S Hi 
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SPERGULA, spurrey, a genus of .plants 
belonging to the class of decandria, and the 
order ot pentagvnia, and in (he natural sys- 
tem arranged under lhe22ud order, caryophyl- 
lea;. The calyx is pentaphyllous ; the petals 
five, and undivided ; the capsule oval, unilo- 
cular. and containing five valves. There 
are seven species, five of which are British; , 
1. The arvensis, corn-spurrey, has linear fur- j 
rowed leaves, from eight to twenty in a j 
whorl. The flowers are small, white, and 
[ terminal, It is frequent in corn-fields. In 
Holland it is cultivated as food for cattle, 
and has the advantage of growing on the very 
poorest soils, but does not afford a great 
deal of food. Poultry are fond of the seeds ; j 
and the inhabitants of Finland and Norway J 
make bread of them when their crops of corn 
fail. Horses, sheep, goats, and swine, eat 
it. Cows refuse it. 2. The nodosa, knotted 
spurrey. 3. Pentandra, small spurrey. 4. 
Laricina, larch-leaved spurrey. 5. Saginoides, 
pearlwort spurrey. 
SPERMACETI. This peculiar oily sub- 
stance is found in the cranium of the piiyseter 
mocrocephalus, or spermaceti-whale. It is 
obtained also from some other species. At 
first it is mixed with some liquid oil, which is 
separated by means of a woollen bag. The 
last portions are removed by an alkaline lev, 
and the spermaceti is afterwards purified by 
fusion. Thus obtained it is a beautiful white 
substance, usually in small scales, very brit- 
tle, has scarcely any taste, and but little 
smell. It is distinguished from ali other 
fatty bodies by the crystalline appearance 
which it always assumes. It melts, according 
to the experiments of Bostock. at the tempe- 
rature of 112°. When sufficiently heated' it 
may be distilled over without much altera- 
tion; but when distilled repeatedly, it loses 
its solid form, and becomes a liquid oil. It is 
soluble in boiling alcohol, but separates 
again as the solution cools. About 150 parts 
of alcohol are necessary to dissolve it. Ether 
dissolves it cold, and very rapidly when hot : 
on cooling it concretes into a solid mass. It 
dissolves also in hot oil of turpentine, but pre- 
cipitates again as the liquor cools. 
The acids have hardly any action upon it, 
but it unites with the pure alkalies. With 
hot ammonia it forms an emulsion which is 
not decomposed by cooling nor by water. 
It dissolves sulphur, and is dissolved by the 
fixed oils. . _ 
SPERMACOCE, button-mood, a genus of 
plahts belonging to the class of tetrandria, 
and order of monogvnia, and in the natural 
system arranged under the 47th order, stel- 
Jat;c. I’he corolla is monopetalous and fun- 
nel-shaped, and there are two bidentate seeds. 
The species are 20, all stove plants from 
warm climates. 
SPHACELUS. See Surgery. 
SPHjERANTHUS, a genus of plants be- 
longing to the class of syngenesia, and to the 
order of polygamia segregata; and in the na- 
tural system arranged under the 49th order, 
composite. Each partial calyx contains 
eight florets; the florets are tubulated, the 
female being scarcely distinguishable. The 
receptacle is scaly ; and there is no pappus. 
The species are four, the indices, the africa- 
mis, the chinensis, and another. 
SPILER1A, a genus of the class and or- 
der cryptogamia fungi. The fructifications 
are mostly spherical, opening at the top; 
while young filled with jelly, when old with 
blackish powder. They grow on the bark or 
wood of other plants. There are 29 spe- 
cies. 
SPIIiEROCARPUS, a genus of the cryp- 
togamia class of plants, and order alga;, con- 
sisting of foliaceous matter, expanded on the 
ground, and producing very large and obvi- 
ous fructifications. Dr. Hill thinks it proba- 
ble, that the male flowers are produced on se- 
parate plants from the female, and have not 
been discovered to belong to the same spe- 
cies: no male parts of fructification are de- 
scribed to us; the female parts consist of a 
tubulated and inflated vagina, within which 
is contained a large globular capsule, con- 
taining a great number of small loose seeds. 
SPHAGNUM, bog-moss, a genus of 
plants belonging to the class of cryptogamia 
and order of inusci. The anther® are glo- 
bose; the mouth entire, and closed by an 
operculum; the calyptra is warning. There 
are three species, the palustre, aipuium, and j 
arboreum. 1. The palustre, common bog- | 
moss, grows on our bogs in wide patches, so 
as frequently to cover a large portion of their 
surface. The stalks are from two inches to 
two feet long, irregularly surrounded with 
numerous, conical, pendant branches, and 
terminated with a rotaceous cluster of erect 
short ones. It is generally believed, that the 
roots and decayed stalks of this moss consti- 
tute a principal' part of that useful bituminous 
substance called peat, which is the chief fuel 
of the northern regions. The Lapland ma- 
trons are well acquainted with this moss. 
They dry and lay it in their cradle, to sup- 
ply the place of bed, bolster, and every co- 
vering ; and, being changed night and morn- 
ing, it keeps the infant remarkably dean, 
dry, and warm. It is sufficiently soft of it- 
self; but the tender mother, not satisfied with 
this, frequently covers the moss with the 
downy hairs of the rein-deer; and by that 
means makes a most delicate nest for the 
young babe. 2. The alpinum, green bog- 
moss. Its branches are subulate and erect ; 
the anther® are oval. It grows in mountain 
bogs in South Britain. 3. The arboreum, 
creeping bog-moss, is branched; the anthe- 
rs; are numerous, sessile, hairy, and grow 
along the branches chiefly on one side. It is 
found on the trunks of trees. 
SPHENOIDAL SUTURE. See Ana- 
tomy. 
SPHENOIDES. See Anatomy. 
SPHERE, is a solid contained under one 
uniform round surface, such as would be 
formed by the revolution of a circle about 
a diameter thereof as an axis. See Geome- 
try. 
Sphere, properties of dhe, are as follow: 
] . A sphere may be considered as made 
up of an infinite number of pyramids, whose 
common altitude is equal to the radius of the 
sphere, and all their bases form the surface of 
the sphere. And therefore the solid content 
of the sphere is equal to that of a pyramid 
whose altitude is the radius, and its base is 
equal to the surface of the sphere, that is, the 
solid content is equal to §• of the product of 
its radius and surface. 
2. A sphere is equal to 4 of its circum- 
scribing cylinder, or of tht cylinder of the 
same height and diameter, and therefore equal 
4 S 2 
to the cube of the. diameter multiplied by 
.523(1, ©r | of .7854 ; or equal to double a cone 
of the same base and height. Hence a\ 0 
different spheres are to one another as the 
cubes of their diameters, and their surfaces 
as the squares of the same diameters. 
3. The surface or superficies of any sphere, 
is equal to four limes the area of its great cir- 
cle, or of a circle of the same diameter as the 
sphere. Or, 
4. The surface of the whole sphere is equal 
to the area of a circle whose radius is equal to 
the diameter of the sphere. And, in like 
manner, the curve surface of any segment, 
whether greater or less than a hemisphere, is 
equal to a circle whose radius is the chord 
line drawn from the vertex of the segment to 
the circumference of its base, or the chord of 
half its arc. 
5. The curve surface of any segment or 
zone of a sphere, is also equal to the curve 
surface of a cylinder of the same height with 
that portion, and of the same diameter with 
the sphere. Also the surface of the whole 
sphere, or of a hemisphere, is equal to the 
curve surface of its circumscribing cylinder. 
And the curve surfaces of their corresponding 
parts are equal, that are contained between 
any two places parallel to the base. And 
consequently the surface of any segment or 
zone of a sphere, is as its height or altitude. 
Most of these properties are contained in 
Archimedes’s treatise on the sphere and cylin- 
der. And many other rules for the surfaces 
and solidities of spheres, their segments. 
Zones, frustums, &c. may be seen in Bonny- 
castle’s Mensuration. 
Hence, if d denotes the diameter or axis of 
a sphere, s its curve surface, c its solid con- 
tent, and a.=s .7854 the area of a circle whose 
diam. is 1 ; then we shall, from the foregoing 
properties, have these following general va- 
lues or equations, viz. 
f = ffr 
d — 
6c 
■=* — 
V 4a 
Sphere, in astronomy, that concave orb, 
or exuanse, which invests our globe, and in 
whit h th 1 heavenly bodies appear to be fixed, 
and at an equal distance from the eye. 
Sphere, annill. 11 /. See Armii.lary 
Sphere. 
SPHERICS, the doctrine of the sphere, 
particularly of the several circles described on 
its surface, with the method of projecting the 
same on a plane. See Projection of the 
sphere. 
A circle of the sphere is that which is made 
bv a plane cutting it. If the plane passes 
through the centre, it is a great circle ; if not, 
it is a little circle, 
The pole of a circle, is a point on the sur- 
face of the sphere, equidistant from every 
point of the circumference of the circle. 
Hence every circle lias two poles, which are 
diametrically opposite to each other; and all 
circles that are parallel to each other have the 
same poles. 
Properties of the circles of the sphere. 
1. If a sphere is cut in any manner by a 
