Sugar, a name used in nearly all languages, in various forms, to designate a limited number of sweet products of plants, which is made by the chemist to include several organic com-pounds, many of which may be artificially produced from similarly constituted organic bodies. Sugars are therefore divided into natural and artificial. In general terms they are now included among a group of compounds called hexatomic alcohols. Two of the natural sugars, mannite and duleite, having the composition C6H14O6, are saturated hexatomic alcohols, derived from the saturated hydrocarbon C6H14. Several others, called glucoses, have the formula C6H12O6, and may be regarded as aldehydes of these alcohols. It may be remarked that ordinary glucose or grape sugar is converted into mannite by the action of nascent hydrogen, just as acetic aldehyde, C2II40, is converted into common alcohol, C2H6O. There are also diglucosic alcohols, C12H22O11, the most important of which are cane sugar and milk sugar. - Mannite, C6H14O6, is the chief component of manna, an exudation from a species of ash. It is also found in several sea weeds and in mushrooms. It may be prepared by dissolving manna in boiling alcohol and filtering while hot. It crystallizes on cooling in tufts of slender, needle-like, four-sided prisms.

It may be formed artificially by the action of sodium amalgam on glucose, the latter taking up two atoms of hydrogen. By oxidation with nitric acid mannite is converted into saccharic acid, C6H10O8, and ultimately oxalic acid. The boiling point is 329° F. Dulcite, or dulcose, having the same formula, is obtained from a crystalline substance of unknown origin, imported from Madagascar, by boiling water. Crystals belonging to the monoclinic system form on cooling the solution. It thus differs from mannite, the crystals of which are trimetric, and also in its boiling point, which is 300°. - The glucoses are a group of sugars having the common formula C6H12O6, and consisting, as far as known, of eight members : 1. Ordinary glucose or dextro-glucose, so named from its power of rotating a ray of polarized light to the right, is made by hydration of starch by the action of dilute acids or of diastase. It is found in honey and various fruits, especially grapes, and therefore also called grape sugar. (See Fermentation.) Its rotatory power is +56° at all temperatures. 2. Maltose is produced by the limited action of diastase on starch, and differs from ordinary glucose only in its power of rotating a ray of polarized light, having a dextro-rotatory power three times as great as that of ordinary glucose.

It is converted into ordinary glucose by boiling with dilute acids. 3. Laeulose is isomeric with the others, but distinguished from them by turning the plane of polarization to the left. It also, unlike other sugars, has its rotatory power changed by varying the temperature, the power diminishing with increase of temperature, being - 106° at 57° F, - 79.5° at 125.5° F., and -53° at 194° F. It occurs, associated with dextro-glu-cose, in honey and many fruits. A mixture of laevulose and dextro-glucose constitutes fruit sugar, fructose, or invert sugar, which is also laevo-rotatory, because the specific rotatory power of laevulose at ordinary temperature is greater than that of dextro-glucose. 4. Man-nitose, produced by the oxidation of mannite, is uncrystallizable and fermentable, but has no action on polarized light. 5. Galactose, formed by the action of acids on milk sugar, crystallizes more readily than ordinary glucose, has a dextro-rotatory power of 83.3°, and is easily fermentable. 6. Inosite occurs in the muscular substance of the heart and other organs of the animal body, in green kidney beans, and in other plants. It forms prisms resembling gypsum, soluble in water, but insoluble in alcohol and ether.

It does not ferment with yeast, but in contact with cheese, decaying flesh, or membrane, with chalk, it undergoes lactous fermentation, producing lactic, butyric, and carbonic acids. It has no optical rotatory power. 7. Sorbine occurs in the juice of the mountain ash berry. The juice on standing deposits brown crystalline matter, which by recrystallization forms crystals belonging to the trimetric system. It dissolves easily in water, and has a very sweet taste. It is converted by hot nitric acid into oxalic acid, and does not ferment with yeast, but like inosite undergoes lactous fermentation. It has a rotatory power of about - 47°. 8. Eucalyne is found with other kinds of sugar in the so-called Australian manna, which falls in opaque drops from various species of eucalyptus. Its optical rotatory power is about +50°. - Besides these glucoses, there are sugars which may be regarded as formed by the combination of two or more molecules of glucose with the elimination of a number of molecules of water.

These sugars have been called polygluccsic alcohols, having the formula Ci2H22011. 1. The most important member, as well as the most important of all the sugars, is cane sugar, or saccharose, whicli is found in the juice of many of the grasses and the sap of several forest trees, particularly the hard maple, in the roots of the beet, parsnip, mallow, and several other plants, and in most sweet fruits, associated with laevulose and dextro-glucose (currant sugar, fructose). Walnuts, hazelnuts, and almonds contain only cane sugar. Honey and the nectaries of flowers contain cane sugar together with invert sugar. Pure cane sugar separates from a solution by slow evaporation in large transparent colorless crystals, having the figure of a modified monoclinic prism. From hot saturated solutions it is obtained in masses of smaller crystals (loaf sugar). Its optical rotatory power is +73.8°; its sp. gr. PC, unchangeable in the air. When heated a little above 320° it is converted, without loss of weight, into a mixture of dextro-glucose and laevolusan, the anhydride of laevulose (C12H22011 = C6H12O6 + C6H10O5 or laevolusan). It changes with loss of water into other substances as the temperature rises, until at 410° a brown substance called caramel is formed, which consists of a mixture of several compounds, all resulting from the elimination of the elements of water from sugar.

As the temperature rises gases are evolved, consisting of carbonic oxide, marsh gas, and carbonic acid, and a distillate is obtained consisting of brown oils, acetic acid, acetone, and aldehyde, a quantity of charcoal remaining in the retort. By prolonged boiling with water, cane sugar is converted into invert sugar, the transformation being accelerated by the presence of acids, especially sulphuric. It is not directly fermentable, but by the action of yeast is resolved into dextrose and laevulose, which then enter into fermentation. It is a reducing agent, capable of readily taking the oxygen from several oxides and metallic salts. It forms with chlorate of potassium a mixture which detonates on percussion, and burns vividly in contact with oil of vitriol. It is distinguished from glucose by not turning brown when triturated with alkalies; but it combines with the alkalies, forming compounds called su-crates. 2. Parasaccharose, C12H22O11, is produced by the spontaneous fermentation of a solution of cane sugar containing ammonium phosphate. Its rotatory power is +108°. 3. Melitose, C12H22011, is found in the Australian manna, associated with mannitose.

The crystals which are deposited from the aqueous solution are hydrated, the formula being C12H22O11 + 3H2.O. At 212° F. they give off two molecules of water, and at 286° become anhydrous. Its rotatory power is +102°. Melitose ferments by the action of yeast, but is first resolved into glucose and eucalyne. 4. Melezitose, C12H22011, is a kind of sugar found in the so-called manna of Briancon, which exudes from the young shoots of the larch. It is not as easily acted on by reagents as the foregoing. Its rotatory power is about +94°. 5. Trehalose, C12II22011, 2H20, is obtained from trehala manna, the produce of a species of echinops growing in the East. It forms rhombic crystals, which when heated below 212° F. slowly give off their molecules of water. Its rotatory power is +199°. With strong nitric acid it forms a detonating nitrocompound. It is not readily acted on by reagents. 6. Mycose, isomeric with trehalose, and also containing two molecules of water, is obtained from the ergot of rye by precipitating the aqueous extract of the fungus with basic acetate of lead, removing the lead from the filtrate by hydrosulphuric acid, evaporating to a sirup, and leaving the liquid to crystallize.

Its rotatory power is +192.5°. 7. Milk sugar, or lactose, contains one molecule of water, the formula being C12H22011+H20. It is an important constituent of milk, and is obtained by evaporating the whey to a sirup, from which on standing it separates in impure crystals, and may be purified by redissolving in water and filtering through animal charcoal. It forms white, translucent, four-sided, trimetric prisms of great hardness. It dissolves slowly in cold water, requiring five or six times its weight. Its optical rotatory power is +59.3°. Very strong nitric acid converts milk sugar into nitro-lactine. It is brought very slowly into alcoholic fermentation by the action of yeast, but when cheese or rennet is used it is readily converted into lactic acid, alcohol being formed at the same time. A kind of sugar called glycyrrhizine or liquorice sugar, having the formula C24H36O9, is found in liquorice root (glycyrrhiza). It has a peculiar sweet taste, but cannot be made to ferment. According to Gorup-Besanez, when boiled with dilute acids, it splits up into a resinous body called glycyrretine, C18H26O4, and glucose. - Saccharimetry. There are various methods of estimating the proportion of sugar in a given solution, which are embraced under the generic term saccharimetry.

They are usually employed for the estimation of cane sugar. There are four principal methods: 1, by the specific gravity of the solution; 2, by the amount ot* carbonic anhydride or of alcohol it will yield in fermentation; 3, by the amount of suboxide of copper precipitable from a solution by the action of grape sugar, into which the cane sugar present is first converted; 4, by the degree of rotation given to a beam of polarized light in passing through the solution. In the first and fourth methods instruments called saccharometers are employed, the term sac-charimeter being often applied to the polarizing instrument. The specific gravity or hydrometric saccharometer is used by brewers for determining the amount of saccharine matter which has been produced in wort by the fermentation of malt. (See Brewing, and Hydro meter.) The instrument is also employed by sugar makers and distillers. The brewer's saccharometer is usually graduated so as to indicate the excess of weight of 1,000 parts of a liquid by volume over that of the same volume of distilled water. For this purpose the hydrometer is marked 1000 upon its stem at the point to which it sinks in water, and with increasing numbers below this point.

If the tested solution is dense enough to float the instrument till the number 1065 is at the surface, it is said to have a specific gravity of 65; if only to 1020, its gravity is said to be 20. Tables are used by which the quantity of sugar may bo estimated from the specific gravity thus ascertained, and the tables may be adapted to differently graduated instruments, but the one above described (Baume's) is usually employed. As beer wort holds other substances besides sugar in solution, the method is not exact, but in experienced hands it answers all the purposes of the brewer. "When the solution is purely saccharine, or nearly so, as in clarified cane juice, the process is more nearly accurate; but when other substances are pres-ent the precise amount of sugar may be de-termined by the second method, that of producing fermentation and estimating the quantity of carbonic anhydride or of alcohol which is thereby formed. The third method, that by precipitation of suboxide of copper from an alkaline solution of tartrate of copper and potash, is briefly as follows: A standard solution, known as Fehling's, is prepared with 1 oz. of crystallized sulphate of copper, 3 oz. of bitartrate of potash, ½ oz. of pure carbonate of potash, and 14 or 16 oz. of a solution of caustic potash of spgr. 1.12, with sufficient water to make the solution weigh 15,160 grs.; 200 grs. of this solution contain an amount of copper which is completely precipitated by 1 gr. of grape sugar.

In using Fehling's solution a temperature approaching the boiling point should be maintained, and the saccharine solution should be slowly added from a graduated burette. It is necessary before testing to convert the cane sugar into glucose, which is done by adding sulphuric acid and boiling. The method by polarized light is performed by employing an instrument first devised by Biot, but since modi-fied and improved by Soleil. In the article Light, vol. x., pp. 449, 450, it is shown that several substances have the property of rotating the plane of a polarized ray, some to the right and some to the left, and also that substances having the same chemical composition may rotate the ray in both directions. A so-lution of dextrose (grape sugar or glucose) has the property of right-handed rotation, while laevulose, having the same chemical composition (C6H12O6), turns the plane of polarization to the left. Quartz also, by reason of a difference in its molecular structure, is in some specimens right-handed and in others left-handed in its power of rotation.

The original apparatus devised by Biot employed a tube containing the solution of sugar to be examined, the depth of the liquid producing a certain degree of rotation indicating the proportion of glucose it contained, and therefore the amount of cane sugar, this being first converted into glucose. The saccharimeter devised by M. Soleil does not measure the degree of rotation produced directly, as in Biot's instrument, but employs the principle of compensation, and furthermore employs a comparison of color, using therefore white instead of homogeneous light. The amount of compensation is measured by an attachment called a compensator, which is made of two wedge-shaped pieces of quartz whose combined thickness may be varied by sliding them over each other. A copper tube, m, figs. A and B, tinned on the inside and containing the solution to be tested, is closed at both ends by two glass plates, and rests upon the support X; which also bears at its ends the tubes a and r. These tubes contain the analyzers and polarizers, which are represented in section at B. The light of a common lamp is passed through the aperture S and the double-refracting prism r, the polarizer which transmits the ordinary ray, the extraordinary being thrown out of the field of vision. (See Light, vol. x., pp. 445, 446.) The prism is so placed that the plane of polarization is in the axis of the instrument and also vertical.

After passing through the double-refracting prism the polarized ray meets a refracting plate q, shown in section at E, composed of two pieces of quartz placed side by side, one having right-handed and the other left-handed polarizing powers. These plates are each 3.75 millimetres thick, producing a rotation of 90° and a rose-violet tint, called the transition tint. These two quartz plates, having equal powers of rotation, turn the ray in opposite directions, and therefore when viewed through a double-refracting prism they appear of the same tint when the plane of the ray is perpendicular; but if it has been turned by passing through a rotating solution, a difference of tint will be produced. After passing through the double quartz plate q, the ray traverses the solution in the tube w, and a single quartz plate i, fig. B, of any thickness and either right-handed or left-handed. The compensator n, composed of two wedge-shaped pieces of quartz, shown in section at C, both either right-handed or left-handed, but of opposite rotation to the plate i, is next traversed by the ray. This compensator can be varied in thickness' and therefore in rotating power so as to balance exactly the degree of rotation produced by the solution.

Its thickness is regulated by means of a rackwork and pinion turned by the milled head screw b, figs. A and B. A scale and vernier shown at D is affixed to the plates, by which the thickness of the compensation may be read, the vernier pointing to zero when the thickness of the two plates is equal to that of i. A double-refracting prism c, fig. B, is placed next behind the compensator to act as an analyzer which has been acted upon by the solution and the various plates. When the liquid in the tube is inactive and the compensator is not at zero, the plate i and the compensator will neutralize each other's 'effect, and the two parts of the double quartz q will have the same tint; but when the tube m contains a solution having a rotatory power, like sugar, this power added to that of one of the plates will rotate the plane of polarization of the transmitted ray either to the right or to the left. If the solution contains cane sugar or dextrose, or a certain excess of either, it will rotate it to the right; if it contains laevulose or a certain excess, it will rotate it to the left? and therefore a difference in tint will be observed in the two halves of the double quartz plate q, one half perhaps being red and the other blue.

The thickness of the compensator is then adjusted by turning the milled head b until the tints become the same, and the increase or decrease in the thickness of the two plates will indicate the rotatory power of the solution, either right-handed or left-handed, and may be read upon the scale. The following standard of comparison is employed : If 16.471 grs. of pure cane sugar is dissolved in sufficient water to make 100 cubic centimetres, this solution placed in a tube 20 centimetres long will produce the same degree of rotation as a right-handed quartz plate one millimetre thick. Or if a tube exactly 37.65 in. long is filled with a solution containing 10 per cent, of pure cane sugar (crystallized sugar candy), and a polarized ray from the middle of the yellow band of the spectrum is passed through it, the rotation of the plane will be 73.8°. This, compared to the rotation produced by a solution of pure cane sugar of a different strength, will show the relative proportion it contains; or if the depth of the solution is less, the rotation will be less in the same proportion. If the solution contains left-handed sugar, the result will be vitiated and corrections have to be made.

This may be done by converting all the sugar into left-handed sugar by the action of hydrochloric acid, and making a second observation, when by a comparison of the results obtained at both observations the amount of cane sugar may be estimated. The optical rotatory power of the various sugars mentioned in this article has been determined according to the standard of comparison here given. The arrangement of prisms and lenses placed behind the double-refracting prism c forms what M. Soleil calls the producer of sensible tints. The particular tint which allows the most delicate difference in the color of the two halves of the double quartz to be distinguished is not the same for all eyes. This effect is produced by placing in front of the prism c a quartz plate o cut perpendicular to the axis, then a small Galilean telescope, consisting of a double convex lens g and a double concave lens f, with adjustable focal distance. The double-refracting prism c acts as polarizer to the quartz o, while the prism a is the analyzer, and on being turned to the right or left may be made to produce that tint to which the eye of the observer is the most sensitive. - Sugar Cane. Commercial cane sugar is made from species of saccharum, especially S. officinarum, a genus of grasses of the tribe andropogonem, of which subdivision the cultivated sorghum and broom corn are familiar examples.

Sugar cane is a perennial grass, with solid stems from 6 to 20 ft. high, the older plants throwing up numerous stems or suckers from the root; the leaves, 3 ft. or more long and 3 in. broad, have thin sheaths, usually glaucous with a bloom or waxy exudation, which is also found upon the stem, especially in the dark-colored varieties; the flowers are in a large, ample, and showy panicle, about 2 ft. long, the ultimate branches of which are notched or jointed, bearing at each joint two flowers, one of which is sessile and neutral, the other on a short pedicel and perfect; both kinds of flowers are surrounded by a tuft of long hairs, which gives the cluster a soft silvery appearance. The sap or juice of the plant contains from 15 to 20 per cent, of sugar. It has not been found in the wild statu in any part of the world; and while there is much doubt as to its native country, the most careful investigations point to Bengal as the origin of S. officinarum, and it was there that the manufacture of sugar commenced. If, as botanists are disposed to admit, the sugar cane of China is a distinct species (S. Sinense), it would appear that the cultivation of related plants for the extraction of sugar was undertaken separately in two distinct and widely separated countries.

While 'the product was anciently referred to as "honey of canes," and by other names, sugar as we know it is not mentioned before the commencement of the present era. Dioscorides, about A. D. 100, mentions saccharon. In the 9th century the cultivation had extended to Persia, and in the 10th and 11th centuries Avicenna and other eastern physicians used sugar in medicine. Its cultivation was carried on in Spain in the 10th century, at which time sugar was an article of trade, especially by the Venetians, through whom the English received their supply. The cane was introduced into Madeira in 14-20, and some time after into the Canaries. "With the discovery of America, its distribution was very rapid, Santo Domingo, Brazil, Mexico, Guadeloupe, and other countries undertaking its culture in quick succession. Meanwhile it spread to Africa and the Indian archipelago. In 1852 it was taken to New South Wales; it had long previously been cultivated in most of the islands of the Pacific. Several early writers mention the sugar cane as one of the indigenous products of the United States, and it was said to grow in Virginia and in Louisiana; of course some other large grass was mistaken for the sugar cane; both the common reed (phrag-mites) and the southern cane (arundlnaria) have a sufficiently near resemblance to sugar cane to lead a careless observer into this error.

The plant appears to have been cultivated in this country for the first time about 1751, near the site of New Orleans, by some Jesuits from Santo Domingo. In 1758 the first sugar mill was built, a little further down the river, by M. Dubreuil. According to a statement of E. J. Forstall in Do Bow's "Industrial Resources," vol. iii., p. 275, the manufacture of cane into sugar does not seem to have commenced before 1764; but sugar is said to have been one of the staple products of the colony in 1770. After the revolutionary war it was prosecuted so successfully by emigrants from the United States that in 1803 there were 81 sugar estates on the Mississippi delta alone. The cession of Louisiana to Spain seems to have arrested the industry, as no accounts of sugar making are found until 1791, when the first sugar house under the Spanish government was erected by a Mr. Solis at Torre aux Boeufs, in the parish of St. Bernard. The next was established in 1796 on a plantation where now stands Carrollton. The success of this enterprise was the foundation of the sugar culture in Louisiana. In 1818 the production was 25,000 hogsheads, and the cane was ground altogether by cattle, steam power not being introduced till 1822. The sugar-growing district in Louisiana is on both sides of the Mississippi, from 57 m. below New Orleans to nearly 190 m. above; on the Red river and its tributaries; and on many of the bayous.

But even Louisiana is rather too far north to allow of the perfect ripening of the plant, which is sometimes killed by the frost in the spring, and also injured in October and November. In Texas the crop is important, and cane is grown to a considerable extent in several of the other gulf states, especially in Florida, and to a limited extent in South Carolina, Tennessee, and Kentucky. In the more northern localities it is profitably cultivated mainly for the manufacture of sirup. - It is not definitely settled whether the sugar cane from China (S. Sinense) is really a distinct species, but all others formerly so regarded are now considered as only forms of S. saccharatum, of which each sugar-growing country has several varieties. The country or Creole cane, the kind first introduced into the West Indies and Louisiana, and regarded as the original form of the species, was at one time much esteemed, but has greatly deteriorated. The ribbon cane, so called from the yellow and purple stripes upon the stem, is inferior to the following varieties. The Otaheite or Bourbon cane was introduced into Georgia in 1805, and is also a favorite variety in some parts of the West Indies, its stem being thicker than that of the others.

It has been supposed that this was a native of Otaheite or Tahiti. The violet or Batavian cane has a purple stem, varying in depth of color with the nature of the soil; its leaves are luxuriant and of a dark green color, and the flowers are purplish; it has been described as a distinct species, S. violaceum, but there is nothing to warrant its separation from the ordinary cane. Besides these leading varieties, there are the claret, imperial, Mont Blanc, and others, with numerous local subvarieties. The dark-colored canes are found to resist the attacks of disease much better than the light-colored ones, a peculiarity of which there are numerous other illustrations among plants and animals. - In none of the sugar-producing countries does the sugar cane ever perfect seeds, and it is quoted as an illustration of the fact that plants which have long been propagated by other methods lose the power of producing seeds. The cane is always propagated by cuttings, and as the lower portion of the stem is the richest in sugar, the upper and comparatively worthless portions are used for cuttings, a practice to which the deterioration of varieties is ascribed.

The details of cultivation vary in different countries; in the cooler cane regions there is a season when growth must cease, while in others it is continuous; in some prolonged rains modify the culture, and in others irrigation must supply the needed moisture. But wherever it is grown, it must have a fertile soil; it is a plant which quickly exhausts the soil, and unless manure is used, the land is fallowed, or the crop forms part of a rotation, the soil is soon run down. In some sugar-growing countries the ground is prepared by penning cattle upon the fields; in others some crop is grown which, with the weeds, is turned under; and in the British West Indies fertilizers of various kinds are used. The distance between the rows varies from 2½ to 8 ft., the latter distance giving a better crop than closer rows. In the best culture the land is well ploughed, and then thrown up into ridges with the plough, at the desired distance apart; a trench, 3 in. or more deep, is opened upon the top of the ridge, in which the cuttings, about 2 ft. long, are laid in a single and sometimes a double row; the cane is then covered by hoes, or by a cane coverer drawn by horses, which will cover 10 acres in a day.

After the shoots appear they are kept clear of weeds until they shade the ground, and prevent all other growth. In dry countries it is customary to "trash" the cane when it gains a sufficient size; the lower leaves are broken off and laid upon the earth to prevent evaporation. The shoots produced the first year from the cuttings are called "plant canes;" it is known to have attained its full growth by "arrowing;" the lower joints are usually about 3 in. long, but above they increase in length while they diminish in diameter and are much less rich in sugar, until finally a long joint (in tropical countries G or 8 ft. long) shoots up, which if permitted would bear the flower cluster; this shoot is termed the " arrow," and its appearance indicates that the cane should be topped, or cut up at once, else the accumulated sugar in the juices of the plant would be expended in the production of flowers. In climates where the season is short the cane does not arrow, and the time for cutting is governed by the probable appearance of frost.

In Louisiana it begins to ripen at the bottom in August; as each joint ripens the leaf belonging to it withers, and when it is time to harvest the upper part of the cane is cut back to a joint upon which the leaf is dry, and the crop is cut off close to the ground; if frost is apprehended, the cane is "mattressed," the product of three rows being so laid together that the leaves of one armful will cover the buts of the preceding; being thus thatched, the canes are protected from frost and will keep in this state for several weeks without injury. The second year after planting numerous shoots start up from the old plants; these are called "rat-toons" (Fr. rejetons), and the crop is thereafter a rattoon crop, the value of which, though less than that of the plant cane, depends upon the original fertility of the soil, or the manner in which this has been maintained. In Louisiana but one or two rattoon crops are taken, requiring a replanting every second or third year; while in some of the West Indies the plantation lasts from six to ten years, and in the East even longer; but when thus long continued, the yield is small and the impoverishment of the soil correspondingly great. - Manufacture of Cane Sugar. As soon as the canes are cut they are ground in a mill.

There are many forms of mills, and those in use in the East Indies from the earliest times are exceedingly rude, slow, and inefficient, and very rude mills are still used by small planters in the West Indies; but powerful mills driven by steam are employed upon the larger estates, the crushing apparatus usually consisting of three heavy cast-iron rollets. The canes are usually passed twice through the mill. About two thirds of all the juice is extracted, and the crude liquor contains, besides sugar, woody fibre, soluble salts, albumen, caseine, wax, etc. In the hot climate of the sugar plantations the juice if left to itself begins to ferment in the course of an hour; it is therefore immediately treated with from 1/3000 to 1/800 of its weight of lime, and heated to 140° in large flat-bottomed copper pans or clarifiers holding from 300 to 400 gallons each. This coagulates the albuminous portions, which rise to the surface as scum. Some planters treat the juice with sulphurous acid, by which fermentation is delayed. The clear liquid, after cooling for an hour or two, is drawn off for concentration by boiling. The fuel used is usually the dried crushed canes, the ashes of which are returned to the soil.

By the old method practised in Asia a series of 11 kettles or earthen boilers is set in a line in a rudely constructed range, at one end of which is the fire, with a large iron boiler over it, and at the other the chimney. The juice is first put into the boiler furthest from the fire, and is gradually transferred to the others, as the process goes on, until the final concentration is effected in the iron boiler. The product is afterward drained and the sugar is clarified by boiling again with water, an alkaline lye, and milk. A somewhat similar arrangement of kettles, to the number of four, five, or six, has been employed in this country and the West Indies, each kettle having its own fire, and the defecation or partial purifying being effected during the boiling by "tempering" the liquor with slaked lime. This, when used in small quantity, causes the glutinous matters present to coagulate and rise upon the surface in a scum, which may be continually removed by skimming. It also neutralizes any acid that may have formed.

In Louisiana it has been the practice to concentrate the sirup to 42° Baume in the last kettle, called the battery, and then transfer it to large wooden vats, called coolers, for granulation; but the operations have been variously modified there, and different methods too have been pursued in the Wesl Indies. Instead of kettles, each one requiring a separate tire, large copper caldrons are heated by steam, either by being enclosed in a steam jacket or by containing a coil of steam pipe. The clarification is effected as before by means of lime added to the sirup diffused through a portion of juice, or in the form of milk of lime of known strength and carefully graduated, so that exact quantities may be used. Just enough should be used to neutralize exactly the sirup, which may be known when litmus paper indicates neither an acid nor alkaline reaction. An excess of lime should be particularly guarded against, as it involves a loss of sugar; and when it occurs the effect should be corrected by careful addition of alum, or better of sulphate of alumina, which contains no potash. The heat employed in clarifying should not reach the boiling point of the sirup. At a less degree a scum gathers upon the surface, and when this breaks up into white froth, the clarification is completed.

The heat is then stopped, and the liquor is left to repose for an hour, when it is drawn away from the scum, and is seen as it flows into the first of the evaporating pans to be of a clear bright wine-yellow color. These pans, to the number of three or more, are set in succession over a flue heated by a fire at one end. The liquor is gradually transferred to the smaller pans, and as it boils away the scum that rises is taken off. It is the skimmings in these operations that furnish the best materials for distillation, and the manufacture of rum is very "generally carried on in connection with that of sugar. In the smallest and last pan, to which sometimes the term "teache" is exclusively applied, the sirup is finally collected; and when it is judged to be sufficiently concentrated for granulating, it is transferred into the coolers, and thence into the vessels, also called coolers, in which the granulating takes place. These are of wood with thick sides, about 7 ft. in length, 5 or 6 ft. in width, and not less than a foot deep. This depth and the thick sides are requisite to secure slow cooling, without which the grains could not be coarse. In about 24 hours the graining takes place, the crystals forming a soft mass in the midst of the liquid portion or molasses.

The separation of the two products is effected by drainage in what is called the curing house. This is a large building covering an open reservoir. Frames are provided for hogsheads so that the drippings from these shall flow into the reservoir. In the bottom of each hogshead several holes are bored, and into each hole is put a crushed cane or the stalk of a plantain leaf, the lower end projecting several inches below the bottom. The hogsheads being rilled with the soft sugary mixture, the molasses gradually drains away from it, dripping from the stalks. The operation goes on for three to six weeks, till, the sugar is considered sufficiently dry for shipping. It still retains considerable molasses, and in the moist hold of the ship the- separation continues, the molasses leaking away and involving a serious loss. The "Julius Robert diffusion process" for extracting sugar from cane is in use at the sugar establishment of Messrs. Koch, in Bayou Lafourche, Louisiana. A series of tall cylinders connected by pipes are filled with thinly sliced canes and water. The diffusion allows the hydraulic pressure to carry off the dissolved sugar. The water is heated by steam to about 190° by a boiler through which the diffusion juice passes.

It is said that a much greater proportion of the sugar is extracted by this method, and that the clarifying process is much simplified and abridged. - Sugar Refining. The preparation of the purest varieties of sugar did not originate in the sugar-producing countries, but the art was applied first by the Venetians to the crude sugars brought from Egypt. It was practised in Antwerp in the 16th century, and was thence introduced into England. At present it is an important branch of manufacture in most of the principal commercial cities of the United States and of Europe. As formerly practised, raw sugar was dissolved with lime water in a large open boiler, and, when warm, bullock's blood was added, which as it coagulated on boiling collected most of the lighter impurities and carried them to the surface in the form of a thick scum. This being removed, the liquor was partially evaporated by boiling, filtered through woollen cloth, then concentrated and grained on the general plan already described. The best sugar refiners do not now use blood or any other coagulating substance to collect suspended matters, but separate them entirely by filtration. The process, in the best establishments is substantially as follows: On the ground floor the raw sugar is dissolved in hot water in large cisterns.

Water enough is added to produce a specific gravity of about 1.25, or 29° Baume. By a large pump near each cistern at the same level the solution is drawn off through a connecting pipe provided with a coarse wire strainer, which prevents all except the smaller solid particles from entering the pump. The saccharine solution is pumped up into the highest story, which is usually the seventh or eighth, it being cheaper as well as more convenient to elevate the sugar in solution than in a solid state. It is pumped into vessels called " blowup pans," because steam was formerly blown into them to heat them. They are now heated with close coils to about 208° or 210° F. Milk of lime is added to the solution in these pans for the purpose of neutralizing any acid which it may contain. From these pans the sirup passes down to the next floor and into filters by which it is completely deprived of all suspended solid particles. These filters consist of a great number of bags 4 or 5 in. in diameter and 8 or 10 ft. long, made of two thicknesses of cloth, an outer of coarse and an inner of fine material. They are enclosed in sets of about 200, in boxes, to prevent cooling. After a time they become foul, when they are turned inside out and washed.

After leaving the bag filters, which it does at a temperature of from 170° to 180°, the sirup is run through filters of animal charcoal or bone black. These are immense cylinders, G or 8 ft. in diameter and usually from 20 to 25 ft. high, filled with pulverized bone black, which substance has the property of absorbing all the coloring matter in the sirup, which runs from the bag filters of a sherry wine color. After a time the charcoal becomes foul and loses its property of absorbing coloring matter, when it is taken to a neighboring room and reburned in kilns. The sirup which runs from the charcoal filters at a temperature of about 150°, and, in a perfectly colorless condition, is now pumped into vacuum pans.and concentrated to the granulating or crystallizing point. These vacuum pans were invented by Howard and patented in 1812. They are large conical or ovoid vessels heated by steam and exhausted with air pumps, by which the air and vapor are rapidly removed. In the later stages of the process the pressure is reduced to only 3 in. or less of mercury. The pans are sometimes supplied with an apparatus for condensing the steam by a cold spray.

In making hard sugars, at the commencement the evaporation is conducted at a temperature of 170° to 180° F., but as soon as granulation begins it is. lowered to 160°, and just before the evaporation is I completed it is reduced to 140°, this being the i lowest temperature at which crystallizing sugar boils at a pressure of 3 in. of mercury. An ingeniously devised sliding tube, by which a " proof " may be taken without admitting air, is attached to the vacuum pan. In making soft sugar the temperature is kept rather lower. As soon as crystallization begins the sugar is run off, and if it is to be made into soft sugar, the sirup is discharged by means of centrifugal mills. If it is for hard sugar, it is run into a vat which has a gate in its bottom; from this it is run into conical moulds placed upon carriages, which are drawn under the gate. In the bottom of each mould there is an orifice which is kept closed by a stopper for several hours, until the sugar crystallizes, when it is removed and the sirup allowed to drain away. The loaf which remains has a slight yellow tint, which is removed by allowing a colorless solution of sugar to pass through it.

The loaves are then taken out of the moulds and dried in ovens at a temperature of about 160°. The sirup which drains from the moulds still contains a small percentage of cane sugar, but too small to recover with profit. It is therefore sold as sirup. It may be here remarked that raw molasses contains enough cane sugar to make it profitable for some establishments to make a specialty of extracting it. The muscovado molasses from Cuba, Porto Rico, and Antigua is esteemed the best. - Beet Sugar. In 1747 Marggraf, a Berlin chemist, found that the white beet yielded 6.2 per cent, and the red beet 4.6 per cent, of sugar, but the manufacture was not developed till the close of the year 1800. (See Beet.) The beets preferred in Europe for the manufacture of sugar are varieties of the white Silesian, yielding a juice richer in sugar and more free from salts than that of other kinds of beet. The weight of the larger ones is about 5 lbs. each; and the yield per acre in France and Belgium is 14 or 15 tons, and about Magdeburg 10 to 12 tons of beets. The crop is successful over the greater part of Europe, but more particularly N. of lat. 45°, and upon light dry soils, in a dry atmosphere.

The richness of the juice is injured by direct application of manures to the growing crop, and it is less in large beets than in small ones. When the leaves begin to die, the beets are dug, the heads cut off, and the roots are thrown together and covered to protect them from light and frost. They may be thus kept for some time, though there is always risk of portions of the sugar passing into the uncrystallizable variety. The proportion of sugar contained in the fresh root varies from 5 to 12 per cent., and the product in a large way is usually about 6 per cent., sometimes 7½ The other contents of the root are: water, 83 to 94 per cent.; ligneous fibre and albumen, 2 .5 to 5 per cent.; together with a small proportion of what is supposed to be pectine, and a trace of mineral substances. In the factory the beets are first washed clean in a cage revolving on a horizontal axis, and partly immersed in water; and when washed they are discharged by the action of the machine itself. As the juice cannot be forced out from the cells by compression alone, it is found necessary to tear open the cellular tissue, and this is done by a grating machine of the form of a rotating drum, the inner surface of which is studded with teeth. The pulp is then subjected to powerful hydraulic pressure.

Maceration has also been employed to separate the juice. For this purpose the beets are cut into thin slices and put into a cistern with about their own bulk of hot water. In half an hour the liquor is let down upon other slices in another cistern, and so on through three to five vessels, until it acquires a density of 5½° to 7° B. By this process the juice is rendered very weak and apt to ferment, and requires much fuel to concentrate it. Perhaps the best method is to expel the juice by centrifugal force. Another method practised near Heidelberg is, as soon as the beets are gathered and washed, to cut them into small rectangular pieces and dry them upon floors. Their bulk is thus reduced about 84 per cent., leaving 16 of dry matter, which may be kept for any time and transported to any distance. The sugar is then extracted by infusion or by maceration through a long series of vessels. The factory where this operation is carried on at Waghau-sel is of immense extent, the buildings, formerly a Benedictine monastery, covering 12 acres of land. The infusing vessels, 20 in number, are 12 to 14 ft. deep and 7 ft. wide. The beets when dried produce about 40 per cent, of sugar. The juice, however obtained, is rendered alkaline by the addition of lime water, and is then boiled.

Excess of lime is removed by the chemical process of converting it into carbonate by passing a current of carbonic acid gas into it, which may be generated by a coke furnace according to the method proposed by Barruel of Paris in 1811, or the gas may be generated by the action of sulphuric acid on chalk, as since proposed by Michaelis. This process is called de-liming, and it may also be effected by filtering the solution through animal charcoal. Several other methods have been employed or proposed. Dubrunfaut and Massey patented a method with caustic baryta, which forms with cane sugar at the boiling point an insoluble saccharate, C12H22011,BaO, sufficient baryta being used to throw down all the sugar. The supernatant fluid, which contains all the impurities, is then run off, when the sugar is recovered by treating with carbonic acid, by which the baryta is withdrawn in the form of insoluble carbonate, the sugar dissolving. The subsequent processes of filtration, concentration, and granulation are similar to those already described.

The manufacture of beet sugar has been attempted in the United States, but as yet with little success except in California, where it promises to become an important industry. (See California, vol. iii., p. 605.) - Maple Sugar. Several species of the maple afford, when the sap begins to flow in the spring, a juice containing crystallizable sugar. That yielding the richest juice is the acer saccliarinum, the rock or sugar maple. The swamp or river maple, known also as the white or soft maple, produces a juice of inferior quality, but which is sometimes employed in sugar making. The manufacture is said to have originated in New England about the year 1752. It thence extended throughout the wooded portions of the country where the sugar maple abounds, particularly New York, Michigan, Pennsylvania, and Ohio, and on the range of the Alleghanies further south. It is carried on in Canada both by whites and Indians. (See Maple.) - Production and Trade. Louisiana produces the great bulk of the cane sugar crop of the United States, and is the only state which exports sugar, the other cane-growing states producing scarcely sufficient for local consumption.

The product of Louisiana from 1860 to 1873 is given under Louisiana. The crop of 1874 is estimated at 125,000 hhds., and of 1875 at 135,000 hhds. The total exports of sugar from Havana and Matanzas from Jan. 1 to Nov. 23, 1875, were 1,018,296 boxes, 249,331 hhds., or 332,-105 tons, of which 344,187 boxes, 204,001 hhds., or 184,455 tons went to the United States. The imports of sugar from all sources, from Jan. 1 to Dec. 1, 1875, were: at New York, 408,981 tons; Boston, 111,192 tons; Philadelphia, 34,030 tons; Baltimore, 63,141 tons; total for the Atlantic coast, 617,944 tons, against 611,124 tons in 1874, and 598,995 tons in 1873, or an average of 609,354 tons for three years. The imports at San Francisco from Jan. 1 to Oct. 1, 1875, were: from Manila, 10,503 tons; Hawaiian islands, 0,079 tons; China, 2,038 tons; Central America, 324 tons; total, 19,544 tons, against 27,438 tons in 1874, and 21,132 tons in 1873. or an average of 22,705 tons for three years. The consumption of cane sugar on the Atlantic coast in 1874 was 710,-309 tons; on the Pacific coast, 30,046 tons; of sugar made from molasses, 43,600 tons; of maple sugar, 15,000 tons; total, 799,015 tons, against 738,525 tons in 1873, and 720,873 tons in 1872, an increase in 1874 of 8 per cent, over 1873, and 11 per cent, over 1872. In nine months ending Sept. 30, 1875, the Atlantic ports exported of refined sugar 13,088 tons, against 3,030 tons in 1874, and 3,412 tons in 1873. The imports at the principal European depots in 1873, 1874, and for nine months ending Sept. 30, 1875, are shown in the following table:

Soleil's Saccharirneter.

Soleil's Saccharirneter.

Sugar Cane (Saccharum officinale).

Sugar Cane (Saccharum officinale).

DEPOTS.

IMPORTS.

1873.

1874.

1875.

Holland . . . .

tons.

77,400

82,850

46,750

Antwerp . . . .

"

6,130

8,540

9,580

Hamburg . . . . .

"

34,700

35,000

17,000

France . . . . . .

"

157,033

136,542

180,000

Bremen . . . . .

"

980

1,890

3.840

Trieste . . . . .

"

7,950

9,730

9,330

Genoa . . . . .

"

18,900

21,000

17,500

On the continent . . . . .

"

303,093

295,552

284,000

In Great Britain........

"

653,588

676,488

760,652

Total...............

"

956,681

972,040

1,044,652

The imports from all sources into Great Britain were: in 1872, 784,000 tons; 1873, 833,-500 tons; 1874, 835,000 tons. The consumption in the same years was 715,000, 786,000, and 836,000 tons. The importations of foreign refined, mainly beet sugar from France, were: in 1872, 87,700 tons; 1873,118,000 tons; 1874, 136,000 tons. The production of beet sugar holds the balance of power in the sugar markets of the world. In the ten crop years from 1864-'5 to 1874-'5 the production increased from 545,000 to 1,054,000 tons. The principal producing countries are France, about 450,000 tons, and Germany, about 280,000 tons; the remainder is produced in Austria, Russia, and Holland. - Among the treatises on cane culture and the manufacture of sugar are : Champomier, " Statement of the Sugar Crop made in Louisiana" (annual reports, New Orleans, 1845-'57); Evans, "Sugar Planter's Manual" (London, 1847; Philadelphia, 1848); Wray. "Practical Sugar Planter" (London, 1848;'latest ed., 1871); Leon, "Sugar Cultivation in Louisiana, Cuba, and the British Possessions " (London, 1848); Kerr, " Practical Treatise on the Cultivation of the Sugar Cane, and the Manufacture of Sugar " (London, 1851); Burgh, " Manufacture of Sugar and the Machinery Employed" (London, 1866); Reed, " History of Sugar and Yielding Plants" (London, 1866); and Soames, " Treatise on the Manufacture of Sugar" (London, 1872). The manufacture of beet sugar is described by Dumas in his Traite de cliimie appliquee aux arts, vol. vi.; see alsoDureau, De la fabrication du sucre de bettcrave (Paris, 1858); Grant, " Beet-Root Sugar and Cultivation of Beet" (Boston, 1867); and Crooks, "Manufacture of Beet-Root Sugar" (London, 1870).