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AN

INTRODUCTORY MANUAL

FOR SUGAR GROWERS

BY

PRANGCIS. WAITS, .F.€:S. 09 L€:

ASSOC. MASON COLL., BIRMINGHAM, AND GOVERNMENT CHEMIST, ANTIGUA, W. I,

LONDON
LONGMANS, GREEN, AND CO.

AND NEW YORK: 15 EAST 16th STREET
1893

All rights reserved

COPYRIGHT, 1892, BY

LONGMANS, GREEN, AND CO.

TROW DIRECTORY
PRINTING AND BOOKBINDING COMPANY
NEW YORK

-_ -

“ 6F

PREFACE,

_ AN experience of some years in the West Indies
has led me to see the necessity for some simple
hand-book for the use of those engaged in the sugar
industry—a hand-book containing an outline of the
principles of agriculture based on modern scientific
discoveries, and also an outline of the principles
underlying the manufacture of sugar.

An attempt is made in the following pages to col-
lect together in as simple a manner as possible a
series of observations on these points, in the hope
that they will serve as a starting-point for young
overseers about to begin their training in the sugar-
fields and boiling-houses, and also, perhaps, as a
means of rendering more easy and accessible to
older men the information to be obtained from
larger works and from scattered papers and pam-
phlets.

One difficulty which sugar growers experience is
that writers on agriculture have rarely written
upon their special subject, but have treated of the
methods and productions of temperate climates ;
hence there has often been a doubt as to the
extent to which the writers’ remarks could be with

vi PREFACE.

safety applied to a tropical plant and under tropical
conditions.

A sugar literature is now springing up, and it is
hoped that this little book may be one of a series
of hand-books, each dealing in a more exhaustive
manner than in the present case with some one
branch of the sugar industry. If a number of com-
petent writers could be induced to contribute to
this end, such a course would do much to give
accuracy and precision in the place of the old
“rule of thumb.”

FRANCIS WATTS.

GOVERNMENT LABORATORY, ANTIGUA, W. L,
November, 1892.

PABLE: ‘OF CONTENTS:

PAGE
LUSTER Ue > Say a aS Oe Ses ei ye Cy 5,
PSP OW CONTENTS -. --< sc « 3s. # wlio oo 3 oo AH
Pie CuLLUSTRATIONS. ele. 20 oo 3. SC Oa 2 Ee

CHAPTER I.

Introduction.—Chemical Elements and Symbols.—Cells, Tis-
sues, and Fibro-vascular Bundles.—Structure and Func-
tion of Roots, Stems, and- Leaves .-. ./:...°. . 1-14

CHAPTER II.

Origin of Soil, Clay, Chalk or Marl, Sand.—Fertile Soil.—
Conditions Influencing Fertility.—‘‘ Condition or Heart.”
—Function of Vegetable Matter in the Soil.—Moisture.—
Mineral Plant-food. — Analysis of Soils. — Nitrogenous
Plant - food. — Nitrification. — Leguminous Crops and
Nitrogen.—Root-nodules.—Retention of Plant-foods by
Soils.—Drainage - . 15-39

CHAPTER III.

Sugar-cane. — Preparation of Land, Planting, Manuring,
Weeding.—Cutting Cane.—Methods of Dealing with the
rash: —Moglding.. 5 6 <0 ie ek ew 40-50

CHAPTER IV.

Manures.—Farm-yard or Pen Manures, their Function and
Use.—Management of Pen Manure.—Open and Covered
Pens.—Green Dressing.—Chemical Manures.—Potash,
Phosphates, Mineral Phosphates, Superphosphates, Basic
Slag or Thomas Phosphate. — Nitrogenous Manures.—
Pail aceler. Prone” a: “s)he. Ses coe oe ee, ee

vill CONTENTS.

CHAPTER V. siee
Cane-mills. — Three-roller Mill. — Fletcher-Le Blanc Four- |
roller Mill—Mirlees’ Four-roller Mill.—Skegels’ Mill.—
De Mornay Mill.—Hydraulic Attachment, etc.—Double
Crushing.—Maceration.—Diffusion . .. . . . 7-84

CHAPTER VI.

Cane-juice. — Composition. — Tempering. — Use of Lime. —
Phenol-phthalein Test for Lime.—Clarifying. —Forma-
tion of Scum.—Treatment of Scum.—Filter Presses. —
Composition of Filter-press Cake.—Uses of the Cake.—
Watavie: Cakes 2s oti lw Ge 2 aes oe a oe

CHAPTER VIL.

Manufacture of Sugar. — Inversion. — Open-fire Process, —
Steam Pans. — Muscovado Sugar. — Vacuum Pan. —
Method of Operating. — Triple Effect. — Centrifugals.
—Production of High-class Sugars.—Use of Sulphur.—
Carbonation.—Phosphoric-acid Process.—Animal Char-
COAL MMe Fale ihe bode: | «2st b iar ie ae: ae as ae eee

CHAPTER VIII.
Hydrometers or Saccharometers, and their Use . . . 117-121

CHAPTER IX.
‘Molasses.—Production, Composition, and Uses.—Recovery of
ugar from Molasses. -.... 2 ...v: =< | = . -elee—iee
CHAPTER X.

Fermentation.—Nature of Ferments.—Conversion of Cane
Sugar into Alecohol.—Setting up Wash.—Yield of Alco-
hol.— Distillation.—Forms of Stills . ... . . 127-136

TABLE OF TEMPERATURE OF STEAM UNDER VARIOUS
PRESSURES .s. -02: ae Ve ee 2 Se eee

LisT OF ELEMENTS, WITH THEIR SYMBOLS AND Com-
BINTNG: WEIGHED (5 2) 0 ak, fae et or 7 ee

TABLE OF DENSITIES, ETC., OF SACCHARINE SOLUTIONS, 139, 140
ERDEX 4 - gos 604, 20 2 a)” oS) be eee eee oe

FIia.

Lisl! OF ILLUSTRATIONS:

PAGE

. Fibro-vascular Bundles in Sugar-cane, Longitudinal and

EREARSVCTSE SECHIONS 0 Acts oe aid Coe ae eee ee ak ern

. Fibro-vascular Bundles in pee showing Fibres

Bnd VESSEIS 2, is. Us: @s SOS ARAM <2. ool SERRE:

. Rootlet, with Root-hairs and ee Pe es ed 3)
. Transverse Section of Sugar-cane Leaf ...... ii
. Epidermis of Sugar-cane Leaf, with Stomata . . . . 11
mmechonor Hogt-nodule. 3 (e4 .. 2 2. Ba) = 29

. Diagram of Pipes and Jointsin Tile Drain . . . . . 87
. Diagram of Three-roller Mill. . . . Be okra dO)
. Diagram of Fletcher-Le Blanc Four-roller Mill. . . . 6
. Diagram of Mirlees' Four-roller Mill . . . .... 77

= wiasram of De Mornay Mill .*.° .- 2.2 «7. 3 . 98
menmemplo Of Hydraulic Press). ee es eG. ar ee 09
. Diagram of Hydraulic Attachment toCane-mill . . . 79
poliarram, of Diftusion: Battery ..:. +... %s 0. : «... 2. 88

. Diagram of Curves, Illustrating the Increase of Glucose

with Increasing Concentration in Various Processes of
pucar Manntactare 3 1 ot pn a ee ee! = 108

moideram of Vacuum Pan 0. -.° i. 4) s,s ee 2 AOD
- Diagram of Triple-effect Apparatus. . .°. . » «.-. 109

. Beaumé’s Hydrometer or Saccharometer . . . . . . 118
MEAS PAANE 6) 50 58 ak aes Sow an a Bele.
eriseram.of Continuous Still... 2 » .« % Ge «'. «feb

MANUAL FOR SUGAR GROWERS.

CHAPTER I.

Introduction.—Chemical Elements and Symbols.—Cells, Tissues,
and Fibro-vascular Bundles.—Structure and Function of
Roots, Stems, and Leaves.

N the study of agriculture an acquaintance with
a number of sciences is necessary. Promi-
nent among these are chemistry and botany, some
knowledge of chemistry being necessary in order
that the changes taking place in soils under tillage
and cropping may be understood and the require-
ments of the crops economically supplied. The
sugar grower, being also as a rule a sugar manu-
facturer, requires to know some chemical facts in
order that he may understand the changes to which
sugar is liable, and how to promote advantageous
ones while preventing those which are harmful. A
knowledge of the fundamental principles of plant
life and nutrition is quite invaluable to all engaged
in agriculture.
One of the most important facts which chemistry
has taught us is the indestructibility of matter:
nothing is created, nothing is destroyed in the con-

2 MANUAL FOR SUGAR GROWERS.

tinuous changes which are observed daily, these
changes being simply the result of the re-arrange-
ment of the same matter over and over again in the
ever-varying forms existing on the earth.

Another important fact is the knowledge that all
the things in the world result from the combination
of two or more of some sixty-five simple substances,
or, as chemists call them, elements. These elements
are each composed of one kind of matter only, “and
out of each no two or more essentially differing
substances can be obtained.”

A list of the elements, with their combining
weights, is given in the table on page 138.

Some of these elements are extremely rare sub-
stances, while others exist in enormous quantities.
The following are those which enter into combina-
tion to form all the various parts of plants and plant
products :

Hydrogen. Potassium. Sodium.
Oxygen. Calcium. - Manganese.
Carbon. Magnesium. Silicon.
Nitrogen. Tron. Chlorine.
Sulphur. Phosphorus.

From this it follows that if some particular ele-
ment be wanted—say, for instance, potassium—to
supply plant-food in a soil deficient in that element,
then something containing potassium must be used
to supply the defect, for out of no combination of
substances can potassium be created. It must ex-
ist in the substance employed, for matter cannot

MANUAL FOR SUGAR GROWERS. 3

be created or destroyed, nor can the elements be
changed one into the other; potassium is always
potassium, nitrogen always nitrogen, and so on,
though the substances which can be obtained by
combining these elements in various ways are end-
less in number.

For the sake of convenience it is customary to
represent each element by means of a symbol, usu-
ally the first letter of its name, and this symbol also
indicates a definite quantity of the element, the
equivalent or combining weight. Thus the symbol
C indicates carbon, but it also stands for twelve parts
by weight of carbon. (See equivalent weights in
table.) Again, the symbols H and O stand for one
part by weight of hydrogen and sixteen of oxygen
respectively. Compounds are formed by the union
of two or more elements and are represented sym-
bolically by writing the symbols of the constituent
elements together, the quantity of any particular
element present In a compound being indicated by
a small figure placed a little below and to the right
of the element in question: thus, water is found by
experiment to be composed of the elements oxygen
and hydrogen, and also to contain two parts by
weight of hydrogen to sixteen parts by weight of

oxygen. ‘These facts are represented by the sym-
Hot FF O.*

* For a full explanation of this subject any good elementary
text-book should be consulted, this outline being merely given
in order that the chemical formule, etc., necessarily employed
may be to some extent understood by those having no chemical
knowledge.

+ MANUAL FOR SUGAR GROWERS.

All vegetable structures are built up of minute
cells of very various shape. The simplest cell is a
chamber whose walls are thin and
usually has fluid contents : these
cells joined together form a tissue,
and aggregates of different tissues
form the root, stem, and leaves,
the three portions of which plants
consist. In order to study these
cells the microscope must be em-
ployed. A thin slice of the soft
part of the sugar-cane, cut length-
wise, presents the appearance
shown in Fig. 1, where it will be
seen that the greater portion of
the stem is composed of cells

Fie. 1. — Fibro-vascular :
bundles in sugar-cane; Which are of about the same

, longitudinal;
oe eee length as breadth, with thin walls,

transverse section. :
and having, as seen in section, a

honeycomb -like appearance ;
these are usually spoken of as
cells—ordinary cells, without
any qualifying term. Travers-
ing this cellular tissue will be
seen a number of thread-like
cells running parallel with each
other ; a closer inspection, on
magnifying these threads to @ 4... o yibro-vasenlar bum
ereater degree, as seen dn, Fis?) tesmeeaseae
2, shows that the thread-like

cells are not all alike. Some are tubes with thin
walls, having rings arranged on the inside of the

MANUAL FOR SUGAR GROWERS. 5.

tube, in others a fine thread is wound in a spiral
throughout the length of the tube, while others pre-
sent the appearance of being perforated with minute
holes. These thin-walled long cells are known as
vessels, and are named, according to the markings
on their walls, annular or ringed vessels, spiral ves-
sels, dotted vessels, etc. Lying round these vessels
just described will be seen a number of long thread-
like cells, the walls of which are thicker and display
no particular marking; these cells are generally of
smaller diameter than the vessels, and the walls are
considerably thickened ; they are commonly spoken
of as fibres or fibrous cells: hence the collection of
fibres and vessels which has been described is gen-
erally known as a fibro-vascular bundle, and these
bundles will be found traversing the cellular tissue
in all parts of the plant.

When vegetable tissues are burned one portion
disappears in the form of gas or vapour, while a small
portion remains behind as ash; the portion which
disappears is composed of the elements carbon, hy-
drogen, oxygen, nitrogen, with some of the sulphur ;
the ash contains the remaining elements mentioned
in the list on page 2; these are combined with oxy-
gen, and are generally spoken of as mineral constit-
uents, or sometimes as ash constituents. These facts
are familiar to planters from burning megass.

The walls of the cells already described are com-
posed of carbon, hydrogen, and oxygen arranged
in the following proportions, C,H,,O,,* forming a

* Inspection will show that this substance is composed of six
equivalents of carbon with five equivalents of water. These com-

6 MANUAL FOR SUGAR GROWERS.

substance known as cellulose. In the interior of
each living cell is a little mass of jelly-like sub-
stance known as protoplasm ; this is a substance of
the greatest importance, for it is the source of all
the vital functions of the plant, which plant may
be compared to a large barracks, each cell being a
little room, the inhabitant of each room being the
living protoplasm. All growth, all production of
useful substances, depend on the life and changes
taking place in the protoplasm. To support life
and to maintain growth, food of course is necessary,
so the protoplasmic contents of the cells must be
fed. The food consists of mineral matter with
nitrogen compounds brought up from the root,
together with compounds containing much carbon
obtained from the leaves. The functions of the
roots and leaves will be shortly explained.

The usual method of propagating the sugar-cane
is by planting short lengths of the stem or cane, the
upper portion or top being usually selected for this
purpose. When placed in moist soil a number of
roots make their appearance from the double row
of marks arranged just above each joint, and a new
stem or cane grows from each bud, or eye.

The Root.—The sugar-cane has no main root, but
like all grasses possesses a great number of fine
rootlets; these spread to a great distance and to

pounds—in which hydrogen and oxygen exist in the same propor-
tion as in water, namely, two equivalents of hydrogen to one of oxy-
gen—are called carbo-hydrates. Cane-sugar, C:2H2.0;;, glucose,
C.H.20¢, starch, C;Hi,0O;, and a vast number of other substances,
are carbo hydrates.

_MANUAL FOR SUGAR GROWERS. 7

a considerable depth in suitable soil. The results
would be of considerable interest and value if
planters would make a series of observations on the
range of the roots of the sugar-cane. The observa-
tions of Mr. Henry Ling Roth are among the best
known, and as the result of these it may be stated
that in good soil the majority of the rootlets reach a
depth of about two feet, a smaller number extend-
ing even to four and five feet ; the lateral spread is
from three to four feet. The author’s observations
lead to the conclusion that in moderately well-tilled
soil the roots grow downward until they reach the
layer of soil but little disturbed by cultivation, and
then spread laterally; so that the depth to which
the roots descend in stiff soil depends on the depth
of the tillage. If the extremities of the rootlets be
examined they will be found to be very fine and
tender and also to adhere closely to the particles of
soil with which they come in contact. A closer in-
-spection will show why this is. If examined with a
magnifying-glass it will be seen that the fine rootlet,
instead of being perfectly smooth, is, on the con-
trary, clothed with a quantity of exceedingly deli-
cate hair, but only for a short distance near the tip ;
a short way back the hairs die off and the rootlet
becomes smooth. These root-hairs are of interest,
for it is by means of these that the plant absorbs
moisture from the soil, and with the moisture the
mineral plant-food which the soil supplies. If the
extremity of the rootlet be examined it will be
found to be clothed with a little cap or sheath, the
use of which a moment’s consideration will render

8 MANUAL FOR SUGAR GROWERS.

evident: roots increase in length only at their ends,
so that the end always consists of young and deli-

Fie. 3.—Rootlet, with root-hairs and root-cap.

cate cells which must be protected from injury
while being thrust through the soil; the root-cap
therefore affords protection to the delicate cells
lying beneath it. The root at intervals throws out
branches which from their earliest appearance are
clothed with a root-cap, and root-hairs soon de-
velop near the end. It will easily be seen why it is
impossible for roots to lengthen except at their ex-
tremities, for the root-branches imbedded in the soil
would be torn off if the main root grew in length
in the parts between their respective bases. *

*In taking up a rootlet for examination for root-hairs and
root-cap, care must be taken in removing the soil, as these organs

are very delicate. The examination of rootlets growing under a
flat stone is often highly satisfactory.

MANUAL FOR SUGAR GROWERS. )

Internally, the structure of the root may be
briefly described as a mass of cellular tissue through
the centre of which passes a heart or core composed
of fibro-vascular bundles; the outside is covered
with a layer of somewhat hardened cells forming a
kind of bark.

The function of the root is twofold: it serves to
fix the plant in the ground and also to absorb certain
food-materials from the soil ; it is in doing this that
the root-hairs play an important part. Only plant-
food in a state of solution can enter the root, and
that almost entirely through the root-hairs ; the older
parts of the roots are almost destitute of absorbing
power, and thus the extremities of the roots and
rootlets are the only parts by which water with
plant-food in solution can enter the plant,—a point
to be borne in mind in the application of manures.
The actual manner in which the root absorbs food
is by the process known as osmose; this may be
thus explained : When two fluids are separated from
each other by a thin membrane, various substances
dissolved in one of the fluids have the power of pass-
ing through the membrane and thus appearing in the
fluid on the other side, and this transfer of material
will go on until the two fluids become of the same
strength ; this may be experimentally illustrated by
placing some strong solution of salt in a bladder, and,
after tying it up securely, placing it for a few hours
in a basin of water. On examining the water it will be
found to be quite salt, the salt having passed through
the bladder by the process of osmose. Only those
substances which are capable of crystallising can

10 MANUAL FOR SUGAR GROWERS.

thus pass through the membrane ; they are distin-
ouished as crystalloids. Now crystalline substances
like gelatine, albumen, etc., cannot pass through,
and are known as colloids. In the root the cells
are the bladders, but with the solution of plant-food
outside them; this is continually passing into the
cells; the solution inside the cells is prevented from
becoming of the same strength as that on the out-
side, owing to the transfer of the plant-food by fur-
ther osmose into other cells, till it is finally used in
the process of growth.

The Leaf.—The leaf of the sugar-cane is about four
feet long and two inches wide, tapering to a point; the
leaf-stalk is developed into a sheath which closely
embraces the stem. In internal structure the leaf is
somewhat complicated ; the upper and under surfaces
are covered with a skin or tissue called the epider-
mis, which is composed of thin-walled flat cells hay-
ing colourless contents ; between the upper and under
epidermis is a mass of tissue the cells of which are
filled with green contents ; running from end to end
of the leaf are veins which are continuations of the
fibro-vascular bundles of the stem. It will be seen in
the drawing (Fig. 4) that these cells having green-
coloured contents are not packed closely together,
but that there are air-spaces between them, these
air-spaces being very large in some places ; it will be
noticed, too, that these air-spaces are in connection
with the outer air by means of openings through the
epidermis. If a little of the epidermis be stripped
off and examined with the microscope, these open-
ings may be readily distinguished ; the epidermis is

MANUAL FOR SUGAR GROWERS. OE

seen to consist of cells of somewhat irregular out-
line, while the contents are colourless; at intervals

\

Seco
aN

Fia. 4.—Transverse section of sugar-cane leaf (magnified); a, fibro-vascular
bundles surrounded by (0) layer of cells containing chlorophyll; ¢, cells with
colourless contents and air-cells ; d, epidermis ; e, stomata.

there will be seen pairs of cells having green con-
tents ; these are crescent-shaped and lie with their
points touching, so that there is a space between their
opposing faces ; this space is the opening communi-
cating with the interior air-spaces of the leaf ; these
- erescent-shaped cells are known as guard-cells and
the whole (guard-cells and aperture) is termed a
stoma or mouth; by means of these stomata the in-
terior cells of the leaf are in
intimate contact with the at-
mosphere. The atmosphere,
which for the most part is
composed of two gases, nitro-
gen and oxygen, contains also
a very small quantity of a gas
known as carbonic acid or
carbon dioxide, a substance composed of carbon and
oxygen and having the composition represented by

Fie. 5.— Epidermis of leaf
with stomata (magnified).

12 MANUAL FOR SUGAR GROWERS.

the formula CO,; this gas is produced whenever any
organic substance is burned, thus every fire is a
source of it ; it is present in the breath of all animals,
a human being giving off about seven hundred pints
every day, containing nearly eight ounces of carbon.
This gas is fatal to animal life, and unless some
means for its removal existed the whole atmosphere
would become poisonous and animal life would cease.
This gas is one of the most important plant-foods,
for the cells possessing the green colouring matter
above referred to have the power of decomposing it,
retaining the carbon and returning the oxygen to the
atmosphere. Animal and vegetable life are thus de-
pendent on each other. ‘Two things are necessary
for this process of plant-respiration: the green col-
ouring matter (or chlorophyll, as it is called) and
sunlight,—the process ceasing in the absence of light.
This affords an explanation of the fact that plants
become sickly if grown in rooms or dark places
where they are not exposed to sufficient light.

It is from this source that all the carbon found in
vegetable structures and products is obtained ; and
what an important part of plant life, and how entirely
the production of such substances as sugar depends
on it, will be readily recognised if it be remembered
that sugar contains nearly half its own weight of
carbon.

The first substance produced by the plant from
the carbon obtained by respiration is starch ; this
is composed of carbon, oxygen, and hydrogen, hay-
ing the formula C,H,,O,; the starch thus formed is
quickly converted into other and soluble substances,

MANUAL FOR SUGAR GROWERS. 13

and conveyed down the leaf-stalk into the stem, to
be used as food in the development of new tissues ;
or stored up as a reserve food-supply in the form of
sugar (in some plants as starch) to support growth
when the daily supply of carbon is insufficient to
meet some rapid development. An experiment
shows the formation of starch in the leaf, the in-
fluence of light on its production, and the fact of its
removal. The leaf of a plant—such, for instance, as
a rose—is placed in spirit for a short time until all
the green colouring matter is removed and the leaf
left white; the leaf is now washed with water and
finally placed in water containing iodine in solution ;
the effect of the iodine on the starch is to turn it
blue, so that the leaf becomes of a blue-black colour
from the presence of starch. A small plant is taken
and excluded from sunlight for from twelve to
twenty-four hours, by being covered with a_ box,
or by other suitable means: if the leaves of this
plant be treated in the manner described above,
they will not be coloured blue by iodine, showing
the absence of starch,—the starch formed during the
period of exposure to sunlight being removed from
the leaf by vital processes, and used as a food-
material in the ordinary course of nutrition and
erowth.

Another important function of the leaf is transpi-
ration, or the evaporation of the superfluous water of
the crude sap in the form of vapour. The quantity of
water given off from the leaves of various crops has
been made the subject of experiment; the amount
transpired is found to be very great,—as much as two

-

14 MANUAL FOR SUGAR GROWERS.

or three thousand gallons per acre per day in some
cases. The effect of this transpiration is to concen-
trate the crude sap, thus promoting the absorption
of water by the roots, and also causing free circula-
tion of the sap in the plant. In this way the leaf
acts both as a feeding and circulating organ.

The Stem.—Most plants, during their period of
erowth, assimilate a greater quantity of material than
is immediately employed in building up tissues,
and this excess of food-material is stored away in
some part of the plant adapted for its accumula-
tion. The form in which the reserve is accumulated
varies ; thus there is the starch in the root of cas-
sava and arrowroot, oil in the seeds of various plants,
and in the sugar-cane sugar is stored up in the stem.
These reserves are generally drawn upon to meet the
demands of rapid growth at the times of flowering
and fruiting, and doubtless it is with this object that
the sugar-cane still accumulates sugar, though by
cultivation the production of seed has been dis-
couraged, while the tendency to secrete sugar has
probably been fostered and increased.

Thus we have: 1. The root, supplying mineral
and nitrogenous food and water. 2. The leaf, sup-
plying carbonaceous food under the influence of
sunlight, and throwing off the surplus water. 3.
The stem, acting as a storehouse of reserve food-
material, sugar.

The reader is advised to consult a botanical text-
book for a more complete account of the structures
and functions briefly given in outline here.

CHAPTER II.

Origin of Soil, Clay, Chalk or Marl, Sand.—Fertile Soil.—Condi-
tions Influencing Fertility.—‘‘ Condition or Heart.” —Func-
tion of Vegetable Matter in the Soil.—Moisture.—Mineral
Plant-food.—Analysis of Soils.—Nitrogenous Plant food.—
Nitrification.—Leguminous Crops and Nitrogen.—Root-nod-
ules.—Retention of Plant-foods by Soils.—Drainage.

N practical agriculture the first thing to be con-

sidered is the soil, for on the nature of the soil

will depend the kind of crops which can be grown,

and whether the undertaking will prove remunera-
tive.

Soils have their origin in the decomposition of
rocks, and will differ in composition and character
according to the nature of the rocks from which
they are derived. A cursory glance in almost any
country will show soils in process of formation ; the
rocks exposed and supporting a scanty vegetation,
the roots of which, penetrating the small fissures,
tend to enlarge them, while the whole plant causes
soil to accumulate by preventing the rain and wind
from removing the finer particles, to which the
action of the weather, amongst other things, gives
rise. On the death of the plant its decaying remains
increase the amount of soil and render the spot
capable of supporting a much more vigorous growth
of plants ; and this combined action of weather and
vegetation goes on till often a very considerable

16 MANUAL FOR SUGAR GROWERS.

depth of soil is formed. The action of the weather
alone might give rise to a clay, the presence of vege-
table matter being necessary to render this a true soil.
Rocks are divided into two classes, according to
whether they owe their origin to volcanic agency or
have been deposited in water; and these facts have
an important bearing on the nature of the soil and
on the agricultural operations to which it should be
subjected. Apart from their geologic origin, soils
may be divided into clays, marls, and sands, and
this division is of immense service in agriculture.
Clay has its origin in the decomposition of rocks
containing felspar, and when pure consists of sili-
cate of alumina; it very rarely occurs in a pure
state, being usually mixed with varying amounts of
sand, marl, etc. Itis characterized by its coherence,
plasticity, want of porosity, and slow permeability
by water; many of these properties are disadvan-
tageous from an agricultural point of view, and re-
quire to be modified by judicious operations of tillage,
ete. Pure clay also contains no plant-food, but the
clays usually existing as soils contain considerable
admixture of substances of value. Clays may have
their origin in both volcanic and sedimentary rocks.
Chalk,—or, as it is frequently termed, marl, —
when pure, is carbonate of lime, but, as existing as
soil, it owes its origin to the decomposition of coral,
shells, and the like, and thus contains a variety of
substances valuable as plant-food, particularly phos-
phate oflime. Mazrls, not containing much sand or
stony matter, tend to set into a stiff, clay-like soil,
which may be termed coral clay or marly clay; and

MANUAL FOR SUGAR GROWERS. L¢

this, though often rich in plant-food, requires skilled
management to keep it in good condition and ena-
ble it to produce large crops.

Sand is the term applied to those soils possessing
but little coherence and very permeable by water ; the
mineral of which it is composed is frequently silica
or various silicious minerals. When the fragments
or individual particles are large, the term gravel is
employed. Pure sand, like pure clay and pure chalk,
is incapable of supporting vegetable life, so that nei-
ther of these substances in a pure state will consti-
tute what is generally understood by the term soil.

A fertile soil consists of an admixture in varying
proportions of the three substances above named,
together with a suitable amount of vegetable matter
in a state of partial decay, and known as humus,
aiding the supply of nitrogen, and also such min-
eral matters as will supply the requisite potash,
phosphoric acid, lime, magnesia, iron, sulphuric
acid, and those mineral substances already referred
to; for a soil to be fertile these must be in appro-
priate quantity, and in such condition that the grow-
ing plant constituting the crop can readily absorb
them, and the varying fertility of soils depends,
amongst other things, on the amount of available
plant-food present. These mineral matters are
usually present in the rocks from which the soils
are derived: thus volcanic rocks contain, felspar,
whethorwhele or decomposed into clay; and the soil
thus formed is generally rich in potash. Marls, or
chalky soils, frequently contain much phosphoric

acid, owing to the presence of that substance in the
2

18 MANUAL FOR SUGAR GROWERS.

living animals whose remains give rise to this kind
of soil.

The knowledge of the conditions influencing fer-
tility constitutes a large portion of the science of
agriculture; among the chief of these conditions
are: 1. Weather, with its supply of rain, sunlight,
and warmth. 2. Plant-food required by the partic-
ular crop under consideration,—in this case, the su-
gar-cane. 3. The condition of the land as regards
what agriculturists usually know as heart.

In order to constitute what is known as good
condition or heart, several things are necessary. It
is essential that the soil be sufficiently loose and
friable, that the roots may penetrate it with ease ;
the soil must also possess the power of retaining
sufficient moisture to sustain the life of the plant,
and at the same time must not retain too much, or it
will become waterlogged, when most plants will re-
fuse to grow init. It is essential, too, that the soil
contain air, for plants will only grow in the pres-
ence of air and will refuse to penetrate a soil whose
pores are devoid of it, as in the case of wet or under-
drained soils, where the growth is always checked.
The influence of air upon root-growth is often well
shown when roots obtain access to drains, the growth
often being so abundant as to choke the drains.

These three conditions are favourably developed
by the operations of ploughing, digging, or forking,
the soil being loosened, the particles separated from
each other, the capacity for retaining air and moist-
ure much increased, at the same time that the re-
moval of excessive moisture is facilitated.

MANUAL FOR SUGAR GROWERS. 19

The presence of humus or decayed vegetable mat-
ter is essential ; this humus plays many important
parts : in stiff clay soils it keeps the minute parti-
cles of the soil apart from each other, thus causing
the soil to remain both friable and porous ; in sandy
soils it holds the particles together, thus giving the
requisite coherence. Its presence assists the reten-
tion both of water and air, factors which have been
shown to be essential to fertility. The correct ap-
preciation of the part played by vegetable matter in
the soil is of vast importance to the sugar grower.

The porosity of a soil which, as has been seen, de-
pends largely on two things, tillage and humus, has
a great influence on the retention of moisture dur-
ing a dry season and its escape during a wet one.
A compact, non-porous soil becomes much hotter
under the influence of the sun’s rays than does a
porous one; consequently during a drought moisture
is much more rapidly lost from a compact than
from a porous soil. Further, in a compact soil
moisture is drawn up from a considerable depth by
capillary attraction ;* in a porous soil, the air-spaces
being larger, capillary attraction is lessened: hence a
porous soil remains moist for a considerable time,
while a compact one becomes dry and cracked. The
importance of this fact can hardly be too strongly
insisted on, particularly in tropical agriculture. A
simple experiment clearly demonstrates the truth of
what has been said. Into two tins of similar size
and shape equal quantities of dry soil are placed,

* Capillary attraction is the force which causes fluids to ascend
tubes or cavities of very small bore.

20 MANUAL FOR SUGAR GROWERS.

and an equal quantity of water added to each; the
two tins and their contents are now precisely alike
in weight and other conditions ; one is left thus, but
the contents of the other are closely pressed together,
so as to imitate the condition of a badly tilled soil.
The two tins are now exposed to the sun for several
hours, care being taken that the conditions of ex-
posure are equal; after a time they are carefully
weighed to ascertain the quantity of water lost by
evaporation. It will be found that the porous soil
loses moisture much less rapidly than the other.
The following results were obtained by the author
in an experiment conducted as described :

Two TINS, EACH CONTAINING 694 GRAMMES OF AIR-DRIED
Sort AND 100 GRAMMES WATER.

Compact soil. Loose soil.
Loss Ist day ......s.% 5 Roce 24 grammes | 19 grammes
Boss 20 days 223.026 aS Senor 15 es 10 s
EOg8, 0007.5 5. + samen seer ties < 8 te 7 ag
qUOSS 10, SAYA... 23's eae ee eee oe 47 36 a

The loose soil at the end of three days has twelve
and a half per cent. more moisture than the com-
pact one.

It must also be remembered that in tropical and
sub-tropical climates, during a period of drought,
heavy dews are not uncommon ; if the soil is porous
a certain amount of moisture in the form of dew will
be deposited in the soil itself, thus assisting plant-
life at a critical time.

That a porous soil parts with its surplus water

MANUAL FOR SUGAR GROWERS. 21

more freely than a compact one, is self-evident and
calls for no further comment here.

Porosity of soils, then, must be maintained by til-
lage and the introduction of vegetable matter as a
means both of retaining the requisite quantity of
moisture and of enabling the excess to drain away.

Plant-food in soils.—All plants appear to require
essentially the same kinds of plant-food, but in va-
rying proportions; the adjustment of the kind and
quantity by artificial means constitutes the art and
Science of manuring.

Plant-food derived from soil may be classed as
mineral and nitrogenous. The mineral matters found
in plants are potash, lime, magnesia, oxide of iron,
silica, phosphoric acid, sulphuric acid, chlorine (as
chlorides), with others of apparently less importance,
such as soda, alumina, manganese, ete.

Now, from what has been already said it is evident
that, to be of value, these must exist in the soil in a
form capable of being absorbed by the plant-roots ;
that is, they must be capable of being dissolved. It
might therefore be assumed that the quantity of
mineral matter available as plant-food in a soil might
be easily estimated by finding how much was capable
of being extracted by water. If the experiment be
made, it will be found that little or no potash or
phosphate, for instance, can be removed by treatment
with water, even from soils bearing luxuriant crops ;
it follows, therefore, that the root must possess some
solvent power not possessed by water, by which
means it is enabled to dissolve and assimilate that
portion of the plant-food insoluble in water. From

22 MANUAL FOR SUGAR GROWERS.

the root some acid exudation takes place, and this
attacks the plant-food, dissolving it and fitting it for
entrance into the root by the process of diffusion.
This power is well shown by an experiment devised
by Professor Sachs (“‘ Text-book of Botany,” first
English edition, p. 625). Tf polished plates of mar-
ble or phosphate of lime are covered with sand to a
depth of a few inches, and seeds are then sown in
the sand, the roots which strike downwards soon meet
the polished surface of the mineral and grow upon
and in close contact with it. After a few days an
impression of the root-system is found corroded in
rough lines on the smooth surface; every root has
at the points of contact dissolved a small portion of
the mineral by means of the acid water which per-
meates its outer cell-walls.

The author, therefore, in the process of soil-analy-
sis makes use of very dilute cold hydrochloric acid to
extract the available mineral plant-food, believing
that by this means he obtains a fair approximation
to the process of nature.

The quantity of plant-food removed by a crop
varies, as has been said; Warington gives the fol-
lowing quantities in pounds per acre.

————— —

nam ae

R =| = Ss 5 o

2 Ad iD i > ‘a a | =|
i=} fm o a
meslelal| 2 ia¢ls|h/asl5| 4
Sons | 6 1S) 8 is leat |S
E | a| eG jalal|ae |oja
Wheat-erain .............. 1,800| 33 | 2.7; 9.3 | 0.61.0 3.614.2 0.1| 0.6
Wheat, total crop ......... | 4,958 | 48 | 7.8 28.8 | 2.6 9.2 7.121.1) 2.5/96.9
Barley, total crop ...... .. 4,527 | 48 | 6.1) 35.7 | 5.0; 9.2, 6.9.20.7| 4.1|68.6
Osis: total crop. 5... | | 4,725 | 55 | 8.0) 46.1.| 5.411.6 8.7|19.4) 6.6|85.3
Meadow hay, total crop ...| 3.360 49 | 5.7 50.9 | 9.2 32.114.412.3 14.6/56.9
Turnips, total crop.... ... 49,504 112 |20.9 148.8 24.5,74.0) 9.5)33.1/22.1) 7.7
Potatoes, total crop ....... \17,714| 67 | 5.2, 79.7 | 4.2,26.8,19.1/24.3) 5.9) 4.7

MANUAL FOR SUGAR GROWERS. 23

The weight of an acre of soil to a depth of nine
inches is about 3,000,000, or 3,500,000, pounds ; it
will thus be seen that even a small proportion of
plant-food will amount to a very large weight when
calculated to pounds per acre; and this is important
in considering chemical analyses, where the propor-
tion of various constituents is often stated in parts
per one hundred ; thus one per cent. would represent
30,000 or 35,000 pounds, or about sixteen tons per
acre to a depth of nine inches. The quantity of solu-
ble matter shown by chemical analysis may often
seem to be extremely small, and very accurate
methods must be followed if trustworthy results are
to be obtained. The following table gives some idea
of the amounts of plant-food soluble in dilute acid,
in the manner already alluded to, in the case of cer-
tain soils under cultivation in sugar-cane.

MINERAL PLANT-FOOD PER MILLION POUNDS OF SOIL, OR
PER ACRE THREE INCHES DEEP, SOLUBLE IN DILUTE
ACID.

Mineral substance. We MS [enn Vial Wie Wales | WAGE || \A00G) IDG |) ore
STILTCE (SH OF) een eae 970 |1050)1010 6995 1323/1874! 1776 | 1121 1028; ?
ime (CaO) . 225602 3. 1932 |2597|2538 4266 4420/4083 3810 | 5415 100000 400000
Magnesia (MgO) ..... 300 | 400) 320 1203 500\19384 760 980 |100000 400000
Oxide of Iron (Fe,03) 750| 850 800) 45, 210) 144; 120 ? 3650) 3500
otrashi(KO) ..)..052 52% 37| 94) 38) 256, 80] 61) 33 27 169 267
Phosphoric acid | |

(P,0;)| 47] 28) 28) 65) 86] 37 70 18 185 8T
Sulphuric acid (SO) . trace | |

I., I1., and III., volcanic soils, Montserrat, W.I. IV., V., and VI., volcanic
soils, Antigua, W.I. VII. and VIII., sedimentary, non-calcareous soils, An-
tigua, W.I. IX. and X., calcareous soils, Antigua, W. I.

Now, the undecomposed portion of the soil usu-
ally contains a very appreciable amount of plant-

24 MANUAL FOR SUGAR GROWERS.

food not readily dissolved by plant-roots, but which
by the action of the atmosphere is slowly brought
into such a condition as to be capable of being dis-
solved ; we can thus divide the plant-food into that
which is available and that which is slowly avail-
able. In a chemical analysis it is usual to regard
those constituents which are insoluble in cold dilute
acid, but which are soluble in warm strong hydro-
chloric acid, as slowly available. This slowly avail-
able plant-food is by no means to be overlooked in
forming an estimate of the value of a soil, as it con-
stitutes a kind of capital and indicates that soils
possessing an abundant store will yield abundant
crops with the minimum of manure, or of that
special constituent which happens to be present.
Below is given a comparison of the amount of cer-
tain substances soluble in dilute and strong acids,
respectively, in certain soils.

1B | 10 F

2)

trong. | Dilute. gee Dilute,

LR eee ee Oper cae 6460 | 541

5 | 7770 | 6227 | 12820] 5248
Magnesia: i... -%.. - 5514 | 283 | 8280 | 13880 | 13193 57
(ch ne 159 20 Ate 20 | 1340 | -8e74
Phosphoric acid..... | 146 | 45 209 129

Where no crops are removed from the soil, as in
the case of forests and prairies, the fertility of the
soil will actually increase from year to year, owing
_ to the gradual conversion of the slowly available
into the available mineral plant-food; at the same

MANUAL FOR SUGAR GROWERS. 25

time the decaying vegetable matter increases the
humus and returns to the soil those mineral mat-
ters which entered into its own structure, thus
increasing the soil’s fertility. These soils are gen-
erally spoken of as virgin soils, and will often bear
luxuriant crops for years without manures; but
sooner or later they become more or less ex-
hausted, and the art of the farmer is required,
that by proper manuring they may be kept in a
condition to produce remunerative crops.

The constituents of mineral plant-food which are
usually first exhausted are phosphoric acid and pot-
ash. Hence the importance attached to the pres-
ence of these substances in manures. To these in
certain cases may be added lime and iron.

Thus far attention has been directed to the min-
eral plant-food, there yet remains a great deal to be
said on the subject of manures supplying nitrogen.

Nitrogen is an essential constituent of the food
of both plants and animals, just as carbon and the
various mineral constituents are. It has been seen
how the mineral matters are obtained from the soil,
and how the carbon is obtained from the atmosphere ;
now, four-fifths of the atmosphere consists of nitro-
gen, which would thus appear to provide an abun-
dant supply of this important plant-food; yet it is
found that plants cannot derive their nitrogenous
food from the air, but that it all comes from the
soil. (As to the nitrogen in the case of leguminous
plants, see page 28.) All organic matter contains
more or less nitrogen, and thus organic matters,.
such as animal excreta, pen manures, green dress-

26 MANUAL FOR SUGAR GROWERS.

ings, dried blood, etc., are nitrogenous manures,
several of these being humus-supplying manures as
well. The need for humus and its action on the
soil has been already dwelt upon.

The various nitrogenous compounds in the or-
ganic substances, and in the ammonia salts above
mentioned, are not in a fit condition to serve as
plant-food without undergoing change; careful ex-
periments have demonstrated that plants usually
absorb their nitrogen in the form of a salt of nitric
acid, or a nitrate, as it is termed.* Now, when
organic matters or ammonia salts are mixed with
soil, chemical changes take place, and the greater
part of the nitrogen is converted into nitrate by
a process very similar to fermentation. The re-
searches of recent years—prominent among them
being those of Warington, Schlosing, and Muntz—
have proved that this conversion into nitrate is the
work of a minute microbe or germ which is present
in all fertile soil. This microbe is found in greatest
number and in greatest vigour near the surface of
the soil, and penetrates to various depths according
to the character of the soil. For its active growth,
and in order that it may carry on its useful function
of converting organic matter into plant-food, sev-
eral conditions are necessary: 1. A substance con-
taining nitrogen and capable of being acted on by
the microbe; such things as organic matter or

* Nitric acid is a compound of hydrogen, nitrogen, and oxygen,
having the formula HNO;; the hydrogen may be replaced by
metals, as in the case of potassium nitrate or saltpetre, KNOs, or
sodium nitrate, NaNQs.

MANUAL FOR SUGAR GROWERS. 27

ammonia salts fulfil this condition. 2. Air; and
this is one of the reasons why tillage and working
the soil increases the fertility, as it leads to more
rapid nitrification. 3. Moisture. 4. A tempera-
ture of from 40° F. to 110° F., nitrification being
most active at a temperature of about ordinary
summer heat. From this it will be seen that the
natural condition of affairs in the tropics — high
temperature with abundant moisture—is conducive
to rapid nitrification. 5. It is necessary that some
base be present in the soil, 7.e., some substance capa-
ble of neutralising acids; in almost every case this
condition is fulfilled by the presence of carbonate of
lime or chalk, and this is one of the reasons why
this substance is so important as a constituent of
soils. It is very evident, then, that many of the
points which were regarded as of importance in
connection with condition or heart are those which
are favourable to nitrification ; and thus the theory
of nitrification supplies us with a reason for per-
forming many agricultural operations which previ-
ously rested only on a basis of tradition of success-
ful practice.

The author has seen certain West Indian soils
exceptionally rich in nitrogen, yet containing barely
a trace of nitrate, owing to the non-fulfilment of
some of the conditions given above, and this chiefly
due to defective tillage and to the trampling of cat-
tle on wet lands. In one instance a sample of soil
which, when taken from the field, contained nitrate
equal to only six pounds per million, after being kept
in the laboratory for twenty-eight days, contained

28 MANUAL FOR SUGAR GROWERS.

nitrate equal to one hundred and thirty-three pounds
of nitrate of soda per million, thus proving that con-
dition and not manure was what this particular field
lacked.

From what has been said, it follows that nitrate
of soda is practically the only nitrogenous manure —
absorbed by the plant without having to undergo
change under the influence of the nitrifying mi-
crobe.

Recent researches have led to the conclusion that
plants belonging to the natural order Leguminose,
which includes all plants of the pea and bean tribe,
take up their nitrogenous food in a different manner
from other plants ; they can apparently freely assim-
ilate nitrogen compounds other than nitrates, and
it has been found that the weight of nitrogen in a
leguminous crop may exceed the weight of nitrogen
in the soil and manure used before the crop was
srown. The inference is, then, that leguminous
plants, unlike others, can make use of the nitrogen of
the atmosphere. It is also found’ that leguminous
plants have curious little swellings or nodules upon
their roots, varying in size and shape on different
plants; on the pigeon-pea (Cajanus indicus) these
swellings assume large dimensions, sometimes being
an inch or more in diameter. The internal struc-
ture of these nodules, as far as they have been ex-
amined by the author, appears to be as follows:
There is an external layer resembling the bark of the
root; immediately within this comes a cellular layer
traversed by fibro-vascular bundles; in the centre
of the nodule is a mass of cellular tissue (a, Fig. 6),

MANUAL FOR SUGAR GROWERS. 29

many of the cells of which contain starch ; distrib-
uted throughout the central mass of tissue are a
number of what the author distinguishes as “ special
cells” (b); these are usually rather large in size and
do not contain starch, but are filled with countless
bacteria or microbes. Not very much is known re-
specting these root-nodules,
the active agents in which
appear to be the bacteria or
microbes ; for the nodules do
not form on the roots of
plants grown in sterilised
soil, that is, in soil subjected
to such treatment, before the
seeds are planted, as will de-
stroy vegetable life, and that
they will form if a little unsterilised soil be af-
terwards added to the sterilised. It has been as-
sumed (for very little has been proved so far) that
these bacteria, which appear to exist in all fer-
tile soils, have the power of forming colonies on
the roots of certain plants, and that so situated
they have the power of assimilating atmospheric
nitrogen ; and that after its assimilation by the bac-
teria the nitrogen becomes available for the food-
supply of the host on which the nodules are found.
It has even been suggested that these bacteria are
capable of assimilating atmospheric nitrogen without
being associated with another plant. The increase
of nitrogen in a leguminous crop renders these
plants very valuable for the purpose of green dress-
ing, as this will result in a gain of nitrogen to the

iN
J
dis
ue
PSY
/

Fia. 6.—Section of root-nodule

(magnified).

30 MANUAL FOR SUGAR GROWERS.

soil as well as a gain of vegetable matter or humus ;
whereas green dressings of other classes of plants
merely restore the nitrogen taken from the soil.

It is found that some of the plant-food constitu-
ents of the soil are soluble in water, as for instance,
nitrates and chlorides, and therefore these substances
are found in the drainage-water ; on the other hand,
some of the constituents are insoluble, as potash,
phosphates, and ammonia; these things are seldom
found in drainage-water (see page 21). Pure sand
possesses little or no retaining power for the various
food constituents; and thus, if soluble phosphates,
or potash salts, or ammoniacal chemical manures are
mixed with sand, it is found by experiment that they
are readily washed out by water. If, however, these
substances be mixed with a good soil containing
clay and humus, it will be found that they are not
washed or removed by water. Potash, ammonia, and
phosphoric acid are retained by soil by virtue of
chemical action ; precisely how this takes place is
not clear, but the hydrated oxides of iron and
alumina, the hydrated forms of silica and humus,
doubtless play an important part in the process.
(See Warington, “ Chemistry of the Farm,” p. 28.)
The retention of the phosphoric acid is largely due
to the oxides of iron and alumina and to lime; the
potash is probably chiefly retained by humus and
the hydrated silicates of alumina; the ammonia is
chiefly retained by humus. In the case of potash
and ammonia salts, it appears necessary that they
should present themselves in the form of carbonates ;
if the sulphates, etc., of the substances be used,

MANUAL FOR SUGAR GROWERS. dl

they undergo decomposition with the carbonate of
lime in the soil, forming carbonate of potash or am-
monia and sulphate of lime, and the potash and am-
monia in this form is retained by the soil. From
this it will be seen how necessary it is to have a suf-
ficient quantity of lime in the soil, and why marling
tends to improve certain soils.

Now, for certain substances the soil possesses but
little retaining power, such as nitrates and chlorides,
and these substances are always found in drainage-
waters ; it will at once be seen that this fact has an
important bearing on the application of nitrogenous
manures. It will be remembered that all compounds
of nitrogen are converted into nitrate by the action
of the nitrifying organism of the soil, and now it is
seen that soils have but little retaining power for
nitrates ; hence it follows that if heavy dressings of
nitrogenous manures, particularly nitrates, are placed
on the soil, there is a risk of loss by washing out in
the form of nitrates, unless the substance nitrifies
slowly and at about the same rate as the plant ab-
sorbs its nitrate. Nitrate of soda or sulphate of am-
monia should therefore be appled in small quanti-
ties, at tolerably frequent intervals, while organic
matter containing nitrogen, which nitrifies more
slowly, may be applied in larger quantities and at
greater intervals. In the tropics, the high tempera-
ture increases the rate of nitrification, and this, with
the usually heavy rainfall, renders the risk of loss of
nitrogen greater than in cold climates; hence the
proper comprehension of the relationship of.soils to
nitrogen, and particularly to nitrified nitrogen, is a

2 MANUAL FOR SUGAR GROWERS.

subject worthy of attention and study on the part of
all practical sugar growers.

Even if plant-food is present in sufficient quantity
for the requirements of a crop, there are various cir-
cumstances, as we have seen, greatly influencing
fertility ; it is well known, for instance, that varia-
ations of the weather will cause greater differences
in crops than can be obtained by manuring.

A soil must be capable of retaining plant-food and
moisture, and thus, as shown above, must contain a
due proportion of clay and humus. A clay soil, on
the other hand, may become so close as to be un-
fertile, owing to the absence of sufficient air, so
essential for root-growth and for nitrification, and
also be so dense as to offer great resistance to the
entrance of the fine, delicate root-tips and root-hairs.
This question has been already discussed when
treating of condition or heart (page 18).

It is important to remember that the points by
which good condition is determined are such as do
not admit of expression by figures in a statement of
a chemical analysis; so that two soils may show a
very similar chemical composition, yet differ materi-
ally in fertility, owing to difference in condition.
In this the practical field observations of the planter
are of great value, and chemical analysis can only
supplement, and not supplant, this. The application
of purely chemical manures to land in bad heart is
a mistake frequently made, and tends to discredit
the value of chemical aid in manuring. ‘The planter
should carefully avoid this error, the remedy for
which lies in the correct exercise of his own judg-

MANUAL FOR SUGAR GROWERS. 33

ment. Chemical manures will only exert a full and
beneficial action on soils already in good condition,
but which are deficient in some one or more sub-
stances constituting plant-food ; and of these, phos-
phoric acid, potash, and nitrogen are those usually
deficient, and which it is the function of the ordi-
nary chemical manure or fertilizer to supply. The
necessity for supplying other ingredients, such as
lime, magnesia, iron, etc., is sometimes pointed to by
special investigations, when the defect must be
remedied.

Drainage-—When a heavy shower of rain falls, a
certain quantity of water sinks into the ground, and
when the soil becomes saturated—if the fall is more
rapid than the absorption—a certain quantity flows
over the surface and is carried away by the ditches
and streams. If the rainfall continue for some
time, the soil becomes entirely saturated, the water
occupying the space previously occupied by air.
Now, it has already been shown that this condition
is highly unfavorable to the growth of such a crop
as the sugar-cane, which, as with most other crops,
requires a soil containing both air and moisture. It
is necessary, then, that the excess of moisture be re-
moved. Some porous soils are so situated that
when the rain ceases they naturally part with their
excess of moisture with sufficient rapidity to permit
the entrance of the necessary air; such soils are said
to possess natural drainage, and merely require
attention to be directed to the channels for the es-
cape of the surface water; such soils, however,

are not common. Other soils retain water for too
3

34 MANUAL FOR SUGAR GROWERS.

long a period, and are said to be cold or wet ; this
may arise from want of porosity, as in the case of
stiff clays, or from a flat and low-lying situation,
or more frequently from a combination of the condi-
tions. The remedy for this lies in draining.

Draining may be accomplished by two principal
methods—surface or open-trench draining, and sub-
soil draining. So far, in our West Indian colonies,
the former method is the only one regularly prac-
tised, and the author’s experience is that one of the
real objects of the operation is frequently lost sight
of or ignored. It is commonly supposed that sur-
face drainage, as here accomplished, has for its ob-
ject merely the removal of the superfluous surface
water, and, that being accomplished, that it is well to
leave the land wet. How erroneous this is has al-
regdy been shown. It is necessary to remove all
superfluous water to a considerable depth, so as to
admit air, and thus—particularly on flat lands—it is
desirable to dig the trenches to as great a depth as
possible. The depth and distance apart of the
trenches of course entirely depends on the nature
of the land. A loose porous soil resting on a por-
ous subsoil will only require such open trenches as
will carry off the surface water during heavy rains.
A stiff clay resting on an impervious subsoil will
require close and deep trenching. The most con-
venient distance for trenches is thirty or forty feet
apart, and in stiff soil they should be at least eigh-
teen inches deep.

Open trenches, however, possess many and great
disadvantages ; and in countries where agricultural

MANUAL FOR SUGAR GROWERS. 35

practice has made any substantial advance, some form
of subsoil draining is resorted to. If we dig down
a sufficient depth into the soil we shall reach a level
where the soil is always moist, except in periods of
prolonged drought,—a level at which the amount of
moisture is but slightly affected by the changes from
wetness to dryness, etc., experienced by the soil
nearer the surface ; the pores of the soil at this level
are practically permanently filled with water, and
we may designate this the permanent water-level.
The depth at which the permanent water-level will
be met with entirely depends on the character and
position of the soil; should it be at such a depth
that there is ample room above it for the de-
velopment in the overlying soil of the full root-
system of the crop, then such a soil will not be bene-
fited by subsoil drainage ; it is drained naturally.
But such soils are rarely met with, the permanent
water-level is usually at no great distance from the
surface, and it has been repeatedly explained that
roots will only grow in soil whose pores are filled
with air. The roots never grow down below the per-
manent water-level ; if this is near the surface, it fre-
quently happens that the depth of soil available for
healthy root-development is far too limited to allow
the growth of a full and luxuriant crop; consequently,
if the season be a favorable one, the root-develop-
ment being limited, the crop can only be moderately
large ; while, if the season be wet, the small depth of
soil becomes waterlogged, and active root-growth is
impeded ; on the other hand, if the season be dry, the
roots, having only a shallow range, soon lack mois-

36 MANUAL FOR SUGAR GROWERS.

ture and suffer from the effects of the heat of the
sun. If, however, the permanent water-level be
lowered by subsoil drainage, the roots have room
for luxuriant growth, thus ranging over a greater
space to absorb moisture and plant-food,—a state of
things which soon shows an abundant result in the
increased growth of the portion above ground, with
its consequent increase of the crop. Again, a deep-
rooted plant is much better protected against changes
of season than a shallow-rooted one: in a wet season
the porous upper soil absorbs a large amount of
moisture which the subsoil drain quickly removes,
- leaving the soil in good condition for plant-growth ;
in a dry season the small amount of moisture from
passing showers, dew, etc., is much more effectively
retained, and the roots of the crop, having a deeper
range, find a greater amount of moisture and are
farther removed from the hurtful effects of the heat
of the sun. The deep porous soil also retains a use-
ful amount of moisture for a longer period than a
shallow one. It follows, then, that subsoil drainage
is beneficial, both in wet and in dry seasons.
Various methods of subsoil draining have been
devised, all of which are carried out by opening a
trench to the required depth of the drain, and plac-
ing in the trench something to leave a channel or
waterway along the bottom when the earth is
thrown back again into the trench. Many kinds of
material have been used for this purpose, such as
brushwood, loose stones, stones or brick or tiles
roughly built to form a small culvert; and finally
coarse unglazed earthenware pipes. This last ma-

MANUAL FOR SUGAR GROWERS. 37

terial has been found to answer most successfully ;
the other forms of drain are found, sooner or later,
to become filled with earth and are thus rendered
useless, whereas the earthenware .drain-pipe prop-
erly laid will remain in good order for a long term
of years, probably twenty or thirty.

The actual operation of laying tile drains in a
piece of land is one which requires careful consid-
eration beforehand, and if possible the work should
be conducted by workmen having practical knowl-
edge and experience of tile-laying. The points to
be considered are, the size of pipe required, the
depth of the drains, and their distance apart. For
most work pipes having an internal diameter of one
and a half inch will serve for the drains, and if
these are connected with a main drain, as they fre-
quently require to be, this main drain must be of
sufficient capacity to remove freely all the water
collected by the small secondary drains, and its size
will be determined by their number. In laying
tiles, levels are carefully taken, and trenches are
opened, with specially shaped tools, to the required
depth ; care is taken that the earth at the bottom of
the trench is disturbed as little as possible, all
treading or walking in the trench being avoided ;
the tiles are laid end to end, and the joint is covered
with a short length of pipe Ce
of larger size, as shown
in the figure ; the earth F-. 7.—Diagram of pipes and joints
is returned to the trench ta eae
and is firmly pressed down. It is desirable to leave
the earth at the surface somewhat raised over the

38 MANUAL FOR SUGAR GROWERS.

trench, to prevent the surface water converting the
trench into an open channel, whereby the drain is
injured. Proper precautions must be taken to
prevent the access of rats and other small animals
to the drains. The danger of the drain silting up is
avoided by a careful adjustment of levels, so that
the water runs with equal velocity throughout the
length of the drain, or perhaps, with advantage,
with slightly increased velocity near the outlet.
Silting up depends to a great extent on the relation
of the size of pipe to the water flowing through it ;
a small pipe running nearly full not silting so much
as a large one carrying only a small quantity of
water. For details respecting tile draining the
reader is referred to special works on the subject.
For sugar-cane the author would suggest that the
drains be laid about thirty to forty feet apart and
four feet deep. This system of draining is some-
what costly, requiring a large outlay at first, and up
to the present time it has been but little practised
in the West Indies ; in the sugar-growing districts
of the United States it is being adopted with suc-
cess, an example which should be followed by West
Indian sugar growers; it is doubtless the way of
preventing losses from short crops during droughts.
It is difficult, in the absence of actual trials, to state
the cost of such a system of draining in the West
Indies, but there is little reason to doubt that it
would prove remunerative, as it would increase the
crop and at the same time decrease the cost of work-
ing the land; for the surface trenches would only
require to be deep enough to deal with the surface

MANUAL FOR SUGAR GROWERS. 39

water, and would not be required to act as drains in
the true sense of the word; this would reduce the
cost of opening and cleaning out trenches, and
ereatly facilitate the cartage of the cane crop off the
land; the work of ploughing would also be rendered
easier, the deep trenches, frequently deepened and
widened by the action of the water, offer serious ob-
stacles to these operations, entailing considerable
outlay, and rendering the work of the cattle and
mules hazardous and cruel. With a system of tile
draining it will doubtless be possible to cultivate
the sugar-cane on land kept flat or nearly so, instead
of being “holed” as at present, in which case the
use of horse-hoes and weeding-machines will be
possible, thus reducing the expenses incidental to
the early stages of sugar-growing.

CHAPTER III.

Sugar-cane.—Preparation of Land, Planting, Manuring, Weed-
ing.—Cutting Cane.—Methods of Dealing with the Trash.—
Moulding.

AVING briefly sketched the general principles

on which a scientific system of agriculture

should be based, it is now necessary to confine at-

tention more particularly to the methods of cultiva-
tion employed in the case of the sugar-cane.

For several months the planter has been carefully
ploughing and preparmg the land to be planted, and
in November or December the actual planting of the
cane usually commences and is carried on for seve-
ral months, so that there may be a succession of
fields, one ripening after the other, in such a manner
as to render the proper reaping and manufacture
practicable.

On land of a fairly stiff character and lying some-
what flat, so as not to be subject to loss of surface
mould by the rush of water during the heavy rain-
storms of the tropics, it is usual to prepare the land
in furrows and banks, an operation known as “ hole-
ing ;” the furrows are generally four and a half feet
or five feet from centre to centre, a distance of six
feet being sometimes adopted; the banks vary in
height, ranging from one to one and a half feet above

MANUAL FOR SUGAR GROWERS. 4]

the bottom of the furrows. If farm-yard or pen
manure is used,—and either this or green dressing is
generally very necessary,—it should be well ploughed
in during the preparation of the land for planting,
preferably before the holeing or banking process.
It is not an uncommon practice to defer the appli-
cation of manure of this kind until the preparation
of the land is completed, and often until after the
cane has been planted. This is a mistake, as the
function of pen manure is a double one: first, to sup-
ply vegetable matter to form humus, the importance
of which has been fully dwelt upon and its action in
loosening the soil explained ; and it is as a mechani-
cal manure, as a means of improving condition or
heart, that pen manure is most useful; its second
property, that of a fertilizer, is not to be overlooked,
but is secondary to the one already alluded to; and it
is to secure the full benefit of the first of these prop-
erties that complete covering and mixing with the
soil is desirable.

Another method of preparing the land for plant-
ing, which has some good features, consists in cross-
holeing ; this differs from the plain holeing or bank-
ing in having a cross-bar raised at right angles to
the furrow, thus forming a number of square holes,
and in the bottom of each a cane-plant is placed.
The use of cross-holeing appears to be twofold : in
the first place it restrains the flow of surface water
and prevents loss of mould by washing in heavy rain ;
if the land be sufficiently porous the water retained in
the holes will soak through the soil and drain away
without injury to the plant ; on stiff land or in a wet

42 MANUAL FOR SUGAR GROWERS.

season there is some danger of waterlogging. The
second beneficial effect of this operation is due to
the extra tillage caused by the raising of the cross-
bar, some increase of nitrification resulting from this.
Some of these beneficial effects—probably all, and to
a greater degree—could be obtained by tile draining
with flat cultivation and machine weeding and tillage.

In whatever way the ground has been prepared,
the next operation to be performed is the actual
planting. For this purpose it is customary in the
West Indies to use the upper part of the sugar-cane ;
this, as it contains but little sugar and a large pyro-
portion of glucose or molasses sugar, is useless for
erinding, hence there is no loss of cane for seed or
planting purposes. In some countries it has been
the custom to employ the whole of the cane for
planting, either laymg whole canes in single or
double rows in the furrows and covering them with
earth, or planting short lengths of one, two, or three
joints. As these methods of planting offer no
advantages over the use of the top or end of the
cane, there appears to be no reason why they should
be retained. Some exercise of judgment is required
on the part of the planter so to arrange matters that
he may have canes to reap to supply himself with
plant-tops at the required time, and in December
and January it is not usual for the regular crop to
be ready for reaping ; it is therefore a common prac-
tice to leave a late field of canes as “ stand-overs,” or
to allow a ratoon crop to grow for the special pur-
pose of providing tops for planting. These ratoons
are cut while probably the canes are but short, the

MANUAL FOR SUGAR GROWERS. 43

land is quickly broken up and planted, thus provid-
ing plants for itself and for other fields besides.

The plant-top consists of the three or four upper
joints of the cane which are yet immature ; the leaves
are cut off, leaving a piece of the cane about ten
inches long, having two or three healthy buds or
eyes. The plant-tops should be carefully picked over
in order to reject any suffering from the attacks of
borer or from any other disease, and as a precau-
tionary measure they should invariably be soaked
for a short time (an hour or two) in slaked lime and
water, two pounds of lime to a gallon of water being
a convenient strength; this treatment destroys a
ereat many animal and vegetable parasites, though
unfortunately there are some, particularly the eggs
of certain insects, which are not destroyed by it. In
cases where diseases persistently attack the young
plants the following method of treatment suggested
by Dr. Bancroft is useful : Carefully clean the joints
from all trash; then immerse the plants in a mixture
of carbolic acid and water heated to such a tempera-
ture as the hand can bear, using one pound of acid
to fifty gallons of water ; allow the plants to remain
in this mixture for twenty-four hours; then immerse
in a mixture of lime and water of the strength given
above for a few minutes. Careful selection of plant-
tops, followed by soaking in lime-water, greatly as-
sists In securing an even, well-established growth of
young canes.

In selecting tops for planting there are several
points to remember. The upper portion of the top
should be cut off sufficiently low down to cut out the

+4 MANUAL FOR SUGAR GROWERS.

terminal bud, or when the top is planted the terminal
bud will grow in preference to the lateral buds or
eyes, giving rise to the appearance known as ‘ capon
tail,” from the fact that the first leaves springing
from the terminal bud have been partly cut off; the
young leaves having thus lost their tips present a
truncated appearance suggestive of a capon’s tail.
Plants grown in this manner do not bunch well, and
the early developed cane arising from the terminal
bud ripens before the other canes, and thus tends to
arrow. ‘Tops for planting should be taken from
sound, ripe canes, those taken from sound but soft
green canes rarely grow well. Mr. J. Sutherland
was kind enough to make the following experiment
at the author’s suggestion: Three tops were planted
in three tubs, care being taken to make the condi-
tions equal in all three; two of the tops were from
mature cane, and one was from young green cane.
The two tops from mature cane sprouted in eleven
days, while the immature one did not throw out a
shoot until the twenty-second day.

Mr. E. R. Hall made the following experiment on
the author’s behalf: Three adjacent plots were
planted, one with tops from ratoon canes, the indi-
vidual tops being carefully picked in order to obtain
those of a large size; the second plot was planted
with selected small ratoon tops, and the third with
sood average tops from plant-canes ; all these canes
are now growing, and, so far as the eye can judge,
there is no difference between them. |

From these experimeuts, as well as from general
experience, it follows that any good, sound, mature

MANUAL FOR SUGAR GROWERS. 45

cane will provide a top suitable for planting. On
the other hand, it does not seem probable that the
selection of tops is likely to lead to any improve-
ment in the variety of sugar-cane ; what is gained is
a better growth and more certain establishment of
the crop. This view is, perhaps, contrary to the
ideas of some planters, but is proved by the follow-
ing considerations: Under existing circumstances
the tops used for planting are, on the whole, not
from the best canes grown on the estates, being fre-
quently taken from ratoons not considered worth
keeping ; hence it may be held, taking one field with
another, that the tops used for planting are from
canes in quality something below the best, and if the
matter be looked at carefully, they will be found to
be from canes below the average quality grown.
Now, if selection of good qualities can produce im-
provement, selection of inferior kinds—and this is
what the present method amounts to—should pro-
duce deterioration ; yet it is not suggested that there
is any falling off in the quality of the sugar-cane.
The above is no argument for careless work, which
will produce deterioration only too surely. The top
planted reproduces the parent variety with all its
characteristics ; new varieties must be sought in
canes from seed, or from occasional sports or bud
varieties.

The plant-tops are planted in the following man-
ner: The ground is marked out by means of a line
and marks placed to indicate the spot where each
plant is to go, the distances apart varying from four
and a half to six feet according to custom (about

46 MANUAL FOR SUGAR GROWERS.

41x 5 feet or 5x5 feet being convenient and profit-
able distances). Some discussion has taken place
recently as to the advisability of so planting that the
plants, instead of occupying the corners of a square,
shall stand at the angles of an equilateral triangle :

* * * * * * * %
* * * * * * *

The diagrams will make this statement clear. By
the latter method it is evident that for a given mini-
mum distance between the plants the maximum
number of plants per acre can be grown. ‘To carry
this into practice, the planting will require to be ar-
ranged as follows: if the distance between the plants,
measured from-right to left in the above diagram,
be taken as 1, then the distance between the rows
measured from top to bottom in the diagram must
be 0.866; or if a uniform distance of five feet is re-
quired between each plant, then the plants must
be five feet apart in the rows, and the rows four feet
four inches apart, with the plants arranged in an al-
ternate manner with those in the preceding row.
When planting trees and the like, where the dis-
tances apart are considerable, this method is worth
carrying out, but for cane cultivation it does not ap-
pear to the author to possess much merit. Regu-
larity in planting greatly assists many of the sub-
sequent operations of cane culture, such as weeding,
manuring, etc., and is a great aid in detecting miss-
ing or weakly growing plants and admitting of
healthy ones being substituted. The ground being
marked out, a laborer, armed with an iron bar or

MANUAL FOR SUGAR GROWERS. 47

drill, makes a hole by thrusting the bar into the
eround, then places a plant-top in the hole in such
a manner that the head of the piece planted is just
below the level of the ground, and then covers the
whole by an adroit movement of the foot. In about
seven to fourteen days the eyes or buds burst into
leaf, and growth above ground fairly sets in; but be-
fore this the rootlets have commenced to grow from
the double row of dot-like markings to be seen
above each joint, thus the young plant obtains a
supply of moisture and plant-food quite as soon as
active transpiration and growth take place.

Various experimenters have recorded observa-
tions on the results of planting various parts of the
cane, and also of selecting large or in other respects
fine tops for planting. The results obtained do not
appear to be definite; so far as the author’s experi-
ence goes it would seem that any sound, healthy
“top,” which has not arrowed or flowered, is suita-
ble for planting, and that it will reproduce the vari-
ety of cane from which it arose, with all its pecu-
harities, including the saccharine richness, ete.

When the young plants have just begun to spring
is the most favourable time to apply manures con-
taining potash and phosphates. It seems best, to the
author, to apply at this time a mixture of sulphate
of potash and superphosphate of lime, with lime,
marl, or ashes, if the soil is at all deficient in lime.
The quantities to be employed will vary with the
soil, but generally two hundredweight of super-
phosphate and one-half to one hundredweight of
sulphate of potash per acre will be found useful

48 MANUAL FOR SUGAR GROWERS.

amounts in the absence of any special information.
This mixture should be evenly distributed in proper
quantity on the surface of the soil, around and at a
short distance from each plant; this is best done im-
mediately before weeding, the operation of weeding
tending to distribute the manure and to mix it with
the soil. It will be observed that no nitrogen is
recommended at this stage. If the land is in good
condition, and has been treated in the manner de-
scribed at the beginning of this chapter, there will
be a sufficient quantity of nitrogen, and much of
that nitrogen in the readily available form of ni-
trate, already in the soil. In about May or June, or
earlier, if the growth of the plant shows lack of vig-
our, a light top-dressing of sulphate of ammonia
in quantity of about one hundredweight per acre
should be applied in the same manner as the super-
phosphate and potash, and a second dressing of the
same quantity should be given six or eight weeks
after the first ; a third dressing is seldom necessary
or remunerative.

It has been stated that ammoniacal manures
should not be applied to soils containing more than
10 per cent. of carbonate of lime, as there is as-
sumed to be a loss of ammonia owing to the con-
version of the sulphate or other salt into the vola-
tile carbonate of ammonia. The author recently
made a series of experiments on two soils, one
containing 1.3 per cent. and the other 40 per cent.
of carbonate of lime. The soil was placed in a
shallow glass dish, to a depth of about an inch
and a half, a known quantity of sulphate of ammo-

MANUAL FOR SUGAR GROWERS. 49

nia was added in solution, and a definite quantity of
water added. A very shallow dish, the bottom of
which was moistened with sulphuric acid, was placed
above the soil. Any ammonia escaping from the soil
would be speedily absorbed by the acid.

Proceeding in this manner, and using one part of
sulphate of ammonia to five hundred of soil, the non-
calcareous soil gave off in two days ammonia equal in
quantity to .017 per cent. of the sulphate of ammonia
employed. The results in the case of the calcare-
ous soil are given in tabular form below.

500 grms. |500 grms.
soil and .5| soil and .2
grms. s.|/ Srms. 8.
ammonia. | ammonia.

Per cent. of added ammonia lostin first2 days) 1.10 0.90
" = ue of. ext 3-6 1.02 0.60

42 ee 5 os ae ae 0.72 0.41

Per cent. of added ammonia lost in Sdays| 2.84 1.91

Now, as in all probability the loss is greater un-
der the conditions of the experiment than it would
be in the field, it does not seem necessary to aban-
don the use of sulphate of ammonia on calcareous
soils, provided that they are in fairly good condi-
tion; in the case of poor calcareous soils contain-
ing but little vegetable matter, the loss would no
doubt be much greater than in the above experi-
ments.

The amount of various substances removed from
the soil by a cane crop has been most carefully esti-

mated by Professor Harrison. (See report of Dodds’
4

50 MANUAL FOR SUGAR GROWERS.

Experimental Station, Barbados, 1889, etc.) He
found the amount of phosphoric anhydride to range
from 23.5 pounds with a crop of 22.3 tons of cane,
to 45.3 pounds with a crop of 32.5 tons, per acre.
The potash varied from 55.5 pounds with a crop of
28.5 tons of cane per acre, to 116 pounds with a
crop of 38.8 tons per acre. These figures deal with
the potash and phosphoric acid in the canes only,
irrespective of the amount in the tops. The tops
will contain about nineteen or twenty pounds of
phosphoric anhydride, and seventy to seventy-five
pounds of potash, but on a well-conducted estate
these will ultimately find their way back to the soil
after having been used for food for the working
stock. <A certain amount of the potash and phos-
phate, too, will be returned to the soil in the ashes
from the furnaces and in the scums removed from
the juice, so that, making allowance for these, the
quantity of plant-food removed from an acre of land
by an average crop of say twenty-five tons of cane
per acre will be about fifty pounds potash, twenty-
five pounds phosphoric anhydride, and seventy
pounds of nitrogen per acre; these amounts of
plant-food will be contributed to the soil by the
methods of manuring here recommended, and this,
with good and careful tillage, should, under reason-
ably favourable circumstances, produce satisfactory
crops.

Weeding is an operation which will occupy much
of the planter’s time and care. This operation has
a beneficial action for several reasons: not only are
weeds killed and the ground left unencumbered for

MANUAL FOR SUGAR GROWERS. Sill

the full growth of the cane, but the constant stirring
of the surface-soil keeps it loose and friable, and
the stirring of the soil distributes the manures, thus
ensuring an even distribution. Weeding is gen-
erally done with the hoe. It would seem, however,
as if a time were not far distant when this operation
will be done by machines; this will result in more
effectual stirring of the surface-soil, with its bene-
ficial action, and will make the operation less costly.
After the canes reach a certain height the operation
of weeding becomes unnecessary, as the dense foli-
age of the cane effectually prevents the growth of
weeds.

In some places it is the custom to remove the
dead leaves or trash from the canes when they are
nearly mature, in order to allow air and moisture to
circulate more freely and thus hasten the ripening.
In damp situations this operation is doubtless bene-
ficial ; how far it can be advantageously followed in
dry places does not seem to be clear. The author is
not aware of any systematic experiments undertaken
to throw light on this subject; such experiments
could be easily made and would be of interest.

When the canes are ripe, a fact which is ascer-
tained by the cessation of growth, and in most vari-
eties of canes by a tendency to deepen in colour,
the reaping will begin. The canes are cut close to
the ground, and the tops are cut off, the immature
joints, containing but little sugar, are thus removed
and are used for planting, the canes are tied in bun-
dles and carried to the factory to be crushed.

If the roots from which the canes have been cut

52 MANUAL FOR SUGAR GROWERS.

are allowed to remain in the ground, a new growth
of canes arises, and these are known as first ratoons,
or second ratoons, etc., according to the number of
erowths thus raised without replanting. Except in
soils of extreme fertility the yield of canes steadily
diminishes by ratooning, so that on ordinary soils
it is not profitable, as a rule, to grow more than sec-
ond ratoons. In some districts the growing of ra-
toons is regarded with disfavour, and fresh planting
is resorted to for every crop. The method of ra-
tooning possesses some advantages, and, if the land
is well tilled and cared for, would appear to be eco-
nomical. One point requiring attention in ratoon-
ing is the effectual opening up of the soil to ensure
the loose pulverulent condition essential to fertility.
It is a good plan, as soon as the canes have been re-
moved, to arrange the trash or leaf residues of the
old crop on alternate banks, leaving alternate banks
clear, then with a double-mould-board plough a
good deep furrow is made in each bank free from
trash ; half of the trash is now placed in this furrow
and the soil is drawn over it by means of the hoe;
the remaining trash is buried under the other bank
by a repetition of the process. The trash should be
covered with soil as completely as possible, in order
to promote decay; this decay taking place under
the soil will keep it light and porous, thus rendering
the operation of breaking up the soil of much more
lasting effect than if no vegetable matter had been
buried. All those parts of the field which have
been much trampled in the removal of the previous
crop should receive extra attention in the matter

MANUAL FOR SUGAR GROWERS. 53

of ploughing or forking to assist in undoing the
harm done by compressing the soil and thus de-
stroying its good condition.

The practice of burning the trash has been advo-
cated and followed by some planters, under the im-
pression that this renders the mineral constituents
of the trash available as plant-food, and more partic-
ularly the potash. A moment’s thought willshow the
fallacy of such a proceeding. The mineral constitu-
ents are present in the trash whether it is burned or
no—the act of burning cannot surely be credited
with creating the potash, even by anyone ignorant
even of the simplest of scientific laws. If the trash
decay in the ground, as it will speedily do, the min-
eral matters are then as available as plant-food as if
the trash had been burned; nay, more so, for owing
to the large proportion of silica present in cane-trash
much of the potash is rendered insoluble by fusion
with the silica to form a kind of glass; the phos-
phates, too, are rendered less soluble and so less
active by burning. But the loss of the vegetable
matter by burning is of the greatest consequence.
The importance of vegetable matter in the soil has
been so frequently insisted on in the foregoing
pages as to require no repetition here. Sometimes,
however, if the fields are badly infested with animal
or vegetable parasites or diseases, it may be desir-
able to burn the trash in order to kill the harmful
plant or animal (as various kinds of fungus, termites,
mole-crickets, etc.), but this is evidently quite an-
other question. Under certain circumstances it
may be worth while to suffer some loss by burning

54 MANUAL FOR SUGAR GROWERS.

the trash for some gain in destroying certain pests,
and the practical planter will readily discriminate
between wise and unwise burning.

It is a common practice for planters to remove
the fine mould accumulated in hollows and water-
courses and return it to the land. There are several
things to be considered in estimating the value of
this practice. In the first place it 1s very necessary
that ponds and watercourses should be kept from
silting up, so that the accumulated mould must be
removed at intervals ; in the second place it is de-
sirable that the soil washed from the fields should, if
possible, be restored to them ; again, it frequently
happens that the soil in certain places is shallow, so
that increased crops will result if by covering with
mould an increased depth can be obtained. Mould
obtained from watercourses and ponds often contains
a fair amount of plant-food, but not to the extent
which planters often think, and thus they frequently
overéstimate its value. The following analysis of
mould from a watercourse, which was forwarded to
the author as an illustration of a good mould, will
prove instructive if compared with the analyses of
soil given on page 23, when it will be seen that
it is deficient in both potash and phosphoric acid.

ANALYSIS OF ‘‘ MOULD,” POUNDS PER MILLION.

21) Ett am eens, Bee ie / = 1,480 | Oxide of manganese ..... 900
Binet Sissies seen. see S.Sou,| Potash <. 7 22 whee ec 41
Macnesis 4.525: coats 1,350 | Phosphoric acid. .....%.° 47
Oxide. OF ION ...3.25 420806) Ag LOU |) REO ROR fie cece sane 1,687

The cost of removing mould and spreading it on
the land is often very great, from £6 to £10 per acre

MANUAL FOR SUGAR GROWERS. 55

being prices commonly paid. It appears to the author
that money is frequently wasted in this way ; and it
would seem best to use mould only when it becomes
necessary to remove it for some other purpose than
as a dressing for the soil, and to improve the soil by
green dressings and better cultivation and manuring ;
this course will prove less costly and will be followed
by better results, except where it is necessary to in-
crease the depth of soil, as in the case where the
soil is very thin.

CHAPTER IV.

Manures.—Farm-yard or Pen Manures, their Function and Use.
*—Management of Pen Manure.—Open and Covered Pens. —
Green Dressing.—Chemical Manures.—Potash, Phosphates,
Mineral Phosphates, Superphosphate, Basic Slag or Thomas
Phosphate.—Nitrogenous Manures.—Sulphate of Iron.

BRIEF summary of the manures commonly
employed by sugar growers in the West In-
dies may prove of interest.

The excreta of the various animals kept on a
plantation, together with their bedding, constitute
one of the most important manures the planter can
employ ; this is known by a variety of names, as
pen manure, farm-yard manure, etc. There are sev-
eral reasons why this is of extreme importance to
the planter. It must first be clearly understood that
the function of pen manure is a twofold one: on ac-
count of the vegetable matter—derived from litter
and uneaten and undigested food—which it contains,
it is a manure by which condition is maintained, and
this is probably its most important function; on
the other hand it acts as a fertilizer on account of
the nitrogen, phosphoric acid, and potash in it; this
fertilizing property is of less importance than the
former or mechanical manurial power, for nitrogen,

MANUAL FOR SUGAR GROWERS. 57

potash, and phosphates can be readily and cheaply
supplied from other sources.

A curious fallacy exists respecting the action of
the animal on the food, and the manurial value of
the excreta as compared with the food eaten. It
seems to be fully believed by many planters that
the excreta have greater manurial value than the
food. Nothing could be further from the truth. If
all the excreta of an animal which had ceased grow-
ing were collected, the manurial value of these would
be just equal to that of the food ; there might be a
little difference in the rapidity of the action, but the
ultimate effect would be the same. How impossible
it is to collect all the excreta will be immediately
recognised. In the case of a growing animal the ex-
creta will contain less potash, phosphates, nitrogen,
etc., owing to the retention of these by the animal
in order to build up new tissues in the form of bone,
muscle, fat, etc. The following tables are taken from
Mr. Warington’s “Chemistry of the Farm,” and are
based on the experiments conducted at Rotham-
sted.

NITROGEN IN ANIMAL PRODUCE AND VOIDED AS URINE, FOR
100 CONSUMED AS Foop.

Obtained as | Voided as | Voided as

carcase or| solid ex-| liquid ex- In total ex-

milk. crement. crement, ees
Fattening oxen ...... 3.9 22.6 73.5 96.1
Fattening sheep...... 4.3 16.7 79.0 95.7
Fattening pigs ....... 14.7 22.0 63.3 85.3
MATING COWS J. 2.0.26. 24.5 18.1 57.4 75.5

58 MANUAL FOR SUGAR GROWERS.

AsH CONSTITUENTS IN ANIMAL PRODUCE AND VOIDED, FOR
100 CONSUMED AS FOoopD.

Voided in excre-

Obtained as live ments and per-

weight or milk.

spiration.
Patiening oxen x's. .2.5 202 ante 2.3 97.4
Fatienine sheep: 7. % <.-sese ce eee 3.8 96.2
Patienine pigs. 2. ieis.c's0'se ene e ee 4.() 96.0
NEP COWS ee oe om eat eee OS 10.3 89.7

In these experiments very great care was taken to
avoid loss of any kind,—such precautions as are im-
possible in agricultural practice. The following ac-
count of another series of experiments is taken from
Dr. Griffiths’ treatise on manures, p. 39:

“ The Muntz-Girard Experiments.—Drs. A. Muntz
and C. Girard (‘ Annales Agronomiques,’ tome Xi,
429-436) have performed a series of well-conducted
experiments to establish the proportions of the ni-
trogen of foods stored up in the increase of live
weight, that recovered in the manure, and also the
proportion of nitrogen lost. The food given was
weighed and analysed, the increase of live weight or
the quantity of milk yielded during the experiments
were noted, and the manure carefully collected and
analysed. The following results were obtained :

Kilograms. Per cent.
Nitrogen feonsumed +): 5-05-5554 £ 22%. < 21.817
Nitrogen converted into flesh ....... 4.3000 21.7
Nitrogen recovered in manure ...... 5.588 19.72

Wiirogen lost... Svuas tossed, Seemee 12.129 55.58

MANUAL FOR SUGAR GROWERS. 59

The experiments were conducted with thirty-two
sheep kept in a fold with asphalt floor, so as to pre-
vent loss of manure. Some of the loss of nitrogen
is due to the escape into the atmosphere of ammo-
nium carbonate.

“ Muntz and Girard fed two Normandy cows each
with 53.5 kilograms of lucerne and 49 kilograms of
water daily. Hach cow furnished 33 kilograms of
solid excreta and 18 kilograms of urine. The weight
of the animals increased by 15 kilograms during the
experiments, and they yielded 361 litres of milk.
With these cows the quantity of :

Kilograms. Per cent.
Murofen consumed. .. 22... 5.060% 14.146
Nitrogen assimilated as flesh ....... 0.544
Nitrogen assimilated as milk........ 2.560 21.95
MrOLeW 1 MANUTC. ...,. . sos. sees: 7.461 52.75
BREGECH AOSt. 5. 0210 oSem «nso oie ss 3.081 25.30

The loss of nitrogen is much less than in the case
of sheep, due to the fact that the fermentation of
cow’s dung is less active, therefore less ammonium
carbonate is formed.

“From these experiments it will be seen that farm-
yard manure does not return to the soil all the nitro-
gen which was originally extracted from it by grow-
ing crops. A portion goes to form flesh and milk,
and another portion is lost in the form of ammonia.”

From these experiments it will also be seen that
pen manure is of somewhat less manurial value than
the combined food and bedding from which it is de-

60 MANUAL FOR SUGAR GROWERS.

rived, even when preserved with the greatest care.
It seemed necessary to the author to emphasise this
statement, as he has so frequently heard planters
talk of “ keeping cattle to make manure,” and heard
objections to the use of tramways on sugar estates
on the ground that the lack of pen manure under
such a system would be fatal to successful manage-
ment; and he has seen almost daily vegetable matter
carted long distances to put into the cattle-pens when
it should have been ploughed into the land on or
near which it grew.

One important point of difference between farm-
ing in the tropics and in temperate climates may
here be insisted on. In temperate climates it is
desirable to have the farm-yard manure in a well-
rotted state, in order that it shall act quickly when
placed on the land. In the tropics decay takes
place so rapidly that the rotting of the manure be-
fore application to the land is almost, if not quite,
unnecessary ; if this is recognised a considerable
saving will result.

Of course, a certain quantity of pen manure must
necessarily be produced from the ordinary working
of a sugar estate. This is extremely valuable and
should be preserved with all possible care. But to
endeavour by forced means to ‘make manure” is a
wasteful fallacy. The author’s advice is to make
the health and comfort of the animals the first con-
sideration, giving them the most suitable food ob-
tainable and adding enough litter for bedding to
keep the pens dry and sweet; to apply this manure
as quickly as possible, in good quantities at a time,

MANUAL FOR SUGAR GROWERS. 61

to the land in preparation for planting ; and to thor-
oughly manure with green dressings all land not
manured with pen manure.

The value of pen manure depends very largely on
the manner in- which it has been kept. Fresh ma-
nure has the highest manurial value, as, in rotting, a
certain amount of nitrogen is lost, even under the
most favourable conditions. If, in addition to rot-
ting, the fluids from the manure-heap are allowed to
drain away, then the loss becomes very great, as the
nitrogen and potash are found largely in the fluid
portion. If the heap be exposed to rain, so that
every shower washes out the soluble portion, the
loss may become so great as to render the remain-
der of little value as a fertilizer. -Where possible, it
is desirable to use pen manure as quickly as it is
produced, and it has been shown that this can be
done more readily in the tropics than in temperate
climates. However, it frequently happens that the
manure cannot be applied to the land directly, but
must be kept for some time; and the value of the
resulting manure largely depends on the way in
which it is kept. In the West Indies it is the prac-
tice to herd the cattle at night in uncovered pens,
into which large quantities of vegetable matter——in
the form of cane-tops for food, and trash for litter—
are thrown, so that a layer of manure of consider-
able thickness is soon formed. In many instances
the drainage—and with the heavy rainfall of the
tropics this is usually abundant—runs away with-
out any attempt being made to preserve it; hence a
large proportion of the nitrogen and potash is lost,

62 MANUAL FOR SUGAR GROWERS.

the remaining manure acting chiefly as a mechanical
agent and possessing but little fertilizing power.
When these pens are made in the fields, as frequent-
ly happens, it is advisable to lead the drainage from
the pens in such a manner that it may flow over the
land, and not find its way directly to the drains. A
little care in this direction will prevent a great deal
of waste which otherwise occurs. In the case of un-
covered pens, not in the fields, it is well to have a
catch-pit into which the drainage from the pen may
run. The contents of this may be distributed upon
the land at intervals. It is true that it is difficult to
prevent the catch-pit running over in wet weather,
so that this method only effects a partial saving at
best ; but still it is easily and cheaply carried out.

Covered pens are to be recommended, as by this
means the manure is kept dry and free from drain-
age. It is no uncommon sight to see a cattle-pen
half covered, and yet no provision exist to prevent
the water running from the roof into the pen, when
a small outlay for spouting would prevent the loss
of much of the fertilizing portion of the manure-
heap.

During the process of fermenting or rotting, the
vegetable matter becomes converted into humus,
and the nitrogenous portions into ammonia and
ultimately into nitrates. If the fermenting heap
become too hot—above 150° F.—there is consid-
erable loss of nitrogen, and the heap should be
watered with the fluid collected in the catch-pits.
If the amount of vegetable matter or litter in the
heap is too small—not a common danger in the

MANUAL FOR SUGAR GROWERS. 63

West Indies—there is some risk of loss of am-
monia, and this condition is recognized by a strong
smell coming from the heap. This may be cor-
rected by adding more litter and covering with soil.
The addition of soil to the pen from time to time is
to be recommended, as soil is a useful agent in fix-
ing ammonia.

The food upon which the animals are fed has a
ereat influence on the value of the manure ; indeed,
in purchasing food-stuffs the farmer also largely
takes into consideration the value of the resulting
manures, and may be said to purchase his artificial
manures in the form of food-stuff. This method of
working is economical where cattle are raised for
the sake of their milk or for the market, and the
manure is carefully preserved, but becomes less eco-
nomical in the case of sugar estates where cattle are
used for draught purposes, with some necessary loss
of manure, and where the system of keeping the ma-
nure is faulty. The sugar plantation too, if well
worked, will provide all, or nearly all, the food re-
quired for its stock, and thus the importation of
concentrated chemical manures becomes the most
economical method of working. The following table,
composed by Sir J. B. Lawes and Dr. Gilbert in
1885, gives the theoretical value of manure pro-
duced from the consumption of one ton of certain
foods :

64 MANUAL FOR SUGAR GROWERS.

Oats .o2duee s ainale ie eee Ee I Re oN oe £1910
W h@ate oo 4.e ts cesee eer hae tee ibs este Lo
ety oe es ste nee SA ae ee 1. 0 oe
Hay (clover). ..2. se -- op 8 ae tie Ae 2 i
Hay: (qHeadow) .\.. cy se o> winless oe Sw ewe wes 1 C= ae
Mangels tuto Ache ee ee 5 eee teas eee 8, 70
Turnip Waite) oo tec eee cine sr eas)» Se 4 0

In the following table analyses of farm-yard ma-
nure by various chemists are given:

COMPOSITION OF FARM-YARD OR PEN MANURE PER 100

PARTS.
HARRISON. VOELCEER. - | WARINGTON.
ANDER-
A Covered Average com-
field pen. | Fresh. | Rotten. position.
pen. f ai
MoIstnre 255. >2-ee- | 49.89 45 .64 66.17 | 15 .42 72.48 | 65.0 to 80.00
Organic matter*.... | 12.17 23.67 28.24 16.53 13 94 | 15.00 to 30.00
Phosphoric acid ...| 0.14 0.29 0.32 0.45 0.31 0.2 to 0.4
IMC AL Behe oss 0.95 0.72 1.19 1.78 0.59
Magnesia .......... sata rae 0.15 0.14 0.02
Oxide of iron and
ALTEIMVTA rs. ose e 15.30 12.61 0.42 0.67 0 45
ROtashy? seen ee 0.11 0.38 0.58 0.58 0.32 0.4 to 0.7
* Contains a 0.22 0.35 0.64 ? 0.38 0.40 to 0.65

In applying pen manure to the land it is neces-
sary to cover it thoroughly; this is best done by
ploughing it in or by covering it during the process
of raising the banks or “holeing:” unless it is
buried its condition-giving or mechanical action,
the importance of which must be recognized, is not
fully exercised. The quantity to be applied should
be about twenty tons per acre.

Where the quantity of pen manure produced on
an estate is insufficient to cover the whole area to
be planted, that portion receiving no pen manure

MANUAL FOR SUGAR GROWERS. 65

should be green-dressed, 7.e., a crop should be grown
upon the land and turned in. This has been pre-
viously discussed in Chapter II., and it has been
shown that plants of the pea and bean tribe (le-
guininosce) are preferable for this purpose. When
leguminous crops are grown and turned in, there is,
as has been said, a-gain of nitrogen; there 1s no ac-
tual gain in potash, phosphates, and other mineral
matters, though this treatment will bring up mineral
matters from below and deposit them near the sur-
face in an available condition ; hence green-dressing
should be followed by a lberal manuring with the
necessary mineral manures, potash, phosphates, and
the like.

Amongst the plants suitable for green-dressing
may be mentioned the pigeon-pea (Cajanus indicus),
woolly pyrol (Phaseolus mungo), Bengal bean. These
plants take from three to six months to grow to suf-
ficient size to be ploughed in; when they are suffi-
ciently developed they are cut down and arranged
in rows to enable the plough to open furrows ; the
green dressing is laid in the furrows and covered
with soil, the banks being raised over the green
dressing.

In some cases where the soil is in very bad con-
dition it is often expedient to raise a green dress-
ing on the banks between the canes, even after
the canes are planted and while they are growing.
This may be done by planting pigeon-peas, woolly
pyrol, or the like, upon the banks as soon after their
preparation as possible ; the green crop then grows
up with the cane, and, if it be carefully watched, will

9)

66 MANUAL FOR SUGAR GROWERS.

in no way interfere with the growth of the latter.
When the green crop has grown as long as is con-
sidered prudent, it is cut down or pulled up and
buried in the banks by the weeding gangs, who find
very little difficulty in accomplishing this. By work-
ing in this manner even very stiff clay soils may be
got into good condition in a comparatively short
space of time. This method of working can only be
followed advantageously in a moist season; in a
dry season the double crop appears to remove too
much moisture, and the cane crop suffers.

In some places seaweed can be readily obtained.
This forms a valuable manure when ploughed in ;
by this means nitrogen and potash are supplied
together with vegetable matter. About twenty or
thirty tons per acre form an excellent dressing.

Now as pen manure and green dressings merely
return to the soil for the most part potash and phos-
phates, ete., derived from the land itself, it follows that
as the exported crops carry away certain quantities of
various substances forming plant-food the land must
be rendered less fertile from year to year, so far as
mineral matters are concerned ; hence it is imper-
ative that manures supplying potash, phosphates,
etc., be imported if fertility is to be maintained.
Farm-yard manure alone is insufficient to maintain
fertility.

The following brief sketch of some artificial or
chemical manures may prove of interest.

Potash Manures.—Formerly potash salts were ob-
tained entirely from the ashes of plants: in coun-
tries where forests prevail, as in North America,

MANUAL FOR SUGAR GROWERS. 67

Russia, Sweden, etc., large quantities of wood are
burned for the sake of the ash; the potash is ex-
tracted from the crude ash by solution in water, and
recovered by evaporation to dryness, the potash
being thus obtained as carbonate. Of late years ex-
tensive mineral beds of salts containing large quan-
tities of potash have been discovered in Germany,
and it is from this source that the potash used
for manurial purposes is chiefly obtained. One of
the most important of these minerals is kainit, a sub-
stance containing sulphates of potash and magnesia
together with common salt and other substances.
A good sample of kainit should contain twenty to
thirty per cent. of sulphate of potash; from this
substance sulphate of potash in a comparatively
pure state can be extracted, and where, as in the case
of the West Indies, the manures have to be trans-
ported long distances, it is found more economical to
purchase the purified and concentrated form of sul-
phate, although the first cost is higher. Thus, with
freight at £2 per ton, if kainit containing twenty-
four per cent. of sulphate of potash were purchased,
the cost of the sulphate of potash would be increased
by £8 per ton, while with purified sulphate of ninety-
six per cent. the increase in cost is only a little over
£2 per ton. This forms a very good illustration of
what has been said before, namely, that in the West
Indies it is economical to purchase manures in as con-
centrated a form as possible, and thus the use is de-
nied to the planters of many forms of manure which
in some countries are economical and useful.
Another mineral containing potash, and which is

68 MANUAL FOR SUGAR GROWERS.

often employed as a manure, is carnallite. This
contains chloride or muriate of potash and chloride
of magnesia. It is found, however, that it is pref-
erable to employ potash salts in the form of sul-
phate rather than chloride, hence carnallite is not
a manure likely to attract the attention of sugar-
cane growers. Amongst the manures obtainable
locally, wood ashes, leaves, etc., and urine are rich in
potash, and should on no account be wasted.

Practically, then, the best form of potash manure
to import is the sulphate ; this can now be obtained
of a very high degree of purity. A guarantee as to
the amount of potash it contains should always be
required.

Phosphatic Manwres.—The first phosphatic ma-
nure employed was bones, and bones are used at the
present time when itis necessary to employ a phos-
phatic manure whose action shall extend over a
long period. Raw bones contain about forty to fifty
per cent. of phosphate of lime, and if they have
been steamed or boiled to remove the gelatine, the
quantity of phosphate of lime is raised to about sixty
per cent., while the nitrogen, of which there is about
four per cent. in raw bones, is reduced to about one-
fifth per cent. Bones being very insoluble and thus
requiring a very long time for their disintegration,
a method was devised by Liebig by which they
could be rendered soluble and so caused to act more
quickly. He suggested the treatment of the bones
with sulphuric acid. By this means an acid phos-
phate of lime is formed, together with sulphate of
lime, or gypsum, and this in a little time forms

MANUAL FOR SUGAR GROWERS. 69

a dry mass which can be ground, and is then ina
very suitable form for use as manure. Phosphate
of lime submitted to this process is known as super-
phosphate. |

Phosphate of lime suitable for conversion into
superphosphate is found very widely distributed in
nature, in the fossilized remains of animals and
their excreta; of this character are the coprolites
of the eastern counties of England, the phosphate
beds of Sombrero, Aruba, Florida, Canada, ete.
These mineral phosphates are found in various de-
erees of purity—from those containing seventy or
eighty per cent. of phosphate of lime down to those
containing a mere trace.

Good superphosphate should contain fifteen to
twenty-four per cent. of the soluble or mono- or
acid- phosphate of lime, as it is variously termed,
equal to about twenty to thirty-two per cent. of in-
soluble or tri-calcium phosphate rendered soluble.

Finely ground mineral phosphates are sometimes
used without being treated with acid; it is neces-
sary that the substance be used in a state of very
fine powder. In this condition good results have
been obtained in the case of the sugar-cane. If
lime be added to superphosphate, the mono-calcium
phosphate is reconverted to tri-calcium phosphate.
This is sold under the name of precipitated phos-
phate. Ground mineral and precipitated phos-
phates, from the fact that they are not acid, are well
suited for soils containing but traces of lime.

Intermediate in character between natural ma-
nures and mineral phosphates are the manures known

70 MANUAL FOR SUGAR GROWERS.

as guanos; these for the most part consist of the
excrement of various birds. Guanos vary in com-
position according to the length of time they have
been deposited, fresh guano closely resembling
farm-yard manure in its general character, except
that it is extremely concentrated from the absence
of litter; hence, guano of this type is a general
manure, supplying nitrogen, phosphate, and a small
quantity of potash. In the older guanos the am-
monia has largely disappeared, so that these gua-
nos are essentially phosphatic in their nature. Ni-
trogenous or ammoniacal guanos are becoming less
and less abundant, so that much of the manure sold
under the name of guano is a manure artificially
compounded, usually being of excellent quality and
preferable to raw guano.

There is one form of phosphatic manure which,
so far, has received but little attention from West
Indian planters,—basic slag, basic phosphate, or
Thomas phosphate, as it is variously termed. In
the manufacture of steel from cast iron some diffi-
culty was experienced, owing to the presence of
phosphorus in the iron. It is found possible to re-
move this by the use of lime, from which results the
basic slag, a substance containing the phosphorus
in combination with the lime as basic phosphate of
lime. This substance contains from fifteen to
twenty per cent. of phosphoric acid, equal to about
thirty-four to forty-five per cent. of tri-calcium phos-
phate ; hence, it is more concentrated than super-
phosphate. Jt is not an acid manure, as super-
phosphate is, and on soils deficient in lime, as so

MANUAL FOR SUGAR GROWERS. 7

many sugar soils are, there appears to be some ad-
vantage in this. It is very essential that basic
phosphate be used in the state of the finest powder ;
when rubbed between the fingers, it should feel al-
most as smooth as flour. A guarantee of the quan-
tity of phosphoric acid which it contains, and of its
degree of fineness, should always be obtained from
the vendor. This manure is cheaper than super-
phosphate. It can be stored without loss or deteri-
oration for any length of time, and, as it is not acid,
does not destroy packages as superphosphate does,
whereby some loss of superphosphate is frequently
incurred. It appears, therefore, well worthy of
careful trials in the cultivation of the sugar-cane.
The author has trial- plots manured with basic
phosphate under observation, and the results ap-
pear highly satisfactory.

Nitrogenous Manures.—The chief nitrogenous
manure used in sugar-growing in the West Indies
is pen manure, and this is frequently increased in
richness and value by feeding the stock on oil-cake.
In a very few instances oil-cake has been applied
direct to the land and serves as excellent manure.
In districts—as in portions of the United States—
where cotton-seed cake is easily and cheaply ob-
tained, the plan of using oil-cake direct as manure
may perhaps be followed with advantage, but in
the West Indies such a course is hardly likely to
prove economical, and cake is best used as food.

Practically the only nitrogenous manures it pays
to import are nitrate of soda and sulphate of am-
monia. These, from their concentration, are very

72 MANUAL FOR SUGAR GROWERS.

economical, the former, when pure, containing 16.4
and the latter 21.3 per cent. of nitrogen; hence the
expenses in handling are reduced to a small amount,
the point to be considered in colonial agriculture.

Nitrate of soda is found as a deposit in certain
parts of South America where the rainfall is ex-
tremely limited ; it is found mixed with clay, gypsum,
and other impurities, and is purified by dissolving
out the nitrate with water and recovering the nitrate
by evaporation. Good commercial nitrate of soda
as employed for manures usually contains from
ninety-five to ninety-eight per cent. of real nitrate
of soda. This manure is, as will be seen from what
has already been said upon the subject of nitrifica-
tion, a quick-acting one. It must be remembered
that the soil has no retentive power for nitrates,
hence in wet seasons or on wet lands there is great
liability to loss from drainage.

Sulphate of ammonia is obtained from the am-
moniacal liquor produced in the manufacture of coal-
gas; it usually occurs In commerce in a very pure
state, containing from ninety to ninety-eight per
cent. of real sulphate of ammonia. It 1s sold on the
basis of the ammonia it contains; thus twenty-four
per cent. of ammonia is equal to ninety-three per
cent. of sulphate of ammonia, while twenty-five
per cent. of ammonia is equal to about ninety-seven
per cent. of sulphate of ammonia. Like all chemical
manures it should be purchased on the basis of
analysis. Sulphate of ammonia is the most satis-
factory nitrogenous manure the sugar grower can
import; it should be employed as a top-dressing in

MANUAL FOR SUGAR GROWERS. 13

small quantities at a time, to obtain the best results ;
about one hundredweight per acre being a conve-
nient quantity.

Ferrous sulphate, or sulphate of iron, is attracting
some attention as a manure: the author has several
trial plots laid down this 1891-92 season. In one
experiment last season there was a most marked dif-
ference in the appearance of the canes manured with
this substance; throughout the whole period of
erowth they were greener and taller than the ad-
joining canes—part of the same field—not manured
with sulphate of iron, but otherwise similarly treated.
Unfortunately, accurate quantitative results were not
obtainable, but, as far as could be ascertained by
weighing the canes from one-fifth of an acre from
each plot, there was an increase of six per cent. in
the weight of the canes in favor of the sulphate of
iron, and this on second ratoons in a very dry season.
The individual canes, too, from the sulphate of iron
plot were finer looking. 'The juice from the canes
manured with sulphate of iron and those not so
treated was carefully analysed to discover if the iron
exerted any influence on the juice ; no difference could
be detected. The figures obtained are given below.

Cane-sugar.| Glucose. Giucee
Pounds per
Gallon: Pounds.
Juice from canes with sulphate iron.... 2.04 0.0378 1.85
Juice from canes without sulphate iron. 2.04 0.0373 1.83

*

These results agree within the limits of analytical
error.

14. MANUAL FOR SUGAR GROWERS.

Sulphate of iron should be purchased in fine
crystals or powder, and should be applied as a top-
dressing in quantities not exceeding one hundred-
weight per acre. Many sugar soils are deficient in
soluble iron; under this circumstance the use of
sulphate of iron is likely to prove beneficial.

No attempt is made here to discuss those manures
not likely to be met with in the West Indies. In
districts where manufacturing operations and the like
are carried on, various waste products are obtained
which are often of value as manure, but too bulky to
admit of shipment to a distance ; hence they are not
referred to here. Nor is any attempt made to com-
pare or contrast the merits of the many manures
specially compounded for sugar soils; most of these
are composed of mixtures of the various substances
herein referred to, and as a rule are skilfully pre-
pared and of good money value.

It is important to remember that artificial manures
can only exert their full action on soils in good con-
dition. To apply artificial or chemical manures to
land in bad condition is a most wasteful proceeding,
and one likely to lead to results discouraging to the
experimenter and to the discredit of scientific manur-
ing generally. Again, it must be remembered that
artificial manures must be used in such a manner as
will pay ; it is quite possible—nay, easy—to employ
these manures in excess, and thus to spend more
money on the manure than the increase of the crop
will pay for. Artificial manures are in most cases ab-
solutely necessary. They are costly, hence their use
calls for the exercise of a considerable amount of skill.

CHAPTER V.

Cane-mills.—Three-roller Mill.—Fletcher-Le-Blane Four-roller
Mill.—Mirlees’ Four-roller Mill.—Skegels’ Mill.—De Mornay
Mill.—Hydraulic Attachment, ete. —Double Crushing. —Ma-
ceration.—Diffusion.

HE usual method of extracting the juice from
the cane is to crush the canes between the
rollers of various forms of cane-mill. The mills
most commonly employed have three rollers, one
roller being on the top and pressing on the two be-

neath, as in Fig. 8. The canes enter between A

Fie. 8.—Diagram of three-roller mill.

and B, the feed rollers, and emerge between B and
C, the megass roller. The distance between A and
B is so arranged that the canes shall enter with
sufficient freedom to ensure good feeding, and at
the same time be subjected to a certain degree of
pressure, while B and C are set as closely to-
gether as possible, leaving only sufficient space for
the escape of the fibrous portion of the cane—the
megass, or begass, as it is called. Skill is required
in adjusting the rollers so as to secure as perfect

76 MANUAL FOR SUGAR GROWERS.

crushing as possible, and yet not endanger the safety
of the mill by straining or breaking it from over-
pressure. In the space between the rollers A and
C is fixed a bar or plate-—the trash-turner, or
dumb returner, which serves to direct the crushed
cane between the rollers B and C. The mass of
crushed canes sometimes becomes jammed between
the dumb returner and the rollers, leading to stop-
page, and sometimes even to breakage, of the mill.
Hence efforts are being made to construct mills in
which the use of a dumb returner is dispensed with.
Other mills are constructed with four or more rollers.
Many kinds of mill have been designed, for each of
which some special advantage has been claimed.
Many of these are simply of the ordinary three-
roller type, with various modifications in their con-
struction to afford greater strength or security.

Fie. 9.—Diagram of Fletcher-Le Blanc four-roller mill.

Among those calling for special comment may be
mentioned Fletcher & Le Blanc’s four-roller mill,
in which the cane is submitted to three crush-
ings, as will be seen from the diagram, Fig. 9.

MANUAL FOR SUGAR GROWERS. 1

This mill is fitted with two dumb returners, which
are hollow, to admit steam or water being forced
into the megass, so as to combine the advantages of
maceration with effective crushing.

In Mirlees’ four-roller mill the cane is only submit-
ted to two crushings, but from the construction of

Fig. 10.—Diagram of Mirlees’ four-roller mill.

the mill these can be made very effective, Fig. 10.
This mill has no dumb returner. There is a dis-
position in some quarters to prefer mills of this
type in which the rollers work in pairs, each pair
only crushing once, instead of three rollers giving
three crushings, as in the ordinary three-roller mill.
Messrs. Thompson & Black’s auxiliary rollers,
which can be fitted to any ordinary mill, are worth
the attention of those whose mills are in fair order,
but not powerful enough to give high expression.
The mill invented by Mr. Skegels, of Demerara,
is attracting some attention, and reports of its work-
ing power are looked forward to with interest. It is
a modification of the three-roller mill, and is without
a dumb returner,* having besides some new features
in its construction. In the De Mornay mill (Fawcett,

* A revolving bar or small roll is now added to take the place
of a dumb returner.

78 MANUAL FOR SUGAR GROWERS.

Preston & Co., Liverpool) the trash turner is dis-
pensed with. The mill has four rollers, two of
which are large and two are
small. The construction of

the mill will be easily under-
stood from the diagram, Fig.
oe “

It would appear that dis-
Fie. 11.—Diagram of De Mor- pensing with the dumb re-
nay mill. Saree

turner, and obtaining three

distinct crushings of increasing power, the final one

from the heavy rollers is an important advance in

mill construction. Mills of the De Mornay type will
doubtless find increasing favour in the near future.

Another important improvement in the construc-
tion of cane-mills consists in holding the rollers in
place by flexible, instead of rigid, supports. In the
older mills the rollers were held in place by means
of screws passing into the framework of the mill, so
that the rollers were kept almost inflexibly in one
position—the result being that if anything, either
cane or some foreign body, were forced into the mill
in such quantity that it could not pass between the
rollers, the mill must either stop—choke as it is
termed—or something must break. It thus be-
comes a question of relative strength of mill and
engine.

In improved mills the rollers are kept in place by
what is known as the hydraulic attachment. This
consists of a simple modification of the ordinary
hydraulic press. It is well known that if pressure
be applied to a fluid, the pressure is transmitted

MANUAL FOR SUGAR GROWERS. 79

equally in all directions, and thus if in any one
place a pressure of say one ton per square inch
be applied, then a pressure of one ton per square
inch will be exerted at ev-

ery part of its surface. IH, a

then, weights be applied
to the fluid in the vessel |

A until the pressure is one
ton per square inch, and F
the vessel A is connected

with a second vessel, B, by Fie. 12.—Principle of hydraulic
means of a pipe, then ev- ae

ery part of the sides of the vessel A, of the pipe, and
of the sides of the vessel B, will also be subjected to
a pressure of one ton per square inch. Now, if in B
there be a piston moving freely, the piston, too, will
share the pressure. Suppose the area of the piston
to be twelve square inches, then the piston will have
a pressure of twelve tons exerted upon it. H, now,
the piston be made to press upon the rollers, the

Fig. 13.—Diagram of hydraulic attachment to cane-mill.

rollers will be thrust forward with a pressure of
twelve tons. How this is applied to the cane-mill
will be seen from the diagram, Fig. 13; from which

80 MANUAL FOR SUGAR GROWERS.

it will be seen that with a piston at each end of the
roller, and with the pressures mentioned, the roller
so fitted will be held in its place with a pressure of
twenty-four tons, no more and no less, so that no ex-
tra strain can be put upon the mill by over-feeding or
by a foreign body, such as a stone. Hence the dan-
ger of breaking is reduced toa minimum. And what
is quite as important, the same pressure of twenty-
four tons is exerted upon whatever is between the
rollers, whether much or little, so that the same
pressure is exerted whether the mill is only partially
filled with canes or when fed full. Those who have
carefully watched how the crushing varies with the
feed in a mill not provided with the hydraulic at-
tachment will at once see the value of this flexibility
with unvarying pressure.

Various devices have been arranged to apply
springs in the place of the hydraulic press; some
of these are very useful and easily attached to exist-
ing mills, and from their simplicity they have much
to recommend them.

It is usual to speak of mills as expressing so much
per cent. of the weight of the cane in the form of
juice ; it is well at the outset to see that this is an
unsatisfactory method of statement, as canes will
vary very much in the amount of juice which they
contain, so that the same mill might express, say
65 per cent. from one lot of canes, and only 60 per
cent. from another. A better method would be to
ascertain the quantity of moisture left in the me-
sass. This should vary less than the quantity of
juice expressed.

MANUAL FOR SUGAR GROWERS. 81

How important good crushing is to the planter
will be seen in a moment from the following figures :
If one mill expresses 55 per cent. and another 70
per cent. from the same canes, then the gain 1s fif-
teen on every fifty-five, or 26.1 per cent. The aver-
age expression of what are regarded as fairly good
mills in the Leeward Islands is probably not over
60 per cent.; the possible expression is certainly
not under 75 per cent. ; in other words, over 25 per
cent. of the sugar now grown, and which with good
machinery could be extracted, is at present thrown
away. It is evident that this condition cannot last
in these days of keen competition.

In large factories it is the practice to resort to
double or even triple crushing ; two or three mills
are arranged one behind the other, the canes being
thus submitted to two or three grindings. It is
usual to blow steam into the megass in its passage
from one mill to the other; by this means the ex-
traction of sugar 1s increased. This would appear
to be due to two causes: one, the dilution of the
cane-juice, and the remaining moisture therefore
containing less sugar; the second, that the cooking
resulting from the use of steam or hot water coagu-
lates the albuminous matter of the cane, and thus
facilitates the expression of the juice.

It may be worth while briefly to sketch out here
the principles on which the diffusion process of
extracting sugar from the cane is based. Those who
are interested in the practical application of the
process will find abundant information in the cur-
rent literature of the sugar industry, as in the

82 MANUAL FOR SUGAR GROWERS.

“Sugar-cane,” “The Louisiana Planter,” “Sugar,”
ete.

It has already been shown that by means of the
process known as osmose (see page 9) certain sub-
stances—namely, those capable of existing in a crys-
talline form—can pass through vegetable membranes
when those membranes are in contact with water on
both sides.

Now, if thin slices of sugar-cane are placed in
water, we have the vegetable membrane of the cell-
wall separating water from the solution of sugar and
other matters in each cell; consequently the sugar
of the cell, being crystallisable, finds its way through
the cell-walls into the water, and the greater part of
the impurities, being non-crystalline, is left behind.
By repeated treatment of the chips with fresh water,
the whole of the sugar is removed.

In practice this is carried out by slicing the canes
by means of revolving knives, and placing the result-
ing chips into large vessels into which hot water can
be forced; the vessels vary in number from six to
twenty, and are arranged either in a circle or in
parallel rows. When the water has been in contact
with the chips for a given time, it is drawn off. In
order to effect complete extraction of the sugar,
the water—or, as it may now be termed, diffusion-
juice —is drawn down upon a fresh lot of chips,
and another charge of water or weak diffusion-juice
is run upon the partially exhausted chips. The
juice in this way passes through all the diffusion-
vessels in turn, water entering at one end of the
series, and strong diffusion-juice being drawn off

MANUAL FOR SUGAR GROWERS. 83

at the other. The following diagram will help to
make this clear :

EXHAUSTED
CANE CHIPS

Fig. 14.—Diagram of diffusion-battery.

A, B, C, D, E are five diffusion -vessels. E has
just been filled with fresh chips, while the chips in
A are nearly exhausted. Hot water is forced into
A, thence it passes into B, then into C and D, and
finally comes in contact with the fresh chips in E,
after which it is drawn off to the evaporators. The |
chips in A, being now exhausted by the fresh water,
are discharged, and the vessel, refilled with fresh
chips, now becomes the last of the series, the fresh
water entering at B, and the diffusion-juice drawn
off at A, and so on, each vessel becoming alternately
first and last of the series.

The question whether diffusion is to supersede
crushing is one which is being most vigorously dis-

84 MANUAL FOR SUGAR GROWERS.

cussed ; the chief points for and against the process
may be briefly summed up as in the table.

ADVANTAGES. | DISADVANTAGES.
Complete removal of sugar. | Difficulty in slicing canes.
Greater purity of juice. Process and machinery com-

plicated.

Juice being diluted, cost of
evaporation increased.

Chips, being saturated with
water, are unfit for burning
without drying, hence ill adapt-
; ed for fuel.

So far as the smaller sugar-growing colonies are
concerned, diffusion at present appears to be quite
out of the question. Even where it has been tried
on a large scale in the West Indies its success has
been in several cases problematical. Double or triple
crushing is for the present the safest line on which
to advance when all the circumstances influencing
sugar growing in the West Indies are taken into
account. This is no place for a lengthy discussion
of the merits of diffusion as compared to crushing,
and this brief outline must suffice.

CHAPTER VI.

Cane-juice.—Composition.—Tempering.—Use of Lime.—Phenol-
Phthalein Test for Lime. — Clarifying. —Formation of
Scum.— Treatment of Scum.— Filter-presses.— Composition
of Filter-press Cake.—Uses of the Cake.—Value of Cake.

HE eane-juice as it runs from the mill may be
regarded as a solution of sugar in water, with —
various impurities. It varies considerably in com-
position according to the variety and ripeness of
the cane, the soil, the season, whether wet or dry,
and numberless other circumstances. A fair sam-
ple of cane-juice will contain about

Per cent.
MG UMN MET AD 5 a yov'ais ais 2 onal sidie. 3: SaaS aoe Pe aD
RGIGECOSEP Er ishel Vora fare tess! oc, os leialoe ET ee ee m9)
Miameral Maiter ey. stsyaas S< wis chs ote Sha asta hoes 3
Organic Matter other than Sugar............. a
DVabeie Stoic se Sos See clon ocean sete 81.0
EUGENE ecto. arch lteter n oe eae eae aoe o state ce Sere 100.0

The organic matter other than sugar consists of
albumen, fat, wax, colouring matter, and a variety of -
substances the properties of which are but little
understood.

The juice is received into vessels termed clari-
fiers. These in the case of windmill estates are
placed over the flues leading from the battery, and
are thus heated by direct firing. On estates possess-
ing steam plant the exhaust steam from the engine

86 MANUAL FOR SUGAR GROWERS.

is led into a steam-jacket surrounding these vessels,
so that the juice is made hot as quickly as possible.
Cane-juice is always slightly acid, so, as soon as the
clarifier is about one-third or half full, a quantity of
slaked lime, made into a thin cream by mixing with
water, is thrown in, and the lime kept in slight
excess until the clarifier is nearly full. When the
clarifier is full the contents are vigorously stirred,
and the quantity of lime carefully adjusted. This
operation is known as tempering; its effect is to
neutralise the acidity of the juice and to cause the
precipitation of the greater part of the impurities.

Until recently this final adjustment of the quan-
tity of lime was left to the unaided judgment of the
workman in charge of the clarifiers. Consequently
there was great irregularity in the manner in which
the lime was used, sometimes an excessive, some-
times a deficient quantity being employed. Asarule
an insufficient amount was used. The sugar thus
produced of course varied considerably in quality.
- After a number of experiments, the author, in an
article contributed to “Sugar,” April, 1890, sug-
gested a method of working which is now very gen-
erally followed on-estates making muscovado sugar,
with satisfactory results. The article is here repro-
duced :

“When using lime for the purpose of neutralising
the juice of the sugar-cane and thus causing the pre-
cipitation of the albumen, some means of ascertain-
ing with precision when sufficient lime has been
added is highly desirable.

“To meet this requirement Dr. John Shier, many

MANUAL FOR SUGAR GROWERS. 87

years ago, devised a method of testing based on the
use of litmus-paper as an indicator of the point of
neutrality. It is found, however,—and Dr. Shier’s
directions for using his test contain a tacit admis-
sion of this fact,—that litmus-paper does not afford
acorrect indication of the point of neutrality in cane-
juice ; hence the test had to be supplemented by
observations of the manner in which the flocculent
precipitate of the juice separated. This complicates
the working of the test and greatly impairs its use-
fulness. That litmus is not an accurate indicator in
the case of organic acids is perfectly well known,
and certain other bodies are now largely used in the
laboratory in place of it.

“These considerations led the writer to make a
series of experiments with other indicators, when
it was found that phenol-phthalein could be em-
ployed with ease and certainty, and that it could be
placed in the hands of the workmen in charge of
the clarifiers, who quickly acquire the small degree
of skill necessary for its successful use.

“The following are required for making the test:
test-tubes, a pipette, and a drop-bottle containing
a solution of phenol-phthalein in spirit; and the
method of testing is as follows :

“ The clarifier is filled with juice, and lime added in
the usual manner. When the greater portion of the
lime required has been added, a little of the juice is
taken from the clarifier by sucking it into the pipette
with the mouth ; two of the test-tubes are about half
filled with juice from the pipette, and one or two
drops of the phenol-phthalein solution are added to

*

88 MANUAL FOR SUGAR GROWERS.

one of them. If sufficient lime has been used the
addition of the phenol-phthalein solution will cause
a slight change of colour to pink ; if the quantity of
lime is insufficient there will be no change of colour ;
in this case a little more lime must be put into the
clarifier, care being taken that it is well mixed, and
afresh portion of the juice put into the tubes and
tested as before; and this must be repeated until a
very faint pink coloration is obtained. If too much
lime has been used the addition of the phenol-phtha-
lein solution will cause a strong pink to red colour-
ation, and in this case the excess of lime must be
corrected by adding a sufficiency of fresh juice until,
on applying the test, only a faint change of colour is
observed.

“This method of working has been employed
successfully on several sugar estates, resulting in
much more uniform work than has hitherto been
obtained ; it is also found that juice thus tempered
eives very little scum in the subsequent process of
evaporation, Inversion is checked, and consequently
the yield of molasses is lessened.

“To prepare the test solution, about ten grains of
phenol-phthalein are dissolved in about half a pint
of alcohol, white rum, or high-wines. The alcohol
being frequently slightly acid, the acidity is neutral-
ized by adding lime-water drop by drop to the solu-
tion until a faint pink colour makes its appearance
and remains permanent. This faint colour is next
destroyed by adding a small quantity of spirit until
the colour just disappears ; with good spirit the use
of lime-water to correct acidity is unnecessary.”

MANUAL FOR SUGAR GROWERS. 89

It may be added, as the result of longer experi-
ence, that it is a common fault, when using phenol-
phthalein for the first time, to add too much lime,
thus obtaining a decided red instead of a faint pink
colour when testing in the manner described. It is
very important to avoid this. Every clarifier should
be tested ; it is not sufficient to test one or two in
the course of the day’s work.

Muscovado sugar tempered with the aid of phenol-
phthalein, taking care that only the smallest excess
of lime is used, is firm and hard, delivers its mo-
lasses freely, and is usually somewhat dark with a
ereenish-grey colour easily recognized ; this colour
is easily removed in refining,—far more easily, in
fact, than the colour of under-tempered sugars, which
frequently have a red tinge.

The quantity of molasses produced is greatly re-
duced when this method of working is adopted,
pointing to the fact that under-tempering leads to
inversion.

This process has been found of great service to
sugar-makers, as they are thus able to work with a
degree of precision otherwise unobtainable, and are
also able to keep a check on the workman, the pro-
cess being rendered independent of the opinion or
skill of the man in charge of the clarifiers. The
author has received many gratifying accounts of the
success with which the use of the process has been
attended.

These directions apply to the manufacture of mus-
covado sugar: if a light-coloured sugar is required,
it is advisable to under-temper somewhat, still using

90 MANUAL FOR SUGAR GROWERS.

phenol-phthalein as a guide ; or, better, to temper as
for refinery muscovado, and, after clarifying, to boil
to a density of about 20° B., and then subside,—that
is, allow the syrup to stand for twelve hours, in or-
der that any sediment may fall to the bottom of the
tank, the clear syrup being removed by carefully
drawing down, leaving the sediment undisturbed.
After subsiding, the syrup is made slightly acid by
means of sulphurous acid produced by burning sul-
phur and passing the fumes into the syrup. (See
Chapter VIL.)

Light-coloured sugar may also be made by tem-
pering and clarifying in the usual manner, then ren-
dering the juice slightly acid with phosphoric acid,
various forms of which are now sold for this purpose.

In the analysis of cane-juice on page 85 there
appears ‘organic matter other than sugar.” This
consists largely of albumen, a substance not unlike
white of egg in character. On adding lime in proper
quantity and heating this, albumen is thrown out
of solution, and, as the liquid becomes hot, rises to
the surface in the form of a scum.

It is well to remember why a scum forms. It is
due to the fact that the heat drives out of the liquid
a certain quantity of the air which the cane-juice
contains in solution. The presence of dissolved air
in the juice is readily understood if the foaming con-
dition in which it leaves the mill is observed: this
air as it is liberated attaches itself in little globules
to the floating solid particles in the juice, the albu-
men, etc., and buoys them up to the surface, where
a thick scum is formed. It will at once be seen that

MANUAL FOR SUGAR GROWERS. 91

to obtain a perfect scum it is necessary to leave
the liquid undisturbed so that the minute bubbles
of air do not become detached from the solid par-
ticles.

When the temperature is about five degrees below
boiling-point it will be found that the liquid is almost
clear, all the floating matter having been carried to
the surface as scum. This is the point known as the
“cracking point” by the work-people, as at this
point the dark upper scum tends to crack and dis-
play a white frothy scum beneath. The juice is now
ready to be drawn off: if this is done with care, the
ereater part of the juice can be drawn off clear, leav-
ing a thick scum behind in the clarifiers ; this scum
is drawn off into another vessel, to be treated as de-
scribed below.

On estates where rum is made, the scum is con-
veyed to the distillery and is used in setting up
the wash for fermentation: many estates, however,
from various reasons, have ceased to make rum, and
on these it is desirable to extract as much sugar as
possible from the scum; this is done by two
methods. The first consists in accumulating all the
scum obtained in a day’s working in a steam-heated
vessel termed a defecator or scum-heater, and the
clear juice is run off from time to time. By keeping
the scum until the following morning a considerable
quantity of juice can be recovered, the residue af-
ter this treatment usually in practice amounting to
four per cent. of the volume of the juice obtained
from the mill.

In the second method the scum is submitted to

92 MANUAL FOR SUGAR GROWERS.

pressure in bags: at first men bags were filled with
the scum and pressed in various modifications of the
presses used for cheese or cider making in England ;
these, although troublesome, yielded a fair quantity
of cane-juice, and if carefully worked and kept clean
did good service.

These presses are now entirely superseded by the
various kinds of filter-press so largely used in al-
most every industry where filtration 1s necessary.
The filter-press consists of a series of chambers,
usually of iron. Each chamber is lined with a
cloth. The substance to be filtered is forced into
the chambers until they are all completely filled
with compact and nearly dry solid matter, the fluid
portion having meanwhile escaped through the cloth
into suitable channels provided for it. The cham-
bers are thus filled either by means of a pump, or
preferably by means of the apparatus known as
a monte-jus. This consists of a strong closed iron
vessel provided with a pipe passing nearly to the
bottom, and leading to the chambers of the press.
A second smaller pipe just reaching through the
top connects the vessel with a steam boiler. A
third opening provided with a stop-cock serves to
admit the scum. The scum is run in until the
monte-jus is nearly but not quite full; steam is
turned on, and the pressure of the steam forces the
scum up the outlet pipe into the chambers, the
pressure obtained being the pressure of the steam
in the boiler. A pressure of from twenty to fifty
pounds per square inch is found suitable for the
working of filter-presses for cane-juice scums.

MANUAL FOR SUGAR GROWERS. 93

A great many filter-presses are on the market, all
based on the principles here stated, but varying -
‘greatly in the details of their construction.

When sugar-cane scums are treated in a good
filter-press with a pressure of about forty-five
pounds per square inch, a very large quantity of
Juice is recovered, and there remains in the press a
solid, nearly dry cake, which in practice is about
one per cent. of the volume of the juice obtained
from the mill. It is thus seen that a good filter-
press effects a saving over the first method—where-
by four per cent. of residual scum is obtained—of
three per cent.

The following analyses of the scum-cake, after
drying, will serve to show its general character :

COMPOSITION OF FILTER-PRESS CAKE, PER 100 PARTS.

Harrison. Watts.
PSUS IEC a: Lon tan tors aac Nene ciate Aeon 14.76 10.04
Wreamic MACR™ . F. .6ce fe 2 ne Bu 66.93 68.45
mildea, Sad). Cts sso. see lose 3.20 5.40
hesphate of lime... o<..'.<sssas 12.95 13.86
sider Ol TOWNS .: 6661s oc ateejee ee. soe .02
PMU UATE ts 5 <e/8 wiinnaru deareinte Hotes 43 .08
REPORT ik dash Sivas cia Pinte ve a 222
Parte eA oe ajacdaln oemee eke Ag -15
SLUTID OSA ee gee Sa ee as 10
Matter not estimated........... 1.12 1.68

100.00 100.00

SIOoOntalns, MitrOPEM).\.. .)- «ocsesis cece cies 2.07 il oul

The amount of phosphate of lime in the cake de-
pends upon the manner in which the operation of
tempering has been conducted. If the juice be un-

94 MANUAL FOR SUGAR GROWERS.

der-tempered only a portion of the phosphoric acid
is precipitated, and the resulting scum will contain
only a small proportion of phosphate of lime; if,
on the other hand, the lime be added in sufficient
quantity, practically all the phosphoric acid is pre-
cipitated, and the resulting scum is rich in phos-
phate of lime, as shown in the above analyses.

The quantity of sugar in the fresh cake 1s from
two to four per cent., and, as the cake amounts to
about one per cent. of the volume of the juice,
the loss of sugar in the cake will be about one-
fourth per cent. of the total sugar in the juice ; or,
say, from three hundred to five hundred pounds-on
a crop of one hundred hogsheads; whereas, if the
scum thrown away were four per cent., as in the
case of the defecator, the loss would be about three
and one-fourth hogsheads. These figures will suffice
to show the value of a filter-press.

The cake from the filter-press forms excellent
food for cattle. The nitrogen present in the dried
cake is equal to about twelve per cent. of albumi-
noids, being equal in quantity to that contained in
such foods as oats and maize, and somewhat less than
half that contained in linseed cake, peas, and beans.

When fresh, cattle will eat both the fluid scum
from the defecators or the solid cake from the press
with avidity. But owing to the rapidity with
which it becomes sour, there is danger of produc-
ing colic in the animals unless the greatest care is
taken. In the case of the defecator scum it is Im-
possible to preserve it. Hence, only what can be
eaten by the stock at once is of any use as food.

MANUAL FOR SUGAR GROWERS. 95

The remainder is generally run into the lees pond,
where it undergoes fermentation, giving rise to
most offensive smells and losing a considerable part
of its manurial value.

The filter-press cake, on the other hand, can be
dried, without difficulty, without fermenting, and,
once thoxoughly dried, it can be ground and will
then keep for any length of time. It thus forms an
excellent food for stock. When the practice of
using scum-cake meal, as this may be termed, is in-
troduced for the first time, it is well to mix it with
other food, gradually increasing the quantity of
the scum-cake from day to day. It may be given
mixed with chaff and molasses, or mixed with mo-
lasses and given in the same manner as oil-meal.
Cattle fed upon this, together with their ordinary
diet of cane-tops or grass, fatten and keep in ex-
cellent condition and work well. No ill effects will
follow from its use if care be taken to reject in the
drying process any that is not perfectly sweet and
good. By following this plan the quantity of oil-
meal purchased on a sugar estate may be reduced,
and in this way the filter-press effects another im-
portant saving.

In order to dry the cake, the author advises that,
every time the press is opened, the softer portions
of the cake, which will be found in the pipes, etc.,
of the press, be fed to the stock as soon as possible,
thus getting rid of this, which it would be difficult
to dry, and providing a considerable portion of the
daily food. The firm cake should then be exposed
to the sun, if the weather be dry, and the cakes

96 MANUAL FOR SUGAR GROWERS.

turned from time to time. At night, or in damp
weather, the cake is broken into small pieces, say
one- to two-inch cubes, and placed on shelves made
of galvanised iron-wire netting of one-inch mesh.
These shelves should be placed one above the other,
about eighteen inches apart, and may extend from
near the floor to the roof of the room they occupy.
A free current of air should be maintained through
the room, and rain be carefully excluded. When
thoroughly dry the cake should be ground in a
mill to a fine meal, and then may be stored in
casks. It is advisable to spread the meal in a thin
layer on a dry floor, and turn it occasionally, to dry
it thoroughly, before packing it in casks. Thorough
drying is of the utmost importance. It is well to
have two hand-mills, one to break the cake into
small cubes, and the other to grind the dry cake to
meal.

The cake from the press is valuable as manure,
and, after it has been eaten by the stock, a large
proportion of the constituents of manurial value
will be recovered, if the cattle-pens and stables are
well arranged.

From the analyses it will be seen that as dried
scum-cake contains about twelve to fourteen per cent.
of phosphate of lime, and superphosphate contains
thirty to thirty-three per cent., five hundredweight
of scum-cake will be required to take the place of
two hundredweight of superphosphate, and this
will contribute about eleven pounds of nitrogen,
equal to thirteen and one-half pounds of ammonia,
or about half a hundredweight of sulphate of am-

MANUAL FOR SUGAR GROWERS. 97

monia; and thus five hundredweight will be worth
about twenty shillings, or fully four pounds per ton,
if used direct as manure.

What scum-cake is produced in excess of what
the stock can eat should be ploughed into the soil
at the rate of about five hundredweight per acre, or
sold if a profitable market can be found.

The quantity produced will be roughly half a
hundredweight per hogshead of sugar made. It
will thus be seen that no estate can afford to be
without a filter-press, and it is somewhat surprising
to notice how slowly proprietors have placed them
in their boiling-houses.

Of the nature of the colouring matter of cane-
juice very little is known; it becomes darker when
the solution is alkaline, and also when submitted to
the oxidising action of the air; hence, when it is
desired to obtain sugar of fine colour, it is neces-
sary to render the juice slightly acid ; and for this
reason only those chemical agents which bleach by
reduction are of any value in bleaching sugar solu-
tions.

7

CHAPTER VIL.

Manufacture of Sugar.—Inversion.—Open-fire Process. —Steam
Pans.—Muscovado Sugar.—Vacuum Pan.— Method of Operat-
ing.—Triple Effect. —Centrifugals.—Production of High-class
Sugars.—Use of Sulphur.— Carbonation.— Phosphoric-acid
Process. —Animal Charcoal.

HATEVER kind of sugar is to be made, the
process of manufacture is practically that de-
scribed in the preceding chapter, up to this point.
From this point the processes differ according to the
apparatus employed in evaporating the juice, and
the kind of sugar produced. In general terms the
process consists in evaporating the juice to a thick
syrup and allowing the sugar to crystallise out.

A word upon the chemistry of sugar is necessary
here. Cane sugar has the composition represented
by the formula C,,H,,O,,, and if this be heated for
a long time with water, H,O, it is decomposed
and forms another kind of sugar,—glucose or invert
sugar, this change being represented by the equa-
tion :

OcHOm: Ei. HiOs p= 0; Cee

Cane Sugar and Water yield Glucose.

If any acid be present, this change takes place
with very great rapidity, and this is one of the rea-
sons for neutralising the acid of the cane-juice in

MANUAL FOR SUGAR GROWERS. 99

the operation of tempering. Various acids act with
different degrees of rapidity. The mineral acids, as
a rule, effect the change in a very brief space of
time. The organic acids act much more slowly.
This change of cane sugar to glucose is known as
inversion, from the fact that cane sugar, when ex-
amined by polarized light, rotates the plane of po-
larization to the right, while invert sugar rotates it
to the left. The art of the sugar-manufacturer
consists in extracting the sugar from the juice with
as little inversion as possible, for to inversion is due
the production of molasses, with its consequent loss
of sugar and loss of money, molasses being of small
value. The chief agents causing inversion are
acids, heat, and certain ferments to be referred to
later.

The simplest method of manufacture consists in
boiling down the clarified juice to a thick syrup in
iron pans over a fire, and pouring out the syrup into
shallow trays to crystallise. These iron pans are
nearly hemispherical and are arranged in a series—
usually of four or five—diminishing in size from
the large one, into which the juice from the clarifier
flows, to the small one in which the final concentra-
tion is completed. These pans are placed over a
continuous flue, the fire being under the small pan,
the object of this arrangement being to diminish as
much as possible the time of final concentration ; for
as the syrup becomes dense it boils at a very high
temperature, and therefore inversion proceeds with
ereat rapidity.

This in effect is the common method of manufac-

100 MANUAL FOR SUGAR GROWERS.

turing muscovado sugar on estates not provided with
steam machinery. Its chief defect lies in the fact
that as the evaporation of the syrup is finished over
the open fire there is considerable inversion: at
the same time the process is difficult to control,
hence the resulting syrup contains much glucose and
is subject to great variation in density.

On estates possessing steam plant this process is
modified by evaporating the syrup to a moderate de-
gree over open fires, and finishing the evaporation in
steam-heated pans. By employing this method the
inversion is very much less than in the one just de-
scribed, though even here the inversion is very rapid
and has led to the abandonment of this method of
working in those places where sufficient juice is dealt
with to justify a large outlay for machinery.

To complete the description of the muscovado
process: the syrup is boiled until the workman in
charge of the pan judges by the manner in which
the liquid boils that it is sufficiently concentrated,
it is then run out in thin layers in coolers to crys-
tallise. It is better to use a thermometer to ascer-
tain the correct point at which to “strike” or dis-
charge the contents of the pan. It is found that
good results follow from striking when the temper-
ature of the boiling mass reaches 238° to 240° F. ;
in this way much more regularity in the character
of successive strikes is secured.

The coolers into which the concentrated syrup is
run are usually about 10 x6 feet and 2 feet deep; a
number of these are employed, and the syrup is run
into them in thin layers ata time. After being run

MANUAL FOR SUGAR GROWERS. 101

into the coolers the syrup is gently stirred at inter-
vals to promote crystallisation. When the coolers
are full, the crystallised mass is dug out and packed
in hogsheads, boxes, bags, etc., in order that the fluid
uncrystallised portion—the molasses—may drain
out. This is aided by boring holes in the wooden
packages to permit of the escape of the molasses.
The polariscopic test of the sugar depends entirely
on the extent to which the draining extends. The
object of the sugar-maker, of course, should be to
obtain a sugar testing as high as possible, and at the
same time yielding the minimum quantity of mo-
lasses. Sugar in the manufacture of which much
inversion may have taken place may yet test high
by efficient draining, but at the same time an ex-
cessive quantity of molasses will be produced.

Muscovado sugar, by thorough draining, may be
obtained testing as high as 94° by the polariscope.
Good ordinary muscovado should test from 88° to
91°. Careful attention to the tempering and the
correct “ striking-point”’ are important factors in se-
curing a high test. Care should also be taken that a
sufficient number of free outlets are provided in the
packages in which the sugar is cured: it is a good
practice to burn the holes in the hogsheads, to pre-
vent the fibres of the wood swelling up and closing
the hole.

From a large number of analyses the author finds,
on estates fairly conducted, that to make a hogshead
of sugar of 2,000 pounds net and its accompanying
molasses, —say about 30 gallons,—requires 2,600
pounds of cane-sugar in the juice. This on estates

102 MANUAL FOR SUGAR GROWERS.

having steam pans but not filter-presses ; where filter-
presses are used the quantity will be about 2,525.
The packages in which the sugar is placed to drain
are arranged in a curing-house, the floor of which is
furnished with beams or stanchions on which the
packages stand, the molasses draining down onto a
floor beneath, where gutters conduct it to molasses
tanks, whence it is filled into puncheons for sale.
The packages in which the sugar is cured are usually
closed up and shipped without any further treat-
ment; sometimes it is the custom to remove the sugar
from the hogsheads or boxes and repack it in bags.
This is the outline of the process followed in mak-
ing muscovado sugar for refiners’ use. It will be
seen that the process is simple, requiring neither
elaborate machinery nor highly skilled labour ; at the
same time it is very wasteful. The rate of inversion
may be judged from the following analyses: The
samples in Series A were obtaimed from an estate
provided with a windmill, the concentration of the
juice being finished over the fire. The samples in
Series B were from an estate having steam plant, the
syrup being concentrated to a certain density over
the fire, and the evaporation finished in a steam pan.

Glucose per
Total sugar.|Cane sugar.| Glucose. 100 cane
sugar.
A.
Syrup, 1st copper.........- 21.48 21.09 0.396 1.87
Syrup, 3d copper .......... 39.88 38.94 0.942 2.44
Syrup, as struck.........-- 83.57 71.12 12.45 17.54
B.
Sugar as supplied to pan.. 66 94 62.10 4.85 7.24

Sugar as struck from pan.. 83.81 75.12 8.69 10.36

MANUAL FOR SUGAR GROWERS. 103

The last column gives the quantity of glucose in
the syrup for every one hundred parts of cane sugar,
or what is known as the glucose ratio.

In the case of the vacuum pan, about to be de-
scribed, the inversion is but very slight. These re-
sults are expressed graphically in the diagram,
curves representing the work of the vacuum pan
and the concretor being added for comparison.

Glucose in

0 1 20° «80e 40 BO 60-70 60 - 90" 100
Total sugar in syrup.

Fig. 15.—Curves illustrating the increase of glucose with increasing concen-
tration in various processes of sugar-manufacture.

It is necessary here to say a few words on the
theory of boiling. It is well known that the tem-
perature at which a liquid boils depends entirely
on the pressure to which it is subjected. The
pressure to which liquids in open vessels are sub-
jected is the pressure of the atmosphere, and this
under ordinary conditions is a pressure of nearly

104 MANUAL FOR SUGAR GROWERS.

fifteen pounds per square inch. This is measured .
by means of the barometer, in which the mercury
usually stands at a height of about thirty inches.
From this it follows that a liquid boils at a higher
temperature when the barometer rises, and at a
lower temperature when it falls.

If, by means of an air-pump, the vapour be re-
moved from above a liquid boiling in a closed ves-
sel, the temperature of the boiling-point will be
reduced, according to a well-known law. In the
case of water, the following table gives the boiling-
point under various pressures :

Temp., F iineies |e Fb epee
A eo ke acacioiee 0 ISO oc Kelas KR Sate 254
a || Line es ape Sheer ales eh 64 DS tt .2 aes nee oe 26
PQ rene Mee Soe ae 10 OAD econ clan oe ore aera 264
(bs!) Sgt ne ere el aa Sey 15 ec eae hoe eee 27
PGW fois atest eee 20 x | ay ie Ii Dye a 274
Te oes ede eee 224 SU ( Ses | Seeing MOB arte! 2
5 6 Se Pe ae oe hy EO 24

Now, from the figures given in connection with
the manufacture of muscovado sugar, it will be seen
that it is the increased heat, as the syrup becomes
concentrated, which leads to such rapid inversion
and consequent loss. Hence, by boiling the syrup
under reduced pressure we have the means of pre-
venting this loss. This, in practice, is carried out by
means of the vacuum pan (Fig. 16), which consists
of a closed vessel, A, in which the syrup is boiled, the
heat being supplied by a series of steam coils, B, at
different heights. The steam, as fast as it is formed,
is drawn off through the pipe, C, by means of the

MANUAL FOR SUGAR GROWERS. 105

air-pump, D, worked by a steam-engine. The steam
is condensed as quickly as possible by being

STEAM PIPE

Fie. 16.—Diagram of vacuum pan.

brought into contact with cold water in C and HE,
the condenser. From the table of pressures and
boiling-points on page 137, it will be seen that the
more effectually the air-pump and condenser pro-
duce a vacuum in A, the lower will be the boiling-
point of the syrup.

In practice, the pressure in the interior of the
pan A is about one to two pounds less per square
inch, instead of fifteen pounds as in open vessels, and
the syrup boils at a temperature of 110° to 120° F.
An additional advantage of this low temperature is
that it allows the syrup to crystallise, or “ grain,”
even during the process of boiling, so that the syrup,
as discharged. from the pan at the end of the opera-
tion of concentrating-——masse cuite, as it is called—
is a mass of crystals. On allowing this to stand for
a few hours, further crystallisation takes place, and
the mass is then ready to be cured.

106 MANUAL FOR SUGAR GROWERS.

A certain amount of skill is required to adjust the
conditions during the concentration, that the crystals
may be properly formed, and in this the art of the
pan-boiler consists.

The following is an outline of the method of work-
ing: The air-pump is first started so as to create
a vacuum in the pan; the cock connected with the
syrup or feed-pipe is next opened, and syrup drawn
into the pan in sufficient quantity to cover the
lower steam coils ; steam is turned on, and the syrup
rapidly boils down. Fresh syrup is drawn in, in
small quantities, from time to time, until the boiling
mass begins to show signs of crystallising or grain-
ing. When this takes place the successive charges
of syrup are admitted with care, so as to build up
the grain slowly. Larger quantities of syrup being
admitted at a time, as the pan becomes filled, and
steam being turned on in the successive coils as the
syrup covers them, the progress of the operation
can be watched through sight-glasses let into the
upper part of the pan. Small quantities of syrup
can be withdrawn for inspection by means of an ap-
paratus known as a proof-stick, an ingenious piece
of apparatus fitted to every vacuum pan.

Attached to the pan are thermometers, by means
of which the temperature of the contents of the pan
can be ascertained. Vacuum gauges are also at-
tached, which show the extent to which the pan is
exhausted of air and vapour. The vacuum gauge
indicates “inches of vacuum,” or the height in
inches to which a column of mercury would rise in
a tube one end of which was connected with the

MANUAL FOR SUGAR GROWERS. 107

pan while the other dipped into mercury. If the
vacuum were perfect, the mercury would rise to the
same height as in the barometer, — about thirty
inches. During the ordinary working of the pan the
vacuum is about twenty-six to twenty-eight inches.

If the formation of grain be allowed to take place
when only a small quantity of syrup is in the pan,
this is known as “ graining low down.” It is often
the custom not to allow grain to form until a con-
siderable quantity of concentrated syrup is in the
pan, and this method of working is known as “ grain-
ing high up.” By graining high there is some sav-
ing in time; but as a rule, particularly with small
pans, the grain is not so large or so regular as when
the syrup is grained low down. To obtain large and
uniform crystals it is necessary to allow the grain to
form slowly, admitting thin syrup in small quanti-
ties, and allow the boiling to take place slowly and
steadily.

It sometimes happens from bad manipulation
that the whole of the mass becomes cloudy from the
formation of minute crystals. This condition of
things, known as false grain, is to be guarded
against most carefully, as it leads to considerable
loss; the masse cuite under these conditions will not
part with its molasses, and a sticky unsaleable pro-
duct results. If the appearaiice of false grain be
detected at once, the difficulty may be overcome
and the false grain destroyed by admitting a consid-
erable quantity of thin syrup into the pan and rais-
ing the temperature of the boiling syrup by wholly or
partially destroying the vacuum for a short period.

108 MANUAL FOR SUGAR GROWERS.

This causes the minute crystals constituting the false
grain to dissolve.

It is customary to discharge only a portion of the
masse cuite from the pan and to take fresh syrup
upon the remainder ; this is known as doubling. By
working in this manner the size of the grain is in-
creased and some time is saved. Care is required in
conducting the operation of doubling. Some syrup
will get sticky after the operation is performed once,
while in the case of other syrups it may be performed
three or four times in succession. In doubling it is
necessary to take in the fresh syrup to open up the
masse cuite in the pan with the greatest care ; if the
syrup be admitted too rapidly false grain will result.

If a glance be given to the diagram of the vacuum
pan it will be seen that the pipe C, conveying away
the steam from the pan, must be heated to a certain
extent, and the idea occurred to engineers that this
heat might be utilised; the result was the invention
of multiple-effect evaporation, a system in which a
liquid is concentrated in a series of closed vessels,
the steam from one vessel serving to heat the liquid
in the next. It is evident that the pressure in the
successive vessels must be gradually diminished, in
order that the steam—having the temperature of the
boiling liquid—from one vessel may be of a higher
temperature than the’ boiling-point of the liquid in
the next. The following diagram of a triple effect
will enable the reader to follow the description of
the method of working.

Juice or thin syrup is run into Vessel 1, and this
is heated by means of a steam-drum supplied with

MANUAL FOR SUGAR GROWERS. 109

steam from some suitable source; the vapour or
steam generated from the boiling juice passes by

STEAM FROM
JUICE IN VESSEL2

Fie. 17.—Diagram of triple-effect apparatus.

means of the conducting-pipe into the steam-drum
of Vessel 2, and the steam from Vessel 2 passes into
the steam-drum of Vessel 3. Now, in Vessel 1 the
vacuum is but very slight, so that the boiling-point
of the liquid, and consequently the steam produced,
have a temperature of about 180° F., corresponding
to a vacuum of about five inches; in Vessel 2 a
vacuum of about fifteen inches is maintained, and
in consequence the boiling-point in this vessel is
about 150° F., so that there is a difference of 30°
between the temperature of the steam and the boil-
ing-point of the liquid, a sufficient difference to
cause the liquid in Vessel 2 to boil, and thus supply
steam at 150° F. to the steam-drum of Vessel 3, in
which the vacuum is maintained at about twenty-
seven inches and the liquid boils at 120° F. Thus
the liquid in Vessel 3 is boiled by the steam from
Vessel 2, which has a temperature 30° above the
boiling-point of the liquid in Vessel 3. Suitable

110 MANUAL FOR SUGAR GROWERS.

air-pumps are attached to the apparatus, and pumps
to remove the condensed water from the steam-
drums, which, being under a pressure below that of
the atmosphere, require to be pumped out, except 1 in
the case of the steam-drum in Vessel 1.

The syrup flows in a slow, continuous stream
through the whole apparatus, and on the correct
adjustment of the rate of flow depends the success-
ful working of a multiple - effect apparatus. The
syrup is concentrated in the triple effect to a suffi-
cient density to be taken into the vacuum-pan, in
which it is boiled to grain as above described.

The principle is the same whether the series con-
sists of two, three, four, or more vessels. Various
improvements in the details of the parts of the
apparatus have been devised from time to time, in
order to increase the efficiency or to render the
working simpler.

In some of the most improved evaporators of this
type the economy of working is very great, nearly
forty pounds of water being evaporated for each
pound of coal burned. It will be remembered that
one pound of coal will convert only fourteen pounds
of boiling-hot water into steam when the evaporation
is accomplished in ordinary open vessels ; indeed,
this is the theoretical quantity, and in practice the
quantity evaporated is very much less than this,
usually not more than eight or nine pounds.

The latest evaporators aim at allowing the fluid to
be evaporated to enter Vessel 1, and, after flowing
over the steam-heated surface, to pass into Vessel 2,
and over the heating surface of this into Vessel 3 ;

MANUAL FOR SUGAR GROWERS. Lh

the evaporators thus contain but a small quantity of
liquid at one time, but this passes through with con-
siderable rapidity, a point of great importance in
sugar-manutacture. The above statements briefly
indicate the importance of the multiple system of
evaporation ; and this system must in time replace
the processes In use in the West Indies, if these isl-
ands are to compete successfully with other sugar-
erowing countries.

Curing Sugar.—tn the case of muscovado sugar
it has already been said that the only treatment to
which the sugar is subjected to fit it for the market
is to permit the uncrystallised syrup—molasses—to
drain away through holes in the packages, a process
which is very tedious and seldom complete. Where
the crystals of sugar are of fair size, as in the case
of vacuum-pan sugars or large-grained muscovado,
the molasses is usually removed by the aid of a cen-
trifugal drier.

It is well known that if any body be made to re-
volve rapidly there is a tendency for all the parts
to fly outward from the centre; this may easily be
shown by twirling the handle of an umbrella be-
tween the hands, when the ribs will fly out. The
same thing is seen in the governor of the steam en-
gine, where the two heavy balls fly out from the
centre as soon as they begin to revolve, and fly
farther out the greater the speed at which they are
driven.

The apparatus in which this principle is applied
to the draining of molasses from sugar crystals con-
sists of a shallow, circular drum or basket, closed at

112 MANUAL FOR SUGAR GROWERS.

the bottom and open at the top, the sides being
perforated and constructed of various materials,
either perforated copper or wire gauze, or some sim-
ilar substance. This basket is capable of being re-
volved horizontally at a very rapid rate. The sugar,
or masse cuite,is thrown into the basket, which is
then made to revolve. The sugar soon flies from
the centre and spreads itself upon the sides of the
basket. Here its progress is arrested, but the mo-
lasses escapes through the perforations in the walls.
The basket revolves in an iron casing which serves
to collect the molasses, and from this the molasses
is run into suitable tanks. After a few minutes’
treatment in the centrifugal machine the sugar is
freed from its molasses. If a fine-coloured sugar is
required, it is the practice to wash the crystals dur-
ing their revolution with a small quantity of water
or bright syrup. In order to obtain a large yield of
sugar it is advisable to allow the masse cuite to be-
come cold before centrifugalling, as a considerable
quantity of sugar crystallises out from the syrup
during the process of cooling. Brighter coloured
sugars can be obtained, though in somewhat smaller
quantity, by centrifugalling the masse cuite warm.
The syrup or molasses thus drained from the
crystals is usually boiled again in order to recover
another lot of crystals. That this may be done suc-
cessfully it is advisable that the syrup be used as
quickly as possible, as any fermentation is very
detrimental to the yield of sugar ; if it can be worked
up as it leaves the centrifugals, so much the better.
The syrup is mixed with sufficient hot water to re-

MANUAL FOR SUGAR GROWERS. 1138

duce the density to about 20° B., and lime added,
phenol-phthalein being used as an indicator; the
mixture is heated in a steam-heated vessel or ‘‘ blow-
up,” carefully skimmed, to remove impurities, and
boiled to grain in the vacuum pan, yielding second
crystals. It is often the practice to submit the
syrup obtained by this operation to similar treat-
ment, thus obtaining a small quantity of third sugar.

It is possible to obtain upwards of ninety-two to
ninety-three per cent. of the total cane sugar in the
juice in the form of crystallised sugar, and upwards
of seventy-four per cent. should be in the form of
first crystals. With good working the quantity of
molasses should not exceed fifteen to twenty gallons
per ton of sugar made.

Various processes are employed to produce sugar
of fine colour direct from cane-juice. The one most
commonly employed consists in decolourising the
syrup by means of sulphurous acid. When sulphur
is burned, pungent fumes of sulphur dioxide are
given off, which dissolve in water, forming sulphur-
ous acid. This substance has powerful bleaching
action on most vegetable colouring matters and in
the act of bleaching is itself converted into sul-
phuric acid. To apply this in the sugar industry
sulphur is burned in a small furnace, and the fumes,
urged forward by means of a steam jet, are brought
into contact with the cane-juice, by which they are
dissolved and which they decolourise. There is
some difference of opinion as to the best time in
the treatment of the juice at which to apply the sul-

phurous acid. Some apply it as the juice runs
8

114 MANUAL FOR SUGAR GROWERS.

from the mill, before tempering, while others apply
it after tempering ; the author believes that it is used
to best advantage as late in the process of concen-
tration as possible, say after subsiding or just be-
fore the syrup is taken into the vacuum-pan. Ii
used early in the process there is danger of inver-
sion from the presence of the sulphuric acid gen-
erated, while if used before tempering a good deal
of the bleaching action is lost, as the solution must
be slightly acid to obtain a fine colour, and efficient
clarification cannot be obtained with acid juice.

In making high-class sugars it is usual to “sub-
side,” z.e., to allow the syrup, boiled to a density of
about 20° B., to stand for twelve hours, in order that
the impurities may settle to the bottom. Bright
juice, free from floating impurities, is thus obtained.
No fermentation or inversion takes place if the pro-
cess is properly conducted.

Decolourisation of the juice is often effected by
forming a precipitate of some solid substance in the
juice. The carbonation and phosphoric-acid pro-
cesses may be taken as types of processes of this
class; their success depends on the fact that precip-
itates tend to remove many kinds of vegetable col-
ouring matter from solution.

In the carbonation process a quantity of lime far
in excess of that required to neutralise the juice is
added. This dissolves in the form of mono-sac-
charate of lime. Carbonic-acid gas is afterwards
forced into the solution, which decomposes the sac-
charate, with the formation of cane sugar and car-
bonate of lime ; the latter, being an insoluble sub-

MANUAL FOR SUGAR GROWERS. 115

stance, falls to the bottom of the vessel, carrying
with it a considerable amount of impurities and col-
ouring matter. The carbonic acid required for this
process is usually obtained from the kiln in which
the lime for the use of the factory is burned.

In the phosphoric - acid process, lime is added to
the juice in somewhat larger quantities than is re-
quired to effect clarification in the ordinary way. Af-
ter the removal of the scum, phosphoric acid is
added to the juice, when an insoluble phosphate of
lime is produced, which is best removed by sub-
siding ; this precipitate carries down with it colour-
ing matter and other impurities. Various forms of
phosphoric acid are on the market, so prepared as to
render them easy of carriage. The process is one
requiring no special appliances, and is easily carried
out.

The use of animal charcoal is but rarely resorted
to in the colonies. For the removal of the colouring
matter from the juice no other agent so completely
decolourises sugar solutions. The difficulties attend-
ing its use are such as can only be successfully coped
with when the manufacture is conducted on a very
large scale. Its use is almost entirely confined to the
process of refinmg. The charcoal is placed in iron
cylinders 5 or 6 feet wide and 20 or more feet high.
The juice after clarification is allowed to flow in at
the top of the column, and after percolating slowly
through the charcoal it flows out at the bottom in a
colourless state. After having been in use for some
time the charcoal loses its decolourising properties ;

116 MANUAL FOR SUGAR GROWERS.

it is then reburned and after washing is again fit for
use.

It is worth while remembering that only those
bleaching agents that bleach by reduction are of -
value in the sugar industries. Oxidizing agents,
which are frequently used as bleaching agents in
other industries, do not bleach, but darken cane-
juice and its products.

CHAPTER VIII.

Hydrometers or Saccharometers, and their Use.

HE sugar in cane-juice being subject to very
ereat variation, it is convenient to have some
means of ascertaining approximately the richness of
the juice. This is usually done by means of the hy-
drometer, the use of which depends on the following
points: When a solid substance, such as sugar, is
dissolved in water, the density or specific gravity *
of the solution is found to be greater than that of
water, and increases in proportion to the quantity
of solid substance dissolved ; hence, if the fluid con-
tain only one substance in solution, it is easy to
ascertain precisely the amount dissolved by merely
finding the specific gravity ; but when the fluid con-
tains two or more substances, this becomes quite
impossible, as both have a similar effect in increas-
ing the specific gravity, and it is impossible to say
how much of the increase is due to one substance

and how much to a second.
When any body floats in a fluid it sinks until the
part submerged displaces exactly the same weight
* Density or specific gravity is the weight of any substance

compared with the weight of an equal volume of water taken as
unity.

118 MANUAL FOR SUGAR GROWERS.

of fluid as the body itself weighs ; thus any floating
body will be more or less submerged as the fluid in
which it floats is less or more dense. ‘This princi-
ple is applied to the construction of hydrometers,
which serve to measure the density of fluids by the
depth to which they are submerged when they are
floated in the fluid. Hydrometers
are usually made of the form shown
in the figure, and may be of glass or
metal; a scale marked on the stem
measures the amount submerged,
and thus the density of the fluid.
Hydrometers are made with scales
of various values, according to the
uses for which they are to be em-
ployed.

The hydrometer commonly used on
sugar estates is graduated with the
scale known as Beaume’s. In the
table on pages 139 and 140 is given
Fia. 18.—Beaumé’s the quantity of sugar in solution cor-

uiccceet eda responding to the various degrees

Beaume.

For use in the West Indies it is most convenient
to have the hydrometer graduated to indicate from
6° to 12° B., this range covering the. variations of
ordinary cane-juice, and on an instrument thus
eraduated the marks are sufticiently wide apart to
admit of their being read with considerable accu-
racy. The use of instruments having a scale rang-
ing from 0° to 50° or 60° B. cannot fail to be mis-

MANUAL FOR SUGAR GROWERS. LS

leading. The instrument should be graduated at a
temperature of 84° F’.; sometimes instruments are
found graduated at 60° F., the temperature em-
- ployed when they are to be used in a cold climate ;
the readings of such instruments may be corrected
by noting the temperature of the liquid tested and
adding .0265 for every degree F’. above the temper-
ature at which the instrument is graduated, or one-
tenth for every four degrees difference of tempera-
ture.

Another hydrometer, known as Balling’s or Brix’s,
is commonly employed in the sugar industry. The
readings of this scale indicate the percentage of sugar
present in solution; thus 14° Balling indicates a
solution containing fourteen per cent. of sugar.

From what has been said it follows that, when ap-
plied to cane-juice, the quantity of sugar can only
be estimated approximately by the hydrometer,
which is unable to distinguish between cane sugar,
elucose, or other dissolved substances.

In ascertaining the density of cane-juice, it is the
common practice to take the juice as it comes from
the mill, and to put the hydrometer into this; this
method involves several sources of error. Owing to
the presence of air, the fluid appears to be lighter
than it really is, and by taking a series of observa-
tions on the same sample in rapid succession, a
number of increasing densities will be obtained ; at
this stage, too, the juice contains in solution a quan-
tity of organic matter other than sugar, which is
shortly to be removed in the process of clarification.

120 MANUAL FOR SUGAR GROWERS.

When the instrument is used as a saccharometer
it is preferable, then, to take the density after clari-
fication, when the air and a considerable quantity of
impurities have been removed. To do this, a sample
should be taken from the clarifier and rapidly cooled
by pouring into a shallow metal dish floating in
water ; when cooled, the juice is poured into a deep
narrow vessel, and the density taken; the tempera-
ture of the liquid being noted, and a correction
made if the temperature differ from that at which
the hydrometer is graduated. Much more trust-
worthy results are obtained by this method, as the
density is taken in juice containing much less im-
purities and free from air.

The following method of using the hydrometer
may be found useful in muscovado boiling-houses,
where chemical control is rarely obtainable ; in larger
factories more accurate methods are usually em-
ployed. By taking the density in the manner di-
rected, and calculating the amount of sugar present
in the juice from the table, the planter can ascertain
approximately how the work of the boiling-house is
being carried on ; for, by dividing the total pounds
of sugar by 1.3, he will obtain the number of pounds
of cured muscovado sugar which should be made.
This, of course, will only be approximately true, but,
being so easily carried out, serves as a useful control.
It is advisable to make a deduction of seven or ten
per cent. from the total sugar in the case of young
canes, or of three per cent. in the case of sound ripe
canes, on account of the glucose, etc., present.

MANUAL FOR SUGAR GROWERS. 121

The following example will explain the method :

Pounds per

gallon.
5,000 galls. juice at 10° B., corrected, = 1.9896 = 9,698
4,000 galls. juice at 11° B., corrected, = 2.1513 = 8,605

Pounds.

Dos eee ocean ees S 18,303
Hiessae Per CONLY.c ai< rer ia be see's se o epee 549
Pounds sugarestimated « . ces sscce omc 17,754
Mivided! Dyed. 256 s.aiias eo ape dee crete ees 13,657

The 9,000 gallons of juice should therefore pro-
duce 13,675 pounds of muscovado sugar, or 6.8
hogsheads of 2,000 pounds net ; or 1 hogshead from
1,176 gallons of juice.

It will be found instructive to test each week’s
working on the above lines. Careless working or
waste will be thus detected.

CHAPTER IX.

Molasses.—Production, Composition, and Uses.—Recovery of
Sugar from Molasses,

OLASSES will vary very greatly in character °
according to the manner in which the sugar
from which it drains has been produced. That pro-
duced in the manufacture of muscovado sugar with-
out steam pans will frequently be dark in colour
from slight charring. When steam pans are used
the colour is usually improved, the composition re-
maining about the same. When the vacuum pan is
employed, the cane sugar is usually more perfectly
extracted, so that vacuum-pan molasses contains
much more glucose and impurities than molasses
obtained in the muscovado process.
The following analyses may be taken as represent-
ing the various qualities of molasses:

Muscovado Vacuum-pan

molasses. molasses.
Cand Saar y Ju eee tune sec nae aeiek 40 to 50 30 to 40
HHCOSE 2s. cada pee aint eee ae 15 to 25 20 to 35
Mineral nratter’ 37. os.s 3202 \s cen acces 2to 6 5to 8
Organic matter other than sugar....... 3 to 10 10 to 20
Water. 2:2. atedencme eee eens 20 to 30 20 to 30

The quantity of molasses made per hogshead or
per ton of sugar also varies greatly, and depends

@

MANUAL FOR SUGAR GROWERS. 123

both on the quality of the juice and on the skill of
the sugar-manufacturer.

The production of molasses or uncrystallizable
syrup is due to the fact that glucose, mineral mat-
ters, and organic impurities other than sugar, prevent
the crystallisation of cane sugar. Hence the quan-
tity of molasses will be greater in proportion to the
quantity of these substances present in the juice.
But by far the most important agent is the glucose
formed by inversion during the process of boiling ;
so that it is at once seen that, not only does the for-
mation of glucose mean the loss of so much cane
sugar by inversion, but also the further loss of
another portion by preventing its crystallismg. In
careful working with vacuum pans it is found that
one part of glucose prevents the crystallisation of an
equal weight of cane sugar. In the molasses of the
muscovado process the proportion of cane sugar to
glucose is much greater than this.

The quantity of molasses produced in the musco-
vado process is largely dependent on the manner
in which the process is conducted. It varies from
30 to 50 gallons, or more, per hogshead of 2,000
pounds. There are two points by attention to
which the quantity of molasses can be kept low,—
care in tempering, and brisk boiling in the steam-
pan ; long-continued boiling of concentrated syrup
is one of the greatest producers of molasses.

In the vacuum-pan process the yield of molasses
depends chiefly on the amount of impurities in the
juice, inversion during manufacture in this case

being but slight. Where only first and second

124 | MANUAL FOR SUGAR GROWERS.

sugars are made, the quantity of molasses will vary
from 10 to 20 gallons per 1,000 pounds sugar pro-
duced. But where third sugar is made from the
molasses, the quantity may be reduced to from 5 or
10 gallons per 1,000 pounds of sugar produced.

After the molasses has been made, considerable
loss is often experienced from fermentation. The
packages overflow, and often arrive at their desti-
nation nearly half empty. It is believed that this
could be remedied by heating the molasses to about
200° to 212° F., in order to destroy the germs to
which fermentation is due; a clarifier or steam pan
would afford a means of doing this.

The question arises, What is to be done with the
molasses? In the case of muscovado molasses of
good colour and flavour, there is a ready outlet as a
food material, and this doubtless has enabled the
wasteful muscovado process to hold its own in
the West Indian islands for so long, the value of
the molasses with a steady demand, together with
the small cost of the machinery and appliances, ren-
dering it suitable to the small-estate system so gen-
eral in these islands.

With molasses of inferior quality, and vacuum-
pan molasses, from which so large a proportion of
sugar had been extracted, leaving a high percentage
of impurities, the case is different. Molasses of this
kind may serve as food for cattle, pigs, ete. But its
value is so small as to scarcely counterbalance the
cost of packages, freight, and other expenses. No
doubt the right use to which to apply it is to con-
vert it into alcohol, though the excise regulations of

MANUAL FOR SUGAR GROWERS. 125

some colonies impose difficulties which render the
use of small stills on small estates unremunerative.
One or more large distilleries in each colony would
probably be able to overcome these difficulties.

Many processes have been suggested, from time
to time, for dealing with molasses. These, however,
apply almost exclusively to the molasses of beet
sugar, and it will be seen that it will not pay to ap-
ply any of these processes to the molasses obtained
from the sugar-cane. These processes have for
their object the recovery of sugar, or the recovery
of potash, or both. Several processes for the recov-
ery of cane sugar depend on the fact that this sub-
stance will combine with lime, strontia, etc., to form
a compound insoluble in water, while glucose will
not. The glucose is separated by washing the pre-
cipitate or sediment with water, and the cane sugar
recovered by treating the insoluble compound with
carbonic-acid gas, which converts it into carbonate
of lime or strontia, insoluble in water, and sugar
which dissolves. Now, beet molasses contains far
more cane sugar than molasses from the sugar-cane,
and but little glucose. An average sample of beet-
molasses will contain :

eR. SAAT sos oo tral since soln eines miners, ele rein es 50
MICO E. okt sek sw cce besos Sas eis an ee wees o's 1.5
ENCE AE MAAGLOR c.g Saas 2 spice Sos ales 12
Organic matter other than sugar f......... 16.5
DN alec a 2) wa ce na 2 ai mys Sins wom -w, os ohne 20
GANG ie oa ian ois ac aint wee ee oa ees 100

* Contains potash = 5 per cent.
+ Contains nitrogen = 1.5 per cent.

126 MANUAL FOR SUGAR GROWERS.

The value of the sugar recovered will be insufti-
cient to make processes of this character remunera-
tive in the case of sugar-cane products.

Beet molasses contains a very large quantity of
potash,—on an average four or five per cent. On
mixing molasses of this character with sulphate of
alumina, a considerable quantity of alum, which is
a double sulphate of potash and alumina, crystal-
lises out. Processes of this kind have been worked
successfully, but are quite inapplicable to cane mo-
lasses, as the quantity of potash present is usually
only about one-half per cent.

The problem of finding a remunerative outlet for
vacuum-pan molasses is undoubtedly one of the
most difficult ones which owners of large factories
have to solve, and for them the distillery appears
to offer the easiest solution.

CHAPTER X.

Fermentation.—Nature of Ferments.—Conversion of Cane Sugar
into Alcohol.—Setting up Wash.—Yield of Alcohol, —Dis-
tillation.—Forms of Stills.

HEN cane-juice is allowed to stand for some
hours various changes take place. The
sugar disappears and a certain quantity of alcohol
is found in its place. This change is known as fer-
mentation. This term, however, is not limited to
the conversion of sugar into alcohol, but is ex-
tended to other changes of the most various kinds,
e.g., the conversion of alcohol into acetic acid,
etc.

It is now a matter of common knowledge that all
these changes—which we term fermentation, putre-
faction, and decay—are due to the life and growth,
in the changed substance, of various minute organ-
isms, and that if steps be taken to kill those present
in a given substance, and to prevent the access of
others, even the most easily putrescible substances,
such as meat, fish, soup, milk, fruit, and the like,
may be kept without change indefinitely. We have
commercial examples on an enormous scale of the
truth of this, in the various canned foods of all de-
scriptions now so abundantly used. These are, for

the most part, prepared by closing the food-sub-

128 MANUAL FOR SUGAR GROWERS.

stance in the tin, leaving a small hole in the lid for
the escape of air. The tin and its contents are now
heated to the temperature of boiling water in order
to kill the putrefactive germs which are present,—
not merely to remove the air, as is sometimes
supposed,—and while hot the small hole is closed
by means of a drop of solder. Cane-juice treated
in the same manner would remain unchanged for
any length of time. Air free from germs will not
cause any fermentative or putrefactive change.

If a drop of liquid in which sugar is undergoing
change from sugar to alcohol be examined under a
microscope, a great number
of little bladder-like bodies
will be seen floating about in
it, the appearance when high-
ly magnified being as in the
figure. These are the germs
of alcoholic fermentation, or
the yeast-plants, as they are
ED more ome called. Each little plant con-

Se sists of a single cell, and mul-
tiplies by budding. A pro-
jection forms on one side of the parent cell, and this
gradually grows until it becomes a perfect cell like
the parent. This is known as reproduction by gem-
mation or budding. The yeast-plant also multiplies
by forming spores in its interior. The contents col-
lect into masses which, on the rupture of the sur-
rounding cell-wall, are set free and develop into
new yeast-cells. This method of multiplying is less
common than the former.

MANUAL FOR SUGAR GROWERS. 129

These cells are very minute, measuring on an
average about zo/5q Of an inch in diameter, so that
the enormous number of 64,000,000,000 could go
into the space of one cubic inch.

The change of sugar into alcohol is due to the
life and growth of this particular organism. The
sugar may be regarded as its food, and the alcohol
as its waste product. Now, there are a great variety
of these ferments, each of which produces certain
definite changes. Thus we have the alcoholic fer-
ment; the acetic ferment, which converts alcohol into
acetic acid; the viscous ferment, which converts
cane-juice into a thick, ropy fluid; the lactic fer-
ment, which produces lactic acid; and many others.
If any one of these be placed in a suitable medium
it produces its own particular change. Hence, the
alcoholic ferment always produces alcohol; the vis-
cous ferment, the gummy matter which thickens
the fluid and renders it ropy. The effect is just as
certain and definite with the minute organisms as
with larger ones, the resulting growths having the
character of the organism sown: just as we get a
maize crop if we sow maize, pigeon-peas if we plant
pigeon-peas, and cane if we plant cane.

From this it follows that to get the best results it
is necessary to exercise some care in the selection
of the ferment when it is desired to convert sugar
into alcohol for commercial purposes ; for, if other
ferments be sown into the fermenting liquid, other
changes will go on at the expense of the sugar, less
alcohol thus resulting.

Certain ferments require oxygen (air) for their
9

130 MANUAL FOR SUGAR GROWERS.

growth, hence their growth can be stopped by ex-
cluding air, or hastened by admitting it. The acetic
ferment belongs to this latter class, and thus in the
manufacture of vinegar it is necessary to have free
access of air to the fermenting liquid. The alcoholic
ferment belongs to the former class, and thus can
live and grow in vessels from which air is excluded.

In the case of alcoholic fermentation of cane
sugar the changes take place in two stages: I.
The sugar is rapidly converted into glucose or in-
verted. This change is effected by a soluble fer-
ment, “invertase,” secreted by the yeast-plant, the
change only taking place if the solution is slightly
acid, and is at once arrested if the solution is alka-
line. This point is one well worth remembering
by sugar-makers, as by tempering their juice as
quickly as possible, and by keeping any juice which
cannot be boiled at once slightly alkaline to the
phenol-phthalein test, this inversion can be largely
prevented. It is this inversion, of course, which
prevents “sour” cane-juice yielding sugar when
boiled, although it may have a high density when
tested by the hydrometer before boiling. 2. The
elucose thus produced is acted on by the yeast-
plant, and converted into alcohol and carbonic-acid
gas according to the following equation :
Under the action of invertase,

CigH20,: so 2 OL = Robe
cane-sugar and water become glucose.
Under the action of the yeast-plant,
C;H120¢ = 2CO2 + 2C,H,0,
elucose becomes carbonic-acid gas and alcohol.

MANUAL FOR SUGAR GROWERS. 131

The presence of a large amount of alcohol arrests
the development of the yeast-plant. Hence in the
presence of a considerable amount of sugar the fer-
mentation comes to an end before all the sugar is
converted into alcohol; it is therefore wasteful to
employ solutions which are too concentrated, as this
results in loss of sugar.

When filter-presses are used in the manufacture of
sugar there is no waste product to be converted into
rum (the name given to the spirit produced from
sugar-cane products) save molasses. This is mixed
with water in such proportion that the resulting
“wash ” has a density of about 8° B. The wash is
set up to ferment in vats of various sizes, depending
on the size of the distillery, 1,000 gallons being a
convenient size. Fermentation, as a rule, soon sets
in without the addition of any ferment. Bubbles
of carbonic-acid gas rise briskly to the surface, the
liquid becomes slightly heated, and the density
rapidly diminishes, falling to about 1° to 2° B. when
the process is completed. This process usually oc-
cupies three or four days. This time could doubtless
be shortened by adding to the fresh wash a small
quantity of yeast or ferment taken from vats in which
fermentation was active. It has been already stated
that it is necessary that the solution be slightly acid
in order that the cane sugar may be converted into
glucose. It is usual, therefore, to add a small quan-
tity of sulphuric acid to the wash to obtain this
necessary condition. It is only necessary to add so
much acid as will render the wash very slightly acid
to litmus-paper, indicated by turning blue litmus-

132 MANUAL FOR SUGAR GROWERS.

paper slightly red. All waste products containing
sugar, such as washings of various appliances, skim-
mings, etc., should be sent to the distillery to be
utilised in setting up wash.

A great deal has been said, though but little defi-
nite seems to be known, about the production of a
fine aroma and flavour inrum. This is no doubt
due to the formation of various ethers and compound
ethers during the process of fermentation. Good
results in this direction appear to follow from set-
ting up the wash at a higher density than 8° B., say
from 10° to 13° B., allowing the fermentation to pro-
ceed slowly until all fermentation ceases, after which
the washis kept for twenty-four hours before distil-
lation. Probably working in this way secondary fer-
mentations set in, as the action of the alcoholic fer-
ment becomes feeble. The subject is one which has
been but little studied, and would repay further in-
vestigation. There are, of course, two courses open
to the distiller: one, to produce rum when flavour
and aroma must be obtained even at some expense
of sugar, time, and trouble ; the other, to make recti-
fied spirit when quantity and freedom from aroma
and flavour will be the objects aimed at.

When a solution of cane sugar is fermented under
the most favourable conditions, 100 pounds of cane
sugar yield 51.11 pounds of pure alcohol, or, in other
words, slightly over 100 pounds of proof spirit, or
10.9 gallons; this is the theoretical yield, which is
never reached in actual practice. With good apph-
ances and careful working it ought to be possible to
obtain from eighty to eighty-five per cent. of the

MANUAL FOR SUGAR GROWERS. 133

theoretical yield, or every 100 pounds of sugar in
the wash ought to yield from eight and three-quayr-
ters to nine and a quarter gallons of proof-spirit.

When the fermentation of the wash has ceased, the
alcohol is recovered by distillation, an operation
depending on the fact that alcohol boils at a lower
temperature than water, so that, when a mixture of
water and alcohol is boiled, the vapour which first
escapes consists very largely of alcohol, the vapour
containing more and more water as the boiling con-
tinues, until at last it consists of little else than water.
The simplest form of still in which the operation of
distilling is conducted consists merely of a vessel in
which the wash is boiled, provided with a long tube,
usually coiled into a spiral form for convenience,
into which the vapour passes and in which it is
cooled as rapidly as possible ; this cooling is effected
by placing the coiled tube in water.

The only improvement commonly employed in
this class of still consists in introducing one or two
vessels or retorts between the body of the still and
the condenser or worm. The use of these is to in-
tercept the heavier vapours, thus rendering the recti-
fication more perfect at one operation than it would
be if the whole of the vapour passed direct to the
condenser worm and so into the receiver.

Alcohol having a density of .864, or 40 over-proof,*

* The term proof-spirit is derived from the curious method of
testing in use many years ago. A little of the spirit to be tested
was poured upon a small heap of gunpowder, and the spirit
ignited. If, when all the spirit had burned away, the gunpow-
der also took fire, the spirit was said to be ‘‘ above proof ;” if, on

134 MANUAL FOR SUGAR GROWERS.

is the usual strength of commercial rum. Spirit of
a density from .864 to .900, or from 40 to 50 over-
proof, is termed high wines, while weak spirit, from
.900 to .967, or from 15 over-proof to 50 under-proof,
is termed low wines, and from both of these spirit
of full strength is recovered by redistillation. This
redistillation is often economically effected by plac-
ing a quantity of low wines in the first retort and
high wines in the second, the heat of the vapour
from the wash in the still driving the alcohol, in a
high state of concentration, into the condensing-
worm.

In large distilleries what are known as continuous
stills are employed. There are a great many modi-
fications of this kind of apparatus; the principles
underlying their construction and method of work-
ing will be understood from Fig. 20 and the follow-
ing brief description.

The chief parts of the apparatus are: A, the
wash-tank’; B, condenser; C, the rectifying -col-
umn; D, the condensing-worm.

The wash flows, in the direction indicated by the
arrows, from the wash-tank into the condenser,
where it serves to cool the vapour which passes
from the rectifying-column into the worm of the
condenser ; from the condenser the wash, now par-
tially heated, flows by means of a pipe into the
rectifying-column. This contains a number of hori-
zontal plates or discs, perforated, yet so arranged

the other hand, the quantity of water in the spirit was so great as
to render the gunpowder too wet to burn, the spirit was said to be
‘*under-proof.’”’

. MANUAL FOR SUGAR GROWERS. 135

as to retain a thin film of moisture on the surface
of each disc; the wash in its downward course over

STEAM FROM BOILER

[J OUTLET FOR EXHAUSTED WASH

Fic. 20.—Diagram of continuous still.

the perforated discs meets the ascending hot va-
pours generated by means of steam admitted from
a steam-boiler not shown in the figure. The more
volatile portion of the wash—the alcohol—escapes
through the pipe into the worm of the condenser,
where it is condensed as already described. The
less volatile portion passes downward into the cham-
ber at the bottom of the rectifying-column, whence
it is run off as it accumulates.

The exhausted residue from which the spirit has
been distilled is known as dunder. It contains vari-
ous mineral matters, as potash, phosphoric acid, ete.,
together with any sugar which has escaped fermen-
tation. A certain quantity of it is usually employed,
instead of water, in setting up fresh wash for fer-
mentation, the unfermented sugar being thus saved,

136 MANUAL FOR SUGAR GROWERS.

while the mineral matter serves to supply plant-
food, which is quite as necessary to the yeast-plant
as to any other vegetable organism.

The value of rum depends largely on its flavour
and aroma, and as the substances conferring the
distinctive character are very volatile they are
found in greatest quantity in the first runnings from
the still; hence stills of the old or discontinuous
type are often preferred, as by this means the first
half of the returns, or any desired portion, can be
kept separate in order to produce a spirit of first
quality. From the continuous stills the spirit flows
in a stream of almost unvarying quality, and in this
case it is impossible to separate the product into
portions differing in flavour and aroma.

Rum is usually coloured by means of burnt
sugar. The colouring matter is prepared by heat-
ing muscovado sugar in an iron pan until it is con-
verted into caramel, having a fine black colour.
When sufficiently heated the fire is withdrawn, and
strong proof rum is added, the whole being briskly
stirred meanwhile. This solution is added to rum
in such quantity as to produce the desired colour.

MANUAL FOR SUGAR GROWERS.

137

TABLE SHOWING TEMPERATURE OF STEAM AT PRESSURES

Temperature,
Fahrenheit.

Degrees,
212
215
220
225
230
235
240
245
250
260

FROM 0 TO 120 PoUNDS PER SQUARE INCH.

ure, pounds
per square

inch.

Steam press-

Water boils
90

2.50
4.23
6.11
8.13
10.32
12.62
15.20
20.83

Temperature,
Centigrade.

l oanlll aon
of
Exes)
ae}

i.

104.

107.2
110.0
112.8
115.5
119 4
121.1
126.6

Temperature,
Fahrenheit.

Degrees.

ure, pounds
per square

Steam press-
inch.

Temperature,
Centigrade

A Ad

poh pane
Co OO
0
-~2 09

145.3
148.8
154.4
159.9
165.5
Dele
176.6

138

MANUAL FOR SUGAR GROWERS.

List OF ELEMENTS WITH THEIR SYMBOLS AND COMBINING

ATA . << << Al.
ANTINONGY 52.6 sds «oie Sb.
APSE MEG a socal a. os As.
Barn o625.2%4. Ba.
Bimuthascels 1.2% Bi.
IOEOH. Fo ole iccie. cae B.
Bromine, | ono Set Br.
Cagmirai 2 i452. Cd.
PASM 4 22> eke Ne Cs.
Calemem .2 2 o2enoe2 Ca.
Cambor. . sh 540ioee C.
Ceri. . 253% jnic Ce.
CHiorment= 32%). 2 Ck
Chremrgm< «6.45 = Cr.
Coates ee wae kine ow Co.
Coppers tis. s isk... Cu.
Didymiigm: - +s. 5. 2 D.
Er bramicy. 2 ode s.065 5 E.
Plgorine =... sates F.
Glucmunt<.. 4... dee Gl.
Gold. 2 tee Au.
Hydrogen gs os suie Fe
Indinm. 3.4 2. ae Seas b
AGAIMC S38" sates ce ‘a
Bidinm ¢ jean ee.t ir:
PEAR: 62 so ce eee Fe.
Lanthanum ....... La.
Ley a re ee ED:
ap goes oe ss Li.
Magnesium........ Mg.
Manganese ........ Mn.
Mereary 5.32. 5.5.0 <0 Hg.

WEIGHTS.
27.3 | Molybdenum ..... . Mo.
NS Or eet IN ACACEN eile asic p xc % Ni.
Cy SEIN O DTI: 2 ph, cc0e fs 2 ok Nb.
Lae 4 Nitrogen 22 1). !: 62: N.
D120 | Memigm 4.5... Os.
PE) WOON 28 ote esse O.
$0:0'| Palladium: -. =.2. 33 Pd.
112.0} Phosphorus ....... Fr
135.0: Piatinuni +, oi. fos... PE
AQ0)|-Rotassium:... .¢o36 K.
12.0,| Rhodium... 2°. 226. Rh.
02.3 | Hubidium ... 224. Rb.
0,0: | RiUtheninm <2... Ru.
Ho ak.| Selena x22 2 a ec Se.
oe Ae LIGOW 27: «7. es ate oe Si.
Gant Silvers ae es cto. 2 Ag.
Of OL. SOG ui. ott. ec: Na.
Ato -G | Stroutiqm .'2 2.6 2s <:. Sr.
19) | Salphur.y.3. sets... S.
Ors | Lantalwim. \.. x12. «ct < Ta.
196575) Tellurium .2<.:.. 2 a:
4) Palais hoe ss Tl.
Pte) | (Chori... 6c3 te ote Th.
1269 Pine OL ete ee Sn.
296;9 | TWataniums 32 04-00 Ta:
56.04) Tungsten... <..¢25-.% W.
92.6) Uraniwim 22:55. 52 o0¢ Uz.
206.9 | Vanadium, ..2..... V.
Ou) SN GETAIR, Cs oe Betas V2
rot: EA Oe a aeietlee ene Zn.
54:0) | Zirconium? 3.35 23-6 Zr
200.0

MANUAL FOR SUGAR GROWERS.

TABLE OF DENSITIES, ETC., OF SACCHARINE

Specific
gravity.

1.0000
1.0035
1.0070
1.0105
1.0141
1.0177

1.0213 |

1.0249

1.0286 |

1.0323
1.0360
1.0397
1.0435
1.0473
1.0511
1.0549
1.0588
1.0627
1.0667
1.0706
1.0746
1.0787
1.0829
1.0868
1.0909
1.0951

In one gallon.

(et

Pounds Pounds

| sugar. water.
0.0000 | 10.0000
0.0903 | 9.9447

0.1812 | 9.8888

0.2718 | 9.8332

0.3640 | 9.7770

0.4569 | 9.7201
0.5504 | 9.6626
0.6446 | 9.6044
0.7395 | 9.5465
0.8351 | 9.4879
0.9324 | 9.4276
1.0293 | 9.3677
1.1269 | 9.3081
1.2253 | 9.2477
1.3254 | 9.1856 |
1.4251 | 9.1239
1.5267 | 9.0613 |
1.6280 | 8.9990
1.7312 | 8.9358
1.8350 ; 8.8710
1.9396 | 8.8064
2.0452 | 8.7418 |
2.1513 | 8.6757 |
2.2583 | 8.6097
2.3661 | 8.5429 |
2.4749 | 8.4761

139

SOLUTIONS.

ge | ge | ai || Dione gallon
bos Ee 25 Pounds Pounds
AmMm|-a| We | sugar. water.
13.0 23.52} 1.0992 | 2.5853 | 8.4067
13.5 24.43 | 1.1034 | 2.6956 | 8.3384
14.0 25.35} 1.1077 | 2.8080 | 8.2690
“145 26.27 | 1.1120 | 2.9212 | 8.1988
| 15.0 | 27.19 | 1.1163 | 3.0342 | 8.1288
| 15.5 | 28.10 | 1.1206 | 3.1488 | 8.0572
“16.0 29.03 | 1.1250 | 3.2658 | 7.9842
“16.5 29.95 | 1.1994 | 3.3885 | 7.9105
17.0 30.87 | 1.1339 | 3.5003 | 7.8387
| 17.5 | 31.79 | 1.1883 | 3.6186 | 7.7644
(18.0 32.72 1.1429 | 3.7395 | 7.6895
(18.5 33.65 | 1.1474 | 3.8610 | 7.6130
19.0 34.58 | 1.1520 | 3.9836 | 7.5364
(19.5 35.50 | 1.1566 | 4.1059 | 7.4601
20.0 36.44) 1.1613 | 4.2317 | 7.3813
20.5 37.87} 1.1660 | 4.3573 | 7.3027
21.0 38.30) 1.1707 | 4.4837 | 7.2238
(21,5 39.24 1.1755 | 4.6126 | 7.1424
(22.0 40.17, 1.1803 | 4.7412 | 7.0618
99.5 | 41.11| 1.1852 | 4.8723 | 6.9797
| 23.0 42.05 1.1901 | 5.0043 | 6.8967
93.5 42.99 1.1950 | 5.1373 6.8127
“94.0 | 43,94 1.2000 | 5.2728 | 6.7272
24.5 44.88 1.2050 | 5.4080 | 6.6420
25.0 | 45.83 | 1.2101 | 5.5458 | 6.5552

1.2152 | 5.6847 | 6.4673

| 25.5. 46.78

140 MANUAL FOR SUGAR GROWERS.

TABLE OF DENSITIES, ETC.— Continued.

| =e

| In one gallon. | | ¥

*

male al) 3S S| =] Ls | Inone gallon.

o wo ees o a eis .

eal ge koe | ol ea gs | ay ae

we 5, | $= Pounds Pounds) | $s | on == |Pounds Pounds

S3\|22 | we sugar. water.|/Ag|@2| wh | su t

As = gar. : fea) a gar. water.
| |

26.C | 47.73 | 1.2203 | 5.8244 | 6.3786 | | 39.0 | 73.23] 1.3714 | 10.0427 | 3.6713

26.5 48.68 1.2255 5.9657 | 6.2893 | 39.5 | 74.25) 1.3780 10.2216 | 3.5584
1.2308 6.1084 | 6.1996 | 40.0 | 75.27| 1.3846 | 10.4218 | 3.4249
1.2361 6.2534 | 6.1076 | | 40.5 | 76.29| 1.3913 | 10.6142 | 3.2988

28.0 51.55 1.2414 6.3994 | 6.0146 | | 41.0 | 77.82] 1.3981 | 10.8101 | 3.1709
93.5 | 52.51 1.2468 6.5469 | 5.9211 | | 41.5 | 78.35 | 1.4049 | 11.0073 | 3.0417

|

29.0 | 53.47 1.2522 | ,6.6955 | 5.8265

29.5 | 54.44 1.2576 | 6.8463

| | |
30.0 | 55.47 1.26382 7.0069 5.6251 | | 43.0 81.47 | 1.4267 | 11.6233 | 2.6437
| | } |

30.5 56.37 1.2687 | 7.1516 | 5.5354 | 43.5 | 82.51) 1.4328 | 11.8220 | 2.5060
31.0 57.34 1.2743 | 7.3068 | 5.4362 | | 44.0 | 83.56 | 1.4400 | 12.0826 | 2,3674
31.5 58.32 1.2800 7.4649 5.3351 | 44.5 | 84.62 1.4472 | 19.2462 | 2.9958

ne
ro
[—}

79.39 | 1.4118 | 11.2082 | 2.9098
5.7297 | | 42.5 | 80.43 | 1.4187 | 11.4106 | 2.7764

32.0 59.29 1.2857 7.6229 5.2341 | 45.0 | 85.68 | 1.4545 12.4621 | 2.0829
32.5 60.27 | 1.2915 | 7.7838 | 5.1312 | 45.5 | 86.74) 1.4619 12.6805 | 1.9885
33.0 61.25 1.2973 | 7.9459 5.0271 | | 46.0| 87.81 | 1.4694 12.9028 | 1.7912
33.5 62.23 1.3032 8.1098 ; 4.9222 | 46.5 | 88.88| 1.4769 | 13.1266 | 1.6424
34.0 63.22 | 1.3091 | 8.2761 | 4.8149 | 47.0) 89.96 | 1.4845 13.3395 | 1.5195
(84.5 64.21 | 1.3151 | 8.4442 | 4.7068 | 47.5 | 91.03 1.4929 | 13.5834 | 1.3886

35.0 65.20 1.3211 8.6135 4.5975 | 48.0 | 92.12 1.5000 (13.8180 | 1.1820

35.5 66.19 | 1.3272 | 8.7847 | 4.4873 | | 48.5 | 98.21 1.5079 | 14.0551 | 1.0239
36.0 67.19 | 1.3333 | 8.9584 | 4.3746 | 49.0 94.30 | 1.5158 14.2939 | 0.8641
36.5 68.19 | 1.3395 | 9.1340 | 4.2610 | 49.5 95.40 | 1.5238 | 14.5370 | 0.7010
37.0 | 69.19 | 1.3458 | 9.3115 | 4.1465 | 50.0 | 96.51. 1.5319 | 14.7843 | 0.5347

| |
37.5 70.20 | 1.3521 | 9.4917 | 4.0293 | 50.5 97.62 1.5401 15.0344 0.3666

38.0 | 71.20 | 1.3585 | 9.6725 | 3.9125 51.0 | 98.73 | 1.5484 15.2873 | 0.1967
38.5 | 72.22 | 1.3649 | 9.8573 | 3.7917 | | 51.5 | 99.85 | 1.5568 | 15.5446 | 0.0234

LN DE x

ACETIC acid, formation of, 129

Acetic ferment, 129, 130

Acid phosphate of lime, 68, 69

Acids, those in soil must be neu-
tralised, 27; cause of inversion,
99; use in tempering, 99

Agriculture, science in, v, vi, 1,
18

Air, influence on root-growth, 18,
19, 27, 52, 33; putrefactive pro-
cesses in the, 128

Albumen, amount in cane-juice,

85; precipitation in clarifying, |

86, 90

Alcohol, formation of, 124-127, |
129, 180 ; conversion into acetic |

acid, 127; yield from cane sugar,
152, 183; condensation of, 155
Alcoholic ferment, 129, 130
Alum, extracted from beet mo-
lasses, 126

-Alumina, presence in plants, 21;_

amount in pen manure, 64;
amount in filter-press cake, 93
Ammonia, insoluble in water, 30;
retention by soil, 30, 63 ; loss of,
from pen manure, 59; forma-
tion from nitrogenous matter,
62; ratio of sulphate of ammonia
to, 72

Ammoniacal manures, restrictions
on use of, 48

Analysis, purchase of chemical
manures on, 68, 71, 72

Anderson’s analysis of pen ma-
nure, 64

Animal charcoal, use in decolour-
isation, 115, 116

Animal excreta, a nitrogenous
manure, 25, 26. See also PEN
MANURE.

Animal life, dependence on vegeta-
ble life, 12

Animal manure., See PEN Ma-
NURE.

Animals, care of, 60

_‘** Annales Agronomiques,” quoted,

58, 59

Antigua, analysis of volcanic soil
at, 23

Arrowing, 44

Arrowroot, 14

Aruba, phosphate beds of, 69

Ash constituents obtained from
and voided by cattle, 58

Ashes, 47

Atmosphere, composition of, 11,
25; action on plant-food, 24;
the source of carbon for plants,
25; absorption of nitrogen from,
by Leguminose, 28

BAcTERIA, assimilation of atmo-
spheric nitrogen by, 29

142

Bacteria-cells of Leguminose, 29
Balling’s hydrometer, 119
Barley, consumption of plant-food

INDEX.

head of sugar, 101, 102; ascer-
taining richness of, 117-121; fer-
mentation of, 127

by, 22; value of manure pro- Cane-mills, their forms, principles,

duced from consumption of, by
cattle, 64

Barometer, use of, 104

Basic phosphate of lime, 70, 71

Basic slag, 70, 71

Bean plant, its mode of feeding,
28

Beans, value of manure produced
from their consumption by cat-
tle, 63; value as green dressing,
65

Beet molasses, analysis of, 125, 126

Beet sugar, different processes ap-
plicable to, from those for cane
sugar, 125

Begass. See MEGAss.

Bengal bean, value as green dress-
ing, 65

Bleaching agents, 97, 113, 116

Blood, a nitrogenous manure, 26

Blow-up, 115

Boiling, 99; theory of, 103, 104;
how produces molasses, 123

Bone, constituents of, 57

Bones, use as manure, 68

Borers, 45

Botany, connection with agricul-
ture, 1

Brix’s hydrometer, 119

Budding of yeast-plants, 128

Burnt sugar, use of, 156

CAJANUS INDICUS, peculiarity of,
28; value as green dressing, 65
Calcareous soil, analysis of, 25;

experiments on, 49
Calcium, 2
Canada, phosphate beds of, 69
Cane-juice, analysis of, 85;
amount required to make a hogs-

and use, 75-81

Cane sugar, amount in cane-juice,
55; formula of, 98; amount in
molasses, 122; effect of glucose
on, 123 ; combinations with, 125 ;
alcoholic fermentation of, 150;
yield of alcohol from, 132, 133

Canned foods, how preserved, 127,

128
Capillary attraction, 19
Capon-tail, 44
Caramel, 136

_Carbo-hydrates, 6

Carbolic acid, use of, 48

Carbon, its presence in plants, 2,
5, 6, 13; its symbol, 3; source
of, 11,12; proportion in sugar,
12; essential to plant-food, 25

Carbonate of ammonia, 30, 31, 48,
59

Carbonate of lime, composition of,
16; presence in soil, 27, 31, 48;
in decolorisation process, 114,
115

Carbonate of potash, presence in
soil, 30, 31 ; how obtained, 67

Carbonation, decolorisation by,
114, 115
Carbon-dioxide. See CARBONIC-
ACID GAS.

Carbonic-acid gas, its presence and
use, 11,12; use in decolorisation,
114, 115; use in recovery of
sugar from molasses, 125; pro-
duction from glucose, 130

Carnallite, use as manure, 65

Cassava, 14

Catch-pit for liquid manure, 62

Cattle, injurious effect of, on wet
lands, 27; West Indian practice

INDEX.

in herding, 61; choice of food
for, in relation to manure, 63 ;
filter-press cake as feed for, 94;
molasses as food for, 124

Cattle-pens, recommendations as
to, 62

Cells, 4

Cellulose, 6

Centrifugal process, 111, 112

Chalk. See CARBONATE OF LIME.

Charcoal. See ANIMAL CHAR-
COAL.

Chemical manures, proper and im-
proper uses of, 32, 53

Chemical symbols, 3; table of, 138

Chemistry, connection with agri-
culture, 1

‘‘Chemistry of the Farm,” quoted,
30, 57

Chloride of magnesia, presence in
carnallite, 68

Chloride of potash, presence in
carnallite, 68

Chlorides, soluble in water, 30;
found in drainage-waters, 31

Chlorine, 2, 21, 22

Chlorophyll, 12

Clarification, 85, 90, 119, 120

Clay, its origin, composition, and
properties, 16, 17; excessive
density of some, 52; mixed with
nitrate of soda, 72

Clover hay, value of manure pro-
duced from its consumption by
cattle, 64

Coal, consumption of, in evapora-
tion of water, 110

Coal-gas, manure products from,
12

Colic, induced in cattle, 94

Colloids, 10

Colouring-matter, amount in cane-
juice, 85; in sugar, 97

Colour of sugar, 112, 116

143

Combining weights of elements,
138

Concentration, 99, 100, 104-108,
110, 114

Condenser, 134, 135

Condensing-worm, 134, 135

Condition, maintained by pen ma-
nure, 56

Continuous stills, 184-136

Coolers, 100

Coprolites, 69

Cotton-seed cake, value of manure
produced from its consumption
by cattle, 63 ; use as food and as
manure, 71

Cows, nitrogen and ash constitu-
ents obtained from and voided
by, 57, 58

Cracking-point of scum, 91

Cross-holeing, 41

Crystallisation, 99-101,
112, 118, 128

Crystalloids, 10

Curing-house, the, 102

Curing sugar, 111-113

105-108,

DECAY, causes of, 127

Defecator, use of, 91, 94

De Mornay mill, 77, 78

Densities of saccharine solutions,
139, 140

Density, 117

Dew, 20

Diffusion process, 81-84

Digging, 18

Disease, prevention of, 45; eradi-
cating by burning trash, 53

Distilleries, 125, 126

Distilling, 91, 151-136

Dodds’ Experimental Station, 49,
50

Double-crushing, 81, 84

Doubling, 108

Drainage, principles, methods,

144

INDEX.

etc., of, 33-39; loss of nitrates | Forking, 18

by, 72
Drainage-water, plant-food in, 30
Drying filter-press cake, 95, 96
Dumb returner, 76-78
Dunder, 185

Economy, importance in colonial
agriculture, 72

Elements, the, 2 et seg. ; table of,
138

England, coprolites in, 69

Ethers, formation of, in distilla-
tion, 152

Evaporation, 98-100

Excise regulations, obstacle in way
of using molasses, 124, 125

Excreta of animals. See PEN Ma-
NURE.

FALSE grain, 107, 108

Farm-yard manure.
NURE.

Fat, constituents of, 57; amount
in cane-juice, 85

Fawcett, Preston, & Co.’s mill, 77,
78

Felspar, 16, 17

Fermentation, effect on molasses,
124; causes of, 127; secondary,
132

Ferments, cause of inversion, 99

Ferrous sulphate, use as manure,
73, 74

Fertility of soil, necessary condi-
tions for, 27

Filter-press, its use and product,
92-97

Filter process, economy of, 131

Fish, how preserved, 127, 128

Fletcher & Le Blanc’s four-roller
mill, 76

Florida, phosphate beds of, 69

Forest soil, 24

See Pen Ma-

Fossil manures, 69

Fruit, how preserved, 127, 128

Fungus, destruction of, by burning
trash, 53

GEMMATION, reproduction of
yeast-plants by, 128

Gilbert, Dr., table of value of ma-
nure, 63, 64

Glucose, amount in cane-juice, 85 ;
formation of, and formula, 98;
production of, 100; amount in
molasses, 122; effect on cane su-
gar, 123 ; non-combining proper-
ties of, 125; action of yeast-
plant on, 130; conversion of cane
sugar into, during alcoholic fer-
mentation, 150

Glucose ratio, the, 102, 103

Graining, 105-108

Gravel, 17

Green dressings, nitrogenous char-
acter of, 25, 26; use of, 41, 65,
66

Griffiths, Dr., quoted, 58, 59

Guano, its composition and use,
70

Gypsum, mixed with nitrate of
soda, 72

Hatt, E. R., experiment by, 44

Harrison, Prof., estimate of matter
removed from soil by cane crop,
49, 50; analysis of pen manure,
64

Hay, value of manure produced
from consumption of, 64

Heart, 18, 52

Heat, influence on soil, 18; cause
of inversion, 99

High wines, 154

Holeing, 40, 41, 64

Horse-hoes, use of, 39

INDEX.

Humus, 17 et seg.; produced by
certain manures, 26, 41, 62; value
of Leguminose in formation of,
30

Hydraulic attachment to cane-mill,
78-80

Hydraulics, principles of, 78-80

Hydrochloric acid, use of, in anal-
ysis of soil, 22, 24

Hydrogen, 2, 3, 5, 6, 12, 26

Hydrometer, its construction, prin-
ciples, and use, 117-121

INVERSION, a result of under-tem-
pering, 89; cause of production
of molasses, 99, 101 ; rapidity of,
100; rate of, in making musco-
vado sugar, 102; amount in
vacuum-pan process, 103; cause
of rapid, 104; danger of, in
bleaching, 114; formation of glu-
cose by, 123 ; how prevented, 130

Invertase, 130

Invert sugar, formation of, 98

Iron, 2, 17, 21, 23, 25; deficiency
of, 53; removal of phosphorus
from, 70

KAINIT, its source and value, 67
Keeping cattle to make manure, 60

Lactic acid, formation of, 129

Lawes, Sir J. B., table of value of
manure, 63, 64

Leaf of sugar-cane, 10-14

Leaves, value as manure, 68

Lees pond, the, 95

Leeward Islands, average expres-
sion of cane-mills in, 81

145

Liebig, Baron von, treatment of
bones, 68, 69

Light, influence on plauts, 13; in-
fluence on soil, 18

Light-colored sugar, manufacture
of, 89, 90

Lime, essential to fertility of soil,
17, 21, 25; quantity removed from
soil by a crop, 22; amount in
soil, 23, 24; retainer of phos-
phoric acid, 30; deficiency of, 33;
as manure, 47; amount in mould
from watercourse, 54; amount
in pen manure, 64; employed to
remove phosphorus from iron,
70; use in clarifying cane-juice,
86; use in decolorisation, 114,
115; combination of cane sugar
with, 125

Lime-water, use of, 45

Line and marks, use of, 45

Linseed cake, value of manure pro-
duced from its consumption by
cattle, 65

Litmus-paper, testing with, 87

‘* Louisiana Planter, The,” quoted,
82 ;

Low wines, 134

MACHINE weeding, beneficial ef-
fects of, 42

Magnesia, essential to fertility of
soil, 17, 21; quantity removed
from soil by a crop, 22; amount
in soil, 23, 24; deficiency of, 33 ;
amount of, in mould from water-
course, 54; amount in pen man-
ure, 64; presence in kainit, 67;
amount in filter-press cake, 93

Magnesium, 2

Leguminose, peculiarities of for- | Manganese, 2, 21

mation, 28; value for green
dressings, 29, 65; consumption
of nitrogen by, 25, 28, 29

10

Mangel wurzel, value of manure
produced from its consumption
by cattle, 64

146

Manure, experiments on nitrogen
in, 28, 59; rotting, 60; influence
of food of animals on, 63 ; use of
concentrated chemical, 63; table
of values, 63, 64; filter-press cake
as, 96, 97

Manures, summary of those used
in West Indies by sugar- growers,
56-74 ; chemical, 66-74

Manuring, 21, 24, 25, 41, 47, 50

Marble, power of plant roots over,

22; origin, composition, and prop- |

erties, 16, 17; as manure, 47

Marling, an improvement to some
soils, 51

Masse cuite, 105, 107, 108, 112

Matter, indestructibility of, 1 et
seq.

Meadow hay, of
plant-food by, value of ma-
nure produced from its con-
sumption by cattle, 64

Meat, how preserved, 127, 128

Megass, 75, 77, 80, 81

Microbes, action of, 26, 29

Microscope, use of the, 4

Milk, nitrogen consumed in form-
ing, 57-59; how preserved, 127,
128

Mineral acids, use in tempering, 99

Mineral matter, amount in cane-
juice, 85; amount in molasses,
122

Mineral phosphates, 69

Mirlees’ four-roller mill, 77

Moisture, necessary to fertility of

consumption
99.

wy

soil, 27, 33, 35, 36; necessary in|
soil for sugar-cane, 33 ; amount |

in pen manure, 64; amount in
filter-press cake, 95

Molasses, reduced production of,
under phenol-phthalein process,

89; production due to inversion, |
99; drainage of, 101, 102 ; centri-

INDEX.

fugal process for removing, 111,
112; reboiling, 112, 118; its pro-
duction, proportions, and use,
~ 122, 126; production of rum
from, 1381
Mole-crickets, destruction of, by
burning trash, 53
Mono-phosphate of lime, 69
Mono-saccharate of lime, 114
| Monte-jus, its use, 92
Montserrat, analysis of volcanic
soil at, 25
| Mould from watercourses, 54, 55
Multiple-effect evaporation, 108,
111
_Muntz’s chemical researches, 26
_Muntz-Girard experiments on ni-
trogen, 58, 59
Muriate of potash, presence in
carnallite, 68
Muscle, constituents of, 57
Muscovado process, 86, 90, 99, 102;
method of estimating amount of
sugar from cane-juice, 120, 121;
influence of glucose in, 123
Muscovado sugar, character of mo-
lasses from, 122

}

NATURAL drainage, 33, 35
Nitrate, conversion of nitrogen

| into, 26; amount in soil, 27, 28,

48

| Nitrate of soda, 28; its composi-

tion, origin, and use as manure,

31, 71, 72

Nitrates, soluble in water, 30;
found in drainage-waters, 31;
formation of, from nitrogenous
matter, 62

Nitric acid, 26

Nitrogen, 2, 3, 5, 27, 31, 48; con-
stituent of the atmosphere, 11,
25, 29; essential to fertility of
soil, 17; amount removed from

INDEX.

soil by a crop, 22; how absorbed
by plants, 26, 28, 29; chemical
changes in, to render availabl-
as manure, 26; deficiency of, 33 ;
quantity removed from soil by
cane crop, 50; amount in mould
from watercourse, 54; presence
in pen manure, 56; material in
animal growth, 57; quantity ob-
tained from and voided by cattle,
57; Muntz-Girard experiments
on, 58, 59; loss in rotting ma-
nure, 61; loss from overheating
manure, 62; amount in pen ma-
nure, 64; supplied by leguminous
crops, 65; supplied by seaweed,
66; constituent of bones, 68;
constituent of guano, 70; pro-
portions in nitrate of soda and
sulphate of ammonia, 72; amount
in filter-press cake, 93, 96

Nitrogenous manures, their compo-
sition and use, 31, 71, 72

Oats, consumption of plant-food
by, 22; value of manure pro-
duced from their consumption
by cattle, 64

Oil-cake, use as food and as ma-
nure, 71

Open-fire evaporation, 100

Open-trench draining, 34

Organic acids, use in tempering, 99

Osmose, 9, 10, 82

Oxen, nitrogen and ash constitu-
ents obtained from and voided
by, 57, 58

Oxide of alumina, 30

Oxide of iron, 21, 23, 30; amount
in mould from watercourse, 54;
amount in pen manure, 64;
amount in filter-press cake, 95

Oxide of manganese, amount in
mould from watercourse, 54

147

Oxygen, 2, 3, 5, 6, 11, 12, 26; nec-
essity of, for some fermenta-
tions, 129, 130

PARASITES, destruction by burning
trash, 53

Pea-plant, its mode of feeding, 28

Peas, value of manure produced
from their consumption by cat-
tle, 63; value as green dressing,
65

Pen manure, its use, constituents,
etc., 25, 26, 41, 56-64, 66

Permanent water-level, 35

Perspiration, quantity of ash con-
stituents voided by cattle in, 58

Phaseolus mungo, value as green
dressing, 65

Phenol-phthalein, use of, 87-90,
113, 180

Phosphate of lime, 16; effect of
plant-roots on, .22; constituent
of bones, 68; where found, 69;
amount in filter-press cake, 93,
94, 96; in decolourisation pro-
cess, 115

Phosphates, 21, 70; insoluble in
water, 30; when to apply, 47;
injured in burning of trash, 53;
material in animal growth, 57;
dressing with, to follow green
crops, 65; importance of keeping
up supply of, 66

Phosphatic manures, their compo-
sition, and use, 68-71

_Phosphorie acid, 17, 21-25; reten-

tion by soil, 50; deficiency of,
30; amount of, in mould from
watercourse, 54; in pen manure,
56, 64; constituent of basic phos-
phate of lime, 70, 71; precipita-
tion in under-tempering, 94; de-
colourisation by, 114, 115; con-
stituent of dunder, 135

148

Phosphoric anhydride, quantity
removed from soil by cane crop,
50

Phosphorus, 2; removal of, from
iron, 70

Pigeon-pea, peculiarities of forma-
tion, 28; value as green dressing,
65

Pigs, nitrogen and ash constituents
obtained from and voided by,
57, 58

Pipe drains, 36-38

Plant-food, 6 et seq. ; proportions
in soil, 21 ef seg. ; consumption
by various crops, 22; amount
soluble in dilute acid, 25; avail-
able and slowly available, 24;
exhaustion of, 25 ; how produced
by microbes, 26; constituents
soluble in water, 30; produced
from trash, 53; in mould from
watercourses, 54

Planting, 40, 42-47, 51, 52

Plants, respiration of, 12; transpi-
ration of, 13; influence of light
on, 13; death of, 15

Plant-tops, 43-45

Ploughing, 18, 39, 40, 52, 53

Polariscope, use of the, 99

Polariscopic test, dependence on
proper draining, 101

Potash, 17, 21-25, 48; insolu-
ble in water, 30; retention by
soil, 30; deficiency of, 33; when
to apply, 47; quantity removed
from soil by cane crop, 50; fused
with silica in burning trash, 53;
not created by burning trash, 53 ;
in mould from watercours:, 54 ;
in pen manure, 56, 64; material
in animal growth, 57; loss of,
in rotting manure, 61; dressing
with, to follow green crops, 65;
importance of keeping up supply

INDEX.

of, 66; its sources and use, 66,
67; sulphate preferable to chlor-
ide, 68; constituent of guano, 70;
amount in filter-press cake, 93;
constituent of dunder, 135; re-
covery of, from beet-sugar, 125;
amount in beet molasses, 126;
amount in cane molasses, 126

Potassium, 2, 3

Potassium nitrate, 26

Potatoes, consumption of plant-
food by, 22

Prairie soil, 24

Precipitated phosphate, 69

Proof spirit, origin of the term,
183, 134

Proof-stick, the, 106

Protoplasm, 6

Putrefaction, causes of, 127

RAIn, influence on soil, 18

Ratoons, 42, 44, 45, 51, 52

Reaping, 51

Rectified spirit, when to make, 132

Rectifying-column, 184, 135

Redistillation, 154

Rocks, classes of, 16

Root, of sugar-cane, 6-10 ; powers
of assimilation of minerals, 21, 22

Root-cap, the, 7, 8

Root-growth, 35, 56

Root-hairs, 7-10, 32

Rootlets, growth of, 47

Root-nodules, 28, 29

Roots, growth of, 8

Root-tips, in clay soils, 32

Roth, Henry Ling, observations
of, 7

Rothamsted, experiments
ducted at, 57, 58

Rule of thumb, displaced by mod-
ern agriculture, vi

Rum, manufacture, 91; flavor and
aroma, 132; strength of com-

con-

INDEX.

mercial, 184; value, 186; how
coloured, 136

SACCHARINE solutions, table of
densities of, 18, 159, 140
Saccharometer, its construction,
principles, and use, 117-121
Sachs, Prof., experiment by, 22
Salt, presence in kainit, 67
Saltpetre, 26

Sand, origin, composition, and
properties, 17; power of retain-
ing food constituents, 30;

amount in filter-press cake, 95
Sap, concentration of, 14
Schlosing’s chemical researches,

26
Science, connection with agricul-

ture, v, vi, 1
Scum, formation of, 90, 91
Scum-cake, its manufacture and

use, 92-97
Seaweed, use as manure, 66
Sedimentary soil, analysis of, 23
Selection of plant-tops, 43-45, 47
Setting up the wash, 91
Sheep, nitrogen and ash constitu-

ents obtained from and voided

by, 57, 58
Shier, Dr. John, test for clarifying,

86, 87
Silica, 17, 21-23, 30; fused with

potash in burning trash, 53;

amount in mould from water-

course, 54; amount in filter-

press cake, 93
Silicate of alumina, 16, 30
Silicon, 2
Silting of drains, 38
Skegel’s mill, 77
Soda, 21, 22;

press cake, 93
Sodium, 2
Sodium nitrate, 26

amount in filter-

149

Soil, origin, composition, and prop-
erties, 15 e¢ seg. ; necessary con-
ditions for fertility, 17, 18, 27;
porosity of, 19-21; plant-food in,
21 et seg. ; analysis of, 22 ef seg. ;
weight of, 23; presence of mi-
crobes in, 26; defects in, 27;
importance of air to, 27; sterili-
zation of, 29; power of retaining
food constituents, 30; nitrifying
organism of, 51; condition of,
32; proper conditions of, 32;
drainage of, 33-59; cold or wet,
34; waterlogging, 35, 42 ; experi-
ments on, 48; matter extracted
from, by cane crop, 49, 50; re-
turn of matter to the, 50; a use-
ful agent in fixing ammonia, 63 ;
improvement of stiff clay, 66;
non-retentive of nitrates, 72

Sombrero, phosphate beds of, 69

Soup, how preserved, 127, 128

Specific gravity, 117

Sports, 45

Stand-overs, 42

Starch, 6, 12-14; production of,
by plants, 12

Starch-cells of leguminose, 28, 29

Steam, temperature of, under vari-
ous pressures, 157

Steam pans, 100; character of mo-
lasses from, 122

Stem, functions of, 14

Stills, 183-136

Stomata, 11

Striking the pan, 100, 102

Strontia, combination
sugar with, 125

Subsiding, 114, 115

Subsoil draining, 54-39

Sugar, proportion of carbon in, 12;
amount in filter-press cake, 94;
chemistry of, 98 ; conversion into
alcohol, 129

of cane-

150

‘* Sugar,” quoted, 84, 86-88
Sugar-cane, its structure, 4 et seq. ;

method of propagating, 6; root |

of, 6-10; necessities of, 33 ; cul-
tivation, harvesting, etc., of, 40-
55

‘*Sugar-Cane, The,” quoted, 82

Sugar industry, necessity for lit-
erature of, v, vi

Sulphate of alumina, use with beet
molasses, 12, 126

Sulphate of ammonia, its composi-
tion, origin, and use as manure,
31, 48, 49, 71, 72

Sulphate of iron, use as manure,
73, 74

Sulphate of lime, 31

Sulphate of potash, 47; presence in
kainit, 67

Sulphur, 2, 5, 22

Sulphuric acid, 17, 21, 23, 49; treat-
ment of bones with, 68; forma-
tion of, 115; use in distillation,
181

Sulphurous acid, use in syrup, 90,
113, 114

Sunlight, influence on soil, 18

Superphosphate, compared with
filter-press cake, 96

Superphosphate of lime, 47, 48, 69 ;
an acid manure, 70

Surface draining, 34

Sutherland, J., experiment by, 44

TEMPERATURE, effect ou fertility
of soil, 27

Tempering, 86-90, 99; care neces-
sary to keep down molasses, 123

Termites, destruction of, by burn-
ing trash, 53

‘*Text-Book of Botany,’’ 22

Thermometer, guide for ‘‘ strik-
ing” the pan, 100; part of vacu-
um-pan apparatus, 106

INDEX.

Thomas phosphate, 70

Thompson & Black’s
rollers, 77

Tile draining, beneficial effects of,
42

Tile drains, 37-39

Tillage, importance of, 16, 19, 21,
27; results of careful, 50

Tramways, objections to use of, on
sugar estates, 60

Transpiration of plants, 13, 14

Trash, removal and use of, 51-54

Trash-turner, 76

Tri-calcium phosphate, 69, 70

Triple-crushing, 81, 84

Triple-effect evaporation, 108-110

Tropical climate, conducive to fer-
tility, 27 ; increases nitrification,
31; use of manure in, 61

Turnips, consumption of plant-
food by, 22; value of manure
produced from their consumption
by cattle, 64

auxiliary

UNDER-TEMPERING, results of, 89,
94
Urine, value as manure, 68

VACUUM gauges, 106

Vacuum pan, use of the, 103-109;
character of molasses from, 122;
influence of glucose on process,
128

Vegetable life, 6 et seg. ; depend-
ence on animal life, 12

Vegetable tissue, composition of,
4 et seg. ; the decomposition of, 5

Vinegar, free accessof air neces-
sary to manufacture of, 130

Virgin soil, 25

Viscous ferment, 129

Voelcker’s analysis of pen manure,
64

Volcanic soil, analysis of, 23

INDEX.

WARINGTON’S chemical researches,
26; ‘‘Chemistry of the Farm”
quoted, 30; chemical analyses
of, 57, 58

Warmth, influence on soil, 18

Wash, 151-135

Wash-tank, 134, 135

Waste products, utilized in distil-
lation, 132

Water, composition of, 3; influ-
ence on root-growth, 18, 19;
constituents soluble in water,
30; amount in cane-juice, 85;
boiling-point under various press-
ures, 104; coal consumed in
evaporation of, 110; amount in
molasses, 122

Watercourses, mould from, 54, 55

Wax, amount in cane-juice, $5

Weather, influence on soil, 15 ef
seg., 18, 52

151

Weeding, beneficial effects of, 45,
50, 51

Weeding-machines, 39, 51

West Indies, economy of purchas-
ing manures for, 67; conditions
necessary to success of sugar in-
dustry in, 111

Wheat, consumption of plant-food
by, 22; value of manure pro-
duced from its consumption by
cattle, 64

Wood ashes,
68

Woolly pyrol, value as green dress-

* ing, 65

value aS manure,

YEAST-PLANT, growth of, 128, 129;
development arrested by alcohol,
131; necessity of plant-—food
for, 136

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ELECTRICAL ENGINEERING FOR ELECTRIC LIGHT
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By W. SLINGO, Principal of the Telegraphists’ School of Science, and A.
BROOKER, Instructor on Electrical Engineering at the Telegraphists’

School of Science. With 307 Illustrations. Crown 8vo. 640 pages,
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Contents.—I. Current — Potential — Conductors —Insulators. II. Practical
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TELEPHONE LINES AND THEIR PROPERTIES.

By Prof. W. J. Hopxins, of the Drexel Institute, Philadelphia. With
numerous Illustrations. 1I2mo. [March, 1893.

The intention of the author has been to provide a book which should prove
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ELECTRICITY AND MAGNETISM.

By FLEEMING JENKIN, F.R.SS.L. and E., M.LC.E., late Professor of En-
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(TEXT-BoOKS OF SCIENCE.) I2mo. 415 pages. $1.25.

Contents.—Electric Quantity, Potential, Current, Resistance, Electro-Static
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ELEMENTARY PHYSICS.

By MARK R. WRIGHT, author of ‘‘Sound, Light, and Heat.” With 238
Illustrations, I2mo, 256 pages. 80 cents.

This work will serve as a suitable text-book for any class beginning the
study of physics. The leading facts are brought under the notice of the stu-
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appendix. The author believes that in early lessons it is inadvisable to trouble
the student either with theories or with the generalizations that prove such a
valuable aid to the advanced student.

BOWDOIN COLLEGE,

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PRACTICAL PHYSICS.

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SOUND, LIGHT, AND HEAT.

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HEAT.
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By Mark R, WricHt. With numerous Illustrations and Diagrams. Crown
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PHYSICAL OPTICS.

By R. T. GLAZEBROOK, M.A., F.R.S., Fellow and Lecturer of Trinity
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Contents.— Wave Motion, The Rectilinear Propagation of Waves, Reflection
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THEORY OF HEAT.

By J. CLERK MAXWELL, M.A., etc., etc. Tenth Edition, with Corrections
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LESSONS IN ELEMENTARY SCIENCE.

LONGMANS’ OBJECT LESSONS. Hints on Pre-
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plete Courses of Lessons on Elementary Science.

By Davip SALMON, Principal of the Training College, Swansea ; Revised
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PART I.—HINTS ON PREPARING AND GIVING LESSONS.

Should Science be Taught?—When should Science Teaching Begin ?—
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PART II.—NOTES OF LESSONS.

First Year.—(a) Lessons on Common Properties. (4) Lessons on Common
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(c) Lessons on Plants.

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THE ELEMENTS OF MECHANISM.
By T. M. GooDEvE, M.A, With 342 Woodcuts. New Edition, Revised
and Enlarged. Crown 8vo. 350 pages. $2.00.

Contents.—Introductory : On the Conversion of Circular into Reciprocating
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PRINCIPLES OF MECHANICS.

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ELEMENTS OF MACHINE DESIGN.

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EXERCISES IN WOOD WORKING for Handicraft Classes in Ele-
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THE STEPPING-STONE TO ARCHITECTURE: Explaining
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A HANDBOOK OF CRYPTOGAMIC BOTANY.

By A, W. BENNETT, M.A., B.Sc., F.L.S., Lecturer on Botany at St.
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ELEMENTARY TEXT-BOOK OF BOTANY. For
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ELEMENTARY BOTANY, THEORETICAL AND
PRACTICAL.

By HENRY Epmonps, B.Sc. London. New and Revised Edition. . With
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PRACTICAL ELEMENTARY BIOLOGY.

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A TEXT-BOOK OF ELEMENTARY BIOLOGY.

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ELEMENTARY PHYSIOGRAPHY. An Introduc-
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