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5 ee ae — -— —-. — -—- — —_— ———~ et en a 
248 SOAPWORT. 
ceptible difference. A waggon load is said to be 
equal to five loads of rotten dung, and more con- 
fidently that one load of soap waste, with 5 of 
dung, would be more valuable than 10 of dung, 
both in effect and in duration. The first sub- 
stance will cover less ground at the same rate of 
application, and if laid on the same extent of 
space, one would think that the superior or 
equal quality has much to contend against,—in 
- one case, more extent of ground,—and in the 
latter, the effects of nearly twice the quantity of 
the substance of which it is chiefly composed.” 
SOAPWORT,—botanically Saponarza. A genus 
of ornamental herbaceous plants of the carnation 
family. The officinal species, S. officonalis, grows 
wild in meadows, under hedges, on river banks, 
and in similar situations in many parts of Eng- 
land. Its root is perennial, creeping, spreading, 
ramose, and rather fleshy, and soon occupies a 
large space of ground; its stems are jointed, 
erect, cylindrical, purplish, leafy, and about 18 
inches high; its leaves are opposite, ovate-lance- 
olate, smooth, pale green, and about 3 inches 
long and 14 inch broad; its flowers come out in 
dense panicles from the wings of the leaves, and are 
large, handsome, and of a flesh or pale pink colour, 
and emit an oppressively sweet odour, and bloom 
from July till October; and its capsules are oval 
and one-celled, and are filled with many small 
seeds. A decoction of this plant has been used 
in some countries as a substitute for soap, and is 
well capable of cleansing woollen fabrics; and 
the leaves were formerly used in medicine, and 
are accounted opening, attenuating, and some- 
what sudorific. A variety with double flowers, 
S. 0. plena, has long been known in the flower- 
garden; but it spreads so rapidly and far, that 
it ought not to have a place among better flower- 
ing-plants.—Four or five perennial-rooted spe- 
cies, one biennial, and seven or eight annuals, 
have been introduced to Britain, principally from 
Continental Europe and the Levant ; and all are 
hardy, most have either pink or red flowers, 
some are truly beautiful, and well worthy of a 
place in the flower border, and the majority love 
a soil of sandy peat, but will thrive in all com- 
mon light garden soils. The basil-like species, 
S. ocymoides,—a native of Hrance, a low ever- 
green trailer, with handsome red flowers, bloom- 
ing from May till July—is well adapted for rock- 
work. 
SODA. The protoxide of sodium. It is ob- 
tainable in large quantities from sea-water, and 
occurs profusely, though somewhat mixedly or 
impurely, as an efflorescence on the marshes and 
lake-banks of some hot countries, and is an im- 
portant ingredient in soils, and can be manufac- 
tured from some large deposits of the saliferous 
sandstone formation,—and, for all these reasons, 
as well as for the sake of distinction from potash 
and ammonia, it has been not inappropriately 
called the mineral alkali; but it is also an im- 
portant constituent of many plants,—and, in 
SODA. 
point of fact, was long obtained for commercial 
and manufacturing and economical and medi- 
cinal purposes mainly through the medium of 
kelpfrom marine alge, and through the medium 
of barilla from the plant called Salsola soda and 
from other plants of the goosefoot order. See 
the articles Kenp, Barina, ALKALizs, Asuus, 
Sars, and Goosrroot; and see also the articles 
Nitrates, Natron, and Saur (Common). 
Sodium is an elementary substance of a me- | 
tallic nature; and was discovered in 1807 by Sir 
Humphrey Davy. It does not naturally occur 
in a simple state; but may easily be obtained 
from its natural compounds by means of gal- 
vanism, or by similar processes to those used for 
obtaining potassium from the salts of potash. 
It has a colour similar to that of silver, and a 
strong metallic lustre, and a specific gravity of 
0:972; it is compressible by the fingers at com- 
mon temperatures, and melts at 200° Fahrenheit, 
and rises into vapour at ared heat; and when 
thrown upon water, it causes a violent efferves- 
cence, emits a hissing noise, and rapidly com- 
bines with oxygen so as to form soda. The per- 
oxide of sodium, consisting of two equivalents of 
sodium and three of oxygen, may be artificially 
formed by heating sodium to redness in excess 
of pure oxygen; but it is of small economical 
importance, and is resolvable by water into soda 
and oxygen. 
Soda, or protoxide of sodium, is obtained in - 
purity by burning sodium in dry atmospheric air. 
It consists of one equivalent of sodium and one 
equivalent of oxygen; and isa grey white solid, 
difficult of fusion. It forms with water, equi- 
valent to equivalent, a solid hydrate; and this | 
is soluble in water and alcohol, easily fusible by 
heat, very caustic, and exceedingly analogous in 
all its chemical relations to potash. All the 
salts of soda are soluble in water, and are incapa- 
ble of being precipitated thence by any reagent ; 
all, on being exposed by means of platinum wire 
to the blow-pipe flame, communicate to it a rich 
yellow colour; and soda itself combines with 
sulphuric acid to form a salt which is easily re- 
cognised by its taste and form to be Glauber’s 
salt; and by these three characters is soda che- 
mically and readily distinguishable from other 
alkaline bases. 
The common uses of soda are mentioned in 
the articles Knnp and Baritna; and two of the. 
most important salts of it are noticed in the 
articles GLAUBER’s Saut and Nirrates.—The car- 
bonate of soda is prepared by a purifying process 
from barilla ; and forms into large, transparent, 
octahedronal crystals with a rhombic base ; and 
has a mild alkalescent taste; and is used in 
medicine as an antacid and a deobstruent.’ Its 
crystals contain a large proportion of water of 
crystallization ; and when exposed to a dry atmo- 
sphere, they effloresce and crumble into a white 
opaque powder.—The bicarbonate is prepared 
from the carbonate ; and forms into very white 
