Cooley's Cyclopaedia of Practical Receipts Volume I Part 153

Coffee contains three active principles, viz. an essential oil, caffeia, and tannic acid, and these exercise a powerful influence on the system, r.e.t.a.r.ding the waste of the tissues of the body, exciting the brain to increased activity, and exhilarating without intoxicating. Chicory contains none of these const.i.tuents.

Coffee exerts on the system highly beneficial physiological effects; chicory possesses medicinal properties, which are not desirable in an article of food.

Chicory, therefore, is very objectionable, and when a dealer sells a mixture of coffee and chicory for pure coffee, as is almost invariably the case, he is guilty of selling an adulterated article, and ought to be punished accordingly.

The adulteration with caramel or chicory may readily be detected as follows:--

1. A spoonful of pure coffee placed gently on the surface of a gla.s.s of cold water will float for some time, and scarcely colour the liquid; if it contains caramel or chicory, it will rapidly absorb the water, and, sinking to the bottom of the gla.s.s, communicate a reddish-brown tint as it falls. Another method of applying this test is by expertly shaking a spoonful of the suspected coffee with a wine-gla.s.sful of cold water, and then placing the gla.s.s upon the table. If it is pure, it will rise to the surface, and scarcely colour the liquid; but if caramel or chicory is present, it will sink to the bottom, and the water will be tinged of a deep red as before.

2. The brown colour of decoction or infusion of roasted coffee becomes greenish when treated with a per-salt of iron; and a brownish-green, flocculent precipitate is formed. The colour of chicory is only deepened, but not otherwise altered, and no precipitate is formed, under the same treatment. A mixture of chicory and coffee retains a brownish-yellow colour after the precipitate has subsided, and the liquid appears brownish yellow by refracted light. The addition of a little weak ammonia water aids the subsidence of the precipitate.

[Ill.u.s.tration]

3. Under the microscope (see _Chicory_) the presence of chicory may be readily detected by the size, form, and ready separation of the cells of the cellular tissue, and by the presence and abundance of the pitted tissue or dotted ducts, which are absent from coffee, and by the size of the spiral vessels, which are very small in coffee. The most characteristic structure, however, and that by which chicory can be easily identified, is the lactiferous tissue. Roasted corn, and other amylaceous substances, may also be detected, in the same way, by the peculiar size and character of their starch grains.

Under the microscope the berry is seen to consist of a hard, tough tissue, that resists even long soaking. The testa covering the berry is made of lengthened cells with oblique markings resting on a thin membrane, almost structureless. These oblique markings of the cells are so characteristic as to render the cells distinguishable from every other tissue. The substance of the berry consists of angular cells, each one of which contains minute drops of oil. This oil is in some measure driven off during the process of roasting, which, however, leaves the structure unimpaired where it is not charred.

[Ill.u.s.tration]

Roasted corn, beans, &c., may be detected by the cold decoction striking a blue colour with tincture of iodine. Pure coffee is merely deepened a little in colour by this substance.

4. (A. H. Allen.) The amount of ash in genuine coffee does not exceed 45 per cent.; chicory yields 5 per cent. The silica in coffee ash never exceeds 1 per cent., while in chicory it varies from 10-36 per cent. The average soluble ash in coffee is 324, while in chicory it is 174 per cent. By determining the soluble ash S, the per-centage of pure coffee C may be calculated thus:--

(100 S - 174) C = 2 --------------- 3

The density of coffee-infusion is determined by heating the powder with 10 times its weight of cold water, raising the liquid to the boiling point, filtering, and taking the gravity at 155 C. Taking the density of pure coffee-infusion at 10086, and that of chicory at 10206, the per-centage of pure coffee C in the sample may be calculated from the equation

100(1020 - D) C = ------------ 12

where D represents the density of the infused sample. The relative tinctorial power of an infusion of a sample of coffee is determined by boiling a given weight with 20 c. c. of water for a few minutes, filtering, and again boiling the residue until thoroughly exhausted. An equal weight of a standard mixture of equal weights of pure coffee and chicory is treated in a precisely similar manner. The standard solution is made up to 200 c. c., that of the sample to 100 c. c.; 10 c. c. of the latter are put into a narrow burette, and some of the standard into a test tube of exactly equal bore. If the tints are exactly the same, the sample consisted of pure coffee; if chicory is present, water must be added to the sample until the tints are the same. Each c. c. of water represents 5 per cent. of chicory. The presence of leguminous seeds or cereals may be detected by boiling the sample with animal charcoal and water, filtering, and testing for starch in the cold liquid with iodine. Neither coffee nor chicory contains starch.

_Obs._ A few years ago the attention of the scientific world was drawn to the value of roasted coffee leaves, as furnis.h.i.+ng materials for a beverage unexcelled in excellence by the coffee berry itself. It appears that the leaves, prepared for use, may be purchased for 1-1/2d. per lb., or packed ready for export at 2d. per lb. "That this preparation contains a considerable amount of the nutritious principles of coffee is evident from the a.n.a.lysis; but as the leaves can only be collected in a good state at the expense of the coffee-bush, it is doubtful whether the coffees produced by the berries be not, after all, the cheapest, as it certainly is the best." (Jury Report, Exhibition, 1851.) Coffee for the table is best prepared with the aid of a French cafetiere, or coffee biggin, furnished with a percolator or strainer, which will permit a moderately rapid filtration. To produce this beverage in perfection, it is necessary to employ the best materials in its preparation--fresh roasted and fresh ground. "At least 1 oz. of coffee should be used to make 3 common-sized coffee-cupfuls, with 1 teaspoonful of freshly roasted and ground chicory.

If desired strong, the quant.i.ty of both should be doubled." (Cooley.) Many habitual coffee drinkers cannot tolerate the use of chicory, which is a doubtful improver of coffee. The prevailing fault of the coffee made in England is its want of strength and flavour. The coffee-pot should be heated previously to putting in the coffee, which may be done by means of a little boiling water. The common practice of boiling coffee is quite unnecessary, for all its flavour and aroma is readily extracted by boiling hot water. Indeed, all the "useful and agreeable matter in coffee is very soluble, it comes off with the first waters of infusion, and needs no boiling." (Ure.) Should prejudice, however, induce the housewife or cook to boil her coffee, it should be only just simmered for a minute, as long or violent boiling injures it considerably.

When coffee is prepared in a common pot, the latter being first made hot, the boiling water should be poured over the powder, and not, as is commonly the plan, put in first. It should then be kept stirred for 4 or 5 minutes, when a cup should be poured out and returned again, and this operation repeated 3 or 4 times, after which, if allowed to repose for a few minutes, it will generally become fine of itself. In all cases, where a percolator is not used, the liquor should be well stirred up several times before finally covering it up to settle for use.

Amongst the various descriptions of coffee pots in use we may mention those of French make, consisting of two cylindrical vessels, the upper having a metal strainer, on which the ground coffee is placed, and through which the clear infusion runs into the lower one; Loysell's--an apparatus making very good coffee, and as one of the latest, an ingenious and inexpensive coffee pot, known as the "Kaffee Kanne," devised by Mr Ash, of Oxford Street. Ash's "Kaffee Kanne" consists of an ordinary biggin, surrounded by a jacket containing boiling water. The coffee is made by percolation in the inner vessel, and being kept at the point of ebullition by the surrounding boiling water, yields a beverage of excellent flavour and aroma.

Coffee is sometimes clarified by adding a shred of isingla.s.s, a small piece of clean eel- or sole-skin, or a spoonful of white of egg. An excellent plan, common in France, is to place the vessel containing the made coffee upon the hearth, and to sprinkle over its surface half a cupful of cold water, which from its greater gravity descends, and carries the 'foulness' with it. Another plan sometimes adopted is to wrap a cloth, previously dipped into cold water, round the coffee-pot. This method is commonly practised by the Arabians in the neighbourhood of Yemen and Moka, and rapidly clarifies the liquor, unless a very large quant.i.ty of chicory is present. It should be recollected that the use of isingla.s.s, white of egg, and all like artificial finings, remove much of the astringency and vivacity of the liquor.

The French, who are remarkable for the superior quality of their coffee, generally allow an ounce to each large coffee-cupful of water, and they use the coffee both newly ground and freshly roasted. A shred of saffron, or a little vanilla, is frequently added, whilst the percolating coffee-pot is generally employed. When the Parisian uses a common coffee-pot he generally divides the water into 2 parts. The first portion he pours on boiling hot, and allows it to infuse for 4 or 5 minutes; he then pours this off as clear as possible, and boils the grounds for 2 or 3 minutes with the remaining half of the water. As soon as this has deposited the sediment it is decanted, and mixed with the infusion. The object of this process is to obtain the whole of the strength as well as the flavour. The infusion is thought to contain the latter, and the decoction the former; a plausible, but erroneous idea, since both of them were carried off by the first water.

A much better method, and one we can recommend from experience, is to divide the coffee into 2 parts. Boil the first portion in the coffee-pot for 4 or 5 minutes, then add the other portion, and allow it to infuse slowly for about 10 minutes, the coffee-pot lid being kept well closed.

This gives a coffee possessing a flavour which even the French cannot excel.

=Coffee, Essence of.= A highly concentrated infusion of coffee, prepared by percolation with boiling water, gently and quickly evaporated to about 1/3rd or 1/4th of its bulk, and mixed with a thick aqueous extract of chicory and syrup of burnt sugar, so as to give the whole the consistence of treacle. The proportions of the dry ingredients should be--coffee, 4 parts; chicory, 2 parts; burnt sugar (caramel) 1 part. It should be kept in well-corked bottles in a cool place. This preparation is very convenient for making extemporaneous coffee; but the beverage so made, though superior to much of that sold at coffee-houses, is inferior in flavour, aroma, and piquancy, to that we are accustomed to drink at home.

Much of the so-called 'Essence of Coffee' is simply treacle and burnt sugar, flavoured with coffee.

=Coffee, Searle's Patent.= This is prepared by mixing condensed milk with a very concentrated essence of coffee and evaporating at a low temperature (_in vacuo_, if possible), until the mixture acquires the consistence of a syrup (coffee syrup), paste (coffee paste), or candy (coffee candy). The last may be powdered (coffee powder, dry essence of coffee).

=Coffee, Subst.i.tutes for.= These are numerous, but are now seldom employed, owing to the cheapness of the genuine article, and the stringency of the revenue laws. Among the princ.i.p.al are the following:--

1. COFFEE, ACORN. From acorns deprived of their sh.e.l.ls, husked, dried, and roasted.

2. COFFEE, BEAN. Horse-beans roasted along with a little honey or sugar.

3. COFFEE, BEET-ROOT. From the yellow beet-root, sliced, dried in a kiln or oven, and ground with a little coffee.

4. COFFEE, DANDELION. From dandelion roots, sliced, dried, roasted, and ground with a little caramel.

5. COFFEE, GERMAN. _Syn._ SUCCORY C., CHICORY C. From chicory or succory.

Used both for foreign coffee, and to adulterate it.

_Obs._ All the above are roasted, before grinding them, with a little fat or lard. Those which are larger than coffee-berries are cut into small slices before being roasted. They possess none of the exhilarating properties or medicinal virtues of foreign coffee.

COINS. See MEDALS and ELECTROTYPE.

=c.o.kE.= Charred or carbonised coal. The principle of its manufacture is similar to that of charcoal. There are three varieties of c.o.ke:--

1. KILN-MADE c.o.kE; STIFLED c.o.kE. Made by burning pit-coal in a pile, kiln, or stove. It has a dull-black colour, and produces an intense heat when used as fuel. By condensing the bituminous vapours which are given off during the process, about 3% of tar may be obtained from common coal, and from some strong coal, by careful treatment fully 10% of its weight. The screenings of dust coal, separated from the better kinds of bituminous coal, is the sort commonly used for making c.o.ke in ovens.

2. GAS c.o.kE; DISTILLED c.o.kE. The cinder left in the gas retorts. Grey; produces a weak heat, insufficient to smelt iron.

3. SHALE c.o.kE; MINERAL CARBON. From bituminous shale, burnt in covered iron pots, in a similar way to that adopted for making bone-black; or in piles. Black and friable. Used to clarify liquids, but is vastly inferior to bone-black, and does not abstract the lime from syrups. See FUEL, PIT-COAL, &c.

=COLCHICIN'A.= _Syn._ COL'CHICINE. COLCHICIA. A peculiar principle discovered by Gieger and Hesse in the seeds of the _Colchic.u.m autumnale_ or common meadow saffron. It also exists in the corms or bulbs.

_Prep._ Macerate the bruised seeds in boiling alcohol, add magnesia, to throw down the alkaloid, digest the precipitate in boiling alcohol, and filter. By cautious evaporation colchicine will be deposited, and maybe purified by re-solution and crystallisation in alcohol.

_Prop., &c._ Odourless; bitter; soluble in water and alcohol; form salts with the acids. It is very poisonous. 1/10th of a grain, dissolved in spirit, killed a cat in 12 hours. It differs from veratria in being soluble in water and crystalline, and in the non-production of sneezing when cautiously applied to the nose. Strong oil of vitriol turns this alkaloid of a yellowish-brown; nitric acid turns it of a deep violet, pa.s.sing into indigo-blue, green and yellow. It is not used in medicine.

=COL'CHIc.u.m.= _Syn._ MEA'DOW SAF'FRON; COLCHIc.u.m AUTUMNALE (Linn.), L. The recent and dried corms or bulbs (_colchici cormus_), as well as the seeds (_colchici semina_), are official in the British Pharmacopia. The corms are ordered to be dug up in the month of July, or before the autumnal bud has projected. The dry coatings having been torn off, cut the corms transversely in thin slices, and dry, at first with a gentle heat, but afterwards slowly increased to 150 Fahr.

_Dose_ (of the corms), 2 to 8 or 9 gr.; (of the seeds), 2 to 7 gr., made into a pill or bolus with syrup or conserve; chiefly, as a specific in gout, to alleviate or check the paroxysm. This drug forms the base of almost all the advertised gout nostrums. It is, however, an active poison, and its administration requires care. "After all that has been said respecting colchic.u.m in gout, and admitting that it rarely fails to allay pain and check a paroxysm, I would record my opinion that he who would wish to arrive at a good old age should eschew it as an _ordinary_ remedy, and consider that he is drawing on his const.i.tution for a temporary relief, with a certainty of becoming prematurely bankrupt in his vital energies." (Collier.)

_Antidotes._ An emetic consisting of one scruple of sulphate of zinc dissolved in water, followed by a brisk dose of castor oil, then stimulants, and also charcoal.

=COL'COTHAR.= See OXIDES OF IRON.

=COLD.= _Syn._ FRI'GUS, L. The privation of heat. The term is also applied to the sensation and effects which this privation produces.

When the body of an animal is immersed in an atmosphere at a temperature below the healthy standard, a sensation of coldness is experienced, produced by the pa.s.sage of the caloric or heat of the body into the colder medium. If this extraction of caloric exceeds the quant.i.ty produced by the vital system, the temperature of the body decreases, until it sinks below the point at which the functions of life can be performed. This declination of the heat of the body is gradual; the extreme sensation of coldness changes into a disinclination for voluntary motion; next comes on drowsiness, followed by numbness and insensibility. At this point if the sufferer is not rescued, and remedial measures had recourse to, death inevitably and rapidly ensues.

The prevention of the effects of cold consists in the use of ample food and clothing proportioned to the inclemency of the weather, the exposure to be endured, and the habits of the wearer. The circulation of the blood should be promoted by active exercise, and any disposition to sleep shaken off by increased bodily exertion. The princ.i.p.al endeavour should be to keep the extremities and chest warm, as, if this can be accomplished, no danger need be feared.

In cases of asphyxia produced by intense cold, the patient should be laid in a room remote from the fire, and bathed with cold salt-and-water, or water to which some brandy or vinegar has been added; after which the body should be wiped dry, and friction a.s.siduously applied by the hands of the attendants (warmed); as many operating at once as can conveniently do so.

Gentle stimulants should be administered by the mouth, and the bowels excited by some mild, stimulating clyster. The lungs should also be inflated, and an effort made to re-establish the respiration. As soon as symptoms of returning animation are evinced, and the breathing and circulation restored, the patient should be laid in a bed between blankets, and a little wine-and-water administered, and perspiration promoted by heaping an ample quant.i.ty of clothing on the bed. Should the patient have suffered from hunger as well as cold, the appet.i.te may be appeased by the administration of a limited quant.i.ty of light food, taking especial care to avoid excess, or anything indigestible or exciting, &c.

See ASPHYXIA, BRONCHITIS, CATARRH, &c.