The Commercial Products of the Vegetable Kingdom by P. L. Simmonds

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By a reference to the foregoing table it will be easily understood how
slight a change in the proportion of the ingredients of any one of the
substances contained therein will convert it into an entirely
different one. In chemistry we are able, to a certain extent, to
imitate the operations of nature; but we must follow in the same
course laid down by her; thus, we can convert woody fibre, or sawdust
and starch, into sugar, gum, alcohol, and acetic acid; but we cannot
convert alcohol, acetic acid, or gum into sugar, starch or woody
fibre; and of such importance is a slight alteration of the
proportions of these elements--carbon, oxygen, and hydrogen--that the
abstraction of carbon from sugar, and the addition of a portion of the
prime support of life, vegetation and combustion, oxygen, changes the
harmless sugar into the most violent of poisons, oxalic acid, which
consists of 26.57 carbon, 70.69 oxygen, and 2.74 hydrogen.

Let us now examine the action of lime on sugar, and we shall find it
equally, if not more, injurious than on the other substances. Sugar is
capable of dissolving half its weight of lime, by which its sweet
taste is destroyed, and it becomes converted into gum; the lime
abstracting carbonic acid from it to form a carbonate of lime or
chalk. It will be seen by the above table that--

100 parts of sugar contain 42.47 carbon.
100 parts of gum contain 42.23 ditto.
-----
Difference 24

So that, if we extract 24-100ths of a grain of carbon from 100 grains
of sugar, we convert them into gum. Let us suppose that about two
ounces of lime, or say 1,000 grains, remain in solution in a pan, (say
200 gallons of liquor,) those 1,000 grains of lime will require 761 of
carbonic acid to convert them into carbonate of lime or chalk, 100
grains of which consist of 56.2 lime and 43.8 carbonic acid. So that
1,761 grains of chalk consist of 1,000 lime and 761 carbonic acid. Now
100 grains of carbonic add consist of 27.53 carbon and 72.47 oxygen;
therefore 761 grains will consist of 209.50 carbon and 551.53 oxygen.

Consequently, 1,000 grains of lime will require 209.50 grains of
carbon to convert them into carbonate of lime; and as we have seen
that the abstraction of 24 from 100 grains of sugar convert them into
gum, it follows, that the abstraction of 209.50 grains would have a
similar effect on 87,000 grains, or about 15 lbs. of sugar, which,
being converted into gum, would prevent the crystallisation of several
times its weight of sugar; and this is the cause of the formation of
molasses. The loss of sugar is not the only bad consequence of the use
of lime, as the greater the quantity of gum in the liquor, the more it
must be boiled--the more it is boiled the darker it gets--and the
higher the temperature at which the skip is struck, the smaller the
grain. The following is a good proof that lime dissolves albumen, and
becomes converted into chalk:--Take a spoonful of syrup out of the
tache of any estate on which the liquor is tempered cold; it will be
found filled with small flakes; these are albumen set free from its
solution in the lime by the conversion of the latter into carbonate of
lime, and coagulated by heat. It is perfectly possible to temper
liquor, so that scarcely any uncrystallisable sugar will remain; but
planters do not like this; they must have molasses for the
still-house; they could, however, boil low, by which the grain and
color would be improved, and plenty of uncrystallised, although not
uncrystallisable, syrup would be left to take the place of molasses.

I think I have now fully proved the following facts, viz.:--That the
use of lime in sugar-making is not to neutralise an acid; that if
acidity be present, the application of lime is injurious; that its
action on gluten, albumen, wax, resin, and chlorophyle is equally so;
that by decomposing the sugar and forming gum, the quantity of
molasses or uncrystallisable sugar is much increased, whereby high
boiling is rendered necessary, with its consequent heightening of
color and injury to the grain of the produce, and that therefore it is
perfectly unfit for the purpose of tempering cane-juice.

Messrs. Thomas Begg and Co., of London, have procured from E.F.
Telchemacher and J. Denham Smith, an analysis of one gallon of
ordinary plantain juice, and one gallon of Ramos' prepared plantain
juice "for the purpose of ascertaining whether any substance can be
used which, in conjunction with water, will answer as a substitute for
the plantain juice in the receipt which accompanied the samples." The
chemists say they find that one gallon of ordinary plantain juice
holds in solution;--

Extract similar to tannin 25.60 grains
Vegetable extract and fatty matter 57.70 "
Carbonate of potash 150.40 "
Muriate of potash 33.60 "
Muriate of soda 2.00 "
Silica 1.20 "
-------------
Contents of one imperial gallon 270.50 grains

--whilst one gallon of "Ramos' prepared plantain juice" contains,
besides vegetable extract, 226 grains of solid matter, consisting of
sulphuret and potash, in the following proportions:--

Sulphur 40 grains
Lime 156 "
Potash 30 "
----------
226 grains

They do not think it likely that the potash exists in fresh plantain
juice as carbonate, but rather that this salt is the product of
decomposition, arising from a compound of potash and a vegetable acid,
such as tartaric or oxalic acid present in the fresh juice; be this as
it may, any utility derivable from the plantain juice is evidently
owing to the potash it contains.

They then give as a substitute for Ramos' liquid, and to be used in a
similar way, the following--

Take of subcarbonate of potash 2 ounces, avoirdupois; sulphur, 21/4
ounces; best British lime slaked, 11/2 lb.; mix them into a paste in an
earthen pan or wooden tub, with one quart of water (warm) and when
thoroughly mixed, pour in ten gallons of boiling water--rain water is
the best to use--and stir from time to time until it has cooled, when
it may be drawn off from the sediment and kept for use. If rain water
cannot be obtained, the purest water obtainable may be used.

One of the causes most fatal to West Indian prosperity, is that
exuberance of advantages which they enjoy from serenity of climate and
fertility of soil--causes which, in the absence of proper stimulus to
industry and improvement, have led to an improvident system of
cultivation, and to a blind and ignorant adherence to wasteful methods
of manufacture.

The cane is believed to contain from 90 to 95 per cent. of its own
weight of saccharine juice; and yet (as Mr. Fownes, a Professor of
Practical Chemistry in University College, London, informs us, in an
excellent paper "On the Manufacture of Sugar in Barbados,"[17] from
which much of what follows has been borrowed) owing to the defective
construction of the mills, hardly so much as 50 per cent. is obtained,
although he believes it practicable, by an improvement in the mills,
to obtain from 70 to 75 per cent.; and of the remaining 10 or 15 per
cent. which he regards it as impossible to extract, much, if not the
whole, might, I conceive, be obtained, by macerating the pressed canes
or megass, as it issues from the mill, and repassing it through the
rollers; and, be it remembered, that from 40 to 45 per cent. of
saccharine juice is nearly, if not altogether, equivalent to a similar
per centage of sugar; so that by these initiatory improvements alone,
and with little additional trouble, the produce of sugar might be
nearly doubled from any given quantity of canes.

From the action of lime-water when added in a slight excess to the
cane juice or raw liquor, as it is vernacularly termed, immediately on
issuing from the mill, as well as from the effect produced by ammonia
or potash, this liquid appears to contain a considerable quantity of
cane sugar, mixed with much glucose, or that saccharine matter which
is found in fruits; gum or dextrine, phosphates, and probably malates
of lime and magnesia, with sulphates and chlorides, potash and soda,
and a peculiar azotised matter, allied to albumen, which forms an
insoluble compound with lime, is not coagulable by heat or acids, and
runs readily into putrefactive fermentation.

To free it from these constituents, and enable it to yield pure and
crystallisable sugar, the liquor, on entering the boiling-house, is
received into the first of three clarifiers, of the capacity of from
three hundred to a thousand gallons each. Here it is subjected to the
action of lime-water, which checks the tendency to fermentation, and
neutralises any free acid which it may contain. "The common defection
process," says Mr. Fownes, "in careful hands, seems susceptible of
little improvement. Many other substances than lime have been proposed
and tried with more or less success, some of which, in particular
states of the cane juice, may prove very useful; but, for general
purposes, nothing seems to answer so well as neutralisation by lime,
either in the form of lime-water or milk of lime, added until the
slightest possible tendency to alkalinity, as ascertained by delicate
reddened litmus paper, is perceived. The juice should be somewhat
heated before the lime is added, and afterwards raised quite to the
boiling point. The fire is then to be withdrawn, and the whole allowed
to rest a short time." Such is Mr. Fownes' description of the process
of clarification; to which I will venture to add, upon the authority
of those who have experienced its good effects, the joint use of the
mucilage of the _Guazuma ulmifolia_, or gun-stock tree, as it is
popularly termed in Nevis from the use to which its timber has been
applied. This is the bastard cedar of Jamaica, or Orme d'Amerique, and
Bois d'Orme of the French, which may be found described by Lunan, in
the first volume of his "Hortus Jamaicensis," page 59, under the name
of _Bubroma Guazuma_.

This tree presents in the interval between its outer bark of sap-wood,
a mass of fibrous matter about half an inch in thickness, richly
impregnated with mucilage, which is obtained by macerating the fibrous
mass, conveniently divided into small shreds, for about twelve hours,
in warm water, in the proportion of about two handsful to eight
gallons of water. Of this solution, which is of a light, straw color,
and somewhat thickened, one gallon is to be added for every hundred
gallons of cane juice, after the clarifier has been charged with the
proper quantity of lime-water, and has become lukewarm. The mixture
should then be stirred, and afterwards allowed to settle till the scum
has risen to the surface. The fire must next be cautiously and
gradually raised to the point of boiling, when it must again be
slackened, and the whole left to stand for about forty minutes, by
which time the mass of feculencies will have risen to the surface,
when the clear liquor underneath may either be drawn off by a siphon
or cock; the whole may be filtered as Mr. Fownes recommends, by which
means the liquor would be more effectually clarified, and much, if not
all, the subsequent labour of skimming dispensed with. The matter
remaining on the filter may be employed, either as a ferment in the
still-house, or added to the manure heap. Much of the beneficial
effect of the mucilage of the _guazuma_ arises probably from an
admixture of tannin, or some other astringent; for I have often been
struck with the peculiar whiteness of the potted sugar in the
curing-house, in the immediate vicinity of the Banana stalks,
resulting, no doubt, from their powerful astringency; and tannin has
already been found useful in the manufacture of sugar from beet-root
in France, and is no doubt equally applicable to cane-sugar.

The liquor, when clarified in the manner described, must be
concentrated, by regulated evaporation, to the degree requisite for
crystallisation. This Mr. Fownes advises to be done by steam of a
moderate pressure circulating in a spiral of copper-pipe laid at the
bottom of the evaporating vessels, which should be large and shallow,
and wholly unlike those in present use. Here it may be rapidly boiled
down till the heat rises to about 225 deg., without risk of burning.
When cold, it should have a density of about 1.38, and mark the 38th
degree of Baume's hydrometer; beyond which point of inspissation it
would be dangerous to go. The remaining concentration will be most
safely conducted in the vacuum pan, where a scarcity of water does
not, as in Barbados, militate against its use.

Mr. Fownes exposes the absurdity of using shallow coolers, exposing a
large surface, and producing a rapid evaporation, for the process of
crystallisation. By the use of the shallow coolers formerly, and, I
believe, yet to be found on most estates, from the rapidity of the
evaporation, the sugar is obtained in a mass of confused and
imperfectly-formed crystals, entangling in their interstices a
considerable quantity of molasses, which impairs the color of the
product, and escaping slowly, and with difficulty, is, to a
considerable extent, lost on the homeward voyage by drainage into the
hold, occasioning much positive loss to the owner, and giving the
bilge-water a most offensive odor. He therefore recommends the use of
deep vessels, and avoidance of all agitation in this part of the
process, so as to enable the crystallisable portion of the syrup to
effect a more complete separation from the uncrystallisable portion or
the molasses. By this simple method, not only sugar of a finer and
whiter quality would be obtained, but a large per centage of loss both
of crystallisable and uncrystallisable sugar at present caused by the
leakage of the hogshead into the hold, would be prevented, not only to
the great advantage of the planter, but to the great comfort of the
captain, passengers, and crew of the vessel freighted with it.

It is not improbable that, by re-boiling the molasses in the
vacuum-pan, and employing tannin in the manner adopted in the process
for making sugar from beet-root, from one to five per cent. of
crystallisable sugar could be recovered from it, and this per centage
might possibly even be found to admit of increase by the further
treatment with lime-water and the gun-stock tree s already suggested,
for the first clarification of the liquor received from the mill. With
this view, Mr. Fownes recommends the substitution of puncheons, or
casks, for the molasses cisterns ordinarily employed in the
curing-house, to receive the molasses as it drains from the new sugar,
and thus retaining it until after the busy period of crop time has
closed.

Should sugar of a whiter quality than the ordinary muscovado of
commerce be desired, this advantage may be readily obtained, as Mr.
Fownes judiciously observes, by filtering the thin syrup, ready for
the vacuum-pan, through a bed of fine charcoal, as is done by the
sugar refiners, and afterwards washing the crystals of sugar with
white syrup, when the molasses has thoroughly drained from them. By
this process, which, however, is attended with some increase of
expense, and may not, in consequence, be always advisable, muscovado
sugar may be obtained, of a quality hardly inferior to that of refined
sugar. Mr. Fownes thus sums up the principal points to which he is
desirous of calling the attention of the intelligent and enterprising
planter.

1. "To obtain, by the use of a properly-constructed mill, the greatest
possible amount of juice from the cane."

By this, according to Mr. Fownes, a gain of from 20 to 30 per cent.,
equivalent to as much marketable sugar, may be obtained without any
additional expense; but as, from Mr. Fownes' own showing, there is a
residuum of 10 to 15 per cent of liquor obstinately retained by the
megass, or cane trash, after the most powerful pressure to which it
can be subjected; much, if not all, even of this loss might be
prevented by subjecting the megass, on issuing from between the
rollers, to the action of water for a brief time, passing it once more
through the mill, and adding the saccharine solution so obtained, or
that obtained directly from the cane on its first crushing. The water
thus employed would serve for many successive portions of megass,
until at length it became so richly loaded with saccharine matter as
to be worth attention in the boiling-house; or, at all events, it
would be serviceable for the cattle, who would fatten rapidly upon it.
By this additional process a further gain of at least five per cent.
might be expected, raising the total gain from improvements in this
_first_ stage of the process, to from 25 to 35 per cent.

2. "To clarify and filter this juice with expedition, and to evaporate
it rapidly, either over the open fire or by steam heat, as far as it
can be done with safety."

By the use of steam, not only is a vast economy of fuel effected, but
the temperature is maintained at a uniform and sufficient standard,
and the liquor effectually guarded against the risks of carelessness
or ignorance. Coal may be obtained on far cheaper terms, in exchange
for produce, from the United States or from Cape Breton, than from
England; and as colliers from those quarters would find it their
interest to bring cargoes at their own risk, and take return cargoes
of sugar, rum, or molasses, at the market price, the planter will be
doubly a gainer by the system, obtaining his fuel at a reduced rate,
and having his trash and megass left free as manure for the use of his
cane fields.

3. "To complete the concentration in a vacuum pan, or by other means,
at a moderate temperature, not hurtful to the sugar, and facilitate
the natural process of crystallisation, so as to obtain sugar of a
large and distinct grain."

4. "To drain and dry the sugar perfectly, and to save all the
molasses."

The advantages to be anticipated from these improvements, superadded
to an improvement in cultivation, cannot be estimated at less, upon a
moderate calculation, than from 150 to 200 per cent. of increase in
the production of sugar, with hardly an appreciable increase of labor
or expense; for we have, in the first place, a gain by improved
culture of, at least, two hogsheads an acre in sugar, equivalent to
100 per cent.; in the next, by employing improved mills and extracting
the residuum, 30 per cent.; by conducting the process of manufacture
more judiciously, 10 per cent.; and by the prevention of waste during
the transit to market, 10 per cent., making a total of at least 150
per cent.

The common sugar-mill consists of three cylinders, tightened either by
wedges, if in a wooden frame, or by screws in a cast-iron frame. If in
an iron frame, the above-mentioned noise is obviated, but the friction
and loss of power is the same, which is ascertainable by subsequent
investigation. The cylinders or rollers, which are moving either
horizontally or vertically, are from eighteen to twenty-four inches in
diameter, with bearings or shafts of one fourth of their diameter. If
the bearings or shafts of the cylinders were of less substance, they
could not resist the great strain to which they are subjected when in
operation. The whole of the prime mover (steam-engine, water-wheel, or
animals), minus the friction of intermediate machinery, is transmitted
to the plains of these rollers and resisted by their bearings; hence
the action is equal to a weight moving on low wheels of eighteen or
twenty-four inches in diameter, on axles of from four to six inches
thickness, which weight is equal to the force applied; consequently,
if the strain is greater than the resistance of the rollers or the
bearings, they must be wrenched off, or if greater than the force
applied, the mill will be stopped. The power necessary to move weights
upon wheels, on a smooth and level surface, is in proportion to the
respective diameters of wheels and axles. The same pull which moves
one ton at a given velocity upon a wheel of two feet, with an axle of
six inches, will move four tons, if on a wheel of four feet diameter,
with an axle of six inches. Consequently, cylinders of small diameter,
with strong and substantial bearings, are only admissible as working
machines, if no other mechanical means are applicable, as, for
instance, in rolling out metals, compressing the surface of various
bodies for a glossy appearance, or, generally speaking, to produce a
certain and equal form of the substance which is pressed and passed
between them. They compress the atoms of bodies, and for this reason
alone are ill suited to separate the fibres of the sugar canes, and to
express effectively the saccharine matter between them. A practical
proof of this demonstration is furnished by every sugar cane which has
gone through the mill. Fresh megass is at present better suited for
fattening animals than for fuel under the sugar pans.

The loss of material thus sustained, which is, on an average, equal in
every mill, whether driven by steam, water, or animal power, is
entirely chargeable to the construction of the mill, and amounts to
about ten per cent. of the saccharine matter contained in the sugar
canes.

M. Duprez, an agent of the French Government, having experimented on
the canes in Guadaloupe, found the quantity of juice in every 100 lbs.
crushed--

lbs.
1 By mills having horizontal rollers; the
motive power not stated 61.2
2 By mills, motive power, steam 60.9
3 By mills, motive power, wind and steam 59.3
4 By mills, having vertical rollers 59.2
5 By mills, motive power, cattle 58.5
6 By mills, motive power, wind * 56.4

[* Dr. Evans' "Treatise on Sugar," p. 75.]

The average of all these experiments being 56 per cent. only. The
result of M. Avequin, on Louisiana cane, was 50 per cent. Mr.
Thompson, of Jamaica, states 50 per cent. as the average throughout
the island of Martinique. Dr. Evans ventures 47 per cent. as the
lowest, and 61 per cent. as the highest in the West Indies. A mill in
Madeira gave 47.5 and 70.2 of juice--the larger yield being obtained
by bracing the horizontal rollers more than usually tight, and
introducing only a few canes at a time, the motive power being cattle.

The three roller mill has the disadvantage of re-absorbing a part of
the cane juice in the spongy megass, (or trash as it is termed in the
West Indies), and a loss of power.

Those with five rollers have been used in Cuba, Bourbon and the
Mauritius, which gave 70 per cent., but a great increase of motive
power is necessary. Four roller mills, two below and two above,
requiring little more motive power than three rollers, have given 70
to 75 per cent of juice.

Some years since, the East India Company instituted inquiries relative
to the cultivation of the sugar cane in Hindostan, and the information
obtained was published in a large folio volume. The Reports furnished
by their officers, from almost every district, concur in stating that
there were three kinds cultivated:--1. The purple. 2. The white. 3. A
variety of the white, requiring a large supply of water. The epitome
of the Reports affords this information:--

1. The purple colored cane yields a sweeter, richer juice, than the
yellow or light colored, but in less quantity, and is harder to press.
Grows on dry lands. Scarce any other sort in Beerbhoom, much in
Radnagore, some about Santipore, mixed with light colored cane. Grows
also near Calcutta; in some fields separate, in others mixed with
pooree or light colored cane. When eaten raw, is more dry and pithy in
the mouth, but esteemed better sugar than the pooree, and appears to
be the superior sort of cane. Persons who have been West Indian
planters do not know it as a West Indian cane.

2. The light colored cane, yellow, inclining to white; deeper yellow
when ripe, and on rich ground, it is the same sort as that which grows
in the West India Islands; softer, more juicy than the Cadjoolee, but
juice less rich, and produces sugar less strong; requires seven maunds
of pooree juice to make as much goor or inspissated juice as is
produced from six of the Cadjoolee. Much of this kind is brought to
the Calcutta markets, and eaten raw.

3. The white variety, which grows in swampy, lands, is light colored,
and grows to a great height. Its juice is more watery, and yields a
weaker sugar than the Cadjoolee. However, as much of Bengal consists
of low grounds, and as the upland canes are liable to suffer from
drought, it may be advisable to encourage the cultivation of it,
should the sugar it produces be approved, though in a less degree than
other sugars, in order to guard against the effects of dry seasons.
Experience alone can determine how far the idea of encouraging this
sort may answer.