than a fresh good sponge, or the reverse when not kept thoroughly clean.
Without the greatest care, a sponge is apt to get slimy long before it is
worn out. It may be made almost as good as, in fact often better than,
new, by the following process:——Take about 2 or 3 oz. of carbonate of
soda, or of potash; dissolve in 2-1/2 pints of water; soak the sponge in
it for 24 hours, then wash and rinse it in pure water. Then put it for
some hours in a mixture, 1 glassful of muriatic acid to 3 pints of water;
finally, rinse in cold water, and dry thoroughly. A sponge should always
be dried, if possible, in the sun every time it has been used.
=SPONGES Employed in Washing Wounds, Purification of.= M. Leriche advises
the sponge to be first saturated with a solution of 4 parts of
permanganate of potassium in 100 parts of water; then passed through a
solution of sulphurous acid, and finally washed thoroughly with water. The
sponges are said to become perfectly disinfected and deodorised, whilst
the tissue is not affected by the treatment.
=SPOROKTON.= See SULPHUROUS ANHYDRIDE.
=SPOTS and STAINS.= 1. OIL and GREASE SPOTS on boards, marble, &c., when
recent, may be removed by covering them with a paste made of fullers
earth and hot water, and the next day, when the mixture has become
perfectly dry, scouring it off with hot soap-and-water. For old spots, a
mixture of fullers earth and soft soap, or a paste made of fresh-slaked
lime and pearlash, will be better; observing not to touch the last with
the fingers.
2. RECENT SPOTS of OIL, GREASE, or WAX, on woollen cloth or silk, may be
removed with a little clean oil of turpentine or benzol; or with a little
fullers earth or scraped French chalk, made into a paste with water, and
allowed to dry on them. They may also be generally removed by means of a
rather hot flat-iron and blotting-paper or spongy brown paper, more
especially if the cloth, or one of the pieces of paper, be first slightly
damped. OLD OIL and GREASE SPOTS require to be treated with ox-gall or
yolk of egg, made into a paste with fullers earth or soap. PAINT SPOTS,
when recent, generally yield to the last treatment. Old ones, however, are
more obstinate, and require some fullers earth and soft soap made into a
paste with either ox-gall or spirit of turpentine.
The ‘American Chemist’ gives the following method for extracting
grease-spots from books or paper:——Gently warm the greased or spotted part
of the book or paper, and then press upon it pieces of blotting paper one
after another, so as to absorb as much of the grease as possible. Have
ready some fine, clear, essential oil of turpentine heated almost to a
boiling state;[191] warm the greased leaf a little, and then with a soft,
clean brush, wet with the heated turpentine both sides of the spotted
part. By repeating this application the grease will be extracted. Lastly,
with another brush dipped in rectified spirits of wine go over the place,
and the grease will no longer appear, neither will the paper be
discoloured.
[Footnote 191: This operation ought to be very carefully accomplished, as
the turpentine is a highly inflammable body.]
FRUIT and WINE STAINS, on linen, commonly yield easily to hot
soap-and-water. If not, they must be treated as those below.
INK SPOTS and RECENT IRON MOULDS on washable fabrics may be removed by
dropping on the part a little melted tallow from a common candle, before
washing the articles; or, by the application of a little lemon juice, or
of a little powdered cream of tartar made into a paste with hot water. Old
ink spots and iron moulds will be found to yield almost immediately to a
very little powdered oxalic acid, which must be well rubbed upon the spot
previously moistened with boiling water, and kept hot over a basin filled
with the same.
Boettger recommends the use of pyrophosphate of soda for the removal of
ink stains from coloured woven tissues, to be applied in the form of a
concentrated solution. The recent ink stains are readily removed, but
older stains require washing and rubbing with the solution for a long
time.
STAINS arising from ALKALIES and ALKALINE LIQUORS, when the colours are
not destroyed, give way before the application of a little lemon juice;
whilst those arising from the weaker acids and acidulous liquids yield to
the fumes of ammonia, or the application of a little spirit of hartshorn
or sal volatile.
STAINS OF MARKING INK may be removed by soaking the part in a solution of
chloride of lime, and afterwards rinsing it in a little solution of
ammonia or of hyposulphate of soda; or they may be rubbed with the
tincture of iodine, and then rinsed as before.
NITRIC ACID STAINS, TO REMOVE. The yellow stain left by nitric acid can be
removed either from the skin or from brown or black woollen garments by
moistening the spots for awhile with permanganate of potash, and rinsing
with water. A brownish stain of manganese remains, which may be removed
from the skin by washing with aqueous solution of sulphurous acid. If the
spots are old they cannot be entirely removed. See BALLS, CLOTHES, HANDS,
SCOURING, STAINS, &c.
=SPRAIN.= _Syn._ SUBLUXATIO, L. An injury of a joint, in which it has been
strained or twisted in an unnatural manner, without actual dislocation.
Pain, swelling, and inflammation, are the common consequences, which must
be combated by purgatives, repose, and a low diet, with refrigerant
lotions, or warm fomentations, according to circumstances. In extreme
cases, blood should be taken. Where there is simple stiffness and
weakness, exercise is often serviceable.
_Treatment for the Horse and other Animals._ Foment. Apply lead lotion and
refrigerants.
IF FOR CURB use counter-irritants, or red iodide of mercury ointment, or
the firing iron; and if for a horse a high-heeled shoe.
=SPRAT.= The _Clupea Sprattus_ (Linn.), a small fish of the herring
family, abounding on our coasts. Gutted, coloured, and pickled, it is sold
for anchovies, or as British anchovies, and much used to make the sauce of
that name. Sprats contain about 6 per cent. of fat.
=SPRENGEL’S PUMP.= See AIR PUMP.
=SPRINKLES.= See BOOKBINDING.
=SPRUCE.= See BEER, ESSENCE, and POWDERS.
=SPUNK.= See AMADOU.
=SQUILL.= _Syn._ SCILLA (B. P., Ph. L., E., & D.), L. The bulb of
“_Urginea Scilla_,” sliced and dried. In small doses, squill acts as a
stimulating expectorant and diuretic; in larger ones, as an emetic and
purgative. With the first intention it is generally given in substance
(powder), in doses of 1 to 3 or 4 gr.; with the latter, either made into
vinegar or oxymel (which _see_). It is an excellent remedy in coughs,
&c., after the inflammatory symptoms have subsided.
=STAGGERS.= There are two varieties of the disease known under this name
by which horses are affected, viz. stomach staggers, and grass or sleepy
staggers. The first, which occasionally kills the horse in twelve or
fifteen hours after the attack, is generally induced by an overladen
stomach and improper food. The animal has perhaps partaken largely and
rapidly, and after too long a fast, of some diet to which it is
unaccustomed, such as vetches, clover, or grass. These undergo
decomposition within the stomach and intestines, and give rise to such an
evolution of gas, as either to set up inflammation of the stomach and
intestines, or to lead to their rupture, in which latter case the result
is, of course, fatal. The symptoms are a quick and feeble pulse, attempts
at vomiting, a staggering gait, whilst very frequently the animal sits on
its haunches like a dog. Sleepy staggers, which is a more chronic
manifestation of the disease, is most common during the summer and autumn
months, and generally occurs amongst horses fed on tough and indigestible
food, such as vetches or rye grass, from which circumstances the complaint
has been called ‘grass staggers.’ Both kinds of the disease require the
same treatment.
Mr Finlay Dun prescribes a brisk purge, consisting of 6 dr. of aloes in
solution, with a dr. of calomel and 2 oz. of oil of turpentine; also the
injection every hour of clysters, consisting of salt, soap, or tobacco
smoke, the abdomen being at the same time diligently rubbed and fomented
with water nearly boiling. To ward off stupor he recommends the frequent
administration of 2 or 3 dr. of carbonate of ammonia, with an ounce or two
of spirit of nitrous ether, or of strong whiskey toddy, combined with
plenty of ginger. To guard against a return of the attack light and easily
digestible food should be administered every four or five hours, and
occasional mild purgatives should be given.
Horses are also subject to another form of staggers called ‘mad staggers.’
This disease originates, however, in causes wholly dissimilar from those
just stated, being the result of phrenitis or inflammation of the brain.
The animal is frequently very furious and excited, and seems wholly unable
to control itself, throwing itself madly about, and attempting to run down
anybody that comes in its way; it is also frequently unable to keep on its
legs, and when it falls, plunges, and struggles violently.
The treatment recommended is prompt and copious bloodletting, combined
with active purges and enemas, with refrigerant lotions to the head.
=STAINED GLASS.= The art of painting or staining glass resembles enamel
painting, in the effect being produced by fluxing certain metallic
substances, as oxides or chlorides, on its surface, by means of heat
applied in a suitable furnace. The operations it embraces are difficult,
and require great promptitude and experience to prove successful. The
colours or compounds employed are, for the most part, similar to those
noticed under ENAMEL and PASTE.
=STAINS.= Discolorations from foreign matters. Liquid dyes are also
frequently termed ‘stains.’ See SPOTS, &c., and _below_.
=Stains, Blood.= Spots of dried blood on wood, linen, &c., however old,
are easily recognised by the microscope; but simple stains or marks of
blood of a slight character, especially those occurring on iron or steel,
are recognised with greater difficulty. To obviate this, H. Zollikofer
adopts the following plan:——The spot is removed, by scraping, from the
surface of the metal, and the resulting powder is digested in tepid water,
when a liquid is obtained which exhibits the following reactions:
1. The liquid is neutralised with acid, and heated to ebullition, when
opalisation occurs, or a dirty red coagulum forms.
2. The coagulum is dissolved in hot liquor of potassa; the solution, if
blood (hæmatin) be present, is diachromatic, or appears green by
transmitted light and red by reflected light.
3. By the addition of concentrated chlorine water, in excess, to either
solution, white flocks of albumen and chlorhæmatin separate, which are
free from iron, as tested by sulphocyanide of potassium.
_Obs._ The last two reactions are said to be characteristic. Very old
spots must be boiled in water containing a little liquor of potassa. See
Dr Taylor’s ‘Medical Jurisprudence,’ and BLOOD.
=Stains, Bookbinder’s.= See LEATHER, MARBLING, &c.
=Stains, Confectioner’s.= These are similar to those noticed under
LIQUEUR. Mineral colours, especially mineral blues, greens, and yellows,
must on no account be used, as they are nearly all dangerous poisons; nor
is there any inducement to use them, since the vegetable substances
referred to afford, by proper management, every shade that can be possibly
required. These stains are also used for cakes and pastry.
=Stains, Liqueur.= See LIQUEUR.
=Stains, Map.= See MAPS, VELVET COLOURS, &c.
=STAM′MERING.= _Syn._ BLÆSITAS, L. Occasionally this depends on some
organic affection, or slight malformation of the parts of the mouth or
throat immediately connected with the utterance of vocal sounds; but, much
more frequently, it is a habit resulting from carelessness, or acquired
from example or imitation. When the latter is the case, it may be
generally removed by perseveringly adopting the plan of never speaking
without having the chest moderately filled with air, and then only slowly
and deliberately. Hasty and rapid speaking must not be attempted until
the habit of stammering is completely subdued. Nervous excitement and
confusion must be avoided as much as possible, and the general health
attended to, as circumstances may direct. This variety of stammering is
commonly distinguished by the person being able to sing without
hesitation. Stammering depending on elongation of the uvula, and other
like causes, may be generally removed by a simple surgical operation.
=STAN′NIC ACID.= Peroxide of tin.
=STARCH.= C_{6}H_{10}O_{5}. _Syn._ AMYLACEOUS FECULA; AMYLUM, L. One of
the most important and widely diffused of the proximate principles of
vegetables being found, in greater or less quantity, in every plant. The
mealy and farinaceous seeds, fruits, roots, and the stem-pith of certain
trees, consist chiefly of starch in a nearly pure state. Wheat contains
about 75% and potatoes about 15% of this substance. From these sources the
fecula is obtained by rasping or grinding to pulp the vegetable structure,
and washing the mass upon a sieve, by which the torn cellular tissue is
retained, whilst the starch passes through with the liquid, and eventually
settles down from the latter as a soft, white, insoluble powder, which,
after being thoroughly washed with cold water, is dried in the air, or
with a very gentle heat.
WHEAT STARCH (AMYLUM, B. P., Ph. L., E., & D.) is commonly prepared by
steeping the flour in water for a week, or a fortnight, during which time
the saccharine portion ferments and the starch granules become freed, for
the most part, from the glutinous matter which envelops them, by the
disintegrating and solvent action of the lactic acid generated by the
fermentation. The sour liquor is then drawn off, and the feculous residue
washed on a sieve; what passes through is allowed to settle, when the
liquid is again drawn off, and the starch thoroughly washed from the
slimy matter; it is then drained in perforated boxes, cut up into square
lumps, placed on porous bricks to absorb the moisture, and, lastly, air-
or stove-dried.
In the preparation of starch from potatoes (potato starch) and other like
vegetable substances, the roots or tubers, after being washed and peeled,
either by hand-labour or by machinery, are rasped by a revolving grater,
and the pulp washed on hair sieves until freed from feculous matter.
Successive portions of the pulp are thus treated until the vessel over
which the sieves are placed, or into which the washings run, is
sufficiently full. The starch held in suspension in the water having
subsided to the bottom, the water is drawn off, and the starch stirred up
with fresh water, and again allowed to subside. This operation is repeated
several times, with fresh water, until the starch is rendered sufficiently
pure for commercial purposes, when it is washed and dried as before. The
waste fibres and the washing waters are used as manure.
The starch manufactory at Hohenziatz treated 1216 tons of potatoes for
starch between the 4th October, 1874, and the 6th February, 1875. The
waste water after passing through precipitating vats, &c., for the purpose
of collecting all the particles of starch, was conducted into a reservoir
and mixed with spring water. This water was conducted over a meadow of
18·5 acres, and then passed to a meadow of 4·95 acres, and from this to
the third and last, which contained 6·19 acres. The 29·64 acres received
the water from 1064 tons of potatoes, or for each acre 4·38 cwt. of
potash, 1·26 cwt. of phosphoric acid and 1·27 of nitrogen.
The following table shows analysis (1) of potato water; (2) of the same
diluted; (3) of water from the first meadow; (4) water from the second
meadow; 1 litre contained——
1. 2. 3. 4.
mg. mg. mg. mg.
Whole solid matter 1857·8 323·8 322·8 262·0
Organic matter 1134·2 101·8 38·0 78·8
Inorganic matter 723·8 222·0 348·8 183·2
Potash 212·5 55·0 41·2 8·2
Phosphoric acid 56·6 5·5 trace trace
Nitrogen 140·7 12·0 4·0 9·1
Ammonia 37·4 0 0 0
Nitric acid 3·8 trace trace trace
The disappearance of ammonia and phosphoric acid in 2 is accounted for by
the precipitation of phosphate of magnesium and ammonium on the addition
of the spring water.
The harvest in hay before the use of potato water was 19·13 cwt. per acre,
and afterwards 31·88 cwt. The composition of the hay is better than
before, as will be seen by the following comparative table:——
1 2
Moisture 15·00 15·00
Woody matter 22·66 22·88
Mineral matter 7·64 8·69
Sol. in ether 2·00 2·30
Albumen 10·89 15·85
Extractable matter }
not containing } 41·81 35·34
nitrogen }
—————— ——————
100·00 100·00[192]
[Footnote 192: ‘Dingl. Polyt. Jour.,’ ccxxv, 394-396 (‘Journ. Chem.
Soc,’).]
In the manufacture of starch from rice and Indian corn (rice starch, maize
starch), a very dilute solution of caustic soda, containing about 200 gr.
of alkali to each gallon of liquid, is employed to facilitate the
disintegration and separation of the gluten and other nitrogenised
matters. A weak solution of ammonia, or sesquicarbonate of ammonia, is
also similarly employed with advantage. The gluten may be recovered by
saturating the alkali with dilute sulphuric acid. Such starch does not
require boiling, and is less apt than wheat starch to attract moisture
from the atmosphere. Most of the so-called ‘wheaten starch’ of commerce
used by laundresses is now prepared from rice.
To whiten the starches made from damaged roots and grains, and the coarser
portions of those from sound ones, a little solution of chloride of lime
is occasionally added to the water, followed by another water containing a
very little dilute sulphuric acid; every trace of the last being
afterwards removed by the copious use of pure soft or spring water.
The bluish-white starch used by laundresses is coloured with a mixture of
smalts and alum in water, and is regarded as unfit for medicinal purposes.
_Prop., &c._ Starch is insoluble in cold water, and in alcohol and most
other liquids, but it readily forms a gelatinous compound (amidin) with
water at about 175° Fahr.; alcohol and most of the astringent salts
precipitate it from its solutions; infusion of galls throws down a copious
yellowish precipitate, containing tannic acid, which is redissolved by
heating the liquid; heat and dilute acids convert it into dextrin and
grape sugar; strong alkaline lyes dissolve it, and ultimately decompose
it. Sp. gr. 1·53.
To the naked eye it presents the appearance of a soft, white, and often
glistening powder; under the microscope it is seen to be altogether
destitute of crystalline structure, but to possess, on the contrary, a
kind of organisation, being made of multitudes of little rounded
transparent bodies, upon each of which a series of depressed parallel
rings, surrounding a central spot or hilum, may be traced. The starch
granules from different plants vary both in magnitude and form. Those of
potato starch and canna starch (tous les mois) are the largest, and those
of rice and millet starch the smallest, the dimensions ranging from 1/200
to the 1/10000 of an inch. The granules of arrow-root and tous les mois
are ovoid, those of potato starch both oblong and circular those of
tapioca muller-shaped, and those of wheat starch circular.
_Identif._ One of the commonest frauds practised upon the profession and
the public is the admixture of the cheaper kinds of starch, chiefly potato
farina, with arrow-root, and vending manufactured for genuine tapioca,
sago, and other articles of diet, used for invalids and children. These
sophistications are most easily detected with a good microscope.[193]
[Footnote 193: Drawings of the principal starches will be found under the
substances from which they are obtained, as “arrow-root,” &c.]
=Starch, I′odide of.= _Syn._ AMYLI IODIDUM, AMYLI IODATUM, L. _Prep._ (Ph.
Castr. Ruthena.) Iodine, 24 gr.; rectified spirit, a few drops; rub them
to a powder; then add of starch, 1 oz., and again triturate, until the
mass assumes a uniform colour. Recommended by Dr A. Buchanan, of Glasgow,
as producing the alterative effects of iodine, without the usual irritant
action of that medicine.——_Dose._ A teaspoonful, or more, in water-gruel,
or any bland liquid, twice or thrice a day.
=Starch, Soluble Iodide of.= (Petit.) _Prep._ Iodine, 12 grammes; starch,
100 grammes; ether, q. s. Dissolve the iodine in the ether, pour the
resulting solution over the starch, and triturate until the ether has
sufficiently evaporated. Put the product in a porcelain capsule and expose
it to the heat of a boiling water bath for half an hour, with occasional
stirring. This treatment is sufficient to render it entirely soluble in
hot water.
Dr Bellini strongly recommends iodide of starch as a valuable antidote in
cases of poisoning by caustic alkalies, alkaline, or earthy sulphides, and
vegetable alkaloids. The advantages attending its employment, he says,
are: that it may be administered in large doses; that it does not possess
the irritating properties of free iodine; and that it readily forms
harmless compounds with the substances named. To avoid the subsequent
decomposition of the latter, he advises its administration to be followed
by an emetic. As an antidote to alkaline and earthy sulphides, the author
thinks it preferable to all others. In cases of poisoning by ammonia,
caustic potash, or soda, it is applicable when acid drinks are not on
hand.
=STARCHING (Clear).= Muslins, &c., are ‘clear-starched’ or ‘got-up’ by
laundresses in the following manner:——Rinse the articles in three waters,
dry them, and dip them into thick-made starch, which has been previously
strained through a piece of muslin; squeeze them, shake them gently, and
again hang them up to dry; when they are dry, dip them twice or thrice
into clear water, squeeze them, spread them on a linen cloth, roll them up
in it, and let them lie an hour before ironing them. Some persons put a
morsel of sugar into the starch, to prevent its sticking whilst ironing,
and others stir the starch with a candle to effect the same end; both
these practices are as injurious as unnecessary. The best plan to prevent
sticking is simply to use the best starch, and to make it well, and to
have the irons quite clean and highly polished. Mr W. B. Tegetmeier
recommends the addition of a small piece of paraffin (a piece of paraffin
candle-end) to the starch, to increase the glossiness of the ironed
fabric.
=STARS.= (In pyrotechny.) _Prop._ 1. (Brilliant——Marsh.) Nitrate, 52-1/2
parts; sulphur and black antimony, of each 13 parts; reduce them to
powder, make them into a stiff paste with isinglass, 1-1/2 parts,
dissolved in a mixture of vinegar, 6-1/2 parts; and spirits of wine, 13
parts; lastly, form this into small pieces, and whilst moist, roll them in
meal gunpowder.
2. (WHITE——Ruggieri.) Nitre, 16 parts; sulphur, 7 parts; gunpowder, 4
parts; as the last.
3. (GOLDEN RAIN.)——_a._ (Ruggieri.) Nitre and gunpowder, of each 16 parts;
sulphur, 10 parts; charcoal, 4 parts; lampblack, 2 parts; mix, and pack it
into small paper tubes.
_b._ (Ruggieri.) Nitre, 16 parts; sulphur and gunpowder, of each 8 parts;
charcoal and lampblack, of each 2 parts; as the last.
_c._ (Marsh.) Mealed gunpowder, 66-3/4 parts; sulphur, 11 parts; charcoal,
22-1/4 parts; as before. Used for the ‘garniture’ of rockets, &c. See
PYROTECHNY.
=STAVES′ACRE.= _Syn._ STAVESACRE SEEDS; STAPHISAGRIÆ SEMINA, STAPHISAGRIA
(Ph. L. & D.), L. “The seed of _Delphinium Staphisagria_, Linn.” (Ph. L.)
This article is powerfully emetic and cathartic, but is now scarcely ever
used internally. Mixed with hair powder, it is used to kill lice. An
infusion or ointment made with it is said to be infallible in itch, but
its use requires some caution.
=STAYS.= _Syn._ CORSET. Stays, “before womanhood, are instruments of
barbarity and torture, and then they are needed only to give beauty to the
chest. It is the duty of every mother, and every guardian of children, to
inquire the purpose for which stays were introduced into female attire.
Was it for warmth? If so, they certainly fulfil the intention very badly,
and are much inferior to an elastic woollen habit, or one of silk quilted
with wool. Was it to force the ribs, while yet soft and pliable, into the
place of the liver and stomach, and the two latter into the space allotted
for other parts, to engender disease and deformity to the sufferer and her
children for generations? Truly, if this were the object, the device is
most successful, and the intention most ingeniously fulfilled.” (Eras.
Wilson.)
“Only observe,” exclaimed Dr John Hunter——“only observe, if the statue of
the Medicean Venus were to be dressed in stays, and her beautiful feet
compressed into a pair of execrably tight shoes, it would extort a smile
from an Heraclitus, and a horse-laugh from a Cynic.”
“The Turkish ladies express horror at seeing Englishwomen so tightly
laced.” (Lady M. W. Montague.) See DISTORTIONS.
=STEAM.= The application of steam of the laboratory, as a source of heat,
is commonly effected by means of double pans, to the space between which
steam, at a moderate pressure, is introduced, the arrangements being such
as to permit of the condensed steam, or distilled water, being removed, by
means of a cock, nearly as soon as formed, or as may be desirable. Another
plan is to place coils of metal pipe along the bottom of cisterns, vats,
&c., formed either of wood or metal, and to keep them supplied with
high-pressure steam.
“It is quite susceptible of positive proof that by no arrangement yet
discovered, can more than two thirds of the heat generated by a given
quantity of coal, during combustion, be fairly absorbed and utilised in
any of our manufactories; and, moreover, there are undeniable facts, which
demonstrate that seldom, in the burning of coal, are more than three
fourths of the total heat, which might be eliminated, actually obtained;
thus justifying the supposition that one half of all the coal now consumed
is virtually wasted and lost to society.” To lessen, as much as possible,
this loss various improvements have been made, “which, for the most part,
have consisted in lengthening the flues, and exposing a larger surface of
the boiler to the action of the heated air passing from the furnace to the
chimney.” “Remembering that air is an extremely bad conductor of heat, and
that water about to be converted into steam is also a bad conductor, it is
evident that time must form an important element in the perfect
transmission of heat from one of these to the other; and hence, with a
great velocity of current existing in the flues, very little heat would
pass from air, however high its temperature, to water contained in a
boiler, and so circumstanced with respect to its all but gaseous
condition.” The results of the experiments on fuel made at the Museum of
Practical Geology by Sir H. de la Beche and Dr Lyon Playfair go clearly to
show that “to open the damper of a steam-boiler furnace is pretty
generally to diminish the effective power of the fuel.” “Great waste of
coal now arises from this simple circumstance; and much of the heat of the
fire, which ought to go to the boiler, is lost by its (too) hasty
transmission up the chimney. If, however, there be thus far room for
improvement in the direction just indicated, still wider is the vacant
space, caused by imperfect combustion, or, in technical phrase, ‘bad
stoking,’ merely because the stoker, to economise his labour, and to avoid
trouble, throws on to the bars of his furnace a thick layer of fuel, by
which loss is caused in two or three directions.” These are, principally,
imperfect combustion, and the volatilisation of fuel, as smoke, &c., from
an insufficient supply of air, and from a mass of mere red-hot coke or
cinder, two or three inches thick, lying between the boiler and the
hottest part of the furnace; which last, according to Dr Kennedy, is about
one inch above the fire-bars. Besides which, “in passing over this
red-hot coke, the carbonic acid would be converted into carbonic oxide,
and thus not only remove a quantity of carbon equal to its own, without
yielding any additional heat, but actually with the production of cold,
or, in other words, the absorption of heat.” (‘Dict. Arts, Manuf., and
Mines.’) This points to the evident policy of using a smoke-consuming
furnace, as noticed elsewhere.
Another matter worthy of remark is the constant waste of heat, and,
consequently, of fuel, in laboratories and manufactories in which steam is
employed, owing to the exposed condition of the pipes, boilers, and pans.
All of these should be well ‘clothed’ or covered by some non-conducting
medium, to prevent loss of heat by radiation, and by contact with the
atmosphere. Not only does economy dictate such a course, but the health
and comfort of the workpeople demand that the atmosphere in which they
labour should be as little heated and poisoned as possible.
TABLE _of corresponding Pressure and Temperatures of
Steam_. By ARAGO and DULONG.
+------------------+------------++------------------+------------+
|Pressure |Temperature,||Pressure |Temperature,|
|in | ||in | |
|Atmospheres.[194] | Fahr. ||Atmospheres.[194] | Fahr. |
|------------------+------------++------------------+------------+
| | _Degrees._ || | _Degrees._ |
| 1 | 212· || 13 | 380·66 |
| 1-1/2 | 234· || 14 | 386·94 |
| 2 | 250·5 || 15 | 392·86 |
| 2-1/2 | 263·8 || 16 | 398·48 |
| 3 | 275·2 || 17 | 403·83 |
| 3-1/2 | 285· || 18 | 408·92 |
| 4 | 293·7 || 19 | 413·78 |
| 4-1/2 | 300·3 || 20 | 418·46 |
| 5 | 307·5 || 21 | 422·96 |
| 5-1/2 | 314·24 || 22 | 427·28 |
| 6 | 320·36 || 23 | 431·42 |
| 6-1/2 | 326·26 || 24 | 435·56 |
| 7 | 331·7 || 25 | 439·34 |
| 7-1/2 | 336·86 || 30 | 457·16 |
| 8 | 341·78 || 35 | 472·73 |
| 9 | 350·78 || 40 | 486·59 |
| 10 | 358·88 || 45 | 499·14 |
| 11 | 366·85 || 50 | 510·6 |
| 12 | 374· || | |
+------------------+------------++------------------+------------+
[Footnote 194: Estimating 14·6 lbs. = 1 atmosphere.]
A cubic inch of water, during its conversion into steam, under the
ordinary pressure of the atmosphere, expands into 1696 cubic inches, or
nearly a cubic foot.
One part, by weight, of steam, at 212° Fahr., when condensed into cold
water, is found to be capable of raising 5·6 parts of the latter from the
freezing to the boiling point. See FUEL, PIT-COAL, SMOKE, &c.
=STEAR′IC ACID.= HC_{18}H_{35}O_{2}. _Syn._ STEARIN (Commercial). This is
obtained from stearin (see _below_), by saponification.
_Prep._ 1. Repeatedly dissolve and crystallise commercial stearic acid in
hot alcohol, until its melting point becomes constant at not less than
158° Fahr. Pure.
2. (Chevreul.) Saponify mutton suet with caustic potassa, and dissolve the
newly formed soap in 6 times its weight of hot water; to the solution add
40 or 50 parts of cold water, and set the mixture aside in a temperature
of about 52° Fahr.; after a time separate the pearly matter (stearate and
margarate of potassa) which falls, drain and wash it on a filter, and
dissolve it in 24 parts of hot alcohol of sp. gr. ·820; collect the
stearate of potassa which falls as the liquid cools, recrystallise it in
alcohol, and decompose it, in boiling water, with hydrochloric acid;
lastly, wash the disengaged stearic acid in hot water, and dry it.
3. (Commercial.) Ordinary tallow is boiled in large wooden vessels, by
means of high pressure steam, with about 16% of hydrate of lime (equiv. to
11% of pure lime), for 3 or 4 hours, or until the combination is complete,
and an earthy soap is formed, when the whole is allowed to cool; the
product (stearate of lime) is then transferred to another wooden vessel,
and decomposed by adding to it 4 parts of oil of vitriol (diluted with
water) for every 3 parts of slaked lime previously employed, the action
being promoted by steam heat and brisk agitation; after repose, the
liberated fat is decanted from the sediment (sulphate of lime) and water,
and is then well washed with water, and by blowing steam into it; it is
next allowed to cool, when it is reduced to shavings by means of a number
of knives worked by machinery, and in this divided state is placed in
canvas bags and submitted to the action of a powerful hydraulic press, by
which a large portion of the oleic acid which it contains is expelled; the
pressed cakes are then a second time exposed to the action of steam and
water, again cooled, and coarsely powdered, and again submitted to the
joint action of steam and pressure; they are, lastly, melted, and cast
into blocks for sale.
_Obs._ This product is a more or less impure mixture of stearic acid and
other fatty bodies, particularly the so-called margaric acid, now
generally regarded as a mixture of palmitic and stearic acids. The hard,
fatty acids of vegetable origin (palmitic, cocinic, myristic, &c.), now so
extensively used as candle materials, are obtained from the natural oils
and butters by the process known as ‘sulphuric acid saponification,’ which
consists in treating the fatty bodies with 5 or 6% of concentrated
sulphuric acid at a high temperature (about 350° Fahr., produced by
superheated steam), and distilling the resulting mass by the aid of steam
heated to about 560° Fahr. Frequently the operations of hot and cold
pressing are resorted to in order to free the product from the softer
fats.
By a patent process employed at Price’s candle works the natural vegetable
fats are decomposed into their constituents (fatty acids and glycerin) by
the action of superheated steam alone, without previous ‘saponification’
with lime or sulphuric acid.
Another method for the preparation of commercial stearic acid is that of
Messrs Moinier and Bontigny. This process is thus described in the
‘Chemical Technology’ of Messrs Ronalds and Richardson:——Two tons of
tallow and 900 gall. of water are introduced into a large rectangular vat
of about 270 feet capacity.
The tallow is melted by means of steam admitted through a pipe coiled
round the bottom, and the whole kept at the boiling heat for an hour,
during which a current of sulphurous acid is forced in. At the end of this
period 6 cwt. of lime, made into milk with 350 gall. of water, are added.
The mixture soon acquires consistence, and becomes frothy and viscid. The
whole is now agitated in order to regulate the ebullitions, and prevent
the sudden swelling up of the soapy materials. The pasty appearance of the
lime soap succeeds, and it then agglomerates into small nodular masses.
The admission of sulphurous acid is now stopped; but the injection of the
steam is continued until the small masses become hard and homogeneous. The
whole period occupies eight hours, but the admission of the sulphurous
acid is discontinued at the end of about three hours. The water containing
the glycerin is run off through a tube into cisterns prepared to receive
it.
The arrangements for preparing sulphurous acids are retorts, into which
are put sulphuric acid and pieces of wood; upon the application of heat
the sulphurous acid passes off, and is conveyed by leaden pipes into the
vessels containing the tallow. The lime soap formed is then moistened with
12 cwt. of sulphuric acid, at 150° Fahr., diluted with 50 gall. of water.
The whole is thoroughly agitated and the steam cautiously admitted, so as
not to dilute the acid too much until the decomposition is general at all
points. This occupies about 3 hours, and in 2 or 3 hours more the sulphate
of lime has collected at the bottom, while the fatty acids are floating on
the surface of the solution of the bisulphate of lime. Several processes
of washing with steam and water are necessary to ensure the removal of the
sulphate of lime, &c., and after settling for 4 hours the fatty acids are
forced through a fixed siphon, into a vat, where they are again washed
with water; they are then siphoned at last into a trough lined with lead,
on the bottom of which are placed leaden gutters, pierced below by long
pegs of wood. The fatty acids are then placed in clothes and subjected to
pressure in the stearin cold press.
In 1871 Professor Boek of Copenhagen, after a careful microscopic and
chemical investigation, discovered that the neutral fats were composed of
a congeries of little globules enclosed in albuminous envelopes. To the
presence of these latter substances in the fat he attributed the
difficulty of eliminating the fatty acids from it by means either of
sulphuric acid, except in excess, or of alkali, except under great
pressure; conceiving that both these agents as employed under the usual
methods were expended in rupturing and destroying the albuminous
coverings.
The inconveniences arising from the above processes are, in the case of
the excess of the sulphuric acid, a considerable destruction of the fatty
acid, as well as the necessity of its distillation, and the consequent
danger of conflagration; whilst in the case of the alkali, this must
either be used in quantities much greater than theory requires, or else be
heated under great pressure, at the risk of giving rise to an explosion.
In Professor Boek’s process these dangers, together with the waste of
material, are avoided. By submitting the fat for a limited time and at a
given temperature to the action of a small quantity of sulphuric acid, the
albuminous envelopes are broken and partly destroyed. The neutral fat thus
liberated is then placed in open tanks in water, by which, after the
expiration of several hours, it becomes decomposed. When this is
completely effected the glycerin, dissolved in the water used for the
decomposition, is removed; the fatty acids which remain behind, and which
amount to 94 per cent. of the original fat, being at this stage of the
operation dark brown or blackish in colour.
In this condition they are placed in open tanks, and dilute solutions of
certain agents are poured upon them, whereby the albuminous débris as well
as the colouring matters with which they are associated become oxidised,
whilst the specific gravity of these latter is in consequence so increased
as to cause them to subside to the bottom of the tank, leaving the fatty
acids, now greatly whitened, on the upper part of the liquid.
The acids after being washed 2 or 3 times with dilute acid and water are
then cooled, and hot-pressed in the usual manner, and the stearic acid
thus obtained is said to have a higher melting point, and to be larger in
yield than that obtained by any other method, an oleic acid of excellent
quality being at the same time produced.
In 1874 a French patent was taken out for an improvement in the
manufacture of stearic acid. The patentee employs carbon disulphide to
increase the fluidity of the oleic acid, so that the warm pressure of the
crude stearic acid is avoided. The addition of the carbon disulphide may
be made either before or after the cold pressing of the stearic acid. The
crude fat acid is melted in a special apparatus, and 20 per cent. of the
disulphide is mixed with it whilst in the fluid state. It is then left to
cool and subjected to cold pressure. The stearic acid thus obtained should
be free from oleic acid.
_Prop., &c._ Pure stearic acid crystallises in milk-white needles, which
are soluble in ether and in cold alcohol, and forms salts with the bases,
called stearates. The commercial acid is made into candles. See CANDLES,
FAT, OILS (Fixed), and TALLOW.
=STE′ARIN.= C_{57}H_{110}O_{6}. The solid portion of fats which is
insoluble in cold alcohol.
_Prep._ Pure strained mutton suet is melted in a glass flask along with 7
or 8 times its weight of ether, and the solution allowed to cool; the
soft, pasty, semi-crystalline mass is then transferred to a cloth and is
strongly pressed as rapidly as possible, in order to avoid unnecessary
evaporation; the solid portion is then redissolved in ether, and the
solution allowed to crystallise, as before. The product is nearly pure.
_Prop., &c._ White; semi-crystalline; insoluble in water and cold alcohol;
soluble in 225 parts of cold ether, and freely so in boiling ether. It
melts at 130° Fahr. The stearin of commerce is stearic acid.
=STEAROP′TEN.= The name given by Herberger to the concrete portion or
camphor of volatile oils. Bizio calls it stereusin.
=STEEL.= This important material may be defined as iron chemically
combined with sufficient carbon to give it extreme toughness and hardness
without brittleness. According to one of our greatest authorities on
metallurgy, steel should contain from ·833% to 1·67% of carbon, these
numbers referring respectively to the softest and the hardest varieties.
By some authorities silicon in small quantities is supposed to be a useful
ingredient in steel, and to increase its capacity for being hardened; an
opinion dissented from by others, who hold that its presence has a
tendency to interfere with the welding of the metal. Faraday and Stodart
believed that the addition of small quantities of chromium and iridium to
steel served to improve its quality, and the same has been asserted of
tungsten and titanium; but on these points there is still a divergence of
opinion, and no satisfactory decision has yet been arrived at concerning
them.
Manganese has also been credited with the property of improving steel, but
as it has been found that only a very minute quantity of the manganese is
taken up by the steel, an indirect influence may possibly be exercised by
it, viz. its power of uniting with the stage, and of carrying away any
prejudicial excess of sulphur and phosphorus with it; and in this manner
it may contribute to the increased purity of the metal. The addition of
manganese to cast steel constitutes Mr Heath’s patent, the chief advantage
of which is that blistered steel made from British bar iron can be
substituted for the much more expensive Swedish and Russian iron, in
certain branches of iron manufacture.
“Among the various substances which are frequently present in malleable
iron and in cast iron, those which are more prejudicial to the quality of
steel are sulphur, phosphorus, and copper. The amount of sulphur in steel
of the best quality rarely exceeds ·012; within the limit of ·1 per cent.
it is considered to render the metal more capable of being welded at a
moderate heat, but to make it red short. Phosphorus also renders steel
more capable of being welded, and at the same time makes its cold short
when it amounts to ·1 per cent. The best steel rarely contains so much.
Copper renders steel decidedly red short when present in very small
amount, and for this reason iron smelted from ores containing copper
pyrites is not suitable for making steel.”[195]
[Footnote 195: Payen.]
Within the last few years great attention has been paid to the
investigation of the chemistry of steel. The researches of Despretz and
Fremy tend to the conclusion that nitrogen exercises a very important
influence over the phenomena of ‘steeling,’ and that carbon plays a less
necessary part; while those of Caron and Deville still refer the formation
of steel to the chemical combination of iron with carbon. There is no test
of the value of steel beyond its elasticity and temper, and the fineness,
equality, and smoothness of its grain.
Cast iron, wrought iron, and steel are all combinations of iron and
carbon, differing in the amount they contain of the latter element. As
cast iron contains a larger and wrought iron a smaller proportion of
carbon than steel, it follows that to convert the cast iron into steel,
its excess of carbon must be removed; whilst conversely, to make the
wrought iron into steel, the requisite amount of carbon must be added to
it.
Thus it is that the various processes for the manufacture of steel (with
the exception of those which propose to obtain it direct from the ores)
are directed to one or other of these ends, viz. the decarburation of cast
or pig iron, and the carburation of wrought or malleable iron.
1. In the first, or decarburation method, the oxygen of the air plays an
important part. Best carbon is heated with coal or charcoal, in some works
on the refining hearth, in others upon the bed of the puddling furnace.
The oxygen burnt off the excess of carbon from the iron and steel is left.
Payen says that when the iron contains slag, the ferrous silicate present
in this takes part in the reaction.
The steel obtained by this method is called natural steel. It is
afterwards subjected to forging, and being of inferior quality is employed
in the manufacture of springs for machinery, railway carriages, wheel
tyres, ploughs, and other farming implements.
_The following Table, from ‘Payen’s Industrial
Chemistry’ gives the Composition of several kinds of
Steel._
+--------------+---------+------+------+------+---------------+
| | | | | | Carbon. |
| | | | | +------+--------+
|Kind of Steel.|Locality.| Fe. | Mn. | Cu. |Comb- |Graphi- |
| | | | | |ined. | tic. |
+--------------+---------+------+------+------+------+--------+
|Natural Steel |Siegen | ... | ... |·379 |1·698 | ... |
|Ditto |Solingen | ... | ... | ... |1·570 | ... |
|Puddled Steel |Hartz | ... |0·12 | ... |1·380 | ... |
|Cement Steel |English | ... | ... | ... |1·807 | ... |
|Ditto |German | ... | ... | ... | ·416 | ·080 |
|Cast Steel |Sheffield| ... | ... | ... | ·950 | ·220 |
|Ditto |Ditto | ... | ... | ... | 1·758 |
|Ditto |French | ... | ... | ... | ·65 |
|Sword Steel |Damascus | ... | ·070 | ... | 1·089 |
|Ditto |Ditto | ... |trace | ... | ·775 |
|Wootz |Indian | ... | ... | ... | 1·500 |
|Ditto |Ditto |98·092| ... | ... |1·333 ·312 |
|Cast Steel |German | ... |trace |·300 | 1·180 |
|Ditto |English | ... |·024 |·066 | 1·275 |
|Bessemer Steel|Dowlais | ... |·576 |·025 | ·490 |
|Ditto |Sweden | ... |trace | ... | ·085 |
|Ditto | ... | ... |·179 | ... | ·300 |
|Ditto | ... | ... |·256 | ... | ·700 |
|Ditto | ... | ... |·468 | ... | ·950 |
|Ditto | ... | ... |·355 | ... | 1·050 |
|Wired |Barrow- | ... |·214 | ... | ·200 |
| |in-Furness | | | |
|Rail Heads |German | ... |·386 | ... | ·138 |
|Rails | ... | ... |·264 | ... | ·150 |
|Ditto | ... | ... |·638 | ... | ·046 |
|Boiler Plates | ... | ... |·136 | ... | ·250 |
|Ditto | ... | ... |·273 | ... | ·300 |
+--------------+---------+------+------+------+---------------+
+--------------+-----+-------+-----+----------+
|Kind of Steel.| Si. | S. | P. |Authority.|
+--------------+-----+-------+-----+----------+
|Natural Steel |·038 | ... | ... |Karsten. |
|Ditto |·020 | ... | ... |Lampadius.|
|Puddled Steel |·006 |(at·12)|trace|Brauns. |
|Cement Steel |·100 | ... | ... |Berthier. |
|Ditto | ... | ... | ... |Bromeis. |
|Cast Steel | ... | ... | ... |Ditto. |
|Ditto | ... | ... | ... |Karsten. |
|Ditto |·040 | ... | ... | ... |
|Sword Steel | ... |(Ni·07 Wo·01)| ... |
|Ditto | ... |(Ni·21 | ... |
| | |Co trace | |
| | |Wo trace) | |
|Wootz |·600 | ... | ... | ... |
|Ditto |·045 |(as 037) ... |Henry. |
|Cast Steel |·330 |(Ni ·12) ·020| ... |
|Ditto |·213 |(as·007) ...| ... |
|Bessemer Steel|·009 |·003 | ·036| ... |
|Ditto |·008 |trace | ·025|Brusewitz.|
|Ditto |·044 | do. | ·033| Ditto. |
|Ditto |·032 | do. | ...| Ditto. |
|Ditto |·047 | do. | ·032| Ditto. |
|Ditto |·067 | do. | ...| Ditto. |
|Wired |·179 |·030 | ·026| Ditto. |
|Rail Heads |·306 |·040 | ·034| Ditto. |
|Rails |·091 |·025 | ·032| Ditto. |
|Ditto |·634 |·045 | ·093| Ditto. |
|Boiler Plates |·016 |·010 | ... | Ditto. |
|Ditto |·056 |·040 | ·041| Ditto. |
+--------------+-----+-------+-----+----------+
Krupp’s cast steel, manufactured at Essen, near Cologne, is a natural
steel, being made on the bed of a puddling furnace. It is obtained from
hæmatite and spathic ore, coke being used for the smelting. The proportion
of carbon in Krupp’s steel is about 1·2 per cent. When required for
ordnance it is fused with a little bar iron in pots, each of which holds
30 lbs. It sometimes happens that in the manufacture of a huge gun or
cannon the contents of as many as 1200 of these pots are required. When
this is the case the pots are emptied of their molten contents
simultaneously into a channel leading to the cast, 400 well-drilled men
being required to carry out the operation.
It is very essential that castings of such magnitude should be allowed to
cool very gradually. They are therefore enveloped in hot cinders for two
or three months, after which they are ready for the forging.
2. _The carburation method._ This is generally effected by the process
known as ‘cementation,’ which is carried out as follows:——Two chests, made
of fire-brick or stone, one narrow end of each of which is shown in the
accompanying plate, are so fixed in a dome-shaped furnace, so that the
flames from the hearth beneath can effectually play around them.
The process renders it necessary that the temperature of the furnace
should be steadily maintained for some days; and this is achieved by
surrounding the furnace with a conical wall of brick-work, as shown in the
cut. The chests are usually about 10 or 12 feet in length, 3 feet in
height, and 3 feet in depth. A layer of charcoal of a fineness to pass
through a sieve of a 1/4 inch mesh, or of soot, is placed on the bottom of
each chest, and upon this the bars of wrought iron which are intended for
conversion into steel. The bars inside must be of iron of the best
quality, and generally about 3 inches broad and 3/4 of an inch thick. When
arranged regularly a little distance apart, the interstices between them
are filled up with charcoal, with which they are then covered to a depth
of about an inch. Similar layers of bars, similarly arranged, succeed to
this first one, until the chests are filled.
They are then covered in to a depth of 6 inches with a luting of damp clay
or sand. Each chest when thus filled contains from 5 to 6 tons of iron.
One of the bars projects through an opening at the end of the chest, to
facilitate an inspection of it from time to time by a workman, so that he
may be enabled to judge of the progress of the operation. The materials of
which the chests are composed render it important that the temperature of
the furnace should be carefully and gradually increased, as a too sudden
accession of heat would lead to the splitting of the chests. The
temperature necessary to effect the carburation of the iron has been found
to be that required for the melting of copper, viz. 1996° Fahr. When this
temperature is reached it is maintained for eight or ten days, or even
longer, the period depending upon the thickness of the iron, and the
degree of hardness it is desired it shall possess. Six or eight days are
sufficient to yield steel of a moderate degree of hardness. At the end of
the requisite time the fire is gradually put out, and the chests as
gradually cooled, a process which occupies about another ten days.
[Illustration]
The effect of the treatment to which the iron bars have been subjected has
been, in the first place, to entirely alter their interior structure; for
if they are broken asunder at any part, instead of showing the fibrous
arrangement observable in bar iron, they present a closely granular one.
In the second place, chemical analyses demonstrate that the iron has
combined with about 1 per cent. of carbon, and that this combination has
not only taken place on the surface of the bar, but has extended
throughout its whole substance. It is because of this perfect impregnation
of the iron by the solid carbon that the process by which it has thus been
converted into steel is called ‘cementation.’
Two suggestions have been offered in explanation of the blistered surface
presented by the steel. One of these, the theory of Mr T. H. Henry, is
that part of the carbon in penetrating into the body of the bar iron had
combined with the small quantity of sulphur present in the iron, and that
the bisulphide of carbon thus formed becoming vaporised by the elevated
temperature, in escaping through the soft surface of the metal, has caused
its blistered condition. The second conjecture is that the blebs have
arisen from the extrication of carbonic oxide, which had been formed in
the bar by the union of the carbon with the small quantity of oxide of
iron or slag accidentally remaining in it.
Graham has shown that soft iron has the power of absorbing or occluding at
a low red heat 4·15 times its volume of carbolic oxide, which the metal,
when it becomes cold, retains, but which it parts with when subjected to a
temperature such as that which prevailed in the cementation box. This fact
seems to offer a reasonable confirmation of the reaction it has been
surmised takes place during the cementation process, and which is supposed
to be as follows:
The small quantity of atmospheric oxygen remaining in the chest unites
with the carbon to form carbonic oxide. This carbonic oxide gives up half
its carbon to the iron (which thereby becomes converted into steel), and
in doing so changes to carbonic acid, which becomes reduced to carbonic
oxide by the absorption of more carbon from the charcoal, which carbon the
carbonic oxide again transfers to the iron.
The above reaction may not improbably occur throughout the substance of
the bar. By some chemists, cyanogen compounds are supposed to be present
in the cementation powder, and the cyanogen contained in these is supposed
to be the carrier of the carbon to the iron.
“The blistered steel obtained by this process is, as would be expected,
far from uniform, either in composition or texture; some portions of the
bar contain more carbon than others, and the interior contains numerous
cavities. In order to improve its quality it is subjected to a process of
fagotting similar to that employed in the case of bar iron; the bars of
blistered steel, being cut into short lengths are made up into bundles,
which are raised to a welding heat, and placed under a tilt hammer
weighing about 2 cwt., which strikes 200 or 300 blows in a minute; in this
way, the several bars are consolidated into one compound bar, which is
then extended under the hammer till of the required dimensions.
“The bars, before being hammered, are sprinkled with sand, which combines
with the oxide of iron upon the surface, and forms a vitreous layer which
protects the bar from oxidation. The steel which has been thus hammered is
much denser and more uniform in composition; its tenacity, malleability,
and ductibility are greatly increased, and it is fitted for the
manufacture of shears, files, and other tools. It is commonly known as
shear steel. Double shear steel is obtained by breaking the tilted bars
in two, and welding these into a compound bar. The best variety of steel,
however, which is perfectly homogeneous in composition, is that known as
cast steel, to obtain which about 30 lbs. of blistered steel are broken
into fragments, and fused in a fire-clay or plumbago crucible, heated in a
wind furnace, the surface of the metal being protected from oxidation by a
little glass melted upon it. The fused steel is cast into ingots, several
crucibles being emptied simultaneously into the same mould. Cast steel is
far superior in density and hardness to shear steel, but, since it is
exceedingly brittle at a red heat, great care is necessary in forging it.
It has been found that, in addition to 100 parts of the cast steel, of one
part of a mixture of charcoal and oxide of manganese, produces a very fine
grained steel, which admits of being cast on to a bar of wrought iron in
the ingot mould, so that the tenacity of the latter may compensate for the
brittleness of the steel; when the compound bar is forged, the wrought
iron forming the back of the implement, and the steel its cutting
edge.”[196]
[Footnote 196: Bloxam’s ‘Chemistry Inorganic and Organic.’]
Another distinct method from the cementation one, by which the carburation
of iron is affected, is that in which scrap or malleable iron is mixed
with pig or cast iron, this latter being fused with the scrap iron in
quantity sufficient to afford such an amount of carbon as is necessary to
convert the mixture into steel. Steel made by this operation is entirely
homogeneous, the tilting process which precedes the casting of the steel
obtained by cementation is therefore unnecessary. The pig iron is placed
on the bed (made of refractory sand) of one of Siemens’ regenerative
furnaces, heated by gaseous fuel. The temperature in this furnace is so
intense that the pig iron becomes perfectly liquid, and, when in this
condition, the scrap iron, which has been previously heated to redness in
an adjoining refractory furnace, is added, it becomes dissolved by it.
Iron may also be carburetted by heating wrought iron bars in carburetted
hydrogen. This process, however, is seldom had recourse to.
In the manufacture of Bessemer steel both the carburation and
decarburation processes are practised. From 1 to 5 tons of pig or cast
iron in a molten state are run from a contiguous blast, cupola, or
reverberatory furnace, with an apparatus known as a converter, which is
previously heated up to redness by means of coke. The converter is figured
under two aspects in the annexed engraving.
This vessel, which is generally made of boiler plates of sheet iron, has
an inside lining, consisting of a siliceous fireproof material, and is
perforated at the bottom with a number of concentric little openings,
which are the orifices of as many little tubes or tuyeres, that lead into
an outside main tube, as shown in the plate. By means of these tubes
condensed air is forced into the mass of melted metal, which is soon
thrown into violent commotion, and sends out a shower of ignited sparks.
The oxide of iron formed at the same time being set into active movement
by the incoming blast of air, is brought into intimate contact with every
particle of the carbon and silicon contained in the cast iron, and
converts the former into carbonic oxide, which burns with its
characteristic flame at the mouth of the converter, and the silica into
silicic acid, which enters into the slag, and floats, in the form of foam,
on the top of the heavier molten iron.
[Illustration]
The removal of the carbon (which is known by the discontinuance of the
carbonic oxide flame) being thus accomplished, the iron has next to be
submitted to the carburetting operation. This is performed by running into
the liquid iron in the converter such a quantity of molten pig or cast
iron as contains the required proportion of carbon.
The pig iron used for this purpose generally contains, in addition to a
large amount of carbon, a very perceptible quantity of manganese. The
converter (as shown in the plate) is then by means of the trunnion tilted,
so that its contents can be run into a ladle and transferred to the
necessary moulds. The time of conversion occupies from ten to twenty
minutes.
By Bessemer’s process the sulphur present in the pig iron is almost
entirely eliminated; the greater part of the silicon is also separated,
together with the carbon, and almost in the same proportion; but the
phosphorus is not removed, and, owing to the oxidation of some iron, the
amount is actually greater in the finished steel than in the pig
iron.[197]
[Footnote 197: Payen’s ‘Industrial Chemistry,’ edited by B. H. Paul,
Ph.D.]
Bessemer’s steel is in large demand, and is excellently suited for rails
for railroads, cannon, boiler plates, armour plates, and similar heavy
material, for the manufacture of which it has largely supplanted wrought
iron, but not at all adapted for the manufacture of knives, razors,
lancets, or similar instruments, in which a sharp or keen edge is
desirable.
The Bessemer process, which is largely adopted by the manufacturers of
steel throughout Europe and America, has proved a source of princely
income to its inventor, who obtains a bounty of a shilling on every ton of
steel made by it. In Europe alone in 1859 5-1/2 million cwts. Seventy per
cent. of this quantity was the produce of British industry.
Latterly, attempts have been made to obtain steel direct from the ores.
The efforts made in this direction have been greatly stimulated by the
invention of the regenerating furnace of Siemens. In these furnaces, in
which an intense temperature is obtained by means of the combustion of
inflammable gases (chiefly consisting of carbonic oxide, hydrogen, and
carburetted hydrogen), the ore after (in one process) being melted in
hoppers by means of the burning gases, runs down, and is gradually
dissolved in some melted pig iron placed on the hearth of the furnace.
When this latter has been sufficiently diluted with the decarbonised iron
the operation is complete.
_Properties of Steel._ The effects of temperature upon steel are
remarkable, and a knowledge of them has proved of great practical utility
in the manufacture of the various steel-ware articles that are so
indispensable to our every-day wants and needs. If forged and soft steel
is heated, and then suddenly cooled, it becomes hard, the hardness varying
with the temperature and the rapidity with which this has been reduced.
The higher the temperature and the more rapidly it is cooled, the greater
will be its hardness. Steel, which has been heated until white-hot, and
then suddenly plunged into a bath of cold mercury, acquires a hardness
nearly equalling that of the diamond. That, however, which the steel gains
in hardness, it loses in pliancy and elasticity, besides becoming so
brittle as to be of no possible use.
Soft steel, which has been made hard by heating it to redness, and by
subsequent sudden immersion in cold water, may be reconverted into soft
steel by again heating it to redness and allowing it to cool suddenly. By
stopping short, however, of heating it to redness, its hardness may be
proportionally modified.
Hence steel articles, varying as much in the qualities of hardness and
elasticity as a lancet and watch-spring, are made either by ‘heating down’
hard steel to requisite temperature and allowing it to cool, or by
‘heating up’ soft steel to the necessary point and also letting it
gradually cool. When steel is so treated it is said to be _tempered_ or
_annealed_. If polished steel be heated over a flame to a temperature of
430° F. its surface becomes of a very pale yellow colour; the colour
passes through different shades of yellow and blue with each successive
increase of temperature, until when raised to 600° F. it becomes blackish
blue.
These effects are due to the formation on the surface of the steel of
films of oxide of different degrees of thickness, and to the action of the
light on these. They are precisely analogous to those which are caused
when a ray of reflected light falls upon any other body, the surface of
which is composed of thin layers, which are continually changing in
thickness, such as a soap-bubble, or a thin coating of tar or oil swimming
on water, and which are exemplified in Newton’s rings.
As each shade of colour is an index of the temperature of the steel, and
as this determines its adaptability for various purposes, all that the
workman has to do, when he requires it for any special object, is to heat
it by the proper methods (such as a bath of oil, or tallow, or melted
metal) until it acquires the desired colour, and then to allow it to
gradually cool.
The following table, exhibiting the different melting points of steel when
employed in the manufacture of different kinds of works, together with the
corresponding colours, the composition of the metallic baths, &c., is from
Dr Wagner’s ‘Handbook of Chemical Technology,’ edited by W. Crookes, Esq.,
F.R.S.
Composition of
Metallic Mixture.
_____¦_____ Melting
Lead. Tin. Point. Temperature.
Lancets 7 4 220° C Hardly pale yellow.
Razors 8 4 228° ” Pale yellow to straw yellow.
Penknives 8-1/2 4 232° ” Straw yellow.
Pairs of scissors 14 4 254° ” Brown.
Clasp-knives, joiners’ and } 19 4 265° ” Purplish colour.
carpenters’ tools }
Swords, cutlasses, watch- } 48 4 288° ” Bright blue.
springs }
Stilettos, boring tools, and} 50 2 292° ” Deep blue.
fine saws }
Ordinary saws {in boiling linseed}
{oil } 316° ” Blackish blue.
Steel is of a greyish-white colour, and has a sp. gr. varying from 7·66 to
7·93. During hardening the sp. gr. becomes reduced from 7·93 to 7·66,
whilst it experiences a slight increase of volume. The property (already
pointed out) that steel possesses of becoming hard after being heated to
redness, and suddenly chilled, does not belong to pure iron, such as may
be obtained by electrolysis. Unlike pure iron, too, steel presents a
granular instead of a fibrous structure when broken; the best samples
closely resembling silver in this respect. The chemical difference between
hard and soft steel appears to consist in the much more intimate
combination of the carbon with the iron in the hard variety than in the
soft. In this latter kind the carbon seems to be only mechanically mixed,
for if it be immersed in hydrochloric acid the iron is dissolved, and
leaves the carbon behind. Steel is the most tenacious of all the metals,
being greater than that of either cast or malleable iron.
What is termed _case-hardening_ (which _see_) is a process by which small
articles of iron, such as keys, gun-locks, &c., are superficially
converted into steel. It is performed by heating the articles in contact
with iron filings or powdered charcoal. Another method is to make the iron
substance red hot, and then to sprinkle powdered potassic ferrocyanide all
over it.
=STEREOCHROMY.= This is a branch of the pictorial art confined to the
embellishment of walls and monuments. In the operations by which it is
accomplished it will be seen that the soluble silicates (water glass) play
an important part.
The foundation for the future picture or coloured design must be of some
durable stone or imperishable cement. Over this is first placed a layer of
lime mortar, to which is applied when it is dry and has become
sufficiently hard, a solution of water glass, by which all the interstices
of the mortar are filled up. Another coating of mortar made of sharp sand
and a lye of chalk is next laid on, and this, after it has been carefully
smoothed, properly levelled on the surface, and become quite dry, is
washed over and thoroughly impregnated with water-glass solution. When
this last layer has become dry it is ready to receive the painting, which
must be executed in water colours. After laying on these colours may be
permanently fixed by covering them with water glass. The following are the
colours used:——Zinc white, chrome green, chrome oxide, cobalt green,
chrome red, zinc yellow, oxide of iron, sulphide of cadmium, ultramarine,
ochre, &c. Vermillion is inadmissible, since, in fixing, it turns from red
to brown. Cobalt ultramarine, on the contrary, increases greatly in
brilliancy upon the application of the fixing solution. Stereochromatic
paintings are found to be very durable, and impervious to damp, smoke, or
variations of temperature.
=STE′REOTYPE METAL.= See TYPE METAL.
=STER′LING.= The truth of the old proverb, that “all is not gold which
glitters,” is often painfully experienced by the purchaser of modern
jewelry. The following table will, therefore, prove highly useful to the
reader in determining the value of articles in gold, provided he ascertain
the ‘fineness’ of the metal, either by examination or written warranty:——
_Sterling value of Gold of different degrees of
‘Fineness,’_
Carats. Value per
Fine. oz. Troy.
£ _s._ _d._
24 _carats_ 4 4 11-1/2
23 ” 4 1 5
22 ” (_British standard_) 3 17 10-1/2
21 ” 3 14 4
20 ” 3 10 9-1/2
19 ” 3 7 3
18 ” (_lowest Hall-mark_) 3 3 8-1/2
17 ” 3 0 2
16 ” 2 16 7-1/2
15 ” 2 13 1
14 ” 2 9 6-1/2
13 ” 2 6 0
12 ” 2 2 5-1/2
11 ” 1 18 11
10 ” 1 15 4-1/2
9 ” 1 11 10
8 ” 1 8 3-1/2
7 ” 1 4 9
6 ” 1 1 2-1/2
5 ” 0 17 8
4 ” 0 14 2
3 ” 0 10 7-1/2
2 ” 0 7 1
1 ” 0 3 6
=STEREO-METAL.= A remarkable alloy recently invented by Baron de Rosthorn,
of Vienna, and used in place of ordinary gun-metal. It consists of copper
and spelter, with small proportions of iron and tin, and to these latter
its peculiar hardness, tensile strength, and elasticity, are attributed.
=STETH′OSCOPE.= An instrument employed in auscultation. It consists of a
tube (usually made of wood, sometimes of gutta percha) widening
considerably at one end, and but slightly at the other. The wide end is
applied to the chest or other part of the patient, the physician putting
his ear at the other end; and from the sounds emitted by the heart, lungs,
&c., the state of these parts is ascertained.
=STEW′ING.= A method of cooking food intermediate to frying and boiling,
performed by simmering it in a saucepan or stewpan, with merely sufficient
water to prevent burning, and to effect the object in view; the whole
being served up to form the ‘dish.’ It is undoubtedly the most simple and
economical, and, when skilfully conducted, one of those best calculated to
develop the flavour and nutritious qualities of animal food. The following
is one of the most popular stews:——
=Stew, Irish.= _Prep._ (Soyer.) Take about 2 lbs. of scrag or neck of
mutton; divide it into ten or twelve pieces, and lay them in the pan; add
8 large potatoes and 4 onions cut into slices, season with 1-1/2
teaspoonful of pepper, and 3 do. of salt; cover all with water, put it
into a slow oven, or on a stove, for two hours, then stir it all up well,
and serve it up in deep dishes. If a little more water is added at the
commencement, you can take out, when half done, a nice cup of broth.
=STILL.= A vessel or apparatus employed for the distillation of liquids on
the large scale. The forms of stills, and the materials of which they are
made, vary according to the purposes for which they are intended, some
being exceedingly simple, whilst others are equally elaborate and
complicated. The _engr._ represents the most common and useful apparatus
of this kind, and the one almost exclusively employed in the laboratory.
It is used as follows:——After the fluid and other matters (if any) are put
into the still, the head is placed on and connected with the worm-tub or
refrigerator, and the joints are all securely luted. For ordinary liquids,
a stiff paste made with linseed meal and water, to which a little chalk
may be added, answers well for this purpose. For corrosive liquids,
nothing is better than elastic bands or rings interposed between the
joints, which are then ‘brought home,’ as it is called, with screws or
clamps. Heat is next applied, and the worm-tub is supplied with cold water
in sufficient quantity to preserve its contents at a proper temperature;
the application of the heat being so regulated that the liquid may drop
from the end of the refrigerator quite cold and unaccompanied with vapour.
For highly volatile liquids a closed receiver should be provided.
[Illustration:
_a._ Body of still, which may be either placed in a steam jacket or in
a brick furnace.
_b._ Still head or capital.
_c._ Worm-tub.
_d._ Pewter-worm or refrigerator.
_e._ Cold-water pipe.
_f._ Waste-pipe.
_g._ Receiver.]
Of the various forms of distillatory apparatus that patented by Coffey in
1832 is the one almost universally employed in this country. It yields the
strongest spirits obtainable on a large scale. Coffey’s still (of which a
drawing is given on the next page) effects a great economy in the
expenditure of heat, by causing the liquid to be exposed to a very
extended heated service; whilst it effects the evaporation of the alcohol
from the wash by passing a current of steam through it.
[Illustration: Coffey’s Still.]
The wash is pumped from the ‘wash charger’ into the worm-tub, which passes
from top to bottom of the rectifier. In circulating through this tube it
experiences a slight elevation of temperature. Arrived at the last
convolution of the tube in the rectifier, the wash passes by the tube M in
at the top of the ‘analyser.’ It falls, and collects on the top shelf till
this overflows, whence it falls on the second shelf, and so on to the
bottom. All the time this operation is going on steam is passed up from
the steam boiler through fine holes in the shelves, and through valves
opening upwards. As the wash gradually descends in the analyser it becomes
rapidly weaker in alcohol, partly from condensation of steam which is
passed into it, and partly from loss of alcohol, either evaporated or
expelled by the steam, till when it arrives at the bottom it has parted
with the last traces of spirits.
At the same time the vapour, as it rises through each shelf of the
analyser, becomes constantly richer in alcohol, and contains less and less
water because of its condensation; it then passes from the top of the
analyser in at the bottom of the lower compartment of the rectifier. Here
it ascends in a similar way, bubbling through the descending wash, until
it arrives at F, above which it merely circulates round the earlier
windings of the wash pipe; the low temperature of which condenses the
spirits; which, collecting on the shelf at F, flows off by the tube into
the finished spirit condenser.
To still further effect a saving of heat, the water for supplying the
boiler is made to pass through a long coil of pipe, immersed in boiling
spent wash, by which means its temperature is raised before it enters the
boiler.
Another variety of distillatory apparatus is that of Siemens’ (see page
1566), much employed in the distillation of brandy.
It consists of two mash stills set in a boiler, and capable of being
alternately used by means of the three cocks (_a_, _b_, and _c_). L is the
boiler; P one of the mash retorts; K is the low wine receiver; R the fore
warmer, a reservoir in which the condensed water intended as feed water of
the boiler is collected; C is the dephlegmator; B a reservoir for the
vapours condensed in C.
From the dephlegmator the vapour passes to a condenser, not shown in the
engraving.
The mash warmer consists of a cylindrical portion (_i i_), the lower part
of which has an indentation (_c_). In the cylinder is placed a narrower
portion (_o o_) of the real mash, containing a vessel, fitted with the
heading tube (_f n_). The upper part of the fore warmer is fitted to the
lower part by means of the flange (_h h_); _r_ is a stirring apparatus,
which is frequently set in operation during the process of distillation.
The vapours from the second still are carried into the depression (_c_)
under the fore warmer, which, in order that the vapours may come into
contact with the phlegma, is covered with a sieve.
[Illustration: Siemens’ Distillatory Apparatus.]
The vapours surround the under part of the mash reservoir, and enter into
the tube (_f_), through which they pass to the lower cylinder of the
dephlegmator. The condensed water of the dephlegmator is conducted into
the reservoir (A). The upper and under part of the fore warmer are made of
cast iron, but the interior bottom and heating surfaces are made of
copper. This kind of fore warmer has the advantage of uniformly
distributing the heat, while it can be easily cleansed.
The dephlegmator (C) is so contrived that the rectified vapour can be
conveyed to the condenser by two separate pipes placed in an opposite
direction to each other, which are joined again in close proximity to the
condenser.
The remainder of the details will be seen by studying the engraving.
Another distilling apparatus is that known as Derosne’s, which is an
improvement upon one invented by Cellier-Blumenthal. This apparatus is
only designed for the distillation of wine, and not, like the previous
ones, of mash.
The engraving on page 1568 gives a representation of it.
It consists of two stills (A and A′); the first rectifier (B); the second
rectificator (C); the wine warmer and dephlegmator (D); the condenser (F);
the regulator (E); a contrivance for regulating the flow of the fluid wine
from the cistern (G).
The still A′, which, as well as the still A, is filled with wine, acts as
a steam boiler. The low wine vapours evolved come, when they have arrived
in the rectifiers, in contact with an uninterrupted stream of wine,
whereby dephlegmation is effected; the vapour, thus enriched in alcohol,
becomes stronger in the vessel (D), and thus arrives at the cooling
apparatus (F). In order that a real rectification should take place in the
rectificators the stream of wine should be heated to a certain
temperature, which is imparted to it by the heating of the condensed
water. The steam from the still A′ is carried by means of the pipe (Z) to
the bottom of the still A.
Both stills are heated by the fire of the same furnace. By means of the
tube B′ the liquid contained in the still A can be run into the still A′.
The first rectificator (B) containing a number of semicircular discs of
unequal size, placed one above the other, and which are so fastened to a
vertical centre rod that they can be easily removed and cleansed. The
larger discs, perforated in the manner of sieves, are placed with their
concave surfaces upwards.
[Illustration: Derosne’s Distillatory Apparatus.]
In consequence of this arrangement the vapours ascending from the stills
meet with large surfaces moistened with wine, which, moreover, trickles
downward in the manner of a cascade from the discs, and comes, therefore,
into very intimate contact with the vapours. The second rectificator (C)
is fitted with six compartments; in the centre of each of the partition
walls (iron or copper plates) a hole is cut, and over this hole, by means
of a vertical bar, is fastened an inverted cup, which nearly reaches to
the bottom of the compartment wherein it is placed. As a portion of the
vapours are condensed in these compartments, the vapours are necessarily
forced through a layer of low wine, and have to overcome a pressure of a
column of liquid two centimètres high. The fore warmer and dephlegmator
(D) is a horizontal cylinder made of copper fitted with a worm, the
convolutions of which are placed vertically. The tube (M) communicates
with this worm, the other end of which passes to O. A phlegma collects in
the convolutions of this tube, which is richer in alcohol in the formost
windings, and weaker in those more remote; this fluid, collecting in the
lower part of the spirals, may be drawn off by means of small tubes,
thence to be transferred, at the operator’s pleasure, either all or in
part, by the aid of another tube and stopcocks, to the tube (O), or into
the rectificator.
By means of the tube (L) the previously warmed wine of the dephlegmator
can be run into the rectificator. The condensor (F) is a cylindrical
vessel closed on all sides, and containing a worm communicating with the
tube (O).
The other end of the condensing tube carries the distillate away. On the
top of this portion of the apparatus the tube (K) is placed, by means of
which wine is run into the dephlegmator. The cold wine flows into the
cooling vessel by the tube (I).
Another variety of distillatory apparatus, invented by Langier, is that
represented in the accompanying cut.
[Illustration]
The fluid intended for distillation flows from the tube (_s_) into the
funnel (_p_), thence into the vessel (A), entering its lower part, and
serving to condense the alcoholic vapour. From this vessel the warmed
fluid passes by means of the tube (_r_) into the lower part of the second
vessel (B), where dephlegmation takes place by means of a condensing tube.
From B the fluid flows through the tube (_c_) into the second still (C),
which is heated by the hot gases evolved from the fire, kept burning under
the first still (D); in the still (C) the fluid undergoes a rectification,
and the vinasse flows by the tube (_e_) into the still (D); _m_ is the
pipe for conveying the hot vapour from D into C; the tube (_b_) carries
the alcoholic vapours into the dephlegmator. The tube (_d_) conveys the
phlegma into the still (C); _g_ and _h_ are glass gauging-tubes for
indicating the height of the fluid in the interior of the stills; the tube
(_l_) conveys the uncondensed vapours from the dephlegmator into the
condensing apparatus, while _i_ carries the vapours formed in the vessel
(B) into the condensing apparatus.
The alcohol condensed in the cooling apparatus flows, as shown in the cut,
into the vessel (_o_), provided with a hydrometer, which shows the
strength of the liquid. The cooling apparatus of the vessel (B) consists
of seven compartments or sections formed by wide spirals, to each of
which, at its lower level, is attached a narrow tube, all of which tubes
are connected to the tube (_d_), which latter conveys the condensed fluids
back into the still.
A very simple form of apparatus in use is that figured below.
[Illustration]
A is a cylinder made of cast iron or copper, in which the fluid to be
distilled is heated by a spiral tube made of copper. The inlet of this
tube is shown at _b_ and the outlet at _a._; c serves to carry off the
vinasse; B is the dephlegmator, through which the fluid to be distilled
continually flows in a downward direction, while the vapour of the low
wine evolved in A ascends uninterruptedly.
The dephlegmator is so constructed as to have as large a surface and as
many points of contact as possible. The vapour ascends to the reservoir
(E), and passes into the rectifier (C) by the tube (F). The condensed
portion returns through the tube (H) to the dephlegmator, whilst the
uncondensed vapour passes on to the condenser of the vessel (D), where it
becomes condensed, and is carried off through M. The liquid intended for
distillation is kept in a tank (not shown in the engraving), placed above
the apparatus, and is conveyed to the latter by the tube (L I), fitted
with the stop-cock (K), so that the liquid arrives first in D, is next
conveyed to C, thence through G into the dephlegmator, and finally into
the cylinder.
Divers adaptations for heating by steam have been arranged, in a very
convenient form, by Mr Coffey. His so-called ESCULAPIAN STILL affords the
pharmaceutical chemist the means of conducting the processes of
ebullition, distillation, evaporation, desiccation, &c., on the small
scale. The following cut represents his apparatus.
[Illustration: B, a burner supplied with gas by a flexible tube; C. the
boiler or still; I, an evaporating pan fixed over the boiler, and forming
the top of the still head; K, a valve for shutting off the steam from I,
when it passes through the tube (M), otherwise it would pass through L,
and communicate heat to the drying closet (O O), and from thence to the
condenser (T T). _o_ is a second evaporating pan over the drying closet.]
For further information on the subject of stills consult ‘Ure’s
Dictionary,’ ‘Illustrated Chemistry,’ and Wagner’s ‘Chemical Technology.’
=STIM′ULANTS.= _Syn._ STIMULANTIA, L. Medicines or agents which possess
the power of exciting vital action. They are divided in general
stimulants, or those which affect the whole system, as mercury or bark;
and local or topical stimulants, or those which affect a particular organ
or part only, as mustard applied as a poultice. Diffusible stimulants are
general stimulants the effects of which are rapid but fugacious, as ether
or alcohol. “Much discrimination and caution are required in the
administration of articles of this class, because, if given when
inflammation is present, they are liable to create more mischief than
benefit; but they are called for when, on the decline of that condition of
an organ or organs, a state of relaxation or torpidity exists. In this
state of things a gentle stimulation materially assists the functions, and
is productive of much benefit.”
=STINGS.= See BITES.
=STIR-ABOUT.= Thick gruel formed of oatmeal and water boiled together.
When eaten with cold milk, it forms the porridge of the Scotch; and when
mixed with the liquor in which meat or vegetables have been boiled, it is
called beef brose, kale brose, &c.
=STOCK.= Among cooks, is condensed soup or jelly, used to make
extemporaneous soup, broth, &c.
=STOM′ACH AFFEC′TIONS.= Those of a character to admit of being usefully
noticed in a popular work are referred to under the heads APPETITE,
DYSPEPSIA, SICKNESS, &c.
Dr Budd recommends small doses of ipecacuanha as a remedy for those cases
of indigestion in which digestion is slow, and the food lies heavily on
the stomach, and there is an inability for mental or bodily exertion for
some time after meals. He says it should be given in the morning, fasting,
and in quantity barely sufficient to occasion a slight feeling of
vermiculating motion in the stomach, but without causing any sensation of
pain or nausea. The dose to produce this effect varies from 1/4 to 2 gr.
He thinks there is no other medicine which appears so effectual in
removing the affections in question. Small doses of rhubarb, ginger, and
cayenne pepper, have a similar kind of action, and may be given singly or
together for the same purpose. “I generally prescribe from 1/2 to 1 gr. of
ipecacuanha, in a pill, with 3 or 4 gr. of rhubarb. With many, a favourite
remedy for the discomfort resulting from slow digestion is a grain of
cayenne pepper, with 3 or 4 gr. of rhubarb. The best time for giving these
medicines is shortly” (say 1/2 an hour) “before any meal after which a
sense of oppression is usually felt.”
=STOPP′ERS=, when obstinately immoveable in bottles, are the most safely
treated by patiently hitting them upwards alternately on opposite sides
with a piece of wood. When this fails the part may be dipped into hot
water.
“Another method of removing a bottle-stopper is to insert its head into a
chink, and then endeavouring to turn the bottle with both hands. If the
neck of the stopper break, the hand is out of the way of danger. An
upright board, such an one as supports the ends of a set of shelves,
should be selected in a convenient situation in the laboratory, and a
vertical slit cut through it about a foot in length, an inch in width
above, but gradually decreasing in size, so as to be about one third of an
inch at the bottom. The top of the hole may be about the height of the
breast. This aperture will in one part or another receive and retain the
head of almost any stopper, and prevent its turning with the bottle. Then
by wrapping a cloth about the bottle and grasping it with both hands, the
attempt to turn it round so as to move the stopper may be made with any
degree of force which it may be thought safe to exert. The force employed
should never be carried so far as to cause fracture anywhere, but the
attempts, if unavailing with the application of a moderate degree, should
be desisted. Another and very successful method of removing a stopper is
to turn the bottle round when held horizontally over the small flame of a
spirit lamp or candle applied to the neck. The heat should be applied only
to the part round the plug of the stopper, and in a few moments, when that
has become warm, the stopper should be tapped with the piece of wood as
before stated. As soon as the stopper moves by tapping it is to be taken
out, and must not be replaced till the glass is cold.
“The application of heat in this manner must be short and the operation
altogether, to be successful, must be a quick one. If the contents of the
bottle are fluid, it should be so inclined that they must not become
heated; if they are volatile this method should be tried very carefully,
lest the vapour formed within should burst the bottle.
“It is often advantageous to put a little olive oil round the edge of the
stopper at its insertion, allowing it to soak in for a day or two. If this
be done before the heat be applied, it frequently penetrates by increased
facility; by oil, heat, and tapping very obstinate stoppers may be
removed.
“When a stopper has been fixed by crystallisation from solution, water
will sometimes set it free, and it is more efficacious in such cases than
oil, because it dissolves the cement. When the cementing matter is a
metallic oxide or sub-salt, a little muriatic acid may be useful if there
be no objection to its application arising from the nature of the
substance within.”[198]
[Footnote 198: Faraday.]
A writes in ‘New Remedies’ suggests that, in attempting to extricate the
fixed stopper by means of knocking with a piece of wood, the motion given
to it when putting it in should be reversed, that is, the stopper should
be knocked from _right_ to _left_.
=STORM-GLASS.= A philosophical toy, consisting of a thin glass tube about
12 inches long and 3/4 inch in diameter, about three fourths filled with
the following liquid, and covered with a brass car having an almost
capillary hole through it, or else tied over with bladder.
The solution. Take of camphor, 2 dr.; nitre 1-1/2 dr.; sal ammoniac, 1
dr.; proof spirit 2-1/4 fl. oz.; dissolve, and place it in the tube above
referred to. Used to foretell changes of the weather.
=STOVES.= In England the open grate or fireplace, because of its cheerful
appearance and the sense of comfort it suggests when filled with glowing
coal, is the favorite and general receptacle for the fuel with which we
warm our apartments. The cozy appearance, however, of our old-fashioned
English grate, constitutes its chief, if not its only merit; for it not
only fails in uniformly warming and effectively ventilating our
apartments, but it more or less sets into circulation a number of draughts
of cold air, and besides occasionally filling our rooms with smoke and
spoiling our furniture by the deposition of soot and dust, wastes our
fuel, by allowing it to escape unconsumed in the shape of smoke, and thus
pollutes the atmosphere of our cities and towns.
In France, Germany, Belgium, Russia, and other European countries, as well
as in America and Canada, the stove or closed fireplace is used. The
domestic stove of these countries is made either of sheet or cast-iron, or
fire-clay. The iron stoves, being mostly composed of thin plates, soon
absorb and radiate the heat; and although this property enables them to
rapidly warm an apartment, it has the disadvantage, if the stove becomes
red-hot, of allowing the escape through the heated metal into the
surrounding air of the carbonic acid generated in the stove; and
furthermore, in its immediate vicinity converts a portion of it into
carbonic oxide. Such stoves must necessarily be unsafe unless used in
well-ventilated apartments.[199] Another effect of the over heating of the
stove is to desiccate or parch the air, and to render it irritating when
breathed. The fire-clay stoves are free from these drawbacks, and continue
to radiate from their surfaces a large amount of heat, even when the fuel
with which they have been supplied is consumed. But although we exclude
the close stove from our sitting rooms and dormitories, it is in frequent
requisition in halls, picture-galleries, churches, theatres,
lecture-rooms, and the like.
[Footnote 199: Dr Bond has suggested coating them with soluble glass, as a
remedy for this.]
“Stove literature,” if such a term may be applied to the various treatises
descriptive of the multitude of patterns in use, which have emanated alike
from inventors and their critics, is so voluminous that it is impossible
for us to attempt to give even a list of the numberless stoves in use, to
say nothing of a commentary on their relative value. Of close stoves
suitable for heating spaces other than dwelling or sleeping-rooms, mention
may be made of Arnott’s stove, and one known as “The Belfast.” These
stoves are serviceable when it is desirable to keep up a fire for some
time, as in heating a lobby. They have the advantage of requiring little,
if any, attention after the fuel has been placed in them and ignited.
Of late years, gas-stoves, both for heating and cooking purposes, have
come largely into use. One of those for the former purpose is called the
“Pyropneumatic.” The inner part of this apparatus is formed of lumps of
fire-clay traversed by vertical air-passages which communicate with the
external air by a special channel. The air becomes heated as it passes
through the lumps of fire-clay, and rising to the top of the stove,
escapes therefrom by an outlet into the room. Another so-called
“ventilating” warming gas-stove is Mr George’s “Culirogen.” It consists of
a stove made of thin-rolled iron, inside of which is a coil of
wrought-iron tubing open at the top of the stove. The lower end of this
tubing is in connection with an iron pipe which is carried through the
wall of the apartment, and fed with air from without. Gas is the fuel
generally used to heat the inside of the stove. The continuous current of
air as it rushes into the iron pipe from without, thus becomes warmed as
it ascends into the coil, which it leaves to become diffused into the
surrounding apartment, whilst the products of combustion of the gas used
as fuel are, by means of a pipe attached to the stove, carried into the
chimney, as with coal fire.
A gas-cooking apparatus possesses many advantages over an ordinary coal
fire. In the first place, it is more cleanly; in the second, it affords a
much more uniform and equable temperature; in the third, it forms no
smoke, and in the fourth it is more economical as well as expeditious.
Mr Eassie gives the following practical suggestions to intending
purchasers of gas-stoves:——
“It is not necessary here to enter into a description of any of the
numberless common patterns extant, but it might be well to record the
opinion of the best engineers, that the simplest gas-stove is the best.
They should not be surrounded by a non-conducting material, as that
affords no advantage, but the contrary. An Argand or fish-tail burner
should also be used instead of rings pierced for so many separate jets,
and where practicable, the Bunsen-burner should be employed, as the
mixture of common air with the gas not only prevents the formation of
soot, but also intensifies the heat.”
=STRABIS′MUS.= _Syn._ SQUINTING. This need not be described. When one eye
only is affected, an excellent plan is to blindfold the sound eye during
several hours each day, until the affection be removed. When both eyes are
affected, a projecting piece of pasteboard, in the line of the nose, may
be worn as much as possible with the same object. In bad cases of
squinting inwards, as it is called, the division of the internal rectus
muscle of the eyeball by a skilful surgeon, is said to often relieve the
deformity.
=STRANGULATION.= See HANGING.
=STRAP′PING.= Spread adhesive plaster. Used to dress wounds, &c.
=STRASS.= See ENAMEL.
=STRAW′BERRY.= _Syn._ FRAGARIA, L. The fruit of _Fragaria vesca_ (Linn.),
or strawberry plant. Strawberries are, perhaps, the mildest of all the
cultivated fruits; they are cooling, and slightly laxative and diuretic;
rubbed on the teeth, they dissolve the tartar, and whiten them. They were
formerly in repute in gout, stone, and consumption. The root of the plant
is aperient.
=Strawberry essence, factitious.= Nitric ether, 1 part; acetate of ethyl,
5 parts; forminate of ethyl, 5 parts; butyrate of ethyl, 5 parts;
salicylate of methyl, 1 part; acetate of amyl, 3 parts; butyrate of amyl,
2 parts; glycerin, 2 parts; alcohol, 100 parts.[200]
[Footnote 200: ‘Pharm. Journ.’]
=STRAW PLAIT=, and the articles made of it, are bleached by exposing them
to the fumes of burning sulphur in a close chest or box; or, by immersing
them in a weak solution of chloride of lime, and afterwards well washing
them in water. Water acidulated with oil of vitriol or oxalic acid is also
used for the same purpose. Straw plait may be dyed with any of the simple
liquid dyes.
=STRINGHALT.= The same as CHOREA, which _see_.
=STRON′TIUM.= Sr. The metallic base of the earth strontia. It was
discovered by Sir H. Davy, in 1808. It closely resembles barium, but is
less lustrous. With chlorine it combines to form a chloride of strontium,
a somewhat deliquescent salt, soluble in 2 parts of cold and in less of
boiling water, and freely soluble in alcohol. With oxygen it forms an
oxide.
_Test._ Strontium salts are precipitated by sulphuric acid and alkaline
carbonates and sulphate. They are distinguished from barium by not giving
such a decided precipitate with sulphates, and by not being precipitated
by bichromate of potassium. From calcium, by sulphates of calcium
solution giving a precipitate, and by concentrated solutions giving a
precipitate with chromate of potassium. It is distinguished from magnesium
by the insolubility of its sulphate.
=Strontium, Oxide of.= SrO. _Syn._ PROTOXIDE OF STRONTIUM, STRONTIA.
_Prep._ Quite pure crystalline nitrate of strontium. _Prop._ Greyish-white
powder, uniting with water to form a white, somewhat soluble substance,
the hydrate of strontium, Sr(HO)_{2}.
With acids it forms various salts, of which the carbonate is a white
insoluble powder, and the nitrate a white crystalline salt, soluble in 5
parts of cold water, and in alcohol; communicating a brilliant red colour
to flame.
=STROPH′ULUS.= A papular eruption peculiar to infants. There are several
varieties:——In strophulus intertinctus, red gum, or red gown, the pimples
rise sensibly above the level of the cuticle, possess a vivid red colour,
and are usually distinct from each other; they commonly attack the cheeks,
forearm, and back of the hand, and, occasionally, other parts of the
body.——In strophulus albidus, or white gum, there are a number of minute
whitish specks, which are, sometimes, surrounded by a slight redness. The
two preceding varieties commonly occur during the first two or three
months of lactation.——In strophulus confertus, rank red gum, or tooth
rash, which usually appears about the fourth or fifth month, the pimples
usually occur on the cheeks and sides of the nose, sometimes on the
forehead and arms, and still less frequently on the loins. They are
smaller, set closer together, and less vivid, but more permanent than in
the common red gum.——In strophulus volaticus small circular patches or
clusters of pimples, each containing from 6 to 12, appear successively on
different parts of the body, accompanied with redness; and as one patch
declines another springs up near it, by which the efflorescence often
spreads gradually over the whole face and body.——In strophulus candidus
the pimples are larger than in the preceding, and are pale, smooth and
shining; it principally attacks the upper parts of the arms, the
shoulders, and the loins. The last two varieties commonly appear between
the third and ninth month.
The treatment of the above affections consists chiefly in removing acidity
and indigestion and duly regulating the bowels by an occasional dose of
magnesia or rhubarb, or both combined. Diarrhœa may be met by the warm
bath and the daily use of arrowroot (genuine), to which a teaspoonful or
two of pure port wine has been added; and itching and irritation may be
alleviated by the use of a lotion consisting of water, to which a little
milk, lemon juice, borax, or glycerin, has been added.
=STRYCH′NINE.= C_{21}H_{22}N_{2}O_{2}. _Syn._ STRYCHNINA, STRYCHNIA (B.
P., Ph. L., E., & D.), L. _Prep._ 1. Dissolve hydrochlorate or sulphate
of strychnine in distilled water, and throw down the alkaloid with
ammonia, carefully avoiding excess; redissolve the precipitate in hot
rectified spirit, and collect the crystals which form as the liquid cools.
2. (Ph. D.) Nux vomica (in powder), 1 lb., is digested for 24 hours in 1/2
gall. of water acidulated with 2 fl. dr. of sulphuric acid, after which it
is boiled for half an hour, and the decoction decanted; the residuum is
boiled a second and a third time with a fresh 1/2 gall. of water
acidulated with 1 fl. dr. of the acid, and the undissolved matter is
finally submitted to strong expression; the decoctions are next filtered
and concentrated to the consistence of a syrup, which is boiled with
rectified spirit, 3 pints, for about 20 minutes, hydrate of calcium, 1
oz., or q. s., being added in successive portions during the ebullition,
until the solution becomes distinctly alkaline; the liquid is then
filtered, the spirit distilled off, and the residuum dissolved in diluted
sulphuric acid, q. s.; ammonia, in slight excess, is added to the filtered
solution, and the precipitate which falls is collected upon a paper
filter, and dried; it is next redissolved in a minimum of boiling
rectified spirit, and digested with 1/2 oz. of animal charcoal for 20
minutes; the filtered liquid, as it cools, deposits strychnine, in
crystals.
3. (Ph. B.) Nux vomica 1 lb., acetate of lead 180 gr., solution of ammonia
q. s., rectified spirit q. s., distilled water q. s. Subject the nux
vomica for two hours to steam in any convenient vessel; chop or slice it;
dry it in a water bath or hot-air chamber, and immediately grind it in a
coffee mill. Digest the powder at a gentle heat for 12 hours with two
pints of the spirit and 1 pint of the water, strain through linen, express
strongly, and repeat the process twice. Distil off the spirit from the
mixed fluid, evaporate the watery residue to about 16 oz., and filter when
cold. Add now the acetate of lead, previously dissolved in distilled
water, so long as it occasions any precipitate; filter; wash the
precipitate with 10 oz. of cold water, adding the washings to the
filtrate; evaporate the clear fluid to 8 oz., and when it has cooled add
the ammonia in slight excess, stirring thoroughly. Let the mixture stand
at the ordinary temperature for 12 hours; collect the precipitate on a
filter, wash it once with a few ounces of cold distilled water, dry it in
a water-bath or hot-air chamber, and boil it with successive portions of
rectified spirit, till the fluid scarcely tastes bitter. Distil off most
of the spirit, evaporate the residue to the bulk of about 1/2 oz., and set
it aside to cool. Cautiously pour off the yellowish mother-liquor (which
contains the brucia of the seeds) from the white crust of strychnia which
adheres to the vessel. Throw the crust on a paper filter, wash it with a
mixture of two parts of rectified spirit and one of water, till the
washings cease to become red on the addition of nitric acid; finally,
dissolve it, by boiling it with 1 oz. of rectified spirit, and set it
aside to crystallise. More crystals may be obtained by evaporating the
mother-liquor. [Strychnine is more readily obtained, and in greater
purity, from St Ignatius’s Bean.] The usual dose of strychnia and its
salts to commence with is from 1/30th to 1/12th of a grain, to be very
slowly increased, carefully watching its effects. Magendie says the salts
are more active than their base.
_Prop._ A white, inodorous, infusible powder; or small, but exceedingly
brilliant, transparent, colourless, octahedral crystals; soluble in about
7000 parts of water at 60°, and in 2500 parts at 212° Fahr.; freebly
soluble in hot rectified spirit; insoluble in absolute alcohol, ether, and
solutions of the caustic alkalies; imparts a distinctly bitter taste to
600,000 times its weight of water (1 part in 1,000,000 parts of water is
still perceptible——Fownes); exhibits an alkaline reaction; and forms salts
with the acids, which are easily prepared, are crystallisable, and well
defined.
_Tests._——1. Potassium hydrate and the carbonate produce, in solutions of
the salts of strychnia, white precipitates, which are insoluble in excess
of the precipitant, and which, when viewed through a lens magnifying 100
times, appear as aggregates of small crystalline needles. In weak
solutions the precipitate only separates after some time, in the form of
crystalline needles, which are, however, in this case, perfectly visible
to the naked eye.——2. Ammonia gives a similar precipitate, which is
soluble in excess of the precipitant.——3. Bicarbonate of sodium produces,
in neutral solutions, a like white precipitate, which is insoluble in
excess, but which redissolves on the addition of a single drop of acid; in
acid solutions no precipitate occurs for some time in the cold, but
immediately on boiling the liquid.——4. Nitric acid dissolves pure
strychnia and its salts to colourless fluids, which become yellow when
heated. Commercial strychnine, from containing a little brucine, is
reddened by this test.——5. A minute quantity of strychnine being mixed
with a small drop of concentrated sulphuric acid, placed on a white
capsule or slip of glass, forms a colourless solution, but yields, on the
addition of a very small crystal of bichromate of potassium, or a very
minute portion of chromic acid, a rich violet colour, which gradually
changes to red and yellow, and disappears after some time. The 1/1000th of
a grain yields very distinct indications.——6. Pure oxide or peroxide of
lead produces a similar reaction to the last, provided the sulphuric acid
contain about 1% of nitric acid.
_Pois._ The characteristic symptom is the special influence exerted upon
the nervous system, which is manifested by a general contraction of all
the muscles of the body, with rigidity of the spinal column. A profound
calm soon succeeds, which is followed by a new tetanic seizure, longer
than the first, during which the respiration is suspended. These symptoms
then cease, the breathing becomes easy, and there is stupor, followed by
another general contraction. In fatal cases these attacks are renewed, at
intervals, with increasing violence, until death ensues. One phenomenon
which is only found in poisonings by substances containing strychnine is,
that touching any part of the body, or even threatening to do so,
instantly produces the tetanic spasm.
_Treat._ The stomach should be immediately cleared by means of an emetic,
tickling the fauces, &c. To counteract the asphyxia from tetanus, &c.,
artificial respiration should be practised with diligence and care. “If
the poison has been applied externally, we ought immediately to cauterise
the part, and apply a ligature tightly above the wound. If the poison has
been swallowed for some time, we should give a purgative clyster, and
administer draughts containing sulphuric ether or oil of turpentine, which
in most cases produce a salutary effect. Lastly, injections of chlorine
and decoction of tannin are of value.”
According to Ch. Gunther, the greatest reliance may be placed on full
doses of opium, assisted by venesection, in cases of poisoning by
strychnia or nux vomica. His plan is to administer this drug in the form
of solution or mixture, in combination with a saline aperient.
_Uses, &c._ It is a most frightful poison, producing tetanus and death in
very small doses. Even 1/24 gr. will sometimes occasion tetanic twitchings
in persons of delicate temperament. 1/4 gr. blown into the throat of a
small dog produced death in 6 minutes. In very minute doses it acts as a
useful tonic in various nervous diseases, chronic diarrhœa, leucorrhœa,
&c.; in slightly larger ones, it has been advantageously employed in
certain forms of paralysis, in tic douloureux, impotence, &c.——_Dose_,
1/24 to 1/16 gr. (dissolved in water by means of a drop of acetic or
hydrochloric acid), gradually and cautiously increased until it slightly
affects the muscular system. Externally, 1/8 to 1/4 gr. at a time.
The Edinburgh College ordered the nux vomica to be exposed for two hours
to steam, to soften it, then to chop or slice it, next to dry it by the
heat of a vapour bath or hot air, and, lastly, to grind it in a
coffee-mill. In the process of the Ph. L. 1836 magnesia was employed to
effect the precipitation. In the last Ph. L. strychnine appears in the
Materia Medica. Most of that of commerce is now obtained from St
Ignatius’s bean, which, according to Geiseler, yields 1-1/4% of it;
whereas 3 lbs. of nux vomica produce little more than 1 dr. Commercial
strychnine may be freed from brucine by digesting the powder in dilute
alcohol.
The salts of strychnine, which are occasionally asked for in trade, are
the acetate (strychniæ acetas), hydrochlorate or muriate (s. murias——Ph.
D.), hydriodate (s. hydriodas), nitrate (s. nitras), phosphate (s.
phosphas), and sulphate (s. sulphas). All of these may be easily formed by
simply neutralising the acid previously diluted with 2 or 3 parts of
water, with the alkaloid, assisting the solution with heat; crystals are
deposited as the liquid cools, and more may be obtained by evaporating the
mother-liquor.
=STRYCHNOS.= See NUX VOMICA and BEAN, ST IGNATIUS’S.
=STUC′CO.= The name of several calcareous cements or mortars. Fine stucco
is the third or last coat of three-coat plaster, and consists of a mixture
of fine lime and quartzose sand, which, in application, is “twice hand
floated and well trowelled.” See CEMENTS.
=STUFFING.= Seasoning, placed in meat, poultry, game, &c., before dressing
them, to give them an increased relish. The same materials formed into
balls, are added to soups, gravies, &c., under the name of FORCEMEAT.
_Prep._ 1. (For fowls, &c.) Shred a little ham or gammon, some cold veal
or fowl, some beef suet, a small quantity of onion, some parsley, a very
little lemon peel, salt, nutmeg, or pounded mace, and either white pepper
or cayenne, and bread crumbs, pound them in a mortar, and bind it with 1
or 2 eggs.
2. (For hare, or anything in imitation of it.——Mrs Rundell.) The scalded
liver, an anchovy, some fat bacon, a little suet, some parsley, thyme,
knotted marjoram, a little shalot, and either onion or chives, all chopped
fine, with some crumbs of bread, pepper, and nutmeg, beaten in a mortar
with an egg.
3. (For goose.) From sage, onion, suet, and crumb of bread. Geese are now,
however, more commonly stuffed with veal stuffing.
4. (For veal——Soyer.) Chop 1/2 lb. of suet, put it into a basin with 3/4
lb. of bread crumbs, a teaspoonful of salt, a 1/4 do. of pepper, a little
thyme or lemon peel chopped, and 3 whole eggs; mix well.
_Obs._ 1 lb. of bread crumbs and one more egg may be used; they will make
it cut firmer. This, as well as No. 1, is now commonly employed for
poultry and meat. Ude, a great authority in these matters, observes that
“it would not be amiss to add a piece of butter, and to pound the whole in
a mortar.” “Grated ham or tongue may be added to this stuffing.”
(Rundell.) This is also used for turkeys, and for ‘forcemeat patties.’
=STUFFING (Birds, &c.).= The skins are commonly dusted over with a mixture
of camphor, alum, and sulphur, in about equal quantities; or, they are
smeared with Bécœur’s arsenical soap, noticed under SOAP. According to
Crace Calvert, carbolic acid, which is worth only about 2s. per gall., is
superior to all other substances for preserving the skins of birds and
animals, as well as corpses. See TAXIDERMY, PRACTICAL.
=STURDY.= This disease, known also by the name of GAD, which attacks
cattle and sheep, but more particularly the latter, is caused by the
presence in the brain of the animal, of a hydatid——a creature enclosed in
a sac of serous fluid. This hydatid develops from the ova of the tape
worm, in the animal’s body, whence it has gained an entrance, with the
grass which constitutes the cattle or sheep’s food upon which it has been
voided by dogs and other animals.
It is most common in sheep of from 6 to 8 months old, and, as might be
expected, with those which feed in damp meadows. The animals attacked by
it turn round and round in one position, lose their gregarious habits,
seem dazed, and refuse their food; which latter circumstance frequently
causes death by inducing starvation.
As regards the treatment of this disease Mr Finlay Dun writes: “A stout
stocking wire thrust up the nostrils has long been used with occasional
success, to get rid of the hydatid; but the use of the trocar and canula
now sold by most surgical instrument makers is much safer and better. The
sheep is placed with its feet tied upon a table or bench, and the head
carefully examined, when a soft place may often be detected, indicating
that the hydatid lies underneath. A portion of the skin is dissected back
and the trocar and canula introduced, when the hydatid will often come
away as the trocar is withdrawn.” Mr Dun says “that, should the trocar
fail to extract it, it must be drawn to the surface by a small syringe
made for the purpose. Furthermore, the wound, after the removal of the
hydatid, must be treated with a cold water dressing.”
All cattle similarly affected should be treated as above.
=STUR′GEON.= Several species of _Acipenser_ pass under this name. The
common sturgeon is the _Acipenser sturio_ (Linn.). The roe is made into
‘caviare,’ the swimming-bladder into ‘isinglass.’
=STY.= _Syn._ STYE, STIAN; HORDEOLUM, L. A small inflamed tumour, or boil,
at the edge of the eyelid, somewhat resembling a barleycorn. It is usually
recommended to promote its maturation by warm applications, since “the
stye, like other furunculous inflammations, forms an exception to the
general rule, that the best mode in which inflammatory swellings can end
is resolution.”
=STYP′TICS.= _Syn._ STYPTICA, L. Substances which arrest local bleeding.
Creasote, tannic acid, alcohol, alum, and most of the astringent salts,
belong to this class.
=Styptic, Brocchieri’s.= A nostrum consisting of the water distilled from
pine tops.
=Styptic, Eaton’s.= A solution of sulphate disguised by the addition of
some unimportant substances. “Helvetius’s styptic was for a long time
employed under this title.” (Paris.)
=Styptic Helvetius’s.= _Syn._ STYPTICUM HELVETII, L. Iron filings (fine),
and cream of tartar, mixed to a proper consistence with French brandy.
See POWDER, HELVETIUS’S.
=STY′RAX.= _Syn._ STORAX, STORAX BALSAM; STYRAX (Ph. L., & E.), L. “The
liquid balsam of an uncertain plant.” (Ph. L.) The “balsamic exudation of
_Styrax officinale_, Linn.” (Ph. E.), or cane storax tree. Two or three
varieties are known in commerce:——Liquid storax (_styrax liquida_), lump
of red storax (_s. in massis_), which is generally very impure; storax in
tears (_s. in lachrymis_), and storax in reeds (_s. calamita_). The last
are now seldom met with in trade.
PREPARED STORAX (_styrax colata_; _s. præparata_, B. P., Ph. L.) is
obtained by dissolving storax, 1 lb., in rectified spirit, 4 pints, by a
gentle heat, straining the solution through linen, distilling off greater
part of the spirit, and evaporating what is left to a proper consistence
by the heat of a water bath. It is less fragrant than the raw drug.
Storax is stimulant, expectorant, and nervine. It was formerly much used
in menstrual obstructions, phthisis, coughs, asthmas, and other breath
diseases. It is now chiefly used as a perfume.——_Dose_, 6 to 20 or 30 gr.
(10 to 20 gr. twice a day, B. P.).
=A factitious strained Storax= is made as follows:——1. Balsam of Peru, 1
lb.; balsam of tolu, 4 lbs.; mix.
2. Gum benzoin, 8 lbs.; liquid storax, 6 lbs.; balsam of tolu and
Socotrine aloes, of each 3 lbs.; balsam of Peru, 2 lbs.; N.S.W. yellow
gum, 7 lbs.; rectified spirit, 7 gall.; digest, with frequent agitation,
for a fortnight, strain and distil off the spirit (about 5-1/2 galls.)
until the residuum has a proper consistence. _Prod._ 28 lbs.
3. Liquid storax, 1 oz.; Socotrine aloes, 1/4 lb.; balsam of tolu, 2 lbs.;
rectified spirit, q. s.
=SUB-.= See NOMENCLATURE and SALTS.
=SU′BERIC ACID.= Obtained by boiling rasped cork for some time in nitric
acid.
=SUBLIMA′TION.= The process by which volatile substances are reduced to
the state of vapour by heat, and again condensed in the solid form. It
differs from ordinary distillation in being confined to dry solid
substances, and in the heat employed being, in general, much greater.
=SUB′STANTIVE COLOURS=, in the art of dyeing, are such as impart their
tints to cloth and yarns without the intervention of a mordant; in
contradistinction to adjective colours, which require to be fixed by
certain ‘intermedes,’ or substances which have a joint affinity for the
colouring matter and the material to be dyed.
=SUCCIN′IC ACID.= C_{4}H_{4}O_{4}H_{2}. _Syn._ ACIDUM SUCCINICUM. _Prep._
From amber, in coarse powder, mixed with an equal weight of sand, and
distilled by a gradually increased heat; or from the impure acid obtained
during the distillation of oil of amber; the product in both cases being
purified by wrapping it in bibulous paper, and submitting it to strong
pressure, to remove the oil, and then resubliming it.
From malic acid, by fermentation, or by digestion with hydriodic acid in
sealed tubes.
_Prop., &c._ Colourless; inodorous (when pure); crystallises in oblique
rhombic prisms; soluble in 5 parts of cold and in 2-1/2 parts of boiling
water; fusible and volatile, without decomposition. Its salts are called
‘succinates,’ most of which are soluble. Succinate of ammonium is used as
a test for iron. Succinic acid is distinguished from benzoic acid by its
greater solubility, and by giving a brownish or pale red bulky precipitate
with ferric chloride in neutral solutions; whereas that with benzoic acid
is paler and yellower.
_Uses, &c._ Succinic acid is antispasmodic, stimulant, and diuretic, but
is now seldom used.——_Dose_, 5 to 15 gr.
=SUC′CORY.= Chicory, or wild endive. (See CHICORY.)
=SUDORIF′ICS.= See DIAPHORETICS.
=SU′ET.= _Syn._ SEVUM, SEBUM, L. This is prepared from the fat of the
loins of the sheep or bullock by melting it by a gentle heat, and
straining the liquid fat. In this state it forms the ADEPS OVILLUS (Ph.
D.), SEVUM (Ph. L. & E.), SEVUM OVILLUM, or SEVUM PRÆPARATUM, employed in
medicine and perfumery, as the basis of ointments, cerates, plasters,
pommades, &c.
=Suet, Mel′ilot.= _Syn._ SEVUM MELILOTI, L. _Prep._ From suet, 8 lb.;
melilot leaves, 2 lb.; boil until the leaves are crisp, strain, and allow
it to cool very slowly, so that it may ‘grain well.’ Used by farriers, and
to make melilot plaster.
=SUFFOCA′TION.= The treatment varies with the cause. See ASPHYXIA,
CHARCOAL, DROWNING, HANGING, SULPHURETTED HYDROGEN, &c.
=SUG′AR.= C_{12}H_{22}O_{11}. _Syn._ CANE SUGAR; SACCHARUM, L.; SUCRE, Fr.
This well-known and most useful substance is found in the juice of many of
the canes or grasses, in the sap of several forest trees, and in the roots
of various plants. In tropical climates it is extracted from the
sugar-cane (_Saccharum officinarum_), in China from the sweet sorgho
(_Sorghum saccharatum_), in North America from the sugar-maple (_Acer
saccharinum_), and in France, Germany, Russia, and Belgium, from white
beet-root (_Beta vulgaris_, var. _alba_).
Until of late years the ordinary sugar consumed in this country was that
chiefly sent from the West Indian Islands, South America, the Mauritius,
&c., and was the produce of the sugar cane; recently, however, large and
increasing quantities of beet-root sugar have found their way into the
English markets from the Continental factories.
The _Saccharum officinarum_, of which there are several varieties, the
sugar-cane ranges in height from 6 to 15 feet, and in diameter from 1 to 2
inches. In order to obtain the saccharine juice contained in it, the cane,
stripped of its leaves, is cut just before the commencement of
inflorescence, the period in which it is richest in juice. As this sap or
juice is found to abound most in sugar, when taken from the lower part of
the stem, the cane is cut off nearly close to the ground.
The stump which remains develops into a fresh plant, and one plant thus
treated will last several years, not, however, without a gradual
diminution in the size of the successive crops.
In South America and the West Indies a variety known as the Otaheita cane
is extensively cultivated, since it is very productive and yields a large
amount of juice.
The annual average produce in raw sugar for a hectare (about 2-1/4 English
statute acres) of land is in
Martinique 2000 kilos.[201]
Guadaloupe 3400 ”
Mauritius 4000 ”
Brazil 6000 ”
[Footnote 201: A kilo = 2·2046 lbs.]
Sugar-cane growing in the below-mentioned places has, according to the
analysis of the three chemists whose names are appended, the following
composition:——
(_a._) (_b._) (_c._)
Péligot. Dupuy. Icery.