Coffee (French, Café; German, Kaffee). This important and valuable article of food is the produce chiefly of Coffea arabica, a Rubiaceous plant indigenous to Abyssinia, which, however, as cultivated originally, spread outwards from the southern parts of Arabia. The name is probably derived from the Arabic K’hawah, although by some it has been traced to Caffa, a province in Abyssinia, in which the tree grows wild. In the genus Coffea, to which the common coffee tree belongs, from 50 to 60 species were formerly enumerated, scattered throughout the tropical parts of both hemispheres; but by referring the American plants to a different genus, the list is now restricted to about 22 species. Of these 7 belong geographically to Asia; and of the 15 African species 11 are found on the west coast, 2 in Central and East Africa, and 2 are natives of Mauritius. Besides being found wild in Abyssinia, the common coffee plant appears to be widely disseminated in Africa, having been seen on the shores of the Victroia Nyanza and in Angola on the west coast. Within the last year or two considerable attention has been devoted to a West African species, C. Liberica, belonging to the Liberian coast, with a view to its extensive introduction and cultivation. Its produce, obtained from native plants, have been several years in the English market.
The common coffee shrub or tree is an evergreen plant, which under natural conditions grows to a height of from 18 to 20 feet, with oblong-ovate, acuminate, smooth, and shining leaves, measuring about 6 inches in length by 2 _ wide. Its flowers, which are produced in dense clusters in the axils of the leaves, have a five-toothed calyx, a tubular five-parted corolla, five stamens, and a single bifid style. The flowers are pure white in color, with a rich fragrant odor, and the plants in blossom have a lovely and attractive appearance, but the bloom is very evanescent. The fruit is a fleshy berry, having the appearance and size of a small cherry, and as it ripens it assumes a dark red color. Each fruit contains two seeds embedded in a yellowish pulp, and the seeds are enclosed in a thin membranous endocarp (the parchment). The seeds which constitute the raw coffee of commerce are planoconvex in form, the flat surfaces which are laid against each other within the berry having a longitudinal furrow or groove. They are of a soft, semi-translucent, bluish or greenish color, hard and tough in texture. The regions found to be best adapted for the cultivation of coffee are well-watered mountain slopes at an elevation ranging from 1000 to 4000 feet above sea-level, in latitudes lying between 15o N. and 15o S., although it is successfully cultivated from 25o N. to 30o S. of the equator in situations where the temperature does not fall beneath 55o Fahr. The Liberian coffee plant, C. liberica, which has been brought forward as a rival to the ordinarily cultivated species, is described as a large leaved and large-fruited plant of a robust and hardy constitution. The seeds yield a highly aromatic and fine-flavored coffee; and so prolific is the plant, that a single tree is said to have yielded the enormous quantity of 16 lb weight at one gathering. It is a tree, moreover, which grows at low altitudes, and it probably would flourish in many situations which have been proved to be unsuitable for the Arabian coffee. Should it come up to the sanguine expectations of Ceylon planters and others to whom it has been submitted, there is no doubt that it will prove a formidable rival to the species which has hitherto received the exclusive attention of planters. It grows wild in great abundance along the whole of the Guinea coast.
The early history of coffee as an economic product is involved in considerable obscurity, the absence of historical fact being compensated for by an unusual profusion of conjectural statements and by purely mythical stories. According to one Arabic account cited by De Sacy, Chrestomathie Arabe, 2nd ed., i. 412, the use of coffee was introduced into Aden from the African coast by Sheikh Shinab al-din Dhabhani before 875 of the Flight, or 1470 A.D. Another account, cited in Playfair’s history of Yemen, names a different sheikh, Jamal al-din ibn Abdallah, cadi of Aden, but agrees as to the date. According to the latter account, the use of coffee as a beverage was prevalent among the Abyssinians from the most remote period, and in Arabia the beverage when first introduced only supplanted a preparation from the leaves of the cat, Celastrus edulis. Its peculiar property of dissipating drowsiness and preventing sleep was taken advantage of in connection with the prolonged religious services of the Mahometans, and its use as a devotional antisoporific stirred up a fierce opposition on the part of the strictly orthodox and conservative section of the priests. Coffee was by them geld to be an intoxicant beverage, and therefore prohibited by the Koran; and the dreadful penalties of an outraged sacred law were held over the heads of all who became addicted to its use. Cahwa is ancient Arabic, but in the old literature means wine. Notwithstanding the threats of divine retribution, and though all manner of devices were adopted to check its growth, the coffee-drinking habit spread rapidly among the Arabian Mahometans, and the growth of coffee as well as it use as a national beverage became as inseparably associated with Arabia as tea is with China. For about two centuries the entire supply of the world, which, however, was then limited, was obtained from the province of Yemen in South Arabia, where the celebrated Mocha or Mokha is still cultivated.
The knowledge of and taste for coffee spread but slowly outwards from Arabia Felix, and it was not till he middle of the 16th century that coffee-houses were established in Constantinople. Here also the new habit excited considerable commotion among the ecclesiastical public. The popularity of the coffee-houses had a depressing influence on the attendance at the mosques, and on that account a fierce hostility was excited among the religious orders against the new beverage. They laid their grievances before the sultan, who imposed a heavy tax upon the coffee-houses, notwithstanding which they flourished and extended. After the lapse of another hundred years coffee reached Great Britain, a coffee-house having been opened in 1652 in London by a Greek, Pasqua Rossie. Rossie came from Smyrna with mr. D. Edwards, a Turkey merchant, and in the capacity of servant he prepared coffee daily for Mr. Edwards and his visitors. So popular did the new drink become with Mr Edwards’s friends that their visits occasioned him great inconvenience to obviate which he directed Rossie to establish a public coffee-house, which he accordingly did. The original establishment was in St Michael’s Alley, Cornhill, over the door of which Rossie erected a sign with his portrait, subsequently announcing himself to be "the first who made and publicly sold coffee drink in England." It is remarkable that the introduction of coffee into England encountered the same hostility that it was fated to meet in other countries. Charles II., in 1675, attempted to suppress coffee-houses by a royal proclamation, in which it was stated that they were the resort of disaffected persons "who devised and spread abroad divers false, malicious, and scandalous reports, to the defamation of His Majesty’s Government, and to the disturbance of the peace and quiet of the nation." On the opinion of legal officials being taken as to the legality of this step, an oracular deliverance was given to the effect "that the retailing of coffee might be an innocent trade, but as it was used to nourish sedition, spread lies, and scandalize great men, it might also be a common nuisance." In England as well as in other countries the most effective check on the consumption of coffee was found to be a heavy tax, which, while restricting honest trade, opened a channel for extensive smuggling operations. Coffee is spoken of as being in use in France between 1640 and 1660, and thereafter it may be said that the use of coffee was an established custom in Europe. It is noteworthy that the three principal dietetic beverages of the world were introduce into Great Britain within a few years of each other. Cocoa was the first of the three which actually appeared in Europe, having been brought to Spain from South America; coffee followed, coming from Arabia by way of Constantinople; and tea, the latest of the series, came from China by the hands of the Dutch.
Down to 1690 the only source of coffee supply was Arabia, but in that year Governor-General Van Hoorne of the Dutch East Indies received a few coffee seeds by traders who plied between the Arabian Gulf and Java. These seeds he planted in a garden at Batavia, where they grew and flourished so abundantly that the culture, on an extended scale, was immediately commenced in Java. One of the first plants grown in that island was sent to Holland as a present to the governor of the Dutch East India Company. It was planted in the Botanic Garden at Amsterdam, and young plants grown from its seeds were sent to Surinam, where the cultivation was established in 1718. ten years later the plant was introduced in the West Indian Islands, and gradually the culture extended throughout the New World, till now the progeny of the single plant sent from Java to Holland produces more coffee than is grown by all the other plants in the world. The cultivation is now general throughout all civilized regions of the tropical world. In point of quantity Brazil heads the list of coffee-growing countries, its annual produce probably exceeding that of all other localities combined. It is calculated that no less than 350,000,000 coffee trees are at present flourishing throughout that empire. During the Brazilian financial year ending 1872, more than 2,000,000 bags, each containing 160 lb, were exported from Brazil; and the United States alone absorb upwards of 200,000,000 lb of Brazilian coffee annually. The other principal American localities for coffee-growing are Costa Rica, Guatemala. Venezuela, Guiana, Peru, and Bolivia, with Jamaica, Cuba, Porto Rico, and the West Indian Islands generally. In the East the principal coffee regions, following Brazil in amount, but superior in the quality of their produce, are java and Ceylon. The annual produce of Java reaches to about 130,000,000 lb.; and from Ceylon about 100,000,000 lb is annually exported. The culture of coffee is an important and rapidly growing feature in Southern India, and it is also prosecuted in Sumatra, Reunion, Mauritius, and Southern Arabia, and on the west coast of Africa. The present total annual production of the world has been estimated to amount to not les than 1,000,000,000 lb. At the beginning of the 18th century, while Arabia was still the only source of supply, probably not more than 7,500,000 lb was yearly exported from that country; the consumption of Europe in 1820 was stated by A. Von Humboldt at about 140,000,000 lb, while 300,000,000 lb probably represented the quantity used throughout the world. The yearly consumption in Great Britain has for about 30 years been drooping in the face of a rapidly increasing population and consuming capacity, while the quantity absorbed by other countries has increase with extraordinary rapidity. The whole amount entered for home consumption in 1790 was 973,110 lb; and an increase in the duty charged caused the consumption to drop in 1796 to 396,953 lb. A reduction in the duty caused the consumption in 1808 to shoot up suddenly from 1,069,691 lb in that year to 9,251,837 lb in 1809. the quantity consumed never again mounted so high till in 1825 it was affected by another reduction of duty, and 10,760,112 lb was retained for the home market. Thereafter the consumption rapidly and steadily increased, reaching 22,669,253 lb in 1830, 28,664,341 lb in 1840, and in 1847 coming to its maximum of 37,441,373 lb, from which point it again declined. In 1857 the consumption had fallen to 34,352,123 lb; in 1867 it was 31,567,760; and in 1869 it fell so low as 29,109,113 lb. The total imports for the year 1874 amounted to 157,351,376 lb, but of this only 31,859,408 lb were retained for home consumption. The chief cause of the declining popularity of coffee in Great Britain is doubtless to be found in the extraordinary hold which its rival beverage-tea-has taken on the community; but something of the falling off is also attributable to the extent to which coffee was for a long period made the subject of adulteration and sophistication. Indeed for some years, between 1840 and 1852, much of what was sold under the name of coffee was actually chicory, a root which at that period was cultivated and manufactured duty free, while coffee was subject to a heavy import duty.
The different estimation in which coffee is held in various countries is well brought out in the following estimate of the consumption per head calculated from the official returns for 1873:-
Total imports of CoffeeAverage
For consumptionper head
France……………………..98,635,000 lb2.73 lb
Belgium……………………49,771,00013.48
Switzerland………………..18,779,5007.03
Russia, European………….14,740,9200.19
Sweden……………………26,555,2136.11
Norway…………………….17,636,0809.80
Denmark……………………26,035,65213.89
Holland…………………….72,395,80021.00
Hamburg (Germany)………178,715,936
Austria (1871)76,876.5762.13
Greece……………………2,131,3671.42
Italy (1871)………………28,511,5601.00
United Kingdom…………32,330,9281.00
United States…………….293,293,8337.61
The commercial distinctions as established in the British market relate-first, to qualities, as "fine," middling," "ordinary," "low," and "triage," the last being broken and damaged seeds; and secondly, to localities of production.
Shape, size, and color of seeds are the principal elements which determine the commercial value of coffee. Shape, according to Mr. W.P. Hiern (in a communication to the Linnean Society, April 20, 1876), is related to the particular part of the plant upon which the seed grows; size and succulence correspond with the nature of the locality of growth; and color has reference to the degree of maturity attained by the fruit at the time of gathering. The highly prized variety known as peaberry is the result of the coalescence of the two seeds within the fruit, thus producing the appearance of a single rounded seed, usually of small size, whence the name. Regarding the famous Mocha or "Mokha" coffee of Arabia, Mr W.G. Palgrave has the following remarks:-
"The best coffee, let cavilers say what they will, is that of Yemen, commonly entitled ‘Mokha,’ from the main port of exportation. Now, I should be sorry to incur a lawsuit for libel or defamation from our wholesale or retail tradesmen; but were the particle not prefixed to the countless labels in London shop windows, that bear the name of the Red Sea haven, they would have a more truthy import tan what at present they convey. Very little, so little indeed as to be quite unappreciable, of the Mokha or Yemen berry ever finds its way westward of Constantinople. Arabia itself, Syria, and Egypt consume fully two-thirds, and the remainder is almost exclusively absorbed by Turkish and Armenian oesophagi. Nor do these last get for their share the best or the purest. Before reaching the harbors of Alexandria, Jaffa, Neyrout, &c., for further exportation, the northern bales have been, while yet on their way, sifted and re-sifted, grain by grain, and whatever they may have contained of the hard, rounded, half-transparent, greenish-brown berry, the only one really worth roasting and pounding, has been carefully picked out by experienced fingers; and it is the less generous residue of flattened, opaque, and whitish grains which alone, or almost alone, goes on board the shipping. So constant is this selecting process that a gradation, regular as the degrees in a map, may be observed in the quality of Moha, that is, Yemen coffee, even within the limits of Arabia itself, in proportion as one approaches to or recedes from Wadi Nejran and the neighborhood of Mecca, the first stages of the radiating mart."
The "Mocha" of the English market is principally the produce of India, but a good deal of American coffee is also passed into consumption under that abuse name.
The conditions most favorable for coffee planting are found in hilly situation, where the ground is at once friable, well drained, and enriched by the washing down of new soil from above by the frequent rains. The seeds are first sown in a nursery, and the young plants when they are a few inches high are planted out in the permanent plantation at distances from each other of from 6 to 8 feet. The operation of planting is one which requires great care, and much labor must be expended on drainage, weeding, and cleaning the plantation, and in pruning or "handling" the plants. Chiefly for convenience of securing the crop, the trees are rarely allowed to exceed from 4 to 6 feet in height, and being so pruned down they extend their branches laterally in a vigorous manner. The plants begin bearing in their second year, and by the third year they should yield a fairly remunerative crop. The berries are ready for picking when they have assumed a dark-red color and the skin shrivels up. immediately after the berries are gathered they are conveyed to the storehouse, where they undergo the operation of pulping; and on some hill estates in Ceylon, having suitable situation and water supply, the gathered berries are carried by a water run through galvanized pipes to the store. The pulping is performed in an apparatus having two roughened cylinders which move in opposite directions. Between these the berries are carried forward with a flow of water, and the seeds are deprived of their surrounding pulp, being left invested in the skin or parchment. In this condition they are spread out to dry, and as soon as practicable they are freed from the husk or parchment b y passing them between heavy wooden rollers and winnowing away the broken husks. The shelled coffee is then sized by passing it down a tube perforated throughout its length with holes of regularly increasing diameter, and the various sizes are next hand-picked to free them from defective or malformed seeds, the coffee is then ready to pack for export. A tree in good bearing will yield from 1 _ to 2 lb of berries in a year; but its fertility depends largely upon conditions of climate, situation, and soil. Generally trees planted in lofty dry situations and in light soils yield small berries, which give a rich aromatic coffee, while in low, flat, moist climates a more abundant yield of a large-sized berry is obtained. The greater weight of the coarser qualities of coffee more than makes up for the smaller price obtained for them as against the higher cost of the finer growths; and therefore quality is too often sacrificed to quantity.
The cultivation of coffee is attended with many risks and much anxiety. It Ceylon, where British capital and enterprise have hitherto found their principal scope, the estates are exposed to the attacks of a most mischievous and destructive rodent, the coffee or Golumda rat. A species of insect called the coffee bug, Lecanium coffee, is a still more formidable and alarming pest with which planters have to contend. Of recent years prominent attention has been drawn to two diseased conditions arising in Singalese and Indian plantations by fungus growths. The first, called the coffee-lead disease, appeared in Ceylon in 1869, and in Mysore a year later. The fungus in this case, Hemileia vastatrix, is endophytous, growing within the substance of the leaf, and while no effective cure has been discovered for it, it is not yet clear that it seriously affects the quality or amount of coffee yielded by the plants. The second, known as the coffee-rot, on the other hand, works great havoc in the Mysore plantations, in which it has been observed being especially hurtful in wet seasons. This fungus has been examined by Mr M. C. Cooke, who names it Pellicularia kolerota, and describes the affected leaves as being covered with a slimy gelatinous film, under which the leaves become black and quickly drop off, as do also the clusters of coffee berries.
Raw coffee seeds are tough and horny in structure, and are devoid of the peculiar aroma and taste which are so characteristic of the roasted seeds. In minute structure coffee is so distinct from all other vegetable substances that it is readily recognized by means of the microscope, and as roasting does not destroy its distinguishing peculiarities, microscopic examination forms the readiest means of determining the genuineness of any sample. The substance of the seed, according to Dr Hassall, consists "of an assemblage of vesicles or cells of an angular form, which adhere so firmly together that they break up into pieces rather than separate into distinct and perfect cells. The cavities of the cells include, in the form of little drops, a considerable quantity of aromatic volatile oil, on the presence of which the fragrance and many of the active principles of the berry depend" (see fig. 2). The testa or investing membrane of the seeds has a layer of long cells with a peculiar pitted structure. In chemical composition the seeds are complex,, and they contain variable proportions of proximate principles. The following represents the average constitution of raw coffee according to the analysis of M. Payen:-
Cellulose………………..34
Water…………………..12
Fate……………………10 + 13
Glucose =, dextrin, and organic acid……..15.5
Legumin and casein………10
Other nitrogenous substances…3
Caffeine……………………….0.8
Caffetannate of caffeine and potassium..3.5 to 5.0
Viscid essential oil (insoluble water)0.001
Aromatic oils (some lighter some
Heavier than water)………..0.002
Ash………………………………6.7
The physiological and dietetic value of coffee depends principally upon the alkaloid caffeine which it contains, in common with tea, cocoa, mate or Paraguay tea, guarana, and the African kola nut. Its commercial value is, however, determined by the amount of the aromatic oil, caffeine, which develops in it by the process of roasting. By prolonged keeping it is found that the richness of any seeds in this peculiar oil is increased, and with increased aroma the coffee also yields a blander and more mellow beverage. Stored coffee loses weight at first with great rapidity, as much as 8 per cent having been found to dissipate in the first year of keeping, 5 per cent. in the second, and 2 per cent. in the third; such loss of weight is more than compensated by improvement in quality and consequent enhancement of value.
In the process of roasting, coffee seeds swell up by the liberation of gases within their substance,-their weight decreasing in proportion to the extent to which the operation is carried. Roasting also develops with the aromatic caffeine above alluded to a bitter soluble principle, and it liberates a portion of the caffeine from its combination with caffetannic acid. Roasting is an operation of the greatest nicety, and one, moreover, of a crucial nature, for equally by insufficient and by excessive roasting much of the aroma of the coffee is lost; and its infusion is neither agreeable to the palate nor exhilarating in its influence. The roaster must judge of the amount of heat required for the adequate roasting of different qualities, and while that is variable, the range of roasting temperature proper for individual kinds is only narrow. In Continental countries it is the practice to roast in small quantities, and thus the whole charge is well under the control of the roaster; but in Britain large roasts are the rule, in dealing with which much difficulty is experienced in producing uniform torrefaction, and in stopping the process at the proper moment. The coffee-roasting apparatus is usually a malleable iron cylinder mounted to revolve over the fire in a hollow axle which allows the escape of gases generated during torrefaction. Messrs W. and G. Law of Edinburgh have introduced a very ingenious adaptation of the cylinder whereby a compound simultaneous horizontal and vertical motion is secured, causing the seeds to be tossed about in all directions and communicating a uniform heat to every portion of the cylinder. The roasting of coffee should be done as short a time as practicable before the grinding for use, and as ground coffee especially parts rapidly with its aroma, the grinding should only be done when coffee is about to be prepared. Any ground coffee which may be kept should be rigidly excluded from the air.
While Arabia produces the choicest variety of coffee, the roasting of the seeds and the preparation of the beverage are also here conducted with unequalled skill. Mr W. G. Palgrave gives the following account of these operations in his Central and Eastern Arabia:-
"Without delay Sowelylim begins his preparations for coffee. These open by about five minutes blowing with the bellows, and arranging the charcoal till a sufficient heat has been produced. Next he places the largest of the coffee-pots, a huge machine, and about two-thirds full of clear water, close by the edge of the glowing coal pit, that its contents may become gradually warm while other operations are in progress. He then takes a dirty knotted rag out of a niche in the wall close by, and having untied it, empties out of it three or four handfuls of unroasted coffee, the which he places on a little trencher of platted grass, and picks carefully out any blackened grains, or other non-homologous substances commonly to be found intermixed with the berries when purchased in gross; then, after much cleanisng and shaking, he pours the grain so cleansed into a large open iron ladle, and places it over the mouth of the funnel, at the same time blowing the bellows and stirring the grains gently round and round till they crackle, redden, and smoke a little, but carefully withdrawing them from the heat long before they turn black or charred, after the erroneous fashion of Turkey and Europe; after which he puts them a moment to cool on the grass platter. He then sets the warm water in the large coffee-pot over the fire aperture, that it may be really boiling at the right moment, and draws in close between his own trouserless legs a large stone mortar with a narrow pit in the middle, just enough to admit the black stone pestle of a foot long and an inch and a half thick, which he now takes in hand. Next pouring the half-roasted berries into the mortar he proceeds to pound them, striking right into the narrow hollow with wonderful dexterity, not ever missing his blow till the beans are smashed, but not reduced into powder. He then scoops them out, now reduced to a sort of coarse reddish, grit, very unlike the fine charcoal powder which passes in some countries for coffee, and out of which every particle of real aroma has long since been burned or ground. After all these operations… he takes a smaller coffee-pot in hand, fills it more than half with hot water from the larger vessel, and then, shaking the pounded coffee into it, sets it on the fire to boil, occasionally stirring it with a small stick as the water rises, to check the ebullition and prevent overflowing. Nor is the boiling stage to be long or vehement; on the contrary, it is and should be as slight as possible. In the interim he takes out of another rag-knot a few aromatic seeds called heyl, an Indian product, but of whose scientific name I regret to be wholly ignorant, or a little saffron, and after slightly pounding these ingredients, throws them into the simmering coffee to improve its flavor-for such an additional spicing is held indispensable in Arabia, though often omitted elsewhere in the East. Sugar, I may say, would be a totally unheard-of profanation. Last of all, he strains off the liquor through some fibres of the inner palm-bark, placed for that purpse in the jug-spout, and gets ready the tray of delicate party-colored grass and the small coffee-cups ready for pouring out."
There is no doubt that were proper attention bestowed upon the preparation of coffee it would become a much more popular beverage in Great Britain than it now is; but to obtain it in perfection much greater care is requisite than is necessary in the case of tea. To obtain coffee with a full aroma it must be prepared as an infusion with boiling water, or the water may simply be allowed to reach the boiling point after infusion and nothing more. Dr Parkes has, however, pointed out that by infusion alone much of the valuable soluble matter in ground coffee remains unextracted; and the recommends that the coffee which has already been used for infusion should be preserved and boiled, and that the liquor therefrom should be used for infusing a fresh supply. By this means the substance of the previously infused coffee and the aroma of the new are obtained together. Among the numerous devices which have been proposed for preparing coffee, none is more elegant and efficient than an apparatus constructed by Mr James R. Napier, F.R.S., for which a patent was obtained by Mr David Thomson of Glasgow. It consists of a glass globe a (fig. 3), an infusing jar b, of glass or porcelain and a bent tube c. of block tin or German silver fitted by a cork stopper into the neck of the globe and passing to the bottom of the jar, where it ends in a finely perforated disc. The apparatus also requires a spirit lamp d or pother means of communicating a certain amount of heat to the globe. The coffee is infused with Boiling water in the jar, and a small quantity of boiling water is also placed in the globe. The tube is then fitted in, and the spirit lamp is lighted under the globe. The steam generated expels the air from the globe, and it bubbles up through the jar. When the bubbles of air cease to appear almost the whole of the air will have been ejected, and on withdrawing the lamp the steam in the globe condenses, creating a vacuum, to fill up which the infused coffee rushes up through the metal tube, being at the same, time filtered by the accumulated coffee grounds around the perforated disc. An error of very frequent occurrence in the preparation of coffee, which results probably from the habit of tea-making, consists in using too little coffee. For a pint of the infusion from an ounce to an ounce and half of coffee ought to be used. According to the experiments of Aubet a cup of coffee made from a Prussian loth (587 oz.) contains from 1.5 to 1.9 grains of caffeine.
Coffee belongs to the medicinal or auxiliary class of food substances, being solely valuable for its stimulant effect upon the nervous and vascular system. It produces a feeling of buoyancy and exhilaration comparable to a certain stage of alcoholic intoxication, but which does not end in depression or collapse. It increases the frequently of the pulse, lightens the sensation of fatigue, and it sustains the strength under prolonged and severe muscular exertion. The value of its hot infusion under the rigors of Arctic cold has been demonstrated in the experience of all Arctic explorers, and it is scarcely less useful in tropical regions, where it beneficially stimulates the action of the skin. It has been affirmed that coffee and other substances containing the alkaloid caffeine have an influence in retarding the waste of tissue in the human frame, but careful and extended observation has demonstrated that they have no such effect.
Although by microscopic, physical, and chemical tests the purity of coffee can be determined with perfect certainty, yet ground coffee is subjected to many and extensive adulterations. Chief among the adulterant substances, if it can be so called, is chicory root; but it occupies a peculiar position, since very many people on the Continent as well as in Great Britain deliberately prefer a mixture of chicory with coffee to pure coffee. Chicory is indeed destitute of the stimulant alkaloid and essential oil for which coffee is valued; but the facts that is has stood the test of prolonged and extended use, and that its infusion is, in some localities, used alone, indicate that it performs some useful function in connection with coffee, as used at least by Western communities. For one thing, it yields a copious amount of soluble matter in infusion with hot water, and thus gives a specious appearance of strength and substance to what may be really only a very weak preparation of coffee. The mixture of chicory with coffee is easily detected by the microscope, the structure of both, which they retain after torrefaction, being very characteristic and distinct. The granules of coffee, moreover, remain hard and angular when mixed with water, to which they communicate but little color; chicory, on the other hand, swelling up and softening, yields a deep brown color to water in which it is thrown. The specific gravity of an infusion of chicory is also much higher than that of coffee. Among the numerous other substances used to adulterate coffee are roasted and ground roots of the dandelion, carrot, parsnip, and beet; beans, lupins, and other leguminous seeds; wheat, rice and various cereal grains; the seeds of then broom, fenugreek, and iris; acorns; and "Negro coffee," the seeds of Cassia occidentalis. These with many more similar substances have not only been used as adulterants, but under various high-sounding names several of them have been introduced as substitutes for coffee, but they have neither merited nor obtained any success, and their sole effect has been to bring coffee into undeserved disrepute with the public.
The leaves of the coffee tree contain caffeine in larger proportion than the seeds themselves, and their use as a substitute for tea has frequently been suggested. The leaves are actually so used Sumatra, but being destitute of any attractive aroma such as is possessed by both tea and coffee, the infusion is not palatable. It is, moreover, not practicable to obtain both seeds and leaves from the same plant, and as the commercial demand is for the seed alone, no consideration either of profit or of any dietetic or economic advantage is likely to lead to the growth of coffee trees on account of their leaves.( J. PA.)
The above article was written by James Paton, F.L.S.; Superintendent of Museums and Art Galleries of Corporation of Glasgow from 1876; Assistant in Museum of Science and Art, Edinburgh, 1861-76; President of Museums Association of the United Kingdom, 1896; editor and part-author of Scottish National Memorials, fol. 1890.