Francis Lieber.

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

. (page 142 of 203)
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study and investigation.

2 In regard to method, Socrates was the author of still greater innovations. It was
to little purpose that men applied themselves to human affairs, if they conceived them
loosely, and with no regard to evidence. Socrates introduced at least one element of
logical precision into the handling of questions, by insisting on accuracy in definition
and classification. His mode will be seen in the statement, of Xenophon. "Socrates
continued incessantly discussing human affairs, investigating "What is piety? What is
impiety? What is the honorable and the base? What is the just and the unjust? Men
that knew these matters, he accounted good and honorable; men that were ignorant of
them, he assimilated to slaves."

His investigation thus took the form of ascertaining the exact meaning that is, the
definition of the leading terms in ethics and in politics, the settling of what J. S. Mill
calls the connotation of. a general word, which determines how to apply it rightly to each
individual case. The very idea of defining a general term, now so obvious, never seems to
have suggested itself to any cue previous to Socrates. And his manner of seeking out
those definitions is also characteristic, and links itself to his conversational method, and his
convicting men in general of ignorance in things that they thought they knew. Profess-
ing himself to be able to furnish no exact definition (this professed ignorance was called
the Socratic irony) of justice, temperance, courage, etc., and finding every one else quite
confident in their ability to supply the want, he asked some one to state his definition;
Jind on its being given, he put a few further interrogations (as he said) by way of making
sure that he understood the meaning, but with the speedy effect of driving the respond-
ent into a humiliating self-couU-adictiou. His method is moist fully exemplified in certain
of the Platonic dialogues, as the first AldbiacUs, Laches, CLaiiuiaes, Euthyphron, etc.
According to Xenophon, he could pass from his severe cross-examining method, with its
humiliating shock of convicted ignorance, and address to his hearers plain and homely
precepts, inculcating self-control, temperance, piety, duty to parents, brotherly love,
fidelity in friendship, diligence, etc. such direct admonitory influence being common
to him with the so-called sophists. He probably went beyond the ordinary teaching of
the sophists in exhorting men "to limit their external wants, to be sparing in indul-
gence, and to cultivate, even in preference to honors and advancement, the pleasures
arising from a performance of duty, as well as from self-examination and the conscious-
ness (if internal improvement." 'This strain of exhortation, his manner of life in har-
mony therewith, and the virtual self-immolation of his death, may Le considered as the
conjoint root of the cynic and the stoic philosophers.

As regards doctrine, Socrates was distinguished chiefly by his theory of virtue-.
Virtue, he said, consisted in knowledge. To do right, was the only road to happiness;
and as every man sought to be happy, vice could arise only from ignorance or mistake
as to the means; hence the proper 'corrective was an enlarged teaching of the conse-
quences of actions.

We cannot, on any fair interpretation of knowledge, regard this as other than a one-
sided view. It takes note of one condition of virtue, since there can be no right conduct
without understanding the tendency of actions, or. at all events, the meaning of rules;
but it omits, what is also essential, the state of the emotions or dispositions, which may
he directed either to exclusively self-regarding ends, or to ends involving also the good
of others. There is an obvious connection between the doctrine and the Socratic anal-
ogy of virtue to the professions. The virtue of an artisan is almost exclusively contained
in his skill or knowledge; his dispositions can usually, though not always, be depended
on, through the pressure of his immediate self interest. But the practice of Socrates
was larger than his theory; for, as already remarked, his exhortations were addressed to
men's feelings or sentiments as well as to their intellect. His political doctrines were
biased by the same analogy of special professions. The legitimate king or governor
was he alone that knew how to govern well.

In the year 899 B.C., an indictment was laid against Socrates, in the following terms:
"Socrates is guilty of crime: first, for not worshiping the gods whom the city worships,
and for introducing new divinities of his own; next, for corrupting the youth. Th



Soda.



614



penalty due is death." The trial took place before a dikastery, or law-court, composed
of citizen-judges, like our juries, but far more numerous; the number present seeins to
have been 557. His defense is preserved by Plato, under the title Apology of Socrahs.
The tone of it, so admirable to us, was such as to make acquittal all but impossible,
from the number of enemies created by his cross-questioning annoyance of all classes of
men, and from various other causes. He dwelt on his mission to convict men of ignor-
ance for their ultimate benefit; pronounced himself a public blessing to the Athenians;
declared that, if his life was preserved, he would continue in the same course; and
regarded the prospect of death with utter indifference. By a majority of either five or
six, the charges were declared to be proven. A vote had then to be taken on the sent-
ence. By the Athenian practice, the accuser named a penalty, and the accused was
asked to do the same; the judges were restricted to one or other of these. The accuser
named death. Socrates, maintaining the same high tone, declared at first that he
deserved the highest public reward; but, on the instigation of his friends, he ended by
proposing a trifling fine. The court, by a majority, decided for the capital sentence.
There was an accidental interval of 30 days before the execution, during which Socrates
in prison conversed with his friends as usual; on the last day occurred his conversation,
on the immortality of the soul, referred to in the Platonic dialogue called PJuedon. He
then drank the hemlock, and passed away with the dignity and calmness becoming his
past life.

" There can be no doubt," says Mr. Grote, " that the individual influence of Socrates
permanently enlarged the horizon, improved the method, and multiplied the ascendant
minds of the Grecian speculative world, in a manner never since paralleled. Subsequent
philosophers may have had a more elaborate doctrine, and a larger number of disciples
who imbibed their ideas; but none of them applied the same stimulating method with
the same efficacy; none of them struck out of other minds that lire which sets light to
original thought; none of them eiihfer produced in others the pains of intellectual preg-
nancy, or extracted from others the fresh and unborrowed offspring of a really parturient
mind." See Grote's Greece; Zeller's Philos. der Oriechen.

SODA. See SODIUM.

SODA, MANUFACTURE OF. Soda, or, more correctly, carbonate of soda, occupies the
chief place among our leading chemical manufactures, alike from its own importance,
and also on account of its influence on other groat chemical industries, such as glass-
making, soap-making, bleaching, etc.

A native carbonate of soda, or rather a sesqui-carbonate, called natron (q.v.), is found
in Egypt and some other parts of the world. In Hungary, several manufactories exist
for the purification of a native soda found there. Formerly, most of the soda in use
was extracted from certain plants; and two kinds were known in commerce under the
names of barilla (q.v.) and kelp (q.v.).

But the quantity of soda got from all other sources is now insignificant in comparison
with that manufactured from common salt (chloride of sodium see SODIUM). The pro-
cess was invented by a Frenchman named Leblanc, and was first mnde known to the
world by a commission of the French republic in 1794, although dating some years
earlier. It is unquestionably the most valuable discovery in the entire range of chemical
manufactures; and it has been practiced for nearly ninety years without any important
alteration. It is sad to think that, the author of this invention reaped no benefit from it
himself, but spent the last of his days in an hospital, " aHvreck in fortune, health, and
hope." Owing partly to the war between France and England, and partly also to the
existence of a duty of 30 per ton on common salt, which continued for eight years
after the close of the war, Leblanc's process was not adopted in Great Britain except on
a very limited scale till 1823. After the repeal of the tax in that year, Mr. James
Muspratt erected his celebrated works at Liverpool, adopted the process in its entirety,
and succeeded, after overcoming many difficulties, in establishing in Great Britain a
chemical manufacture which has since become the most important in the world, and for
which nearly 000,000 tons of common salt are now annually required.

The object of the soda-process is to separate the sodium of the salt, and unite it with
oxygen to form caustic soda, or, what is more generally done, to unite the sodium with
both oxygen and carbonic acid to form carbonate of soda. The several stages of the
process are as follows:

Firxt Operation The Production of Sulphate, of Soda, The decomposition of the com-
mon salt is effected by treating it with sulphuric acid, which transforms it into sulphate of
oda and hydrochloric acid. This operation was long conducted in a common reverbera-
tory furnace (q.v.), and the hydrochloric acid was suffered to escape into the air. Not
only was the acid thus lost, but it destroyed all vegetation in the neighborhood of soda-
works, and involved their owners in serious law-suits for damages. The great chimneys
of the St. Rollox works, Glasgow, and Mr. Muspratt's, Liverpool, which are nearly 500 ft.
high, were erected with a view of curing this evil, but they were found to be ineffectual.
The most improved furnaces now in use for the purpose arc built in pairs, and in the front
part, of each there is a shallow cast-iron pan, nine ft. in diameter, with a sheet-iron cover,
and so built that the fire may act on the bottoms and sides. Behind this, an oblong brick-



615



Soda.



chamber, 30 ft. by 9 ft., is situated, with separate fire-places, and called the salt-cake
furnace. Acid tlues are led from each compartment of the double furnace into one main
flue, which has its outlet into a condensing tower, to be presently described. Separate
flues are also provided for the conveyance of smoke to a main chimney. The furnace is
worked in the following w:iy: when it is properly heated, salt to the amount of 1'Jewts.
is thrown in >i\- an opening, and about 80 gallons of strong sulphuric acid are heated
and run in. The mixture, which is well stirred with an iron rake, gradually thickens,
and in about an hour the pasty mass, not yet all decomposed, is pushed through the
opening into the salt-cake chamber. Here if is spread out on the sole, and maintained
at a red heat for another hour, when the whole of the hydrochloric acid is expelled, and
the conversion into sulphate of soda complete. A pair of furnaces, about one-half
larger than those above described, will produce about 19 tons of sulphate of soda in a
day, for which 16 tons of common salt are required. At the St. Kollox chemical works,
Glasgow, about, 500 tons of common salt are decomposed weekly.

A very important part of this operation is the condensation of the hydrochloric acid
gas, which is disengaged in large volumes during the decomposition of the salt. As already
slated, it was formerly allowed to escape into the atmosphere. The acid flues convey
it to the condensing towers, which are generally tilled with pieces of burnt coke, through
which a supply of water is kept running. The gas enters at the bottom of the tirst tower,
pa.sses upward, and descends tiie second, and is gradually absorbed by the water, form-
ing strong liquid acid, which is run out by openings at the bottom of the condenser. So
perfect is the system of condensation now in use at some works, that of the acid pro-
duced by 100 tons of pure chloride of sodium which should yield 62 tons, as much as
58| tons have actually been collected; and it has been instanced, as a curious illustration
of this in another way, that Mr. Mu>pratt's great works, which were at one time forced
out of Liverpool as a nuisance, have been established there again without causing any
protest. Nevertheless Mich works being still considered obnoxious to their neighbor
hoods, an " alkali act" was passed by parliament in July, 1863, " For the more effectual
condensation of muriatic (hydrochloric) acid gas in alkali works." It compels every
manufacturer of alkali to secure the condensation of not less than S5 per cent of the
muriatic gas evolved in his works, under a penalty not exceeding 50. This act was
amended in ISTi Ly which copper and sulplmrie acid works weiv placed under similar
restrictions. The hydrochloric acid obtained in this process is mostly used in the
manufacture of bleaching-powdcr.

id ()fn raliitn- /won of lite Sulphate of Soda into Black ash, called .'**

Ball-soda. This is effected by heating a mixture of sulphate of soda, carbonate of lirne,
and coal, in a rcverheratory furnace. The proportions now used are the same as those
iirst recommended by Loblanc viz.. sulphate of soda, 100 parts: carbonate of lime, 100
parts; carbon (charcoal'). 55 parts. But as cord is employed in England instead of char-
coal, the quantity u<ed is generally 75 to 100 of each of the otiier two ingredients. The
" balling furnace" used in this operalion has two beds, the one being raised a few inches
above the other. The waste heat from the fire-place is usually employed in boiling down
the soda-lye. The charge is thrown into the bed of the balling furnace away from the
fire-place after it has been raised to a bright red heat, and remains till it becomes sutn-
cientlv heated throughout the whole mas?. It is then transferred to thcfl>t.iiny bed, which
is next the tire, and exposed to a higher heat, when it shortly begins to soften and flux
into a mass like dough. In about half an hour the charge is withdrawn in a red-hot
state by the working door, and received into iron barrows, where it solidifies into blocks of
crude soda termed ball-soda, or black-ash. A new kind of balling furnace, first introduced
at the Jarrow Chemical works, South Shields, is now becoming extensively used. It differs
from the one described in having that portion of it for receiving the mixture of sulphate
of soda. coal, and lime in the form of a brick-lined iron cylinder, large enough in some
insMnces to decompose 50 tons of the sulphate in 24 hours. This cylinder lies in a hori-
xontal position, and is made to revolve slowly by engine-power. The materials are intro-
duced by means of a hopper; the fire-place, which does not rotate, is placed nt one end
of the cylinder; and the arrangement for evaporating the lye is somewhat similar to that
employed in the furnace described. This rotary furnace admits of the work being much
better done than by the older reverberatory furnace, as it not only saves labor, but pre-
vents loss of snda by volatilization.

In thi< process there is first a reduction of sulphate of soda to sulphide of sodium with
evolution of carbonic acid; then a conversion of the sulphide of sodium and carbonate
of lime into carbonate of soda and sulphide of calcium; and finally the excess of car-
bonate of lime is reduced by the carbon to caustic lime and carbonic oxide.

Third Operation The Preparation of CV//''"'''/V of 8odafrom >lif B'ni'l - axli. /// T/t.nria-
ti'tii n nd Eranorati'in. For some purposes the crude soda, or black-ah. is used without
further purification: for example, in the making of soap. Its lixiviation is effected by
the use of a series of iron tanks, or vats, into which it is placed with water. Several
tanks, each of the capacity of 600 gallons, rise above one another in successive stages,
so that the liquor of the highest can be run into the next lower, and so on. The black-
ash is introduced fresh into the lowest vat; it then passes from vat to vat. and is taken
away exhausted at the highest one. The water, on the contrary, comes in fresh at the



Soda.
Sodium.

top, and in passing downward encounters less exhausted ash in each succeeding
vat, and finally passes away from the lowest a fully saturated solution. In most soda-
works, the vats are now arranged differently, although the ash may be said to be ex-
hausted in the same way. In the new arrangement, the vats are placed horizontally, and
advantage is taken of the fact that solutions in becoming richer become also heavier,
so that, although the tanks are all on a level, the water runs through them with what is
virtually a downward flow. We have not space to describe minutely this very elegant
and economical plan; it will be enough to say that it completely obviates the necessity
of lifting the ash from vat to vat, because any two contiguous ones can be made a't
pleasure the highest and lowest points, and, therefore, those of ingress and egress for the
lixiviating fluid. " Each vat, in due rotation, is emptied and refilled; and thus each
in turn successively occupies the highest, lowest, and all intermediate points of the de-
clivity."

The next stage is the evaporation of the soda-lye, which is conducted in a variety of
ways. A common method consists in using the waste heat of the balling furnace," the
flame from which passes over the surface of the liquor. With proper manipulation the
soda falls to the bottom, and is raked out at intervals through a side-door, and drained
upon a sloping surface.

The soda-salts (chiefly carbonate of soda), thus obtained by evaporation of the lye,
contain caustic soda, which requires to be carbonated, and a little sulphide of sodium,
which it is necessary to get rid of. They are accordingly transferred to a reverberator}*
furnace, and calcined, at a moderate heat, along with sawdust, or sometimes with small
coal, the mixture being stirred with iron paddles. By this treatment, the caustic soda is
converted into carbonate of soda, the sulphur is mostly expelled, and we now obtain
the soda-ash, or alkali of commerce, which generally contains about. 50 per cent of real
soda, NaO; the other ingredients, besides the carbonic acid with which it is combined,
being chiefly water, sulphur, and common salt. Sometimes it is further purified, and it
is then known as white allMli.

Soda crystals, or what is commonly called " washing-soda," are obtained by dissolv-
ing the soda-ash in hot water, then filtering the solution and boiling it till the specific
gravity reaches 1.3, when it is transfered to the crystallizing coolers; Bars of wood or
iron are laid across these vessels to sustain the mass of crystals which form, and in ten
days at most the crystallization is complete. Crystals of soda are purer than soda-a.-h,
but they are of much less value, weight for weight, because of the large quantity of
water which enters into their constitution, amounting to 62 per cent.

The manufacture of caustic-soda is now an important branch of the alkali trade.
For soap-making, bleaching, and several other purposes, carbonate of soda requires to
be rendered caustic by quicklime. Manufacturers have, accordingly, taken to the plan
of treating the black-ash liquor with hydrate of lime, and so obtain caustic-soda at this
stage, instead of sending it into the market as a purified carbonate of soda, for purposes
where it requires to be decarbonated again. Another plan consists in mixing a srnail
quantity of chloride of lime, or nitrate of soda, with the soda-lye from the black-ash. It
is then concentrated into a strong solution, and finally brought to the slate of a fused
mass in round iron pots heated to redness. Great attention is now given to the recovery
of sulphur from the enormous " waste heaps" which accumulate at all large alkali
works, since there is fully 'a ton of this "waste" produced for every ton of common
salt used. It consists largely of noxious sulphides of calcium, and is a source both of
river and, in warm weather especially, of atmospheric pollution. Mond's process, or
some modification of it, is usually adopted. Some chemical changes are first produced
in the waste by the action of common air, and the sulphur afterward precipitated by
hydrochloric acid.

Various processes have been at different times proposed, and many have been pat-
ented, for making carbonate of soda by other methods than that of Lcblanc; but only
one of these has had any measure of success. We allude to what is called the "ammo-
nia process," patented by Dyer & Hemming in 1838. Several improvements some of
them quite recent have been made on the original method, and the process is now
worked on the large scale at Northwich in Cheshire, and at several places on the conti-
nent. It consists in treating a solution of common salt with bicarbonate of ammonia,
by which bicarbonate of soda is produced, and the chloride of ammonium remains in
solution.

Sulphate of soda is made at Widnes, in Lancashire, by Mr. Hargreaves's process of
decomposing bricks of common salt with sulphurous acid and steam. This method, by
avoiding the direct use of sulphuric acid, saves the expense of nitrate of soda; and there
is also a saving in the wear and tear of apparatus, owing to the lower temperature
required.

SODA-WATER. See AERATED WATEKS.

SODERMANLAND, a province of s.e. Sweden, bounded n. by lake Maelar, s.e. by
the Baltic; 2,600 sq.m.; pop. '74, 138.696. The surface is level. The soil is fertile.
Agriculture and fishing are the chief occupations. Capital, Nykoping.



Soda.

Sodium.

SO'DITJM (symb. Na, cquiv. 23, spec. grav. 0.972) is one of the metals of the alkalies
its oxide being soda. It properties closely resemble those of the allied metal, potassium.
It is of a bluish-white color, is somewhat more volatile than potassium, and further dif-
fers from that metal in having a higher fusing-point (about ~OS ), a greater specific
gravity, and in not catching lire when dropped in water (unless the water is heated),
although like potassium under similar conditions, it partially decomposes it and liberates
hydrogen; and at the same time communicates a strong alkaline reaction to the solution.
If, however, a piece of unsized paper is placed on the surface of cold waler, and the
sodium be placed on the paper, the metal takes fire, and burns with a deep yellow
flame. Strictly speaking it is the liberated hydrogen rather than the metal which burns,
the yellow tint (which is characteristic of the sodium compounds) being due to a little
sodium volatilized by the heat, mixing and burning with the hydrogen. When heaied
in the air, it burns with its characteristic yellow flame, and is converted into so: !a.
When exposed ///. me/to to a red heat it assumes the form of vapor, and admits of distil-
lation. Like potassium, it must be kept immersed in naphtha, so as to exclude tho
oxidizing action of the air. As a reducing agent, it is little inferior to potassium, and as
its combining power is lower, and it is obtained much more cheaply, it may usually
he advantageously substituted for potassium in reducing operations. Sodium does
not occur in the metallic form in nature, but its compounds are very widely distributed.
It is found by far the most abundantly in the form of chloride of sodium (or common,
salt), but it likewise occurs as albite or soda-feldspar, cryolite (the double fluoride of
sodium and aluminium, and the principal source from whence aluminium is procured),
borax (the biborate of soda), trona (the sesquicarbouate of soda), arid Chili saltpeter
(nitrate of soda).

The methods of obtaining sodium are similar to those already described for obtain-
ing potas-iiun. The following procedure recommended by Deville is regarded as the
best for obtaining it in large quantity, Intimately mix 717 parts of dried carbonate of
so:la with 17.~> parts of finely powdered charcoal and 108 parts of finely ground chalk,
knead them into a stiff paste with oil, heat them in a covered iron pot till the oil is
decomposed, and finally distil them in an iron retort with the precautions which aro
noticed in descyibmg the preparation of potassium (qv.). The object of adding tho
chalk is to prevent tha separation of the charcoal from the carbonate of soda when tha
latter fuses. This mixture ought to yield nearly one-third of its weight of sodium.



Online LibraryFrancis LieberLibrary of universal knowledge. A reprint of the last (1880) Edinburgh and London edition of Chambers' encyclopaedia, with copious additions by American editors (Volume 13) → online text (page 142 of 203)