Cantor lectures on sugar, coffee, tea, and cocoa : their origin, preparation, and uses / by Richard Bannister.

  • Bannister, Richard.
Date:
1890
Catalogue details

Licence: Public Domain Mark

Credit: Cantor lectures on sugar, coffee, tea, and cocoa : their origin, preparation, and uses / by Richard Bannister. Source: Wellcome Collection.

    12/82 (page 8)
    to be potash, silica, phosphoric acid, lime, and magnesia, with a certain amount of nitrogen. Good stable manure and well fer¬ mented farmyard dung are much superior to superphosphate, which suits root crops better than graminaceous plants. Green soiling is much in favour, and attention is beginning to be paid to proper rotation of crops. The canes having been gathered, the next operation is naturally that of extracting the juice. This is contained in small cells ; and there are, broadly speaking, two methods of obtaining it. The older is by pressure, whereby the cells are broken, and the juice squeezed out; and for this purpose heavy roller mills, combined (or not) with disintegrators, are in use. The other depends on the fact that a solution of a crystallisable body, separated from another liquid by a thin membrane, is gradually deprived by that liquid of a part of the dissolved substance. That is, when cells containing cane juice are immersed in water, some of the sugar passes through the cell wall into the water, and by renewing the water systematically, the greater part of the sugar can be so extracted. Beet. The other great source of commercial sugar, the beet-root {Beta vulgaris), is a hardy biennial indigenous to Southern Europe, but cultivated with success in the United States, Canada, and New Zealand, and, as far as climatic conditions are concerned, in this country also. Its production here has always been extremely limited, although, about 22 years ago, Mr. Duncan, a London sugar refiner, tried to make sugar-beet production a success at Lavenham, in Suffolk. He there established a factory for extracting the juice from the beet, which juice, when brought to charge and concentrated, was sent for refining to his London factory. The growth of beet was stimulated by the offer of prizes to the most successful growers, but owing to circumstances arising out of the bounty system, the local factory was closed in 1874, and afterwards the London refinery was shut up. The general characteristics of good beets are regular pear-shape, smooth skin, firm flesh, uniform structure, clean, sugary flavour, high specific gravity, and a weight seldom exceeding 1^—2^ lbs. Perhaps the most esteemed of the many varieties are “white Silesian,” “green neck,” “red neck ” (a favourite in France), and the “grey neck,” all producing from 2\ to 3^ tons of sugar per acre. Internally, the beet is built up of concentric rings of small cells con¬ taining sugar and other bodies (principally salts of potash) in a watery solution. The sugar itself is identical with cane sugar, but the larger proportion of potash salts causes more difficulty to the refiner, and commercial samples are not quite so sweet as those from the cane. Beets contain no uncrystallisable sugar ; molasses are pro¬ duced by unavoidable changes in the course of manufacture. Manure must be applied to beet soils with great caution, and only in the early autumn. Neglect often brings about big watery roots abounding in nitrogenous matters, Sowing should take place at the beginning or middle of April ; if earlier, frost is apt to nip the young plant; if later, it runs a risk of not ripening. If the autumn is dry the roots may be left in the ground while the juice in¬ creases in gravity, but of all things frost must be avoided. After taking up, a good plan is to cover loosely in the field for two days, then trim and stack. The roots are well cleaned, sliced or rasped, and pressed or macerated much in the same manner as the cane is treated. The Table IV. on p. 9 is of special interest, as it shows the steady increase in the quantity of beet sugar produced from the year 1873 to 1887, and the corresponding diminution of cane sugar. No doubt the increased con¬ sumption of refined sugar has accomplished this result; for while the beet cannot, on account of its strong objectionable flavour, be consumed in the raw state, still its freedom from molasses or uncrystallisable sugar causes it to be very much in demand for the use of the refiner, and at the present time there is very little refined sugar made exclusively from cane without any admixture of beet. The loaf sugar either of British or foreign manufacture now on the market will, when warmed in the hand, speedily reveal its origin, and however crystalline it may be, or faultless the colour, refined sugar containing beet will never lose entirely its offensively-objectionable smell and flavour. lo the refiner, however, it possesses, as before stated, invaluable qualities, and on this ground its consumption is not likely to decrease, because refined sugar is steadily coming into more general use, even in those countries where raw cane sugar can be easily obtained.