub-um-
bilicated.

UMBILI'CUS. (umbilicus, Lat.) The navel.
In conchology, a circular perforation in
the base of the lower whorl, or body, of
many spiral univalves, and common to
most of the Trochi, in some of which it
runs from the base to the apex.

U'MBO. (umbo, Lat.) A boss or protu-
berance. In conchology, that point of a
bivalve shell situated immediately above
the hinge. This word makes umbones in
the plural.

U'MBONATED. Bossed ; knobbed in the
centre.

UNCONFO'RMABLE. In geology, a term
applied to a stratum or strata lying in a
different plane from the subjacent strata
upon which they rest. Strata not lying
parallel with those beneath them. Sup-
posing certain strata to have been up-
heaved, so that their inclination is at an
angle with the horizon, or even vertical,
such strata may all be, notwithstanding,
conformable one with another ; if, how-
ever, upon these tilted strata, fresh strata
be deposited, the more recent strata lying
horizontally upon the subjacent vertical
or inclined strata, then the superjacent
strata are termed unconformable.

UNCONFO'RMABLY. Not being in the same
plane with those upon which they are
deposited. Strata lie unconformably
when placed upon others having a differ-
ent line of direction or inclination.

UNCTUO'SITY. Greasiness. A character
belonging to certain minerals, which is
very useful in assisting to distinguish
them. Some minerals, when the finger is
passed over their surface, or their powder
is rubbed between the finger and thumb,
feel as if they were coated with some
greasy matter. The sensation is different
from that produced by mere smoothness
of surface.

U'NDATED. (undatus, Lat. from unda, a
wave.) Waved ; having a waved surface.

U'NDULATED. (undulatus, Lat. from ten-
dula, a little wave.) Waved ; having a
waved surface. In botany, applied to
leaves when the margins are waved ob-
tusely up and down.

UNFA'THOMABLE. Of a depth that cannot
be ascertained ; that cannot be sounded,
or the depth of which cannot be dis-
covered, by a lead and line.

U'NGUAL. (from unguis, a nail or claw,
Lat.) A name applied to such bones of
the feet as have attached to them a nail,
claw, or hoof.

U'NGUICAL. The name given to the claw-
bone of certain animals.

UNGUJ'CULATED. Clawed ; possessing
claws.

U'NGULATE. (from ungula, a hoof, Lat.)
Shaped like the hoof of a horse.

UNICA'PSULAR. (from unus, one, and
capsula, a capsule, Lat.) Having one
capsule only to each flower.

UNILO'CULAR. (from unus, one, and locu-
lus, a cell or partition.) Having one
chamber or cell only. In conchology,
applied to shells which are not divided by
septa into chambers. In botany, applied
to seed vessels not separated into cells.

U'NIO. (unto, Lat. a pearl.) A genus of
freshwater bivalve shells, placed by La-
marck in the family Nayades, and by
Cuvier in the family Mytilacea. Uniones
are equivalve, inequilateral, transverse,
internally pearly, externally covered with
an epidermis, bivalves ; they are com-
monly called fresh-water muscles. Mr.
Parkinson states that uniones are not
known in a fossil state ; Dr. Mantell,
however, mentions five species as being
found in the strata of Tilgate Forest,
namely, Unio aduncus, U. antiquus, U.
porrectus, U. compressus, and U. cordi-
formis. Of these he states Unio antiquus
to be the most abundant.

UNIPA'ROUS. (from unus, one, andpario,
to produce, or bring forth, Lat.) Pro-
ducing one only at a birth.

U'NIVALVE. (from unus, one, and valva,
a shell, Lat.) A shell which is complete
in one piece. The Linnsean arrangement
of shells consists of three orders, namely,
multivalves, bivalves, and univalves.
Univalves are far more numerous than
either multivalves or bivalves, both in
genera and species. Univalves are divided -
into sections ; those having a spire, called
also turbinated shells, and those without
a spire. Some conchologists have named
those spiral univalves having an opercu-
lum, sub-bivalve shells.

UNIVA'LVULAR. Having but one shell or
valve.

UNMA'LLEABLE. That cannot be extended
by hammering; that cannot be hammered
out into plates or laminae.

UNO

[ 268 ]

V E G

UNO'RGANIZED. Having no parts instru-
mental to the motion or nourishment of
the rest.

UNO'XIDATED. }Not converted into an

UNO'XIDISED. J oxide by combination
with oxygen.

UNOXY'GENATED. Not combined with
oxygen.

UNSTRA'TIFIED. A term applied to rocks
that are not stratified, or not arranged in
strata. Mr. De La Beche observes, " the
terms stratified and unstratified have been
commonly considered as respectively sy-
nonymous with aqueous and igneous.
Practically, this division is highly valua-
ble ; but theoretically, it is not so satis-
factory, at least, if we are to infer that all
rocks divided into tabular masses, one
resting on another, must have been de-
posited either chemically or mechanically
from water. We should be careful not
to couple too far stratification with
aqueous deposition, as sheets of igneous
rocks may cover pre-existing sheets of
similar rocks, and the result be stratifi-
cation.1'

UPHEA/VED. Lifted up by some expansive
or elevating power from below.

U'PPER TE'RTJARY STRA'TA. These strata
are considered to be of more recent origin
than those usually denominated tertiary,
and, by some geologists, have been termed
quaternary. They are supposed to be of
more recent origin than any of the strata

composing the formations of the London
and Paris basins.

U'RANITE. An ore of Uranium of a black
or green colour, called also Pechblende.

URA'NIUM. (Thus named by Klaproth,
who discovered it in 1789.) A metallic
substance of a grey colour, obtained with
great difficulty from a mineral called
pechblende. It is infusible. Specific
gravity 9*0. It is found in Saxony and
Cornwall. It imparts a deep orange
colour to the enamel of porcelain. Little
however is known of its properties, nor is
it much used, in consequence of the ex-
treme difficulty that exists in obtaining it.

U'RCEOLATE. (from urceolus, Lat. a water-
pitcher.)

1. In conchology, a term applied to a
shell that swells in the middle, and is
therefore supposed to bear a resemblance
to a water-pitcher.

2. In botany, applied to a calyx or corolla
swelling out like a pitcher.

U'RCHIN. (erinaceus, Lat.) The hedge-
hog. The name of sea urchin has been
given to the echinus.

U'TRICLE. (utriculus, Lat, a little bottle.)
In botany, a term applied to a species of
capsule resembling a small bladder, or
capsule of one cell, which never opens by
valves, and drops with the seed. It is
thin and transparent, and is more fre-
quently considered to be the external coat
of the seed than a real capsule.

V

VA'GINATED. (from vagina, a sheath, Lat.)
A term used in botany, sheathed.

VAGINOPE'NNOUS. (from vagina, a sheath,
andj^enwa, awing, Lat.) Sheath-winged;
having the wings covered with hard cases.

VAGINU'LA. A genus of minute pyramidal
shells, known only as fossils, and found
in the tertiary strata near Bordeaux.

VALVA'TA. A genus of small freshwater
univalves belonging to the family Peristo-
mata. Valvatse are found both recent
and fossil. Dr. Mantell mentions one
species, Valvata piscinalis, as occurring
in the alluvial deposits of Sussex.

VALVE, (valva, Lat. valve, Fr. valva, It.)

1. In conchology, the shell. When the
whole shell of the animal is in one piece,
it is called an univalve ; when there are
two shells, or the shelly covering consists
of two pieces, as in the oyster, muscle,
&c., they are called bivalves ; and when
the covering consists of more than two
pieces, multivalves.

2. In anatomy, a folding door or lid at-
tached to a hollow vessel by means of a

hinge, which allows the valve to open in
one direction only for the passage of
fluids, and prevents their retrograde mo-
tion, or regurgitation. Thus there are
valves in the heart ; valves in the veins ;
valves in the lymphatics, &c.

VANA'DIUM. A metal recently discovered
in Sweden, and thus named after Vanadis,
a Scandinavian deity. Its properties are
not yet known.

VARIE'TY. (varietas, Lat. variete, Fr.
varieta, It.) A subdivision of species,
arising from accidental, or unimportant
and trifling, differences.

VARI'OHTE. (from variola, Lat.) The
name given to an amygdaloidal or por-
phyritic rock, merely in consequence of
its spotted appearance.

VA'SCULAR. (from vasculvm, Lat. a littte
vessel; vasculaire,~Fr.) Containing ves-
sels or tubes ; full of vessels within which
the fluids are confined, and by which their
course and their velocity are regulated.

VE'GETABLES. The first appearance of
vegetable existence may be discovered in

V E I

[ 269

V E I

the transition slate, which contains im-
pressions of algae or sea-weeds. A few
fronds of ferns have been found in some
of the transition rocks. " It appears,1'
says Prof. Buckland, " that nearly at the
same points in the progress of stratifica-
tion, where the most striking changes
take place in the remains of animal life,
there are found also concurrent changes
in the character of fossil vegetables."
VEIN, (vena, Lat. veine, Fr. vena, It.)

1. In anatomy, elastic tubes pervading
every part of the body, and conveying
dark or venous blood from the arteries to
the heart. The veins are larger and more
numerous than the arteries, and may be
compared to rivers, which, collecting all
the water that is not imbibed by the soil,
and reconveying it into its general recep-
tacle, the ocean, perform an analogous
office in the economy of nature.

2. In geology and mineralogy, fissures in
rocks filled up by mineral or metallic
substances differing from the rocks in
which they are situated. Mineral reposi-
tories of a flat or a tabular shape, which in
general traverse the strata of mountains,
crossing the strata, and having a different
direction from them, and filled with mi-
neral matter differing from the nature of
the rocks in which they occur. Mr.
Bakewell, in his admirable work " Intro-
duction to Geology," says, " perhaps the
reader may obtain a clearer notion of a
metallic vein, by first imagining a crack
or fissure in the earth a foot or more in
width, and extending east and west on the
surface, many hundred yards. Suppose
the crack or fissure to descend to an un-
known, depth, not in a perpendicular
direction, but sloping a little to the north
or south. Now, let us again suppose
each side of the fissure to become coated
with mineral matter of a different kind
from the rocks of which the fissure is
made, and then the whole fissure to be
filled by successive layers of various me-
tallic and mineral substances ; we shall
thus have a type of a metallic vein. Its
course from east to west is called its
direction, and the dip from the perpendi-
cular line of descent its hading. Thus it
is said to hade or dip to the north or
south."

Veins appear to have been originally
fissures cutting through different beds of
rocks, that have been subsequently filled
with metallic ores, intermixed with other
mineral matter, of a different nature from
that of the rock which is intersected.
Metallic veins are generally of a more re-
cent formation than the rocks they inter-
sect. They occur principally in the pri-
mary and transition rocks, but they are also
found in the lowest of the secondary series.

As regards the geographical distribu-
tion of mineral veins, it is an established
fact, that while extensive plain countries
are totally destitute of them, there are
few mountainous districts in which they
are not abundantly found. It has been
very generally observed that the character
of metalliferous veins changes with the
structure of the rock through which they
pass. It is itot necessary that there
should be an absolute difference of rock,
such as from slate to granite : a change
in the hardness and general mineralogical
structure of the same system of rocks
will frequently cause alterations of the
vein sufficiently remarkable. Among the
best conditions for expecting to find fis-
sures filled not only with an abundance of
metals, but also with kinds most useful to
a civilized state of society, is the proxi-
mity of some mass of granite, porphyry,
green-stone, or rocks of that class, to
stratified rocks, such as slates and others.

The depth to which metallic veins
descend is not known, all large veins
continuing beyond the reach of the deep-
est mine. The expense of working them
beyond a certain depth rendering it un-
profitable, and the influx of water impos-
sible, to proceed. They frequently con-
tain totally different ores at different
depths.

Veins vary in width from less than an
inch to thirty feet and upwards ; some-
times the same vein at one part con-
tracting, so as to be almost lost, and then
expanding to an immense width. This,
however, is not always the case, some
veins continuing of nearly the same width
throughout.

Werner supposed that veins had be-
come filled by matter descending into
them from above, in a state of aqueous
solution : Hutton, on the other hand,
imagined that their contents were in-
jected from below, in a state of igneous
fusion. A third hypothesis refers the
filling of veins to a process of sublima-
tion from subjacent matters of intensely
heated mineral matter, into apertures and
fissures of the superincumbent rocks. A
fourth hypothesis attributes these metal-
lic collections to segregation, or infiltra-
tion. Professor Buckland, in his wonted
delightful style, says, " Whatever may
have been the means whereby veins were
charged with their precious contents ;
whether segregation or sublimation were
the exclusive method by which the me-
tals were accumulated ; or, whether each
of the supposed causes may have ope-
rated simultaneously or consecutively in
their production ; the existence of these
veins remains a fact of the highest impor-
tance to the human race : and although

V E I

[ 270 ]

YEN

the disturbances, and other processes in
which they originated, may have taken
place at periods long antecedent to the
creation of our species, we may reason-
ably infer, that a provision for the comfort
and convenience of the last, and most
perfect creatures He was about to place
upon its surface, was in the providential
contemplation of the Creator, in His pri-
mary disposal of the physical forces,
which have caused some of the earliest
and most violent perturbations of the
globe."

VEINED. Variegated ; streaked ; marked j
with lines, either parallel to, or intersect-
ing, each other.

VEIN-STONE. The earthy, stony, saline, or
combustible substance, which contains the
ore, or is mingled with it, without being
chemically combined, is called the gangue,
or vein-stone.

VE'NA CA'VA. A large vein which trans-
mits the blood from the extremities to
the heart. There are two venae cavae ;
the superior or descending, which con-
veys the returning blood of the head,
neck, superior extremities, and part of
the thorax ; and the ascending, which
returns the blood of the lower extremi-
ties, abdominal viscera, &c. These two
great veins pour their accumulated tor-
rent of blood into the general reservoir,
the heart.

VENERICA'RDIA. A genus of equivalved,
inequilateral, marine, oblong bivalves ;
ribbed longitudinally on the outside ; two
thick hinge-teeth disposed obliquely, and
in the same direction : muscular impres-
sions two. Venericardiae are found recent
and fossil. The recent are met with at
depths of the ocean varying to fifty fathoms
in mud and sands. Fossil venericardiae are
found in the secondary and tertiary for-
mations. Dr. Mantell enumerates se-
veral species as occurring among the fos-
sils of the Sussex strata ; Venericardia
planicosta, and V. acuticosta, in the Lon-
don clay ; V. Brongniarti in the Bognor
sandstone ; and one species in the chalk
marl. Mr. Parkinson states that the
most beautiful species of this genus is
V. planicosta, a remarkably thick shell,
obliquely cordated, with flat smooth longi-
tudinal ribs : one specimen in his pos-
session measured four inches and a half.

VE'NTRICLE. (from ventriculus, Lat. ven-
tricule, Fr.) A chamber or cavity ; the
stomach. A term applied to different
cavities of the body. The heart contains
two chambers distinguished as the right
and left venjtricles, as well as two others,
termed auricles. Certain cavities found
in the brain are also called ventricles.

VE'NTRLCOSE. ) 1. In botany, applied to

VE'NTRICOUS. 5 parts of plants which are

distended, bellied, or swelling out in the
middle.

2. In conchology, applied to shells, in-
flated, or swelling in the middle.

VKNTRI'CULITE. A zoophyte found fossil
in flints and in the chalk. Dr. Mantell
has fully described different species of
ventriculites in his Geology of the South-
East of England, and from that work,
and from his Wonders of Geology, I
have made the following extracts. The
ventriculite, when living, must have been
of a cyathiform figure, and composed of a
tough, jelly-like substance, capable of
expansion and contraction. The smaller
extremity was attached to the rock by
root-like processes ; the outer tissue con-
sisted of a net work of cylindrical, perhaps
tubular, fibres ; the inner surface of the
funnel-like cavity was studded with poly-
piferous cells or openings. The speci-
mens enveloped in flint are usually of a
cyathiform or turbinated shape, while
those imbedded in chalk are more fre-
quently expanded into a broad circular
disk. When contracted into a cylindrical
form, the ventriculite is from one to six
inches in length ; when expanded, its
diameter generally exceeds nine inches :
the thickness of its substance is rarely
more than 0*2 inch.

Whether the recent ventriculites were
stationary, being confined to one spot by
their radical processes, or possessed a
power of locomotion, cannot be posi-
tively ascertained ; but Dr. Mantell con-
siders it more probable that, like the alcyo-
nia and actiniae, they were permanently
attached to the rock on which they grew.

VE'NUS. (from Venus, the goddess of
beauty.) A genus of exceedingly beauti-
ful marine bivalves. Equivalve, inequi-
lateral, subglobose, transverse shells, the
frontal margin flattened, with incumbent
lips ; hinge with three teeth, all of them
approximate, the lateral ones divergent
at the tip. The middle tooth, which is
sometimes bifid, is placed straight, and
the one on each side obliquely. The
shells of this genus have only been known
to inhabit the ocean ; they are found at
depths varying to fifty fathoms, lurking
in mud and coarse sands. Some of the
shells are of the most elegant and beauti-
fully diversified description, being rugose,
striated, and ribbed. Twenty-five spe-
cies have been discovered in the seas of
our coasts. Lamarck enumerates six fos-
sil species which are found in the neigh-
bourhood of Paris, and Dr. Mantell, five
species as occurring in the Sussex beds,
namely, Venus Ringmeriensis in the chalk
marl, and four species, V. parva, V. an-
gulata, V. Faba, and V. ovalis, in the
Shanklin sand.

v P: R

[ 271 ]

V E S

Cuvier places Venus in the family Car-
diacea. The common clam is a true
Venus.

VERDE-ANTI'QUE. A very beautiful marble,
highly prized, and used for ornamental
purposes. It is an aggregate of serpen-
tine and white crystallized marble, irre-
gularly mingled.

VE'RRUCOSE. > (verrucosus, full of warts,
VE'RRUCOUS. ] from verruca, Lat.)

1. In entomology, applied to the surface
of insects, when studded with large smooth
elevations, resembling warts.

2. In conchology, applied to shells beset
with excrescences resembling warts.

3. In botany, applied to the surface of
stems, beset with hard tubercles or warts.

VE'RTEBER. ) (vertebra, Lat. from verto, to
VE'RTEBRA. $ turn ; vertebre, Fr.) A
bone of the spinal column, or back-bone.
The different vertebrae composing the
back-bone are distinguished into cervical,
dorsal, and lumbar. The vertebral column
or spine, from the constancy with which
it has been found in all animals of this
type, and from the uniformity of plan
with which, amidst endless variations, it
is modelled, has been chosen as the dis-
tinctive character of all that great assem-
blage of individuals denominated Verte-
brata. In man the number of vertebrae
is twenty-four, namely, seven cervical,
twelve dorsal, and five lumbar. In dif-
ferent animals the number of vertebrae
varies exceedingly ; the vertebral column
of the Ichthyosaurus consisted of more
than one hundred joints. The cervical
vertebras alone of the Plesiosaurus were
about thirty, three in number. In birds
the number varies from nine to twenty-
three, and in living reptiles from three
to eight. In the Mososaurus, the whole
number of vertebrae amounted to one
hundred and thirty-three.
VERTEBRA'TA. The whole animal king-
dom has been distributed into four great
divisions, namely, Vertebrata, Mollusca,
Articulata, and Radiata. In the ascend-
ing series, the first of the true vertebrated
animals is the class of Fishes ; then fol-
lows Amphibia, comprehending the vari-
ous forms of frogs, toads, and tritons ;
the third class is the reptiles. These
three classes are all cold-blooded. The
fourth class comprises the birds ; these
form the first class in the ascending series
of hot-blooded animals ; the fifth, or
highest class, comprehends Mammalia,
and includes man.

VE'RTEBRATED. (vertebratuSf'La.t.) Pos-
sessing an osseous spinal column.
VE'RTEX. (vertex, Lat.) The crown, or
top of the head ; the summit. In con-
chology, in some shells the most promi-
nent part, in others the apex.

VE'RTICAL. (vertical, Fr. verticale, It.)
In a direction perpendicular to the plane
of the horizon.

VE'RTICIL. (verticillum, Lat. a whirl.)
In botany, a little whorl ; thus when,
instead of two opposite leaves, three or
more are produced from points forming a
ring on the stem, such ring is termed a
verticil.

VERTICI'LLATE. } (verticillatus, Lat. ver-

VERTICI'LLATED. $ ticille,Fr.) Whorled ;
growing in rings or whorls. Leaves pro-
duced from three or more points, forming
a ring on the stem, are called verticillate
leaves. Verticillate leaves are considered
as being produced by the non develope-
ment of several adjacent internodia.

VE'SICLE. (vesicula, a little bladder, Lat.
vesicule, Fr. vescichetta, It.)

1. A small bladder filled with serum.

2. A small membranous cavity, either in
animals or vegetables. The simplest and
apparently the most elementary texture
met with in vegetables is formed of ex-
ceedingly minute vesicles, the coats of
which consist of transparent membranes
of extreme tenuity. These vesicles vary
from the one-thousandth to the thirtieth
of an inch in diameter.

VESI'CULAR. Consisting of vesicles ; con-
taining vesicles ; full of small cavities,
hollows, or interstices.

VE'STIBULE. (vestibulum,~Lat.) The name
given to a cavity of the internal ear.

VESU'VIAN. (from Vesuvius.) The Ido-
crase of Haiiy ; the Vesuvienne of Bro-
chant. Pyramidal garnet. A mineral of
different shades of green, brown, red, and
sometimes, though rarely, of a blue co-
lour, occurring in granular distinct con-
cretions, crystallized, and massive. The
primitive form is a four- sided prism with
square bases, and one side of the base is
to the height nearly as 13 to 14 ; hence
it differs but little from a cube, and is
divisible into triangular prisms for the
integrant particles. Haiiy has described
eight modifications of its primitive form.
It is somewhat harder than quartz. Spe-
cific gravity from 3'2 to 3'4. It is often
translucent, sometimes transparent, and
sometimes nearly or quite opaque. It
possesses double refraction. Fracture
uneven, inclining to small conchoidal.
Before the blow-pipe, it fuses easily into
a yellowish translucent glass which after-
wards becomes black. Its constituents
vary, in some degree, according to the
locality whence it has been obtained.
Klaproth obtained from a specimen from
the neighbourhood of Vesuvius, silex
35-50, lime 33-00, alumine 22-2, oxide of
iron 7'50, oxide of manganese 0'25. It is
found abundantly in the vicinity of Mount
Vesuvius, from which circumstance it has

VEX

[ 272 ]

VOL

obtained its name, and in primary rocks
in Ireland, Scotland, and other parts of
Europe. — Cleat-eland. Jameson.

VE'XIL. ) (vejcillwm, a standard, or

VEXI'LLUM. \ banner, Lat.) In botany,
the upper large petal of a papilionaceous
flower.

VI'BRATILE ORGANS. See Cilia.

VI'LLI. (from villits, a hair, Lat.)

1. In anatomy, fine small fibres, resem-
bling a covering of down.

2. In botany, fine downy hail's, covering
fruits, flowers, and plants.

VI'LLOUS. (villosus, Lat.) Downy; pu-
bescent ; shaggy.

VI'SCERA. The plural of viscus. See
Viscus.

VI'SCID. > (viscidus, Lat. visqueux, Fr.

Vi'scous. $ viscoso, It.) Glutinous; te-
nacious ; clammy.

Vi'scus. (viscus, Lat.) In the plural,
viscera ; this term is generally applied to
the organs connected with digestion ;
sometimes to the bowels only. Any organ
of the body may be denominated a viscus.

VI'TREOUS. (vitreus, Lat. vitre, Fr. vitreo,
It.) Glassy ; resembling glass.

1. In mineralogy, a term used to denote a
particular lustre of some minerals.

2. In anatomy, a term applied to one of
the humours of the eye. The vitreous
humour occupies more than three-fourths
of the globe of the eye ; it is contained
in an exceedingly delicate texture of cel-
lular substance, and is situated behind
the crystalline lens.

VITRIFA'CTION. ^ (vitrification, Fr.) The

VITRIFICA'TION. $ conversion of any mat-
ter into glass by the application or aid of
heat.

VI'TRIFIED. (vitrifie, Fr.) Converted into
glass by heat.

VI'TRIFY. (vitrifier, Fr. vitrum, glass,
and facio, to make, Lat. ) To convert
into glass by the assistance of heat.

VI'VIANITE. The Vivianit of Werner ; the
Fer Phosphate of Haiiy. Phosphate of
iron. A mineral of a green or blue co-
lour. Its constituents are, protoxide of
iron 47*5, phosphoric acid 32'0, water
20-0.

VIVI'PAROUS. (viviparus, Lat. from vivus,
alive, and pario, to bring forth ; vivipare,
Fr.) Animals are termed viviparous in
which no egg, properly so called, is form-
ed, but bring forth their young alive and
perfect.

VOLCA'NIC. Relating to volcanoes; pro-
duced by volcanoes.

VOLCA'NIC PRODUCTIONS. These are nu-
merous and diversified. Lava, scoria,
enamel, and glass, comprise by far the
most important and interesting volcanic
productions. The different states of lava,
whether vitreous, compact, or scoriaceous,

depend on the different circumstances
under which it has cooled. Aqueous
vapour is in general very abundant. The
principal gases hitherto detected consist,
according to Dr. Daubeny, of muriatic
acid gas, sulphur combined with oxygen
or hydrogen, carbonic acid gas, and ni-
trogen. The sublimations of Vesuvius
are, according to Sir H. Davy, chloride of
sodium, chloride of iron, sulphate of
soda, muriate and sulphate of potash, and
a small quantity of oxide of copper. The
principal metallic substances in volcanic
rocks are iron and titanium ; but ores of
antimony, copper, and manganese, have
sometimes been found in the craters of
volcanoes. Tellurium, gold, and mer-
cury are also said to occur in some vol-
canic rocks. The island of Ischia, which
is entirely volcanic, contains a mine of
gold. — Bakeicell. Cleaveland. Phillips.

VO'LCANITE. Another name for augite.

VOLCA'NO. (volcan, Fr. volcano, It. from
Vulcan, the god of fire.) An opening in
the earth's surface made by internal fire.
Volcanoes exist in all quarters of the
globe, and, .according to Jameson, about
one hundred and ninety-three active vol-
canoes have been observed; of which 13
belong to Europe and its islands, — 66 to
Asia and its islands, — 8 to the islands of
Africa, — and 106 to America and its
islands. Volcanoes have been long con-
sidered in the light of safety valves, and
this was the opinion entertained of them
by Strabo, and it can scarcely be doubted
that the tranquillity of the incandescent
fluid mass, composing the earth's centre,
is owing to these numerous vents for the
passage of steam, &c. Although volcanoes
generally exist in the neighbpurhood of
the sea, yet this is not invariably the case,
as was once supposed. In central Asia
there is a volcanic region with an area of
2500 square geographical miles, at a dis-
tance of upwards of 300 leagues from the
ocean. Volcanoes frequently will remain
in a quiescent state for many centuries,
and again burst forth with renewed ac-
tivity and vigour.

VO'LVA. (volva, Lat. that wherein a thing
is wrapped.) In botany, a species of
calyx. A term applied to a membranous
wrapper or covering of the fungus tribe,
which conceals their parts of fructifica-
tion : in due time it bursts, and forms a
ring upon the stalk.

VOLVA'RIA. A genus of cylindrical con-
voluted shells known only in a fossil
state. The spire is not extruded ; aper-
ture narrow, extending the length of the
shell : the columella plicated at its base :
outer lip dentated. Volvaria approaches
very near to Bulla cylindrica.

VOLU'TION. A spiral wreath or turn. The

VOL

[273]

WAT

wreaths or turnings of the shells of uni-
valves are termed volutions.

VO'LVOX. (volvox, Lat. from volvo, to
roll. ) A genus of globular animalcules.
To the presence of one species of volvox,
the volvox globator, a loricated animalcule,
and to its great abundance in such situ-
ations, pools of stagnant water owe their
green colour.

VU'LCANIST. One who supports the Vulca-
nian theory, namely, that all rocks are of
igneous production. The Vulcanists were

opposed to the Neptunians, who, on the

other hand, maintained that all rocks

were of aqueous origin.
VU'LCANIAN THE'ORY. That theory which

explained the formation of all rocks by

the agency of fire.
VU'LPINITE. A mineral of a greyish-white

colour; thus named from its beingfound

at Vulpino in Italy.
VULVA. (Lat.) In conchology, a spatu-

lated mark in shells of the Venus tribe.

W

WACKE. ) A name given by the Germans
WACKE'. $ to a soft earthy basalt, to
which it is nearly allied, and of which it
may be deemed a variety. Its colours are
greenish grey, sometimes passing into
blackish green, brown, and greyish black,
with sometimes a shade of yellow or red.
It is invariably opaque. It occurs in
amorphous masses, compact or vesicular.
Fracture uneven, or slightly conchoidal.
Hardness moderate. It is easily broken,
and may be cut by a knife. Specific
gravity from 2'5 to 2-8. Before the blow-
pipe it fuses into an opaque, porous
mass. It appears to be intermediate be-
tween clay and basalt, often passing into
basalt. It does not adhere to the tongue,
which circumstance distinguishes it from
clay, nor will it form a paste with water.
It does not, as does marl, effervesce with
acids. Wacke is included among the
trap rocks. When wacke, being vesicular,
contains within* its cavities calcedony,
agates, &c. it forms a variety of amygda-
loid. It is found more abundantly in
Germany than in any other country, but
it is not confined to Germany.
WAD. } Another name for plumbago, or
WADD. $ black-lead. See Black Lead.
WADD BLACK. An ore of manganese. A
name given to the earthy manganese of
Devonshire : it is a hydrate of manga-
nese, and has the peculiar property of
taking fire when dry, moderately heated,
and mixed with linseed oil.
WARM-BLOODED ANIMALS. In the as-
cending series of the four great divisions
of the animal kingdom, the highest, or
vertebrata, alone contains what are called
warm-blooded animals. Of this division,
consisting of five classes, two classes only,
namely aves, or birds, and mammalia, are
warm-blooded ; the remaining three are
cold-blooded. In warm-blooded animals
the circulation is two-fold, there being,
in fact, two hearts, perfectly distinct from
one another, and separated by thick par-
titions, which do not permit any direct

transmission of fluid from one to the
other. These two hearts are joined toge-
ther, and enclosed within one capsule or
envelope. The following is the course of
circulation in warm - blooded animals.
From the left ventricle the blood is pro-
pelled into the aorta, the great artery of
the body, to be by it forwarded into all
the arterial ramifications of the whole
system ; from these arteries it passes on
through the veins into the vense cavse,
and by them is carried into the right
auricle ; from the right auricle it passes
into the right ventricle, and by the right
ventricle is propelled into the pulmonary
arteries, to be conveyed through the
lungs, in its passage through which it
becomes aerated, loses its dark and as-
sumes a florid colour, and is once more
arterial blood ; it then passes into the
pulmonary veins, and is conveyed into the
left auricle, whence it is forced into the left
ventricle, and once more into the aorta.

WART. A hard excrescence ; a protu-
berance.

WA'RTY. In botany, a term applied to the
stems of trees when covered, or studded,
with knobs or excrescences.

WA'TER. (wasser, Germ.) When pure,
water is transparent, and destitute of
colour, taste, and smell. The specific
gravity of water is always supposed =
1*000, and it is made the measure of the
specific gravity of all other bodies. When
water is cooled down to 32° Fah. it as-
sumes the form of ice. When heated to
the temperature of 212° Fah. it boils, and
is converted into steam. Pure water con-
sists of two parts of hydrogen and one of
oxygen.

WA'TER OF CRYSTALLIZA'TION. A variety
of substances in crystallizing, combine
chemically with a certain portion of
water, which in a dry state forms an es-
sential part of their crystals, and seems,
in some cases, to give the peculiar deter-
mination to their constituent molecules. —
Mrs. Somerville.

N N

W A T

[ 274 ]

WEN

WA'TER-WORN. Worn away, rounded,
smoothed, by the action of running water.
WA'VED. Variegated ; undated.

1. In botany, applied to the margins of
leaves, when bordered alternately with
numerous minute segments of circles and
angles.

2. In entomology, applied to insects when
the margin of the body is marked with
a succession of arched incisions.

WA'VELLITE. A rare mineral, first disco- j
vered in Devonshire by Dr. Wavell, and
named after him. Its colours are either pure
* white or white tinged with grey, green, or
yellow ; lustre silky. Specific gravity from
2'25 to 2' 70. It consists essentially of |
alumine, being composed of alumine 71*5, |
water 28*0, oxide of iron 0'5. Sometimes }
a trace of silex and lime is present.

WEALD, (from wald, Germ, a wood.) The
name given to a valley, or tract of country, I
lying between the North and South Downs
of Kent and Sussex.

WEALD-CLAY. A tenacious blue clay, con- i
taining subordinate beds of sandstone and !
shelly limestone, with layers of septaria j
of argillaceous ironstone, forming the i
subsoil of the wealds of Sussex and Kent, |
and separating the Shanklin sand from the
central mass of the Hastings beds. — Dr.
Mantell's Geology of the South-east o/j
England.

WEA'LDEN FORMATION. > The term Weal- j

WEALDEN STRATA. $ ^en was SUS- !
gested, as the most appropriate that could
be assigned to the strata of the Wealds of
Kent and Sussex, by J. P. S. Martin, j
Esq. of Pulborough. The Wealden for- !
mation, group, or strata, have been sepa-
rated into three principal divisions.

1. The Wealden clay, above described.

2. The Hastings sands : grey, white, yel-
low, and reddish brown sands, and friable
sandstone, passing into limestone.

3. The Purbeck beds, called also Ashburn-
ham beds, consisting of grey limestone,
alternating with blue clay and sandstone
shale. The whole of these are freshwater
or fluviatile deposits. Dr. Mantell may
be considered the great geological cham-
pion and hero of the Wealden, for to his
indefatigable exertions in that field, are
owing some of the most splendid disco-
veries in Palaeontology. Until the ap-
pearance of Dr. Mantell 's works on the
Geology of Sussex, the peculiar relations
of the sandstones and clays of the interior
of Kent, Sussex, and Hampshire, were
entirely misunderstood. No one sup-
posed that these immense strata were
altogether of a peculiar type, and inter-
polated amid the rest of the marine for-
mations, as a local freshwater deposit. —
Prof. Phillips.

It was not until the appearance of Dr.

Mantell's illustrations of the Geology of
Sussex, that the full value of the evidence
which this district affords was made to
appear. In that excellent work the au-
thor clearly showed that the extraordinary
remains which he had discovered in the
beds of Tilgate Forest must have origi-
nated in a lake or estuary, and have been
the produce of a climate much warmer
than that which is now enjoyed in Eng-
land.— Dr. Fitton.

To the indefatigable and scientific re-
searches of Dr. Mantell we are indebted
for a knowledge of the true geological
characters of the Wealdean beds. — Mr.
Bakewell.

Dr. Mantell observes that the Wealden
may be considered as covering an area
200 miles in length, from west to east,
and 220 miles from north-west to south-
east, the total thickness averaging about
2000 feet. Of this series of deposits,
clays or argillaceous sediments, with
limestone almost wholly composed of
freshwater snail-shells, occupy the upper-
most place ; sand and sandstones, with
shales and lignite, prevail in the middle ;
while in the lowermost, argillaceous beds,
with shelly marbles or limestones, again
appear ; and, buried beneath the whole,
is a petrified forest, in which the trees are
still standing, and the vegetable mould
undisturbed. The organic remains of the
Wealden consist of leaves, stems, and
branches of plants of a tropical character ;
bones of enormous reptiles of extinct
genera, of crocodiles, turtles, flying rep-
tiles, and birds ; fishes of several genera
and species, and shells of a fluviatile
character. Not a vestige of the mamma-
lia has been discovered in the Wealden.
For a knowledge of that enormous reptile,
the Iguanodon, we are entirely indebted
to the indefatigable and scientific re-
searches of Dr. Mantell ; and for a most
interesting and elaborate detail of all
matters relating to the Wealden deposits
and their contents, the reader is referred
to Dr. Mantell's Geology of the South-
east of England and his Wonders of
Geology.

WEDGE-SHAPED. In botany, applied to
leaves that are broad at the summit and
gradually taper toward the base.
WEIGHT OF THE ATMOSPHERE. The air
is an elastic fluid resisting pressure in
every direction, and is subject to the law
of gravitation. The pressure of the at-
mosphere is calculated to be about fifteen
pounds to every square inch, so that the
surface of the globe sustains a weight of
11,449,000,000 hundreds of millions of
pounds. — Mrs. Somerville.
WE'NLOCK FORMATION. The lower forma-
tion of the upper Silurian rocks, compris-

WEN

[ 275 ]

w o o

ing the Wenlock limestone and Weulock
shale.

WE'NLOCK SLATE. Called also Wenlock
shale. An argillaceous, dark-grey or
liver-coloured shale, constituting the lower
member of the Wenlock formation, and
containing nodules of sandstone.

WE'RNERITE. A rare mineral of a greenish-
grey, olive-green, or, sometimes, white
colour, occurring in eight-sided prisms,
terminated by four-sided summits, whose
faces form with the alternate lateral
plates, on which they stand, an angle of
about 121°. It is found at Arendal in
Norway, and in Sweden and Switzerland.
It has been named after Werner. It
consists of silex 45'5, alumine 33'5, lime
13*22, oxide of iron 5'75, oxide of man-
ganese 1'47,—Cleaveland.

WHEEL-SHAPED. In botany, a term ap-
plied to a corolla of a salver-shaped form,
having scarcely any tube.

WHET SLATE. i The Novaculite of

WHET-STONE SLATE, f Kirwan ; the
Wetz-Schiefer of Werner ; the Schiste
coticule of Brongniart ; the Argile schis-
teuse novaculaire of Hatiy. For a de-
scription, see Hone.

WHI'NSTONE. A provincial term applied
to some of the trap rocks.

WHITE-STONE. Felspathic granite, called
by the French Eurite, and by Werner
Weiss-stein. See Eurite.

WHORL. In conchology, a wreath, volu-
tion, or turn of the spire of a univalve ;
the axis of revolution is termed the
columella, and the turns of the spiral are
denominated whorls.

2. In botany, a species of inflorescence,
in which the flowers surround the] stem
in the form of a ring ; also applied to
leaves, when they arise in a circle round
the stem.

WING.

1. The limb of a bird or insect by the aid
of which it is able to fly.

2. In botany, a membranous appendage
to some seeds, serving to waft them along
in the air : applied also to the two side
petals of a papilionaceous corolla.

WINGED. Having wings. In botany, ap-
plied to stems, when the angles are ex-
tended into leafy borders ; also to petioles
having a leafy border on each side.

WI'THERITE. (A mineral first discovered
at Anglesark, in Lancashire, by Dr.
Withering, and named in honour of him.)
Carbonate of Barytes. The Baryte
carbonatee of Haiiy ; the Witherit of
Werner ; the Barolite of Kirwan. See
Barolite.

WOLF, (wolf, Germ.) The wolf affords
an excellent illustration of the complete
extinction of species. Wolves were for-
merly exceedingly numerous in Great Bri-
tain, and were met with in Ireland even
so late as the beginning of the 18th cen-
tury. At the present day, unless seen in
a menagerie, or read of as still existing in
other countries, and formerly in this, the
natives of these islands might be per-
fectly unaware that the wolf ever had any
existence. In our own days, as it were,
the Dodo, a large bird, of the size of a
turkey, a fews years since only existing
in great numbers in the Isle of France,
has become extinct ; a foot and a head, in
the Museum at Oxford, being the only
remains we possess, with the exception of
fossil bones.

WO'LFRAM. The name given by Werner
to the ferruginous oxide of tungsten.
Wolfram occurs in Germany, Sweden,
France, Spain, and Great Britain. It is
met with, generally accompanied by ores
of tin, in primary and transition rocks.
It is of a dark brown, brownish black, or
nearly black colour. Specific gravity be-
tween 6-8 and 7 -3. Texture foliated.
Easily separated into plates by percussion.
Hardness 6 to 8. Before the blow-pipe
it decrepitates, but it is wholly infusible.
It consists of oxide of tungsten 67 '0, oxide
of iron 18'0, oxide of manganese 6-25,
silex 1-50.

WO'LLA-STONITE. A mineral, thus named
in honour of Dr. Wollaston. Prismatic
augite.

WOOD-COAL. Another name for brown
coal. See Brown Coal.

WOOD-OPAL. Opalized wood. The Holz-
opal of Werner ; the Quartz resinite
xylo'ide of Haiiy : Ligniform, opal of
Kirman. A variety of opal, occurring in
various vegetable forms, and being in
reality opalized vegetable matter. It is
found in Hungary.

WOOD-STONE. Another name for petrified
wood.

WOOD-TIN. The Etain oxide concretione
of Haiiy ; the Kornishches Zinnerz of
Werner. A variety of oxide of tin ; fi-
brous oxide of tin. This has been hitherto
found only in Cornwall and Mexico. It
occurs in fragments which are generally
rounded. Its colours are light or ches-
nut brown, reddish brown, and yellowish
grey. It is opaque ; of a fibrous texture ;
easily broken. Specific gravity from 6*4
to 6'7. It is infusible before the blow-
pipe, and irreducible. It consists of
oxide of tin 91 '0, oxide of iron 9.

X Y L

[ 276 ]

Z A M

X

XYLO'PHAGI. (from £t-Xoi>, wood,

to eat, Gr.) A family of coleopterous
insects, comprising several genera.

XI'PHIAS. (£i0iae, from £i$0£, a sword,
Gr.) The sword-fish.

XI'PHOID. (from £('0oc, a sword, and ti£oc,
form.) Resembling a sword : a term ap-
plied to the cartilage placed at the lower
extremity of the sternum or breast-bone.

YA'NOLITE. The name given by Lamethe-
ric to the Axinite of Haiiy and the Thum-
merstone of Kirwan. See Axinite.

YE'NITE. So named from Jena. Called
also Lievrite. It is found in the Isle of
Elba and in Norway. A mineral of a
black or blackish-green colour, occurring
crystallized and massive. It is opaque ;
scratches glass ; gives sparks with steel.
Specific gravity from 3'8 to 4. Longitu-
dinal fracture foliated ; cross fracture
conchoidal or uneven : lustre resinous.
Before the blow-pipe it fuses into a dull,
opaque, black globule, strongly attracted
by the magnet. It consists of silex 30'0,
lime 12'5, oxide of iron 57'5.

Y'TTRIA. A name given by Ekeberg to a
new earth discovered by Gadolin, in 1797,

in the quarry of Ytterby in Sweden. It
has also been named Gadolinite, after
Gadolin. See Gadolinite.

Y'TTRIUM. The name given by Ekeberg to
a metal forming the basis of Yttria. In
that mineral it is combined with the oxides
of iron and manganese, and a small portion
of lime, and silica. When separated from
these substances, it has the appearance
of a fine white powder, without either
taste or smell. It is infusible, and is in-
soluble in water.

YTTROTA'NTALITE. The name given by
Brochant to Ittrious oxide of Columbium.
Yttrotantalite, like Yttria, is found in the
quarry of Ytterby in Sweden. It is of a
dark grey colour ; shining, metallic lus-
tre ; found in reniform masses.

ZA'FFRE. An impure oxide of cobalt, ob-
tained by roasting the ore of cobalt, by
which process the arsenic and sulphur
contained in the ore are driven off. Zaf-
fre melted with silex and potash, and
reduced to powder, constitutes the article
known under the name of powder blue.

ZA'MIA. For the following description of
this genus of plants, I am indebted to the
kindness of Mr. William Munday, of
Worthing, who has obligingly extracted
and forwarded it to me : —

" Zamia, in botany, a genus of the
class Appendix palmae, Dioecia, order Po-
lyandria, natural order of Palmse, Filices
(Juss). Generic character: Male, — calyx;
ament strobile-shaped, ovate, obtuse ;
scales horizontal, pellate, obovate, very
blunt, one-flowered, thickened at the top,
permanent. Corolla none. Stamina :
filaments none. Anthers subglobular,
clustered, accumulated in the lower sur-
face of the scales, sessile, two-valved,
opening above by a longitudinal cleft.
Pollen, farinaceous. Female, — calyx ;
ament strobile- shaped, larger, ovate, im-
bricate ; scales pedicelled, pellate, angu-

lar, finally distant, permanent. Corolla
none. Pistil : germs two, irregular, an-
gular, inserted into the margin under the
pelta of the scales, solitary on each side,
nodding. Style none. Stigma obtuse,
obscurely cloven at the side. Pericarp :
berries to each scale two ovate, barked at
the base, fleshy, one-celled. Seed one in
each berry, ovate. Essential character:
Male, — ament strobile-shaped, scales co-
vered with pollen underneath. Female,
ament strobile-shaped, with scales at each
margin ; berry solitary."

"1. Z. furfuracea, or broad-leaved
zamia. Leaflets wedge-shaped, straight,
very smooth from the middle to the tip,
serrate, scurfy underneath; stipe spiny,
stem thick, seldom rising more than two
feet high. It was discovered by Dr.
Houstoun in the sands near Vera Cruz in
America.

"2. Z. integrifolia, or dwarf zamia.
Leaflets mostly quite entire, bluntish,
awnless, straight, shining ; stipe unarmed.
The spadix is divided into florets after the
manner of the fruit of the cypress. Na-
tive of EasJ; Florida.

Z A M

[277]

Z E U

" 3,. Z. debilis, or long-leaved zamia.
Leaflets linear, awnless, serrulate at the
tip from spreading, recurved, longer than
the channelled rachis ; stipe three-sided,
compressed, unarmed. Native of the
West Indies.

" 4. Z. pungens, or needle zamia.
Leaflets awl-shaped, spreading, strict,
rigid, mucronate ; the outer margin of
the base rounded ; stipe roundish, un-
armed. Native of the Cape.

" 5. Z. zycadis, or narrow-leaved za-
mia. Leaflets oblique, linear, lanceolate,
awl-shaped, hairy, curved, one, two, or
three-spined at the tip ; stipe unarmed.
Native of the Cape of Good Hope." —
Encyclopedia Londinensis.

Fossil zamise have been discovered in
the coal formation of Bohemia. In
Lindley and Button's Fossil Flora figures
of cones are given which are referred to
the genus Zamia, from the sandstone of
the Wealden formation at Yaverland, on
the south coast of the Isle of Wight. The
mode of inflorescence of the zamia is
splendidly shown in Prof. Buckland's
Bridgewater Treatise.

ZA'MITK. A fossil zamia. M. Ad. Brong-
niart has referred the ' zamite,. or fossil
zamia, to a new genus, to which he has
assigned the name of Mantellia nidiformis.

ZECH-STEIN. > The second member of the

ZETCHSTEIN. $ red sandstone series, in
the ascending order. The zech-stein is a
calcareous deposit, or- magriesian lime-
stone, of a somewhat variable aspect ; it
is fossiliferous, and in it, as far as obser-
vations have yet gone, are found, for the
first time, those shells known by the name
of Productse. Some geologists are of
opinion that the connection between the
two formations of red sandstone and
zech-stein is so intimate, that the latter
may be regarded as a subordinate forma-
tion to the former. The zech-stein lies
immediately under the red sandstone and
above the marl slate, or kupfer schiefer,
of the magnesian limestone formation. It
is a deposit not widely spread over the
European area, and is principally known
in Germany and England.

ZE'OLITE. (from £*'w, to swell or foam,
and Xidog, a stone, Gr.)
1. Under this name some mineralogists
comprise eleven subgeriera of the mineral
genus zeolite, namely, 1. Trapezoidal
zeolite, or leucite ; 2. Dodecahedral zeo-
lite, or lapis lazuli ; 3. Hexahedral zeo-
lite, or analcime ; 4. Paratomous zeolite,
or cross-stone ; 5. Rhombohedrai zeolite,
or chabasite ; 6. Diatomous zeolite, or
laumonite ; 7. Prismatic zeolite, or me-
sotype ; 8. Prismatoidal zeolite, or stil-
bite ; 9. Hemiprismatic zeolite, or heu-
landite ; 10. Pyramidal zeolite, or apo-

phyllite ; 11. Macrytopous zeolite, or
Brewsterite. These will all be found de-
scribed under their several names.
2. A translucent and, sometimes, trans-
parent mineral of a white, yellow, or
brownish-yellow colour, exhibiting double
refraction. Zeolite is electric by heat,
one summit of its prisms becoming posi-
tive and the other negative ; the latter is
usually that summit which was connected
with the gangue. It is found in distinct
crystals, whose surfaces have a strong
lustre, slightly pearly ; and in masses
composed of several fascicular groups of
minute crystals ; and in each group the
crystals or fibres diverge, or even radiate,
from one point, and at the surface fre-
quently appear distinct from each other,
or exhibit pyramidal terminations. Some
zeolites phosphoresce by friction. Before
the blow-pipe zeolite fuses with much
ebullition or intumescence into a whitish
spongy enamel, and it is from this pro-
perty that it has obtained its name. When
reduced to powder and thrown into nitric
acid, it is converted into a jelly in the
course of a few hours. This property of
becoming gelatinous, as well as that of
becoming electric by heat, sufficiently
distinguish zeolite from stilbite, analcime",
chabasic, harmotome, and prehnite. Zeo-
lite most frequently occurs in amygdaloid,
basalt, greenstone, and clinkstone por-
phyry. It is also found in granite and
gneiss. — Cleaveland.

ZEOLI'TIC. Pertaining to zeolite ; con-
taining zeolite ; resembling zeolite.

ZE'RO. (ztro, Fr. zero, It. ) This word is
of Italian derivation, and means a cipher
or 0. The expression is used to denote a
certain point or mark on the thermome-
trical scale. In the thermometers of
Celsius and Reaumur, zero is the point
at which water congeals. In Wedge-
wood's pyrometer, zero corresponds with
1077° of Fahrenheit's scale. The ques-
tion has been propounded, " at what de-
gree would a thermometer stand (suppos-
ing the thermometer capable of measuring
so low) were the body to which it is ap-
plied totally deprived of caloric ? or what
degree of the thermometer corresponds to
the real zero ? " This question does not
appear to have ever been satisfactorily
answered. Dr. Crawford placed the real
zero 1268° below 0. Mr. Kirwan fixed
the real zero at 1048° below 0. Lavoisier
and La Place placed the real zero at 2736°
and 5803° below 0.

ZE'US. (zeus, Lat.) A genus of fishes of
the thoracic order, having the head com-
pressed and sloping, the upper lip arched,
the tongue subulated, the body com-
pressed, thin, and shining, and the rays
of the first dorsal fin ending in filaments.

Z E Y

[ 278 ]

ZOO

In Dr. Mantell's Geology of the South-
East of Fngland, a species of zeus, found
in the chalk, the zeus Lewesiensis, is
beautifully figured. This ichthyolite is
from six to eight inches long, and its
width is nearly equal to the length of the
body.— Dr. Mantell.

ZEY'TANITE. The name given by Werner
to the mineral ceylanite. See Ceylanite.

ZI'GZAG. Having contrary windings and
turnings ; having short turns.

ZINC. } (zink, Germ. Dr. Webster states

ZINK. j[ that the common orthography of
this word, zinc, is erroneous ; it may be
so, but it is the customary and usual or-
thography of the best English writers.)
One of the fifty-five simple or elementary
bodies. A metal of a bluish-white co-
lour, with a fine {rrsnular fracture. Zinc
was not obtained in its metallic form till
the sixteenth century, though its ores
were known to the ancients, and used by
them in the formation of their brass or
bronze. It does not occur native ; its
most abundant ore is the sulphuret, called
Blende, common in most veins which
contain sulphurets of iron, lead, copper,
&c., in every country. The structure of
zinc is foliated. As regards its hardness,
it may be easily cut with the knife. Spe-
cific gravity from 6-9 to 7'2. It is mal-
leable, but its malleability is greatly in-
creased by heating it to a temperature of
300 Fahrenheit. By exposure to the air
it tarnishes and loses its lustre, but it is
but little oxidated. United with copper
it forms brass. The ores of zinc are few.
Its presence may be determined by roast-
ing the ore, and then fusing it by the
blow-pipe on charcoal with filings of pure
copper. If zinc be present, the copper
will be converted into brass. The ore
called calamine is a carbonate of zinc.
ZI'RCON. A mineral occurring in rounded
grains or fragments, or in regular crystals.
It is harder than quartz, and possesses
double refraction in a high degree. It is
transparent, or sometimes only translu-
cent. Specific gravity from 4*3 to 4-7.
Before the blow-pipe it is infusible, but
loses its colour. It may be distinguished
from garnet, idocrase, staurotide, &c., by
its int'usibility, specific gravity, and strong
double refraction. There are two varie-
ties of zircon, called zircon jargon and
zircon hyacinth. Zircon jargon consists
of zircoaia'69'0, silica 26'5, oxide of iron
0'5. Zircon hyacinth of zirconia 70*0,
silica 25-0, oxide of iron 0'5. The finest
specimens are brought from the island of

- (Jfeylon. It occurs in primary and tran-
sition rocks, but is usually obtained from
the sand of rivers.

ZIRCO'NIA. An earth, when pure, white
and tasteless, supposed to be a compound j

of zirconium, its metallic basis, and oxy-
gen. An oxide of zirconium.
ZIRCO'NIUM. The metallic basis of the

earth zirconia.

ZO'DIAC. (zodiaque, Fr. zodiaco, It. zodi-
acus, Lat. £wc)iaKt)C, Gr.) A broad cir-
cle or region in the heavens remarkable,
not from anything peculiar in its own
composition, but from its being the area
within which the apparent motions of the
sun, moon, and all the great planets are
confined. The centre of the zodiac is the
ecliptic, which is inclined to the equinoc-
tial at an angle of about 23° 28', inter-
secting it at two opposite points, called
the equinoctial points. The zodiac ex-
tends 9° on either side of the ecliptic.
ZODI'ACAL. Pertaining to the zodiac, as

the zodiacal constellations, &c.
ZOI'SITE. ?A mineral, thus named from
ZOI'ZITE. $ Baron Von Zois, its disco-
verer. A variety of Epidote, of a grey,
brown, or yellowish colour.
ZOOLO'GICAL. Pertaining to zoology.
ZOO'LOGIST. One who studies, or is versed

in, the natural history of animals.
ZOO'LOGY. (from £wov an animal, and
Xoyoc, discourse, Gr. zoologie, Fr. zoo-
logria, It.) That branch of natural his-
tory which treats of animals, their habits,
structure, classification, &c. Prof. Buck-
land says that the study of zoology has
become as indispensable to the progress
of geology, as a knowledge of mineralogy.
ZOO'LOGY, FOSSIL. That division of zoology
which treats of fossil animals. The exa-
mination of the fossil remains of a former
state of creation has demonstrated the
existence of animals far surpassing in
magnitude those now living, and brought
to light many forms of being which have
nothing analogous to them at present,
and many others which afford important
connecting links between existing genera.
ZOO'PHAGA. (from £wov, an animal, and
tyayliv, to eat, Gr.) A tribe of animals
which attack and devour living animals.
The animals of this tribe have three kinds of
teeth, namely, cutting teeth, canine teeth,
and grinders ; their paws are armed with
claws ; their muzzle is often set with
whiskers, usually called smellers ; their
mammary organs are dispersed ; their in-
testines are less voluminous than those of
herbivorous animals.
ZOO'PHAGOUS. Attacking and devouring

living animals.

ZOO'PHYTE. (£w60vra, from £wov and
0uo>, Gr. qua mediae sunt nature inter
animalia etplantas ; zoophyte, Fr. zoojito,
It.) Animal plants, corals, sponges, and
other aquatic animals which have obtained
the name from an opinion formerly enter-
tained that they were intermediate be-
tween animals and vegetables. In conse-

zoo

[ 279 ]

Z U R

quence of their aggregation, which pro-
duces trunks and expansions of various
forms, together with the simple nature
of their organization, and the radiating
disposition of their organs, resembling
the petals of flowers, these animals owe
their name of zoophytes or animal plants.
But possessing the power of voluntary
motion, enjoying the sense of touch, feed-
ing on matters which they have swallowed,
and digesting these in an internal cavity,

they must, in every point of view, be con-
sidered to be animals. Zoophytes are
either free in the sea, or are attached for
life after a very early period of growth.

ZOOPHYTO'LOGY. (from £w60vra, a zoo-
phyte, and A6yo£, discourse, Gr.) That
branch of natural history which treats of
the structure, habits, &c. of zoophytes.

ZU'BLITE. The name given to a recently
discovered Vesuvian mineral.

LONDON :

PRINTED BY STEWART AND MURRAY,
OLD BAILEY.

14 DAY USE

RETURN TO DESK FROM WHICH BORROWED

EARTH SCIENCES

This book is due on the last date stamped below, or

on the date to which renewed.
Renewed books are subject to immediate recall.

w,-

LD 21-40m-5,'65
(F4308slO)476

General Library

University of California

Berkeley

"Stora