SUGAR. Cane sugar is the crystallized portion of the juice expressed from the sugar cane, and forms the main article of a grocer's stock. We therefore treat it very fully in the following pages, and for the greater convenience to the reader divide the subject into the following heads : 1. The history of its cultivation, page 220, 2. The manufacture of raw sugar, " 221.
3. Refining processes, .?" 224.
4. Centrifugal separator, " 226.
5. Granulated sugars and other grades, " 227.
6. Beet root sugars,• . " 228.
7. Grape or starch sugars,?" 230.
8. Sorghum cane sugar, " 205.
9. Corn stalk sugars,." 231.
10. Tares on packages, .
" 231.
H. The question of profit, " 231.
The cultivation of the sugar cane (see full-page cut) and the manufacture of sugar were introduced into Europe from the East by the Saracens, soon after their conquest in the ninth century. It is stated by the Venetian historians that their countrymen im ported sugar from Sicily, in the twelfth century, at a cheaper rate than they could obtain it from Egypt, where it was then exten sively made. The first plantations in Spain were at Valencia, but they were extended to Granada, Murcia, Portugal, Madeira and the Canary Islands, as early as the beginning of the fifteenth cen tury. From Gomera, one of these islands, the sugar cane was into the West Indies by Columbus in his second voy• age to America in 1493. It was cultivated to some extent it. St. Domingo in 1506, where it succeeded better than in any of the other islands. In 1518 there were twenty-eight plantations in that colony, established by the Spaniards, where an abundance of sugar was made, which for a long period formed the principal part of the European supplies. Barhadoes, the oldest English settlement in the West Indies, began to export sugar in 1646, and as far back as the year 1676 the trade required ships of four hun dred and fifty tons burden.
Cane sugar is obtained from the cane juice in various ways, and the following very condensed account of the process of making sugar in Java, extracted from Chamber's Encyclopedia, will give some idea of the operation : The canes, freed from all loose leaves, are passed through be tween the rollers under the greatest possible pressure that can be brought to bear upon them. The rollers revolve only from two to four times per minute. From 100 pounds of canes, 65 to 75 pounds of cane juice will be expressed. This juice, which ;s of a sweetish taste, and of the color of dirty water, passes direct from the mill to a small reservoir, where it usually receives a small dose of quicklime, and without delay runs off to large iron or copper vessels, heated either by a fire underneath or by steam-pipes in the liquid. As the temperature of the juice rises, a thick scum comes to the top, which is either removed by skimming, or the warm juice is drawn off from below the scum. The concentration of the juice is partly effected in a series of large open hemispherical iron pans about six to eight feet diameter, of which five or six are placed in a row, with a large fire under the one at the end. This
one fire, which runs along the whole row of pans, is found suffi cient to make two or three of them nearest the fire boil violently, and in addition, it warms the juice in the pans furthest from the fire. As the juice first enters the pans furthest from the fire, it gets gradually heated, and the vegetable impurities rise in scum to the top, and are carefully removed. As the juice is ladled from one pan to the next, it boils with greater and greater vigor as it approaches nearer the fire, until in the pan immediately over the fire it seethes and foams with excessive violence ; and this seems to be essential to the successful making of sugar. It is known that the presence of all those impurities which constitute the scum interferes with the crystalizing of the sugar ; and the rapid ascent of bubbles of steam through the liquid in the pans carries all im purities dispersed through the body of the liquid to the top, where they can be removed with facility. It is well known that great heat is very destructive to cane juice ; that is to say, it turns much of the crystallizable sugar into treacle or uncrystallizable sugar, hut the gain arising from of much of the impurity in the cane juice more than compensates for the destruction of part of the sugar. After the concentration has been carried to a given point, and all the scum has been got rid of, the application of a high heat, which would act with an increasingly destructive effect as the condensation becomes greater, is suspended, and the liquor, now of the color of turbid port wine, and of the consistency of oil, is drawn into the vacuum-pan, where the concentration is completed at the lowest possible temperature, generally about 150 degrees Fahrenheit. The vacuum pan is in universal use in all European sugar-refineries, and in all well-provided sugar planta tions. It is generally made of copper, of a spherical form, and from six to nine feet diameter. The bottom is double, leaving a space of an inch or two for the admission of steam between the two bottoms, and there is generally a long coiled copper pipe of three or four inches diameter above the inner bottom, so as to still further increase the amount of heating surface. This apparatus is made perfectly air and steam tight. Leading from its upper dome there is a large pipe communicating with a condenser, into which a rush of cold water is continually passing, so as to con dense all the steam or vapor that arises from the liquid boiling in the vacuum pan. The water which is constantly rushing into the condenser is a4 steadily withdrawn again by the pump. There is thus a constant vacuum in the pan, and, consequently, the liquid in it will boil at a much lower temperature than it would in an open pan or boiler. There is an extraordinary advantage in being able to effect the later stages of the concentration at a low tem perature, for it is when the liquid becomes thick that the destruc tive results of a high temperature become most excessive.