6. (P. B. 1867.) Differs from the process of the Ph. L. 1836 in some
unimportant detail only.
7. (Dr Price.) The crude juice is saturated with ammonia, potassa, or soda
(carbonates), or with the ammoniacal product distilled from gas-liquor;
chalk, 150 parts, or hydrate of lime, 90 parts, are then added for every
192 parts of citric acid contained in the liquor, and the whole stirred
well together; heat is next applied, and the ammonia distilled into
another quantity of lemon juice; the citrate of lime thus obtained is then
decomposed with dilute sulphuric acid, and the whole process conducted as
before. When potassa or soda is used the distillation is omitted, and the
expressed liquor, after filtration, used to decompose fresh lemon juice.
8. (Ordinary manufacturing process.) To crude lemon or lime juice, mixed
with water, is added ground chalk; the precipitate is washed to free it
from the impurities dissolved in the water, and afterwards decomposed by
sulphuric acid. If the citric acid is not sufficiently white, it is
decolorised by digestion with animal black.
9. (Kuhlman.) This chemist proposes saturating the hot lemon juice as far
as possible with very finely divided barium carbonate, and afterwards
completing the neutralisation with barium hydrate or sulphide. The
precipitated barium citrate is then to be washed, and decomposed with the
requisite quantity of sulphuric acid. The advantage of barium over lime as
a precipitant is the more ready crystallisability of the citric acid from
the solution thus obtained. Sulphate of baryta is absolutely insoluble in
solution of citric acid, whilst sulphate of lime is not; and the presence
of the latter impedes the crystallisation of the acid.
_Obs._ If the lemon or lime juice be allowed to ferment a short time, the
mucilage and other impurities will, to a certain extent, separate and
subside. See _Concluding Remarks_.
_Prop., Uses, &c._ Citric acid forms rhomboidal prisms, which are clear,
colourless, odourless, sour, and deliquescent in a moist atmosphere. It is
an agreeable acid, at once cooling and antiseptic. It is much used in
medicine as a substitute for lemon juice, and to form effervescing
draughts, citrates, &c.
17 gr. citric acid, in crystals, or 1/2 fl. oz. of
lemon juice,
\---------------------v--------------------------/
are equivalent to
/----------^---------------\
25 gr. bicarbonate of potash;
20 " carbonate of potash;
15 " carbonate of ammonia;
20 " bicarbonate of soda;
35 " carbonate of soda.
The bicarbonate of potassa is that generally preferred for making saline
draughts with citric acid; and when flavoured with a little tincture of
orange peel and simple syrup, or syrup of orange peel alone, it forms a
most delicious effervescing beverage. Citric acid in pure crystals or in
lime juice is much used by the calico-printer, being the best known
'resistant' for iron and alumina mordants.
_Pur._ Citric acid is frequently met with adulterated with tartaric acid;
the fraud is easily detected by dissolving the acid in a little cold
water, and adding to the solution a small quantity of acetate of potash.
If tartaric acid be present, a white, crystalline precipitate of cream of
tartar will be produced on agitation. When pure it is devoid of colour, is
entirely, or almost entirely, decomposed by heat. It is soluble in water
and in spirit, and what is thrown down from its watery solution by acetate
of lead is dissolved by nitric acid. No salt of potassium precipitates
anything with citric acid except the tartrate. When a few drops of a
solution of citric acid are added to lime water, a clear liquid results,
which, when heated, deposits a white powder, soluble in acids without
effervescence. By the action of nitric acid citric acid is converted into
oxalic acid.
When the crystals of citric acid are very deliquescent, the presence of
free sulphuric acid may be suspected. This latter may be detected with
facility by dissolving the citric acid in a little water, strongly
acidifying the solution with hydrochloric acid, and adding chloride of
barium, when, if sulphuric acid be present, an insoluble precipitate of
sulphate of barium will fall down after a short time. Oxalic acid is
sometimes present in citric acid, the cause of its presence being
explained further on. To test for it proceed as follows:
Dissolve a small quantity of the citric acid in water, and add to the
solution an excess of ammonia; acidify with acetic acid, filter, and test
the filtrate with calcium sulphate.
_Estim._ See ACIDIMETRY and LIME JUICE.
_Tests._ See _above_.
_Concluding Remarks._ The preparation of citric acid has now become an
important branch of chemical manufacture, from the large consumption of
this article in various operations in the arts. In conducting the
different steps of the process some little expertness and care are,
however, necessary to ensure success. The chalk employed, which should be
dry, and in fine powder, is added to the juice from a weighed sample,
until the latter is perfectly neutralised, and the quantity consumed is
exactly noted. The precipitated citrate of lime is next thoroughly washed
with water, and the sulphuric acid, diluted with 6 or 8 times its weight
of water, whilst still warm, is poured upon it, and thoroughly mixed with
it. The agitation is occasionally renewed for 8 or 10 hours or longer,
when the solution of citric acid is poured off, and the residuum of
sulphate of lime thoroughly washed with warm water, the washings being
added to the liquid acid. This last is then poured off from the impurities
that may have been deposited, and evaporated in a leaden boiler, over the
naked fire, or by high-pressure steam, until it acquires the gravity of
1·13, when the process is continued, at a lower temperature, until a
syrupy aspect is assumed, and a pellicle appears on the surface of the
liquor. Without great care at this part of the process the whole batch may
be carbonised and spoiled. At this point the concentrated solution is
emptied into warm and clean crystallising vessels, set in a dry apartment,
where the thermometer does not fall below temperate. At the end of 4 days
the crystals are found ready for removal from the pans. They are
thoroughly drained, redissolved in as little water as possible, and after
being allowed to stand for a few hours to deposit impurities, again
evaporated and crystallised.
The acid of the second crystallisation is usually sufficiently pure for
the market; when this is not the case a third, or even a fourth,
crystallisation must be had recourse to. The mother-liquors from the
several pans are now collected together, and a second or third crop of
crystals obtained from them, by evaporation as before.
A frequent cause of difficulty in obtaining crystals from the solutions is
the employment of too little sulphuric acid to decompose the whole of the
citrate of lime; the consequence of which is that a little of that salt is
taken up by the free citric acid, and materially obstructs the
crystallisation. Forty parts of dry sulphuric acid are required to
decompose 50 parts of chalk. Commercial sulphuric acid (oil of vitriol) is
usually of the sp. gr. of 1·845, and it therefore requires 49 lbs. of this
acid for every 50 lbs. of chalk employed in the process. In practice it is
found that a very slight excess of sulphuric acid is preferable to a
preponderance of undecomposed citrate of lime.
The first crop of crystals is called 'brown citric acid,' and is chiefly
sold to the calico-printers. Sometimes a little nitric acid is added to
the solution of the coloured crystals, for the purpose of bleaching them,
but in this way a minute quantity of oxalic acid is formed. A more general
plan is to bleach the citrate of lime by covering it with a weak solution
of chloride of lime, exposing it in shallow vessels to the sun's rays, and
rewashing it before decomposing it with sulphuric acid. A safer plan is to
dissolve the crude citric acid, digest with animal charcoal, and again
concentrate the solution to the crystallising point.
When the aqueous solution of citric acid obtained, as already described,
is concentrated by boiling in an open evaporating pan, the acid is not
only liable to suffer partial decomposition by its long exposure to the
air, but it not unfrequently acquires a brown colour from the
carbonisation those portions of the liquid undergo which are in contact
with the bottom of the pan, which being heated by high-pressure steam
frequently reaches a temperature exceeding 200° F. This latter result is
brought about in consequence of the slight movement in the dense acid
liquor in the pan. To remedy the loss and inconvenience arising from the
employment of the open evaporating pan, some years back Mr Pontifex
devised an apparatus which effects the evaporation of acid liquor _in
vacuo_ (and therefore out of contact with air), and at a temperature never
exceeding 130 F°. Moreover, in Mr Pontifex's boiler the time necessary for
the concentration of the citric-acid liquor is diminished to about an
eighth, and as the strong ebullition keeps the liquid in constant motion
its charring is entirely prevented.
Mr Row says that lemon juice may be purified to a great extent by diluting
it with water until it contains about 12 oz. of acid to the gallon, and
then filtering from the flocculent precipitate of mucilage thus thrown
down. The citrate of lime obtained from juice so treated is comparatively
pure.
Good lemon juice yields about 6-1/2% of crystallised lemon acid; 2 galls.
yield fully 1 lb. of crystals. See LEMON JUICE, LIME JUICE. &c.
=CIT'RON.= The fruit of the citron tree (_Citrus medica_) is acidulous,
antiseptic, and antiscorbutic; it excites the appetite, and stops
vomiting; and, like lemon juice, has been greatly extolled in chronic
rheumatism, gout, and scurvy. Mixed with cordials, it is used as an
antidote to the manchineel poison.
=Citron, Oil of.= See OIL.
=Citron Peel.= This is prepared in the same way as candied orange and
lemon peel, which it for the most part resembles.
=Citron.= _Syn._ LEM'ON COLOUR. The term applied to a pale and delicate
shade of yellow. See YELLOW DYES, &c.
=CIT'RONELLE.= See LIQUEURS and OILS (Lemon-grass).
=CITRUS.= A genus of plants belonging to the natural order _Aurantiaceæ_,
the species of which yields useful fruits. From _Citrus Aurantium_, and
its varieties, all the various descriptions of sweet oranges are obtained.
The species _C. Bigaradia_ or _vulgaris_ yields the bitter or Seville
orange; _C. Limonum_ and its varieties, yield the lemons; _C. Limetta_ is
the source of the lime; _C. medica_ of the citron; _C. Decumana_ of the
shaddock; _C. paradisi_ of the forbidden fruit; _C. Pampelmos_ of the
Pampelmoose; and _C. japonica_ of the kumquat.
=Citrus Bergamia.= (Ind. Ph.) _Syn._ THE LIME TREE. _Habitat._ Commonly
cultivated in India and other tropical countries.--_Officinal part._ The
fruit (lime) closely resembles the lemon, but is smaller, with a smoother,
thinner rind, and of somewhat less fragrant odour. Its juice (lime juice)
has the same pungent acid taste, and contains the same ingredients as
lemon juice, though in somewhat different proportions, that of the citric
acid being larger and that of the mucilage less in quantity. Much of the
article imported into England under the name of lemon juice is obtained
from the lime.--_Properties and Uses._ Very similar to those of the lemon,
the juice being equally refrigerant and antiscorbutic; indeed, it is
preferred by many tropical practitioners.
The fresh juice of the lime is procurable in almost every portion of the
tropics, and is considered more effectual than preserved lemon juice.
Lime juice may be advantageously employed in the manufacture of citric
acid, the proportion of this acid being larger than in lemon juice.
=CIV'ET.= _Syn._ CIVET'TA ZYBETH'UM, L. A perfume obtained from the civet
cat (_Viverra civella_, Linn.), a fierce, carnivorous quadruped, somewhat
resembling a fox, found in China and the East and West Indies. The civet
is secreted in a sort of pouch between the anus and the sexual organs.
"Several of these animals have been brought into Holland, and afford a
considerable branch of commerce, especially at Amsterdam. The civet is
squeezed out in summer every other day, in winter twice a week; the
quantity procured at once is from 2 scruples to 1 drachm or more."
Civet is frequently adulterated with spermaceti and butter, and a similar
substance to civet, but of a darker colour, obtained from the polecat.
When pure it has an odour intermediate between that of musk and ambergris,
but less refined; a pale-yellow colour; an acrid taste; and the
consistence of honey. It is used in perfumery.
=CLAIRET.= See LIQUEUR.
=CLAR'ET RAGS.= _Syn._ TOURNESOL EN DRAPEAU, Fr.; BEZET'TA C[OE]RU'LEA, L.
1. Pieces of clean linen coloured with Auvergne--or ground archil.
2. Pieces of linen dipped into the juice of mulberries, blood-red grapes,
lees of red wine, &c. Used to colour jellies, confectionery, the rind of
cheeses, &c.
=CLARIFICATION.= The act of clearing or making bright; commonly applied to
the process of 'clearing' or 'fining' the liquids by chemical means,
instead of by filtration. The substances used for this purpose are
popularly known as 'clarifiers' or 'finings.'
The substances employed in the clarification of liquids operate by either
mechanically embracing the feculous matter, and subsiding with it to the
bottom of the vessel, or by inducing such a change in its nature or bulk
that it subsides by its own density, in each case leaving the liquor
transparent. Albumen, gelatin, the acids, certain salts, blood, lime,
plaster of Paris, alum, heat, alcohol, &c., serve in many cases for this
purpose. The first is used, under the form of white of egg, for the
clarification of syrups, as it combines with the liquid when cold, but on
the application of heat rapidly coagulates and rises to the surface,
carrying the impurities with it, forming a scum which is easily removed
with a skimmer. It is also much used for fining wines and liqueurs,
particularly the red wines and more limpid cordials. Gelatin, under the
form of isinglass, dissolved in water or weak vinegar, is used to fine
white wines, beer, cider, and similar liquors that contain a sufficient
quantity of either spirit or astringency (tannin), to induce its
precipitation. Sulphuric acid is frequently added to weak liquors for a
similar purpose, either alone or after the addition of white of egg or
gelatin, both of which it rapidly throws down in an insoluble form. A
pernicious practice exists among some unprincipled manufacturers of using
certain salts of lead and potash to clear their liquors; especially those
that are expected to sparkle in the glass, as 'cordial gin,' &c. For this
purpose a little sugar of lead, dissolved in water, is first mixed up with
the fluid, and afterwards a little more than half its weight of sulphate
of potassa, also dissolved in water, is added, and the liquor is again
'roused' up. By standing, the sulphate of lead, formed by this mixture,
subsides, and leaves the liquor clear. Bullock's blood is used in the same
way as isinglass or white of eggs, for fining red wines, beer, and porter.
Lime, alum, alcohol, acids, and heat, act by curdling or coagulating the
feculencies, and thus, by increasing their density, induce their
subsidence. Plaster of Paris acts, partly like the above, and partly like
albumen, or gelatin, by developing and forcing down the suspended matter.
Sand is often sifted over liquors (especially cordials and syrups), for
the simple purpose of acting by its gravity, but appears to be quite
useless, as it sinks too rapidly. The juices of plants are clarified by
heat, which coagulates the albumen they contain. Marl or clay is
frequently used to clear cider and perry. A strip of isinglass is
generally employed to clarify coffee. See WINE, BREWING, CORDIALS, COFFEE,
FININGS, INFUSION, &c.
=CLAY.= Clay is formed from the disintegration of felspathic rocks, by the
combined action of air and water. Its plasticity, when moist, and its
capability of being made hard by heat, are properties which render it
available for many useful purposes. The purest kind of clay is kaolin, or
China clay, which consists almost entirely of silicate of aluminum. It is
found in China; but a precisely similar substance is obtained from
deposits in Cornwall and some parts of France. Pipe-clay, a white clay
nearly free from iron, is found in large quantity in the island of
Purbeck. Potter's clay is found in many parts of Britain; that of
Devonshire and Dorsetshire is much valued. Brick clay contains varying
proportions of iron; hence the different colours of the bricks used in
different countries. See ALUMINUM, FULLER'S EARTH, OCHRE, &c.
=CLEAN'ING.= In domestic economy the best way to clean a house is to keep
it clean by a daily attention to small things, and not allow it to get
into such a state of dirtiness and disorder as to require great and
periodical cleanings. Some mistresses, and also some servants, seem to
have an idea that a house should undergo regular cleanings, or great
washing and scrubbing matches, once every three or six months, on which
occasions the house is turned almost inside out, and made most
uncomfortable. All this is bad economy, and indicates general slovenliness
of habits. (Chambers.) For hints upon cleaning, see CARPETS, CLOTHES, &c.
=CLEAN'LINESS.= See ABLUTION, BATHING, and SICKNESS.
=CLIPPING= (HORSES). Some horses should be worked in autumn in cloths, or
with their coats on, as, on account of the extra sweating thus caused,
they will be in better condition for the hunting season. Such horses
should be clipped or shaved. The horse's coat should be fully set before
it is clipped. Those horses which sweat much in autumn should be singed.
Singeing cannot be begun too early. The fresh growth must be removed every
week. Singeing may be best accomplished by means of gas.
=CLOTHES.= Economy and cleanliness require due attention to be paid to
every article of clothing, but more especially to those which are the most
exposed to dirt and the weather. The following remarks, having reference
chiefly to woollen articles, may prove useful to the reader:--If very
dusty, hang them on a horse or line, and gently beat them with a cane;
then lay them on a clean board or table and well brush them, first with a
stiff brush, to remove the spots of mud and the coarsest of the dirt, and
next with a softer one, to remove the dust and to lay the nap properly. If
clothes are wet and spotted with dirt, dry them before brushing them, and
then rub out spots with the hands. The hard brush should be used as little
as possible, and then with a light hand, as it will, if roughly and
constantly employed, soon render the cloth threadbare. Spots of
tallow-grease on the clothes may be taken off with the nail, or, if that
cannot be done, have a hot iron with some thick brown paper, lay the paper
on the part where the grease is, then put the iron upon the spot; if the
grease comes through the paper put on another piece, till it ceases to
soil it. Moths may be prevented attacking clothes by putting a few cloves
or allspice into the box or closet with them. See BALLS, CLOTHES, and
SCOURING, &c.
=CLO''THING.= In our changeable climate great care should be taken to
clothe the body effectually; for when the skin is chilled the blood is
determined in increased and injurious quantity to the internal organs,
causing colds and inflammations. The ordinary materials for clothing are
cotton, linen, woollen, and silk. Cotton is generally employed for
undergarments, for which its softness and warmth render it well adapted.
Linen is not nearly so warm, but it keeps its colour better; it is more
expensive, and although it wears much longer, it is not so economical as
cotton. Woollen garments are, in cold and variable climates, almost
essential to comfort; the warmth obtained by wearing flannel next the body
is very beneficial, and the slight stimulating effect arising from its
roughness tends to keep the skin in healthy action.
The practice of dressing infants in long clothes is a very objectionable
one, for besides being injurious to health it cramps the action of the
legs, the feet, and the toes, and by so doing prevents their proper and
healthy development.
An infant should be so clothed as to combine sufficient warmth with
perfect freedom of the limbs; hence his garments should be loose instead
of tight, more particularly round his waist.
In the selection of winter clothes for children, if for in-door wear,
choice should be made of a dark woollen frock, and of stockings in
preference to socks. The stockings should be of merino, and made to draw
above the knees and fastened to the dress with a loop and tape instead of
garters, which are very objectionable.
A child's out-of-door attire in winter should additionally comprise a warm
and properly-lined coat, made of cloth or some woollen fabric. It should
button close to the chin and cover his neck. Mr Chavasse says, for this
latter purpose a woollen neckerchief or scarf is preferable to furs. It is
very important that the child's feet and legs should be kept warm, but not
too warm. In infancy and childhood--in summer as well as winter--the
wearing of flannel next the skin is more necessary, and beneficial even,
than when practised by adults.
=CLOVE.= _Syn._ CARYOPH'YLLUM (B. P.), L. The flower-buds of the
_Ciryophyllus aromaticus_ (Linn.), or clove tree collected before they
open, dried, and smoked. Cloves are aromatic, stimulant, carminative, and
stomachic; and, according to some, possess febrifuge properties. They are
chiefly used as an adjuvant in compound medicines. A few cloves kept in a
closet or box prevent moths or mould attacking furs, woollens, &c.
It is a common practice to adulterate this spice in the same manner as
cinchona bark. Cloves from which the oil has been distilled are dried and
rubbed between the hands, previously moistened with a little sweet oil, to
brighten their colour, after which they are mixed up with fresh spice for
sale.
=Cloves, Mother of.= The unripe fruit of the clove tree; they are
frequently imported preserved (preserved mother of cloves), and are
reputed stomachic and antispasmodic.
=Cloves, Oil of.= _Syn._ O'LEUM CARYOPH'YLLI (B. P.), L. This possesses
similar virtues to the unexpanded flower-buds, and is esteemed as a remedy
for the tooth-ache. Used to flavour liqueurs and confectionery. Sp. gr.
1·055-1·060.
M. Jacquemin recommends the following as a very delicate test for the
presence of carbolic acid when used as an adulterant for oil of cloves.
One drop of the suspected oil is mixed with a small trace of solution of
aniline by means of a glass rod, and then shaken with 5 or 6 c. c. of
distilled water. By the addition of a few drops of sodium hypochlorite to
the mixture the characteristic blue coloration due to carbolic acid will
be developed in a few minutes, whereas with the pure oil nothing but the
purplish-violet colour of aniline will be perceived. Stirring or shaking
must be avoided after the addition of the hypochlorite.
=CLYS'TERS.= See ENEMA.
=COAL.= The varieties of this valuable substance may be conveniently
described under the three heads ANTHRACITE, LIGNITE, and PIT-COAL (which
_see_). See also FUEL.
=COAL-TAR.= Coal-tar, one of the products of the destructive distillation
of the coal employed in the manufacture of gas, is a very complex
substance, consisting of various hydrocarbons, acids, and bases, together
with certain resinoid and empyreumatic substances. The principal
hydrocarbons yielded by coal-tar on distillation are: benzol, toluol,
propyl, naphthalin, and anthracin; of these the first three are fluids,
and the last two solids; the most important acids are: carbolic, cresylic,
phlorylic, and nosolic; the chief bases are: aniline, chinoline, and
lepidine. The quantity as well as the quality of the tar obtained from the
distillation of coals varies considerably with the kind of coal used, as
well as with the temperature at which the distillation is carried on, the
yield of tar being smaller at very high temperatures than when lower ones
are employed. Coal-tar, from its antiseptic properties (due chiefly to the
carbolic acid it contains), is painted on wood to preserve the latter from
decay when exposed to wind and weather. Mixed with coal-dust, saw-dust,
and peat-dust, it forms a useful artificial fuel, and when incorporated
with pebbles makes an excellent artificial asphalt for pavements. The
chief value of coal-tar, however, consists in its being the source of
those brilliant dye-stuffs, the coal-tar colours. These, together with the
naphtha obtained from its distillation, have converted coal-tar from a
worthless and unwelcome waste product of gas manufacture--for the removal
of which from their premises the gas makers were formerly only too glad to
pay--into a very considerable and important branch of profit and revenue.
The different constituents of the tar are separated from each other by
distillation, the various products so obtained being further purified by
various processes.
See TAR COLOURS, NAPHTHA, BENZOL, ANTHRACENE, &c.
=CO'BALT.= Co. _Syn._ REG'ULUS OF COBALT; COBALT'TUM, L. A metal
discovered by Brandt, in 1733. It generally occurs in the same ore as
nickel, and the separation of the two metals is a task requiring great
patience and expertness. Speiss cobalt and cobalt glance are the ores from
which the metal is commonly extracted.
_Prep._ 1. Dissolve oxide of cobalt in hydrochloric acid, and pass
sulphuretted hydrogen gas through the solution, until all the arsenic is
thrown down; filter, and boil with a little nitric acid, then add
carbonate of potassium, in excess, and digest the precipitate in a
solution of oxalic acid, to remove any oxide of iron; wash and dry the
residuum (oxalate of cobalt), and expose it to great heat, in a covered
crucible lined with charcoal; the product is pure metallic cobalt.
2. Mix equal parts of oxide of cobalt or roasted Cornish cobalt ore, and
soft soap, and expose them to a violent heat in a covered crucible.
3. Pass hydrogen gas over oxide of cobalt strongly heated in a porcelain
tube.
_Prop., Use, &c._ Cobalt is a white, brittle metal; unchanged in the air;
feebly acted on by dilute hydrochloric and sulphuric acids; has a high
melting-point, and is strongly magnetic; sp. gr. 8·5. It is seldom
employed in the metallic state, from the great difficulty of reducing its
ores, but its oxide (black oxide) is largely employed in the arts. It
forms salts with the acids, which are interesting from the remarkable
changes of colour which they exhibit. See INK, SMALTS, ZAFFRE, and
_below_.
_Char., Tests._ Solutions of the salts of cobalt are known as follows:--1.
Ammonia gives a blue precipitate, slightly soluble in excess, giving a
brownish-red colour.--2. Potassa gives a blue precipitate, turning to
violet and red when the solution is heated.--3. Carbonate of ammonium and
carbonate of sodium give pink precipitates; that from the former is
soluble in excess.--4. Cyanide of potassium gives a yellowish-brown
precipitate, soluble in excess; and the clear solution, after being
boiled, is unaffected when mixed with hydrochloric acid.--5. Sulphuretted
hydrogen produces no change in acid solutions.--6. Sulphydrate of ammonium
gives a black precipitate in neutral solutions.--7. Melted with borax,
before the blowpipe, it gives a bead of a magnificent blue colour, almost
verging on black, if much is present. Phosphate of sodium and ammonium
give a similar bead; but the colour is less intense.
=Cobalt, Ac'etate of.= Co(C_{2}H_{3}O_{2})_{2}. _Prep._ From the carbonate
or protoxide and acetic acid. It forms a sympathetic ink which turns blue
when heated.
=Cobalt, Arseniate of.= Co_{3}2AsO_{4}, 8H_{2}O. A hydrated native
tricobaltous arseniate of cobalt, known as "cobalt bloom."
=Cobalt, Car'bonate of.= CoCO_{3}. _Prep._ By adding an alkaline carbonate
to a solution of the nitrate or sulphate. A pale peach-coloured powder,
soluble in acids. It contains some hydrate.
=Cobalt, Chlo''ride of.= CoCl_{2}. _Syn._ HYDROCHLO''RATE OF C., MU''RIATE
OF C. _Prep._ By dissolving the carbonate or protoxide in hydrochloric
acid; the solution deposits deep rose-red crystals on standing, which
contain water. By evaporating the solution by heat, anhydrous blue
crystals of the chloride are obtained. Both of them yield a deep rose-red
solution with water, which is turned green by a little acid. This solution
forms a well-known sympathetic ink, the traces of which become blue when
heated. If the solution contains either chloride of iron or chloride of
nickel, the traces become green. (Klaproth.) The addition of a little
nitrate of copper to the above solution forms a sympathetic ink, which by
heat gives a very rich greenish-yellow colour. (Ure.) The addition of a
very little common salt makes the traces disappear with greater rapidity,
on the withdrawal of the heat. In each case, when the paper is laid aside,
moisture is absorbed, and the writing once more disappears. If, however,
much heat has been used the traces become permanent.
=Cobalt, Ni'trate of.= Co(NO_{3})_{2}. _Prep._ As the last, substituting
nitric for hydrochloric acid; it forms deliquescent crystals.
=Cobalt, Ox'alate of.= CoC_{2}O_{4}. _Prep._ As the acetate, from oxalic
acid and the carbonate or protoxide; or by double decomposition.
=Cobalt, Ox'ides of.= Of these there are two, the protoxide and the
sesquioxide; besides an acid compound of cobalt and oxygen, to which the
name cobaltic acid has been given.
1. =Cobalt, Protox'ide of.= CoO. _Syn._ OXIDE OF COBALT, GREY O. OF C.,
BLACK O. OF C., COBALT BLACK. _Prep._ 1. By precipitating a solution of
sulphate of chloride of cobalt with carbonate of sodium, and washing,
drying, and igniting the powder which subsides.
2. By boiling powdered bright-white cobalt ore (from Cornwall) in dilute
nitric acid, and adding a solution of carbonate of potassium, very
gradually, until the clear liquor, after the impurities have settled,
becomes of a rose colour; and then as long as a precipitate falls; wash
and dry it as before.
_Prop., &c._ A grey powder, turning black on exposure to the air; strongly
basic; and forming salts with the acids, having a fine red tint. It is
remarkable for the magnificent blue colour it communicates to glass, and
by this character its presence may be readily detected before the
blowpipe; the substance to be examined being fused with borax on a loop of
platinum wire. Used to make blue colours for painters, stains and glazes
for enamellers, glass-melters, potters, &c. In _medicine_ it has
occasionally been given as a remedy for rheumatism.
2. =Cobalt, Sesquiox'ide of.= Co_{2}O_{3}. _Syn._ PEROX'IDE OF COBALT. A
black, insoluble, neutral powder, obtained by mixing solutions of cobalt
and of chloride of lime; or, by heating the protoxide to redness in an
open vessel.
=Cobalt, Phos'phate of=. Co_{3}(PO_{4})_{2}. _Prep._ As the acetate,
substituting phosphoric for acetic acid. An insoluble purple powder,
which, when heated along with eight times its weight of gelatinous
alumina, produces a blue pigment (COBALT BLUE, COBALT ULTRAMARINE), almost
equal in beauty to ultramarine. (See _below_.)
=Cobalt, Sul'phate of.= CoSO_{4}. By boiling sulphuric acid on the metal,
or by dissolving the oxide in the acid. It forms reddish crystals, soluble
in 24 parts of water.
=Cobalto-Ultramarine.= A fine blue pigment, prepared by mixing freshly
precipitated alumina, 8 parts, with phosphate or arseniate of cobalt, 1
part; drying the mixture, and then slowly heating it to redness. By
daylight the colour is pure blue, but by artificial light it is violet.
See BLUE PIGMENTS.
=COCA. Erythroxylon Coca.= This plant is grown largely in Peru and
Bolivia. The Bolivian coca is said to be much superior to the Peruvian.
The best kind is believed to come from the province of Yungas, and the
most inferior description from Peru. The consumption of Coca in Peru,
Bolivia, and in some of the provinces of the Argentine Confederation
is enormous. In small doses it is supposed to act as a stimulant and to
aid digestion; in large ones it is said to possess dangerous narcotic
properties. The mountaineers in South America state they are enabled to
reach high elevations without difficulty of respiration, and to stave off
the feeling of hunger by chewing the leaves during their ascents. "Good
quality coca should have its leaves unbroken, of a medium size, bright
green in colour, and of an odour somewhat combining that of hay and
chocolate. The taste is bitter, and when masticated, coca is said to yield
easily to the teeth. Infused in hot water, it has a beautiful green
colour, which, however, is much darker from inferior leaves. An infinite
number of varieties are recognised between the best and the lowest
quality, which has a disagreeable smell and a colour resembling roasted
coffee. The leaves are also bent and broken, scarcely a whole leaf being
found amongst them."[249] The statements as to the effects of coca are
conflicting, as will be seen from what follows:--Sir R. Christison,
writing to the 'British Medical Journal,' April 29th, 1876, states he was
hardly sensible of the fatigue of two mountain descents made from Ben
Vorlich after chewing coca leaves. That, as a consequence of his doing so,
hunger and thirst were suspended for a long time, but that eventually
appetite and digestion were unaffected. He made trial during the first
descent of 60 grains, and of the second, undertaken eight days after, of
90 grains of coca.
[Footnote 249: 'Pharmaceutical Journal.']
Mr Dowdeswell, in a communication to the 'Lancet,' May 6th, 1876, says
that, contrary to the experience of Sir R. Christison, he found no decided
effects produced after consuming nearly a pound of the leaves, which were
taken in all forms and at all hours for nearly a month. They failed to
produce the slightest excitement, not giving rise even to the feeling of
buoyancy and exhilaration which is experienced from mountain air or a
draught of spring water.
In the 'Canadian Pharmaceutical Journal' for August, 1877, there is a
paper by Mr Shuttleworth, wherein results the opposite to those of the
last-named gentlemen are recorded. Mr Shuttleworth states that the members
of a club established at Toronto for the purpose of playing at La Crosse,
a very violent and fatiguing pastime, were almost unanimous in ascribing
their invariable success over their numerous adversaries to the use of
coca leaves during their contests; their opponents not employing the
plant. The antagonists of the club were men of stronger build and physique
as well as more accustomed to out-of-door pursuits, and were besides
trained players.
The same writer says that in South America care is taken to procure the
leaves in as fresh a state as possible, and that many writers have
ascribed the want of effect to old leaves.
The 'British Medical Journal' of March 10th, 1877, contains a
communication from Dr T. McBean, who states that he has found the
administration of coca leaves useful in typhoid fever, as well as in other
febrile diseases.
=CO'COA= (k[=o]'-ko). _Syn._ CACA'O. An alimentary substance formed of the
roasted seeds of the _Theobroma Cacao_, a tree belonging to the natural
order _Byttneriaceæ_. This definition is equally applicable to chocolate,
but we commonly class the preparations containing sugar and flavouring
substances under that head, and the unsweetened and cheap preparations
under COCOA. The cocoa-seed or berry must not be confounded with the
cocoa-nut, which is the fruit of a palm (_Cocus nucifera_). The cocoa tree
is a native of Mexico, and is now more or less extensively grown
throughout Central America, Brazil, Peru, Venezuela, Caraccas, Ecuador,
Grenada, Demerara, Essequibo, Guayaquil, and Surinam; with some of the
West India Islands, foremost among which stands Trinidad. It has also been
introduced with more or less success into Africa, the Mauritius,
Madagascar, Bourbon, the East Indies, Australia, and the Philippine
Islands. The following is a list of the principal kinds of cocoa, in the
order of their commercial value:--Caraccas, Surinam, Trinidad, Grenada,
Jamaica, Dominica, Guayaquil, Venezuela, Bahia, Brazil, St. Lucia. It
seems probable that some of the highest kinds of cocoa do not find their
way into this country, but are consumed by the inhabitants of Spain.
_Prep._ The pods containing the seeds are gathered when ripe, and after
having lain for a day and a night are opened, and the seeds, which are
taken out by hand, are submitted to what is termed the sweating process.
They are first placed on a sloping floor or in baskets, so that the chief
part of the pulp in which they are enveloped may drain off, and are then
shut up in a close box, and left for 24 to 48 hours, according to the
season and weather, after which they are turned out in the sun to dry.
Upon a nice performance of the sweating process, which may be likened to
malting, the value of the cocoa greatly depends. When quite dry, the seeds
are packed in barrels or bags, and are ready for shipment. The process of
roasting is effected in a metal cylinder, with holes at each end, through
which the vapour generated is allowed to escape. When the aroma is
sufficiently developed the seeds are cooled, and then passed to a 'kibling
mill,' which removes the husks and skins from the 'nibs' (see _below_).
_Prop., Constituents, &c._ Cocoa, when unadulterated, forms a wholesome
and highly nutritious beverage. Its active principle is theobromine, an
alkaloid greatly resembling caffeine, the active principle of coffee and
tea. A peculiar concrete oil, called cocoa-butter, or, more correctly,
butter of cacao, is another important constituent, forming more than half
the weight of the seed. The presence of about 20% of albumen gives to
cocoa its nutritive character.
_Average composition of cocoa seeds._--(Wanklyn.)
+-------------------------------+-----------+
| | Per cent. |
| Fat (cocoa butter) | 50·00 |
| Albumen, fibrine, and gluten | 18·00 |
| Starch | 10·00 |
| Gum | 8·00 |
| Colouring matter | 2·60 |
| Water | 6·00 |
| Theobromine | 1·50 |
| Ash | 3·60 |
| Loss | 0·30 |
+-------------------------------+-----------+
| | 100·00 |
+-------------------------------+-----------+
Dr Letheby calculated that a pint of cocoa made with 1 oz. of ground nibs
would contain the following proportions of nutritious matters:--
+-------------------------------+--------------+
| Nitrogenous matters | 96·2 grains |
| Patty matter | 218·8 " |
| Gum, sugar, and extractive | 65·6 " |
| Mineral matters | 17·5 " |
+-------------------------------+--------------+
| Total extracted | 398·1 |
+-------------------------------+--------------+
_Adult._ Much of the cheap stuff sold as genuine cocoa is shamefully
adulterated. Out of 68 samples of cocoa and chocolate examined by the
'Lancet' commission, 39 contained coloured earthy substances, as reddle,
Venetian red, umber, &c. To some, chalk or plaster of Paris had been
added, for the purpose of increasing the weight. Many of the samples
consisted of sugar and starch, with only sufficient cocoa to impart a
flavour. Cocoas containing a moderate amount of arrow-root or other starch
must not be considered adulterated articles, for it is impossible to
render cocoa soluble, or rather emulsive, without the addition of some
diffusible substance.
[Illustration]
[Illustration]
[Illustration]
By an examination of the ash the presence of any mineral adulterant may be
detected. Mr Blyth says the amounts of ash in genuine cocoa should never
exceed 5 per cent. The seed of the cocoa consists of husk and seed proper.
Under the microscope the husk exhibits on its surface a number of tubular
fibres, filled with granular matter and minute corpuscles. It consists of
three membranes; the first being a single layer of elongated cells; the
second (forming the chief portion of the husk) of angular cells, enclosing
mucilage, and also containing a few spiral vessels and woody fibres. The
third membrane is very thin and delicate, and is made up of small angular
cells containing minute globules of fat. The seed is composed of minute
cells containing starch. The starch corpuscles are very small, with a
trace of inulin. (See cuts on previous page.)
=Cocoa, Flake.= This is formed by grinding the nibs in a mill, consisting
of two cones, working one inside the other. Pure flake cocoa is not a
diluted or amalgamated article; in other words, it contains no sugar, and
but a trace of starch.
=Cocoa Nibs.= The bruised, roasted seeds, freed from husk and membrane.
They ought to be of a dull-red or greyish colour, but are frequently given
a bright-red colour by a coating of Venetian red.
=Cocoa, Sol'uble.= From cocoa nibs and substances which are readily
soluble or diffusible in water, ground together. Sugar and sago or
arrow-root are the diluents used by respectable makers, but all kinds of
starches, coloured with Venetian red, are used for the trashy articles
which are sold to the poor. No form of cocoa is really soluble, but by the
addition of easily diffusible substances an article is produced which is
capable of forming an emulsion with boiling water. The following are the
principal varieties of the so-called soluble cocoa:--
1. COCOA, GRANULATED. From cocoa nibs and sufficient sugar and arrow-root
to keep the fatty particles from forming a pasty mass. As it is impossible
to granulate the nibs without the admixture of some other substance, those
makers who declare that their granulated cocoas are perfectly pure do not
act honestly towards their customers.
2. COCOA, HOM[OE]OPATHIC. A kind of soluble cocoa prepared with
arrow-root, but without sugar.
3. COCOA, ICELAND-MOSS. From cocoa and Iceland moss, freed from its bitter
principle, cetrarine. This form of cocoa was introduced by Messrs Dunn and
Hewett, and is said to form a very valuable article of diet for invalids.
4. COCOA, MARAVILLA. This is stated to be "the perfection of prepared
cocoa." It consists of cocoa, sugar, and sago flour, the last two being in
great excess.
5. COCOA, CARACCAS. This is similar to the last, being a mixture of cocoa,
sugar, and sago flour. The cocoa used in its manufacture is said to be
imported from the Caraccas, on the north coast of South America, and to
possess a peculiarly delicious flavour.
The amount of flour or starch in these so-called soluble cocoas frequently
exceeds 40 per cent., and the amount of sugar 20 per cent. They have been
not inaptly called "soups."
Within the past year or two a new variety of soluble cocoa has been
brought into the market. It is sold under various names, thus,
'Theobromine, or Concentrated Cocoa,' 'Cocoa Essence,' 'Cocoatina,' &c. We
have examined many of these varieties, and find them to consist of pure
cocoa deprived of about two thirds of its fat. It appears very suitable
for people of weak digestion.
_Obs._ No warm drink that we take approaches cocoa in its nutritive
character, because, while performing to a certain extent the exhilarating
work of coffee or tea, it presents to the stomach a very considerable
quantity of nitrogenous and carbonaceous matter; this advantage is partly
due to the fact that cocoa is taken in the form of an emulsion, instead of
an infusion or decoction.
COCOA FOR THE TABLE is readily prepared from the soluble varieties by
simply pouring boiling water upon the powder. From cocoa nibs, or flaked
cocoa, the beverage is prepared by first pouring boiling water upon them,
and then allowing the mass to simmer from 4 to 6 hours. The cocoa must on
no account be allowed to boil, for in that case a coagulum will be formed,
which cannot be dissolved in water.
=COCOA-NUT OIL.= A species of vegetable butter obtained from the common
cocoa nut--the fruit of _Cocos nucifera_, the cocoa palm. It is separated
from the dried kernel by hydraulic pressure. It contains olein, and a
solid fat often used as a candle material. Large plantations of the cocoa
palm, connected with Price's candle company, exist in Ceylon. Cocoa-nut
oil is often confounded with cocoa- or cacao-butter, which is the produce
of a very different plant, namely, _Theobroma cacao_. See COCINIC ACID,
COCOA, STEARIC ACID, &c.
=COC'CULUS IND'ICUS.= _Syn._ INDIAN BERRIES, INDIAN COCKLES, LEVANT NUT,
LOUSE GRAINS; BAC'CA ORIENTA'LIS, COCOULUS PISCATOR'IUS, &c., L. The fruit
of the _Anamirta paniculata_, a shrub which abounds on the sandy shores of
Malabar, and several other islands in the Indian Ocean. The kernels should
fill at least two thirds of the fruit.
It is a dark, tough, hard, wrinkled berry, about the size of a cherry, and
possesses an intensely bitter taste. The berry consists of two parts, the
husk and the kernel, the former being hard and difficult to bruise, and
the latter soft and containing a large proportion of fatty matter.
_Uses, &c._ Cocculus indicus is poisonous to all animals, and to most
vegetables. It is never employed internally in medicine, but an ointment,
formed by mixing the powder with lard, has been used to destroy pediculi
and in porrigo. Its active principle is picrotoxin, a peculiar
needle-shaped, crystalline substance, possessing all the poisonous
properties of the berry in an exalted degree, and of which it contains
about 2 per cent. Its effects on the system are, to produce giddiness,
convulsions, and insensibility, frequently ending in death. A small
portion of the cocculus indicus imported is used by poachers, and a still
smaller quantity to destroy vermin, the remaining, and by far the greater
part, being employed to adulterate beer and even wine. "In our own
analytical experience we have seldom found this substance in beer
purchased from a respectable house. We have detected it, however, in beers
purchased in the lowest localities in London and elsewhere, but have every
reason to suspect that the adulterants had been added by the publican
himself, in the form of an extract known in the trade by the name of 'B.
E,' or black extract." (Harkness.)
Chemists and druggists are liable to severe penalties if they are found
supplying cocculus indicus, or any extract of the same, to brewers or
publicans. See BEER, PORTER, &c.
=COCH'INEAL.= _Syn._ COC'CUS (B. P.), L. GRANA FINA, Span. The _Coccus
Cacti_ (Linn.), an insect found upon the cactuses of Mexico. It is of
great value as a dye stuff. The female insects, when matured, are brushed
off the plants and dried by artificial heat. The entire insect is used.
There are two varieties known in commerce--silver cochineal, which has a
purplish-grey or silver-grey colour; and black cochineal, which is
smaller, and of a reddish or purplish-black colour. The former is that
commonly met with.
_Adult._ Genuine cochineal has the sp. gr. 1·25. It is commonly increased
in weight by slightly moistening it with gum-water, and then rouncing it
in a bag, first with sulphate of baryta, and then with finely powdered
bone-black. In this way its sp. gr. is raised to 1·35, in consequence of
being loaded by about 12% of useless foreign matter.
Herr Durwell, a German chemist, states that he found a sample of cochineal
adulterated with sulphate of zinc. He thinks the sophistication was
probably effected by immersing the cochineal in sulphate of zinc, and then
in an alkali, whereby the white pulverulent aspect of the genuine article
was imparted, and the weight increased.
The following is a method which has been given for estimating the value of
samples of cochineal:--Grind the samples to be tested to a fine powder,
weigh out 2 or 2-1/2 grammes, and boil this amount in a capacious
narrow-necked flask, with 750 c. c. of water for 1 hour; filter
immediately through dry paper filters, and allow it to cool. To test it 50
c. c. are measured in a flask of that capacity, and poured into another
flask of about 200 c. c., and the measuring vessel rinsed with a definite
quantity of water, say 10 to 15 c. c. A weak solution of permanganate is
then run in from a burette with a glass cock, the flask being shaken after
the addition of every 10 c. c. So much permanganate solution is then added
that the cochineal extract shall be charged from its original colour to a
pink of the faintest shade--almost yellow, in fact, but never reaching a
full yellow. This pink shade should be persistent, that is, it should not
turn yellow after standing fifteen minutes; and after a little practice it
will be found very easy to obtain the tinge, which shows that the
colouring matter is almost but not quite destroyed.
When a number of samples are to be compared, arrange an equal number of
200 c. c. flasks and test-tubes on the table, a tube standing in its rack
in front of each flask. Then the same number of c. c. of the permanganate
solution (which should be, at least, so weak that bulk for bulk of this
and the cochineal solution will be required) is run into each flask,
taking care to use too little to completely destroy the colouring matter
in _all_.
The flasks are well shaken and allowed to stand for ten minutes. Part of
the contents of each is then poured into the corresponding test-tube, and
a glance of the tubes as they stand side by side will show which is the
least affected by the bleaching liquid. This sample having been selected
to serve as a standard, the contents of the test-tube are returned to the
flask, and more permanganate solution is cautiously added, until a very
faint pink tinge, which a fraction of a c. c. will turn to a full yellow,
is obtained. The number of c. c. used having been noted, a fresh trial is
made, in which the c. c. required, minus one, are used, the flask
agitated, and the last c. c. or part of it, as the whole may not be
necessary added.
If the two results agree, the next sample is treated in the same way, and
so until all are tested.
A final trial may be made by measuring 50 c. c. of each solution into its
flask, running in the permanganate in the ascertained amount into each as
quickly as possible, letting the flasks stand ten minutes, and then making
a comparison of all in the test-tubes. If the shades are not exactly
alike, a pretty good guess can generally be made of the fractions of c. c.
required, which should be added, the contents of the tubes being joined to
that in the flasks, and a second or third comparison thus made.
This is a rather long description of what is in practice a very simple and
good process, the three principal points to be borne in mind being--
1st. To use a weak solution of permanganate.
2nd. To have a very faint pink colour as a standard of comparison.
3rd. To let the liquids remain after agitation together ten or fifteen
minutes before comparing them.
_Uses, &c._ Cochineal is principally used to prepare lake and carmine, and
in dyeing. Its colouring principle is freely soluble in water. It imparts
every variety of scarlet and crimson to textile fabrics previously
prepared with alum, tin, and other mordants. It is also used to colour
liqueurs, tinctures, and confectionery. It has been recommended as an
antispasmodic and anodyne, in hooping-cough and neuralgia.--_Dose_, 10 to
60 gr., in powder, confection, or tincture. See CARMINE and CARMINIC ACID.
=COCIN'IC ACID.= _Syn._ COCOSTEAR'IC ACID. A crystalline, fatty acid,
obtained by the saponification of COCOA-NUT OIL. See STEARIC ACID.
=COCK-METAL.= _Syn._ POT METAL. Copper, 20 lbs.; lead, 8 lbs.; litharge, 1
oz.; antimony, 3 oz. Another variety consists of copper, lead, and
sometimes a little zinc.
=COCKROACH.= See BLATTA.
=COD.= _Syn._ GA'DUS MOR'RHUA (Ph. L.), MOR'RHUA VULGARIS (Linn.),
ASEL'LUS (Pliny), L. A fish common in the seas of the northern hemisphere,
from about 40° to 75° of latitude. The flesh forms a most wholesome and
excellent article of food. The best fish are very thick about the neck;
and, when fresh, are marked by the redness of the gills, freshness of the
eyes, and the whiteness and firmness of the flesh. The fish so largely
imported from Newfoundland (NEWFOUNDLAND FISH) are cod beheaded, split
open, gutted, and salted. They are caught by millions on the 'Grand Bank.'
COD-SOUNDS are pickled in brine and also made into isinglass. The spawn is
made into CAVIARE, and the liver is both pressed and boiled for its oil
(see _below_).
COD IS GENERALLY COOKED by boiling it, but is sometimes baked, or cut into
slices and broiled or fried. Cod's head and shoulders with oyster sauce is
a favorite dish. Shrimp and anchovy sauce are also good additions.
=COD-LIV'ER OIL.= _Syn._ MOR'RHUÆ O'LEUM, B. P.; O'LEUM JECOR'IS ASEL'LI,
L.; HUILE DE MORUE, Fr. The oil obtained from the liver of the common cod
(_oleum e jecore comparatum_).
_Prep._ 1. The livers, being removed from the fish, are piled on layers of
fir-twigs placed in tubs perforated at the bottom, and are allowed to
remain for a considerable time exposed to the sun and air. As the livers
putrefy, the oil runs out and flows through the holes in the tubs into
vessels placed to receive it.
2. The partially decomposed livers, cut into pieces, are heated in iron
pots without water, and the oil is poured off and set aside to deposit
impurities.
3. (Savory.) The livers taken from the fresh fish are carefully washed.
The large veins are then divided through their whole length, and any blood
in them is carefully rinsed away. The livers are now cut into pieces,
again washed and drained, and afterwards placed with a small quantity of
water in vessels gently heated by steam. As the heat increases, the oil
separates and rises to the surface, from which it is skimmed off; and
after well cooling, to allow the deposit of some of the margarin, it is
repeatedly filtered through flannel bags and finally through paper. This
process gives a fine, clear, straw-coloured oil, having but a slight smell
and taste.
4. (Donovan.) The perfectly fresh livers are placed in a metallic vessel
and heated with constant stirring to 180° Fahr., by which treatment they
break down into a uniform pulpy, liquid mass. This mass is immediately
transferred to calico bags, whence the oil drains out; after filtration,
while still warm, this oil is sufficiently pure for use.
_Obs._ Three kinds of cod-liver oil are usually distinguished--the pale
yellow, pale brown, and dark brown. The latter is the most impure; its
odour and taste are extremely disagreeable. The most conflicting opinions
have been expressed by medical men as to the relative value of the light
brown and yellow varieties. Ozonised cod-liver oil is said to be prepared
by passing oxygen into the oil, and then exposing it to sunlight. Dr
Letheby applied the most delicate tests to this much-vaunted remedy, but
was not able to detect the slightest trace of ozone.
_Prop. and Uses._ Cod-liver oil has acquired much reputation for its
remedial powers in pulmonary consumption, scrofulous and other glandular
affections, chronic gout and rheumatism, certain skin diseases, and
several other ailments. It is generally supposed that the iodine and
bromine, which are present in minute quantities in this fish, are the
substances to which it owes its efficacy. "Dr De Jongh refers its virtues
to the presence of both iodine and the elements of the bile. Our own
researches lead us to infer that one of its most active constituents is
free phosphorus. Good cod-liver oil contains fully ·02 of this substance,
as well as about ·09 of phosphoric acid. Now, the marked action of minute
doses of phosphorus on the nervous, vascular, and secreting organs, is
well known to every experienced surgeon. The difficulty, however, of
bringing it into a form adapted for administration has hitherto prevented
phosphorus being extensively employed as a therapeutic agent. This
obstacle is removed by the employment of cod-liver oil. Nature has here
provided a simple remedy, which the ingenuity of man has failed to produce
artificially. This opinion is borne out by the facts, that cod-liver oil
cures those forms of scrofula and other diseases which do not yield to
iodine, and that those varieties of the oil are the most active which
contain the most free phosphorus. We, therefore, think it reasonable to
conclude, that the efficacy of cod-liver oil depends on the joint action
of the minute quantities of iodine, phosphorus, and the elements of the
bile which it contains, and not on any one separately; and that no
substance, at present known, can be used as a substitute for it."
(Cooley.)--_Dose_, 1 to 8 dr., in water, syrup, or orange juice; or made
into an emulsion with 1 fl. oz. of peppermint water.
M. Duquesnel states that cod-liver oil flavoured with essence of
eucalyptol, in the proportion of one part of the essence to a thousand,
has neither the taste nor the odour of cod-liver oil. It is taken with
facility, only leaving at the back of the mouth and on the tongue the
taste of the essence. M. Duquesnel adds that the offensive eructations
arising from cod-liver oil are completely corrected.
=Cod-liver Oil Jelly.= Take of cod-liver oil, 85 parts; isinglass, 3
parts; sugar, 8 parts; water, 4 parts. It forms a semi-transparent jelly
of a yellowish-green colour, having a strong odour, but less strong taste
of the oil. The advantages of this preparation are--its easy
administration, complete retention, and assimilation by the weakest
stomach. A teaspoonful is said to be equal to a tablespoonful of the
ordinary oil. A lemon flavour may be imparted to it with advantage if
desired.
=Cod-liver Oil and Lacto-Phosphate of Lime.= (Shinn.) Cod-liver oil, 1
pint; oil of bitter almonds, peppermint, and winter green, of each 10
drops; powder of gum Arabic 4 oz.; sugar, 6 oz.; solution of
lacto-phosphate of lime (60 gr. to 1 fl. oz.), 6-1/2 fl. oz.; lime water,
6-1/2 fl. oz. Mix the gum and sugar in a capacious mortar, and make a
smooth mucilage with the lime water and 3 oz. of the solution of
lacto-phosphate of lime. Add the volatile oils to the cod-liver oil, and
gradually triturate them with the mucilage, until a perfect emulsion is
formed. Finally, add the rest of the solution of the lacto-phosphate of
lime, and mix thoroughly. The solution of lacto-phosphate of lime is made
by saturating a solution of lactic acid with freshly precipitated
phosphate of lime.
=Cod-liver Oil with Iodide of Iron.= Triturate iodide of iron, with
cod-liver oil, 4 gr. to the ounce, until dissolved. HORSLEY'S patent is as
follows:--Dissolve 22 scruples of iodine in a gallon of cod-liver oil, at
a temperature of 140° Fahr., in a water-bath. Add to the solution 8
scruples of iron (reduced by hydrogen), and heat to 180° Fahr., until the
combination is complete.--_Dose_, 1 dr. to 1/2 oz.
=Cod-liver Oil, Phosphorated.= (Lancet.) Pure unoxidised phosphorus, 2
gr.; almond oil, 2 oz. Put into a bottle, stoppered, and immerse the same
in a water-bath; apply heat until the temperature of the oil is about 180°
Fahr., as directed by the B. P., in the preparation of _oleum
phosphoratum_; shake up occasionally, and again put the bottle into the
water if necessary, until a perfect solution is obtained; then add about
10 oz. of cod-liver oil, and again immerse in the water-bath; finally,
make up the measure with cod-liver oil to 25 oz. One drachm so prepared
will contain over the 1/100th of a grain of pure phosphorus.
=Cod-liver Oil, Emulsion of.= Cod-liver oil, 8 fl. oz.; tragacanth, 1 dr.;
powdered white sugar, 4 dr.; oil of gaultheria, 9 drops; oil sassafras, 1
drop; oil bitter almonds, 10 drops, water, 8 oz. Dissolve the tragacanth
and sugar in water, and strain. Add to this first the essential oils, and
then incorporate the cod-liver oil.
=Cod-liver Oil and Hypophosphites, Emulsion of.= (Canadian 'Pharmaceutical
Journal'). Powder of gum tragacanth, 1/2 oz.; glycerin, 3 oz.; water, 9
oz. Rub the tragacanth with the glycerin, and add the water gradually. To
this mucilage add the following solution:--Hypophosphite of lime, 4-1/2
dr.; hypophosphite of soda, 2-1/4 dr.; hypophosphite of potash, 2-1/4 dr.;
sugar, 3/4 lb.; boiling water, 12 oz. Make the admixture gradually with
brisk trituration. To this medicated mucilage add the following:--Otto of
almonds, bitter, 10 drops; otto of cinnamon, 5 drops; otto of canella, 5
drops; alcohol, 6 oz. The whole will now form a semi-transparent
mucilaginous liquid of about 37 fl. oz. in bulk. To this add gradually an
equal measure of cod-liver oil, and mix thoroughly. In practice it is
advisable to work on small quantities, say half a pint of each in a No. 8
mortar. If care is taken the product will be very satisfactory.
=CODE'IA.= C_{18}H_{21}O_{3}. Aq. _Syn._ CODE'INE. An alkaloid discovered
by Robiquet associated with morphia.
_Prep._ Dissolve commercial hydrochlorate of morphia in water, and
precipitate the morphia with ammonia. Codeia is left in solution, and is
obtained in octahedral crystals by spontaneous evaporation. It may be
further purified by solution in ether. By the addition of a little water
to the ethereal solution and spontaneous evaporation it may be obtained
quite pure and in a crystalline state.
_Obs._ The morphia may be recovered by digesting the precipitate in weak
solution of potassa.
_Prop., &c._ Freely soluble in alcohol and ether; soluble in 80 parts of
cold and 17 parts of boiling water. Its solution in the latter, by slow
evaporation, yields large, transparent octahedra. With the acids it forms
crystallisable salts. These possess the singular property of producing a
general and violent itching of the surface of the body when administered
internally. The same symptoms frequently follow the exhibition of opium
and hydrochlorate of morphia, and are referred to the presence of codeia.
The commercial muriate of morphia frequently contains 3% to 4% of codeia.
_Tests._ It is distinguished from morphia by not becoming blue on the
addition of perchloride of iron, nor turning red with nitric acid; and by
not being precipitated by ammonia, when dissolved in hydrochloric acid and
mixed with a large quantity of water. Unlike morphia, it is insoluble in
weak solution of potash, and is soluble in ether. The salts of codeia are
known by tincture of galls throwing down a copious precipitate from their
solutions; this does not occur with the salts of morphia. It is
distinguished from meconia by its aqueous solution showing an alkaline
reaction with test-paper.
=COFFEE.= The seeds or berries of the _Coffea arabica_ (Linn.) or coffee
plant; a shrub of the natural order Cinchonaceæ, sub-order Coffeæ,
indigenous in the low mountainous districts of Arabia Felix, and largely
cultivated in various other parts of the world. About 40 millions of
pounds of coffee are annually consumed in this country, and the
consumption for the whole world has been estimated at about 600 millions
of pounds. The seeds are roasted and ground, and used in the form of a
decoction or infusion. The term coffee is applied to the prepared beverage
as well as to the seeds. The valuable properties of coffee are mainly due
to the presence of the alkaloid CAFFEIA or CAFFEINE.