SO A 
SOA 
S O A 
root, has roundish, prickly stalks and red 
berries, and is a native of China and Japan. 
The pseudo-china, or occidental species, has 
rounder smooth stalks and black berries, 
grows wild in Jamaica and Virginia, and bears 
the colds of our own climate. At present 
the China root is very rarely made use of, 
having for some time given place to sarsapa- 
rilla, which is supposed to be more effectual. 
Kfosper Alpinus informs us, that this root is 
in great esteem among the Egyptian women 
for procuring fatness and plumpness. 
SMITliELlY, or Smithing, a manual 
art, by which an irregular lump of iron is 
wrought into an intended shape. 
SMITH 1A, a genus of the decandria order, 
in the diadelphia class of plants ; and in the 
natural method ranking under the 32nd order, 
papilionacex. The calyx is monophyllous 
and bilabiated ; the corolla winged; the ie- 
gumen inclosed in the calyx, with three or 
four joints, and containing as many seeds, 
which are smooth, compressed, and kidney- 
shaped. There is only one species, viz. the 
sensitiva, an annual of the East Indies. 
SMOKE. See Evaporation, Vol. I. 
p. 687. 
Smoke-jack. See Jack. 
SMUT. See Husbandry. 
SMYRNIUM, Alexanders ; a genus of 
plants belonging to the class of pentandria, 
and to ihe order of digynia; and in the na- 
tural system ranging under the 43th order, 
umbetlatai. The fruit is oblong and striated : 
the petals have a sharp point, and are keel- 
shaped. There are seven species: 1. The 
perfoliatum, or perfoliate alexanders, which 
is a native of Candia and Italy ; 2. The 
iEgyptiacum; 3. The aureum, or golden 
alexanders, which is a native of North Ame- 
rica ; 4. The integerrimum ; 5. The olusa- 
trum. common alexanders, a native of Bri- 
tain ; the leaves of which are cauline, ternate, 
petiolated, and serrated.. It grows on the 
Sca-coast at Dnnglass on the borders of Ber- 
wickshire, North Britain. Since the intro- 
duction of celery into the garden, the alex- 
anders is almost forgotten. It was formerly 
cultivated for salading, and the young shoots 
j or stalks blanched were eaten either raw or 
-stewed. The leaves too were boiled in broths 
and soups. It is a warm comfortable plant 
to a cold weak stomach, and was in much 
esteem among the monks, as may be inferred 
by its still being found in great plenty by old 
abbey-walls. 6. Laterale. 7. Apiifolium. 
SNAIL. See Helix, and Limax. 
SNAKE. See Anguis. 
SNIPE. See Scolopax. 
SOAL-FISIt. See Pleuronectes. 
SNOW. See Meteorology. 
SNOWDROP. See Galanthus. 
Snowdrop-tree. See Ghionanthus. 
SNUFF, a powder chiefly made of tobac- 
co, the use of which is too well known to 
need any description here. See Nicotiana. 
SNAPDRAGON, in botany. See An- 
tirrhinum. 
SOAP. The fixed oils have the property 
of combining with alkalies, earths, and me- 
tallic oxides, and of forming with these bo- 
dies a class of compounds which have receiv- 
ed the name of soaps. As these soaps differ 
from each other very materially, according 
as their base is an alkali, an earth, jor an 
oxide, it will be proper to consider each set 
separately. 
Yol. II. 
Soaps, alkaline. As there are a great 
number of fixed oils, all or most of which are 
capable of combining with alkalies, earths, 
and oxides, it is natural to suppose that there 
are as many genera of alkaline soaps as there 
are oils. That there are differences in the 
nature of soaps corresponding to the oil which 
enters into their composition, is certain ; but 
these differences are not of sufficient import- 
ance to require a particular description. It 
will be sufficient, therefore, to divide the 
alkaline soaps into as many species as there 
are alkalies, and to consider those soaps which 
have the same alkaline base, but differ in their 
oil, as varieties of the same species. 
Soap of soda, or hard soap. The word 
soap (sapo (xat-irwn) first occurs in the works of 
Pliny and Galen, and is evidently derived 
from the old German word, sepe. Pliny in- 
forms us that soap was first discovered by the 
Gauls ; that it was composed of tallow and 
ashes ; and that the German soap was reckon- 
ed tire best. 
Soap may be prepared by the following 
process : a quantity of the soda of commerce 
is pounded, and mixed in a wooden vessel, 
with about a fifth part of its weight of lime, 
which lias been slacked and passed through 
a sieve immediately before. Upon this mix- 
ture a quantity of water is poured, consider- 
ably more than what is sufficient to cover it, 
and allowed to remain on it for several hours. 
The lime attracts the carbonic acid from the 
soda, and the water becomes strongly im- 
pregnated with the pure alkali, which in that 
state is caustic. This water is then drawn 
olf by means of a stop-cock, and called the 
first ley. Its specific gravity should be about 
1 . 200 . 
Another quantity of water is then to be 
poured upon the soda, which, after standing 
two or three hours, is also to be drawn olf by 
means of the stop-cock, and called the se- 
cond ley. 
Another portion of water is poured on ; 
and after standing a sufficient time, is drawn 
off like the other two, and called the third ley. 
Another portion of water may still be 
poured on, in order to be certain that the 
whole of the soda is dissolved ; and this weak 
ley may be put aside, and employed after- 
wards in foVming the first ley in subsequent 
operations. 
A quantity of oil, equal to six times the 
weight of the soda used, is then to be put 
into the boiler, together with a portion of 
the third or weakest ley; and the mixture 
must be kept boiling and agitated constantly 
by means of a wooden instrument. The 
whole of the third ley is to be added at inter- 
vals to the mixture ; and after it is consumed, 
the second lev must be added in the same 
manner. The oil becomes milky, combines 
with the alkali, and after some hours it begins 
to acquire consistence. A little of the first 
ley is then to be added, not forgetting to 
agitate the mixture constantly. Portions of 
the first ley arc* to be added at intervals; the 
soapy substance acquires gradually greater 
consistency, and at last it begins to separate 
from the watery part of the mixture. A 
quantity of common salt is then to be added, 
which renders the separation much more coni-' 
plete. The' boiling is to be continued still 
tor two hours, and then the fire must be with- 
drawn, and the liquor must be no longer 
09 1 
agitated. After some hours repose, the soap 
separates completely from the watery part, 
and swims upon the surface of the liquor. 
The watery part is then to be drawn off; and 
as it contains a quantity of carbonat of soda, 
it ought to be reserved for future use. 
Tiie fire is then to be kindled again ; and*, 
in order to facilitate the melting of the soap, 
a little water, or rather weak ley, is to be 
added to it. As soon as it boils, the remain- 
der of the first ley is to be added to it at in- 
tervals. When the soap has been brought to 
the proper consistence, which is judged of by 
taking out small portions of it and allowing 
it to cool, it is to be withdrawn from the 
fire, and the watery part separated from it as 
before. It is then to be healed again, and a 
little water mixed with it, that it may form a 
proper ’paste. After this let it be poured 
into the vessels proper for cooling it; in the 
bottom of which there ought to be a little 
chalk in powder, to prevent the soap from ad- 
hering. In a few days, the soap will have ac- 
quired sufficient consistence to be taken out, 
and formed into proper cakes. 
The use of the common salt in the above 
process is, to separate the water from the 
soap ; for common salt has a stronger affinity 
for water than soap has. 
Olive-oil lias been found to answer best for 
making soap, and next to it perhaps tallow 
may be placed ; but a great variety of other 
oils may be employed for that purpose, as 
appAics from the experiments of the French 
chemists. They found, however, that Un- 
seed-oil and whale-oil were not proper for 
making hard soaps, though they might 
be employed with advantage in the manufac- 
ture of soft soaps. Whale-oil has been long 
used by the Dutch for this last purpose. 
Soap may also be made without the assist- 
ance of heat ; but in that case a much longer 
time and a larger proportion of alkali are ne- 
cessary. 
Manufacturers have contrived various me- 
thods of sophisticating soap, or of adding in- 
gredients which increase its weight without 
increasing its value. The most common 
substance used for that purpose is water ; 
which may be added in considerable quanti- 
ties, especially to soap made with tallow 
(the ingredient used in this country), with- 
out diminishing its consistency. This fraud 
may be easily detected, by allowing the soap 
to lie for some time exposed to the air. The 
water will evaporate from it, and its quantity 
will be discovered by the diminution of the 
weight of the soap. As soap sophisticated 
in this manner would lose its water by being 
kept, manufacturers, in order to prevent th^t, 
keep their soap in saturated solutions of 
common salt ; which do not dissolve the soap, 
and at the same time, by preventing all eva- 
poration, preserve, or rather increase, the 
weight of the soap. Messrs. Darcet, Le- 
lievre, and Pelletier, took two pieces equal 
in weight of soap sophisticated in this manner, 
and placed the one in a dry place in tiieopen 
air, and the other in a saturated solution of 
common salt. After a month the first had lost 
0.56 of its weight, the other had gained about 
0.10 parts. Various other methods have 
been fillen upon to sophisticate soap ; but as 
they are not generally known, it would be 
doing an inju y to the public to describe 
them here. 
Different chemists have analysed soap, ia 
