As sugar is most abundantly supplied by the sugar-cane, much interest has been excited respecting the early history of this plant. It has been supposed that the Hebrew word, which frequently occurs in the Old Testament and is sometimes translated calamus, sometimes sweet-cane, means the sugar-cane. It is mentioned for the first time in Exodus, where Moses is commanded to make an ointment with myrrh, cinnamon, sweet calamus, cassia, and oil olive. The calamus does not appear to have been a native of Egypt or of Judaea; for in Jeremiah it is mentioned as coming from a far country. “To what purpose cometh there to me incense from Sheba, and the sweet-cane from a far country?” It has been argued, that if the cinnamon mentioned in the passage of Exodus were true cinnamon, it must have come from the East Indies, the only country in the world from which it is obtained; and that it is therefore, highly probable that the sugar-cane was exported from the same country. Among the ancient writers of Greece, Herodotus alludes to the “honey made by the hands of men. Nearchus, Alexander’s admiral, relates that “the reed in India yields honey without bees.” Theophrastus describes three kinds of honey; one from flowers, another from the air, (referring probably to honey-dew,) and a third from canes or reeds. Other ancient writers are more or less precise in their mention of sugar, until we arrive at the time of the Roman Emperor, Nero, when Dioscorides uses the word saccharum, or sugar: his description refers to a species of sugar-candy, but he was evidently not aware of the mode of preparing it. He says: “There is a sort of concreted honey, which is called sugar, found upon canes in India and Arabia, Felix: it is in consistence like salt, and it is brittle between the teeth, like salt.” Seneca was also ignorant of the real character of sugar: he describes it as honey found on the leaves of canes, and produced by the dew or the sweet juice of the cane itself concreting. Pliny describes sugar as brought from Arabia and India: “It is honey collected from canes, like a gum, white, and brittle between the teeth; the largest is of the size of hazel-nut; it is used in medicine only.” Galen, who wrote in the second century, also speaks of sugar; and in the seventh century, Paulus Aegineta quotes an earlier writer, who describes sugar as “the Indian salt, in colour and form like common salt, but in taste and sweetness like honey.” It appears that, during a long period, the sugar cane was confined to the islands of the Indian Archipelago, the kingdoms of Bengal, Siam &c., and that the sugar was imported with perfumes, spices and other merchandise, to the countries on this side of the Ganges. The traffic in sugar being lucrative, the Indians concealed the knowledge of the sugar-cane: they informed the merchants at Ormus that they extracted sugar from a reed, whereupon many attempts were made to obtain it from the reed-like plants of Arabia; but these were all unsuccessful. The doubts respecting the real
nature of sugar were not resolved until the year 1250, when Marco Polo visited
the country of the sugar-cane. On
his return, the merchants, who had hitherto purchased sugar at Ormus, repaired
to the country of its growth. They
brought away the sugar-cane and the silk-worm, and from Arabia Felix these
valuable productions passed into Nubia, Egypt, and Ethiopia, where sugar was
soon produced in abundance, although its quality was very inferior, from
ignorance of the means of preparing the juice.
In 1420, the Portuguese introduced the sugar-cane from Sicily to Madeira;
and, during the same century, it was probably carried from Spain to the
Canaries. So successful was the
cultivation that the sugar of these countries was preferred to any other. The Portuguese also successfully transplanted the sugar-cane to the
island of St. Thomas and other islands on the African coast. Soon after the discovery of the New World, the Spaniards established
sugar-works in Hispaniola, or St. Domingo: workmen were sent from the Canaries to manufacture the sugar, and the
cane flourished so well, that its produce afforded a large revenue to the mother
country. In 1641 the cane was transplanted from Brazil to Barbadoes,
and thence to the other West India Islands.
For a long period the use of sugar
in England was confined to medicines and feasts; and this continued until 1580,
when it was brought from Brazil to Portugal, and thence to our country.
Mr.
Porter remarks, that “The merchants who introduced the cane from India
certainly neglected to bring, also, the necessary instructions as to the methods
of preparing the juice; and the difficulties which the Arabian cultivators
experienced, doubtless caused them to try the use of all kinds of ingredients
for its purification, and to invent conical vessels for crystallizing and
cleansing the sugar.” The
Venetians introduced the art of sugar refining into Europe at the end of the 15th
century. At first they imitated the
Chinese and sold the sugar which they purified in the shape of candy, cleaning
and refining the coarse sugar of Egypt three or four times over.
They afterwards adopted the use of cones, and sold refined sugar in the
loaf. This example was soon followed by the establishment of sugar
refineries in all the commercial cities of Europe.
We
are accustomed to associate sugar only with the sugar-cane, yet it is one of the
most abundant productions of the vegetable world. It is found in a liquid state in most plants; it is
manufactured from beet-root, from the sap of the maple, and other vegetable
bodies; and this wide distribution of so valuable an article of food is one out
of the many instances of the bounty of Providence in supplying our wants.
Of the numerous varieties of
sugar, some can be made to ferment, others not; some can be formed into
crystals, others not; but it often happens that two kinds of sugar are mixed, as
in the sugar-cane, the juice of which yields the finest crystals, and also
molasses, or treacle. The size of
the crystals, however, depends greatly upon the mode of treatment: when they are rapidly formed, as in common refined sugar, the crystals
are small and confused; but when obtained by the slow evaporation of a strong
solution, they are large and transparent, as in sugar-candy.
Sugar is the principal food of the
vegetable world. It exists
largely in the succulent parts of the plants and seeds when they begin to shoot. It is formed in several kinds of seeds in the process of malting, which
consists merely in steeping seeds in water until they sprout. In the ripening of many fruits there is a similar change.
When palms are about to flower, the starch contained in their stems is
changed into sugar. If plants are
allowed to flower, the gum and sugar disappear from the roots or stems:
this change applies to such common roots as the parsnip,
carrot, beet etc, as well as to the sugar-cane maize, and other plants rich in
sugar matter. The stems of grasses
are also sweet at an early stage of their growth, when they are most nutritious
and palatable to cattle, a circumstance which ought to regulate the time for
making hay. In certain trees the
starch formed in autumn is converted into sugar by the ascending sap in spring,
and sugar is formed in considerable quantities from the sugar-maple. The sap of the birch-tree, on being fermented, yields an agreeable
beverage, called birch-wine.
The juice of grapes furnishes a
peculiar kind of sugar, called grape-sugar, which has been traced in many
fruits, such as pears, peaches, cherries, melons, dates, figs and the chestnuts
which grow in warm countries. Grape-sugar
is also formed in the nectarines of many flowers and is collected by bees; hence honey belongs to this variety of sugar.
Grape-sugar can be procured from
starch by the action of dilute sulphuric acid. Lignin, or woody fibre, or any substance containing it, can also be
converted into sugar by the same means. If
sawdust, linen-rags, paper, or other ligneous substance, be rubbed up with
sulphuric acid, and the acid
afterwards removed by adding an alkali or some powdered chalk, the ligneous body
will be changed into a species of gum, which, being boiled for some hours in a
weak acid, is gradually converted into sugar. It has been well observed that, “however clumsy and
inconvenient this process is in our laboratories, being, as we are, but
Nature’s journeyman, Nature herself carries on these transmutations with the
most wonderful results, as we see in the ripening of fruits, when the hard woody
texture gradually softens down into sweet and luscious pulp, as in the ripening
of the pear, the grape, the strawberry, and, in short, almost all fruits.”
The above varieties of sugar are
granular or crystalline, and are all capable of undergoing the venous
fermentation. The only sugar which
refuses to crystallize, but which can be fermented, is the molasses which
remains after refining cane and other sugars, and this is largely used in the
distillation of rum. Sugar of
milk and manna sugar do not ferment. The former, sometimes called Lactine, is obtained by evaporating
the whey of milk; the latter, also called Mannite, is contained in the
manna which exudes from several species of ash: it is also found in the bark of
the olive tree, in some species of pines, in the root and leaves of celery, in
the bulb of the onion, in many kinds of sea-weed, and in couch grass. By long exposure to the air the juices of many plants, such as beet,
carrot, generate manna sugar.
Sugar is extensively employed to
preserve animal and vegetable substances, such as meat, fish, fruits, jellies
and many medicinal substances; and in some cases is preferable to salt in not
destroying the true flavour of animal food. The sugar which is naturally formed in many fruits is sufficient to
preserve them, as in raisins, figs, and other dried fruits.
In temperate climates sugar is
rather a luxury than a necessary of life; but in tropical countries it is
extensively used as an article of food, and has been ranked inferior only to
corn. Enormous quantities of
sugar-canes are sent from the sugar islands to the markets of Manilla, Rio
Janeiro, and the surrounding countries. The
crude plant is called Dutrone, “the most perfect alimentary substance in
nature,” and this praise does not seem to be exaggerated when we consider its
effects upon the Negroes at the time of cane-harvest. “The time of crop is in the sugar islands,” says Mr. Edwards, “is
the season of gladness and festivity to man and beast. So palatable, salutary, and nourishing, is the juice of the
cane, that every individual of the animal creation, drinking freely of it,
derives health and vigour from it use. The
meagre and sickly among the Negroes exhibit a surprising alteration in a few
weeks after the mill is set in action. The
labouring horses, oxen, and mules, though almost constantly at work during this
season, yet, being indulged, with plenty of the green tops of this noble plant,
and some of the scummings from the boiling house, improve more than at any other
period of the year. Even the pigs
and poultry fatten on the refuse.”
In separating the sugar from the
juice some of the nutritive substances are removed; and it should not be
forgotten, that the praises bestowed on sugar by different writers on this
subject apply to the fresh juice of the cane, and not to the crystallized sugar
in use among ourselves.
The process by which raw or brown
sugar is converted into white sugar are of a striking and interesting character. Of late years they have been subject to considerable improvement, and
they now partake largely of the scientific character of our most important
manufactures.
The principle sugar refineries in
London are situated in Whitechapel and its neighbourhood: most of them are extensive buildings, each consisting of seven or eight
stories; the rooms, or working-floors, as they are called, present a
singular appearance. Each floor is paved with stone, is of small height, and the
ceiling is formed of brick arches, supported on iron pillars; the object being
to render the building fire-proof and of great strength, and also to provide an
extensive surface for arranging the sugar in the different stages of the
process. A square opening is left
at the side of each floor, over which, in the top floor, is a crane, for the
purpose of removing the sugar as occasion requires.
The reader may perhaps be able to
form a tolerably accurate idea of the art of sugar refining, from the following
attempt to trace the sugar from its raw to its refined state. The description applies to an extensive refinery at Whitechapel (Messrs
Fairrie’s), which, in company with an artist, the writer was privileged to
visit.
Sugar from the West Indies is
packed in hogsheads, and that from the East Indies in canvas bags, covered with
matting. These are received into
the first floor of the refinery, situate in a little above the street, where
they are broken open and unpacked by the side of a large circular vat or
cistern, which is pouring forth clouds of steam, and filling the floor with an
oppressive sickly vapour. In this
cistern, the sugar is first mixed with water, with the addition of a small
quantity of lime water and bone black. Heat
is applied by means of steam, which issues from a number of small copper pipes,
contained at the bottom of the vessel, and from this method of applying heat the
vessel is called the blow-up cistern, the steam forcing itself by its own
pressure, or blowing up, through the mixture.
The perfect solution of the sugar is promoted by stirring with long
poles. Shortly before the liquid
has attained the boiling point it is allowed to flow along a channel into a
filtering apparatus, situated in the room beneath; on leaving which it appears
as a clear reddish syrup.
The chief object of this process is
to separate mechanical impurities, such as dust, dirt etc. from the sugar. Until within a few years the process was conducted in a ruder and far
less direct manner. The raw sugar,
mixed with lime-water, was heated in a large open copper by a fire from below,
and when warm a considerable quantity of bullocks’ blood, technically called spice,
was stirred in. The serum or watery
part of the blood, (consisting chiefly of albumen, of which white of egg is a
familiar example) becoming curdled by the heat, and entangled most of the
impurities floating in the solution raised them to the surface in the form of a
thick scum, which was carefully removed. This
process was sometimes repeated two or three times, with fresh quantities of
blood, and from the scummings a low quality of sugar was afterwards obtained. The liquor being thus clarified, was filtered through a thick woollen
cloth, and afterwards boiled in an open copper until sufficiently concentrated
for graining. So imperfect was this
method, that, in order to produce loaves of the finest quality, a second
refining was necessary; the loaves first produced were broken up and
re-dissolved, and clarified with white of egg; this being carefully skimmed off,
a small portion of indigo was added, the effect of which was to neutralize the
yellow colour of the syrup. These
costly methods, which of course greatly increased the price of sugar, are now
rendered unnecessary; for, in the modern process, a clear liquor is obtained
without the aid of so offensive a substance as bullocks’ blood, a portion of
which generally become entangled with the sugar, and was not separated by
crystallization.
The filtering apparatus now in use,
is arranged in an ingenious manner. It
consists of square vessels of iron, about eight feet high, connected with
cisterns above and below, and containing a number of twilled cotton cloth tubes,
closed at the lower ends, but open at the upper ends, which are screwed into the
floor of the upper cistern. Within
each tube is a bag of cotton cloth, which, being considerably wider than the
tube, hangs down in folds. About
sixty tubes, thus arranged, are contained in each filter, so that by this means
an extensive filtering surface is obtained; the liquor from above, having to
pass through the meshes of the cloths, is strained of most of its solid
impurities, and a clear reddish syrup drops into the cistern below. The bags soon become clogged up, and are frequently removed for the
purpose of being cleansed. A black
viscid mud is scraped off, but, as this contains a portion of saccharine matter,
it is again boiled and otherwise treated before it is transferred to the dealers
in manure.
It is obvious that, in order to
produce white sugar, the syrup or liquor must be without colour. When it leaves the filters it is of a dark red colour, and to remove this
is the object of the next process, the introduction of which is one of the great
modern improvements in the art of sugar refining.
Chemists have discovered the
existence of a remarkable attraction between animal charcoal and the colouring
matters furnished by animal or vegetable substances. This kind of charcoal (or as it is sometimes called, bone-black,
or bone-charcoal) is produced by heating bones to redness in a close
vessel, or when covered over the sand. The
bones lose about half their weight by being calcined; they are then pounded in a
mill into a coarse granular state like gunpowder, in which they are fit for use.
The charcoal filter at Messrs
Fairrie’s are oblong vessels, about five feet in height furnished with a
double bottom, the upper one being pierced with holes and covered with cloth to
prevent the holes being choked up and the particles of charcoal being carried
away by the liquor. The charcoal is
heaped up on this cloth to the depth of three feet, and the reddish liquor from
the cistern above is allowed to flow in a gentle stream over the surface; it
slowly sinks through the mass, gradually losing its colour, until it arrives at
the space below, when it is colourless. A
series of pipes and siphon tubes from the various “charcoal cisterns” as
they are called, conveys the filtered liquor into reservoirs, whence it is
pumped up to the sugar boilers in the room above.
In the course of a few days the
charcoal becomes foul and unfit for use. Water
is passed through it to remove all saccharine matter, and it is then taken to
the retort-house and re-calcined, a process which restores all its valuable
properties.
The next process which the liquor
undergoes, namely, the boiling preparatory to crystallizing, is one of the most
important in the whole range of operations to which the sugar is subjected. By the old method the syrup was concentrated in the open pans, standing
over fires, and heated to 240° or 250° Fahr. This high degree of heat was very injurious to the sugar, for it changed
a large portion of it into treacle, which had to be got rid of in the moulds. The method was also objectionable on account of its danger, and the
difficulty of managing the heat. Many
plans were adopted for heating the liquor, by passing steam pipes through it, or
hot oil under it, but they were all superseded by the valuable invention of the
Honourable Edward Charles Howard, now in general use under the name of
Howard’s vacuum-pan, first introduced in 1813. The principle of this invention rests on the fact, that the boiling
points of all fluids are considerably lowered by placing them in vacuo. Thus, under ordinary circumstances, water boils at 212°, the pressure of
the air, which is equal to about fifteen pounds on every square inch of surface,
preventing the rapid formation of vapour at a lower temperature; but if water,
at the temperature of 90° or 100°, be placed under the receiver of an
air-pump, and the air be exhausted, the water will boil rapidly and pass off in
vapour. The object, therefore,
which the inventor of the new method had to view was to collect a sufficient
quantity of syrup in a closed vessel placed in connextion with an air-pump; then
to remove the air, and apply a very moderate degree of heat, by which means the
syrup could be boiled at a low temperature, and brought down to the granulating
pitch. After numerous trials and
failures the inventor was rewarded with success, and continued during several
years to derive a large income from premiums paid by sugar refiners for
permission to use the patent process. The
patent having now expired, no restriction is placed upon its general use.
The vacuum-pan consists of a large
copper vessel, about six feet in diameter, supported on legs, so that every part
may be conveniently inspected. The
lower part of the pan is double, for the purpose of letting in the steam which
is used to heat the syrup: within
the pan, in contact with the syrup, is a coil of copper pipe, through which also
steam is passed. The bottom cavity,
or steam-jacket as it is called, is supplied with low pressure steam, but
the spiral pipe is filled with high pressure steam, which is considerably hotter
than boiling water, and greatly promotes the evaporation of the syrup. From the centre of the dome rises a neck, which, by means of a bent tube
and other apparatus, connects the interior of the pan with the air-pump used for
extracting the air and vapour. The
interior of the pan is also connected by means of pipes with vessels containing
the clarified syrup which may by situated in the upper stories, or in the
charcoal-filtering room below. In
the former case, the syrup runs down into the pan on turning a stop-cock in the
pipe, and in the latter case it rises by atmospheric pressure, as soon as a
partial vacuum is formed in the pan. The
pan is furnished with a barometer or manometer, for showing the state of vacuum,
and also with a thermometer, for indicating temperature. There is also a cistern-pipe for receiving any syrup which may
accidentally boil over; but the too rapid boiling, and also the danger arising
from the pressure of the air on the outside, which might crush in the pan, are
prevented by a safety valve, which admits air in case the exhaustion should at
any time be made too perfect. There
are numerous other minor details, which need not be particularised.
The pans generally contain each
about 100 gallons of syrup, which yield about eleven cwt of granulated sugar at
every charge. Sometimes the pans
are of larger dimensions. Dr. Ure
mentions one in use at a London house, which works off eighteen tons of
sugar-loaves daily.
The pans being properly charged,
and steam admitting within the steam-jacket and the coiled pipe, and the
air-pump is set in action, its moving power being supplied by the steam-engine
of the establishment; the syrup
soon attains a temperature of about 130°, when it boils, and throws off vapour
of water, which is pumped off, and condensed in a vessel placed in the open air,
over which a steam of cold water is constantly flowing. As the syrup becomes more concentrated,
its boiling point becomes higher: the temperature is, therefore, gradually raised to about 150°, which is
about 100° lower than would be required for open vessels. The attendant is enabled to watch the process by means of a very
ingenious contrivance, called a proof-stick. This consists of a cylindrical rod, exactly fitting a hollow tube which
enters the pan in a direction slanting downwards. The upper end of the rod is open; the lower end, which dips into the
syrup, has a slit on one side of it, about half an inch wide. Within this tube is another shorter tube, which can be moved round in it
through half a circle: near the lower end of this tube is a lower hollow which
corresponds with the slit in the outer tube; and the upper end is connected with
a handle. By making the slit and
the cavity coincide, the latter is filled with sugar; then, by turning the stick
round through half a circle, the slit is covered by the fixed tube, and the
inner tube can then be drawn without allowing air to enter the pan.
The sugar is tried by the touch, as
already explained: the small crystals which appear in it are examined, and the
moment the liquor has attained the granulating pitch, the connection of the pan
with the air pump is cut off, air is admitted to equalise the pressure, and a
plug at the bottom of the pan is opened, by means of a lever attached to it,
when the whole of the syrup flows down a pipe into a receiver situated in the
room below.
In our notice of the process of
sugar-boiling in the West Indies, it was stated that, as soon as the syrup was
boiled down to the point of granulation, it was transferred to a vessel called a
cooler, the process of boiling in open vessels raising the liquor to so
high a temperature, that cooling is absolutely necessary to crystallization. The introduction of vacuum pan has wrought a curious change; for, after
the boiling is complete, the syrup is removed, not to a cooler, but to a heater,
where it is raised to the temperature of 180° or 190°, the object being to
make the syrup more fluid than the comparatively low temperature of the pan
admits of, and also to prevent crystallization before the sugar is poured into
the moulds; for, were this to take place, the colouring matter would be so
imbedded in the mass of crystals, that no after treatment, short of re-melting,
would get rid of it. Not only,
therefore, is the temperature of the syrup raised, but men are employed with
poles in beating and stirring it up, where it is being removed to the moulds.
The heater is a shallow vessel of
copper, surrounded with an iron steam-jacket for keeping up proper degree of
heat. The syrup which flow into it
from the pan is no longer a limpid, colourless fluid, as it was in the
filter-cisterns; it is now exceedingly thick and viscid, and the process of
boiling has concentrated the colouring matter, the molasses, and
uncrystallizable parts of the sugar, to get rid of which is one of the objects
of the concluding processes.
The sugar is next removed to moulds
in the fill-house, which is situated in the lowest story, and on a level
with the heater. The conical sugar
moulds are made of brown earthenware, or of sheet iron well covered with paint;
the pointed ends are open; and the moulds vary in size according to the quality
of the sugar, the largest moulds being used for the inferior sorts. At the time of the writer’s visit to the fill-house, one set of men
were engaged washing the moulds, and putting them up in piles to drain. A second set rolled these piles to another part of the floor, and placed
them one by one, with their points upwards; a third set were occupied in
twisting pieces of paper, with which they plugged up the holes in the moulds; a
fourth set were setting up the moulds, points downwards, an operation simple in
appearance, but requiring a level floor, and that kind of ready skill which can
only be attained by long practice. Beginning
at one corner, the moulds were arranged in ranks, four or five deep, along the
whole length of the floor. A fifth
set of men, eight or ten in number were engaged in filling the moulds; each man
was naked from the waist upwards, and was furnished with a copper basin, which
he filled at the heater by opening a kind of sluice at the side, and then with a
rapid step conveyed the syrup to the moulds, and poured it into them. Each man carried enough
to fill one mould, and about half of another. A sixth set of men immediately stirred round the sugar in the moulds, to
diffuse the crystals equally through the viscid mass. In this way the filling proceeded until the contents of the heater were
exhausted, and as the moulds were filled, fresh rows were arranged in front of
the former; until at length a considerable portion of the extensive floor was
occupied. Part of this busy scene
is represented in the frontispiece.
Matters remain in this condition
until the next day, when the sugar has become partially solid: the moulds are then moved through the pull-up hole into an upper
floor, which is maintained, by means of steam-pipes, at a temperature of 80°;
the paper plus are removed, and a wire is passed through the hole to ensure an
open channel; the moulds are then set in earthen jars, or are hung in a frame
work over a gutter terminating in a
sunken cistern. The syrup which
flows off is of a greenish colour, and being collected and reboiled with raw
sugar, it produces an inferior quality of lump sugar; this again furnishes a
syrup, which supplies a yet lower description of sugar, and when all the
crystalline particles have been removed, the residue is sold as treacle.
In the course of two or three days
the drainage is complete: but there
still remains a portion of syrup and uncrystalline matter entangled with the
solid sugar. To get rid of this, a
process of washing is adopted, which, under the old method, was performed by claying,
as
already described; but now by a process, one of Mr. Howard’s valuable
improvements, which accomplishes the work in one-fourth of the time formerly
required. Some finely clarified
syrup is made by dissolving warm water loaf sugar, consisting of the turnings
obtained by a subsequent process and such loaves as do not satisfy the critical
eye of the refiner, either by their shape or crystalline texture. The syrup thus obtained is poured to the depth of about an inch, upon the
broad part of each cone, the surface of which has been previously broken up and
made level by an iron tool called a bottoming trowel. As
this syrup is concentrated, it can dissolve none of the sugar already
crystallized but readily unites with molasses and colouring matter which do not
crystallize, and gradually drains away with them. The loaf improves in whiteness, from the base to the point, every time
this operation is performed. A few
moulds are emptied from time to time to examine the success of the blanching;
and when the loaves have acquired as much colour (as the whiteness is called by
the refiners) as is judged necessary, and are sufficiently dry, they are netted,
that is made net, or neat, in appearance.
The
moulds are taken one by one, and placed across a trough, and the base scraped
with the bottoming-trowel, so as to produce an even surface: this operation is
called brushing-off. A few blows being applied to the mould, the sugar is loosened, and turned
out upon its base. If the sugar is of the best quality, it is of a perfectly
pure white, from the base to within five or six inches of the point, and here a
portion of moisture and colouring matter still remains, which is removed by the
process of turning off. This is
effected by cutting blades, arranged in a conical form, connected with
wheel-work, to which motion is given by one man, while another gradually
introduces the loaf within the space formed by the knives, whereby the coloured
damp portion is removed, and the loaf improved in shape. Loaves of coarser sugar are not turned off, but the damp ends are cut
off, leaving them in the form of a truncated cone. The loaves are then removed to an oven, which occupies nearly
the whole height of the building, upon a base of not more than ten feet square. This oven is provided with open frames,
from the base to the top, upon
which the loaves are arranged, and a constant temperature of about 140° is
maintained, by a numerous assemblage of steam pipes. When sufficiently dry, the loaves are taken out, tied up in paper, and
are then fit for the grocer’s shop.
The routine of operations at the
refinery takes about a fortnight, during which various qualities of sugar are
produced; first, white loaves of the finest quality, obtained directly from the
raw or muscovado sugar; secondly, a second quality called lumps, composed of the
second runnings, which are the syrup used in washing the loaves after the green
syrup is separated; thirdly an inferior quality, composed of the green syrup,
mixed with the raw sugar, producing what are called bastards. These are crushed into powder, and sold as a superior kind of moist
sugar; fourthly, several inferior kinds of sugar are produced from the refuse
matter, consisting of the impurities collected in the bag-filters, the scrapings
of the various floors and the waste, which in the several departments of an
extensive refinery is necessarily great. All
these sources of sugar are carefully collected; the crystalline particles
separated from the treacle, and this again from dirt, and other impurities,
which are finally sold as manure. Every
third week the routine is again commenced, and carried on during another
fortnight of twelve days; for it is satisfactory to learn that, in this
manufacture, Sunday is a day of rest.
As some of the different qualifies
of sugar are being forwarded a stage at the same point of time, the stranger is
somewhat embarrassed to notice such various results produced, as it were, by the
same means. But on clearly
understanding the economy of the refinery, he will be able to trace the pure
white loaves, from the raw sugar in the hogshead to its final completion,
passing over, as accidental or subsidiary, the various arrangements whereby
inferior loaves are produced, or in other words, whereby waste is prevented. In such a case
the refinery presents points of the highest interest. It is curious to witness the application
of so much science, ingenuity,
skill, and capital; to the production of an article which, after all, is one of
mere luxury, and according to Dr. Prout, is inferior in nutritive properties to
the raw sugar which furnishes it, a circumstance which may afford some
satisfaction to those persons whose means will not allow them to use white
sugar. The working floors of the
refinery, containing many thousand moulds filled with sugar, are peculiarly
striking. The utmost care is taken
to guard the sugar from speck or stain, but the floors themselves are not so
privileged: during the processes of
filling and washing, small quantities of syrup are being constantly spilt, and
this is soon trampled into a thick viscid mud, which adheres to the feet, and in
some places actually impedes motion. Heat
is every where present, and often to an oppressive degree, but its source is
seldom seen; the system of heating by steam has enabled the refiner to regulate
the supply of heat as he may desire, and has also rendered perfectly safe a
process which was formerly very hazardous. The effect of the various modern improvements has greatly reduced the
price of refined sugar; at one time its price was 40 per cent greater than raw
sugar, but now the difference in price is not more than 20 per cent.
The consumption of sugar
in different years is liable to great fluctuation, arising from variation in
price, and the means of the people to purchase; but it has been calculated that
the annual consumption averages about 20 lbs per head for Great Britain; about 5
lbs per head for France; 4lbs for Germany; and about 2½ lbs for other parts of
Europe.
In the year 1839, the
quantity of cane sugar produced in different parts of the world was estimated as
follows:
Cwts
The British Sugar Colonies
Exported
3,571,378
British India
Exported
519,126
Danish West Indies
Exported
450,000
Dutch West Indies
Exported
260,000
French Sugar Colonies
Exported
2,160,000
United States of America
Exported
900,000
Brazil
Exported
2,400,000
Spanish West Indies
Exported
4,481,342
Java
Exported
892,475
Exported for internal consumption, exclusive of China,
India, Siam, Java and the United States
2,446,337
18,080,718
Between one-fourth and one-fifth of this quantity is consumed
in the United Kingdom. The
quantities imported during three years are as follows:
1839
Cwts
1840
Cwts
1841
Cwts
West India, of British Possessions
2,823,931
2,202,833
2,145,500
East India, of British Possessions
518,925
482,824
1,239,738
East India, of Foreign Possessions
722,777
-
803,668
Mauritius
612,009
545,009
716,112
Foreign
722,777
805,179
-
The duty of sugar from British possessions was during many
years 24s per cwt; foreign sugars paid a duty of 63s per cwt. The net revenue from this source, for 1839 was 4,586,936l.; for 1840,
4,449,033l; and for 1841 5,114,390l. By
a recent act of the legislature the duties payable on the importation of sugar,
subject to minor exceptions, depending on reciprocity treaties, and other
circumstances, are as follows:
Sugar grown in British West Indies or East India
Per Cwt
Double Refined
£1.
1. 0
Refined
0.18.8
Clayed
0.16.4
Brown or Muscovado
0.14.0
Molasses
0.5.3
Sugar grown in other British Colonies
Clayed
1.1.9
Brown
0.18.8
Sugar grown by free labour in Foreign Countries
Clayed
1.8.0
Brown
1.3.4
Sugar grown by slave labour in Foreign Countries
Refined
8.8.0
Brown
3.3.0
Molasses
1.3.9
Before these alterations, refined sugar was not allowed to be
made in any of our colonies, but was reserved for the advantage of this country: considerable
quantities were, therefore, annually exported. In the year ending 25th June 1840,
the chief export of British
refined sugar was as follows:
Cwts
To Italy
40,000
To British North America
37,000
To Turkey
30,000
To Russia
20,000
To Australian Settlements
11,000
To British West Indies
10,500
Although foreign sugar paid nearly three times the duty
charged on our colonial sugar, yet the refiner was permitted to refine it in
bond for exportation, a drawback being allowed in the proportion of 34 cwt. of
raw to 20 cwt. of refined.
The men engaged in the sugar refinery appear to enjoy average
good health. In some of the
processes, they are exposed to a warm damp atmosphere and in others to hot dry
air; but they are not long enough at them to suffer injuriously, the nature of
the work leading them to conduct other processes which are rather healthy than
otherwise. The preparation of the
bone black is peculiarly disagreeable and dirty, the air of the room in which it
is performed being very hot, and loaded with particles of dust; but this is
usually a separate trade.
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