1902 Encyclopedia > Sugar

Sugar




SUGAR. Formerly chemists called everything a "sugar" which had a sweet taste, and acetate of lead to this day is known as "sugar of lead" in commerce and familiar chem ical parlance; but the term in its scientific sense soon came to be restricted to the sweet principles in vegetable and animal juices. Only one of these—cane sugar—was known as a pure substance until 1619, when Fabrizio Bar-toletti isolated the sugar of milk and proved its individu-ality. In regard to all other " sugars " besides these two the knowledge of chemists was in the highest degree indefinite, and remained so until about the middle of the 18th century, when Marggraf made the important discovery that the sugars of the juices of beet, carrots, and certain other fleshy roots are identical with one another and with the sugar of the cane. Lowitz subsequently showed that the granular part of honey is something different from cane sugar ; this was confirmed by Proust, who found also that Lowitz's honey sugar is identical with a crystallizable sugar present largely in the juice of the grape. Proust's investigations extended to other sweet vegetable juices also.

Species

All those investigated by him owed their sweetness to one or more of only three species,—(1) cane sugar, (2) grape sugar, (3) (amorphous) fruit sugar. Proust's results obtain substantially to this day; a number of new sugars strictly similar to these three have been discovered since, but none are at all widely diffused throughout the organic kingdom.

Quantitative determination.

The quantitative elementary composition of cane sugar was determined early in the 19th century by Gay-Lussac and Thenard, who may be said to have virtually established our present formula, C12H22On. Under FERMENTATION (vol. ix. p. 93) it has been explained how Gay-Lussac (in 1811) came to mis-correct his numbers so as to bring them into accordance with what we now express by C6H1206 = |C12H24012. Dumas and Boullay, some years later, found that cane sugar is what Gay-Lussac and The-nard's analysis makes it out to be, while the " corrected " numbers happen to be correct for grape sugar. Dumas and Boullay's research completed the foundations of our present science of the subject. "Sugar" is now a collect-ive term for two chemical genera named saccharoses (all C12H22On) and glucoses (all C6H1206). All sugars are colourless non-volatile solids, soluble in water and also (though less largely) in aqueous alcohol; from either solvent they can in general be obtained in the form of crystals. The aqueous solution exhibits a sweet taste, which, however, is only very feebly developed in certain species.

Action on polarization of light

All sugars and their solutions have the power of turning the plane of polarization of light. In a given solution of a given kind of sugar the angle a through which the plane is turned is governed light. by the equation a=±[a]lp, where I stands for the length of solu-tion traversed (the customary unit of length being the centimetre) and p for the number of grams of dry sugar present in a volume of solution equal to that of (say) 100 grams (3'52 oz.) of water, where, however, " gram " must be taken as merely a convenient word for "unit of weight" ; ±[a], i.e., the special value of a for 1 = 1 and p=l, is called the specific rotatory power of the sugar operated upon. The sign ± indicates that the plane of polarization is turned either to the right or to the left according to the nature of the species. For a given species and a given temperature [a] has a constant value. Supposing its value to have been determined by standard experiments and I to be known (or to be kept constant throughout and taken as unit of length), the determination of a for a given solution suffices for the calculation of p. This method is largely used industrially for the assaying of cane sugar.

Sugars, though neutral to litmus and inert towards such substances as carbonates on the one hand and aqueous acids (qua acids) on the other, combine with strong bases, such as caustic potash, baryta, and lime, into saccharates, and, when brought into contact with the strongest nitric acid (or a mixture of the same with oil of vitriol) or (at the proper temperature) with acetic anhydride, unite with these into nitrates and acetates respectively, with elimination of water. These nitrates, &c, are related to the respective sugar exactly as (to take an analogous case) nitrate of methyl, CH3(N03), is to methyl-alcohol, CH3(OH); only in the case of a sugar a plural of N03's is capable of entering into every one molecule and turning out so many HO's ; hence sugars are said to be polyvalent alcohols. Of the several points of difference between saccharoses and glucoses the most important is that, -while the latter remain unchanged when boiled with highly dilute sulphuric or hydrochloric (or certain other kinds of) acid, the former take up water and every molecule breaks up into two molecules of glucose, which in general are of different kinds. Cane sugar, for instance, yields dextrose and laevu-lose (so called from the direction in which they turn the plane of polarized light), thus—

CJ2H22On + H20 = C6H1206 + C6H1206

Cane sugar turns the plane of polarized light to the right; the mixed glucose produced is ltevo-rotatory; hence the process is spoken of technically as involving the inversion of cane sugar, and the mixed product is called invert sugar. The term " inversion," however, has come somehow to be used for all decompositions which fall under the above equation ; occasionally it is used even in a wider sense, to include any decomposition of a carbo-hydrate (e.g., itarch) into two less complex carbo-hydrates.

Fermentative changes.

All sugars are liable to fermentative changes; a special character of the three principal vegetable sugars is that, when brought into contact as solutions with yeast (living cells of saccharomyces), under suitable conditions, they suffer vinous fermentation, i.e., break up substantially into carbonic acid and alcohol. Dextrose and lsevulose break
:2C2H60 + 2C02. Cane sugar
first, under the influence of a soluble ferment in the yeast, gets inverted, and the invert sugar then ferments, the dex-trose disappearing at a greater rate than the Irevulose.

Artificial production.

It is remarkable that no sugar has ever been produced artificially even in the sense of being built up from other native organic substances of less chemical complexity. It is easy to produce dextrose from starch, or lsevulose from inulin, or both from cane sugar, by inversion; but none of these processes is reversible by known methods. Yet the problem of producing cane sugar artificially may in a sense be said to have found a virtual solution at the hands of a German-American chemist, Fahlberg. [623-1] Fahlberg, by subjecting toluene, CBH5CH3 (one of the components of coal-tar naphtha), to a series of operations has produced CO from it a body, C6H4gQNH, which he called saccharine, because he found it to be about 230 times as sweet as cane sugar. This saccharine is a white crystallized solid, only slightly soluble in coid water, but sufficiently so to admit of its incorporation with jellies, puddings, beverages, &c. A mixture of one part of it with 1000 parts of ordinary grape sugar (as produced industrially from starch) is as sweet as the best cane sugar. The substance, though an antiseptic, is said to be perfectly innocuous.

Glucoses

Glucoses.

Of these a pretty large number are now known, but only laevulose and dextrose need be noticed here. Both are largely present in all kinds of sweet fruit juices and in honey. In most of these materials they are accompanied by a small proportion of cane sugar, which forcibly suggests that the glucose in fruit juices is really inverted cane sugar. But, in opposition to this surmise, the proportion of cane sugar in oranges increases during the process of ripening, and the sourest of all fruits—the lemon—contains four parts of cane for every ten of invert sugar; besides, the juices of grapes and sweet cherries contain no cane sugar whatever. Accord-ing to Stammer, the young leaves of the sugar cane contain abun-dance of invert sugar, which gradually disappears and gives way to cane sugar as the leaves develop and ultimately dry up. In the living body of man dextrose is constantly being produced from the glycogen of the liver, to be taken up by the blood and oxi-dized into carbonic acid and water. In certain diseases, however (see NUTRITION, vol. xvii. p. 681), the sugar survives and passes into the urine ; as much as one pound avoirdupois may be dis-charged by a diabetic patient in twenty-four hours. A numerous class of vegetable substances, known as glucosides, contain glucose of some kind in the sense that, when decomposed by boiling dilute sulphuric acid or by the action of certain ferments, they split up into glucose and some product—not a sugar—which is characteristic of the respective species. For examples, see FERMENTATION, vol. ix. p. 96.

Dextrose is being produced industrially from starch by inversion (see below), and sold as grape sugar. Such grape sugar, however, is very impure. I or the preparation of pure dextrose rich diabetic urine, honey, and cane sugar are convenient materials. The method recommended by Soxhlet is to dissolve 160 grams (5'64 oz.) of powdered cane sugar in a mixture of 500 c. c. of alcohol of 85 per cent, by weight and 20 c.c. of fuming hydrochloric acid at 45° C. and to allow the solution to stand. After about a week dextrose begins to crystallize out, and, if the mixture is being frequently agitated, the deposit of crystals increases gradually. A small crop of crystals thus obtained suffices for inducing crystallization in a large supply of fresh liquor. Dextrose crystallizes from its highly concentrated aqueous solution—somewhat tardily—in minute soft crystals, united into warts or cauliflower-like masses, which contain 1H20 of crystal water beside C6H1206. The crystals lose their water at 100° C. From absolute alcohol it crystallizes as C6H1206. It dissolves in 1*2 parts of cold and far less of boiling water. 100 parts of alcohol of 0'837 specific gravity dissolve 1*94 parts at 17°'5 C. and 21'7 parts on boiling. In a given volume of aqueous solution 5 parts of dextrose produce the same degree of sweetness as 3 parts of cane sugar. Dextrose fuses at 146° C. and at 170° passes into glucosan, C6Hw05, an almost tasteless solid, which when boiled with dilute sulphuric acid is reconverted into dextrose. If a solu-tion of dextrose in absolute alcohol is saturated with hydrochloric acid gas at 0° C., di-glucose, C12H2„On, is produced, which, however, is only isomeric with cane sugar (Gautier).

Laevulose.—The liquid part of crystalline honey consists chiefly lose of laevulose ; but its purification is difficult. From invert sugar it can be extracted, according to Dubrunfaut, by cautious addition of slaked lime at a low temperature. The lsevulose separates out as a difficultly soluble lime compound, which is separated from the mother-liquor containing the dextrose by pressure and by judicious washing with cold water. The lsevulosate of lime is de-composed by the exact equivalent of oxalic acid solution; then the oxalate of lime is filtered off, and the filtrate evaporated on a water-bath. The lrevulose ultimately remains as a thick syrup, which formerly was supposed not to be susceptible of crystallization ; but Jungfleisch and Lefranc have succeeded lately in obtaining crystals from it by means of alcohol. Lrevulose is very largely soluble in water, and fully as sweet as cane sugar. It fuses at 95° C.; at 170° it passes into lfevulosan, C6H10O5, analogous to glucosan.

Reaction. The following reactions, though studied chiefly with dextrose, apply also to lsevulose, and, substantially at least, to glucoses gener-ally. If a solution of glucose is mixed with excess of caustic potash or soda, a solution of alkaline glueosate is formed, which, however, has little stability. If the solution is heated, the glueosate is decomposed with formation of dark-coloured (soluble) alkali salts of acid products, which, whatever they may be, are not reconvertible into glucose. Cane sugar, in these circumstances, remains sub-stantially unchanged, and can be regenerated by elimination of the alkali. If a solution of glucose is mixed with (not too much) sul-phate of copper, and an excess of caustic potash or soda be then added, no precipitate of cupric hydrate is formed, but an intensely blue solution, which, on standing in the cold gradually, and on heating promptly, deposits a red precipitate of cuprous oxide, Cu»0, the glucose being oxidized at the expense of the dissolved CuO into soluble alkali salts of little known acids. By means of this (Trammer's) test the least trace of glucose in a solution can be dis-covered. Cane sugar, in the circumstances, yields cuprous oxide only on long-continued boiling. Fehling has brought this test into the following more convenient form, which, besides, admits of quantitative application: 34-65 grams(l-22 oz.) of sulphate of copper, CuS04i-5H20, and 173 grams (6 oz.) of Rochelle salt (double tartrate of potash and soda) are dissolved in a solution of 70 grams (2'46 oz.) of solid caustic soda, and the intensely blue solution produced is diluted to 1000 c.c. Every c.c. of Fehling solution oxidizes about 5 milligrams ('077 grain) of dextrose (not of glucose generally). To de-termine an unknown weight of glucose, its solution is added to an excess of suitably diluted Fehling solution at a boiling heat, which is maintained for a sufficient time to oxidize the glucose as com-pletely as possible,—the requisite time depending on the nature of the glucose. The cuprous oxide precipitate is allowed to settle, is then collected on a filter, and weighed directly or indirectly. From its weight the weight of the glucose is calculated,—a standard experi-ment with a known weight of the respective kind of pure glucose furnishing the factor. A less exact but more expeditious method is to dissolve the sugar to be analysed in water, to dilute to a known volume (not less than 200 c.c. for every gram of glucose), and to drop this solution from a burette into a measured volume of dilute Fehling solution at a boiling heat until the blue colour is just destroyed, i.e., the copper just precipitated completely as Cu20. This method is largely used in sugar-houses in the assaying of crude cane or beetroot sugars.





Saccharoses

Cane sugar. Of these only cane sugar, milk sugar, and maltose can be noticed here. The highest qualities of commercial cane sugar are chemi-cally pure. Pure cane sugar crystallizes from its supersaturated syrup in colourless, transparent monoclinic prisms (exemplified in colourless candy sugar). The crystals are barely, if at all, hygro-scopic ; they are rather hard, and when broken up in the dark give off a peculiar kind of bluish light. Sp. gr. 1-593 at 4° C. The aqueous solution, saturated at t° C, contains p per cent, of dry sugar. For t= 0. 10. 20" SO" 40" 50" J)=65'0 65-6 67-0 69-8 75-8 82'".

From 50° upwards the solubility increases at such a rate that a given quantum of water dissolves any quantity of sugar if the mix-ture is constantly kept boiling. Accordingly a sugar syrup when boiled down deposits nothing, but passes gradually into the condi-tion of fused sugar when the boiling-point merges into the fusing-point of sugar, which lies at 160-161° C. Even a cold-saturated solution of sugar has the consistence of a syrup. Absolute alcohol hardly dissolves sugar at all; aqueous alcohol dissolves it the more largely the greater its proportion of water. Fused sugar freezes into a transparent glass, which is colourless if pure, but in practice gener-ally exhibits a yellowish hue, and, if really anhydrous, remains glassy for an indefinite time. Barley-sugar and certain other confections are substantially fused sugar ; but from their mode of manufacture they retain a trace of enclosed water, which constantly dissolves particles of the surrounding sugar glass to redeposit them in the less soluble form of crystals, so that barley-sugar in the course of time loses its transparency through conversion into an aggregate of minute crystals. If fused sugar is kept at a few degrees above its fusing-point for some time, it passes into an alloy, CjHuOe + C6H10Os, of dextrose and leevulosan (see above). At higher temperatures it loses water and passes into anhydrides not reconvertible into cane sugar, which are known in the aggregate as "caramel,"—a most intensely brown viscous solid, easily soluble in water and in aqueous alcohol, with formation of intensely coloured solutions. Caramel (often made of dextrose) is much used as an innocent colouring agent for sauces, liqueurs, &c. A pure solution of cane sugar is said to remain unchanged on boiling (it being understood, of course, that local overheating be carefully avoided); but continued contact with even so feeble an acid as carbonic induces at least partial inversion. The statement of the unchangeability of sugar solution on boiling seems hardly credible, because a syrup boiling at all considerably above 100° C. contains plenty of molecules at temperatures above 160° C, which are bound to suffer irreversible conversion into dextrose and lcevulosan (or lrevulose), and even, if hot enough, caramelization. In ordinary practice, at any rate, sugar solutions on boiling do behave as indicated by this theory. Cane sugar, as already stated, unites with alkalis, alkaline earths, and other of the more strongly basic metallic oxides into saccharates. A soluble saccharate of lime, which is readily decomposible by carbonic acid and even by filtration through bone charcoal, plays a great part in the manufacture of sugar. The fol-lowing strontium salt must be named, because it at least promised some years ago to occupy a similar position industrially. Accord-ing to Scheibler, if strontia hydrate, SrOH20 + 8H20, is added to a boiling 15 per cent, solution of cane sugar, then as soon as 2SrO is added for every C12H22On the salt C12H220n + 2SrO separates out as a sandy powder, and after addition of 2-5 times SrO al-most all the sugar is precipitated. The precipitate is easily washed and decomposed by water and carbonic acid, with formation of insoluble carbonate of strontia (from which the hydrate can be reproduced) and a solution of cane sugar. The ultimate molasses produced in sugar making or refining, though they refuse to deposit crystals under any conditions, contain some 30 to 40 per cent, of real cane sugar ; Scheibler's process applies to them,—to put the industrial bearings of the discovery in the proper light,—and it has led to quite a series of patents for the production of strontia ; but, as far as we know, it has failed to take root in the sugar industry.

Milk Sugar occurs in the milk of mammals, and it is doubtful whether it occurs anywhere else, although Bouchardat once proved sugar, its presence in a sample marked as sugar obtained from Sapota Achras (the sapodilla of the West Indies). It is made industrially in Switzerland as a bye-product in the making of cheese. It passes into the whey, from which it is extracted by evaporation to a small volume, decolorization with animal charcoal, and crystallization. From the commercial product the pure substance can be obtained by repeated recrystallization from water; and ultimately by pre-cipitation from the aqueous solution by alcohol. Milk sugar as it crystallizes from water under the ordinary conditions forms hydrated crystals of the composition C]2H„2On + H20 ; under certain conditions anhydrous crystals separate out. The hydrated crystals have pretty much the aspect of candy sugar, but they are less transparent, far harder, quite free from every soupçon of hygroscopicity, and far less sweet. They dissolve in six parts of cold and in 2-5 parts of boiling water ; the solutions are not syrupy. Milk sugar is hardly soluble in alcohol. The ordinary crystals, as the formula shows, have the composition of a glucose ; indeed milk sugar solution behaves to caustic alkalis and to Fehling solution as if it were a glucose. But the hydrated crystals lose their water at 130°, with formation of a residue reconvertible into the original substance by the mere action of water ; besides, milk sugar is susceptible of inversion into dextrose and a specific galactose. The optical behaviour of a milk sugar solution varies according as it is derived from the ordinary crystals or the anhy-dride produced at 130°, and according to the time which has elapsed since its preparation ; but if it stands sufficiently long the specific rotatory power assumes ultimately the same (constant) value. Milk sugar solution when brought in contact with yeast does not suffer vinous fermentation ; but certain Spaltpilze induce a fermentation involving the formation of alcohol and of lactic acid. This process is utilized by the Kirghiz in the production of their native drink, "koumiss," made from mare's milk (see MILK, vol. xvi. p. 305). Milk sugar is used in medicine as a diluent for dry medicines. Homceopathists use it by preference. A solution of milk sugar in certain proportions of water and cow's milk is used occasionally as a substitute for mother's milk.

Maltose does not occur in nature ; it is largely produced along with dextrin when starch paste is acted upon by dilute sulphuric acid or the ferment called "diastase," which is supposed to he the active agent in malt. For its preparation 2 kilograms (4'40 It) of potato starch are made into a paste with 9 litres (15'84 pints) of water over a water-bath ; after allowing it to cool down to 60° or 65° C, an infusion of from 120 to 140 grams (4'23 to 5
oz.) of malt made at 40° C. is added. The mixture is kept at from 60° to 65° for an hour ; it is then boiled and filtered. The filtrate is evaporated to a syrup, which is exhausted twice with alcohol of 85 per cent, by weight and then once with absolute alcohol. The dextrin (mostly) remains ; the maltose passes into solution. The alcoholic extracts are evaporated to a syrupy consistence and allowed to stand. _ The absolute alcohol extract soon yields a crop of impure crystals of maltose, which are used to induce crystallization in the other two syrups. In regard to the somewhat tedious methods of purification we refer to the handbooks of chemistry. Maltose crystallizes (from alcohol on spontaneous evaporation) in fine needles of the composition C12H22On +H20. The H20 goes off at 100° C. Maltose is less soluble in alcohol than dextrose, to which it is otherwise very similar. To caustic alkalis and Fehling solution it behaves exactly as dextrose does. Like it, it suffers vinous fermentation under the influence of yeast. When boiled with dilute sulphuric acid it breaks up into (so to say) dextrose and dextrose. Maltose plays an important part in the brewing
of alcoholic malt liquors. (W. D.)

History

The original habitat of the sugar-cane is not known, but it seems to have been first cultivated in the country extending from Cochin China to Bengal (De Candolle). Sugar reached the West from India, and at a comparatively late date. Strabo (xv. i. 20) has an inaccurate notice from Nearclms of the Indian honey-bearing reed, and various classical writers of the first century of our era notice the sweet sap of the Indian reed, or even the granulated salt-like product which was imported from India, or from Arabia and Opone (these being entrepots of Indian trade), [625-1] under the name of saccharum or sacchari [Gk.] (from Sanskr., sarkara, "gravel," "sugar"), and used in medicine. The art of boiling sugar was known in Gangetic India, from which it was carried to China in the first half of the 7th century ; but sugar-refining cannot have then been known, for the Chinese learned the use of ashes for this purpose only in the Mongol period, from Egyptian visitors. [625-2] The cultivation of the cane in the West spread from Khuzistan in Persia. At Gundé-Shapúr in this region "sugar was prepared with art" about the time of the Arab conquest, [625-3] and manufacture on a large scale was carried on at Shuster, Siis, and Askar-Mokram throughout the Middle Ages. [625-4] It has been plausibly conjectured that the art of sugar-refining, which the farther East learned from the Arabs, was developed by the famous physicians of this region, in whose pharmacopoeia sugar had an important place. Under the Arabs the growth and manufacture of the cane spread far and wide, from India to Sris in Morocco (Edrisi, ed. Dozy, p. 62), and were also introduced into Sicily and Andalusia.

In the age of discovery the Spaniards became in their turn the great disseminators of the sugar cultivation : the cane was planted by them in Madeira in 1420 ; it was carried to San Domingo in 1494 ; and it spread over the occupied portions of the West Indies and South America early in the 16th century. Within the first twenty years of the 16th century the sugar trade of San Domingo expanded with great rapidity, and it was from the dues levied on the imports brought thence to Spain that Charles V. obtained funds for his palace-building at Madrid and Toledo. In the Middle Ages Venice was the great European centre of the sugar trade, and towards the end of the 15th century a Venetian citizen received a reward of 100,000 crowns for the invention of the art of making loaf-sugar. One of the earliest references to sugar in Great Britain is that of 100,000 lb of sugar being shipped to London in 1319 by Tomasso Loredano, merchant of Venice, to be exchanged for wool. In the same year there appears in the accounts of the chamberlain of Scotland a payment at the rate of Is. 9Jd. per pound for sugar. Throughout Europe it continued to be a costly luxury and article of medicine only, till the increasing use of tea and coffee in the 18th century brought it into the list of principal food staples. The increase in the consumption is exemplified by the fact that, while in 1700 the amount used in Great Britain was 10,000 tons, in 1800 it had risen to 150,000 tons, and in 1885 the total quantity used was almost 1,100,000 tons.

In 1747 Andreas Sigismund Marggraf, director of the physical classes in the Academy of Sciences, Berlin, discovered the existence of common sugar in beetroot and in numerous other fleshy roots which grow in temperate regions. But no practical use was made of the discovery during his lifetime. The first to establish a beet-sugar factory was his pupil and successor, Franz Carl Achard, at Cunern (near Breslau) in Silesia in 1801. The processes used were at first very imperfect, but the extraordinary increase in the price of sugar on the Continent caused by the Napoleonic policy gave an impetus to the industry, and beetroot factories were established at many centres both in Germany and in France. In Germany the enterprise came to an end almost entirely with the downfall of Napoleon I. ; but in France, where at first more scientific and economical methods of working were introduced, the manufacturers were able to keep the industry alive. It was not, however, till after 1830 that it secured a firm footing; but from 1840 onwards it advanced with giant strides. Now it is an industry of national importance, especially in Germany, control-ling in the meantime the market against the cane-sugar trade. While cane sugar was practically without a rival, the cultivation was in general highly profitable, but it was conducted under tropical skies, largely by slave labour and entirely removed from scientific supervision. The staple produced at the plantations was raw sugar, which was sent to Europe to be refined. It was not till the pressure of the competition with beet sugar began to make itself felt that planters realized the necessity for improving their methods of working. It has now been found possible to apply many of the processes and appliances devised in connexion with the production of beet sugar to the extraction of its older rival.

Manufacture

CANE SUGAR MANUFACTURE. —The sugar-cane (Saccharum officinarum) is a species of grass, the stalks or canes of which reach a height of from 8 to 15 feet, and attain a diameter of 1 1/2 to 2 inches. The stalks are divided into prominent joints or inter-nodes, the long sheathing alternate leaves springing from each joint. As the canes approach maturity they throw up a long smooth hollow joint termed the arrow, whence springs the flower head, consisting of beautiful feather-like loose panicles. The points are filled with a loose spongy fibrous mass, saturated with a juice which is at first watery but afterwards becomes sweet and glutinous. As the joints ripen, the leaves wither and fall away and the stem becomes externally smooth, shining, and hard, containing much silica. The varieties of sugar-cane in cultivation are very numerous, and are distinguished from each other by external colour, length of internodes (3J to 10 inches), height to which they grow, richness in juice, and many other characters. The four principal classes cultivated in the West Indies are the Creole or country cane, the Tahiti cane, the Batavian cane, and the Chinese cane. An average sample of Tahiti cane at maturity contains—water, 71'04 per cent.; sugar, 18'00 ; ligneous tissue and pectin, 9'56 ; albumen, colouring matter, and insoluble salts, 1'20 ; silica, 0'20. The sugar-cane requires a rich, well-drained, but moist soil. It is propagated by slips taken from the upper part of the canes, which are planted at intervals about 5 feet apart or in close-set rows 6 feet apart. In the West Indies the planting takes place between June and October, and in the case of the Creole variety the canes are ready for cutting down by the beginning of January in the second following year. When mature the canes are cut down close to the ground, the remaining leaves and upper shoot removed, and the stalks immediately taken to the mill for crushing. The stocks left are liberally manured with crushed remains and ashes of former crops, combined with nitrogenous manures, and are covered over; they then send up a crop of new stems, termed rattoons. The system of rattooning can be continued for several years, but the canes so treated go on declining in size and in yield of sugar. The yield of canes, of course, varies within wide limits ; but 20 tons per acre may be regarded as a good average crop.





Cane-Crushing.—The juice is extracted by pressing the canes in a sugar-mill between three, or sometimes five, heavy close-set rollers of iron, placed horizontally in a powerful framework or cheeks. In a three-roller mill they consist of a cane, top, and megass roller respectively. The top roller is set above and between the other two, and under its periphery is a fixed metal plate called the trash turner, which guides the cane coming from between the cane and top rollers into the bite between top and megass rollers. Generally the cane roller is screwed up to within half an inch of the top roller, while the free space between top and megass rollers is considerably less. The mill is set in motion by steam power, and the canes are fed by nand on a travelling band or carrier into the rollers. If a thick feed is placed at one side and little at the other, one portion passes through imperfectly crushed, while the other severely strains the mill and may either stop the machinery or cause a breakdown by some portion giving way. The yield of juice obtained with an ordinary mill varies from 60 to 65 per cent. One of the most useful devices for improving the machinery is the substitution of an hydraulic attachment, which can be applied to the headstocks of any of the rollers, in place of the rigid and im-movable screws and wedges of the ordinary mill. This secures a uniform pressure with the most irregular feed and much greater pressure than is possible with rigid rollers, resulting in a greatly increased yield of juice (67 to 70 per cent.) and a megass or refuse proportionately drier and therefore more available for fuel for steam-raising. The juice from the mill is led into a trough, whence it is carried by pipes to the clarifiers. But even the most perfect system of mechanical pressure leaves a large percentage of sugar in the refuse cane, and to remedy this the diffusion method (see below), which has been attended with remarkable success in the beet in-dustry, has been also applied to the extraction of cane juice. At Aska (Madras) in India it has been found possible by that process to obtain as much as 87J of the 90 per cent, of juice present in canes. Considerable difficulty was at first found in slicing the silicious stalks for diffusion ; but this process seems to promise a much more exhaustive extraction of the juice than can be secured by mechanical means. The juice is a turbid frothy liquid of a yellowish green colour, with a specific gravity of from D070 to about l'lOO. The variety of cane cultivated, its age, and especially the nature of the season in which it has grown as regards rain, all have an important influence on the yield of sugar. The expressed juice contains from 15 to 18 per cent, of solids, showing on a good average—sugar, 14'55 per cent.; glucose, 1'65 ; non - saccharine solids, -917 ; ash, -283. The juice got from sugar-cane is much richer in sugar and less contaminated with non-saccharine solids than that yielded by beet; and its pleasant taste and aromatic odour contrast markedly with the acrid taste and unpleasant smell of beet juice.

Purification of the Juice.—In the hot climates where sugar-canes tion of grow a process of fermentation is almost immediately set up in cane the impure juices from the canes, causing the formation of invert juice. sugar and later products of fermentation, and thereby a serious loss of sugar. It is therefore essential that with the least possible delay the manufacturing processes should be proceeded with. The , juice is first filtered through a set of sieves to remove the mechanical impurities it carries from the mill. Then it is run into the clarifiers, a series of iron vessels capable of holding six or eight hundred gallons of juice, and in these it is heated up to about 130° Fahr., and milk of lime is added in quantity sufficient to neutralize the acid constituents it contains. The heat is then raised to just under the boiling-point, when gradually a thick scum rises and forms on the surface, and when the defecation thereby effected is complete the clear liquid below is drawn off. Various other sub-stances besides lime are employed for the defecation of juice, one of which, the bisulphite of lime in the so-called leery process, has attained considerable favour. The bisulphite is added in excess ; the acids of the juice decompose a certain proportion of it, liberat-ing sulphurous acid, which by its influence promotes the coagula-tion of the albuminous principles and at the same time promotes the bleaching of the liquid. In another process the green juice is first treated with sulphurous acid, which (with the natural acid constituents) is subsequently neutralized by lime. Recently also phosphoric acid has come into favour as a defecating agent.

Boiling Down.—From the clarifier the juice passes on to the battery, a range of three to five pans or "coppers," heated by direct fire, in which it is concentrated down to the crystallizing point. The juice, gradually increasing in density, is passed from the one into the other till it reaches the last of the series, the striking teach, in which it is concentrated to the granulating point. The skimmings from these pans are collected and used for making rum. From the striking teach the concentrated juice is removed to shallow coolers, in which the crystals form. A few days later it is transferred to hogsheads in the curing-house, and the molasses is drained away from the crystallized raw sugar into tanks. The sugar so obtained is the muscovado of the sugar-refiners, and both that and the molasses form their principal raw materials. Clayed sugar consists of raw sugar from which a portion of the adherent molasses has been dissolved by the action of moisture percolating through it from moist clay laid over its surface. Labour difficulties and scarcity of water operate against the general introduction of improved systems of working cane-juice, but in many plantations central usines or sugar-factories have been established with great success. In these the canes of many growers are worked up with the aid of the triple effect apparatus, the vacuum pan, and the centrifugal separator employed by beet manufacturers. Wetzel's pan, Fryer's concreter, and similar devices for the efficient evapora-tion of juice by exposing it to the action of heat in thin films over an extended surface are also in use.

BEET SUGAR MANUFACTURE.—The sugar beet is a cultivated variety of Beta maritima (natural order Chenopodiaceae), other varieties of which, under the name of mangold or mangel wurzel, are grown as feeding-roots for cattle. The plants are cultivated like turnips, and the roots attain their maturity in about five months after sowing, being gathered during September and October. The efforts of growers have been largely directed to the development of roots yielding juice rich in sugar; and especially in Germany these efforts have been stimulated by the circumstance that excise duty on inland sugar is there calculated on the roots. The duty is based on the assumption that from 12J parts of beet 1 part of grain sugar is obtained ; but in actual practice 1 part of raw sugar is now yielded by 9'27 parts of root. Moreover, when the sugar is exported a drawback is paid for that on which no duty was actually levied, and hence indirectly comes the so-called bounty on German sugar. In 1836 for 1 part of sugar 18 parts of beet were used, in 1850 13'8 parts, in 1860 12'7 parts, and now (1887) about 9'25 parts only are required. In France till recently the inland duty was calculated on the raw sugar ; hence the French grower devoted himself to the production of roots of a large size yielding great weight per acre, and had no motive to aim at rich juice and econo-mical production. Many processes, therefore, have come into use in German factories which are not available under the French methods of working. But since 1884 the French manufacturers have had the power to elect whether duty shall be levied on the roots they use or on the raw sugar they make, and a large propor-tion have already chosen the former. The nature of the seasons exercises much influence on the composition of sugar beet, especially on its richness in sugar, which may range from 10 to 20 per cent. The following represents the limits of average composition :—

Water i„i»„i 84'5 to T9'°
Sugar and other soluble bodies } ,., 3 \ 11 -5 to 17 -0
Cellulose and other solids j-sonas 4.Q 4.Q

The non-saccharine solids in the juice are very complex, embrac-ing albumen, amido-acids, and other nitrogenous bodies, beetroot gum, soluble pectose compounds, fat, colouring matter, with the phosphates, sulphates, oxalates, and citrates of potash, soda, lime, and iron, and silica. The relation and relative proportion of these to the sugar present are of the utmost importance.

Extraction of juice. Two distinct ways of obtaining the juice from beet are now principally employed,—pressure and diffusion. The mechanical methods of pressure are principally used in France ; the process of diffusion is all but universal in Germany. Formerly a modified diffusion process—maceration—was in use ; but it has now been generally abandoned, as has also a means of separating the juice by centrifugal action. For the mechanical processes the roots have first to be reduced to a condition of fine pulp.

Method of pressure. For this purpose the roots, thoroughly trimmed and washed, are fed into a pulping machine, in which a large drum or cylinder, armed with close-set rows of saw-toothed blades, is revolved with great rapidity, so that the fleshy roots on coming against them are rasped down to a fine uniform pulp. The operation is assisted by pouring small quanti-ties of water or of watery juice on the revolving drum, which thins the pulp somewhat, and aids the free flow of the juice in the sub-sequent operation. The expression of the juice is effected either by the hydraulic press or by continuous roller presses. From the hydraulic press the juice flows freely at first; but in order to obtain the largest possible yield it is necessary to moisten the first press-cake and submit it to a second pressure, whereby a thin watery juice is expressed. After having been pressed twice, the cake that is left should amount to not more than 17 per cent, of the original roots; hence, allowing 4 per cent, for ligneous tissue, &c, only about 13 per cent, of water, sugar, and soluble salts, &c, remain in the refuse. For the system of continuous pressure presses ana-logous to the mills employed for cane-crushing are used. Many modifications of the roller press have been introduced, and, although the best express from 3 to 5 per cent, less juice than the hydraulic press, they have several advantages under the system formerly common in France, which bound the maker to return press-cake containing a certain proportion of sugar for use as a feeding-stuff on the farm. In certain forms of press the lower rollers are per-forated to allow the escape of the expressed juice ; in some the rollers are covered with india-rubber, so that they give an elastic squeeze on an extended surface ; and in others the pulp is carried in an endless cloth through a series of rollers, being all the while subjected to gradually increasing pressure.

Diffusion process. The diffusion process for obtaining beet juice depends on the action of dialysis, in which two liquids of different degrees of concentration separated by a membrane tend to transfuse through the membrane till equilibrium of solution is attained. In the beet the cell-walls are membranes enclosing a solution of sugar. Supposing these cells to be brought into contact with pure water, then by theory, if the cells contain 12 per cent, of juice, transfusion will go on till an equal weight of water contains 6 per cent, of sugar, while by the passage of water into the cell the juice there is reduced to the same density. Taking the 6 per cent, watery solution and with it treating fresh roots containing again 12 per cent, a 9 per cent, solution will be attained, which on being brought a third time in contact with fresh roots would be raised to a density of 10'5. Thus theoretically seven-eighths of the whole sugar would be obtained at the third operation, and it is on this theory that the diffusion process is based. In working the process a range of ten or twelve diffusers are employed, eight being in operation while the others are being emptied, cleaned, and refilled. These diffusers consist of large close upright cylinders capable of holding each two or three tons of sliced roots. They are provided with manholes above, perforated false bottoms, and pipes communicating with each other, so that the fluid contents of any one can be forced by pressure into any other. In working, pure water from an elevated tank is run into No. 1 cylinder, which contains the slices almost exhausted of their soluble contents ; it percolates the mass, and by pressure passes into No. 2, where it acts on slices some-what richer in juice. So it goes through the series, acquiring density in its progress and meeting in each successive cylinder slices increasingly rich in juice. Before entering the last cylinder the watery juice is heated, and under the combined influence of heat and pressure the juice within the cylinder becomes richly charged with sugar. No. 1 cylinder when exhausted is disconnected ; No. 2 then becomes No. 1, and a newly charged cylinder is joined on at the other extremity; and so the operation goes on continuously. The juice ultimately obtained is diluted with about 50 per cent, of water; but it is of a comparatively pure saccharine quality, with less gummy, nitrogenous, and fibrous impurities than accompany the juice yielded by mechanical means.

Purification of juice. If the juice obtained by any process were a pure solution of sugar the manufacturing operations would be few and simple. But beet beet juice is at best a very mixed solution, containing much gum, acid bodies, nitrogenous matter, and various salts. These adhere to the saccharine solution with the utmost obstinacy ; they attack the sugar itself and change crystalline into invert sugar, communicat-ing to it a dirty brown colour and a disagreeable acrid taste and smell. To separate as far as possible the non-saccharine constituents and to remove the colour from the juice are troublesome tasks. The preliminary purification embraces two sets of operations,—first the treatment of the juice with lime and carbonic acid, secondly, filtration through animal charcoal. Under the old method of working the juice is first boiled in a copper pan with milk of lime to the extent of from J to 1 per cent, of lime to the weight of juice operated on. The boiling serves to coagulate the albuminoids, while the lime forms with certain of the other impurities an insoluble precipitate, and in part combines with the sugar to form a soluble saccharate of lime. The insoluble lime combination and the coagulum rise as a scum over the surface of the juice, and the latter, now comparatively clear, is drawn off by a siphon pipe, to be treated in another vessel with carbonic acid. The acid breaks up the saccharate of lime and forms insoluble carbonate of lime, which in precipitating carries down further impurities with it. After settlement the clear juice is drawn off and the precipitated slime pressed in a filter press, whereby it gives up the juice it contains. As now commonly conducted these operations—treating with lime and carbonic acid—are combined, according to the method devised by Jelinek. The juice to be purified is heated and treated with as much as 5 per cent, of lime, while carbonic acid is simultaneously injected into the mass. The juice meantime is raised to a temperature just under boiling-point. The addition of such a large amount of lime effects the precipitation of a great proportion of the non-saccharine constituents of the juice. The whole mass of turbid liquid formed by this treatment is forced into a filter press, and there the lime compounds and impurities are separated with great rapidity from the saccharine juice. Numerous other methods of purification have been proposed, and to some extent have met with favourable reception ; tut of these we can only mention that of Dubrunfaut and De Massy, in which baryta is substituted for lime, thereby producing an insoluble barium saccharate, and the analogous process of Scheibler, in which strontia is employed in the same sense, producing likewise insoluble strontia saccharate. The juice, which still contains much saline and other non-saccharine matter, is next filtered through animal charcoal; this largely removes colouring matter and carries away a further proportion of the salts. Charcoal filtering is an expensive process; being, moreover, a feature of the subsequent refining, many attempts have been made to dispense with it, and the success of the Jelinek method in producing a comparatively pure and colour-less juice has given rise to hopes that it may at this stage be yet dispensed with.

Crystallization. The next operation consists in concentrating the comparatively pure but thin and watery juice,—a work formerly done in open pans by direct firing, but now carried out in closed vessels, in which the vacuum pan principle of boiling is brought into play. The apparatus consists of a series of three closed vessels, hence called a "triple effect," although in some cases a two-vessel apparatus or double effect is employed. These pans are provided internally with a series of closed pipes for steam-heating, the steam from the boiler of the first passing by a pipe into the worm of the second, and similarly the steam from the second into the worm of the third when a third pan is. employed. The steam which rises in the third pan is drawn off by a condenser and vacuum pump, and, as the vacuum so created acts through the whole series, the juice is evaporated and concentrated at a comparatively low temperature by the agency of the steam supplied to the first pan. The juice increases in gravity as it is drawn from the one pan to the other, till by the time it is run off from the third cylinder it has attained a concentration representing a gravity of about 25 Baume. This concentrated juice is while in a heated condition filtered through fresh charcoal, from which it comes ready for boiling down to orystallization. To bring the dense juice to the crystallizing point it is necessary to conduct the evaporation at the lowest possible temperature. High temperature increases the uncrystallizable at the expense of the crystallizable portion, and burns some proportion into caramel, which darkens the liquid and the resulting sugar crystals. Boiling down at low temperature is effected by the use of the vacuum pan, a closed globular vessel in which by the aid of a condenser and air-pump a vacuum is maintained over the boiling juice and the boiling-point is lowered in proportion to the decrease of air pressure. In vacuum pan boiling the thick juice may simply be concentrated to that degree of density from which, on cooling, the crystals will form, or the crystals may be allowed to separate from the mother-liquor in the pan while the boiling proceeds; these crystals, forming nuclei, increase in size from the concentra-tion of fresh charges of juice added from time to time. By this method the boiled-down juice as it leaves the pan consists of a grainy mass of crystals floating in a fluid syrup.

Separation of crystals from molasses. After being allowed to cool, the mass is fed into the drum or basket of a centrifugal machine, which by its rapid rotation separates the fluid molasses from the crystals, driving the liquid portion through the meshed wall of the basket. For further cleaning of the crystals from adherent syrup a small quantity of either water or pure syrup is added to the drum, and is likewise forced through the sugar crystals by centrifugal action. Steam also is employed for cleaning the crystals whilst in the centrifugal machine. The syrup from the first supply of sugar is returned to the vacuum pan, again boiled, and treated as above for a second supply of less pure sugar; similarly a third supply is yielded by the drainings of the second. The molasses from the third supply is a highly impure mixture of crystallizable and invert sugar, potash, and other salts, smelling and tasting powerfully of its beet origin. Many methods have been tried to recover the large amount of sugar contained in this molasses. That most extensively employed is the osmose process originated by Dubrunfaut, in which, by the application of a dialyser, it is found that the salts pass through the membrane more rapidly than does sugar. The elution process of Scheibler, which depends on the formation of a saccharate of lime, and the more recent strontia process of the same chemist, in which a strontiate of lime is formed, are also much employed. Another means of utilizing the molasses consists in fermenting and distilling from it an im-pure spirit for industrial purposes.

Sugar-Refining.— Sugar-refiners deal indifferently with raw cane and beetroot sugars which come into the market, and by precisely the same series of operations. The sugar is first melted in charges of 5 or 6 tons in bloio-ups,—cast-iron tanks fitted with mechanical stirrers and steam-pipes for heating the water. The solution called liquor is brought to a certain degree of gravity, from 25 to 33 Baume, and formerly it was the practice to treat it, especially when low qualities of sugar were operated on, with blood albumen. The hot liquor is next passed through twilled cotton bags encased in a meshing of hemp, through which the solution is mechanically strained. From 50 to 200 of these filters are suspended in close chambers, in which they are kept hot, from the bottom of a per-forated iron tank, each perforation having under it a bag. These bags have from time to time to be taken off for cleaning out and washing. From the bag filter the liquor is passed for decolorizing through beds of animal charcoal enclosed in cisterns to a depth of from 30 to 50 feet, the sugar being received into tanks for con-centration in the vacuum pan. In that apparatus it is " boiled to grain," and the treatment is varied according to the nature of the finished sugar to be made. To make loaves small crystals only are formed in the pan, and the granular magma is run into steam-jacketed open pans and raised to a temperature of about 180° to 190° Fahr., which liquefies the grains. The hot solution is then cast into conical moulds, the form of the loaf, in which the sugar as it cools crystallizes into a solid mass, still surrounded and mixed with a sjyrup containing coloured and other impurities. After thorough settling and crystallization, a plug at the bottom of the mould is opened and the syrup allowed to drain away. To whiten the loaves they are treated with successive doses of saturated syrup, ending with a syrup of pure colourless sugar. These doses are poured on the upper side of the cone, and, percolating down through the porous mass, carry with them the impure green syrup which still may adhere to the crystals. The liquor which obstinately remains in the interstices is driven out by suction or centrifugal action; the loaf is rounded off, papered, and placed in a stove for drying. The syrup which drains from the loaves is sold as golden syrup. When refined crystals are to be made the contents of the vacuum pan are passed into the centrifugal machine; the syrup is then driven off by rotation, and the crystals purified either by adding pure syrup to the revolving basket or by blowing steam through it. There are numerous modified and subsidiary processes connected with refining, as well as with all branches of the sugar industry, regarding which it is not possible here to enter into detail. The industry is essentially progressive and subject to many changes.

SORGHUM SUGAR.—The stem of the Guinea corn or sorghum sugar (Sorghum saccharatum) has long been known in China as a source of sugar, and the possibility of cultivating it as a rival to the sugar-cane and beetroot has attracted much attention in America. The sorghum is hardier than the sugar-cane ; it comes to maturity in a season; and it retains its maximum sugar content a consider-able time, giving opportunity for leisurely harvesting. The sugar is obtained by the same method as cane sugar. The cultivation of sorghum sugar has not found much favour in the United States ; the total yield from that source in 18S5 did not exceed 600,000 lb.

MAPLE SUGAR.—The sap of the rock or sugar maple, Acer saccharinum, a large tree growing in the United States and Canada, yields a local supply of sugar, which also occasionally finds its way into commerce. The sap is collected in spring, just before the foliage develops, and is procured by making a notch or boring a hole in the stem of the tree about 3 feet from the ground. A tree may yield 3 gallons of juice a day and continue flowing for six weeks; but on an average only about 4 lb of sugar are obtained from each tree, 4 to 6 gallons of sap giving 1 lb of sugar. The sap is purified and concentrated in a simple manner, the whole work being carried on by farmers, who themselves use much of the pro-duct for domestic and culinary purposes. The total production of the United States ranges from 30,000,000 to 50,000,000 lb, principally obtained in Vermont, New York, Ohio, and Pennsylvania. In Canada also a considerable quantity of maple sugar is collected for domestic use.

PALM SUGAR.—That which comes into the European market as jaggery or khaur is obtained from the sap of several palms, the wild date (Phoenix sylvestris), the Palmyra (Borassus flabelliformis), the cocoa-nut (Cocos nucifera), the gomuti (Arenga saccharifera), and others. The principal source is Phoenix sylvestris, which is cultivated in a portion of the Ganges valley to the north of Calcutta. The trees are ready to yield sap when five years old; at eight years they are mature, and continue to give an annual supply till they reach thirty years. The collection of the sap (toddy) begins about the end of October and continues, during the cool season, till the middle of February. The sap is drawn off from the upper growing portion of the stem, and altogether an average tree will run in a season 350 lb of toddy, from which about 35 lb of raw sugar—jaggery—is made by simple and rude processes. Jaggery production is entirely in native hands, and the greater-part of the amount made is consumed locally; it only occasionally reaches the European market.

STARCH SUGAR. —This, known in commerce as glucose or grape sugar, an abundant constituent of sweet fruits, &c. (see p. 623 above), is artificially elaborated on an extensive scale from starch. The industry is most largely developed in Germany, where potato starch is the raw material, and in the United States, Indian corn starch being there employed. The starch is acted on by a weak solution of sulphuric acid, whereby soluble starch is formed, which ulti-mately results in a mixture of glucose and dextrose in varying proportions, constituting the starch sugar of commerce. The operations embrace the boiling of the starch with water containing the requisite proportion of acid, the neutralization of the acid with lime, and the formation of a precipitate of sulphate of lime, which is separated by filtration in a filter press. The filtered liquid is, when necessary, deprived of colour by passing it through a bed of animal charcoal, and then it is concentrated to a density of from 40 to 45 Baumé in a vacuum pan. If the resulting syrup contains little dextrin it will on cooling slowly solidify into a granular con-cretionary mass ; but if much dextrin is present it remains in the condition of a syrup. Starch sugar is very largely used by brewers and distillers, and by liqueur makers, confectioners, and others for making fruit and other syrups. Burnt to caramel, it is also employed to colour beverages and food substances. As an adulterant it is largely employed in the honey trade and for mixing with the more valuable cane sugar. In 1885 there were about fifty factories in Germany engaged in starch sugar making, in which 10,000 tons of hard sugar, 20,000 tons of syrup, and 1250 tons of "colour" were made.

Commerce

At the present time, judging by the amount sent to the market, cane and beet sugars are produced in about equal amount; but, since vast quantities of cane sugar are grown and consumed in India, China, and other Eastern countries of which we get no account, there cannot be a doubt that the annual production of cane far exceeds that of beet sugar. Still, as a growth of not more than forty years, the dimensions to which the beet sugar trade has attained are certainly remarkable. But these dimensions would not have been so suddenly attained had it not been for the system of protection established in the producing countries and of bounties paid to the beet manufacturers on exporting their produce. The United Kingdom is the only open market for sugar, which is con-sequently sold there at an unprecedentedly low price. The follow-ing table shows the relative proportions of the beet and the cane sugar trade and the principal sources of the supply for 1880-85 :—
The relative value of beet and of a low quality of raw cane sugar for 1879-86 are shown in the following table:

== TABLE ==

(J. PA.)



Footnotes

623-1 See Amer. Chem. Jour., i. p. 170, ii. p. 181, and i. p. 425 ; short notices in Jour. Soc. Chem. Ind., iv. p. 608, and February 1886.

625-1 Lucan, iii. 237; Seneca, Epist., 84; Pliny, H. N., xii. 8 (who supposes that sugar was produced in Arabia as well as in India); Peripl. Mar. Eryth., § 14; Dioscorides, ii. 104. The view, often repeated, that the saccharum of the ancients is the hydrate of silica, sometimes found in bamboos and known in Arabian medicine as tabashir, is refuted by Yule, Anglo-Indian Glossary, p. 654 ; see also Not. et Extr. des MSS. de la Bibl. Nat., xxv. 207 sq.

625-2 Marco Polo, ed. Yule, ii. 208, 212. In the Middle Ages the best sugar came from Egypt (Kazwini, i. 202), and in India coarse sugar is still called Chinese and fine sugar Cairene or Egyptian.

625-3 So the Armenian Geography ascribed to MOSES OF CHORENE (q.v. for the date of the work) ; St Martin, Mém. sur L'Arménie, ii. 372.

625-4 Istakhri, p. 91; Yákút, ii. 497. Tha'álibí, a writer of the 11th century, says that Askar - Mokram had no equal for the quality and quantity of its sugar, "notwithstanding the great production of 'Irak, Jorjan, and India." It used to pay 50,000 pounds of sugar to the sultan in annual tribute (Latáif, p. 107). The names of sugar in modern European languages are derived through the Arabic from the Persian shakar.



The above article was written by:

(1) Introduction. Glucoses. Saccaroses.
Prof. Dittmar

(2) History. Manufacture. Commerce.
James Paton.



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