vJ^ hF>R 1 1^ G H

Ptr '^f^ " -■ isJ, . jfT' 15'' dM^-fi

i^/fM ig. -^ '^ •^'^'■^

'■M'^;mi^^'<^'^^ ^^

iaiii

THE

MANUFACTURE OF CHEMICAL MANURES

THE MANUFACTURE OF

CHEMICAL MANURES

BY

J. FRITSCH

TRANSLATED FROM THE FRENCH, WITH NUMEROUS NOTES, BY

DONALD GRANT

WITH SIXTY-NINE ILLUSTRATIONS AND ONE HUNDRED

AND EIGHT TABLES

1 , <> '.

LONDON
SCOTT, GREENWOOD & SON

"THE OIL AND COLOUR TRADES JOURNAL" OFFICES
8 BROADWAY, LUDGATE, E.G.
1911

[The sole right of tratislation into English rests '.mth Scott, Greemvood &-■ Son]

sk^^

r

AGRIC>
LIBRARY

AUTHOR'S PREFACE.

Notwithstanding the magnitude which the manufacture of
Chemical Manures has assumed m France, no author has
hitherto attempted to make it the subject of a special treatise
in the French language. The author has endeavoured to
fill this gap in spite of the difficulties inherent to the subject.
From a technical point of view% French hterature supphes
but little material for such a purpose. French chemists and
works managers rarely write. They are tied down by pro-
fessional secrecy, and when they do risk writing their prose is
comphcated by an embarrassed reticence which deprives it of
all practical interest. Foreign publications, German especially,
are better equipped in this respect. In addition to numerous
special treatises, annual reports on the progress of different
industries are available, edited most often by retired practical
. men or bv old works managers, knowing everything, calhng
things by" their names, discussing the value of the new pro-
cesses recommended or apphed, pointing out their merits and

defects. • u i. u

The numerous and valuable data which the author has
thus collected have largely recompensed him for the ill-will
which he encountered elsewhere. Certain constructors, it is
true that they are not precisely at the head of mechanical
progress, made a wry face. Others omitted to reply to our
letters. This explains why French engineering firms are but
little represented in this treatise. This explanation is due to
the reader : it is for him to draw^ the moral.

The author, however, hastens to add that he met with
the best reception from specialists eminent by their know^-
ledge and long experience, and obtained from them the most
complete information. He here returns them his smcere
thanks, as well as to the scientists who have aided him by
their counsel and encouragement.

The author makes no pretension of presenting a pertect
treatise, yet he is confident that it will be useful to every one
in any way connected with chemical manures.

Paris, March, 1909.

256601

TRANSLATOK'S PREFACE.

From a long experience as works uiana.s^er and chemist in
the sulphuric acid and chemical manure trade, the translator
has been able to add from his own knowled^/e acquired in
actual practice numerous original practical notes to the
Enghsh edition of M. Fritsch"s work, solely with the object
of increasing the utihty of the treatise. It is to be hoped
that the book which, independent of these notes, has unique
merits of its own, will appeal in its Enghsh dress not only to
manure manufacturers but to farmers themselves, as well as
to agricultural students and all those who take an intelligent
interest in the subject of agricultural chemistry. Common
sense dictates that it is equally important for the student of
agriculture to be able if need be to eti'ect the synthesis of a
manure as to be able to carry out the analysis thereof. The
student who can construct mentally a formula for a manure
to yield, whether by dry mixing or wet mixing, certain pre-
determined results on analysis, is more highly trained than he
who can only use the faculties of destruction to resolve a
manure into its constituent elements by slavishly following
a treatise on agricultural chemical analysis, and that too often
by methods which he would have to unlearn if he entered a
manure factory, where he wrfiild have to analyse manures
and raw materials against chemists of world-wide reputation.

DONALD GRANT.

May, V.ni.

VI

CONTENTS.

CHAPTEE I.
PHOSPHORIC ACID.

PAGES

Historv— Origin and distribution of phosphoric acid m nature— Properties
of phosphorus-1. Physical properties-2. Chemical properties-
Hvpophosphorous acid— Phosphorous acid— Phosphoric acid^Meta-
phosphoric acid-Pvrophosphoric acid-Orthophosphoric acid-
Monometallic orthophosphate-Dimetallic orthophosphate— In-
metallic orthophosphate-Phosphate of lime-Monocalcic phosphate
or acid phosphate of lime CaH,{PO,),-Dicalcic phosphate or
monacid phosphate of lime-Tricalcic phosphate-Neutral phosphate
of lime-Tribasic phosphate of lime Ca,(PO,),-Phosphates of
ammonium and sodium— Basic phosphate of ammonium (MHJr.^ ^4
—Monacid phosphate of sodium (ordinary commercial phosphate ot
soda Na.HPO, + 12H..O) — Monacid phosphate of ammonium and
sodium— Monacid phosphate of ammonium -Monacid phosphate ot
mac^nesium— Double phosphate of ammonium and magnesium
NH^MgPO, + 6H2O— Phosphates of iron— The phospTaates of alumina i-id

CHAPTEE II.

PRINCIPAL PHOSPHATE DEPOSITS.

I France :-Pas de Calais, Somme, Oise-1. Somme phosphate-2. Pas
de Calais phosphates-3. Meuse and Ardennes phosphates--4. Cote
d'Or phosphates-5. Cher phosphate— 6. Quercy phosphates (Lot and
neighbouring departments)-?. Gard and Ardeche phosphates-8.
,Dr6me and Isere phosphates-9. Pyrenees or Arieges phosphates li.
Belgium -.—Ciply phosphates— Liege phosphates. ^/I^- -^^§^^^,7,
Lyme Regis coprolites-Cambridge coprolites-Suffolk coprolites.
IV. Sweden and Norway :— Norwegian apatite. V. Germany, vi.
Austria-Hungary :— Bohemian phosphates. VII. Russia. viii.
Spain -.-Estremadura apatite. IX. North America -.-Canada-
South Carolina-Land phosphate and river pliosphate— 1 loricla—
Hard rock-Plate rock o? sheet rock-Soft phosphate-River pebbles
—Land pebbles— Tennessee— Tennessee rock phosphate— Remarks
on the actual condition of the phosphate industry m America. A.
Africa :-Tunis and Algeria-Marly phosphates m i^odules-Phos-
phatic limestones. XL Asia :-Phosphates of Oceania. (I-West
India Islands :-Redonda Isles, Sombrero, Navassa, Aruba, Cura(^ao,
Los Roques, Alta Vela, Rata. (H.) Islands of the Pacific Ocean .-
Baker, Jarvis, Maiden, Fanning, Starbuck Howland, Phoenix^
Sidney ,Enderbury, Minerva, Aves, Lacepede, Flmt Browse (? Brown ,
Fluon, Chesterfield, Abrolhos, Mona, Cayman Chpperton Nauru
Angaur, Makatea, etc. (I.) West India Islands:-!. Redonda

vii

viii CONTENTS.

PAGES

j)liosphate — 2. Sombrero phosphate — 3. Navassa phosphate — 4.
Aruba phosphate — 5. Alta Vela phosphate — 6. Rata or Fernando
Noronjo phosphate — 7. Monk's Island (Caribbean Sea) phospho
guano — 8. Christmas Island phospho guano. (II.) Pacific Ocean
Isles: — Baker Island guano — Jarvis guano — Fanning Island guano
— Brown Island guano — Mejillones guano — Lacepede Island guano —
Clipperton Island guano — Angaur Island phosphate — Makatea Isle
phosphatic deposits — Distribution of phosphates in the different
geological formations. (I.) Gneiss Epoch. (II.) Paleozoic (or primary)
epoch — 1. Silurian formation — 2. Devonian formation — 3. Carbon-
iferous formation. (HI.) Mesozoic or secondary epoch — 1. Trias for-
mation— 2. .Jurassic formation — 3. Cretaceous — Cainozoic or Ter-
tiary epoch — Eocene formation — Quaternary and recent epoch - 14-49

Geographical distribution of phosphate of lime and guano deposits and

their chemical composition — Table ------- 50-59

CHAPTEE III.

DRYING AND ENRICHMENT OF PHOSPHATES.

Drying — Calcining the nodules — Two tests — Different methods of
strengthening and utilizing poor quality phosphates : — 1. Dumonceau
and Nicolas — 2. Simpson — 3. Brochon — 4. Winsinger — 5. O. lahne
— 6. Martin — 7. Thonnar and Huxton — 8. Schucht — 9. Carr — 10.
Glaser — 11. Petermann — 12. Hodgkins — Manufacture of precipitated
phosphate by electrolysis - . _ . 60-66

CHAPTEE IV.

HISTORICAL REVIEW OF SUPERPHOSPHATE MANUFACTURE.

The manufacture of superphosphates from 1850 to 1870—1871 to 1880—

1880 to 1894—1895 to 1908 - 67-72

CHAPTEE V. -

THEORY OF MANUFACTURE OF SOLUBLE PHOSPHATES.

Effect of the impurities in phosphates on their behaviour in the process
by which they are rendered soluble— Carbonates of lime and magnesia
— Iodine — Calcium fluoride — Organic matter — Method of determin-
ing the amount of acid to use in order to render the phosphate
soluble 73-83

CHAPTEE VI.

MANUFACTURE OF SUPERPHOSPHATE.

1. The grinding of the raw phosphate — 2. Dissolving the ground phos-
phate in sulphuric acid — 3. Drying the superphosphate — 1. Grind-

CONTENTS. ix

PAGES.

ing the raw phosphate — Crushers— Edge runners— Flatstoue mills —
Ball mill — Pfeiffer's mill, with combined air separator—Jaw-breaker
mills— Crac-king mills— Toothed roller mills— Disintegrators— Mills
with percussion blades fitted in circular revolving boss — Elevators
—Sieves— Filter press— Mixing of the phosphate with sulphuric acid
— Evacuation of the toxic fumes ------ 81-110

CHAPTER VII.

CRUSHING, SIFTING, DRYING, AND STORING OF SUPER-
PHOSPHATE. RETROGRADATION.

Emptying and shifting the superphosphate house or den — New methods-
for the mechanical extraction of superphosphate from the " den " —
AUegri's plant for shifting superphosphate from the "dens ' — Break-
ing up and sifting or screening of superphosphate — Carr's disin-
tegra:or— Cvlindrical crusher fitted with teeth — Cylindrical crusher,,
with two rolls fitted with teeth— Artificial drying of superphosphate
—Theoretical review of drying— Moller and Pfeiffer's drying machine
— Heymann and Nitsch's process for drying superphosphates — Dr.
Lorenz' process- Dr. Lutjens' successor — Superheated superphos-
phates— Drying superphosphates in the cold — Drying of the super-
phosphate by dusting and mixing in the Georges crusher-sifter —
Storing (preservation) of superphosphate — Retrogradation (reaction)
of phosphoric acid — Forestalling retrogradation by Schucht's
method - - - - HM-i^i

CHAPTER VIII.

COMPOUND MANURES.

Superphosphate of ammonia — Ammoniated superphosphate — Super-
phosphate of ammonia and potash— Nitrophosphate— Tables for the ^
calculation of " superphosphate of ammonia "'- Dry mixings - 142-150

CHAPTER IX.

THE MANUFACTURE OF PHOSPHORIC ACID, DOUBLE SUPER-
PHOSPHATES AND VARIOUS PRODUCTS.

Historical review — Manufacture of phosphoric acid — Manufacture of
double supeiphosphate— Manufacture ot superphosphate of potas-
sium and ammonium — Manufacture of sulpho-phosphates — Bisul-
phate SHperphosphate — Phosphatic peat ----- 151-1 6&

APPENDIX.

THK MANUFACrrRE OF PHOSPHORUS IN THE ELECTRIC FURNACE.

Wing's process— Readman's patent— Harding's process— Gibb's furnace
—Irvine's furnace— Duncan's patent— Parker's patent— Landis'
method - 167-17^

X CONTENTS.

CHAPTER X.

PA.OBS

MANUFACTURE OF BONE DUST AND OF BONE SUPER-
PHOSPHATE (VITRIOLIZED BONES).

Fertilizing value of bone — Storing, classifying, sorting and crushing bones
— Storing — Classification of bones — 1. Kitchen bones — 2. Horse
bones or knackers' bones — 3. Buried bones — 4. Bullocks' heads
(sheep's heads)— 5. Scraps and waste — 6. Hornpiths — Boue picking
— Bone crushing — 1. Slow-speed crusher — 2. Very quick-speed
machine — Extraction of fat from bones — 1. Extraction of fat from
bones by water — 2. Fat extraction from bones by steam — 3. Extrac-
tion of fat from bones by benzine — Purification of bone fat — Bleach-
ing of brown bone fat — Manufacture of bone dust — Classification of
bone dust — 1. Normal bone dusts or bone dust No. 0 — 2. Bone dusts
(without any other designation) — 3. Degelatinized boue dusts — 4.
Mixed manure dusts — Meat dust (meat meal) — Adulteration —
Manufacturing of bone superphosphates — Vitriolized bones —
Vitriolated bones — Mixture of bone superphosphate (dissolved bones)
and nitrogenous matter — Blood — Horn — Leather waste — Animal
Charcoal — Bone ash — Manufacture of precipitated phosphate of
lime ------------ 178-196

CHAPTER XI.

MANUFACTURE OF BASIC SLAG.

Origin of basic slag — The nature of basic slag — Tetraphosphate of calcium
^Solubility of basic slag — Crushing of basic slag — Remarks on the
use of basic slag — Graphic illustrations of the manufacture of basic
slag — Basic slag contracts — Sampling analysis - - - - 197-217

CHAPTER XII.
NITROGENOUS MANURES.

Nitrate of soda — Nitric acid — Chili nitrate of soda — The caliche terra
salitrosa — 1. Open cast-iron pans — Paradas — 2. Cylindrical vertical
pans — Maquinas — 3. Vessels heated by a closed tubular bundle
(■? steam coil) — Storing and handling of nitrate — ProduC^ion of
nitrate in 1907 — Ammoniacal salts — Manufacture of sulpbate of
ammonia by distillation of gas liquor — Production of ammonia in
the manufacture of coke — Recovery of auunouia from blast furnaces —
Recovery of ammonia formed in gas producers — Siemens', Schilling's,
Powson's, Wilson's and Mond's — Mond's process — 2. Bourgeois and
Lencauchez's process — Manufacturing plant — Condensers — Stan-
dard washer — Distilling plant - Naked tire stills— The English still
— Mallet's still — Lunge's still — Feldmaun's still— Gruneberg and
Blum's still — Manufacture of sulphate of ammonia from urine —
Utilization of peat in the manufacture of ammoniacal salt —
Recuperation of the ammonia — Gaillot and Brisset process — Muntz
and Girard's process — Manufacture of sulphate of ammonia from peat
by the Mond process — Crude ammonia from spent oxide - - 218-254

CONTENTS. xi

CHAPTER XIII,

PAGES

MANUFACTURE OF MANURE FROISI ANIMAL WASTE.

Preliminary remarks— Blood — Dried blood — Donard and Boulet's drying
machine — Meat meal — Drying blood by lime — Commercial meat
meal — Horn — Leather waste — Comparative value of different nitro-
genous manures 255-267

CHAPTER XIV.

RECOVERY OF NITROGEN FROM DISTILLERY SPENT WASH.
MANUFACTURE OF CYANAMIDE AND OF NITRATE OF LIME.

Utilization of distillery spent wash — General remarks — Recovery of
nitrogen b}' Vasseux's process — Treatment of the spent wash by
biological agents — Effront's methods — Treating spent wash by
fermentation — The manufacture of cj'anamide and of nitrate of
lime — Agricultural experiments with cyanamide — Rules for the use
of cyanamide — Drawbacks in the use of nitrate of lime - - 268-277

CHAPTER XY.
NITROGENIZED PHOSPHATIC MANURES.

Peruvian guano — Its composition — Dissolved Peruvian guano — Other
nitrogenized guanos — Bat guano — Hungarian bat guano — Eboli bat
guano — Egyptian bat guano — Fish guano: historical review — The
early manufacture of fish guano in Newfoundland and in Great
Britain — Manufacture of fish guano in Norway — The fish guano
industry in Britain - . . - 278-294

CHAPTER XVI.
POTASSIC MANURES.

:Stassfurt salts— Crude potash salts — 1. Carnallite — 2. Sylvine or sylvinite
— 3. Kainit — 4. Schoenite — 5. Polyhalite — 6. Krugite — Dissolving
the crude salts — Clarification — Crystallization — Clarifying — Treat-
ment, of the mother liquor from the potassium chloride — Drying tlie
chloride of potassium — Potassium sulphate — Double carbonate of
potassium and magnesium — Double sulphate of potassium and
magnesium — Other fertilizing salts — Commercial brands of potas-
sium chloride (muriate of potash) — Manufacture of potash from
felspar and other potassic minerals — Manufacture of potash from
sunflower stalks in the Caucasus 295-315

xii CONTENTS.

CHAPTEE XVII.

PAGES

TRANSFERENCE AND HANDLING OF RAW MATERIALS AND

FINISHED PRODUCTS.

Electric transhipment of phosphate and superphosphate in a manure
factory — General arrangement of electrical conveying machinery in
Pommersdorf chemical factory— General arrangement of electrical
conveying machinery in Emmerich chemical manure factory —
Electrical transhipment plant, St. Gobain's chemical factory,
Boucau— Electrical transhipment plane in a German factorv— Cable
transhipment system of Algerian phosphate factory - - "" - 316-332

INDEX 333.339,

LIST OF TABLES.

TABLE PAGE

I. Showing percentage of phosphoric acid in various rocks - 2

II. Analyses of three different cypes of Sonime phosphates - 15

III. Analysis of average sample of a field of Orville phosphate

dried in vacuo at 98° C, density at 16° C. 3-1307. (H.
Lasne) ---]6

IV. Beauval phosphate deposit. Analysis made by Nantier

at the date of discovery ...... it^

V. Analyses of Pas de Calais phosphates - - - - - 18

VI. Analysis of Meuse phosphates ----_. 19

VII. Analyses of various phosphates in the Meuse, Ardennes,

etc., districts. (Delattre) ------ 19

VIII. Analysis of Ardennes nodules. (Maret and Delattre) - 20

gB£;\ IX. Analyses of Auxois phosphates. (Delattre) - - - - 21

X. Analysis of Quercy phosphates 22

XI. Analyses of Ciply phosphates --..__ 24

XII. Analyses of Liege phosphates --.--. 24

XIII. Analyses of Lyme Regis coprolites. (Thompson Herapath) 25

XIV. Analysis of Cambridge coprolites ----- 26
XV. Analysis of Suffolk coprolites ------ 25

XVI. Analyses of fossil bones from Sutton bone bed - - - 26

XVII. Analyses of Suffolk, etc., coprolites ----- 26

XVIII. Analysis of Norwegian apatit (crystals) - - - - 27

XIX. Analysis of Bohemian phosphates ----- 27

XX. Analysis of Russian phosphorite nodules - . - . 28

XXI. Analysis of Central Russia phosphorite - - - - 28

XXIa. Analyses of samples of Estremadura phosphates - - 29

XXII. Average composition of Carolina phosphate - - - 31

* XXIII. Analysis of a fine sample of hard rock phosphate - - 32

XXIV. Analyses of hard rock phosphate from Blue River Co. - 33

.\XV. Analysis of land pebble phosphate ----- 35

XXVI. Analysis of Tennessee rock phosphate - - . - 35

XXVII. Complete analysis of au Algerian phosphate - - - 38

XXVIII. Analyses of two samples of Djebel Gournia phosphate in

the natural condition - - - - — - - 38

XXIX. Analyses of Redonda phosphate 39

XX A. Analysis of Sombrero phosphate. (Voelcker) - - - 40

XXXa. Analyses of Nevassa phosphate - - - - - - 40

xiii

XIV

LIST OF TABLES.

- 50-9

83

TABLE PAGET

XXXI. Analysis of Alta Vela phosphate ----- 41

XXXII. Analysis of Monk's Island phosphate - - - - 41

XKXIII. Analysis of Baker Island guano 43

XXXIV. Analysis of Jarvis Island guano ------ 44

XXXV. Analyses of Fanning I^iland guano ----- 44

XXXVI. Analyses of Brown Island guano ----- 44

XXXVII. Analyses of Lacepede Island guano 45

XXXVIII. and XXXIX. Analyses of Mejillones guano - - - 46-7

XL. Analysis of Clipperton Island guano 47

XLa. Geographical distribution of phosphate of lime and guano
deposits and their chemical composition

XLI. Amount and strength of acid required to dissolve various
phosphates ---------

XLII. Results of experiments with ordinary superphosphate and
superphosphate dried at different temperatures on
Ligouro oats ---------

XLIII. Showing changes in composition which Tennessee super-
phosphates undergo in four and a half months from
date of making --..---.

XLIV. Showing for a succession of years the increase in hay from
one application of basic slag to a poor meadow

XLV. Number of cwt. required in a 5 ton mixing, or of tons in a
100 ton mixing of a superphosphate ot a given strength
in P«0.:, to produce a manure of a given strength
in P^g - - -

XLVI. Showing in cwt. the amount of sulphate of ammonia of
different strengths that must be contained in a 5 ton
heap to get a manure containing from 1'850 up to 5
per cent nitrogen .---.-

XLVII. Showing the analysis of double superphosphate -

XLVIII. Chemical composition of ossein . - - - -

XLIX. Analysis of an ox bone. (Berzelius) - - - -

XLIXa. Rosinate analysis of bones as supplied to manure factories

L. Analysis of bone dust from fat extracted bones -

LI. Analyses of new and used and spent bone char. (Pierre)

LII. Showing the composition of five samples bone ash. (Voelcker) 193

LIIL. Analysis of precipitated phosphate of lime - - - - 194

LIV. Analysis of cast-iron showing phosphorus content - - 200

LV. Analyses of crystals of tetrabasic phosphate of lime found

in basic slag --------- ^04

LVI. Analyses of hexagonal crystals found in basic slag - - 204

LVII. Analyses of black needles, magnetic and non-magnetic,
found in basic slag -------

LVIII. Analyses of blue crystals found in basic slag . - -

LIX. Solubility of basic slag in water saturated with carbonic
acid - - . ..---.-

LX. Showing the results of Jensch's researches on basic slag

LXI. Effect of composition of basic slag on facility of grinding -

LXII. Showing the influence of the ratio of the peroxide of iron

to protoxide on the ease of grinding of basic slag - - 213

129

1.37

141

146

149-50
156
173
174
174
185
192

206
206

209
210

213

LIST OF TABLES. xv

TABLE PAf^

LXIII. Analysis of blue and bi'own crystals in basic slag - - 216-

LXIV. Showing composition of caliche ------ 220

LXV. Analysis of Ciiilian nitrate of soda 221

LXVI. Analysis of better quality nitrate of soda . - - - 221

LXVII. Analyses of a double nitrate of potash and soda - - - 222

LXVIII. Analyses of gas liquor from coals of different origin - - 226

LXIX. Analysis of British gas liquor ------ 226-

LXX. Analysis of spent Lamming's mixture from gas works - 251
LXXI. Percentage of different nitrogen compounds present in a

series of samples of spent oxide from gas works - - 252.
LXXII. Table for conversion of nitrogen per cent into ammonia

per cent and vice versa ------- 254

LXXIII. Analyses of bullocks, calves, sheep, and pigs' blood - - 256-

LXXIV. Composition of meat meal - 262

LXXV. Showing agricultural value of nitrogenous manures (nitrate

100) - ^6T

LXXVI. Showing comparative agricultural money value of nitro-
genous manure in francs per kilogram - - - 267

LXXVII. Showing value and amount of manure from spent wash

from 1 ton molasses .-_-.-- 270

LXXVIII. Analyses of cyanamide 27S

LXXIX. Analyses of Peruvian guano 280-

LXXX, Analyses of Peruvian guano _.---_ 280

LXXXI. Analyses of Peruvian guano 281

LXXXII. Analyses of Peruvian guano ------ 281

LXXXIII. Analyses of guano from middle bed of Peruvian guano

deposits ---------- 283'

LXXXIV. Analysis* of Peruvian guano nodules (lower bed) - - - 283.

LXXXV. Analyses of different cargoes of Peruvian guano - - - 284

LXXXVI. Analysis of bat guano :287

LXXXVII. Analysis of Hungarian bat guano 28T

LXXXVIII. Analysis of Egyptian bat guano 288

LXXXIX. Analysis of Eboli bat guano 288.

XC. Analysis of Brittany lisli guano ------ 291.

XCI. Analyses of Norwegian fish ^uano . . - . - 293.

XCII. Showing the composition of nitrogenous manures - - 294

XCIII. Potash content of various plants 295-

XCIV. Analysis of first borehole sample of Stassfurt potash salts - 297

XCV. Analysis of carnallite 298

XCYI. Analysis of sylvinite (pure) 298

XCVII. Analysis of sylvine as it comes from the mine - - - 299

XCVIII. Showing analysis of kainit. (Reichardt) - - - - 299

XCIX. Analysis of polyhalite 30O

C. Analysis of krugite. (Mercker) 301

CI. Analysis of crystals from potash salt crystallizers - - 303

CII. Analysis of mother liquor from clarification of potash salts 304

CIII. Analysis of mother liquor from potassium chloride - - 305-

svi LIST OF TABLES.

TABLE • PAGE

CIV. Analysis of schoenite. (Mercker) 307

CV. Analysis of sludge from clarification of potash salts - - 308

CVI. GomiDositiou of Stassfurt potash salts ----- 309

CVII. Chlorine content of crude potash salts ... - 311

•CVIII. Effect of soluble mineral salts on grain crops - . - 313

CHAPTER I.
PHOSPHORIC ACID.

History. — The discovery of phosphorus is due to the alchemists.
In 1669, Brandt, a Hamburg merchant, searching for the philo-
sopher's stone in human urine, discovered an interesting substance
which he called yhosphorus, i.e. a body luminous in the dark. All
the phosphori known up to then — and there was quite a series of
them — to become luminous had to be previously exposed to sun-
light, and yet their luminosity soon vanished, whilst the new body
emitted a glow of its own accord, and preserved that property
permanently. It was, therefore, termed pJiosj^horus. Brandt kept
his process secret. But, in his turn, Kunkel, a Beilin chemist,
soon discovered phosphorus. In 1688, Albinus extracted phos-
phorus from mustard seed and cress seed. Thus within a few years
phosphorus was found in both the animal and vegetable kingdoms
without, however, anyone dreaming of its connexion with inorganic
nature. According to the cosmic theories of the times this sub-
stance was held to be the product of other bodies, or even the
result of spontaneous generation under the influence of ill -defined
vital forces. The scientists of the time had not yet distinguished
the chemical elements, the very simple theory of which was destined
in the future to furnish the very basis of the science of these bodies.
It is interesting, however, to observe that free phosphorus was
prepared and examined for seventy years without its compound
with oxygen, phosphoric acid, from which it had been isolated and
to which it so easily reverts, being known. Phosphoric acid was
not discovered till 1743, by Margraff, who ascertained its exact
nature and succeeded in re-converting it into phosphorus by calcining
it with charcoal. In 1769, Gahn, a Swedish chemist, found this
acid in bones, and a few years later Scheele, his countryman,
published a process by which phosphorus could be extracted from
bones, which is still used in its main features.^ Ten years after the
discovery of phosphoric acid in bones, and more than 100 years
after the first preparation of phosphorus, Gahn found this body
in the mineral kingdom also, viz. in lead phosphate (pyromorphite) ;
Vauquelin and Klaproth soon afterwards found, phosphoric acid in
apatite, that beautiful mineral, met with in large masses, the com-

1 Scheele was by birth a Prussian. See Scheele's " Chemical Essays," Scott,
Greenwood and Son.

1

CHEMICAL MANURES.

position of which is analogous with the earthy parts of bone. Such
are, briefiy summarized, the chief historical facts regarding the
discovery of phosphorus and phosphoric acid in the three kingdoms
of nature. Since then chemists have continued their investigations ;
they have searched for this substance everywhere, and they have
found it more and more as analytical methods have been improved.
Its presence in urine and in bones led to its presence in all the
fluids and organs of man and animals being suspected, and very
soon it was found to be so. It was found in all plants and in all
their organs. It was thenceforth recognized that the phosphorus
contained in the body of animals was of vegetable origin. But
from whence do plants derive this substance ? The answer to that
question was sought for a long time. Even up to the middle of
the eighteenth century, when scientists like Saussure (1740-1799)
and others were led by simple logic to look for phosphoric acid in
the soil, agronomists persisted in regarding it as a derivative of
other substances, because very little of it was found in the soil, and
this little might very well be brought on to the land by farmyard
■dung. However, improved analytical methods were bound gradu-
a,lly to elicit the truth.

Origin and Distribution of PhospJioric Acid in Nature. — If it
be interesting for the farmer and the chemist to follow the migrations
of an air-bell, and the curious phenomena under the influence of
which the molecule of nitrogen becomes successively ammonia or
nitric acid, then vegetable organism, then finally muscular fibre, it
is none the less instructive to follow the migrations of the molecule
of phosphorus. Let us endeavour to grasp these migrations, and
to trace them, starting from the point of origin of phosphoric acid,
i.e. the presence of this body in the primitive and crystalline rocks.
The analysis of the primitive rocks, and of the metalliferous veins
which they contain, proves that phosphoric acid is almost always
one of their constituent elements. ^ Associated with lime, the

1 The two men of science who studied the question most profoundly were
Forchammer of Copenhagen and Stockhardt of Germany. The latter found
phosphoric acid in several rocks in which it was believed to be absent. The
I)ercentages of phosphoric found in different rocks are as follows : —

TABLE L— PERCENTAGE OF PHOSPHORIC ACID IN VARIOUS

ROCKS.

Rock.

Per cent.

Rock.

Per cent.

Feldspar (Rochsbourg

) . 1-70

Melaphyre (Plauen)

0-38

Gneiss (Gerlusdorf)

0-7S

Syenit (Plauen) .

0-18

Granulet (Penig)

0-()8

Gneiss (Tharandt)

0-2-5

Grauit (Hellsdorf)

0-.58

Felsite (Tharandt)

0-21

(Burgstaldt)

0-08

Limestone (Schweindorf)

O-ol

Basalt (Tharandt)

MO

1

PHOSPHOEIC ACID. 3

oxides of iron, manganese, lead and copper, this body constantly
reveals its presence to the expert chemist who makes a special search
for it. Its proportions are most often very minute, but that
matters little, as plants have a marvellous faculty of freeing from
the soil the principles necessary to their development. And let
us remark with Bobierre, "how everything hangs on a chain, to
explain to us the distribution of phosphoric acid in our crops. Let
us go back, in imagination, to the origin of things, to those great
natural phenomena, all the traditions in regard to which are in ac-
cordance with what geology reveals to us of these gigantic phases.
The igneous rocks contain phosphoric acid. The disintegration of
these rocks under the combined influence of Vv^ater, air, temperature,
and carbonic acid, soon favours the physical divisions of the rock
masses. Vegetation develops, vivacious, luxuriant, immense, ac-
cumulating at the same time both carbon from the atmosphere —
which it is to return as coal to far-off generations — and phosphates
which its organs, immersed in a virgin soil, assimilate to abandon
one day in a fine state of division on the surface of the soil. And
as an energetic, active, incessant medium of this providential dis-
tribution, the animal world supervened with its powerful capacity
of condensation of principles, rich in phosphorus and in nitrogen.
Thus it is that vegetation supplies phosphates clothed in a new dress
for the alimentary needs of new individuals. The molecule of phos-
phoric acid is no longer the inert crystalline portion of the igneous
rock, it is no longer the mineral framew^ork of the plant, it is the
osseous substance of the animal, it is both its skeleton and its flesh,
its nervous fibre, and its entire being. Our ideas of the organism
and of phosphorus are inseparable the one from the other." The
beds of the different geological periods all contain fossils, more or less
rich in phosphoric acid. The Cambrian yields Licjulides and Dis-
cenides, forerunners of the Brachmpods, whose calcareous shells were
comparatively rich in phosphoric acid. At a later period vertebrae
appear ; first, the Silurian fish, then the saurians of the Carbonifer-
ous and Permian, and finally, the birds (Jurassic) and mammals
(Trias), the skeletons of which form the principal elements of the
accumulation of phosphoric acid. Thus the soil of all formations
may contain phosphates, but they are not found in large quantity
except in certain formations and under peculiarly favourable circum-
stances, which we vaguely perceive, but of which it is impossible
to give a really satisfactory explanation. The solution of phosphoric
acid by rain water, charged with carbonic acid, traversing the
superficial layer of soil covered with vegetation and thus rich in
humus, its entrainment into the subsoil, and its accumulation
in the subjacent rock, the chemical affinity of which favours its
combii.ation — such seems to be the genesis of phosphate deposits.
I leeting hme, oxides of iron, and alumina the phosphoric acid solu-

4 CHEMICAL MANUEES.

tions form phosphates of Hme, kon, and alumina. On the phosphate
beds so formed new layers of phosphates were deposited as soon as-
the carbonic acid acting as the phosphoric acid solvent had set free
sedimentary phosphates. When the solution percolated into
hollows it formed pockets. The carbonated water could even con-
vert already formed phosphate into a special form, for example
that of vitreous statfelite. Nodules w^ere formed when the rock to
which the phosphoric acid was combined was deficient in consistency,
or had lost it, for example owing to the upheaval of the deposit,
the different portions of which were washed and removed by water,
thus rounding the fragments. Nodules may a^ain be formed by
the fixation of phosphoric acid round a centre, for example around
grains of sand swimming in the solution on the impulse of a crystal!
growing in an appropriate solution, or organisms or even bells of
gas rising in the solution drawing to it particles of the same nature
as itself. Finally, another hypothesis of the formation of nodules
is that where precipitated phosphate of lime had been gradually re-
united into compact nuclei by water through the intervention of"
pebbles of silex. Apatite was the first phosphate formed by the
crystallization of the incandescent rocky magma. Its crystaUine
form is hexagonal. As it cooled slowly, the mass of liquid apatite
formed crystals of different sizes, from capillary needles, scarcely
visible, up to 12 in. in length. Their interior always assumes a.
lamellar structure. Apatite is found massive, w^ith this crystalline
structure, or even compact and massive when it is embedded in
basalts. But compact massive apatite always comes from crystalline
apatite. Pseudo-apatite is disintegrated apatite. All these forms of
phosphate, from the crystalline form to the amorphous, from isolated
nodules to rock phosphate, go back to an identical origin. Sum-
ming up, phosphorus existed in the beginning of things in the
primitive rocks. It has become more assimilable in virtue of its-
distribution in sedimentary and transported soils; vegetables have
absorbed it, then they have given it up to the animals, which have
condensed and accumulated it in numerous points of the globe. Let
us note, with Buckland, that it is astonishing that the human race
should, for so many centuries, have remained ignorant of the fact that
a considerable portion of the surface of the globe was formed by the
debris of the animals w^hich inhabited the ancient seas. There
exists, according to the same author, vast plains and enormous
mountains which are merely, so to speak, the charnel houses of
preceding generations, in which the petrified debris of extinct
animals and vegetables are piled up to form marvellous monuments.
These monuments attest the work of life and death during incalcul-
able periods. Cuvier, appreciating these curious natural phenomena,
declared that the sight of such a spectacle as that of the debris of
life forming almost all the soil on which our feet tread was so-

PHOSPHORIC ACID. 5

terrible as to render it difficult for him to retain his imagination on
the causes which have produced such great effects. These etfects,
so terrifying to the genius of Cuvier, are really only the result of
one and the same cause — an efficient cause, which is confirmed under
the most diverse conditions, and in all latitudes, with a wonderful
unity of design. Only the Sovereign Master of Life and Death
could accomplish such wonders. Let us now try to find the
amount of phosphoric acid in different media — phosphoric acid in
the soil, in plants and animals. About the time when British agro-
nomists 1 were exploring the deposits of phosphate of lime of Estra-
madura, it was discovered, in Surrey, that the use of ground bones,
and other bodies rich in phosphoric acid, produced no beneficial re-
sult when applied to soils, fertile enough in themselves, the subsoil
of which belonged to certain deposits of the lower and upper Green-
sand. This led to the supposition that phosphate of lime, which is
one of the fertilizing constituents of ground bones, is naturally pre-
sent in these soils in sufficient proportion. Mr. J. C. Nesbit, an
expert chemist, immediately collected the soils and rocks of these
districts so as to ascertain the cause of their fertility. Amongst
others, he received from Farnham samples of a fertile marl, situated
on the property of Mr. J. M. Paine. A rapid examination showed
the presence, in this marl, of an unusual amount of phosphoric acid,
and in November, 1847, he informed Mr. Paine of this discovery.^
From this marl 28 per cent of phosphoric acid, corresponding to
60-67 of phosphate of lime, was extracted. The general mass of
the marl contained 2 to 3 per cent of phosphoric acid, equal to 4-33
to 6-5 per cent of phosphate. It will be seen that in presence of
such a proportion of phosphoric acid the application of phosphatic
manures was quite superfluous. In the Tchermo Sem, so fertile in
Russia, where from time immemorial the highest yields of wheat
have been obtained w.thout any manure, 0*6 per cent of phosphoric
acid is present, whilst mediocre soils only contain 0*1 ; fertile soils,
0-2 to 0-5 ; very fertile soils, 0-8 and upwards. Regarded by them-
selves these figures are very small, but applied to a given surface,
are considerable. A hectare of arable land, say 2 '5 acres, with a
depth of 0-2 metre, say 10 in., w^eighs 5000 tons, say 2000 tons per
acre, and if such soil contains 0*6 per cent of phosphoric acid that

^ This very evidently refers to Dr. Daubeny, who inspected and reported on
these deposits (Estramadura) in 1843. His report is given in the " Journal of
the Royal Agricultural Society of England,'^ Vol- V, Part II.— Tr.

2But Mr. Paine himself, in conjunction with Professor Way, the then chemist
of the Royal Agricultural Society of England, in 1848 published the results of
their then combined elaborate researches on the phosphoric strata of the chalk
formation in a paper in the " Journal of the Royal Agricultural Society of Eng-
land," Vol. IX, Part I, pp. 56-84. The reader is referred to this memoir : suffice
it to mention here that the marl contains nodules much richer in phosphate of
lime than the marl in which they are diffused. — Tp.

6 CHEMICAL MAXUEES.

makes 30 tons of that acid per hectare or 12 tons per acre. The
ditfiision of phosphoric acid in arable land responds, moreover, to a
providential law, that element being as indispensable to plant life
as to animal life. In the absence of phosphoric acid, none of our
cultivated plants can pass through all the phases of vegetation ; the
seed may germinate, produce leaves, stem, branches, but these
organs remain attenuated, lingering, till the plant dies prematurely
without bearino; flowers or fruit. Co ren winder made researches to
follow up phosphorus in plants. Analyses of roots, stem, and fruit
proved that phosphorus exists in nascent organs w^here it contri-
butes to organization. It diminishes proportionally in the root ;
thus the root of beet-root does not contain phosphorus after the
maturity of the seed. It is to be found in the seed. Corenwinder
found that in the pollen of flowers there is a considerable amount
of organic phosphorus recovered as phosphoric acid in the ash
of these minute organisms. In this respect pollen is analogous
with the seminal fluid. Saussure and, later, Garreau, Professor
of Botany at Lille, pointed out that the leaves of a tree give, on
estivation, ashes more rich in phosphorus than at any other epoch
of vegetation. If now we gradually ascend to the examination of
animals, we find that their bones, their muscles, their nervous and
cerebral substance, the fluids of their organism, blood, milk,
urine, seminal fluid, are always and everywhere permeated with
phosphorus. Intimately associated with organic substances, phos-
phorus abounds in the cerebral mass and the nervous system. One
may almost say that it is organized. Combined with oxygen and
lime it forms one of the important elements of the skeleton. Dis-
solved by the animal fluids, it is unceasingly carried from one point
to the other of the individual, and if its total amount remains fixed,
for a given animal, its molecule nevertheless displaced by solvent
or vital actions is excreted, then replaced by a new molecule,
brought by the digestive system. To remove phosphoric acid and
lime from the diet and try to nourish an animal on purely nitrogen-
ous principles is to attempt its life. The animal in this respect
behaves like the plant (Bobierre). Thousands of analyses made
of recent years by Thezard show that, amongst invalids, the elimina-
tion of phosphoric acid through the urine follows a progress parallel
with that of the disease. The further the latter progresses the
more does the phosphate content of the urine increase ; in these
conditions vrhen the loss resulting from the elimination cannot be
repaired by a diet appropriate to the needs of the individual, which
has led to phosphoric acid being regarded as the vital element j^o^f
excellence, the human organism perishes with frightful rapidity.
According to Elie de Beaumont, a human skeleton weighs, on
an average, 4*6 kg., say 10 lb., and assuming that human bones
contain 53 -04 per cent of phosphate of lime, a skeleton ought to con-

PHOSPHORIC ACID. 7

tain 2-440 kg., say 5^ lb. But a human body weighs, on an aver-
age, 75 kg., say 165 lb. ; deducting the weight of the skeleton there
remains 70 kg., say 154 lb. of soft parts, which on incineration yield,
like ox-beef, 1*5 per cent of ash entirely composed of phosphate of
soda, potash or lime, and alkaline chlorides. The amount of phos-
phoric acid which they contain may be taken as equal to an amount
of phosphate of lime equal to 80 per cent of the weight of the ash,
or to 1-5 per cent of the weight of the soft parts multiplied by 0-8,
say 840 grm. These 840 grm. added to the 2-440 kg. contained in
bones, give a total of 3-28 kg. of phosphate of lime, say 1-439 kg. of
phosphoric acid or 639 grm. of pure phosphorus. These figures show
the importance of the role which phosphoric acid plays in the support
of the globe. They ought to teach us also to use, with wise fore-
sight, the stores of phosphoric acid with which bygone ages have
endowed us, because, whatever may be the importance of the deposits
now knowm and exploited, and even of those w^hich may be discovered
in the future, they are far from being inexhaustible ; besides the danger
of dispersion of phosphoric acid by default of restitution to the soil
actuahy exists, more threatening for a future less distant than that
of the dispersion of nitrogen and potash.

Properties of Phosphorus — (1) Physical Properties. — Phosphorus
obtained by Scheele's method, i.e. by the distillation of phosphate
of hme and charcoal, is a colourless yellow translucent body. It is
found in commerce mainly as sticks. At the ordinary temperature
it is soft like w^ax, brittle in the cold. It has the odour of garlic.
Its density varies bet^veen 1-82 and 1-84. It is insoluble in water
and in alcohol, very soluble in essential oils, ether, benzol, carbon
disulphide, sulphur chloride, and phosphorus chloride.^ Phosphorus
melts at a temperature of 44 -z" C. and forms a colourless, oily liquid ;
if melted phosphorus be rapidly cooled it is converted into a black
mass w^ith a metallic appearance ; if, on the contrary, the molten
mass be still further heated — up to a temperature of 250-260° C. —
it is converted into a red modification w^hich, at 280° C, reverts to the
ordinary form. Phosphorus is highly poisonous. The absorption
of a few centigrammes suffices to produce the death of a man by

^ The solution of phosphorus in carbon disulphide was used by the Irish
Fenians to burn the farms of their countrymen who were refractory to the Land
L i'rigue. This solution evaporates spontaneously and leaves phosphorus in a state
of extreme division. The phosphorus then inflames spontaneously. If wooden
objects be coated with a solution of Fenian fire nothing can prevent a confiagra-
tion. The solution of phosphorus in carbon disulphide, mixed with sulphur
chloride, can be preserved well in close vessels but inflames with violence if a few
drops of ammonia are allowed to fall thereon. This is the Lorraine tire of
Nickles of 1869. Care must be taken to work in the open air on small quan-
tities and to pour the ammonia by aid of a long tube. The new Lorraine tire of
P. Guyot, 1871, is a solution of phosphorus in carbon disulphide to which sulphur
bromide has been added. It inflames in 1 or 2 minutes after ammonia has
been added.

8 CHEMICAL MANURES.

the excitation of the nervous centres which it produces. Its anti-
dote is spirits of turpentine. The vapours of phosphorus frequently
respired induce necrosis of the bones, chiefly those of the face. The
ordinarv phosphorus industry and the manufacture of matches are
amongst the most unhealthy of unsanitary trades. Chemical Pro-
perties.— (2j Ordinary phosphorus oxidizes slowly in the air, and this
oxidation is accompanied by a phosphorescent glow, from which
phosphorus takes its name. Its suffices, moreover, to cut it with a
knife to inflame it, by the heat produced by the friction ; that is
whv it should be cut under water. Chemically combined oxygen
exercises on phosphorus the same oxidizing action as free oxygen.
Water, which is a very stable compound of oxygen and hydrogen,
is destroyed, though slowly, by this body with formation of phos-
phoric acid and phosphoretted hydrogen. The transformation is
more rapid when the water is rendered alkaline by caustic potash,
soda, or lime. Nitric acid oxidizes phosphorus very energetically,
converting it mostly into phosphoric acid. Owing to its great
affinity for oxygen, phosphorus is not found in nature in the free
state, it is always met with as phosphoric acid combined with
bases.

Oxygenated Compounds of Phosphorus. — Phosphorus forms
with oxvgen and hvdrogen the following anhydrides and acids : —

Anhydrides.

Acids.

H,POo

PgO,

hIpo:

p.o:

H,PO,

Hypophosphorous acid ...
Phosphorous acid ....
Phosphoric acid ....

There are three phosphoric acids known, viz. :- —

Metaphosphoric acid H.,OP.,0, = HPO.,
Pyrophosphorie acid 2HoOP.,6, = H^P-.O;
Orthophosphoric acid .3H..OP.,6- = H-PO^

Hypophosphorous acid is monobasic, that is to say, only one of its
atoms of hydrogen can be replaced by a metallic atom. Phos-
phorous acid is dibasic, and phosphoric acid tribasic. There are,
therefore, three phosphoric acids, which differ in the fact that one,
two, or three atoms of H may be replaced by as many basic atoms.
It is to Graham that we owe the discovery of their characteristic
reactions. Metaphosphoric acid only gives one species of meta-
phosphate. Pyrophosphorie acid gives two species of pyrophos-
phates. Orthophosphoric acid gives three species of salts corre-
sponding to the formulae M._,PO, ; M.,HPO^ ; MH.PO,. These acids
are distinguished the one from the other by the following reaction :
the meta acid gives a white precipitate, with barium chloride and
silver nitrate, and .coagulates a solution of albumen ; the pyro acid
gives no precipitate with barium chloride, gives a white precipitate
with silver nitrate, and does not coagulate albumen ; the ortho acid

PHOSPHORIC ACID. 9

gives no precipitate with barium chloride, gives a yellow precipitate
with silver nitrate, and does not coagulate albumen.

Phosjohoric Acid Anhydride, PqO-, is obtained by the combustion
• of phosphorus in a current of very dry air. It forms imponderable,
highly deliquescent, white flocks. It dissolves in water with the
hissing noise of red-hot iron. Hence its use to dry gases at temper-
atures at which sulphuric acid would be decomposed, and to prepare
by dehydration certain acid anhydrides or certain organic com-
pounds, nitriles for example. Heated to redness with charcoal it
yields carbonic oxide and phosphorus.

Metaphosplioric Acid. HPO3, is monobasic. It is prepared by
hydrating the cold anhydride, by heating orthophosphoric acid to
redness, or by calcining ammonium phosphate at a red heat. It is
a vitreous substance, volatile at a red heat, very soluble in water,
with which it combines to reproduce orthophosphoric acid. It is
used to dry gases. The metaphosphates prepared by calcining
monometallic orthophosphates are only partially reduced by char-
coal.

Pyrophosphoric Acid is dibasic. It is prepared by subjecting
•orthophosphoric acid to prolonged heat at 200° C. Calcined, it gives
metaphosphoric acid ; with water it reproduces orthophosphoric
acid. Pyrophosphates, prepared by calcining bi-metallic orthophos-
phates, or by heating phosphoric acid with an oxide, are reducible
by charcoal.

As far as the manufacture of chemical manures is concerned, the
•only important modification to be borne in mind is the ordinary or
orthophosphoric acid. However, pyrophosphoric acid is sometimes
met with in phosphates that have been roasted to facilitate grinding,
and metaphosphoric acid in superphosphates dried at too high a
temperature.

OrtkophospJioric Acid, HgPO^. — This, the ordinary phosphoric
acid, is tribasic. It is obtained mixed with phosphorus, in
the slow oxidation of phosphorus in moist air. It is prepared in
■the laboratory by oxidizing red phosphorus by the aid of heat with
fifteen times its weight of nitric acid of 20 B. The reaction may be
expressed thus : 3P -f- 0HNO3 + 2Hp = 3H.3PO, + 5N0. The phos-
phorus is only added gradually and in small portions at a time.
Orthophosphoric acid is produced, which remains in the retort, and
a little nitrogen dioxide, which carries over some nitric acid. Care
is therefore taken to redistil " cohobitate," until the whole of the
phosphorus has disappeared; the residue is then evaporated in a
platinum basin to expel all nitric acid and to convert any phos-
phorous acid which may have been formed into phosphoric acid,
taking care not to exceed 188° C, otherwise pyrophosphoric acid
will be obtained. Orthophosphoric acid is also produced by the
■action of hot water on metaphosphoric acid, by igniting hypophos-

10 CHEMICAL MANUEES.

phorous or phosphorous acids, or by the action of water in excess
on pentachloride of phosphorus. In the concentrated state or-
dinary phosphoric acid forms a thick, inodorous, very acid, non-
poisonous syrup, of density 1-88. It crystalhzes with three mole-
cules of water when evaporated under a bell jar over sulphuric
acid. It is very soluble in water, and highly deliquescent. Under
the action of heat, it is converted at about 213° C. into pyrophos-
phoric acid, and towards a red heat into metaphosphoric acid. It
is reduced by red-hot charcoal, yielding phosphorus. It gives no
precipitate with barium chloride, nor with perchloride of iron, nor
with a solution of silver, nor with albumen. But if ammonia be
cautiously added, barium chloride gives a brownish precipitate, and a
solution of silver a yellow one ; both precipitates are soluble in acetic
acid. A characteristic test for phosphoric acid is the production of
the double phosphate of magnesium and ammonium, by " magnesia
mixture," consisting of ammonia, magnesium chloride, and water.
This precipitate is white and crystalline ; it suffices to see it once
not to confuse it with any other precipitate. A reagent which
enables traces of phosphoric acid to be detected, consists of a nitric
acid solution of ammonium molybdate. If the mixture of the two
solutions be heated the liquid assumes a bright yellow coloration.^
Ordinary phosphoric acid is a very stable compound. It displaces
sulphuric and nitric acids from their compounds.

Phosphates of Lime. — It has just been se:;n that phosphoric
acid is tribasic, i.e. it contains three atoms of hydrogen, replaceab'e
by metals.

I OH i OM ( OM C OM

PO { OH PO { OH PO OM PO { OM

I OH I OH I OH I OM

Orthophosphoric Monometallic Dimetallic Trimetallic

Acid Orthophosphate Orthophosphate Orthophosphate

When the hydrogen of phosphoric acid is replaced by calcium, a
divalent element, three types of phosphates are obtained to which
the commercial varieties of phosphatic manures correspond in a
very characteristic fashion.

I ^H (^-^r., r^->ra

PO OH PO [ 0^'^'^ PO { 0^^^

■^\p '^C^^^ ^O-^Cr

0>Ca Q>Ca 0>^''

PO OH PO OH PO - O^p,^

Uh Uh ^ 0>^''

Monocalcic phos- Diealeic phosphate Tricalcic phosphate,

phate or acid or monacid Neutral phosphate of lime,

phosphate of lime, phosphate of Tribasic phosphate of lime,

CaH,(PO,).. lime Ca3(P0,)._j

^ But ammonium molybdate in nitric acid solution gives a yellow coloration
even in the absence of phosphoric acid. Unless there is a decided yellow pre-

PHOSPHOEIC ACID. 11

Monocalcic phosphate or superphosphate is characterized by
its complete sohibihty (a) in water, (6) in ammoniacal citrate of
ammonia (aqueous solution of ammonium citrate with excess of
ammonia), and (c) in strong mineral acids. The sole object of
superphosphate manufacture is to convert the tricalcic phosphates
of bones and mineral phosphates into monocalcic or acid phosphate,
assimilable by plants. Dicalcic phosphate, or precipitated phos-
phate, is insoluble in water, but soluble in ammoniacal citrate of
ammonia, and strong mineral acids. It is obtained in the treating
of bones by hydrochloric acid, in the manufacture of gelatine (glue),
as will be seen in the sequel. Tricalcic phosphate forms the chief
mass of the substance of bones which resists combustion (bone ash)^
of phosphorites, of apatite, and of a great number of guanos. In
the calcined state, or as apatite, it is insoluble in w^ater, slightly
soluble in water saturated with carbonic acid. It is completely
soluble in nitric and hydrochloric acids, which convert it into mono-
calcic phosphate, displacing two-thirds of the lime to form, w^ith it,
calcium nitrate or calcium chloride. Sulphuric acid completely
decomposes it into free phosphoric acid and sulphate of lime
(gypsum). Phosphoric acid is precipitated from acid solutions, by
excess of lime water, as a fine white powder, which is partly soluble
in water, especially when it contains potassium sulphate, common
salt, nitrate of soda, ammoniacal salts, or carbonic acid.

PJiosjjhates of Aimnonium, Sodium, etc. — Let us examine a few
other phosphates of importance in manure manufacture : —

1. Basic Phosphate of Ammonium, (NII^)3P04, is a slightly sol-
uble, very unstable salt, obtained by mixing syrupy phosphoric acid
with excess of ammonia. Its aqueous solution exposed to the air
loses one-third of its ammonia, and is converted into the monacid
phosphate ; heated, it loses a second third, and is then converted
into the acid phosphate.

2. Monacid Phosphate of Sodium {ordinary commercial phos-
phate of soda, Na^HPO^ -f- ISH^O) is contained in urine. It forms
large crystals, which turn dull in the air, through loss of a portion of
their water. Heat converts it into pyrophosphate by expulsion of
water. It is prepared on the large scale by saturating crude phos-
phoric acid with soda to alkaline reaction and crystallizing.

3. Monacid Phosjjhate of Ammonium and Sodium, NaNH^
HPO4 + 4H^0. — This salt is prepared by dissolving ammonium
chloride in a solution of ordinary phosphate of soda. Heat converts
it into sodium metaphosphate, NaPOg, with liberation of ammonia
and water. Putrefying human urine yields a deposit of this salt.
It forms crystals as clear as water, and is found in that state in

cipitate on warming gently, phosphoric acid may be taken as absent. Even a
precipitate is no sign of the presence ot phosphoric acid unless all traces of
arsenic have previously been removed. — Tr.

12 CHEMICAL MANUEES.

guano, under the name of stercorite. Its solution on standing gives
off ammonia.

4. Monacid PJiosjjliate of Ammonmm is, likewise, found in
Peruvian guano. It is formed from the neutral salt through loss of
ammonia. It has an alkaline reaction, like all monacid soluble
phosphates. The acid phosphates of potassium, of sodium and of
ammonium are still more soluble in water than the preceding. Their
solutions turn red litmus paper blue.

5. Magnesium PJiospJiates — (1) Basic PJios2}hate of Magnesium,
Mg3(PO^).2, is found in small quantities in seeds. It is ver}' soluble
in acids ; it is precipitated from its acid solution by ammonia as
phosphate of ammonia and magnesia. (2) Monacid PliosjjJiate of
Magnesium. — This, like the corresponding lime compound, is a very
soluble salt. (8) Double Pliosphate of Anwionium and Magnesiinn,
NH^MgPO^ + 6H.,0, is precipitated from solutions which contain
at one and the same time phosphoric acid, magnesia salts and
ammonia, as a white crystaUine powder slightly soluble in water
and almost insoluble in ammonia water. Ignited, it leaves a
residue of pyrophosphate. This interesting compound was found
in large crystals as clear as water in excavating the soil for the
foundations of the church of St. Nicolas in Hamburg. The name
of struvite was given to it. In this locality there was a cesspool,
from w^hich the matter spread into the peaty soil. As peat contains
a large amount of ammoniacal salts, the phosphate of magnesia
from the urine had formed the double phosphate of ammonia and
magnesia, which remained in solution for a somewhat lengthened
period in the ammoniacal salts in excess. By slow precipitation
crystals were formed, some as large as a hazel nut. This same
salt is met with in different varieties of guanos, but in much
smaller crvstals. Its formation is analogous to that which occurs
in putrefying urine : the phosphate of magnesia is brought by the
urine, the ammonia results from the putrefaction of the nitrogenous
constituents of the guano.

6. Phosphates of Iron. — The basic phosphates of iron are ^\ddely
distributed in nature, but their composition is very variable.
They are formed wherever phosphates dissolved by the moisture
in the soil come in contact with oxide of iron. In arable land,
which as is well known always contains oxide of iron, a portion
of the phosphoric acid is in all probability combined with that
oxide. The phosphate of the protoxide of iron (ferrous phosphate)
is formed in an analogous manner ; it is only reduced to pro-
toxide by decomposing organic matter. This product is found in
large masses in certain peaty districts. A basic artificial phos-
phate is obtained by mixing perchloride of iron with excess of
phosphate o£ soda. It possesses a yellowish colour, w^hich turns
brown on heating. But the compound so obtained is never pure,

PHOSPHORIC ACID. 18

and its composition never corresponds to definite proportions. The
pure basic phosphate is obtained from the preceding by moistening
it with pure syrupy phosphoric acid, and washing it with a great
excess of water. The product so obtained remains white on
ignition. It is soluble in hydrochloric acid, perchloride of iron, and
in acetate of iron, and insoluble in acetic acid. The acid phosphate-
of iron is prepared by dissolving the freshly precipitated, air-dried,
basic phosphate in pure, syrupy phosphoric acid. Properly pre-
pared, and the water abstracted, the solution has an analogous-
composition to other acid phosphates ; it is rose-red, and may be
converted by means of a large excess of water into free phosphoric
acid and basic phosphate. It likewise yields a precipitate on heat-
ing. Tartaric, citric, and other non- volatile organic acids prevent
the formation of the precipitate ; mineral acids only possess this
property but imperfectly.

7. T]ie PJiosjjliates of Alumma behave in a general way like the
phosphates of iron. Wavellite, a crystallized mineral phosphate, is.
a phosphate of alumina. Redonda phosphate, which forms an
important deposit, consists chiefly of a compound of this nature.

The phosphates just described are met with in different phos-
phatic manures, natural or artificial. The majority of them, such
as the alkaline and ammonium phosphates, are only represented in
small proportions it is true ; however, one cannot but acknowledge
their vast importance from the point of view of the mobility of
phosphoric acid in the soil, and in the organism. The only phos-
phates found in preponderating amount in manures are the phos-
phates of lime. The basic phosphates of lime are spread over
numerous points of the globe ; as will be seen further on considerable^
deposits of them exist which are wrought commercially. But these
phosphates are more or less mixed with impurities, that is why they
serve exclusively as raw material for the manufacture of phosphatic
manures, properly so called, which are acid phosphates of lime,
or s2iperphos])hates.

Moreover, various industries supply important quantities of
basic phosphates, obtained as bye-products. They deliver them to-
manure manufacturers, who use them in making superphosphates.,
or they dispatch them direct to the farmers (basic slag).

CHAPTEE 11.
PRINCIPAL PHOSPHATE DEPOSITS.

1. Franx'E. — Pas de Calais, Somme, Olse. — In these departments
the deposits of phosphates are naet with in the Cretaceous formation,
at three distinct levels in this formation. These are in ascending
order. 1. The Gault, to which the Boulogne workings belong. The
nodules found in these beds contain 20 per cent of phosphoric acid.

2. The Glauconian chalk, which forms the phosphate basin of
Pernes and of Fauquemberg, with 25 per cent of phosphoric acid.

3. The Upper Chalk bed, characterized by Belemnites quadratus, the
most important of all. The phosphate deposits of Orville, Beauval,
and Hardivillers are on this horizon. In these workings phosphate
rich in sand is found in pockets, in the upper chalk, below the
clay or surface bief (? boulder clay). These pockets, which are
wrought verv energetically, are only of limited duration, and are in
process of exhaustion. Besides the pockets of rich sand, there
exist in the Belemnites chalk cliffs parts sufficiently rich in phos-
phate of lime to be worth extracting and treating by one of the
enrichment processes to be described further on. This phosphatic
chalk, called also " grey chalk " {craie tuffeau), etc., forms in certain
points masses of considerable dimensions. The percentage does
not exceed 38 to 40 per cent of trihasic phosphate of lime. Below
28 or 30 per cent of trihasic phosphate of lime, the chalks are
mostly considered as of no industrial yalue. At Breteuil near
Clermont, for example, an extremely important bed of this chalk
with 32 per cent of trihasic phosphate is only partially exploited,
the enriched product not exceeding 45 per cent of trihasic phosphate.

1. Somme Phosphate. — The presence of phosphatic chalk in the
Somme was first observed by Buteaux as far back as 1849. On
the other hand, M. de Mercy discovered in 1863 and 1867 two other
similar deposits, the one at Hardiyillers near Breteuil (Oise), the
other at Hallencourt near Abbeville, Somme ; he showed their
analogy with that of Beauval, and classed them like the latter in
the Belemnites quadratus chalk. The Beauval deposits were
discovered in 1886 by two geologists, Merle and Poncin. The
phosphatic sands of that locality, and its environs, are accumulated
on the edges of pockets in the form of reversed cones excavated
in a bed of chalk, filled with small brown-yellow grains of phosphate
of lime situated at the base of the Belemnites quadratus chalk, and

(14)

PRINCIPAL PHOSPHATE DEPOSITS.

15

resting on the Micraster Coranguinum white chalk. This forma-
tion is found therefore about the middle Senonian horizon. The
phosphatiferous chalk is of a bright chamois colour and is known
in the district under the name of grey chalk ; its phosphoric acid
content is from 10 to 15 per cent at the point of contact of the grey
chalk and the white, Micraster, chalk. There is at Orville a dis-
continuous, almost horizontal bed of phosphatic nodules of a
yellowish-white colour. Some are coloured black on the exterior,
•due to a bright coat which would appear to be manganese dioxide ;
they are rarely the size of a small nut and contain 70 to 80 per
cent of tribasic phosphate. They are agglomerated by a gangue of
white carbonate of lime. The phosphatic sands of the Somme con-
tain a rather large quantity of the teeth of dogfish, which appear to
have been preserved by their enamel. Neither fossils nor bones are
found there, though they exist in the Beleinniies chalk. At Orville,
where the phosphatic chalk is separated from the Micraster chalk
by a bed of nodules, no nodules come from this bed except from
the bottom of pockets which descend below the grey chalk. At
Beauval, where the bed of nodules is absent, there is only to be seen
at the apex of the funnels granular hard parts somewhat rich in
phosphoric acid. The amount of rich phosphatic sand in the
deposits of the neighbourhood of Doullens, including that of Orville,
which though situated in the department of the Pas de Calais
ought to be considered as belonging geologically and commercially
to the Somm.e group, has been estimated at about 1,500,000 tons.
But these deposits are on the road to exhaustion. Soon, as Olry
remarks, this region will re-enter the calm of olden times, and of
this era of untold riches, beyond the fortunes acquired by certain
privileged persons, there will only remain the memory aggrandized
by tradition of a time of fever and of gain almost unique in French
industrial annals. Some analyses of the phosphates of these de-
posits are now^ given.

TABLE II.— ANALYSES OF THREE DIFFERENT TYPES OF SOMME

PHOSPHATES.

75-80

70-75

60-65

Per cent

Per cent '

Per cent

Phosphate.

Phosphate.

Phosphate.

Moisture at 100° C

0-o9

1-4-2

2-80

Organic matter and combined water

1-45

—

Phosphoric acid .....

3o-59

34-10

29-10

Lime .......

51-02

50-01

41-23

Oxide of iron .....

0-83

1-30

' 4-07

Oxide of ahmiina ....

0-56

0-23

( * "'

Magnesia and carbonic acid

9-17

CO,, 3-05

Insoluble in acids ....
Equal to tribasic phosphate of lime

0-79

1-60

8-55

77-69

74-44

63-53

16

CHEMICAL MANUEES

TABLE III.— ANALYSIS OF AVERAGE SAMPLE OF A FIELD OF'
ORYILLE PHOSPHATE DRIED IX VACUO AT 98° C. DENSITY AT
16° C. 3-1307. (H. LASNE.)

Per cent.

Sand and clay insoluble in hydrochloric acid

1-36

Organic matter and wp

ter volatile at a red heat

3-40

Soluble silica

. ■ . • ■

0-47

Carbonic acid

3-70

Sulphuric acid (SO..,) .

0-75

Phosphoric acid .

33-86

Liuie .

47-54

Magnesia .

1-20

Alumina

1-70

Oxide of iron (FeoO-,)

1-22

Calcium fluoride .

4-65

99-85

TABLE IV.— BEAUVAL PHOSPHATE DEPOSIT. ANALYSIS MADE BY
NANTIER AT THE DATE OF DISCOVERY.

Phosphoric acid
Lime .
Carbonic acid
Fluorine
Sulphuric acid
Peroxide of iron
Alumina
Magnesia
Sihca .

Organic matter
Water .

Per cent.

30-89

45-33

2-04

1-60

1-84

0-50

0-32

0-16

0-38

2-26

15-99

101-31

Which corresponds before drying to a content of —

Phosphate of lime ....... 67-43

Carbonate of lime . . . . . . . 4-60

Calcium fluoride . . . . . . .3-24

„ sulphate ....... 1-43

Drying raises the phosphate of hme content of this product to>
80 per cent.

2. Pas de Calais Phosphates. — The phosphate bed situated be-
tween the Gault and the Greensand extends over vast tracts. In
the Pas de Calais it forms the prolongation of deposits recognized
in England as of the same stratigraphical horizon in the counties
of Kent, Sussex, and Surrey. There is reason also to assimilate
it with the geological horizon exploited in the Ardennes and in the
Meuse. It was in the Pas de Calais at Wissant that Berthier first
discovered in France the presence of phosphate of lime in nodules.

PRINCIPAL PHOSPHATE DEPOSITS. 17

amongst pyrites being wrought at the base of the Gault clay for
the manufacture of green vitriol. The stony matter mixed with
the pyrites yielded on analysis 57*4 per cent of phosphate of lime.
Later on, Dr. Turner discovered phosphatic nodules in the Gault
at Lottinghem. Finally, the investigations of Meugy, Desailly,
and de Molon in the Ardennes, from 1852 to 1856, having drawn
public attention to the phosphates of the Greensand, these were
not long in being exploited in the Pas de Calais, which has since
become one of the principal centres of production. The nodules or
lumps of this bed to which the name of coquins are still given, are
generally round in form smooth or mamillary. Their size varies
from that of a nut to that of the fist. They are grey or brown on
the surface, with sometimes a bluish, sometimes a greenish cast.
In the interior they are dark brown or black. Some of them are
penetrated by iron pyrites, glauconite, gypsum, or quartz. In the
Pas de Calais they are consolidated by an argillaceous cement con-
taining 25 per cent of glauconitic sand, which makes a sort of con-
glomerate, of which the mass is formed of 35 to 40 per cent of
nodules, and 60 to 65 per cent of argillo-silicious matter ; sometimes
shells, woody fragments, coniferous fruits, dog-fish teeth, fish bones,
crystals of carbonate of lime, are found therein. The bed of nodules
is fairly regular ; its thickness varies from 6 to 8 inches.

Chemical Composition of the Pas de Calais Nodules.— The
chemical composition of the nodules varies, as two analyses by
Delattre show.^ It follows from these analyses that the Gault
nodules consist essentially in the Pas de Calais of phosphate of
lime, carbonate of lime, fluoride of calcium, clay, sand and glauconite,
the whole associated with a certain proportion of organic matter,
about 0-10 per cent of nitrogen (ammoniacal) ; the glauconite brings
also a certain amount of potash. The extent believed to be exploit-
able in the bed situated at the base of the Gault clay is estimated
at 600 hectares, say 1500 acres, in the Boulogne district. At the
base of the Cenomanien formation or Glauconitic chalk, there are
in certain localities in the Pas de Calais workable beds of phosphate
of lime. Also, in the district of Audincthem, Dennebroeucq and
Reclinghem, and in that of Elechin, Febvin-Palfart, Nedonchelle,
Bailleul-les-Pernes, Aumerval and Pernes-en-Artois, at a short dis-
tance from the coal basin. The bed of phosphate has a thickness
of 5 to 10 inches ; the nodules are greenish, rather large and ag-
glomerated by a sandy clay. They are more friable than those of
the Boulogne district, and yield, on washing, about 25 per cent of
by-products. They titrate from 50 to 60 per cent of phosphate of
lime.

1 See Table V, p. 18.
2

18

CHEMICAL MAXUEES.

TABLE v.— ANALYSES OF PAS DE CALAIS PHOSPHATES.

I'Jws-phate.
Nabringhem. Fiennes.

1-40

1-40

5-60

5 30

23-52

•20-72

1-(J6

0H9

4-30

4-20

1-90

1-83

34-77

33-71

0-04

traces

3 -03

3-25

3-19

3 15

20-60

25-20

99-91

99-65

0-80

0-77

9911

98 8S

0-89

1-12

100-00

100-00

51-36

45-23

9-77

9-54

3-90

376

Moismre at 100° C. .

Matter volatile at a dull red heat

Phosphoric acid (1)

Sulphuric acid .

Carbonic acid (2

Fluorine (3)

Lime

Magnesia .

Alumina .

Oxide of iron

Silica

Deduct oxygen equal to the fluorine .

Undetermined and loss .

Total

(1) Equal to tribasie phosphate of lime

(2) Equal to carbonate of lime

(3) Equal to calcium fluoride .

3. Meuse, Ardennes and La 2Iarne Phosphates. — The phosphates
exploited in this district come almost entirely from the base of the
cretaceous (Greensand). This formation forms almost a continuous
zone which extends over 187 miles from the department of Ardennes
as far as Yonne, crossing those of la Meuse, la Marne and the
Haute Marne and Aube. It consists mostly of one, sometimes of
two beds of nodules of phosphate of lime, of a thickness of 6 to 8.
inches, but in certain districts it thins out so much as to be
no longer workable, the phosphate disappearing entirely, or not
existing in sufficient quantity. The existence of Greensand noduies
in les Ardennes was first pointed out in 1842 by Bauvage and
Bauvignier, and their chemical composition was determined in
1852 and 1853 by Meugy. The first extraction works were under-
taken by Desailly in 1856 and are still in existence. But, in a
general way, the works are very unstable, the sheds removing as
soon as the dead ground becomes too powerful, oi- the nodule bed
thins out. The Meuse nodules have much the same appearance
and composition as those of the Boulogne district ; their phosphoric
acid content generally varies from 14 to 20 per cent; it rarely
exceeds the latter limit. Sometimes they are small, sometimes

they reach or exceed the size of an ostrich's e^rg ; thev exhibit ir

oo

regular contours into the spaces between wh'ch a green argillaceous
sand penetrates, which forces them to be broken in bulk so as to
clean them. At other times the phosphate of lime instead of being;

PRINCIPAL PHOSPHATE DEPOSITS.

19

in lumps isolated in the sand assumes the form of a conglomerate
with a sandy cement known under the name of Crassins. These
C:assins are very difficult to clean and yield products poor in
phosphoric acid. " A sample of nodules from the neighhourhood of
Grandpre, analyzed at the Bureau cVEssais cle VEcole cles Mines,
had the following composition : —

TABLE VI,— ANALYSIS OF MEUSE PHOSPHATES.

I'er cut.
Clay and quartz ...... 1-i 0

Alumina and oxide of iron
Lime ....
Phosphoric acid
Carbonic acid

Total .

25 5

32-5

17-5

9 0

98 5

Other and more complete analyses have been published by
Delattre. The following are quoted : —

TABLE YIL ~ ANALYSES OF VARIOUS PHOSPHATES IN THE MEUSE,
ARDENNES, ETC., DISTRICTS. (DELATTRE.)

1

I

Source

of the Phosphates.

Chesnors

•

' Islettis.

DoinViasle.
1-75

Graiulpi-e.
2-20

or
Boncourt.

Moisture at 100° C. . . .

1-90

2-15

Matter volatile at a red heat

5-05

4-80

4-55

3-75

Phosphoric acid

18-74

18-23

19-57

16-69

Sulphuric acid

1-20

0-79

0-85

0-79

Carbonic acid

: 4-80

4-50

5-80

4-70

Fluorine

1-43

1 31

1-66

1-75

, Lime

29-23

27-66

31-81

26-88

Masnesia

0-39

traces

' 0-36

traces

Alumina

2-57

2-30

3-36

2-47

Oxide of iron .

; 5-46

5-83

4-89

3-77

Silica

; 28-74

32-06

24-80

37-16

99-56

1 99-25

99-95

100-11

Deduct oxygen equal to tluorine

0-62

0-55

0-69

0-75

1

98-94

98-70

99-16

99-38

Undetermined and loss .

Totals ....

, 1-06

1-30

0-84

0-62

10000

100-00

100-00

100-00

Equal to phosphate of lime .

; 40-90

39-79

42-73

36-43

Equal to carbonate of lime

; 10-90

10-22

13-18

10-68

j Equal to calcium tiuoiide

3-05

i

2-70

3-40

3-59

1 Is made to total to 99-25 in original French, but only adds to 99*23.

20

chi:mical manures.

TABLE VIII. ANALYSIS

OF AIIDENNES

NODULES.

(MAEET AND

DELATTKE.)

Per cent.

Moisture

■ •••><

2-20

Organic matter .

.^•35

Carbonic acid

4 -BO

Sulpliuric acid

0-7o

Phosphoric acid

18-85

Fluorine

1-37

Lime .

27-52

Magnesia

0-Os

Alumina

2-37

Oxide of iron

5-20

Potash soluble in ni

trie acid

0-99

Silica .

•

32-42

99-20

Deduct oxygen equal to fluorine ....

0-57

98 -(33

Undetermined and loss .....

1-37

100-00

Carbonate of lime

• •■•••

10-45

Phosphate of lime

•

40-08

Calcium fluoride .

2-81

Nitrogen

•

.

0-084

These analyses show that the Meuse and Ardennes nodules are
similar in composition to those of Boulonnais and the neighbourhood
of Pernes-en-Artois, which is quite natural, both being of the same
origin and situated at almost the same geological horizon.

4. Cote d'Or Phospliates. — As far back as 1822, De Bonnard dis-
covered near St. Thibault (Cote d'Or), in a cutting of the Burgundy
Canal, greyish-white nodules which contained, according to an
analysis by Berthier, 74 per cent of phosphate of lime. These
nodules associated with grains of ammonite were impasted in a
m.ass of brown clay, but at that period but little importance was
attached to the discovery, and it was only in 1872 that CoUenot
re-discovered them in excavations made on the plan of the railway
from Cravant to Laumes. He collected samples which Georges
Ville found to contain 60 to 61 per cent of tribasic phosphate. In
1873-1 this formation was examined by Poncin, who immediately
profited thereby. It was thus that towards the end of 1876 the
phosphate works of Auxois came into being. The horizon exploited
belongs to the Lower Lias of Burgundy ; it is situated towards the
summit of the gryphesis arquees (? gryphea incurva) limestone
zone with Ammonites SteUarls. Towards the top this limestone
is rich in soft, almost friable phosphatic nodules, which are enclosed
in the marly mass, the whole forming a mixture, the phosphate
content of which varies from 30 to 45 per cent. The phosphatic

PRINCIPAL PHOSPHATE DEPOSITS.

21

limestone is known in the district as "calf's liver" {toie de veaii).
It is not workable in the natural state owing to its irregular com-
position, but over large stretches the gryphea lim.estone has been
altered and dissolved by the surface water which has left in situ,
as an insoluble residue, an argillo-ferruginous mud in which the
phosphate bed is represented by a layer of nodules cemented by
a gangue of a similar nature. In such conditions the phosphate
nodules may be exploited, for it is easy to separate them from the
substance with which they are mixed, by drying and sorting, followed
by washing. The thickness of the bed varies from 10 to 20 cm.
(4 to 8 inches), but this thickness sometimes reaches 30 and even 10
cm. (12 to 16 inches , whilst elsewhere the bed is lost completely and
ceases to be exploitable. The nodules are irregular in shape and
greyish- white or yellowish; they are soft, almost friable. Their
fracture shows grev spots with some blackish veins. Theii- size
varies from that of a hazel nut to that of the fist. They generally
have rounded edges, exhibiting a more or less angular shape. The
mass contains 20 to 25 per cent of nodules, and 75 to 80 per cent
of mud. The thickness of the mud or clinker which covers the
bed is verv variable, 4 to 3 metres (20 to 120 inches) at the most.
The Auxois nodules "contain 27 to 30 per cent of phosphoric acid,
equal .to 59 to 65 per cent of tribasic phosphate of lime. The
following are the results of three analyses by Delattre : —
TABLE IX.— ANALYSES OF AUXOIS PHOSPHATES. (DELATTEE.)

Water at 100

Matter volatile at

I red heat

Phosphoric acid

.

Sulphuric acid

Carbonic acid

Fluorine

Lime

Magnesia

Alumina

Oxide of iron

SiHca .

Deduct oxv<Ten enr

lal to the t

uo

Undetermined matter and loss

Totals . . . .

Equal to phosphate of lime .
Equal to carbonate of lime .
Equal to calcium tluoride

Per cent

•2-10
•2- 10

27-00

traces

2-»i0

l-7o

85 -84

traces

2-40

7 -So

18-00

IF.
Per cent

1-60
2-50

28-59
0-17
2-50
2-40

B7-92
0-18
2-47
7-24

14-40

III.

Per cent

1-20
2-50

■29-71
0-17
2-20
1-55

38-08

traces

2-63

7-45

14-20

99-20
0-75

99-97
1-01

^ 99-49
0-65

98-47
1-53

98-96
1-04

98-84
1-16

100-00

59-07

5-90

3-59

1 Totals to 99-69.

22

CHEMICAL MANUEES.

According to the French mining statistics of 1887, the approxi-
mate extent of the Cote d'Or phosphate deposits is estimated at 5000
hectares (12,500 acres), containing 1,500,000 tons of that product.

5. Cher Pliosjjliate. — Beyond the districts described, a bed with
nodules 15 cm. to 20 cm., say 6 to 8 inches thick, situated in the
upper Albin, has lately been wrought in the department of Cher.
These nodules, of a yellowish-w^hite colour and sometimes loaded
with silex, are associated with white quartzose sand and gravels in
the proportion of about one- third. They only contain 14 to 16 per
cent of phosphoric acid. They are hard, and hence difficult to
grind, and their freight was heavy owing to the great distance from
a railway station. They were wrought exclusively in the open air,
within the radius of Vailly sur Saldre, then after having been
washed on the spot, they were ground and dispatched. The irregu-
larity of the deposit, the poor phosphoric acid content of the nodules,
their great hardness and the heavy cost of freight, rendered these
workings expensive, and they were abandoned.

6. Quercy Phosj)hates {Lot and Neighbouring Departments).—
Phosphate deposits occur over a wdde area in Quercy. The phos-
phate occurs in concretions in the form of big pockets or vertical
veins in the limestone (causses) belonging to the lower oligocene.
They are only found in the high limestone plateaus which have
been traversed by the fresh waters of the eocene, and almost always
in the immediate neighbourhood of tertiary Hots (outliers) left on
the spot. These outliers never exceed 350 metres (1148 feet) high,
and it would be use'ess to seek for phosphate pockets on Jurassic
plateaus of greater altitude. The pockets are very variable ; some
have a diameter of 35 metres (115 feet), others are crevasses of 3
to 6 metres (10 to 20 feet), foUow^ing a straight line over 90 metres
(say 300 feet). All the known pockets end in a point at the bottom,
and widen near the surface. The irregular nature of these deposits
seems to form an obstacle to their development. Their high phos-
phoric acid content seems to have led to a multiplication of badly
organized works which ceased to be self-supporting when it was
necessary to go lower down. These phosphates are chiefly used in
the manufacture of superphosphates to increase the percentage of
poor phosphates, so as to bring them to the commercial standard
of 15 to 16 per cent of phosphoric acid soluble in ammonium
citrate. Their average composition is as follows : —

TABLE X.— ANALYSIS OF QUERCY PHOSPHATES.

Per cent.
Water and organic matter ..... 5*31

Phosphoric acid
Lime .
Carbonic acid
Sulphuric acid
Fluorine
Magnesia
Oxide of iron
Alumina
Insoluble

35-33

48-72

3-42

008
2-24
2-78
2-12

100-00

PKINCIPAL PHOSPHATE DEPOSITS. 23

7. Garcl and Ardeche Phosj^hates. — The Gard deposits are
chiefly phosphorites, the formation of which has been contemporane-
ous with those of Quercy. They are found in irregular excavations
amongst the compact hmestone of the Urgonian age. The workings
are underground. The chief producing centres are on the lands of
the communes of Tavel and Lirac. There are a 'so deposits of
nodules in Saint-Julien-de-Peyrolas and Salazac, also in the de-
partment of Ardeche at Saut-de-l'Eygue, la Eousette, Beyne, etc.
Production almost nil.

8. Drome and Isere Phosphates. — In Drome they chiefly work
the Greensand nodules at Saint-Paul-Trois-Chateaux in the district
of Montehmar. The content of these nodules does not exceed 55
per cent of tribasic phosphate of lime ; it averages 45 per cent. The
workings are unimportant, are solely in the open air, and consist of
screening the nodules and scrubbing them in water to separate
adhering sand. In Isere there are fossiliferous and phosphatic
beds (Gault) of great regularity, but the rock is sometimes so com-
pact that the nodules cannot be washed and enriched by simple
economic means, such as screening and scrubbing, which are the
only methods that can be applied to material so poor in value.

'9. Pyrenees or Arieges Phosphates. — These phosphates, described
by Dr. Levat in a memoir presented to the Academy of Sciences,
form a vast bed developed in the valleys of Bonnes, Luchon, Salat,
in the neighbourhood of Prades, ascending tow^ards the north in
les Corbieres as far as the environs of Cannes. Pyrenees or x\rieges
phosphates have a brilliant black appearance recalling that of anthra-
cite. The composition of the bed is characterized in its rich parts
by numerous black, brilliant, usually flattened nodules consisting of
almost pure phosphate of lime and testing 65 to 75 per cent of tribasic
phosphate of lime. The gangue encrusting these nodules is itself
phosphatic. Moreover, there has been found in it an important
amount of organic matter containing organic nitrogen in the pro-
portion of 11 lb. per ton. The extent of the bed reaches 8 to 10
metres (26 to 33 feet). The nodules are concentrated sometimes
on the roof, sometimes on the wall of the deposit.

11. Belgium.— About 1874, Cornet discovered at Mesvin and at
Ciply near Mons, below the landenien sands, a bed of 8 to 10 metres
thick of brownish, friable, slightly coherent chalk containing 75 per
cent of brown grains of carbonate and phosphate of lime, the largest
of which are not bigger than a pin's head. This speckled chalk,
known in the district as brown chalk {craie brune), contains 25 to
30 per cent of tribasic phosphate, with a slight enrichment at the
base. It occurs at a higher level than the Beauval chalk. In the
upper part it exhibits pockets, in which there are found masses
of pudding-stone cdAledi poudingue de la Malogne, consisting of brown
coloured nodules containing 50 per cent of phosphate, cemented

24:

CHEMICAL MANUEES.

together by a calcareous paste. These nodules have an analogous
composition with the brown grains. The calcareous tufa of Maest-
richt, itself phosphatic, rests on them. Other pockets, containing
a chestnut-coloured phosphatic sand, like a highly ferruginous sand,
tests 60 per cent of tribasic phosphate. This sand, which coats
the sides of the excavations, is only about 30 cm., say 12 inches
thick. It consists of the same small phosphatic grains that are
met with in the brown chalk. The phosphatic chalk of Mesvin
and Ciply, like that of Somme, is not commercially utilizable, but
its extreme friability, and the facility with which the phosphatic
grains are detachable from their chalky envelope, enable it to be
enriched and to bring its content up to 50 and even 60 per cent of
phosphate. It suffices to pulverize it and to submit it afterwards
to an ascending current of air which removes the chalk dust and
leaves the small heavier phosphatic grains, or to roast it slightly
and to wash it in mechanical preparation plant. Other important
phosphatic deposits occur in the district of Liege, at Eocour,
Yottem, Hesbaye, on the right bank of the Meuse. It likewise
occurs at Liers, Yoroux, Milmort, Ans and Monteguee.

TABLE Xr. ANALYSES OF

CIPLY

PHOSPHATES.

I.

II.

1

III.

IV.

Water

0-65

0-30

1-40

Organic matter .....

3-00

2-50

2-12

1-90

Phosphoric acid

18-68

22-14

24-69

26-29

Sulphuric acid .....

0-01

1-61

Lime .......

49-90

50-72

50-31

51-98

Carbonic acid .....

18-40

15-70

15-06

12-80

Magnesia ......

0-59

0-67

Oxide of iron and alumina

2-28

1-72

1-31

0-86

Insoluble ......

5-20

3-30

1-23

0-74

Undetermined .....
Totals . . . . • .

1-29

3-62

5-28

1-75

100-00 i

100-00

100-00

100-00

Equal to tribasic phosphite of lime

40-72

48-25

53-82

57-39

Equal to carbonate of lime .

41-81

35-64

34-24

29-09

TABLE XII.— ANALYSES OF LIEGE

Water ....
Chemically combined water
Phosphoric acid
Carbonic acid
Soluble silica
Lime

gnesia
Oxide of iron and alumina
Calcium fluoride, calcium sulphate, etc.
Insoluble .....

PHOSPHA

TES.

I.

II.

Per cent.

Per cent

0-93

0-85

2-83

2-53

•27-20

25-08

3-10

3-0(>

0-80

0-75

40-64

38-01

0-79

0-81

2-39

3-30

5-93

4-40

15-34

21-27

PRINCIPAL PHOSPHATE DEPOSITS.

25

III. England. — True coprolites or fossil excrements rich in
phosphate of lime in the form of more or less round lumps, 6 to>
20 cm. (2| to 8 inches) in diameter, are found in England in the
Lias marls, chiefly at Lyme Eegis. The interior is earthy like
hardened clay, but amongst these there can be readily distinguished
the teeth and the bones of the fishes and reptiles which served as
food to the saurians of the epoch such as the ichthyosaurus, the
pleiosaurus and the teleosaurus. Coprolites have been found at
the mouth of the Severn near Bristol.

TABLE XIII.— ANALYSES OF LYME EEGIS COPROLITES.
(THOMPSON HERAPATH.)

Water

Organic matter

Sodium chloride and sulphate

Carbonate of lime .

Carbonate of magnesia

Sulphate of lime .

Phosphate of lime .

Phosphate of magnesia

Phosphate of iron .

Phosphate of alumina

Ferric oxide .

Alumina

Silica, calcium fluoride, and loss

Nitrogen

Density

I.

Per cent.

j 6-182

traces
23-674

1-077
60-769 I

traces '

4-057
traces

1-994
traces

l-o52

100-009 1
0-082
2-700

11.

Per cent,
2-976
2-001

•28-121
0-423
0-026

53-996

6-182
1-276

0-738

100-000-
Undeter mined
2-799

TABLE XIV.— ANALYSIS OF CAMBRIDGE COPROLITES.

Moisture
Organic matter
Silica .

Phosphate of lime
Carbonate of lime

Per cent.
8-00
3-00
9-00
77-70
2-30

100-00

TABLE XV.— ANALYSIS OF SUFFOLK COPROLITES.

Combined water .

Sand oxide of iron

Carbonate of lime

Phosphate of lime

Calcium fluoride sulphates and alkaline chlorides

Per cent.
10-00
21-00
10-00
56-00
3-00

100-00

1 Totals to 99-305.

2 Totals to 95-759.

26

CHEMICAL MANUEES.

As tar back as 1848 antediluvian bones were dug out of the
Suffolk and Norfolk Crag. The upper Norfolk Crag contains
fossil bones of the elephant, rhinoceros, ox, etc. They are found
mixed with sand and gravel at a depth of 70 to 80 cm. (27 to 31
inches). The samples from the bone bed in the neighbourhood of
Sutton (Suffolk) are sometimes spongy and friable, sometimes
fibrous and resistant. The latter readily take a fine polish, and
itheir porosity can only be seen under the microscope. Their
analysis gives the following figures : —

TABLE XVI.— ANALYSES OF FOSSIL BONES FROM SUTTON BONE

BED.

Water extracted at 150° C. to 170° C.
Water and organic matter volatile at

red heat
Carbonate of lime .
Carbonate of magnesia .
Sulphate of lime .
Phosphate of lime combined with a

phosphate of magnesia .
Phosphate of iron .
Phosphate of alumina .
Calcium fluoride
Silica .....

Nitrogen in 100 parts

a

little

I.

II.

Per cent.

Per ceyit.

8-361

2-'.ll2

4-351

3-361

27-400

26-800

0-371

0-286

0-514

traces

49-632

59-966

6-600

4-800

3-400

4-638

3-617

undetermined

0-626

0-098

99-872

99-861

0-1244

undetermined

Three other samples from the same locality intended for super-
phosphate manufacture, yielded 58"61 and 6^ per cent of tribasic
phosphate of lime. Besides these deposits of phosphorites, result-
ing from the burying of bones, phosphorites are also found in the
•county of Suffolk, at Felixtowe, Sutton and Walton ; these deposits
are 20 inches deep. The phosphorites occur there as brilliant
black nodules, exceedingly hard, and were formerly used as pebbles
for road-making. Their composition is as follows : —

TABLE XVII.— ANALYSES OF SUFFOLK, ETC., COPROLITES.

Water and organic matter
Tricalcic phosphate
Carbonate of lime
Silica .
Oxide of iron
Oxide of alumina .
Fluorine

Per cent.

Per ce

4-0

70-9

54

10-28

10

5-79

—

o

4

3

Finally, deposits of pseudo coprolites are found in the Welsh,
Cambrian and Silurian at Mowdry, Pennyganedd, and at Beroin.

PRINCIPAL PHOSPHATE DEPOSITS.

27

But the English superphosphate industry is almost entirely stopped,
< owing to • the competition of other countries that possess more
readily workahle deposits. (See footnote p. 5 and context.)

IV. Sweden a.nd Norway. — Sweden. Apatite with 36 to 41
per cent P.2O5 is found in quartz at Horesjobera.

Norivaif. — In the Kragero schists, near Christiania, likewise
in the granite and gneiss, crystalline apatite is met with rarely in
crystals. Its colour is yellowish-white or greenish-grey or red.
The crystals have the following composition 1 —

TABLE XVIII.— ANALYSIS OF NORWEGIAN APATITE (CRYSTALS).

Fer cent

Water 0-14

Loss on ignition

0-27

Phosphoric acid

89-44

= 8t;-10 Ca.,PoO,.

t» ^ 0

Lime

-50-90

of which 2-28 is free

lime

Magnesia

(f(54

Oxide of iron

0-51

Oxide of alumina

0-86

Carbonic acid

0-15

Sulphuric acid

0-12

Chlorine

2-62

Insoluble

3-62

V. Germany. — Germany possesses almost no deposits of phos-
phate of lime industrially utilizable, and the recent geological exam-
inations that have been made have hardly given any result.

VI. Austria-Hungary. — ^Deposits of poor phosphates exist in
Bohemia, at Kostic and at Teplitz, the composition of w^hich is
as follows : —

TABLE XIX.— ANALYSIS OF BOHEMIAN PHOSPHATES.

Per cent

Phosphoric acid ....

15-15

Lime . . . . . .

32-62

Carbonic acid ....

12-95

Sulphuric acid ....

0-82

Cilcium fluoride ....

3-51

Magnesia .....

1-04

Oxides of iron and alumina .

5-17

Silica .......

2-14

Sand

26-14

Moreover, vast deposits of phosphorite are ^found in Galicia and
Bukovina, which are connected with those of Central Russia, as
^will be seen further on.

VII. Russia. — There are two deposits of phosphorite in Russia
,of considerable extent, one of which, part of Podolia, 500,000
hectares (1,250,000 acres), and of Bessarabia, 70,000 hectares
(175,000 acres), extends into Austria. Its most important centre is
in the basin of the Dneister, between St. Urzica and Nozileu. The

28

CHEMICAL MAXUEES.

phosphorite is found as nodules with a smooth and pohshed surface,,
rarely rugose or exfoliated, sometimes greasy to the touch and
resembling polished cast-iron, 2 to 2^ inches in diameter ; some are
8 inches in diameter. Their composition is as follows : —

TABLE XX.— ANALYSIS OF RUSSIAN PHOSPHOEITE NODULES.

Per cent

Phosphate of lime .....

75 -OU

Carbonate of lime up to

12-23

Calcium fluoride ......

6-98

Sulphate of lime ......

1-6)

Phosphate of magnesia up to

1-80

Oxide of iron and alumina . . . . ,

5-(»(i

Organic matter .......

1-00

The richest and most extensive phosphate deposits are those
of Central Eussia. They occur chiefly in the governments of
Podolsk, Kostromo, >molensk, Koursk, Woronesch, Simbirsk, Tam-
bow, and on the banks of the Volga, from which they trend towards
the West as far as Niemen ; they occupy a surface of 20,000,000
hectares (50,000,000 acres). The richest deposits consist in part of
phosphate of lime, mixed with organic matter. According to a
recent announcement it has been found that the building- stone
used in the whole district is nothing but phosphate of lime. That
is a highly interesting fact. The phosphorite contains :• —

TABLE XXL— ANALYSIS OF CENTRAL EUSSIA PHOSPHORITE.

Per cent

Water .5-10

Phosphoric acid .

27-45

Lime ....

43-00

C:irbonic acid

4-60

Oxide of iion

3-40

Oxide of alumina

1-09

Sulphuric acid

1-04

Fluorine

0-47

Silica ....

13-82

These immense deposits are not utilized. They are to all
appearance destined to form the reserve from which Europe will
draw^ when the deposits now being used up will be exhausted.

YIII. Spain. — There exist in the province of Estremadura ex-
tensive phosphate deposits, forming well-defined veins. At Log-
rosan the veins occupy a space of 12 to 20 sq. miles, they
traverse the granite and the Silurian schists and only contain
phosphate and quartz. The phosphate is apatite. It occurs as
regular, generally dull hexagonal prisms of a yellowish or greenish
colour, and unequal. It is found in its gangue first as more or less
voluminous, crystalline fragments of 0-2 to 1 inch in length, then
as crystals almost invisible to the naked eve, and distributed

PRINCIPAL PHOSPHATE DEPOSITS.

29

through the paste of the rock. The Caceres deposits are more
extensive, but the material is less rich in phosphoric acid. The
veins traverse a compact limestone regarded as Devonian, and
disperse themselves in the subjacent schists with thinning-out zones
in contact. Phosphate veins also occur in the Silurian schists,
which extend to the north of Alcantara, province of Caceres, of
Badajoz, Elvas, Zarza Mayor, Albala, Montanchez, Majadas,
Malpartida, Ceclavin, as far as Portalegre and Morvao in Portugal.
The size of the veins varies from 20 cm. (8 inches) to 8 metres (25
feet). The phosphate and the containing rock are of the same nature
as at Logrosan. The composition of Estremadura phosphate varies
very considerably, as the very complete analyses of Schucht repro-
duced here show. (See also p. 5.)

TABLE XXL (a).— ANALYSES OF SAMPLES OF ESTRAMADURA

PHOSPHATES.

Apatite ex-
tracted from
Granite.

Phosphorite extracted
from Granite.

Phosphorite
Fibrous
Earthy.

Phosphorite Scaly j
extracted from I.,ime- '
stone.

Phosphorite Earthy
• extracted from
o Limestone.

Crystallized.

Crystalline.

Extracted
from Schist.

Extracted

from liime-

stone.

Water

0-25

0-15

0-05

0-85

Tricalcic phosphate .

93-82

89-68

78-16

87-21

74 40

80-77

79-46

Calcium fluoride

, 5-44

5-38

2-18

8-00

3-08

1-03

4-53

Calcium chloride

. 0-31

0-16

—

traces

005

Carbonate of lime

1

■

— •

11-30

1-16

20-4.5

17-00

13-64

Sulphate of lime

0-92

traces

traces

traces

traces

Silicic acid

: 0-30

1-90

5-60

2-00

1-10

0-10

0-20

Oxide of iron

1-15

1-10

0-84

0-50

0-08

0-90

Oxide of alumina

. —

1-30

traces

traces

Manganese dioxide

0-39

traces

traces

traces

traces

Undetermined .

0-13

0-15

0-34

0-64

0-42

0-17

0-33

IX. North America. — There are four centres of phosphate
production in North America, viz. Canada, South Carolina, Florida,
Tennessee. In addition to these, deposits of less importance occur
in North Carolina, Pennsylvania, Massachusetts, Indiana, Kentucky,
and Alabama.

Canada. — Deposits of apatite, crystallized in pockets and in
veins, are wrought in Canada. The pockets of apatite are met
with in beds of pyroxenit of variable magnitude but of great regu-
larity in stratified conformable layers in the gneiss. The paleozoic
limestones on which this gneiss lies are of the Laurentian age. The
gneiss is itself pierced by numerous crystals of apatite. Apatite is

30 CHEMICAL MANUEES.

found in the province of Quebec, at Templeton, Buckingham, Port-
land, Egonville, Lievre-river ; in the province of Ontario, at Leeds,
Lamarck, Fontenac, Addington, Kingston, Perth and Eenfrew
County. The most important deposits are those of North Burgess,
South Burgess, and North Emslev in Lawrence Countv.

The utilization of Canadian phosphates is embarrassed not only
by the depression more or less transitory in the price of the goods,
but further and still more by the irregular mode of occurrence of
the deposit, and the obligation created by the dearness of freights^
and commercial customs, of only regarding as marketable and fit
for export products containing 80 per cent of tribasic phosphate.
Now this content cannot be secured except at great expense, and
an enormous waste of low content material unutilizable, which is--
piled up on the outskirts of the mines. In fact, every mineral with
less than 60 per cent is of no value in Canada, as not being capable
of paying for the freight. Attempts have been made with the wash-
ing processes, with the result that certain deliveries have tested
87 "83 of tribasic phosphate of lime. That is the highest figure
attained in Canada. [Working has ceased for some years. — Tr.]

South Carolina. — The South Carolina ]3hosphate deposits oc-
cur in Miocene strata from the Charleston basin as far as North
Carolina, Georgia, and Florida. They are very extensive, and the-
nodules of phosphorite extracted therefrom are very analogous-
with those which exist in Central Eussia and in the London Basin.
They were discovered in 1869, i.e. long before the other North
American deposits. The Carolina deposits extend along the coast
with a breadth of 10 to 45 miles from the source of the Eiver Wandc
and from the eastern arm of the Eiver Cooper, which both flow
into the Atlantic at Charleston, as far as the sources of Broad Eiver.
They are often found on the surface of the ground. At other times-
they are covered with sand and clay deposited by diluvial water.
The rock phosphate is distinguished from the river phosphate'
{Land PJiosphate and Biver Phosphate). The first is usually found!
10 feet from the surface, the second on or under the bed of the-
rivers. Their colour varies according to their origin. That of the
rock phosphate is yellowish or pale grey. Eiver phosphates are
black owing to presence of organic matter. The phosphorite occurs-
as nodules or balls, with a rugose surface, and smooth or pitted,
sometimes shining as if enamelled. It is often mixed with shells,
petrified bones, the teeth of terrestrial and marine animals. The-
diameter of the lumps varies from a few centimetres to 1 metre.
Before the discovery of the Florida phosphates, the South Carolina
deposits furnished about one-fifth of the world's consumption.
Their product was perfectly suitable for making superphosphates--
with 18 per cent of phosphoric acid = 28*4 per cent soluble phos-
phate. The annual export amounted to 150,000 tons. But since

PRINCIPAL PHOSPHATE DEPOSITS.

31

Per cent.

25 to

28

5 „

11

0-5 „

2

35 „

42

traces

to 2

1 to 4

1 .,

2

4 „

12

2 „

6

0-5 „

4

1890, Florida has not ceased to increase its production, and the
low price caused thereby has led a certain number of those engaged
in the industry in Carolina to stop work. Since that time the
Carolina production has continued to diminish. The average com-
position of South Carolina nodules is the following, by Dr. C. W.
Shepard of Charleston :■ —

TABLE XXII.— AYEKAGE COMPOSITION OF CAROLINA PHOSPHATE _

Phosphoric acid

Carbonic acid .

Sulphuric acid .

Lime

Magnesia .

Ferric oxide

Fluorine .

Sand and silica

Organic matter and combined water

Moisture .....

Florida. — This peninsula of the American continent contains,,
throughout its whole length, phosphatic deposits of great magnitude,^
but which were not utilized before 1890. Dr. Simmons of Haw-
thorn in 1879 discovered that the chief quarries of building-stone*
of Central Florida contained a considerable amount of phosphoric
acid. Again, Francis Le Baron, a French engineer of Jacksonville-
(Fla.), discovered in 1884 the deposits of fossil bones forming the
bars of Peace River, and also sent at the time several barrels to the
Smithsonian Institution in Washington. This engineer returnee!
to the district in 1886, made measurements and estimated the
profits to be drawn from the working of these superficial deposits.
When these were published, Col. T. S. Menchald installed in 1877
phosphate works to exploit the nodules, and sent his first delivery
to the Scott Manufacturing Co. of Atlanta, Georgia. In June,
1889, Albert Vogt discovered the hard rock phosphate in sinking-
for water about twenty miles S.W. of Ocala, a small town in
Central Florida. The Dunellon Phosphate Co. was then formed to
buy and exploit several thousand acres on the alignment of the-
hard rock phosphate. Since that time the different kinds of phos-
phate as rocks, and as nodules, have been actively prospected for,
and recognized over a tract 200 miles long by 6 miles in width..
This belt is developed, parallel with the coast of Florida, at an
average distance of 26 miles, and extends from the district of
Richland. Pasco County, to the north as far as the environs of the
River Apalachicola, bending towards the west and the bouth.
The most important deposit of nodules (Land Pebbles) was dis-
covered in 1890, in the neighbourhood of Bartow (Palk County).
As far back as 1892, both rock phosphates and nodule phosphates
were known with diverse percentage contents and values far beyond

32 CHEMICAL MANURES.

the rivers Apalachicola in the west and north, and Caloosabatchee
in the south. Throughout all these districts, representing a length
of 400 miles, the exploitation has been followed up with feverish
enterprise, and the quantities marketed, not only in the United
States but in Europe, have rapidly increased. So as to be able to
give some details of the nature of the phosphates collected in this
region, the geology of Florida will not be discussed.

Description of the Deposits. — Four kinds of phosphates are
differentiated by the following names, viz. Hard Rock, Soft Phos-
phate, Land Pebbles, River Pebbles.

Hard Bock. — Rock phosphate as a type is hard, compact, with
a fine homogeneous grain, usually a pale yellow with irregular
cavities often coated with mamillary concretions of phosphate of
lime. These cavities are sometimes filled with amorphous phos-
phate of argillaceous aspect, due to the transport by water of
particles of phosphate in suspension. The hard rock deposits of
the Eocene are concentrated in a narrow belt of about 144: miles
long, almost parallel with the West Coast of Florida, and at a dis-
tance from the sea varying between 25 to 50 miles. Taken as a
whole, hard rock occurs as a conglomerate of boulders, cemented
by a gangue, consisting of phosphatic sand, clay, or other detritus
from the disintegration of the hard rock, and which constitutes the
soft phosphate. The magnitude of these deposits of hard rock
vary considerably. Near Dunellon they are often 40 to 50 feet
thick, elsewhere only 5 to 10 feet. On certain points phosphate
is found on the outcrops, especially in Levy County, but more often
it is covered by a layer of sand 10 feet thick. There are two kinds
of rock phosphate, solid rock and laminated rock. The solid
rock is more or less homogeneous, of a white, grey, or yellow colour,
sometimes deep blue or black, but more often it is marbled. The
hard rock of good quality contains 77 to 82 per cent of phosphate
of lime, and 3 per cent of oxides of iron and alumina. The analysis
of a fine sample of hard rock gave the following figures : —

TABLE XXIII.— ANALYSIS OF A FINE SAMPLE OF HARD HOCK

PHOSPHATE.

Per cenf.'^
Water 0-92

Calcium fluoride .
Phosphate of lime
Carbonate of lime
Oxide of alumina .
Oxide of iron
Silica .

4-4
83-14
8-63
1-52
8 -40
4-l:-5

The analysis of two cargoes of 800 tons each, from the Bhie
River Phosphate Co., gave : —

^ Totals to 106-19 ; the error is evidently in the oxide of iron. — Tr..

PEINCIPAL PHOSPHATE DEPOSITS. 33

TABLE XXIV.— ANALYSES OF HARD ROCK BLUE RIVER PHOSPHATE.

I.

11.

Per cent.

Per cent

0-52

2-80

81-59

78-19

2-06

2-95

Water .......

Phosphate of lime .....

Oxides of iron and alumina ...

The laminated rock, the crevices of which are generally filled
with clay, rarely sand, frequently contain 5 to 8 per cent of clay,
from which it is partially freed by roasting, grinding, and sifting. It
then only contains 3 to 4 per cent of oxides of iron and alumina,
and is exported. The material passing through the sieve contains
up to 10 per cent of clay, and is utilized in the country itself.
This roasting of the phosphate is carried out in a very primitive
manner : on a layer of wood 1 foot thick is placed a layer of phos-
phate 3 to 4 feet thick, and fire applied. This method is decidedly
economical, but it yields a bad product. Whilst the phosphate of
the lower layer is roasted, that on the top is barely dried, and the
whole mixed with ashes and pieces of charcoal. But the roasting
has little effect on the moisture content of the phosphate, for it
suffices to expose it to the open air for it to recover 1 to 3 per cent
of water.

Flate Bock or Sheet Bock. — This kind of phosphate is the most
interesting of all. It is found near Ocala, especially near Anthony,
Spar and Montague. It occurs as small tablets, or as large as the
hand, of irregular shape of one to several centimetres thick, of a
white or brownish-yellow colour. The heavy, brittle fragments are
the richest in phosphoric acid, whilst the soft, light fragments
contain the most clay. The sorted pieces contain sometimes as
much as 80 per cent of phosphate, and only 1 to 2 per cent of oxide
of iron and alumina ; the average is 74 to 78 per cent of phosphate of
lime, with 3 to 4 per cent of oxide of iron and alumina. This high
iron and alumina content comes from the gravel mixed with it,
which forms irregular fragments of phosphate, the crevices of which
are filled with clay. The plate rock rests always on the dolomitic
limestone which forms columns and irregular cones. The cavities
comprised between these columns are filled with phosphate, mixed
with sand or clay. In certain places the phosphate bed is very
pure and contains 50 to 80 per cent of pure phosphate. The
superficial layer of sand is usually not very thick, but it is some-
time 45 to 50 feet thick.

Soft Phosphate. — There is known under this name, in Florida,
a phosphatic clay of soft, friable, or kneadable consistency, with a
very variable moisture content, which constitutes the filling between
the pebbles. As the following analyses show, a small portion of its
phosphoric acid is sometimes soluble in water or in citrate : —

3

34 CHEMICAL MANUEES.

Soft PhospJiate of Palk County. — Water 835 per cent ; phos-
phoric acid, total 28 '9 per cent, of which 0'87 per cent is soluble
in citrate (Wagner's method) and 2'05 soluble in citrate (Peter-
mann's naethod) ; 2'83 per cent of oxide of iron, and 0*86 per cent
of clay.

Soft Phosphate of Alafia Creek. — Water 5*8 per cent ; phosphoric
acid, total 9*4 per cent, of which 0*62 per cent is soluble in water;
oxide of iron 7 '5 per cent ; clay 10'26 per cent. This quality of
phosphate is used directly as manure, being simply ground fine.

River Pebbles are found in several rivers of the west part of
Florida, chiefly in Peace Eiver and Alabama Eiver, where they
sometimes form considerable deposits. This phosphate can be
extracted cheaper than all others. Powerful dredges fitted with
centrifugal pumps lift the sand and pebbles ; these are afterwards
separated from the sand by a slightly inclined rotary sieve consist-
ing of iron rods. The sand passes through the meshes, and returns
with the water into the river, whilst the phosphate issues from the
sieve at the lower extremity, mixed with stones and pieces of wood.
It is taken to the dryer without further cleaning. The daily yield
of a dredge varies according to the quality of the material lifted
by the pump. Thus on certain points of the river the phosphate
is very pure, whilst on others nothing but sand is found. Some
days 100 tons of phosphate are collected, other days only 20 tons.
The installations at work on Peace Eiver produce on an average
-50 tons of phosphate per day. The cost of extraction of river
pebbles is in general not heavy; however, the cost price per ton
exceeds a dollar on an average. The waters of Peace Eiver in-
cessantly bring phosphates to certain points, and remove it from
others. Whatever may be the importance of the deposits of Peace
Eiver phosphates, they are not inexhaustible, and the time can be
seen when they will cease to be workable. Eiver pebbles are in the
form of nodules, the size of which varies from sand grains to nuts.
The corners are rounded, and the surface is often polished and
brilliant. The colour is dark-grey, blue, or black. The land pebbles,
from which the river pebbles are formed by washing, are generally
pale, and it is believed that the black colour of the river pebbles
comes from the tannin of the plants which grow on the banks of
the rivers. Analysis reveals no difference between the two phos-
phates. Both have the same composition, 65 to 70 per cent of
phosphate of lime, with less than 3 per cent of oxide of iron and
alumina. However, the impurities found mixed with river pebbles
have the effect of bringing the phosphates of lime down to from
60 to 65 per cent.

Land Pebbles. — All the country, between Peace Eiver and
Alafia Eiver, in the counties of Polk, Hilsborough, de Soto, Manatee,
contain phosphate deposits. The richest region is a strip of land

PRINCIPAL PHOSPHATE DEPOSITS.

35

about 160 square miles, between Barlow, Fort Meade, Chicora,
and Callsville. The land of this district is flat like all South
Florida, with low undulations here and there. Under the surface
bed of sand, phosphatic clay is found almost everywhere. As
already mentioned, land pebbles can hardly be distinguished from
river pebbles. They are paler and purer than the latter; their
phosphate of lime content reaches 72 to 75 per cent, on an average
66 to 68 per cent, with 2-3 per cent of oxide of iron and alumina.
An average sample gave the following results : —

TABLE XXV.— ANALYSIS OF LAND PEBBLE PHOSPHATE.

Per cent.
Phosphoric acid 33-61

Loss on ignition

Lime .
Oxide of iron
Oxide of alumina

Magnesia
Carbonic acid
Silica .

0-79
48-08
1-20
1-38
5-54
2-29
7-15

Tennessee. — As far back as 1892, the presence of a very ex-
tensive phosphate level in the south of the central region of Ten-
nessee, chiefly in Mount Pleasant County, in the districts of Maury
and Perry, was discovered. The bed is found below the Devonian
schists of Chattanooga. The phosphate occurs under two different
forms; in the upper part, that is to say, immediately below the
greyish-blue shales of Harpeth, phosphatic nodules are found,
then comes a bed of black schists termed Chattanooga, and finally
a uniform bed of about 1 metre in thickness of rock phosphate
resting directly on limestone which ends the formation. Samples
of this rock phosphate from the best-known parts gave the follow-
ing average results (D. Levatt) : —

TABLE XXVL— ANALYSIS OF TENNESSEE ROCK PHOSPHATE.

Phosphoric acid

Oxide of iron

Insoluble matter

Lime

Sulphur

Carbonic acid, COg

Moisture

Per cent.

26-74 to 31-94
2-32 „ 6-92
2-70 „ 7-06

29-60 „ 41-30
0-00 „ 4-00
0-00 ., 1-50
0-20 „ 0-60

Bemarks on the Actual Condition of the Phosphate Industry in
America. — In the Southern States of the Union, there is a manifest
tendency to concentrate businesses into the same hands. Thus for
the hard rocks of Florida, there were 70 declarations of exploita-
tion in 1902, 60 in 1903, 18 in 1904, 14 in 1905, and 16 in
1906. On the exploitations declared in 1906, 10 were at work.

36 CHEMICAL MAXUEES.

3 idle, and 3 in preparation. The total amount of rock phosphate
marketed in 1906 was 2,080,957 long tons, of a value of 8,597,437
dollars, against 1,947,190 long tons in 1905. The production of
Florida alone reached 62-1: per cent of the total production of the
United States. The exports of hard rock were 565,953 long
tons in 1906, against 595,491 long tons in 1905 ; they however exceed
those of previous years. The exports of land pebbles to America
and foreign ports, reached 482,232 long tons, against 385,915
in 1905. Eiver pebbles were not exported in the two last years.
The South Carolina output has continually decreased since 1893.
The production of Tennessee rose in 1906 to 528,888 long tons.
Tennessee phosphate occurs in three varieties, which are the blue
or black rock, the brown, and the white. The quantities marketed
in 1906 consisted of 93 per cent brown, 6-5 of blue, and 0*3 per
cent of white. In the west part of Putnam County, a new deposit
of blue rock phosphate has been discovered. This contained on an
average 65 to 75 per cent of tricalcic phosphate and only 5 per cent
of oxides of iron and alumina. Amongst the other phosphate
producing states, during the years 1901 to 1906, there may be
mentioned North Carolina, Pennsylvania, Arkansas, and Idaho.
But the production of these states was very low, except Idaho.
North Carolina produced 45 long tons in 1903, Pennsylvania 100
long tons in 1904.

In Arkansas the production continually increases, though
slowly. Idaho promises to become a big producer of phosphates.
The bed, at a certain place, has a thickness of 85 feet ; the main bed
is 5 to 6 feet thick.

X. Afeica. — Tunis and Algeria. — These two countries contain
enormous deposits of phosphates. As far back as 1873, Thomas
discovered the existence in the region south of the Tell, in the pro-
vince of Algeria, of a Suessonian formation, rich in phosphate of lime.
In 1886, the same geologist, after a scientific expedition, published
his first researches on the phosphate beds of the Eegency. He had,
more especially, examined the deposits in the neighbourhood of
Gafsa, in Tunis, showing their continuation through the South
Algerian region. The phosphate of these regions is found at the
bottom of the Eocene in contact with the Cretaceous, from which it
is separated unconformablv bv black muddv clavs of variable thick-
ness saturated with chloride of sodium and gypsum, with the
characters of silex. These j^hosphate beds consist of alternations
of marl and nodules of phosphatic limestones, covered in the south
of the Eegency by a bed of shelly limestone, which gives place to
a thick formation of nummulitic limestone as it ascends to the
north. The phosphate beds become at the same time more sandy
and glauconitic.

Marly P]ios2)hate in Xodules, — The phosphate of hme occurs in

PEINCIPAL PHOSPHATE DEPOSITS. 37

nodules, in the foliated and generally highly gypsiferous marls
which alternate with limestone beds. Teeth and debris of saurians
and fish are found therein. These marls are unctuous and greasy
to the touch, and contain as much as 7 to 8 per cent of organic
matter still badly examined, but which neither dissolves in carbon
disulphide nor in benzine. These foliated marls often pass to a
nodular structure. They contain irregular layers of phosphatic
nodules which occur in various sizes and shapes, generally rounded
or striated, covered with a shining brown crust of characteristic
appearance. The large nodules which are met with in these con-
ditions, and which have the appearance of enormous coprolites,
are on the contrary very poor. The phosphate is entirely concen-
trated in the shining surface crust, the interior is limestone. The
small nodules of identical appearance, on the other hand, have a
content which may reach 70 per cent of tribasic. The phosphatic
marls contain besides their phosphates, small interstratified crystals
of gypsum, nodules of celestine, strontium sulphate, and alkaline
salts.

PJiospliatic Limestones. — These phosphates alternate with the
nodular marl. They occur as a granular, rather friable rock, the
colour of which varies from a yellowish-grey to a greenish-brown.
The quality most appreciated crushes easily between the fingers,
and its density does not exceed 2 for the rock in situ. This rock is
formed by the agglomeration into a more or less calcareous cement
by manv fine grains of all shapes ; some round, covered with a
brown, brilliant crust, consist essentially of yellowish phosphate of
hme, with an earthy fracture, or of fibrous appearance ; the others,
grass green, of scaly texture or in very small masses, of a scori-
aceous or corroded appearance, recall, by their aspect, certain
glauconites. There also occur very small grains of hyaline angular
quartz, and chemical analysis always shows in this rock an ap-
preciable amount of free or hydrated gelatinous silica ; finally, it is
also very rich in organic debris, such as coprolites, similar to those
of the foliated marls, teeth and fish bones, or of saurians, more
or less disintegrated. When the calcareous element predomin-
ates in this rock, it becomes greyish, and much resembles the grey
chalk (calcareous tufa) of Ciply. .These bands of phosphatic lime-
stone are extensive, and occupy a very variable position in the
different deposits, but very constant in each of them. Their thick-
ness varies from only a few centimetres up to three metres and
more, which they maintain without interruption over distances of
50 to 60 km. (western chain of Gafsa). The deposits may be
divided into four main groups. 1. Those of the Tebessa district;
2. Those of the district of Setif ; 3. Those of the Guelma district ;
4. Those of the Ain-Beida district. They contain 24 to 30-5 per
cent of phosphoric acid.

38

CHEMICAL MANUEES.

TABLE XXVII.— COMPLETE ANALYSIS OFJAN ALGERIAN

PHOSPHATE.

Moisture ......

Loss on ignition (less 7-5 per cent COg)

Phosphoric acid .

Calcium oxide

Sulphuric acid

Oxide of iron

Oxide of alumina

Magnesia

Potash

Insoluble, etc.

Per cent.
5-03
9-26
30-38
49-53
2-01
0-32
0-47
1-01
0-15
1-85

100-01

TABLE XXVIIL— ANALYSES OF TWO SAMPLES OF DJEBEL
GOURNIA PHOSPHATE IN THE NATURAL CONDITION.

I.

II.

Per cent.

Per cent

Moisture

• • • •

6-64

8-18

Organic matter

• • • •

1-24

0-52

Silica .

• • • ■ 4

6-80

5-96

Pho'^phoric acid .

• • • •

24-93

27-01

Equal to tri basic ph

osphate of lime

54-42

58-96

Carbonic acid

• • • • <

8-52

7-30

Equal to carbonate

of lime . . . .

19-34

16-57

Total lime .

• • • ■

46-12

45-40

Magnesia

■ • ■ •

0-11

0-08

Manganese .

• • • •

traces

traces

Fluor .

• • • •

4-0

4-10

Calcium chloride .

• • • •

8-22

8-43

Oxide of iron

• ■ ■ •

0-98

0-86

Alumina

.

0-20

0-16

On the dry sample

Phosphate of lime

• • • •

58-30

64-05

XI. Asia. — Phosphate of hme deposits have also been dis-
covered in Egypt, but their percentage of phosphate of Hme does
not exceed 50 per cent.^ It has also been found in Palestine, to the
west of the Jordan, near to the route followed by the caravans going
from Damascus in Arabia, and testing 80 per cent of phosphate of
lime, with 1 per cent of iron and alumina, and testing 10 per cent
of calcium fluoride. These deposits are not yet exploited com-
mercially.

XII. Phosphates of Oceania. — There is found in certain isles
and on the coast of the Pacific Ocean considerable deposits of phos-
phatic material. Like Peruvian guano, which will be dealt with in
the sequel, they are of animal origin, but they differ essentially from
Peruvian guano by the almost complete absence of nitrogen, which
they have lost either by decomposition or under the influence of

1 Needless to say, Egypt is in Africa. — Tr.

PEINCIPAL PHOSPHATE DEPOSITS. 39

climatic conditions in which they are found in the deposits, or by
being carried away in its train by rain water. All phospho guanos
resemble each other in their composition. They consist mainly of
phosphate of lime, the content of which varies between 65 and 80
per cent and about 12 per cent of water. They moreover contain
from 1 to 13 per cent of carbonate of lime coming from the coral
limestone which serves to them as substratum, and about 1 per cent
of nitrogen yielded by the organic matters which imparts to them
a colour varying from yellow to dark brown. Finally, small
amounts of oxide of iron and alumina, calcium fluoride, and analo-
gous bodies, the presence of which, as will be seen further on, is
calculated to interfere with the dissolving of the phosphates.

Phospho Guanos were formerly the most highly esteemed raw
material of the manufacture of superphosphates and the most ■
easily preserved. Unfortunately, the greater part of the deposits
are partially exhausted, and those which still exist are not wrought,
owing to the fall in price and the scarcity of labour. Phospho
guanos differ much from each other in their appearance, their form,
and their colour. They are met with, most often, in a pulverulent
state, mixed with lumps, easy to crush between the fingers. They
sometimes consist of masses, amalgamated with coral debris, some-
times as crusts, or again in masses as hard as stone. The chief
deposits of these phosphates are met w4th in a great number of
small islands in the West Indies and the Pacific Ocean, and also
in the Bay of Mejillones on the West Coast of South America.
A rapid description indicating their characteristics will now be
given.

I. West India Islands. — Eedonda Isles, Sombrero, Navassa,
Aruba, Curasao, Los Roques, Alta Vela, Rata.

II. Islands of the Pacific Ocean. — Baker, Jarvis, Maiden,
Fanning, Starbuck, Howland, Phoenix, Sidney, Enderbury, Minerva,
Aves, Lacepede, Flint, Brov/se (? Brown), Fluon, Chesterfield,
Abrolhos, Mona, Cayman, Clipperton, Nauru, Angaur, and Makatea
Isles, etc.

West India Islands.— 1. Eedonda Phosphate. — This phosphate,
like that of Alta Vela, does not contain phosphate of lime, but
hydrated phosphate of alumina and phosphate of iron. It is thus
unfit for making superphosphate. It is yellovv- in colour, more or
less dark with black points. Its composition is as follows : —

TABLE XXIX.— ANALYSES OF EEDONDA PHOSPHATE.

Voelcker. Tate.

Per cent. Per cent.

Water 24-20 21-50

Phosphoric acid 38-52 38-50

Oxide of iron and alumina . . • 35-33 32*50

Insoluble 1-95 6-50

ttO

CHEMICAL MANURES.

2. Sombrero Phosj)hate. — Two sorts are to be differentiated :
one of oolitic structure and variegated in colour, which contains
besides tribasic phosphate of lime, phosphate of magnesia, phos-
phate of iron, phosphate of alumina, silica, and alumina ; the other
has a more homogeneous structure, a white or yellowish colour, is
rich in phosphoric acid and contains in addition carbonate and
sulphate of lime. This deposit was known in 1814, but it was only
in 1858 that it was begun to be worked, and since then there has
been drawn from it during long years excellent phosphate of lime,
containing 75 to 80 per cent of CagP^O^^, 10 per cent of carbonate of
lime, and 2 per cent of oxides of iron and alumina. But for the
quality of the product since it began to be extracted below the sea-
level, Voelcker gives the following analysis: —

TABLE XXX.— ANALYSIS OF SOMBRERO PHOSPHATE. (VOELCKER.)

^Yatel• .
Phosphoric acid
Lime .
Oxide of ir )n
Alumina
Magnesia
Sulphuric acid
Carbonic ac.d
Fluorine

Per cent.
2-94
85-52
47-99
3-70
7-55
0-58
0-36
0-96
0-43

3. Xavassa Phosphate. — The isle of Navassa is of coral origin,
with escarpments in some places, and beaten by the waves in
others. Phosphate was worked here as far back as 1856, but it
was soon seen that it was rich in oxides of iron and alumina, and
was abandoned. It is mostly granular, or in the form of grains,
the size of which varies from that of a pin -head to that of the fist,
and which are often agglomerated into big lumps of almost pure
phosphate of lime. Its composition is the following according to
Bretschneider (I) and Gilbert (II) : —

TABLE XXX. (a)— ANALYSES OF NAVASSA PHOSPHATE.

Wat-r

Combined water and organic matter

Phosphoric acid

Lime ....

Oxide of iron .

Alumina

Sulphuric acid and fluorine

Cirbonic acid

Insoluble

4. Aruba Phosphate. — This phosphate occurs as yellowish stones
traversed sometimes by dark-coloured veins and spots. It contains

I.

II.

Per cent.

Per cent.

5-73

3-01

4-i)3

7-17

31-69

33-28

38 00

40-19

4-25 ,

8-81 /

11-67

1-10

2-40

2-15

3-09

2-53

PEINCIPAL PHOSPHATE DEPOSITS.

41

about 30 per cent of phosphoric acid, and 6 per cent of oxide of
iron and akimina.

5. Alta Vela Phosphate. — This phosphate has a composition
analogous to that of Redonda phosphate, as the following analysis
■shows : —

TABLE XXXI.— ANALYSIS OF ALTA VELA PHOSPHATE.

Phosphoric acid .

Oxide of iron

A umina

Lime ....

Sasquioxide of c premium

Per cent.

37-00

24-00

15-00

1-00

0-7o

6. Rata or Fernando Noronjo PhosjjJiate. — This phosphate occurs
as a fine powder ; it also is very rich in oxides of iron and alumina,
.and thus unfit for superphosphate manufacture. It contains about
26 per cent of phosphoric acid and up to 20 per cent of oxides of
iron and alumina.

7. Monk's Island (Caribbean Sea) Phospho Guano. — This phos-
phate contains 42 per cent of phosphoric acid and only 40 per cent
of lime. It consists therefore partially of monacid phosphate. Its
analysis gave the following results : —

TABLE XXXII.-

. ANALYSIS OF MONK'S ISLAND PHOSPHATE.

Per cent.
Nitrogenous organic matter and combined water
Sulphate of lime

Phosphate of lime an I magnesia
Alkaline salts
Carbonate of lime
Carbonate of magnesia
Insoluble silicious residue

7-60

8-32

70-00

1-88

10-20
2-00

100-00

The surface of this deposit, which is as hard as a rock, has not the
same composition as the centre. Thus the bed having been care-
fully analyzed yielded 70 per cent of phosphate of lime on the
surface, 74 per cent in the centre, and 75 per cent in the lower part.
8. Christinas Island Phospho Guano (Indian Ocean). — Christ-
mas Island, to the south of Java, belongs to the Straits Settlements.
The phosphate deposit discovered there a few years ago is wrought
by a British Company, The Christmas Island Phosphate Co. Ltd.
The total bulk, of this deposit is estimated at 250,000 tons, with
a percentage of 60 to 90 of phosphate of lime. The samples re-
ceived in Europe tested 85 per cent of phosphate of lime with 1'5
per cent of sesquioxides ; rendered soluble by sulphuric acid at 53°
B., yielded about 20 per cent of phosphoric, of which 05 per cent
was insoluble in water, and 4 per cent of free acid, which is
little. This phosphate is very hard, but easy to crush when it is

42 CHEMICAL MANUEES.

dry, or dried, which is indispensable, as it contains 5 per cent of
moisture.

Pacific Ocean Isles. — There are a series of coral isles in the
Pacific Ocean, in the neighbourhood of the equator, deprived of all
vegetation, which have hardly attracted attention. A sample was
brought in 1853 to America of a non-nitrogenous guano, collected
in one of these islands. Baker Island. Soon afterwards it w^as found
that the other isles of the same group were equally rich in guano,
viz. Howland, Maiden, Jarvis, Starbuck, Enderbury, and finally
the Phoenix Isles, a little further west. As Baker Isle, now for
the most part exhausted, yielded the best guano, the typical guano
of the isles of the group, a short description of it is now" given.

Baker Island Guano. — Baker Island is situated at 0"14 of north
latitude and 176-22| degrees of longitude west of Greenwich ;
1750 metres (say 1 mile) long its w^idth is 1100 metres, and its
height above the level of the sea is about 8 metres (26 feet). The
chain of coral rocks which surround it, is dry over a surface of 160
metres. On this chain is a height of stones, corals and shells,
which surround the actual guano deposit. ^ The vegetation of the
isle only comprises rare species. The bed of guano is 15 cm. (6 in.)
thick on the shore, and 1*60 metres, say b\ feet, in the centre. Its
surface is plane, and it occupies a surface of 62-5 hectares, say 156 J
acres. The guano isles are the refuge of sea fowl, which come
there to make their nests and sit on their eggs. Their excrements^,
the food which they bring there (fish and other marine animals),
and finally their dead bodies give birth to guano which is, therefore,
constantly in course of formation. Looking to its formation, this,
guano, like that of Peru, to be described further on, should be very
rich in nitrogen, but it is not so. Although rain is generally
a rare phenomenon in these tracts, yet the guano is constantly
washed by the waves, which are continually broken against the
coral chain which fringes the islands. To that has to be added the
heat of the day, which is very intense. It follows that the nitrogen-
ous matters are rapidly decomposed, producing ammonia and nitric
acid ; the first is carried away by the wind, the second is converted
into nitrate of soda, which is lost in the depths of the ocean. All
the Pacific guanos are met with as a fine pale or dark brown
powder according to their percentage of moisture. The brown
pow^der is mixed with larger white granules, consisting in great
parts of phosphate of ammonia and magnesia.^ According to an
analysis of Liebig, Baker guano contains : —

^ The Pacific Isles are all protected on the sides of the prevailing winds by
a chain of coral against which the sea waves are broken up.

-It follows from researches made since, that the magnesium phosphate in
the guano is not tribasic but monacid ; only traces of carbonate of lime were
found thei-ein. The composition of the guano is slightly modified since it has

PEINCIPAL PHOSPHATE DEPOSITS.

43

TABLE XXXIIL— ANALYSIS OF BAKER ISLAND GUANO.

Tribasic lahosphate of lime .

Tribasic phosphate of magnesia

Irou phosphate

Sulphate of lime .

Alkalies

Chlorine

Ammonia

Nitric acid .

Water, sand, etc. . •

Pe?- cent.
78-79
6-12
0-12
0-13
0-85
0-13
0-07
0-45
13-34

100-00

Baker Island was the first island in the Pacific Ocean in which
guano was discovered and exploited. It is not, therefore, astonish-
ing that the deposit is partially exhausted.

Other isles in the Pacific Ocean contain vast quantities of
phospho guano, absolutely similar in composition to that of Baker
Island, But the greater part of these deposits are only of historical
value seeing that, if they are not exhausted, their output is insuffici-
ent. Thus the deposits of Baker Island, Lacepede, Malton, and
Pelsart, w^ould appear to be far from exhausted, and still to contain
enormous quantities of guano. But the greater number of the
islands are abandoned, because the cost of working and freights
are too high for the selling price of the guano, which at the present
time cannot compete with mineral phosphate.

Jarvis Guano is a mixture of powder, hard plates, and some-
what friable stratified fragments. The plates have a porcelain char-
acter sometimes semi-milky, already found in analogous guanos.
Perfectly dried in an oven at 100" C. (212° P.) these fragments pre-
serve their appearance. By detaching the stalagmites, which
cover the plates, it has been found that they owe their semi-trans-
parent appearance to the hydration of the phosphate of lime,
evidently precipitated in a very slow manner. The phosphate so
hydrated cannot, in fact, lose its water, except at a red heat, and
the hard Jarvis plates still contain 11 or 12 per cent, which
analysts have often confounded with organic matter, when they
have ignited the manure after simple drying in the oven. This
physical state of the phosphate of lime may be understood by going
iDack to the phenomena which have successively led to the evapora-
tion of the nitrogenous substances in the guano. Such phenomena
cause the partial solution of the phosphate of lime, then later on,

been wrought in an intensive manner. Some per cents of carbonate of lime
are always found in it, and only 75 per cent of tribasic phosphate of lime. The
above analysis may also apply to all analyses of this class, from the point where
they do not contain large amounts of gypsum, sand, and analogous mipunties,
as certain guanos from Jarvis Island.

44

CHEMICAL MANUEES.

its slow precipitation by the ammonia liberated, hence the ex-
planation of the stalagmites and the hydration so conducive to
the solubility of the manure in the soil.

TABLE XXXIV.— ANALYSIS OF .JARVIS GUANO.

Pel' cent.
Phosphate of lime •SC?iO,F^O- = 17-397 , 33-423

2CaO,Po05 = 16-026/
Phosphate of magnesia
Phosphate of iron ....

Sulphate of lime .....
Sulphuric acid, potash, chlorine )
Organic matter and water j

1-24L

0-160

44-549

20 880

100-2.59

The following are some analyses of phospho guanos by Dr. H.
Gilbert :—

TABLE XXXY.— ANALYSES OF FANNING ISLAND GUANO.

Per cent.

or

Per cent.

Water

8-0

Water . . .

8-00

Carbonic acid .

1-30

Carbonate of lime

2-97

Sulphuric acid .

0-19

Sulphate of lime

0-32

Phosphoric acid

34-16

Tribasic phosphate of

Lime

42-84

lime .

73-00

Magnesia .

0-61

Tribasic phosphate of

Fluorine .

1-01

magnesia .

1-33

Organic matter

12-32

Calcium fluoride

2-06

Organic matter

13-32

100-43

Deduct oxygen equal

1 101-00

to the fluorine

0-43

' 100 in original.

100-00

TABLE XXX VL-

-ANALYSES

OF BROWN ISLAND GUANO.

Per cent.

or

Per cent.

Water

15-0 )

Water

15-00

Carbonic acid .

1-48

Carbonate of lime

3-36

Sulphuric acid .

1-01

Sulphate of lime

1-72

Phosphoric acid

31-40

Tribasic phosphate of

Lime

39-94

lime .

68-00

Magnesia .

0-21

Tribasic phosphate of

Oxide of iron .

0-32

magnesia .

0-46

Soda

0-06

Oxide of iron

0-32

Chlorine .

0-08

Sodium chloride

0-14

Fluorine .

0-34

Calcium tluoride

0-70

Organic matter

10-30

Organic nittter

10-30

100-14

100-00

Deduct oxygen equa

I

to fluorine .

0-14
100-00

PEINCIPAL PHOSPHATE DEPOSITS.

45

TABLE XXXVII.—.

ANALYSES 0

F LACEPEDE ISLAND

GUANO

Per cent.

or

Per cent

Water

12-40

Water

12-40

Carbonic acid .

0-86

Carbonate of lime

1-95

Sulphuric acid .

0-10

Sulphate of lime

0-17

Phosphoric acid

33-64

Tribasic phosphate of

Lime

40-80

lime .

71-04

Magnesia .

0-93

Tribasic phosphate of

Oxide of iron .

0-75

magnesia

2-03

Sodium .

0-0(3

Oxide of iron

0-75

Chlorine .

( -10

Sodium chloride

016

Fluorine .

0-77

Calcium fluoride

1-58

Organic matter

9-92

Organic matter .

9-92

100-83

100-00

Deduct 0 =F .

0-33

10000 !

Mejillones Guano.— This guano, so appreciated formerly, is now
only of historical interest. From the rocky coast, for a length of
alrnost twenty-five miles, which Bohvia has conquered from Peru
and Chili, there starts a promontory about ten miles long which
juts into the sea for a length of three miles, under the tropic
of Capricorn, the rocks of which form a shade to the Bay of Morena
on the south, and to the Bay of Mejillones on the north. This
latter bay, well-sheltered from wind and wave by the point of
Leading Bluff Peninsula, forms an excellent harbour, into which
the ships come to load guano. The country, moreover, is almost
unhealthy. The complete absence of rain, the frequency of violent
winds and dense fogs, which last for ten hours, followed by a torrid
heat under a brazen sky, a rocky, sandy soil void of all vegetation,
and above all, the want of potable water, renders a sojourn in these
tracts exceedingly trying. The inhabitants of the capital— the
number of which was formerly very small, and has not increased
by the working of the guano — are revictualled by the Pacific
steamers, which call there and possess coaling-stations. Water is
got by distilling sea water. The rocky peninsula, of an average
height of 350 to 400 metres, looks like a sandy plain, only its
promontory which protects the bay is more elevated, for it rises to
100 metres (5640 feet) to the west of the town ; to the north of this
hill is the culminating point of the promontory, called Morro de
Mejillones, of a height of 866 metres (2730 ft.). On the slope of this
mountain, on the bay side, is the guano deposit. It is reached by
a long road from the town, winding round the mountain. The
principal deposit is found about 560 metres (1836 feet) above sea-
level on the flank of the mountain ; in several points it is 14 metres,
sav 46 feet thick. The published information on the extent of these

46 CHEMICAL MANUEES.

deposits differ considerably ; official data speak of 3,000,000 to
4,000,000 tons, other information represent the situation under
a less alluring aspect, and assert that the reserves are almost ex-
hausted. A road has been built, with great difficulty, across the
mountain to connect the deposit with the loading quay. At a mile
from the works the road divides into two — the one at a very rapid
incline leads to the harbour, whilst the other leads to a tent con-
structed on the edge of the plateau where the guano, which is lifted
there in sacks, is run into a shoot of 233 metres deep, which diverts
into a warehouse situated in the port. In the centre of the port dwell
the workmen, the overseers, the exporters, and the state govern-
ment employees. The latter weigh the guano, which is then con-
veyed in trucks on rails to the other extremity of the harbour, and
discharged into ships. The formation of Mejillones guano is
analogous to that of Baker guano. As the climate here also is
very dry, the absence of nitrogen can only supervene from the
possible contact of sea water. The volcanic nature of these
countries being granted, the periodical upheavals and sinkings of
the ground are known historical facts, and it is known that on
these occasions violent high waves are frequent.

Mejillones Guano, like Baker guano, is a brown powder mixed
with more or less large friable lumps, consisting in part of phos-
phate of ammonia and magnesia. In the early days, this guano
was frequently mixed with granite chips, from the rocky bed on
which the deposits lie. But afterwards the importers installed
crushers and driers, which have enabled them to eliminate the
stones and to dispatch the guano as a uniform powder. Amongst
the numerous analyses published, that by Fresenius and Neubauer
is reproduced here. These chemists found in the sample dried at
100 the following results : —

TABLE XXXVIII. —ANALYSIS OF MEJILLONES GUANO.

Per cent.

Tribasic phosphate of lime

. 60-564 I

with 38-404

Monacid ,, \,

. 17-960 )

total P2O5

Sulphate of lime

. 1-069

Carbonic acid ....

2-052

Phosphate of iron, etc.

. 0-072

Water and orj^anic matter

. 10-161 )

together

Ammonia oxide

0-018 )"

0-729 N

Sulphate of magnesia

1-528

Nitrate of magnesia .

0-034

Common fralt .

. 3-739

Dr. Gilbert gives the following analysis : —

PKINCIPAL PHOSPHATE DEPOSITS.

47

TABLE XXXIX.— ANALYSIS OF MEJILLONES GUANO.

Water .....
Carbonate of lime
Sulphate of lime .
Phosphate of lime basic
Phosphate of lime monacid .
Phosphate of magnesia monaciil
Oxide of iron a id alumina
Silica .....
Sodium chloride . .
Organic matter .

Per cent.

9-14

0-32

3-26

33-64

26-44

10-35

1-35

0-89

7-32

7-29

100-00

As will be seen from these analyses, about one-fourth of the
phosphoric acid is combined with magnesia. And if the phosphate of
magnesia is in itself more soluble than phosphate of lime, it
is so to a still greater extent in the case of monacid phosphate of
magnesia.^

Clipperton Island Guano. — The discovery of guano deposits in
Clipperton Island is more recent. This island is situated in the
open sea off the coast of Brazil. The coral chain surrounds a fresh-
water lake in mid ocean and has served as a refuge to sea birds
for thousands of years. Whilst the nitrogen of the excrement was
carried away by rain water the phosphoric acid combined with the
hme of the coral. The whole of the isle is covered with phosphate
to a depth of six feet. The average analyses of thirteen samples
taken in different sections, has given 83 to 86 per cent of tribasic
phosphate and 0-03 of oxide of iron and alumina. In the dry state
the phospho guano is a yellowish sandy powder. Dr. Gilbert gives
the following analysis : —

TABLE XL.— ANALYSIS OF CLIPPEKTON ISLAND GUANO.

Water

Tribasic phosphate of lime

Phosphate of magnesia

Carbonate of lime

Quicklime .

Sulphate of lime

Sodium chloride

SiOj

Organic matter .

Oxide of iron and alumina

Undetermined .

Per cent.
3-80
78-09
0-55
6-73
2-S4
0-78
0-15
0-28
4-83
0-04
1-91

100-00

^ The translator dissents ; no superphosphate made from material con-
taining organic matter to the extent to which phospho guano does, approaches
a bone ash superphosphate in this respect. For whiteness free from a yellow

48 CHEMICAL MANURES.

The points of the Chipana Coast, Pabellon de Pira, Punta de
Lobos, Huanillos, the Ballestas Isles, Guanape, Macabi, Lobos de
Afuera, etc., contain considerable deposits.

Nauru Guano. — Nauru Isle, attached to the German protectorate
of the Marshall Isles, is in 0-26 of S. latitude and 166-55'' of E.
longitude. Whilst the atolls of the Pacific scarcely rise 3 metres
(10 feet) above high water, the Isle of Nauru rises about 75 metres,
with an area of 2000 hectares (5000 acres). A bank of coral chains
60 to 90 metres wide (195-6 to 295-2 feet) go right round the island.
To that succeeds a flat zone 100 metres wide covered with coconut
trees ; behind rises a rocky region, which consists of a mass of phos-
phate of great richness. No one knows the depth of this deposit,
but the beds known are so extensive that their working may last for
several generations. The quality of this phosphate would appear
to be superior to that of all the phosphates known up to now, both
as regards the richness and regularity of the phosphoric acid
content, 86 to 87 per cent Ca^P^O^, as well as the small proportion of
oxide of iron and alumina.

A good part of the exports of Nauru phosphate goes to countries
washed by the waves of the Pacific, Japan, Australia, New Zealand,
and Honolulu, but France, Belgium, Great Britain, Sweden, Nor-
way, Russia, and especially Germany likewise import large quantities.

AngauT Island Phos2)hate. — The deposits of Angaur Island
phosphate comprise about 2,500,000 tons which may be extracted
in the open air. Four-fifths of the deposit consist of a phosphate
with a content of 80 per cent of tribasic phosphate of lime. Work-
ing reserved for thirty-five years to a German company with a
capital of 4,500,000 marks, say £225,000.

Makatea Isle Phosjjhatic Deposits. — There has been discovered
in the island of Makatea deposits of phosphate containing according
to the analyses made from 60 to 85 per cent and even 90 per cent
of pure phosphate of lime. Makatea Island belongs to the Pau-
motou Archipelago, and lies 120 miles to the north of Tahiti. It is
4| miles long and 1\ miles wide. Its formation differs from all
the other islands of the Paumotou group, in that it has no lagoon,
and rises up to 230 feet, whilst the other islands are simple chains
of an average height of 8 feet above sea-level. Phosphate has been
found in several of these atolls, especially in that of Niau. Guano has
also been found in Puka-Puka in the extreme north-west of the i^roup.

The deposits of Makatea are valued at 30,000,000 tons and
will be exploited by a French company.

cast it is only excelled by apatite. As to Mejillones guano, with 7 per cent
of organic matter, it yields a superphosphate the colour of peat — as it passes
into lignite — and the farmer does not like such a colour even in a compound
manure far less in a superphosphate. So dark is this colour that it can only
be used sparingly even in compound manures where the raw materials are sent
up the cups and not dry mixed. — Tr,

PEINCIPAL PHOSPHATE DEPOSITS. 49

Distribution of Phosj^liates in the Different Geological Forma-
tions.— On examining the subject from a geological point of view,
phosphoric acid, or phosphoric acid and nitrogen, is found in the
following formations : —

1. Gneiss Epoch, as apatite in Sweden, in Finland, in Norway,
in the mountains of the east coast ol North and South America.

II. PalcBOzoic {or Primary) Epoch. — 1. Silurian Formation. —
x\s phosphorites in Spain and in the south of Eussia. 2. De-
vonian Formation. — As phosphorites in Germany. 3. Carhonifer-
OILS Formation. — As Blackband in Great Britain and Germany.

III. Mesozoic or Secondary EjJOcJi. — 1. Trias Formation. — As
Bone Bed and fossil bones in England, Germany, and Switzerland.
2. Jurassic Formation. — As coprolites in Germany and England.
(Lias.) — As phosphatic nodules in France and Germany. (Osteo-
lithes.) — As phosphorite in French Jurassic marls. 3. Cretaceous
Formation. — As coprolites in France, in England, in Germany, and
in Holland. As phosphorite in Spain, in Belgium, in France, in
Austria-Hungary and in Eussia.

Cainozoic or Tertiary Ejjoch. — Eocene Formation. — As copro-
lites in England and Germany. As phosphates in France, Algeria,
Tunis, the Carolinas, Tennessee and Florida.

Quaternary and Becent Epoch.— 1. As fossil hones.

2. As phosphate in the islands of Navassa, Eedonda, Eata, St.
Martin, Curacao, Testigos, Buenos Aires.

3. As guano crusts in the islands of Starbuck, Flint, Sombrero,
Avalo, Los Eoques. As phospho guano in the islands of Baker,
Howland, Fanning, Jarvis, Maiden, Mary, Enderbury, Phoenix,
Sydney, Vivorilla, Mona, George, Eaza, Clipperton, Monk's at
Mejillones, in the islands of Leysan, French, Frigatte Shoal, at
Bramble Cays, Shoal Bay, Shark's Bay, in the islands of Timor,
Ashmore, Brown, Jones, Lacepede, Abrolhos, Huon, Birds, Kurian
Murian, Swan, and at Algoa Bay.

4. As guano in Peru, Chili, Patagonia. In the islands of
Galapagos, Bat, Ishaboe, Damaraland, and Saldanha Bay.

5. Bat guano on the Mediterranean coasts, Egypt, Sardinia,
Galicia, Porto Eico.

It will be convenient to add to this classification, the substances,
manufactured by industry, such as bone black (spent char), bone
ash, artificial guano manufactured from the excrements and the
dead bodies of animals, fishes, lobsters ; in addition to the precipi-
tated phosphate of glue and gelatine factories, and finally the
phosphates of basic slag. The following table prepared by Dr. M.
Ullmann contains the analyses of all phosphates known up to the
present time. x\s this document is absolutely unique in scientific
literature it is given here at the risk even of repeating what has
been said previously.

4

50

CHEMICAL MANUEES.

Geograjjhical Distribution of Phosphate of Lime and

Localities.

Longitude

of
Greenwich.

Latitude.

Designation.

Analysis.

r

5 a

CO 1-

Ml— 1

2

A. Europe.

1. Sweden and Norivay.

Degrees.

Degrees.

Per
Cent.

Per
Cent.

Per
Cent.

Krageroe
Langesund

HE.
9-7 E.

59 N.

59 N.

Apatite .
Chlorapatite .

0-45
0-32

45-58
51-02

2. Germany.

Hartz ....
Helmstedt
Wasserleben .
Lahn et Dill .

11 E.
11 E.
11 E.

8E.

52 N.

52 N.

52 N.

50-5 N.

Apatite .
Phosphorite .

,, ...

,, • •

1-2
4-2
6
3-85

37-31

Peine ....
Horde ....
Amberg ....
Delme (Lorraine) .

10-2 E.

7-5 E.

12 E.

6 E.

52-3 N.

51-5 N.

49-5 N.

49 N.

Coprolites
Phosphorite .
Osteolite

• •

3. Austria-Hungary.

Schlaggen\vald(Boliemia)
Lavanthal (Oarinthia) .
Starkenbach (Bohemia)
Cracow (Galicia) .

13 E.

15 E.

15-5 E.

20 E.

50 N.

47 N.

50-5 N.

50 N.

Apatite .
Phosphorite .
Coprolites
Bat guano

7-50

74 08
75-20

12-26

4. Belgium.

Liege ....
Ciply ....

5-5 E.
4E.

50-6 N.
50-5 N.

Phosphatic chalk .

0-93
1-52

2-83

40-64
45-45

5. France.

Bellegarde-sur-Rhone .

Somme ....

Lot ....

Vaucluse

Ardennes

Boulogne

4-5 E.

2 E.
1-5 E.

5E.
4-6 E.
1-5 E.

48-7 N.

50 N.
44-5 N.

44 N.

50 N.
50-7 N.

Coprolites
Phosphorite .

>>

M

!>

Coprolites

4-70
1-69
4-27
2-45

0-84

0-2
3-14

32-50
47-34
50-10
26-57

33-06

6. Italy.

Sardinia (Cagliari)

9 E.

89 N.

Bat guano

18-77

61-14

5-17

7. Spain.

Caceres ....
lEstremadura.

6-5 E.
6W.

39-5 N.

40 N.

Phosphate
Phosphorite .

0-721
0-30

43-41

PEINCIPAL PHOSPHATE DEPOSITS.

51

Guano Deposits and their Chemical Composition.

Analysis.

•^ >"

^O

ffi

^T3
2 C '^

as;

2S

Per
Cent.

Per
Cent.

1-00
0-90

Per
Cent.

0-77

2-4

2-86
1-72
4-75

3-08

Very rich in iron
Up to 19 °/o of iron

Phosphate of iron
& alumina 13-

20 7o

19-18

9-17

4-85

2-39

1-75

16-90

1-11

2-21
2-96
3-30

4-6
2-89

trace

0-91

2-3
3-09

trace

0-427

1-64

a:

a

Per
Cent.

0-80

0-18

1-31

0-79

0-78
0-26
0-o3

0-58

0-86

S-4

o
& .

Per
Cent.

34-30
38-02

18-32
19-27
18-18
29-19

34-35
19-5-21
36-64
18-04

30-59

29 -.30

6-99

3-82

27-25
22-17

1212
32-25
37-07
19-90
18-04
21-06

502

29-455
32-60

be
o

-1^

Per
Cent.

9-17

5-72

.-2 °>-^

Per
Cent.

74-87
82-99

35-45
41-48
39-70
63-72

abt. 75
44-20
80
33-44

o c

o o

Per
Cent.

7-10

8-9

7-9

66-79

8-54

64-39

13-5

15-25

8-33

59-49

7-04

48-44

26-40

70-42

9-10

80-92

3-43

43-44

0-84

36-43

10-13

45-97

—

10-95

59-594
71-16

13-227

1 "^

Per
Cent.

Name of Chemist

who made

the Analysis.

A. Retter
E. Giissefeld

4-88
fluorine

3-0

5-26

E. Schulte
Dietrich & Konig

3-0

Mouse]

Reuss
Scheibler

Anglo-Cont. G. W.
A. Grimm

Duglere

A. Grimm

Ulex

E. Giissefeld

Delattre

Pavesi & Rotond

0*983

2-57

fluorine

Niederstedt
A. Grimm

52

CHEMICAL MANURES.

Geographical Distribution of Phosphate of Lime and

Localities.

Longitude

of
Greenwich.

Latitude.

Designation.

Analysis.

a.z.

Ml— 1

a

Logrosan

Truxillo ....

Degrees.
5-5 W.
6 W.

Degrees.
39-4 N.
39-5 N.

Phosphorite .

Per

Cent.

2-40

Per
Cent.

Per
Cent.

8. Russia.

Podolia ....
Kursk ....
Woronesch

27-5 E.
36 E.
39 E.

48-5 N.
52 N.
52 N.

Phosphorite in balls
Phosphorite .

3-57

9. Great Britain.

Ipswich (Suffolk) .

IE.

52 N.

Coprolites

Cambridge

Bedford ....

Wales ....

Lyme Regis .

Goodrich

OE.
1-5 E.

4 W.

3 W.
2-5 W.

52 N.

52 N.

52 N.

50-7 N.

52 N.

j» • •
Mineral phosphate

4-01

1-4
(

■>

45-39
23-49

42-84

B. North America,

10. Canada.

Ontario ....
Ottawa ....

SOW.
75 W.

45 N.

45 N.

Apatite .

1)

0-08

11. United States.

New York
South Carolina
Charleston

75-5 W.
80 W.
SOW.

44-4 N.
33 N.
33 N.

Apatite Laurenzia .
Phosphate

02

1-56

9-95

6-65

51-48
42-28
31-12

Port Royal

Tennessee

Florida ....

Tallahasee .

Barlow

Peace River

81 W.
86 W.
SOW.

84-4 W.

82 W.
82 W.

32-5 N.

35 N.

25-30 N.

30-5 N.

28 N.
27-5 N.

1) * •
)>

,, (Hard rock) .
,, (Land pebbles)
,, (River pebbles)

0-58
0-80
0-55
0-25

1-05

1-01

37-79
50-60
50-46

C. West Indies and
Mexico.

12. West Indies.

Havana ....
Guanahani .
Vivorilla (Isle)
Puerto Rico (Ponce)

82 5 W.
74-3 W.

67 W.

23 N.

24 N.

18 N.

Phosphate
Phospho guano

Bat guano

1190
9-83
7-0

17-68

6-46
51-66

30-60
45-26
10-17

PKINCIPAL PHOSPHATE DEPOSITS
Giiano Deposits and their Chemical Comjoosition — continued.

53

Analysis.

Per
Cent.

7-20
9-12

2
"5

x P

Per j Per
Cent. I Cent.

2-22

little

1-95

5-0

1-87

7-47
1-00
2-36

4-0

2-57

5-70

0-09

0-57

1-07
2-86 2-38

2-82

112

3-32

1-95

0-82

1-27

0-80

1-37

0-52

1-64

2-88
5-77
0-25
1-59

a

Per
Cent.

0-48

0-15

1-62

0-5

1-27
0-17

a, .
.a «

Per

Cent.

38-95
35-50

34-0

35-42

13-74

24-73

26-75

18-32

15-4

27-95

27-63

39-98
39-0

37-0

26-89

20-92

23-67
36-69
35-80
35-42
31-59
28-08

34-08

11-60

32-24

7-57

s
o

Per
Cent.

0-73
0-13
8-35

01

5 x.S

-H Sj o

Per
Cent.

85-03
75-80

74-23
77-34
30-0

54-0

57-12
about 40
33-62

6-1
60-32

86-61
85-24

79-59
58-70
45-66

51-67
80-09
78-15
77-32
68-96
61-30

74-40
25-32
70-38
16-52

2 6

Per

Cent.

10-35
little

6-92

24

100

24 0
9-54

4-47
0-06

2-32

9-18

s ^

Per

Cent.

14-0

3
fluorine

7-22

6-8

6-42

5-11 of
fluor.

Name of Chemist
who made
the Analysis.

De Luma

Schwackhofer
Pieper

Volcker

Herapath

W. R. Hutton.

H. Gilbert

Volcker

Ulex

H. Grimm

Pieper

Volcker

Gilbert

Pieper
A. Grimm
H. Gilbert
A. Grimm

54

CHEMICAL MANURES.

Geographical Distribution of Phosphate of Lime and

Localities.

Longitude

of
Greenwich.

Latitude.

Designation.

A.nalysis

A,

•

m P

•

a

13. Lesser Antilles.
(a\ Windward (Isles).

Degrees.

Degrees.

Per
Cent.

Per
Cent.

Per
Cent.

Avalo (Isle) .
Navassa (Isle)
Mona (Isle) .
Sombrero (Isle)
St. Martin (Isle) .
Redonda (Isle)
Alta Vela

81 W.

75 W.
67-5 W.
63-5 W.

63 W.

62 W.
71-5 W.

22 N.

18-2 N.
18-1 N.

19 N.

18 N.

17 N.
17 5 N.

Guano in crusts
Coralline phosphate
Phospho guano
Guano in crusts
Mineral phosphate
Phosphate of alumina

20-12
2-7
7-66
9-06
5 04
23-23
16-49

31-15
37-6

86-17
47-69

14. Loiver Antilles.
(6) Leeward (Isles).

Aruba (Isle) .

>> ...
Curasao (Isle)

70 W.

69 W.

12-5 N.
12 N,

Mineral phosphate .

3-46
2-16
0-84

48-72
47-84
51-00

Buenos Aires (Isle)
Los Aves (Isle)

Los Roques (Isle) .
Testigos Isle .

68 W.
67 W.

66-5 W.
63 W.

12 N.
12 N.

12 N.

12 N.

>5

Phospho guano

>»

),
Guano in crusts
Phosphate of iron .

>»

20-0
5-93
10-35
14-90
10-22

12-17

10-22
12-17

37-92

38-67
0-37

15. Mexico.

George (Isle) .
Raza (Isle of)
Clipperton (Isle) .

113 W.
113 W.

108 W.

31 N.

29 N.

9N.

Phospho guano
>>

>>

4-08
3-80

4-83

35-28
49-25

D. South America.

16. Venezeula.

Maracaibo (Monkey Is-
land)

71 W.

12 N.

Phospho guano

2-39

39-48

17. Brazil.

Fernando Naronha (Isle
of Rata) .

33 W.

4 S.

Phosphate

10-0

30-6

18. Patagonia.

East Coast .
Falkland (Isle)

67-5 W.
60-0 W.

49 S.
52 S.

Guano

,, ...

16-15

8-86

28-06
17-10

20-20

PRINCIPAL PHOSPHATE DEPOSITS.

55

Gumio Deposits and their Chemical Compositioji — continued.

Analysis.

o o^

2 8'^

Per
Cent.

11-25

6-79

1-95

a)
X ?

Per
Cent.

5-88

c5

.s

'S
s

Per
Cent.

trace

14-8
0-75

2-42
1-21

6-89
2-99

36-38
19-24

3
1-36
0-2

25

0-61

1-02
0-164 I .

0-35
0-40 I ■

40-5
13-30

1-50
1-14
0-04

it

9-56

11

0-99

Per
Cent.

0-44
0-6

0-36
0-38

trace
0-97

2-75
0-57

1-18
0-25

1-17

o

a. .

Per
Cent.

24-36

33-5

27-85

34-41

24-14

36-95

^0-45

36-29
33-82
39-96

21-76

26-32

29-02

22-40

40-49

37-0

17-41

37-71
39-70
36-07

41-34

26-5

15-43
9-75

O
u

Per
Cent.

0-45
0-11
0-25

0-36

0-40
0-06

0-139

4-40
1-24

Per
Cent.

53-18
73-13
60-79
74-55
52-70
80-66
44-64

79-22
71-65
87-23

45-50
57-45
63-37
48-90
60-80
80-77
38-0

82-33
86-66

78-84

90-24

33-68
21-29

sa

O O

Per
Cent.

5-6
3-80

.32-27

10-66
6-99

12-83
7-05

1-0

•Go

75 pi

Per
Cent.

0-48
fluorine

Name of Chemist

who made

the Analysis.

6-72

1402

A. Schlimper
Ulbricht
Weiss
Volcker

J)

5»

E. Giissefeld
A. Better
E. Giissefeld

A. Grimm

Taylor
Schucht
Ure & Teschen-
macher

E. Giissefeld
Fr. Voigt
H. Gilbert

Volcker

Schucht

A. Grimm

Anderson

56

CHEMICAL MANURES.

Geograjjhical Distribution of Phos2)hate of Lime and

Localities.

19. Peril.

Lobos de Tierra (Isle)
Lobos de Afuera (Isle)
Maeabi ,, (Isle)
Guanape ,, (Isle)
Chinchas (Isle)
Ballestas (Isle)
Independencia Bay

20. Chili.

Pabellon de Pica

Punta de Lobos

Huanillos

Mejillones

Angamos

Corcovado

E. Pacific Ocean.

21. Sporadic Isles.
Fanning (Isle)

Jarvis (Isle) .
Maiden (Isle)
Starbuck (Isle)

22. Phcenix Group of Isles.

Mary (Isle) .
Enderbury (Isle) .
Phcenix (Isle)
Sidney (Isle) .

23. Gilbert Group of Isles.
Ocean (Isle) .

24. Baker Isles
Howland (Isle)

F. Australia and
Australian Isles.

25. Australian Continent.
Shark's Bay .

Longitude

of
Greenwich.

Degrees.

82 W.
81 W.
81 W.
79 W.
77 W.
76-5 W
76 W.

70 W.
70 W.

70 W.

71 W.
71 W.
73 W.

159 W.

159-5 W.

155 W.

156 W.

171-6 W.

171 W.

170-45 W.

171-50 W.

169 E.

176-25 W.

177 W.

114 E.

Latitude.

Degrees.

6-5 S.
7S.

7-5 S

8-5 S.
13-5 S.
13-5 S.

14 S.

21 S.
21 S.
21-5 S.
23 S.
23 S.
43 N.

4S.

0-5 S.

4S.

5-5 S.

2-75 S.
3 S.
3-5 S.
4-5 S

1-5 S.

0-13 S.

0-5 S.

26 S.

Designation.

Guano

Guano

Phospho guano
Guano

Phospho guano

Guano in crusts

Phospho guano

Phosphate
Phospho guano

Analysis.

Per
Cent.

23-79
19-60
30-33

25-88

14-87
] 3-22

13 05
14-12
14-12
4-44
7-39
18-19

11 e

9 3c

Per
Cent.

8-00

12-118
4-78

64-81

s

Per
Cent.

18-91

10-99
12-59

14-23

37-64

5-11

13-67

12-32

5-992
5-18

10-01

Phospho guano

5-63
8-76
4-93
7-38

1-01

3-945
5-34

15

8-81
8-66
7-59

2-7

7-75P

42-84

34-83

46-229

44-96

44-40
40-76
44-91
42 96

49-5

43-379

44-48

PRINCIPAL PHOSPHATE DEPOSITS.

57

Guano Deposits and their Chemical Comjwsition — continued.

Analysis.

->-

3J

a)

Xame of Chemist

r

.

not
lined

o

2

OW

"t.

2

-4J

-'AS

= 5^

who made
the Analysis.

2-=^

S

si

sc^

^

j: I—::

-P '"^

■•3 o

Oh3

<

c •—

S2

£s?

^Cw c»_

SI

Per

Per

Per

Per

Per

Per

Per

Per

Per

Cent.

Cent.

Cent.

Cent.

Cent.

Cent.

Cent.

Cent.

Cent.

_

1-

B9

0-27

17-54

5-58

—

Anglo-Cont. G. W.

16-70

3-60

a

11-95

11-05

—

'S

Ohlendorff & Co.*

1225

11-0

-1.3

»>

0-30

1-19

13-52

14-.39

§1

»>

12-23

12-50

o o

t»

—

1-52

0-39

10-89

7-68

53 ^

Anglo-Cont. G. W.*

§;r^

0°

m 1

2-73

0-20

12-78

8-88

0)

>»

—

15-10

5-70

r~

>»

13-30

6-60

0-12

0-66

0-90

2-90

31-72

0-59

69-24

A. Grimm

0-

88

1-11

7-13

19-28

. .

Anderson

0-

20

1-17

15-14

10-52

Anglo-Cont. G. W.

—

0-61

34-10

74-57

1-01

fluor.

H. Gilbert

0-09

0-568

17-67

0-647

38-57

V. Liebig

34-75

75-86

8-29

Volcker

40-12

87-58

>>

9-89

0-

23

29-26

0-54

63-87

A. Grimm

28-74

0-38

62-74

16-50

—

Vdlcker

0-23

36-10

0 63

70-80

4-54

0

0

2-.:8

34-41

0-28

75-13

6-0

0-82

H. Gilbert

3-19

0-

42

38-73

84-65

4-91

1-0

V. Grueber

0 067

2-207

40-329

1-35

88-03

V. Liebig

2-29

0-

18

29-75

0-53

64-94

A. Grimm

*Samefirm.— Tr.

—

23 59

50-53

4-6

58

CHEMICAL MANUEES.

Geographical Distribution of Phosphate of Lime and

Localities.

Longitude

of
Greenwich.

Latitude.

Designation.

Analysis.

i

0.2

a: c

% it

26. Australian Isles.

Degrees.

Degrees.

Per
Cent.

Per
Cent.

Per
Cent.

Brown (Isle) .

123-5 E.

14 S.

Phospho guano

15-00

10-30

39-94

Jones (Isle) .
Lacepedes (Isle)
Abrolhos (Isle)

J)
Huon (Isle) .

Bird's (Isle) .

Bat (Isle)

126 E.
122 E.
113 E.

163 E.
156 E.
146 E.

13 S.

17 3.

28 S.

18 S.
22 S.

3 S.

»

»
»>
»»
>»

Guano .

7-93

6-78

4-48

10-10

9-74

10-70

14-53

10-92
10 54

6-20

19-90

9-70

42-86
41-33
43-20

37-60

14-64

G. Asia.

27. Palestine.

Country East of Jordan

35-5 E.

32 N.

Phosphorite .

28. Ai-abia.

Kurian Murian (Isle) .

56 E.

17-5 N.

Phospho guano

8-70

9-30

29. Malay Archipelago.

Timor (Isle) .
Christmas (Isle) .

124-127 E.
105-5 E.

8-10 S.
10-5 S.

Phospho guano
Phosphate

6-25
3-05

40-33

H. Africa.

80. North Africa.

Algeria ....

Tebessa ....

Toqueville

Tunis ....

Sfax ....

Gafsa ....

Egypt ....

3 E.

8 E.
8E.

10 E.
10-5 E.

9 E.
29 E.

37 N.
35-5 N.

36 N.

37 N.
34-5 N.
45-4 N.

31 N.

Mineral phosphate

>»
»»

Phosphate
Bat guano

2-39
1-97
0-77
5-

2-6
17-19

95

2-99
29-50

50-10
50-30

45-35

45-12

31. South Africa.

Damaraland .
Ichaboe (Isle)
Saldanha Bay
Algoa Bay

14 E.

15 E.
18 E.
26 E.

22 S.

26-5 S.

38 S.

34 S.

Guano .

n • • .
)i • • .

Phospho guano

18-89
17-97
17-04
20-25

17-0
12-10

12-42
24-26

PEINCIPAL PHOSPHATE DEPOSITS.

59

Guano DejJosits and their Chemical Composition — continued.

Analysis.

— r^ '^

3 8'$

Per
Cent.

2-38
5-56

3-49

14-09

2-76

c

I

s

Per
Cent.

Per
Cent.

0-32 —

0-33 0-54
1-61 —

3-10

1-67
0-24

0-40

0-64

0-57

0-48

1-48
0-71 1-22

0-53
0-55
0-98

0-81
1-2

0-62
0-6

1-68

2-27

.2

2
Sd

Per
Cent.

0-21

0-55

097
0-09

traces

0-26

0 50

0-81
0-6

0-5

0-97

o

Per

Cent.

31-40

34-22
35-22

33-67
28-59

7-30

38-24

26-24

31-14
39-18

30-44

28-16

26-32

27-25

27-2

27-23

13-40

11-19

24-52

6 68

fee

o

Per
Cent.

0-38

1-16
1 24
7-54

1-37

0-82

11-81

8-88

1-41
0-43

r-— c

Per
Cent.

68-54

74-70
76-88
69-46
70-32
62-41
23-15
15-94

83-68

57-30

67-98
83-53

66-45

61-47

57-46

59-48

59-0

59-44

29-25
24-44
55-40
14-60

o s

-£'13

Per
Cent.

4-25

r- '^

o 2

36-45
6-97

6-23
4-82

20-19

22-80

11-52

14-0

11-95

Per
Cent.

0-34
fluorine

traces

2-57
traces

9-8

3-44

Name of Chemist

who made

the Analysis.

H. Gilbert

A. Grimm

Cherson

A. Grimtm

H. Gilbert

Chevron

Anderson

Volcker

EJschner

Huson

A. Grimm
H. Gilbert

A. Grimm
A. Better

Schucht

Schucht
Volcker

A. Grimm
Anderson
H. Gilbert
Grouven

CHAPTER III.
DRYING AND ENRICHMENT OF PHOSPHATES.

Drying. — Phosphates, for all uses to which they may be put, must
be dried and finely ground. When the phosphates are massive
(rock phosphate) or in lumps, they ma\- be completely dried in
summer by storage in a warehouse with vents in the side ; in winter,
drying is finished in a drying machine. Formerly phosphates
were calcined to increase the percentage of phosphoric acid and
facilitate grinding (p. 85 et seq.). Drying is indispensable in the case
of the sandy phosphates of Mons, Somme, and Cambresis. This
operation is conducted in a naked fire drier, on cast-iron plates, about
two-fifths of an inch thick, in contact with the flames of one or more
furnaces, but protected from over-heating. The phosphate is spread
on the drier, in layers of 4 to 5^ inches thick, according to the
nature of the phosphate. The drying reduces this thickness about
one-third. An operation is finished in 6 hours over the fines above
the fiames ; in 8 hours on the flues, forminoj the first circuit of the
flames ; and in 10 to 12 hours on the flues, forming the second
and the third circuit. A drier of 250 square metres (820 square
feet) may yield 35 to 40 tons of dry phosphate per day of 24
hours. The consumption of coal is about 2 cwt. per ton of sand
obtained. The sands, so dried, pass into cylindrical sifting ma-
chines, with polygonal section like those of an ordinary mill covered
w4th wire gauze Nos. 70, 80, 90, 100, 110, and fitted with baskets
inside, in which to collect the larger fragments. The dry sand
passes successively through the different mesh sieves, commenc-
ing with the larger sizes. The exit of the products is thus re-
gulated m a uniform manner over the whole length of the ap-
paratus. The residues on the sieves are crushed in fiat stone mills
revolving at a speed of 100 turns a minute. Each pair of stones
absorbs 6 to 7 H.P. The sifted phosphate is generally 7 to 8 per
cent richer in tribasic phosphate than the ground phosphate : the
whole is mixed so as only to have one average quality of the ap-
pearance of finely ground pepper. When the phosphate is in
nodules, as in Auxois, they must be crushed or cracked before
grinding. The crushers and cracking machines, used in the jMeuse
and Ardennes, consist of two cast-iron cvlinders, studded with

(60)

DRYING AND ENRICHMENT OF PHOSPHATES. 61

projecting teeth in the form of pyramidal trunks, which mutually
intersect each other. At other times the crusher consists of a
grooved mohile blade which crushes the phosphate against a fixed
plate (see Fig. 12 and context). Where the nodules to be crushed
are not quite dry, the working of the mills produces steam, which
finds vent through wooden pipes fitted either to the boxes which
collect the ground phosphate, or to the mill covers. These pipes,
acting as evaporators, end on the roof. The steam carries with it
entrained phosphate dust. Of late mechanical driers have been in-
stalled for drying raw phosphates.

Calcining the Nodules.— Before crushing the nodules, they were
at first only dried in the sun, or on iron plates heated artificially.
Lately thev are calcined in special furnaces to free them completely
from water and carbonic acid ; their weight per cubic metre is thus
lowered from 1000 kg. to 950 kg , say from 20 cwt. to 19 cwt.,
and the percentage of phosphoric acid is increased prj rata. These
furnaces are i'O metres, about 14 feet 9 inches high, and about 25
cubic metres in capacity, with a diameter of 2-65 metres, say 8 feet
8 inches at the top, 1-8 metres, say 5 feet 11 inches at the base,
and 3 metres, say 9-84 feet in the centre. Their bottom consists of
a busk formed bv two incline ! planes ending in two wide discharg-
ing orifices. The phosphate rests on iron bars, supported at one of
their ends by the inclined planes of the busk and at the other by
the horizontal metallic lintels whi-h form the crown of the discharg-
ing orifice. These bars form two grates at the bottom of each
furnace, and thev are used to regulate at will the descent of the
products. It suffices to draw one to let the calcined nodules fall
through the opening. They can thus be withdrawn at any point
of their contact with the grate ; above each grate the side of the
furnace is pierced by an opening to inspect the progress of the
operation. The furnaces are built of bricks or masonry ; they are
filled with nodules in layers of 4 inches thick which are separated
by very thin layers of fuel, small coke, or anthracite. A furnace of
the above dimensions yields 4J cubic metres of calcined phosphate
in twenty-four hours. The matter thus remains in the apparatus five
to six days. The roasting of a ton of nodules takes 1 cwt. of fuel
costing about 5d. The nodules first go to a crusher with smooth
blades; they then pass by an elevator chain of cups to the top of
the building where thev are dropped into an iron trough which
feeds the mills underneath. The ground phosphate passes auto-
maticallv to an elevator which raises them to the level of the two
sifting machines between which they are fed. From the siftmg
machine the substance falls into a wooden reservoir fitted with
two bagging-up machines. Whilst in the Pas de Calais phosphates
are always washed after simple hand sorting from the bulk of the
gangue, in the Meuse and Ardennes they are now beginning—

62 CHEMICAL MANUEES.

after disintegration by the pick and breaking up on the spot — to
screen them by throwing them on a trelhs of iron wire called a
billard, the square meshes of which are 8 to 20 mm., or a screen
of iron bars 8 to 10 mm., say one-third to two-fifths inch apart, so as
to free them from one-third or sometimes one-half of their impurities,
but at the same time small nodules and fragments broken off by
shock are lost. This method is profitable when the nodules are not
friable, and easily separated from their gangue. Screening is followed
by washing with a current of water in mechanical washers, or in
washers fitted with blades, or dry sorting known as fanage. The
phosphate nodules occur near the outcrop of the Greensand at a
shallow depth, and the sock of the plough often brings them to the
surface. An extensive business is done in collecting them and
selling them in bulk to the phosphate cleaners. Fanage consists in
passing the raw material through a screen after exposure to the air,
so as to dry it completely and thus render the argillaceous sands
more easily separated from the nodules. The operation is repeated
five or six times so as to get a satisfactory cleaning. Drying is facili-
tated by spreading the nodules in a thin layer on the ground and
turning them like hay, and from that comes the name given to the
process. Fanage only succeeds if the gangue lends itself to the
process. The nodules fanes, poorer than washed nodules, contain
10 to 15 per cent of impurities. They are exposed to rain to
wash the impurities away as mud. Fanage is completed by rapid
washing.

Sorting and Sale of Baw Phosphates. — Eaw phosphates are
sold by P2O5 content. Thev are bagged up into 5 grades each
differing by 5 units— 50-55, 55-60, 60-65, 65-70, 70-75, 75-80 per
cent. It is thus easy to supply any strength required. To control
strength of wagon loads, buyer's and seller's agents take counter scaled
samples at station from each wagon, four random samples from 25 to
30 bags. One is tested by seller's chemist, the other by the buyer's.
When there is more than 2 per cent between the results, the third
sample is analysed by a third chemist and the average of the nearest
taken. The fourth sample is kept as a check. In case of ship-
ment the goods are sampled in the wagons as they reach the harbour.
Sampling is done either by the broker alone or by the broker in
presence of the seller's agent.

Different Methods of Strengthening and Utilizing Poor Quality
Phosphates. — Numerous methods have been suggested to utilize
the large quantities of low grade phosphates unfit for making super-
phosphates. These methods consist of (1) To fortify them in various
ways ; (2) To free them from the sesquioxides of iron and alumina,
or (3) To increase their solubility or to extract from them their
phosphoric acid. But none of these processes have been adopted
in actual practice, because they are too costly and incompatible with

DEYING AND ENRICHMENT OF PHOSPHATES. 63

the present state of the manure trade, and they will continue to be
so as long as high grade phosphates, with a low oxide of iron and
alumina content, are available, which only require to be rendered
soluble to produce excellent superphosphates. The following are
the chief patents taken out for this purpose : —

1. Dumonceau and Nicolas (French patents Nos. 201,427 and
5101,461) seek to fortify low grade phosphates, consisting of phos-
phate of lime and carbonate of lime, by the use of sulphur. The
principle of the two methods is as follows : Phosphatic chalk is
calcined so as to obtain a mixture of phosphate of lime and quick-
lime, which is mixed with water and sulphur in iron pans. The
insoluble phosphate of lime is separated from the soluble sulphides
formed. The strength is thus fortified 20 to 30 per cent. A
current of carbonic acid is injected into the solution, and sulphur
and sulphuretted hydrogen separated, the latter being converted
into sulphur by sulphurous acid.

2. Simpson replaces sulphur by sulphuretted hydrogen (German
patent 58,925), and after calcination of the raw phosphates, injects
it into water, holding the phosphates in suspension. The calcium
sulphides are afterwards treated by carbonic acid, or by sulphate
■of soda, to transform them into gypsum and sulphurous compounds ;
the latter treated by carbonic acid yield sulphuretted hydrogen
and soda.

3. Brochon (French patent 215,577) extracts phosphates rich
in carbonate of lime by carbonic acid under pressure after crushing
and stirring up with water. The liquid containing the acid carbon-
ate of lime is separated from the insoluble phosphate and treated
for the recovery of the carbonic acid. But carbonate of lime is
only feebly soluble in carbonated water even under pressure (1 cubic
metre of water only dissolves 3 kg. (or 100 gallons, 3 lb.) under
a pressure of 4 atmospheres at 5^ C). The process is thus too costly.

4. Winsinger, to prepare bicalcic phosphate free from oxide
of iron, completely soluble in citrate of ammonia (German patent
No. 51,739), extracts all the phosphoric acid of the phosphate of
lime by sulphuric acid, converts half the solution into monocalcic
phosphate, by carbonate of lime and milk of lime, which precipi-
tate iron ; he adds this precipitate to the other half, and obtains by
.addition of sodium sulphate, sodium carbonate and quicklime,
phosphate of lime insoluble in water free from oxide of iron, which
he finally adds to the solution of monocalcic phosphate. A bicalcic
phosphate is thus obtained, and gypsum and caustic soda as bye-pro-
ducts. This process is rather complicated.

5. 0. lahne (German patent 57,295) prepares phosphate of
lime free from oxide of iron, alumina and silica, by acting on
phosphates rich in oxide of iron and alumina, by sodium bisulphate.
'The raw phosphates (coprolites, etc.) treated with an aqueous solu-

64 CHEMICAL MANURES.

tion of sodium bisulphate, carbonate and phosphate of Ume, dis-
solve whilst the silica, and iron, and alumina compounds remain
insoluble, and may be separated by filtiation along with the gypsum.
By evaporating the solution a yellow^ salt is obtained, the composi-
tion of which corresponds to the formula QNa^^SO^ + CaH^P^,Og + H.^0,
which may be employed as such, as a manure, or mixed with
gypsum, horn meal, peat ; it may also be used in stables, to fix

ammonia.

6. 'In making superphosphates, Martin proposes to use the acid
sulphate from manufacture of nitric acid. The acid sulphate from
the cylinders is dissolved in water, so as to get a solution of 45^ to
50° B. The precipitate consists of bisulphate, which it is easy to
convert into sulphate by recrystallization, whilst the strongly acid
solution is used to dissolve raw phosphates. All the phosphoric
acid is dissolved, and the resultant superphosphates have less
tendency to retrograde than those made with sulphuric acid of 50°

to 53° B.

7. Thonnar and Huxton s Belgian patent No. 96,109, and Bol-
lancVs Belgian patent 196,190, to eliminate the oxides of iron and
alumina, may also be mentione i.

8. Schitcht proposed to make superphosphates from ferruginous
^' phosphate thus : As soluble oxides of iron induce retrogradation

of the phosphoric acid in superphosphates, whilst protoxides are
inactive, and as sulphate of ammonia possesses the property of
forming with protoxides of iron readily oxidizable in the air double
salts very stable in air, Schucht, on such data, proposed to dissolve
phosphates in presence of sulphate of ammonia, then to effect the
] eduction and so obtain very stable superphosphates of ammonia.
With this end in view, the finely ground superphosphates are mixed
with sulphate of ammonia. One part Fe^g requires 175 per cent
of that salt to form the double salt FeSO^ + (MHJoSO^ + 6H.p.
Reduction can only be effected by weak sulphurous acid which is
injected under pressure into the diluted mixture of superphosphate
heated to 80° to 100° C. Schucht thinks that the small amount of
sulphurous acid in the product will quickly oxidize and become in-
nocuous to plant life. The author is not aware if this method has
ever been used ; in any case, Schucht makes no mention of it in
his book. Besides, a phosphate containing 3 to 4 per cent of
sesquioxide of iron and alumina will on'y cause an inversion of
050 per cent in stored superphosphate, a loss say of Id. a cwt.
That is why the above process scarcely merits attention, except
perhaps in those cases where the purchaser also pays for nitrogen.
Otherwise the process would hardly be worth the trouble.

9. Carr's process dealing with phosphates rich in oxides of iron
and alumina is analogous. It consists in calcining the phosphate,
grinding it fine and then mixing 1000 parts with 400 parts of sul-

DEYING AND ENEICHMENT OF PHOSPHATES. 65

phate of ammonia dissolved in 400 c.c. of hot water, and then to
add 800 parts of sulphuric acid of 53° B. A violent reaction ensues,
the mass intumesces and heats to 110° C. After an hour it solidifies
.and is easily ground ; it contains 18 per cent of phosphoric acid,
two-third^of which are soluhle in water. This process is interesting ;
moreover, it is simple, and yields good results ; it might he advan-
tageous to use it in the manufacture of phosphate of ammonia, if
the raw materials were to be got cheap. Besides, this process seems
to preclude the retrogradation of the soluble phosphoric acid.^

10. Glaser manufactures precipitated phosphates from insoluble
phosphates of alumina, by treating the latter with a cold alkaline
solution or with a hot concentrated solution of alkaline carbonate.
In this operation the phosphate of alumina is dissolved. In using
the alkaline solution, the liquid separated from the residues is
treated with carbonic acid. If a hot solution of alkaline carbonate
be used, it is cooled, and the dissolved phosphate of alumina is
precipitated. The solution is then used for a new operation. But
from tests made, raw phosphate of alumina does not dissolve in
a hot solution of alkaline carbonate.

11. Peternmnn of Gembloux recommends treating the raw
phosphate at a high temperature, to convert the phosphoric acid
into a very soluble form. Bazin has based a British patent No.
15,237 on this principle. He heats phosphates in retorts to a
temperature of 1300° to 1500° C.

12. Hodgkins (American patent No. 423,320, 1890) mixes the
phosphate in fine powder, with quicklime, which he then slakes.
But it is not easily seen how that treatment can render phosphates
more soluble. Besides, no field experiments appear to have been
made to bring out the value of the resultant manure.

Manufacture of Precijnfated Pliosphate by Electrolysis.—.^ new
method of manufacture, based on electrolysis, has been invented
by Prof. W. Palmer of Stockholm. It consists in converting the
raw phosphate by the wet w^ay into a readily assimilable form,
and that at the ordinary or a slightly elevated temperature. The
raw material is ground apatite. It need not be finely ground. In
an apparatus specially constructed for the purpose, a solution of
chlorate or perchlorate of soda is electrolyzed, which disengages
free chloric acid, sometimes even perchloric acid, in the anode cell.
The acid anode liquid is made to react on the raw phosphate in a
battery of wooden cases, fitted with perforated bottoms, so that the
solvent first comes in contact with almost exhausted apatite.
The alkaline liquid from the cathode is added to the saturated

iBut it is evident on the face of it that such generalizations are futile.
The data given can only have been applicable to the particular phosphate to
which Carr applied it. All phosphates rich in oxides of iron and alumina
nvould not respond to such treatment so as to yield the above results.

5

66 ■ CHEMICAL MANURES.

solution, in special precipitation vats, taking care to stir, until a
slightly acid reaction ensues. There is thus formed crystalline
precipitate of acid phosphate of lime bicalcic. It is freed as-
completely as possible from the mother liquor, by filtration and
washing, which is greatly facilitated bv the solubility of the phos-
phates. The yield is very satisfactory, because only about 1 per
cent of the phosphate in the raw material remains in the solution..
The latter, which contains a third of the amoant of lime originally
eliminated from the apatite, is mixed with the residual alkaline
cathode liquid, and the greater part of the lime is precipitated as
hydrate ; finally a current of carbonic acid gas is injected. After
precipitating the lime the solution is withdrawn and run into the-
electrolyzer. The electrolyte is thus continuously regenerated.
The product so obtained generally contains 86 to 38 per cent of
total phosphoric acid (the formula CaHPO^ + 2H.p requires 46-07
per cent of ^.Pr,). About 95 per cent of the phosphoric acid is
soluble in Petermann's solution of ammoniacal citrate of ammonia.
The composition of the product depends, moreover, on the amount
of lime in the raw material ; when it is rich in lime it requires a
greater amount of acid, and consequently of electric energy. There-
is a bye-product of slaked lime equal to 33 per cent of the bicalcic
phosphate formed. This process, which was the subject of several
years' laboratory work, was applied industrially last year [? 1909] in
an installation of 6 to 8 electric horse- power. One electric horse-
power can produce annually 20 cwt. of bicalcic phosphate soluble
in citrate, or 23 cwt. of 32 per cent. The cost of manufacture has
been provisionally estimated at 8-44: Swedish crowns per cwt. These
figures refer to an annual production of 2200 tons of bicalcic phos-
phate of 34 per cent. Comparative experiments on oats cultivated
in pots and continued for five years, show that the phosphate pre-
cipitated by electrolysis, provided that its composition responds
to that of bicalcic phosphate, exerts as energetic a fertilizing action
and as durable a one as superphosphate. The addition of important
amounts of carbonate of lime has not diminished the assimilability of
the former, whilst with tribasic phosphate the contrary is the result.

CHAPTEK IV.

HISTORICAL REVIEW OF SUPERPHOSPHATE MANUFACTURE.

It can l)e safely asserted that the superphosphate indiistrv is the
issue of Lie big's theory. He was, in fact, one of the first to recom-
mend restoring to the soil, not only the nitrogen removed by crops,
but also the mineral matter, more especially phosphoric acid. For
this purpose he recommended the use of bone dust, and also of
phospho guanos. But having remarked that the phosphoric acid
of these substances only acted very slowly, he advised that they
should be treated by sulphuric acid so as to render the phosphoric
acid soluble, and immediately assimilable by plants. His method
was adopted, and yielded remarkable results, thus giving birth to
the superphosphate industry which spread rapidly in Germany,,,
Great Britain, and France.^

The Manufacture of Superphosphates from 1850 to 1870. — It
is interesting to follow^ the new industry in the dilferent phases of
its evolution. The theory of superphosphate manufacture is in
itself very simple. Eaw phosphates contain phosphoric acid, as
tribasic phosphate of lime, insoluble in water, and consequently
not assimilable by plants. The task of the manufacturer of super-
phosphate consists, therefore, essentially in converting the insoluble
phosphoric acid of raw phosphates into water soluble or citrate
soluble phosphoric acid. This is done by treating them with
sulphuric acid, which removes, as gypsum, two parts of the lime,
with which the phosphoric acid is combined, leaving one part of
the lime combined with the phosphoric acid, as the monobasic or
acid phosphate of lime soluble in water. The product so converted
is called superphosphate, i.e. superior phosphate. -

^ The writer has no intention of dispRragin.s Liebig's claim to the treatment
of bones by acid ; but the treatment of coprolites and mineral phosphate by acid
was first suggested by the Rev, Mr. Henslow. Mr. Lawes was either present at
Mr. Henslow's lecture or read a reporc of it. and took out a patent for the pro-
cess and proceeded to interdict Mr. Purser for ( igging for coprolites on his (Mr.
Purser's) own land for the purposes of treating them by acid so as to dissdve
them. Long litigation ensued, afterwards settled amicably. Lawes established
a factory at Deptford and Purser at Miliwall. with the river Thames between
them. Purser's Miliwall factory was closed in the early nineties. Lawes'
manure factory is now at Barking. The mineral superphosphate industry is
a British-born industry, like sulphuric acid manufacture. — Tr.

■^This etymology is hardly satisfactory. Super here is not an abbreviation

(67/

68 CHEMICAL MANURES.

As regards the simplicity of the process, the installation of the
first superphosphate factories was very primitive. They contained
little or no machinery. Three sheds, one to cover the raw phos-
phates, the other the den in which to dissolve the phosphate, and
the third the superphosphate. So much for the factory. The tools
in the beginning consisted of a few harrows, hoes, rakes, and a
sieve called a screen — that was all. As to the indoor installation,
it included a sulphuric acid tank, a few lead-lined measuring tanks,
and three or four rectangular round or square dens. These dens
were first made of brick steeped in l:)oiling tar ; afterwards cast-iron
cases one inch thick, and sunk in the ground, were used. The
method of manufacture was the following. A certain amount of
■sulphuric acid of 50^ to 5T B. was run into the den ; at the same time
the phosphate was weighed and heaped on the edge of the den. Three
men, each armed with a rake, agitated the acid, whilst the third
gradually shovelled in the phosphate. The mass soon thickened,
and even set before the "mixing" was complete. Nevertheless, to
obtain a homogeneous mixture the mass was triturated by bringing
it from one side of the den to the other ; finally it was filled into
barrows and shifted into the superphosphate shed. There it lay in
heaps for a month ; finally it was hand screened and sent out to
customers. When well dissolved, it gave no core, any lumps
being crushed by the back of the shovel, until sufticiently fine to
pass through the screen. By such simple means sufficiently dry
superphosphates were obtained, comparatively fine and well dis-
solved. These methods sufficed then, because the very pure raw
phosphates were delivered in the ground state, or at least sufficiently
fine to pass through the screen.

1871 to 188Q. — As raw phosphates, spent bone l^lack from sugar
w^orks, and guano from the Pacific Islands, Baker, Jarvis, etc., were
chiefly used. From 1871 Mejillones guano began to be used, and
then the first difficulties in the manufacture began. The larger fac-
tories then installed flatstone mills, roller mills, or stamp mills. This
(equipment, however, soon became defective when it was a question
of working mineral phosphates such as Canadian or Norwegian
apatite. Sombrero, Navassa, Curacoa and Aruba phosphates, Mexican
guano, rock phosphate, bone ash, etc. Powerful crushers were
then added to the flatstone mills, for it was soon found that fine
grinding played an important part in dissolving the phosphate, and
in drying the superphosphate. At the same time, the need was
felt for a mechanical crusher and sifter for the superphosphate.
It was thus that the crusher called Carr's disintegrator was adopted.

of superior, but is the Latin word super used to show that in superphosphate
the ratio of phosphoric acid to the lime is in excess of that in the normal tri-
basic phosphate. Super in fact has the same meaning here as in supersaturate,
superheat. It has nothing whatever to do with quality. — Tr.

EEVIEW OF SUPEEPHOSPHATE MANUFACTURE. 69

This machine did not at first alwa^^s and everywhere give the
result expected ; the superphosphates unless suitably dissolved were
converted into paste. Such was the state of affairs about 1880.
But to follow^ up the treatment of the phosphates : At the outset
of the manufacture of superphosphate, the manufacturer was him-
self his own chemist ; he submitted his raw phosphates to a series
of dissolving experiments, varying the quantity of acid each time.
He then sent samples to an analyst of the superphosphates which
appeared to have succeeded best, then he applied to the stock of
phosphates the treatment established by groping in the dark.
Each new raw material required fresh experiments. It is hardly
necessary to remark that such a method of working was fertile in
disagreeable surprises for the manufacturer. ^

1880 to 1894. — In spite of the good quality of the raw phos-
phates, and their low percentage of oxide of iron and alumina,
hitches in manufacture were frequent, and gradually the need was
felt for a permanent control. Thus since 1880, factories of any
importance have each a chemist whose duty it is to follow the
material throughout all the phases of its treatment.'-^ This control
became more urgent when it was observed in certain mixed
manures, that a certain amount of the phosphoric acid had retro-
graded, that is to say, it had returned to the condition insoluble
in water. At the same time the use of Canadian and Norwegian
apatite, and Florida and other mineral phosphates, gave off chlorine
and fluorine compounds highly injurious to the health of the work-
men, and annoying to the neighbourhood. The machine for mixing
the acid with the phosphate was then substituted for the treatment
in the open den. The first machine of this nature was an inclined
cylinder, in which a shaft fitted with blades arranged in a helicoid
manner revolved ; it was charged w4th acid and phosphate at the
top end, and the mixture w^as run out at the low^er end. Afterw^ards
this apparatus w^as replaced by a flat mixer of cast-iron, likewise
furnished wdth an agitator, and in which the acid and phosphate
were agitated two to three minutes, then run out into a truck under-
neath, whilst the gas given off by the phosphate was led out on to
the roof through a wooden chimney. These machines answered
all requirements so long as only guano or other phosphates rapidly
attacked by sulphuric acid were being treated ; however, the pro-
ducts were generally awanting in porosity because the greater part

1 It would be possible to'name several British manure manufactories the work
of which was controlled by chemists 15 to 20 years prior to 1871, and flat stone
mills were also in use prior thereto. The writer has handled works, laboratory
journals of the early fifties, which show the manufacture was even then under
strict chemical control by qualified men on the spot. British manure patent
literature of the earlier days speaks for itself. — Tr.

'" See above note.

70. CHEMICAL MANURES.

of the carbonic acid was disengaged owing to a too long stay in the
mixer. Then the system of closed chambers or dens was adopted,
because in dissolving very hard mineral phosphates, such as
Canadian apatite, pebbles, Florida phosphate, etc., a higher tempera-
ture was required, which it was easier to attain and maintain in
the closed chamber, where the superphosphate remained for about
twelve hours ; further, because in connecting it with a well-con-
structed flue for the disengagement of the acid vapours, the health
of the workmen was safeguarded. When the chamber possesses
two flues for the disengagement of gas each 1 metre (3 "28 feet) wide,
and when these flues are each fitted with a fan, and can be put in
connexion with the chimney stalk of the factory at will, or with
a condensation plant, it is easy to eliminate steam and acid gases.
A more dry superphosphate is thus obtained, and during the
emptying of the chamber or " house " the workers can enter without
running the risk of getting "gassed '". But in actual practice
hitches frequently occur. As already mentioned, as far back as
1880 it was necessary to instal plant to condense the gaseous
chlorine and fluorine compounds ; they consisted mostly of wooden
or masonry towers drenched with water, by a Koerting's vaporizer.
The hydrofluosilicic acid obtained under these conditions can be
converted into silico- fluoride of sodium, the selling price of which
covers the cost of condensation, and leaves even a slight margin.
This product, unfortunately, has only a limited use, and ends by
becoming cumbersome. The mixer installed above the closed
"dens " or "houses " is that of Lorenz, which is universally used.^
Lately, dissolving chambers have i^een installed at a higher level,
and belt conveyors passed underneath to facilitate emptying. This
system has been adopted bv certain factories.

1895 to 1908.— Such was the situation from 1880 to 1891:.
Superphosphate factories possessed mills, machines for mixing acid
with phosphate, installed above a closed den, into which the mixture
is discharged and left to itself for twelve hours ; arrangements for
elimination and condensation of acid gases, disintegrators, or roller
mills, armed with teeth for grinding superphosphates. Mean-
while ball mills appeared, then ball mills combined with tube
crushers, then Gritfln's pendulum crusher, etc. ; dust chambers, on
different plans, were installed ; new systems of transport, such as
aerial conveyors, belt conveyors, to bring the phosphate to the
crushers, coal to the boilers, the crushed and screened superphos-
phate to the storehouse. The adoption of aerial conveyors was
a real step in advance in the supeiphosphate industry, for inde-
pendently of the economy in hand labour, they enabled the super-
phosphates to be thrown on the heap from above, thus ensuring the
good preservation of the product. The installation of aerial con-

^ Possibly on the continent, but not in Great Britain. — Tr.

EEVIEW OF SUPEEPHOSPHATE MANUFACTURE. 71

\eyoYS (with a useful effect of 85 per cent) inaugurated a new era
in the manufacture of superphosphates. It is closely connected
with electricity, the ingenious applications of which allow the use
of mechanicar equipment in all parts of the factory where it would
be impossible to erect shafting. Electricity and aerial conveyors
form a sort of connecting link between the different appliances in
the factory, and contribute greatly to their increased output.
Electric light spreads cheerfulness in all directions; the electric
motors driven from a central station work silently in the most
distant parts of the factory, the different organs of which thus work
in perfect harmony. A "vexed question is that of knowing the
treatment to which' superphosphates should be subjected from the
moment it is shifted from the den, so as to obtain in the most
simple and the most rapid manner a good product which will
keep well. To solve it, numerous processes have been elaborated,
all converging to the same end, which is to secure a dry pulverulent
phosphate easily distributed by the drill sowing machine. The
point of departure of these researches was Florida phosphate, which
from 1880 [? 1890] was and still is one of the most important raw
materials of superphosphate factories, afterwards the phosphates of
Tennessee, Algeria, and Tunis. Superphosphates made from Florida
phosphate are distinguished by a high percentage of free phos-
phoric acid which gives them a damp feeling when touched. The
rhost simple means of remedying this inconvenience consists m
drving them, and thus quite a series of driers have been constructed
for the purpose. At the present time all superphosphates, and
especially those intended for export, are dried. But it was soon
observed that if drying diminished the percentage of moisture m
the superphosphate, it increased their percentage of free phosphoric
acid, and of hvdrofiuosilicic acid, and in such conditions, whilst
appearing dry, they possessed the property of attracting moisture
and attacking the canvas of the bags.^ In 1896, it was found that
degelatinized bones, and more recently Gafsa phosphate, afforded
simple means of drying superphosphates and rendering them pulveru-
lent without exposing them to retrogradation. This point will be
reverted to in the sequel. At the same time several specialists m
this kind of work, independently of each other, have tried to find
methods of obtaining good superphosphates whilst imparting great
rapidity to the working process. In this way the grating machine
was invented (Heymann and Nitsch's process). But experience
proved that perfect"^ results could only be obtained by finely dividing
the superphosphates from the mixing den and by diminishing then-
free acidity. This result has been fully obtained. Owing to im-
proved equipment, means are available of producing from all raw

1 Steeping in gum kino extract is found in Australia to render manure bags
rot proof. — Tc.

72 CHEMICAL MANURES.

phosphates, superphosphates which answer all requirements since
it has been recognized that dryness and the pulverulent state of the
superphosphates depends in the first place not on their percentage
of moisture but on their free acid content. The recently discovered
phosphates of Christmas Island and Ocean Island likewise enable
phosphates with 20 to 21 per cent of phosphoric acid soluble in
water to be produced. Thus, as already observed, it is Florida
phosphate which has been the occasional cause of the methods of
working which we have just enumerated. This same phosphate
more than any other has put chemists to the test owing to its high
percentage of oxide of iron and alumina, which are the great
enemies of superphosphate manufacturers. The retrogradation of
the soluble phosphoric acid caused disagreeable surprises for the
chemist and manufacturer, and if the means of prevention be not
possessed by a factory working on the large scale, the causes and
conditions under which they are produced have been determined.
Chemistry, the inseparable companion of industry, has taken a con-
siderable part in the progress realized in superphosphate manufacture
from its birth to the present time. Chemists are attached to all
manure factories ; to them belongs the merit of freeing this industry
from empiricism so as to establish it on a truly scientific basis. French
chemisis have had a large part in the development of the manure
industry. Their learned researches joined to that of French geo;
logists have greatly contributed to the realization of the value of
the French phosphate deposits, the immense reserves of which will
suffice for a long time to cover the requirements of French
agriculture.^

^ That we in Great Britain have not a voluminous special literature dealing
with the chemistry of manure manufacture, in no way detracts from the merits
and claims of British agricultural and manure works chemists. Our Patent
Office records prove that they have been first in the field in all branches of
research in this domain. Both French and German current methods of pre-
cipitated phosphate manufacture, double superphosphate manufacture, and such
like, are all borrowed from British patents like those of Professor ^Yay,.
Benjamin, Tanner, etc., away back in the sixties and seventies.

CHAPTER V.

THEOEY OF MANUFACTURE OF SOLUBLE PHOSPHATES.

It has already been seen that to render the phosphoric acid in
raw phosphates soluble, when it exists as tribasic phosphate of lime
Ca3(P0J.,j i^ suffices to replace [each of] the two atoms of dyad
calcium by two atoms of hydrogen by means of sulphuric acid, the
monobasic phosphate of lime, or acid phosphate of lime CaH^(P0j2>
soluble in water, the calcium displaced by sulphuric acid forming
gypsum CaS042H20, according to the following equation : —

Ca.iPOJ- + 2H2SO4 + 5H2O = CaHj(P04)2H20 + 2CaS042H20

T_ . \ Sulphuric -r-rr x Monocalic Sulphate

phosphate '- . ^ Water. u u 4. * f-

'- £ ,. acid. phosphate. of hme.

of hme. ^ ^

310 196 90 252 344

596 596

As the equation shows, the sulphuric acid used is sulphuric
acid which has not been concentrated, that is, it contains a certain
amount of water incidental to its manufacture. This water assists-
in the crystallization of the two new compounds formed, monocalcic
phosphate and gypsum ; it, moreover, assists in thinning the mix-
ing and thus facilitates decomposition. In fact, if the mass formed
by the mixing of phosphate and acid be too thick, the new salts,
especially gypsum, would set and harden rapidly and thus bury a
certain amount of the raw phosphate which would escape the action
of the acid. Gypsum forms, as it were, the skeleton of the super-
phosphate. But the conversion of raw insoluble phosphate into
soluble phosphate is not accomplished in such a complete and
adequate manner as the equation appears to indicate. Experiments
have proved that the insoluble phosphate is rendered soluble in two-
somewhat parallel stages. The first yielding free phosphoric acid
and gypsum only extends to two- thirds of the tricalcic phosphate.
In the second the free phosphoric acid acts on the remainder of
the tricalcic phosphate, and combines with it to form acid phosphate-
of lime or monocalcic phosphate.

(73)

74 CHEMICx\L MANUEES.

(1) 8Ca3(PO,)-^ + (3H,S0, + 12HoO = 4H,P0^ + Ca.tPO^)^ + 6(CaS04 + 2H2O)
Calcium Sulphuric ,„ Phosphoric Tribasic GvDsum

phosphate. acid. Watei. ^d^^ phosphate. "^^

■(2) 4(H,P0J + Ca,(P0J2 + SH^O = 3[CaH4(P04)2 + HoO]

Phosphoric Tribasic „, , Monocalcic ^^r ,

• 1 ■^ u i. Water. . 1 . Water,

acicl. phosphate. phosphate.

One can demonstrate the soundness of this equation by treating
after equation (1) 310 parts of tribasic phosphate of hme with 196
parts of monohydrated sulphuric acid and 90 parts of water, dikit-
ing the mass rapidly with water and filtering quickly. Two-thirds
of the phosphoric acid are then present in the filtrate in the free
state. But if the mass be only diluted after it has set, all the
phosphoric acid exists in the filtrate as monocalcic phosphate. The
explanation is that phosphoric acid is a much weaker acid, and
acts much more slowly than sulphuric acid, and that is why the
reaction of equation (2) is accomplished more slowly than equation
(1). If an insufficient amount of sulphuric acid be used for con-
version, only bicalcic phosphate is obtained.

Ca,(PO,)^ + H,SO, + 6H2O = Ca,H2(POJ2,4H,0 + CaS042H20

In this conversion, a portion of the tribasic phosphate of lime is
transformed first into monocalcic phosphate CaH^(P04)^, but that
re -combines with the remainder of the tribasic phosphate of lime.

CaH,(PO,)^H.,0 + Ca..(P0J2 + 7H.0 = 2Ca.,Ho(PO,)22H.O
2o2 ^ 310 126

(5s,s 688

But the free phosphoric acid makes the superphosphate damp,
pasty, and unfit for distribution (passing through the drill, etc.) in
that condition. If the raw phosphate be rendered soluble, by
hydrochloric acid or by nitric acid, no free phosphoric acid is
obtained, but merely acid phosphate of lime, very soluble in water.
Dry superphosphates can be obtained in that way. But such acids
are less abundant and much dearer than sulphuric acid. However,
hydrochloric acid when it is to be had cheap, is sometimes added
in the proportion of 10 per cent to the sulphuric acid. But the
phosphate is not rendered soluble by pure hydrochloric acid, as
that would give rise to calcium chloride, which is highly deliques-
cent, and cause the superphosphate to be damp and unsaleable.
Moreover, calcium chloride is injurious to vegetation when present
to any great extent. In presence of sulphuric acid, the calcium
chloride is again converted into calcium sulphate and hydrochloric
.acid, which assists in dissolving the phosphate.

MANUFACTUEE OF SOLUBLE PHOSPHATES. 75

From the following equation the quantities of sulphuric acid
and water required to dissolve a given amount of phosphate may
be readily calculated : —

Ca.(P04)2 + 2HoS0, + oHoO = CaH,(P04)'-^HoO + 2(CaSO,'2H..O)
;:310 196 90 252 844

-596 596

In this connexion it will be well to bear in mind that the
symbols indicate not only the elements but precise and accurately
■determined quantities. Thus the formula for water (H^O) indicates
not only that w^ater is composed of the two elements, hydrogen and
oxygen, but also that it results from the combination of one atom
of oxygen with two atoms of hydrogen. As the atomic weight
of hydrogen = 1, and that of oxygen == 16, it will be at once seen
that eighteen of water consists of two of hydrogen and sixteen of
■oxygen. These figures apply just as much to grams as to tons.
The following is a similar calculation for phosphates, thus tribasic
phosphate of lime contains : —

Atomic

Weight.
Calcium (Ca) = 40
Phosphorus (P) = 31
Oxygen (0) = 16

1. A molecule therefore of Ca^fPOj., weighs : —

Ca^ = 40 X 3 = 120
P^ = 31 X 2 = 62
0^ = 16 X 8 = 128

310

2. A molecule of sulphuric acid H.,SO^ (H = 1 : S = 32 ;
O = 16) = 2 + 32 + 16 X 4 = 98. But tribasic phosphate of lime
requires two molecules of sulphuric acid to render it soluble ; we
thus get 2 X 98 = 196 of sulphuric acid and 5 x 18 = 90 of water.
Sulphuric acid may be calculated as SOy and H.,0, say as the
hydrate of sulphuric acid and water. To render the phosphate
soluble 5 + 2 = 7 molecules of w^ater are required. It follows,
therefore, in order to dissolve 310 parts of tribasic phosphate of
lime, that these 310 parts of Ca3(P04)., must be put in contact with
160 parts of SO3 and 126 parts of water. One part (say one ton) of

•Ca.,P.,0^ requires therefore -—^ = 0-516 parts SO., and vvv. = 0--406

parts water.

100 X 0-516 = 51-6 paits SO-
100 X 0-406 = 40-6 „ H.d

92-2 a,SOj

76 CHEMICAL MANUEES.

Now as 92-2 parts of H.^SO^ contain 51-6 parts of SO3, 100'

. 51*6 X 100 ^r f^n rir\ t • i > • -i

parts contain — qt^-t = 00 'yb SO3. It is, therefore, acid con-

taining 56 per cent of SO3 that has to be used. By consulting the
table by Lunge and Isler, at the end of the book, it will be found
that acid of that strength has the specific gravity of 1-600 = 54"" B.
or 120° Twaddel. But in actual practice it happens that the acid
used is more concentrated or more dilute. Suppose that the acid
marked 60^ B., according to the table above mentioned, contains 63-7

per cent SO3, it will, therefore, be necessary to use — ^^-^ = 81

Do ' I

parts to render 100 parts of tribasic phosphate of lime soluble, and
it would be necessary to add the required amount of water thereto.
If the acid weighs less than 54° B., say 50° B., the same calculation
is made. Acid of 50° B. contains 51 'Ol per cent SO3 of acid of that.

strength, therefore it would be necessary to use ^^ ^, — = 101
» -^ 51-04

parts for 100 of Ca3P.O.,.

Effect of the Impurities in Phospliates on their Beliaviour in
the Process by which they are Rendered Soluble. — But raw phos-
phates, moreover, contain several other compounds besides tribasic
phosphate of lime — such as carbonate of lime, oxides of iron, and
alumina, calcium fluoride, decomposable silicates, etc. If, therefore,
only the amount of sulphuric acid required for the phosphate were
taken, the latter would not be rendered completely soluble, because
the sulphuric acid would first attack the carbonate of lime and then
the tricalcic phosphate. It is thus necessary to determine the
percentage of these ingredients in the phosphate and allow for them
in calculating the acid.

Carbonates of Lime and Magnesia. — In treating phosphates
with sulphuric acid, the carbonates are attacked first. It is
generally a question of carbonate of lime, as carbonate of magnesia
is only met with rarely, for example in Carolina and Florida phos-
phates. Carbonate of lime is, therefore, dissolved at the very first,
then follow the other compounds in the order of their decomposa-
bility by acid. The decomposition of the carbonate of lime and the
consequent formation of gypsum which follows it at an equal pace,
causes an energetic reaction, which is very favourable to the
progress of the process by which the phosphates are rendered
soluble. The heat disengaged re-heats the mass, the carbonic acid,
in its efforts to escape raises the mixture and renders it porous and
spongy like a well-risen loaf in the baker's oven, and thus facilitates
drying. More than 5 per cent of carbonate acts unfavourably, in
this sense that leaving the expense of the extra acid ^ that it entails

^ But the acid is the raw material on which the manufacturer makes his.
profit !— Tr.

MANUFACTUKE OF SOLUBLE PHOSPHATES. 77

out of account, it gives rise to an excessive amount of gypsum which
brino-s numerous drawbacks in its train as will be seen in the sequel.
The quantity of acid absorbed by the carbonate of lime in normal
amount (1 part of CaCOg in tribasic phosphate of lime requires
1-5 parts of SO3 ^) is compensated to a great extent by the ad-
Tantages got in " mixing " and by the quality of the superphosphate.
Phosphates free from carbonate of lime do not heat but very
poorly in contact with acid ; the reaction is consequently slow, the
■operation takes longer and the final product is difficult to dry. To
remedy this drawback in treating phosphates of this nature, apatites
for example, it is best to mix them with phosphatic chalk when
being ground, but the superphosphate which results is not so
homogeneous as that got from the chalky phosphates of Algeria.
The amount of acid required to decompose the carbonates is calcu-
lated from the following equations : —

CaCO. + H0SO4 + HoO = CaS0;2H._,0 + CO,
100" + 98 + 18 ^ , —- ^

172 + 44

21(3 ^ . '

216
MJ.CO, + HoSO, + 6H2O = MgSO.TH^O + CO.,
84 " + yS + 108 246 + 44

•- Y

290 290

Magnesia is also met with, but in smaller quantities, as tribasic
or neutral phosphate. The following reaction then occurs : —

Mg..(P04)2 + 2H0SO, + 16H„0 = MgH4(POJ22H,0 + 2MgS047HoO
2MgHP04 + H0SO4 + 9H.p = MgH4(P04)2,2HoO + MgSO^THaO

Acid phosphate of magnesia is not deliquescent and not decomposed
by water.

Iodine. — Certain phosphates contain iodine, as calcium iodide
(CalJ, which is converted by the sulphuric acid into hydriodic acid
at the ordinary temperature of the " mixing " ; when the mass heats
the acid reacts on the hydriodic acid, and the iodine liberated
escapes as a violent vapour. Phosphoric acid has no action on
hydriodic acid.

Calcium Fluoride. — Most phosphates contain more or less
calcium fluoride. This substance is likewise decomposed by sul-
phuric acid at a temperature above 40'' C. (104° F.). It is then
given off as gaseous hydrofluoric acid. But the latter acts in its
turn on silicic acid and forms with it silicic fluoride. These two
reactions may be represented thus : —

CaF. + H,SO, + 2H.,0 = CaS0,2H.,0 + 2HF
SiO, + 2CaF, +" 2H,S0, + 2HoO = SiF^ + 2CaS0^2H,0.

1 Evidently dilute acid of 120° Tw.— Tr.

78 CHEMICAL MANURES.

The silicic fluoride makes itself felt by a penetrating acrid odour ; it
decomposes in presence of water into gaseous hydrofluosilic acid
which volatilizes, and into orthosilicic acid

3SiF, + 4Hp = 2H,SiF,, + SiO, + •2R.p

Gaseous hydrofluoric acid acts on sflicates to render them soluble : —

Al.,(SiO..)=^ + 6HF ^ Al.F, + 3H.,SiO,
Ai:,(SiO;;)=^ + ISHF -^ A1.,F, + 3SiF, + 9H.,0
CaSiO.3 + 2HF = CaF.. + H.^SiO.^
CaSiO;3 + 6HF = CaF: + SiF^ 3^,0

Ost observed that in the "dissolving" process two-thirds of the fluorine-
contained in the phosphates escapes as gas, whilst one-third remains,
as calcium fluoride; but according to Klippert 50 per cent of the
fluorine is disengaged as gas, 30 per cent remaining undecomposed,
and 20 per cent absorbed mechanically by the mass as SiF,.H^,..
Fossil bones contain up to 16 per cent of CaF^.

Silicates of Lime and Alumina. — The silicates CaSiO.,, Al^fSiOj.^
are partly soluble in sulphuric acid and partly insoluble. The lime
silicates in Algerian phosphate are decomposable by sulj^huric
acid, the silica being precipitated as a gelatinous thick swollen mass,
and can thus enclose a certain amount of insoluble phosphate of
lime which escapes being rendered soluble. The undecomposed
silicates of alumina absorb acid mechanically and are gradually de-
composed by it.

Oxides of Iron and Alumina. — The presence of oxides of iron
and alumina in raw phosphates has serious drawbacks. It may
in some cases prevent their use in superphosphate manufacture.
The iron is present in different forms, more often as oxide combined
with the phosphate, more rarely as free oxide or as protoxide (ferrous
oxide j. It also occurs as sulphide FeS- either infinitely divided, as
in Tennessee phosphate, which contains as much as 4 per cent in
the river pebbles of the Carol inas, in certain Belgian phosphates,.
or as lamellae in the phosphates of Podolia. But sulphide of iron
is generally present in too small a quantity to cause serious mishaps..
Phosphates containing protoxide of iron, ferrous oxide FeO, have a
greyish-black or a bluish-grey colour like certain Florida, Tennessee,
and Carolina river pebbles. In the process of "dissolving" phos-
phates the iron compounds are decomposed more or less rapidly
and completely according to the form in which they occur, accord-
ing to the density (? compactness) of the phosphates, the amount
and the state of concentration of the acid used, and finally according-
to the extent to which the "mixing"' becomes heated during the:
re-action.

Decomposition takes place thus : —

3FeP0, + 3H,S0, Ii (FeP0,2H,P0j + Fe,(SOj,

MANUFACTURE OF SOLUBLE PHOSPHATES. 79'

If sulphuric acid be employed in excess all the phosphoric acid is
liberated.

2FeP0, + 3H,S0, -^ 2H,P0, + Fe,(S0j;3

The decomposition of the phosphate of iron therefore gives phosphoric
acid and sulphate of iron. A portion of this sulphate ot n-on reacts
on the acid phosphate of lime and occasions a gelatmous precipitate,
whilst a small fraction remains inactive and can be detected m the
aqueous extract of the superphosphate. This amount is about 2 per
cent Consequently the presence of 2 per cent of oxide ot iron m
(raw) phosphate has practically no bad effect, that amount remammg^
as soluble sulphate if the acid be slightly increased ; as much as 3 to 4
per cent of oxide of iron always causes a loss of soluble phosphoric
acid Bevond 4 per cent the phosphate becomes unfit for super-
phosphate manufacture. In his excellent treatise on superphosphates,
Schucht insists on this special point and explains the precipitation
of the phosphate of iron thus : —

CaH,(POJ-^H.,0 + Fe2(S0,)3 + sh.O ==FeP0,2H,0 +
' CaS0/2H.0 + 2H,S0,
H.SO, + CaH,(POJ,H,0 +''H,0 = CaS0,2H,0 +^|^H ^0,
' 2(FePO,2H,0) + 4H3PO, = FeP0,2H,P0, + 4H,0

He demonstrates the course of these reactions by the following
small experiment. If one adds to a solution of a superphosphate
say an acid solution of a salt of oxide of iron, phosphate ot iron is
precipitated. But according to their degree of concentration super-
phosphate solutions act differently on solutions of oxide ot iron ; thus-
a 2 per cent solution precipitates immediately all the oxide ot iron a
4 per cent solution gives a weaker reaction, and m a 6 per cent solu-
tion the reaction occurs slowly. Consequently the greater the amount
of free phosphoric acid in a superphosphate solution, the more it
retains the iron in solution. If a solution of a ferruginous supei-
phosphate be evaporated to dryness and the residue taken up with
water, a clear solution is not obtained, but a solution with a con-
siderable precipitate. This hydrated phosphate of iron may pass m
the superphosphate into the completely insoluble state when it&
constitutional water is removed from it by the crystallization ot
the amorphous suljDhate of lime.

FeP0,2H,0 + CaSO, = CaS0,2H.p + FePO,

This explains why an incompletely dissolved or retrograded
superphosphate cannot be improved by fresh treatment with

80 CHEMICAL MANUEES.

sulphuric acid. There is then only obtained a wet tacky mass, the
acid uniting with the gypsum to form CaH2(S0J-. It is only after
a certain time, after numerous treatments followed by drying, that
this free acid ends by acting on the non-decomposed phosphate, but
not on the phosphate of iron. On the other hand, the hydrated
phosphate of iron is soluble in the free phosphoric acid of the
superphosphate, but only in a transitory fashion.

Oxide of alumina in the proportion in which it generally occurs
as AlPO^ in raw phosphates does not exert directly any influence
on the retrogradation of the phosphoric acid. Contrary to what
takes place with oxide of iron, the hydrated oxide of alumina
AloO^H.^O does not become soluble in acid until after ignition.
The hydrated phosphate of alumina as well as the anhydrous
phosphate of alumina is soluble in the precipitated condition in
phosphoric acid. That is why it is unnecessary to eliminate the
phosphate of alumina from raw phosphate so long as it exists in
normal limits. Alumina as silicate may prove injurious ; if it be
not decomposed by the sulphuric acid it may in certain cases cause
the retrogradation of a portion of the phosphoric acid.

Organic Matter. — According to the origin of the phosphates
matter is present which is carbonized in the mixing process
•either by sulphuric or phosphoric acid. The dust given off by
•certain phosphates (Algeria, Gafsa) during grinding diffuses a bad
smell which it is impossible to eliminate during manufacture.
Ignition alone suppresses it. Coprolites, Carolina phosphate, pebbles,
Algerian phosphate give off an odour of ichthyocol or of naphthene
analogous to that given off on heating petroligneous shale, limestone,
etc. These odours are due to the decomposition of the remains of
the fat of marine animals. More often, however, a penetrating odour
is given off from phosphates, resulting from the decomposition of
the remains of slightly volatile organic matter, which are
not decomposed by sulphuric acid except at the high tem-
perature incidental to the mixing process. These remains
form a nitrogenized and sulphurous charcoal, which is then con-
verted into compounds with an acrid and penetrating odour.
Certain coprolites even exude a sort of tar during drying, forming
up to 0'5 per cent of the mass. The above shows how variable the
raw materials are which are met with in course of manufacture.

Method of Determining the Amount of Acid to use in Order to
Bender the Phosphate Soluble. — It was a long time before an agree-
ment could be come to as to the quantity of sulphuric acid to use
to render the raw phosphate soluble. There v/as a plausible
reason, for the manufacturer had the alternative of completely dis-
solving the phosphate by the use of a large quantity of sulphuric acid,
and then the superphosphate so produced was too moist to be
spread by means of the drill, or of using less acid and only incom-

MANUFACTUKE OF SOLUBLE PHOSPHATES. 81

pletely dissolving the phosphate. The difficulty has been got over
by installing superphosj)hate drying machines, so that there now
need be no fear in using the requisite amount of acid to dissolve
the phosphate completely. To calculate the acid some proceed in a
purely empiric manner, by using 1 ton 4 cwt. of sulphuric acid of
50° B. for one ton of tribasic phosphate of lime, and adding the
surplus of acid necessary to saturate the carbonate of lime ; others
saturate two atoms of calcium with 550 grammes of sulphuric acid of
50° B. and increase this quantity by that necessary to saturate the
carbonate of lime and the sesquioxide, three of sulphuric acid of
50° B. for one of sesquioxide; others finally starting from the
analysis of the raw phosphate, use the amount of acid necessary to
saturate the sesquioxides and the total lime, less the portion of the
latter inherent to the formation of acid phosphate of lime. The
last method is evidently the best, seeing that it is based on
theoretical figures ; it was always used for treating guanos, which
owing to the presence of bibasic phosphate of lime, were dissolved
with the greatest ease. But as already mentioned, mineral
phosphates often contain small amounts of silicates, which likewise
absorb sulphuric acid. From the foregoing practical men have
concluded that the best method is to make a trial mixing. These
trials ought to be carried out each time on a sufficient amount of
material to fill the mixer. Accordingly the phosphate and acid are
mixed by the aid of the agitator and the process is conducted exactly
as in normal working. The reaction, which takes place in the
mixing den, does not consist solely in the heating of the materials,
as one would be inclined to imagine, because if that were the case
the same result would be attained by heating the sulphuric acid or
even the material on which it acts when working on the small
scale. In the case of certain mineral phosphates, such as Canadian
apatite, mixing test trials never succeed, because the phosphoric
acid formed in the first phase of the operation cannot immediately
exercise its action on the rest of the phosphate. The operation
drags, the substance remains pasty, the sulphuric acid attracts
moisture, its action gradually becomes weaker, and, finally, a bad
quality superphosphate results.^

It is thus necessary when new phosphates are to be used, the
behaviour of which in mixing is unknown, to make trial mixings
with a larger quantity of acid than that got by calculation, and to
adhere afterwards to the amount which gave the best results. With

lA rough trial test giving useful indications may be made when new
phosphates of unknown behaviour are being bought in the slack season by
treating the phosphate with acid in an earthenware bread pan, not stirring too
much and setting aside with the pan Ud on and inspecting the result after
24 hours' standing in a warm place. If the mixture dries, then it will dry far
better on the large scale. — Tb.

6

82 CHEMICAL MANURES.

Florida phosphate good results are obtained by increasing the
theoretical amount by 5 per cent. It is easy to understand, more-
over, that the richer the raw material is in phosphoric acid the less
it should be over-acidified, because the phosphates of that category
generally contain little sesquioxides or silicates capable of absorb-
ing the acid added in excess. Phosphates rich in carbonate of lime,
such as Somme and Algerian phosphates, stand much acid ; how-
ever, the excess of acid rarely surpasses 5 per cent of the quantity
calculated according to their percentage of phosphoric acid.^

If the trial mixing be well conducted it gives very satisfactory
results. The superphosphate obtained should be comparatively
dry and porous when it is cold. After each trial the phosphoric
acid, soluble in water, is determined, the free phosphoric acid and
the insoluble phosphoric acid. Bone phosphates are almost com-
pletely rendered soluble. But it is not so with mineral phosphates,
which always leave a small amount of insoluble phosphoric acid.
This fraction amounts to about 1*4 for Gafsa superphosphate, 1*7
for Algerian, 1'4 for Peace River and Pebbles, 0*5 to 1 for Florida,
1-7 for Carolina, and 2-1 for Tennessee (Schucht). Up to now the
efforts of scientists and practical men have been powerless to
abolish this loss. The density and strength of the acid play a
<;ertain role in mixing. Phosphates rich in carbonate work best
with cold acid, whilst those poor in carbonate require hot acid. It
has been found, moreover, that the soluble phosphoric acid is better
preserved in superphosphates prepared with acid of 54° B. than in
superphosphates made with acid of 60° B.

Damp phosphates and those difficult to dissolve require stronger
acid than when dry and rich in carbonate of lime.

Finally, it is well to bear in mind that superphosphates should
contain a certain amount of free phosphoric acid. That has the
effect of retarding the decomposition of the acid phosphate of lime
in the soil, and regarded from that point of view it constitutes an
indispensable element of the superphosphate.

Schucht shows in the following table the amount and the
strength of acid which it is convenient to use in rendering various
phosphates soluble.

^In the translator's experience with Somme phosphate, 60 to 62 per cent
Ca-PaOj,, he found that it invariably took exactly its own weight of sulphuric acid
calculated as B.O.V. He preferred to use acid heated to 150° F. Somme
phosphate rises much more in the mixing den than Carolina, so that it will hold
nearly twice as much Carolina super as it will of Somme super. But great care
must be taken that there is no flaw in the closed steam pipe heating the acid, or
the acid may gain access to the boiler. The translator had a ease of this sort
where the engineer, after ruining his boiler, in order to escape censure, tried to
blame his well-water as being naturally acid I — Tr.

MANUFACTURE OF SOLUBLE PHOSPHATES. 83

T\BLE XLL— AMOUNT AND STRENGTH OF ACID REQUIRED TO
DISSOLVE VARIOUS PHOSPHATES.^

Ca3P208

Per cent.

Bone ash .
Maiden guano .
Aruba phosphate
Curasao phosphate
Podolia coprolites
Carolina phosphate
Canadian phosphate
Somme phosphate
Liege phosphate
Ciply phosphate

Florida phosphate
Pebble phosphate
Peace River phosphate
Tennessee phosphate

Algerian phosphate

Gafsa phosphate
Clipperton guano
Peruvian guano .
Precipitated phosphate
Steamed bone dust
Degelatinized bone dust

82-1
72-4
78-6
88-0
74-7
56-0
76-8
67-0
55 -5
40-7
48-2
53-8
57-4
78-0
.68-0
61-7
80-5
69-9
58-2
65-0
59-6
78-7
26-2
32-0
22-0
31-0

Oxide of
Iron and
Alumina.
Per cent.

Carbon-
ate of
Lime.

Per cent.

100 lb. of
Phos-
phate re-
quire lb.
of Acid.

Degree
Baume.2

0-3
0-3

3-8

0-
5-
2-
3
3
3
2
1
1

0-8
2-0
1-8
2-9
3-4
2-3
0-5
0-6
1-7
0-1
0-5

0-4

4-4
12-5
4-2
7-0
4-7
12-0
6-6
10-2
16-8
41-8
35-6
34-2
29-1
4-4
6-3
8-4
5-2
6-0
20-8
16-0
9-7
6-7
1-8

5-2

95
82
100
105
120
100
110
105
105
131
125
130
125
110
100
95
110
105
110
100
100
100
25
55
70
74

52

60

52-5

50

50

50

55

51

50

49

49

49

49

50

50

50

50

50

50

52

50

52

60

60

50

55

1 Such a table is of course very valuable, but it is better to calculate all
acid to B.O.V. whatever be the strength used. That keeps the acid account
correct. At stocktaking the manufacture then shows a gain in weight, but that
is all to the good, a sort of manufacturer's own private bonus. But if the
different strengths of acid used be all entered at the actual weight taken then
there can be no chemical control of the amount of acid used; nor if the
manure manufacturer makes his own acid of the amount of acid he has made.
The general rule is to take the stock of acid in hand, calculate it to B.O.V. ,
add to it the amount used in mixing, and take that as the amount of acid made
in the season, which, checked against the pyrites burnt, say Rio Tinto, should
give a yield of 30 cwt. B.O.V. per ton of pyrites burnt.— Te.

2 (1) 49° B = D = 1-515 = 103 Tw. (2) 50° B = D =1-530 - 106 Tw. (3) 51=
B = D L 1-546 = 109-2° Tw. (4) 52° B - D = 1-563 = 112-6 Tw. (f) -52-0° B
= D = 1-572 = 114-4° Tw. (6) 55° B = D = 1-615 = 123° Tw. (7) 60° B = D
= 1-710 = 142° Tw. (8) Acid in Great Britain is generally used as near D -
1-60= 120° Tw. as practicable. B.O.V. is acid of D = 1-700 or 140 Tw.— Ik.

CHAPTEK VI.

MANUFACTURE OF SUPERPHOSPHATE.

The manufacture of superphosphate comprises three principal opera-
tions: 1. Grinding the raw phosphate. 2. Rendering the ground
raw phosphate soluble by sulphuric acid. 3. The drying of super-
phosphate.

Grinding Raw Phosphate. — Eaw phosphate should be carefully
ground, because it is found that the fineness of the phosphate con-
tributes to a great extent to a perfectly successful superphosphate.
Thus the powder should not leave more than 10 per cent of residue
on a 70 mesh sieve, and this residue should not exceed the size of
groats ; it is only at this cost that all the phosphoric acid is rendered
soluble. Certain phosphates are delivered ground, others in lumps
of the size of the fist. To lend itself well to grinding the phosphate
should be dry. Florida phosphate especially should not contain
more than 1 per cent of moisture, whilst Algerian phosphate grinds
very well with 5 per cent of w^ater. When dealing with phosphate
drenched with sea water in transit or accidentally in the warehouse,
it is extended on a drying platform of sheet iron heated by the com-
bustion gases [over the fiues from the boiler furnaces]. In the
grinding of phosphate at the present day ball-mills — continuously
feeding and discharging — are in general use, which owing to their
strong construction and their stable working answer well for the
purpose. In older factories flatstone mills are frequently used.
Griffin's crusher with walking beam has likewise some rare partisans,
but it is costly and requires frequent repairs w^hich become heavy
in the end. The material to be introduced into this mndins-
machme ought preferably to be reduced, and for that purpose edge
runners are suitable. The crusher, with blades — disintegrator — is-
likewise used, but only to crush phosphate in large nodules or rock
phosphate. These machines will now be briefly described, along with
the other grinding machines commonly used in the manufacture of
chemical manures.^

^ But superphosphate and chemical manures generally were made in Great
Britain by mechanical means for the last tifty years at least. However,
if France was originally twenty years behind the times in manure manu-
facture, it has more than made up for it by recent progress. But Great Britain

(84)

MANUFACTUEE OF SUPEEPHOSPHATE.

85

Grijiding Machines — Edge Bunners. — Edge runners consist
generally of two stones turning on a circular plate round a
vertical shaft ; at the same time each stone turns round its own
horizontal axis, and grinds the material both by crushing and
rubbing. The horizontal axes of the two mills are independent of
one another, and each connected with the vertical shaft by means
of a hinged crank. The stones can thus be raised or lowered inde-
pendently the one of the other. The material is fed into the mill
directly, by the shovel or by an elevator ; it is drawm continually

Fig. 1. — Vertical Edge Runner.

under the stones by collectors, and when it is sufficiently ground,
it is evacuated by the automatic discharge, sifted and bagged up.
Fig. 1 shows a pair of edge runners. Tw^o men suffice to attend to
the mill, the elevator and the sifting machinery.

Flatstone Mills.— Ylntstone mills are built either with the upper
stone stationary or the lower stone stationary, according as it is
the upper or lower stone that revolves. Mills of the first kind are

is not standing idle. A manure work at Forres away in the " Farther North "
has recently been equipped with automatic shifting machinery for removing
manure from the " den". — Tr.

86

CHEMICAL MANUEES.

used for crushing very hard phosphate, those of the second kind
for soft phosphates. The foundation consists of cast-iron cohimns
or a hollow cast-iron support, on which the cage of the mill is
fitted up. The shaft of the mill is sustained by a movable bearing
with collar ; its lower part rests in a socket. The bearing with
collar is screwed to the bottom of the mill cage and completely
protected from dust. The adjustment of the revolving millstone is

Fig. 2. — Flatstone Mill. (Lower stone dormant.)

done by means of an endless screw or by lever transmission with
screw, and hand fly-wheel. The number of revolutions is 120 per
minute for mills 5 feet in diameter, under which conditions a mill
can grind about 5 tons of phosphate per hour, with 20 H.P. The
mill is fed by a cup elevator and a shaking hopper, a single work-
man w^ith an assistant can attend to two pairs of stones placed
side by side. The mills of the same group are generally driven by

MANUFACTUEE OF SUPERPHOSPHATE.

87

a single main shaft by direct cog-wheel gearing. Generally three
pairs of stones are in use, two of which are at w^ork and the other
pair being faced. Fig. 2 shows two mills w^ith the lower mill station-
ary arranged in a group driven with a common shaft by conical gear-
ing.

Ball Mills. — The ball mill consists essentially of a rotary drum
enclosed in a double cast-iron envelope and sieves. It contains a
certain number of balls of different sizes. The inside face of the

Fig. 3. — Ball Mill on Masonry Foundation.

bottom of the drum is lined with smooth plates of hardened cast-
iron or of cast-steel. The circumference consists of triturated plates
of cast- steel, and of such a shape that it creates a fall between two
consecutive pieces. It follows that during revolution the balls fall
from one plate to the other, and roll during the interval between
two falls. Grinding is thus effected, by the shock of the balls and
by crushing. The substance ground in the ball mills passes through
holes in the triturating plates and falls on a first sieve, called the

88

CHEMICAL MANUEES.

protection sieve, which retains small fragments of material and only
allows particles of a certain fineness to pass through. The fine
grains then fall on a second sieve, which is the outside sieve, the
wire gauze of which is selected according to the degree of fineness
desired. The powder of the desired degree of fineness passes through
this gauze and falls into the discharging funnel at the bottom of the
machine, where it is bagged up. The cores from the two sieves are
collected inside the mill by two openings arranged for the purpose,
and again submitted to the action of the balls. The mill is fed

Fig. 4. — Ball Mill on Masonry Foundation — the Sieves exposed.

through a hopper fitted over one of the bosses, which has helicoid
blades. During rotation of the mill these bring the lumps into the
interior after the style of an endless screw. The wrought-iron
cover is connected by a cloth jacket with a chimney which maintains
the pressure of the air in the cover in equilibrium and evacuates the
dust which is given off during grinding. The weight of the balls
varies according to the nature and quality of the material to be
ground. The mills in general use have a diameter of 6^ feet and a
section 39-3 inches. The charge of balls is 1 metric ton. These

MANUFACTUEE OF SUPEEPHOSPHATE.

89

naturally wear. It has been found that in grinding Florida phos-
phate forged steel balls lost 1 kg. (2'2 lb.) in a year working day and
night whilst cast-iron balls lost 420 grms. (nearly 1 lb. : 0*924:) in
twenty-four hours. Their weight must thus be verified from time
to time. To start the mill it is turned empty for half an hour to
see whether the bearings heat. Then only is it charged with balls
and phosphates. The drum ought always to be sufficiently full of
material to be ground so that the falling balls produce a dull or

siilsJiUirsluaiiiiuiiiiutjaei'iilwiailL

Fig. o. — Ball Mill on Masonry Foundation — the Trituration Plates exposed.

'deadened sound. Consequently, as soon as a bag of ground material
is taken from the mill, it is fed with another through the hopper.
When the mill has not sufficient feed its output is small and the
workman is tempted to increase the load of balls, which has many
•drawbacks. The outside sieves are mounted on marked oak-frames,
which prevent them being inverted, for they are not interchangeable.
To stop up gaps or tears the simplest way is to glue pieces of calico
■above them with fish glue. During stoppages the inside of the

90

CHEMICAL MANUEES.

drum is carefully inspected, the screws of the frames tightened, and
those of the manhole doors, because, in spite of the use of double

tea c- ' VJ.-f ' ' "%
IpHlliili'i ' S i ^ :il

o

ice

screws, they are liable to become loose under the trituration to which
they are exposed. Care must be taken to keep the sieves in perfect

MANUFACTUEE OF SUPERPHOSPHATE.

91

condition. If the output of the mill decreases, the inside and out-
side of the sieves must be speedily cleaned. For that purpose the
double envelope must be removed by a chain and counterpoise.
In grinding wet phosphate the sieves get choked and they must be
replaced bv new at close intervals. It suffices in order that the
phosphates"^ can be rendered soluble that they pass through Nos. 60
to 80 mesh sieves, according to their origin and their nature. Thus
Algerian phosphates and Carolina phosphates are passed through a
No. 60, whilst coprolites, apatites, and Florida phosphates must pass^
through a 70 mesh sieve. Guanos and bone phosphates do not
require to be ground so fine, owing to their capillarity, which lets the
sulphuric acid penetrate easily into the interior of the granules.
It suffices to i^ass them through a No. 50.

Eist of the separate pieces forming Krupp's Ball ^Mill.

a

b

b'

n

c

ci

cl

<1

e
f

9
h

k

k^

I

Triturating perforated plates.

)i

Damper.

Collar screws.

P

Anchor plates.

Chimney plate.

r

Cog wheel.

Chimney cover.

yi

Pinion.

Lateral plates ifeed side).

r2

Fixed pulley.

Lateral plates (rear side).

7-3

Loose pulley.

Screws of lateral plates.

,.4

Case for same.

Coarse screen.

.,.5

Lubricator.

Screw of same.

s

Dust cage.

Fine sieves (frame and cloth).

.si

Wooden supports.

Screws of sieve frame.

s-

Collecting hopper and pipe.

Discharging funnel of dust cage.

t

x^nterior lateral side.

Kevolving blades.

t^

Lateral posterior side with man

Blade screws.

hole m.

Protection screens.

f-

Manhole lid.

Support of coarse screen.

V

Cog wheel shaft.

Opening for the return of

w

Main shaft.

material.

X

Frame work of dust cage.

Feed hopper.

x^

Corner of the frame work.

Screw of hopper leg.

y

Aeration chimney.

Feed and boss.

y'

Coarse cloth union.

Screw of feed boss.

z

Eear boss.

Column supporting hopper.

z^

Screw^ of boss.

Rear column.

z^

Fixing screw.

Gearing columns.

As already mentioned, the ball mill is surmounted by a chimney^
This ends in'' a dust chamber on the floor above ; this chamber is
itself provided with a ventilating pipe on the side opposite to that
of the mill. When the chamber is not sufficiently well ventilated,
the entrained steam condenses, the dust becomes wet, and the
wood rots. It is, therefore, well to cover the sides with a coat of
tar. In front of the chamber, that is to say on the spot where the
dust collects, start two pipes closed by dampers, through which the
dust falls into the grinding-room. It is, likewise, advisable to add
a fan to the dust chamber, so as to renew the air in the grindmg-

92 CHEMICAL MANUEES.

room. A greater quantity of dust then collects in the chamber,
Avhich then requires more frequent cleaning out. A fan making
200 revolutions suffices for two mills. A ball mill 6^ ft. requires
20 H.P. ; it grinds 7^ tons of Florida phosphate, so as to pass
through a 70 mesh sieve in twentv-four hours. It works contin-
uously, and yields in a single operation a sifted and ground substance
without other preparation than previous "cracking" up of the
phosphate so as to reduce it to lumps the size of the fist.

In certain cases, especially in grinding basic slag, particles of
iron may remain in the mill, which cannot be ground. They are
removed through an opening made in the side which in normal
work is closed by a lid which can be replaced by a discharge grating.
The distance between the bars of this grating being inferior to the
normal diameter of the balls, it suffices to give a few turns to the
xnill to evacuate the residual matter. In large-sized mills a man-
iiole, fixed in one of the cheeks, enables the interior to be inspected.
Ball mills have been the subject of many improvements. Those
made by the firm of F. Krupp, Grussonwerk, Magdeburg, are of
such solid construction as to stand anv test and work for years
^thout any repairs. The construction of this machine requires,
in fact, a powerful equipment and select materials, conditions to
which sixth-rate constructors can make no pretension.

P/eiffer's Mill loitli Combined Air Separator. — This ball mill,
amongst those just described, is the most interesting owing to its
•originality and its great working capacity. But its yield is per-
force limited by the simultaneous sifting of the ground material ;
it gradually diminishes the fineness of the sieves, the surface of
which is, moreover, too small compared with the work of the mill.
Moreover, if the mill be overfed, the substance treated penetrates
into the cavities of the sieve before being reduced to the desired
fineness ; the sifting is then retarded as well as the normal work of
grinding. But affairs are radically altered if the powder be sifted
separately. There is then no obstacle to the enlargement of this
machine. This improvement has been effected by the firin of
Pfeiffer Brothers of Kaiserlantern. Bv combining the ball mill
with an air separator they have succeeded in creating a system of
.grinding remarkable for its great simplicity, and in increasing con-
siderably the useful effect and output of the mills. The construc-
tion of the machine differs from that of the ball mill in the following
details. The grinding-stages are comparatively small, each consists
of a single piece of crucible cast-steel made with particular care,
they have no slopes nor orifices of any kind to weaken them.
Consequently they maintain their mechanical resistance to the
last stage of wear and tear. There is no fear with this machine of
the balls plugging the escape orifices, besides there is no need to
-enlarge these orifices by a rimer. The good construction of the

MANUFACTURE OF SUPERPHOSPHATE.

m

Fig. 8.— Pfeiffer Separator.

YiG. 9.— Pfeiffer's Separation Cone.

94

CHEMICAL MANUEES.

triturating plates and the quality of the metal used render them
almost everlasting. The elevations (? incline) from one stage to
another are fitted with orifices which allow the sufficiently ground
material to escape. These orifices can be regulated from the out-

FiG. 10. — Section of Pfeiffer's Crusher- Separator.

«ide. They may be contracted or enlarged as required, so as to
reduce the material to the required degree of fineness. As in
ordinary ball mills, the wrought-iron cover which surrounds the
drum ends in its lower part in a hopper ; this collects the ground
material and leads it to a cup elevator, which conveys it to an air

MANUFACTUEE OF SUPEEPHOSPHATE.

95

•separator, generally placed above the eqUI. In this air separator,
the fine flour is separated from the grains by means of a current
of air produced in the machine itself and circulating there. The
machine has only three orifices, the feed entrance, and the exits for
the granular material, and for the flour. It requires neither sieve,
dust chamber, nor auxiliary apparatus of any kind. The separator is
shown in section in Fig. 10. The machine is constructed of wrought-
steel, and consists of a cylindrical envelope with exterior cone and

v;(.'.yi'*«iift;i-

Fig. 11. — Perspective view of Pfeiffer's Crusher- Separator.

an interior cone arranged at a certain distance from the other.
The ventilator g is driven by the shaft /. On the same shaft,
below the ventilator, are two plates, b and d, which receive the
material from the feed funnel a. In consequence of the rotation,
the distributors y project the substance in all directions, and the
current of air produced by the ventilator passes from below, up-
wards. The force of the current raises the fine particles and
carries them in its train through the ventilator, and projects them
against the exterior side, whence they fall into the exterior cone

96

CHEMICAL MANUEES.

and issue from the central aperture. The larger granules contained
in the material which have traversed the current of air, without
being carried away in its train, fall into the interior cone and issue
by the lateral pipe, to repass into the mill if need be. The air
returns naturally to the space below the distributor, so that the
separator works constantly with the same amount of air, and so as
to disengage no dust. The rods, with pins, to be seen on the cover
of the separator, serve to raise or lower the annular obturator
which regulates the degree of fineness of the substance. The force
of the current of air diminishes in proportion as the obturator is
raised. By these simple means, any degree of fineness can be
secured. Once regulated, it works without interruption and super-
vision, and always gives a very uniform product. The ground
phosphate can be bagged up directly or conveyed to silos, etc.,
whilst the granules return to the mill to be further ground.

Jaw-hreaker Mills, Cracking Mills. — The jaw-breaker mill
shown in Figs. 12 and 13 consists essentially of two jaws, a and A',

Fig. 13. — Jaw-breaker Mill (view from
above).

Fig. 12. — Jaw-breaker Crusher.

of hardened cast-iron, dented or smooth. One of these jaws A" is
fixed on the anterior side of the framework, the other A' is mobile
and fixed on a jaw-holder which is animated by a to and fro motion
round its axis /. This motion is transmitted by the excentric
driving shaft c, through the intermediary of the excentric crank
B' and of a folding lever, formed by two hinge plates, BB, applied
one on the framework in d and the other on e on the lower part
of the movable jaw- holder. To avoid shocks the latter is joined
in an elastic manner with the crank B, by means of the spring g.
For each revolution of the shaft c the space A comprised between
the fixed jaw-blade and the movable jaw is contracted, and its

MANUFACTURE OF SUPERPHOSPHATE.

97

minimum aperture determines the size of the crushed pieces."^ The
angle of the aperture of the jaws is easily adjusted by a very simple

I

p
>

(D

'o

o
o

•^

t^

regulating arrangement, according to the nature of the material to
be ground, and the degree of fineness required. The size of the
pieces may varv from 2 to 7 cm. in section, with a proportion of

7

98

CHEMICAL MANURES.

core, which depends on the degree of friabihty of the material.
The hinged plates BB form safety pieces, they avoid all sudden
shock, such as would be caused by the passage of a hard body,
a piece of iron, for example, and then yield without any of the
essential part of the machine being damaged. This mill is used
for the preliminary crushing of rock phosphate, or phosphate in
nodules of a certain size. It is fitted with two very powerful fly-
wheels, which ensure regularity in working. A crusher of this

^^ liil^

m^mm^

Fig. 15.— Double EoUer Mill.

sort making 200 revolutions a minute can crush 5 tons of phosphate
an hour with 3 H.P. Hand cracking, formerly in vogue, is now
only adopted occasionally, when the quantity of phosphate in large
lumps is not enough to warrant the use of the engine.

Toothed Boiler Mills. — To crush green (raw) bones for fat ex-
traction simple and double mills are used with toothed steel rollers.
The rollers of the simple mill consist of a certain number of steel
discs fitted with teeth, and of united intermediary rings in juxta-

MANUFACTURE OF SUPEEPHOSPHATE.

99

position, in such a manner that the teeth of one of the rollers corre-
sponds to the rings of the other. The discs resist any test and are
readily replaced. The distance between the rollers can be regulated
according to the size of the grain desired, by means of a regulating

Fig. 16.— Stamping Mill.

screw fitted with a spring stud. This machine reduces the_ bones
to the size of a nut, mixed with granules [?| inch bones], which are
separated by sifting. The double mill comprises two pairs of rollers
in a strong lateral framework. The upper pair is provided with big
teeth and turns at a less speed than the lower pair, the teeth of
^hich are finer. These double mills take bigger bones (whole ox

100

CHEMICAL MAXUEES.

or horse heads) than the simple mills. They thus grind fineiv
which is an advantage in making gelatine, when it is desired to
make as complete an extraction as possible and to obtain gelatine
of good quality. The output of these machines is about 1^ tons of
crushed bones per hour.

To grind degreased bones cast-iron stamping mills, fitted with a
steel grate in the bottom, and on the longitudinal side with wrought-
iron sieves, are used. The fineness of the holes in the grating and in
the wrought- iron sieves depends on the fineness of grain desired.
Stamping mills are of 1, 2, 3, 4, 6, 8 or 10 stamps of 1 cwt. to 2
cwt. ; their yield per hour is about ^ ton of ^ inch bones.

Disintegrators — Mills luitli Percussion Blades Fitted in Circular
Bevolving Boss. — For grinding raw bones, dried meat, and blood.

Fig. 17.-

-Disintegrator.

disintegrators are used with advantage. The mill consists essenti-
ally of a framework with vertical grinding cage, in which a bo ss-
fitted with blades revolves at great speed. The cage consists of
two lateral sides and of a cover of wrought-iron, and a semicyli n-
drical grate in two pieces, or completely cylindrical in four piec es.
The lateral sides are lined inside with grooved plates of harden ed
cast-iron. According to the size of the mill the material to be
ground may be in fragments of the size of an egg to that of the fi st.
When it is fed through the hopper it is seized by the blades a nd
projected against the grinding plate and the steel bars ; it th us.

« 4 •

MANUFACTUEE OF SUPEEPHOSPHATE.

]C1

undergoes very energetic grinding ; when it is reduced to the desired
fineness it passes through
the bars of the grate as a
pulverulent product con-
taining more or less core.
For a width of | of an
inch the yield per hour is
about 2 tons of degreased
bones. 1 (See pp. 173 et
seq.)

Elevatcrs. — Cup ele-
vators are generally used.
Gall'swTOught-iron chain
and Ewart's chain de-
serve notice. These con-
sist of small elements
moving one within the
other after the style of
a hinge. Leather belts
and rubber belts are only
used exceptionally. The
cups are of wrought-iron
and furnished in the front
w^th a steel armature ;
they are screwed on the
elevator. Their dimen-
sions vary with the size
of the factory. Cup
chains are generally fitted
with a tight cover, enclos-
ing the whole machine,
and thus preventing the
disengagement of dust in
the factory. This cover
comprises a cast-iron feed
vessel with the top part
of wrought-iron, and two
square wrought-iron pipes
carrying at their upperex-
tremity a hood or coping
of wrought-iron fitted with
a discharge pipe ; wooden
feed vessels and covers

may be made on the spot.

Fig. 18. — Cup-chain Elevator.

^ This output abnormally high even for degreased bones through such a fine
sieve, seems quite out of the question for raw bones. Bone grinding to such fine-
ness is a tedious process. These machines, moreover, are like " short distance
sprinters " — they soon fall out of gear, the belt comes off or breaks, the
machine is blocked or the blades are smashed. — Tr.

102

CHEMICAL MANUEES.

Sieves. — The sieves used in the chemical manure trade are of
two kinds, viz. sorting sieves and sieves for fine flour. The
sorting sieves are combined with the coarse crushers and serve
to sort the crushed material ; what passes through the sieve is
taken to the mills to be reduced to a fine powder, whilst the core is
returned to the crusher to be again crushed. Machines of this nature
are conical or cylindrical. They consist essentially of an axis,
which passes through their entire length, and carries iron stays, on
which a perforated sheet-iron sieve, more rarely a metallic wire
gauze sieve, is mounted, the meshes of which have a section varying
with the nature of the material to be ground. They are fitted with
a feed hopper and a discharge pipe.

The second class of sieves are more especially used for the
sifting of the flour produced by the mills. They are also used to

Fig. 19. — Sifting Machine (driven direct, enclosed in wood cover).

sort bone' dust. The matter which passes through the sieve is
bagged up, whilst the core is returned to the mills to be reduced
to the desired fineness. As this material gives off much dust the
sieve is generally covered in. Discharge pipes pass through the
bottom of the cover. The construction of this machine varies
according to the nature of the material treated — with substances
easily sifted, the cylindrical form is used, whilst with substances
which pass through difficultly, a hexagonal sieve fitted with a beater
is used ; the frames of the sieve are interchangeable and easy of
access. Fig. 19 shows a sifting machine, driven direct, with
wooden cover, constructed by Krupp. Besides these cylindrical
sifters, shaking sieves are also used, comprising one or more flat
sieves lodged inside a cover. The cover rests on springs or is
suspended or driven by a crank shaft.

MANUFACTUEE OF SUPEEPHOSPHATE. 103

Filter Press. — The filter press is capable of interesting applica-
tions, not only in the manufacture of double superphosphates and
precipitated phosphates, but also in the treatment of raw phosphates,
in view of their enrichment each time that they have to be washed
or mixed.

After mixing, the materials have a semi-fluid, non-pasty con-
sistency. It is, therefore, necessary to separate the solids from
the liquid mass in which they are suspended. The old decantation
process gave good results. But it is easy to understand that the
enormous quantity treated daily adapted itself badly to such an
extremely slow process requiring numerous vessels and consider-
able space. In well-organized factories at the present day, a rapid
decanter answers an urgent want. This rapid decanter is
nothing more or less than the filter press, the yield of which is
twenty times greater than that of the old process.

Under a small compass the filter press is, therefore, an apparatus
presenting such a filtering surface that the solids and liquids are
automatically and instantaneously separated. This apparatus con-
sists essentially of a certain number of wood or metal plates
separated by hollow frames, in which the solid matter aggregates
as more or less compact cakes, whilst the liquid is pressed outside,
passing through appropriate filter cloths.

The filter press is fed by a pump which propels the mud into
the filtering chambers. The chambers are made tight by the pres-
sure system of the filter and by the packing which the filter cloths
give between the different plates when the latter are pressed in
the centre. As regards the filtration of phosphatic material,
manures, etc., the filter presses ought to exhibit such peculiarities
of construction as to ensure the flow from the material without the
formation of channels during the course of the operation. On the
other hand, when the cakes are formed in the frames of the filter
presses they still contain a certain amount of mother liquor. To
obtain products as pure as possible these cakes must be washed
thoroughly to purge them from the liquids which they contain.
The filters should be so arranged that this operation of washing is
thoroughly and absolutely effective. The " Etablissement des Filtre
Philippe " of Paris, with whom the author has had business relations
for more than twenty years, has specialized for many j^ears in the
construction of special filter presses for manures. Its make
exhibits all guarantees for good working according to the nature
and consistency of the products to be treated.^

Mixing of the Phosphate icith Sulphuric Acid.— As already
mentioned, the phosphate was formerly rendered soluble m pits,
where the acid and phosphate were hand-mixed with suitable tools.

1 The best duck (cotton) fabric will not stand superphosphate liquor a day.
The writer found a woollen blanket to stand well. — Tr.

104

CHEMICAL MANUEES.

PL,

Fh

o

O

MANUFACTURE OF SUPERPHOSPHATE. 105

In other words, they wrought hke masons making mortar. But for
thirty years this work has been done exchisively by mechanical
means, which enables the work to be done more rapidly and in
larger quantities at a time.

Consequently the mixing pit has been enlarged so much that in
its new form it constitutes the chamber, or more familiarly the " den "
or " house " in which the phosphate is rendered soluble. This
chamber is closed, and care has to be taken to eliminate and render
inoffensive the toxic gases which are disengaged from the material
during its decomposition.

To mix the acid with the phosphate a "mixer" or mixing
machine is used, constructed and installed thus : The mixer con-
sists of an egg-shaped pan 1-6 metre wide at top (say 64 in.), and
1-20 metre (say 48 in.) wide at bottom, fitted with two discharge
doors, with lever and counterpoise, which enables the mixing to be
run into an enclosed space, called the decomposition chamber (" den "
or " house "), which is built on the ground floor or sunk in the ground.
In the pan a vertical shaft turns, driven by cog-wheel gearing,
and carrying blades of a special form arranged in a helicoid
manner ; . these lift, throw down, and triturate the mass, after the
style of a plough as it works the ground, and prevent it at the
same time from being deposited and attached to the sides. It
suffices to pull the bent levers to open the discharge doors, and
thus let the hquid a jniree fall into the decomposition chamber
("den" or "house").

The work is easy and rapid. The pan is made of cast-iron, with
2 per cent of a special alloy which renders it very resistant to acid.
The arms of the agitator and the blades as well as the valves are of
cast-steel. The mixing shaft makes sixty turns a minute ; the mix-
ing is triturated (churned) until the pulverized phosphate is intimately
mixed with the acid. When the ground phosphate is too coarse to
pass through a 70 mesh sieve the mixture remains longer in the
liquid state, and then the length of time occupied in mixing must
be prolonged. The acid, contained in a lead-lined tank, is drawn into
a measuring tank by turning a valve ; it flows through a If inch
lead pipe into the mixer in the form of a shower of rain. At the
same time the crushed phosphate — previously weighed and laid on
sacks on two inclined planes to right and to left of the mixer — is run
into the mixer. In certain factories the phosphate is brought to the
mixer by an elevator, and received in buckets by means of which it
is run into the mixer. The bags retain about 1 per cent of phos-
phate in the fabric. The mixer can take a charge of 225 to 250
kg. (495 to 550 lb.). When the phosphate is rich in carbonate of
lime the mixture froths and threatens to prime. Such a mishap
is obviated by diminishing the amount of x^hosphate. The acid and
phosphate ought to be run in simultaneously and never after each

106

CHEMICAL MANUEES.

other. The mixer works continuously ; no stop is made except in
case of a breakdown. When one " mixing " is finished the sides of
the mixer are rapidly dusted with a little phosphate to neutralize-

J S -M—

Trn , ^u: J L '

r ^1 ■lii, ; - ~ — .

Mim\\mmimAAmmmmm]sm-

iii!»iiiiiii iiiimiifii niiiiiini'i ii'iiiii iiiiriiiiiii nin|i|iiii' liiilinm

Fig. 21. — Mixer installed above the Superphosphate " Den ".

any free acid left there which might corrode the metal. The work-
ing of the mixer requires three men ; the first takes charge of the
machine, the second superintends the measuring and running in of
the acid, the third brings the sacks of phosphate. The charging of

MANUFACTURE OF SUPERPHOSPHATE.

107

the mixer lasts 1-j minutes ; agitation takes two minutes, according-
to the nature of the phosphate ; discharge takes half a minute.
The " den " may be filled to | of its height ; the vacant space serves as.
a regulator for the evacuation of the gas. The decomposition of the
phosphate by acid is effected not in the mixer, but principally in the
"den" or "house". Cold acid is used, i.e. acid the temperature
of which varies between 25^ and 30° C. (77° to 86° F.), and of a
density between 50° and 55° B. (106' to 128° Tw.). When the-
acid is at a lower temperature, the mixing does not heat enough
to drive off the water, and yield a dry superphosphate. When the
acid is too hot the mixing thickens too much in the mixer, in w^hich
case the acid may be further diluted.

Fig, 22, — A. Mixer. B. Counterpoise. C, Gas Escai:e Pipe. D. Cup-
Elevator bringing the Eaw Phosphate, E. Phosphate Reservoir. F. Balance
for Weighing the Phosphate. G. Screw Conveyor, H, Feed Hopper. I. Acid

KK, Underground Conveyor. L. Exit of Toxic Gases.

Measuring Tank

Owing to the gas given off, the thick liquid effervesces, and forms-
air-bells which rise to the surface ; at the same time it heats up to
120" to 250° C. (248° to 302° F,), Gradually it settles in the " den,"
and after an hour it sets. An addition of dolomite carbonate of
lime plus carbonate of magnesia keeps it liquid for some time
longer, so that the water evaporated is then much greater.^

All the heat given off by the reaction ought to be utilized with
that end in view (carrying off the water) . It is only when this is-

1 A more valid reason for the greater dryness, if any, appears to be that
magnesium sulphate crystallizes with seven molecules of water, and that is
an efdorescent salt, not a deliquescent one. However, it is not usual to send
a manure drier up the cups. — Tr.

108 CHEMICAL MANURES.

done that perfect solution is realized, and that a superphosphate
that will behave well on subsequent manipulations is obtained. Of
recent years attempts have been made to use hot sulphuric acid and
inject hot air into the chamber, so as to render the phosphate
perfectly soluble and to start the drying of the superphosphate, so
as to simplify the final operations. But the results obtained were
not satisfactory. The opinion of certain specialists may be endorsed.
Such experiments will never be successful, because it is irrational to
•exceed a temperature of 100° C. (212° F.) in the "den " except in
the case of phosphates of very good quality of which there is no need
to fear retrogradation. It is better to leave the substance to itself dur-
ing its chemical transformation and let it be settled by insensible
gradations. Experience shows, moreover, that the injection of hot
air into the mass gives it the consistency of mastic, and that the
manure manufacturer always tries to avoid, knowing full well that
the porosity of the superphosphate is the best condition to realize for
subsequent operations. The construction of the decomposition house
or "den " is not very complicated. The Vv^alls are two-brick thick ;
they are covered inside with a coating which resists acid. To con-
solidate them and prevent them yielding under the pressure of the
mixing, they are fortified by iron T pieces, fixed to the base by
masonry, and joined to the roof by cramping irons. The roof
consists of iron T pieces, three feet apart, laid on the vralls and con-
nected together by iron rods or arches of masonry, the whole being
covered by a coat of cement. All the ironwork is covered by paint
to resist acid fumes. The house is fitted with a solid oak or pitch
pine door consolidated inside by planks placed crosswise in the
gutters. The chinks of the planks and the door are luted with a
paste of clay so as to prevent air penetrating.^

In the early days of manure manufacture only one " house "
was used, and the mixer was installed in the centre of the ceiling of
the house ; then two houses were installed with the mixer stride-legs
hetween them ; finally, later on, four houses have been built and
the mixer placed at the crossing of the party walls. This plan gives
excellent results. The mixer in that case is fitted with 1 discharge

1 The great difficulty with the doors is that the acid eats away the bolts of
any opening handle ; the men must then perforce lever it open by the pick. The
result is that where the pick is applied a chink is formed which gradually
enlarges. But it is not a case of &>\x penetrating into the Jionse, but of fumes from
the mixer or house esccvping into the air through chinks. Both the district
authority and the Local Government Board in Great Britain would at once
proceed against any manufacturer letting the fumes escape into the air. If
means be taken to prevent the escape of fumes, then it follows, ^9^7- contra, that
no air can gain access, because the pressure from within outwards is far gi'eater
than from without inwards. The air cannot penetrate until the gaseous fumes
have condensed, and th'^n the quality of the manure from that batch is fixed and
determined. It is not advisable, however, to open the door too soon, unless in the
■case of hurried mixing specially. The doors are best of pitch pine.— Tr.

MANUFACTURE OF SUPERPHOSPHATE.

109

doors each of which empties into a house of its own. Each " den "
has a capacity of 50 to 100 tons, according to the size of the factory.
Attempts have been made to find methods of rendering phos-
phate sokible more rapidly and more completely than by the pro-
cesses actually used. To accomplish this the phosphate is reduced
to a very line state, i.e. to pass through a No. 100 sieve. A paste
is made of it by drenching it with w^ater or with acid of 10° to 20° B.
and finally adding the rest of the acid at 60° B. But this process
was soon abandoned, for the action was too violent and the metal of
the mixer was attacked bv the acid.

r!)J/ll/>!'/j/

^\\\\\\\\\\\\\V\\\V\\V^\VV\V\V^^^^

///.•//^/^/^/^J,\

U

m

\\\\\\\\\\v\\^v\\\\v\V\V^\\\\'<\\\\\\\\\Vn\\^^^ ^x ^^^^^^ .^^^ sil^

I"

Fig. 2.3. — Toxic Gas Condensers (Benker and Hartmann's System).

Attempts have been made to render phosphates soluble by
mixtures of hydrochloric and sulphuric acids without any great
advantage. The superphosphate contained 0'30 per cent of hydro-
chloric acid which rotted the bags, besides the mixture of sulphuric
acid and hydrochloric acid attacks the metal.

Evacuation of the Toxic Fumes. — The gases formed in the
superphosphate " dens " cannot be allowed to escape into the atmos-
phere without being purified, in consequence of their bad smell and
corrosive action. They are generally passed through a wash tower
bv means of a fan. Benker and Hartmann make very simple

110 CHEMICAL MANUEES.

installations and use for this purpose indestructible fans with washer
purifiers which purify the gas completely. The fans should be rather
powerful, so that the amount of air drawn into the "den " during
•discharge is sufficient to allow the labourers to empty the " den "
under good conditions. Fig. 23 represents the tow^er constructed
by F. Benker and E. Hartmann. It has several compartments and
no packing. The gas penetrates into the first compartment, and
^ascending it meets a jet of w^ater in the form of rain, produced by
^ebonite pulverisers (Kestner Lille). From the first compartment
they pass into the second through the top, from the second they
pass into the third through the bottom, and so on up to the seventh
■compartment, when they are exhausted. The silicic fluoride is de-
'Composed by w^ater into silica and hydrofluoric acid ; the first can
be separated by the filter press and the second can be concentrated
to 12 to 15 per cent by volume and by mixing w^ith alkaline chlorides,
•or even sulphates into the corresponding fluosilicates, which find
a use in opaque glass manufacture and in flux enamelling.^

1 The translator thinks it advisable to offer here a few criticisms on the
method of making superphosphate as described by the author. First of all,
the measuring tank has to discharge itself before it can be refilled, so the re-
ifilling cannot start before the phosphate is all in the mixer. However, it is just
possible that it can be refilled in the two minutes taken up in continuing the
mixing process, after all the acid and phosphate are run into the mixer — that
is to say if no hitch occurs. But if the same principle were adopted, with 2 to
2J ton mixers, as used in Great Britain, and the agitation prolonged, in accord-
ance with the weight of the mixing, then a 5 cwt. mixing taking two minutes'
-agitation, a 50 cwt. mixing ought to take twenty minutes, whereas it is shot into
the " den " shortly after the last bag is up the cups and the last drop of acid run
in. When the mixer is hand-fed and the lid removed, the fumes escape into the
air of the building, and that is bad for the men at work. Again, a cast-iron
mixer is a dead-weight on the boundary wall between the two " dens," and these
eaten away by acid are none too strong. Again, in Fig. 22 the phosphate should
all be weighed before it is shot at the foot of the cups, and the elevator should
then discharge right into the mixer, and the spray of acid and the spray of
phosphate should meet at the same spot. Then with a horizontal instead of
a vertical mixer a wooden tank fined with 5 lb. lead can be used. The only cost
is the mixing shaft and blades and the gun-metal discharge sluice valves. With
such a mixer, to take 2J tons of superphosphate, the mixing shaft is best made
in two pieces, and the middle extremities ending in projecting studs turned in a
lathe are screwed up with bolts and nuts. Then if one-half of the shaft break,
the other part can remain i7i situ, and the whole shaft need not be recast. But
care must be taken that the two halves revolve in perfect symmetry. Again,
it is a very awkward thing to empty a vertical mixer when it sets. All that has
to be done with a horizontal lead-lined mixer is to remove the (loose) boards by
which it is covered and set a man at work to dig it out, and if the mixer is near
the eaves all that he has to do is to remove a tile or two to secure ventilation.
But in a vertical mixer, were it not for the tiny mixings described by the author,
it must be a more than ordinary trying task. Coming now to hot acid versus
cold acid: some phosphate can be mixed very well with acid, e.g. Carolina
TDhosphate. But Somme phosphate requires hot acid, and the translator found
it advantageous to keep a 10 ton tank at 140° F. This he diluted with water
as mixed as the author suggests. Somme is not in any way the heau ideal of
a raw material. — Tr..

CHAPTEE VII.

CRUSHING, SIFTING, DRYING, AND STORING OF SUPERPHOSPHATE.

RETROGRADATION.

Emptying and Shifting the Sujjerphosphate House or " Den " —
Emptying the superphosphate "den" is still done in a primitive
manner, which consists in charging the superphosphate with the
shovel into the receiving vessel of an elevator or into half-ton
wagons.^ The latter are run towards a crane that lifts them and
spreads their contents over the heap from a certain height. In
default of the elevator the heap could not be raised high enough
and more capacious warehouses would be required.

Another method of shifting the superphosphate out of the houses,
consists in emptying them from below. In that case the house is
built over a sort of cellar, in which the material drops on to an end-
less belt 20 in. wide, through holes in the floor covered by iron lids.
The belt drops the superphosphate on an inclined plane ending in the
receiver of an elevator, which discharges the superphosphate either
on the heap or into a Carr's disintegrator, or into a jigger, according
to the method of working adopted. The best plan is to give the
elevator a certain slope and use comparatively large cups, because
fresh superphosphate ought to be j)ressed as little as possible, other-
wise it is converted into a gluey mass difficult to manipulate and to
dry. The emptying of the superphosphate " den " is not exactly a"
pleasant job, even if the heat and the gases, still persistent there
und disengaged when the superphosphate is displaced, be not taken
into account. The workmen are therefore obliged to work with
aspirators, the sponge of which they should keep moist, so as to
prevent any accident. The superphosphate ought to be extracted
from the chamber whilst it is still hot, so that the vapour may be
eliminated and not condense by cooling. If the superphosphate

1 T^;i But in working even on a fairly large scale, in Great Britain the
work of shifting is sometimes still done by barrow, plank, and gang sack. One
man " gets " the stuff with the pick, two men fill the barrow, a fourth or fifth
man, if need be, wheels it on the ground at first, then up a plank, and when the
plank is too steep the barrow men cease to ply their barrows and take to gang
sacks, their heads and shoulders being protected by a " backing " cap or at a
pinch by a sack. — Tr.

(HI)

112

CHEMICAL MANUEES.

has been well made it soon crumbles when exposed to the air ; if
badly made it forms lumps which do not crumble in the air, and
the outside of which is damp from free phosphoric acid, whilst the
inside forms any nucleus of neutral phosphate of lime : this occurs
when too strong acid has been used. The core, sifted from the
material, is dried in an oven if it cannot be crushed in a Carr's
disintegrator.

In a general manner the reaction which superphosphate under-
goes during the process of being rendered soluble, and which consists
in the precipitation of sulphate of lime and its conversion into
crystallized gypsum, is accomplished rapidly. Certain phosphates,
however, form exceptions to this rule : crystallization is stimulated

Fig. 24.— A. Superphosphate Den. B. Discharge Apertures,
veyor. D. Elevator Eeceiver. E. Elevator.

C. Belt Con-

by stirring them with the shovel and the process finished by

drying.

Neiu Methods for the Mechanical Extraction of SujJerjjhosjjhate
from the ''Den'\ — The manipulation of superphosphate being
dangerous, on account of the toxic gases which are disengaged,
efforts have been made to empty the houses mechanically. But
the appliances used are costly and defective, especially owing to the
false position at the door of the excavation plant. Benker and
Hartmann's mechanical extractor suppresses these drawbacks, in so
far that the excavating organ is arranged so as to support its shaft
at its two ends. Figs. 25-28 show the arrangement which forms the
subject of their invention. Fig. 25 is a longitudinal section. Fig.
26 is an end view. Fig. 27 is a plan. Fig. 28 is a detail.

STORING OF SUPERPHOSPHATE

113

Fig. 25. — Benker and Hai'tmann's Mechanical Remover of Superphosphate
from " Den" (longitudinal section).

W.L.J

Fig. 26. — Benker and Hartmann's Mechanical Remover
of Superphosphate from " Den " (end view).

8

114

CHEMICAL MANURES.

The superphosphate " den " a has interior lateral sides b arranged
in grades, reversed above, in such a way as to give to the final block
a form approaching that of a cylinder. The floor of the " den "
is pierced in its centre by a longitudinal opening c covered by a
vv^ooden trap d, one of the ends of which is fitted with a ring handle

Pig. 27. — Benker and Hartmann's Mechanical Remover of Superphosphate from

" Den" (plan).

e. The " den " has in its face a circular opening/ shut by a door g in
two parts. This " den " is traversed through its whole length by a
shaft h, supported on two suitable bearings so as to dovetail into
and continue a screw shaft i mounted in a fixed screw j. A cog-
wheel k, geared to the outside screw part of the shaft i, has a claw

* l^'NT^V^Z/^^Ay^^VVV^,

Fig. 28.— Benker and Hartmann's Mechanical Remover of Superphosphate

from " Den " (detail).

m, which penetrates into a longitudinal gutter ?i of that shaft, so as
to' connect the shaft i with the wheel k in the direction of rotation,
but letting it glide freely. On the shaft h two arms o and p are
fixed diametrically opposite one another, one of which o forms a
sort of compound knife, fitted with teeth q projecting from the

STOEING OF SUPEKPHOSPHATE. 115

blades r. The other arm _/:>, conveniently fixed behind the first, is
fitted at its free end with a sort of shovel or spoon s. A con-
veyor t, of known construction, is arranged below the opening c of
the den and empties into a suitable elevator u. A band of stuff v,
fitted with suitable counterpoises x and ij, is arranged above the
screw shaft i, so as to cover it when it enters inside the den. A
mixer z is fixed at the top of the " den," and the installation may be
completed with fans and condensers of any desired construction.
The cog-wheel h may be driven by any suitable means, for example
by a play of pulleys fixed and movable, 1 and 2 acting in different
directions. The working is as follows : During the mixing of the
mass of superphosphate the trap door d covers the opening c and
the door g covers the circular opening in the front of the " den," the
two arms, o and_/;, being kept outside the " den ". After the super-
phosphate has set, the trap door d is withdrawn by aid of a hand-
winch, not shown on the drawings, then the door g is removed.
The whole of the shafts, h and i, are caused to revolve in a suitable
direction to bringthe mechanism inside the " den ". When the teeth
q of the arms o come in contact with the mass of superphosphate, it
penetrates into the interior of the mass, detaching ribbons which
lireak, forming small fragments, which fall to the bottom of " den ".
The blades r in turn come in contact with the portion of the matter
projecting between the teeth, detach these likewise in the form of
ribbons, which collect at the bottom of the " den ". The shovel s at
the aperture C brings these fragments, from where they fall into the
conveyor t. Whilst the shaft i is penetrating inside the "den," the
.cloth V unrolls and covers this shaft so as to prevent it being crushed
by lumps of superphosphate. When all the matter in the " den " has
been reduced to fragments and evacuated by the conveyor the rota-
tion of the shafts h and i are reversed, until the arms o, jj are outside
the "den " ; the sliding door d is replaced as well as the door g, and
the mixing of a fresh batch started. This arrangement is simple and
•economical. The arms supporting the cutting knife is fixed on a
shaft supported at both ends, which prevents all work in false direc-
tions and secures a better output. The attack of the material by
a vertical knife facilitates the conveyance of the fragments it turns
out. This arrangement may be applied to all existing "dens " by
modifying or not the inside shape of these "dens," so as to render
them cylindrical. During the mixing of the superphosphate no
•delicate piece of the mechanism comes in contact with the material,
so that the mechanism is practically unwearable and little liable to
damage. The screw shaft may be replaced by any other arrange-
ment giving to the arms o, _/9 a forward helicoidal motion, and
fitting the whole mechanism with an arrangement allowing the
speed of the displacement of the arms to be increased at will ;
for example, for their return. The invention applies to the

116 CHEMICAL MANURES.

extraction of superphosphate as well as to manures, or analogous
chemical products. Summing up, the inventors claim : —

(1) An arrangement for the mechanical shifting of superphosphate
consisting of a vertical shaft o, mounted on a horizontal axis h,
and driven with a simultaneous movement of rotation and trans-
lation of which the blade r comprises projecting teeth q, prefer-
ably incurved on the axis, with the object of first of all bringing the-
teeth in contact with the material so as to commence the attack
of the material by the teeth, and finish it by the blade.

(2) A method of applying the arrangement described in (1), in
which the horizontal shaft h of the knife, comprising a radial arm
p, fitted w4th a shovel s, is supported at its two extremities and
forms part of a screw shaft i, engaging into a fixed screw j, and
gearing with a driving cog-wheel A-, in which it can glide so as to-
avoid any false working.

Allegri's Plant for Shifting Superphosphate from the ''Dens ". —
Allegri, the engineer of the united factories of the Italian agricul-
turists, has also patented a machine to replace manual labour in.
shifting superphosphate from the mixing "dens ". His appliance-
consists essentially of a sort of plough, to which a horizontal and
vertical motion is imparted. This plough traverses the chamber in
the direction of its length, and at each passage it detaches a small
slice of superphosphate and discharges it through the door in the
top of the chamber into a conveyor of some sort. A single work-
man can overlook several of these machines. This machine shifts-
10 tons of superphosphate an hour. The force necessary is 4 H.P.
The cost of upkeep is limited to changing the plough from time to-
time, which is the only part exposed to contact with the superphos-
phate. The appliance maybe fitted to any existing "den" with
a few alterations.

Another method of shifting superphosphate " dens " is comprised
in British patent No. 20,446 (25 Feb., 1907). It consists in
shifting the superphosphate by a movable platform, on which it
rests so as to expose sides and top, so that the mass can be
broken up in the open air. With this end in view the floor of
the decomposing " den " is mounted on wheels ; in this way it may
be drawn out of the " den " by appropriate mechanism through a
movable door made in one of its sides. The superphosphate shifted
out of the *' dens " is then broken up by any mechanical arrangement
and charged into conveyors to be conducted to the drying machine^
Finally, the following arrangement of the superphosphate " dens, ' in
a Bordeaux factory, is described, as an interesting improvement.
The new " dens " consist of long channels in a mass of masonrv work
below the mixer. These channels are 1*6 to 1*8 metres above the
floor of the factory. A metallic cradle placed inside these channels,
of which it assumes the form (naturally !), is propelled by a winck

STOEINCx OF SUPEEPHOSPHATE. 117

lixed on the floor on the side opposite the discharge. During mix-
ing the superphosphate as it comes from the mixer adheres as an
immense cake to the bars of the cradle. To shift it, it suffices by
means of the winch to bring the cradle out of the den, where the
product is collected in trucks. The workmen have only to detach
what adheres to the bars and to let it fall into the trucks, by means
of rather long tools, so as to keep at a suitable distance. A hood
connected with a fan is placed on the discharge door, so that the
fumes are drawn from the exit of the " dens " and cannot inconveni-
ence the workmen. The superphosphate is then conveyed by wagons
into the Persian wheels which elevate it into the drying ovens. ^ A
fan draws vapour and dust from the dryers, and propels the first
into a condensation tower and the second into a dust chamber.
The manufacture of superphosphate, owing to these new arrange-
ments, presents no serious drawbacks as regards the health of the
workmen or of the neighbourhood.

Breaking up and Si/ting or ScreeniJig of Super j^hosphate. —
The superphosphate placed in a heap in the fresh state consolidates
itself so much that it has to be broken down or "got" by the pick
and shovel. In order to get it to a proper degree of fineness, it was
formerly projected against an inclined sieve (screen) and the " core "
crushed with the back of the shovel. This sieve, of 6-8 mm. in
section, that is a quarter inch sieve, is still in use in small factories. ^
Shaking and regulating sieves are also in use. To get the super-
phosphate from the heap, the best plan is to attack it at the tail
corner by drawing it towards oneself with the pick. By lifting it
in successive layers it would run the risk of being compressed.
Care is taken not to excavate underneath when the heap is more
than 6 ft. high.-

Compact superphosphate is reduced to a pulverulent state by
Carr's disintegrator or a crusher fitted with steel teeth.

Carr's Dismtegrator. — This disintegrator was invented by
Thomas Carr of Montepelier, near Bristol, and patented in Great
Britain. It consists essentially of two, four, six, or eight concentric
cages, the cylindrical sides of which consist of metallic bars h,

1 Well-made superphosphate does not require to be put through quite
so tine a screen as a one-fourth inch screen except for the dry mixing of com-
pound manures. Good made superphosphate passed through an inch screen
is fine enough for most purposes, and through half an inch for all purposes, and
the price is now cut so fine that to add to the cost by passing it through a
needlessly close sieve is irrational, the more so as superphosphate, as dis-
tinguished from wet mixed compound manures, has little or no core. It only
wants a touch with the shovel to break it up to fine powder. — Tk.

'^ But that is exactly what the man who gets the manure with the pick does.
He knows the right time to stand clear, and only the undermined portion falls,
and that quite gradually and without undue precipitation.— Tf.

118

CHEMICAL MANUEES.

encased on one side in plain discs a, on the other on crowns a. The
first (inside), third and fifth cages form an aggregate of a single
piece, screwed with the boss of the disc on to a driving shaft. In
the same way the second, fourth and the sixth cages form an ag-
gregate mounted on the other shaft. The machine is driven from
the same shaft by means of two belts, one of which is straight and

:l

■L.j/!n/m/im.,i,Wli

Fig. 29. — Carr's Disintegrator.

the other crossed, so that the cages formed by one of the elements
of the drum fit into the annular spaces of the other and turn in a
contrary direction. The machine is generally enclosed in a tight
cover and surmounted by a hopper e, into which the material to be
pulverized is charged. These fall into the interior cage, and the
machine being in motion, they are projected by the centrifugal
force across the bars of the first cage into the second ; turning in an

opposite direction from the second they
are projected in the same way into the
third which turns in the same direction
as the first, then into the fourth, and so
on. Finally, they are projected on the
outside on all the points of the periphery
through the bars. The operation does
not last a second. This rapid grinding
is not astonishing if the great number
of shocks to which the matter is sub-
jected be considered ; the power of
these shocks consists in the sum of the
speed of the substance in one direction
and of the bars of the cage in the other.
The substance issuing from the crusher falls into a side channel
hollowed out of the foundation of the machine, from there it

o o

Fig. 30. — Carr's Disintegra-
tor. Plan of the Cylindrical
Cages.

STOKING OF SUPERPHOSPHATE.

119

collects in the receiving vessel of an elevator, which removes it.
The size of the drums, number of revolutions a minute, the
force and the number of bars, vary according to the nature and
the quantity of the material to be treated and according to the
fineness to be imparted. A product, consisting of granules of
no matter what size, can be obtained by turning the drums at a
greater or less speed and using a suitable distance between the bars.
The experience of the constructor is here the best guide. Carr's
disintegrator is one of those which utilizes, to the best advantage,
the energy which is transmitted to it, which explains its extraordin-

FiG. 31. — Carr's Disintegrator or Toothed Crusher, C. Sieve.

G. H. Transmission Shafting.

F. Elevator.

ary high output compared with other disintegrators, of whatever
nature. It is used, not only for crushing superphosphates, but also
for degelatinized bones. It also renders good service in making com-
pound manures provided that the ingredients possess the same or
but slightly different densities.

Cylindrical Crusher Fitted ivith Teeth.— This crusher consists
essentially of a cast-steel foundation, on which are mounted two
rolls, one of which is smooth, and the other lined with steel teeth.
The first of these rolls has a diameter of 350 mm. (say about 14
in.), and makes 100 revolutions a minute. The second has a

120 CHEMICAL MANURES.

diameter of 290 mm. (say 11| in.), and makes 1000 turns a minute.
This latter roll consists of a cast-steel nucleus on which are
mounted toothed rings, easy to remove and replace. The machine
is surrounded by a protecting cover, with a hopper, into which the
material to be ground is fed. The substance passes between the
rolls where it is subjected to powerful grinding, produced both by
the steel points and the differential speed of the rolls. The machine
frees itself automatically from all adherent matter, which is not so
with Carr's disintegrator. It is particularly suitable for moist
gluey superphosphates.

Cylindrical Crusher luith tico Bolls fitted luitJi TeetJi. — This
machine is used for the same purpose as the foregoing; it is, more-
over, used in making compound manures from superphosphate
and sulphate of ammonia. The two rolls have a length of 500
mm. (say 20 in.) by 500 mm. ; the one turns slowly, the other
rapidly. The teeth of one of the rolls pass through the interstices
between those of the other, and thus exert a powerful crushing action
on the material. It is fitted with a cover forming a hopper, and
is combined with an elevator and a shaking sieve. These machines
may be grouped in two ways, according to the nature of the super-
phosphate. The crusher may be installed at a higher level than
the sieve, or on the floor. In the first case, the superphosphate
is fed into the receiver of an elevator which discharges it at
a higher level into the hopper of the crusher. The superphosphate
after passing through the jigger falls on a shaking sieve, the fine
material passes through the sieve and falls into the discharge
hopper, whilst the core in the sieve returns to the elevator, which
brings it back into the crusher, and so on.

In the second case, where the crusher is fixed on the floor, the
matter is charged directly into the crusher, from whence it falls
into the cup of the elevator, which spreads it over the sieve higher
up. The routine of the operations is absolutely the same as in the
first case. But this second method has drawbacks. The cups of
the elevator in seizing the material, crush it and transform it into
a pasty gluey mass which resists sifting and returns, incessantly,
from the sieve into the crusher again, to take the same road and
choke up the whole of the apparatus. This drawback disappears
if the machines be grouped in the manner indicated in the first
instance, in which the superphosphate is elevated before being
crushed ; it is then in consistent lumps and stands the action of the
cups very well. The sieve itself consists of a shaking table ani-
mated by a to and fro motion driven on each side by a pulley and
crank. The frame of the sieve is hung in an iron frame, on which
the driving pulley is mounted. The sieve is wire woven. It must
be kept perfectly clean so that the superphosphate passes through
and does not return to the crusher or become gluev. If the sieve

STORING OF SUPERPHOSPHATE. 121

be obstructed, the machine must be stopped and the sieve cleaned.
It is cleaned by beating and scraping with a broom, using sand if
need be. A mechanical beater is often installed on the sieve, but
it can only be used for cylindrical sieves. The latter again can
only be used for very dry superphosphates, because in spite of the
mechanical beating they are rapidly obstructed and difficult to
clean.

If the superphosphate is in a pulverulent condition, it is simply
sifted without crushing ; only the core from the sieve then passes
through the crusher at a lower level, from which it falls into the
receiver of the elevator, which spreads it again on the sieve. The
elevator, crusher, and sieve act simultaneously. However, it is
better to drive the crusher independently, or by an electric motor,
for in many cases the core on the sieves is not important, and the
action of the crusher only intervenes usefully at rare intervals.
It is hardly necessary to say that these machines should be easy
of access. Fig. 31 represents a unit consisting of elevator, crusher,
and sieve, mounted on iron frames. This unit, movable on rollers,
may easily be conveyed from one depot to another as required.
Manipulations and cost of conveyance, often heavy, are thus avoided.
An installation of this nature only requires three workmen. The
first feeds the cups, the second looks after the machine and bags
up, the third conveys the superphosphate to the depot. In case of
a break-down the three mutually assist each other. It is to be
noted that damp weather is bad for grinding and sifting ; the
superphosphate is very deliquescent, and adheres to the machine.

Artificial Drying of Superjjliosphate. — If it be hardly possible
to effect economy in crushing and dissolving with the machinery
described above, it is quite otherwise with the operations relating
to the finishing of the superphosphate, that is to say, those that
intervene between " dissolving " and dispatch of the finished pro-
duct. There are factories where these operations cost double what
is required in a rational installation. In the present economical
conditions of the industry, it is necessary to supplant ineffective
hand labour, always costly, as much as possible by mechanical
methods ; a machine can be stopped when desired, whilst hand
labour must be kept on continually, otherwise it goes. It must,
therefore, be reduced to a minimum, the superphosphate finished
with the least possible delay, without having to store it for a
longer or shorter time, to render it saleable. In this chain of
reasoning, the attention of manufacturers is drawn to the machinery
and processes described further on.

Theoretical Review of Drying. — The moisture of a superphos-
phate is not wholly due to a high water content per cent, but also
to the presence of an important proportion of free phosphoric acid
in supersaturated .superphosphates. Thus, when a superphosphate

122 CHEMICAL MANUEES.

contains 5 per cent of orthophosphoric acid it may contain up to
15 per cent of water, without being actually wet. According to
Stocklassa, acid phosphate of Hme heated to 100'' C. loses, in ten
hours, 1-83 per cent of water; in twenty hours, 2-46 per cent ;
in thirty hours, 5-21 per cent; in forty hours, 6-32 per cent;
in fifty hours and upwards, 6-43 per cent constant. At 260' C.
phosphoric acid changes slowly into pyrophosphoric acid.

2H3PO, - H.O = H.PP-.

Moist superphosphate may be dried by evaporating the water
which it contains, either by absorbing a part of the free phosphoric
acid w^hich it contains by inert material, such as calcined gypsum,
which combines chemically with the water, kieselguhr, peat dust,
sawdust, or in fact by combining a portion of the free phosphoric
acid. From an industrial point of view, we have to examine the
application of heat to drying, direct heating, and cold drying.
The drying machine, by direct heating, utilized for drying bones,
may be used as in the drying of raw phosphates, sulphate of
ammonia MP 140° C, beyond which it volatilizes, but it does
not suit for superphosphate. It is, moreover, very trying and
dangerous for the health of the workmen owing to the disengage-
ment of the acid gases of the superphosphates. Besides, the
material being pressed by the workmen during shovelling, readily
sticks to the plates, and undergoes a sort of combustion from which
a retrogradation of as much as 4 per cent may result. Moreover,
it is very difficult to regulate the heat of a coal fire, which requires
constant attention. The principal systems of drying in actual use
are the following : —

Lambert's Dryer. — The inventor gives the following deliciously
laconic description : The apparatus consists of a masonry chamber
divided into three compartments : (1) A hearth of refractory
materials, in which there are mixed the hot gases from the generator
hearth and the air propelled by the blowers. (2) A chamber
succeeding the preceding one, into which pass the mixture of gas
and hot air before entering the drying machine. (3) A stove
heated by the heat radiated from the hearth, and in which the ap-
paratus described below moves. The dryer, properly so-called, has^
the form of a highly-elongated truncated cone and is arranged
horizontally on rollers ; it is entrained by means of gearing in a
continuous system of rotation. In the interior this apparatus is
fitted with corners intended to raise the material in an unin-
terrupted manner and to project it into the hot current during its-
whole stay in the apparatus. At the extremity of the small diameter
of the apparatus is a feed hopper, at the other end are apertures,
the object of which is to drop the dried material and allow the
escape of hot air and steam during evaporation. .

STOEING OF SUPERPHOSPHATE. 123

Zimmermann's Drying Machine. — Zimmermann's drying
machine consists of an oven 8 metres (26 feet) high, heated by
combustion gases. The hot air comes in contact with the material
on iron plates suspended by chains and fitted with a system of
agitation. An oven of this kind, occupying a space of 50 square
metres (538 square feet), dries four wagons of superphosphate
in twenty-four hours. The latter only remains exposed two-
minutes to the heat of a very bright coke fire ; it there becomes-
heated to 80^ C. and loses 5 to 6 per cent of water. The motor
power to shake the plates is three horse, and the coke burnt, in
twenty-four hours, half a ton. Three men can work two ovens. The
iron plates have the drawback of not allowing the hot gases to pass,,
which thus take the shortest path along the sides of the oven.
Lately the inventor has replaced them by sieves. The combustion
gases and the acid gases pass into a dust chamber, where the-
latter is deposited, whilst the acid gases are purified in a con-
denser tower. The acid contained in the gas which is disengaged
from the dryer is chiefly hydrofluoric acid. This gas, as well as-
the hydrofluosilicic acid, exists dissolved in the superphosphate
water, and is partly re-formed when the substance is heated, the
sulphuric acid, as CaH^SO^, [?] acting then on the still undecomposed
calcium fluoride. The hydrofluosilicic acid is decomposed by heat,
into hydrofluoric acid and silicic fluoride.

The drying machine forming the object of the German patent
85,273, only differs from the above oven in the arrangement of thfr
interior and in the method of agitation. The shaking plates are-
not suspended by chains, they rest on cross pieces and are moved
by manuals.

MoUer and Pfeiffer's Drying Machine. — M oiler and Pfeiffer have
constructed a drum drying machine in which they have striven ta
avoid shocks and sudden motion, which are absolutely injurious to
the structure of superphosphate. On the other hand, these makers-
secure energetic ventilation by superheated air. This apparatus is
based on this principle, that each matter requires appropriate treat-
ment according to its nature. It consists of four principal parts,
which are : (1) A heating system for heating dry air. (2) An ex-
hauster for ventilating and absorbing combustion gas. (3) An
arrangement for mixing air with the combustion gas, and to receive-
the superphosphates. (4) The drum, properly so-called. The work-
ing is as follows : The superphosphate is fed from a cup elevator into-
a hopper where it falls into the drying machine, w^here it is seized
by a strong current of hot air, which dashes it into the rotating drum.
The current of hot air is produced by a powerful fan with a conical
aperture ; the jet of compressed air that issues from this aperture
drives an ejector which absorbs the combustion gases. The air and
the gas are mixed in varying proportions at the will of the operator,.

124

CHEMICAL MANUEES.

^vho can thus obtain whatever initial temperature he desires. This
temperature may be somewhat high without there being any reason
to fear retrogradation in the superphosphate treated, for the drying
of the latter is so energetic that the temperature of the gas lowers
-considerably. Owing to the rotation of the drum and its sloping
position the superphosphate circulates to the opposite extremity
and is reduced to crumbs, consequently the interior of the granules
is laid bare and submitted in its turn to the action of the hot gases.
At the end of the drum the superphosphate falls into a "den," from
which it is taken to be stored. The hot air which comes from the
drum is not saturated with moisture ; it is therefore in great part
absorbed by the exhauster, mixed again with combustion gases,
w^hich bring it to the desired temperature, and afterwards it is
again sent in to the drying machine, to carry on the work of
desiccation. In this way the gases having already served, and still

Fig. 32. — Moller and Pfeift'er's Dryer (vertical section).

at 85" C. (165° F.) are again utilized, only the small quantity required
for rational working of the combustion is allowed to escape into the
air, the loss of heat is reduced to the difference between the exterior
temperature and that of the escaping gases. However, this circula-
tion cannot be indefinite, it is limited, naturally, by the final saturation
of the escaping gas. It is then necessary to start once more with
-completely renovated air so as to secure regularity in the drying.
This drying machine is one of the best, and has received numerous
applications.

Heymann and NitscWs Process for Drying Swperplws'ph cites. —
Heymann and Nitsch try to utilize the heat produced by the reaction
of fresh superphosphate to vaporize the water brought to the surface
of the lumps by crushing. They manage in this way to conduct
drying and crushing simultaneously. The superphosphate, at a
temperature of . 90° C, is charged into slightly inclined rotary
drums, the angle of inclination of which may be regulated at will.
It is there crushed and sifted. The fine flour falls from the drum
into a pit, and when it is cooled it has acquired the necessary degree

STORING OF SUPERPHOSPHATE.

125-

of dryness. But this condition, being incapable of being realized in
the manner indicated, the inventors remedy it by injecting a-
current of hot air to meet the superphosphate as it falls from the-
machine into the pit. This process does not appear to have been
adopted in practice.

Dr. Lorenz' Process (Dr. Lutjens' successor). — Dr. Lutjens-
has endeavoured to impart great rapidity to all the stages of super-
phosphate manufacture. With him it is a case of terminating the
whole series of operations in twenty-four hours, so that the product
may be warehoused or dispatched. The process which he uses is-
kept secret, and Dr. Lutjens has refused to give the author any^

Fig. 33. — Lutjens' Superphosphate Dryer. A. Entrance of superphosphate-
from "den". B. Entrance for hot air under pressure. C. Diying
trough. D. Entrance of cold air under pressure. E. Cooling trough..
F. Sieve. G. Fine superphosphate. H. Core.

information. Although his process more particularly interests-
German manufacturers, who are obliged to make high strength-
superphosphates, sold according to their content of phosphoric acid
soluble in water, the author thinks it his duty to give the description
for the edification of his readers. The superphosphate, whilst at.
100° C. (212° F.) in the "den," is taken by a conveyor on to a plat^
form, under which a scraping machine works, and run into the top
part of the latter, through a hopper. The scraping machine, and
its application, are the object of German patents 95,756 and 96,046^
the author's translation of which from the original German follow,
the translations at the end of the brevet being almost unintelligible.
German Patent No. 95,756 of 16 March, 1897, Delivered to the-
Chem. Fabrik Aktien GeseUschaft Vorm Carl Scharffet Co., Breslau^

126 CHEMICAL MANUEES.

— The object of the new process is to divide superphosphates, so as
to facihtate their distribution in the soil, for, in the state of lumps,
they only give up their phosphoric acid slowly and difficultly.
Besides, the fine division of a superphosphate is indispensable
from the point of view of the actual manner of distributing manures
by the manure drill, which greatly facilitates the work of the
farmer. The superphosphate, such as it comes from the mixing
" den," contains about 15 per cent of water, and in that condition it
is very sensitive to shocks and crushing, so much so, that the
processes used to pulverize it up to now are unsuitable. The new
process is based on this observation, that hot solid superphosphate
such as it exists in the mixing " den," possesses a property which has
not been hitherto recognized, that of being capable of being cut into
very fine slices, which exposed to the air break up and fall to powder.
The process of which the present patent is the object, consists pre-
•cisely in cutting the mass in very fine slices in the condition in
which it comes from the mixing " den ". Practically that is done as
follows : the superphosphate is run into a drum in which knives,
animated by a very rapid motion, cut (scrape) the superphosphate
-so as to divide it without crushing it. The thin slices are then
reduced to a fine powder, the tenuity of which facilitates the ex-
pulsion of the. moisture contained therein. The product thus ob-
tained can be very easily and uniformly distributed.

German Patent No. 96,046 of 16 March, 1897. Addition to
patent 95,756 of 16 March, 1897, delivered 19 March, 1897, maxima
•duration, 15 March, 1912. — The process of which this patent is the
subject, is a form of application of a process claimed in chief patent,
above-mentioned, the object of which is to cut up fresh superphosphate
in a rotary drum armed w^th knives. Up to now the superphos-
phate from the " den " was stored, and as soon as it was cold and
dry, it was pulverized in a crusher. As it comes from the " den "
the superphosphate is hot and soft, on cooling it becomes consistent.
It has been remarked that only the superphosphate which comes
from the den in lumps becomes consistent, whilst the portions that
are in a pulverulent state do not agglutinate but remain in the
condition of powder in spite of the pressure of the mass and the
high temperature. This observation has suggested the idea, that
superphosphate could be reduced to a dry and pulverulent condition
as soon as it comes from the mixing " den ". The crushing process
used hitherto, such as passage through a Carr's disintegrator, cannot
be applied to fresh superphosphate because they would render it
gluey. The present invention enables the desired state of division
to be imparted to superphosphate immediately it comes from the
mixing "den" without grinding or crushing it. The process em-
ployed for the purpose is based on this fact, that if superphosphate
is cut into very fine slices in its actual condition it is immediately

STOEING OF SUPEEPHOSPHATE. 127

converted into a fine powder. The superphosphate is transferred
by a conveyor into a hopper which feeds it into a drum armed with
knives. This drum consists of a posterior disc and an anterior
ring. Between the disc and the ring there are arranged tangentially
at fixed distances steel blades or knives, covering the openings for
the exit of the finished superphosphate. Sixteen blades of this
sort pass in front of the hopper aperture, at a speed of 300 revolu-
tions a minute, consequently 4800 blows per minute. The slices
so produced are very fine and do not set on accumulating. The
drum is driven by shaft and pulley. On the hopper side and
beneath it are w^rought-iron plates, on which the finished super-
phosphate, issuing from the drum, falls; from these plates it falls
into trucks. The working of the installation is as follows : The
drum is driven by a pulley and turns at great speed. This speed,
which is thus transmitted to the knives, is calculated in such a
w^ay as to exceed the rapidity of the fall of the superphosphate into
the^ feed hopper. In that way, all the superphosphate is forced to
pass over the knives, and the uncut lumps are prevented from pass-
ing through the apertures and falling into the truck. The spaces
between the knives are regulated according to the speed of the
periphery of the drum and reciprocally. It follows that the knives
succeed each other in their action, penetrate into tha material and
scrape it through successive layers. Very thin slices are thus
obtained, which fall to powder. This division is still further
favoured by the speed of rotation of the drum, which produces
a strong current of air acting on the substance, and producing
a cyclonic motion in the parts detached by the knives. The
pulverized material falls from the plates into a truck. The current
of air produced by the rotation of the drum imparts a certain speed
to the phosphate powder detached by scraping. The wrought-iron
plates also serve to turn this current of air in its tangential course,
so that the powder only falls into the trucks at the speed it would
fall by its own weight. The too abrupt fall of the material is thus
avoided. Finally, the current of air produced in the drum frees the
superphosphate from any gases with bad odour, and expels them

outside.

Dr. Lutjens afterwards modified his processes, first, in combining
drying with the scraping machine, afterwards in cooling the dried
superphosphate. The process thus modified realizes to the letter
the problem enunciated above, to produce a superphosphate ready
for dispatch in twenty-four hours. For this purpose the superphos-
Xohate cut in very fine slices, falls into an upper drying trough,
where it is exposed on all sides to the action of hot air ; this
completely traverses the mass, heats it and renders it friable.
From the upper trough the superphosphate falls into a second
trough placed underneath, where drying is com^Dleted by a current

128 CHEMICAL MANUEES.

of cold air under pressure, which lowers the temperature to 20" C.
The superphosphate is then sifted ; it quits the sieve in a very fine
state, ready to be dispatched. The cold air treatment not only
prevents the substance from aggregating into lumps, but it at the
same time prevents retrogradation, as will be seen later on. The
plant dries [it is claimed] 10 tons of superphosphate per hour. It
requires few repairs. Fuel is well utilized, for on burning ordinary
coke, only 1 cwt. per 5 tons of superphosphate is used to remove
5 per cent of moisture.

It is right to add that to work regularly, this machine requires
to be manned bv workmen familiar with this class of work ; it
increases the output of the factory, and superphosphate can be
dispatched from the heap.^ The cooling of the superphosphate was
the object of the German patent No. 112,151 of 14 April, 1899, of
which the following is the translation. The processes employed up
to now for drying superphosphates have the drawback of leaving
these products at a high temperature, so that if run on to a heap
thev onlv cool very slowlv. Now, heat is very iniurious to the
superphosphate in the heap, and it then acquires a great tendency
to form lumps. Under the pressure to which it is subjected by its
own weight, it becomes compressed more strongly the longer the
warehousing is prolonged, and it is then necessary to pulverize it
once more before dispatching it. To this drawback a graver one
has to be added, stored superphosphate has a great tendency to
retrograde, the phosphoric acid rendered soluble then returning to
the insoluble condition, because heat favours retrogi^adation and
the dried superphosphates preserve their heat when in high heaps,
and only cool slowly. The object of the present invention is to
avoid retrogradation of the soluble phosphoric acid in superphos-
phates which have to be stored. For this purpose the heat is
removed from the dried, hot, pulverized superphosphate by a
current of cold air. The conveyance of the superphosphate thus
finished, to the store, is done in tilting trucks or by aerial conveyor.
This latter system is the best and the most economical in the manu-
facture of superphosphates, where it is indispensable to utilize as
much as possible the covered space to store the goods. This is
what a manufacturer who uses the Lutjens process says : "I could
not be better satisfied with the scraping machine. The super-
phosphate obtained by this process is exceedingly fine, free from
lumps, and so dry that it may be dispatched a few days after it is
cooled. It responds to all exigencies. Before dispatching it I pass
it through a sieve of 6 mm. (a quarter inch sieve), and I get no

^ With say three screens on to a heap, one man with a pick is occupied in
"getting "the superphosphate for the other six men — two men to each screen
— a left-handed man mated with a right-handed man, but most men accustomed
to this class of work are ambidextrous. — Tr.

STORING OF SUPEEPHOSPHATE. 129

core. The scraping machine enables superphosphates, of a quality
hitherto unknown, to be made cheaply." Dr. Eiemann, a master
of superphosphate manufacture, says : " We have only O'O to O'T
per cent of insoluble P0O5 in Florida superphosphate. As a general
rule we obtain an increase in the phosphate rendered soluble, and
we have not observed retrogradation in Florida superphosphate
even after several months' storage."

Superheated Sujjerphosjjhates. — Crispo draws attention to the
.changes which occur in overheated superphosphates. After a
certain temperature orthophosphoric acid is changed into meta-
phosphoric acid. Experiments on this point have shown that
orthophosphoric acid, heated to 105° C. during three hours, is con-
verted into metaphosphoric acid to the extent of 10 per cent, whilst
if heated to 200' C. it is converted to the extent of 90 per cent, by
the loss of a certain amount of combined water. If the soluble
phosphoric acid by the citrate method be determined in over-
heated superphosphates, it is to be observed that metaphosphoric
is not precipitated by magnesia mixture, and that only the ortho-
phosphoric acid is found in the precipitate. If the determination
be made by the molybdate of ammonia method, the sum total of
the two phosphates is found, the nitric acid bringing the meta back
into the ortho form. Crispo considers metaphosphoric acid of less
Talue than the ortho. However, experiments made in Germany
have shown that under the first of these two forms phosphoric acid
lias given good results. Experiments at the Agronomical Station of
GomlDlouse, by Gregoire and Hendrich, have shown : —

1. That the alterations undergone by the dried superphosphate
in no way diminish the fertilizing value of that product.

2. That desiccation at a temperature of 165° C. has appreciably
increased the activity of the phosphoric acid.

3. That the metaphosphate and the pyrophosphate of lime re-
■spectively, the products of dehydrating mono and bicalcic phos-
phates, are. without fertilizing value. In pot culture experiments in
the Liege laboratory, each of the pots containing 4, kilos (8-8 lb.) of
soil, Ligouro oats gave, on an average, according to the phosphates
used : —

t:able xlil— results of experiments with ordinary super-
phosphate AND superphosphate DRIED AT DIFFERENT

temperatures on ligouro oats.

Grain and Proportional

Phosphate used. straw gr. yield.
Without phosphoric acid . . . 12-3 100

Ordinary superphosphate . . . 28-8 234

Superphosphate dried, slightly calcined . 26*9 219

Metaphosphate 19-3 157

.Superphosphate di-ied at 160° C. . . 28-8 234

?>

27-6 224

130 CHEMICAL MANUEES.

These results show that superphosphate dried at 160° C. and
shghtly calcined, produce the same effects as ordinary super-
phosphates. On the other hand, the action of commercial meta-
phosphate is comparatively feeble in the sandy clay experiments.
In an experiment on sandy soil the dried and calcined super-
phosphate had a less effect than superphosphate simply dried at
leO'^ C. (320° F.).

Drying SiqjerpJiosjjJiates in the Cold. — Cold drying processes
consist essentially in mixing dry substances intended to combine
with a portion of its phosphoric acid with the superphosphate.
Eumpler advises the use of bone black and degelatinized bones.
These substances possess a great absorbent power and may be used
with success for the drying of high strength superphosphates. As-
regards the use of bone dust, 1 per cent may be added to the super-
phosphate, according to its percentage of free acid. The bone dust
should pass through a 70 mesh sieve. The phosphate taken from
the " den " is spread out, the bone dust sprinkled over it, the mass,
turned over and passed through an inclined screen. After twenty-
four hours the bone dust is almost all dissolved, and the super-
phosphate may be dispatched. It is clear, however, that this work
done by hand can only partially attain the object in view. Dr.
Klippert has the merit of applying this principle by means of an
improved equipment, the construction of which is kept secret.

Drying of the Superjjhosphate by Dusting and Mixing in the
Georges Crusher -Sifter. — In France an analogous process to that just
described is adopted. This process consists in mixing 3 per cent
of raw Gafsa superphosphate well dried and in the condition of fine
powder. For this purpose the superphosphate from the "den " is
spread by an aerial conveyor on a platform (Fig. 34) ; a workman
dusts the product with Gafsa superphosphate and charges it into the
grinding sifter shown in the figure. In this machine a shaft with
blades driven at a suitable speed triturates the mass and mixes it
intimately, whilst the sieve turns it in a contrary direction. The
fine material falls from the sieve into the bin of an aerial conveyor
which conveys it to the warehouse, where it remains until the time
for delivery. Before being dispatched the superphosphate i&
crushed and sifted through the Coster crusher. When the super-
phosphate is suitably prepared, the treatment indicated suffices to
obtain it dry. A great number of factories have installed this pro-
cess, which enables them to dispense with a drying machine. It is
necessary to add that it is only applicable to superphosphates for
home consumption, as superphosphates intended for exportation,
especially those for the East, ought to be dried artificially in the
drying machine. In the Lutjens process, 1 per cent of degelatin-
ized bones is also added, or Algerian phosphate, so as to dry the
product and avoid the formation of lumps. The choice between

STOEING OF SUPEEPHOSPHATE.

131

>>vV^W

(U

CO

r/j

Q

tsD

;-4

o

a

ej

^^

fl

•

o

a

-tj

fl

o

s

H

(D

t-(

^

cc

^

W

O

n

c

^

St;

0)

,i4

CO

a

U

<D

pq

to

(—1

Q;! =4-1

s •

o^
.5 -^^

=^ s

CD

m

C3
'^

O

=4-1

<D

132 CHEMICAL MANUEES.

bone dust and Algerian phosphate, as the drier to be added to the
superphosphate, depends on circumstances. If the superphosphate
is to be dispatched in a week or thereabouts, one remains satisfied
with 1 per cent of Algerian phosphate. On the other hand, if it
should not require to be dispatched before a month or six weeks,

0 5 of bone dust and 0"O per cent of Algerian phosphate is added.
When the phosphate has to be kept longer, 1 per cent of bone dust
is simply added. The reason of this method of proceeding is, that
the addition of the phosphate tends to harden the superphosphate
in the heap so that it has to be screened again before dispatch,
or even passed through Carr's disintegrator. The new methods of
Lutjens for the working of superphosphates present real advant-
ages. But such installations are somewhat costly ; moreover, they
are only used where high strength superphosphates are required or
when agriculture requires pulverulent products capable of being
spread by the drill. It is necessary, in that case, that the super-
phosphate contain an important proportion of free phosphoric acid
intended to dissolve the raw phosphate added as mentioned above.
A Florida superphosphate of 18 per cent, for example, should not
contain more than 1 to 5 per cent of free phosphoric acid if it be
not desired to add raw phosphate thereto ; if on the other hand

1 per cent of Algerian phosphate be added thereto, the free acid
may be increased to 7 to 8 per cent. Certain foreign countries
stipulate for superphosphates of very high strength. Thus Scandi-
navia stipulates for 20 per cent, which is nonsense, as products of
this kind run relatively dearer than 15 to 18, which are current
types.

Storing (Preservation) of SiqjerjjJiosjjhate — Betrogradation [Be-
duction) of Pliosj^lioric Acid. — Superphosphate keeps well from one
season to another when the phosphate from which it was made does
not contain more than 2 per cent of sesquioxides, but it is not so if
kept longer. The phosphoric acid of the superphosphate commences
to retrograde (" reduce ") if the raw phosphate was not pure.
Betrogradation sets in much sooner if the raw phosphate contained
more than 2 per cent of sesquioxides, or if mistakes have been made
in its manufacture. Eetrogradation (" reduction ") occurs under the
influence of different causes, physical and chemical. The heat and
pressure of the superphosphate heap appear to be the direct pre-
determinating causes. Stored superphosphate forms, first of all,
packed layers. The granules of which it consists have only a slight
superficial contact, but as the thickness of the layer increases the
substance compresses in virtue of its own weight, afterwards in
virtue of the length of contact, so that finally the particles are
glued together to form a very compact mass. There is thus estab-
lished between each an exchange of chemical energy which means
decomposition. Experience shows that these changes are more

STOKING OF SUPERPHOSPHATE. 133

rapid in moist hot superphosphate than in dried cooled superphos-
phate. The crystalUzation of the sulphate of lime, unfinished in
superphosphate, stored hastily, is completed in the superphosphate
heap. The superphosphate of lime, combining with the sulpho
sesquioxides, forms once more sulphate of lime ; free syrupy phos-
phoric acid acts on the silicates, etc. Now, all these reactions give
place to a disengagement of heat, consequently the matter expands
and tension is produced. Each of these reactions occur at a fixed
temperature, which it is impossible to gauge directly owing to the
isolating influence of the sulphate of lime. Finally, agglutination
is still further induced by the rarefaction of the air between the
granules cooled in the heap. For a difference of 10° C. (18° F.) the
difference is 3*5 percent. It has been observed that the phosphoric
acid of the superphosphate does not commence to retrograde
("reduce") until the moment when the particles agglutinate, i.e.
when it is subjected to a fixed pressure. It is, therefore, pressure
which causes retrogradation by destroying the friable compounds
of the superphosphate. The part played by temperature has also
been determined by direct experiments. These show that it may
rise to 100° C. without hurting pulverulent friable superphosphate,
and up to 50° C. for agglutinated superphosphates higher tempera-
tures are only injurious under pressure. Smetham, in examining
"the influence of the oxides of iron and alumina on the retrogradation
of phosphates, observed an essential difference in the action of the
two oxides, as had been observed for a long time in actual practice.
Whilst 1 part of oxide of iron will cause 2 parts of phosphate of
lime to retrograde, the oxide of alumina can only retrograde its own
weight of phosphate (theoretically it retrogrades 3 times its own
weight). In Florida phosphate, Pebbles and Eiver phosphate, the
greater part of the sesquioxides are present as alumina. The ratio
of the alumina to the iron is, on an average, 1 to O'l. According
to the same authority, iron forms two insoluble compounds, the
mono-di-ferri phosphate and the di-tri-ferri phosphate ; alumina only
forms one compound. The free ortho phosphoric acid would appear to
be rendered insoluble in the soil more rapidly by iron and alumina
compounds than monocalcic phosphate, as previously determined by
Gerlach ; the latter also remarks that phosphoric acid, combined
with oxide of iron and alumina, does not dissolve in carbonic acid
water, contrary to w^hat occurs with the acid combined with lime
or magnesia. Phosphates of iron and alumina are only very
slightly soluble in the solutions of organic acids ; phosphate of iron
is almost insoluble therein. As the moisture in the soil is not more
acid than this artificial solution, it may certainly be taken for
granted that the phosphates of sesquioxides remain insoluble in the
soil. When retrogradation starts nothing can stop it ; it pursues
a very rapid course, even when the cohesion of the matter is

134 CHEMICAL MANURES.

broken, as is the case when orders are being dispatched. When
superphosphates of this kind arrive at their destination they some-
times yield, on analysis, different results from those obtained on
dispatch, but the sample then retained shows identical results,
which shows that the superphosphate retrogrades in sample bottles.
If retrogradation cannot be stopped, nor the chemical action which
determines it, one can in a way prevent it in a bad superphosphate.
It suffices to dry it as completely as possible, store it cold, shorten
the storage, or preserve the superphosphate in a thin layer in the
beginning by spreading it over all the available space, extracting the
lumps by sifting, using it to prepare superphosphate of ammonia
(the sulphate of ammonia may hinder retrogradation) or low
strength superphosphates. By mixing 10 per cent of wood sawdust
of bad quality with an 18 per cent P^O- superphosphate which had
retrograded 1-5 per cent, it was observed that the phosphoric acid
did not retrograde further in the low strength manure thus prepared.
In this case the amount of liquid contained in the superphosphate
HgPO^ + H^O lost 45 per cent of its mobility in consequence of
this dilution. On the other hand, the superphosphate was loosened
from its pressure, the latter being spread over all the ballast. It
is clear that this remedy has limits, but it gives good results.

Forestalling Retrogradation bij ScJiitchfs Method. — To ascertain
if a superphosphate is going to retrograde, and at what moment it
will retrograde, are points which it is important for the manure
manufacturer to know. Schucht has used for years a method which
gives results appreciably agreeing with facts. It is generally very
difficult to get access to the lower layers of a superphosphate heap.
It is, therefore, impossible to analyse them, and another means of
control must be found. This means is supplied by the retrograda-
tion indicator about to be described. The apparatus consists of a
graduated lever a, on which is a movable runner of 15 kg. (33 lb.).
This lever is movable, round a point of support b, fixed on a fork c.
A very strong flat-bottomed porcelain vessel e, is used to receive the
superphosphate, which is compressed by means of the plug / fixed
on the lever. The operation is conducted as follows : 100 grms. of
superphosphate are run into the porcelain dish with 25 grms. of
hot water, and the mixture crushed with the pestle ; the excess of
water is expelled on the water bath and the vessel is put under the
press plug, which compresses the contents of the dish. The ap-
paratus is kept under pressure for twenty-four hours at a temperature
of 50° to 70° C. (122° to 158° F.), water, soluble phosphoric acid, and
free phosphoric acid are estimated in the superphosphate, treated as
above, after having already made the same estimations in the
original superphosphate. By comparing the results of the two
analyses a valuation of the superphosphate can be made. The
differences existing between manufacturing localities and in storing

STOEIXG OF SUPERPHOSPHATE.

135

in no way influence the accuracy of the method. If the exact tem-
perature and pressure be found, they remain the same in all cases
so long as the raw material is not changed. This method is far
from solving the question of retrogradation, but it is interesting,
because an idea can be gained from it of the retrogradation of a
given phosphate. Dr. Grueber gives the results of experiments
which he has made with Schucht's apparatus, of which the following
is a brief summary : —

1. A Florida phosphate, 35 per cent P.,0., and 2-52 of sesqui-
oxides, when rendered soluble gave 18' 7 per cent PoO- soluble
in water, and 1-21 of insoluble PoO.. Treated after Schucht's
method, under a pressure of four atmospheres and at a tempera-
ture of 40" C. (10i° F.) (the apparatus being home-made could not
do better), it contained 18"2 per cent of PoO^ soluble in water, and
1-76 of insoluble PoO-. A second Florida phosphate, with 35-96
per cent PoO^ and 2'38 per cent sesquioxides, gave immediately

Fig. 35. — Retrogradation Indicator (Schucht).

after being rendered soluble, 18-8 per cent PoO_:^, and 0'81 insoluble.
After Schucht's process, 16-67 per cent soluble PoO^, and 2-62 per
cent insoluble, which shows the efficiency of Schucht's apparatus,
that is to say, that the particles of phosphate, intimately mixed
and pressed hot, show an accentuated tendency to retrograde.

2. A comparison was made with a superphosphate stored hot in
a big heap. A Florida phosphate with 35-8 per cent P0O5, and
2-09 per cent of sesquioxide, was in use. This phosphate, tested
immediately after being "dissolved," gave 18'1:0 per cent P0O5 and
1-1 per cent insoluble. With Schucht's method it gave 17-25 per
cent soluble P..O5, and 2-06 per cent insoluble. The stored heap
showed at the end of a year 17*28 per cent PoO.,, and 1*96 per cent
insoluble. Consequently the stored phosphate confirms the accuracy
of Schucht's method. In the middle (height) of the heap a- retro-
gradation of only 0-21 per cent occurred and no retrogradation in
the top.

136 CHEMICAL MANUEES.

3. Another experiment was made ^vith a Florida phosj^hate^
with 35-49 per cent P0O5 and 2-25 per cent of sesquioxides. When
"dissolved" it gave 18-98 per cent of soluble P0O-, and 0-95 per
cent of insoluble. Schucht's method was applied in three ways,,
using a Schucht's instrument constructed by Kohler and Martini
of Berlin, by which a higher temperature and pressure could be
applied. The following are the results : —

(a) Pressure and average temperatures as above : ■! mm. (? atmos-
pheres) of p)ressure at 40"" C, 17-09 per cent soluble P.>0-, 1-85
insoluble ; (b) increased pressure and average temperature : 7 mm.
(? atmospheres) of pressure at 40^ C, 16-67 per cent soluble phos-
phates, and 1-91 per cent insoluble; (c) increased temperature and
pressure : 7 mm. (? atmospheres) pressure at 70° C, 16-72 per cent
soluble PoO., and 2-28 per cent insoluble. It will be seen that
retrogradation increases with the temperature and pressure. This-
superphosphate, though piled in a heap 16 ft. high, did not retro-
grade even in its lower part, which Dr. Grueber attributes specially
to the storing of the superphosphate, after complete cooling, by Dr.
Lutjens' scraping and cooling appliance. The fact that the cooled
superphosphate did not retrograde is not sui-prising, because as far
back as 1870 this important fact was observed in the case of super-
phosphates made from Lahn phosphorite, very hable to retrograde,
that the more rapidly it was cooled the less the soluble phosphoric
acid retrograded. Dr. Grueber concludes that, in order to explain
retrogradation, decisive results will onlv be obtained bv working on
the large scale ^^-ith supei-phosphates to which different materials
have been added. With the data so obtained, the treatment of
phosphates could be modified according to their composition and
the manner in which they behave.

Dr. W'^. Paj'san considers retrogi'adation is a rather exceptional
phenomenon.! He supports his view by personal experiences with
Algerian phosphates with 0-5 of sesquioxides, and Peace Eiver
Pebbles with 2-5 per cent of sesquioxides. The solubihzation of the
first was always pushed in a constant manner to 0*75 per cent of
insoluble, that of the second to 1 per cent. He never found retro-
gradation in either even after long storing. He considers that in
valuing phosphates up to now too much importance is attached to
the percentage of sesquioxides. To prove it he quotes trial mixings
he made with this end in view. It was a case of three Tennessee
phosphates (a), (o) and (c) which are characterized from this point
of view by containing 79 per cent phosphate of lime, 2-36 per cent
oxide of iron, and 2-24 per cent of alumina, say a total of 4-6 per
cent of sesquioxides. The results are given in the following
table : —

1 See note 1, p. 14-2.

STORING OF SUPERPHOSPHATE.

137

TABLE XLIII. — SHOWING CHANGES IN COMPOSITION WHICH
TENNESSEE SUPERPHOSPHATES UNDERGO IN FOUR AND A
HALF MONTHS FROM DATE OF MAKING.

Mixings made
2 September, 189S.

PoO. insoluble

Soluble Al.,0, + FeoO-

Insoluble ALO, + Fe^O.

Free Acid

a

h

c

a

b

c

a

b

c

a

b

c

2-27
2-20

1-98
0-90
1-07

1-28

+ 0-2G
+ 0-27
+ 0-29

U _
5-50
5-o0
6-10

+
+

l-Oo
1-01

Sample of same

Superphos-
phate Analysed
17 November,

1898.

2-35

2-33

2-32
0-65 + 0-17
0-87 + 0-18
1-09 + 0-22

— + 1-21

— + 1-20

— + 1-17
4-20
4-30
4-80

1

Sample of the
same Phosphate

Analysed ,
17 January, 1899.

2-30

2-23 '

2-48

1-14 + 0-17

1-08 + 0-22

1-22 + 0-16 !

+ 1-0

+ 1-12 ,

+ 1-12

4-90

4-80

0-30

Paysan adds that not being able to find the cause of retrogradation
in the sesquioxides, he tried to find it elsewhere, and he quotes the
follo\Ying case of a delivery of Florida phosphate. The samples taken
the first day at four different points looked well ; the next day fresh
samples were taken, this time going further forward than the points
explored the day before, and it was found that in certain places the
phosphate was darker than in others, and contained much impurity.
Two samples of this kind, taken at two different points, gave the

following figures

Phosphate of lime
Sand

a

'?• cejit.

Per cent.

71-97

64-65

8-85

19-00

An average sample of the whole cargo gave the following
analysis. Phosphate of lime 77*73, oxide of iron and alumina 2-13
per cent. The pure phosphate behaved in a normal fashion. In
working it dissolves completely and gives no retrogradation, but
when wrought up with the impure part retrogradation was rapid,
1-52 to 2-14 per cent of insoluble was obtained against 0-75 with the
pure superphosphate. This example well explains contradictions
and obscure points. But Dr. Paysan does not admit the theory of
pressure in the question of retrogradation. He has often remarked
a tendency to retrograde in superphosphates as soon as they have
gone through Carr's disintegrator. He does not ascribe trans-
cendent merit to Dr. Lutjens' processes. He regards them as-
elegant and useful auxiliaries in superphosphate manufacture, but

138 CHEMICAL MANURES.

which do not dispense with passing the manure through Carr's
disintegrator.

Basis on lohich Superphosphates are Sold} — In the beginning of
the superphosphate industry, superphosphates were sold according
to their percentage of phosphate of Hme sokible in water. But
there were disputes between buyers and sellers, the former not
finding the strength given them by the latter. A portion of the
phosphate had become insoluble on delivery. The British were the
first to determine that that part of the phosphate originally soluble
in water, and at the end of a certain time was no longer so, was,
however, soluble in weak reagents, such as carbonate of soda or oxa-
late of ammonia, whilst the phosphate, originally insoluble, did not
dissolve appreciably in these reagents. At first it was thought that
this phosphate which British chemists called " reduced " phosphate,
but now termed retrograde phosphate, was formed by the action
of the monocalcic phosphate on the tricalcic phosphate producing
an intermediate bicalcic phosphate. Such, at least, was the current
explanation fifteen years ago. Be that as it may, manufacturers
have got over the difliculty, not by improving their manufacture,
but in altering the basis of sale of superphosphates, i.e. by selling
them according to their content per cent of phosphoric acid soluble
in cold alkaline ammonium citrate which they term assimilable
phosphoric acid. This method of sale is evidently very convenient
for the manufacturer, and enables the works chemist to cease from
worrying over retrogradation whether it arise from bad manufac-
ture or the presence of impurities in the raw phosphates.

Now, as Mr. J. Joffre observes : " When a superphosphate is
treated with citrate of ammonia in analysing it, both the citrate

^ A 25 per cent soluble phosphate, say phosphoric acid = ll'4o per cent, is
the current British make of soluble phosphate. A 12 per cent Somme will give
a 30 per cent soluble phosphate which will bear an addition of 3 cwt. of
gypsum to the ton to bring it down to 25 per cent if the superphosphate is
dispatched as soon as made. Or the gypsum may be partially replaced by
a little Belgian phosphate. But in Britain it is not considered good business
policy to add a nitrogenous mnnure like bone dust to a superphosphate, and the
tendency of the workmen is always to use far more bone dust than that in the
formula, for reasons which will be readily appreciated ; the result being that
^vhen it comes to stocktaking the leakage of bone meal and bone dust is exces-
sively large. What the translator cannot understand is the magical effect of
1-0 per cent of bone dust, say one-fifth of a cwt., i.e. 22 lb. to the ton. If the
superphosphate was very damp such a pinch of bone meal would be a drop in
the ocean ; 3 per cent of raw Gaf sa phosphate can be understood. It will
readily be seen that only by strict book-keeping by double entry can the amount
•of phosphate and bone dust used as driers be conU'oUed. The translator fears
the author is somewhat over-sanguine as to the efficacy of some of the drying-
machines and grinding machines which he describes. It appears to the former
that if a manure will dry naturally, as it should do, these machines are not so
indispensable as would be inferred, and where the manure will not dry naturally
one may be pardoned from doubting if the machines are quite so efficacious as
one is led to believe. — Tr.

STOEING OF SUPERPHOSPHATE. 139

•soluble phosphoric acid, and the water soluble phosphoric acid,
enter into solution simultaneously. It results that when the
•analysis is made by the citrate method (without a separate estima-
tion of the phosphoric acid soluble in water) there are confused
together both the phosphoric acid soluble in water, of great fertiliz-
ing value, and the phosphoric acid combined with iron, which has
but very little. The citrate method is, therefore, uncertain. The
results may represent bodies which are very good for plants if they
-consist of monocalcic phosphate or free phosphoric acid which are
■dissolved in this reagent. They may, on the other hand, represent
substances which only have a very mediocre action, if they are
phosphates of iron, called retrograde phosphates, which have passed
into solution. Analysts ought, therefore, to give preference to
estimating by the solubility in water as in Great Britain, Germany,
and the United States. They ought, at least, to estimate separately
the soluble in water and likewise separately the citrate soluble."

It is now admitted, without going further, that there is no great
difference from a fertilizing point of view between the water soluble
phosphoric acid and the citrate soluble. There is, however, a sharp
line of demarcation between the two products ; the first is im-
mediately assimilable by plants, the second is rendered soluble and
assimilated in the soil to the same extent as the phosphoric acid
in basic slag. But then there is no occasion for the difference in
price between the selling price of superphosphates (supposing them
to be partially retrograded since they are sold' as such) and basic
slag. Now this difference is considerable. On 1 January, 1909,
for basic slag at Paris stations the price of the unit of phosphoric
acid in basic slag and superphosphates was exactly in the ratio of
3 to 4, which makes the phosphoric acid in retrograde phosphates
25 per cent dearer than the citrate soluble phosphoric acid of basic
■slag. It is asserted, it is true, that if retrogradation has not already
occurred in the superphosphate before spreading it occurs rapidly
in the soil. The validity of this assertion will be examined later
on in giving Dr. P. Wagner's opinion on the matter. In Germany
superphosphates are sold by their content per cent of water
soluble phosphoric acid, the citrate soluble not being taken into
consideration. Now, in superphosphates containing 1 per cent of
insoluble phosphoric acid this latter is two-thirds soluble in water ;
the manufacturer is thus prejudiced. In Spain and in the Medi-
terannean regions the customs are the same as in France. In
Austria-Hungary customs vary with the localities ; in some super-
phosphates are sold according to their content of water soluble
phosphoric acid, in others according to their content of citrate
soluble. It is the same in Eussia. In America sales are also
Teased on the citrate soluble which enables manufacturers to work
low grade phosphates w4th a high percentage of sesquioxides At

140 CHEMICAL MANURES.

present it is Germany which manufactures the most chemical
manures to respond to the increasing demands of agriculture.

Pkosjjhatic Mannres — Do they become Insoluble in the Soil ? —
The benefits of enriching the soil in phosphoric acid has sometimes
been questioned on the ground that phosphatic manures become
insoluble in the soil, and consequently inactive in a period of time
varying from one to three years. This objection has been refuted
by Dr. Wagner. If superphosphate or basic slag be buried and the
soil be left to itself without tilling it or sowing it, what happens ?
The result will be that the rain, filtering through the layer of soil, will
insensibly dissolve the phosphoric acid of the superphosphate and
the basic slag, and will transport it always a little further into the
subsoil, where it comes in contact with oxides of iron, alumina, and
lime. It will combine with these salts forming less and less soluble
compounds, to pass finally after fifty or a hundred years perhaps,
one does not know exactly, to almost the same state of insolubility
as the phosphoric acid contained in the minerals in the soil.

" This transformation will require a very considerable time. It
is also certain that in a cultivated soil tilled, laboured, sov/n, and
manured, the process of being rendered insoluble is unceasingly op-
posed to the tendency to become insoluble ; the cultivated soil
opposes the contrary one, that of becoming soluble. The humic
acid, the carbonic acid, the nitrate of soda, the roots of plants,
fungi, bacteria, the circulation of air and moisture, are constant
agents of activity which do not allow the soluble phosphoric acid
to come to rest. As soon as precipitated phosphates are formed in
the soil with a portion of the phosphoric acid whether from super-
phosphates or basic slag, the agents in the soil just enumerated
exert their solvent action and bring back the phosphoric acid to the
soluble state, the lime, alumina, and oxide of iron reprecipitate it
again in part, the agents in the soil bring it back unceasingly to the
soluble state, and so on. The phosphoric acid, therefore, is not at
rest in the soil ; it passes from one state of combination into
another ; it unites to one element for a fleeting union and quits it
to unite to another element to form a union quite as ephemeral,
for the agents of combination and solution contained in the soil
are engaged in an incessant struggle to seize and carry away the
phosphoric acid for themselves ; sometimes it is the one, sometimes
the other, that remove it in a transitory fashion. But the phos-
phoric acid retains its instability. The more intensive the culture,
the more the soil is aerated, rich in humus, the more abundant the
manuring with nitrate, ammoniacal and potash salts, the deeper the
tilth, the heavier the crops, the less chance has the phosphoric acid
in excess entrusted to the soil of passing to the soluble state, at
least in large enough amount to occasion fears as to its action."

In support of these arguments Wagner relates the results he

STORING OF SUPERPHOSPHATE.

141

got with experiments on basic slag on a meadow, poor in phos-
phoric acid, which only yielded about 1^ tons per hectare of hay
(say 12 cwt. per acre). A series of plots received 800 kilos of basic
slag per hectare, say 320 kilos (704 lbs.) per acre on 30 October,
1889, another series remained mimanm-ed. As an auxiliary manure
the same amount of kainit was applied and the same dose applied
■every year. The phosphatic manure was not renewed. The 800
kg. of basic slag per hectare (704 lb. per acre) applied once have
produced : —

TABLE XLIV.— SHOWING FOR A SUCCESSION OF YEARS THE IN-
CREASE IN HAY FROM ONE APPLICATION OF BASIC SLAG TO
A POOR MEADOW.

Year.

Increased

yield.

1890

750 kilos of hay

per hectare

1891

2300 „ ,

> ))

M ?»

1892

2600 „ ,

» ))

M >5

1893

1440 „ ,

) j>

)5 5»

1894

2930 „ ,

) 5)

)) >)

1895

1310 „ ,

? ))

55 55

1896

1060 „ ,

) »)

5) 55

1897

920 „ ,

5 )5

55 55

1898

570 „ ,

) >)

55 55

13,880

The manuring with 800 kg. per hectare (704 lb. per acre) of
"basic slag, once applied, has continued to act during nine consecu-
tive years, and has produced during this interval 13-880 metric
tons of hay per hectare, say 5 tons 12 cwt. per acre. In this ex-
periment the basic slag has not been rendered insoluble, and the
reserve of manure entrusted to the soil has been nothing less than
profitable. It goes without saying that this experiment, by itself
alone, ought to afford instruction as to how a phosphate manure
•once applied behaves in its restorative action, for to entrust a soil
with a reserve of manure, and to allow this manure to act for nine
years without restoring the amount consumed by vegetation, would
be quite irrational ; moreover, the abgve experiments, which have
been varied by others in different directions, have shown that a
yearly application of manure still further increases the yield.^

1 It is hardly sound or logical reasoning to apply the permanently basic slag
in the soil to that of superphosphate. This meadow possibly was sour and
wanted lime which basic slag supplied. Part of a 25-acre field was limed, then
planted with Scots pine ; the pasture under the trees on the limed portion was
easily differentiated by its excellent quality 40-50 years afterwards from the
almost bare unlimed portion. — Tr.

CHAPTEE VIII.

COMPOUND MANUKES.i

Manufacture of Mixed Manures. — The manures generally used foi"
admixture with superphosphates are Peruvian guano, bone dust,.
sulphate of ammonia and nitrate of soda, but the Peruvian guano dis-
patched from the spots of ]3roduction now is much less rich in nitrogen
than that imported in the past. Its place is taken by sulphate of
ammonia, ground horn, dried blood, dried meat, etc. Superphos-
phate of potash is also prepared. The mixing is done as much as
possible after the phosphate is dissolved. Mixing is not done ia
the dry state, except when it cannot be done otherwise.

Hand labour is the best for this kind of work. The materials,
previously weighed and sifted, are made into a 2 ton heap by means
of a portable box (? barrow) capable of holding 100 kilos (2 cwt.).-
To turn the matter properly the shovel is plunged into it vertically,,
so as to mix it, then after having sifted it, it is made into a heap in

1 In the wet mixing of compound manures where such things as sulphate
of ammonia, meat meal, fish guano, bone meal, kainit, shoddy, etc., go up the
cups, retrogradation is less marked. The other ingredients apparently, at
least, retard retrogradation, if they do not prevent it to a great extent. A
30 per cent soluble phosphate which retrograded 3 to 4 per cent in a few months
when dry mixed so as to give 20 per cent soluble phosphates and 7*0 per cent
ammonia, maintained that composition exactly for several months in a 250 ton
heap. It is better to use up superphosphates with such a marked tendency to
retrograde in the making of wet mixing compound manures. — Te.

2 The British manure manufacturer works in cwts. to the ton, thus.
a very easy calculation shows that 8f cwts. of sulphate of ammonia (of 20*5 per
cent N) to the ton mixing, gives 9 per cent of nitrogen in the mixing ; a similar
easy calculation shows 11^ cwts. of superphosphate with 35 per cent of soluble
phosphate to the ton mixing, gives as near as may be 19-647 per cent of soluble
phosphate in the mixing, and 19-647 of soluble phosphate is equal to 9 per cent
of soluble phosphoric acid (9 x 2-183).

It IS all very well for the author to say inert ingredients should not be used,
but it is often impossible to avoid the use of gypsum, the more so as it dries the
manure and gets the core through the screen. To get the core in this case through
the screen with bone dust would be a waste of money, as apparently no value
is attached to insoluble phosphate. Supposing the superphosphate used tests
in this case 38 per cent of soluble phosphate, it is a clear case for the addition
of gypsum instead of using two grades of superphosphate. Moreover, a manure-
of this nature with neither potash nor bone meal would have no backbone. — Tr.

(142)

COMPOUND MANUEES. 143

the inverse order, that is to say, by lifting it from the ground to
throw on to the middle of the heap. ^

These manipulations are sometimes rather unpleasant, such as
the disengagement of dust, etc., nevertheless they form the best
method of mixing. The materials so mixed are afterwards passed
through a Carr's disintegrator or through the toothed crusher and
a very homogeneous mixture is thus obtained. Inert materials
should be avoided in these mixings. By mixing high strength
superphosphates with low strength superphosphates common sorts
can be made without recourse to inert materials, sand, plaster, etc.

[Sujjerplios'pliate of Ammonia ^J Ammoniated Superjjhosphate. —
Although the composition of this manure is very variable, the most
usual strength being 9 x 9, 5 x 10, or 6 x 12, the first figure in-
dicating the percentage of nitrogen, the second the percentage of
soluble phosphoric acid, this manure is in great esteem. It is
analogous to dissolved Peruvian guano to which farmers are
accustomed. It, moreover, presents this advantage, that its acid
retrogrades less easily in the soil than that of pure superphosphate,
seeing that the sulphuric acid combines first with the bases which
it encounters in arable land. The mixture of superphosphate with
sulphate of ammonia is easily made. Sulphate of ammonia is
delivered in a finely ground granular condition. It contains 24*5 per

1 This explanation is not very intelligible ; possibly the following will make
it plainer : —

Take a 10 ton mixing according to the following formula : —

'Tons. Cicts.
15 cwt. superphosphate . . . . . . = 7 10

3 cwt. sulphate of ammonia =1 10

1 cwt. bone meal .......= 10

1 cwt. muriate of potash .....= 10

First ot all the 7^ tons of superphosphate would be laid down in a heap and
accurately levelled, then the IJ tons of sulphate of ammonia would be spread
uniformly over the levelled top of the heap, then the J ton of bone meal uni-
formly over that, then the muriate over that. Then a screen with two men
would be placed at one end of it and a man to get the stuff for them, that is by
digging down the heap vertically and mixing it for the two men to shovel it
through a ^ inch or 1 inch screen. When this first screening is done the
material is screened through in the reverse direction, but this time through
a I inch sieve. If the heap has been laid down anything like proportionately
and uniformly, samples taken from any point will agree in analysis in a manner
that those who have not seen it done would hardly credit. If the 7 J tons of
superphosphate were taken from the superphosphate heap, if the foreman has
a good eye for bulk and weight there need be no necessity to weigh the 7^ tons ;
he can tell to a nicety its bulk. — Tb.

2 This name as used by the author is misleading, applied as it is to
a mere mechanical mixture of sulphate of ammonia and superphosphate of lime,
and would not pass muster in a court of law in Great Britain. The translator
has altered it to ammoniated superphosphate. Superphosphate of ammonia
seems to imply that it is a superphosphate of lime in which the lime is replaced
by ammonia. But that does not occur until the manure is dissolved by the
moisture in the soil. — Te.

lU CHEMICAL MANUEES.

cent NHS = 20*2 per cent N and about 1 per cent moisture, which
is an advantage for the manufacturer, for the mixtures 9x9 have
to be delivered with a maximum of 6 to 7 per cent of moisture, those
of 0 X 10 with a maximum of 8 to 9 of moisture, if it be not desired
to be exposed to annoyances by the formation of lumps (? loose
caking in the sacks). To obtain very homogeneous superphosphate
of ammonia (ammoniated superphosphate) the sulphate of ammonia
is added during the " dissolving" of the superphosphate by dissolv-
ing this salt in the sulphuric acid used to decompose the super-
phosphate, but this method of proceeding is not applicable except
with small amounts of sulphate of ammonia.^

The process generally used in making "superphosphate of
ammonia " (or ammoniated superphosphate) is as follows. The
dry superphosphate of ammonia delivered in 10 ton wagons, being
stored and analysed, the amount of superphosphate and sulphate
required to give a mixture of 9 x 9 has to be calculated. Suppose
that the sulphate of ammonia contains 20-5 N, then 20-5 kg.
correspond to 100 kg. (NHJ^SO^, 9 kg. correspond therefore to

100 X 9

— ^ — - — = 12 kg. (NHJ.^SO^. There remains then for the super-

AiJ'D

phosi^hate 100 - 42 = 58 kg. These 58 kg. of superphosphate
must contain 9 kg. of soluble phosphoric acid, which corresponds to

77 — = 15-5 per cent of phosphoric acid. To make the mixture

oSt

the 10 metric tons of sulphate of ammonia are laid in a heap 33 ft.

long and on each heap the necessary portion of superphosphate to

the total of 12-777 metric tons. Two labourers mix the two with

the shovel, making the whole into one heap and recommence the

same in an inverse direction. The mixer is then passed through

Carr's disintegrator or the toothed crusher, then it is laid on a big

heap in the warehouse for the ingredients to combine.-

Mixtures of superphosphate and sulphate of ammonia exhibit

phenomena of a peculiar nature. They gradually heat and become

damp to the touch ; they dry again, and owing to the formation of

gypsum, they harden more and more. The reaction lasts for a

variable time. It depends on the nature of the superphosphate and

1 Quite so, but there is no necessity to actually mix the ammonia
with the acid before running the latter into the mixer. The sulphate can go
up the cups like other ingredients, and precede the other ingredients if the man
in charge fancies that style of mixing. The translator, however, has no great
faith in the solvent action of sulphuric acid after it has been so far converted
into an acid sulphate of ammonia. He prefers to send the sulphate up the
cups last, after the acid has done all the work it is intended to do. — Tr.

2 A disintegrator, whether Carr's or any other make, has its use in manure
factories, but it is not at all necessary to resort to it on every occasion and
to put all the manure made in the factory through it without rhyme or
Teason. — Tr.

of ammonia 5 x 10. For 100 kg. of mixture, take — ,^^ ^ = 24:'4:.

COMPOUND MANUEES. 145

its manner of manufacture, and may end in fifteen days, when the
mass is in a large heap and exposed to a certain pressure. " Super-
phosphate of ammonia " (ammoniated superphosphate) forms a
hard, sometimes locky mass, the shifting of which is expensive, for
one is obliged to blow it up wdth gunpowder (! ! ! ).^ It is crushed by
Carr's disintegrator, is j^assed through the sieve, and bagged up
immediately afterwards, for it does not solidify again if made
according to rules, that is to say, if each grain of sulphate of
ammonia is united to its grain of superphosphate to form a sulpho-
phosphate. To diminish the hardening as much as possible, sand,
or better still, powdered peat, sawdust, wool dust (? scutch), or chim-
ney soot are added, and in the second place, immediate saturation of:
the sulphate of lime by the addition of a little water. The secondil
grinding is therefore necessary to effect the perfect mixing of the-
two ingredients. In fact, if the substance be analyzed after the first
crushing, there w^ill be found 8-8 per cent of phosphoric acid andl
9*2 per cent of nitrogen, together 18 per cent, but after the second
crushing the product uniformly shows 9 per cent of phosphoric acid
and 9 per cent of nitrogen. This method of preparation serves,
equally, for all the mixing it is desired to make superphosphate

100 X 5

20^
kg. of sulphate of ammonia of 20*5 per cent N, and consequently

n^r ^ ,■ u i . . • ■ 100 x 10 , .3 ^

7o"b kg. of superphosphate contammg — --— — = 13-2 per cent.

phosphoric acid. If it be a case of a wagon of 10 tons of sulphate-
of ammonia, 41 tons of the mixture will be obtained of the 5 x 10'
mixture, requiring consequently 31 tons of superphosphate. It is.
easy to bring the superphosphate to the right strength by mixing a*
high strength superphosphate with a low strength superphosphate-
or with gypsum free from iron, alumina, and carbonate of lime, a
poor superphosphate with a rich superphosphate, or wdth a double-
superphosphate.

^ In the hardening of the author's so-called superphosphate of am-
monia he seeni"^ to confuse mixing operations by the wet w.-.y with those by
the dry way. It is perfectly feasible that through bad manipulation a mixing,
might so harden in the " dens " that it might almost require blasting operations
to break it up, but only through culpable, nay wilful, neglect on the part of the
man in charge of the mixer in not running in the proper amount of acid,.
Bone meal and sulphate of ammonia give a very hard glutinous mixing when
sent up the cups, but sulphate of ammonia and phosphate alone should do no.
such thing. The translator has made numerous dry mixings of superphosphate
with sulphate of ammonia in all proportions and never found the hardening
to go further than caking, but he always made a point of having at least 1 cwt=.
to IJ cwts. or even 2 cwts. to the ton of bone meal in such mixings, and this,
kept it friable and open, and when the stimulant elements of the manure hacJ.
done their work then the plant had something to fall back upon. — Tn.

10

146

CHEMICAL MANURES.

TABLE XLV.— NUMBER OF CWTS. KEQUIRED IN A o TON MIXING,
OR OF TONS IN A 100 TON MIXING OF A SUPERPHOSPHATE OF
A GIVEN STRENGTH IN P.^O-, TO PRODUCE A MANURE OF A
GIVEN STRENGTH IN P.,0,. '

the Super-

phosphate, g.g

P2O5 in the Mixture.

8-9

9-0

9-8

9-9

lO-O 1 11-8 11-9 1-2-U 14-S 14-9 | IS'O

■1

lo

15

15-3

15-4

15 '5

15 -fi

15-7

15-8

15-9

16-0

lG-1

l(v2

if;-;-3

1(3-4

16-5

lG-6

16-7

16-s

16-9

17-0

17-1

17

17

17

17

17

17

17

17

38-0

18-1

18-2

18-3

18-4

18-5

18-6

18-7

18-8

18-9

•2
•3

•4
•5
•6
•7

•8
•9

58

57

57

57

56

56

56

55'

55-

55'

54'

54'

53'

53-

53-

53'

52'

52'

52

51'

51

51

50

50

50

50

49

i49

49

!48

148

48

:48

!47

i47

^47

|47

46

46

■2S 58'

■90 58'

•7158'

•15|57

•78o7'

•41 57'

•06 56'

•69 56'

•35 55

•0655'

•6755'

•33:54'

•99 54'

•67 54

•33 53

•02 53

•7053

•38 52'

•07 52

•7752

•46; 52

•1751

•8851

•58 51

•29 50

•0550

•72 50

•4450

•1649

•89'46

•62 49

•35 48

•08 48

•83148

•5648

•3247

•0747

•80|47

•50!47

•93 59-
•56 59
•17 58-
■80 58-
•42 58 ■
•05 57-
•69 57^
•32 56-
•98 56-
■63 56'
•29 55-
■99 55-
•61 55"
•28 54-
•9454-
•62 54-
•30 53'
•98 53'
■66 53'
•3652
•05 52'
•7552
•45 52
•1651
•87 51
•5851
•28 50
•00 50
•72 50
•4449
•17 49
•90 49
•63 49
•38 48
•10 48
•85,48
•60;48
•34147
09 47

60 64-89 65^5 66^22 78
21 64-6S 65-13 65^95 77
62 64^04 64^71 65^36 77
43 63^63 64-28 64^94 76
06 63^23 63^87 64^52 76
69 (V2^82 63^46 64^10 75
32 62^41 63^05 63-69 75
96 62-01 62^65 63^28 74
59 61^63 62-26 62-90 74
24 61-25 61-87 62-50 73
90 60-87 61-49 62^12 73
55 60 49 61-10 61-73 72^
2160-12 60-73 61-35 72-

88 59-75 60-37 60-98 71-
5459-38 59-99 60^60 71-
21 59-03 59-64 60-24 71'

89 58-68 59-28 59-88 70'
57 58-33 58-92 59^53 70-
•25 57-98 58^55 59-17 69'
94 57^65 58^24 58^83 69
62 57^31 57^89 58^48 69
•32 56^98 57^55 58^15 68
•02 56^65 57-23 57^81 68
•72 56^32 56^90 57^48 67
•42 56^01 56-57 57^15 67
•23 55^68 56^24 56^82 67
•84 55-37 55-93 56-49 66
•56 55-05 55-62 56^18 66
•27 54^74 55^30 55^86 65
•89 54^44 54-99,55^55 65
•72 5414 54-69 55-25 65
•44 53^84'54-39 54-94 64
-17 53-55 54^0y 54-64 64
•91 53^26 53-80 54-36i64
•64 52^97 53^51 i54^05 63
•39152-69 53^22 53-76,63
-12 52-41 52^94 53-48!63
•86 52^12 52^65 53-19:62
•6li51^84 52-37'52^90 62

14 78

64 78
1377
63 77
14 76

65 76'
1675^
67 75 •
22 74^
75 74-

73^30 73^

85 73^^-
40 73^
96 72-
52 72 •
09 71^
()671^
25 70-
72 70-
42 70-
01 69-
61 69-
■22 68-
82:68-
4468-
05 67-
•67 67-
•3066-
92 66'
•55 66'
•1965

83 65-37 65
•48 65
-13 64
-7864
-45 63
•1163
•7663
•4362

79 79-

29 78-
76 78-

27 77-
78 77-

28 76-
78 76-

30 75-
84 75-

91 74-
45 74-
00 73^
56 73 •
1172-
68 72-
25 71-
8171-
4171-
00 70-
58 70'
18 69'
■79 69-
•39 68'
00 68
61 68
22 67
■84 67
•46 67
•10 6i)
•7366
37 65
0165
•68i65
31;64
97 64
•63|64
2863
95i63

47

96
45

93
43
93
43

97

48

01

54

08

62

18

73i

30

86

44

01

60

18

77 86-

37 85-

■9885 ■

•58 84-

•19 84'

■79 '83'

•4283'

•04 82'

•67i82'

•3081

-9481

-5780

-2280

-86^80

•52,79

•18:79

•83 '78

•4978

06 86

57 86
07:85
59 85
1084
62 84
16 83
68 83
22,82
■77 82
32 81
■87 81
•4480
•00 80
•58 80
•1679
•78 79
•30 78

64:87-

1486-

6586-

1585'

67 85^

18 84'

7i;84'

24 83'

77:88'

3182'

87 82'

4181

97 81'

54.^1

1180

69 80

2579

8379

22
72
22

72
23

74i
28^
79
33
87'
41
96-
53!
08'

66;

23;

79!

36l

Su2)e7y]ios2)h'ate of Ammonia and Potasli} — This (a mechani-
cal mixture of sulphate of ammonia and potash salts) is prepared in

^ This also is a uauie which would not pass muster in Great Britain,
implying as it does that it is superphosphate of lime in Avhich the lime has

COMPOUND MANURES. 147

the same way. Suppose it is desired to prepare a mixture of this
nature with 5 per cent of nitrogen, 7 '5 per cent of potash, and 9 per
cent of phosphoric acid, and that there was to he used for the j)ur-
pose sulphate of ammonia wdth 20*5 N, and potash salts with
37 per cent K. To get 100 kg. of superphosphate of ammonia and
potash it is therefore necessary to use : —

— ^7^^— = 24-4 ks. of sulphate of ammonia.
20-O

^^i^^ — = 20*3 kg. of potash salt, and consequently

5o'3 kg. of superphosphate testing.

100 X 9

— - = 16'27 per cent of phosphoric acid.

OO'o

Ten tons of the sulphate of ammonia used would therefore give
41 tons of the comi^ound manure. It would thus be necessary to use
31 tons of potash salt plus superphosphate, say 8-32 tons of the first,
and 22-680 of the second. These manure mixtures find an outlet
chiefly in regions where the vine, tobacco, the hop, and vegetables
for preserves are cultivated. They are likewise esteemed for the
culture of the sugar beet, barley, and potatoes. Mixtures of super-
phosphate and potash salts become readily moist in the store, so
that they cannot be prepared a long time in advance. The use of
calcined salts ^orepared from the waste of potash factories, have the
drawback that they nearly always contain magnesium chloride.
When they are dried with precaution at 100° C, they are exempt
from basic magnesium compounds. The retrogradation of the
soluble phosphoric acid in mixed manures under the action of the
basic salts of potash, have been studied by Emmerling as a result of
experiments thereon. By treating salts of potash in the reverbera-
tory furnace to partial fusion, about 800° C. (1472° F.), the mag-
nesium chloride which they contain is decomposed in the moist
condition as follows : —

MgCl, + H.O = MgOHCl + HCl

According to the equation —

CaH,(PO,)-' + MgO = CaMgHiPOj- + H,0,

a molecule of magnesia can retrograde a molecule of phosphoric
acid, from which it follows that one part of MgO can render 3-55 per
cent of phosphoric acid insoluble. If one use, for example, twenty-
been chemically replaced by equivalent proportions of ammonia and potash,
whereas it is a mere mechanical mixture of superphosphate with sulphate of
ammonia and potash salts. — Tn.

148 CHEMICAL MANUEES.

nine parts of potash salts with 2-05 per cent of free magnesia

2 X 0'5 X 29

(percentage controlled by estimation), the -^ = 0"59 part

MgO suffices to combine 0*59 x 3*55 = 2 parts of phosphoric acid ;
as an actual fact, only 1'4 of insoluble was obtained, which proves
that the magnesia did not exert all its action. The cause lies in
the slight solubility of magnesia, and in the fact that the salts of
potash combine partially with the precipitate formed, so that a part
of the phosphoric acid of this latter remains in solution.

Nitrophos-phate. — The use of nitrate of soda in compound
manures is rather restricted ; it is used in making nitroiDhosphate,
sometimes in nitrophosijhate of ammonia. It is found that nitrate
of soda and sulphate of ammonia are incompatible, and that in
fact it is better to use these manures separately. Besides, mixtuies
of superphosphate and nitrate sometimes enter into spontaneous
combustion in the bags.^ The mixtures of superphosphate and
nitrate must be dry mixing. They are no longer objects of tenor
to the manufacturer, provided that the superphosphate used has
been properly made, for dry nitrate of high percentage mixed with
a superphosphate, likewise dry, does not give off nitric acid and
cause loss of nitrogen as was often the case formerly when supei-
phosphates were wet and the nitrates charged with chloride of
sodium. The sodium chloride decomposed by the free phosphoric
acid caused the bags to burst in transit, for there is no substance
which rots bags like free chlorine and fluorine, two elements given
off when nitrate and damp superphosphates are mixed.

Finally, a manure is made for meadows by mixing kainit with
superphosphate or with basic slag."^ The mixing entails no difficulty.
The ingredients are mixed with a shovel, then the heap is turned
over, the product perhaps passed immediately to the centrifugal
crusher, then to the sifting machine. If the kainit be in blocks or
lumps it must be passed to the crusher to reduce it to the desired
fineness.

It has already been remarked that in the case of the super-
phosj^hate of ammonia of high strength, the phosjjhoric acid soluble
in water did not retrograde even when the superphosphate entering

1 When manure containing nitrate takes fire spontaneously in the bags it
is not a case of clamp or wet superphosphate, nor is it a case of impure nitrate ;
but it is due wholly and solely to the superphosphate fresh from the mixing
" den " being mixed with the nitrate and bagged up before it has had time to
cool. Cold superphosphate, however damp, does not act on nitrate of soda,
unless in very warm weather. — Te.

- Kainit long in stock is generally so damp that it blocks and chokes up
the crusher. The only way to grind it is by hand labour, by the aid of wooden
mallets with long arms, and it is altogether a costly piece of work. Kainit
should not be stored in sacks but in bulk on a concrete Hoor where the water
can drain away from it. — Tr..

COMPOUND MANUKES.

149

into the mixture was of such a nature as to readily lend itself to
retrogradation. The causes of this phenomena are of both a
physical and chemical nature. The more the superphosphate is
distended by ballast, which is here sulphate of ammonia, the more
distant the particles are from one another and preserve their con-
dition. From a chemical point of view, sulphate of ammonia
230ssesses the property of hindering the basic sesquioxides from
precipitating themselves, but it is clear that a retrograded super-
phosphate cannot be improved by mixture with sulphate of
ammonia.

Tables for the Calculation of Siiperj^hosjjhates of Ammonia. —
The first vertical column of Table I gives the content of sulphate
of ammonia in per cents of nitrogen, from one-tenth to the next
tenth within the limits which are generally met with in practice.
The top horizontal column contains the usual percentages in
nitrogen of " superphosphates of ammonia," say 2, 3, 4, 5, 6, 7, 8,
9 per cent of nitrogen. The figures contained at the points of
intersection of these vertical and horizontal columns show the
number of cwts. of sulphate of ammonia that must be added to the
heaps to get 100 cwts. of the mixture with the desired nitrogen
content. Thus, for example, to get a suj)erphosphate of 5 x 10,
with 4-9 per cent of nitrogen from a sulphate of ammonia, of 20-2
per cent of nitrogen, it is necessary to add for 100 cwts. of mixture
sand (!) and superphosphate, including 24 to 25 cwts. of sulphate
of ammonia. Table II gives corresponding values for calculating
the superphosphates.

T\BLE XLYI.— SHOWING IN CWTS. THE AMOUNT OF SULPHATE
OF AMMONIA OF DIFFERENT STRENGTHS THAT MUST BE
CONTAINED IN A 5 TON HEAP TO GET A MANURE CONTAINING
FROM 1-850 UP TO o PER CENT NITROGEN.

Per cent
N

1-85

1-90

1-95

•20-0

•2-85

2-90

1
2-95

3-0

19-0

9-49

9-74

10-00

10-26

14-62

14-87

15-13

15-38

19-6

9-44

9-69

9-95

19-21

14-54

14-79

15-05

15-31

19-7

9-40

9- 65

9-90

10-15

14-46

14-72

14-97

15-23

19-8

9-34

9-69

9-85

10-10

14-39

14-64

14-89

15-15

19-9

9-30

9-55

9-80

1005

14-32

14-57

14 82

1508

20-0

9-25

9-50

9-75

10-00

14-25

14-50

14-75

15-00

20-1

9-20

9-45

9-70

9-95

14-18

14-43

14-68

14-92

20-2

9-16

9-41

9-65

9-90

14-10

14-.35

14-60

14-85

20-3

911

9-36

9-61

9-89

1404

14-29

14-53

14-78

20-4

9-67

9-.30

9-56

9-80

13-97

14-22

14-46

14-71

20-5

9-02

9-27

9-51

9-75

13 90

14-15

14-42

14-63

20-6

8-98

9-22

9-47

9-71

13-83

14-08

14-32

14-56

20-7

8-94

9-18

9-42

9-66

13-77

14-01

14-25

14-50

150

CHEMICAL MANUEES.

Per cent
N

3-S5

19 -o
19-6
19-7
19-8
19-9
20-0
20-1
20-2
20-3
20-4
20- 5
20-6
20-7

19-74
19-64
19-54
19-45
19-35
19-25
19-15
19-05
18-97
18-88
18-78
18-69
18-60

3-90

3-95

4-0

20 00

19-90
19-80
19-70
19-60
19-50
19-40
19-31
19-22
1912
19-02
18-93
18-84

20-26

21-5

20-04

19-95

19-85

19-75

19-65

19-55

19-45

19-30

19-27

19-17

19-08

20-51

2041

20-31

20-20

20-10

20-0

19-90

19-80

19-71

19-61

19-51

19 42

19-32

4-85

24-^7
•24-74
24-61
•24-49
24-36
24-25
•24-13
•24-01
23-89
23-78
23-65
23-54
23-43

4-9(1

i

4-i).T

5-(J0

i

25-13

25-39

•25-64 i

25-00

25-25

•25-51

24-87

25-13

25-38

•24-75

25-00

25-25 i

24-62

'24-87

•25-13

24-50

24-75

25-00 j

•24-38

24-62

•24-88 i

24-25

•24-50

24-75 j

•24-14

•24-39

•24-63 j

24-02

•24-27

'24-51 !

•23 -'JO

24-14

24-39 ;

23-79

24-03

24-28 ,

23-67

23-91

24-15 i

I

CHAPTER rx.

THE MANUFACTURE OF PHOSPHORIC ACID, DOUBLE SUPER-
PHOSPHATES, AND VARIOUS PRODUCTS.

Historical Review. — The manufacture of phosphoric acid has lost
much of its former importance. The market for raw materials and
finished products constitutes one of the most important factors in the
development of an industry. Formerly, when pure phosphates of
high strength were rare, whilst phosphates of low stiength abounded,
the phosphoric acid industry and its derivatives were in an excellent
condition for living and prospering. The extensive deposits of
phosphorite in Germany induced manufacturers to devote them-
selves to the manufacture of a product which, separated from the
impurities which accompany it in the raw material, was admirably
adapted for the manufactuie of one of the most esteemed manures,
which is the double superphosphate. The discovery of the Lahn
phosphorite beds took place at the same epoch as the Strassfurt
deposits of potash salts, when Liebig had just formulated his
mineral manure theory. Lahn phosphorite, which, as is known,
contains a large proportion of iron and alumina, was received with
open hands by manufacturers, Init great was their astonishment
when they realized that this material was absolutely unfit for super-
phosphate manufacture. Dissolved by sulphuric acid, it yielded a
product, the soluble phosphoric acid content of which, already low
enough, diminished still further in such great pi'oportions, owing to
retrogradation, that superphosphate manufacturers had to abandon
its US9. Two large chemical factories, which owned a great part of
the Lahn phosphorite deposits, tried to utilize the material in
phosphoric acid manufacture.

The fundamental idea of the process ot manufacture is con-
tained in Graham's method of analysis. It consists in digesting the
pulverized phosphate with 5 per cent sulphuric acid, in titrating
the dissolved phosphoric acid by uranium solution, leaving the oxide
of iron intact. The principle of the process is thus represented by
the following equation : —

(151)

152 CHEMICAL MANUEES.

Ca,(P0,)2 + 3H.,S0, = 3CaS0, + 2H,P0,
310 2M 408 196

604 604

By a strange coincidence, the old manuals state that by treat-
ing tricalcic phosphate with dilute sulphuric acid, monocalcic phos-
phate is obtained. Now this statement is erroneous because, as will
be seen further on, only a small amount of phosphoric acid enters
into solution. But even by using sulphuric in insufficient amount
hke that calculated for the preparation of monocalcic phosphate, free
phosphoric acid is obtained seeing that a part of the Ca^fPO^)- re-
mains undecom posed. As far back as 1870, the firm of H. & E.
Albrecht at Biebrich, installed an experimental factoiy for the manu-
facture of phosphoric acid, but the affair turned out badly because
at that time suitable appliances for separating the phosphoric acid
from its insoluble residue were not in existence. It was only by
the use of the filter press already known at that time in sugar
works, that the manufacture of phosphoric acid became lucrative,
for the conversion of dilute phosphoric acid into double super-
phosphates did not in the beginning present insurmountable diffi-
'Culties. Now this double superphosphate — with a minimum of 40
per cent P^Og — soon became in very great demand, as much by
agriculturists as by manure manufacturers, to whom it afforded a
■simple and easy means of securing a high percentage of P.,0_v
But let us examine the manufacture of phosphoric acid a little more
closely.

Manufacture of Pliosplwric Acid. — A 50 per cent phosphate
(CaaP^Oj,) is used. If damp, it is dried on metal plates. If lumpy
the lumps are crushed by a jaw-breaker and then reduced to the re-
quisite fineness by a flatstone mill or a ball mill. The ground phos-
phate is then fed into the vats by a chain elevator, 1 to 2 tons per
charge ; the sulphuric acid and the necessary water (wash water con-
taining P.O.) to dilute the acid to 16° B., is run in at the same
time. The charging of the vats lasts twenty minutes, and during this
time decomposition is completely effected, the phosphoric acid is
liberated, the sulphuric acid has taken its place and combined with
the lime to form gypsum, which has to be separated from the
liquid. For this purpose the muddy liquids from the decomposi-
tion vats are collected in a collecting tank lower down, fitted with
an agitator, its role is to maintain the solid particles in suspension
ointil the mixture is forced to the filter presses bv a membrane
pump, m which the acid liquid alone comes in contact with rubber
or lead. The filter presses used have 50 plates, and are capable
of treating 14 tons of phosphate in twenty-four hours (say three tons
•^2^5)- The filter plates are of pitch-pine, the frames are of the
same wood or of oak. The gutters are of plum-tree wood. When
the filter press is charged, its contents are washed with water under

THE MANUFACTURE OF PHOSPHORIC ACID. 153

pressure until the liquid which flows away only tests 0*25° B., a
density equal to that of gypsum -saturated water. The wash water
then contains on an average 3 per cent P^O:, ; it is used, as already
seen, to reduce the sulphuric acid to 16" B. The phosphoric acid
collected in a "weak solution " tank tests about 12" B., say about
1° B. less than the sulphuric acid used ; there is reason to conclude
that a part of the latter has combined with the lime present in the
phosphate as CaCOgCaFU, CaSiO^. A weak phosphoric acid
solution of average quality has the following composition : —

Per cent.

PA ^*^ ■

so, 0-2

CaO 0-4

(FeAl)oO, 0'3

and small quantities of HF, Si, MgO, etc. For most applications,
especi:dly for the manufacture of double superphosphates, the
phosphoric acid must be concentrated to a certain extent. It
w^as at first attempted to concentrate it by evaporation by lead
steam coils, but the pipes became rapidly incrusted with lead salts
and lost their conductivity. This process was therefore abandoned,
and attempts made to concentrate the acid by bottom heat. Great
flame ovens were constructed heated by combustion gases. These
gases are led underneath the liquid contained in a pan sur-
mounted by an arch. The pan is of strong wa^ought-iron, lined
inside with stones which resist acid, and thus was protected from
direct contact with the flame and the x^hosphoric acid. On the other
hand, the exterior side of the pan is naked. The dilute solution of
phosphoric acid runs in continuously in the back part of the pan,
until after two or three days an average concentration of 50° B. is
obtained. The concentration is then finished and the phosphoric
acid, making 56' to 58° B., is finally run out by a central gutter,
whilst the contents of the pan are continuously agitated so that no
mud remains. It is collected in wooden vats, or in lead-lined iron
ones. In this condition the phosphoric acid is turbid and blackish
owing to the presence of soot deposited by the combustion gases. It
contains about 54 per cent P.p.,, I'S per cent of FeAip^, and
variable amounts of gypsum, phosphate of lime, calcium fluoride,
hydro-fluosilicic acid, arsenic, etc.

Up to 1890, the factory of H. & E. Albrecht treated about 60 tons
of phosphate in twenty-four hours. Five large evaporation ovens,
analogous to those described, were installed, which evaporated the
enormous amount of 200 tons of water in twenty-four hours. The
largest of these evaporation pans was 16-5 metres (say 54 feet)
long, and 5-5 metres (say 18 feet) wide, but it was divided into two
compartments by a longitudinal diaphragm. It had a capacity of
36 cubic metres, and yielded at one operation 55-8 tons of 54 per

154 CHEMICAL MANUEES.

cent phosphoric acid, vaporizing 270 tons of water with an expense-
of 349 tons of coal, 100 kg. (220 lb.) of coal vaporized, 770 litres
(1694 lb.) of water (say 1 lb. of coal furnished nearly 8 lb. of
steam), and yielded 160 kg. (352 lb.) of concentrated phosphoric
acid. The evaporation was at the rate of 1626 litres (say 32^ cwt.)
per hour.

The ovens installed at the Wetzlar factory were not so big. When
the acid was brought to the desired density it sometimes happened,
owing to want of supervision, that in the parts of the pan most
exposed to the heat the phosphoric acid was evaporated to dryness,
and vitreous lumps of a greyish-blue colour, partially diaphanous,
formed. The analysis of this vitreous mass was very difficult, be-
cause it was impossible to dissolve it by ordinary methods. Prof..
Krantt, of Hanover, succeeded in dissolving it, by heating it with
borax ; the analysis gave 70 per cent of P^.O^, besides alumina, iron,
lime, alkali, and hydrofluoric acid ; silica, supposed, to be present
in large amount, looking to the vitreous nature of the mass, was
only found in traces combined with fluorine. The substance thus
consisted chiefly of metaphosphate. In the evaporation of the
phosphoric acid, the steam entrains a great part of the dissolvedi
HF and H.SiFg.

Manufacture of Double Superphosjjhate. — The greater part of
the phosphoric acid so produced was used in the manufacture of
double superphosphates. This manufacture is distinguished from
ordinary superphosphate manufacture by the fact that phosphoric
acid is substituted for the sulphuric acid. The phosphate is then
rendered soluble according to the following equation : —

Ca-.(PO,)., + 4H..P0, = 3CaH,(P04).,

310 8U2 ■ . -^

. ^ 702

702

It is clear that in actual practice the method of conversion is
not so simple, because phosjohates containing all manner of im-
purities are used, and the nature of the phosphoric acid, as well as
that of the superphosphate, plays a preponderant role. The phos-
phates which are the most easily dissolved by phosphoric acid, are^
sandy phosphates with a high percentage of carbonate of lime, such
as Somme phosphate and Malogne phosphate. This phosphate is
mixed in the proportion of 1 ton to 4 tons of 54 per cent phosphoric-
acid. This mixing is done in the same manner, and with the plant,
as that in which the phosphate is dissolved by sulphuric acid.
To elevate the concentrated phosphoric acid and bring it to the^
mixing apparatus, either a membrane pump, a centrifugal pum.p, or
an^ injector is used. The lirst of these pumps is sure in its working
and can elevate the acid to any desired height ; the second, which
lends itself more particularly to the elevation of dilute phosphoric-
acid, is liable to stop work ng when the acid is concentrated or-

THE MANUFACTURE OF PHOSPHORIC ACID. 155-

mnddy ; injectors are the most convenient, Init it must be remem-
bered that they dilute the acid 1° to 2 " B. ^

The principal difference which exists between double superphos-
phate and ordinary superphosphate lies in the fact that the lattei' is a.
mixture of monocalcic phosphate and gypsum, whilst double super-
phosphate only contains as impurities a few per cents of gypsum,
and forms essentially a monocalcic phosphate containing free phos-
phoric acid in excess. That is why double superphosphate is less-
easily dried than ordinary superphosphate, and must therefore be
very carefully dried by artificial means.

The process of manufacture just described ap]3ears very simple ;
it none the less requires the control of a good chemist, the more so-
as the raw material used is always contaminated with impurities.
The following example will show what field of action is here open
to the chemist. Wetzlar's factory, of which the daily production of
double superphosphate was about 12 tons, made a product in 1883
containing 34 per cent P^O,-, soluble in water and 13 per cent
P.,0- insoluble in water ; two years afterwards the Pp., soluble in
water had risen to 43 to 45 per cent with 3-6 insoluble in water.
100 kg. of phosphoric acid in the merchandise consisted therefore —

In''l883 of 72-3 [34 x 100 ^ 47] of phosphoric acid solube in water..

In 1885 of 90-8 [45 x 100-^48] per cent phosphor c acid soluble

in water.

As at that time phosphoric acid soluble in water was valued at
0-65 francs the kg., whilst insoluble in acid was not generally paid
for at all, the above improvement represents an increase in profit
of £25 per day without taking into account the other advantages-
attached to the improvement in the working. The capital point in
the manufacture of phosphoric acid is to dissolve the least possible
amount of sesquioxides (FeAl).O.^, because it is to their presence in
superphosphate that its retrogradation is due. It is clear also that
the phosphates ought to be exhausted as completely as possible ta
reduce the expenditure of sulphuric acid to the minimum and to-
have the least impurities, lime, hydrofluoric acid, etc., in the weak
solutions. Up to 1884, it was believed that the longer the action
w^as prolonged in the mixing tank, the more complete was the ex-
traction of the phosphoric acid. It was further believed that a
temperature of 60' to 80° C. or 140" C. (176= F.j was necessary, or
was at least conducive to the progress of the operation. Thus the
acid and the water were mixed in the mixing vat, and the heat of the
reaction brought the temperature of the mixture to 70" C. (158° F.) ;

1 It is difficult to see why the ordinary appliames for raising sulphuric acid
in manure works cannot be used, viz. the ordinary " montejus," sometnnes-
called the egg or air vessel. This air vessel is tilled with acid by a syphon trom
a tank alongside. When full, air is pumped into it by one pipe and the acid
rises from it up another pipe into the ten ton store tank overhead. Any hitch
with the pumps described by the author mean of course the stoppage of the
mixing when the store tank is empty. The air vessel with ordinary attentioa
gives no trouble. — Tp..

156

CHEMICAL MANUEES.

the phosphate was then run in and the agitator was wrought for
two to three hours. But that was bad working. Systematic manu-
facturing tests have led to the following conclusions : —

1. The percentage of sesquioxides in the weak solution increases
with the length of the agitation and with the rise of temperature,
and the other impurities behave in the same way, HF, H.,SiF,;, CaO.

2. The percentage of phosphoric acid in the insoluble residue
is least when the agitation only lasts about twenty minutes, from
that time onwards it decreases with the duration of the agitation,
"but in proportion to the oxide of iron content. There would appear
to be a retrogradation of the free phosphoric acid, dissolved under
the influence of the oxide of iron, as in superphosphates.

3. The expenditure of sulphuric acid increases with the duration
of the agitation and the elevation of the temperature. Under
opposite conditions, the sulphuric acid content of the " weak solu-
tions " naturally decreases. These experiments were made in
•course of manufacture from Lahn phosphorite ; afterwards they
were generalized, especially for verifying the facts pointed out in
1 and 3, which are likewise applicable to Liege phosphate. The
results thus ascertained were applied immediately in industrial
practice. To diminish the duration of the mixing process was
•easily done : to lower the temperature of the mixing during working,
the sulphuric acid was diluted with the wash water and the hot
dilute acid passed through a tubular condenser, cooled by circulation
of water ; finally, to decompose the phosphate by sulphuric acid, half
quantities were taken. Great advantage arises from this style of
working, less handling, abolition of night work by installing of new
filter presses, economy of sulphuric acid, more complete extraction
of the phosphoric acid from the phosphates, longer life of the filter
cloths, and above all, obtaining a product richer in phosphoric
acid soluble in water. This product then had the following com-
position : —

TABLE XLVII.— SHOWING THE ANALYSIS OF DOUBLE ST'PEK-

PHOSPHATE.

Monocalcic phosphate CaH^

(POJ, . . . .
Free phosphoric acid H-l'O^
Dicalcic phosphate CaoH.,

(P0,)o . . " :
Tri basic phosphate C;;(P04)o .
Phosphate of iron and ahimina

(FeAl)PO,
Hydrated pulphate of lime

CaS0^2H,()
Macfne^ia, silica, Hnorine .
Sand, etc. ....
Moisture . . . .

Per cent.

(50-0
9-5

4-.-)

2 Ml 4S-1 per cent of total PoO-.

4-U 43-3 per cent of P^.O., soluble in water.

o-O
2-0
4-0
9-0

100-0

THE MANUFACTUEE OF PHOSPHOEIC ACID. 157

But all the manufacturing problems were not solved. An import-
ant point is the exact determination of the amount of sulphuric
acid required to decompose the phosphate. That amount cannot
be fixed, except by inference from the SO3 in the weak solution of
a preceding operation, and to determine that it is necessary to
make a quantitative analysis. If a sufficient amount of acid be
not used the solution contains lime in excess, and after evaporation
it is often converted into a thick broth, which it is impossible to
work in that condition. This drawback is remedied by introducing
sulphuric acid, but it would be better not to use that expedient
owing to the disengagement of hydrofluoric acid fumes. Another
drawback which arises from a deficiency of sulphuric acid, is that
the extraction of the phosphoric acid is incomplete. But an excess
of sulphuric acid causes even greater drawbacks. In fact, if the
phosphoric acid solution, with excess of sulphuric acid, be evapor-
ated, it becomes inactive towards the phosphate which it is intended
to dissolve, which is likewise the case with too concentrated sul-
phuric acid. The phosphate is not attacked by the acid, and the
manufacturer is at his wits' end to know what to do with this
dilute mixture of phosphate and phosphoric acid. At the Wetzlar
factory when this mishap occurred, the phosphoric acid was ab-
sorbed by powdered peat, in the ratio of three to one ; the product
contained about 33 per cent of P^O^, and when it could not be got
rid of directly, it was aftervv^ards mixed with double superphosphate.
Once finished, the percentage of phosphoric acid soluble in water
was thus considerably increased, but at the expense of its physical
properties.

Afterwards, a very simple way was found to restore its activity
to the phosphoric acid which had become inactive. All that has to
be done is to treat it with finely powdered quicklime. But phos-
phoric acid so treated 'does not behave like normal acid in the
course of the work. As already stated, the residual gypsum left
in the filter presses forms a very cumbersome waste product. It
contains 4:0 to 50 per cent of water. It is run on to a heap. In
summer it dries on the surface, it is then turned over with the
plough, and passed through a Carr's disintegrator, and marketed
as a powder. In wet years it is dried in a simple drying machine,
when there is an outlet for it. This product is known in commerce
as phosphatic gypsum ; it contains 60 per cent of gypsum and 3 to
4: per cent of phosphoric acid, of which 1 per cent is soluble in
citrate and 0*25 soluble in water. It has been tried to have this
gypsum specially adopted as a preservative agent of the fertilizing-
principles of farmyard manure, and it has been proposed to spread
it in stables, and on farmyard manure. This use is very rational,
for precipitated gypsum combines very readily with the ammonium
carbonate of farmyard dung. But it is clear that this material

158 CHEMICAL MANURES.

-cannot stand heavy freight charges, for its selHng price is almost
entirely absorbed by drying expenses and loading. It is easy to
understand that to a factory which produces 100 tons of phosphatic
gypsum a day, the sale of this waste is of no great importance in
itself, whilst the shifting of it and its storage form a big item in
the general expenses account. Thus the Wetzlar factory was
forced to purchase a piece of land for 30,000 marks (£1500) for
this purpose and to instal on it an aerial conveyor at a cost of
16,000 marks (£800). It has already been seen that double super-
phosphate must be dried artificially. The principle of this opera-
tion consists in passing over the sul^stance a great amount of air at
a uniform temperature, the degree of which depends on the super-
phosphate. The dryers installed at first fulfilled none of these
conditions ; the product obtained therefore was very unequal, one
part was superheated and its phosphoric acid had partially retro-
graded. To improve the drying laboratory, experiments were
undertaken to find the limit of temperature at which the phosphoric
acid ceased to retrograde. These researches were made on Lahn
•double superphosphate and gave quite unexpected results. Up to
120^ C. (248" F.) the content of phosphoric acid soluble in water
underwent no modification, it even appreciably increased between
120^^ C. (248° F.) and 170' C. (338° F.), and it is only above 170° C.
that the much-dreaded retrogradation occurred. At first sight one
would be inclined to explain this fact in the sense that the H^PO^
and G3j.,H.,(P0^)., are at a low temperature in a state of equilibrium
in superphosphate, and react the one on the other at a high
temperature to form CaH^(POj)o. It was then a question of realiz-
ing this temperature of 170° C. in actual practice. But this problem
is a difficult one and does not appear to have ever been perfectly
solved. It will be seen in the sequel that double superphosphate
made from Liege phosphate behaves in quite a ditf'erent manner ;
not only is there no increase in the phosphoric acid soluble in water,
JDut retrogradation commences as soon as the drying temperature
exceeds 120° C. The true cause of that difference in the behaviour
of the two superphosphates has not been ascertained, but it may
be concluded that each phosphate has a nature of its own, and
requires to be treated in accordance therewith. It is the phos-
phates poor in sesquioxides which work best, such as Florida
phosphate which is used in a Swedish factory. The crushing of
the dried superphosphate is done in a Carr's disintegratoi', like
an ordinary superphosphate, and presents no difficulty. The plant
required for making 7^ tons of 55 per cent phosphoric acid is the
following : —

4 to 5 filter presses.

1 large and 3 small mixing vats.

THE MANUFACTURE OF PHOSPHORIC ACH). 159

2 centrifugal pumps.

3 membrane pumps.
Cooling and dilution plant.

Sulphuric acid store tank, 10 cubic metres capacity.

^^ per cent sulphuric acid store tank, 20 cubic metres capacity.

2 sulphuric acid measuring tanks.

2 wash water tanks, 15 cubic metres capacity.

Dilute phosphoric acid tank, 40 cubic metres capacity.

Concentrated phosphoric acid tank, 10 cubic metres capacity.

Membrane pump for concentrated phosphoric acid.

Oven for drying the phosphoric acid.

Lead piping.

1 steam engine 25 H.P. with shafting.

As mentioned at the outset, the phosphoric acid industr}" has
lost much of its importance. Of twelve large factories at work
twenty years ago, there are only four or live still at work, which
also make various kinds of phosphates, of which a few words will
now be said.

Manufacture of Superpliosphate of Potassium and Ammonium.
— -The oldest and the most important of the phosphoric acid deriva-
tives is the neutral phosphate of sodium, Na.,HPOj, which occurs in
the form of beautiful monoclinic crystals consisting of 20 per cent
Na.,0, 20 per cent P.,0,- and 60 per cent of water, and can therefore
be prepared easily in the pure state. The phosphate of sodium is
not employed as manure, but rather the phosphate of potash and of
ammonia about to be described. The m.anufacture of phosphates of
potassium and ammonium presents no difficulties, especially that of
potassium, owing to its weak crystallizing power. From that point
of view, the mono-ammonium phosphate AmH.,PO^, which is the
most stable of all the phosphates of ammonia, behaves much better.
It crystallizes without water of crystallization in beautiful tetragonal
prisms with a pointed apex. The acid phosphates are generally
very difficult to filter when they are neutralized with soda. Now, as
the pure non-ammoniacal phosphate is much less used as a manure
than the impure phosphate of ammonia, the manufacture of the
latter furnishes a pure ammoniacal salt as a secondary product.
The most simple process to manufacture phosphate of ammonia as
well as sulphate of ammonia, is to use gas liquor, working with the
well-known apparatus of Feldmann. The salt is not separated from
the muddy precipitate obtained, which is likewise used as manure,
but there forms at the surface fine crystalline efflorescences of
AmH^POj, which it is easy to collect apart and to purify by fresh
crystallization. In order to prepare in the same manner a crude
phospho-potassic manure, potash must be employed as the raw

160 CHEMICAL MANURES.

material, but that is too clear. Nevertheless, in 1892, the Biebrich
factory produced small quantities of phosphate of potash by satura-
tion of potash by phosphoric acid, although the product was of
bad quality (much insoluble P^Or, and H._,0}.

Manufacture of Sulplio-phosphates. — During this time chemists-
tried new methods of manufacture. At that time Dr. Paul Wagner,
1892, published his pamphlet on the use of chemical manures in
horticulture, and gave the idea of manufacturing pure and con-
centrated chemical manures. This idea was taken up by H. Albrecht,
director of the Biebrich factory, which henceforth manufactured
phosphates of potash and ammonia and nitrate by mixing the
ingredients in different proportions. As a matter of fact, a sort of
phosphate of potash was known as early as 1886, but its percentage
of sulphuric acid rendered it unfit for the purposes to which such
mixtures are applied. This product is the sulpho-phosphate of potash
which was at first made by Meyer, as well as an analogous product,
the sulpho-phosphate of ammonia.

The sulpho-phosphates are interesting from several points of
view, and possess such valuable properties that thei'e is reason
to ask why agriculture and the chemical manure trade do not make-
more frequent use of them. So long as the Wetzlar f actor v was at
work, it produced great quantities intended chiefly for export to the
Dutch East Indies, but from that time they have not been heard of.
If equal parts of 55 per cent phosphoric acid and of sulphate of
ammonia or sulphate of potash be mJxed together and heated to
80" C, the components unite, and form a dry pulverulent salt. An
addition product of the two substances is formed : —

Am.,SO^ + H3PO, - AmHSO^ + AmH.PO,
K2SO, + H.PO, = KHSO, + KH.PO^

The product contains respectively, 25 per cent P.^O^ and 10 5 N, and
21 per cent P2O- and 27 per cent K,0. The phosphoric acid is present
in a condition almost entirely soluble in water. The percentage of sul-
phuric acid is about 30 per cent. (Peculiar thing, an analogous com-
pound cannot be obtained from soda in this way.) The manufacture
is exceedingly simple. There is dissolved in the "weak solution,'"
obtained in the manufacture of phosphoric acid ; an equivalent quan-
tity of alkaline sulphate, viz. 100 Am^SO^ for 55 Pp^ and 100 K.^SO^
for 18 P.20;^, and the solution is evaporated until the boilino-point
rises to llO'' C. (230' F.) for the potash salt and 140' C. (284° E.) for
the ammonia salt. Finally, the hot mass is run into a cooling beck
and agitated until it solidifies. This process is much more simple
and cheaper than that of making double superphosphate. It is well

THE MANUFACTURE OF PHOSPHORIC ACID. 161

to take into account the advantages which the sulpho-phosphate
possesses in virtue of its acid nature. It may be used in larger
quantities in calcareous and heavy soils, either alone or mixed with
basic slag or powdered lime. We know that in virtue of its high
lime content, basic slag can be mixed neither with ammoniacal
salts nor with superphosphates, for in the first instance there would
be a loss of nitrogen, and in the second of phosphoric acid soluble
in water. Now, not only does the mixture of basic slag with the
sulpho-phosphate of ammonia exclude losses of this nature, but it
also has the effect of increasing the percentage of phosphoric acid
soluble, in w^ater. According to experiments made on this subject,
this increase reached 13 per cent of the total phosphoric acid in the
mixture. Another advantage arising from the acid character of the
sulpho-phosphates resides in the possibility of using particularly
impure phosphates, such as those containing oxide of iron and
alumina. It is precisely this fact which will bring the sulpho-
phosphates into good repute some day, when the abundance of pure
phosphates has given place to penury.

But there is a class of mineral phosphates of low content in lime,
and the base of which is -alumina with more or less oxide of iron.
Redonda phosphate consists of important beds of this nature. These
phosphates can be treated neither by the ordinary dissolving process
nor by the process of extraction of the phosphoric acid, because the
latter is present in a form difficult of attack. Now the manufacture
of sulpho-phosphates gives us the means of profiting excellently by
these phosphates, otherwise unutilizable, w^hich explains their cheap-
ness. The method about to be described, and which is absolutely
unpublished, is based on the following equation : —

2A1P0, + AmHSO, -f- H.SO, =
AU(S0,)2 + 2AmHS0„AmH,P0^

The ground phosphate is fused at a temperature of 120° to 140° C. with
super acid ammonium bisulphate. The duration of this operation
depends on the degree of resistance of the substance. Most often
it requires two to three hours. It is clear that the water evaporated
in that time must be replaced. The phosphate is dissolved much
more rapidly and more completely when done under pressure and
at an elevated temperature. The plant required by that style of
working is certainly more costly, but the work would be done better
and factory expenses run less.

The product so obtained is a sulpho-phosphate of ammonia and
sulphate of alumina. The presence of the latter renders it very
hygrometric and little fitted for its intended use. But there is a
very simple method of remedying this drawback. If an equivalent
quality of sulphate be added thereto it combines with the sulphate

11

162 CHEMICAL MANUEES.

of alumina to form an aluminate of ammonia. A product is thus
obtained which remains as dry as ordinary phosphate. The
chemical transformation then becomes : —

AIPO4 + 3AmHS0^ = AlAm(SOj- + AmHSO^,AmH,PO^

If the Eedonda phosphate contains, for example, 40 per cent
P.,Or,, one calculates thus : —

100 phosphate 4OP0O.3

112 sulphate of ammonia ...... 'i4N

130 sulphuric acid of 50" B 8IH0SO4

342

We thus get a manure containing in round figures : —

Pei' cent.

Nitrogen 8-0 ^

P0O5 total 13-0

P2O5 soluble in water ...... 11"0

In many cases it would be advisable to replace a portion of the
nitrogen by potash. This substitution is easily effected. It suffices
to replace t le sulphate of ammonia to form alum by sulphate of
potash : —

AlPp + 2AmHS0, + KHSO, = A1K(S0J2
+ AmHSO^,AmH,PO^

The addition of potash in quantity greater than to combine with the
alum complicates the work. It is clear, moreover, that one can
likewise combine with this process the production of aluminate
of ammonia ; the expense adherent to washing, evaporation, and
crystallization appears, to be largely covered by the sale of the sul-
phate of alumina as a current article of commerce, whilst the
richness of the manure would be increased at will.

By working as described, it is easy to utilize Eedonda phosphate
up to 90 per cent. As already mentioned, the sulpho-phosphate of
potassium does not combine the conditions required in a concen-
trated potassic manure. Its sulphuric acid, amounting to almost
30 per cent, must be removed. Lime provides the easiest means.
It has been proposed to combine monocalcic phosphate with
sulphate of potash, but the process is not applicable because the
gypsum is precipitated in the form of very attenuated crystals,
which render filtration impossible after evaporation. But if lime
in an insoluble form be used, i.e. as carbonate, and if it be made to

1 If 312 of tinished manure gives 21X, 100 only gives 7, not 8. — Tu.

THE MANUFACTURE OF PHOSPHORIC ACID. 163

react on the dissolved sulpho-phosphate of potash, the gypsum is
precipitated in the same state, and its ehmination from the Hquid
by filtration presents no ditficiilty. The free sulphm-ic acid of
the sulpho-phosphate combines with the lime to form gypsum ; by
addition of phosphoric acid, the K.,SO^ is again transformed into
KHSO^ + KH0PO4, and the acid of this new bisulphate is in its
turn removed by CaCOg. The sum of these reactions is represented
by the following equation : —

K,SO, + 2H3PO, + CaCOg = 2KH,P0, + CaSO, + CO, + H,0

However, these reactions are not effected in such a simple manner.
Thus the direct action of calcium carbonate on phosphoric acid is to
form insoluble phosphate of lime. Jf it was desired to treat a mere
solution of potassium sulphate in dilute phosphoric acid there would
be a considerable loss of phosphoric acid. Moreover, the washing of
the precipitated gypsum containing P..,0-, and the evaporation of the
wash water would entail great expense, capable perhaps of absorb-
ing all the profit of the manufacture. An elegant and simple solu-
tion to the proiDlem has been found i5y the use of grey phosphatic
chalks. These phosphates, for which formerly no use could be
found in spite of all the researches and tentatives made, contain
about 30 per cent of Ca3(P04)2, and a preponderant quantity of
CaCOg ; they are sold cheap. It is clear that, if in the process now
described, calcium carbonate be added as phosphatic chalk, there
will be obtained as a filtration residue a mixture of phosphate and
gypsum, the phosphoric acid content of which is low but which can
be perhaps utilized for the extraction of phosphoric acid. And if the
phosphoric acid extracted from it is afterwards used in the manu-
facture of sulpho-phosphate of potash, it will suffice to treat the above
phosphatic gypsum in the filter press to eliminate the adherent
solution of potassic phosphate, but it would be useless to wash it,
because the remainder of the potassic phosphate which it contains
returns to the process by the extraction of the phosphoric acid. In
this way the small amounts of phosphoric acid precipitated by
the chalk would also be utilized. This detail also brings out better
the advantages resulting from the use of phosphatic chalk in this
case; in fact the amount of phosphoric acid precipitated is exceed-
ingly small, because the conversion is effected in a less violent and
more regular manner. Another very disagreeable drawback due to
the carbonate of lime, is eliminated by phosphatic chalk ; it is the
entrainment of soluble potash by the gypsum sludge, owing, no
doubt, to the formation of a double phosphate of calcium and
potassium. The process just enunciated was the subject of a
patent delivered to H. & E. Albrecht ; it is applied on the large scale
at the Biebrich factorv, in the manner about to be described.

164 CHEMICAL MANURES.

There is run into a lead-lined vessel, fitted with an agitator, a
measured quantity of a 10 per cent solution of phosphoric acid, in
which a corresponding quantity of sulphate of potash is dissolved.
iVfterwards, whilst constantly stirring the mixture, but without heat-
ing, the calculated quantity of pulverized phosphatic chalk is slowly
incorporated. When, after about an hour, the conversion is accom-
plished, the phosphatic solution is separated from the residue by filter
presses, and the liquor evaporated to a pasty consistency by steam
heating. The dry salt is afterwards obtained, fit to be centrifuged
by drying it in a special chamber heated by steam at a temperature
of 70° to 80° C. From the filter presses, the residue falls directly
into a second mixing tank with agitator, likewise lined w4th lead, and
containing the quantity of sulphuric acid necessary to decompose
the phosphate. When this decomposition is complete, the residue
is separated from the liquid by means of the filter press, completing
the extraction this time by washing, for the wash water afterwards,
serves to dilute the sulphuric acid. The filtrate, which consists of a
mixture of phosphoric acid and potassic phosphate, flows from the
filter press directly into the first receiver-mixer. The product thus.
obtained contains 38 to 40 pet- cent of PoO^ almost entirely soluble
in water, 31 to 33 per cent K^O, in addition to a few per cents of
sulphuric acid, lime, etc.

The Salz Werke Co., Neustassfurt, have likewise succeeded in
producing a pure and concentrated phosphate of potash from
potassium chloride. The experiments made by this company led
to quite an unexpected result. It is known that the metaphosphate
obtained by the decomposition of potassic chloride, by phosphoric,
acid, at the temperature of fusion, is by itself completely insolul^le
in water, and even in acids. Now it has been found that by cooling
it suddenly, it is converted into a modification very soluble in water.
The decomposition is effected in a muffle furnace for sulphate, the
evolved hydrochloric acid is condensed, and the liquid metaphosphate-
flows boiling from the oven direct on to cold plates, in a thin layer.
After crushing, the product forms a dry salt easily preserved and
containing 50 per cent P.jOj and 45 per cent K^O. x\lthough
phosphate of potash, and similar concentrated manures, have not
assumed, in agriculture, the importance that w^as at first anticipated,,
especially for cereal cultivation, they have none the less a great im-
portance in certain special cultures, and above all in the Colonies-
owing to freight charges, which are heavy. Their rational use in
horticulture likewise presents very great advantages which will
end by being appreciated. Here is an example : In the garden
attached to the mansion house of Biebrich, in 1892, phosphate and'
nitrate of potash was applied to the raspberry plantations so as to
obtain a heavier and an earlier yield. The success was such that-
the gardener of the mansion house had already sold £15 worth

THE MANUFACTUEE OF PHOSPHORIC ACID. 165

of fruit collected in the squares so treated before the raspberries in
the plants cultivated without manure were ripe (end of April). Now
the amount used hardly came to the value of Is.

Bisulphate Superjjkosphate.—lt now remains to say a word
«,bout another product absolutely unpublished, i.e. the bisulphate
superphosphate. Bisulphate, as is well known, is a bye-product
of the manufacture of nitric acid, and finds hardly any use, except
in glass works and in the manufacture of Glauber s salt. But it is
difficult to sell, and it is got quit of at any price, for the local
authorities forbid it being run into streams. Dr. Graeber tried to
utilize it in the manufacture of superphosphates. By mixing 500
kg. of bisulphate with 150 kg. of Algerian phosphate he obtained
a superphosphate, but the product was very deliquescent because
it wanted the water of constitution necessary to the formation of
sulphate of lime. Dr. Grueber remedied that by adding to the
phosphate 60 kg. of water. He thus obtained a dry superphosphate,
with 7 to 8 per cent of soluble phosphoric acid ; the addition of a
small amount of Algerian phosphate enabled it to be passed through
. the centifrugal crusher and to obtain it in a pulverulent form. As
all manure factories require low superphosphates to adjust the
analysis, this product would thus readily find a use.i

Phosphatic Peat. — It now remains to describe a manure m
which the phosphoric acid is present, not in chemical combination
but in simple admixture — we mean phosphatic peat. In 1892
the Society of German Agriculturists greatly recommended the
manufacture of this product as a microbicide, as a preventative of
epidemics, and fit to render both human and animal excreta in-
offensive. The first steps made in this direction with hydrochloric
and sulphuric acid have not given conclusive results ; hydrochloric
acid is too volatile, sulphuric acid carbonizes the fibre of the peat,
so that it is difficult to use more than 2 per cent in the mixture.
Phosphoric acid has not that drawback, and there is nothing there-
fore to prevent phosphatic peat being prepared with 10 to 15 per
cent of P2O.-. Experiments on a manufacturing scale, and applica-
tion of this procLuct, were made in 1893 by Dr. Meyer, who, more-
over, exhibited samples at the show of the German Society of
Agriculturists, who made him an award. There is no doubt that

1 A.fter the afcid over and above that required to form the normal sulphate
of poda was killed by the pho-phate, the water very evidently acted by com-
bining with the excess of sulphate of soda to form Na2SO^,10H.,O, an elHorescent
salt. The "free" acid must have formed sulphate of lime ab initio or the
phosphate could not have been dissolved. Of course the water would enable
the dissolved phosphite of lime to react on the excess of sulphate of soda to
produce phosphate of soda and sulphate of lime. But why not send the bi-
sulphate up the cups and mix it in the mixer with the acid and phosphate in
the usual way ? This seems to have been a sort of compost heap, and the fewer
of these about a factory the better. — T^ .

166 CHEMICAL MANUEES.

phosphatic peat possesses the properties which recommends it,
more particularly for spreading on farmyard dung in stables. The
excrements of animals commence to decompose as soon as they
are eliminated by the animals, and this decomposition is accom-
panied by a great loss in nitrogen. The addition of the phosphoric
acid not only retains all the nitrogen in the manure, but also
enriches it. It also destroys the germs of infectious disease, typhus,
cholera, etc., as the experiments of Fraenkel, Klipstein, and Burow
have shown. Klipstein formally declares that phosphatic peat
behaves better in this way than sulphated peat, which he had
prepared with 10 per cent of sulphuric acid. The manufacture of
phosphated peat is very simple. The peat is made to absorb the
quantity of hot phosphoric acid diluted to the desired strength.
Prepared peat or crude peat may be used. In the latter case, the
peat should be passed through a slicing machine and then through
a press. This manufacture should be profitable. To obtain the
phosphoric acid the most impure phosphates, otherwise of no value,
can be used ; moreover, the phosphoric acid absorbed by the peat
retains its solubility in water. On the other hand, it should not
be very difficult to create a market, for peat has been employed for
a long time as litter, as well as other additional matter, gypsum
from superphosphates, which is spread in the stables. But there
is no substance of this nature which possesses the antiseptic
properties of phosphatic peat. It retains the nitrogen, destroys
infectious germs, absorbs urine, purifies the air of stables, amplifies
and enriches farmyard manure. The use of phosphatic peat for the
disinfection of faecal matter constitutes a problem more difficult to
solve. The main obstacle is the system of everything to the drain,
that all large towns have adopted, to free themselves of their excreta
in a radical but far from economical manner. In small localities
(there are some in Germany where the use of phosphatic peat is
obligatory) its purchase, its use, and the sale of the human manure
under the control of the authorities, to prevent fraud, present real
difficulties. But in large properties which have the use of the
manure in their own hands, the use of phosphatic peat would be very
rational in so far as one could then economize the cost of drying.
But if it be desired to dry the manure, plant similar to that used to
dry poudrette may be used. The manure, consisting of faecal matter
and phosphatic peat, after desiccation forms a manure analogous to
guano. It does not give off any bad smell, and contains 1 per cent of
N, 1-5 per cent P2O- (4 soluble), 1 per cent potash and about 45 per
cent of peat.

THE MANUFACTURE OF PHOSPHORUS. 167

APPENDIX.

THE MANUFACTURE OF PHOSPHORUS IN THE ELECTRIC

FURNACE.

In a recent publication of the United States Geological Survey,
entitled " The Production of Phosphate Rock and Phosphorus in
1906," G. W. Stose makes an interesting summary of the progress
made in phosphorus manufacture, and points out the role which the
electric furnace has played in this development. Formerly phos-
phorus was only extracted from bones and other organic matter.
It is only quite recentlv that it has been extracted from mmeral
products."^ First of all, phosphorus was extracted from phosphatic
rocks, such as the impure fluophosphates of calcium, with which
the superphosphates used in agriculture are generally made.
Apatite, which is a fluophosphate or a chlorophosphate of calcium,
was only used to a slight extent in Europe or in Canada. Quite
recently wavellite phosphate of alumina has been used as a source
of phosphorus. It is furnished in sufficient quantity for the purpose
by deposits situated at Mount Holly Springs (Pennsylvania). The
old process of phosphorus manufacture which was m use m the
beginning of the nineteenth century is as follows. The bones are
burnt, then ground ; the bone ash superphosphate of lime is treated
by a sufficient quantitv of sulphuric acid to convert the whole or a
part of the calcium into calcium sulphate and the phosphorus into
metaphosphate of calcium and even into phosphoric acid, which is
concentration by evaporation mixed with wood charcoal and reduced
bv heating in a furnace in a fireclay retort. The vapour of phos-
IDhorus and carbonic oxide is given off. The phosphorus which is
condensed under water has a waxy appearance and yellowish
colour. Theoretically the reaction should be : —

2Ca3(PO,)o + 6H,S0, + 12C =
6CaS0, +"12C0 + P4 + ^H.O

Practically, however, it is found that the following reaction better
represents what occurs : —

3Ca3(PO,)- + 6H.,S0, + IOC =
6CaS0, + Ca3(P0,^ + lOCO + P, + 6Hp

In this process the loss due to destruction of the retorts by sulphuric
acid and bv the great heat is considerable. Only a portion of the
phosphorus therefore present in the charge is recovered. There is
also the danger of seeing the phosphorus inflame when withdrawn,
and it is necessary to take the greatest care to prevent the phos-

168 CHEMICAL MANUEES.

phorus condensing in the tubes and obstructing them. Numerous
improvements or alterations on this process have been patented in
recent years. Woehler was one of the first to heat phosphate of
lime as it occurs in bone ash or phosphatic rocks with silicious sand
and charcoal without resorting to the sulphuric acid treatment.
Wing's patent, 1891, is based on the same principle.

Wing's Process. — In Wing's process, bone ash or pulverized
rock phosphate and silica are moistened and made into balls which
are placed by layers alternating with layers of coal in a cuhilot.
The coal yields the incandescent carbon required for the reduction
of the phosphoric acid. The silica expels the phosphoric acid fi-om
the phosphate as anhydride P^O^, which is reduced to the condition
of phosphorus by the incandescent carbon and the reducing atmos-
phere. The vapours pass to condensation chambers kept at a
temperature of 500° F. (260° C), in which the greater part of the
phosphorus is deposited as red phosphorus and the remainder in
a water chamber as white phosphorus. The process is continuous,
the charge is introduced at the top through the furnace mouth, the
residues are evacuated by the grate at the bottom, and two con-
densation chamloers are used alternately.

In using the ordinary furnaces this method was found imprac-
ticable owing to the high temperature necessary to treat a charge
as refractory as that just indicated. It is well known that
electricity can furnish the high temperature necessary, and it was
w^ell imagined that it ought to solve the problem, but manufacture by
this process has only become possible commercially quite recently,
and since the invention of the electric furnace. Consequently the
process has been introduced both in Europe and America, where
it enables phosphorus to be made at a profit.

Beachnans Patent. — This process, which dates from 1889, is
applied in most countries. The bone ash or the crude phosphoric
acid is mixed with ground coal or wood-charcoal. If mineral
phosphate be used it is roasted, pulverized, and mixed v/ith wood-
charcoal, silica or a basic salt. The mixture is reduced in an
electric furnace working continuously in a reducing atmosphere.
The currents brought by retort carbon electrode traverse the charge
placed between them, acts as a resistance and is heated to incan-
descence. The silica combines with the calcium to form a slag of
silicate of lime. The phosphorus and carloonic oxide are given
off as before. The disengagement commences at 1150" C. and
requires a temperature of 1400° C, and even 1500° C. may be reached
to complete the reactions. The reaction is the following : —

2Ca3(PO,)-' + 6SiO, = 6CaSiO, + lOCO + P^

Harding s Process. — In Harding's process, 1898, the pulverized
rock phosphate is heated with sulphuric acid ; the phosphoric acid

THE MANUFACTUKE OF PHOSPHOEUS. 169

thus separated from the lime is filtered and evaporated to a sympy
■consistency. It is mixed with granular retort charcoal, heated in a
reverberatory furnace, and treated in an electric furnace, the arc
issuing impetuously between the electrodes and traversing the
mass. An atmosphere of hydrogen is produced by injecting
petroleum spirit pulverized in the furnace.

CHbVs Furnace.— In this furnace, which was specially designed
•for the manufacture of phosphorus, the electric current instead of
•traversing the whole of the mass, passes without interruption into
■an intermediate circuit of great resistance, such as a cylinder of
retort charcoal placed above the charge. This cylinder becomes
incandescent and the arch of the furnace reflects the heat as in a
reverberatorv furnace.

Irvine s !F«r«ace.— Eeadman's process was modified in Irvine's
1901 patent. The charge is made up as in the original method ;
Ihowever, phosphates of alumina or calcium may be used indifferently
with the silica or basic flux. The tv/o electrodes of retort charcoal
•are suspended vertically, and their lower parts reunited at the
beginaing of the operation by coal through which the current first
passes. When the charge has melted, the slag formed collects on
the top and reunites the two electrodes ; that is, henceforth it is
through this slag that the current passes. The fusion is continued,
the excess of slag is run off as it is produced, so that the extremities
■of the electrodes are never uncovered.

Duncan's Patent. — In Duncan's process, patented in 1903,
seventy-seven parts of ground phosphate are taken, whether of organic
-or mineral origin, twenty-three parts of ground coal, and mixed with
tar acting as an agglutinant. The paste is dried, and after heatmg,
which is done for economy in a hydrogen flame, a bye-product of the
manufacture, the product is placed in an electrical furnace; this
•continuously produces phosphide of calcium. This phosphide m
.contact with water in an atmosphere of hydrogen, gives off phos-
phuretted hydrogens, which, when heated, are converted into red
and white phosphorus according to the temperature at which con-
'densation is effected.

Parker s Patent. — This process, which was patented in Great
Britain by Parker in 1902, concerns the treatment of phosphate of
aluminium. This phosphate is treated by sulphuric acid, then by a
sulphate capable of forming an alum with the sulphate of aluminium,
which is produced. All the alumina is separated by crystallization
•of the alum, and before the electric treatment. The residual liquid
is mixed with coal or other bodies rich in carbon, and reduced in an
■electric furnace.

Landis Method. — The American Phosphorus Company of
Philadelphia possesses a factory at Yorkhaven where phosphorus
iis extracted from wavellite, using a method designed by G. G.

170 CHEMICAL MANURES.

Landis, the company's chemist. The process, which is kept secret,
is, as far as can be ascertained, analocjoiis to that of Eeadman as-
regards the mineral and the furnace. The wavelUte, the phosphate
of ahiminium, and the phosphate of calcium, are roasted, mixed with
silica and wood charcoal, and reduced in an electric Imnace which
is one of the subjects of the invention. In January, 1907, a patent
was taken out to protect certain improvements on the furnace, with:
the view^ of preventing the escape of gas or vapours or their absorp-
tion by the lining of the furnace. This is realized by the use of a.
second exterior lining made of non-absorbent bricks, and by the use
of hydraulic joints for closing all the apertures of the furnace. The
furnace is fitted with an interior lining of bricks of retort charcoal
acting as electrode ; there are also several vertical electrodes of the
same material, which can be regulated either to establish a current
through the charge or to form an electric arc. The slag is run off
every three or four hours ; the phosphorus vapours are condensed
under water. It is very probable that it would be necessary to re-
sort to a supplementary treatment to eliminate the alumina con-
tained in the charge, and that the treatment is analogous to that
used in the Parker process ; that is the point which is kept secret..
The phosphorus made by the greater number of the industrial pro-
cesses is a crude white phosphorus having the appearance of yellow
wax, and containing sand, charcoal, clay, and other impurities.
These impurities are removed in different w^ays, either by filtering-
the fused phosphorus under water on wood charcoal or through a
cloth, or by pressing by means of steam the fused mass through
porous porcelain, or by redistilling it in iron retorts. The best
method of purification, how^ever, is again to treat the crude fused
phosphorus, either by a mixture of bichromate of potash and
sulphuric acid, or by hypobromite of sodium. Some of the im-
purities dissolve, the others collect on a scum which floats to the
surface of the fused phosphorus.^ Owing to its highly poisonous-
nature, and the danger in manipulating white phosphorus, attempts
have been made to produce it in another form. Eed phosphorus,

1 There is no occasion whatever to dissolve these materials in the acid pre-
vious to mixing. If the acid be heated to about 150° F. and the shoddy, leather
cnttines, greaves, scutch, etc., sent up the cups like the bone meal itself, the
acid completely dissolves the whole in one operat on. But that is in the case
of mixings where there is no pretence of making dissolved bones, and an odd
piece of core would tell no tale as it would in what purported to be a bone
manure. The translator has sent as much as 4 cwts. of leather to the ton of.
finished mixing up the cups, and not a particle of it was to be seen in the aggre-
gate 50 to 60 ton mixings when the doors of the " den " were opened three or-
four hours later.

As already mentioned, such materials as leather and shoddy are invariably
used in Great Britain with mineral phosphates. They would absolutely spoil
the colour of pure dissolved bones and at once point to sophistication. — Tr.

THE MANUFACTUEE OF PHOSPHOEUS. 171

which is not poisonous, is easily prepared by heating to 250' Cv
the white variety in a closed vessel. It, however, has not the same
properties as the crystalline white phosphorus. A crystalline
variety of red phosphorus, recently discovered in Germany, is ob-
tained bv heating to boiling a 10 per cent solution of white phos-
phorus in phosphorous tribromide. This variety is not poisonous,
and advantageously replaces white phosphorus in the manufacture
of matches. The phosphorus industry is so new in France that
it is very difficult to get statistical figures, moreover information
is awantmg on the state of the industry in other countries. The
world's vearly production has been valued between 1000 and 3000
tons ; up to quite a recent period this manufacture was localized
abroad. The greater part of the world's phosphorus comes from
the factorv of Allbright and Wilson of Wednesfield, Oldbury, Eng-
land ; it was there that the Eeadman process was discovered. Its-
annual product may be 500 tons. There are other big factories at
Lvons, France, at Griesheim and at Frankfort, Germany. There
is^likewise a factory in Sweden, and others, small and numerous, in
Eussia, of which six, situated near Perm, produced about 110 tons
in 1890. In the United States, the first phosphorus factory was
constructed forty years ago at Philadelphia by Moro Phillips ; this
establishment is still at work. The factory of J. J. Allen el- Son
was founded at Philadelphia in 1891, and in competition with im-
ported phosphorus has furnished for a long tmre the phosphorus
required bv the Diamond Match Co., the largest match factory m
the United States ; but in 1897, the firm of Allbright and Wilson,
under the trade name Oldbury Electro-Chemical Co., erected a factory
of 300 H.P. working the Eeadman process at Niagara Falls, and it
is this factorv which up to now has supplied the Diamond :Match
Co., and furnished the greater part of the phosphorus produced m
the United States. Eecently that compauy has brought a new im-
provement to bear on the manufacture by installing Irvine's furnace,
by means of which 80 to 90 per cent of the phosphorus contained
in the raw material used can be extracted, which is a high strength
rock phosphate. This result is comparable to that which the English
factories obtain, extracting 86 per cent of phosphorus. There are
six furnaces of 50 H.P., each with a production of 170 lb. ot phos-
phorus per dav, say an average of a total of 1000 lb. of phosphorus
manufactured" daily. The production varies according to the de-
mand ; however, the factory produces at the present time half of
that which is produced in the United States.

The General Chemical Co. has recently acquired Duncans
patent, and another company is installed at Long Island, where
they utilize for their furnaces the cuiTcnt which is distributed in
the town.

The American Phosphorus Co. made its first installation at

172 CHEMICAL MANUEES.

Moore's Mill, near to Mount Holly Springs, Pennsylvania, where
there is a mine of waveliite, which it possesses. The old method of
heating by gas is used. The factory having been destroyed by a
fire, another was constructed and started in March, 1905. Electric
furnaces were installed and started during 1905, but the production
of electricitv bv means of steam engines was too costlv, and in
1906 the factorv was transferred to Yorkhaven, Pennsvlvania,
where electricity yielded by a fall of water could be used. This
company announces that it produces 500 lb. of phosphorus a day,
and that it could produce 1200. The census of 1900 states three
factories were at work in the United States, but that of 1904-
1905 only shows the Oldbury Electro-Chemical Co. of Niagara
Falls. Besides what it produces, the United States annually im-
ports 30,000 to 40,000 lb. of phosphorus, which pays an import
duty of 18 cents per lb. The price on New York market varies
with the quahty from 45 to 70 cents per lb.

CHAPTER X.

MANUFACTUKE OF BONE DUST AND OF BONE SUPEEPHOSPHATE

(VITRIOLIZED BONES).

The use of bone dust as a manure goes back to somewhat distant
times. It rapidly extended when Liebig advised that it should be
dissolved by sulphuric acid, so as to obtain more rapid and certain
effects. At the present time this product has to compete against
nitrate of soda and basic slag. Moreover, certain manufacturers
find it more advantageous to use bones in the manufacture of glue,
and then to transform them into superphosphate afterwards.
Whatever be the method of utilizing bones, it is indispensable
previously to free them from fat, as will be seen in the sequel.

Chemical Compontion of Bones. — The bones which form the
framework of vertebrae, consist like all vegetable and animal matter
of organic elements, and of mineral elements of combustible matter,
and of ash. The combustible matter (moisture excluded) consists
essentially of ossein (yielding gelatine) and of fat. Bone ash consists
in great part of phosphate of lime. If the previously fat-extracted
bones be digested with dilute hydrochloric acid, the phosphate of
lime is dissolved, and a residue of ossein is obtained as a white
elastic translucid substance which consists of : —

TABLE XLYIII.— CHEMICAL COMPOSITION OF OSSEIN.

Carbon

Hydrogen

Nitrogen

Sulphur

Oxygen

Per cent.

50-1

7-1

18-8

0-2

24 -2

100-4

Ossein dissolves very slowly in boiling water when bones are boiled
with water, and more rapidly when treated in a close vessel under
pressure. By prolonging the operation for a sufficient length of
time the bones can be completely freed from ossein. A residue of
phosphate of lime is thus obtained with the initial form of the bone.
Finally, ossein may be extracted by boiling with dilute potash lye.

(173)

174

CHEMICAL MANURES.i

On cooling, the solution of ossein previously concentrated by evapora-
tion assumes a gelatinous consistency, and on drying it is converted
into solid tablets which are marketed as glue. The ratio between
the organic substance and the mineral matter in bones continually
varies, not only with the origin and race of the animal from which
they come, but also in one and the same individual, according to
whether the bones are hard or spongy. In spongy bones the or-
ganic matter is higher by 4-5 per cent than in hard bones; the
amount of carbonate of lime is likewise higher by 11 per cent,
whilst the percentage of phosphate of lime is less by 15-5 per cent.
It is evident that the percentage of nitrogen and phosphoric acid
in bones is very variable! Their fat content calculated on the
dry substance is from 10 to 12 per cent. Berzelius has given the
following analysis of an ox bone freed from periosteum : —

TABLE XLIX.— ANALYSIS OF AX OX BOXE. (BERZELIUS.)

Cartilage completely soluble in water )
Vessels „ „ „ „ J

Tribasic phosphate of lime and a little CaFo
Carbonate of lime . . . . .

Phosphate of magnesia . . , .

.Soda with very slight trace of XaCl

Per cent.

33-30

58 •35
3-87
2-05
2-45

100-00

This theoretical composition of bone built up from a select bone
does not represent the average composition of the bones used by
glue manufacturers, because the bones have undergone various
treatments, such as boiling, fermentation, which may have altered
their nature. Besides, bones are supplied by different animals.
Practically ordinary bones received in factories respond in round
figures to the following analysis : — ^

TABLE XLIX. (a).— ROSINATE ANALYSIS OF BONES AS SUPPLIED

TO MANURE FACTORIES.

Per cent.
Moisture ........ 12

Organic matter .....
Tribasic phosphate of lime and magnesia

X ciX •••••••

Carbonate of lime, sand, etc.

28

44

10

5

99

Commercial bones always contain more or less moisture,
butchers' bones up to 30 per cent, and they are mixed with other

1 This looks very much like an average analysis of ordinary " rag ' bones.
Ordinary London '-rag" bones yield 11 per cent of fat when extracted by
petroleum spirit. — Tr.

MANUFACTUEE OF BONE SUPEEPHOSPHATE. 175

waste such as debris of skins, gut, etc. It is impossible to give a
complete analysis, seeing the difficult}^ of taking a fair average sample.
The skill and experience of the buyer, and inspection by a glance
of his eye, are the best guides. Fossil bones naturally ditfer in
their composition, thus their fluorine content rises to as much as
16 per cent. Miiller found 17 per cent of gelatine in diluvian
bones.

Fertilizing Value of Bones. — The use of bones as a manure has
been known for a long time. They have been used for centuries
in the manuring of vines in the south of France. Hunter, in
Endand, drew the attention of farmers to bones in 1771. In that
country the use of bones doubled and trebled the production of
mediocre land, at a time when certain continental agronomists were
still protesting against what they called the spoliation {gaspillage)
by the bones used in fertilizing the land. England knew how to
profit adroitly by this situation, by importing thousands of tons of
bone 3 at a vile price. At a certain time all the production of bones
took the road to Great Britain, although it had itself an enormous
production, and in spite of a rise in freights. In 182:^, the battle-
fields of Central Europe, in themselves alone, furnished her with
33,000 tons.

But the introduction of Persian guano, the pioneer of all other
concentrated manures, completely altered the situation. There is
not now to be found a single farmer who does give to bone
manures all the credit which they deserve, even when he is in-
different to other manures. However, uncrushed raw bones are
absolutely valueless to the farmer, as they do not become soluble
in the soil until after a very long time. Now, in order to obtain
good crops, the farmer requires rapid decomposition of the nitro-
genous matter and of the phosphate in the soil. The bones must
therefore undergo an appropriate operation. In chemical manure
factories it is reduced to a fine powder or the gelatine is extracted
from it, and it is afterwards made into superphosphate (dissolved
bones). The use of bones in any other form is spoliation. Bone
waste (fleshy fibre), which can be often bought cheap, should be
similarly treated.

Storing, Classifying, Sorting and Crushing Bones. — Storing. —
The first duty of the manufacturer is to bring all his care to bear
on the storing of bones, because when they begin to rot they give
off a smell which the workmen cannot stand. Besides, the decom-
position of nitrogenous matter gives rise to a disengagement of
ammonia, and there is a loss of nitrogen which may exceed 0"5 per
cent. The drying of fresh bones requires fastidious and costly
manipulations ; that is why they rest content with sprinkling them
with water containing O'Oo percent of carbolic acid or with spirits
of turpentine.

176 CHEMICAL MANUEES.

Classification of Bones. — Market bones are classified as fol-
lows : —

(1) Kitchen Bones. — These consist of ox, calf, sheep, goat, and
some game bones. They are fresh, dry or fused (fttse, ? roasted).
They often contain 20 to 25 per cent of water. Dry bones are called
country bones. Their percentage of moisture is from 8 to 12 per
cent. Thev are generally crushed and often fat -extracted by the
vendors, which is readily recognized by the farinaceous tint of the
bones on the outside. Fused bones enter into the class of the fossil
bones ; they are unfit for glue- making, for the organic matter has in
great part disappeared owing to fermentation and exposure to all
sorts of weather. Amongst kitchen bones are to be found sheep
bones and those of kids, with down, and pork bones, which are less
esteemed. Kitchen bones generally contain remains of horns, horn-
piths, glass, scrap iron, earth, bread. Hand picking enables the
value of the goods to be appreciated.

(2) Horse Bones or Knackers' Bones. — These bones yield a less
valuable glue than kitchen bones, and they have to be sold cheaper.
Ten per cent of these bones are tolerated amongst kitchen bones..
The fat and glue which they yield are inferior.

(3) Buried Bones. — Buried bones are those of animals (ox, horse)
w^hich have remained a certain time in the ground to destroy the
flesh. They are the bones of infected animals which have taken a.
bistre colour owang to burial. They are depreciated and the manu-
facturer refuses those with hanging flesh.i

(4) Bullocks' Heads and Canards {Sheep's -Heads) pass into
the kitchen bone class, but they are generally sold apart for the
acidulator (? glue maker,? manure maker : both are acidulators).

(5) Scraps and Waste.— These are the residues of the " turnery "
trade. They are in great request for acidulation and are sold

separatelv.

(6) Hornpiths.— They are used like "scraps" for acidulation.
Thev are fresh or drv. The dry piths are often fused and are then

of less value.

Bones, therefore, in consequence of the different material which
they contain, are classed and assorted so that the operations which
they have to undergo furnish satisfactory products. As the bones
are most often mixed with impurities which are of a nature to
damage the machines, it is necessary to pick or assort them.

Bone Picking. — In factories of a certain size the picking is done
on shaking tables, driven mechanically or by means of large sifting
machines, both appliances being fitted with meshes of % of an inch.
Soil and small particles of bone fall through the grating, whilst

1 The resurrection of the bones of infected animals is a most dangerous
practice. The earth mould from the remains of animals dead of anthrax is
Btill infectious after twenty years.— Tr.

MANUFACTUKE OF BONE SUPERPHOSPHATE. 177

horns, glass and scrap iron are separated by hand on the shaking
table, or on a revolving table placed at the end of the shaking
table, or the sifting machine. Generally, they rest content with
receiving the bones on an inclined endless band, along which the
female sorters are arranged. The band moves slowly, so as to give
time for sorting, and its slope enables the bones to be fed into the
hopper of a bone crusher. Before falling into the crusher, the
bones issuing from the chain fall on to a narrow iron plane inclined
at 45°, divided into two parts and soldered by a copper band. Each
of these parts corresponds to one of the poles of a strong electro-
magnet situated underneath. It follows that if the iron falls on the
inclined plane it is retained, and eliminated by the sorter who had
allowed it to pass on to the chain. In this method of sorting, the
earth necessarily follows the bones into the crusher ; nevertheless, a
certain part of the earth is not fed on to the chain when the man
feeding uses as a shovel a fork with close teeth in shovelling the
bones thrown on to a perforated sheet of iron over a pit where the
earth collects. Although this earth may be removed in subsequent
operations, it is always more advantageous to remove it before
crushing, so as not to have pulverulent matter in the fat extraction
and in the glue autoclaves. There is little useful matter in this
earth, from which the small particles of bones are removed by finer
sifting. They are mixed with bone meal for manure.

Bone Crushing. — Two sorts of tools are used in bone crushing ;
one working at a slow speed, which is the toothed crusher, and the
centrifugal crusher at great speed, such as that constructed by
Weidknecht. It is well to have several successive crushers with
duplicate exchange pieces, so that they may be replaced rapidly.
The first crusher is the coarse crusher, and the second the finishing

mill.

(1) Sloio-speed Crusher. — It consists of two large rolls formed
by thick circular toothed bosses and with teeth a little obtuse,
alternately with non-toothed bosses of the same thickness, but of a
less diameter by the height of two teeth ; the aggregate of the bosses
is mounted on a hexagonal steel axis. The rolls are fitted up in
such a manner that the teeth of the one correspond to the circular part
of the smaller diameter of the other. They are separated by the
space desired, to crush coarser or finer. For that purpose, they are
driven by steel cog-wheels with deep teeth, allowing a certain dis-
placement. One of the rolls is on movable bearings, capable of
sliding if the resistance to be overcome is too gi^eat, being brought
back to the original position by a system of springs. A good fly-
wheel is necessary to overcome passing obstructions. The crushers
built by Krupp attain the same end, and are made of very hard
special steel. There are two crushers, the one after the other, fed
by cup chain elevators in the case of the second crusher, so as to

12

178 CHEMICAL MANURES.

arrange two pair of rolls on the same framework. The second
crusher has shorter teeth, and its rolls nearer. The largest pieces
issuing from the second roll must not be larger than a small hen's
egg, in order subsequently to get a good fat extraction.

(2) Very Quick-speed Machine. — To this class belong Weid-
knecht's (F.) and Carr's. Weidknecht's excellent crusher consists
of a very strong framework properly so-called of cast-iron in two
pieces, the lower part or pedestal, and the upper part or hood ; these
pieces are bolted at their point of contact. The hood is adjusted to
the framework, on the one hand, by a joint forming a hinge, and on
the other hand bv a screw and bolt joint. Bv this arrangement
a single workman is able to inspect the machine, or change the
grating in a few minutes. All he has to do is, by a turn of the
spanner, to reverse the screw of the bolt joint, and to lift the hood
which hinges on its axis. The bearings are of great scope and
constant lubrication. Moreover, to diminish the friction surface
of the shaft, the plummer blocks are suppressed, and to keep up
the lateral play they are replaced by abutment screws which are
fitted to each end of the shaft and in contact with the tempered
sheaths adjusted consequently in the end of the shaft.

The shaft thus maintained is filled in its middle with a jacket
or boss, on which fixed levers are arranged, at the end of which
levers hinged hammers are fixed which work like flails, the hinge
enabling the hammer to fold itself back when at work if overfed or
if a foreign body be fed into the machine. The mobility is also in-
tended to keep the machine from stopping if the belt comes off,
if it be not fed automatically. In fact, the hammers, by fold-
ing backwards, let the fine 'material pass through the grating
arranged in the lower part of the framework ; the apparatus being
thus freed, the shaft regains its normal speed without having to
stop. The hammers thus form a fly-wheel, storing up active energy.
The machine is fitted on its interior lateral faces by toothed steel
plates of great hardness ; they are kept in position by bolts and can
thus be easily replaced. The hood or upper part is fitted up in the
same way on its lateral faces ; moreover, it has on the roof linings,
likewise fitted with projections, and fixed by bolts on the shaft
is the driving pulley. The machine is in fact very strong, and the
pieces easy to replace. There is no heating in spite of the speed,
for the ventilation due to the motion is very energetic. The fine-
ness of the product depends solely on the dimensions of the grating,
which in the case of bones consists of bars wide apart, through
which the hammers drive the crushed bones. A crusher with bars
less far apart acts as a final crusher, and, as before, a chain cup
elevator serves to feed the second with the crushed bones from the
first. 1

1 But each machine built on the disintegrator principle is sold to make fine
hone meal. Although the translator has not had much experience of bone crush-

MANUFACTUEE OF BONE SUPERPHOSPHATE. 179

It is asserted that crushers working by shock develop more
heat than need be. With crushers such as those described work-
ing at a great speed, mth the bars of the grating far apart, the
temperature does not rise more than with a toothed C3dinder, for
the ventilation is very energetic and the friction reduced by the width
of the passages.-^

Extraction of Fat from Bones. — The extraction of fat from bones
is an indispensable operation, even when it is a question of merely
converting the bones into dust for the farmer. In fact, bone dust
not deprived of its fat is of less value, because the fat decomposes
very slowly in the soil, and constitutes an obstacle to the phosphoric
acid becoming soluble.

Fat may be extracted from bones by three processes : (1) By
simple boiling in open pans. (2) By the action of steam in closed
vessels. (3) By solvents. The extraction of fat by simply boiling
leaves the ossein almost intact, but generally there is only obtained
a portion of the fat in the bones.

By extracting the fat by steam, a higher yield of fat is obtained,
especially if the operation be continued long enough, but a portion
of the ossein is then transformed into gelatine. Now, in manure
manufactories this gelatine constitutes a loss and becomes cumber-
some because it decomposes rapidly ; if it be diverted into a stream,
it infects the rivulets. It is best used in irrigation. Bone dust
from bones treated by steam is more soluble than that of bones
from which the fat has been extracted by simple boiling ; moreover,
it is also more in request by farmers. -

ing by two machines running tandem as it were, yet here the fine meal made at the
outset apparently passes along with the core to the second machine, which it would
most certainly block up if fed into it as rapidly as it came from machine No. 1.
The crushed bones from No. 1 machine should certainly be screened before
passing to No. 2, so that the haunners can get at the lumps without the smaller
particles removed by the screen acting as bulfers. There is no getting over the
fact that the grinding of bone meal by such machines is costly. It is a pleasant
sight to see one go ahead for an hour. It is another to see four or five men idle
through blocking up for a quarter to half an hour. — Tr.

1 The bearings should be kept clean and free from dust as far as practicable ;
oily bone dust is liable to set the bearings aflame. The bearings should be
covered during grinding and only uncovered for lubrication. Machines revolv-
ing at 2000 to 8000 revolutions a minute develop quite enough heat on the
bearings without it being increased by fine air-driven bone dust. — Tr.

2 As far as Great Britain is concerned the translator dissents (see previous
note). Moreover, there is no absolute necessity whatever for the manure manu-
facturer to turn bone boiler, whatever there may be for the bone boiler to turn
manure manufacturer.

Whether fat extracted or non-fat extracted ground bones decomposes
most rapidly in the soil, will depend on circumstances. Many years ago the
translator superintended the dispatch of some 30 tons of bone meal made from rag
bones, i.e. non-fat extracted. The next year the same customer was supplied with
ground bones from bones that had been boiled under pressure. He made a most

180 CHEMICAL MANUEES.

But this preference is not justified, for bone dust from steam-
extracted bones is less rich in nitrogen. The extraction of bones
by solvents (benzene, petroleum, ether) gives a larger yield in tallow
whilst preserving integrally the ossein of the bones ; these then form
a powder rich in nitrogen. This process is undoubtedly to be pre-
ferred whatever may be the point of view at which it is looked
(manufacture of gelatine, or manufacture of manure). It is the only
rational process to apply.

Extraction of Fat from Bones by Water. — This process is the
most ancient, and recalls the skimming of the cook's " stock " pot.
In a cylindrical cast-iron pan a little wider below than above, there
is introduced by means of a crane a basket of perforated wrought-
iron containing about one-half ton of bones. The bottom of this
basket, likewise perforated, can open into two semi-circular parts
held by hinges on a cross bar, dividing the basket into two equal
parts. ' These two doors are closed by hooks, so as to receive the
charge. The basket is cylindrical, a little smaller in diameter than
the pan which contains it, and shorter by 4 inches. A strong
circular hoop at the top supports the sheet iron, and carries four
strong handles, by means of which the cross-piece of the crane can
lift it. The cast-iron pan is fitted with a gutter or throat, so as to
separate the fat from the water in a continuous manner. The
basket, therefore, being charged with bones in the fat extraction pan,
water is run in to immerse the bones and steam caused to bubble
in the bottom from a perforated steam coil. The water, brought to
about 100^ C. (212° F.), causes the fat to rise from the bones
through holes in the gutter at the same time as the excess of water.
The fat flows constantly from the gutter by the horizontal exit tube,
whilst the water in the bottom issues through a bent tube without
taking any fat with it. The exit of the fat may be facilitated by
a superficial push, or by a paddle driven mechanically, mounted
on a vertical shaft fixed on the side of the pan, capable of being
rotated and raised at the end of the operation, so as to allow the
basket to be freely removed from the pan. The bones are extracted
in this way for about an hour and a half, after which they are re-
moved from the basket to the washer. Certain factories slightly
acidulate the water by an addition of sulphuric acid, 4 litres for
500 kg. of bones (say 1 gallon for ^ ton), so as to free the grease
from its calcareous compounds. There is obtained 1 to 5 per cent
of fat according to the quality of the bones. The same water can

grievous complaint, and he was right too, because boiling removes ammonia.
Bones, the fat of which is extracted by petroleum spirit, are possibly not depreci-
ated in value to the farmer. The author seems to have written this chapter
more from the point of view of the glue manufacturer than the maker of arti-
ficial manures. The farmer who knows his business will not take ground steamed
bones when he wants ground kitchen or rag bones. — Tr.

MANUFACTURE OF BONE SUPERPHOSPHATE. 181

serve for several successive operations, and finally gives a boiling of
gelatine concentrated enough for making glue. If gelatine be not
made, the boiUngs are collected and concentrated by evaporation
to add them to the bone dust as shown in the sequel. But the
same water cannot serve indefinitely for fat extraction. After a
certiin time, it is remarked that the fat which it dissolves no
longer rises to the surface. The solution takes a milky appearance ;
it is a sign that it is saturated with gelatine and that its concentra-
tion obstructs the ascent of the globules of fat. It must then be
drawn off and replaced by fresh water. Unless fresh bones are
operated on, the fat obtained on extraction by water is generally
of inferior quality, it gives off a bad smell and is more or less dark
in colour. It is purified as indicated further on.

Fat Extraction from Bones by Steam. — Fat extraction from
bones by steam is done in large cast-iron cylinders, capable of con-
taining 4 to 5 tons of crushed bones, the upper opening serving for
the introduction of the bones, the lower opening for their discharge.
These openings are closed by hinged lids as in an autoclave. Steam
enters at the top and the fat runs off from the bottom by means of
pipes situated near the aperture. Steam of from two to four
atmospheres is used ; for one to two hours the steam entrains the
fat with it. The condensed water, charged with fat and gelatine,
collects in the space reserved below the false bottom and is after-
wards added in the manufacture of nitrogenized superphosphates,
although the fat exercises an unfavourable influence on the dis-
solving of the phosphate. This water generally contains 1 to 2 per
cent of nitrogen and 0-3 per cent of P2O5, in the concentrated state.
It contains as much as 7 per cent of nitrogen, 3 per cent of ash, 50
per cent of organic matter, and 45 per cent of water. The solution
of fat and gelatine is withdrawn from time to time, and the treat-
ment by steam continued until a sample of the liquid contains no
more fat. To separate the two, the different draw-offs are united in
a wrought-iron pan with a conical bottom, fitted with a steam
jacket into which steam is injected, and a tap for drawing off the
fat. The object of heating is to keep the gelatine fluid enough for
the fat to separate on standing. When separation is complete,
the fat runs off by the above-mentioned tap, and the gelatine is run
into an evaporation pan through a valve in the conical bottom of
the pan. Whatever may be the quality of this gelatine, it may be of
advantage to reduce it to a marketable form by a series of mani-
pulations which the author has described elsewhere. By submitting
bones to systematic storing, all the gelatine may be extracted, and
the resulting bone dust, almost destitute of nitrogen, contains 35 per
cent of phosphoric acid. Bone dust is often mixed with moist
superphosphate to dry it.

Some manufacturers only make degelatinized bone dust which

182 CHEMICAL MANUEES.

constitutes an excellent food for animals and a very active chemical
manure for meadows.

The fat extracted from bones by steam has perceptibly the same
colour as that got by boiling, but it is of better quality and gives off
a less unpleasant smell. When the bones treated have begun to
decompose, as very frequently is the case, the volatile bad smelling
products are in great part volatilized during the operation. Bang
and Ruffin have suggested steaming combined with centrifuging.
The fat with a little gelatine can first be extracted in a centrifugal
machine, then the gelatine. This process has not been adopted by
bone-boilers, but it is used in extracting fat from fish.

Extraction of Fat from Bones by Benzine. — For a long time
efforts were made in France to extract fat from bones by benzine.
Deiss used carbon disulphide, but as the bones, the fat of which was
extracted by this solvent, gave bad quality glues, the process hardly
extended. In 1871, Vohl suggested canadol (gasolene) as an advan-
tageous substitute for carbon disulphide ; then in 1876 M. Terne took
out a patent for extraction by petroleum benzine, in America, w^hence
this industry spread to Europe. Petroleum benzine presents, in fact,
less danger than carbon disulphide, and its condensation is more
easy because it boils at a higher temperature. The apparatus con-
structed by Mr. Deroy, sen., for extracting fat from bones by
petroleum benzine consists essentially (Fig. 36) (1) of an extractor
A with a perforated false bottom, and steam coil ; (2) of a re-
cuperator B or distilling pan; (3) of a condenser C; (4) of a
pump E for circulating the solvent. Working. — The routine of the
operation may be resumed thus. A certain amount of water is run
into the extractor according to the capacity of the apparatus, so as to
preserve the coil and the taps from the attack of fatty acids. After-
w^ards, the extractor is charged with crushed bones free from foreign
matter. As soon as the charge amounts to a quarter of the capacity
of the apparatus, the pump is started, and a beginning made by
drenching with benzine the bones introduced. During this time
the autoclave is charged in such a way that the solvent constantly
bathes the bones, which enables the interposed air to escape freely.
When the apparatus is full the top stopper of the extractor is closed
and the tap 23 on the condenser opened. The air is allowed to
escape until condensed benzine appears ; the tap is then turned and
the pressure allow^ed to rise to 1| kgs. on the manometre (9).
This pressure once reached, the steam tap is closed and the ap-
paratus allowed to rest till morning. The benzine is charged with
all the fat of the bones, and the vapours are totally condensed. The
next morning the a]3paratus is emptied into the distilling pan, and
after a rest — about ten minutes — the w^ater, previously run into the
autoclave, and w^hich now occupies the bottom of the pan, is with-
drawn. The benzine is then recovered by distillation and by pass-

MANUFACTURE OF BONE SUPERPHOSPHATE. 183

ing it through the condenser C, by means of the gooseneck 13, and
the tap 21: ; it goes to the reservoir E. The benzine impregnating
the bones is subjected to a current of steam, which finishes by en-
training it into the distilling apparatus. When it has been made
certain that nothing but water passes in the distillate, the extractor
is emptied, first opening the lid of the top manhole, and then the

Fig. 36.— Plant for Extraction of Fat from Bones by Petroleum Benzine.

bottom one. The distillation is urged until no more petroleum
benzine distils. At this moment a current of steam is injected into
the fat by means of a perforated steam coil which carries off the last
traces of solvent. The fat can then be drawn off from the distilling
pan by the tap 21. ^; '

Purification of Bone Fa^.— Fresh bone fat is naturally whiter

184: CHEMICAL MANUEES.

than the fat from ordinary country bones (? rag bones). It is puri-
fied by treatment in a lead-lined pan, by water acidulated with
sulphuric acid, of which an excess must not be used. The fat and
the acidulated water are then heated by a peiforated steam coil,
which beats the two up together. After some time the tallow shows
clear and no turbidity in the spoon. The steam is turned otf and
the whole allowed to stand. The mixture of tallow, gelatine,
carboQ and phosphate of lime, and fatty acids combined with lime
is destroyed, the gelatine is dissolved and oxidized by the acids, and
the lime is precipitated as sulphate of lime with various impurities.
After sufficient resting, the layer of fat is separated by means of a
pipe hinged to the draw-off tap.^ This pipe enables the pure fatty
layer to be run off" and to reject the water and sulphate of lime.
The purified grease falls into a wooden vat lined with lead, where
it is washed several times with boiling or simply tepid water. After
which it is let stand and drawn oft' as before into casks for use in
soap works or candle w^orks.

Bone fat is often bleached as follows : — -

To the melted fat mixed w4th half its volume of water, 2-5 per
cent of chlorate of potash is added and enough hydrochloric acid to
decompose the whole of the chlorate. An excess of this acid is
added to neutralize calcareous compounds. The tallow is purified
and whitened with 2-5 per cent of chlorate and a semi-tint obtained ;
with 5 per cent of chlorate a whiteness of the tallow is obtained
analogous to that of lard. It is w^ashed several times with water,
until the wash water is free from chlorine, which is recognized by
iodized paper. Bleaching by sunlight is equally energetic. The fat
must be run into shallow vats which are exposed to the light.
x\gitatiou in presence of ozonized air also constitutes a method of
bleaching. At the normal temperature, bone tallow is soft, unc-
tuous, and does not rancidity easily. Although insoluble in water,
like all fats it contains about 2 per cent of water, which it is im-
possible to ehminate even by heating it to 100^ C. To obtain it in

^ Bone fat is rather too viscous and easily cooled to be readily syphoned.
It is transferred from the refining pan to the wash pan by short-handled ladles
or dippers, and filled from the wash tank into barrels standing alongside by the
same dippers. After the bone fat has cooled and set the casks are headed up by
a coop?r or handy man. — Tr.

2 The author does not differentiate between the bleaching of white bone
fat got by boiling of fresh bones and of brown bone fat got by extracting
rag bones by benzine. The best results the translator got with chlorine as
a bleaching agent of brown bone fat, was a canary colour. Brown bone fat takes
up tons of water to form a white emulsion, but deprived of the emulsive water, it
is a long way oft' white. Sulphurous acid is said to give good results, and
possibly in soap-making it could very well be bleached by hydrosulphite or
" blankit " in the soap-pan. But possibly it is impossible to eliminate the
fusty smell of brown bone fat even from soap made frcm it. — Tn.

MANUFACTUEE OF BONE SUPEEPHOSPHATE. 185

an anhydrous state, it is necessary after having refined it to heat it
up to 150° C, and to maintain it for some time at that temperatm-e.
But it easily finds a buyer even when it contains a httle water.

Manufacture of Bone Dust. — Fat extracted non-degelatinized
bones are reduced to powder which passes through a No. 50 sieve
and dispatched to farmers without other treatment. If on the
contrary the bones have been deprived of the greater part of their
nitrogen, they decompose with difficulty in the soil, and it is better
to convert them into super^^hosphates. The crushers used being
the same in both cases, the reader is referred to the description
already given. The mode of action in the soil of the non-degela-
tinized bone dust is based in the first instance in the solubility of
phosphate of lime in putrefying gelatine. It behaves in a certain
sense like raw Peruvian guano, which has been described, and in
which the basic phosphate of lime is rendered soluble by the nitro-
genous elements which accompany it. The bone dust in the soil
is distinguished by this peculiarity, that its phosphoric acid is not
absorbed by the soil, and it can thus penetrate into the deeper layers,
whilst every other solution of phosphoric acid is retained by the sur-
face soil. This property of bone dust is sometimes of great benefit to
the farmer. The return in the same soil during several successive
years of plants with a tap root, may have exhausted the subsoil of
phosphoric acid. In that case bone dust furnishes the means of re-
storing to it new stocks of that element so necessary to vegetation.
The finer the bone dust the more easy is it dissolved and decomposed.
Coarse powder only acts feebly, but its action makes itself felt for
several years. The fine powder decomposes rapidly in the soil and
acts energetically the first year. That is why farmers always re-
quire a fine powder. It is to the interest of the manufacturer to please
them by looking after the crushing and the grinding of the powder.
Bone dust made from fat extracted bones has the following com-
position, according to Holdefleiss : —

TABLE L.— ANALYSIS OF BONE DUST FROM FAT EXTRACTED BONES.

Fer cent.

Nitrogen

4-14

Phosphoric acid .

21-68

say 45 per cent Ca-P„Og

Water . . . .

6-51

and 1-49 per cent MgAC>

Organic matter

.36-29

Carbonic acid

2-30

Sulphuric acid

0-41

Lime .

27-83

Magnesia

0-68

Oxide of iron

0-37

Fluorine

0-52

Sand .

3-60

Stored and fat extracted bone dust does not contain more than
:2 to 3 per cent of fat.

186 CHEMICAL MANUEES.

The efficiency of bone dust as manure has been the subject of
many discussions. P. Wacjner and Mercker seem to have misunder-
stood its fertihzing value, whilst other experimentalists have obtained
excellent results. According to recent experiments, it is recognized
that the efficacy of bone dust was perceptibh' increased by an
addition of solvents (? conversion into vitriolized bones) ; nitrification
bacteria likewise intervene. A small quantity of the solvent (sul-
phuric acid) suffices to give to bone dust a remarkable activity, as
experiments on this point testify. This agent has the effect of
disintegrating the bone dust, and rendering it soluble in citrate.
Stoved bones, non-fat extracted nor degelatinized, do not dissolve in
a satisfactory manner. The organic matter of such bone dusts is
transformed into a gluev matter verv difficult to drv.

Classificatioji of Bone Dust. — J. Konig has proposed the follow-
ing classification of bone dusts : —

1. Normal Bone Dusts, or Bone Dust No. 0. — Those bone dusts
which are made from bones which have not undergone any treat-
ment for the extraction of gelatine, and containing 4 to 5" 3 per cent
of nitrogen and 19 to 22 pei' cent of phosphoric acid, in which, more-
over, after deduction of the matter extractable by chloroform is as
1 : 4 to 5'5.

2. Bone Dusts {without any other designation). — Those bone-
dusts which contain 3 to 1 per cent nitrogen and 21 to 25 per cent of
phosphoric acid, and in which after deduction of the matter extract-
able by chloroform, the ratio of the nitrogen to the phosphoric acid
is 1 : 5-5 to 8-5.

3. Degelatinized Bone Dusts. — Those which contain 1 to 3 per
cent of nitrogen and 24 to 30 per cent of phosphoric acid, and im
which after deduction of the matter extractable by chloroform, the
ratio of the nitrogen to the phosphoric ac:d is 1 : 8'5 to 30.

To these kinds of bone dusts must be added the bone dust made
in some countries from raw bones. However, there is sometimes
sold as raw bone dust the waste from bone-black making after the ex-
traction of the fat bv benzine. Nothing should be designated as-
raw bone dust unless actually made from raw bones. [The bone-
black factories sieve the bone dust from the meal or granules before
charring the bones, as the dust is not so efficacious as a decolorizer
as the granules. — Te.]

4. Mixed Manure Dusts. — The manure dusts which after deduc-
tion of the matter extractable by chloroform containing 1 per cent
of nitrogen as ossein, and in which the ratio of nitrogen to phos-
phoric acid is from 1 : 30, should not be designated as hone dusts,
but as 7nixed manure dusts.

Meat Dust {Meat Meal). — An exception to this rule is formed
by the manure prepared in the manufacture of meat extract, and
which ought to be designated as meat dust (meat mealj, which suffi-

MANUFACTUEE OF BONE SUPEEPHOSPHATE. 1ST

ciently differentiates it from the above-named bone dusts. Thus
established, the differentiation of the different quaUties of bone dusts
is very sharp, and they are no longer confused with mixture of horn,

hair, etc.

Adulteration.— Bone dust is the subject of numerous sophistica-
tions. Finely crushed gypsum and corozo powder are often found
therein, substances which it is impossible to recognize by the naked
eye. In that case the analysis of the product shows that its per-
centage of nitrogen and phosphoric acid is inferior to the normal,
for corozo only contains 2*44 per cent phosphoric acid and^ 0-96
per cent nitrogen, and gypsum contains neither of these ingredients.
But the most frequent adulteration consists in adding to it phos-
phorite, or the phosphatic lime of the glue manufacturers, or a mix-
ture of phosphate of lime and greaves. As all these products are rich
in phosphoric acid, their effect is to increase the total phosphoric
acid of the product, and to diminish considerably its percentage of
nitrogen. To hide as much as possible the difierence between the
two elements which w^ould be revealed by analysis, sophisticators-
resort to sulphate of ammonia. But, as already pointed out, the
essential element besides phosphoric acid is ossein, or gelatine,
which cannot be replaced by nitrogenous debris of animal origin,
and far less by sulphate of ammonia. The above sophistications.
are therefore very prejudicial to the farmer, even if he receives in
that w^ay more nitrogen and phosphoric acid than furnished to him
by normal bone dust. The mixture of phosphorite or of phosphate
of lime and ammoniacal salt can never replace bone dust. Na
more can the mixture of phosphate of lime and greaves replace it,
for the nitrogenous elements of this mixture do not consist of ossein,
but rather of a substance analogous to horn.

As regards the impurities, sand, etc., and the degree of moisture,,
they should not exceed certain limits. Like all pulverulent sub-
stances, bone dust draws moisture from the air and the manufacturer
cannot be responsible for it. The normal moisture is 4-7 and the
percentage of sand 2*4 per cent.

Manufacturing of Bone SujJeiyhosjjhates.—As just seen, bone
dust differs in composition with the nature and quality of the bones,
from W'hich it is derived and the method of manufacture. In
normal bone dust, the ratio of the nitrogen to the phosphoric acid is-
as 1 : 5. Generally, however, there is found 0-5 to 1-0 per cent of
nitrogen from different debris of animal origin. Bone dust of this
nature may be delivered to farmers w^ithout other treatment. But if
the ratio between the nitrogen and the phosphoric acid is less, say 1
to 6, or beyond (Holdefleiss found a sample w^as 1 : 23-55), it is a
proof that the bones were too much degelatinized, and the dust is-
of less value if used diiectly as manure. It would behave in the
soil like a mixture of normal bone dust and phosphorite pow^der.

188 CHEMICAL MAXUEES.

or if its percentage of nitrogen has been artificially increased, as a
mixture of normal bone dust, phosphorite and of dried blood. All
the phosphoric acid in excess above the ratio of the proportion of
ossein nitrogen to phosphoric acid should be regarded as raw phos-
phate, and of no value to the farmer.

But these sorts of bone dusts yield excellent results if converted
into superphosphates. In fact, if all the phosphoric acid be dis-
solved, the latter has no need of ossein in the soil ; the bone dust
so treated constitute-s a nitrogenized superphosphate. The manu-
facture of bone superphosphate (pure dissolved bones) is very simple.^
The bones, previously crushed and degreased, are reduced to powder

^ The author does not quite do justice to the grave technical difficulties
which beset the making ot pure dissolved bones. It is almost an impos-
sible task. The difficulties begin at the outset. First of all, working with
a mixer that will easily make 2^ tons of mineral superphosphate at a mix-
ing, the charge must be reduced to ton mixings, and with certain intractable
bone meals to | ton mixings. The reason is that the interaction between
the acid and the bone dust is more energetic than in the case of mineral
phosphate, and owing to the r ipid formation of sulphate of lime the mixer tends
to set. This perforce leads to the use of water to get the charge out of ihe
mixer. In the " den "' the finished mass looks like dirty porridge, white inside
but brown on the surface where exposed to the air. The only way to dry it is
to cut it into pieces with the shovel and sprinkle it with bone meal, dry in an
oven, and then try to coax it through a wide-meshed screen with more bone
meal and then through a finer screen again with more bone meal. Bone super-
phosphate, pure dissolved bones, vitriolized bones, will never dry in the heap.
But the translator found it to dry well in the sun by turning the pieces over and
sprinkling with bone meal. It will thus be seen that to make pure vitriolized
bones is a costly operation and one which in no way pays the conscientious
manufacturer who looks askance at any order for it. As to putting bone black
up the cups before the bone dust, the only advantage the translator can see is
that the bone black is more tractable, but he never found it to have any great
drying properties. Bone ash if available would be far less objectionable. For
one thing it would not make the manure unsaleable. Farmers when they see
a black manure always think of soot, and the translator will always remember
the anathemas hurled at him by a farmer whose order for a 37 per cent soluble
phosphate he had executed with a bone black superphosphate. A little bone
black goes a long way, a- paint manufacturers know, and a farmer decidedly
objects to a manure as black as his hat. He can only te t the manure organo-
leptically, and he fiatters himself he knows soot when he sees it. But ihen a
pure dissolved bone should consist of nothing but raw bone and acid. Strictly
speaking, bones tre-ited for their fat or the r gelatine cease to be bones, and
their definition must be qualified. As to the addition of nitrate of soda in the
mixing, that will give a good deal more than 2 per cent of salt cake in the
dissolved bones, and that can only be looked upon as an adulterant. Besides,
nearly J cwt. of nitre to the ton of bones would mean that the operation, owing
to the fumes, would be insupportable, as the steam rolls off in billows and
it only wants nitrous fumes to make the position of the man at the mixer a far
from enviable one, especially with a mixer that is open or half open during the
mixing process. Again, why should the manure manufacturer lose o=. per ton
of bones for which he gets no credit ? All the same, nitrate of soda up the cups
will no doubt help the dissolved bone to dry, and as a matter of fact it assists
all manure^, but a black draught may gas the man at the cups who cannot well
get away from it. A rapid current of warm air is what is required to dry vitriol-
ized bones. Diying machines like Figs. 32 and 33 should be etiectual. Stewing
in an oven with a poor draught is not at all effectual and chars the manure. — Tk.

MANUFACTURE OF BONE SUPERPHOSPHATE. 189

by means of a steel ball mill, or by a Carr's disintegrator. The
powder yielded by the crusher is then passed through a No. oO
sieve, and the core returned to the crusher, which finally reduces it
to the desired fineness.

The bone dust is then mixed with the desired amount of dilute
sulphuric acid, using the same mixer as in making mineral super-
phosphates. But bone dust does not behave nearly so well as
mineral phosphate under the action of the sulphuric acid. It
has already been pointed out, that mineral superphosphates contain
free phosphoric acid, which renders them moist to the touch. To
this drawback, another is added in the case of bone superphosphate,
the sulphuric acid converts the organic matter into a viscous mass,
which prevents the drying of the superphosphate.

A multitude of methods have been tried to eliminate this draw-
back, but the greater number have failed. In this way it has been
tried to dry the superphosphate with sand, lignite, ash, and other-
analogous pulverulent matters. But the addition of all these sub-
stances not only diminishes the percentage of nitrogen, but it opens-
the door to sophistication of all sorts. It has been given up.

Another way of attaining the same object, proposed by Rumpler,
was the use of bone black. As this material possesses considerable-
absorptive power for liquids, it may be successfully used to dry
manures with a tendency to remain damp. The bone black is in-
corporated thus: The bone black is first incorporated with the-
quantity of sulphuric acid required to dissolve its phosphate, at the
same time as that for the bone dust. When the decomposition of the'
black is finished, the bone dust is incorporated with the mixture..
If any insoluble phosphate remains undissolved, it is bone phos-
phate, which becomes readily soluble in the soil.

If it be desired to increase the amount of nitrogen, the gelatine
extract obtained by steaming bones may be added to it. But, so as
not to introduce too much water into the manure, care is taken to
reduce its volume to a third by evaporation, and to use sulphuric
acid of high strength. Finally, it is preferable to secure the drying
of the phosphate bv only dissolving it incompletely. In that case,
only f or | of the sulphuric acid required for completely dissolving
the phosphate is used.

Again, the addition of a little nitrate of soda 1 : 2 per cent con-
siderably accelerates drying.

Bone superphosphate dries spontaneously in the heap, and at the*
end of a month the reactions of which it is the seat are terminated.
It suffices then to pass it through a Carr's crusher, and to sift it
to reduce it to a pulverulent form.

Mixture of Bone Superpliosioliate (Dissolved Bones) and Nitro-
genous Matter. — Bone dust from steamed bones only contains on
an average 3 to 4 per cent of nitrogen. It does not contain more than

190 CHEMICAL MANUEES.

2 per cent after its conversion into superphosphate. It is small
compared with the 15 to 17 per cent of soluble phosphoric acid
which accompanies it. Manure manufacturers, therefore, try to in-
crease the percentage of nitrogen by the addition of substances of
animal origin.^ By this means the enormous amount of daily
waste from animal sources in large towns can be restored to the
soil. The process is as follows : The bones, as they come from the
digesters, are mixed still moist with acid of 50° B., and the nitrogenous
matter added. These nitrogenous matters are those already studied,
but their treatment differs a little from that applied to them when
used alone.

Blood. — After coagulating the blood by heat in the manner
described further on, it is added to the bone dust in the propordon
of 300 lb. of fresh blood to 250 lb. of fresh bones. The bone
superphosphate thus obtained is rich in nitrogen, it contains in the
dry state •! tj 5 per cent of nitrogen, and 9 to 11 per cent of phos-
phoric acid ; it only contains 0'51 per cent of insoluble phosphoric
acid. The bone superphosphate to which blood has been added,
■dries much better' ; this latter therefore furnishes a means of obtain-
ing a perfectly soluble powder richer in nitrogen. If it be desired to
still further increase the nitrogen and to bring it to 5 to 6 per cent
for example, the difference can be got over by an addition of dried
blood, meat meal, or an ammoniacal salt."^

Horn. — Although horn previously steamed may be easily crushed
in the flatstone mill, it is better to add it in the state of flour to
the finished superphosphate, because if added before grinding it does
not distribute itself so well as blood. Wool dust and analogous
waste are preferably treated like leather waste, for they are too bulky
to be treated b}^ steam.

Leather Waste. — It has already been observed that ground
leather prepared from tanned leather is one of the least active of
nitrogenous manures. They are best treated as follows : The
leather is charged into a large leaden pan capable of being heated
by a double bottom or by a lead coil, and moistened with sulphuric

^But in Great Britain the manure then ceases by law to be dissolved hones
and enters the chiss of dissolved bone compo2inds, and in this latter class the
units of nitrogen and phosphoric acid are paid for at a much lower rate
than in pare dissolved bones. From a manufacturer's point of view, therefore,
it is better to use these nitrogenous adjuncts in making dissolved bone com-
pounds in which little or no bones are used, the bulk if not all of the phosphates
bsing derived from mineral sources. — Tr.

- But here again the addition of so much blood would cause this manure
in Great Britain to fall into the class of blood manures ; at any rate a
manure with only 9 to 11 per cent of phosphoric acid (say 20 per cent of
soluble phosphates), and no insoluble phosphates, would never pass muster as
a genuine dissolved bone. All these animal substances the British manufacturer
combines with mineral superphosphate and sells as dissolved bone compound,
•or in this case possibly as blood manure. — Tit.

MANUFACTUKE OF BONE SUPEEPHOSPHATE. 191

acid of SO'' to 60" B., and the whole heated to boiling. The leather
rapidly dissolves to form a brovv'n liquid, which is drawn off by a
tap a little below the false bottom, and which is used in place of
ordinary sulphuric acid to dissolve the bones. This method of
treating leather presents great advantages. It enables the manu-
facturer to preserve all the nitrogen, which would otherwise be lost,
as extract. Besides, and it is an important point, the tannin
opposed to the decomposition of the leather in the soil is destroyed.
Flesh, lungs, livers, spoilt greaves and other waste are dissolved by
the acid like leather. The sequel of the treatment is the same as
in the case of leather. Greaves are particularly rich in nitrogen.
They often give up as much as 10 per cent of fat to the sulphuric
acid used to decompose them. If sulphate of ammonia be used to
increase the nitrogen content of dissolved bones, it likewise can be
dissolved in the sulphuric acid, whilst nitraie of soda can only be
added to the finished product. The mixing is then done by aid of the
crusher or by the toothed roller mill. Hair, horn, and wool waste
are also dissolved in the acid. The solubility of the organic matter
is greater in nitrous sulphuric acid than in sulphuric acid alone. For
one part of these materials, two parts of nitrous sulphuric acid at
50" to 60° B. are taken, and if there be no nitrous acid at disposal
residual sulphuric acid is supplied by an addition of 2 per cent of
nitrate of soda.^

Animal Charcoal. — Commercial animal charcoal comes almost
exclusively from sugar refiners and glucose factories. To purify their
juices, the refiners use large amounts of animal charcoal. In the new
state, that is to say, freshly calcined, the black possesses a very ener-
getic decolorizing power. But this property is attenuated by use. To
revivify the black, and to restore to it, at least partially, its decoloriz-
ing and purifying properties, it is fermented, treated by acids,
washed, then again calcined without access of air. Thus revivifying
operations give rise to an important waste under the form of a fine
powder, which is sold as manure. After a series of revivifications,
the granular black is itself spent, and revivification is powerless to
restore to it its initial properties. Formerly animal charcoal was
in current use in sugar works, but within the last fifteen years it
has completely disappeared. The refineries alone continue to use it,
and consequently it is not so important a manure as formerly. The
composition of this product is very variable, according to the
methods of manufacture of the sugar refineries. As the char dust
(revivification) waste comes always from the surface of the granules
of black, and as these parts are the most attacked by the hydro-
chloric acid used to purify it, it contains an important proportion
of carbon, but less phosphate of lime, than the granular black,

1 See note 1, p. 188.

192

CHEMICAL MANURES.

Moreover, it contains much sand. None the less, it is in much re-
quest for the manufacture of superphosphate, because it can be
treated without any previous preparation. Spent char contains 25
to 75 per cent of phosphate of hme, 1-5 to 15 per cent of carbonate
of hme, and up to 1 per cent of sulphate of lime. Spent char dust
contains much less of these substances. As the granular char re-
moves nitrogenous impurities from the saccharine juices, it also
contains up to 1 per cent of nitrogen. Some analyses of animal
charcoal, both before and after its use in the clarification of syrups,
are given in Table LI.

TABLE LI.

-ANALYSES OF NEW AND USED AND SPENT BONE
CHAR. (PIERRE.)

Nitrogen.
Per cent.

Carbon and

Organic

Matter.

Per cent.

Phosphate

of

Lime.

Per cent.

Carbonate

of

Lime.

Per cent.

Various

Con-
stituents.
Per cent.

Charcoal, fine, new ,

1-12

11-6

73-1

8-0

7-3

„ once used .

1-95

21-1

64-6

6-4

7-9

Charcoal, fine, new .

1-22

11-3

72-2

5-3

10-5

,, once used .

2-83

32-0

53-7

4-9

9-4

,, twice used

3-59

42-2

46-0

3-3

8-5

Charcoal, fine, new .

1-61

11-0

75-6

7-0

13-4

,, once used .

2-54

36-2

52-6

lO-O

10-1

„ twice used

3-18

42-5

47-5

4-5

5-2

Bone Ash. ^ — The immense prairies of South America support
numerous herds of cattle ; 1000 head of cattle per inhabitant can
be counted in many of these countries. The animals are
slaughtered for their horns, their skins, and their fat. The flesh is
rarely utilized for human food. It is left to rot, or even as food
for wild animals. The bones are dried and used as domestic fuel and
in the tallow smelteries, sugar factories, etc., for other fuel is scarce
in these districts. It was in that way that from 100 to 200 years
back hillocks of bone ash accumulated near dwellings for which,
till a short time ago, no use was found even as a manure. But owing

^ Bone ash is very hard and difficult to grind, besides it is always wet by
absorption of moisture apparently from the air, and is best dried on the engine
ste.im boilers, over which for the time being it acts as a non-conducting com-
position. Bone ash yields an excellent superphosphate with about 40 per cent
of soluble phosphate and 1 per cent of insoluble. It is sometimes a little
bit difficalt to dry, but it takes kindly to the kiln. The manure manufacturer
keenly feels the want of supplies of this most valuable product. A cheap
machine that would burn spent char to bone ash cheaply and rapidly would
supply a great want and enable spent char to till the place of bone ash, which it
cannot now do, as its colour debars it. Bone ash superphosphates, it is needless
to say, never retrogrades. — Tr.

MANUFACTURE OF BONE SUPERPHOSPHATE. 193

to the enormous extension of the use of chemical manures, the value
of these ashes has been better appreciated. They are sold to out-
ward bound ships, who purchase them as ballast. As they are in
the pulverulent state, bones are also mixed with them, as in
that way they are less cumbersome.

The unceasing demand for this excellent waste bv chemical
manure factories has diminished the stocks ; on the other hand
bones are utilized to better purpose, the result being that bone ash
has now almost disappeared from the market. Five samples ol
bone ash analysed by Yoelcker had the following composition : —

TABLE LII.— SHOWING THE COMPOSITION OF FIVE SAMPLES

BONE ASH. (VOELCKEE.)

I.

II.

III.

IV.

V.

Per cent.

Per cent.

Per cent.

Per cent.

Per cent, i

Water

Organic matter

4-83
4-06

9-91
1-75

15-34 )
2-03 j

3-39

10-30 j

Phosphoric acid .

35-38

33-89

32-63

38-12

29-56 ;

Lime .....

44-27

39-53

37-84

44-47

34-48 !

Lime not combined with

pho-phoric acid

3-53

3-47

1-92

4-45

1-02

Magnesia ....

0-97

0-97

1-48 ^

Alkalis ....

1-89

0-84

j

Oxide of iron and silica ^
Carbonic acid . • •

0-21 >

5-67

4-40 !

3-Oi

0-78

0-84

Sulphuric acid . . ' .

0-37

Sand .....

6-95

8-31

6-50
100-00

3-90

20-24 .
100-00

100-00

100-00

100-00

Phosphate of lime

1

76-65

73-4-2

70-46

82-59

64-04

By picking out the big lumps, which consist of almost pure bone
ash, a product containing about 85 per cent of phosphate of lime is
obtained. The fine powder which contains almost all the sand is,
naturally, less rich in phosphate. Bone ash is chiefly used for
making precipitated phosphate of lime, according to the method
already described. They are worth about £3 per ton. The com-
position of bone ash corresponds to the following formula : —

Ca3(PO,)2 + [Ca3(PO,)oCaOCaHPOJ

but 2 to 3 per cent of CaO are replaced by MgO, K.^O and Na._,0 and
4 to 6 per cent of phosphoric acid by CO.,, CI and F.

MamifacUtre of Precipitated Phosjjhate of Lime. — Precipitated
or basic phosphate of lime is a bye-product of the manufacture of
glue. If hydrochloric acid be poured on fat extracted bones, it

13

19i CHEMICAL MANUEES.

dissolves the phosphoric acid contained therein. An acid sohition
is then obtained of phosphate of Hme, and as a residue the osseous
matter, ossein, the gelatine of which is extracted by boiling. For-
merly, the acid solution of phosphate of lime was not considered of
any value, and to get quit of it, no better outlet could be found for
it than to run it into the river. But now the phosphate of lime is
recovered by precipitating its solution by caustic lime. Unfortun-
ately, the manufacturers are not careful enough in working; the
phosphate of lime which they put on the market often contains 12
to 15 per cent of carbonate of lime, or of caustic lime, and a
large proportion of chloride of lime [? calcium chloride], which
renders it less fit for manure manufacture. The analysis of one
of these products furnished the following results : —

TABLE LIII. — ANALYSIS OF PEECIPITATED PHOSPHATE OF LIME.

of which nitrogen, 2-68 per cent,
phosphoric acid, 28 per cent.

Per cent

Water and organic matter

26-20

Phosphate of lime

53- 50 ^
2-17 -
5-30 J

Phosphate of magnesia

Phosphate of oxide of iron

Sulphate of lime

2-07

Carbonate of lime

0-88

Chloride of calcium .

3-50

Lime ....

0-46

Potash ....

0-21

Soda ....

0-29

Insoluble ....

5-42

100-00

Lately the manufacture of phosphate of lime in glue factories has
been perceptibly improved, and the product put on the market is of
better quality. ' Precipitated phosphates of lime are also made from
phosphates unfit for making superphosphates, and from bone ash, but
in these cases the impurities contained in the raw material, such as
oxide of iron and alumina, are likewise dissolved, and remain in the
product.^

The manufacture of precipitated phosphate of lime consists, as
already mentioned, in decomposing phosphate of lime by hydrochloric
acid, and in , separating the chloride of calcium after the equation —

Ca3(P04)2 + 2HC1 = 2CaHP0, + CaCl,

The phosphoric acid is precipitated from its solution by milk of
lime. The neutralization must be done with care, for it only

1 The author gives no explanation here of why he should select the purest
material, such as bone ash, to make precipitated phosphate, and then go to the
opposite extreme to select the most impure, so impure that they cannot be
used to make even ordinary superphosphate. The analysis given is certainly not
of one made from bone ash. The phosphate of iron content again is too hi<ih
to be made from bones even if indicated by the 2-68 per cent, of nitrogen.— Tr.

MANUFACTUEE OF BONE SUPEEPHOSPHATE. 195

requires a slight excess of lime to form an insoluble phosphate — one
part P.>05 requires 0*4 of CaO, as the following equations show : —

CaH,(POj^^H.,0 + CaO + H.,0 = Ca,H,(POJ,2H.O
CaH,(POj^H;0 + 2CaO ' = CaSPASH^O

To prepare the acid phosphoric solutions, a wooden vat is fitted
with a mechanical agitator also of wood. No mechanical agitator is
required working with bones. The bones are covered completely
by an 8 per cent solution of hydrochloric acid, and left in contact
for two to three days. All the mineral matter is dissolved, whilst
the ossein, a white soft substance, remains undissolved. The
benzine fat-extracted bones decompose more easily than steamed
bones. The decomposition is ascertained to be finished when a
hollow bone placed at the surface as a sample is soft and supple,
and shows well the characteristics of swollen ossein. The solu-
tion is then run off through a tap in the bottom of the vat, the
ossein is washed with the smallest possible amount of 4 per cent
hydrochloric acid, and the liquid is collected in a tank. The

lait de cbau

6ac
de precijailafior

1

Vi

ac
coliecteuf

jL=^ \A/ajcn

Fig. 87. — Plant for Manufacture of Precipitated Phosphate of Lime.

Lnit de cliaux — Milk of Lime. Bac de precipitation = Precipitation Vat.

Pompc = Pump.

Bac collecteur — Collecting Vat.

wash water is used afterwards to dilute the strong hydrochloric
acid, that is why a more methodical extraction is not pursued. As
to the quantity of hydrochloric acid, a little more than the theo-
retical quantity calculated on the lime must be used. When the
phosphate is finally ground, solution is effected in ten to fifteen
minutes ; it is pumped into a filter press by means of a pump with
lead armature. The phosphatic solution is collected in an open
lead-lined vat, not too deep, in which it is neutralized by milk of
lime. To precipitate the Ca^HoPO^, milk of lime, in quantity just
sufficient to neutralize the free HCl, is added, the HCl used,
and the phosphoric acid content of the substance must be known,
then one molecule of CaO for each molecule of CaH^P.^Og. For
this purpose there is installed on a level with the top of the
neutralizing vat, a second lead-lined vat fitted with a tap 15 cm.
above the bottom, in which a milk of lime is prepared, which is run
into the neutralizing vat, care being taken to stir the mixture in the
latter. To make sure that enough milk of lime has been added, a

196 CHEMICAL MANUEES.

sample is filtered from time to time, and tested with molybdate, or
phenol phthalein in the case of C^.^V.fl^. To work in a con-
tinuous fashion, two neutralizing vats are installed below the milk
of hme vat ; the latter is then fitted with two delivery pipes, which
are closed when need be by a cork stopper. When the contents.
of one of the vats is being neutrahzed, the second is being filled
with phosphate solution from the filter press. If excess of milk of
lime be added, it is easy to remedy it by running in phosphate
solution from the other vat. Finally, there is installed below the-
neutralizing vats a pit or collecting vat into which the neutralized
solution runs through a pipe fixed in the bottom of the two afore-
said vats. To neutralize the solution as exactly as possible, a milk
of lime of 15° B. = about 16 per cent CaO is used, of which enough
is added for the solution to remain faintly acid ; when the liquid is.
clarified it is decanted from the precipitate, and the neutralization
finished apart. The first precipitate is CaoH._,(POj2, the second i&
partly Ca3(P0J-. From the collecting vat the neutrahzed material
is draw^n by a suction and propelling pump and forced into a
Phillippe's washing filter press ; the precipitate is freed from adherent
calcium chloride by washing with water, followed by steam washing.
The precipitate filters well. The cakes extracted from the filter
press are dried at a temperature of 60° C. (140' F.) ; at the maximum,
best in the steam drying machine.

They are converted into a fine friable powder containing 30 to-
40 per cent of 'P.,0^. At a higher temperature the CaoHo(POJ be-
comes slightly soluble. (Formation of PP-Cao.) When local facili-
ties lend themselves to it, the vats are installed in such a fashion
that they run from the one to the other. The last filter press for
the precipitate is then at a sufficient height for the cakes to fall
directly into a truck, which conveys them to the drier. The pre-
cipitated phosphate is soluble in a solution of citric acid. The-
manufacture of this product has been the object of numerous re-
searches and several patents.^ '

A precipitated phosphate manufactory requires : —

1 ball mill.

2 agitating vats.

10 filter presses of 250 htres (55 gallons).
5 pumps.

2 lime vats with stirrers.
2 collecting vats.
1 steam dryer.
4 pits with agitator, 2 metres x 2| metres.

1 The whole subject was covered and exhausted, the filter press excepted.,
by the numerous British patents of the 'sixties and 'seventies.— Ti*.

CHAPTER XI.
MANUFACTURE OF BASIC SLAG.

A Betrospectice Glance. — In the early days of the application of the
Thorn IS and Gilchrist process, the hasic slag from the dephosphoriza-
tion formed a cumbersome ballast. Gradually the idea came to use
it as a manure, but agronomists did not, at first sight, come across
the true method of utilizing this waste. They imagined, by analogy
with mineral phosphates, that it would be necessary to cause it to
undergo a similar conversion as the latter. But looking to the
nature of the slag itself, one would not dream of converting it into
superphosphate. Precipitated phosphate of lime was therefore made
from it by Scheibler's patent, which was put on the market as
Thomas jjrecipitate either alone or mixed with nitrate or ammonia.
This precipitate, prepared by the Fertilitas Company, tested 32 to 35
per cent of phosphoric acid, of which 80 to 90 per cent was soluble
in citrate. In May, 1885, The Anglo-Continental Co. took up the
sale of the new product, but in spite of the support of this powerful
company, Thomas precipitate did not have great success, looking
more especially to its high price. At the same time, G. Hoyermann
and Heinrich Albert commenced researches to determine the fertiliz-
ing value of the basic slag in its natural state. Hoyermann engaged
a certain number of farmers of the province of Hanover to spread
finely ground basic slag on marshy lands and meadows. On his
part, Heinrich Albert, who had for a long time recognized the solvent
role of the acids elaborated by the roots of plants, devoted several
years to the study of the action exerted on phosphates by weak
solvents. He remarked that peat finely ground and kept very moist
constituted a somewhat energetic solvent for phosphate. He ap-
plied his methods to basic slag and obtained excellent results. In
1885 the agricultural station of Darmstadt entered the same field,
and in its turn made cultural experiments with basic slag, thanks
especially to the financial support of the syndicate of German manure
manufacturers. These experiments were continued for several years,
and in 1889 Dr. Paul Wagner published the results obtained.
Nevertheless, manure manufacturers themselves remained sceptical,
and only two of them consented to deal with the metallurgical firms
for the supplv of basic slag. Their hesitation will be readilv under-

(197)

198 CHEMICAL MANUEES.

stood if one thinks of the great difficulties which they had to sur-
mount, from a technical point of view, to reduce the slag to a tine
powder, and to obtain with a material at that time of very varyin^:
strength a marketable product of uniform strength. When, later
on, the solubility in citric acid was adopted as the method of
determining the fertilizing value of basic slag in powder, it was again
Hoyermann who, working from his own data, suggested the addition
of silica in the converter, as a means of considerably increasing the
solubility of the phosphoric acid. It is thus that, through appar-
ently insurmountable difficulties, basic slag became a precious-
source of phosphoric acid for agriculture. Its comparative cheap-
ness, its content of lime and silica, and the good results which they
give on meadows, peaty soils, sandy soils poor in lime, have caused
basic slag to be used in all intensive culture countries. It no longer
forms, as previously, a useless and cumbersome ballast, but a pro-
duct of great fertilizing value, the consumption of which increases
from year to year.

Origin of Basic Slag. — Up to a comparatively recent epoch, good
steel could only be obtained by using ores exempt or almost exempt
from phosphorus. A proportion of 0-25 of phosphorus sufficed to
render the iron brittle in the cold. These sort of ores had become
more and more rare, whilst there existed abundant deposits of
phosphorous ore. The attention of metallurgists was, therefore,
iDound to turn in the direction of the latter, and it was necessary to
try to utilize them.

It is to two young Englishmen, Thomas Gilchrist (?) and Percy
Gilchrist, to whom in 1879 the honour of this discovery, which was
to revolutionize the manufacture of steel, is due. It did not enter
into ordinary practice until after five or six years of efforts, varied
tentatives and numerous and delicate trials. It is now the basis of
the manufacture of the greater part of steel. The Thomas process,
as it is called, has a double advantage : it enables an excellent steel
free from phosphorus to be obtained whilst utilizing the phosphorus-
ore ; and on the other hand it gives as a secondary product a fertil-
izing material, the use of which, in agriculture, has assumed a
rapid and considerable extension. Let us now examine rapidly the
manufacture of the cast-iron, then that of the steel which yields the
slag. The ore conveyed to the ironworks is smelted in blast
furnaces which reach to about 65 feet in height by 20 feet in width :
it is there laid alternately with layers of coke, and there is added,
according to the nature of the mineral, calcareous or silicious matter
which forms what is called the castine or erbue. The object of this
lining is to deprive the mineral of any argillaceous or calcareous
gangue present, and to obtain finally, in consequence of the de-oxida-
tion and of the partial carburation of the ore, as a useful product
cast-iron, and as residue, a lighter substance floating on the top

A Steel-Works and its Blast Furnaces.

200

CHEMICAL MANUEES.

constituting the slag, which contains the major part of the impurities
combined with the cashtie.

As to the gases which escape in consequence of this de-oxidation,
they are collected and their heat utilized, either to heat the air which
enters the blast furnaces to a temperature of 750° C, or to produce
the steam necessary to drive the blowing engine, or finally to pro-
duce electricity. The charging of the blast furnace is done con-
tinuously through the top, and its discharge through the bottom
(about every six hours). The temperature of the low^er zone where
the molten iron frees itself by difference of density from its floating
impurities is about 1200° C. The slag is utilized industrially for
making bricks, cement, etc. Let us see what becomes of the cast-
iron, which at this point is still phosphorusetted, as the follow^ing
analysis taken as an example shows : —

TABLE LIV.— ANALYSIS OF CAST-IRON SHOWING PHOSPHORUS

CONTENT.

Per cent.
Iron 91-20

Carbon
Phosphorus
Magnesia
Silicon

3-60
2-75
3-20
0-25

100-00

The conversion of the cast-iron into steel is done in special pear-
shaped appliances, movable round a horizontal axis, and made of
steel lined with refractory stone. These appliances, termed con-
vertors, are in the Thomas process lined in the interior with lime
and magnesia. They are open on the top and pierced in the lower
part by holes through which air at a high temperature can be blown.
To charge them they are turned around on their axes to an angle of
90° and the liquid cast-iron is run in through the upper opening.
Then the pear is raised at the same time that air is driven through
the lower holes at a sufficient pressure for the fused metal to remain
in the convertor and not pass through the holes. Under the in-
fluence of the high temperature prevailing in the convertor, and of
the air injected, the silicon, the sulphur, the phosphorus are burnt
at the same time as a part of the carbon. The heat which is dis-
engaged inside the convertor is such that the metal, which had at
the moment of its introduction a temperature of 1200°, rises to
2100°, all within thirteen minutes. The phosphorus is oxidized and
is converted into ortho-phosphoric acid, and as it is in the presence
of excess of lime, it combines in a peculiar form tetrabasic phosphate
associated with calcium silicate and fotms w^hat is called basic slag.
When the operation is finished, which is ascertained by the appear-
ance of the gas given off* from the top of the convertor, the latter is

MANUFACTURE OF BASIC SLAG.

201

Unloading Basic Slag in Blocks.

Preliminary Breaking-up of Basic Slag.

202

CHEMICAL MANUEES.

inclined on its axes, and the current of air is suspended and the
hquid slag floating on the cast-iron is poured into a metallic truck
forming a case and containing a certain quantity of finely pulverized
fused silica. The weight of the slag in one of these trucks may
reach 4| tons and even more. The whole is conveyed on rails to
the spot where it is to be handled, and after cooling, facilitated by
sprinkHng with water, the mass is removed from the truck and
discharged into a crushing shed.

The Nature of Basic Slag.- — Basic slag occurs as more or less
bulky blackish fragments, porous, strewn with tablets of steel and
of great densitv. It slakes in the air ; the caustic lime absorbs
moisture and carbonic acid and the ferrous oxide oxidizes. Con-
trary to an opinion expressed at first, the absorption of carbonic
acid decomposes the tetrabasic phosphate. In the porous part of
the slag translucid crystals are met with, rhombic tablettes, hexagonal
prisms, and monoclinic needles 10 to 15 mm. long, of a grey, browTi
or blue (produced by FeOj colour intermingled or ranged symmetri-
cally. These crystals consist principally of tetrabasic phosphate of
lime, Ca^P.^Og. They have been the object of very interesting re-
searches, the principal points of which will now be summarized.

Tetrajjhosphate of Calcium. — Ca^P.p., may be regarded as being-
the neutral salt of an octobasic diphosphoric acid P20(0Hjg not yet
produced in the free state, the structural formula of which would
be the following : —

0

OH

OH

OH

OH

OH

OH-

OH

OH

and that of the corresponding
tetra calcic phosphate

O

P -

o>c-

g>Ca
0>Ca

The presence of this compound in basic slag has been determined
by a great number of scientists, so that there can be no doubt as to
the soundness of the hypothesis enunciated above. The small blue
crystals which are found in the paste, and more especially in the
geodes of the slag, were studied from a crystallographic point of
view by A. Eichard, who refers them to the orthorhombic system,
and notes amongst their properties a strong double refraction and
a very marked dichroism, the same crystal appearing colourless or
a beautiful cobalt blue in two rectangular positions. Prof. Carnot
at this time termed these crystals silico phosphates of lime and gave
them the formula PP-SiO.^SCaO. In the same year Hilgenstock
examined the other crystals. He found in the scoriae of these, crystals
in the form of thin rectangular tablets coloui less or of a light brown
according to the thickness. He placed them in the rhombic system.

O

o

-+^
$-1

>
O

O

a

o

J3

■204:

CHEMICAL MANUEES.

He recognized their composition as that of a tetrabasic phosphate
of hnie Ca4P20y or P.^O^CaO. This analysis having given rise to
■certain discussion, it was again taken up by Carnot on the one hand
■iind on the other by Stead and Eidsdale. They found :- —

TABLE LV.— ANALYSES OF CRYSTALS OF TETKABASIC PHOSPHATE

OF LIME FOUND IN BASIC SLAG.

Carnot.

Stead and Ridsdah

Per cent.

Per cent.

Phosphoric acid .... 87*67

38-044

Silica

0-74

traces

Lime

#

o9-54

f)0'20()

Magnesia

traces

0-H2S

Ferrous oxide
Alumina

1-44
0-37

0-100

Vanadium oxide .

—

0-722

Sulphur

0-150

99-7(5

100 -OoO

These results confirm the formula of tetrabasic phosphate of lime,
besides the two forms of crystals described. There were likewise
found brown or almost colourless needles of a hexagonal form. Their
iinalyses give the following figures : —

TABLE LVI.— ANALYSES OF HEXAGONAL CRYSTALS FOUND IN

BASIC SLAG.

• Phosphoric acid .
Silica ^ • • .
Lime f ■•• .
Magnesia 1 .
Manganous oxide
Ferrous oxide
Ferric oxide
Alumina
Vanadium oxide
Sulphur

Hilgenstock.
Per cent.

34-94

3-24

57 -oo

4-00

99-73

Bucking and Link.
Per cent.

36-77
3-81

53-51
0-40

2-22

1-78
1-09

traces

99-58

Head.
Per cent.

33-707
3-900

53-536
0-486
0-790
1-286
4-857

1-343
0-460

100-365

The differences which exist between these analyses are explained by
the difficulty which there is in isolating the crystals from the im-
purities which remain partially adherent thereto. Stead and Eidsdale
liave in fact distinguished two other varieties of crystals, black flat
needles, some of which are magnetic while the others are not so.
They have found the composition to be as follows : —

MANUFACTURE OF BASIC SLAG.

205

Feeding Basic Slag into Ball Mills. (View from above.)

ys' ^iM-, ■■ vv, .^^.ig^

Handling of Ground Basic Slag. (Bagging-up in 100 kilos (220 lb.) lead-sealed bags.)

^06

CHEMICAL MANUEES.

TABLE LVIL— ANALYSES OF BLACK NEEDLES, MAGNETIC AND
NON-MAGNETIC, FOUND IN BASIC SLAG.

Lime .
Magnesia .
Alumina
Ferric oxide
Ferrous oxide
Manganous oxide
Chromium sesquioxide
Vanadium oxide
Silica .
Phosphoric acid

Magnetic.

Non-magnetic

39-088

44-730

1-297 ■

0-936

6-400

9-700

33-857

35-657

8-100

1-748

1-023

5-980

4-200

2-656

2-223

1-100

0-900

traces

0-740

99-826

100-109

According to these authors, these crystals would therefore consist
chiefly of ferrite and of aluminate of lime. The analyses of the blue
crystals give : —

TABLE LVIII.

-ANALYSES OF BLUE CRYSTALS FOUND IN BASIC
SLAG.

Carnot.
Per cent.

Hilgenstock.
Per cent.

Bucking and Link.
Per cent.

Phosphoric acid
Silica
Lime

Magnesia .
Ferrous oxide .
Manganous oxide
Alumina .
Sulphur .

29-65
12-42
53-20
traces

1-80
traces

2-76

30-85

9-42

57-60

2-94

^ 31-19

9-47

57-42

traces

0-95

1-13

traces

99-83

100-81

100-16

These figures correspond exactly with the formula —

8PA, SSiO.,, 36CaO, FeO, A1,0,

By replacing small quantities of oxide of iron and alumina by
equivalent amounts of lime, a more simple formula is arrived at,
P0O5, SiO^S, CaO, which may also be written —

PA> 3CaO + SiO.,, 2CaO
Hilgenstock and Carnot have examined the order of formation of
the crystals, and both have come to the same conclusions.

The first crystals which are formed appear to be the rectangular
tablets on which afterw^ards come the brow^n hexagonal needles. It
is only later that the rest of the slag, becoming richer in silica, iso-
lates the blue and brilliant crystals. These are superposed by the

MANUFACTUEE OF BASIC SLAG. 207

brown and black needles. The order of appearance seems, therefore,
regulated both by the gradually decreasing temperature and by the
composition of the bath of slag which becomes richer in silica and
less rich in phosphoric acid. Cultural experiments have been made
with the object of examining the action of certain elements of basic
slag. They will be examined further on.

Solubility of Basic Slag. — Formerly basic slag was regarded as
a product of no value, because there w^as no means of dissolving it,
owing to its high percentage of iron and lime ; neither any more did
any one dream of utilizing it in agriculture, because they knew
very well that raw phosphates jpossess no direct fertilizing value.
Scheibler suggested the preparation from the basic slag of a pre-
cipitate, German patents 24,130 and 25,020. For that purpose he
treated 100 parts of basic slag in powder wdth 120 to 150 parts of
hydrochloric acid and precipitated the phosphoric acid by milk of
lime. Francke recommended the decomposition of basic slag by
magnesium chloride, German patent 27,106, and to convert the
phosphoric acid into phosphate of magnesia. G. Meyer, on his part,
signalized the treatment of fused basic slag with its own weight of
acid sulphate of potash. The silicate of potash ought to give still
better results. The object of all these treatments w^as to facilitate
grinding on the one hand, and to increase the fertilizing value of
the basic slag, by dissolving it, on the other hand. But up till now
no steel-works has felt it advisable to resort to these mixtures, though
the manipulations w^hich they suppose in no way hinder the pro-
gress of the manufacture. The last-mentioned process would, how-
ever, appear to have the advantage of suppressing the unpleasant
part which the spreading of basic slag now presents. All the pro-
cesses w^hich have been suggested to increase the fertilizing value
of this manure need not be dwelt upon here, besides they have not
been adopted in actual practice. It w^as first of all asserted that
the phosphoric acid of basic slag, looking to its origin, was less
soluble than that under any other form, but V. Eeis and Arens,
amongst others, showed that phosphoric acid combined with the
silicate of lime was soluble in carbonated water. It is from these
researches that the use of basic slag in agriculture dates. The results
obtained by these tw^o are given in the following table (p. 209) ; the
figures of this table show the great solubility of basic slag in water
saturated with carbonic acid compared W'ith that of the other
phosphates. The decomposition of tetraphosphate of lime takes
place according to the equation —

P.PgCa, -f- CO, = CaH,(P0J2 + 3CaH._,(CO.)2 + H.O

There is thus formed an acid phosphate of lime such as is also
found in superphosphates. The solubility of basic slag in citric acid
and in citrate of ammonia and also in tartaric, acetic and oxalic

208 CHEMICAL MANUEES.

acid has been the subject of profound researches by E. Jensch
which are of so much the greater interest because the sokibihty in
the same solvents of the calcareous silicates always present in basic
slag were determined at the same time. Jensch's researches were
made on basic slags of very different ages and origins for comparison.
He determined the solubility of both Podolia phosphorites and
Somme phosphate. The method pursued consisted in mixing each
time 1 grm. of the substance with 150 c.c. of the solvent concentra-
tion 1 in 20, exposing the mixture during twelve hours to a tempera-
ture of 50 to 70° C, then to dilute the solution in 100 c.c. of water.
The liquid was heated to boiling, filtered to separate the insoluble,
ignited, and the phosphoric acid titrated in the usual way. The
difference in the contents of the different elements in the residue on
the one hand and the raw material on the other hand, gives the
quantities dissolved by the organic acid. Jensch operated on eleven
samples of basic slag reduced to a fine powder (1 to 11) ; three
samples of crystals of raw slag (12, 13, 14). A sample of Podolian
phosphorite (15) and a sample of Somme phosphate (16). The follow-
ing table (p. 210) gives on the one hand the content of the substances
examined in silica, lime and phosphoric acid, on the other hand, the
quantities of phosphoric acid dissolved by the different solvents, also
the centesimal amounts remaining undissolved in the residues.
These figures show that the phosphoric acid behaves perceptibly in
the same manner in basic slags containing more than 18 per cent of
that acid as in those which only contain it in small proportion.
Thus it is that rich basic slags in current use in agriculture only
contain O'lS to 0*20 insoluble in citric acid, whilst low strength
basic slags only contain 0-04 to 0-14 per cent. The solubility in
oxalic acid yields equally concordant results. That acid dissolves
tetracalcic phosphate and only gives a slight residue of insoluble
which consists probably of tricalcic phosphate. The crystals sepa-
rated from the iDasic slags (12, 13, 14) show a still greater solubility.
The other organic acids used in this series of experiments act less
energetically on the phosphates of basic slag ; however, here again a
certain uniformity can be established between the solubility of the
different phosphates.

The silicates, which are highly basic, although of a composition
often very variable for the same origin, are distinguished by their
solubility in the organic acids, a property which is absolutely awanting
in the silicate compounds of the natural phosphates, phosphorite,
apatite, etc. It follows that the degree of solubility of the phos-
phoric acid of basic slag depends on the nature of the calcareous
silicates contained therein. Again, if the fragments of basic slags
show a uniform crystalline structure, that is to say if they are de-
prived of agglomerations of caustic lime, which are sometimes ob-
served therein, their content in free lime will be very small and will

MANUFACTUEE OF BASIC SLAG.

209

Q

<

O

I— I

'^

<

<

o

I— I

-<

o

H

pq
o

pq

X o i-r

C^ ^ r: -H »it> X :C

-jt-x— I'M— i^ooxvrx-

»c »--:; '^ ^f o T}i :(.• Tt< re »o .-I i-H ic c<i

::> ri c^ op
t X »^b JC

X

>

- '^ lit- o ^-( c^ i:

X

(M t- LT c^

c<i jc rc rc

X

L^ -r-l O O X >_^ i-( L'? Lt rH

Lf r-H 'M ^t i i•^ ■>^ X lo :«

•M re -M TC 1— I rH '-r -M

X s-

a,

X c: O O re -M r-l rji X C^ t^

X o

;c :c 'H -^ e-

O Le le X -M \Z

^ C^

ei

w

H

'-' >.

K

t; i>

a

H

"^ s

H

■y.^

<

^ °°

M

!Q 33

03 ^

-*1

C «M

m

i-^

3*®

1^

^ ^ ^ 2 ;t 5 ';^ "^ - "^ ^ L- ^ c^ Lo -
^ X X r-H L^ o :p T— I o re r: c^ o m io ■>!

r-l !M C^ M ^1 -M ,H ,-H 'M ^ ?5

CI

-7* :f >-;r X X o l;^ ^ t- :p c; o -* o J^ =^i o

3 *■

X ^

Oh

■-H O I— I C^ CQ lO O C: t^ 'M — i.

o T-H th oi c<J o o c; o :c c<i
I— iro?^(?q'*:e«^^OrH

o
1—1

o

a.

X ri -o L-r X i-o o o Le o lit- re l-':^ o o «o lo

•^xre:er:r-irer-('>Tr--icpo^t-t:-t-ro

X X X O t- X "i -^ rH tH -^ rH tH e-T 'f.l ir^ ITN

^^^ie>^-*^^iorere'*ie:;oreio^

a,

ot^-ore'M'^oc^o^reciirioce
re o re re re L^ o '^t^ ci re o o ^1 X (M

o
o

X >e- rH X -o ic ^ re -;*< re Tj< ,-1 ce i lo -^ cq
rHT-He-ii-ir-ii-Hc^ii— i'Mrei-(>o-*rctM->*co

t^ o o Lt c^ re 'TtH lo X -M o t~

le- c^^ X o :f c: le f-i ITS o i>- , , , ^^

CQ L'S (fl -^H t- i lO X i> X »0 I I I I I rH

M .

O)

CI

g .-S .

"Si^—'o -Q

•^ -*^ C4_, ^ 33 03 =°

— 1 ^ li _::; cc 03 ^^

HH S K ^ > > > • ^ S.-^^ S ^ ^^ "^

^ -7. £ ^ 3 .2 -3 g i i i

•I ' ' ' ' ' '= |,i S ^ "3 g 2 03 g^

^ «^ qT^ >;^ S .i: -d ir fl o

PQ GC ;:iH ;/: in pq H H Ci pq p-i

Itt

210

CHEMICAL MANURES.

i-i (M c;

CO <u

X -M

.- :£> 'Jl ->!

^9 S. I

CC Ci !

X

'-' « O ^-5

^

S-<

X t- o

•^ -M Ci

X 1-C

rH

lO

rH O 'M

T' 9 2

iO c:

CO

o

.-1

"M X X

o o -::

?I i:

X i-H O

X c- c^ cc

CC c^ c- — >-C c:

■*

IC X tH

O ~ --H O

X o r: — 1 71 '^

I-H

?C O I>-

i2! 'M

t- IC Ci c-

ic -^ c- io o X

6

-<# (M I— 1

•
t- O -M O

-* O O Ci ;2; ;^

M

tH O X

t- O M X

-M I— 1 w I— 1 O '-C

zn

X

!M 'M -T

-^ l-t c- ^

•^3 — 00^

"5

1— 1 :C "M

-M --1 •>!

-^ C^ CC CC

I— (
<

>>

G<1

^ o o

Cq rH -^

^ o i

Ci n o t-
cc 'l^ X ?p

i ib X o

CI CC C- IC X c~-

t^ 0 rH CC 0 0

-0 0 -f-i X 0 '^

o cc

re rH re

,-1 X •* >c

"-A

O

c; TC X

^ cc -« i2

c^ c-1 Ci Ci rt 0

lO O rH

O 'M -O O

^ ^ T' "?" 9 T*

^H

c; X I-':'

LC -M •M LC

»— 1 1—1

CC 0 >c- 71 0 0

XX X

K

TT -M rr.

O iC :r CC

1-C 0 X 0 X CO

P5

o T- 9 ?

X ^^ 9 t-

tC 71 't <— 1 ^ >— 1

f 1 i CC i 0 5J

<

-4^

— t- 1 — i

1 — 1 —

X X X

zn

-.*

r: J-T X

-M C~ t^ O

0 -H t^ -f c: t^

W

o

"* -M -M
(—* ...

-M X O -M

~ CC CC -^ 't 1-7

^
a

ri 'M •-

■^ -M CC --C

71 0 71 ^ 0 r-i

T— 1 -^ I— 1

1-H -^

XX X

—4

VH

—

1 -^ C~ -M

c; — ' CI --T

t 0 C: -^ X 0

MH

-^

1 CI O TC

CC -t* ^ o

rH — 1 C: 0 T^l >C

o

^^

ii6

O -^T! X O

CC 0 X 0 --1 ^

CO

':J^ '^

-M -M

0 ?Ci oo

1

1 I>- 1-H ^H

•M •>! O CC

C- CC -^ 71 1-7 t-

►-5

c^ c- -*

CC O --H -M

— . t- --C 0 -+ 0

P^

^ :^ -M

■M CO CO C<1

71 0 >-7 1-7 ^ 0

1 rN tC ^

i-l r-i

t- t- C^

o

! -nu---

X CC X o

r-l X t— Ci UO T-i

cs

O ^ X

c~- :r X c—

0 '^ ^ CC c; 7^1

tH

o ~. --c

tC' CC CC —

-Tji 0 X — 0 —

1— 1

1— 1 ^ -— 1

rH 1— 1

c^ t~ t-

^
X

.-! — r:

uc -M :r^ tr

X 0 71 r-i X c:

S

■;

■<* O -M

rH •M 'Tf O

X --C 71 -t 71 C-

Ph

:«

05 ^ rc

CC "M ■?! CC

-H 0 CC -^ -— 1 1.7

H

'M -r r-l

r-i T— i

XX X

■ ^

O re :c

^ -* C^ LC

tr 'M X 71 X X

3J

i-i X n
^ • • •

-* GO IC

7-1 X CC O

O CO "^ 50

iC rH CC rH 71 -^

CC i i ^ r-l c^

O

.—

!— 1 -* 1— 1

rH r-i

t^ c- t^

1—1

■ -+ ^t

•X --I I-l -*

CI t~ tc c; 0 --t

;:>

=^ 6 i: i

t>- CC "* t>-

0 71 tr- >1 >-7 CO

'^ i t>- i>- 0 C--

o

.— ! rfl -— 1

T— * 1— i

c- c^ t-

TJI

IC TC ^

O C^ -^ -M

-* 0 --C X rH ro

O O u:'

•^ -M CI LC

71 71 71 X :C »-7

<N

L-r iS Ci

CJ -* iO c^

CC 0 X X 0 CO

1 »-'r ^

r-i 1-1

t- 0 X

r-i C^ rH

X O CO ^

X 1—1 '-7 CC L7 ^

P3

'^ r-i Ca

o c^ ro 1-1

C;- t>- 71 C;- 1-7 Cq

v^:!
W

^ ^ X

X CO lO X

'*^ ■— ' ■y^ /-*N ^^ ■^

lO I— I

1-1 I-l

t-^ c- ?-

-<

• • •

H

fl ^

C "S

^ "^ == ■s^S^S

• •

1^

■"' — 'S _ '^3

O

-§ i .2 i ^

* 0 . —

?-t T* -^ ^

C3

-^ - ?e S •-

'-C 'SII -C^ -" :£

X .t^ s § ^

o ?: ^

.2 0H <^C

MANUFACTUEE OF BASIC SLAG. 211

rarely exceed 2 per cent. But the more these calcareous agglo-
merates are present, the higher will be the free lime content. It
is true that that lime not being combined chemically with the
phosphate, but in a state of simple mixture, and up to a certain
point as impurity, cannot exercise any influence on the solubility of
the phosphoric acid in the soil, for those bodies can only act as
solvents which are of a nature to modify the chemical nature of
another body. The neglect of this principle has led some authorities
to ascribe to the uncombined lime in basic slag an importance
which it absolutely does not possess. What determines the solubility
of the phosphoric acid in basic slag is the strongly basic calcareous
silicates with which it is combined.

The magnesia likewise forms with the phosphoric acid a tetra-
phosphate, but the solubility of this body considerabl}' exceeds the
solubility of the corresponding calcareous compounds. Basic slags
rich in magnesia dissolve much more rapidly in organic acids than
those in which magnesia is absent. The action of citric acid on the
slags shows that the magnesia is chiefly combined with the phos-
phoric acid and not with the silica. It is perfectly possible, and in
all cases very likely, that the action of phosphoric acid of basic slag
in the soil depends, in the first instance, on the presence of these
silicates. We would thus be confronted with double compounds^
phosphates, and silicates of calcium which are dissolved with the
greatest facility by water containing carbonic acid, hence, therefore,
the solution of the phosphoric acid and its absorption by plants
follows. It has been remarked, in fact, that the most active basic
slags are always those with a high percentage of silica. Steel works,
therefore, possess a very simple and in no way costly method of in-
creasing the solubility of basic slag in citrate ; it suffices to add hot
sand to it in the convertor, the sand melts like butter, is converted
into silicic acid and combines with the phosphate of lime to increase
its solubility. It is clear, in that case, that lime should not be de-
ficient in the slag. Sihca, therefore, plays a very important role
in the basic slag. CaSiO^ converts the shghtly soluble phosphate
of the slag into Ca^PoOg according to the following equations : —

CagfPO,)^ + CaoSiO^ = Ca.P.O, + CaSiOg
Fe3(POJ2 + 2Ca"_,SiO^ = Ca.P'oOg + Fe3Si,0,

The introduction of an excess of silica helps to decompose Ca^PoO^
afresh. There exists in Germany a factory which makes basic slag
with 24 per cent of phosphoric acid according to Scheibler's patent,
German patents 31:,416 and 41,303. A little less hme than that re-
quired by the complete dephosphorization of the cast-uon is added
to the convertor, and the slag so obtained run out. The remainder
of the lime is then added, and the low strength slag which results
is used as a reducing substance in the convertor. .To increase the
strength of the slag in phosphoric acid, phosphated chalk may also

21:2 CHEMICAL MANUEES.

be added to the cast-iron in lieu of lime, eventually mixed with
sand. Fused phosphatic chalk has the same solubility as the best
slags. (CaCOs melts at 1000° C, the phosphate at 1900° C.)

Crushing of Basic Slag. — In the beginning of the basic slag
industry it was very difficult to crush. Cylindrical crushers and flat-
stone mills were used at that time. But as the basic slag is mixed
with grains of steel of larger or smaller size, the plant was rapidly
worn out. Attempts were then made to eliminate the pieces of
iron in the basic slag by means of magnetic separators. But these
methods did not give good results ; the separation of iron was incom-
plete and the cleaning of the machines involved frequent stoppage.
From 1888 mills with torched steel balls, the wear of which is very
slight, have been used. Ball mills, moreover, almost entirely do
away with dust, owing to the installation of a special chamber in-
tended to collect it, and of a draught chimney which draws it
thereto. The hot air entering the draught chimney entrains the
dust formed in the crusher ; about 1 per cent of dust is got for 100
of fine powder. When fans were used — useless with the present
system — 6 per cent of dust was obtained. The dust chamber is
emptied every eight to fifteen days, according as the work is by
day or both by day and by night. The blocks of basic slag are first
broken up by hand to eliminate pieces of iron, which are laid on one
side to return to the foundry. The basic slag so obtained is then
reduced to a fine powder (passing through a 100 sieve) in ball mills.
The powder is collected in the lower part of the mill and bagged up
in 2 cwt. (220 lb.) bags. Formerly the basic slag was allowed to
slake in the air, and the fragments after eliminating the iron were
ground in flatstone mills. But basic slag slaked after long ex-
posure to atmospheric agents sometimes contain excessively hard
pieces, resisting the most forcible grinding ; this method was aban-
doned. The treatment to which the basic slag is subjected as it
comes from the converter has a considerable effect on the grinding.
V. Eeis has examined the composition of l^asic slag and its con-
catenation with its resistance to grinding. From an outward in-
spection there are two kinds of basic slag, block slag and poured
slag. Block basic slag is got when it is allowed to solidify in the
wagons into which it is poured from the converter. It then cools-
slowly and uniformly, and may be removed in a single block which
is easily detached from the platform of the wagon. Poured basic
slag is obtained by pouring the contents of the wagon on the
ground. It spreads out in a thick layer and cools rapidly. This,
kind of basic slag is generally very hard ; its grinding is difficult
and requires a great expense of motive power. Basic slags in blocks,
on the contrary, are more easily ground, but they also contain very
hard lumps. The following table by Eeis gives the composition
of different slags and their resistance to grinding : —

MANUFACTUEE OF BASIC SLAG.

213

TABLE LXI.— EFFECT OF COMPOSITION OF BASIC SLAG ON

FACILITY OF GEINDING.i

I.

II.

Ill.

IV.

V.

VI.

VII.

Silica

6-77

16-41

6-69

4-88

8-07

6-00

7-07

Phosphoric acid .

16-92

11-75

17-75

19-25

18-48

18-39

22-50

Ahimina

1-68

1-58

0-95

0-59

1-40

1-37

0-89

Ferric oxide

0-96

10-41

5-70

5-14

8-45

2-87

5-27

Ferrous oxide

10-77

10-55

10-65

12-49

10-13

11-43

6-49

Lime .

51-00

31-00

48-42

48-17

46-47

50-77

47-36

Manganous oxide

7-16

14-91

7-71

6-23

9-35

7-28

7-81

Magnesia .

3-01

2-08

2-05

2-38

2-03

1-57

1-67

Crushing .

difficult

easy-

easy

less easy

difficult

difficult

easy

I. Poured slag, dark brown, hard and difficult to grind.
II. Block slag, grey, lamellar, friable, easily ground.

III. Block slag, slate grey, firm, and easily ground.

IV. Block slag, grey, firm, vesicular, less easily ground.

V. Poured slag, dark brown, hard, brittle, difficult to grind.
VI. Block slag, brown, brittle, hard, difficult to grind.
VII. Block slag, grey, lumpy, difficult to grind.

It follows from these figures that in general the chemical com-
position of basic slag has only a slight effect on its physical pro-
perties, whilst the percentage of oxide of iron would appear to
increase their resistance to grinding, as the following table show^s : —

TABLE LXIL— SHOWING THE INFLUENCE OF THE KATIO OF THE
PEROXIDE OF IRON TO PROTOXIDE ON THE EASE OF GRIND-
ING OF BASIC SLAG.

Basic Slag.

Peroxide of Iron.

Protoxide of Iron.

Ratio of FeoOs to FeO.

Grinding.

1

0-96

10-77

1 : 11-2

Difficult

2

10-41

10-55

1: 1-0

easy

3

5-70

10-65

1: 1-9

>)

4

5-14

12-49

1: 2-5

less easy

5

3-45

10-13

1: 3-0

difficult

6

2-87

11-43

1: 4-0

>?

7

5-27

6-49

1 : 1-2

easy

When the ratio of the peroxide of iron to the protoxide < 1 : 3 the
basic slag is generally easily ground, especially when the peroxide
of iron is in preponderant proportion, but when it is the protoxide
of iron which predominates the slags are hard and difficult to grind.
It is important to watch the sieves around the crusher, and see that
they are working well, so as to be able to remedy any defect forth-
with. With this end in view, the basic slag produced each time

1 The translator has transposed the figures relating to lime and manganese.

214 CHEMICAL MANUEES.

by four crushers is carried to a weighing machine roanipulated by
a man of trust ; the latter registers the production of each crusher,
takes a small sample from each bag which he examines by the feel
and the sieve and runs it into a box installed for the purpose, or
each chief grinder weighs his product and is himself responsible for
the good execution of his work and its bagging up. Then the sacks
are carried to the depot. As in the slack season orders must be
executed from stock, it is necessary to use very sound and carefully
sewn bags and to preserve them full in a dry place, because gi^ound
basic slag, owing to its high lime content, is apt to solidify in a damp
place. The moistened powder cakes and cannot be rendered friable
by ignition as one might suppose ; it only becomes harder. The 2
cwt. bags (220 lb.) measure 50 x 90 cm. (say 20 x 36 in.). Even
in using sound bags some of them rot when stored full. That is
why basic slag is stored in iron silos.

It has already been mentioned that the cooling of basic slag is
accelerated by quenching with water. This work is not without
danger. When basic slag solid on the outside but incandescent
inside is exposed to the shower of water, this may penetrate into
the inside of the block by cracks and crevices ; it is converted
into steam which occupies a volume 1600 times greater at 0^ C. and
7500 times greater at 1000° C. When such steam is given off in-
stantaneously a very small quantity of water suffices to cause an
explosion. It may also happen that a block of basic slag still liquid
inside may have an escape, which is particularly dangerous for the
workmen. It is necessarv therefore to draw their attention thereto.
Finally, gas may form inside the basic slag withoiit exterior aid,
which, in virtue of its tension, seeks a vent, and not finding any
causes the block to fly away in pieces. When a crusher has to be
repaired, and if the repairs cannot be done on the spot, it is con-
veyed to the forge on a rolling crane or on a truck running on rails.
Crushing being a work which requires to be continuous, they are
not stopped except for dinner at noon, otherwise they work
continuously, the workmen replacing each other at lunch time.
During the dinner hour the machines are inspected and thei bearings
lubricated. The grinding plant should be simple. Owing to the
peculiar nature of the substance being ground, conveyors and
mechanical feeders are not applicable. A crusher of 2 metres
(6^ feet) can produce 15 tons in 10 hours of ground basic slag, when
the basic slag is fresh cooled and not too hard. P. Mellman, of
Berhn, German patent 107,234, projects a jet of steam or air into the
liquid basic slag at the moment it is discharged by the couvertor.
The basic slag then becomes friable, and is very easily ground.
The basic slag in blocks is sold to the grindiug factories according
to their percentage of phosphoric acid. The determination is
generally made on the powder produced during crushing, supposing

MANUFACTURE OF BASIC SLAG. 215

that they possess covered and very dry warehouses. On the other
hand, the vendor takes a sample from each block by chipping off a
fragment vrith the hammer and takes a fair average sample at the
end of each month. The sample is crushed, mixed, and divided
into three parts ; one part is sent to the buyer, the other to the
sender, and the third is sealed and kept in reserve as a basis of
settlement in case of difference. The exchange of analyses on both
sides is made on a certain day, and the average is taken as a basis
when the difference between the two analyses does not exceed Oo
per cent P.,0^. If the difference be greater, the sample in reserve
is sent to an analytical station agreed on by both sides, and the
analysis which it supplies forms the sole basis of adjustment. The
cost of the analysis is borne by the party whose analytical results
are furthest from those of the analytical station. If the analytical
results on both sides differ to an equal extent from the experimental
station, the costs of settlement are defrayed equally by both parties.

Basic slag is delivered to farmers without being mixed with other
manures. If it be mixed with potash salts it heats and gradually
solidifies ; the caustic lime acting on the magnesium chloride forms
magnesium oxychloride, which is a powerful cement ; if mixed with
sulphate of ammonia, the caustic lime acts on the ammoniacal
nitrogen and causes loss. Finally, if mixed with nitrate, the nitric
acid may be reduced into ammonia by iron, in the form of a fine
pow^der, and the ammonia expelled by the caustic lime.

Customs in the Sale of Basic Slag.— From 1 July, 1895,
according to a decision of the Assembly of German Agricul-
turists, basic slags were sold on the basis of their phosphoric acid
soluble in citrate, without taking into account their total phosphoric
acid, nor the degree of fineness.

But in its General Assembly held in 1898, the Union of Experi-
mental Stations decided no longer to use Wagner's citrate of
ammonia solution. It, moreover, found that steel works, to increase
the solubility of their basic slag in citrate, were adding to the cast-
iron not only silica, but more lime. The effect of this was to
increase the alkaline nature of the basic slag, and the Union esti-
mated that this increase in alkalinity justified the selection of a
solvent of greater acidity in the estimation of soluble phosphoric
acid. The 2 per cent solution of citric acid forms in fact a more
accurate method than citrate of ammonia for basic slag prepared
according to this new process. But Professor Wagner estimates
that the 2 per cent citric acid solution dissolves 7 per cent of PoO^
more in basic slag, that is to say, it shows 16 per cent of soluble
phosphoric acid where the old method only showed 15 per cent.

There is at the present time a tendency to value basic slag on
the basis of its total phosphoric acid content, according to cultural
experiments male on the subject by Meissl and Defert in Austria,

216 CHEMICAL MANUEES.

Bemarks on the Use of Basic Slag. — It is not intended to
examine heie the use of basic slag on vegetation ; that examination
will find its place better in a special work just published by the
author. The remarks made here will therefore be confined to a
few points more immediately connected with the study of basic
slag.

Guffroy, an agricultural engineer, having taken in hand re-
searches as to what fertilizing action the silica and the manganese
had in basic slag, isolated, as well as could be done, the blue crystals,
silico-phosphate, and the brown crystals, tetraphosphate, examined
above and caused them to be analyzed in Professor Grandeau's
laboratory. The following are the results : —

TABLE LXIII.— ANALYSIS OF BLUE AND BROWN CRYSTALS IN

BASIC SLAG.

Br

own Crystals.

Blue Crystals.

Per cent.

Per cent.

Total phosphoric acid

21-71

20-28

Lime

48-88

51-52

Silica .....

1-49

5-17

Manganese calculated to the

metallic gtate

2-46

1-86

Trials were made : —

1. With a basic slag of known composition.

2. With a basic slag presenting the same composition, and of
which the phosphoric acid was furnished by crystals of tetra-
phosphate and silico-phosphate of natural basic slag.

3. With an artificial basic slag, where by using at one time
only tetraphosphate, at another time silico-phosphate, there was

got :—

(a) A basic slag deprived of silica.

{h) A basic slag containing little manganese.

From the comparison of the results obtained it was easy,
consequently, to infer the action of the ingredients, manganese
and silica. The first researches were made in collaboration by
Guffroy, Milon, and Crepeaux. They have been summarized by
the National Society of Agriculture.'

The plants experimented on were buckwheat, wheat, and violet
trefoil. Erom this first series of experiments there is deduced the
double efficacy of manganese and silica, in basic slag Etoile brand.
The second series of experiments, the results of which are not
published, were made by Gutfroy and Milon alone, on wheat,
buckwheat, and hemp ; at the same time the violet trefoil of the first

1 " Bullet, de la Soc. National d'Agric, 1905," pp. 479-83 : " On the Feitiliz-
ing Action of Certain Accessory Products in Basic Slag ".

MANUFACTUEE OF BASIC SLAG. 217

experiment was kept under observation. The result of these experi-
ments may be summarized thus : —

1. Apart from its phosphoric acid, lime and magnesia, Etoile
basic slag has proved efficacious by its manganese and silica.

2. Manganese from an agricultural point of view ought to be
regarded as an important constituent, influencing both the quantity
and the quality.

3. It seems that silica, at least in the condition under which
it exists in Etoile basic slag, also acts in the same direction, but
that its action is weaker, less decided, and requires to be further
studied to be established in a general way.

CHAPTER XII.

NITROGENOUS MANURES.

The most widely distributed nitrogenous manures are nitrate of
soda (Chili saltpetre) and sulphate of ammonia. A third class of
purely nitrogenous manures is that represented by animal waste.
These (latter) products are of considerable agricultural importance^
although the manure trade does not seem to take them sufficiently
into account. These three forms of nitrogenized manures are not
only differentiated by their chemical composition, but by their mode
of action in the soil. They form therefore three distinct classes,
which will now be examined.

Nitrate of Soda. — Nitric acid compounds have been known for
a long period. It is probable, according to Herapath, that the
ancient Egyptians used nitrate of silver to make their inscriptions
on the bands in which they wrapped their dead ; it is the same
chemical compound as that known as infernal stone, which is
used to mark linen and the skin. So far back as the eighth
century of the Christian era, Geber and Marcus described a body
which they called salpetrce, which corresponds with saltpetre, with
nitrate of soda. In the twelfth century, Raymond Lulle called this
body salnitri. Since then the term saltpetre has been used to
designate nitrate of potash, whilst nitrate of soda is called Chili
saltpetre, or nitre, in Great Britain.

Nitric Acid consists of nitrogen, oxygen, and hydrogen ; its.
chemical formula is HNO3. It thus contains fourteen parts of
nitrogen (22-2 per cent), forty-eight parts of oxygen (76-19 per cent),
and one part of hydrogen (1 'oQ per cent). It forms a very caustic
fuming liquid (attacking organic matter, strongly burning the skin).
In the concentrated state it has a density of 1-52 (104° Tw.), but
the commercial acid is generally much weaker : D = 1 '20 to 1 '4
(40" to 80° Tw.). It decomposes easily. It gives up a portion
of its oxygen to oxidizable bodies, such as carbon, sulphur, sulphur-
ous acid, and then passes to less highly oxidized states. Metallic
zinc reduces dilute nitric acid, and converts it into nitrate of
ammonia. With bases it forms salts, which with the exception of
some basic metallic salts, are soluble in water. Nitric acid is formed
almost exclusively by the oxidation of ammonia, or of nitrogenous
matter of animal origin, under the action of the air in presence of

(218)

NITEOGEXOUS MANURES. 219

bases (carbonate of lime)/ However, this spontaneous formation
in the soil is very slow in our climate. It is, on the other hand,
very rapid in Southern countries, Bengal, Hungary, Spain, where
the^ conditions of temperature and of moisture in the air conduce
considerably to the oxidation of nitrogenous animal matter.

For a long time these countries where nitrates exude spontane-
ously from the soil, and cover it wdth a layer like hoar frost, alone
supxDlied Northern Europe, up to the time when they succeeded
in making mixtures of soil to produce saltpetre. This industry was
conducted in saltpetre fields. Limestone, marl, washed wood ashe&
were mixed with animal matter, urine, dung, straw, etc. Heaps were
made, whicli were left to themselves in the open air for nearly a.
year, frequently turning them. When the earth was ready, that.
IS to say enriched, it was Uxiviated. To eliminate the hme from
the liquor obtained, it was treated with wood ashes, and clarified,,
and evaporated to obtain saltpetre. That method, which requires,
much work and only gives poor results, could only be applied in
countries which, deprived from communication with the south, as in
time of war, were obliged to live on their own resources, as France"
and Germany were during the continental hlociis. This method,
therefore, was abandoned.

But the sources of saltpetre indicated above barely met the
wants of industry ; agriculture could not profit. The discovery
of an important deposit of nitrate of soda in Ameiica, the working
of which was commenced in the years 1825-28, enabled the wants
of agriculture to be met.

Chili Nitrate of SWa.— South American nitrate of soda is dis-
tinguished, more especially from ordinary saltpetre, by the fact
that its acid is combined with another alkali. In Indian saltpetre
It is combined with potash (KNO3), whilst in Chili saltpetre it is com-
bined with soda (NaN03). It is met with in the Pampas of Peru,
of Chili, and Bolivia, between 19° and 27° of south latitude; it
abounds especially in the province of Tarapaca (formerly Peruvian,
now Chilian) and in the desert of Atacama. The nitrous mineral
caliche, or terra salitro^a, occurs as a layer of 1 to 6 inches thick
under a bed of conglomerate, consisting of sand, feldspar and
pebbles, amalgamated by a cement consisting of clay and different
salts forming a bed 20 to 30 inches thick. Its colour varies from
grey to brown. The conglomerate bed is sometimes awanting, so-
that the mineral crops out at the surface.

The caliche is never pure nitrate of soda. It contains mixtures
of nitrate of potash, common salt, iodide and bromide of sodium,,
alkaline sulphates, sulphate of lime mixed with sand. It only
contains on an average 25 per cent of nitrate. Picked pieces
contain more. The following gives the percentage in nitrate of
different products : —

Saltpetre.

Common Salt

Per cent.

Per cent.

n-9

12-9

6-5 -7

28-12

64- 7a

32-02

60-50

14-30

68-03

28-12

36-80

20-70

'220 CHEMICAL MANUEES.

TABLE LXIV.— SHOWING COMPOSITION OF CALICHE.

Yellow salt, pure hard, with small crystals .
Yellow salt, pure porous soft, with large crystals
Yellow ' aliche, veined with bro^ii
White caliche, hard and with small crystals
White caliche, porous and large ciystals
^rown caliche, porous and large crystals

Opinions ditfer as to the method of formation of this deposit,
which occupies a surface of about 60,000 hectares (say 150,000
acres) and contains about 170,000,000 tons, ililliger's is the most
Hkely theory ; he beUeves that the nitrate is formed from the nitrogen
of guano deposits, which covered the shores of a great soda water
lake by a process analogous to tlrat to be seen in Hungary in our
own time. The soda salts of the sea water would simply convert
the saltpetre into nitrate of soda. This opinion has in its favour
all the facts and circumstances met with in the deposit. Moreover,
traces of guano are still found in the crude salts. To extract the
crude salt a hole is dug in the ground 50 cm. (20 in.) in diameter;
when the saltpetre bed is reached a chamber 90 to 100 cm. (35 to
40 in.) in diameter by 30 cm. (say 12 in.) deep, and 150 to 200 kg.
(3 to 4 cwt.) of powder inserted. By exploding the powder by
means of a fusee, a considerable surface of the deposit is laid bare
often on a radius 10 metres (say 40 ft.) from the hole. The
crude salt is hand picked, to eliminate stones and fragments of less
value ; it is charged into baskets or into trucks, which camels trans-
port or draw to the melting workshop. To dissolve the crude
caliche three kinds of apparatus are used, viz. : —

1. Open Cast-iron Pans — Paradas. — These are heated bv naked
fires. Two pans 2 metres in diameter (6 ft, 6 in.) are used for one
furnace. Well water or water from a previous operation is run in,
then it is charged with caliche or crude saltpetre reduced to pieces
the size of the fist. When the solution is concentrated enough, it
is run into cases or boxes, where it clarifies ; it is then decanted on
the top of the depot and run into iron or wooden crystallizers ; 40
per cent of crystals is thus obtained and 60 per cent of mother liquor.

2. Ci/rindrical Vertical Pans — Maquinas. — These are heated by
direct injection of steam. They are 8 to 10 metres (26 to 33 ft.),
with a diameter of 4 to 5 metres (13 to 16 ft.). Each of these pans
yields in twenty-four hours 46 to 148 tons of saltpetre. The
clarified solution is poured into wrought-iron crystallizers 4 to 5
metres (say 13 to 16 ft.) square and 0-5 metre (say 20 in.) deep;
crystallization lasts three to four days. The steam given off con-
tains an important amount of iodin-e which can be avoided by an
addition of soda.

NITROGENOUS MANURES.

221

3. Vessels heated by a closed tubular bundle (? steam coil).
which have been introduced by the British and German companies.
These vessels measure 11 metres (86 feet), 1-85 metre (6 ft.) wide by
1-85 metre (6 ft.) high, into which the mother hquor and the wash
water are run and heated to boihng, then six trucks of perforated
wrought-iron containing about 1 tons of caliche. The nitrate dissolves
in the water whilst the residue remains in the trucks. To hasten
solution the liquid is agitated by injection of steam and of hot air
under each truck by means of a Eoerting's injector. This plant
works more economically than the preceding. At the same time
the solutions so obtained are more pure and more concentrated.
To get a ton of nitrate requires 3 tons of caliche. The crystallized
nitrate is left to drain, then it is dried in the open air. Nevertheless
it always remains slightly moist owing to the presence of chlorides
of calcium, of magnesium, and possibly also of nitrates of calcium
and magnesium. It crystallizes in rhombohedra, and has a dirty
reddish-grey appearance, due to its oxide of iron content and to
bituminous substances. The residue left by the solution {rijyio) still
contains from 15 to 35 per cent of NaNOg. It is boiled with water
and a weak solution of 43 to 45° B. obtained, which is utilized to
dissolve a fresh charge of crude salt. The muds from the clarifica-
tion are treated in the same way. According to Dr. Langbein,
they contain 67'1 of common salt and 27-3 of nitrate of soda.

Chilian nitrate of soda, such as dispatched from the spot of pro^
duction, has the following composition : —

TABLE LXV.— ANALYSIS OF CHILIAN NITKATE OF SODA.

Nitrate of soda
Common salt
Potassimn chloride
Sodium sulphate
Sodium iodide
Magnesium chloride
Water
Boric acid .

Per cent.
94-0
l-o'2
0-64
0-92
0-29
0-93
1-36

traces

Per cent.
15-31 N.

99-60

Better equipped factories supply nitrate of the following average
composition : —

TABLE LXVL— ANALYSIS OF BETTEK QUALITY NITRATE OF SODA..

Nitrate of soda .

Common salt

Soluble sulphate of soda

Insoluble

Water

Per cent.
96-00
1-00
O-oO
0-25
2-25

100-00

322

CHEMICAL MANUEES.

Common salt and soluble sulphates may be eliminated by washing
with cold water and by centrifuging. The content in nitrate is
evidently not always constant ; it generally varies between 90 and
100 per cent, which corresponds to a strength in anhydrous nitric
acid of 57-2 t3 63'5 or of 14-8 to la-4 per cent of nitrogen. In
Great Britain the fraction which goes to make up 100 per cent is
regarded as refraction, so that a nitrate of 5° of refraction means a
•nitrate of 95 per cent strength. This remark is important, so as to
understand market reports. On different occasions chlorate and
perchlorate of potash have been found in nitrates. Now these sub-
stmces are liable to spontaneous combustion, besides they are
injurious to vegetation. The presence of perchlorate is attributed
to the negligence of the workmen who have omitted to cool the
solution of caliche in the pan and have set it aside to crystallize in
the hot state. This perchlorate may be extracted from the substance
by the method which was the subject of German patent No. 125,206.
But since the disastrous effect of perchlorate on vegetation has been
recognized and the nitrates which contain it refused, manufacturers
have been more careful, and perchlorate is now only rarely met with

in nitrate.

One hundred parts of water dissolve of nitrate of soda at
■0° 10° 20' 30° 40° 100° 121° Boiling-point of the solution.
.71 78 88 98 109 178 224-8 Parts.

The specific gravity of nitrate of soda is 2-244.

Nitrate of Potash. — A compound of nitric acid vfith potash has
•no interest but for industry ; it is too dear to be used in agriculture, for
up to now it is only made from Chili saltpetre and potassium chloride.
It forms in itself an excellent manure, seeing that it contains not
■only nitrogen but also potash in a very pure form. Lately, however,
important deposits of nitrate of potash have been discovered in South
Africa, especially in the neighbourhood of Mabelstadt, and of Peliska
in Cape Colony. But these deposits do not appear to be exploited.

Before terminating this subject, mention may be made of a
nitrogenous manure put on the market in 1874, which has given
good results. It is a double nitrate of potash and soda ; it contains
in 100 parts, according to Maercker : —

TABLE LXVIL— ANALYSIS OF A DOUBLE NITRATE OF POTASH

AND SODA.

I.

Per cent.

II.

Per cent.

III.

Per cent.

Nitrate of potash ....

Nitrate of soda

Common salt .....

Water

Therefore — .....

Potash ......

Nitrogen ......

34-18
62-22

2-67

0-46

15-92

14-89 -

41-78
55-27

0-57

1-67

19-47 .
15-05

11-51

82-94

3-43

2-02

5-31
15-24

NITEOGENOUS MANUEES. 223

Storing and Handling of Nitrate. — Nitrate of soda is marketed
in the original sacks (catch- weight) weighing 120 to 140 kg. (264 to
308 lb.). It forms a mixture of crystals of ditferent sizes. It also
draws moisture from the air ; when it is preserved in sacks they rot
after some time and tear with the slightest pull. When the sacks
are emptied, one part of the material, always moist, remains adherent
to the fabric, from which there results not only a loss of matter, as
also a loss of sacks, as these gunny bags then become unutilizable
and are liable to catch fire.

Nitrate of soda is often coloured yellow by the presence of chro-
mate of potash or violet by the presence of nitrate of manganese.
The presence of nitrate of potash or of magnesium chloride renders
it deliquescent ; hence arises loss by the drainage of dissolved nitrate ;
that is why the bags are lodged on beds of plaster or clay which
absorb the liquid. But it is best to spread the nitrate intended for
mixing in not too warm a place. The bags are washed w^th tepid
water, and the solution is added in the manufacture of superphos-
phate which has to be mixed wath nitrate,^ or it is concentrated in ^
a pan. Certain manufacturers content themselves with beating the
bags free from the adherent salt. If the nitrate ought to be em-
ployed alone it is screened and the lumps crushed in a Carr's dis-
integrator, or in the toothed roll crusher. It is dried in the old
phosphate drier. However, if it be stored for a certain time in a
place that is not heated, it gradually becomes moist. In consequence
of the risk of fire, the building in which nitrate is stored should be
isolated and built entirely of iron.-

Production of Nitrate in 1907. — The exports authorized by the
syndicate of nitrate of soda manufacturers of Chili, rose to 2,050,000
tons for the-year 1 April, 1907, to 81 March, 1908. Of these quantities
1,750,000 tons had to be delivered before the end of the year 1907,
and the remainder, say 300,000 tons, in the months of January,
February and March, 1908. Now these exports made from April to
December, 1907, only amounted to 1,225,000 tons. The cause of
this decrease lies in the first instance in the labour crisis. The
Chilian labourer more fit than any other to w^ork under the torrid
sun of the Pampas, is as improvident as he can be. He only works
when he must do so to live, and as wages are very high in nitrate

1 This nitrate liquor if used up in wet mixing of manures might aid drying,
but it would all be converted into sulphate of soda. If poured on to a finished
superphosphate it would convert it into a wet paste, and after spoiling the manure
no credit would be given by the analyst for the nitrogen. — Tr.

2 If sulphuric acid be made in the manure works, as is often the case, the
amount of nitre required for the pyrites burners should be fetched daily from
the store referred to in the text. The supports of the chambers are of pitch
pine, and if nitre bags full or empty heat in the neighbourhood of the kilns or
chambers the latter run the risk of being; completely burnt down. Storing nitre
in the original bags is bad management. They are far too heavy and clumsy
to be lugged about by one man.— Tpw.

224 CHEMICAL MAXUEES.

factories he only works a few davs, and then rests under such condi-
tions ; the factories work very irregularly. The present prices are
about 10s. lOd. a cwfc. The rise in the price of nitrate which had
been discounted by the syndicate of manufacturers will always be
limited by competition with sulphate of ammonia. The latter, in
fact, after experiments made by Kraus at Weihenstephan, should
produce the same effect as nitrate, with this difference that it acts
more slowly.

Ammoniacal Salts. — Ammonia is a compound of nitrogen and
hydrogen, according to the formula NH^, and forms a decomposition
product of nitrogenized organic matter. It is a gaseous body, giving
off a characteristic pungent odour. It is very soluble in water.
The solution is generally known as ammonia. It has an alkaline
reaction, and turns red litmus paper blue. Under the influence of
the oxygen of the air, ammonia is partially converted into nitric
acid. It forms salts with acids, by combining with these acids to
form a metalhc radical XH^ which is ammonium. Thus sulphate
of ammonia is formed according to the equation : —

H,SO, + 2XH3 = (XHJ,SO,

and ammonium chloride according to the equation : —

HCl + XH. = XH.Cl.

All ammoniacal salts give off ammonia when they are placed in
contact with alkalies or caustic lime. Ammoniacal compounds are
very widely distributed in nature, but always in small quantities.
Their presence has been determined in the air and in rain water,
also in the juice of almost all plants. Ammonium chloride is found
in salt springs, in volcanic emanations ; carbonate of ammonia in
large quantities in the guano deposits of Peru, Bolivia, and Chili,
and the western part of Patagonia. The principal sources of
ammonia for industry and for agriculture are certain substances of
animal origin (bone, meat, blood) or vegetable (coal, peat), which,
submitted to dry distillation, give off the greater part ot their nitrogen
as ammoniacal compounds.

Ammonia is, likewise, obtained by the distillation of faecal
matters in presence of caustic lime and by the treatment of gas
(wash) liquor. Left to stand, urine putrefies ; the urea is trans-
formed into ammonia, which treated by caustic lime yields
ammonia and carbonate of lime. Ammonia is also found in the
smoke of factory chimneys and in coal soot ; the latter may even
sometimes be utilized as a manure, as the following analysis by
Hutton of Glasgow of coal soot shows : —

Per cent.

Potash 0-30

Phosphate of lime ...... 3-20

Ammonia ........ 2'80

Equal to nitrogen 2-30

XITEOGENOUS MANUEES. 225

Formerly, ammoniacal salts were made solely from matters of
animal origin. They were charj;ed into retorts which were heated
to incandescence, the vapours given off being condensed. The car-
bonate of ammonia thus obtained was collected and purified or
combined with acids to form different salts. The process is still
applied in the manufacture of small quantities of sal-ammoniac, but
solely as a bye-product in the manufacture of animal charcoal. The
calcination of the bones is done after two different methods. The
one, the older, consists in charging the raw material in vessels
placed in a furnace in stages so that one serves as a lid to the other
underneath. The vapours given off during combustion, the details
of which need not be dwelt upon, escape outwards by the chimney.
The other method consists in calcining the bones in a cast-iron re-
tort analogous to that used in distilling coal. The gases which are
given off are collected and condensed. The products of the con-
densation contain among other useful substances ammonia, which
can be extracted by distillation and converted into sulphate of
ammonia. But, as already observed, bone black is no longer used in
sugar factories. With the disappearance of bone black, the bye-
products, especially ammonia, also disappeared. The most important
source of ammonia is at present coal, the percentage of nitrogen in
which varies from 0"O to 1-6 per cent. The extraction of ammonia
will therefore be studied in the following order : (1) In the manu-
facture of gas ; (2) in the manufacture of coke ; (3) in the blast
furnaces, and (4) in the gasogene ovens (Mond's process, Bourgeois
and Lencauchez' process).

Manufacture of Sulphate of Ammonia by Distillation of Gas
Liquor. — When coal is distilled, the nitrogen which it contains
passes partly into the tar as complex products (aniline and its
analogues) and partially in the form of ammonia in the illuminating
gas. The ammonia is eliminated from the latter by washing with
water. According to Eoscoe, only 14*5 per cent of its nitrogen is
obtained from coal as NH3, 35*26 per cent is lost as free N,
w^hilst the coke retains 48 to 68 per cent. This low yield of
ammonia is due to the facility with which this gas is decomposed
(at a temperature of 500° C, Eamsay and Young). This loss may
be avoided by preventing the gas in the retort from coming in con-
tact with the heated sides. According to Beilbv, this desired result
is obtained by distilling coal with steam. By this method as much
as 50 to 56 kg., say 110 to 123-2 lbs., of sulphate of ammonia per
ton of coal may be obtained. Gas liquor consists in reality of a weak
solution of ammonia, carbonate of ammonia, sulphide of ammonia,
cyanide of ammonia, and sulphate of ammonia. Its nitrogen con-
tent varies considerably, as the following analvsis bv Arnold, in
1889, shows:—

15

226

CHEMICAL MANURES.

TABLE LXVIII.— ANALYSIS OF GAS LIQUOR FROM COALS OF

DIFFERENT ORIGIN.

One litre of gas liquor contains
the following ingredients in
grammes, or 100 gallons con-
tains in lbs.

Total ammonia
Hyposulphite of ammonia
Sulphide of ammonia
Bioarbonate of ammonia
Carbonate of ammonia
Sulphate of ammonia
Ammonium chloride

Gas Liquor from the Coal of

■
Zwickau. Zwiekau.

La Rhur. | La Saare.

La Saare.

12-09
1-036
6-340
1-050
1 4-560
0-462
30-495

9-40
1-628
0-646
1-470
7-680
0-858
17-120

18-12
5-032
6-222
2-450 1

33-120 J
1-320 1
3-745 j

15-23
2 072

2-468

33-763

4-922

3-47

6-296.
1-428

5-856-
1-926

According to the same author, the ammoniacal liquor from a
British gas works contained in grammes per litre (lbs. per -1 00
gallons) : —

TABLE LXIX.— ANALYSIS OF BRITISH GAS LIQUOR.

lbs.

pei

' 100 gallons

Ammonia . . . . .

20-45

Sulphur total

3-92

Ammonium sulphide NH4H5

3-03

Ammonium carbonate (NH^jgCO.

39-16

Ammonium chloride

14-23

Rhodanate of ammonia

1-80

Sulphate of ammonia .

0-19

Hyposulphite of ammonia

2-80

Ammonium ferrocyanide . .

0-41

It will be seen from these analyses that carbonate of ammonia pre-
ponderates ; its percentage of ammonia chloride is likewise high.

Production of Amvionia in the Maiiufacture of Coke. — If in the
very beginning of illumination by coal gas steps were taken to col-
lect the ammonia produced an the purifying of gas delivered for
consumption, it was not so in the manufacture of coke, where this-
body was for a long time totally rejected. The coke industry,
as it is now conducted, yields products identical with gas. The first
attempts at recovery of the ammonia were made by Stauf in 1764: in
a Saarbruck foundry. But it was not until 1858 that Charles
Knab constructed at St. Denis the first plant that gave good re-
sults, introduced by Carves at Commentry in 1762. It was erected
in 1866 at the Besseges Forge, then in 1879 at Terre Noire. In
1882, Simon of Manchester improved the Carves coke oven by
recuperating the heat to reheat the air to 500° C. or 600° C. The
shape of these ovens was completely altered. Knab's ovens, wide
and flat, heated under the sole only, and carbonizing at a low tem-
perature, have been completely abandoned to give place to Carvs,.

NITEOGENOUS MANUEES. 227

Simon-Carves, Otto and Semet-Solvay ovens, high, narrow, long,
carbonizing rapidly and at a high temperature. The furnaces
actually in use may be divided into two classes : —

1. Those which are only a modihcation of the ordinary coke
oven, where the heating is effected by the admission of air into the
interior, and burning a part of their carbon as fuel (Jameson, Aitken,
Luhrmann types).

2. Those in which air is not admitted into the interior, the heat
being applied on the outside by the combustion of the gas which
escapes during distillation, and after separation of tar and ammonia.
Almost all modern coke ovens belong to this class (Hoffmann Otto,
Simon-Carves, Bauer, Hussener, Semet-Solvay, etc., t}^es). Here,
in a few words, is the general principle followed iu coke ovens of
the present day. All are built, apart from numerous details, in such
a manner as to have a hermetically sealed chamber, from which the
gas distilled from the coal is aspirated mechanically without admis-
sion of air. The gas afterwards passes through condensers, cooled
on the outside by air or water, w^here they deposit the greater part
of the ammonia and the tar ; the small remaining portions are de-
composed in the scrubbers (coke columns). The residual gas is then
led to the tuyeres which heat the retorts, and inflamed by means of
a current of hot air issuing from the recuperators. After having
accomplished this heating, the residual gases pass into the heat
recuperators. Certain German coals yield 11 -5 kg. (25-3 lbs.) of
sulphate of ammonia. By the Semet-Solvay ovens, as much as 7 to
17 kg., say 15 to 37'4 lbs., of sulphate of ammonia per ton of coal
distilled are obtained.

The w^orking of these ovens is regulated by various conditions.
The coal introduced into the oven ought, to give a good coke, to be
instantaneously submitted to a very high temperature, and the
calcination ought to be conducted rapidly and without stoppage.
That is w^hy the heat is transmitted by as thin ovens as possible, as
in the Semet-Solvay oven. In the Hoffmann Otto oven the gas
given off by distillation escapes through two orifices in the arch of
the oven and passes into gas reservoirs placed above and across the
ovens ; then it is lifted by aspirators, and drawn through pipes to
condensers and washers, in which the tar and ammonia is deposited.
Freed from these two substances the gas is brought back through
another pipe, under the sole of the ovens. The inflamed gas follows
alternatively vertical flues, ascending one half of the flues and
descending the others. In the Semet-Solvay system the flues in
which the gas burns, and which generally are fitted into the main
flue, are here independent, and consist of retorts with their encased
sides the one in the other, and forming a complete and tight circuit.^

1 The Hoffmaun Otto is 10 metres (say 40 feet) long, 0-4 to 0-6 metres (say
1(3 to 24 inches) wide, by 1-70 metres (say 5 feet 8 inches) high. The Semet-Solvay

228 CHEMICAL MANUEES.

The Carves, the Tamaris, the Terre Noire, and Bessege ovens,
producing together about 300 tons of coke per day, yield 6 tons of
tar and 2 to 2-5 tons of sulphate of ammonia.

The advantages of recuperation become more and more evident,
and in spite of the expense which the installation of such plant
involves, many mine proprietors have not hesitated to build similar

ovens.

The working of a battery of four coke ovens entails a supple-
mentary staff to work the gas-extractor, and to keep in order and
clean the recuperation appliances. The cost of the Semet-Solvay
furnace, refractory masonry with lining, oven discharger, discharger
flue, water piping, etc., is £240 sterling. The extractor, pump, and
recuperation appliances cost £140 sterling. Each oven takes 5
tons of coke ; the operation lasts about twenty-four hours. The
Hoffmann Otto takes a charge of 5 to 6 tons. The use of these ovens
has extended very rapidly in France ; there are at present several
hundreds of them. The Hoffmann Otto are almost exclusively used
in Germany and Austria. The Semet-Solvay are used in Belgium,
in France, Great Britain, Germany and the United States.

Recovery of Ammonia from Blast Furnaces. — The recovery of
the ammonia contained in the gas from blast furnaces is only
carried out in Scotland at Gartsherrie. The coal used is a non-
caking coal, which prevents previous conversion into coke. The
gases escaping from the furnace mouth pass through a series of
pipes into apparatus similar to those used in the gas manufacture,
followed by a series of scrubbers, fitted with perforated plates,
leaving the gas to pass alternatively on each side, whilst a thin
stream of water, constantly flowing, dissolves the entrained ammonia.
The liquid is repumped and sent back to the scrubbers, until suffi-
ciently saturated. The yields are on an average 0*9 to 1-36 of the
weight of the coal, which corresponds very nearly with the
amount of ammonia got by the Carves coke ovens.

Becovery of Ammonia formed in Gas Producers. — Heating by
the gas obtained in the semi-distillation of coal is one of the
best processes now known. It suppresses various drawbacks
incidental to a great number of fires, and enables very high tem-
peratures to be obtained. In this distillation, as in all similar treat-
ment of coal, there is given off at the same time as the combustible
gases a rather important amount of ammonia. To give good results
the production of the gas is effected by alternating the two following
operations : —

1. The vapour of superheated steam is directed on to coal, heated

is 9 metres (say 30 feet) in length, by 1-70 metres (say 5 feet 8 inches) high, and
of a width, varying according to the quality of the coals to be treated, of 0-36 to
0-42 metres (say 14 to 17 inches). The air is heated to 200° to 300° C. (392° to
572° F.).

NITROGENOUS MANURES. 229

to redness, which lowers the temperature, owing to the heat ab-
sorbed by the decomposition of water.

2. The combustion is stimulated by a current of air to bring the
temperature to its initial point.

The gas produced in this second phase very much resembles gas
from a gas generator, called Siemens' gas. The mixture of air and
steam is suitably adjusted. Amongst the gasogene plant constructed
on this principle mention may be made of Siemens', Schilling's,
Powson's, Wilson's and Mond's.

1. Mould's Process. — Mond was the first to inaugurate in
England this new process of extracting ammonia from the products
of combustion of coal itself. Coal is burnt in the gas generator in
a mixture of air and steam, in such proportions that there are two
tons of steam per ton of coal distilled. The temperature of the
combustion is lowered to about 500'^ C. (932' F.). This excess of
steam favours the production of ammonia ; the third only of the
steam which passes through the gasogene is decomposed. The gas
producers are rectangular in form and arranged in series. They are
1-82 metres in depth and 3*65 metres long. The ash pits fitted
with a hydraulic joint capable of resisting 0"10 metre water pres-
sure. The air arrives above the level of the ash pit. The gas
escapes from the centre of the top of the gas producer.

The gas which escapes from the gas producer traverses a w^asher
with blades. Standard type, in which the ammoniacal salts are
dissolved. Then at a temperature of 100'^ C. it passes into the first
scrulDber, drenched with a 38 per cent solution of sulphate of
ammonia to which a known amount of sulphuric acid has been added.

The gas contained at its entrance into the scrubber 0"13 per cent
of ammonia by volume, it now only contains 0"013 when it issues
at a temperature of 80" C. It then enters the condenser
containing wooden battles pierced with holes, where they meet
a current of water which is heated to 78" to 80' C. (172-4' to 176' E.)
in condensing the steam. The gas, purified and cooled, passes to
the burners. The hot water obtained passes to a third scrubber, into
w^hich a current of cold air is passed, which it saturates with mois-
ture, and which brings the temperature to 76° (168'8° F.). That air
is then forced into the gas producer. The yields obtained have
been 32 kg. (70*4 lb.) of sulphate of ammonia per ton of coal, which
is a beautiful result.

Attempts have been made to produce ammonium chloride
direct by introducing hydrochloric acid gas into the furnace or by
mixing the fuel with clay impregnated by calcium chloride. The
results were not satisfactory.

Hennin proposes to operate like Mond, but by using high
pressure steam slightly superheated and suitably diffused in the
mass of the fuel, in the proportion of 0*75 to 1 per ton of coal.

230 chp::\iical manures.

2. Bourgeois and Lencauchez' Process. — Bourgeois and Len-
cauchez have patented a process the object of which is to collect
the tar and ammonia in the gas distilled from coal, this operation
not diminishing the calorific intensity of the gas. The plant which
they propose to use therefore appeals to all industries, glass
works, metallurgical industries, etc., which instead of burning coal
under ovens, begins b}" converting it into gas in any kind of
gas producer. It consists of three main columns. The first, cooling
and washing the gases, is intended to retain tar and oils, which
are collected in a lower cistern. In the second, the gas charged
with ammonia meets a shower of acidulated water. The third is
intended to stop the last traces of ammonia and to convey them into
the first, and so on. From the preceding it will be seen that those
industries which formerlv did not utilize in anv wav the nitrosren
contained in their fuel, are gohig to become one of the most import-
ant sources of ammonia.

Minufacturing Plant. — In the various ammonia-producing
industries which have just occupied our attention, the manu-
facturing plant consists, above all, of condensers and distilling
columns.

Condensers. — The condensers are generally refrigerators, the
extractor, the washing condenser of some kind of system, and the
scrubbers, or coke columns. Refrigerators are used in the manufac-
ture of gas. The issuing gas is aspirated by the extractor, which is
nothing but a suction and pressure pump. There exist a certain
number of washing condensers. The following are mentioned :
The Standard washer, the Chevalet washer, the Lunge Plate washer,
the Pelouze and Audoin washer. The Standard washer consists of
a series of cast-iron compartments, variable in number and dimen-
sions according to the capacity of the plant. Each compartment
contains a certain number of wrought-iron discs bolted together
and locked on the shaft. These discs of thin sheet-iron, 2 to 3 mm.
(yV ^o \ inch), thus present an enormous absorption surface. The
latter traverses the washer in an opposite direction to the gas ; the
discs half dip into the water. An improvement has been made by
replacing the sheets of iron by pieces of wood, cut in the form of
a prism and arranged in quincunxes. This apparatus is almost ex-
clusively used in Great Britain. The washers restore to the scrubbers
their true role, which is to arrest the last traces of ammonia. The fill-
ing of the scrubbers varies much ; sometimes washed coke is used,
sometimes wood shavings, fragments of pumice stones, or of perfor-
ated bricks. The lining ought to be done carefully, for on it gi'eatly
depends the amount of water to be introduced. A driblet of water, weU
spread over well-arranged materials, will give as good an exhaustion
as enormous quantities of water over a bad lining. The water
escaping from the scrubbers should be carefully controlled. The

NITROGENOUS MANURES.

231

'^ Q C5 e5

^ OH

r- a; C oj

'"' ^ CD ^

o

<rj !=! 00

? ® ^ =*=•

=2 -« 35 fl
0^ ^, d ^ 5d

o rt^ -^ o

m "^ «8 S *

^ & c g *

|sti«!

&_o o •-' ^

CO _o -+3 <2j as

- 'Hi ^

O

o

"5 aT-r:! 2 o< S

eg

o

o

H ■ >- '^ O ^

o «e

o

p. O 03 33 r^ °
5 fl

00
l-l

5-i S-l -H

^^ V-/ »-4 i— I ^^

232

CHEMICAL MANUEES.

density of the ammoniacal water ought to be taken, and it must be
seen that the escaping gas contains no trace of ammonia.

Chevalet constructed a scrubber of wrought-iron or of cast-iron,,
containing cast-iron vessels 8 inches apart and pierced with a great
number of holes, carrying a chimney a little less in height than the-

Fig. 39. — Standard Washer furnished with its different Discs. — The upper tigure
shows the outside appearance of the face of the washer ; in the lower figure
the washer is seen from above ; the top side has been partly removed to show
the interior arrangement. The discs of Fig. 38 are sho^Mi mounted side by
side on the same shaft ; their lower part dips in the water when the shaft
turns ; the moistened discs come in contact with the gas which passes to the
upper part. This latter is dissolved. A peculiar system of partitions forces
the gas to enter into intimate contact with the rods of the discs and to
dissolve almost completely.

edge of the vessels. Each vessel is fixed in a ring without bottom
of the distilling column. Between each vessel wooden shavings
or coke is packed.

Distilling Plant. — All methods used to manufacture sulphate of
ammonia consist essentially in disengaging ammonia from its salts^
in submitting it to distillation, in conducting the ammoniacal

NITEOGENOUS MANURES. 233

vapours into a receiver containing sulphuric acid, and evaporating
the solution obtained, so as to extract from it the sulphate of
ammonia by crystallization. The ammoniacal salts are decomposed
by lime which is added to the gas liquor before distillation. In old
distilling plant, working by naked fire, the use of lime required pre-
cautions, because it was liable to adhere to the bottom of the boilers ;
in modern plant heated by steam this drawback has disappeared.
Sometimes the two methods are combined, that is to say, the gas-
liquor is first distilled such as it is, and then it is redistilled after
adding lime. The latter is used either as quick-lime or as milk of
lime, and in quantity varying with the content of the ammoniacal
liquor. But the amount used never exceeds 5 j)er cent of the
material. The distillate consists mostly of a mixture of water and.
free ammonia ; organic bases — the most volatile — are also present
along with tarry matter. As amongst all these bodies ammonia is.
the most volatile, the principle of hot or partial condensation has been
applied to its distillation, a method which is especially important in
the distillation of alcoholic liquids. In the older plant the distillate
traversed one or more vessels containing reheated ammoniacal
liquor. By this arrangement the ammonia was separated from the
less volatile products which condensed on the road ; on the other
hand the ammoniacal liquor was brought to a high temperature
before being distilled. However, this method cannot be adopted
except by working continuously. The plant used in distilling
ammonia may be divided into two classes, viz. (1) nal-ed fire stills
and (2) stecmi stills. Although less economical and of much smaller
output, naked fire stills have still numerous advocates, because their
installation is generally less costly and their management very
simple. A few stills of both types will now be described.

Naked Fire Stills— The English Still. — An old still which is
still in use in certain English factories where it gives excellent
results is that shown in Fig. 40. It consists of a small boiler A,
which is fed with gas liquor from a reservoir. If the liquor be
heated to boiling, the free ammonia, and the carbonate of ammonia,
the sulphide, and the cyanide of ammonium, all very volatile pro-
ducts, are given off with the steam, rise in the pipe a, pass into
pipe g, whence they pass by the pipe c into the lead-lined wooden
vat C containing concentrated sulphuric acid. The latter absorbs
the gas and the vapours with effervescence, which renders them
liable to return into the chamber A. To avoid this mishap a valve
li is fitted to the tox^ end of the pipe c, which opens from the out-
side to the inside and lets the air enter as soon as the acid begins
to rise in c, i.e. as soon as the pressure in the apparatus is lower
than the atmospheric pressure. When the operation is thought to
be sufficiently far advanced, the test tap d is opened and the
vapours coming from the boiler are tested with red litmus paper

234

CHEMICAL MANUEES.

to see if they still contain an important proportion of ammonia.
If the test shows that the liquor is exhausted it is run into the
boiler B, placed at a slightly lower level alongside the boiler A.
With this end in view the boiler A communicates on the opposite
side with the boiler B by a pipe d (Fig. 41), which is naturally at
a level high enough not to be reached by the fire. It suf&ces to
open the taps e, f, i, and A-. Milk of lime is added in the boiler B
to the water from A. The boiler A is recharged, and the taps i and
h being closed, the contents of the two boilers are brought to the
boil, whilst the same process goes on as already described in the
boiler A ; pure ammonia gas is formed in the boiler B as the result
of the decomposition by the caustic lime of the chloride and sulphate
of ammonia still contained in the water which had been treated in
A. This gas also passes into the vat C ; when a test at the test-tap

Fig. 40.— Naked Fire Ammonia Still.

shows that all the ammonia is volatilized, it is presumed that the
water in the boiler B is exhausted and is run off. For that purpose
the pipe d is fitted with two short pieces m and I closed with
wooden plugs. To run off the liquid all that has to be done is to
open them as well as the tap A'. Ammonia can also be distilled in
a single boiler, taking care to mix the milk of lime with the gas
liquor beforehand. As the residual liquid would then contain
not only chloride and sulphate of lime, but also carbonate of lime
and various other salts, and as the mass of these insoluble salts
would greatly hinder distillation, it is better to use two boilers,
besides the sides of the boilers would become encrusted with lime
salts and rapidly put it out of use. When the sulphuric acid in the
vat C is saturated with ammonia it forms a fairly concentrated
solution of sulphate of ammonia. In the first phases of the opera-
tion this acid is greatlv diluted bv the steam mixed with the vapour

NITEOGENOUS MANUEES.

235

of ammonia, but as the acid heats considerably, the steam traverses
it without combining with it. The solution of sulphate of ammonia
is not, however, concentrated enough to crystallize on cooling, that
is why it is evaporated in flat becks of lead, iron, or wood heated by
■s, closed coil. This operation must be done with care. Under the
action of heat the organic matter contained in the solution exercises
a reducing action on the sulphate of ammonia ; ammonium sulphite'
hyposulphite and sulphide of ammonium are formed, two substances
which strongly attack the metal of the apparatus ; as, moreover, this
reduction gives rise to a great loss of ammonia in the form of am'-
monium sulphide which is very volatile, the workman ought to
moderate the heating as soon as he perceives the smell (of rotten
eggs) of this latter product. Evolution of (NH^)oS or H.,S infringes
the alkali act. When the solution is sufficiently concentrated it
is run into iron tanks, where the ammonium sulphate is deposited
as it cools. The mother liquor which flows from the crystals
still contains an important proportion of ammonia. Sulphuric
acid is added to it and it is again distilled ; finally it also can
be evaporated and recrystallized. The mother liquor from this

D

Fig. 41. — Details of Pipe commuuicatiiig with the two Stills of Fio-. 40.

second evaporation contains too many impurities again to yield sul-
phate of ammonia by crystallization. However, it still contains a
notable proportion of ammonia in different bodies derived therefrom,
that is why it is run into the boiler B to extract the ammonia by
distillation after adding milk of lime.

Mallet's Still. — This still is shown in Figs. 42 (front view) and
43 (longitudinal section of one of the batteries). It consists of two
batteries of stills AB, BB, CC, DD, which work parallel and impart
to it, as will be seen further on, great capacity of production. The
stills A and B are fitted with a perforated double bottom, in which
the ammoniacal liquor, to which milk of lime has been added, is
brought to the boil. They are fitted with an agitator to keep the
liquor in motion, to prevent it from adhering to the bottom. The
ammoniacal vapours given oft' from these stills pass into the stills
C and D, likewise filled with ammoniacal liquor, where they are
washed to deprive them of their elements more volatile than
ammonia. From the still D they pass into a coil 25 m. (82 ft.) long,
the spirals of which are contained in the receiver F, where they are

,236

CHEMICAL MANUEES.

cooled by ammoniacal liquor. The condensed ammonia flows into
the vessel S, and from there into the collecting reservoir Y.
The uncondensed vapours pass through a pipe, traversing the lid
of the vessel S into an air refrigerator T. From there into the
pipes U, fitted with a safety arrangement, which sends them into
an absorption vessel placed behind E. The unabsorbed bad-smelling
gases are absorbed by special arrangement. We have followed
the progress of the ammonia driven off from the liquid under the

^

;y;^VN\ ^,\\x^\\^^^^^^^^^^^^^^\\s\N'\\\x\\N v ,

' .\XV-\N\\\\\V

~\\x^^x\\\\\\\\\x;■^^^^\^x<-x\^^\\\v^^^\\s^^^!

V//////'/.- /////////////////////■////////////////

■■//:■//////''///.■

- //////////////////////////////////////////////■

Fig. 42. — Mallet's Ammonia Still (front view).

influence of heat ; let us now follow the inverse movement, i.e. that
of the ammoniacal liquor used to feed the stills. This ammoniacal
liquor is contained in a reservoir higher up, whence it passes into
the measuring vessel G, through tap a ; from that apparatus it first
passes into the condenser F, where the steam brought by the coil
gives up its heat to it and warms it; the ammoniacal vapours given
off rise into G by the pipe P. The stills A, B, C, and D are fed
by communication pipes not shown in the illustrations. As already

a
o

o

72

a
o

S

g
<

a)

CO

6

M

238 - • CHEMICAL MANUEES.

said, the ammoniacal vapours formed in the pans A and B pass into
C and D, then into the condenser. The milk of hme is prepared
in the reserv-oir E, whence it passes into the still B by the pipe
M. The still A is emptied from time to time, say every three days ;
the discharged liquid is then replaced by an equal quantity of
ammoniacal liquor coming from the stills B, C, and D. The con-
densed water in the vessel Y may be emptied into the vessel D
throuo-h the pipe 0. For that purpose the three-way tap Z, which
brint^s two of the pipes entering D into communication, is fixed in
the rit^ht place for the ammoniacal vapours not to pass into the
refrigerator F, but into the reservoir Y.

The absorption vessel is lead lined and filled with the sulphuric
acid intended to make sulphate of ammonia. The latter is put to
drain in E, the mother liquor flows into X, and thence into the

absorption vessel.

The air refrigerator T is only used when it is desired to make
liquor ammonia. In the manufacture of sulphate of ammonia it
is replaced by a cylinder 10 ft. high and 20 in. in diameter, into-
which the pipe bringing the ammoniacal vapours dips, until just
above the bottom. By fitting the cylinder with an overflow pipe,
matters are so arranged that it is always one-third full. The water
from the overflow pipe flows into the collecting vessel Y. The
furnace is shown in Q. The combustion gases first impinge on
the still A, and then pass under the still B. The Mallet stills at
work at the Yillette Gas Works produce 10 tons of sulphate of

ammonia dailv.

Lunges Still. — This still is based on the same principle as the
preceding, but it is much more simple ; a is the still, b is the pipe
leading the vapours to the condenser c. The refrigerator d is fed
by ammoniacal liquor ; it communicates with the still by the pipe
e. The contents of the still may be run out by the pipe /, which
is closed when the still is at work by a valve g. The lime which
is deposited at the bottom of the boiler is again brought inta
suspension by the agitator //. The tap on the pipe i is opened
when the liquid from the refrigerator d is heated to the point of
giving off ammoniacal vapours ; the latter pass through i into the
pipe "^h, and afterwards into the coil c, mixing with the vapours
coming from the still a. When the vapours have traversed the
washer h thev pass by the pipe m fitted with a safety arrangement
into the lead-lined wood absorption vessel /, containing sulphuric
acid to absorb the ammonia. The acid flows from the reservoir o
throucrh the syphon }) into the absorption vessel I. Its arrival
is regulated so "^that the liquid in the absorption vessel is always
acidf The vapours given off collect under the hood r, whence they
are forced into the chimney or burned in the furnace. The sul-
phate of ammonia deposited at the bottom of the vessel / is emptied
bv a bucket hung to a chain and counterpoise t.

240

CHEMICAL MANUEES.

Steam Stills. — The intermittent, naked fire stills have been
replaced by continuous stills fitted with a rectification column
similar to those used in alcohol distilleries. Such a column, the
working of which is uniform and continuous, renders it possible
to work much more economically. *• Amoncrst the best known stills

^1

^

1

i

:l^

www^mwwwwwm

Fig. 45. — De Lair's Still.

A. Distilling column composed of circular segments of cast-iron. B. Milk of
lime mixer. C. Milk of lime pump. D.D. Exchange heaters. Entrance
of milk of lime into column. E, Gas escapement.

of this nature, those of De Lair, Feldmann, and Gruneberg may be
quoted.

Feldmann s Still. — The ammoniacal liquor contained in a
reservoir a flows into a measurer h, passes through the pipe c
fitted with a valve r into a tubular reheater j, rises through d
into the rectifier A, and meets the vapours which deprive it of all

NITEOGENOUS MANUEES.

241

volatile ammoniacal compounds. Finally it arrives in the de-
composition vessel B, into which milk of lime contained in the
vessel H is run from time to time by means of the iximp G and the
pipe n. The ammoniacal compounds which have resisted the action
of steam are decomposed in B, where the liquid is kept in motion
by a jet of steam injected through the pipe j;. The ammoniacal
liquor treated by the milk of lime, the non- volatile elements of
which are thus entirely decomposed, flows out in a continuous

Fig. 46. — Feldmarm's Ammonia Still.

mx^:^N^^^\^^^>-

manner through the pipe e into a small column C, where the free
ammonia is volatilized. The water, completely exhausted, collects
in D fitted with a water level q, and flows in a continuous fashion
into /. The steam enters all the parts of the apparatus by the
pipe g, fitted with a valve g'; it passes through the column C, the
pipe h and the column A, the pipe i, and finally charged with
ammonia it enters the saturation vessel F, filled with sulphuric acid
and cooled bv the water of the reservoir E. The gases not absorbed

16

242

CHEMICAL MANURES.

in F, viz. steam, COo, H.,S, are led by the pipe k into the tubular
reheater J, where they transfer their heat to the ammoniacal liquor.
The sulphuric acid contained in the vessel F is sufficiently concen-
trated for the sulphate of ammonia formed to precipitate completely
after saturation. The disengagement of heat accompanying the
combination of ammonia with sulphuric acid gives rise to very
energetic evaporation, which considerably facilitates the precipitation
of the sulphate. Feldmann's stills work very economically and are
very much used in Germany. A large-sized still of this type distils
4J:,600 gallons of ammoniacal liquor in twenty-four hours.

Fig. 47. — Gruneberg and Blum's Ammonia Still.

Gruneberg and Blum's Still. — The liquor first passes into a
tubular reheater B through the pipe a ; it then ascends into the
column A in E by the -pipe h ; it descends the column from plate
to plate to meet the steam ; then it passes through the pipe e into
the boiler F, which contains milk of lime, where the combined
ammonia is liberated. The liquid which fills the boiler F rises
above the level of the pipe /, flows into the mud pocket g, passes
out at h, spreads over the gradations of the column i, and runs
away by the pipe h and the orifice t.

NITROGENOUS MANURES. 243

In the boiler G the water which only contains a portion of the
ammonia liberated by the lime comes in intimate contact with
the steam, which is injected through the perforated coil d. The
steam forced by the concentric sides of I to rise along the gradations
of the column becomes charged with the ammonia it meets, and
passes by the pipe m into the pipe n, which forces it to traverse
the liquid of the milk of lime chamber. The ammoniacal vapours
afterwards rise into the rectifier, and finally when they are entirely
deprived of water they pass through the pipe j) into the saturation
vessel D. The bad-smelling non-condensable gases are collected
in the bell q, whence they return through r and s into the reheater ;
finally they are burnt in a special furnace. The milk of lime is
injected by the pump C into the still through the pipe c. Stills of
this type have been installed capable of treating 5500 to 7920
gallons of ammoniacal liquor in twenty-four hours. They work
•economically and require little superintendence.

Bemarks. — Continuous stills should be entirely of cast-iron.
Copper and bronze should not be used, for they are rapidly corroded
hj the ammoniacal vapours. The presence of ammonium sulphide
in the ammoniacal liquor is very annoying in work. This body
gradually corrodes even cast-iron vessels. Therefore, iron reservoirs
are sometimes replaced by cement ones. According to Kunheim,
gas liquor may be freed from sulphur by a strong current of air,
the effect of which is to decompose the ammonium sulphide into
H2S and NH3.1

Manufacture of Suljjhate of Ammonia from Urine. — Amongst
organic matters putrid urine is one of the most important sources
of ammonia. The putrefaction of urine gives rise to the formation
of carbonate of ammonia, seeing that urea C0N.2H^ contains two
molecules of water. An adult produces on an average 30 grm. of
urea, which corresponds to an annual production of 24-2 kg. or
■53'2 lb., nearly ^ cwt., of sulphate of ammonia.^

As the carbonate of ammonia is very easily decomposed into
CO2 and NH3, it has been thought advisable to utilize it in the
manufacture of sulphate of ammonia. Figuera used the following
apparatus for the purpose. In the furnace V is the boiler W, which
propels steam into the wrought-iron cylinders C C containing about
100 hectolitres (2200 gallons) by the pipes T and T'. The two
cylinders are charged with putrid urine. The ammonium carbonate
vaporized passes by T" into the lead coil e in vat A ; it condenses
with the water and passes in the state of solution into the vessel S
filled with sulphuric acid, where it is converted into sulphate of

iBut ammonia distillers are prohibited in Great Britain from letting
HgS escape. — Tr.

2 Say, for the whole 5,000,000 odd population of London, 2,500,000 cwt. of
sulphate of ammonia, worth say £1,250,000, run into the Thames and carried
out to sea armually. — Te.

244:

CHEMICAL MANUEES.

ammonia. The liquid used to cool the coil in the vat A, containing-
about 250 litres (55 gallons), is putrid urine, which thence passes into-
the cylinder C ancl C by a pipe not shown in the figure. The
boiler^ W contains the hot liquor not entirely exhausted from a
previous distillation which still contains a small proportion of NHg..
The pipe T leads the steam into the vessel C ; m is a pipe which
dips a little above the bottom of the boiler whilst its other end passes,
outside the factory roof ; n is a safety pipe which indicates at the
same time (by the ascent of balls of froth) if the level of the liquid
has lowered to the end of the tube m ; o is a discharge pipe. The
vessels P and P' are to retain the abundant froth which would
otherwise contaminate the distillate. To ascertain the level of the
froth in the vessels P P', these are fitted at different heights with
three lateral apertures closed by wood on plugs, through which the
froth flows when the plugs are removed ; when the distillation which

■piG. 48.— Figuera's Plant for Extraction of Ammonia from Urine.

lasts about twelve hours is finished the boiler o is emptied and again
filled with the urine contained in C C.

Utilization of Peat in the Manufacture of Ammoniacal Salts.—
Eor some years greater and greater efforts have been made to
utiHze peat in the manufacture of sulphate of ammonia. The
abundance of the raw material, its cheapness and the facility of its
extraction, and finally the unlimited outlet for commercial nitrogen
as manure, are all factors which are in favour of the use of peat.^

Numerous x^rocesses have been invented for the extraction of
nitrogen from peat. (1) In that of Van Heefien (1905) the pulver-
ized "substance washed with HCl, then with ordinary water until

1 Deposits of peat are by no means so extensive as generally imagined. There
are few peat mosses that would keep a distilling plant of large capacity at
work for a couple of years. Peat company promoters would lead us to believe^
that every bog was a peat moss and a mass of solid peat. — Tr.

NITEOGENOUS MANUEES. 245

neutral, is placed in the receivers arranged in diffusion battery style,
where they are methodically exhausted by water charged with
ammonia, which facilitates the solution of nitrogenous matters. The
gas is extracted from the final product for re-use. But only
nitrogen in humic acid combination is obtained, which restricts
its use in the manufacture of chemical manures, and the value of
which does not exceed that of organic nitrogen {vide infra). The
value of the organic nitrogen of manures is increased by converting
it into ammoniacal compounds. Eickmann, D.E.P. No. 8238, sub-
mits peat previously heated to from 350'' C. to 800° C. to the action
of a mixture of air and steam ; but, as already mentioned, a great
part of the ammonia is destroyed at such high temperatures, so
•that the yield is very poor. Waltereck, French patent 345,399,
obtains better results by heating peat mixed or not with other
carbonaceous matters to a maximum temperature of 300° to 500° C,
at which the mass is not incandescent. The mixture of air and
steam heated to 300° C. (572° F.) is brought in contact with the
peat in vertical iron retorts surrounded by refractory stones. The
temperature of the mass rises naturally up'^to 400° C. (752° F.) ; the
heating of the arriving gas is stopped, the heat produced by the
reaction being more than sufficient to maintain the heat at a suit-
able degree. The arrival of the air is so timed as to oxidize com-
pletely the carbon of the charge in three to six hours. The quantity
of steam should be proportional to the temperature. The inventor,
cert, of addition No. 6407, has been enabled to suppress all fuel by
replacing the steam with very finely pulverized water in the current
of air injected. The ammonia is extracted from the combustion
gas by cooling with or without bubbling ; ammoniacal liquors are
thus obtained utilized as usual. As Muntz and Laine have deter-
mined, yields much superior to those by dry distillation have been
obtained where the coke retains 1 per cent of nitrogen ; a peat con-
taining 2 per cent of nitrogen abandons 1-6 to 1^8 per cent in the
ammoniacal liquor.

Muntz and Girard distil peat (previously dried and crushed i)
in a current of superheated steam. Water gas, mixed with am-
moniacal vapours, tars, pyroligneous products, are produced. The
combustible gas is used to heat the retorts ; the distillation products
treated by bicarbonate of soda residue from the extraction of the
ammoniacal liquors yield NH3 and COo, re-entering into the manu-
facture ; and acetates of lime and soda, methylic alcohol, and analo-

^ The diying of peat is a costly item even ^Yhen air dried. But here in wet
seasons in many peat districts it cannot be air dried ; resource must therefore be
had to artificial diying, and the whole manipulations— making and maintaining
i-oad to moss, casting, spreading, turning, cocking, carting, stacking, and crushing
the peats— bring peat too near the price of coal for its treatment to prove re-
munerative.— Tr.

246

CHEMICAL MANUEES.

gous products, accumulate iu the mother Hquors of the bicarbonate
of soda, from which they are extracted by distilUng the mixture of
alcohols, NHo neutralizing NHg, and then redistilling. ' Finally,
the residue from the distilled peat may be used as a substitutejfor
animal charcoal in the manufacture of clarifying and purifying
filters. The ammonia is present in the ammoniacal liquors more
especially as carbonate.

Fig. 49. — Gaillot and Brisset's Oven for Eeeovering Ammonia from Peat.

Gaillot and Brisset convert the organic nitrogen of peat' intc
ammonia by slow comJDUstion. The dry or moist peat — pure or
mixed with other nitrogenous matter — is crushed then fed into the
hopper A of the oven (Fig. 49). The bottom of the hopper consists of
a grating of flat rotary bars after the style of the laths of a metallic
Venetian blind, in such a way that if it be turned on its axis the
charge passes entirely into the oven, which is at once closed. The
combustion of the peat is fractionated into two stages ; at first it

NITROGENOUS MANURES. 247

passes from the top of the furnace into the distilHng zone, where it
is dried and then heated to convert it into a sort of coke. The gases
produced charged with steam ammonia and tar pass into h. The
barred grate C enables the admission of the incandescent coke into
the zone of combustion to be regulated — a real furnace, where the
peat burns before passing to the ash-pit. The ammoniacal gases,
dry and very hot, pass out by the pipe utilized as a heating surface
for the concentration of the ammoniacal liquors. Dampers F as
well as shaking grates C and E enable the progress of the combus-
tion to be regulated.

Been Iteration of the Ammonia. — For the manufacture of fertilizers
it is advantageous to substitute for simple condensation a method
of fixing the ammonia in a form immediately utilizable as a manure.
The porosity of peat gives it a considerable absorptive capacity.
Bacqua and Lorette use it to absorb the ammonia from the distilla-
tion gases. These pass into chambers containing perforated boxes
arranged as bafHes and filled with a mixture of peat, sawdust, and
sulphuric acid, and are there deprived of all their ammonia.

Gaillot and Brisset use pure peat impregnated with acid solutions
or mixed with superphosphate of lime as an absorbent. Their re-
cuperator (Fig. 49) consists of a tower K, divided into ten stages by
wide oscillating flat bars driven independently, so as to be able to
regulate from the outside the forced methodical circulation of the
absorbent of whatever nature it ma}^ be. The arrivals respectively
of the hot and cold gas produced in their ovens already described
are in G and H at heights calculated so that the space H I is
sufiicient for the gases escaping by the chimney I not to contain
more than traces of ammonia, and that the path G H suffices to dry
perfectl}^ the manure reaching the discharge door of the oven L.

Muntz and Girard collect ammonia by condensation and
bubbling, purify the ammoniacal liquors by distillation, then treat
them by NaCl. Ammonium chloride and insoluble bicarbonate of
soda are obtained ; the carbonation is finished bv a current of carbonic
acid from the residual bicarbonate, then it is filtered. The calcina-
tion of the product enables the ammonia to be recovered, and gives
COo utilized for the next carbonation. The filtered solution con-
tains an excess of NaCl and ammonia, as ammonium chloride and
carbonate. The carbonate is separated by distillation, and calcined
at a higher temperature. NaCl equally soluble in the hot state as
in the cold crystallizes ; it is separated, and there is finally obtained a
very concentrated solution of ammonium chloride, which is crystal-
lized. The product may afterwards be refined or used directly as
manure.

Manufactiire of Sidphate of Ammonia from Peat by the Mond
Process. — After numerous unfruitful experiments on the utilization
of peat, Dr. Caro has applied the Mond process, by which poor coals

248 CHEMICAL MANUEES.

are utilized, not only to produce gas to drive motors, but also to
utilize their nitrogen as sulphate of ammonia by giving to the gas
producers an appropriate arrangement. Experiments made in this
direction at Stockton by Mond for the utilization of peat have given
very satisfactory results, and as a sequel to these an experimental
factory was installed in Germany capable of treating 50 to 60 tons
of humid peat daily. That factory commenced to work in 1908 by
utilizing 350 tons of peat placed at its disposal by the Prussian
ministry of agriculture. The peat, a portion of v^hich had been
delivered as far back as 1907, and another part in the spring of
1908, after having been kept in the open air was very wet ; certain
parts showed a percentage of 42*47 per cent of water, others 65*70
per cent. The average percentage of nitrogen calculated on the
dry sample w^as 1-05 ; the percentage of ash was, on an average,
3 per cent with the daily treatment of 45 tons of peat with 42 to
47 per cent of water. 1000 kg. (one metric ton) of dry substance
yielded in the gas producer 2800 cubic metres of gas, containing
17'4 to 18*8 per cent of carbonic acid by volume, 9*4 to 11 volumes
per cent of carbonic oxide, 22*4 to 25*6 volumes per cent of hydrogen,
2'4 to 3*6 volumes per cent of methane, 42*6 to 46*6 volumes per
cent of nitrogen, and only traces of oxygen. The combustible
elements of the producer gases rose, therefore, to 36 to 39, and
their calorific intensity was, on an average, 1400 calories per cubic
metre. For peat, with 65 to 70 per cent of water, the percentage
of carbonic acid and the volume of gas was higher, but the total
amount of combustible elements fell to 28"6.^ Now, as the gas from

^It cannot be too much insisted upon that there is peat and there is
peat. On the one hand, it may approach lignite, but peat of that nature only
occurs in pockets and is the remains of buried timber, etc. Again, there is the
fibrous sphagnum peat of bogs, the moss litter style of peat, which holds water
like a sponge, and which when cast contains 200 to 300 per cent of water, and
which when dry shrinks to about a quarter of its bulk. This is the most widely
distributed form of peat, but even it is not distributed to the extent imagined.
If any of those inclined to invest in peat companies saw the gap made in a peat
moss by the extraction of 300 tons of dry peat, they would more than hesitate.
But when the average investors see an analysis of peat with 2*8 nitrogen
par cent = 3-4 per cent of ammonia, closely approaching that of bones, they
begin to imagine what a grand thing peat is and what a wonder it has never been
utilized before. The fact of the matter is, however, that every now and then
history repeats itself, and there is a rejuvenescence and recrudescence of peat
patents, so that now in 1910 we may exclaim' with the editor of the " Chemical
News " in 1860, " yet another peat patent ". But if matters have improved in
extracting ammonia and gas from peat since 1860, so also have methods im-
proved in regard to coal, and it is not a question of the products that can be got
from peat nor of their calorific strength alone, but it is a question of the cost of
production. The Stockton experiment is out of the reckoning altogether, and it
is not fair to compare gas and ammonia from peat by the water gas process with
the same from coal by coke ovens. The author has himself shown that Mond
obtained 32 kg. of sulphate of ammonia per ton of coal. With his process
applied to peat 40 kg. were obtained, calculated to the dry peat, or about half that

NITEOGENOUS MANUEES. 249

Wast furnaces, with 20 per cent of total combustibles, are still
iitilizable to drive gas engines, the gas, with 28*6 per cent of com-
bustibles, yielded by such a wet peat might also be used to drive
explosion motors, and, with greater reason, for heating. A measured
sample of the normal gas, with 36 to 39 per cent of combustible
elements, was taken to a 50 H.P. gas motor, fitted with a Prony
brake, and it was found that for one effective H.P. it was necessary
to use 2-4: cubic metres. Tar dust was almost completely absent.
As 1 ton of peat yields 2800 metres of gas, that gives a yield of
1160 horse-hours, and as the gas, escaping at 500° C, suffices to
produce the steam required for the producers, and as the air-pumps
:and water-pumps, as well as the scrul^ber, require little force, one
is safe in counting on a yield of 1000 horse-hours per ton of dried
peat, that is, on an amount of energy- sufficient to combine 50 kg.
(say 1 cwt.) of atmospheric nitrogen under the form of cyanamide of
•calcium, CaN^Ho, or from 16 to 20 kg., 35-2 to 44 lb., of nitric
acid.

But the agricultural utilization of peat is still more advantageous
if the ammonia be extracted from the gas generated in the gas pro-
ducers. If all the organic substance of the peat be gasified in
a mixture of air and superheated steam, a hydrolysis of the nitro-
.genous substances of the fuel is produced, i.e. of the peat, and this
hydrolysis is so energetic that, if the gas be washed in a sulphuric
acid scrubber, 77 to 80 per cent of its nitrogen is obtained as
sulphate of ammonia. The peat burnt at Sodingen which contained
I'Oo per cent nitrogen gave an effective yield of 40 kg. (88 lb.) of
■sulphate of ammonia per ton. A small lot of peat — gasified in the
"Stockton factory — which contained 2*8 per cent of nitrogen in the dry
substance gave likewise, according to the experiments of Dr. Caro, as
much as 110 kg. (242 lb.) of sulphate of ammonia per ton, whilst coal
generally contains 1 per cent of nitrogen. No account was taken
■of the secondary products of the combustion of peat tar for instance,
which is obtained in somewhat important quantity, as well as acetic
acid and wood-spirit, because time was awanting to estimate the
Talue and importance of these bye-products, and afterwards because
it was thought that the gasification of peat would not develop on a
large scale unless the two chief products which it yielded, motor gas
and sulphate of ammonia, offered sufficient profit without it l^eing
necessary to instal complicated equipment for the treatment of the
bye-products. If afterwards the treatment of the bye-products ap-
pears to be profitable, it is believed that it will always be time to
examine it, but at the present it has not been taken into account.
'To finish, let us quote an arrangement for the extraction of ammonia

•on the wet peat. It would thus take 100 tons of the weather wet peat to produce
•a ton of sulphate of ammonia, — that is, 8 tons of this weather wet peat had to
ibe treated to produce £1 worth of sulphate of ammonia. — Tr.

250

CHEMICAL MAXUEES.

from combustion gases, which is the subject of the American patent
816,035 of 5 March, 1907. The hot gases from the combustion
products of coke ovens, etc., enter by a tube A into an apparatus con-
taining the tubes of a refrigerator B, and from there into a second
refrigerator D, by the pipe C. A pump G aspirates the cooled gas
from the refrigerator D by the pipe F, and propels them into the
tar separator H. The gases freed from tar return by the pipe I
into the refrigerator D, and from there by the pipe K into the re-
frigerator B. In the refrigerators B and D the gases are reheated
by the hot gases which enter by the pipe A and surround the
tubes. Prom there the gases pass through the pipe L into an acid
tower M, which is filled with coke or analogous matter, on which
a reservoir N delivers acid as a fine rain. The gases thus freed
from their ammonia pass through a pipe 0, into a refrigerator P,
and can then be used for different purposes. The ammonia ex-
tracted from the crude gas and combined with acid is absorbed in
the refrigerator D at the same time as the water. The liquid
separated in B and in D is evacuated by the pipe Q into the reser-

Fig. 50. — American Plant for Recovery of Ammonia from Combustion Gases.

voir B, and from there it is directed into a distilling apparatus S.
In that apparatus it is distilled by steam over milk of lime ; the
ammoniacal vapours pass by the pipe T into a saturation reseiToir
U, which is fed at the end of the pipe Y with liquid formed in the
acid tower M. The sulphate of ammonia which is deposited on the
bottom of the apparatus U is evacuated in a continuous manner by
the injector W. The residuary water from the still is conducted by
the pipe W, terminated in the form of a rose, into the chimney X,
the draught of which is stimulated by the fan Z. Sulphate of
ammonia obtained by the processes described is the only kind
used in agriculture. According to its percentage of moisture it con-
tains 20 to 21 per cent of ammonia, which corresponds to 77 to 93 •2
per cent of sulphate of ammonia, or of 16*5 to 19'8 per cent of
nitrogen.

Crude Ammonia from Spent Oxide. — The material used to-
purify coal-gas also contains spent oxide, and furnishes a product
called crude ammonia {criid d' ammoniac). Although ammonia can
be extracted from it in the pure state by treating it like gas liquor,
generally it is simply concentrated 'by evaporation. A product is

NITEOGENOUS MANUEES. 251

then obtained which should only be employed as manure with
great precautions. Some years ago Maercker analysed a product
of this kind, under the name of crude ammonia. He found the-
following products : —

TABLE LXX.— ANALYSIS OF SPENT OXIDE FEOM GAS WORKS.

Moisture ....

Sulphate of ammonia

Insoluble nitrogen compounds

Ferrous sulphate .

Sulphur . . . •

Cyanogen compounds

Ferrous oxide and ferrous sulphide

Lime organic matter

Sand, clay, etc.

Per cent.

8-7
17-8 = 5-3 per cent nitrogen.

5-4 = 1-8
15-6
10-7

1-2
22-3
14-8

3-0

100-0 containing 7-1 per cent N.

Amongst these compounds the sulphate of ammonia is the only
fertilizing material; the insoluble nitrogenous compounds, the
sulphur, the lime, the sand, the clay, are inert materials ; whilst
the ferrous sulphate, the sulphide of iron, and the cyanogen com-
pounds, are plant poisons. These substances should not be em-
ployed as manure under any pretext. ^

Another crude ammonia of this nature exceedingly dangerous,
and also from an English source, and put on the market under the
name of brown sulphate of ammonia, was analysed by C. Schuman..
This product contained : —

Water

Per cent.
4-86

Sulphate of ammonia . . • 14-87 = ^ 3-15 per cent nitrogen.
Ehodanate of ammonia . . 73-94 - 27-24 ,, „

Sand 6-23

99-90 with 30-39 per cent N.

The rhodanate ^ammonium sulphocyanide] contained therein is
exceedingly poisonous to plants, and before using it, it is necessary
to ascertain if it is exempt from this body.

The departmental laboratory of Chalons-sur-Marne analysed m
1907 a somewhat large number of crude ammonias from different
sources. The composition of some of the samples examined is given
in the following table : —

1 Green vitriol has been used as a manure for stimulating etiolated plants
for nearly a century. — Tr.

252

CHEMICAL MANURES.

TABLE LXXL— PERCEXTAGE OF DIFFERENT XITEOGEX COM-
POUNDS PRESENT IN A SERIES OF SAMPLES OF SPENT OXIDE
FROM GAS ^YORKS.

Total
Nitrogen.
Per cent.

Nitrogen
Soluble in

Water.
Per cent.

Aiiimoniacal
Nitrogen.
Per cent.

Nitrogen of

Sulphocvanic

Acid.

Per cent.

Insoluble
Nitrogen.
Per cent.

Moisture.
Per cent.

1

2-69

0-817

0-22

0

1-87

25 -.52

2

.5-61

1-718

1-01

0-157

3-93

14-95

3

2-96

0-89

0-37

0

2-07

2-52

4 '

7-08

4-32

2-89

0-789

2-76

15-68

5

3-80

0-198

0-181

0-068

3-61

12-68

6

3-15

0-396

0-321

0-044

2-76

3-20 .

7

2-7.5

0-396

0-07.5

0-o07

2-36

11-88

8

5-24

1-519

0-922

0-307

3-73

20-40

9

4-19

2-24

1-19

0-832

1-95

17-32

10

2-56

1-38

0-498

0-540

1-18

4-60

11

6-40

2-90

0-915

0-498

3-50

16-14

12

8-04

4-29

1-547

1-210

3-75

24-57

13

.5-43

1-58

0-99

0-195

3-85

5-72

14

9-70

6-34

4-185

0-950

3-36

5-74

15

6-60

4-42

2-51

1-198

2-18

10-41

16

o-BO

1-58

0-697

0-535

5-02

22-67

This table shows that the composition of these crude wastes is
very irregular. There seems to be no relation between the different
forms of nitrogen to be met with therein. Their appearance, smell,
and moisture vary exceedingly, some black, others brown, whilst
others present a whole play of colours, from deep blue to almost black,
to greenish-blue. Sometimes the smell is sulphurous, sometimes
cyanic, at other times the smell of benzine or tar predominates.
Their consistency is generally pulverulent, sometimes, however, it is
damp, pasty, and manipulated with difficulty. All these variations
are explained by recalling the origin of the crude, which is a material
for purifying coal gas. Ammoniacal compounds, sulphides, cyanides,
come from the gas, also naphthalene and tarry matter varying in
proportion according to the coal used and also according to the
arrangement of the purifiers, because efforts are made to retain the
ammonia and the tar before they reach the crude. The matter
used to retain the impurities is not always the classic lime and
sulphate of iron, green vitriol, which yields sulphate of lime and
oxide of iron ; the inert absorbent, generally sawdust, sometimes
consists of shavings, or again of earthy matter. The gasworks
which delivers the waste has therefore a great influence on its com-
position, and this influence farther increases by the care taken in
storing the material as it comes from the purifiers.

NITROGENOUS MANURES. 255

Commercial Sulphate of Ammonia. — Commercial sulphate of
ammonia contains in round figures 20 per cent of nitrogen.
Generally 24-5 per cent of ammonia, the term used in Great
Britain, is guaranteed ; however, there is generally found salts up tO'
25 per cent of ammonia. ^ When pure, sulphate of ammonia is white,
but it generally contains traces of tar or its derivatives. The yellow
colour is often produced by the presence of arsenious sulphide,
the green coloration by cyanide of iron, but these colours dis-
appear on drying. It is known that ammonia is converted in the
soil by a ferment into nitric acid NH3 + 40 = HNO.3 + Hp, but
this nitrification is only possible if the sulphuric acid of this salt be
combined with lime. Commercial sulphate of ammonia should be
neutral and contain as a maximum 2 per cent of water ; when it
contains only 1 per cent of rhodanate of ammonia (NH^SCN),
ammonium sulpho-cyanide, it is injurious to plants, according to-
Maercker. But these impure products are no longer manufactured.
Sulphate of ammonia is dried in a steam dryer, crushed in ball
mills with a No. 50 sieve or in Carr's disintegrator. Bags which
have contained sulphate of ammonia, like nitre bags, are dried and
cleaned bv beating or bv washinc^ with water ; the wash water, if it
be not desired to evaporate it, is sent to the concentration pan.

As already mentioned, the strength of sulphate of ammonia may
be expressed in two ways. In France it is customary to give the
percentage in nitrogen ; in other countries, especially in Great
Britain, it is given as ammonia, so that the same sulphate has a
strength 21'21 per cent or 25-75 per cent according to the designa-
tion adopted. To prevent any confusion, it suffices to multiply the
strength in ammonia by the nuinher 0'8235 to obtain the correspond-
ing p>ercentage of nitrogen. Inversely, by multiplying the pjercentage-
of nitrogen by 1-214 the corresponding piercentage of ammonia is
obtained. The following table gives the calculations for all strengths
met with in commerce : —

1 Pure sulphate of ammonia contains 25-7 of ammonia XH3. But com-
mercial sulphate always contains free acid and other impurities including
moisture. Even good commercial sulphate of ammonia contains enough im-
purities to stultify the " complete " analysis as usually performed. All the nitrogen
is calculated to sulphate, although very evidently it is not all present as sul-
phate. There are traces of substances with lower equivalents than sulphuric
acid, so that when the nitrogen is calculated to ammonium sulphate, the free acid
determined and the combined acid also as well as the moisture, no manipulation
of the figures will bring them down to 100 per cent. A trace of this " rhodanate "
of ammonia, so rich in nitrogen, would explain all this, and the particulars given
in the following paragraph throw still further hght on the subject. The re-
inventor of a back titration process for testing sulphate of ammonia took no
account of free acid ! Needless to say, that when facts like the above were also
brought before him, he could not grasp their significance. An accurate and
complete analysis of even fairly pure commercial sulphate of ammonia is not so
simple a matter as at first sight appears. It shows great lack of skill and
judgment to combine the extraneous nitrogen in sulphate of ammonia with the
free acid, and thus report a larger percentage of sulphate of ammonia than is
actually present.

254

CHEMICAL MANUEES.

TABLE LXXII.— TABLE FOE CONVEESION OF NITEOGEN PEE CENT
INTO AMMONIA PEE CENT AND VICE VEESA.

1 Percentage of

Percentage of

Percentage of

Percentage of

j Xitrogen.

Ammonia.

Ammonia.

Nitrogen.

1 X 1-214

1-214

1 X 0-8235

0-8235

2

2-429

2

1-6470

1 3

3-642

3

2-470

4

4-856

4 „

3-294

i 5

6-070

5

4-117

^ 6

7-284

6

4-935

i '^

8-498

7

5-764

8

9-712

8

6-588

9

10-926

9 „

7-411

10

12-140

10

8-235

11

13-354

11

9-058

12

14-568

12

9-882

13

15-782

13

10-705

1 14

16-996

14

11-527

15

18-210

15

12-352

16

19-424

16

13-176

17

20-638

17

13-999

18

21-852

18

14-823

19

23-066

19

15-646

20

24-280

20

16-470

i 21

25-494

21

17-293

22

26-706

22

18-117

23

27-920

23

18-940

24

29-134

24

19-764

25

30-348

25

20-587

CHAPTEE XIII.
MANUFACTURE OF MANUEE FROM ANIMAL WASTE.

Prelmiinary Remarks. — The utilization of waste of animal origin is
of the same economical importance as of human excreta. like the
latter, the products have come from the soil and been paid for in
the manure. Unfortunately, these wastes are not collected with
sufficient care, in spite of the great facility with which they can be
utilized. Vast quantities of blood are annually lost in the slaughter-
houses of both large and small towns, where the air is infected by
the products of its decomposition. Numerous animal carcases are
buried every year, not only through following an old custom, but
moreover in order to obey certain prescriptions of the sanitary
police. Their conversion into chemical manure is their best dis-
infection. In this conversion all animal matters are boiled, which
not only destroys living organisms, but also the germs of putre-
faction and the germs of contagious diseases. Moreover, as animal
matters are not long in beginning to putrefy if left to themselves
after boihng, manure manufacturers have the greatest interest in
avoiding this decomposition, because it always entails a certain loss
■of nitrogen, its most valuable constituent. This is effected by dry-
ing, for dried animal matter can be stored for years without decom-
posing. By examining the methods used for the manufacture of
manures, it will be seen that they not only afford means of making
an excellent profit from animal waste, but also of destroying all the
•contagious germs which they may contain, and that therefore the
police regulations which require all animals that have died from
infectious disease to be buried, are thus quite contrary to economy
:as well as to well-conceived hygienic measures. The animal matters
rich in nitrogen most often utilized in manure manufacture are —
blood, meat (flesh), horn, and leather waste.

Blood.— Fresh blood forms a red thick liquid of density I'Odo
to 1-575 (6 to 7° B.) (9 to 15° Tw.). In contact with free air it
■soon separates into two parts, one solid, fibrous, forms the clot,
whilst the other, liquid, constitutes the serum. The clot consists
mostly of fibrin, whilst the serum especially contains dissolved
•albumen (7 to 8 per cent). Blood contains per 1000 parts, 796 of
water and 201 parts of solid. The solids consist of : —

(255)

256

CHEMICAL MANUEES.

191 parts of nitrogenous niatter, fibrin, albumen, globulin.
A ,, ,, tat.
3 ,, ,, extractive.
8 ,, ,, mineral matter.

204

Amongst the mineral matters of blood, mention must be made of
chloride of potassium and of chloride of sodium (common salt), and
also phosphoric acid, lime, and magnesia. Phosphoric acid forms
9-8 parts ; potassium chloride, 46 parts : corresponding to 29 parts
of potassium. The composition of blood differs a little according
to the animals from which it comes, as the following analyses by
Wolff show^ : —

TABLE LXXIII.— ANALYSES OF BULLOCKS, CALVES, SHEEP, AND

PIGS' BLOOD.

Bullocks'

Blood.

Per cent.

Calves' Blood.
Per cent.

Sheep's Blood.
Per cent.

Pigs' Blood.
Per cent.

Water

Solids

Nitrogen .
Phosphoric acid
Potash

79
21

80
20

79
21

80
20

3-2

0-04

0-06

2-9

0-06

0-08

3-2

0-04
0-05

2-9

0-09

0-15

Dried Blood. — Up to now (and still at the present time) blood
was mostly coagulated in factories by steam in an open pan, adding
to it 3 per cent of ferric sulphate solution marking 51° B. (110° Tw.)..
The coagulated blood was then laid to drain in perforated cases,
where it remained for a month, and thus lost 40 per cent of the
80 per cent of the w^ater which it contained. The coagulated and
drained product was then dried on hot cast-iron plates in a shelf-
oven traversed by hot gases. This mode of operating has numerous
drawbacks ; odoriferous fumes are given off by the drying itself and
bad-smelling fumes owing to the partial decomposition due tO'
irregular heating of the nitrogenous matter. Attempts have been
made to remedy this, it is true, by condensing the first and de-
naturing the second by fire.

Moreover, not only do the arrangements necessary to secure a
satisfactory result require continuous supervision, but the manu-
facturer does not apply them except against his will, as they per-
ceptibly increase the cost of the products without any marked
advantage as regards quality. The drying of blood in Donard and
Boulet's machine — about to be described — prevents the disengage-

MANURE FROM ANIMAL WASTE. 257

ment of all odoriferous products, and thus avoids costly gas con-
densation and denaturation processes. Before this new application,
this machine was already in use in distilleries to dry dregs, and
this use of it \vas described by the authoi' as far back as 1892.
The drying machine (Fig. 51) consists of a horizontal cast-iron cyhnder
2'5 m. in diameter by 2 5 m. long — say in round figures, 100 in. x
100 in., representing an interior volume of 12 cm. It rests on
two bearings by hollow pivots through which the heating steam
enters and the evaporation steam is ejected. The heating steam
enters a circular vertical steam chamber which forms the left side
of the cylinder. On this side are inserted a series of horizontal
tubes closed at the other extremity which form a heating surface of
59 square metres. The machine is fitted with the necessary ariange-
ments for ruaning off condensed water. The pivot placed at the
other end of the cylinder CDmmanicates by a wide pipe with a
double effect vacuum condensing pump into which the evaporation
vapour passes. The cylinder is fed and emptied through two man-
holes. The charge of moist material — containing 55 per cent of
water — is 5i tons. It makes three revolutions a minute.

Method of Working. — The working is roost simple. The
machine is connected by a pipe with a tank containing the blood,
then by means of the vacuum pump the air in the cylinder is
rarefied so as to force the blood to precipitate itself by suction.
When 5^ tons have been fed into the machine, say an amount equal
to J the capacity of the machine, the aspiration is shut off and the
mass is heated under a pressure of li kilos whilst turning the
cylinder. The blood is then perfectly coagulated under the influence
of the heat without any pait escaping fiom the beating up. After
one hour forty miautes to one hour titty minutes, coagulation is
complete. The apparatus is emptied, the magma is run into cloths
and pressed under a press mounted on a truck. Each press takes
1 ton to 22 cwt. of dried blood as it comes from the curing machine.
After pressure, which is 3 kg., 400 kg. (880 lb.) of cake with 50 per
cent of water are taken out ; 3^ tons of these cakes are used to feed
another machine absolutely identical with the first, but which this
time acts the part of a drying machine. In a medium-sized factory
a siagle machine may act both as curing and drying machine.

In factories with two machines the curer is altered by fitting
two steam circulation pipes perforated in the portion which dips into
the cylinder ; and used to bubble in steam during the coagulation,
they have the advantage of preventing the other heating pipes from
being leit bare.

To dry the cakes the vacuum is stopped, for the vacuum pump
might entrain a portion of the extremely light powder to which the
blood is reduced by drying. During that time the vapours escape
through great w^ooden aspirators passing through the roof. As

17

258

CHEMICAL MANURES.

V •- zs: •- o "•

^ 2^ C -^ -^ fH
^^*5 _£ •- ^ ■ ^ '^

^ii ■ C - ^ -^ H

■'":■ s ^ s ^ a

■-I !LI --' t^

■ : $f "S -J- j; 2

■■■• ulr > ^ ^

•■ : 5 2 ~ - ■"

■:^ -|5 > O -

■;■.• -r P f^
i e -^ •-•-H

^^•: -^ S ^ >^ <=«

O ?H

■:■■ c"^ s:

^ o

• T Qi >: ^ ^

-■"■-- ;^ ce '^ '"' a>

■^■.•.•. '■ - ' -tJ

I O

f Q 2 2

- ^>r

■■:%* rr ^^ ^ ^

'■'■■; C ^ !D .— K*-

- ^ s _ ^

Si t. - -£ ^ -^

.:>: C-._^ •- X O

rSi S^ ;^ =4^ ^ o
■■-;f o ^ ' -i^ -^ :r'

■;> ^ — '"■ — (

- . . — _ ":^ . .- a!
*%■..• ^ ic e ^ ^ =°

' .5 =« ^ C ^ ^

:e . - — ;:: 2 r
;•■ . j:: i) c o

CC, — ■ -tJ -i-= o -t-^
I— I c c> -« "■ ?;

o

'aO

>■- § o o o § -

z: — k-H '^ -^ r^

c =; p:; X o «

n rtv^ X. 7^ •'" eg

MANUEE FROM ANIMAL WASTE. 259

during the process there can be no alteration of the material, either
by fermentation or by superheating, the portion evaporated consists
simply of pure water without trace of smell.

Di-yiag lasts six to seven hours and induces the agglutination of
certain portions into hard masses so as to obtain an impalpable
powder ; the dried mass is pulverized in a Carr's crusher completely
enclosed in a wooden case and in communication with an aspirator
for dust recovery.

All these operations follow each other. The fresh blood is con-
verted in less than ten hours into a powder which is bagged up
ready for immediate delivery. As will be seen further on, 1000
litres (220 gallons, say 1 ton) of blood from the Villette slaughter-
houses yields with these machines 210 kg., say in round figures 4
cwt. of dried blood. According to multiple experiments made at
the Aubervilliers factory, the coal used for all these conversions is
estimated at 0-833 lb. per lb. of dried blood. They calculate that in
actual practice 5 tons of coal suffice to convert 284- tons of liquid blood.
The motor power is at a maximum for three driers of 15 cul3ic metres
each. The improvement in the yield due to these machines is con-
siderable, as results from the following experiment. After previously
mixing, 16 metric tons of blood, coagulated by ferric sulphate, and
containing 62 to 65 per cent of water, was divided into two lots ;
the first lot of 8 tons, dried in a hot-air oven, yielded 2*555 metric
tons, say a yield of 31*5 per cent. The lot of 8 tons, treated in a
Donard machine, gave 3^ tons of dried blood, say a yield of 15 per
cent. The percentage of water in the dried blood from the two
treatments was perceptibly equal, 15 to 16 per cent. The difference
of yield, 13*5 per cent, shows the loss the dried blood undergoes by
overheating in the hot-air oven above-mentioned.

Meat Meal. — As far back as 1863 manure was made at Auber-
villiers (Seine) from dead animals or animals slaughtered in the
department of the Seine and its neighbouring departments. The
fat was first extracted for the knackers and the rest was converted
into manure. The flesh was cooked by steam, then pressed to ex-
tract the fat, dried, and ground. The bones were also boiled, then
dried and crushed to a fine powder. Finally, with the entrails, the
boilings and the residues of the organic matter, composts were made
of low nitrogen content. Thev were mixed with the residues from
the manufacture of fat (? greaves), ground mineral phosphates, bone
residues, fur, etc., were added, and the whole piled in a heap and
drenched with blood and boilings. These substances, difficult to
assimilate, especially ground mineral phosphates after an active and
prolonged fermentation, undergo slow conversion which renders them
assimilable. The composts mixed in different proportions with rich
substances, dried meat meal, dried blood or crashed bones, enable
manures of all strengths to be prepared containing 1*5 to 2*5 per

260

CHEMICAL MANUEES.

MANUEE FROM ANIMAL \YASTE. 261

cent of nitrogen, and up to 25 per cant of phosphate. The mineral
phosphates were coproUtes. From time to lime the compost heap
was watered with sulphuric acid to avoid loss of ammonia and to
reader the phosphates soluble. Tne manure most rich in nitrogen
so manufactured contained 12 per cent and a little phosphate. By
mixing it with bone dust and alkaline salts, Dulac prepared a
manure containing 8 per cent of nitrogen, 12 per cent of phosphates,
15 per cent of potash salts, sod i, magnesia, etc. This manure was
sold at 24 francs the 100 kg. (^ay JtlO a tonj. The x\ubervilliers
factory continues to use meat waste for the manufacture of manures,
but it has considerably improved its processes, as will be seen. The
blood in powder tests 13 per cent of water and 13'2 of nitrogen; it
treats per month on an average 3500 casks of 185 litres (lO*?
gallonsj, yielding 155 metric tons of dried blood.

Drying Blood by Lime. — Recently a simple process has been
used to dry blood and to reduce it to a fine powder. This process
consists in adding 1^ to 3 per cent of quicklime, which converts it
into a solid cake which may be dried in the air without putrefying,
and finally gives a fine and inodorous powder. This process has
the advantage of being capable of being applied everyw^here without
any plant ; moreover, it preserves 0*4 of nitrogen, which otherwise
would be lost with the coagulation water. It mav likewise be
applied in the country by farmers, who thus possess the means of
manufacturing economically an excellent nitrogenous manure.

Boiling Meat. — Butchers' waste of all sorts, skinned animals
cut into pieces, are first boiled in lead-lined vats. The lid of the
vat has in its fixed half a square opening to which a wooden sheath
fits, the other half, movable around two hinges, is used to feed in the
materials to be treated. Each vat is charged with —

Meat, et? SOO kg.

Water loO „

Sulphuric acid . . . . . . . . 50 ,,

The vat being charged, the lid closed, and steam turned on, the
boiling lasts about twelve hours. The vertical wooden sheaths on
the top of the vats form real draught chimneys branching into two
large horizontal collectors which end in a maso iry turret ; there
the vapours from the boiling are constantly precipitated by the play^
of a fan. The tower contains a filter of coke, constantly moistened
by a stream of water. The aspirated vapours are in great part
condensed owing to the freshness of this water ; they then pass with
it into the drain. After twelve hours the vats are opened, the
floating fat removed, in the proportion of 10 to 20 per cent accord-
ing to the nature of the debris, then the bones and the flesh com-
pletely disintegrated. The liquors from the boiling are drained
through special piping into two large tanks. The tallow, as it

262 CHEMICAL MANURES.

comes from the vats, is more or less dark, according to the im-
purities contained in the raw material. Three classes are dis-
tinguished, white tallow, yellow tallow, and green tallow. The
paler it is, the more it is valued by candle-makers and soap-makers.
It is again boiled so as to skim it, and eliminate the impurities which ,
accompany it. It is afterwards run into casks ready for delivery.
After removing the tallow, what remains in the boiler (disintegrated
flesh, bones completely detached, the largest of which are removed)
is put into a press which removes 15 per cent of water and dried.
The Butchers Union of Paris, in its Aubervilliers factor}^ uses two
systems of driers, one naked fire, the other steam. In the steam
drier, Donard's system (Fig. 51), drying lasts seven hours at the most.
The naked fire drier resembles an enormous coffee roaster, fitted with
an agitator ; it is driven by the central shaft ; its furnace is arranged
like that of a boiler ; dr^dng lasts at least ten hours ; the amount of
coal consumed is enormous. Donard's dryer is much more economi-
cal and has the great advantage of yielding an absolutely inodorous
powder. The drying operation is complicated by the comparatively
large quantity of fat which the meat and bones retain after boiling,
and which has not risen to the surface with the tallow. This fat
renders the substance to be dried tacky ; it is inflammable, especially
when air is blown over it at a high temperature. The products
coming from the dryer are brought on to a sorting sieve which
throws the bones on one side, and delivers the finely powdered
meat on the other side ; the latter is bagged up for delivery. By the
use of Donard's dryer all this work can be done in less than twenty-
four hours, from the time the meat entered the factory until it is
bagged up in the state of powder ; 100 kg. of pressed material yield
33 kg. of dried matter ; 100 kg. of pressed material correspond to
140 kg. of original material. Meat meal is sold according to its
percentage of nitrogen. The following is its average analysis : —

TABLE LXXIV.— COMPOSITION OF MEAT MEAL.

Pel' cent.

Water «

Tallow • . . . . B

Nitrogen ......... 4-tt

Phosphoric acid ........ lo

The liquors from the boiling are collected into two cisterns, where
they are left to deposit for several days. Their muddy deposit,
somewhat rich in organic matters, is taken ujd by a montejus and
poured over a very vast area with raised edges, to let it drain better,
then mixed with meat from the boilers or put directly into Donard's
dryer. At the Aubervilliers factory they treat 805 tons of meat, etc.,
per month, which yield 15'8 per cent of tallow, 150 tons of dried
meat, and 50 tons of bones.

MANURE FEOM ANIMAL WASTE. 263

M. A. Louis has organized at Caen an interesting application
of Aime Girard's process, for the destruction and disinfection of
carcases and animal debris by means of sulphuric acid, Louis uses
likewise slaughter-house and butchery residues. In 1889, his first
year of working, Louis made 483 tons of manure containing 16 to
18 per cent of phosphoric acid, 2 per cent of nitrogen, and 5 per
cent of potash; in 1900 his manufacture had risen to 930 tons.

Louis' method of working consists in dissolving the animal
matter in sulphuric acid, and saturating the pasty mass so obtained
by phosphate of lime in powder, which finally yields a nitrogenous
phosphate.

Commercial Meat Meal. — The meat meal of commerce is a
mixture of meat meal and bone meal. It is made from the waste
from the manufacture of extract of meat ; in South America also
from the carcases of animals, knackers' meat, by steam heating,
drying, and grinding. The greater part of the meat meal is
marketed as Fray Bentos guano : it contains 6 "5 to 7'5 per cent
nitrogen and 17'18 to 11*14 of phosphoric acid. Finally, meat meal
is rendered soluble by sulphuric acid.

Horn. — Horn is met with under different forms in commerce.
The horns of ruminants are generally very pure, and contain dry
and free from bone 13 to 14 per cent of nitrogen. Whalebone
waste, when not in too small fragments, is almost equal in value.
Horn and whalebone turnings and shavings are less esteemed,
because they are generally mixed with wood shavings and other
sweepings of the workshop. Their nitrogen content rarely reaches 7
to 8 per cent. Hoofs are richer in nitrogen than ground horn. They
generally consist of pure horn ; on the other hand they are often wet
and soiled by excreta. Hair, wool, wool rags, old felt, and feathers
have the same value as horn. But great care must be taken in
buying, because it is difficult to determine the impurities of all sorts
which may be mixed therein. In the pure state they contain 11
to 13 per cent of nitrogen ; as sometimes delivered to the factories
they only contain 5 to 6 per cent. Wool dust, from the combing
and spinning of wool, is not of a nature to inspire much confidence.
It rarely contains 6 per cent of nitrogen, often only 3*4 per cent of
that element. To serve as manure ail these materials must be
reduced to a fine powder. But even when apparently dry they are
so tenacious that it is impossible to grind them. Wool dust itself
already in a fine powder cannot be ground finer. That is why they
are submitted to a special preparation, which consists in roasting
them or in heating them in a closed vessel. To roast horn, it is
spread on a cast-iron plate or in a shallow pan, which is heated
without interruption so as to avoid overheating and loss of nitrogen.
The matter assumes a dark colour, and when it is cool it is brittle
and easy to crush. When it is a case of horn turnings, it suffices to

264

CHEMICAL MANUEES.

heat them for some time on the roof of a dryer. The roasting may
easily l)e done in a closed vessel into which superheated air or
combustion gases are injected. Horn is steamed in a digester. A
digester is nothing but a horizontal or vertical boiler heated by
steam (Fig. 53). In Fig. 53, a is the steam pipe fitted with a valve
b. On the top is a steam escape valve c, safety valve d, and a
short piece e intended for a steam gauge ; gg is a double bottom of
wrought-iron. The shape and the size of the digester vary con-
siderably and depend on the size of the factory. However, it is
well to keep to certain rules. Thus a wide somewhat low digester

r

ci-^1^

K

-^^

7i

d

r}

IJi

-\

k

-f

"^

/»■«<«., i^ •J^^<S>^ ;ij*^«««? »}<>^5«^ ;>J<SJ«%^ <S<!^%»»^ s;^^

Fig. 53. — Digester foi Treating Horn, Leatlier, etc.

generally runs cheaper, and works more economically than a tall
narrow one, because it condenses less steam on its surface.

The digester being charged with horn through the manhole h
is closed hermetically, the steam valve h is opened and steam of
two to three atmospheres injected. It condenses at first until the
whole mass is heated. The heating lasts two hours for horn in
large pieces. When the operation is finished the valve h is closed
and the apparatus left to itself for some time, and finally the
steam valve c is opened. AYhen the pressure in the digester has
fallen to almost the atmospheric pressure, the digester is emptied.

MANURE FROM ANIMAL WASTE. 265

To do this the Hqaor formed by the condensation of the steam is
run otf through/. It holds a Uttle dissolved horn in solution ; then
the lower manhole i is opened and the horn withdrawn. When
properly boiled, the horn is softened through and through and forms
an elastic mass, like rubber. It is dried in a dryer, and then forms
a black pliable vitreous mass which is crushed in a bone crusher ;
that is the way ground horn of commerce is obtained. In the pure
state, it has a greenish or greyish-yellow^ colour, and contains 13 to
15 per cent of nitrogen. Other analogous materials are treated
along w^ith the horn. Horn shavings, w^ool waste, etc., occupy
a great volume, and it would take a very large-sized boiler to treat
them apart, that is why they are mixed with horn to fill the empty
spaces between the large pieces, at the risk even of slightly diminish-
ing the percentage of nitrogen in the product. The condensed w^ater
(horn liquor) contains 1 to 2 per cent of nitrogen ; it thus has a
certain value, but as its treatment would be costly it is best to add
it in the manufacture of bone dust. Attempts were made to let it
putrefy, and then distil it to recover the ammonia, but this method
was soon abandoned. The steaming of horns has many drawbacks.
It expends much fuel and labour, and a loss of nitrogen in the
condensed water. Finally, the w^ork injures the health of the w^ork-
men. There is in fact disengaged from horn during the digestion
a very volatile organic substance, which strongly attacks the
mucous membranes, especially the workmen engaged in emptying
the digester and who consequently have to come in contact with
the steamed horns, but up to now nothing has been found to
replace this method, because ground horn rendered soluble by steam
is of much greater agricultural value than raw horn. It has been
seen that the horn dissolves partially in the water condensed from
the steam, and that without decomposition it so far proves that it
passes to the soluble condition at least partially. Ground horn
thus rendered soluble possesses a great absorbent capacity for
Av.iter, whilst ground raw horn repels water, and cannot be moistened,
and as putrefastion requires the help of water, it follows that the
soluble horn will deco npose more easily, and produce a more rapid
and more sure fertilizing action than raw horn. From the preced-
ing, it follows that the use as inanures of powdered horn and wool
dust w^hich have not been treated by steam should be abandoned, for
in the raw state these materials cannot be crushed to the requisite
degree of fineness for the rational application of concentrated
chemical mcl^Qures.

Leather Waste. — Tanners' and curriers' waste can be bought
cheap when they are unfit for glue manufacture ; their nitrogen
content is very variable, even w^hen not affected by moisture or
sand. Thus sole leather in the pure state and perfectly dry often
only contains 4 to 5 per cent of nitrogen. The cutting and waste
of new^ leather from saddlers' and shoemakers' shops have a higher

263 CHEMICAL MANUEES.

value ; they contain 7 to 11 per cent of nitrogen, deducting moisture.
Chemical manure manufacturers often treat them in the same way
as horn, roasting or steaming in a closed vessel, and grinding.
The roasting of tanned leather renders it friable without perceptibly
modifying its chemical properties. Steaming under pressure
dissolves it to a great extent. The leather liquor is sometimes so
concentrated that it takes the form of gelatine, and the amount of
ground leather finally obtained scarcely renders the half of that
fed into the digester. This method, therefore, is not economical.
Moreover, steamed leather has onlv a low value as a manure, for
the tannin in the tanned leather prevents the decomposition of
the animal matter in the soil, and is only partially destroyed by the
heat. The powder obtained from roasted leather is even vrorse. It
is true that the manufacturer again finds in it the greater part of
the nitrogsn contained in the raw material, and which varies from
5 to 9 per cent. There has already been described, in discussing
the preparation of bone dust, a process of preparing leather which
is more advantageous both for the manufacturer and the farmer.
Another method of treating woollen rags, leather waste, etc., was
the subject of British patent No. 26,780 of 22 December, 1905.
Kaw materials, such as woollen rags, leather waste, previously
moistened, if need be, are fed into a horizontal cvlindrical receiver
and treated by sulphuric acid which falls on them drop by drop,
by means of a pipe running the length of the cylinder. At the
same time a rotary motion is imparted to the cylinder whilst inject-
ing hot gases from a furnace, then the materials are drenched with
salt water, well mixing the whole, and continuing the heat. If
leather waste be principally used, it is well to add finely ground
phosphate of lime to the acid w^ater. The vapours disengaged by
the material are propelled by a pump into a condensation tower
lined with bricks, washed by a jet of finely divided water. The
non-condensed gases are directed into a filter bed of moss litter,
and from there it escapes into the atmosphere ; the final product is-
discharged into a pit and reduced to a fine powder.^

Comparative Value ofDijferent Nitrogenous Manures. — Peruvian
guano is the most active of nitrogenized organic manures. Popp
has examined the action, of the nitrogen of organic manures com-
pared with that of nitric nitrogen. In his experiments he used all
sorts of organic manures, dried blood, horn dust, castor meal, ground
raw bones, fish guano, meal, meat meal, Bremen poudrette, wool
dust. According to the agricultural experiments which he exe-
cuted, he indicates the ratio which exists between the action of the
different manures. Under the cover of this remark, the following are

1 But usin» 120' T\v. acid heated to 140° F., 4 cwt. of raw leather or 2
cwt. leather and 2 cwt. shoddy can be got into each ton of compound manure
and so well dissolved as not to be seen when the den is opened. So why all this-
unnecessary labour and expense ': — Tr.

MANUEE FEOM ANIT^IAL WASTE.

267

the approximate efficiency values of these maiuufcs, nitrate being
taken as 100 :—

TABLE LXXV.-SHOWING AGEICULTURAL VALUE OF NITKCGENOUS

MANURES (NITRATE).
Dried bood TO

Horn du^t .

Fish guano

Castor meal

Meat meal .

Bremen poiidrette

Ground bones

Krottnauer organic manure

Blankenburg manure .

Distillery spent wash-salts

Wool dust .

Concentrated cattle manure

Ground leather .

70
00
60
60
55
55
45
43
40
25
20
10

The vahie of the dissolved organic manure is 23 per cent of that
of the nitrate. Popp has, moieover, lemaiked that in every case
the organic nitrogen is first converted into ammonia ; he was not
able to determine the effect of the lime. Complete conversion of
organic nitrogen into nitric acid did not occur in any case. In the
most favourable instance of 100 parts of organic nitrogen, 72 parts
were converted into nitric acid ; that is the case especially with
dried blood. The nitrogen of horn dust was converted in the pro-
portion of about 57 per cent, and the nitrogenized organic manure
in the proportion of 21 per cent. Horn dust thus acted more
slowly than dried blcod, and the nitrogenized organic manure about
half as quickly. Neither in this case was the effect of the lime in
the conversion observed. In conclusion, Popp has calculated the
value of the nitrogenized organic manure compared with that of
nitrate of soda, the latter calculated at 3525 francs, all expenses
included. He values 1 kg. of nitrogen in such organic manures
as follows : —

TABLE LXXVL— SHOWING COMPARATIVE AGRICULTURAL MONEY
VALUE OF NITROGENOUS MANURE IN FRANCS PER KILO-
GRAMME.

Dried blood .....
Horn dust .....
Fish guano .....
Castor meal . . .
Meat meal .....
Bremen poudrette ...
Bone dust manure
Krottnauer organic mani.re .
Molasses salts ....
Dissolved nitrogenized organic manure
Lutzel guano ....

Wool dust . . . . -

Concentrated cattle manure .
Ground leather ....

Francs.
1-4
1-4
1-2
1-2
1-2
1-1
1-1
0-9
0-8
0-4
0-7
0-5
0-4
0-2

CHAPTEE XIV.

RECOVERY OF NITROGEN FROM DISTILLERY SPENT WASH.
MANUFACTURE OF CYANAMIDE AND OF NITRATE OF LIME.

Utilization of Spent Wasli. — General Bemarks. — The question of
the utiUzation of distillery spent wash, looking to its great economi-
cal importance, has engaged the attention of chemists for a long
time. In grain distilleries the dregs are generally filtered, then
dried ; the spent wash which flows therefrom contains 80 to 100
grm. of nitrogen per hectolitre ; and as 100 kg. of grain yield
about 3 hectolitres of liquid, the loss of nitrogen is 1 to l-2o6 kg.
per hectolitre of alcohol manufactured, say 1 to 1\ lb. per 10 gal. of
100 per cent alcohol. In beet distilleries the loss in nitrogen is also
very considerable ; the fermented wash issuing from the distilling
column contains 100 to 160 grm. of nitrogen per hectolitre.
Finally, the spent wash from the distillation of molasses and sucrate
liquors contains 1'4 per cent of nitrogen and 9 per cent of salts.
Now, if the spent wash be simply incinerated, to extract the salts
from it according to a process already old, all the nitrogen, of which
the money value is superior to that of the potash, is lost. If in a
molasses distillery they calculate on a yield of 9 per cent of salts,
it will be seen that there is extracted from 1000 kg. (a metric
ton) of molasses 90 kg. of salts, say 198 lb., at 40 per cent of car-
bonate, worth 38 centimes the degree, say 13-68 francs, say lis.,
and that there is lost by incineration all the nitrogen, of which
75 per cent at least is recoverable, say 11 kg. (22-42 lb.), worth 1-50
francs the degree, say 16-50 francs, or 13s. 2d.

It will be seen that the problem of the recovery of nitrogen
from these residues deserves to attract in the highest degree the
attention of distillers. Different processes have been proposed to
recover this nitrogen. Attempts have been made to recover it by dry
distillation as ammoniacal salts or liquor ammonia. There is then
obtained a complex liquid containing tars, methylamines, and other
bodies difficult to purify. These processes have not been adopted
in actual practice, which would tend to the belief that the financial
results did not conform with those which bad been expected.
Attempts were also made to prepare compound manures from
spent wash by adding precipitated phosphate of lime, and inert

(268)

NITEOGEN FEOM SPENT WASH. 269

matters, generally lime, in somewhat larger quantity up to 40 per
cent. But the fertilizing elements in the products so obtained are
present in proportions but little acceptable to farmers, and the pre-
sence of inert matters rendered their transport charges heavy.

Winck has tried to utilize the nitrogen of spent wash as
manure. His process consists in concentrating the spent wash to
40 to 42° B., then to add massive quantities of sulphuric acid.
This acid mixture is afterwards neutralized with carbonate of lime,
and dried in stoves. The addition of acid and of carbonate favours
the drying, the jpresence of sulphate of lime renders the mass
more porous, more easy to treat. The product obtained contains
3 to 5 per cent nitrogen and 12 to 14 per cent of potash. Eiviere
proposes to separate potash from concentrated spent wash by
hydrofluosilicic acid. The organic matter separated from these
salts can be evaporated in the same way as in the Vasseux process
described below. Effront has likewise introduced a process for
separating the organic nitrogen from the mineral substance. This
process is based on the observation that the nitrogenous matter of
spent w^ash becomes insoluble when it is treated with acid at a
temperature of about 200' C. To the concentrated spent wash acid
is added to decompose the organate ; the mixture is maintained for
some hours in stoves at 190 C. A portion of the nitrogen is dis-
engaged and is collected by a fan in the acid. The mass issuing
from the stove is crushed, 'then lixiviated with boiling water. The
cooled liquid deposits sulphate of potash. The insoluble residue is
dried at 100° C. By this method 8 to 9 per cent nitrogen free
from potash is obtained.

Becovery of Nitrogen hy Vasseux s Process.— Bj this method
all the nitrogen freed from the greater part of the potash is easily
recovered, no noxious principle being generated in the process,
which is as follows : The spent wash, previously concentrated to-
32° to 35° B., is treated by sufficient sulphuric acid to convert the
organates of potash into sulphates. The sulphate of potash formed
crvstallizes in the midst of the mass ; it is separated by decantation,
filtration, and centrifuging. This sulphate of potash is afterwards
washed and again centrifuged. It is then sufficiently pure and is
sold as 75 to 80 per cent sulphate. The organic matters which
form the drainage^ are ^ then dried in special vacuum machines;
decomposition is avoided and the distillate glycerine, tar, etc., may

be collected.

^Yhen drying is complete the mass is run into trucks. It is
fluid when hot but soon cools into a mass which is broken up^in a
crusher. An organic manure is thus obtained containing 6 to 7 per-
cent of nitrogen and 6 to 7 per cent of potash. This product, almost
entirely soluble in water, nitrifies very rapidly in the soil and suits all
crops. For every 1000 kg. (metric ton) of molasses treated 150 kg.

270 CHEMICAL MANUEES.

of this manure are recovered (in round numbers 3 cwts. manure per
ton of molasses) : —

TABLE LXXYIL— SHO^YIXG VALUE AND A^.IOUXT OF MAXX'EE

FEOM 1 TON MOLASSES.

1000 kg. (1 metric ton) of molasses yield

Fr.
150 kg. (3 cwts.) of organic manure with 6 to 7 per cent nitro-
gen and 6 to 7 per cent of potash ...... 16-60

75 to 80 kg. (165 to 176 lb., say 1| cwt.) of sulphate of potash . 14-0

Total 30-60

whilst by the old pro3es3 only 90 kg. potash salts, worth 13 to 14
francs, were obtained.

Labour is not more heavy than at the potash furnaces and the
work is less exhaustive, but there is the extra expense in coal and in
acid, which is valued at 5 francs (4s.) per metric ton of molasses. So
that the net profit to be drawn from the application of this process
over and above the potash salts usually obtained is about 12 francs,
say in round figures lOs.

If these figures be applied to a factory working 20,000 tons of
molasses, the value of the bye-products to be obtained is 610,000
francs (£21,100), yielding a profit greater by 210,000 francs (£9600)
than that obtained from the potash salts alone. These figures show
very well the importance attached to the recovery of the nitrogen.
Vasssux's process is, moreover, wrought in Prance and Spain and
gives every satisfaction.

Treatment of the Spent Wash by Biological Agents. — Jean
Effront has studied a new method of treating spent wash by
biological agents. The problem which he set himself was as
follows : To find an active substance (diastase) capable, in the con-
ditions of actual practice, of converting the organic nitrogen of
spent wash into ammouiacal nitrogen, the form under which it is
mosb easily recovered. This substance, called amidase, exists in
brewers' yeast. In the alcoholic fermentation the amidase of yeast
and foreign ferments always accompanying industrial fermentation,
does not intervene, owing to unfavourable conditions. It only
reveals its presence when the yeast finds "itself in an alkaline
medium and in a non-vegetative condition. After numerous but
very simple experiments which demonstrated to him the presence
of amidase in yeast and its power of converting amides into
ammonia, Etfront applied his discovery to the treatment of
distillery spent wash. This produces very large quantities of
ferment which is deposited at the bottom of the vats ; these fer-
ments separated from the fermented liquid before its distillation may
be used to treat spent wash. The method of working is as follows :
The spent wash issuing from the distilling colamn is cooled to

o

NITROGEN FROM SPENT WASH. 271

40" to 45° C. (104" to 113° F.), rendered alkaline by lime, soda, or
salts. One or two kilogrammes of yeast are added per hectolitre
and allowed to work for 3 or 4 days at 40° to 45° C. The conv< r-
sion of amides being finished, the ammonia is separated by distilla-
tion or by ventilation (Kestner method). By this latter method
the consumption of coal is about 50 kg. (say 1 cw^t.) per 100
hectolitres (2200 gal.) treated. By treating molasses spent wash,
100 hectolitres (2200 gal.) yield 40 to 45 kg. (88 to 99 lb.) of
nitrogen, representing a minimum value of 40 to 45 francs (32s. to
36s.). In spent wash from beets 100 hectolitres (2200 gal.) \ield
10 to 15 kg. (22 to 33 lb.) of nitrogen, worth 10 to 15 francs
(8s. to 12s.). The expense in fuel being 1 franc (9'6d.), the actual
profit is remarkable.

Treating Spent Wash by Fermentation. — Beeryeast isnot the only
biological agent capable of converting the nitrogen of spent wash into
ammonia. Certain soil ferments likewise possess ths property. By
innoculating a solution of glutamine by garden soil, the formation
of ammonia can be demonstrated. Effront, using plate cultures,
has isolated three ferments acting on the nitrogen of spent w^ash.
One of them was recognized as the butyric acid ferment, and
Effront has closely examined the conditions which favour its am-
moniacal functions. In practice the general course of w^ork with
this ferment is analogous to that of the manufacture of alcohol.
There is a yeast chamber and fermentation vats; from the feiment
there is prepared a leaven equal to 5 to 10 per cent of the total
volume of the liquid to be fermented, and it is renew^ed every twenty-
four hours as in distillery brewing. To strengthen the ammoniacal
action, recourse is made to aeration to render the liquid strongly
alkaline, and to the use of agglutinants, such as sulphate of alumina,
which paralyses the development of ferments and produces a change
in the function of the cells. For the use of pure cultures, often far
from convenient, garden soil which mav be verv well taken as the
point of departure of ammoniacal fermentation, may be substituted.
Etfront recommends to sterilize this earth mixed w^ith the alka-
linized spent w^ash for an hour at 70° to 80° C. (158° to 176° F.), this
sterilization being sufficient to avoid the formation of noxious fer-
ments without destroying those with an ammoniacal function.
This soil culture in the spent wash may be used as leaven in the
same way as those made from pure cultures on condition that they
be renewed somewhat frequently. This process was experimented
on at the distillery of Quesnoy-sur-Deule, at the end of the season
1907-8. From the point of view^ of yield, the work leaves nothing
to be desired, and the amount of nitrogen extracted from the spent
wash from the manufacture of one hectolitre (22 gallons) of alcohol,
may be valued as 12 kg. (26-4 lb.) of sulphate of ammonia (say 1-2
lb. of sulphate of ammonia per gallon of alcohol). In the course of

272 CHEMICAL MANUEES.

the molasses season, 25 to 30 kg. (55 to 66 lb.) of sulphate of am-
monia were obtained per hectoUtre of alcohol, and it has been found
that in the distilling column an appreciable amount of glycerine
perfectly recoverable is also separated. In treating spent wash by
fermentation, almost all the organic matters, including the nitro-
genous matter, are decomposed. The spent wash from 370 kg. (814
lb.) of molasses, the appioximative quantity to produce 1 hectolitre
(22 gallons) of alcohol, yields besides ammonia about 35 kg. (77 lb.)
of volatile fatty acids. The acids which pass over on distillation are
white and fiee from impurities. The distillery industry could furnish
enormous quantities, and it would be desirable for the trade to find
new outlets for them.

The Mamifacture of Cyanamide and of Nitrate of Lime. —
Atmospheric air is an inexhaustible source of nitrogen. It is calcu-
lated that the column of air which covers a hectare (2*47 acres) of
ground contains about 79,000,000 kg. of nitrogen (say 79,000
metric tons, which gives 31,600,000 metric tons per acre), equal to
500,000,000 kg. of nitrate of soda (say 50,000 metric tons per hectare
or 20,000 tons per acre). But nitrogen exists in the free state in the
air, and to render it assimilable by plants, it is necessary to convert
it into appropriate compounds. We know that this conversion can
be effected by certain bacteria of the soil (leguminous bacteria, etc.),
likewise by certain phenomena which occur in nature, such as-
electrical discharges, especially lightning. But the amount of nitro-
gen brought into the soil in this way is far from being sufficient to
cover the requirements of plants, and vigorous efforts are now bemg
made to capture atmospherical nitrogen under an assimilable form.
Experiments made enable us to affirm that such is possible. But
all the tentatives made in this direction show that the industiial
fixing of atmospheric nitrogen requires the use of great quantities
of electrical energy. There are at present two chief methods of
manufacture : (1) the Frank and Caro process, (2) the Birkeland and
Eyde process. The first consists in combining atmospheric nitrogen
dry and deprived of its oxygen with calcium carbide, obtained by
fusion in the electrical furnace of equal amounts of coal and lime.
The product so obtained is termed lime nitrogen or cyanamide of
calcium. The second process consists in oxidizing atmospheric
nitrogen by electrical means, and converting it into nitric acid,,
which is put into commerce as nitrate of lime with 13 per cent of
nitrogen, which has the greater analogy with nitrate of soda and
which like the latter is assimilable by plants. The two products
come on the market as more or less dark dirty grey powders.
Their percentage of nitrogen varies from 13 to 21 per cent. The
following are the analyses given by Cirandeau : —

CYANAMIDE AND NITRATE OF LIME. 273

TABLE LXXYIIL— ANALYSES OF CYANAMIDE (LIME NITROGEN AND

NITROGEN- LIME). (GRANDEAU.)

Lime nitrogen. Nitrogen lime.

Nitrogen 20-21 20

Calcium 40-42 45

Carbon 17-18 19-5

Chlorine ..... — 6-5

The only difference between the two products is that the nitrogen
lime contains calcium chloride injurious to vegetation.

Manufacture of Cijanamide.—'' Lime nitrogen " is manufactured
in Italy by the Societj\ generale per la Cianamide, the head office
of which is in Rome in association with the Berliner Zyanid
Gesellschaft. This company has acquired all the patents and pro-
cesses relating to the manufacture of cyanamide of calcium and its
derivatives. It afterwards assigned these patents for Italy and Austria-
Hungary to the Societa italiana per la fabricazione di Prodotti azotati,
which has installed at Piano d'Orte a factory capable of producing
10,000 tons a year. It has just acquired at Almissa numerous
waterfalls of a force of 50,000 H.P., which will enable it to manu-
facture 1,000,000 tons per annum. Manufacturing licences have
been granted in France to the Societe francaise des produits azotes
at N.-D. of Briancon; to the Societe Suisse near Martigny, and
to the North- Western Cyanamide Co. near Odde in Norway, the
head office of which is in London. A factory using a fall of water
of 40,000 H.P. is in construction in America, and two others respec-
tively of 2000 and 10,000 H.P. are in construction in Germany. The
manufacture of cyanamide according to the first of these processes
has just been modified by Polzenius, who adds 10 per cent of calcium
chloride to the calcium carbide used so as to fix the nitrogen on
the mixture at a much lower temperature [700° to 800° C. (1292° to
1472° F.)] than in the original Frank and Caro process of 2000° C.
(3632° F.). The product so obtained is called ''nitrogen hme " in
opposition to the product " lime nitrogen " by the old process. But
this distinction is one of pure form, for the two products have per-
ceptibly the same composition. The nitrogen in these products
costs 1-4 francs the kg. (say 6d. per lb.). The factory working this
process is situated at Westerregeln in Germany. It is capable of
producing 4000 tons of lime nitrogen per annum.

Manufacture of Nitrate of Lime. — As just mentioned, this pro-
cess consists in oxidizing atmospheric nitrogen by electric means.
In 1903, Prof. Birkeland of Christiania observed that the electrical
discharges from the alternate current, at an average tension, dispersed
in the magnetic field, which brought about the combustion of the
nitrogen in the air. This process had the advantage over similar
ones of requiring a much lower electric tension, say 5000 volts in
place of 15,000, and to furnish much higher yields of nitric acid.

18

274 CHEMICAL MANUEES.

The air is burnt in an electrical oven having the form of a drum.
This furnace was modified and improved by Samuel Eyde. In
this drum the air is submitted to a temperature of 3000° C. By
rapid cooling the nitrous oxide (NO) formed in the electric flame
is retained almost entirely, whilst in former processes it was in
great part lost. The nitrous oxide issuing from the furnace at a
temperature of 600° to 700° C. (1112° to 1292° F.) combines with
the oxygen to form NO.^, which is passed through a series of towers.
It finally yields nitric acid of 50 per cent strength, which is satur-
ated with lime. The mass is then heated to 450° C. (842° ¥.), which
is its melting-point, then poured into cast-iron cylinders, where it
solidifies slowly. In the beginning, crystallized nitrate of lime was
nianufactured which was difficult to use owing to its hygroscopic
properties. This product melted between the fingers and could
thus only be used mixed with peat dust. That was why they
afterwards set themselves to make basic nitrate of lime ; but this
product only contains 11*7 per cent of nitrogen, which rendered
its freight charges heavy, and formed an obstacle to its sale.
Lately, the partially dehydrated salt tested 13 per cent of nitrogen.
The first manufactory of any importance of this product was built
at Notodden in Norway. The experience acquired in that factory
has induced the management of the company to increase the plant,
so as to make 8000 to 10,000 tons per annum. This factory is main-
tained by the Badische Anilin und Sodafabrik. The unit of nitrogen
in nitrate of lime is sold at the same rate as the nitrogen in nitrate
of soda.

Agricultural Experiments loitli Cyanamide. — Calcium cyana-
mide has of late years been the subject of numerous agricultural
experiments by P. Strohmer, O. Botticher, Otto A. Stutzer and E.
Wein.

It must be observed in a general way that calcium cyanamide
neither suits humic acid soils (? peaty soils) nor light sandy soils.
On the other hand, it may be used in all loamy soils of average
fertility. Owing to the formation of dicyanamide, this manure
aught to be spread at least eight days before sowing and covered in
afterwards in not too superficial a manner. The action of cyanamide
is weaker than nitrate of soda, it is also slower than the latter.
But as the unit of nitrogen is supplied cheaper by the new manure
a greater amount can be used to restore the balance. Without
doubt cyanamide deserves attention. According to the experiments
of Remy, this manure succeeds very well on clay soils, less so in
sandy soils. F. Loehnis has observed that the conversion of
cyanamide into ammonia in the soil is effected by bacteria, for ex-
ample by the B. Megatheriuvi, the mycoid and other species in part
new. We know that the conversion of ammonia into nitrate is like-
wise effected by bacteria, and according to the researches of G.

CYANAMIDE AND NITEATE OF LIME. 275

Muntz and E. Laine, peat is au excellent means for bringing
nitrifying bacteria to very great activity. For this purpose the
peat is moistened with a solution of an ammoniacal salt after having
mixed it with lime to fix the nitric acid formed. From very de-
tailed comparative experiments by P. Wagner, B. Dorsch, S. Mais
and M. Popp, ''Land Versucht," 1907 (Vol. LXVI, p. 285), with
.cyanamide and various nitrogenous manures, it follows that : —

1. Sulphate of Ammonia and Nitrate of Ammonia have not shown
great differences in their mode of action.

2. Carbonate of Ammonia produced in loamy soils exactly the
same results as sulphate and nitrate of ammonia. In sandy soils
it did not act normally on the culture in pots except at a dose of
•0"75 grammes applied once ; stronger doses were injurious.

3. Nitrate of Lime acts normally up to the second dose (1'5
grammes) in loamy soil and up to the third dose in sandy soil
(2-25 grammes). But from that moment there is an injurious action,
•especially in loamy soils. The high percentage of basic nitrate of
lime and the still higher percentage of nitrate of lime produce in-
jurious effects.

4. Cyanamide in a dose of 0*75 grm. once applied has given
•a favourable result in pots, although a little less than other nitro-
genous manures of equal dose.

5. Fish Guano produced an average useful effect of 78, the
action of nitrate of ammonia and of sulphate of ammonia being
supposed to equal 100.

6. Green Manures have produced on sandy ground the same use-
ful effect as fish guano in loamy soils ; they were slightly less effective.

7. Nitrate of Soda, Chili Saltpetre and Sulphate of Ammonia
have regularly produced higher yields and a better utilization of the
nitrogen than cyanamide.

The general result of all these agricultural experiments is the
following : —

If the value of nitric nitrogen be expressed by 100, the value
of the nitrogen in cyanamide is represented by 90. The lime
nitrogen acts a little more feebly when its decomposition in the soil
gives rise to the formation of dicyanamide resulting from the action
■of carbonic acid, humic acid, heat and the absence of bacteria. The
factors which favour the action of cyanamide are uniform distribu-
tion (fifteen days before the time of sowing), perfect mixing of
the manure with the soil, sufficient moisture to the soil, a loamy
soil rich in bacteria, spreading at the latest on 15th February for
^vinter plants.

Bules for the use of Cyanamide. — Immendorf has drawn up
the following rules for the use of cyanamide : —

1. Cyanamide does not suit humic acid soils, w^here its action
ds uncertain and whei'e it may poison plants.

276 CHEMICAL MANUEES.

2. Eor the same reason its use is not recommended in light
sandy, somewhat torpid soils, especially those with an acid reaction.

3. All other soils, especially loose friable soils, which contain
enough lime and are regularly manured with farmyard dung, may
be manured with cyanamide.

This new manure may be successfully applied bearing in mind
the following observations : —

(a) The dose to use per hectare to be from 150 to 300 kg.
(330 to 660 lb., say 132 to 264 lb. per acre), equal to 30 to 60 kg.
(66 to 132 lb.) of nitrogen per hectare (say 26-5 to 53-8 lb. per acre),
according to the fertility of the soil.

(b) As the cyanamide gives off an enormous amount of dust
which is possibly the most unpleasant defect of this manure, the
best thing to do, if a manure distributor be not available, is to mix
it intimately with double its weight of not too moist soil and to
spread it immediately.

(c) The spreading of the manure ought to be done eight tO'
fifteen days before sowing, according to Frank. However, when this
manure is applied to soils which suit it, this delay is not to be
insisted on (unless in case of too great drought) ; if it be spread
three to four days before sowing and suitably covered in, cyanamide
completely loses its properties injurious to the germination of the

seed.

(d) It is essential to mix the manure with the surface layer of
soil immediately after distribution, covering it in with the plough.
Care should be taken not to spread the manure so long as the
surface of the soil is humid and very hot.

(e) In no case should cyanamide be used as a top-di'essing,
at least until after the crop has been removed, for in that case it
would be more injurious than useful.

Dratubacks in the Use of Nitrate of Lime. — A. Pitzewitz has
communicated to the German Agricultural Society the results of
experiments which he made this year with nitrate of lime as
manure.

"I used," he says, " in the spring of this year large quantities
of nitrate of lime as much on grain crops as on beets, and I can say
that from the point of view of the results, nitrate of lime has not
shown itself inferior to nitrate of soda.

" Nevertheless, I will take care not to use it again, for the follow-
ing reasons : —

" 1. Stored for a long time in casks nitrate of lime suffers con-
siderable loss in weight. Having left the casks from January in
dry warehouses, I found at the time of spreading in April-May,
1898, an average loss by volatilization of 20 to 25 lb. per cask. %^\

"2. It is very difficult to regulate its distribution by the drill.
Nitrate of lime, moreover, has the grave drawback of enveloping the-

CYANAMIDE AND NITEATE OF LIME. 277

persons about, or following the machine as well as the horses, in a
layer of tacky dust, so that labourers refuse to apply it. It is there-
fore for that reason that it is impossible to spread nitrate of lime by
hand, for the hands would be injured, and the wind projecting the
nitrate of lime about the body would endanger the eyesight. It is
therefore necessary (1) to find a manure distributor which will
obviate these drawbacks ; (2) to improve the conditions of preserv-
ing the product during storage."

To obviate the deliquescent properties of nitrate of lime, it is
mixed with equivalent quantities of alkaline sulphates, sulphate of
potash or magnesia, or calcined kieserite. The product so formed
is not more deliquescent than nitrate of soda, and forms a dry
powder.

N.B. — The author, following French custom, uses in the text
the term cliaux azote, "lime nitrogen," for cyanamide almost
throughout, but such a term is too vague and misleading. It has
been altered to the more intelligible trade term. Attempts to
differentiate the separate products of mere variation in manufacture
in such a vague way as ringing the changes on the precedence and
sequence of the two main ingredients, can only create confusion
where everything is plain sailing. If a distinction were at all re-
quired, a and y8 cyanamide ought to have been chosen. Such dis-
tinctions'are as ridiculous as "nitrogen sulphate " and " sulphate
nitrogen " w^ould be for sulphate of ammonia from bones and from
coal respectively.

CHAPTEK XY.
NITROGEXIZED PHOSPHATIC MANURES.

Concentrated manures containing both nitrogen and phosphoric
acid in important quantities are only represented on the market
under well-determined forms. Such manures have played a very
important role in the history of agriculture. They were the starting-
point of chemical manures, and it is through them that we first
learned to fertilize the soil and to increase the vegetable production^
otherwise than by farmyard manure. It was only afterwards that
agriculture came to the large series of phosphates, potash salts and
nitrogenous matter which have to-day become the indispensable
factors of all rural exploitation. These manures are Peruvian guanO'
and bones, to which had to be added gradually the different manures
composed from waste of animal origin described in the preceding
chapters.

Peruvian Guano. — Its Comjjosition. — Like phospho-guanos
already described, Peruvian guano is essentially a product of the
decomposition of the excrements of sea-fowl. It has an analogous
origin, but is formed in a different manner ; whilst Baker guano
scarcely contains 1 per cent of nitrogen with about 80 per cent of
phosphate of lime, Peruvian guano has preserved almost integrally
throughout centuries the nitrogenized organic matter, owing to the
climatic conditions which supervene in the countries where such
deposits are found. Birds' excrement (pigeons' and hens' dung) has-
been known for a long time as a valuable manure ; . it is dis-
tinguished by great richness in nitrogen, contrary to what occurs in
the case of mammals. But the excrements of birds of prey
(carnivorse) are particularly rich in nitrogen, and the sea-birds-
which produce guano fall exactly into this category ; whilst in fact
the dried mixture of the solid and liquid dejections of man contain
on an average 10-4:0 per cent of nitrogen and 3-88 per cent of
phosphoric acid, the dried dung of the eagle contains 35-7 to 37-7
of nitrogen and 0*32 to 3'99 of phosphoric acid. This explains why
the guano of sea-birds is very rich in nitrogen, whilst the urine of
these birds, instead of being liquid like that of mammals, is thick,
and thus does not penetrate into the soil.

The deposits of nitrogenized guano extend over a vast surface of
the West Coast of South America, its quality always varying

(278)

NITROGENIZED PHOSPHATIC MANURES. 279

according to the situation of the ditferent deposits The most
esteemed kind was that formerly collected on the Chmcha Isles,
well known to the ancient Peruvians, who came there to search tor
manure to fertilize their wheat and potato fields. But these islands
are now completely exhausted, as well as those of Ballestas, Guanape
and Macabi. It is, therefore, unnecessary to describe them How-
ever, we cannot help quoting the analyses of the samples of guano
brought from these islands by Alexander de Humboldt m 1804, and
of some others because they correspond near enough with the guanos
now imported from these countries (see p. 280). The following are
some of the distinctive characters of Peruvian guano, according to

J. Girardin : — ^ 7 v i 1.,.+ u

It is a dry powder of a pale yellow or caje au lait colour, but it
becomes chocolate as it ages or when it is exposed to the air ; it
absorbs, moreover, in the latter case much moisture, becomes
heavier and sticks to the fingers. It exhales a strong putrid or
ammoniacal odour which induces sneezing. It has a very siiaip
salt taste. It shows in bulk numerous whitish semi-hard concre-
tions which can be crushed between the fingers, and which when
exposed to the air soon slake and fall to dust exhaling a very strong
animoniacal odour. Thrown into water, Peruvian guano soon hnds
the bottom and lets nothing rise ; when heated it blackens burning
with a feeble flame with production of a strong ammoniacal vapour ;
the residue which it leaves is in the form of a white s ightly bluish
cavernous slag ; the weight of this residue only varies between very
near limits, 27-5 to 35 per cent. _ • ^•

Triturated with powdered quicklime, Peruvian guano immedi-
ately gives off a strong ammoniacal odour. When thrown into a glass
containing a concentrated solution of chloride of lime, it soon gives
rise to disengagement of bubbles of gas which continue for a some-
what long time. In contact with hydrochloric acid it only pro-
duces a slight effervescence ; moistened with nitric acid and dned m
a porcelain capsule, it assumes a fine red colour. Imally, tnis
guano only rarely contains silicious pebbles, and it contains only i
to 1-5 per cent of sand ; the maximum is 2-5 to 3 per cent.

In this same report Girardin gives the analyses of thirteen samples
taken by himself on board ship on their arrival m Havre, ihis
document is so interesting that it will be useful to reproduce it here
The guanos delivered, afterwards were less rich m nitrogen ana
more rich in phosphoric acid than those which gave the old
analyses. That is not surprising, and each new sample yields
different results ; for on the one hand the workmen entrusted with
collecting it are not careful enough, on the other hand the deposits
are continually altering under the influence of moisture, however
small the rainfall in these countries. But the chemical transforma-
tion of the guano is not the same in all the parts of a deposit.

280

CHEMICAL MANUEES.

TABLE LXXIX.— ANALYSES OF PERUVL\N GUANO.

Composition.

Urate of ammonia
Oxalate of ammonia .

„ lime
Phosphate of ammonia
Double phosphate of ammonia and magnesia
Sulphate of potash

,, soda

Sodium chloride (common salt) .
Ammonium chloride .
Phosphate of lime
Clay, sand, etc. ....
Water and organic matter .

According to

Vauquelin

and
Fourcioy.
Per cent.

9-0
10-6
7-0
6-0
2-6
■5-5
3-3

4-2
14-3

4-7
32-8

100-00

Klaproth.
Per cent.

16-0
12-75

0-50

10-00
32-00

28-75

100-00

TABLE LXXX.— ANALYSES OF PERUVIAN GUANO.

Dark Yellow

Guano from

Lima

Guano

Liverpool ,

Guano

(Oellacher).

(Bartel).

(Voelcker).

Urate of ammonia ....

12-20

3-444

1-0

Oxalate of ammonia .

17-73

13-351

10-6

„ lime .

1-70

16-360

7-0

Phosphate of ammonia

6-90

6-250

6-0

Double phosphate of ammonia

and

magnesia ....

11-63

4-196

2-6

Sulphate of potash

4-00

4-227

5-5

„ soda .

4-92

1-119

3-8

Common salt

0-40

0-100

Ammonium chloride .

2-25

6-500

4-2

Phosphate of lime

20-16

9-940

14-3

Carbonate of ammonia

0-80

Humate of ammonia .

1-06

Phosphate of soda

5-291

Carbonate of lime

1-65

0-600

Waxy matter ....

0-75

5-904

Sand and clay ....

1-68 -^
4-31 -
8-26 J

Water ......

22-718

4-7

Organic matter and undetermined

1

32-3

99-40

100-000

1

92-0

NITROGENIZED PHOSPHATIC MANUEES.

281

Thus, leaving out of account the superficial lamellary layer which
obviously contains the most recently formed guano, a layer the
stratifications of which may be compared to the annual rings formed
in the trunk of a tree, three superimposed layers may be distinguished
in the deposit — the superficial brown layer, the middle yellow layer,
and the lower brown layer. The richest guano is that of the
middle layer. That of the upper and lower beds is the poorest.
This fact is easily explained by considering the incessant phenomena
incidental to the formation of these kind of deposits.

TABLE LXXXI.— ANALYSES OF PEEUYIAN GUANO.

1

•2

3

4

5

6

Water

8-990

20-054

17-160

20-300

11-100

17-520

' Sand and pebbles

1-2000

1-250

1-000

1-190

10-400

15-400

Phosphate of lime

24-000

24-000

24-500

28-000

25-500

37-000

Other insoluble salts .

2-6000

3-000

0-500

2-700

20-700

11-238

Potash

0-9648

2-319

2-894

1-061

2-180

2-162

Other soluble salts

o-03o2

2-981

4-306

0-239

0-92

1-380

Organic matter and

ammoniacal salts .

.57-2100

46-396

49-640

46-510

29-00

15-300

100-0000

100-000

100-000

100-000

100-000

100-000

Nitrogen per cent

11-30

12-18

13-47

14-58

11-30

2-66

Ammonia ,,

4-90

8-230

7-04

4-90

2-29

2-30

TABLE LXXXIL— ANALYSES OF PEEUVIAN GUANO.

■

-

8

9

lu

11

1-2

13

Water .

18-800

12-740

15-025

19-740

21-500

15-300

18-00

Sand and pebbles .

4-300

3-710

2-245

2-280

17-700

20-000

16-00

Phosphate of lime .

40-300

18-000

31-800

34-800

35-600

11-500

33-800

Other insoluble salts

5-800

38-200

25-200

23-200

1-100

18-350

12-300

Potash

2-026

0-771

0-578

1-824

2-500

0-676

0-4824

Other soluble salts .

10-974

14-329

13-622

8-576

0-300

2-874

8-8176

Organic matter and

ammoniacal salts .

18-100

12-250

11-530

9-580

21-300

31-300

10-600

100-000

100-000

100-000

100-000

100-000

100-000

100-0000

Nitrogen per cent .

4-48

1-28

1-82

1-09

4-82

4-12

1-250

Ammonia „

1-416

0-183

0-183

0-176

0-76

traces

traces

Although rain is very rare in these countries, the surface of the
deposit is none the less moistened in a more or less constant
manner by the mists and fogs of winter. Now, moisture by its

282 CHEMICAL MANUEES.

presence alone diminishes the value of the guano of the superficial
bed, besides it dissolves salts of potash, ammonia, lime and magnesia
in so far as they are soluble and causes them to pass into the middle
bed. To this downward transition there is a corresponding ascend-
ing transition from the lower beds. In fact the guano of the
lower bed in contact with the soil is in a state of incessant
decomposition, and gives off ammonia and carbonate of ammonia,
which being very volatile ascend towards the top. The two opposite
currents meet in the middle zone. The dissolved earthy salts fix.
the ammonia, which is thus converted into stable compounds. It is,
therefore, easy to understand that the middle bed ought to be the
richest in nitrogen, especially in ammoniacal salts. If this transfer
of matter in itself sufficiently explains the great differences in com-
position revealed by analysis, it is not the sole cause. Peruvian
guano does not wholly consist of the excrement of sea-fowL
Remains of seals and other marine animals are found in the lower
beds in a state of curious preservation. It is, therefore, right tO'
admit that these islands at a previous epoch when they w^ere lower,,
served as a refuge to a great number of these animals, and that
after they had become inaccessible owing to their volcanic upheaval
they were the home of sea-fowl. This hypothesis enables us tO'
understand whv the browm euano of the lower bed is of less value ;
for the flesh and the decomposed bones of w^hich it consists are less
rich in nitrogen than the birds' excrement. The composition of
guano, therefore, varies according to whether it comes from the
upper, the middle, or the lower bed of the deposit. The concretions
(nodules) of the upper bed have a composition identical with that of
the powder in which they are embedded. Their colour and their
structm-e enable one at first sight to recognize the guano from the
surface bed. The nuts of guano from the middle bed are dis-
tinguished from the surrounding mass by their colour, which is.
paler, sometimes almost w^hite, and they contain a crystalline nucleus.
or have a crystalline structure here and there. They consist chiefly
of ammoniacal salts, oxalate and carbonate, and consequently con-
tain more nitrogen than the guano in w^hich they are embedded..
The difference is as much as about I'D per cent, and much more
in the case of very pure pieces. The nodules, the analyses of
which are given here, according to Karmrodt and Phipson, come
undoubtedly from the middle bed. They contain : —

NITROGENIZED PHOSPHATIC MANURES. 283.

TABLE LXXXIIL— ANALYSES OF GUANO FROM MIDDLE BED OF

PERUVIAN GUANO DEPOSITS.

Oxalate of ammonia

Carbonate of ammonia .

Urate of ammonia

Alkaline urates

Nitrogenized organic matter

Phosphate of potash
„ soda

,, ammonia .

„ lime (monacid)

Carbonate of lime .

Sulphate of potash .
„ lime

Magnesia and chlorine .

Moisture

Karmrodt.

Phipson.

Per cent.

Per cent.

41-28

76-93

4-09

. 1-09

10-17

9-52

—

9-08

7-57

1-14

9-91

7-49

traces

3-40

traces

traces

7-40

10-93

100-00

100-00

The lower beds of the deposit consist chiefly of salts of the
alkaline earths, and the aggregations which are met with have also-
the same composition. It is sulphate of potash which predominates-
in the nodules of these beds. The following is the analysis of one
of these nodules, according to Kraut : —

TABLE LXXXIV.— ANALYSIS OF PERUVIAN GUANO NODULES

(LOWER BED]

.

Per cent

Sulphate of potash 45-64

,, soda

13-22

„ ammonia

10-23

Oxalate of ammonia .

9-14

Phosphate of ammonia (basic) .

. 12-09

(monacid)

4-78

Organic matter ....

0-94

Insoluble .....

. 1-90

Water .....

. 2-06

100-00

As observed above, the percentage of nitrogen in Peruvian guano
varies between 3-76 and 9-34, it is therefore much lower than about
1860. The Chincha islands deposits have a composition some-
what like those of the old guano, as the following analyses of the
Halle experimental station show.

The guano of different cargoes contained (see Table LXXXV^
p. 284). As will be seen further on, guano is no longer sold except
in the dissolved state. As guano, leaving its nitrogen out of account,
consists mainly of phosphoric acid, in the form of phosphate of lime,
it is, most generally, insoluble in the crude state. In certain very

^84

CHEMICAL MANURES.

favourable circumstances, rarely met with, it becomes soluble in the
soil, owing to the nitrogenous matter with which it is mixed. But
beyond these conditions, it is no more soluble than the guano from
Baker's Island, and consequently it is inactive ; it is no longer sold
except in the soluble condition.

TABLE LXXXV.— ANALYSES OF DIFFEEENT CARGOES OF PERUYL\N GUANO.

I.

II.

III.

IV.

V.

VI.

Per cent.

Per cent.

Per cent.

Per cent.

Per cent.

Per cent.

Phosphoric acid,

total .

8-70

11-40

9-0

9-25

8-65

10-30

Phosphoric acid

soluble in water .

2-6o\

4-2o^

-7-95
3-7oJ

2-15^

-6-75
4-6oJ

2-40^

2-551

-7-25
4-7oJ

5-25]

Phosphoric acid
soluble in citrate.

l7-2o

-7-30

7-05

l-8oJ

after Petermann

4-6oJ

4-90

Nitrogen, total

8-20

13-35

14-60

8-90

8-85

8-60

,, amnion i-

acal .

1-95

3-05

1-85

2-40

2-65

7-20

Nitrogen, nitric

0-00

0-05

0-00

0-10

0-10

0-05

„ organic .

6-25

10-25

12-75

6-40

6-10

1-35

Potash .

2-10

3-05

2-45

1-95

2-30

4-25

Of total phosphoric

acid, soluble in

water and citrate,

per cent

83-33

69-7

75-0

79-0

83-0

68-4

Dissolved Peruvian Guano. — Under this designation the Anglo-
Continental Co. deliver a special sort of guano with a guaranteed per-
centage of 7 per cent of nitrogen, 9 '5 per cent of phosphoric acid
soluble in water ( = 10 to 11 per cent of total phosphoric acid), and 1
to 2 per cent of potash f = 2 to 3 'O of sulphate of potash). As guano
is generally loaded into ships in the bottom of the hold as ballast,
a part of the cargo is perforce drenched with sea water. In the
early days, importers placed this damaged portion on one side ;
but it ended in locking up considerable capital, and means had to be
taken to unlock it. Attempts were made to dry the damaged guano
and to sell it cheap to farmers. But this method of utilizing
damaged guanos had numerous drawbacks. Nothing in fact could
distinguish it from the guano which had not been drenched, neither
the outside appearance nor the smell, nor the chemical analysis
itself, which showed the same percentage of nitrogen as normal

guano.

The importers carefully considered these drawbacks. Accord-
ingly, acting on the advice of the chemists, they attempted to
improve the damaged guano by dissolving it with sulphuric acid.
As the manure so treated gave good results, the result was that this

NITROGENIZED PHOSPHATIC MANURES. 285

treatment was applied to all guanos indifferently, so that for the
past fifteen years, 96 to 97 per cent of the dissolved guanos was
produced from non-deteriorated guano. In the later contracts
between the Peruvian Government and the Peruvian Guano Co.,
this state of things has undergone no alteration. The process used
to dissolve Peruvian guano is as follows : —

As the guano exists in big lumps in the raw state it must first
of all be ground to a fine powder. As it would be idle to pass all
the mass of guano through the crusher, the latter is combined with
a shaking sieve to separate the powder from the big lumps, which
are alone ground.^ The crusher also eliminates from the guano
stones (granite) 'brought from the deposits, which when they are not
too large are fixed between the bars of the machine, from which they
may be removed. In this way about 1 per cent of stones is ob-
tained, which is debited against the su^Dplies of the guano at the
purchase price.

The powdered guano thus obtained is then mixed with 22 per
cent of its weight of sulphuric acid of 66° B., sp. gr. 1-84 (168° Tw.),
or with the equivalent of the acid at 60° B. As the phosphoric acid
exists as dibasic phosphate, the solution requires no plant, and is
done by simple shovelling. The material is then laid in heaps,
where it sohdifies. When the reaction is finished, the guano is
again passed through the crusher to reduce it to powder, the form
under which it is put on the market. Dissolved guano contains
5 to 7 per cent of nitrogen and about 10 per cent of soluble phos-
phoric acid ; it is sold with a guaranteed analysis. -

As the Anglo-Continental Guano Co. can only supply a product
of uniform analysis, by carefully sorting and mixing the raw guanos
and not by the addition of foreign matters, sulphate of ammonia,
etc., it follows that the constant decrease in this nitrogen content
of the raw guanos reacts also on that of the dissolved guano.
Since 1878 the guano has been delivered uniformly with 10 per
cent of phosphoric acid and 5 to 7 per cent of nitrogen, at the wish
of the buyer. Dissolved guano has a considerable advantage over
raw guano — that of acting with absolute certainty. If the phos-
phoric acid of raw guano dissolve in the soil, when the temperature
conditions lend themselves thereto, it is precisely this subordination
which lessens its value and renders it illusory. As the solubility

1 The author seems to the translator throughout the manufacturing section
to have recourse to the disintegrator a little too often when it seems possible less
drastic means would do. But here the author himself owns the futility of grind-
ing powder, but throughout the previous text he seems to recommend passing
everything through the disintegrator — the whole manure such as it is, not only
core but the friable portion as well and even loose friable superphosphate. — Te.

- All manures in Great Britain must be so sold to meet the requirements of
the Fertilizers Act. — Tr.

286 CHEMICAL MANUEES.

of the phosphoric acid, moreover, depends on the percentage of
alkaline salts in the guano, present-day raw guanos are much less
soluble than the old Chincha guanos. Farmers were, therefore,
justified up to a certain point in attributing to the old guanos now
exhausted a characteristic specific action, not only because these
guanos contained 12 per cent of nitrogen against 7 per cent in the
present products, but also because the ammoniacal salts present
are insufficient to bring the phosphoric acid to a soluble condition
in the soil.

By now using 100 lb. of raw guano with 7 per cent of nitrogen
and 14 per cent of phosphoric acid, the same results would be
obtained as formerly with 58 lb. of the old guano (containing 12
per cent of nitrogen and 12 per cent of phosphoric acid), mixed
with 20 lb. of 36 per cent phosphoric acid and bone ash. It
follows that the use of raw guano in these circumstances would be
sheer waste of phosphoric acid. Taking it for granted that all the
phosphoric acid of the old guano was soluble in the soil (which is
•not absolutely demonstrated), it may be asserted with certainty that
•only the half of the phosphoric acid is soluble in the guano of the
present day. Now by dissolving the guano the farmer can utilize
all the phosphoric acid present in the manure. Another advantage
which dissolved guano has over raw guano, is that its nitrogen
cannot be volatilized nor consequently lose its nitrogen in the air.
All the carbonate of ammonia is converted into sulphate, and if
new portions could be formed it would at once be fixed by the
sulphuric acid.

Finally, dissolved guano is more easily applied than raw guano ;
it contains neither lumps, which oblige the farmer to crush it, nor
dry powder, which, spread in stormy weather, lost itself in the
neighbouring field. Dissolved guano is in the form of a moist but
not tacky powder. The farmer has so well understood these ad-
vantages, that he has given up the use of raw guano. ^

1 The farmer has no option but to give up what is not available. \Yhen
the old guano was applied to gi'ain crops at the time of sowing it was appUed
broadcast, and in the north-east of Scotland by an experienced man who dis-
tributed it with both hands, swinging them rhythmically, and alternately throw-
ing to the left with his right hand and to the right with his left hand, in a
manner to be seen to be appreciated. If these farmers could get the old guano
back again they would soon find means of applying it. In former days the bags
were distributed over the field, and the requisite amount carried by women on
their heads, in a wide sieve-shaped vessel with a leather bottom, to the man sowing
it, the whole forming a picturesque scene when the man distributing the manure
had the knack of s'winginghis two hands almost simultaneously and in opposite
direction. Grain was sown in the same way. If the guano burned the cloihes
and got in the eyes that only showed its virtue. Now the fanner only gets the
dead body, whose spirit, volatile ammonia, has departed. The sulphuric acid has
killed it by fixing it, even if it has dissolved the phosphates ; besides it must be
remembered that the sulphuric acid used to dissolve it only costs £2 per ton at
the most, and that the cost of the guano to the concessionaires is diminished
^ro rata. — Tk.

NITEOGENIZED PHOSPHATIC MANUEES. 287

Other Nitrogenized Guanos. — Amongst other nitrogenized
.guanos, mention must be made of Ichaboe guano (Ichaboe is an
island on the West Coast of Africa). This manure has been known
for a long time, but was never of very great commercial importance,
because the first arrivals only contained 8 per cent of nitrogen and
20 per cent of phosphoric acid ; those which followed tested less and
less. Ichaboe guano rather approaches phospho guanos. Latterly
new deposits of guano have been found on the island of Ichaboe,
formed by sea-fowl, and not damaged by moisture. The percentage
•of nitrogen in this guano, which contains feathers and the un-
decomposed carcases of birds, rises to 14:"4 per cent, and its
phosphoric acid content to 17*6 per cent.

Different deposits of guano were discovered a long time ago
on different points of the African coast, such as those of Algoa Bay,
Saldanha, and those of Cape Colony. But these deposits, almost
a,ll exhausted by moisture, never had a great importance.

Seal Guano. — Seal guano has been found in several parts of
the West Coast of South America, in the Bav of Ferrol, in the
Lobos Isles, and in the Isle of Tortuga. The^e deposits are even
now the habitat of seals, so that they are incessantly being formed.
In the Lobos Isles, the guano forms a bed 70 metres (say 230 feet)
thick at many points ; it consists chiefly of the carcases of animals,
bones, fur, hair, etc., all slightly soluble substances. This guano
<3ontains much less nitrogen than true Peruvian guano ; it is analo-
gous to the guanos of the lower bed of the Chinchas deposits above
mentioned.

Bat Guano. — There was formerly on the market a guano of
this kind, under the name of Sarde guano. Stockhardt found in
that product : —

TABLE LXXXVI.— ANALYSIS OF BAT GUANO.

Per cent.
Nitrogen . . . , ' . . . . 2-0o

Phosphate of lime 35-30

Alkaline salts 3-60

It consists chiefly of bat excrements mingled with the dead
bodies of these animals. Bat guano is found in grottoes and rock
fissures, on the shores of the Mediterranean, in Brazil, Hungary,
France, near Vesoul in Egypt. The largest deposit up to now is
that of Kolumbacz, on the Danube, which contains 4000 tons of
guano.

Hungarian Bat Guajio contains, according to Scheibler, 1-88 per
cent of nitrogen and 11-64: per cent of insoluble phosphoric acid ;
it is only, therefore, of small value. The guano found in the

288 CHEMICAL MAXUEES.

neighbourhood of Cracow is richer. It forms a brown mixture of
excrements and bone debris. Analysed by Krocker, it gave : —

TABLE LXXXVII.— ANALYSIS OF HUNGAPJAX BAT GUAXO.

Per cent.
Moisture . . . . . . . . 7-50

Combustible matter ...... 7o-20

Ash 17-20

Its total nitrogen content is from 9* 170 per cent, of which
3'60 per cent is as ammoniacal salts. O'llS per cent as nitric
nitrogen, and 0-452 as urea, and other organic bodies. The ash
consists in part of phosphate of lime, in so far that the phosphoric-
acid content is 3 •825 per cent.

Egyptian Bat Guano contains, according to Popp : —
TABLE LXXXYIU.— ANALYSIS OF EGYPTIAN BAT GUANO.

Per centt
Urea ^^.^^^ Average of 37 analyses :

Uric acid ....
Creatine . . . .

Phosphate of soda (monacid)
Insoluble . . . .
Moisture ....

, .-,_^ I nitrogen 3/ per cent
.-,7' r (soluble phosphoric
acid 7-18 per cent).

13-4o0
0-o7o
3-660

99-285

This guano is not only the richest in nitrogen of all guanos found
up to now, but moreover of all nitrogenized manures.

Eboli Bat Guano (province of Salerno j contains, according tc^
Dr. G. Paris, 2-996 per cent nitrogen, chiefly nitric nitrogen. There
is also found : —

TABLE LXXXIX.— AXALYSIS OF EBOLI BAT GUANO.

Per cent.

Moisture 18-20

Organic matter 29-11

Ash 52-87

100-18

The ash contains 20-69 per cent of phosphoric acid, of which 47'96'
per cent is soluble in citrate. All these deposits are comparatively
unimportant.

Conclusion. — Fifty years ago Peruvian guano completely
dominated the manure market ; no other artificial manure could at
this epoch meet the wants of the farmer.^ Nitrate of soda was too

1 The old raw Peruvian guano was exceptionally highly esteemed by the
farmers in Scotland, where the translator has also seen it in bags branded
" ammonia fixed " in the early 'sixties. The raw guano suited the soil and
climate of the Moray Firth coast better than anv other manure. — Tr.

NITEOGENIZED PHOSPHATIC MANUEES. 289

high in price, the manufacture of sulphate of ammonia was in its
infancy, that of superphosphates was just commencing and could
only maintain itself with a great struggle in presence of guano ; the
preparation of bone manures, although well advanced at the
time, was limited in its scope by the poverty of the raw material.
Under these conditions, Peruvian guano was the sole regulator of the
price of nitrogen and of phosphoric acid on the international
market.

To-day the situation is not the same. The improvement in
the condition of manufacture in the nitrate districts enables the
concessionaires to flood the European markets at prices which
formerly would have been regarded as ridiculous. The production
of sulphate of ammonia in gasworks pursues an ever-increasing
progress. The exploration of the Pacific Ocean is always discover-
ing new islands of phosphatic guano. Enormous deposits of
phosphates have been discovered. Finally, blast furnaces furnish
the farmer with large quantities of phosphoric acid in basic slag.
The 2 or 3 per cent of potash supplied by Peruvian guano is
largely replaced by Stassfurt salts, Aschersleben salts, etc. This
abundance of manure is very reassuring as regards the future, and
the near exhaustion of the phosphatic guanos may be regarded
without apprehension.

But it is not so as regards nitrogen, which only forms a part
of guano. For however important may be the resources of the
farmer from this point of view, and although he now only utilizes
human excreta to a slight extent, nitrogenous manures are none the
less the dearest. The discovery of Hellriegel of plants capable of
fixing atmospheric nitrogen through the intervention of certain
bacteria, now enables the farmer to economize on nitrogenous manure.
Eumpler quotes a rural farm which collects 40 tons of beets to the
hectare (16 tons to the acre) with a very high percentage of sugar,
and using only a small amount of nitrate, by ploughing in green
manures [vetches (tares)] and completing them by a strong ap-
plication of superphosphate. Green manuring completed by a
good dose of phosphoric acid, potash and lime, forms the manure
of the future. It is likely to revolutionize all the present-day systems
of farming by freeing the farmer from paying tribute to exotic
nitrogen. In any case it holds the key to the solution of the ex-
haustion of guano question.

Fish Guano. — Historical Bevieiu. — The sea is an inexhaustible
store of fertilizing matter. Independent of its own richness, it is
incessantly receiving organic and mineral matter removed from the
soil or detached from the mountains bv the rain of storms. More-
over, it receives the human excreta which civilized towns run mto
the rivers. All these materials contribute to maintain the marvel-
lous fertility of the sea. For many years the sardine fishing has.

19

290 CHEMICAL MANUEES.

been a highly important source of profit to the inhabitants of the
Brittany coast, and has powerfully contributed to maintain a sailor's
nursery. As far back as 1620, in the single small village of Port
Louis, 4000 barrels of sardines were packed annually. Up to 1823
the only method of preserving sardines consisted in salting them
and pressing them in barrels ; they were thus put on the market
under the name of "pressed sardines". This method of preserva-
tion was replaced in 1824 by a new process kaown under the name
of Ampere [?Appert], its author. This process consists in removing
the head and the viscera from the sardines, and to pack the latter
in tinned iron boxes, in which they are preserved in oil after having
undergone a preparation known to everybody nowadays. This
new method produced much waste of considerable fertilizing
value for the soil. However, this debris was not utilized ; in the
beginning it was run into the sea, where it was lost without any
profit. It was only in 1847 that Demolon conceived the idea of
-utilizing it as a manure. He desired first of all to use it in the
raw state, but as he received it at a time when the crops had been
already laid down, he was obliged to store it for a certain time.
It then putrefied and became a pest to the neighbourhood. Demolon
then tried to store it by a more efficacious and less annoying pro-
cess. After having tried different means he conceived the idea of
boiling it. In that way he succeeded in extracting the oil, then he
dried it and reduced it into cakes which kept as well as oil cakes.
In 1850 he built a factory in Newfoundland to treat there the
debris left from the cod-fishing. The plant of this factory consisted
of six boilers to boil the fish, sixty presses, two graters and four mills.
The whole was driven by four small steam engines. The fish
as it came to the factory was fed into a revolving horizontal steam-
jacketed pan. The steam entered through the centre of this pan,
heated the double jacket, and in ten minutes the fish was cooked.
The door of the pan was then opened and the fish fell on to an
inclined plane. The water and oil fell into a reservoir, and the
solid parts were pressed, enclosed in scourtim analogous to those
used for the extraction of olive oil. The products were afterwards
dried in a stove with a superficies of 900 metres (say 3000 ft.).
Finally, the oil was run into a sufficient number of vats. When
the fish debris was boiled, pressed and grated, it was placed on
frames lined with cloth which pushed each other through the stove,
so that after half an hour the completely dried debris fell into a
hopper and thence into mills in which it was pulverized.
Without boiling the fish it could never be dried completely
or the oil extracted. By boiling, the oil was extracted, which
sufficed to pay all the costs. This manure contained 5 per
cent nitrogen and 49 per cent phosphate, and was sold at 30 francs

NITEOGENIZED PHOSPHATIC MANUEES. 291

the 100 kg. (12s. a cwt., £12 a ton). But this new industry injured
too many interests. Demolon and his partner were circumvented
by speculators, who, once masters of the factory, found nothing
more urgent to do than to demohsh it. Demolon 's idea was not
long in being taken up again in Norway, where fish manure was
made after the same process, then in America, especially at Boston,
and in Great Britain, always according to Demolon's process. Jules
Loreau & Co. have built at Kernevel, near Lorient, that is at the
door of the sardine factories (sardines a I'huile), so numerous in these
districts, a factory where they convert into manure all the detritus
coming from these factories. This debris, which consists largely
of heads, cartilages and intestines, is received at the factory on
tables or sloped floors which allow the brine charged with blood to
drop into a pit, whence it is afterwards drawn off by a pump ; there
is thus a liquid and a solid portion. The liquid portion, that is the
brine mixed with a certain quantity of oil which is separated to be
sold, is delivered to the local farmers, who utilize it to enrich
their farmyard dung and especially for fertilizing meadows.
A proportion of ten to fifteen barrels to the hectare (say four to
six barrels to the acre) is sufficient to produce very good
crops. This manure undergoes an ammoniacal fermentation
in the pit and its action on vegetation is most energetic ; it
should therefore only be used on moist ground, as after rain, for
example; on analysis it shows a proportion of 1"34 per cent of
nitrogen. The fish debris after draining is lifted, made into a heap
and boiled over a naked fire, when a little water is added and clear
brine ; the boiling lasts two hours for 400 kg. (880 lb.) of sardine heads.
After boiling, the material is piled in layers between two wrought-
iron plates and submitted for five hours to the action of a press,
from which it issues in the form of a cake. The 400 kg. (880 lb.)
yield on an average 100 kg. (220 lb.) of cake with 25 per cent of
water. This cake is air-dried and then pulverized in a flatstone
mill, whence it issues ready to be delivered to the farmer. A pair
of flatstone mills yield 1 ton to 1^ tons of ground cake in twelve
hours, according as the weather is more or less dry. The average
composition of this manure is the following : —

TABLE XC— ANALYSIS OF BEITTAXY FISH GUANO.

Volatile r ^^t^i'. •

, , - Organic matter ....

V Nitrogen . . . . . .

/- Phosphate of lime ....

Ash . J Carbonate of lime and (alkaline) salts

I Silica ......

5-00

50-50 \ .rj,QQ

6-50 j
28-00 ^>

5-50 38-00
4-50 J

100-00

292 CHEMICAL MANUEES.

This fish manure, which is in great part delivered to the farmer
as it is, is also used at Kernevel in the manufacture of com-
pound manures and in that of phospho guano. The chief compound
manure, which is sold under the name of Breton Manure, is merely
fish cake mixed with a sort of fucus (seaweed) extracted at low
water. As to the phospho guano, it is manufactured by treating the
crushed fish cake with sulphuric acid of 50" B. Next morning it
forms a paste and ends by diying. It is advantageously used for
different crops, particularly for beets. It contains on an average 2 '5
of nitrogen. In Brittany the sardine industry commences at
Croisic and ends at Douarnenez; it yields about 6000 barrels of
sardine heads ; a barrel of 225 litres contains on an average 30,000
heads.

Manufacture of Fish Guano in Norway. — At the present day
fish guano is manufactured chiefly in Newfoundland and on the
islands of the Norwegian coasts. The most important factories of
this manure are in the Lofoten Isles to the north of Bergen. The
fishing industry, which is very important in the North Sea, and
the flesh of which is sold under the name of cod, yields a very
abundant raw material ; the head, the fins, the intestines, etc., are
utilized. Norwegian fish guano perceptibly resembles steamed bone
dust, although it does not occur in the same pulverulent form as
the latter. The process generally used is the same as that for
making bone dust. The fish debris is steamed, dried, and ground ;
steaming presents certain difficulties. When the digester described
on page 264 is used, the material cakes so that the steam cannot
pass through it ; steaming is therefore too strong on the edges and
the material is too much degelatinized, whilst the centre escapes
steaming. To remedy this di^awback, the firm of M. Friedi^ich of
Plagwitz, near Leipzig, has built a horizontal digester, an interior per-
forated cylinder revolving around an exterior cylinder. The material
to be treated is fed into the interior cylinder ; it is heated by steam
which is injected into the exterior cylinder ; then a rotary motion
is imparted to the first, the effect of which is to turn the material
over unceasingly and to renew the surfaces in contact with the
steam. The gelatinous solution is separated through a tap at the
bottom of the apparatus, and it is evaporated to transform it into
solid gelatine. After cooking, the material contains a rather large
proportion of water. That is why the material is dehydrated before
passing it to the drying machine by passing it through either a
hydraulic press or a centrifugal machine. A greasy liquor is thus
obtained which separates a little oil on standing. The dry material
is crushed in the same way as bones. For some years back fish
guano has been treated by sulphuric acid. It contains on an average
7-9 per cent of nitrogen^and 12 to 16 per cent of phosphoric acid.
The following are the analvses of several Norwegian guanos: —

NITROGENIZED PHOSPHATIC MANURES. 293

TABLE XCL— ANALYSES OF NORWEGIAN FISH GUANO.

Per cetit.

Per cent.

Pev cent.

Per cent.

Per cent.

Water ....
Organic matter .
Nitrogen ....
Alkaline earthy phosphate .

12-30

53 70

8-15

30-50

18-44 13-02

70-80 49-40

8-15 10-38

4-61 30-26

10-54

50-92

6-39

34-44

8-65
59-15

8-01
25-64

To tell the truth, fish guano has nothing in common but the name
with the different guanos which have been described in this treatise,
for it contains nitrogen in a different form and less assimilable than
in guanos properly so called.

Whale Guano. — Guano is also prepared from whale debris ;
this product is similar to the preceding. Whale flesh contains in
the fresh state about 5 per cent of nitrogen, and in the dry fat-
extracted state about 14 per cent. The bones of the whale contain
3| per cent of nitrogen and 23 per cent of phosphoric acid.

Crab Guano approaches fish guano. It is prepared from a
species of sea-crab or lobster, of which there is enormous con-
sumption on the coast of the North Sea. They are steamed, the
substance pressed, then it is roasted on plates, and finally reduced to
fine powder by grinding like fish guano. It is in the form of a
bright yellow powder mixed with fragments of shells, and contains
on an average 8 per cent of nitrogen and 3 per cent of phosphoric
acid. There is also a manufactory of crab guano at Oporto, Portugal.

To appreciate the fertilizing value of the manures just described,
it must be borne in mind that the greater part of their nitrogen
exists not under the form of readily decomposable gelatine, but as
a horny substance, which moreover always retains a certain amount
of fat. These manures therefore act slowly, after the style of raw
bone dust ; if spread in autumn they decompose sufficiently in the
winter to become active in the spring, supposing always that they
have not been buried too deeply. Meat meal and fish meal
dissolved by sulphuric acid with equal nitrogen and phosphoric acid
content are^ of the same value and produce the same effect as bone
superphosphate ; it is therefore more rational to use these manures
in their soluble condition. The consumption of fish guano assumes
every year a new extension. The best sorts are used to feed cattle
and chickens, while the ordinary sorts are used as manure. The
price in the market per 100 kilos, (say 2 cwt.) was the following at
the end of December, 1907 : —

Norwegian fish guano, 8 x 12 per cent
British „ ,,8x9 „

„ 7 X 11

22-80 to 23-10 francs.
21-55 to 20-85
17-80 to 18

294

CHEMICAL MANUEES.

It would be necessary still to describe a large number of nitrogen-
ous wastes, for substances of animal or vegetable origin when they
are damaged and otherwise unutilizable may always be used for fche
manufacture of manure ; but as these substances rarely occur on the
market in sufficient quantity, it will suffice to indicate them with a
richness in phosphoric acid and potash.

. TABLE XCII. SHO^YING THE C(

3MP0SIT

ION OF NITE

OGENOUS

MANURES.!

The substances contain
per 100 lb.

Nitrogen,
ro.

Phosphoric

acid.

lb.

Potash,
lb.

Nitrogen in

dry substance.

lb.

Nitrate of soda

1.5-3-16-0

_

Nitrate oi potash

13-6-13-7

45-1-46-6

Nitrate of soda and of

potash ....

14-8-lo2

undetermined

Sal ammonia .

19-6-20-9

Dried blood

14-0-1O-0

—

Meat meal

14- 5 about

Hoof and horn dust .

13-16

Wool rags

variable

Leather shavings disin-

tegrated

5-9-30

—

Bullocks' hair .

13-78

Cheese ....

4-53

—

—

Colombine

8-39

1-15

0-25

8-42

Silkworm litter oth and

6th period

3-28

0-15

6-64

Beetles ....

3-29

0-4-0-7

?

10-000

WTiite worms .

7-92

?

?

7-92

Greaves in cakes in mar-

ketable condition .

11-87

12-5-15

Fish waste

5-7

2-3

7-6

Nitrate of soda pure

16-47

,, potash pure

13-86

46-53

Sulphate of ammonia pure

21-21

Ammonium chloride pure .

26-17

1 The nitrogen in several of these nitrogenous manures is more than
usually high, almost double that of ordinary commercial samples, e.g. meat meal,
greaves, etc. No table like this is a guide to the composition of any given
sample on the market, the real value of which actual analysis can alone decide.
— Tr.

CHAPTER XYI.

POTASSIC MANURES.

Preliminary Remarks. — The ash of plants consists for the most
part of carbonate of potash, the caustic and detergent properties of
which were bound to attract attention from the very beginning of
civihzation. And as a matter of fact the ancients knew this sub-
stance and employed it in domestic economy as well as in industry.
Aristotle described the manner of extracting potash from the ash
of plants. His process is still in use in certain countries. It con-
sists in submitting the ash to a series of washings with water,
concentrating the lye by evaporation, and in calcining the residual
salt. As plants only leave a small amount of ash, and as this does
not wholly consist of carbonate of potash, it is clear that the yield
of potash cannot be very great. The plants the most rich in potash
are the following :—

TABLE XCIII.— POTASH CONTENT OF VARIOUS PLANTS.

Potash in ICKJO parts.

Potash in 1000 parts.

-

Pine . . . • .

0-45

Fern ....

6-26

Poplar

0-7o

Reeds ....

7-22

Beech

l-4o

Maize stalks

17-50

Oak .

1-53

Suntlower stalks

20-00

Willow

2-85

Chrysanthemum

25-00

Alder

3-90

Nettle ....

25-03

Wheat straw

3-90

Vetches (tares) stalks

27-50

Thistles .

5-00

Absinth stems .

73-00

Vine .

5-50

Fumitory ....

79-00

Barley straw

O-80

In this category some plants will be remarked as very rich in potash,
such as fumitory, absinth. Did not some persons have the idea about
1850 of cultivating them to extract the potash ? Thus, in Sardinia,
a plant was cultivated called in common language glacialo (Mesem-
bryanthemum cristallineum) so as to obtain potash by burning it.
The analvsis of the ash of this plant, cultivated in le Nord, gave 30

(295)

296 CHEMICAL MANURES.

per cent of carbonate of potash and 6 per cent of carbonate of soda,
and sodium chloride. To appreciate the economic bearing of this
idea, it will suftice to recall that plants can only draw potash from
the soil, and that by growing potash-loving plants too often on the
same ground it would soon become exhausted and sterile, unless the
amount of potash extracted by the plants were restored. But then
that would be going round in a bad circle : furnishing potash to the
soil, as say potassium chloride, only to convert it into carbonate of
potash in the plant which must be extracted by burning. It is un-
necessary to dwell further on the subject.

Until comparatively recently plants were the sole source of
potash, and as the industrial consumption of this plant was formerly
much greater than to-day (they did not then know that soda could
replace potash in most of its applications), the product was always
insufficient to meet the wants of industry.

About the end of the eighteenth century the invention of Le-
blanc, which consisted in extracting soda from common salt, chloride
of sodium came to deliver the farmer from the incalculable tribute
which he was obliged to pay annually to industry under the form of
potash. Some industries, however, especiall}^ glass manufacture,
continue to use potash owing to the impossibility of their replacing
it by soda. Attempts were then made to reduce the potash which
occurs in abundance in a great number of insoluble and difficultly
soluble minerals such as granite, porphyry, potash-felspar with
16"6 per cent of potash. But soon the discovery and the exploitation
of the enormous deposits of potash salts of Stassfurt rendered this
useless. Now, and for some time back, potash, or better carbonate
of potash (for the word potash is no longer used except to denote
the impure product), has been made in considerable quantities by
the Leblanc process. The raw material used, the kainit, hard salt
(p. 299), is supplied by the Stassfurt mines.

Stassfurt Salts. — In the Stassfurt mines very soluble potash
salts occur in sufficient quantity to meet the wants of industry for an
unlimited period. Far from having recourse, henceforth, to the
farmer to borrow potash, industry is enabled to restore to him the
enormous quantities which it had taken from him in the course of
centuries. Encouraged by the geognostic conditions of the Stassfurt
region, the first boring was begun on 3 April, 1839, in the hope
of finding new deposits of common salt, the production of which was
insufficient in the district. In the month of June, 18i3, the first
portions of salt were brought to the surface, and in 1851 a bed of
salt 325 metres thick had been passed without reaching the bottom.
The borehole was then 581 metres deep. The salt extracted from
the borehole in 1843 had a density of 1*205, and the deeper the bed
was penetrated the more the density increased. The analysis of
the product gave the following results : —

POTASSIC MANURES. 297

TABLE XCIV.-ANALYSIS OF FIRST BOREHOLE SAMPLE OF

STASSFURT POTASH SALTS.

Per cent.

Magnesium sulphate 4-01

chloride 19-43

Potassium „ . • . • • • .2-24

Common salt ......•• •5'o2

31-89

The poor content of this product in common salt caused a deep de-
jection which seemed likely to put an end to the researches. But
as far back as 1848 Prof. Marchand of Leipsic asserted that the
bed of salt ought to be pure and that the magnesium salts must
come from the upper beds of the deposits. They commenced
to dig the first pit (Yon der Heydt) on 4 December, 1851, and the
second (Von Manteuffel) on 31 January 1852. In 1856 they reached
the exploitable bed at 333 metres (1092 feet) depth.

In 1858 the government of the Duchy of Anhalt likewise
caused two pits to be excavated for the working of salt. A very
pure bed of rock salt was found 300 metres (984 feet) in thickness.
But after a few years it was seen that the bed of rock salt was far
from representing the chief value of the mine. It was observed in
fact that the saline beds which covered the common salt and from
which the magnesium salts came which had been found in the
depths of the bed formed enormous deposits, and contained an im-
portant proportion of potassium chloride. This product, which they
did not know what to do with in the beginning, was destined to be-
come a source of richness to agriculture. In 1854 a deposit of
potash salts consisting of pure potassic chloride mixed with a little
common salt was also discovered at Kaluse in Galicia. In 1869 a
factory was built for its exploitation, but after a few years the crude
salts brought to the surface only contained 1 per cent of potassium
chloride. At the present time they there exploit a deposit of kainit
(see under this heading) which is much more extensive than that
of Stassfurt. In 1870 boring operations were conducted by Baron
Douglas at about 3 km. (say 2 miles) from Stassfurt, which ended
in discovering new deposits of potash salts, the working of which
was soon begun. Carnallite, extracted from the mine and treated
in the factory constructed on the working pit, is distinguished by
its great purity. The enterprise was soon taken up by a limited
liability company (Alkali werke Westerregeln), which continues to
work it on a vast scale. Another exploitation of ptotash salts is that
of New Stassfurt. It is interesting on account of the kainit which
it supplies to the farmer. At Stassfurt itself the pit Ludwig II,
which had been abandoned for a long time, has been reopened for
the extraction of carnallite. There are still found a little further

298 CHEMICAL MANURES.

away from Stassfurt the factories of Aschersleben at Bienenburg, of
Thiederhall in Brunswick, the Solvay factories at Bernburg, and the
Wilhelmshall pit near Anderbeck in the neighbourhood of Halber-
stadt. It would be futile to study here in detail the potash salt
deposits of Stassfurt and elsewhere. The reader desirous of more
ample information need only consult the special treatises on the
subject. But as a knowledge of the manufacturing methods about
to be described presupposes a knowledge of the minerals which
enter into the composition of crude potash salts, it is deemed useful
to describe them briefly.

Crude Potash Salts. — 1. Carnallite forms the chief ingredient
of crude potash salts. In the pure state it is clear as crystal, often-
iridescent ; generally however it is coloured red or reddish-brown by
scales of crystallized oxide of iron. Its fracture is conchoidal,
density 1-65. It is rarely found in distinct crystals in nature.
Carnallite crystallizes in the rhombic system. The angles of the
bases are 120° and 60°. The crystals of secondary formation met
with in mines rarely have a tablet form. They are more often
octahedral. Sometimes great masses of carnallite crystals are found
so compressed by pressure that their surfaces appear concave ; the
crystalline form is, however, quite distinct. Pure carnallite responds,
to the formula KCl + MgCl.j + 6H^0, and contains : —

TABLE XCY.— ANALYSIS OF CAEXALLITE.

Per cent.
Potassium chloride . . . • . . .26*76
Magnesium ,, . . . . . . • 34- 50

Water 38-74

100-00

100 parts of water at 18-75° C. (66-75° F.) dissolve 64*5 parts.

2. Sylvine or Sylvmite is a natural product resulting from the
decomposition of carnallite, and consists mostly of pure potassium
chloride. Freed from the common salt with which it is mixed, it.
has the composition represented by the formula KCl, and contains
in the pure state : —

TABLE XCVL— ANALYSIS OF SYLYINITE (PURE).

Per cent.

Chlorine 47-58

Potassium . . . • . • • .52-42

100-00

It is often colourless, rarely reddish or brown, brilliant like glass^
with slightly conchoidal reflection, altogether resembling rock salt,
crystallizing like the latter in regular cubes with an octahedral
surface. Its fracture is angular, its density is 2-025. The potash
salt found at Kalusz consists chiefly of sylvine ; it is coloured blue.

POTASSIC MAXUEES.

299

\Yhich orenerally only occurs with rock salt ; according to certain
authors, however, this coloration is due to admixture with blue rock
salt. Svlvine as it comes from the mine has the following com-
position, according to Mercker : —

TABLE XCVII. ANALYSIS

OF SYLYIXE AS IT

COMES FROM THE

MINE.

Pe7- cent.

Potassium chloride .

30-o5

Sodium ,,

. 46-05

Magnesium ,,

2-54

Potassium sulphate

6-97

Magnesium ,,

4-80

Gypsum .

1-80

Water and insoluble

7-29

100-00
Its potash content is 23-04.

3. Kainit is met with in large quantities, chiefly in the-
Leopoldshall mine and at New Stassfurt. A deposit of more than
25 metres (82 feet) has been found at Kalusz of almost pure kainit.
It is colourless, or yellow to reddish or even a very dark brown.
It is very hard in comparison ^\'ith the other minerals mentioned
in this chapter. Its density is 2-131. Its fracture has a crystalline
lustre ; it rarely gives true crystals. It contains, according ta
Eeichardt : —

TABLE XCYIIL— SHO^YING ANALYSIS OF KAINIT. (EEICHARDT.)

Potash . . . . .

17-37

Soda ....

5-90

Magnesia

14-76

Sulphuric acid (SO,)

30-00

Chlorine

18-56

Insoluble

0-22

86-81

Less oxygen of the chlorine

4-18

82-63

Water ....

17-37

or

Sulphate of potash 32-12 |

,, magnesia 22-87 )

Magnesium chloride

Water 17-37

A -^ -i.- ( Common salt 9*90

As impurities - x i ui a oo

^ ' Insoluble 0-22

54-9^
16-95

100-00

Pure kainit responds to the formula —

KoSO, + MgSO, + MgCl, + H.O.

Kainit is, therefore, a double sulphate of potassium and magnesium
combined with magnesium chloride. It forms, therefore, a peculiar
compound, which no one as yet has succeeded in reproducing-
artificially like svlvine and carnallite. Its mode of formation is thus
uncertain ; it is supposed, however, that it results from the action of
water on a mixture of carnallite and kieserite found in the salt

300

CHEMICAL MANUEES.

deposit. Kaiiiit, as it is extracted in considerable quantities from the
Leopoldshall, New Stassfurt and Kalusz mines, is freed as much as
possible from common salt intercalated with it, then it is reduced to
fine granules in a salt mill. It is put on the market as ground
kainit, and contains on an average 65 to 75 per cent of pure kainit
or 23 per cent of sulphate of potash (equal to 12-4: per cent of
potassium).^ The impurities consist chiefly of common salt and
clay. Formerly, kainit was calcined and ground. This process
has been abandoned in the Stassfurt factories. As it readily cakes
and is then very difficult to break up, it has been mixed, on the
advice of Fleischer, with 2*5 per cent of peat powder, which prevents
this drawback. The same means is used for other potash salts
when they are sold for manure. -

4. Schoenite is the double sulphate of potassium and magnesium
and responds to the formula K.,SO^ + MgSO^ + 6H.,0. Its forma-
tion at the expense of the kainit by elimination of the chloride of
magnesium would therefore be very plausible ; its existence as a
mineral is not established with certainty. Artificial schoenite will
be described further on.

5. Polyhalite. — It is found in veins of 26 to 33 metres thick in
the deposits of rock salt. It is mostly amorphous, rarely crystalline,
of a grey colour and conchoidal fracture. Density 2*72.

TABLE XCIX.— ANALYSIS OF POLYHALITE.

Per cent.
Potassium sulphate ....... 27-90

Magnesium ,,
Calcium ,,

Water ....

Common salt and impurities

19-76

42-64

5-75

3-49

99-54

1 Should be, potassium equal to 12-4 per cent of potassium oxide K^O. — Tr.

2 The breaking up of kainit is a costly job. It should not be stored in bags
piled one on the top of the other, but on arrival it should be shot in a dry place,
covered in of course, and with a smooth dry floor. It can be brought from there
readily in a barrow to where it is wanted . by one man, whereas it takes two men
to lug and tug about the caked bags and cut them open with a knife to get
out the kainit solid as a rock, and then the tiresome job begins of pounding it
with wooden mallets to break it up, and the small amount a couple of men can
break up and screen in a day is well known to those who have been kept waiting
for it to complete the ingredients in a heap that is to be dry mixed. A little
better progress is made with the disintegrator, but even then it is a heart-rending
job, as no sooner is the disintegrator started and well under weigh after a
stoppage than the naturally moist kainit again blocks it. The advice of the
translator is therefore to shoot the bags at the outset. The pressure cannot find
vent without bursting the bags, therefore the kainit must consolidate and perforce
eake into a soUd as hard as in the original rock. 'The store should be an oblong
"building with the door in one end, and the concrete floor should rise gradually to
fthe far end, where kainit and other water-soluble products should be stored be-
jond the reach of floods. — Tr.

POTASSIC MANURES.

301

It responds therefore to the formula —

K,SO, + MgSO, + 2CaS0^ + 2Hp.
When treated with ^Yater it is the potassium salt which preferably
dissolves, whilst the magnesium sulphate and the calcmm sulphate
remain in great part undissolved. Before being discovered m the
Stassfurt mines polyhalite had been already met with m ditterent
places at Ischl, Hallein, Berchtesgaben, etc., partly as rhombio
crystals or fibres or minute crystalline rods. tit-

6. Krugite has a chemical composition similar to polyhalite.
It responds to the formula —

K^SO, + MgSO, + 4CaS0, + 2H,0.

TABLE C.-ANALYSIS OF KEUGITE. (MEECKER.)

Potassium sulphate

Magnesium „

Calcium ,,

Water

Common salt . ,

Per cent.

18-60

14-70

61-00

4-20

1-50

100-00

Density 2-801. , ^ , , -

It now remains to describe the processes used to extract from
these minerals the whole series of products supplied to agriculture

as potassic manures. . . j. , -ui mr,^

Manufacture of Potassium Chloride [muriate of PO^ash].— Ihe
crude salt treated consists of a mixture of all the salts described
above. However, carnallite predominates ; it forms 50 to 60 per cent
of the crude salt, equal to a potassium chloride content ot Id to U
per cent. The processes now used in the treatment of the crude
salt in the manufacture of more pure potash salts (potassium
chloride) are based essentially on the property of carnallite to de-
compose in presence of water into potassium chloride and magnesmna
chloride ; it is therefore dissolved and potassium chloride separated
from the solution by crystallization. The process is m itself very
simple ; what complicates it is the presence of quite a series ot
foreign salts accompanving the carnallite, the most important of
which are rock salt [NaCl], in the proportion of 20 to 25 percent
and kieserite [MgSO, + H.O], which forms lo to 20 per cent
of the crude salt. Other' minerals, such as kamit, polyhalite,
tachydrite CaCl.. + 2MgCl. + 12H,0, etc., are rarely met with m
large proportion,' but they t'hen are very troublesome in the process
CritJmig the Crude Salts.-As the mines deliver the crude salt
in big lumps (in the beginning they delivered them ground) they
must be crushed before being treated. Formerly they were satisfied
with crushing lumps by blows from a mallet with a long handle.

302 CHEMICAL MANURES.

but now all the fac Lories have laid down mechanical crushers for
the purpose ; the machine most used is the jaw-breaker crusher
already described. ^

Dissolving the Crude Salts. — The salt is then fed into a pan,
in which it is dissolved. The crushed salt falls from the mill into
the receiver of a cup-elevator, which delivers it directly into the
dissolving pans or into a wrought-iron shoot. The elevator is
driven by a shaft on which is mounted the belt pulley. The dis-
solving pan is of riveted wrought-iron of a cylindrical form ending
in a conical bottom. At the beginning of the cone is a perforated
short bottom intended to retain the residues from the salt. These
residues are run out through a manhole. The solution is drawn
off by a tap, the pan is steam heated. In the early days the
Stassfurt and Leopoldshall factories wrought in an appreciably uni-
form style, but lately thej^ have adopted ditierent methods more con-
formable to the interests of each factory. The oldest method, still
much employed, is the following : The dissolving pan is first partly
charged with water, mother liquor, which is termed II, with residual
solution I (see further on) and with clarified solution III (see further
on). After having brought this mixture to the boil, by direct injection
of steam, the crude salt is fed into the elevator, whilst continuing to
boil without interruption ; the carnallite soon dissolves and therefore
±he density of the solution increases gradually ; the escaping steam
by a suitable arrangement sets the liquid in motion and mixes its
different components. When the density of the liquid, taken on a
boiling sample, reaches S2^ to 33" B., the elevator is stopped, the
steam turned off and the solution run out ; the residue remaining in
the pan contains a large proportion of kieserite, common salt, and
about 2 to J: per cent of potash salts. In a great number of
factories this residue is again taken up and boiled with a little
water ; the solution thus obtained (I) consists therefore chiefly of
common salt, a little magnesium chloride and magnesium sulphate.
Its potassium content varies from 3 to 7 calculated' as potassium
chloride ; it is used solely to dissolve fresh quantities of crude salt.
The proportions of the different solutions as well as the densities
varv with the factorv. The residues are thus more or less abund-
ant and retain more or less salts. The best results are obtained by
preparing solutions of 32° B. with lower densities ; they retain a large
amount of common salt ; when on the contrary their density is
higher, they retain less common salt and more potassium chloride.

Clarification. — Crude solution as it comes from the pan is
soiled with impurities ; it is therefore run into clarification basins,
where it remains for about fortv-five minutes. These basins are
rectangular, of riveted wrought-iron, fitted with two apertures,
from one of which the clarified solution is run off, and from the
other the sludge. To prevent the clarified solution carrying the

POTASSIC MANURES.

303

sludge with it, different arrangements have been made to retain it.
After the clarified solution has been run off, it is led through a
wrought-iron gutter into underground crystallizers. As the solution
cools in flowing through the gutters, it deposits a certain amount of
salt containing 45 to 50 per cent of potassium chloride. This gutter
salt is most generally used in manure manufacture. It is generally
treated with potassium chloride of a higher strength.

Crystallization.— The crystallizers in w^hich the solution cools
and forms crystals of potassium chloride are of riveted wrought-
iron like the clarification basins ; they vary in size and shape, some-
times flat because the solution cools more quickly therein, some-
times deep because they occupy less space and yield larger crystals.
When the solution is cold, which takes two to four days, the mother
liquor II is decanted from the crystals of potassium chloride ; it is
run off by the gutters fixed under the crystallizers into wrought-iron
basins or into masonry ones lined with cement. It is used either to
dissolve the crude salt or treated directly as will be described further
on. The potassium salt which is deposited in the crystallizers
consists of a mixture of potassium chloride and common salt ; it is
stifl soiled by adhering mother liquor. It crystallizes in the same
form as sylvine, with this difference that the crystals are not always
perfect ; their size depends chiefly on the density of the solution of
crude salt. When that has a density of 32° to 33° B., or a still weaker
density, crystals often one centimetre wide, of a pearly lustre^ are
obtained. ' When the solution is more dense, say about 33° to 35° B.,
it forms soft crystalline needles. It is clear that the size of these
crystals must ^considerably affect the purity of the potassium
chloride, as attenuated crystals must retain more mother liquor
than large ones, and that consequently they contain more magnesium
chloride. The impure, fine, granular salt often only contains but 60
per cent of potassium chloride, whilst the salt with large crystals
yields on analysis : —

TABLE CI.-

Insoluble

-ANALYSIS OF CRYSTALS FEOM POTASH SALT
CRYSTALLIZERS.

Per cent.
0-0876

Magnesium sulphate
„ chloride
Potassium „
Common salt

1-2468

6-9072

68-1504

23-5560

99-9480

It may be remarked in passing that the salt that is deposited on
the sides of the crystallizers is always more pure than that de-
posited at the bottom. To obtain high strength products, a portion of
the two sorts may be taken, especially for continuing the treatment.

304:

CHEMICAL MANUEES.

Clarifying. — As potassium chloride of 60 to 70 per cent strength
is hardly marketable, it is necessary to submit it to new treatment
— darification. For this purpose it is run into vats termed clarifying
vats, fitted \\^th a double bottom covered by cloth or with a network
of osiers. It is covered with water, so that the water is 2 to 3
centimetres above that of the salt, and left in contact 5 to 6 hours ;
then the clarified solution III is run off through a bung- hole in the
bottom of the vat. This liquid runs into a special basin, from which
it is run into the dissolving pans by a pump. The liquid from
the above clarification of 30^ B. contains : —

TABLE CIL— ANALYSIS OF MOTHER LIQUOR FROM CLARIFICATION

OF POTASH SALTS.

^Yater

-L V/ J. -T.kJ-LJ. lJXi.-l_l J. kJ.

72-212

Magnesium sulphate

....

. 1-659

„ chloride

....

. 11-730

Potassium ,,

«...

. -5-930

Common salt .

. • • .

. 8-469

100-000

If the potassium chloride be not sufficiently enriched by a single
clarification, this operation is repeated once or twice until the salt
contains at least 80 per cent of dry potassium chloride. The
above clarifying liquor constitutes a saturated solution. Now a solu-
tion of this nature contains at lo"" C. 25 per cent KCl when it is
prepared from pure potassium chloride, 27 per cent NaCl when
it is made from common salt. If these figures be compared with
those of the above analysis, it will be seen that the magnesium
chloride interferes with the solution of both the potassium chloride and
with the common salt. Now as the object of clarification is precisely
to eliminate this latter, it follows that a potassium salt with low
magnesium chloride content, consequently large -grained, will be
more easy to purify in this way than a salt with high magnesium
chloride content, fine-grained crystals. But clarification is a costly
operation because its object is to redissolve a portion of the finished
salt, therefore to work economically it must be done in such a way
as to clarify as little as possible, that is to say to produce large-
grained crystals as far as possible. Starting from the salt analysed
above, an 80 per cent product would be obtained by a single
clarification, whilst a fine-grained salt often requires two, sometimes
three, clarifications to get a product of the same strength. It is
clear that by this operation 95 per cent products and higher may
be obtained.

Treatment of the Mother Liquor from the Potassium Chloride. —
The mother liquor not used for dissolving is concentrated by evapora-
tion, for it still contains an important amount of potassium chloride.
It has a densitv of about 32" B., and contains : —

POTASSIC MANURES, 305

TABLE CIIL— ANALYSIS OF MOTHER LIQUOR FROM POTASSIUM

CHLORIDE.

Magnesium sulphate 2'-^ to 2-6

,, chloride

Potassium „
Common salt ....

19-5 to 20-9.
5-1 to 6
2 to :-i

In the evaporation the greater part of the common salt separates out
because it is less soluble when hot than when cold, at the same time
as the double salt of potassium and magnesium (schoenite), which is
hardly soluble. This mixture of residual salts often contains 7-5 per
cent of potassium, which corresponds to 12 per cent of potassium chlo-
ride, or to 14 per cent of potassium sulphate. It is utilized by either
extracting the common salt from it or by converting it into manure
of low strength. In rational manufacture the residual salt should
be washed in the pan itself ; for this purpose the mother liquor II
is used, as the salt as well as the pan itself is still very hot. When
the evaporated solution is run off, the mother liquor with which
the pan is drenched, heats rapidly and then dissolves the greater
part of the potassium salt which is still contained therein. This
solution is facilitated by stirring. When the density of the solution
determined whilst boiling reaches 34-5 to 35° B., it is run through
wrought-iron gutters into special crystalHzers, where it deposits not
potassium chloride, but a salt with tetrahedral crystals, the compo-
sition of which is analogous to carnallite. If the solution was
sufficiently concentrated, the liquid which flows from the carnallite
crystals (final liquid) only contains 1 to 1-5 per cent of potassium
chloride, and in addition : —

Per cent.

Magnesium chloride 26 to 28

,, sulphate ....... 4

Common salt . . . . . . . . 2 „ 4

In certain factories the bromine is extracted, in others the magnesia.
The artificial carnallite thus obtained is dissolved in water in smaller
pans than those used to dissolve the crude salt. The solution testing
32 to 33*^ B. is run into vats, where it deposits potassium chloride
more pure than that got from the crude salt. The mother liquor
of this salt is added to the first. As the carnallite from whence it
comes contains less common salt than the crude salt, this mother
Hquor yields little residual salt. The salt yielded by artificial car-
nallite is clarified with very little water, and then yields very high
strength potassium chloride (95 to 98 per cent).

Drying the Chloride of Potassium. — In most factories potassium
chloride is dried in reverberatory furnaces. In recently erected fac-
tories the drying is conducted in cylindrical coil -heated tanks, in
which an agitator with blades revolves, and a roller compressor.

20

306 CHEMICAL MANUEES.

When the shaft revolves the blades turn up the salt, and the roller
which follows makes them into a cake again, so that the surfaces are
coQtinually renewed. When the dryiog is finished the salt is run out
through a shoot and bagged up. In a general way factories which
work according to the processes described above are content with
producing 80 per cent potassium chloride ; they rarely push the
clarifications so far as to make 97 to 98 per cent products, although
the potassium chlorides dissolved by the clarification can be re-
covered immediately in the crystallizers, whilst the mother liquor
is used to dissolve the crude salt. To obtain 98 per cent salt without
effort, the method of dissolving the raw salt is altered. The mother
liquor, the small amount of clarifying liquor and finally the liquor
used to boil the residual salt, are alone used as solvent ; all addition
of water is avoided. After having brought the solvent solution in
the pan to the boil, the raw salt is run in as before and the whole
boiled without interruption until the solution tests 35 to 36" B. At
that density the carnallite in the crude salt easily dissolves if the
liquid be hot enough, i.e. if the steam be of sufficient tension.
Certain factories insert an agitator whose action contributes to mix
the solution, consequently to obtain a better result from the crude
salt. Nevertheless, the residue is sometimes still rich in potassium
chloride ; it is boiled a second time with pure mother liquor. The
solution so obtained is clarified in the same way as in the first
method ; on cooling it deposits not potassium chloride but carnallite,
which is allowed to drain and then dissolved in boiling w^ater to ex-
tract the potassium chloride. As common salt as well as kieserite
only dissolves slightly w^hen hot in a concentrated solution of magne-
sium chloride, whilst potassium chloride is very soluble therein, it
is clear that the solution prepared by this process should contain very
little common salt, and also that the carnallite which crystallizes
therein should contain very little, and the chloride of potassium
furnished by the latter should be of high strength. This method,
however, has the draw^back of yielding a large amount of carnallite,
the removal and solution of which require much labour and steam
and consequently fuel. This drawback is obviated by diluting the
solution which flows from the clarification vats with water, so that
after complete cooling it yields chloride of potassium of high strength
directly, and no longer carnallite. In this way the crystallization
and solution of carnallite are conducted in a single operation. The
advantages of this method of working are evident. Instead of treating
as before two different solutions and two different salts, only a
single solution and a single salt have now to be treated. The
potassium chloride so produced is so pure that when it is freed from
magnesium chloride by a little water it only contains 0*5 per cent
of common salt, all the rest is potassium chloride with a little
moisture and some slight impurities.

POTASSIC MANUEES. 307

Potassium Suljjhate. — This salt is manufactured at Stassfurt,
by drenching potassium chloride with sulphuric acid and calcining
in a reverberatory furnace. The reaction which takes place is the
same as that used to manufacture sodium sulphate from common
salt and sulphuric acid. First of all the material heats, gaseous
hydrochloric acid is given off, and acid potassium sulphate formed
according to the equation —

KCl + H,SO, = HKSO, + HCl.

Afterwards, the temperature continuing to rise, the acid sulphate of
potassium being weak acts on the remainder of the potassium chloride.
A new disengagement of hydrochloric acid gas is produced, and
finally potassium sulphate as a solid mass. This reaction is ex-
pressed by the equation —

KCl + HKSO^ = K,SO^ + HCl.

As the potassium sulphate as it comes from the furnace is in big
lumps, it must be crushed before delivery to farmers. In the same
way as the price of potassium chloride is calculated on the basis of
an 80 per cent salt, that of potassium sulphate is based on a 90 per
cent salt, consequently 100 lb. of this product at 95 per cent equal
110 lb. at 90 per cent. Potassium sulphate of 96 per cent strength
is worth about 2^d. more a cwt. on the 90 per cent basis than the
product which only tests 90 per cent.

Double Suljjhate of Potassium and Magnesium. — This product
has already been mentioned as schoenite, but is never found in that
form ; it is manufactured in large quantities from kainit. It consists
of equivalent quantities of potassium sulphate and of magnesium
sulphate, and contains in the crystalline state six equivalents of water.
The method of manufacture varies with the factories, but all pro-
cesses are based on the lixiviation of the magnesium chloride and
common salt from the kainit by hot saline solutions. The dried
ground salt contains about 48 per cent of potassium sulphate corre-
sponding to about 26 per cent of potassium, and it is put on the
market w^ith the guarantee of a maximum content of 2*5 per cent of
chlorine. This salt is much used as a manure.

It possesses the following composition, according to Mercker : —

TABLE CIV.— ANALYSIS OF SCHOENITE. (MEECKER.)

Per cent.
Potassium sulphate . . . . . • .50-4

Magnesium „ ....... 34-0

Common salt . . . . • • • . 2-o

Water 11-6

Its potassium content is therefore 27"2.

Double Carbonate of Potassium and Magnesium. — The salt
contains 17 to 18 per cent of potassium; it consists chiefly, as its
name indicates, of the carbonates of potassium and magnesium with

308 CHEMICAL MANUEES.

2 to 3 per cent of impurities, potassium chloride and potassium
sulphate. This salt, therefore, contains very little chlorine and
might perhaps he used as a fertilizer for tohacco. But the price of
potassium is about double in it to what it is in potassium sulphate.

Potash not only acts as a manure but it retains the moisture in
the soil. Certain potash salts absorb moisture and cake ; kainit
especially forms very hard blocks like stone. Spread in a thin layer
it absorbs 2 per cent of moisture in twenty-four hours.

Calcined potash salts absorb from dry air up to 6 per cent of
water, in five days 14 per cent, and up to 24 per cent in six days.
To prevent them caking into a solid mass it suffices to add 2-5 per
cent of peat powder ; the mixture so prepared keeps for two months
without drawback.

Other Fertilizing Salts. — The Stassfurt factories sometimes
make a fertilizer from other waste not hitherto utilized. For this
purpose the sludge deposited at the bottom of the clarification pans,
which always contain a little potash, is used. 100 parts of calcined
ground shidge contain : —

TABLE C v.— ANALYSIS OF SLUDGE FROM CLAPJFICATION OE

POTASH SALTS.

Insoluble (oxide of iron, sand, gypsum) . 6*34
Calcium sulphate .... 8'67

Double sulphate of potassium and

magnesium (MgSOj -h KiSO^l
Potassium chloride
Magnesium ,, ...

Common salt ....
Water and loss ....
Say 19-35 KCl or 22-o4 sulphate of

potash

100-00 12-22

Another product of this kind is furnished by the residual salt which
contains about 12 per cent of potassium sulphate ; as we have seen,
this consists of sludge and especially of common salt.

A third salt likewise used as a fertilizer is that extracted from
the gutters, which when diy contains about 50 per cent of potassium
chloride, and 45 to 50 per cent of common salt.

All these salts are treated in the same wav. Thev are dried
in a reverberatory furnace by heating them to nearly the point
of fusion, then they are crushed. Brown fertilizing salts with low
potassium content are hardly met with now on the market. The
salt from the gutters dried and ground is sold under the name of
" manure salt, calcined and ground," with a minimum guarantee of
27 per cent of potassium. Lately a whole series of other potassic
manures has been manufactured, but their high price is an obstacle
to their sale. The composition of the different Stassfurt salts are
summarized in the following table : —

16-46

Equal to potassium

11-01

5-27

10-24

6-95

. 45 -51

1-77

a

IS

s
o

2

9

3

OS

eg

o

0^

01

<v

s

s

be

>

rf< o ■*
-f^ Ot 71

X 00 -rt< ur

• • • ■

iM r: t^ t-

"fi y? -^ o

00 to 3; X »c "-H

rH X »C :0 O "*
iC -* 'M k^ i^ 't

O O O

bio

'M TIT -f

t^ r^ 'M ri tr- '^

t>- c- -M ;o

oi »c »o -^

<>)

O 'M

t- CI :p X> rH »C CI

O CI tH O T-l <>J -^

:o

•c

m
H

a

H

O
Oh

P5
H

20

PR
O

O

O

O
Q

>
O

c s

= 11 ^

ai3

^ 9

.2 -Co

iX

o

£ ®

3^ :,

C 3 5-.

X L^ CI M

O O CO rH

!>• qs CO X

rH tH Cl O

;p -^ t^ C~-

r-i cq CO i
TC CI »C CI

-^ lo :p CI
cq tH <CJ t-

iH Cl r-i

lO fH -^ lO

'^ Cl Cl -^
iH i-i Cl

S 0)

-^-' J— ^^^

o ira CO X

Cl O i '-'
1— I Cl 1— I

0)

CO

1—1

Cl

i-C

Cl TC -O Cl Cl »-C O

000000 -^

cc

rP "?* V

b b b

Cl

b

rH «?1

Cl Cl

Cl

Cl Cl LC 1-H »ff Cl Cl Cl

• ••••• • *

o —I Cl c^ "^ I— I o '-O

-H Cl 'i* ^

Cl

b

Cl

-«* o

b rH

Cl m cc

• • •

000

CO

X

Cl

t^ t- O Cl -^ X ^

b Cl -^ b 0 o o

■^

CJ

4t<

CO CD
b rH

!>• »0 IC

rH CO Ol
35 X t-

y:

CO

tc 10

d to "*

• • •

C- O O
Cl wi LC

O Cl

Cl '-I

O

Si

X

S

m

CO .+J

^ 2

o
• ;-!

.- ce

>
•I— (
(— ^
a>

O

0^ g §

> ?^' o

6C-

?3

o ^

• 35

OJ

ip'

i-C

X

^ c

' 0

r3

to 0

-4^

0

0

0 "^

•— , — '

0

X

^0

0
=♦-1

0

0

^

ri-i

^

m

ft

0

n

is

<-*

/— <

s

•xi

3

a

s

0)

00

Of

0

33

OI

ft

o

S

s

S
2 s

o

ft

o

CO

r3

s

(XI

a

o

ft

o

a>

:3 ft s

CC -l-» OQ

DO f3 00

i£ OI i£

■-2 ^

CO

g ., 00 o

-fJ i -t-i =4-1

o S o o

ft J3 ft

-t= CO -tJ -l-s

fl 2 s: =e

O) ^ OJ o

o

GQ

oS

-*;»
O

-(J

>s
DQ

<o

00

S3
c3

QQ

=5
O
Sh

3

O
OI

bO
03

>

310 CHEMICAL MANUEES.

Commercial Brands of Potassium Chloride {Muriate of Potash).
— The principal commercial brands of potassium chloride supplied
by the Stassfurt factories are the following : —

(a) 70 to 75 per cent potassium chloride (muriate of potash)
containing on an average 45 per cent of pure potash (K.^0) and
21 per cent of sodium chloride, 2*5 per cent of water, 1-7 per cent
of sulphate of potash, 0*8 per cent of sulphate of magnesia.

(b) 80 to 85 per cent potassium chloride (muriate of potash)
containing on an average 50 per cent of pure potash (K^,0), 14 per
cent of sodium chloride and 1*1 of water, etc.

(c) 90 to 95 per cent potassium chloride (muriate of potash)
containing 56*9 per cent of pure potash (K.p), 7 per cent of sodium
chloride and 0*6 per cent of w^ater.

(d) 97 to 98 per cent of potassium chloride. It is the most
concentrated product. For this latter certain factories guarantee
0"5 per cent of sodium chloride, for which an extra charge is made.

The selling price for all sorts is based on 100 kg. (220 lb.) at
80 per cent, bags included, that is to say that products with a plus
value are brought to 80 per cent by calculation. An example will
make this custom more plain. Suppose that the price of potassium
chloride of 80 per cent be 9 '40 francs, bags included, say 3s. 9d. the
cwt. If the muriate bought is of a higher strength (say 95 per
cent) it will cost 11-14 francs (say 4s. 6d. the cwt.), that is to say
100 kg. (220 lb.) of muriate at 95 per cent strength correspond to
118-75 kg. (261-25 lb.) of 80 per cent muriate. It is clear that
the price increases proportionately with the purity of the muriate.

As to sulphate of potash the price is calculated on a 90 per cent
basis. Consequently 100 kg. (220 lb.) of this product at 95 per
cent equal 110 kg. (242 lb.) at 90 per cent. Sulphate of potash
of a guaranteed strength of 96 per cent is worth about 0-50 francs
(4'8d.) more per 110 kg. (220 lb.) or 2^d. more per cwt. (price
based on this basis is price of 90 per cent) than the sulphate which
only tests 90 per cent.

Remarks on the use of Potash Salts as Fertilizers. — As already
seen, the Stassfurt mines furnish crude salts and refined salts as
fertilizers. Which should be preferably used ? This question is of
great practical importance which farmers are far from doubting if
we are to believe the emphatic putfs of kainit dealers and the other
societies " for the encouragement " (so-called) of the diffusion of
manures. In the last thirty years the consumption of potassic
manures has progressed considerably, but instead of using pure
salts the farmer has chiefly used the crude salts, kainit and carnal-
lite. As will be seen in the analyses given below, crude potash
salts contain besides potash, sodium chloride, magnesium chloride,
etc. ; in fact they contain much more chlorine than potash.

POTASSIC MANUEES.

311

The following according to analyses now old are the chlorine
content of crude Stassfurt salts : —

TABLE CVIL— CHLORINE CONTENT OF CRUDE POTASH SALTS.

Percentage of

Parts of

/

Chlorine
per 100

Potash
KoO.

Chlorine.

parts of
Potash.

Kieserite ........

7-44

34-67

46-60

Carnallite ........

9-78

37-03

37-86

Ordinary fertilizing salts .....

12-22

30-53

25-00

Kainit .........

12-76

31-21

24-45

Sylvinit . . .

2.3-04

44-39

19-27

Fertilizing salt, good quality ....

31-55

52-33

16-59

Muriate ot potash, 80 per cent ....

52-05

48-68

9-35

QO

58-37

47-67

8-16

,, ,, "o ., ....

61-48

46-95

7-59

Double fculphate of potassium and magnesium

27-22

1-52

5-5

Potassium sulphate, 90 per cent ....

49-93

2-23

4-5

96 „ . . . .

52-68

0-56

1-0

Carbonate of magnesium and potassium

17-18

?

■p

More recent analyses of kainit in the agricultural experiment
stations have shown for a long time that the proportion of chlorine
has been continually increasing.

Thus, in 1895, B. Sjollemay found 35-8 of chlorine. In 1896,
Adolphe Mayer found still higher figures. In 1908, chlorine and
potash were estimated in fifty-nine samples. A single sample alone
gave the same chlorine content as formerly : —

Per cent.

5 samples . .

30 to 35

18 ,. ...

35 to 40

24

40 t3 45

9 ,. ...

45 to 50

2

.... over 50

It is, therefore, established that kainit has not the same composi-
tion as formerly. It would appear to be mixed with minerals rich
in potash and with a high chlorine content. A more complete
analysis of the kainit showed that some samples only contained
1"50 per cent of sulphuric acid. Potassium chloride (muriate of
potash) contains 50 per cent of potash and 50 per cent of chlorine.
In a number of samples of kainit the chlorine content was also
50 per cent, but the potash content was only one-fourth of the
amount contained in potassium chloride. In this way it would be
necessary to use four times more of a manure of this kind to obtain

31:2 CHEMICAL MANURES.

the same result than with muriate of potash. But the high percentage
of chlorine in crude potash salts has other drawbacks, so much the
greater because it has been forgotten to point them out. Chlorine
exerts a disastrous influence on the physical constitution of the
soil and on vegetation. Moreover, it cannot be denied that the
secondary salts which accompany the potash strongly attack the
reserves of fertilizing ingredients in the soil. The potash is
evidently absorbed by the soil, if it be supplied to it as chloride or
as sulphate of potassium ; the latter combines with the silica of the
silicates of lime, soda, and magnesia, whilst the secondary ele-
ments such as the chlorine in muriate of potash, sulphuric acid in
sulphate of potash, combine with lime, soda, and magnesia. In the
first place calcium chloride is formed, in the second calcium sulphate.
But as calcium chloride is very soluble in water, it is carried by it
down into the depths of the soil, and thus lost to the crop. This
fact agrees perfectly with that other fact w^hich has been established,
viz. that potassic manures, especially the chlorinated manures, rob
the soil of its lime ; thus 100 kg. (220 lb.) of kainit, containing 31
kg. (78-2 lb.) of chlorine, cause the soil to lose 100 kg. (220 lb.)
of lime. It follows, therefore, that the use of potassic manures entails
the use of calcareous manures. Mercker advises to apply to the
soil as much quick-lime as potash salts. It thus follows that the
comparative cheapness of crude potash salts, such as kainit and
sylvinite, is nothing but a snare, because to take everything into
account, the price of these salts ought to be increased by the price
of the lime, the loss of which they entail. In marshy land the
simultaneous application of lime is particularly necessary. In
such soils in fact the potash salts are rapidly robbed of their acid
in such a way that in the absence of lime the chlorine forms free
hydrochloric acid which poisons the plant. Lime, moreover, is an
indispensable corrective to the secondary effects which crude
potash salts never fail to produce, the most important of which is
the prevention of nitrification in the soil. Holdefleiss, in experi-
ments with farmyard dung, completely suppressed it by means of
potash salts. The solvent action exerted by the secondary salts
of potassic manures is very well brought out in Lawes and
Gilbert's experiments. They obtained an increased yield with
salts free from potash. The plots experimented on received every
year from 1854, 4 kg. of sulphate of ammonia and 350 kg. of
superphosphate. The following amount of salts were added per
hectare : —

POTASSIC MANURES.

313

TABLE CVIII.— EFFECT OF SOLUBLE MINERAL SALTS ON GRAIN

CROPS.

Weight of Crops in Kilogrammes per Hectare.

1852-70.

1870-89.

1890.

Grain.

Straw.

Grain.

Straw.

Grain. Straw.

No salt .....
400 kg. sulphate of potash

soda .
,, „ magnesia .

1868
2295
2275

2289

3404
4114
4240
4051

1417
1789

1883
1882

2543
3190
4674
3291

2036 3737
2500 ' 4585
2775 5602
2369 4333

1

It will be seen from these figures that salts free from potash
have furnished yields almost more heavy than the pure potash salt.
These salts, therefore, have mobilized the reserves of fertilizing in-
gredients in the soil, so as to bring them to the support of the
plant. The soil has thus been, in a way, robbed of its normal
reserve in favour of a few^ crops. This robbing of the soil would
have been brought out in a more serious manner if the experi-
menters, instead of using sulphates, had used chlorides, because then
it would be complicated by loss of lime. In fact, it is not stated
that here again the nutritive substances of plants including phos-
phoric acid may not be rendered soluble and consequently carried
down into the depths of the soil. The same phenomena must
perforce occur with kainit, sylvinite and carnallite ; the comparative
low proportion of pure potash salts makes their action almost nil com-
pared with that of the secondary salts which accompany it in these
products. There is here a very interesting subject for study by
agronomists. It would be specially useful to find if drainage water
contains fertilizing substances in those cases where crude potash
salts are used. Amongst these fertilizing substances, phosphoric
acid may be found, for we must not forget that phosphate of lime
is soluble in a great number of saline solutions. There might also
be found in the drainage water as much potash as was spread on
the soil, which would prove that the use of crude potash salts as
manure would be absolutely illusory. It is probable that there will
be no delay in giving up the use of crude potash salts, so as to keep
solely to the pure potash salts, in spite of their higher price, when
the devastating action of the secondary elements which accompany
the potash in the crude salts is realized.^

1 Whilst muriate of potash should be used sparingly and with the greatest
discrimination, kainit when fairly free from chlorine is a safe and most valuable
manure, especially for potatoes. The translator considers it sound practice to

314 CHEMICAL MANUEES.

Potash Salts Dei)osits of Alsace. — Deposits of potash have been
discovered in Alsace. They consist chiefly of sylvinite. According
to report from the President of the district of Upper Alsace, the
deposits of rock salt and of potash occur in the Tertiary. The
territory in question extends to about 200 sq. km. (say 125 square
miles). It is bounded on the north by the line Eegisheim-Soultz,
to the west by the line Soultz Berrweiler-Schweighausen, to the
south by the line Schweighausen-Neidermorschweiler-Ile Na-
poleon, and to the east by the line He Napoleon-Ensisheim-
Esgisheim. The total thickness of the deposit is estimated at 200
metres (656 feet), and the beds of potash salt are included therein,
fairly regularly. These deposits appear destined to play a part in the
German potash industry.

Manufacture of Potash from Felspar and other Potassic
Minerals. — The felspar is finely crushed, beaten up with water, then
run into a wooden vat placed in a large receiver of any material.
The outside receiver is then filled ; the inside receiver is then con-
nected with the positive pole and the outside receiver with the
negative pole of an electric current. This partially liberates the
potash, the soda and the other soluble bases, freeing them from the
compounds which they form with silica. The soluble bases traverse
the wooden wall of the interior vessel and pass into the water of the
exterior vessel which they render alkaline. However, the felspar
soon ceases to decompose. To render the decomposition more rapid
and more permanent the mass in the interior vessel is continually
stirred or hydrofluoric acid added. To obtain nitrates, sulphates,
chlorides, in place of caustic alkali, it suffices to add the corre-
sponding acids into the water of the outside receiver. American
patent No. 851,922 of 30 April, 1907.

Manufacture of Potash in the Caucasus, — The manufacture of
potash is an accessory industry of the cultivation of sunflower, for
the ashes of the stem and the branches of sunflower yield the raw
material. The first potash factory was established in 1899 at
Maikopp, by Schaponalow. Difficulties occurred at first because
experience was awanting. But gradually the conditions of pro-
duction improved, and fresh factories were started. According ta
the official statistics in 1906, eleven factories produced 475,563
poods of potash. According to information supplied by the manu-
facturers twenty-four factories were at work in 1907, and some of
them produced several thousands and up to 200,000 poods of potash.
The total production of these factories was from 700,000 to 900,000
poods, representing a value of 22,000,000 roubles. The stems of the

add 1 cwt. to 2 cwts. of such kainit per ton to all compound manures, that is-
when it can be done without lowering the guaranteed percentage of the phos-
phoric acid and nitrogen below the minimum guarantee. Potatoes respond in a
very remarkable manner to such a manure. — Tr.

POTASSIC MANUEES. 315-

sunflower are generally burnt by the farmers themselves. But
certain manufacturers also burn the plant and buy the stems of
10,000 to 15,000 deciatines, for which they pay 3 to 4 roubles per
deciatine. A deciatine of sunflower yields in good ground 200
to 300 poods of stems and in bad ground 100 poods only, from
which 3 to 5 per cent of ashes may be extracted, and 3 to 4 poods
of ashes give one pound of potash. The percentage of carbonate of
potash is 20 to 35 per cent. The appearance of the ash is improved
by a few turns of the wrist, by throwing the salt in the fire for
instance, which causes the ash to fuse and gives it a vitreous-
appearance.

When the sunflower harvest is finished the stems are burnt.
The purchase of ashes is finished in September, whilst the manu-
facture of potash lasts five to six months. The price of the ashes
up to now has been 35 copecks, but owing to competition it has-
risen to 40 and 60 copecks j)er pood. The manufacture of potash
is conducted in a very primitive fashioQ : it consists in lixivating
the ashes, methodically concentrating the lyes, and in calcining the-
product. The product is packed in casks of 30 to 40 poods. The
analysis of a potash from Kuban gave (per cent) water, 1'74 ; car-
bonate of potash, 89 ; carbonate of soda, 5-0 ; sulphate of potash,
2-01 ; potassium chloride, 6-51 ; insoluble, etc., by difference, 0-74 ;.
the usual potassium carbonate content is 90 to 91. It is dealt with
on a basis of 90 per cent with 2 per cent margin at least.
Three-fourths of the potash is exported to Hamburg, London and
New York.

CHAPTEE XVIL

TRANSFERENCE AND HANDLING OF RAW MATERIALS AND

FINISHED PRODUCTS.

The economic handling of raw materials, fuel, and finished products
is one of the most important problems which the manufacturer — •
desirous of coping with competition, which becomes each day more
bitter and better equipped — has to solve. But up to now it was ex-
<3eedingly difficult to find a universal system of automatic transport
adapting itself to the varying exigencies of different factories, and for
a long time it was only possible to devise special installations for
•each case according to the nature of the materials to be conveyed.
To difficulties of this nature another had to be added arising from
the plan of the factories themselves. The gi-eater part of them, as
is well known, had a very modest beginning. They have de-
veloped gradually and have increased their production in a measure
quite out of proportion with the working space at their disposal, so
much so that there is no room for installing conveyors. These
are reduced to the installing of lifts and small rails of the Decau-
ville type. The systems used for conveying raw materials already
warehoused or to be warehoused may be reduced to three : the
•continuous system, the funicular suspended rails, and the electric
suspended rails, which hardly go back fifteen years. The continuous
system is already known, having been in use for a long time in all
industries. It will suffice to point out a very neat improvement
which has lately been made by Ad. Bleichert and Co. In continuous
■systems, whether the conveyors are bands or cups, work is confined
to the same plane. All cup or chain conveyors known up to now
other than those on the Ad. Bleichert and Go's system have the
drawback of working in the same plane, and consequently entail a
transhipment of the materials when it is desired to convey the
materials in different planes. This transhipment entails costly
plant, consumes motive power uselessly, and exhausts the material.
The mono-rail cup system of Ad. Bleichert and Co. suppresses
these drawbacks, for the cup-chain continues to pass from one plane
to another by aid of suitable guides. Fig. 54 shows the section of
the cups of this ingenious system. Figs. 55 and 56 are photographs
•of installations of this system at work. Fig. 57 is an application of

(316)

HANDLING OF RAW MATERIALS.

SIT

this cup -chain to the handling of fuel and raw material in a
chemical factory. This firm has likewise brought the electric auto-
matic systems with intermittent charges to such perfection that they
have spread enormously for some time back in Europe in metal-
lurgical works and chemical factories. This process of automatic
electric handling consists in causing an automatic car to which is
suspended a bin to convey the material to run over an aerial
railway. The current is led to this electric car by a bronze wire..
Fig. 58 represents this system, which has this great advantage, that
any desired shape may be given in a horizontal plane to the rigid.
aerial railwav, so that it can go round the multiple obstructions-
which it meets not only in old factories but even in those still under
construction. An electric automotor truck such as is shown m,
Fig. 58 can turn in curves of two metres radius. The Americans, it
is true, were the promoters of a system called " Telpherage," which
was likewise based on the conveyance of heavy unitary loads on

t

w

Fig. 54.— Section of Elevating Cups (Ad. Bleichert and Co.).

rigid robust aerial railways suitably sustained, but the principal ob-
stacle to the extension of their system was that it barely attained a-
yield of 12 per cent, due to the want of proportion existing between
the weight of the rolling car and that of the useful load to be con-
veyed. These weights were in fact in the ratio of 5 to 1. But if
the first thing to be done was to reduce the weight of the car and
the bin which form the truck as much as possible, taking into ac-
count the safety of the workmen, it was necessary also to create
from the triple "^point of view of economy, simplicity and rapidity
of transport, all the other parts of a complete installation. The
plant and rolling stock for transport, such as the exigencies of
modern factories demand, should include points and automatic safety
apparatus, and above all the automatic traveUing of the individual
wagons independent of any handling as well as the greatest possible
speed. The system devised by Ad. Bleichert and Co., owing to th^
ingenious arrangements of its rails, points, and curves, combines-

318

CHEMICAL MANUEES.

Figs. 55 and 56. — Electrical Conveyors (Ad. Bleichert and Co.).

HANDLING OF EAW MATERIALS.

319

this as3ociatioQ of the greatest possible speed with the automatic

working of the trucks, and

certainly the solution of the

problem should attract the

attention of manufacturers,

for it effects a remarkable

saving in the working ex-

■^^^^^^v^^^■.<^^■, '■■.'- '-^^C't

penses of factories, particu-
larly in chemical works.
When the railway is on a
level a single motor suffices,
the rigid rail being generally
fixed on a level. But in
most cases it is necessary
to span a difference of
level between the point of
departure and the point of
arrival. It would be, more-
over, very onerous to wish
to employ a uniform slope
throughout all the path of
the raihvay, for it would in-
volve a considerable expendi-
ture of energy and a costly
construction.

The Bleichert system
overcomes the difficultv in
a practical manner by inter-
posing in the network, sus-
pended on bearings, trunk
ways wdth desired incline,
spanning the out of level
w^hilst preserving enough free
space to allow the w^beels not
to lose contact w^ith the rail-
wav, and the bins to maintain
their natural movement of
oscillation. The advantage of
this system consists especi-
ally in the fact that the limit
need not be taken into ac-
count, for the sections are
spanned by aid of organs
absolutely independent of the
driving of the cars. For this purpose the carrying track becomes a
strong stair and rejoins in a few metres an upper part on bearings,

I-

320 CHEMICAL MANURES.

and on this stair the car is not driven by its own motor. A special
system consisting of a motor and a chain or cable, running above the
rail on the stair, pulls the car along in the following manner : A hook
fixed in the car catches the chain which drives the fixed motor of
the stair. The carrying system is drawn up to the moment when
the hook quits it, which happens when the car reaches the ele-
vated part or bearings. When the car catches on the stair the
current from its own motor ceases, whilst it puts the cable in
motion by means of another special motor which animates it with
a uniform motion. At the moment when the car reaches the
upper extremity of the inclined section, the inverse occurs. This

Fig. 58. — Electric Automotor Truck.

manner of traversing the stair is very advantageous ; it permits a
low-power motor to be used on the car. If the car motor had to
ascend a considerable incline of itself, it would require to have a
much greater force, hence a considerable weight increase of the
section of the carrier, and consequently an increase of expense in
the initial installation and working expenses (it would require in fact
motors six to ten times more powerful per car). There are cases,
however, where in consequence of considerations special to the
problem to be solved, it is preferred instead of this mixed solution
to solve the problem of removing material by means of indepen-
dent arrangements enabling each to surmount the difficulties en-

HANDLING OF EAW MATERIALS.

321

21

322

CHEMICAL MANUEES.

countered. Automatic handling installations can in fact be seen
consisting of a network of the system of cup-chain elevators com-
bined with an electric network, or consisting of some one of these
with the third system, that is to say the funicular rope system. For
example, Fig. 59 shows a conveying installation in a superphosphate
factory in which very considerable differences in level had to be
spanned. It was a question especially of conveying the raw phos-
phate discharged from ships into a shed through the whole factory
by an overhead railway to bring it into the superphosphate factory
situated behind, and to lift the superphosphate there and deposit it in
a shed from which it is charged into railway wagons. In these
transfers all handling had to be avoided. The superphosphate shed
is connected with the factory by a cable conveyor starting from the
point g, and reaching about 8 metres (say 26 feet) in height, going
round the factory and bringing its bins into a discharging hopper in
which they are tip-tilted. The finished superphosphate is in its

Fig. 60. — Section a h
of Fig. 59.

Section c d.
of Fig. 59.

Section e f
of Fig. 59.

turn poured by means of an elevator into a hopper installed on the
roof, from whence it is conveyed by means of an electric automatic
superphosphate conveyor installed above the raw phosphate con-
ve^^or. The tilting of the bins in the hall of the depot, their return
and their stoppage at the point of loading, are carried out in an
absolutely automatic manner. Fig. 64: shows the system of rolling
and of tilting the electric superphosphate bins above their depot ;
the sections of the figure (Fig. 60), c d, a b, ef, show the arrange-
ment of the railways. There will be seen on the section c d the
elevator described above, which serves to pour the superphosphate
into the bins of the electric automatic system. This question of the
elevation of material leads to the description of another method
generally used to elevate material to levels capable of sometimes
reaching 10 metres (33 feet) of vertical difference in level. The
svstem of rope traction of cars, ordinary or electrical, on a stair to be
spanned such as that shown in the section g h of Fig. 59, can only

HANDLING OF EAW MATEEIALS.

323

be judiciously employed when the tonnage and the difference in
level warrant it. For average tonnage and less, and for vertical
differences in level up to about 6 to 7 metres, a special system of
automotor car with crane is used such as shown in Fig. 61. It will
be seen in that figure that between the bin and the car properly so
-called there is geared an electric crane with its commutators, mag-
netic brake and different arrangements to render the whole of the
necessary manoeuvres automatic once the current is applied to the
whole of the car. By this system and by the aid of complementary
arrangements of the line, the whole of the car can be arrested in any
desired point of its course to pass the
current automatically from the upper
translating motor to the lower motor of
descent, and of lifting, driving the crane
a,t will ; automatically to tilt the bin of
its contents by the action of the electro-
magnet and its lifting crane, after which
the empty bin coming to its highest posi-
tion acts at the same time on a contact
which again causes the current to pass
from the elevating and descending crane
to the propelling crane, and the whole of
■the car starts in motion again to return
to the place where the bins are filled.
The latter are filled by themselves at the
hopper by a manoeuvre, say exchanged
against others filled between times in the
course of the journey of the preceding
ones. In general, these automotor cars
consist of two cheeks of cast-steel firmly
held together by cast-iron cross-pieces be-
tween which are lodged crucible cast-steel
pulleys with deep grooves, the bosses of
which turn freely on axes of phosphorous
bronze acting as lubricating reservoirs.
A wheel gearing with the steel pinion of

the electric motor is fitted on the outside of one of these pulleys,
and on the boss of the other a brake pulley is mounted, the band
of which stretched on a powerful spring, on the type of a coach-
spring, is automatically liberated when at work by an electro-
magnet. There are a very large number of these types of electrical
cars, so as to respond to the different problems occurring in in-
dustry. For example. Fig. 62 shows a special system of car for
spanning very sharp curves. There will also be seen from the
figure the difficulties which had to be surmounted in a factory
the free space of which at this point is restricted, as shown in

Fig. 61. — Special Automotor
Electric Car with Crane.

324

CHEMICAL MANUEES.

the engraving. It also shows the use of bins with bilateral dis-
charge by the unlatching of the system of closing of their side doors.
Fig. 63 shows a bin of this system hooked to a special car with
a specially arranged crane, and is used in the siloing of various

Fig. 62. — View of Special Electric Car Conveying System turning rapid Curves.

materials before being fed into the different ho]3pers. It will be
seen that the bin shown in the engraving is fitted with a four-
wheeled truck which enables it to run on Decauville rails in the
space through which it proceeds to the filling of the bins. The most

HANDLING OF EAW MATEEIALS.

325

important points of this system of electric traction must be described.
If the railway is straight the speed may reach 2 metres (6 ft. 6 in.)
a second. But this is not generally the case. A system often
contains very sharp curves, in which the car and the suspended bin

Fig. 63. — Electric Conveying Car at Silo.

ought to have a much lower speed than that given above. It will
be seen that the centre of the system in motion being much lower
than the railway on which it rolls, centrifugal force corresponding
to the speed of 2 metres per second would cause the system to
deviate appreciably from the vertical, which might cause mishaps.

326 CHEMICAL MANURES.

To obviate this, in the Bleichert system resistances are fitted on the
conductor at the passage of curves, so as to diminish the speed only
in the curved part of the course ; in the straight lines the speed is
a maximuED. Another pecuharity consists in the arrangement of
the points; so loQg as the apex of the points is not well closed a
commutator electrically isolates on the opening of the latter a
certain length of conductor up to the points itself. The car then
becomes stationary in front of the points if these are badly shifted,
which avoids accidents. The length of this insulated trunk is such
that the truck cannot reach the points in virtue of the acquired
speed. When it is not a case of heavy freights, the most practical
system is that in which the trucks accomplish a double journey on
the same line ; but in the case of important installations the railw-ay
is arranged in a circuit, so that the trucks can circulate in the same
direction and follow each other continuously. So as to stop or start
the trucks at any desired point, the naked conductor which trans-
mits the energy to the trucks is divided into sections, insulated the
one from the other, and as need be such and such sections are
brought into circuit or out of circuit by simple commutators working
automatically which can be placed at any necessary spot.

The division of the line into separate sections has the advan-
tage of forming a block system, w^hich prevents any collision auto-
matically, and any shock between the trucks at the points or the
crossings. Each truck reaching a section interrupts automatically
by means of a commutator the current from the section it has
just quitted, so that the w^agon following, arriving on this section
which is thus out of circuit, stops of its owm accord. As soon as-
the first of the trucks just described arrives at the end of the
section w^hich w^e have seen it enter, it automatically turns a com-
mutator, which re-establishes the current on the section on w'hich
the following wagon is standing, which can in this way continue
its journey, repeating the preceding operations in the same cycle
for the truck follow^ing. In that w^ay no truck can reach crossings
and points until the wagon w^hich precedes is at a sufficient dis-
tance, and before it can pass them in its turn.

This arrangement, indispensable to any suspended electric
railway on which a regular and safe service is required, produces
at certain points — for example, where the trucks are filled — the
following etfects. The truck reaches the spot where it is filled,
stops automatically, the current on the section on w^hich it is placed
having been cut by the truck ahead. The workman, the only one
generally required for operating these installations, opens the
valve w^hich shuts the hopper, thus allowing the matter to run into
the bin, and after having received its charge, brings the section
into circuit. . If, ownng to fortuitous circumstances, the loading of
the truck takes rather long, a larger number of wagons would arrive.

^HANDLING OF EAW MATEEIALS.

327

but it would be impossible for them to advance owmg to the block-
ing of the line, and they would be forced to arrange themselves at
regular intervals along the line. As soon as the charged truck
starts, the following one advances automatically and stops at the
hopper to receive its charge. The other trucks follow the lead
and advance one after the other until their turn comes to take then-
place at the hopper, and the same routine goes on contmuously.

As already mentioned, all supervision during the journey is
absolutely superfluous, the trucks are unloaded automatically, tor

Fig. 64. — Electric Conveying Car tilting Contents into Silo.

the bolts which hinder the bin from tilting or which keep the sides
of the bin closed, unlatch themselves during the working by means
of a bolt. Owing to these arrangements it is possible to obtain
crreat traffic on the whole line. These aerial railways on the electric
automatic system may be supported outside the building on wood
or metal brackets, leaving below them the necessary freedom for
working in the factory and assuming, consequently, shapes ap-
propria'te thereto. At other times, as a measure of simplification
or economy, these rails are hooked on to wall brackets or even to

328

CHEMICAL MANUEES.

o

o

o

X

>

o

o
o

S

S-i

5

;5

existing beams. Fig.
64 shows the auto-
matic filling of silos
by an electric railway
suspended from old
wooden beams, whilst
Fig. 63 shows that the
automatic electrical
railway has been sus-
pended from new me-
tallic structures. The
system of bin and car
of Fig. 64 is a stout
thick-sst system in a
vertical direction, tak-
ing into account that
the old wooden beams
of factories are at this
point surbased, that
they only allow of a
small heap, and that
thus all economy in
the vertical height of
the plant installed is
particularly appreci-
ated. On the other
hand, in a new build-
ing like that of Fig.
63, the necessary ver-
tical height can be
calculated at leisure,
profiting in the de-
signing of the plant
by the advantages of
a sufficient height to
instal an appropriate
system of transport.
This system, so re-
markable and so
simple in itself, in-
sures the conveyance
with a minimum of
handling of big ton-
nages in as automatic
a manner as possible.
The Coinjjagnie
St. Gobain, Chauny

Qf

niv

no (

maf

HANDLING OF EAW MATEEIALS.

329

erected at its Chantenay chemical works near Nantes an important
installation of this natm-e. The photographs (Figs. 65-66) show as
a whole similar installations in chemical factories and superphos-
phate factories. The first is the Pommersdorf chemical factory
and the second the Emmerich chemical manm^e factory. These
automatic conveying installations in factories where quantities of
material arfe treated are of capital importance for go-ahead manu-
facturers desirous of lowering their wages bill and to place them-
selves as far as possible beyond the risk of strikes. It would lead
us too far to develop all the applications which can be made of

Fig. 6G.— General Arrangement of Electrical Conveying Machinery in
Emmerich Chemical Manure Factory.

this system, the more so as each new problem leads to a new
solution. It is to be hoped that enough has been said for readers
to have at their linger- ends all the advantages of these new systems
which not OQly are already spread throughout France, but have
more especially a considerable development abroad. We cannot
terminate this slight review of these automatic conveyors without
bringing to mind that the question of the automatic conveyance of
raw materials from the ships or wagons in which they arrive is
likewise an important question, especially for large factories. Fig.
67 shows the view of an automatic conveyor installed by the Com-
imgnie St. Gobain at its Boucau chemical factory. Fig. 68 shows

330

CHEMICAL MANURES.

Fig. 67. — Electrical Transhipment Plant, St. Gobain's Chemical Factory,

Boucau.

Fig. 68.— Electrical Transhipment Plant in a German Factory.

HANDLING OF EAW MATEEIALS.

331

o

a

ce
o

an
O

Ph
ce

CD

OJ

3

o

6

O

-^=
c3
•+=

OB

s

•i-H

cS
O) o

c6

P

<i)

> •

li s s

^ "^ ^ II

!S s? '^

■^ O ^

^ S c •%

o

'0£>

c3
O

P5

0^

O 53

^

^

*<>*

e
•1^

^
>»

a;

a;

o

J J

-4-9

oc

eg

llin
Dir

-4-3

OQ .r-5

^ >

m =^ =^

CU II 11

-to

5 o

o ■

-+o

. "^ <» O

o

CD 'TS

^.:

^)

«i>

V^

-332 CHEMICAL MANUEES.

a conveyor of this nature installed for a German factory of chemi-
<3al products by Ad. Bleichert & Co. Sometimes, as will be seen
in Fig. 67, the cargo discharged from ships is simply disgorged by
tilting-bins or sUngs into fixed or rolling hoppers or into rolling
stock, or sometimes, on the other hand, these automatic tran-
shipping installations are continued by automatic conveyors like
those described above. The attention of those working phosphate
deposits is drawn to the rope system adopted by the G''' Centrate
des Phosphates d Paris for working its deposits of Bordj E'Dir.

There will be seen in Fig. 69 a considerable development of
these rope railways which collect the phosphate into the great
warehousing hoppers at the railway station of El Anasser Galbois,
Algeria. Local considerations, the price of labour, the greater or
less tonnage to be discharged and handled, the regular or inter-
mittent manner in which these transhipments or shiftings occur,
can alone afford, in each case, the necessary data to solve the problem
in the most satisfactory manner in the interests of the manufacturer.
The best course for manufacturers who occupy themselves with
these questions more and more is to submit the problem to the
study of specialists trained by constant practice.

INDEX.

A.

Abbeville, Somme, phosphates of, 14, 26.
Abrolhos guano, 39, 49, 58-9.
Acid, acetic, 13, 210.

— amount to use in dissolving various

phosphates, 80.

— carbonic, 3, 11.

— citric, 13, 208, 210, 215.

— humic, 140.

— hydrochloric, 11, 74.

— hydrofluoric, 78, 110, 153, 154.

— hydrofluosilicic, 70, 71, 78, 154.

— metaphosphoric, 10.

— nitric, 11, 218, 224.

electrical production of, 271-7.

— orthophosphoric, 10.

— oxalic, 210.

— phosphoric, 1-13.

citrate, soluble, 138-40.

manufacture, 151-4.

— phosphorous, 9.

— pyrophosphoric, 8-9.

— silicic, 4, 154, 209-11, 213, 216.

— sulphuric, 11, 73-83.

treatment of bones by, 67.

of mineral phosphates by,

67-72.
quantity to use for various

phosphates, 80-3.
theory of same, 73-8.

— tartaric, 13, 210.
Adulteration, 22.

Aerial conveyors, 70, 316-31.

African phosphates, 58-9.

Ain-Beida phospates, 37.

Alabama River pebble phosphates, 34.

Albin, upper, 22.

Albumen, 10.

Alcantara phosphates, 29.

Alder, potash in ash of, 295.

Algerian phosphates, 36-8, 58-9, 71, 80,

82, 83, 132, 136.
Algerian phosphate warehousing plans,

331.
Algoa Bay guano, 49, 58-9, 286.

Allegri's automatic removal of super-
phosphate, 116.
Alta Vela phosphate, 39, 54-5.
Alumina, 78, 80.
Aluminic phosphates, 13, 80, 161-2.

— silicates, 80.
Amberg osteolite, 50-1.

America, North, apatite and phosphates^
29-31, 52-3.

— South, bone ash, 190-1.

— — nitrate of soda, 218.
guano, 277-86.

Ammonia blast furnace, 224, 226-8.

— from bones, 225-6.

— — coal, 228.

— — coke ovens, 226.

gas liquor, 225, 228-30.

■ — producers, 228-9.

— — — waste, 255.

peat, 244-9.

spent wash, 268-7.

urine, 243.

— in soot, 224.

Ammoniated superphosphate, 143.
Ammonium and magnesium phos-
phates, 12.

— and sodium phosphates, 11-12.

— chloride, 11, 224, 229, 280.

— citrate, 138-9.

— cyanide, 233.

— oxalate, 280.

— phosphate, 11-12.

— sulphocyanide, 251.

— urate, 280.
Angamos guano, 56-7.
Angaur, Isle of, 39, 48.
Anglo-Continental Guano Co., 197, 284^

285.
Animal charcoal, 191-2.

— debris, origin of phosphates, 4.

— waste, conversion of into manure,.

253.
Apatite, 4 (pseudo do., 4), 11.

— Canadian, 29, 30, 52-3, 69, 81, 83.

— Norwegian, 27, 50-1, 69.

— Spanish, Estremadura, 28, 50-1.

(333)

:334

INDEX.

Arabian phosphates, 38, 58-9.

Ardeche phosphates, 23.

Ardennes phosphates, 19-20, 50-1.

Ariege phosphates, 23.

Arkansas phosphates, 36.

Aruba phosphates, 39, 54-5, 83.

Ash of plants, potash in, 295.

Ashmore Island guano, 49.

Aube phosphates, 18.

Aubervilliers dried blood and meat meal

factory, 256-62.
Australian phospho-guanos, 56-7.
Austria-Hungarian phosphates, 27, 50-1.
Auxois phosphates, 20-1.
Avalo Isle guano, 54-5.
Aves Isle phosphates, 39.

B.

Badajoz phosphates, 29.

Baker Isle guano, 39, 42-3, 46, 56-7, 68.

Ball mills (phosphate grinding), 70, 87,

96.
Barley straw, potash in, 295.
Barlow phosphates, 39, 42-8, 52-3.
Basalt, phosphorus in, 2.
Basic slag, 197-217.
Bat guano, 49, 58-9, 287-8.
Beauval phosphate, 16, 23.
Bedford coprolites, 52-8.
Beech, potash in, 295.
Beetles as manure, 294.
Belgian phosphates, 23-4, 50-1.
Bellegarde-sur-Khone phosphates, 50-1.
Benzine, fat-extraction of bones, 182-4.
Bergkieserite, 39.
Bessarabia phosphates, 27.
Bicalcic phosphate, 138, 209.
Birds' excrement, 278.
Birds' Island guano, 49, 58-9.
Birkeland's nitrate of lime process, 272.
Black bone, 191-2.
Bleaching of bone fat, 184, 185.
Blood, dried, 256-62.

— drying of, 255, 259, 267, 294.

— in manure mixing, 190.

— phosphates, etc., in, 6.
Blue River phosphates, 82.
Bohemian apatite, 50-1.
Boiling meat for meat meal, 261.
Boncourt phosphates, 79.

Bone ash, 83, 177-8.

— bed, 26.

— black, 176-7.

— composition, 173.

— crushing, 177, 179.

— degelatinized, 181.

— dusts, 185, 186.

Bone earth. See Bone ash.

— fat, 179-185.

— meal. See Bone dust.

— mills, 177-9.

— picking, 176-7.

— steamed, 83.
Bones, bullocks', 176.

— buried, 176.

— butchers', 174.

— cattle, 176.

— classification, 176.

— grinding, 177-9.

— horse, 176.

— kitchen, 176.

— sheep, 176.

— storing, 175.

— vitriohzed, 187-9.
Bonnes phosphates, 28.
Boulogne phosphates, 19, 20, 50-1.
Brachiopods, 3, 39.

Brain, phosphates in, 6.

Bromine from Stassfurt salts, 805.

Brown Island guano, 39, 44, 49, 58, 59.

Buenos Aires phosphate, 54-5.

Bukovina phosphates, 27.

Bullocks' heads, 176.

Burgundy lias, phosphates of, 20.

c.

Caceres phosphates, 50-1.
Cakes, filter press, 103.
Calais phosphates, 16-18.
Calcium aluminate, 206.

— carbonate, 53-9.

— chloride, 74, 806.

— fluoride, 11, 77, 194-5, 239.

— iodide, 77.

— phosphate, 4, 50-9, 78-5.

— silicate, 78, 200, 208, 308, 312.

— sulphate. See Gypsum.

— tetraphosphate. See Basic slag.
Caliche, 219.

Cambrian, Welsh phosphates of, 26.

Cambridge coprolites, 25, 52-3.

Canadian apatite, 52-3, 68-9, 81.

Cannes phosphates, 28.

Carbon disulphide, 3, 182.

Carbon in bone black, 192.

Carbonic acid, its function in manure

manufacturing process, 76.
Carinthia phosphates, 50-1.
Carnallite, 297-309, 811, 318.
Carolina phosphates, 30-1, 52-8, 76-8,

80, 82-3.
Carr's disintegrator, 68, 118-9, 137, 144.
Cayman's Isle, 3, 89.
Charleston phosphates, 52-3.

INDEX.

335

Cheese, 294.

Cher phosphates, 22.

Chestertield Isle guano, 39.

Chili guano, 56-7, 218.

Chinchas Isles guano, 56-7.

Chloroform, amount of fat ceded to, by

various grades of bones, 186.
Christmas Isle guano, 41, 58-9.
Ciply phosphates, 23-4, 50-1, 83.
Clipperton guano, 39, 47, 49, 54-5, 83,

226-8.
Coke ovens, 226-8.
Colombine, 294.
Conveyors, 70.
Coprolites, 25-7.
Corcovado guano, 56-7.
Cracow bat guano, 50-1.
Crusher separator, 92-6.
Cup-chain elevator, 101.
Curasao phosphates, 54-5.
Cyanimide, 272-7.

D.

Damaraland guano, 49, 58-9.

Damp superphosphate, 74.

Degelatinized bone dust, 186.

Delme osteolite, 50-1.

Den, manure mixing, 105-7.

Devonian formation, phosphates of, 29,

30.
Dicalcic phosphates, 11.
Dicyanamide, 274.
Dill phosphorite, 50-1.
Dimetallic orthophosphate, 10.
Disce?iides, 3.
Disintegrator, 100.
Dissolved bones, 187-9.

— leather, etc., 190.

— Peruvian guano, 284-6.
Distillery spent wash, ammonia, 268-72.
Dneister phosphate basin, 27.
Dolomite in super manufacture, 107.
Double superphosphate manufacture,

154-9.
Dried blood, 190, 255-62.
Drome and Isere phosphates, 23.
Drying blood, 255-9.

— in vacuo, 257.

— raw phosphates, 60.

— superphosphates, 81, 121 et seq.
Dry mixing of manures, 142.

E.

Eagle, dung of, 278.
Eboli bat guano, 288.
Edge-runner for grinding raw phos-
phates, 85.

Effront's fermentation ammonia, 270-2.
Egyptian phosphates, 38, 58-9.
Electrical conveyors, 316-33.
Electric furnace, manufacture of phos-
phorus in, 167-72.
Elevating phosphoric acid, 154.

— raw phosphates, 101.

— sulphuric acid, 105.
Enderbury Island guano, 39, 49, 56-7.
English phosphates, 25-7.
Estremadura apatite, 5, 29, 50-1.
Experiments on hay, 140-1.

— on oats, 129.

F.

Falkland Islands guano, 54-5.
Fanage of raw phosphates, 62.
Fanning Island guano, 39, 44, 49-50,

56-7.
Fans of superphosphate dens, 110.
Fat, bone-extracting and bleaching,

179-85.
Feldmann's steam still for ammonia

liquor, 241.
Felixtowe coprolites, 26.
Felspar, electrolytic extraction of potash

from, 314.
Ferns, potash in ash of, 295.
Ferric chloride, 12.

— oxide, 12, 79.

— phosphate, 12.
Ferrous oxide, 13, 139, 211.

— phosphate, 211, 213.

— sulphate, 78-9.

— sulphide, 78.

Fertilizing value of basic slag, 196-8.

of bones, 175.

of cyanamide and nitrate of lime,

274-7.
of meta and pyrophosphates,

129.

of phosphate of potash, 164.

of potash salts, 310-3.

Filter press, 103-4. 164.

plates, pitch pine, 152.

Fish guano, 267, 275, 290.

— waste, 294.
Flint Isle guano, 39.

Florida phosphate, 30-5, 52-3, 69-71,

82-3.
Fluorine, 77, 154, 175.
Free phosphoric acid, 74.
Frigatte Shoal guano, 49.
Fuel used in drying superphosphate, 128.
Fumes from mixer, condensing, 70, 107,

109.
meat boiling, condensing, 262.

336

INDEX.

G.

Gafsa phosphates, 37, 58-9, 71, 82-3,

130.
Galapagos guano, 40.
Galician bat guano, 49.

— phosphates, 27.

— salt and potash deposits, 297.
Gard and Ardeche phosphates, 23.
Gas liquor, 225-8, 230.

— Mond's, 228-9.

— puritication waste, 255.

— Siemens', 228-9.

Gault clay, phosphates of, 17, 21.
Gelatine, extraction of, from bones, 179,

181.
George Isle phospho guano, 54-5.
Glauconitic sand, 21.
Gneiss, 2.

Goodrich mineral phosphates, 52-3.
Granulet, 2.
Greaves, 294.
Green manuring, its role in the future,

289.
Grinding bones, 177-9.
— raw phosphate, 84-9.
Guanahani phospho guano, 52-3.
Guano, Abrolhos, 39, 49, 58-9.

— Algoa Bay, 49, 58-9, 286. ■

— Angamos Island. 56-7.

— Angaur Island, 48.

— Ashmore Island, 49.

— Avalo Island, 54-5.

— Aves Island, 39.

— Baker Island, 39, 46, 68.

— Ballestas, 56-7.

— bat, 49, 58-9, 287-8.

— Birds' Island, 49, 58-9.

— Brown Island, 39, 49, 58-9.

— Cayman's Island, 39.

— Chincha Isles, 56-7.

— Christmas Isles, 38-9, 41, 71.

— Clipperton, 39, 49, 83.

— Corcovado, 56-7.

— crab, 293.

— Damaraland, 49, 58-9.

— Eboli bat, 288.

— Enderbury Island, 49, 56-7.

— Falkland Islands, 54-5.

— Fanning Island, 49-50, 56-7.

— fish, 267, 275-94.

— Fray Bentos, 263.

— Galapagos, 49.

— Galician bat, 49.

— George Isle, 54-5.

— Guanahani phospho, 52-3.

— Guanape, 56-7.

— Rowland Islands, 49, 56-7.

Guano, Huanillos, 56-7.

— Huon Island, 58-9.

— Ichaboe, 49, 58-9, 286.

— Independencia Bay, 56-7.

— Jarvis Isle, 43.

— .Jones Island, 49, 56-7.

— Kurian Murian, 49, 58-9.

— Lacepede, 39, 49, 58-9.
■ — Leysan Isle, 49.

— Lobos de Afuera, 56-7.

— Lobos de Tierra, 56-7.

— • Los Aves Isles phospho, 54-5.

— Los Koques, 54-5.

— Macabi, 56-7.

— Makatea, 48.

— Maiden Island, 49, 56-7, 83.

— Maracaibo (Monkev Island), 54-5.

— Mary, 49, 56-7.

— Mejillones, 45, 46, 49, 56-7, 68.

— Monk's Island, 49.

— Nauru, 48.

— Norwegian fish, 267, 275.

— Ocean Isle, 56-7.

— Pabellon de Pica, 56-7.

— Patagonian, 49, 54-5.

— Peruvian, 49, 56-7, 83, 277, 286.

— Porto Rico bat, 52-3.

— Punta de Lobos, 56-7.

— Eaza, 54-5.

— Shark's Bay, 49, 56-7.

— Sombrero, 40, 54-5, 83.

— Starbuck, 49, 56-7.

— Timor Island, 49, 58-9.

— Yivorilla Island, 49.
Guelma phosphate, 37.

Gypsum, 11, 73, 74, 75, 153, 157, 158.

H.

Hair, bullocks', 294.
Hallencourt phosphates, 14.
Hardvilliers phosphates, 14.
Hartz apatite, 50-1.
Hautes Marne phosphates, 20.
Havana phosphates, 52-3.
Helmstedt phosphorite, 50-1.
Hens' dung, 218.
Hoof and horn dust, 267, 294.
Horde phosphorite, 50-1.
Horn dissolving, 190, 263-5.

— liquor, 265.
Hornpiths, 176.

Howland Island guano, 49, 56-7.
Huanillos guano, 56-7.
Human skeleton, 6-7.
Humus, 140.

Huon Island guano, 58-9.
Hydrogen sulphide, 243.

INDEX.

337

Ichaboe guano, 49, 58-9, 28(5.
Ichthyocol, 80.
Ichthyosaurus, 26.
loclme in phosphates, 77.

— in nitrate, 220-1.
Ipswich coprolites, 52-3.
Iron acetates, 13.

— ■ and alumina, phosphates of, 78-80,
133, 155.

— oxide, 2.

— phosphate, liydrated, 78-80.

— phospliate of, 12, 13, 139, 211.

— sulphate, 78-9.
- — sulphide, 78.
Italian phosphates, 50-1.

J.

Jarvis Island guano, 39, 43-4, 49, 58-9.
•Jaw-breaker mills for raw phosphate,

96-7.
Jones Island guano, 49, 56-7.

K.

Kainifc, 299, 300, 309, 311.
Kieserit, 306, 309, 311.
Knackers' bones, 176.
Koerting's injector, 221.
Krageroe apatite, 50-51.
Krugite, 301.

Kuban potash (sunflower), 314-5.
Kurian Murian guano, 49, 58-9.
Kursk phosphorite, 52-3.

L.

Lacepedes guano, 39, 45, 49, 58-9.
Lahn phosphorite, 50-1, 136, 151.
Lair's, de, di-ammonia still, 238.
Lamming's mixture, 251.
Land phosphates, 34-5.
Langesund chlorapatite, 50-1.
Lavanthal phosphorite, 50-1.
Lawes and Gilbert's experiments, 312-3.
Lead-lined vessels, 1,53.
Leather, dissolving, 190-1, 265-7.

— grinding, 190.

— shavings, 294.
Leysan Isle guano, 49.
Lias phosphates, 20.
Liebig's theory, 151.

Liege phosphates, 23-4, 50-1, 83.

Ligulides, 3.

Lime, milk of, 195, 224, 233-4, 238,

241-8.
Lobos de Afuera guano, 56-7.

Lobos de Tierra guano, 56-7.
Logrosan i)hosphorite, 52-3.
Los Aves Isle phospho guano, 54-5.
Los Roques guano, 39, 54-5.

iron phosphates, 54-5.

Lot phosphates. See Quercy.

Lunge's ammonia still, 238.

Lutjens' superphosphate drier, 125-8,

136-7.
Lyme Regis phosphates, 25, 52-3.

M.

Macabi guano, 56-7.
Magnesia, 77, 2U.

Magnesium and potassium, double sul-
phate of. See Kainit.

— carbonate, 107.

— chloride, 305, 308, 309.

— phosphate, 77.

— silicate, 312.

— sulphate, 107, 307.

— tetraphosphate, 211.
Maikopp potash factories, 314,
Maize, potash in ash of, 295.
Makatea guano, 39, 48.

Maiden Island guano, 39, 49, 56-7, 83.
Malogne phosphates, 154.
Maracaibo guano, 54-5.
Mary Island guano, 49, 56-7.
Meadows, manure for, 141, 148.
Measuring tank, acid, 107.
Meat meal, 186-7, 259, 260-1, 294.
Mejillones guano, 45, 46, 49, 56-7, 68.
Metaphosphate of lime, 129, 154.
Meuse phosphates, 18-19,
Mexican phosphates, 68.
Microbicide, phosphatic peat as, 165.
Mills for grinding bones, 177-9.

raw phosphates, 84.

Minerva Isle guano, 39.

Mixer, superphosphate, 105, 110.

Mixing trials, 82.

Mona Isle guano, 39, 49, 54-5.

Mond gas, ammonia plant, 229-230.

Monk's Isle guano, 41, 49.

Monocalcic phosphates, 10, 11, 165.

Monometallic orthophosphate, 10.

Muriate of potash, 301-15.

N.

Naphthenes, 80.

Nauru guano, 39, 48.

Navassa phosphates, 39, 40, 49, 54-5, 68.

Nettles, potash in, 295.

New York apatite, 52-3.

Nitrate of ammonia 275.

22

388

INDEX.

Nitrate of lime, 11, 271-7.

— of manganese, 228.

-^ of potash, 218, 222, 294.

— of silver, 218,

— of Boda, 140, 218, 21J4.

boiling-point of solutions,

221.
Nitric acid, 218.

— nitrogen, 275.
Nitrogen, ammoniacal, 27o.

— nitric, 275.
Nitrophosphate, 148.

Nitrous sulphuric acid as solvent for
leather, etc., 191.

Norwegian apatite,
— fish guano, 292.

09.

0.

Oak filter press frames, 152.
— potash in ash of, 295.
Oats, experiments on, 129.
Ocean Isle phosphates, 56-7.
Ontario apatite, 52-3.
Organism, function of Pj,05 in, 3,
Orthophosphoric acid, 8-iO, 129-B8.
Orville phosphates, 14, 15, Hi.
Ossein, 195.
Osteolite, 50-1.
Ottawa apatite, 52-3.

Pabellon de Pica guano, 5(3-7.
Palestine phosphorite, 58-9.
Pas de Calais phosphates, 15, 16-18.
Patagonia East Coast guano, 54-5.
Patagonian, 49, 54-5.
Peace River phosphates, 34-5, 52-3.
Pebble phosphates, 82-3, 136.
Peine coprolites, 50-1.
Permian saurians, 3.
Pernes phosphate basin, 14.
Phcenix Isle guano, 39, 49, 56-7.
Phosphates, acid required to dissolve,
80.

— drying and enrichment, 60-66.

— geological distribution, 49.

— raw, description and geographical

distribution of deposits, 14, 59.
Phosphoric acid, 1-10.

manufacture, 151-4.

Phosphorus, 1-s.

— manufacture, 167-172.
Pigeon dung, 278.

Pine, potash in, 295.
Plum tree wood for phosphoric acid,
152.

Podolian phosphates, 52-3, 88.

Polk Co. phosphates, 34.

Pollen, phosphorus iiv, 6.

Polyhalite, 800.

Portugal apatite, 29.

Port Royal phosphate, 52-8.

Potash salts, 309, 811, 815.

Russian, from sunflower, 315.

Potassium and magnesium double sul-
phate, 307.
phosphate, 309.

— caibouate, 295.

— chloride, 215, 297, 315.

— nitrate, 218, 222, 294.

— silicate, 309.

— sulphate. 309-11.

— superphosphate, 146-9.
Precipitated phosphate manufacture,

88.
Puerto Rico bat guano, 52-3.
Pump for phosphoric acid. 154, 158-9.

— precipitated phosphate filter press..

195-6.
Punta de Lobos guano, 56-7.
Pyrenees phosphates, 28.

Q.

Quercy (Lot) phosphates, 22, 50-1.
Quick-speed bone crasher, 178.

R.

Rata phosphates, 39, 49, 54-5.

Razii Island guano. 54-5.

Redondii phosphate, 39. 41, 49, 54-5.

utilization of, 161-4.

Reduced phosphates, 151.

Reeds, potash in ash of, 295.

Remover, automatic, of superphosphates^
from den, 112-7.

Retrogradation (reduction) of phos-
phates, 151.

Rocks, primitive P.jO, in, 2.

Roller mill toothed for raw phosphates,.
97.

double for ra^v phosphates, 96.

Russian black earth, Tcherino Scm, 5^

— phosphates, 28, 52-8.

s.

St. Martin's phosphates, 49, 54-5.
Sal ammoniac, 294.
Saldanha Bay guano, 58-9.
Salt, common, 806.
Sardinian bat gnano, 411. 50-1.
Saurian:^, 3.

INDEX.

339

Schlaggenwald apatite, 50.
Schoenite, 309.
Sea-fowl excrement, 278.
Seed, phosphates in, 6.
Setif phosphates, 37.
Sfax phosphates, -58-9.
Shark's Bay guano, 49, 56-7.
Sidney Island guano, 39, 56-7.
Sieves, 87-91, 102.
Sifting machine, 102.
Silicates, calcic, 312.
Silicic fluoride, 110.
Silkworm litter, 294.
Silurian lish, 3.
Skin debris, 175.
Slow-speed bone crusher, 177.
Sodium and ammonium phosphates,
11, 12.

— phosphates, 11, 12,

Soil migration of phosphoric acid in,
3-4.

— superphosphates become insoluble in

the, 129.
Solubility of phosphates in soil, 140-1.
Sombreru phosphates, 39, 49, 54-o, 83.
Sorame phospliates, 14-16, 50-1, 82-3,

1-54.
South Carolina phospliates, 30,
Spanish phosphates, 5, 50-3.
Stamping mill, 99.
Starbuck Island guano, 39, 49, 56-7.
Starkenbaeh coprolites, 50-1.
Steam stills for ammoniacal liquor,

240.
Stercorite, 12.
Struvite. 12.
Suffolk crag, 26.

— coprolites, 26,
Sulphophosphates, 160.
Superheated superphosphate, 121).
Superphosphate, bone, 187-9.

— of ammonia, 143.

— — and potash, 146.

— drying, 81.

— historical review, 67-72,

— manufacture, 84-110.

— mixing, 105-10.

Superphosphate, shifting (mechanical),
116.

— sifting, 68, 137.

— storing and retrogradation, 111.
Swan Island guano, 49.

Syenite, phosphorus in, 2.
Sylvinite, 298, -509, 311, 313.

Tallahasee phosjihates, 52-3.
Tebessa phosphates, 37, 58-9.
Teleosaurus, 25.

Tennessee phosphates, 52-3, 82, 83, 137.
Testigos phosphates, 49, 54-5.
— iron phosphates, 54-5.
Timor Island guano, 49, 58-',>.
Toothed roller mill, 97.
Toque\ille phosphates, 58-9.
Tricalcic phosphates, 50-59.
Truxillo phosphates, 52-3.
Tunis phosphates, 49, 58-9.

V.

Vasseux fermentation i)rocess for re-
coverv of ammoni:;. from spent
wash," 269-70.
[ Yaucluse phosphorite, 50-1.

Yetclies, potash in ash of, 295.

Vine, potash in ash of, 295,

Vitrolized bones, 187-9.

Yivorilla Island guano, 49, 52-3.

w.

Wagner" s researches on basic slag, 197.
Wales phosphate. 52-3.
Wasserleben phosphorite, 50-1.
Waste products, conversion into manure,

2-55-267.
West Indian phosphates and pliospho

guanos, 49, 52-55.
Whale guano, 293.
Wheat straw, potash in ash of, 295.
Willow, potash in ash of, 295.
Wool, waste rags, etc., 194, 265.
W'oronesch phosphate, 52-3. *

ABERDEEN : THE rNlVEUSITY PPESS

TIVO USEFUL BOOKS.

A MANUAL OF

Agricultural Chemistry

BY

WEHT mil fi.Sc. (LBBdsl F.l.C, F.C.S.

SECOND REVISED EDITION, with additional matter relating to Tropical

Agriculture, etc.

DEI^y 6vo. ELEVEN ILLU5TRATIOIN5. 450 pp.

Price js. 6d. net (Post Free, 8s. Home ; 8s. 6a. Abroad).

HOPS

In their Botanical^ Ag'riculturaly and
Technical Aspect^ and as an Article of

Commerce^

TRANSLATED FROM THE GERMAN

OF

EMMANUEL GROSS

DEHiySvo. 5EVEINTy=EI0l1T ILLU5TRATIOrS5.

340 pp.

Price I OS. 6d. net (Post Free, iis. Home; iis. 6d. Abroad).

340

CataloQue

OF

Special (Deednieal JDooks

FOR

Manufacturers, Technical Students and
Workers, Schools, Colleges, etc.

BY EXPERT WRITERS

INDEX TO SUBJECTS.

PAGE
... 10
... 12

... 9
... 9
... 3
... 6
... 4
... 29
... 15
... 7
... 10
... 32
... 23
... 23
... 8
... 31
14,15
... 27

Agricultural Chemistry

Air, Industrial Use of

Alum and its Sulphates

Ammonia

Aniline Colours

Animal F^ts ...

Anti corrosive Paints

Architecture, Terms in

Architectural Pottery

Artificial Perfumes...

Balsams

Bibliography

Bleaching

Bleaching Agents ...
Bone Products
Bookbinding ...
Brick-maUing

Burnishing Brass

Carpet Yarn Printing
Casein

Celluloid

Cement

Ceramic Books ... 14, 15,

Charcoal

Chemical Essays

Chemi al Works

Chemistry of Pottery
Chemistry of Dye-stu<¥s ...

Clay Analysis

Coal-dust Firing

Colour Matching

Colliery Recovery Work ...
Colour-mixing for Dyers ...
Colour Theory

Combing Machines

Compounding Oils

Condensing Apparatus
Cosmetics

Cotton Dyeing

Cotton Spinnmg

Cotton Waste

Damask Weaving

Dampness in Buildings ...
Decorators' Books...
Decorative Textiles

Dental Metallurgy

Drugs

Drying Oils

Drying with Air

Dyeing Marble

Dyeing Woollen Fabrics ..
Dyers' Materials

Dye stuffs

Edible Fats

Edible Oils

Electric Wiring

Electricity in Collieries ..

Emery

Enamelling xMetal

Enamels

21
4
31
29
16
9
9
26
16
22
16 1
26
22
25
22
22
24
6
26
8
22
24
22
20
29
28
20
25
30
5
12
30
, 22
. 22
, 23
. 7
. 7
. 27
. 25
, 32
. 18
. 18

Engraving

Essential Oils

Extracts, Wood

Evaporating Apparatus .,
External Plumbing

Fats

Faults in Woollen Goods.

Flax Spinning

Foods and Drugs ...

Fruit Preserving ...

Fungicides ...

Gas Firing ...

Glass-makmg Recipes

Glass Painting

Glue Making and Testing

Greases

Hat Manufacturing

Hemp Spinning

History of Staffs Potteries 16

Hops 28

Hot-water Supply 28

How to make a Woollen Mill

PAGE

... 31

... 7

... 29

... 26

... 27

...5,6

21

24

30

30

28

26

16

16

8

5

20

24

Pay

India-rubber...
Industrial Alcohol

Inks

Insecticides...

Iron-corrosion

Iron, Science of ...

Japanning ...

Jute Spinning

Lace-Making

Lacquering ...

Lake Pigments

Lead and its Compounds.

Leather Industry

21
.. 13
.. 10
3,11
.. 28
.. 4
.. 26
.. 28
.. 24
.. 20
.. 27

9

11

13

PAGE
... 6

Leather-working Materials 14
Libraries ... ... ... 32

Lithography... ... ... 31

Lubricants ... ... ...5,6

Manures ... ... 8, 10, 11

Meat Preserving 30

Mineral Pigments 3

Mineral Waxes 6

Mine Ventilation 25

Mine Haulage 25

Mining, Electricity ... 25

Needlework ... ... 20

Oil and Colour Recipes .. 3

Oil Boiling 5

Oil Merchants' Manual ... 6

Oils 5

Ozone, Industrial Use of... 12
Paint Manufacture ... 2

Paint Materials 3

Paint-material Testing ... 4

Paint Mixing 28

Paper-Mill Chemistry ... 17
Paper-pulp Dyeing 17

Petroleum ...

Pigments, Chemistry of ... 2

Plumbers' Work 27

Pottery Clays 16

Pottery Decorating ... 15

Pottery Manufacture ... 14

Pottery Marks 16

Power-loom Weaving ... 19
Preserved Foods . . ... 30

Printers' Ready Reckoner 31
Printing Inks ... ... 3

Recipes for Oilmen, etc. ... 3

Resins ... ... ... 10

Risks of Occupations ... 12
Riveting China, etc. ... 15

Sanitary Plumbing ... 27

Scheele's Essays 9

Sealing Waxes 11

Silk Dyeing 22

Silk Throwing 18

Smoke Prevention 26

Soaps ... 7,8

Spinning ... ... ... 21

Spirit Varnishes ... ... 5

Staining Marble, and Bone 30

Steum Drying

Sugar Refining

Steel H.irdening

Sweetmeats...

Tanning Extracts

Technical Schools, Hand

book to the
Terra-cotta ...
Testing Paint Materials ..
Testing Yarns
Textile Fabrics

Textile Fibres

Textile Materials

Timber

Varnishes ...

Vegetable Fats

Vegetable Preserving

Warp Sizing

Waste Utilisation

Water, Industrial Use ..

Water-proofing Fabrics ..

Waxes

Weaving Calculations

Weed Killer

Wnite Lead and Zinc

Wood Distillation

Wood Waste Utilisation..

Wood-Dyeing

Wool-Dyeing

Writing Inks

X- Ray Work

Yarn Sizing ...

Yarn Testing

Zinc White Paints

1?
32
26
30
29

32

15
4

20
18,19
19,24
... 20
... 29
... 5
... 6
... 30
... 21
... 11
... 12
... 21
... 6
... 21
... 28
... 4
... 2^

2S'.

30
22,23..
... 11
... 13;..
... 21
... 20 -
... 4i

PU BLISH ED BY

SCOTT, GREENWOOD & SON,

8 Broadway, Ludgate Hill,
London, E.G.

Telephone, Bank 5403. Telegraphic Address, " Printeries, London,"

Paints, Colours and Printing

Inks.

THE CHEMISTRY OF PIGMENTS. By Ernest J. Parry,
B.Sc. (Lond.), RI.C, F.C.S., and J. H. Coste, F.I.C, F.C.S. Demy
8vo. Five Illustrations. 285 pp. Price 10s. 6d. net. (Post free,
10s. lOd. home; lis. 3d. abroad.)

Contents.

Introductory. Light— White Light— The Spectrum— The Invisible Spectrum— Normal
Spectrum — Simple Nature of Pure Spectral Colour — The Recomposition of White Light —
Primary and Complementary Colours — Coloured Bodies— Absorption Spectra — The Appli=
cation of Pigments. Uses of Pigments : Artistic, Decorative, Protective— Methods of
Application of Pigments : Pastels and Crayons, Water Colour, Tempera Painting, Fresco,
Encaustic Painting, Oil-colour Painting, Keramic Art, Enamel, Stained and Painted Glass,
Mosaic— Inorganic Pigments. White Lead— Zinc White— Enamel White — Whitening-
Red Lead — Litharge — Vermilion— Royal Scarlet — The Chromium Greens— Chromates of Lead,
Zinc, Silver and Mercury — Brunswick Green — The Ochres — Indian Red — Venetian Red —
Siennas and Umbers— Light Red— Cappagh Brown— Red Oxides— Mars Colours— Terre Verte
— Prussian Brown — Cobalt Colours — Coeruleum — Smalt — Copper Pigments — Malachite —
Bremen Green — Scheele's Green — Emerald Green — Verdigris — Brunswick Green — Non-
arsenical Greens — Copper Blues — Ultramarine — Carbon Pigments — Ivory Black — Lamp Black
—Bistre— Naples Yellow— Arsenic Sulphides : Orpiment, Realgar— Cadmium Yellow—
Vandyck Brown— Organic Pigments. Prussian Blue— Natural Lakes— Cochineal— Carmine
— Crimson — Lac Dye — Scarlet — Madder — Alizarin — Campeachy — Quercitron — Rhamnus —
Brazil Wood— Alkanet— Santal Wood— Archil— Coal-tar Lakes— Red"" Lakes— Alizarin Com-
pounds— Orange and Yellow Lakes — Green and Blue Lakes— Indigo — Dragon's Blood —
Gamboge — Sepia — Indian Yellow, Puree — Bitumen, Asphaltum, Mummy — index.

THE MANUFACTURE OP PAINT. A Practical Handbook
lor Paint Manufacturers, Merchants and Painters. By J. Cruickshank
Smith, B.Sc. Demy Svo. 200 pp. Sixty Illustrations and One Large
Diagram. Price 7s. 6d. net. (Post tree, 7s. lOd. home ; 8s. abroad.)

Contents.

Preparation of Raw Material — Storing of Raw Material— Testing and Valuation of Raw
Material— Paint Plant and Machinery— The Grinding of White Lead— Grinding of White
Zinc — Grinding of other White Pigments — Grinding of Oxide Paints — Grinding of Staining
Colours— Grinding of Black Paints — Grinding of Chemical Colours — Yellows— Grinding of
Chemical Colours — Blues — Grinding Greens — Grinding Reds — Grinding Lakes— Grinding
Colours in Water— Grinding Colours in Turpentine — The Uses of Paint — Testing and Matching
Paints — Economic Considerations — Index.

DICTIONARY OP CHEMICALS AND RAW PRO-
DUCTS USED IN THE MANUPACTURE OP
PAINTS, COLOURS, VARNISHES AND ALLIED
PREPARATIONS. By George H. Hurst, F.C.S. Demy
8vo. 380 pp. Price 7s. 6d. net. (Post free, 8s. home ; 8s. 6d. abroad.)

THE MANUPACTURE OP LAKE PIGMENTS PROM
ARTIPICIAL COLOURS. By Francis H. Jennison,
F.I.C, F.C.S. Sixteen Coloured Plates, showing: Specimens of
Eig:hty-nine Colours, specially prepared from the Recipes griven
in the Book. 136 pp. Demy 8vo. Price 7s. 6d. net. (Post free,
7s. lOd. home; 8s. abroad.)

Contents.

The Groups of the Artificial Colouring Matters— The Nature and Manipulation of Artificial
Colours — Lake-forming Bodies for Acid Colours — Lake-forming Bodies' Basic Colours — Lake
Baiies — The Principles of Lake Formation — Red Lakes— Orange, Yellow, Green, Blue, Violet
and Black Lakes — The Production of Insoluble Azo Colours in the Form of Pigments — The
General Properties of Lakes Produced from Artificial Colours — Washing, Filtering and Fin-
ishing— Matching and Testing Lake Pigments — Index.

PAINTS, COLOURS, ETC— continiied.
THE MANUFACTURE OF MINERAL AND LAKE
PIGMENTS. Containing Directions for the Manufacture
of all Artificial, Artists and Painters' Colours, Enamel, Soot and Me-
tallic Pigments. A Text-book for Manufacturers, Merchants, Artists
and Painters. By Dr. Josef Bersch, Translated by A. C. Wright,
M.A. (Oxon.), B.Sc. (Lond.), Forty-three Illustrations. 476 pp., demy
8vo. Price 12s. 6d. net. (Post free, 13s. home ; 13s. 6d. abroad.)

RECIPES FOR THE COLOUR, PAINT, VARNISH, OIL,
SOAP AND DRYSALTERY TRADES. Compiled by
An Analytical Chemist. New Revised and Enlarged Edition.
Demy 8vo. 350 pp. Price lOi Od. net. (Post free, lis. home; lis. 3d.
abroad.)

OIL COLOURS AND PRINTERS' INKS. By Louis
Edgar Andes. Translated from the German. 215 pp. Crown 8vo.
56 Illustrations. Price 5s. net. (Post free, 5s. 4d. home ; 5s. 6d. abroad.)

Contents.

Linseed Oil — Poppy Oil — Mechanical Purification of Linseed Oil — Chemical Purification of
Linseed Oil — Bleaching Linseed Oil — Oxidizing Agents for Boiling Linseed Oil — Theory of
Oil Boiling — Manufacture of Boiled Oil — Adulterations of Boiled Oil — ■ Chinese Drj'ing Oil and
Other Specialities — Pigments for House and Artistic Painting and Inks — Pigment for
Printers' Black Inks — Substitutes for Lampblack — Machinery for Colour Grinding and
Rubbing — Machines for mixing Pigments with the Vehicle — Paint Mills — Manufacture of
House Oil Paints — Ship Paints— Luminous Paint — Artists' Colours — Prmters' Inks: —
VEHICLES— Printers' Inks :— PIGMENTS and MANUFACTURE- Index.

MODERN PRINTING INKS. A Practical Handbook for
Printing Ink Manufacturers and Prmters. By Alfred Seymour.
Demy 8vo. Six Illustrations. 90 pages. Price 5s. net. (Post free,
5s. 4d. home ; 5s. 6d. abroad.)

Contents.

Introduction.— Division of Labour — A Separate Industry — Choice of Materials — Skilful
Maripulation — Some Important Factors — The Medium — Ink and Colour Mixing — A Justihc-
tion. Linseed Oil. — Extraction of the Oil — ClassiKcation — Mechanical Purification —
Adulteration — Boiled Oil— Preparation of Boiled Oil — An Alternative Process. Varnish. —
A Vehicle and Essential Component — A Reference to Lithography — Baltic Oil — Preparation
of Varnish — The Modern Method — An Old Argument — Letterpress Varnish — A Cheaper
Medium — A Suggestive Recipe — Fire Risks — Gradations of V'arnish. Dry Colours. — A
Recommendation — An Endless Variety of Materials — Earth Colours— Mineral Colours —
Substrates — Toning Earth Colours — Physical Characteristics — Colouring Power — Brilliance —
Purity of Tone — Permanence. Dry Colours— Blacks, Whites, Yellows — Lampblack-
Process of ^Manufacture — Calcinati m — Carbon Black — Acetylene Black — A Simple Test — Lead
and Zinc Whites — White Earth Colours — Yellows — Yellow Ochres — Mineral Yellows. Dry
Colours — Reds, Browns. — Classification of Reds — Genuine Vermilions — Preparation —
Imitation Vermilions — Umber, Raw and Burnt — Sienna, Raw and Burnt. Blues, Greens. —
Ultramarine Blue — A Useful Tint — Other Similar Blues — Cobalt Blues — Prussian— Cninese
and Bronze Blues — A Test for Purity — Greens — Compound Greens— Mine ral Greens. Lakes.
— Characteristics — Lake Derivatives — A Point of Importance — Red Lakes — Madder —
Cochineal and Carmine — Brazil Wood — Alizarine a Coaltar Derivative — Yellow Lakes — Blue
Lakes— Green Lakes. The Grinding of Printing Inks. — Ink-grinding Machinery — Ink-
grinding Mill — A Novel Machine — Hand Grinding — Treatment of Gritty Colours— A Question
of Proportion— Approximate Calculation — Soap — Saturation — Friction Heat — Consistent
Grinding. Ink and Colour Mixing. — A Necessary Acquisition— Ink Mixing Defined— Mixed
Green Inks — Mixed Brown Inks — Tints — Ink Mixing — Lithographic Inks — Characteristics of
Yellows — Mixing V'ermilion — Ultramarine and Other Blues — Bronze, Prussian and Chinese
Blues — Working Consistency — Reducing Medium — Letterpress Inks — Gloss Inks — Three-
colour Inks — Ink-mixing Machine. The Characteristics of Some Prnting Processes. —
A Supplementary Discussion — Letterpress Inks — Three-colour Printing — Lithographic Printing
Inks — An Important Feature — Suggestive Points — Tinplate Printing. Driers. — A Valuable
Auxiliary — Energetic Drying Inks — The Theory of Drying — Liquid Driers — Terebene — Paste
Driers — Letterpress Driers — Powder Driers — Turpentine as a Drier. Bronze Powders and
Bronzing. — A Brief Justification — Bronze Printing Inks — Bronze Powders — The Process of
Manufacture — Preparation of the Leaf— Grinding and Grading — Bronzing Mediums — Requisite
Qualities — Wax Varnish. "Things Worth Knowing." — A Record of Notes and
Experiences — Index.

{See also Writing Inks, p. ii.)

THREE HUNDRED SHADES AND HOW TO MIX
THEM. For Architects, Decorators and Painters.

{See page 28.)

PAINTS, COLOURS, ETC.— continued.

CASEIN. By Robert Scherer. Translated from the German
by Chas. Salter. Demy 8vo. Illustrated. Second Revised English
Edition. Ic-O pp. Price 7s. 6d. net, (Post free, 7s. lOd. home;
8s. abroad.)

Contents.
Casein : its Origin, Preparation and Properties. Various Metliods of Preparing
Casein. Composition and Properties of Casein. Casein Paints. — '• Marble-Lime "
Colour for Outside Work — Casein Enamel Paint — Casein Faijade Paint — Cold-Water Paint in
Powder Form — Kistory's Recipe for Casein Paint and Varnish — Pure Casein Paints for Walls,
etc. — Casein Paints for Woodwork and Iron — Casein-Silicate Paints — Milk Paints — Casein-
Silicate Paint Recipes — Trojel's Boiled Oil Substitute^Cal-omine Wash — Quick- Drying
Casein Paint — Boiled Oil Substitute — Rini<'s Cold-W.iter Paint — Formolactin — Waterproof
Paint for Playing Cards — Casein Colour Lake -Casein-Ce:Tient Paint. Tlie Teclinics of
Casein Painting. Casein Adiiesives and Putties. — Casein Glue in Plates or Flakes —
Jeromin's Casein Adhesive — Hall's Casein Glue — Waterproof Glue — Liquid Casein Glue —
Casein and Borax Glue — Solid Casein Adhesive — Casein Solution — Glue Po.vder — Casein
Puttie — Washable Cement for De il Boards — Wenk's Casein Cement — Casein and Lime Cement
— "Pitch Barm" — Casein Stopping — Casein Cement for Stone. Tile Preparation of
Plastic Masses from Casein. — Imitation Ivory — Anti-Radiation and Anti-Corrosive Com-
position— Dickmann's Covering for Floors and Walls — Imitation Lin )lejm — Imitation
Leather — Imitation Bone — Plastic .Mass of Keratin and Casein — Insulating Mass — Plastic
Casein Masses — Horny Casein Mass — Plastic .Mass from Celluloid — Casein Cellulose Compo-
sition— Fireproof Cellulose Substitute — Nitrocellulose and Casein Composition — Franquet's
Celluloid Substitute— Galalith. Uses of Casein in the Textile industry, for Finistiing
Colour Printing, etc. — Caseogum — "Glutin" — Casein Dressing tor Linen and Cotton
Fabrics — Printing C.jlour with .Vlecallic Lustre — Process for Softening, Sizing and Loading —
Fixing Casein and Other Albuminoids on the Fibre — Fixing Insoluble Colouring Alatters — ■
Waterproofing and Softening Dressing — Casein for Mercerising Crepe — Fixing Zinc White on
Cotton with Formaldehyde — Casein-Magnesia^Casem Medium for Calico Printing— Loading
Silk. Casein Foodstuffs. — Casein Food — Synthetic Milk — Milk Food — Emulsifiable Casein
— Casein Phosphate for Baking — Making Bread, Low in Carbohydrates, from Flour and Curd
— Preparing Soluble Casein Compounds with Citrates — Casein Food. Sundry Applications
of Casein.

SIMPLE METHODS FOR TESTING PAINTERS'
MATERIALS. By A. C. Wright, M.A. (Oxon.), B.Sc.

(Lond.). Crown 8vo. 160 pp. Price 5s. net. (Post free, 5s. 3d.
home ; 5s. 6d. abroad.)

IRON - CORROSION, ANTI - FOULING AND ANTI-
CORROSIVE PAINTS. Translated from the German of
Louis Edgar Andes. Sixty-two Illustrations. 275 pp. Demy 8vo.
Price 10s. 6d. net. (Post free, 10s. lOd. home; lis. 3d. abroad.)

Contents.

Iron-rust and its Formation — Protection from Rusting by Paint — Grounding the Iron with
L nseed Oil, etc. — Testing Paints — Use of Tar for Painting on Iron — Anti-corrosive Paints —
Linseed Varnish — Chinese Wood Oil — Lead Pigments — Iron Pigments — Artificial Iron Oxides
— Carbon — Preparation of Anti-corrosive Paints — Results of Examination of Several Anti-
corrosive Paints — Paints for Ship's Bottoms — .Anti-fouling Compositions — Various Anti-cor-
rosive and Ship's Paints — Official Standard Specifications for Ironwork Paints — Index.

THE TESTING AND VALUATION OF RAW MATE-
RIALS USED IN PAINT AND COLOUR MANU-
FACTURE. By M. W. JoxEs, F.C.S. A Book for the
Laboratories of Colour Works. 88 pp. Crown 8vo. Price 5s. net.
(Post free, 5s. 3d. home and abroad.)

THE MANUFACTURE AND COMPARATIVE MERITS
OF WHITE LEAD AND ZINC WHITE PAINTS. By

G. Petit, Civil Enj^incer, etc. Translated from the French. Crown 8vo.
100 pp. Price 4s. net. (Post free, 4s. 3d. home ; 4s. 4d. abroad.)

Contents.

Chapters I., The Fundamental Principles of Painting in Oil. II., The Different Varieties of
AVhite Leads — The Dutch Process — Grinding White Lead in Oil. III., Other Processes of
Manufacturing White Lead. IV., White Lead Substitutes — Sophistication of White Lead-
Analysis of White Lead. V., White Lead Paints— Their Merits and Defects. VI., Toxi-
.cology of White Lead — Hygienic Measures in its Manufacture and Use. VII., Zinc White —
Jts Preparation. IX., Zinc White Paint and Zinc White Coatings — Their Merits and Defects.

STUDENTS' HANDBOOK OF PAINTS, COLOURS, OILS

AND VARNISHES. By John Furnell. Crown 8vo. 12
Illustrations. 96 pp. Price2s.6d.net. (Post free, 2s. 9d. home and abroad.)

Varnishes and Drying Oils,

OIL CRUSHING, REFINING AND BOILING, THE
MANUFACTURE OF LINOLEUM, PRINTING AND
LITHOGRAPHIC INKS, AND INDIA-RUBBER
SUBSTITUTES. By John Geddes McIntosh Being
Volume 1. of the Second, greatly enlarged, English Edition, in three
Volumes, of "The Manufacture of Varnishes and Kindred Industries,"
based on and including the work of Ach. Livache. Demy 8vo. 150 pp.
29 Illustrations. Price 7s. 6d. net. (Post free, 7s. lOd. home ; 8s.
abroad.)

VARNISH MATERIALS AND OIL- VARNISH MAKING.

By J. G. McIntosh. Being Vol. II. of " The Manufacture of Varnishes
and Kindred Industries". Demy 8vo. 70 Illustrations. 220 pp.
Price 10s. 6d. net. (Post free, 10s. lOd. home ; lis. 3d. abroad.)

SPIRIT VARNISHES AND SPIRIT VARNISH
MATERIALS. By J. G. McIntosh. Being Volume III.
of 'The Manufacture of Varnishes and Kindred Industries". Demy
8vo. Illustrated. 464 pp. Price 12s. 6d. net. (Post free, 13s. home ;
13s. 6d. abroad.) Just published.

Contents.
Characteristics of Spirit Varnisli Solvents. Acetic Acid— Acet.c Anhydride— Acetone
— '\myl Acetate— Benzine. Coal Tar Naphtha— Tolvene—Cajeput Oil— Caoutchouc—Carbon
Disulphide— Carbon Tetrachloride— Chloroform— Chlorine Derivati\ es— Dichlorhydrin— Epi-
chlorhydrin Alcoholic Solvents— Ethyl Alcohol— Absolute Alcohol— Ether— Ethyl Acetate
— Ethylic Nitrate— Ethy lie xNitrite— Methyl Alcolol— Methyl Nitrate. Solvents— Naph-
thalene—Petroleum Spirit. Resin Yielding Trees— Canada Balsam— Oregon Balsam—
—Venice Turpentine— Various Resins Sources and Methods of obtaining Turpentine-
Obtaining American Turpentine— Indian Turpertme— Grecian Turpentine— Spanish Turpen-
tine-Swedish Turpentie— Aleppo Pine — Honduras and Mexican Turpentines— Saghalien
Turpentine— Russian Turpentine- French Rosin and Turpentine. Distillation of Turpen =
tine. Turpentine Testing and Turpentine Substitutes. Distillation and Chemistry
of t^osin. Rosin Oil. Chemistry of the Terpenes- Camphor. Wood Tar, etc. Gum
Benzoin, Dammar, Kauri, etc. Dragons' Blood Hlemi, Gamboge, etc —Java Copal-
Gum Accroides, ere. Japanese and Chinese Lacquers. Manilla Copal— Mastic- Sandarac.
Shellac. Colours and Stains. Principles of Spirit Varnish Manufactures. Amber
and Asphaltum, Colodion and Celluloid Varnishes. Copal and Dammar Spirit
Varnish. Indiarubber, Insulating, Mastic and Malt Spirit Varnishes. Rosin Spirit
Varnishes -Sandarac Spirit Varnisnes — Shellac Wa:tr Varnishes— Shellac Spirit Varnishes
— Spirit Varnish Enamels— Sundry Spirit Varnishes Technical Valuation— The Filmo-
meter— Colorimeter— Acid Re-action — Chemical Analysis — Density— Viscometer— Boiling
Point— Flash Point. Rosin Determination and Analysis. General Index. Index to Recipes.

DRYING OILS, BOILED OIL AND SOLID AND
LIQUID DRIERS. By L. E. Andes. Expressly Written
for this Series of Special Technical Books, and the Publishers hold
the Copyright for English and Foreign Editions. Forty-two Illustra-
tions. 342 pp. Demy 8vo. Price 12s. 6d. net. (Post free, 13s. home ;
13s. 3d. abroad.)

Oils, Fats, Waxes, Greases,

Petroleum.

LUBRICATING OILS, FATS AND GREASES: Their
Origin, Preparation, Properties, Uses and Analyses. A Handbook for
Oil Manufacturers, Refiners and Merchants, and the Oil and Fat
Industry in General. By George H. Hurst, F.C.S. Third Revised
and Enlarged Edition. Seventy-four Illustrations. 384 pp. Demy
Svo. Price 10s. 6d. net. (Post iree. lis. home: lis. 3d. abroad.)

TECHNOLOGY OF PETROLEUM : Oil Fields of the
World — Their History, Geography and Geology — Annual Production
and Development — Oil-well Drilling — Transport. By Henry Neu-
BERGER and Henry Noalhat. Translated from the French by J. G.
McIntosh. 550 pp. 153 Illustrations. 26 Plates. Super Royal 8vo.
Price 21s. net. (Post free, 21s. 9d. home; 23s. 6d. abroad.)

Contents.

study of the Petroliferous Strata,

Excavations — Hand Excavation or Hand Digging of Oil Wells.

Methods of Boring-.

Accidents — Boring Accidents — Methods of preventing them — Methods of remedying them
— Explosives and the use of the "Torpedo" Levigation — Storing and Transport of Petroleum
— General Advice — Prospecting, Management and carrying on of Petroleum Boring Operations.

General Data— Customary Formulae— Memento. Practical Part. General Data
bearing on Petroleum — Glossary of Technical Terms used in the Petroleum Industry — Copious
Index.

MINERAL WAXES : Their Preparation and Uses. By
Rudolf Gregorius. Translated from the German. Crown 8vo. 250
pp. 32 Illustrations. Price 6s. net. (Post free, 6s. 4d. home ;
6s. 6d. abroad.)

Contents.

Ozokerite— Ceresine — Paraffin — Refining Paraffin — Mineral Wax — Appliances for
Extracting, Distilling and Refining Ozokerite— Uses of Ceresine, Paraffin and
Mineral Waxes — Paint and Varnish Removers— Leather and Piston=Rod Greases —
Recipes for Silk, Cotton and Linen Dressings — Candles.

THE PRACTICAL COMPOUNDING OF OILS, TAL-
LOW AND GREASE FOR LUBRICATION, ETC.

By An Expert Oil Refiner. Second Edition. 100 pp. Demy 8vo.
iPrice 7s. 6d. net. (Post free, 7s. lOd. home ; 8s. abroad.)

Contents.

Introductory Remarks on the General Momenclature of Oils, Tallow and Greases
suitable for Lubrication — Hydrocarbon Oils — Animal and Fish Oils — Compound
Oils— Vegetable Oils— Lamp Oils— Engine Tallow, Solidified Oils and Petroleum
Jelly — Machinery Greases: Loco and Anti=friction— Clarifying and Utilisation
of Waste Fats, Oils, Tank Bottoms, Drainings of Barrels and Drums, Pickings
Up, Dregs, etc.— The Fixing and Cleaning of Oil Tanks, etc.— Appendix and
General Information.

THE MANUFACTURE OF LUBRICANTS, SHOE
POLISHES AND LEATHER DRESSINGS. By

Richard Brunner. Translated from the Sixth German Edition by
Chas. Salter. 10 Illustrations. Crown Svo. 170 pp. Price 7s. 6d.
net. (Post free, 7s. lOd. home ; 8s. abroad.)

THE OIL MERCHANTS' MANUAL AND OIL TRADE
READY RECKONER. Compiled by Frank F. Sherriff.
Second Edition Revised and Enlarged. Demy Svo. 214 pp. 1904.
With Two Sheets of Tables. Price 7s. 6d. net. (Post free, 7s. lOd.
home ; 8s. 3d. abroad.)

ANIMAL FATS AND OILS: Their Practical Production,
Purification and Uses for a great Variety of Purposes. Their Pro-
perties, Falsification and Examination. Translated from the German
of Louis Edgar Andes. Sixty-two Illustrations. 240 pp. Second
Edition, Revised and Enlarged. Demy Svo. Price 10s. 6d. net.
(Post free, 10s. lOd. home; lis. 3d. abroad.)

VEGETABLE FATS AND OILS: Their Practical Prepara-
tion, Purification and Employment for Various Purposes, the'r Proper-
ties, Adulteration and Examination. Translated from the German of
Louis Edgar Andes. Ninety-four Illustrations. 340 pp. Second
Edition. Demy Svo. Price 10s. 6d. net. (Post free, lis. home;
lis. 6d. abroad.)

EDIBLE FATS AND OILS : Their Composition, Manufacture
and Analysis. By W. H. Simmons, B.Sc. (Lond.), and C. A, Mitchell,
B.A. (Oxon.). Demy 8vo. 150 pp. Price 7s. 6d. net. (Post free,
7s. 9d. home ; 8s. abroad.)

Contents.

Introduction,— Physiological Considerations— Constitution of Fats and Oils— Trygly-
ceride — Glyceride — Butyrin — Isovalerin — Caproin — Caprylin — Caprin — Laurin — Myristin—
Palmitin — Stearin— Olein—Ricinolein— Stearic Acid Series— Oleic Acid Series— Linolic Acid
Series— Linolenic Acid Series— Ricinolenic Acid Series. Raw Materials used in the Manu =
facture of Edible Fats and Oils.— Tallow— Mutton— Beef— Lard— Lard Oil— Cocoanut Oil
—Maize Oil— Cotton-seed Oil— Cotton-seed Stearine— Olive Oil— Arachis Oil (Earthnut or
Pea-nut Oil)— Sesame Oil— Palm Nut Oil (Palm Kernel Oil)— Sunflower Seed Oil— Cacao
Butter or Oil of Theobroma— Palm Oil— Soya Bean Oil— Shea Butter— Mowrah-seed Oil—
Margosa Oil. Bleaching, Deodorising, and Refining Fats and Oils.— Physical Methods
—Washing, Freezing, Filtration, Treatment, Steaming— Removal of Stearines— Methods of
Filtration— Chemical Methods— Caustic Soda— Sodium Carbonate— Alkaline Earths— Fre-
senius— Bleaching of Oils— Charcoal— Fullers' Earth— Ozone— Hydrosulphites— Sodium Bi-
sulphite—Sodium Hydrosulphite Formaldehyde— Organic Peroxides— Deodorisation of Fats-
Treatment of Rancid Fats. Butter.— Butter Fat— Water— Salt— Curd— Keeping Properties
of Butter— Rancidity of Butter— Renovated Butter— Preservatives in Butter— Physical Char-
acteristics—Solubility -Refractorative Examination— Chemical Characteristics— Hehner &
Reichert Values— Influence of the Food of the Cows— Cocoanut Oil in Butter— Artificial
Colouring Matters. Lard.— Lard Oil— Rendering of Lard— Commercial Grades : (1) Neutral
Lard ; (2) Leaf Lard ; (3) Choice Steam Lard or Choice Lard ; (4) Prime Steam Lard ; (5) Guts
- Lard Crystals— Influence of Food— Acidity of Lard— Water— Pole nske— The Iodine Value—
—Lard Oil, Margarine and Other Butter Substitutes.— Margarine, Oleomargarine or
Artificial Butter — Invention and Development — Modern Processes and Formula — Vegetable
Butter— Modern Process —Vegetable Butter— Palm Oil. Salad Oils.— Oils used for Culinary
and Confectionery Purposes— Chocolate Fats— Olive Oils— Sesame Oil— Cotton-seed Oil-
Sunflower Oil— Poppy Oil— Maize Oil -Chocolate Fats— Cocoanut and Palm Kernel Oil Stear-
ines—Other Vegetable Fats. Analysis of Raw Materials and Finished Products.— Raw
Materials— Specific Gravity— Free Fatty Acids— Saponification Value— Saponification Equiv-
alent—Iodine Absorption— Wij's Method— Bromine Absorption -Titer or Solidifying of the
Fatty Acids— Refractive Index— Unsaponifiable Matter— Valenta's Acetic Acid Test— Mau-
mene's Test— Bromine Thermal Value— Baudouin's Test— Tocher's Test— Olive Oil— Cotton-
seed Oil— Halphen's Test— Arachis Oil— Butter— Water— Examination of the Fat— Refractive
Power- Soluble and Insoluble Fatty Acids— Insoluble Fatty Acids— Casein— Curd— Colouring
Matters— Boron Compounds— Fluorides— Margarine, Vegetable Butter or other Butter Sub-
stitutes—Lard—Cheese—Water— Ash— Fat— Nitrogen— Chocolate— Unsweetened Chocolate
— Sweetened Chocolate — Granulated or Ground Chocolate— Chocolate Covered Goods — Milk
Chocolate Fat— Palm-nut Stearine — Dika or Gaboon Fat— Borneo Tallow or Tankawang Fat
— Illipe Fat— Fibre— Total Nitrogen— Sugar. Statistics of the Trade in Edible Oils.—
United Kingdom Trade— Exports— Italian Trade in Olive Oil— Spanish Oil Trade— Vegetable
Oil Trade of France— Cotton-seed Oil in the United States.

Essential Oils and Perfumes^

THE CHEMISTRY OF ESSENTIAL OILS AND ARTI-
FICIAL PERFUMES. By Ernest J. Parry, B.Sc.
(Lond.), F.I.C., F.C.S. Second Edition, Revised and Enlarged. 552 pp,
20 Illustrations. Demy Svo. Price 12s. 6d. net. (Post free, 13s. home ;
13s. 6d. abroad.)

Soaps.

SOAPS. A Practical Manual of the Manufacture of Domestic,
Toilet and other Soaps. By George H. Hurst, F.C.S. 2nd edition,
390 pp. 66 Illustrations. Price 12s. 6d.net. (Post free, 13s. home;
13s. 6d. abroad.)

TEXTILE SOAPS AND OILS. Handbook on the Prepara-
tion. Properties and Analysis of the Soaps and Oils used in Textile
Manufacturing, Dyeing and Printing. By George H. Hurst, F.C.S,
Crown Svo. 195 pp. 1904. Price 5s. net. (Post free, 5s. 4d. home ;
5s. 6d. abroad.)

8

THE HANDBOOK OF SOAP MANUFACTURE. By

Wm. H. Simmons, B.Sc. (Lond.), F.C.S. and H. A. Appleton. Demy
8vo. 160 pp. 27 Illustrations. Price 8s. 6d. net. (Post free,
8s. lOd. home ; 9s. abroad.)

Contents.

Definition of Soap. — Properties — Hydrolysis— Detergent Action. Constitution of Oils
and Fats, and tlieir Saponification. — Researches of Chevreul and Berthelot-- Mixed
Glycerides — Modern Theories of Saponification — Hydrolysis accelerated by (1) Heat or
Electricity. (2) Ferments, Castor-seed Ferment. Steapsin Emulsin and (3) Chemical
Reagents, Sulphuric Acid, Twitchell's Reagent, Hydrochloric Acid, Lime, Magnesia, Zinc
Oxide, Soda and Potash. Raw Materials used in Soap-making. — Fats and Oils — Waste
Fats — Fatty Acids — Less-known Oils and Fats of Limited Use — Various Xew Fats and Oils
Suggested for Soap-making — Rosin — Alkali (Caustic and Carbonated) — Water— Salt Soap-
stock. Bleacliing and Treatment of Raw Materials intended for Soap-making.—
Palm Oil— Cottonseed Oil — Cottonseed " Foots" — Vegetable Oils — Animal Fats — Bone Fat —
Rosin. Soap= making. —Ch.ssification of Soaps— Direct combination of Fatty Acids with
Alkali — Cold Process Soaps — Saponification under Increased or Diminished Pressure — Soft
Soap — Marine Soap — Hydrated Soaps, Smooth and Marbled — Pasting or Saponification —
Graining Out— Boiling on Strength — Fitting — Curd Soaps — Curd Mottled— Blue and Grey
Mottled Soaps — Milling Base — Yellow Household Soaps— Resting of Pans and Settling of
Soap — Utilisation of Nigres — Transparent Soaps— Saponifying Mineral Oil — Electrical Pro-
duction of Soap. Treatment of Settled Soap.— Cleansing— Crutching — Liquoring of Soaps
— Filling— Neutralising, Colouring and Perfuming — Disinfectant Soaps — Framing — Slabbing
— Barring — Open and Close Piling — Drying — Stamping — Cooling. Toilet, Textile and
Miscellaneous Soaps.— Toilet Soaps— Cold Process Soaps — Settled Boiled Soaps— Remelted
Soaps — Milled Soaps — Drying, Mi ling and Incorporating Colour, Perfumes, or Medicaments
— Perfumes^Colouring Matter — Neutralising and Super-fatiing Material — Compressing —
Cutting— Textile Soaps — Soaps for Woollen, Cotton and Silk Industries — Patent Textile
Soaps — Stamping — Medicated Soaps — Ether Soap — Floating Soaps — Shaving Soaps —
Miscellaneous Soaps. Soap Perfumes. — Essential Oils — Source and Preparation — Properties
— Artificial and Synthetic Perfumes. Glycerine Manufacture and Purification. — Treat-
ment of Lyes — Evaporation — Crude Glycerine — Distillation — Distilled and Dynamite
Glycerine — Chemically Pure Glycerine — Animal Charcoal for Decolorisation — Glycerine
resultant from other methods of Saponification — Yield of Glycerine from Fats and Oils.
Analysis of Raw Materials, Soap and Glycerine. — Fats and Oils— Alkalies and Alkali
^alts — Essential Oils — Soap — Lyes — Crude Glycerine. Statistics of the Soap Industry.
Appendix A. — Comparison of Degrees Twaddell, Beaume and Actual Densities.
Appendix B.— Comparison of Different Thermometric Scales. Appendix C. — Table of
the Specific Gravities of Solutions of Caustic Soda. Appendix D.— Table of Strength
of Caustic Potash Solutions at 6o- F. Index.

Cosmetical Preparations.

COSMETICS : MANUFACTURE, EMPLOYMENT
AND TESTING OF ALL COSMETIC MATERIALS
AND COSMETIC SPECIALITIES. Translated
from the German of Dr. Theodor Roller. Crown 8vo. 262 pp.
Price 5s. net. (Post free, 5s. 4d. home ; 5s. 6d. abroad.)

Contents,

Purposes and Uses of, and Ingredients used in the Preparation of Cosmetics — Preparation of
Perfumes by Pressure, Distillation, Maceration, Absorption or Enfleurage, and Extraction
Methods — Chemical and Animal Products used in the Preparation of Cosmetics — Oils and Fats
used in the Preparation of Cosmetics — General Cosmetic Preparations — Mouth Washes and
Tooth Pa?tes — Hair Dyes, Hair Restorers and Depilatories — Cosmetic Adjuncts and
Specialities — Colouring Cosmetic Preparations — Antiseptic Washes and Soaps — Toilet and
Hygienic Soaps — Secret Preparations for Skin, Complexion, Teeth, Mouth, etc. — Testing and
Examining the Materials Employed in the Manufacture of Cosmetics — Index.

Glue, Bone Products and

Manures.

GLUE AND GLUE TESTING. By Samuel Rideal, D.Sc.
(Lond.), F.I.C. Fourteen Engravings. 144 pp. Demy 8vo. Price
10s. 6d. net. (Post free, 10s. lOd. home ; lis. abroad.)

9

BONE PRODUCTS AND MANURES : An Account of the
most recent Impiovements in the iManutacture of Fat, Glue, Animal
Charcoal, Size. Gelatine and Manures. By Thomas Lambert, Techni-
cal and Consulting Chemist. Illustrated by Twenty-one Plans and
Diagrams. 162 pp. Demy 8vo. Price 7s. 6d. net. (Post free, 7s. lOd.
home ; 8s. abroad.)

Contents.

Chemical Composition of Bones— Arrangement of Factory — Properties of Glue — Gliitin
and Chondrin — Skin Glue — Liming of Skms — Washing — Boiling of Skins — Clarification of Glue
Liquors — Glue-Boiling and Clarifying House — Specification of a Glue — Size — Uses and Pre
paration and Composition of Size — Concentrated Size — Properties of Gelatine — Preparation of
Skin Gelatine — Drying — Bone Gelatine— Selecting Bones — Crashing — Dissolving — Bleaching
— Boiling — Properties of Glutin and Chondrin — Testing of Glues and Gelatines — The Uses of
Glue, Gelatine and Size in Various Trades — Soluble and Liquid Glues — Steam and Waterproof
Glues — Manures— Importation of Food Stuffs — S)ils— Germination — Plant Life — Natural
Manures— Water and Nitrogen in Farmyard Manure — Full An lysis of Farmyard Manure
— Action on Crops — Water-Closet System — Seuage Manure — Green Manures — Artificial
Manures — Mineral Manures — Ni rogenous Matters — Shoddy — Hoofs and Horns — Leather
Waste — Dried Meat — Dried Blood — Superphosphates — Composition — Manufacture — Common
Raw Bones— Degreased Bones — Crude Fat — Refined Fat— Degelatinised Bones — Animal
Charcoal — Bone Superphosphates — Guanos — Dried Animal Products — Potash Compounds —
Sulphate of Ammonia — Extraction in Zacuo— French and British Gelatines compared — Index.

Chemicals, Waste Products and
Agricultural Chemistry,

REISSUE OF CHEMICAL ESSAYS OF C. W.
SCHEELE. First Published in English in 1786. Trans-
lated from the Academy of Sciences at Stockholm, with Additions. 300
pp. Demy Svo. Price 5s. net. (Post fr je 5s. 6d. home ; 5s. 9d. abroad.)

Contents.

Memoir : C W. Scheele and his work (written for this edition by J. G. Mcintosh) — On
Fluor Mineral and its Acid — On Fluor Mmeral — Chemical Investigation of Fluor Acid,
with a View to the Earth which it Yields, by Mr. Wiegler — Additional Information
Concerning Fluor Minerals — On MangmLse, Magnesium, or Magnesia Vitrariorum — On
Arsenic and its Acid — Remarks upon Salts of Benzoin — On Silex, Clay and Alum^Analysis
of the Calculus Vesical — Method of Preparing Mercurius Dulcis Via Humida— Cheaper and
more Convenient Method of Preparing PuKis Algarothi — Experiments upon Molybdaena
— Experiments on Plumbago — Method of Preparing a Ne-v Green Colo_r^Of the De-
composition of Neutral Salts by Unslaked Lime and Iron— On the Quantity of Pure Air which
is Daily Present in our Atmosphere— On Milk and its Acid — On the Acid of Saccharum Lactis
— On the Constituent Parts of Lapis Ponderosus or Tungsten — Experiments and Observations
on Ether — Index.

THE MANUFACTURE OF ALUM AND THE SUL-
PHATES AND OTHISR SALTS OF ALUMINA AND
IRON. Their Uses and Applications as Mordants in Dyeing
and Calico Printing, and their other Applications in the Arts iManulac-
tures Sanitary Engineering Agriculture and Horticulture. Translated
from the French of LuciEX Geschwind. 195 Illustrations. 400 pp.
Royal Svo. Price 12s. 6d. net. (Post free 13s. home; 13s. 6d. abroad.)

AMMONIA AND ITS COMPOUNDS : Their Manufacture
and Uses. By Camille Vincent, Professor at the Central School of
Arts and Manufactures, Paris. Translated from the French by M. J.
Salter. Royal Svo. 114 pp. Thirty-two Illustrations. Price 5s. net.
(Post free. 5s. 4d. home ; 5s 6d. abroad.)

Contents.

General Considerations: Various Sources of Ammoniacal Products; Human Urine
as a Source of Ammonia — Extraction of Ammoniacal Products from Sewage —
Extraction of Ammonia from Gas Liquor— Manufacture of Ammoniacal Com-
pounds from Bones, Nitrogenous Waste, Beetroot Wash and Peat— Manufacture of
Caustic Ammonia, and Ammonium Chloride, Phosphate and Carbonate— Recovery
of Ammonia from the Ammonia=Soda Mother Liquors— Index.

10

INDUSTRIAL ALCOHOL. A Practical Manual on the
Production and Use of Alcohol for Industrial Purposes and for Use as
a Heating Agent, as an Illuminant and as a Source of Motive Power.
By J. G. M'Intosh, Lecturer on Manufacture and Applications of
Industrial Alcohol at The Polytechnic, Regent Street, London.
Demy 8vo. 1907. 250 pp. With 75 Illustrations and 25 Tables.
Price 7s. 6d. net. (Post free, 7s. 9d. home ; 8s. abroad.)

Contents.

Alcohol and its Properties. — Ethylic Alcohol — Absolute Alcohol — Adulterations —
Properties of Alcohol — Fractional Distillation — Destructive Distillation — Products of Com-
bustion— Alcoholometry — Proof Spirit — Analysis of Alcohol — Table showing Correspondence
between the Specific Gravity and Per Cents, of Alcohol over and under Proof — Other
Alcohol Tables. Continuous Aseptic and Antiseptic Fermentation and Sterilisation
in Industrial Alcohol Manufacture. The Manufacture of Industrial Alcohol from
Beets. — Beet Slicing .Machines — Extraction of Beet Juice by Maceration, by Diffusion —
Fermentation in Beet Distilleries — Plans of Modern Beet Distillery. The Manufacture of
Industrial Alcohol from Grain.— Plan of Modern Grain Distillery. The Manufacture of
Industrial Alcohol from Potatoes. The Manufacture of Industrial Alcohol from
Surplus Stocks of Wine, Spoilt Wine, Wine Marcs, and from Fruit in General. The Manu-
facture of Alcohol from the Sugar Cane and Sugar Cane .Molasses — Plans. Plant, etc.,
for the Distillation and Rectification of Industrial Alcohol.— The Caffey and other
"Patent" Stills — Intermittent versus Continuous Rectification — Continuous Distillation —
Rectification of Spent Wash. The Manufacture and Uses of Various Alcohol
Derivatives, Ether. Haloid Ethers, Compound Ethers, Chloroform — .Methyl and Amyl
Alcohols and their Ethereal Salts, Acetone — Barbet's Ether, .Methyl .\lcohol and Acetone
Rectifying Stills. The Uses of Alcohol in Manufactures, etc.— List of Industries in
which Alcohol is used, with Key to Function of Alcohol in each Industry. The Uses of
Alcohol for Lighting, Heating, and Motive Power.

ANALYSIS OF RESINS AND BALSAMS. Translated
from the German of Dr. Karl Dieterich. Demy Svo. 340 pp.
Price 7s. 6d. net. (Post free, 7s. lOd. home ; 8s. 3d. abroad.)

MANUAL OF AGRICULTURAL CHEMISTRY. By

Herbert Ingle, F.I.C, Late Lecturer on Agricultural Chemistry, the
Leeds University ; Lecturer in the Victoria University. Second
Edition, with additional matter relating to Tropical Agriculture, etc.
438 pp. 11 Illustrations. Demy Svo. Price 7s. 6d. net. (Post free,
8s. home ; 8s. 6d. abroad.)

Contents,

Properties and Characteristics of the Elements.— Hydroj^en— Oxygen— Heat of Com-
bustion— Nitrogen — Carbon — Sulphur — Phosphorous — Potassium — Sodium — Fluorine —
Magnesium — Iron — Chlorine — Aluminium — Silicon — Borax. The Atmosphere. — Nitrogen —
Oxygen — Argon — Carbon Dioxide — Ammonia — Nitric Acid — Ozone — Solid Matter. The Soil.
— Classification of Rocks— Quartz — Felspar — Mica — Clay — Sandstones — Shales — Limestones
—Calcareous Rocks— Transported Soils. Formation of Soils.— By Water, Air, Earth
Worms, Vegetation and Bacteria — Sand— Clay — Limestone — Humus— Classification of Soils.
Reactions in Soils. — Diffusion — Gravitation— Nitrification — Soil Gases — Water of the Soil —
Biology of the Soil — Electrolytic Dissociation Theory — Mass Action. Analysis of Soils. —
Sampling — Mechanical and Chemical Analyses — Determination of Silica, Alumina, Ferric
Oxide, Total Potash and Phosphoric Acid, Lime, Magnesia. Calcium Carbonate, Sulphuric
Acid, Nitrates and Nitrites. Natural Manures.— Improvement of Soils— Farmyard Manure
— Composition of Animal Excreta — Use of Litter, Straw, Peat, Bracken, Leaves, Sawdust,
Tanners' Refuse — Fermentation and Preservation of Farmyard Manure. Other Organic
Manures. — Guano — Poultry and Fish Manures— Seaweed — Dried Blood— Bones — Meat
Guano— Hair— Soot— Oil-cakes. Nitrogenous Manures.— Sodium Nitrate— Ammonium
Sulphate— Phosphatic Manures — Tricalcum Phosphate— Coprolites— Phosphorites — Mineral
Superphosphates— Basic Slag — Potash Manures— Composition of Principal Potash Salts —
Various Manures— Common Salt — Gypsum — Limestone—Ferrous Sulphate — Gas Lime —
Copper Sulphate. Analysis of Manures.— Constituents— Determination of Nitrogen-
Phosphoric Acid — Potassium — V^aluation of Manures from Analysis. Constituents of
Plants.— Carbohydrates— Sugars— Starch— Dextrin— Glycogen— Inulin— Gums— Cellulose —
Glucose — Fructose— Cane Sugar — Meletrose— Arabinose — Xylose— Lignose — Pectose — Gly-
cerol—Waxes— Organic Acids and their Salts. Essential Oils and Resins.— Terpenes—
Oxygenated Essential Oils— Essential Oils containing Sulphur— Resins. Nitrogenous Sub-
stances.— Albuminoids— Amides — Alkaloids — Chlorophyll. The Plant. — Germination —
Roots — Osmotic Pressure — Leaves — Assimilation — Flowers. Crops. — Cereals — Root Crops
— Fodder Crops — Hay — Ventilating Stacks — Silage — Composition of Crops. The Animal. —
Blood—Bones — Fatty Tissue — Muscle — Digestion — Bile— Urine. Foods and Feeding.—
Composition of Oil-cake — B.ve-Products as Foods — Digestibility of Foods — Calorific Value of
Foods— Feeding Standards — .Manurial Value of Foods. Milk and Milk Products.— Fat —

11

Albuminoids — Milk Sugar — Chemical Composition of Cow's Milk — Influence of Food, Season
and Milking Time — Milk Products — Cream — Skimmed Milk — Butter — Butter-milk — Cheese —
Condensed Milk — Koumiss- -Milk Preservation. Analysis of Milk and Milk Products. —
Milk — Amount of Fat — Determination of Total Solids, Specific Gravity, Proteids, Milk Sugar
— Adulteration of Milk — Detection of Preservatives — Butter — Butter Colouring — Cheese —
Milk Standards. Various Products used in Agriculture. — Arsenious Oxide — Bleaching
Powder — Copper Salts — Disinfectants — Fungicides — Iron Sulphate — Mercuric Chloride —
Plant Poisons. Appendix. — Atomic Weights— Hydrometer Scales — Metric System —
Solubilities. Tropical Agriculture, etc. — Composition of Rain Water — Irrigation Water —
Earth Worms — Motion of Water in Soil — Analysis of Soils — Green Manuring — Kraal Manure
— Bats' Guano — Artificial Manures— The Plant— Rice— Maize— Millet— Cotton— Flax— Castor
Seeds — Sunflower — Composition of Various South African Grown Crops — Ash Constituents of
Foods — Variations in the Composition of Milk — Butter — Fat — Bordeaux Mixture — Insecticides.

THE UTILISATION OF WASTE PRODUCTS. A Treatise
on the Rational Utilisation, Recovery and Treatment of Waste Pro-
ducts of all kinds. By Dr. Theodor Koller. Translated from the
Second Revised German Edition. Twenty-two Illustrations. Demy
8vo. 280 pp. Price 7s. 6d. net. (Post free, 7s. lOd. home ; Ss. 3d.
abroad.)

CHEMICAL MANURES. Translated from the French of
J. Fritsch. Demy Svo. Illustrated. 340 pp. Price 10s. 6d. net.
(Post free, lis. home; lis. 6d. abroad.) [ynst published.

Contents.

Phosphoric Acid — Principal Phosphate Deposits — Drying and Enrichment of Phosphates
— His orical Review of Superphosphate Manufacture^ — Theory of Manufacture of Soluble
Phosphates — Manufacture of Superphosphate — Crushing, Sifting, Drying, and Storing of
Superphosphates — Compound Manures — Manufacture of Phosphoric Acid, Double Super-
phosphates, and Various Products — Manufacture of Bone Dust and of Bone Superphosphate
(Vitriolized Bones) — Manufacture of Basic Slag — Nitrogenous Manures — Manufacture of
Manure from Animal Waste — Recovery of Nitrogen from Distillery By-Products— Nitrogen-
ized Phosphate Manures — Potassic Manures — Transference and Handling of Raw Materials
and Finished Products.

Writing Inks and Sealing Waxes*

INK MANUFACTURE : Including Writing, Copying, Litho-
graphic, Marking, Stamping, and Laundry Inks. By Sigmund Lehner.
Three Illustrations. Crown Svo. 162 pp. Translated from the German
of the Fifth Edition. Price 5s. net. (Post free, 5s. 3d. home ; 5s. 6d.
abroad.)

SEALING-WAXES, WAFERS AND OTHER ADHES-
IVES FOR THE HOUSEHOLD, OFFICE, WORK-
SHOP AND FACTORY. By H. C. Staxdage. Crown
Svo. 96 pp. Price 5s. net. (Post free, 5s. 3d. home; 5s. 4d. abroad.)

Lead Ores and Compounds.

LEAD AND ITS COMPOUNDS. By Thos. Lambert,
Technical and Consulting Chemist. Demy Svo. 226 pp. Forty Illus-
trations. Price 7s. 6d. net. (Post free, 7s. lOd. home ; 8s. 3d. abroad.)

NOTES ON LEAD ORES : Their Distribution and Properties.
By Jas. Fairie, F.G.S. Crown Svo. 64 pages. Price Is. net.
(Post free, Is. 3d. home ; Is. 4d. abroad.)

(White Lead and Zinc White Paints^ see p. 4.)

12

Industrial Hygiene.

THE RISKS AND DANGERS TO HEALTH OF VARI-
OUS OCCUPATIONS AND THEIR PREVENTION.

By Leonard A. Parry, M.D., B.Sc. (Lond.). 196 pp. Demy 8vo.
Price 7s. 6d. net. (Post free, 7s. lOd. home ; 8s. abroad.)

Contents.

Occupations which are Accompanied by the Generation and Scatterinjj of Abnormal
Quantities of Dust — Trades in which there is Danger of Metallic Poisoning — Certain Chemi-
cal Trades — Some Miscellaneous Occupations — Trades in which Various Poisonous Vapours
are Inhaled — General Hygienic Considerations — Index.

Industrial Uses of Air, Steam and

Water.

DRYING BY MEANS OF AIR AND STEAM. Explana-

tions, Formulae, and Tables for Use in Practice. Translated from the
German of E. Hausbrand. Two folding Diagrams and Thirteen Tables.
Crown 8vo. 72 pp. Price 5s. net. (Post free, 5s. 3d. home; 5s. 6d.
abroad.) Contents.

British and Metric Systems Compared — Centigrade and Fahr. Thermometers — Estimation
of the Maximum Weight of Saturated Aqueous Vapour which can be contained in 1 kilo,
of Air at Different Pressure and Temperatures — Calculation of the Necessary Weight and
Volume of Air, and of the Least Expenditure of Heat, per Drying Apparatus with Heated
Air, at the Atmospheric Pressure: A, With the Assumption that the Air is Completely Satur-
ated with Vapour both before Entry and after Exit from the Apparatus — B, When the
Atmospheric Air is Completely Saturated before entry, but at its exit is only %,hof\ Saturated
— C, When the Atmospheric Air is not Saturated with Moisture before Entering the Drying
Apparatus — Drying Apparatus, in which, in the Drying Chamber, a Pressure is Artificially
Created, Higher or Lower than that of the Atmosphere — Drying by Means of Superheated
Steam, without Air — Heating Surface, Velocity of the Air Current, Dimensions of the Drying
Room, Surface of the Drying Material, Losses of Heat — Index.

{See also " Evaporathif^, C' ndcnsing and Cooling Apparatus,'" p. 26.)

PURE AIR, OZONE AND WATER. A Practical Treatise
of their Utilisation and Value in Oil, Grease, Soap, Paint, Glue and
other Industries. By W. B. Cowell. Twelve Illustrations. Crown
8vo, 85 pp. Price 5s. net. (Post free, 5s. 3d. home ; 5s. 6d. abroad.)

Contents.

Atmospheric Air : Lifting of Liquids ; Suction Process ; Preparing Blown Oils: Preparing
Siccative Drying Oils — Compressed Air: Whitewash — Liquid Air: Retrocession — Purification
of W^ater; Water Hardness — Fleshings and Bones — Ozonised Air in the Bleaching and De-
odorising of Fats, Glues, etc. : Bleaching Textile Fibres— Appendix : Air and Gases: Pressure
of Air at Various Temperatures : Fuel: Table of Combustibles: Saving of Fuel by Heating
Feed Water: Table of Solubilities of Scale MaUing .Minerals: British Thermal Units Tables ;
Volume of the Flow of Steam into the Atmosphere : Temperature of Steam — Index.

THE INDUSTRIAL USES OF WATER. COMPOSI-
TION — EFFECTS— TROUBLES — REMEDIES— RE-
SIDUARY WATERS— PURIFICATION— ANALYSIS.

By H. DE LA Coux. Royal 8vo. Translated from the French and
Revised by Arthur iMorris. 364 pp. 135 Illustrations. Price 10s. 6d.
net. (Post free, lis. home; lis. 6d. abroad.)

Contents.

Chemical Action of Water in Nature and in Industrial Use — Composition of Waters —
Solubility of Certain Salts in Water Considered from the Industrial Point of View — Effects on
the Boiling of Water — Effects of Water in the Industries^DifficuIties with Water — Feed
Water for Boilers — Water in Dyeworks, Print Works, and Bleach Works — Water in the
Textile Industries and in Conditioning — Water in Soap Works — Water in Laundries and
Washhouses — Water in Tanning — \\'ater in Preparing Tannin and Dyewood Extracts — Water
in Papermaking — Water in Photography — Water in Sugar Refining — Water in Making Ices
and Beverages — Water in Cider Making— Water in Brewing — W aterin Distilling — Preliminary
Treatment and Apparatus— Substanceh Used for Preliminary Chemical Purification — Com-
mercial Specialities and their Employment — Precipitation of Alatters in Suspension in Water
— Apparatus for the Preliminary Chemical Purification of Water — Industrial Filters — Indus-
trial Sterilisation of Water — Residuary Waters and their Purification — Soil Filtration —
Purification by Chemical Processes — Analyses — Index.

{See Books on Smoke Prevention, Engineering and Metallurgy, p. 26, etc,)

13

X Rays.

PRACTICAL X RAY WORK. By Frank T. Addyman,

B.Sc. (Lond.), F.I.C., Member of the Roentgen Society of London;
Radiographer to St. George's Hospital; Demonstrator of Physics and
Chemistry, and Teacher of Radiography in St. George's Hospital
Medical School. Demy 8vo. Twelve Plates from Photographs of X Ray
Work. Fifty-two Illustrations. 200 pp. Price 10s. 6d. net. (Post free,
10s. lOd. home; lis. 3d. abroad.)

Contents.

Historical — Work leading up to the Discovery ot the X Rays — The Discovery — Appara^
tus and its Management — Electrical Terms— Sources of Electricity — Induction Coils-
Electrostatic Machines — Tubes — Air Pumps — Tube Holders and Stereoscopic Apparatus —
Fluorescent Screens — Practical X Ray Work — Installations — Radioscopy — Radiography —
X Rays in Dentistry — X Rays in Chemistry — X Rays in War— Index.

Lsst of Plates.

Frontispiece — Congenital Dislocation of Hip-Joint. — 1., Needle in Finger. — II., Needle in
Foot. — III., Revolver Bullet in Calf and Leg. — IV., A Method of Localisation. — V , Stellate
Fracture of Patella showing shadow of "Strapping". — VI., Sarcoma. — VII., Six-weeks-old
Injury to Elbow showing new Growth of Bone. — VIII., Old Fracture of Tibia and Fibula
badly set. — IX., Heart Shadow. — X., Fractured Femur showing Grain of Splint. — XI., Bar-
ren's Method of Localisation.

India-Rubber and Giitta Percha.

INDIA-RUBBER AND GUTTA PERCHA. Second
English Edition, Revised and Enlarged. Based on the French work of
T. Seeligmann, G. LaiMy Torrilhon and H. Falconnet by John
Geddes iMclNTOSH. Royal 8vo. 100 Illustrations. 400 pages. Price
12s. 6d. net. (Post free, 13s. home ; 13s. 6d. abn ad.)

Contents.

India- Rubber.— Indiarubber, Latex — Definitions — Laticiferous Vessels — Botanical Origin
— Habitats — Methods of obtaining the Latex — Methods of Preparing Raw or Crude India-
rubber — Rubber Cultivation in Various Counti'ies — Climatolojiy — Soil — Rational Culture and
Acclimatisation of the Different Species of Indiarubber Plants — Classification of the Com-
mercial Species of Raw Rubber — Physical and Chemical Properties of the Latex and of
Indiarubber — General Considerations — Mechanical Transformation of Natural Rubber into
Washed or Normal Rubber (Purification) — Softening, Cutting, Washing, Drying, Storage —
Mechanical Transformation of Normal Rubber into Masticated Rubber — Vulcanisation of
Normal Rubber — Chemical and Physical Properties of Vulcanised Rubber — Hardened Rubber
or Ebonite— Considerations on Mineralisation and Other Mixtures — Coloration and Dyeing —
Analysis of Natural or Normal Rubber and Vulcanised Rubber — Rubber Substitutes —
Imitation Rubber — Analysis of Indiarubber.

Gutta Percha. — Definition of Gutta Percha — Botanical Origin — Habitat — Climatology —
Soil— Rational Culture — Methods of Col ection — Felling and Ringing.' i-ersMS Tapping— Extrac-
tion of Gutta Percha from Leaves by Toluene, etc. — Classification of the Different Species of
Commercial Gutta Percha — Physical and Chemical Properties of Gutta Percha — Mechanical
Treatment of Gutta Percha — Methods of Analysing Gutta Percha — Gutta Perchr Substitutes.

Leather Trades.

PRACTICAL TREATISE ON THE LEATHER IN-
DUSTRY. By A. M. Villon. Translated by Frank T.
Addyman, B.Sc. (Lond.), F.l.C, F.C.S. ; and Corrected by an Emi-
nent Member of the Trade. 500 pp., royal 8vo. 123 Illustrations.

[Out of print.
Contents.

Preface — Translator's Preface — List of Illustrations.

Part I., Materials used in Tanning — Skins: Skin and its Structure: Skins used in
Tanning; Various Skins and their Uses — Tannin and Tanning Substances: Tannin: Barks
(Oak): Barks other than Oak; Tanning Woods : Tannin-bearing Leaves; Excrescences;
Tan-bearing Fruits: Tan-bearing Roots and Bulbs: Tanning Juices; Tanning Substances
used in Various Countries: Tannin Extracts; Estimation of Tannin and Tannin Principles.

Part 11., Tanning — The Installation of a Tannery: Tan Furnaces: Chimneys, Boilers,
etc.; Steam Engines — Grinding and Trituration of Tanning Substances: Cutting up Bark;
Grinding Bark; The Grinding of Tan Woods; Powdering Fruit, Galls and Grains; Notes on
the Grinding of Bark — Manufacture of Sole Leather: Soaking; Sweating and Unhairing;
Plumping and Colouring; Handling; Tanning; Tanning Elephants' Hides; Drj-ing;
Striking or Pinning — Manufacture of Dressing Leather- Soaking; Depilation ; New Pro-
cesses for the Depilation of Skins; Tanning: Cow Hides; Horse Hides: Goat Skins, Manu-
facture of Split Hides — On Various Methods of Tanning: Mechanical .Methods; Physical
Methods: Chemical Methods; Tanning with Extracts — Quantity and Quality: Quantity;
Net Cost; Quality of Leather — Various Manipulations of Tanned Leather: Second Tanning;
Grease Stains; Bleaching Leather; Waterproofing Leather; Weighting Tanned Leather;
Preservation of Leather — Tanning Various Skins.

14
Contents of "Treatise on Leather industry"— continued.

Part 111., Currying — Waxed Calf: Preparation; Shaving; Stretching or Slicking
Oiling the Grain ; Oiling the Flesh Side; Whitening and Graining; Waxing; Finishing; Dry
Finishing; Finishing in Colour; Cost — White Calf: Finishing in White — Cow Hide for
Upper Leathers: Black Cow Hide; White Cow Hide; Coloured Cow Hide — Smooth Cow
Hide — Black Leather — Miscellaneous Hides: Horse; Goat; Waxed Goat Skin; Matt Goat
Skin — Russia Leather: Russia Leather; Artificial Russia Leather.

Part IV., Enamelled, Hungary and Chamoy Leather, Morocco, Parchment, Furs
and Artificial Leather — Enamelled Leather: Varnish Manufacture; Application of the
Enamel; Enamelling in Colour — Hungary Leather: Preliminary; Wet Work or Prepara-
tion; Aluming; Dressing or Loft Work; Tallowing; Hungary Leather from Various Hides
— Tawing: Preparatory Operations; Dressing; Dyeing Tawed Skins; Rugs — Chamoy Leather
— Morocco: Preliminary Operations, Morocco Tanning; Mordants used in Morocco Manu-
facture; Natural Colours used in Morocco Dyeing; Artificial Colours; Different Methods
nf Dyeing; Dyeing with Natural Colours; Dyeing with Aniline Colours; Dyeing with
.^letallic Salts; Leather Printing ; Finishing Morocco ; Shagreen ; Bronzed Leather — Gilding
»nd Silvering: Gilding; Silvering; Nickel and Cobalt — Parchment — Furs and Furriery:
Preliminary Remarks; Indigenous Furs; Foreign Furs from Hot Countries; Foreign Furs
from Cold Countries; Furs from Birds' Skins; Preparation of Furs; Dressing; Colouring;
Preparation of Birds' Skins; Preservation of Furs — Artificial Leather: Leather made from
Scraps; Compressed Leather; American Cloth ; Papier Mache ; Linoleum ; Artificial Leather.

Part v.. Leather Testing and the Theory of Tanning— Testing and Analysis of Leather;
Physical Testing of Tanned Leather; Chemical Analysis — The Theory of Tanning and the
other Operations of the Leather and Skin Industry: Theory of Soaking; Theory of Un-
hairing; Theory of Swelling; Theory of Handling; Theory of Tanning; Theory of the
Action of Tannin on the Skin; Theory of Hungary Leather Making; Theory of Tawing;
Theory of Chamoy Leather Making; Theory of Mineral Tanning.

Part VI., Uses of Leather — Machine Belts: Manufacture of Belting; Leather Chain
Belts; Various Belts; Use of Belts — Boot and Shoe-making: Boots and Shoes; Laces —
Saddlery: Composition of a Saddle; Construction of a Saddle — Harness: The Pack Saddle-
Harness — Military Equipment — Glove Making — Carriage Building — Mechanical Uses.

Appendix, The World's Commerce in Leather — Europe; America; Asia; Africa;
Australasia — Index.

THE LEATHER WORKER'S MANUAL. Being a Com-
pendium of Practical Recipes and Working Formulae for Curriers,
Bootmakers, Leatlier Dressers, Blacking Manufacturers, Saddlers,
Fancy Leather Workers. By H. C. Standage. Demy 8vo. 165 pp.
Price 7s. 6d. net. (Post free, 7s. lOd. home ; Ss. abroad.)

Contents.

Blackings, Polishes, Glosses, Dressings, Renovators, etc., for Boot and Shoe Leather —
Harness Blackings, Dressings, Greases, Compositions, Soaps, and Boot-top Powders and
Liquids, etc., etc. — Leather Grinders' Sundries — Currier's Seasonings, Blacking Compounds,
Dressings, Finishes, Glosses, etc. — Dyes and Stains for Leather — Miscellaneous Information
— Chrome Tannage — Index.

{See " Wood Products, Distillates and Extracts," p. 29).

Books on Pottery, Bricks,
Tiles, Glass, etc.

MODERN BRICKMAKING. By Alfred B. Searle. Royal
Svo. 440 pages. 260 Illustrations. Price 12s. 6d. net. (Post free,
13s. home; 13s. 6d. abroad.)

Contents.

Nature and Selection of Clays. — Lake and River Deposited Clays — Rock Clays — Shale
— Fire-clay. The Colour of Bricks. ^ — Marls — White, Yellow, and Red Bricks — Terra-cotta —
Blue Bricks. General Characteristics of Bricks. — Fletton, Bath, and Accrington Bricks
— London Stocks — Plastic Bricks — Sand-faced Bricks — Glazed Bricks — Fire Bricks — Qualities
of Bricks. Sand, Breeze, and other Materials. — Chalk-water— General Manufacture of
Bricks — Clay-washing — Haulage — Hand-Brickmaking — Preparation of the Paste — Pugging
— Slop-moulding — Sand-moulding — Drying — Shrinking —Pressing — Clamp Kilns — Firing a
Clamp. Plastic Moulding' by Machinery. — Wire-cut Bricks — Brick Machines and Plant —
Crushing Rolls — Grinding Mills — Wet Pans. Mixers and Feeders. — Pug-mills, Mouthpiece
Presses, and Auger .Machines — Expression Roller Machines— Cutting Tables — Repressing —
Screw Presses — Eccentric Represses — Die-Boxes. Drying-.- Transport. Stiff-plastic
Process. — Mill Feeding Machines — Grinding Mills — Elevating — Screens — Sieves — Revolving
Screens — Stiff-plastic Brickmaking Machines — Repressing — Carrying-off — Drying — Kilns.
Senii=Dry or Semi-Plastic Process. — Lamination — Drying Troubles — Moulds and Arrises.
The Dry or Dust Process.-*4-amination. Kilns. — Down-draught Kilns — Horizontal-draught

15

Kilns — Continuous Kilns — Up-draught Kilns — Newcastle Kiln — Gas-fired Kilns — Semi-con-
tinuous Kilns — Hoffmann Kilns — Hot-air Flues — Temporary and Permanent Flues — Chamber
Kilns — Steam — Draught — Mechanical Draught — Gas-fired Continuous Kilns — Muffle Kilns —
Kiln Construction. — Choice of Bricks — Foundations — Construction of Arches and Crowns —
Fire Boxes— Feed-holes— Chimneys— Selecting a Kiln. Setting and Burning:. — Up-draught
and Down-draught Kilns — Horizontal-draught or Continuous Kiln — Glazed Bricks. Firing. —
Dr>'ing or Steaming — Volatilization — Full Fire — Smoking — Seger Cones — Draught Gauge —
Cooling. Vitrified Bricks for Special Worlt. — Clinkers and Paving Bricks — Acid-proof
Bricks. Fire-Bricks and Blocks. — Materials — Grog — Grinding — Blocks — Drying — Dipped
Fire-bricks — Firing — Silica Bricks — Canister Bricks — Bauxite and Magnesia Bricks —
Neutral Fire-bricks. Glazed Bricks. — Pressing — Dipping — Glazes — Coloured Glazes — Ma-
jolica Glazes— Firing — Salt-glazed Bricks. Perforated, Radial, and Hollow Bricks. —
Fireproof Flooring. Moulded and Ornamental Bricks — Drying Raw Clay— Sources of
Difficulty and Loss. — Improper Materials or Site — Unsuitable Methods of Working — Lack
of Capital — Defective Accounting. — Index.

THE MANUAL OF PRACTICAL POTTING. Compiled
by Experts, and Edited by Chas. F. Binns. Third Edition, Revised
and Enlarged. 200 pp. Demy 8vo. Price 17s. 6d. net. (Post free,
17s. lOd. home; 18s. 3d. abroad.)

POTTERY DECORATING. A Description of all the Pro-
cesses for Decorating Pottery and Porcelain. By R. Hainbach.
Translated from the German. Crown 8vo. 250 pp. Twenty-two
Illustrations. Price 7s. 6d. net. (Post free, 7s. lOd. home ; 8s. abroad.

A TREATISE ON CERAMIC INDUSTRIES. A Complete

Manual for Pottery, Tile, and Brick Manufacturers. By E.mile
BouRRY. A Revised Translation from the French, with some Critical
Notes by Alfred B. Searle. Demy 8vo. 308 Illustrations. 460 pp.
Price 12s. 6d. net. (Post free, 13s. home; 13s. 6d. abroad.)

[jfust published.
Contents.

Preface. Definition and Classification of Ceramic Ware. Brief History of Ceramics.
Raw Materials of Bodies. Plastic Bodies — ^Properties and Composition — Preparation — Puri-
fication. Processes of Formation : Thowing, Expression. Moulding, Pressing, Casting, Slip
ping. Drying — Evaporation — Aeration — Heat — Absorption. Glazes: Manufacture and
Application. Firing. Properties of Bodies and Glazes during Firing — Kilns. Decoration:
Materials and Methods. Terra Cottas— Bricks— Hollow Blocks— Roofing Tiles— Paying
Bricks — ^Pipes — Architectural and Decorative Terra-Cotta — Common Pottery— Tonacco Pipes
— Lustre Ware — Tests. Fireclay Goods : Varieties, Methods of Manufacture and Tests.
Faiences: Classification, Composition. Methods of Manufacture and Decoration. Stoneware
—Paving Tiles— Sanitary Ware — For Domestic Purposes — For Chemic il Purposes — Decora-
tive Objects. Porcelain : Classification — Composition — Manufacture — Decoration.

ARCHITECTURAL POTTERY. Bricks, Tiles, Pipes, Ena-
melled Terra-cottas, Ordinary and Incrusted Quarries, Stoneware
Mosaics, Faiences and Architectural Stoneware. By Leon Lefevre.
Translated from the French by K. H. Bird, M.A., and W. Moore
Binns. With Five Plates. 950 Illustrations in the Text, and numerous
estimates. 500 pp., royal 8vo. Price 15s. net. (Post free, 15s. 6d.
home ; 16s. 6d. abroad.)

CERAMIC TECHNOLOGY: Being some Aspects of Tech-
nical Science as Applied to Pottery Manufacture. Edited by Charles
F. Binns. 100 pp. Demy Svo. Price 12s. 6d. net. (Post free,
12s. lOd. home; 13s. abroad.)

Contents.

Preface — The Chemistry of Pottery — Analysis and Synthesis — Clays and their Com-
ponents— The Biscuit Oven — Pyrometry — Glazes and their Composition — Colours and
Colour-making — Index.

THE ART OF RIVETING GLASS, CHINA AND
EARTHENWARE. By J. Howarth. Second Edition.
Pai^er Cover. Price Is. net. (By post, home or abroad. Is. Id.)

16

NOTES ON POTTERY CLAYS. The Distribution, Pro-
perties. Uses and Analyses of Ball Ciays. China Clays and China
Stone. By Jas. Fairie,' F.G.S. 132 pp. Crown Svo. Price 3s. 6d.
net. (Post free, 3s. 9d. home ; 3s. lOd. abroad.)

A Reissue of
THE HISTORY OF THE STAFFORDSHIRE POTTER-
IES : AND THE RISE AND PROGRESS OP THE
MANUFACTURE OF POTTERY AND PORCELAIN.

With References to Genuine Specimens, and Notices of Emment Pot-
ters. By Simeon Shaw. (Originally published in 1829.) 265 pp.
Demy Svo. Price 5s. net. (Po^t free 5s. 4d. home; 5s. 9d. abroad.)

A Reissue of
THE CHEMISTRY OF THE SEVERAL NATURAL
AND ARTIFICIAL HETEROGENEOUS COM-
POUNDS USED IN MANUFACTURING POR-
CELAIN, GLASS AND POTTERY. By Simeon Shaw.

(Originally published in 1837.) 750 pp. Royal Svo. Price 10s. net.
(Post free, 10s. 6d. home ; 12s. abroad.)

BRITISH POTTERY MARKS. By G. Woolliscroft Rhead.

Demy Svo. 310 pp. With Fourteen Illustrations in Half-tone and
upwards of Twelve-hundred Marks in the Text. Price 7s. 6d. net. (Post
free, 8s. home ; 8s. 3d. abroad.)

Glassware, Glass Staining and

Painting.

RECIPES FOR FLINT GLASS MAKING. By a British

Glass xMaster and Mixer. Sixty Recipes. Being Leaves from the
Mixing Book of several experts in the Flint Glass Trade, containing
up to date recipes and valuable information as to Crystal, Demi-crystal
and Coloured Glass in its many varieties. It contains the recipes for
cheap metal suited to pressing, blowing, etc., as well as the most costly
crystal and ruby. Second Edition. Crown Svo. Price 10s. 6d. net.
(Post free, 10s. 9d. home; 10s. lOd. abroad.)

Contents.

Ruby — Ruby from Copper — Flint for using with the Ruby for Coating — A German Metal —
Cornelian, or Alabaster — Sapphire Blue — Crysophis — Opal — Turquoise Blue — Gold Colour —
Dark Green — Green 'com-non) — Green for Malac ite — Blue for Malachite — Black for Mala-
chite— Black — Common Canary Batch — Canary — White Opaque Glass — Sealing-wax Red —
Flint — Flint Glass (Crystal and Demi) — Achromatic Glass — Paste Glass — White namel —
Firestone — Dead White (for moons) — WHiite Agate — Canary — Canary Enamel — Index.

A TREATISE ON THE ART OF GLASS PAINTING.

Prefaced with a Review of Ancient Glass. By Ernest R. Suffling.
With One Coloured Plate and Thirty-seven Illustrations. Demy Svo.
140 pp. Price 7s. 6d. net. (Post free, 7s. lOd. home; 8s. abroad.)

Contents.

A Short History of Stained Glass — Designing Scale Drawings — Cartoons and the Cut Line
— Various Kinds of Glass Cutting for Windows — The Colours and Brushes used in Glass
Painting — Painting on Gla~s Dispersed Patterns — Diapered Patterns — Aciding — Firing —
Fret Lead Glazing — Index.

17

Paper Making, Paper Dyeing,

and Testing.

THE DYEING OP PAPER PULP. A Practical Treatise for

inti ^ Dn„^,-maUers Paoerstainers Students and others. By

t^^^'^^^ o^ ' Pape^' ^I;H• J--lated into English

^^J^^Si^ t^^tr^Sef Municl^r^H^i^P sJf^
nSattons'and 157 patterns Of Papsr dyed in the pulp Ro>^a
8vo, 180 pp. Price 15s. net. (Post free Ids. bd. home; lbs. bd. ab. cad.)

Behaviour of the Paper Fibres^d°«^^^^^^
JVlordant-Colour Fixing ^^f^iums Mordants. -In^^^^^ ^ ^^^^ ^^^

Used-Inorganic Colours-Organic Colours- Pj^act.calAp^ Different

^te-^^Ffb^re^J^^-fe^d^P^^^^^^^^^^

THE PAPER MILL CHEMIST By HbnRv P. Stevbns
MA Ph D F.I.C. Roval 12mo. 60 Illustrations 300 pp. Price
7s. 6d. net. "(Post free 7s. 9d. home; 7s lOd. abroad.)

lntroduction.-Dea,ing with . t^e ^^^^.^^ed . Chej^
■Chemical Manipulation, introducing ^^ e s^bject^^ ^^^^^^^^^ ^ ^^^ Moisture. Ash.

Fuels. -Analysis of Coal, Coke ^"^^^^er Fuels Sa^pi.ng^ and Relative Efficiency.

Calorific Value, etc.-Comparat.veHe.t.ng Value ota.nere generally-Water

Water.-Analys,s for Stean, Raising and ^^^ f^P^ ; ^^„^'",f.,,,/softening Plant giving
Softening and Punfication-A List ""} J^f ^""J^ '\ AoDroximate Cost. Raw Materials
Power required, Weight, Space Occupied, <^"t-p^5,and Approx.ma j^ .^ant Chemicals

and Detection of Adulterants. -Analysis ^"^ Valuation of he ^^^ ^^j^^,.^, ^^j^s.

used in Paper Making, including Lmie, gau^cSoda, Sodium Carhon ^

Bleach Antichlor, Alum, Rosn and ^f '", f '^^'.^^ '^^gfj%l „eral Colours and Aniline Dyes.
Blanc F.xe, Satin Whiteand other loading Materials Mineral CO Boii.nii-Esparto

Manufacturing Operations.-Rags and ^^^J-^^^'^%^^^^:^^,1\ Ash-Experimental Tests
,Boi ling-Wood Boiiing-Testing Spent Lquors and Kecoverea ^' ^^^^ g eets

with Raw Fibrous ^^^terials-Bo.lmg in Autoclaves-Bleach.ng and mak ^ P^^^ff,^^^^^.

-Examination of Sulphite Liquors-bst.mat.on o.^^;^^°'^^^;^f '" f pfo5„ctS.-Paper Testing,

mendat.ons of the British Wood Pulp ^^^ociaion^ Finished Prod„«sp ^ ^^^^^

including Physical, Chemical and Microscopical re-.ts ^7 Machine Dir ct.on, Thickness.

Specific Gra'vits, Bulk or Air Space, ^'^^^"^^p^''?^^^,^ T -aSsparenc • Absorbency and

Strength. Stretch, R sistance to Crumphng ^^"^^ P'-f^^'^j^^^/^^JbSf"" of Filtering Papers-

•other qualities of Blotting P^Pe'-^-^^;^!:":'"^^'^" tile Si.r i^ Pa^ Qualities of

Detec ion and Estimation of Animal ^"^ .^^^'^^^.^'^.j!^^ Efi^cc of Beating

Paper-Fibrous Constituents- M.croscopica^^^^^^ Quantitative Examina-

on Fibres-Staining Fibres - M neral ^^^^^^^.^r"^^^'^^^^^ Colouring Matters in Paper.

tion of Mineral Matter-Examination of Coated Papers ana ^oos^^^^^^.^^ ^j

Tables-English and Metrical ^^^-.^^ ^^^^^"^^,^'^^J7b ,w andTon-Decimal Equivalents
Grams to Grains and vice '''''^'•^"-Eq^'^'^'e^t Costs per lb cv^ta^ VVeights and Molecular

of lbs., qrs.. and cwts.-Thermometric and Barometric Scales^^A^^^^^ g ^^ ^^

Weights-Factors for Calculating the Percentage ^^ Substance Soug^wro^^^^^^
Substance Found-Table of Solubilities of Substances Treated ot ."Paper ^^^.^^ ^^^^^
Gravity Tables of such substances 'as are used n Paper Mak^^^^^^^^^ '^oda.^tc, giving

Hydrochloric Acid, Bleach, Milk of LimeCaustc Soda Car^on^^^^^^ ^^^^^ ^^^^ ^^^p

Percentage Strength with Specific Gravity and De^^^^^^^ ^^^^^ ^j^.-^g

Tests-Dew Point-Wet and Dry Bulb Jf^J^^^Znt^X^^^^nls used in the Pape. Making
Temperature. Pressure and Volume-List o^^iITerent Macmnes usea Approximate

Industry, giving Size, Weight. Space Occupied^ Pcn^er to Dr.se^^U^^ ^.^^_

Cost-Calculation of Moisture .'^P^P-^^^^R^^'j'^^^d other' rIw Materials during Boiling

rw^.t'^^le^^^Sh^T^^^^^^^^^

THE TREATMENT OF PAPER FOR SPECIAL
PURPOSES. By L. E. Andes. Translated from the
German. Crown Svo. 48 Illustrations. 250 pp. Pricebs.net. (Post
free, 6s. 4d. home ; 6 . 6d. abroad.)

,., Parchment Paper. Veget^blf P^c^en^-The Par^^^^^^
Opaque Supple Parchment P^Per-Thick Parchment-Krug ler s Parch^^^ ^ _

:?d^';n^teV2mt%^nd^";;tt^prhm and Ivory from

18
Contents of "The Treatment of Paper for Special Purposes"

— continued.

Parchment Paper — Imitation Parchment Paper — Artificial Parchment — Testing the Sulphuric
Acid. II., Papers for Transfer Pictures. III., Papers for Preservative and Packing
Purposes. — Butter Paper — Wax Paper — Paraffin Paper — Wrapping Paper for Silverware —
Waterproof Paper — Anticorrosive Paper. IV., Grained Transfer Papers. V., Fireproof and
Antifalsification Papers. VI., Paper Articles. — Vulcanised Paper Mache — Paper Bottles —
Plastic Articles of Paper — Waterproof Coverings for Walls and Ceilings — Paper Wheels,
Roofing and Boats — Pa er Barrels — Paper Boxes — Paper Horseshoes. VII., Gummed Paper.
VIII.. Hectograph Papers. IX., Insecticide Papers. — Fly Papers — Moth Papers. X.,
Chalk and Leather Papers. — Glace Chalk Paper— Leather Paper — Imitation Leather.
XL, Luminous Papers — Blue-Print Papers — Blotting Papers. XII., Metal Papers — Medi-
cated Papers. XIII., .Marbled Papers. XIV., Tracing and Copymg Papers — Iridiscent or
Mother of Pearl Papers. XV., Photographic Papers — Shellac Paper — Fumigating Papers —
Test Papers. XVI., Papers for Cleaning- and Polishing Purposes — Glass Paper —
Pumic Paper — Emery Paper. XVII., Lithographic Transfer Papers. XIX., Sundry
Special Papers— Satin Paper — Enamel Paper — Cork Paper — Split Paper — Electric Paper —
Paper Matches — Magic Pictures — Laundry Blue Papers — Blue Paper for Bleachers. XX.,
Waterproof Papers — Washable Drawing Papers — Washable Card — Washable Coloured Paper
— W^aterpronf Millboard — Sugar Paper. XXL, The Characteristics of Paper — Paper Testing.

Enamelling on Metal.

ENAMELS AND ENAMELLING. For Enamel Makers,
Workers in Gold and Silver, and Manufacturers of Objects of Art.
By Paul Randau. Translated from the German. \\'ith Sixteen Illus-
trations. Demy 8vo. 180 pp. Price 10s. 6d. net. (Post free, 10s. lOd.
home; lis. abroad.)

THE ART OF ENAMELLING ON METAL. By W.

Norman Brown. Twenty-eight Illustrations. Crown 8vo, 60 pp.
Price 2s. 6d. net. (Post free, 2s. 9d. home and abroad.)

Silk Manufacture.

SILK THROWING AND WASTE SILK SPINNING.

By HoLLiNS Rayner. Demy 8vo. 170 pp. 117 Illus. Price 5s. net.
(Post free, 5s. 4d. home; 5s. 6d. abroad.)

Contents.

The Silkworm— Cocoon Reeling and Qualities of Silk— Silk Throwing— Silk Wastes— The
Preparation of Silk Waste for Degumming — Silk Waste Degumming, Schapping and Dis-
charging— The Opening and Dressing of Wastes — Silk Waste " Drawing " or " Preparing "
Machinery — Long Spinning — Short Spinning — Spinning and Finishing Processes — Utilisation
of Waste Products — Noil Spinning — Exhaust Noil Spinning.

Books on Textile and Dyeing

iects.

Subj

THE FINISHING OF TEXTILE FABRICS (Woollen,
Worsted, Union and other Cloths). By Roberts Beaumont, M.Sc,
M.I.Mech.E., Professor of Textile Industries, the University of Leeds;
Author of " Colour in Woven Design"; "Woollen and Worsted Cloth
Manufacture" ; '* Woven Fabrics at the World's Fair " ; Vice-President
of the Jur\' of Award at the Paris Exhibition. 1900; Inspector of Tex-
tile Institutes; Society of Arts Silver Medallist; Honorary Medallist
of the City and Guilds of London Institute. With 150 Illustrations of
Fibres, Yarns and Fabrics, also Sectional and other Drawings of
Finishing Machinery. Demj^ Svo, 260 pp. Price 10s. 6d. net. (Post
free, 10s. lOd. home; lis. 3d. abroad.)

Contents.

Woollen, Worsted and Union Fabrics— Processes of Finishing and their Effects — The
Process of Scouring: Scouring Machines— Theory of Felting — Theory of Felting: Fabric
Structure— Theory of Felting: Compound Fabrics — Fulling and .Milling Machinery — The
Theory of Raising — Raising Machinery and the Raising Process — Cutting, Cropping or
Shearing — Lustring Processes and Machinery — Methods of Finishing — Index.

19

DRESSINGS AND FINISHINGS FOR TEXTILE
FABRICS AND THEIR APPLICATION. Description
of all the Materials used in Dressing Textiles: Their Special Pro-
nerties the Preparation of Dressings and then^ Employment in
Finishing Linen, Cotton, Woollen and Silk Fabrics. Fireproof and
Waterproof Dressings, together with the principal machinery employed.
Translated from the Third German Edition of Friedrich Polleyn.
DemySvo. 280 pp. Sixty Illustrations. Price 7s. 6d. net. (Post
free, 7s. lOd. home ; 8s. abroad.) iJ^^st published.

Contents,

The Dressing Process and Materials for Same-5tiffenings and Oiazes-VVheaten
^Jrch Maize Starch-Rice Starch-Buckwheat Starch-Arrowroot-Tapioca-Sago-
ISictlf S^irrch-oTffere'SSinl and Examining f tarches-The Gelatinizat^^^^^^
r,f <;tarches— Flour— Protamol tor Dressings and Sizes— Adhesive UressingS uiuien
Pro^efn Glue-VegetabTe Glue-Arbol Gum-Apparatme-Vegetable Glue Dressing-Pus-
Thpr's Vegetable Glue-Vegetable Glue Containing Fat-Dextrin (British Gum)-Preparation
o^DexSn-Gum Gtrm Arlbic-Feronia Gum-Cherry Gum. Plum Tree Gum-Testing Gum
Ar?b1c-Tragacanthlvegetab!e Mucilage-Carragheen Moss-Iceland Moss-Hai-Thao
Fleawort Seed-Linseed-Peru Gum-Ceylon Moss-Canary Grass Seed-Albumin-Casein
-Caseo Gum-Glutin-Glue-Gelatine-Starcn S>rup-Potato Syrup-Colophony (Rosin -
MllllLii^^ CnftnrPssine-s-Glvcenne-Wax- Paraffin Wax-Steanne-Fats and Fatty

Oifs-?olp -sfffe'nmgs-^

Barium Sulphate-Barium Carbonate-Bleaching Powder-Lead Sulphate-Gypsum-Cal-
dum Chloride-Magnesium Chloride-Sod:um Sulphate-Glauber Salt-Magnesmm Sulphate
r^Fn^nm SaltVMalnesium Carbonate-Magnesia White-Magnesium Silicate-China Clay
AluZiumS^caXS Soride-Alkali Silicates- Wate^^
ngr'dients-Dyeing and Blueing Agents-Ulyamarine B ue-Pans B lu^^
Blue-Indigocarmine- Various Dressings-Endosmm-Eau de Cr>\^^'' ^^'^i?;^^^^^
Lukon-AlSin-Paramentine-Cream Softening-Norgine-Dressing Soaps-Guni l£?gasoi

Glue and P Size-The Preparations of Dressings-Various Adjuncts to Dressing Pre

naratiins-Fatty Adjtmcts-Potato Starch and Rosin Adjunct-Dressing Composition-Hai-
Thao D?essing-App iances for the Preparations of Dressings-Rushton s Size Bo.ler-
Sif?ing Machine-Rec pes for Dressings-Dressings for Linens-For ^f >"•" /'"'^^-For
Heavv Finish-For Very Heavy Finish-Damask Dressings-For Crash L.nens-For Very
Glossy L nens_D° essin Js for Black Cottons-Black Glace D^-.-«.'"g%?'^^^.^;-^^"iL;

bhiirrnXr?or%^o-f^^^^^^^^^^^

Worl ed,-Fi„ishi„8 WoollJns by the Electric Current-Finishing S>lkFabrcs-Sngle

l?Cle!s of vV^erproofin^LLens, Cotins, VVoollens and Sllks-Basw,.z

Flexible Mother-of-Pearl Design on Various Fabncs-Metal ^^ustre '^'•^^^"^^ ^'^P^^^^
Soangles to Fabrics— Colour Photography on Woven Fabrics—Gold ^"^,,^''^^r^,|i^,^'^^^„.

Finish-The Application of Dressing Preparations-Testing Dressings.

THE CHEMICAL TECHNOLOGY OF TEXTILE
FIBRES- Their Origin, Structure, Preparation, Washing,
Bleaching, Dyeing, Printing and Dressing. ^y Dr^ Georg von
Georgie5ics. Translated from the German by Charles Salter.
320 pp. Forty-seven Illustrations. Royal 8vo. Price 10s. 6d. net.
(Post free, lis. home ; lis. 3d. abroad.)

POWER-LOOM WEAVING AND YARN NUMBERING,

According to Various Systems, with Conversion Tables Translated
Fromle^German of a/thon Gruner. With Twenty-S.X Diagrams
in Colours. 150 pp. Crown 8vo. Price /s. 6d. net. (Post tree,
7s. 9d. home ; 8s. abroad.)

20

TEXTILE RAW MATERIALS AND THEIR CON-
VERSION INTO YARNS. (The Study of the Raw
iMaterials and the Technology of the Spinning Process.) By Julius.
ZiPSER. Translated from German by Charles Salter. 302 Illus-
trations. 500 pp. Demy Svo. Price 10s. 6d. net. (Post free, lis-
home: lis. 6d. abroad.)

GRAMMAR OF TEXTILE DESIGN. By H. Nisbet,

Weaving and Designmg Master, Bolton Municipal Technical School.
I emy Svo. 280 pp. 490 Illustrations and Diagrams. Price 6s. net.
(Post free, 6s. 4d. home ; 6s. 6d. abroad.)

Contents.

The Plain Weave and its Modifications. Twill and Kindred Weaves. — Classifi-
cation of Twill Weaves. Diamond and Kindred Weaves. Bedford Cords. Backed.
Fabrics. Fustians. Terry Pile Fabrics. Gauze and Leno Fabrics; Tissue, Lappet,
and Swivel Figuring ; also Ondulk Effixts. and Looped Fabrics.

ART NEEDLEWORK AND DESIGN. POIN x LACE. A

Manual of Applied Art for Secondary Schools and Continnytion Classes.
By M. E. Wilkinson. Oblong quarto. With 22 P:a:2s. Bound in
Art Linen. Price 3s. 6d. net. (Post free, 3s. lOd. ho i c , 4s, aor'^ad.)-

Contents.

Sampler of Lace Stitches — Directions for working Point Lace, tracing Patterns, etc. —
List of Alaterials and Implements required for working. Plate> L, Simple Lines, Straight and:
Slanting, and Designs t<,)rmed from them. II., Patterns formed from Lines in previous-
Lesson. III.. Patterns formed from Lines in previou-; Lesson. IV., Simple Curves, and-
Designs formed from them. V., Simple Leaf form, and Designs formed from it. VI., Ele-
mentary Geometrical forms, with Definitions. VII., Exercises on previous Lessons. VIII.,
Filling of a Square, Oblong and Circle with Lace Stitches. IX., Design for Tie End, based
on simple Leaf form. X., Lace Butterilies (Freehand). XL. Twenty simple Designs evolved'
from Honiton Braid Leaf. XII., Design for Lace Handkerchief, based on previous Lesson.
XIII., Design for Tea-cosy. XIV., Freehand Lace Collar. XV., Freehand Lace Cuff (to-
match). XVI., Application of Spray from Lesson XL XVII., Adaptation of Curves within
a Square, for Lace Cushion Centre. XVI 1 1., Conventional Spray for corner of Tea-cloth.
XIX., Geometrical form for Rosebowl D'Oyley, to be originally filled in. XX., Geometrical
form for Flower-vase D'Oyley, to be originally filled in. Each Lesson contains Instructions
for W^orking, and application of new Stitches from Sampler.

HOME LACE-MAKING. A Handbook for Teachers and
Pupils. By M. E. W. MiLROY. Crown Svo. 64 pp. With 3 Plates-
and 9 Diagrams. Price Is. net. (Post free, Is. 3d. home; Is. 4d.
a broad. 1

THE CHEMISTRY OF HAT MANUFACTURING. Lec-
tures delivered before the Hat Manufacturers' Association. By Wat-
son Smith. F.C.S. , F.I.C. Revised and Edited by Albert Shonk.
Crow n 8vo. 132 pp. 16 Illustrations. Price 7s. 6d. net. (Post free
7s. 9d. home ; 7s. lOd. abroad.)

THE TECHNICAL TESTING OF YARNS AND TEX-
TILE FABRICS. With Reference to Official Specifica-
tions. Translated from the German of Dr. J. Herzfeld. Secondi
Edition. Sixty-nine Illustrations. 200 pp. Demy Svo. Price 10s. 6d..
nt ■. (Post free, 10s. lOd. home ; lis. abroad.)

DECORATIVE AND FANCY TEXTILE FABRICS.
By R. T. Lord. For Manufacturers and Designers of Carpets, Damask,
Dress and all Textile Fabrics. 200 pp. Demy Svo. 132 Designs and
Illustrations. Price7s.6d.net. (Post free, 7s. lOd. home ; 8s. abroad. )>

THEORY AND PRACTICE OF DAMASK WEAVING.
By H. KiNZER and K. Walter. Royal Svo. Eighteen Folding Plates.
Six Illustrations. Translated from the German. 110 pp. Price 8s. 6d.
net. (Post tree, 9s. home : 9s. 6d. abroad.)

Contents.

The Various Sorts of Damask Fabrics — Drill (Ticking, Handloom-made) — Whole-
Damask for Tahlecloths — Damask with Ground- and Connecting-warp Threads — Furniture
Damask — Lampas or Hangings— Church Damasks — The JVlanufacture of Whole Damask.
— Damask Arrangement wiih and without Cross-Shedding — The Altered Cone-arrangement —
The Principle of the Corner Lifting Cord — The Roller Principle — The Combination of the-
Jacquard with the so-called Damask Machine — The Special Damask Machine — The Combina-
tion of Two Tyings.

21

FAULTS IN THE MANUFACTURE OF WOOLLEN
roODS AND THEIR PREVENTION. By Nicolas
?e°°f ^rSed fro. the second Ge^anEdUion. C.o.„ 8vo.
Sixty-three Illustrations. 1/0 pp. Price os. net. ^t-ost
home ; 5s. 6d. abroad.) ^^„t^„tc:

. ,^°"A®" „^; Mixtures-Wrong Treatment of the

Improperly Chosen Raw Matenal °;; ^-^P^^^Pf ^„^J'^7„"„'ing_^^^

Material in Washing. Carbonisation Drymg.Dj^^^^^^^ or Width of the Goods

Soods in the Loom-Wrong Placmg of Colours ^^^^ 8 ^^ g. ^^^^^ Loose.

-Breaking of Warp and Weft Threads Pre. enc ^^^^ ^^^ ^^^ Like-Errors m

and too Hard Twisted Threads as n^ ell ^^ ^|'^fi^^';_Di,ty Borders-Defective belvedges-
Cross-weaving-Inequahties i.e.. Bands and Stnpesu> ^^^ ^^^ Colours-Badly Dyed

^etl^dg^-s'-H^r^ G-o^dti^BriitrCo"^^^^^^ Goods-Removal of Bands. Stripes.

SpTnNING AND WEAVING CALCULATIONS, es^eci^^^^^
relating. to woollens. ^/o^.^^Ji^rrn.^^^^^

Illustrations.

Tables, leopp: D^mySvo. 1904. Pricel0s.6d.net.

lllUStrilLlUllS. xc^^xx,^. rj^ .

(Post free, 10s. lOd. home ; Us. abroad.)

WATERPROOFING OF FABRICS, By Dr. S M'H«^^^/^^J;
Crown 8vo. 104 pp. 29 lUus. Price os. net. (Post tree, os.
5s. 4d. abroad.) »„„4.c

Contents. ,, „ ., ..;.v, ii,prn»e of

Alumina-Impregnation of 'l-e l;»l'"=-°'> ,"» .u^'Vlewllic bxides-Coloured Waterproof

home ; 3s. lOd. abroad.)
p-areT.-°.tort'a\?e°otKS:rr„VSrok^o\l.S^^^^^

YARN AND WARP SIZING IN ALL ITo BRANOilii-a^

|-^a\To-™1.0^^^^'-prerOs-eI^'r^-t-^^

Us. abroad.)
The Materials to be SI.ed-Linen o??,y^?am^; and au.e-VVoo,--,he^^J^^^^^^^^
i„ ^z^ng-The Sized Ma.erial-Tl,e S''J.jZZwiro^ brhandul Machine Sizmg-Sizing

S,zi„g .„gred,e„..^^ ..r^^i/. So«/.S .-«</ O/h " See /-. 7-)

Dyeing, Colour Printing,
Matching and Dye-stuffs.

THE COLOUR PRINTING OF CARPET YARNS, Manua,

for Colour Chemists and Textile Prin^rs. By Dm. dPatbrson,
FCS Seventeen Illustrations. 136 pp. Demy Mo.
net.' (Post free, 7s. lOd. home ; Ss^abroad.)

Structure and Const.tution of Wool Fi^"™""^ >™ S'jf^'" Vjn" Prmtmg-^^^^^^^
Scounng-Bleaching Carpet Varns-ColourMakmg. for Yarn Hr.Mg ^^ ^^^^^^^

Pastes-Colour Recpes for Yarn P/'";-B-S'Jf"5t°„',^°^?Tn Pnnfmg-Steaming Printed

7rs-^as^m"of'^it^-e7YaT:n^Jil.SSu\rSui^^ahle for Yarn IV ng-0,ossar> o,

Dye" and Dye-wares used in Wood Yarn Prmt.ng-Append,^.

22

THE SCIENCE OF COLOUR MIXING. A Manual in-
tended for the use of Dyers, Calico Printers and Colour Chemists. By
David Paterson, F.C.S. Forty-one Illustrations. Five Coloured Plates,
and Four Plates showing: Eleven Dyed Specimens of Fabrics. 132

pp. Demy 8vo. Price 7s. 6d. net. (Post free, 7s. lOd. home ; 8s.
abroad.)

Contents.

Colour a Sensation: Colours of Illuminated Bodies; Colours of Opaque and Transparent
Bodies : Surface Colour — Analysis of Light : Spectrum : Homogeneous Colours : Ready
Method of Obtaining a Spectrum — Examination of Solar Spectrum : The Spectroscope and
Its Construction : Colourists' Use of the Spectroscope — Colour by Absorption ; Solutions and
Dyed Fabrics; Dichroic Coloured Fabrics in Gaslight — Colour Primaries of the Scientist
versus the Dyer and Artist; Colour Mixing by Rotatio " and Lye Dyeing; Hue, Purity,
Brightness; Tints; Shades, Scales, Tones, Sad and Sombre Colours — Colour Mixing; Pure
and Impure Greens, Orange and Violets; Large Variety of Shades from few Colours; Con-
sideration of the Practical Primaries: Red, Yellow and Blue — Secondary Colours; Nomen-
clature of Violet and Purple Group; Tints and Shades of Violet; Changes in Artificial Light
— Tertiary Shades : Broken Hues: Absorption Spectra of Tertiary Shades — Appendix: Four
Plates with Dyed Specimens Illustrating Text — Index.

DYERS' MATERIALS : An Introduction to the Examination,
Evaluation and Application of the most important Substances used in
Dyeing. Printing, Bleaching and Finishing. By Paul Heerman, Ph.D.
Translated from the German by A. C. Wright, M.A. (Oxon.), B.Sc.
(Lond.). Twenty-four Illustrations. Crown Svo. 150 pp. Price 5s.
net. (Post free, 5s. 4d. home ; 5s. 6d. abroad.)

COLOUR MATCHING ON TEXTILES. A Manual in-
tended for the use of Students of Colour Chemistry, Dyeing and
Textile Printing. By David Paterson, F.C.S. Coloured Frontis-
piece. Twenty-nine Illustrations and Fourteen Specimens Of Dyed
Fabrics. Demy Svo. 132 pp. Price 7s. 6d. net. (Post free, 7s. lOd.
home ; 8s. abroad.)

COLOUR: A HANDBOOK OF THE THEORY OF
COLOUR. By George H. Hurst, F.C.S. With Ten
Coloured Plates and Seventy-two Illustrations. 160 pp. Demy Svo.
Price 7s. 6d. net. i Post free, 7s. lOd. home ; 8s. abroad.)

Reissue of
THE ART OF DYEING WOOL, SILK AND COTTON.

Translated from the French of M. Hellot, M. Macquer and M. le
PiLEUR D'Aplign'Y. First Published in English in 1789. Six Plates.
Demy Svo. 446 pp. Price 5s. net. (Post free, 5s. 6d. home ; 6s.
abroad.)

COTTON WASTE : Its Production, Characteristics, and
Regulation. By T. Thornley. Demy Svo. About pages.

[hi the press.

THE CHEMISTRY OF DYE-STUFFS. By Dr. Georg Von
Georgievics. Translated from the Second German Edition. 412 pp.
Demy Svo. Price 10s. 6d. net. (Post free, lis. home ; lis. 6d. abroad.)

THE DYEING OF COTTON FABRICS: A Practical

Handbook for the Dyer and Student. By Franklin Beech, Practical
Colourist and Chemist. 272 pp. Forty-four Illustrations of Bleaching
and Dyeing Machinery. Demy Svo. Price 7s. 6d. net. (Post free,
7s. lOd. home ; Ss. abroad.)

THE DYEING OF WOOLLEN FABRICS. By Franklin
Beech, Practical Colourist and Chemist. Thirty-three Illustrations.
Demy Svo. 228 pp. Price 7s. 6d. net. (Post free, 7s. lOd. home ;:
8s. abroad.)

23

Bleaching and Bleaching

Agents.

A PRACTICAL TREATISE ON THE BLEACHING OF
LINEN AND COTTON YARN AND FABRICS. By

L. Tailfer, Chemical and Mechanical Engineer. Translated from the
French by John Geddes McIntosh. Demy 8vo. 303 pp. Twenty
lUus. Price 12s. 6d. net. (Post free, 13s. home; 13s. 6d. abroad.)

MODERN BLEACHING AGENTS AND DETERGENTS.

By Professor Max Bottler. Translated from the German. Crown
Svo. 16 Illustrations. 160 pages. Price 5s. net. (Post free, 5s. 3d.

home ; 5s. 6d. abroad.)

Contents.

Part I., Bleaching Agents. Old and New Bleaching Methods and Bleaching

Agents. -Bleaching Agents for Wool-Bleaching with Permanganate-Perborates-Acid
Sodium Percarbonate-Bleaching A.uents for Silk-Bleaching Powder and Alkah Hypoch-
lorites-Bleaching Processes-Bleaching Linen-Bleaching with Ozone- Bleaching Straw
and Leather— Discharging Colours-Bleaching Jute and other Vegetable Fibres-Bleaching
Various Substances-Electrical Bleaching Processes. Sodium Peroxide.-Properties-
Dissolving Sodium Peroxide— Preparing the Bleaching Liquor- Compressed Sodium Peroxide
-Sodium Peroxide in Bleaching-Cleaning Materials to be Bleached-Testing the B eaching
Liquor— Bleaching Kier-Charging the Kier with Bleaching Liquor— Bleaching W oollen and
Half-Wool Goods— Preparing the Bleaching Liquor— Drying the Goods— Magnesium Sulphate
in Bleaching Liquor— Bleaching Silk— Bleaching uinen, Cotton Jute and Ramie Goods-
Production of Peroxides— Bleaching Feathers-Sodium Peroxide in Washing Powder-
Barium Peroxide-Bleaching Silk with Barium Peroxide. Perborates.-Salts of Perboric
Acid— Properties of Perborates— Ammonium Perboraces— Sodium Perborates— Perborax—
Merck's Sodium Perborate- Sapozon-Testing Sodium Perborate. Ozone.— Formation of
Ozone— Ozone Generators- Chemical Production of Ozone— Properties of Ozone— Employ-
,ment of Ozone in Bleaching. Sodium Bisulphite and Hydrosulphurous Acid.-Bleachmg
with Sulphur Dioxide— Bleaching Wool with Hydrosulphurous Acid-Sodium Hydrosulphite
—Properties of Sodium Bisulphite— Bleaching Processes- Bleaching Manija Hemp-After-
treatrnent with Bisulphite-Bleaching Straw-Bleaching Leather. Discharging Colour from
Textile Fabrics with Hydrosulphurous Acid.-Prepanng the Discharge-Discharging
Colour from Shoddy and Dved Fabrics-Stable Hydrosulphite— Method of Using Hydrosul-
phite-Eradite—Cassella's Hyraldite — Discharging with Hyraldite — Increasing the Dis-
charging Effect-Stable Hydrosulphites. Permanganate. — Bleaching with Permanganate
—Action of Permanganate-Bleaching Wool or S.Ik-Addition of Magnesium Sulphate to
the Bleaching Liquor— Strength of Permanganate Solution— Xew Process for Bleaching Jute
-Bleaching Skins-Bleaching Straw-Bleaching Ivory. Hydrogen Peroxide. -Constitution
and Properties— Preparation-Crystalline Hydrogen Perovide-Properties of Hydrogen
Peroxide Solutions-Stability— Commercial Hydrogen Peroxide Solutions— Deconiposition
of Hydrogen Peroxide-Purity of Hydrogen Peroxide-Storage \ esseis-Care in Handling
-Instability of Solutions-Reagent for Hydrogen Peroxide-Va uing Hydrogen Peroxide
Solutions-Testing Hydrogen Peroxide-Bleaching Wool with Hydrogen Peroxide-Pre-
liminarv Treatmlnt-Bleaching Bath-After Treatment-Bleaching S.Ik with Hydrogen
Peroxide-Bluing before Bleaching— Bleaching Cotton with Hydrogen Peroxide-Bleaching
Linens with Hydrogen Peroxide-Bleaching Jute with Hydrogen Peroxide— Bleaching Various
Vegetable Fibres with Hydro,?en Peroxide-Bleaching Straw, Wood, etc with Hydrogen
Peroxide-Bleaching Leather with Hydrogen Peroxide-Bleaching Ivorj-, Horn, Bones and
Similar Articles— Bleaching Hair-Bleaching Sponges with Hydrogen Peroxide. Bleaching
Fats, Oils, Wax and Paraffin.-New Process for Bleaching Fats and Oils-BIeachmg Wax
—Bleaching Soap— Decrolin and Blankite for Bleaching Soap-Bleaching Glue Solid, Stable
Calcium Hypochlorite and Bleaching Soda.-Stable Calcium Hypoch orite-Bleachmg
Soda. Electric Bleaching.— Electrolytic Bleaching Lye-Judgmg the Utility of Electric
Bleaching Plant— Bkaching Experiment with Electrolysed Sodium Chloride Solution-
ElectrolvticDecompositionof Sodium Chloride— Observations of Forster and Muller— Types
• of Electrolyser-Electrolytic Bleach-Schuckert Plant— Schoop's Electrolytic Bleaching
Apparatus— Kellner Bleaching Apparatus, Construction— Method of \V orking— Mounting the
Apparatus-Determining the Bleaching Power of Electrolytic Liquors, Volumetric Method-
Bleaching with Electrolytic Bleaching Liquor. _ , . . , r, f ,-v, • ol o^
Part II. Detergents.— Behaviour of Various Fabrics in the Presence of Chemical Re-
agents-Methods of Removing Stains— Chemical Cleaning and Detergents. Benzine Soaps.
—Removing Stains with Benzine Soap and its Solutions-Antibenzme Pyrine. or Richterol.
Extractive Detergents and Detergent Mixtures. Carbon Tetrachloride. -Properties.
Aceto=Oxalic Acid as a Detergent ; Special Methods of Removing Stains. Bleaching
Processes Used in Chemical Cleaning. -Bleaching with Potassium Permanganate--
Reducing Effect of Sulphur Dioxide— Reduction with Hydrogen Peroxide— Reduction with
Hydrosulphurous Acid— Seydas Reduction Process— Combined Method of Removing Stains—
Hyraldite as a Detergent and Bleaching Agent. Hydrogen Peroxide as a Detergent.—
iBehaviour of Hydrogen Peroxide toward Coloured Fabrics. Oxygen as a Detergent.—

24
Contents of " lYIodern Bleaching Agents and Detergents"—

continued.
Behaviour of Oxygenol toward Dyed Fabrics. Sodium Peroxide as a Detergent.— Sodium
Peroxide Soap. Sundry New Detergents and Cleansing Agents.— Tetranol—Lavado—
Novol— Weiss's Benzine Washing Preparation— Hexol —Steinberg's Detergent Oil— Ozonite —
Ozonal— Ouillola— Gruner's Wasning Powder- Eureka Washing Powder— Detergent Soaps
that Liberate Oxygen— Klein's Detergent Snap— Detergent for Sensitive Colours— Poltzow's
Detergent Soap — Wolzendorffs Cyanide and Photographer's Ink — Detergent Liquids —
Hummel s Deterg-nt Liquid— Detergent Paste— B anchissine— He kel's Persil— Reinol, Triol,
Tetra-Isol, Benzin-Isol. Terpin-Isol, Isobenzine S jap and Iso S )ap.

Cotton Spinning and Combing.

COTTON SPINNING (First Year). By Tho.mas Thorxley,
Spinning Master, Bolton Technical School, 160 pp. Eighty-four Illus-
trations. Crown 8vo. Second Impression. Price 3s. net. (Post free,
3s. 4d. home : 3s. 6d. abroad. i

COTTON SPINNING (Intermediate, or Second Year;. By
Thomas Thorxley. Second Impression. ISO pp. Seventy Illustra-
tions. Crown Svo. Price 5s. net. (Post free. 5s. 4d. home ; 5s. 6d.

abroad.)

COTTON SPINNING (Honours, or Third Year). By Thomas
Thorxley. 216 pp. Seventy-four Illustrations. Crown Svo. Second
Edition. Price 5s. net. (Post free, 5s. 4d. home ; 5s. 6d. abroad.)

COTTON COMBING MACHINES. By Thos. Thorxley,

Spinning Master, Technical School. Bolton. Demy Svo. 117 Illustra-
tions. 300 pp. Price 7s. 6,1. net. (Post free, Ss. home ; Ss. 6d. abroad.)

Flax, Hemp and Jute Spinning.

MODERN FLAX, HEMP AND JUTE SPINNING AND
TWISTING. A Practical Handbook for the use of Flax,
Hemp and Jute Spinners. Thread, Twine and Rope Makers. By
Herbert R. Carter, Mill Manager. Textile Expert and Engineer,
Examiner in Flax Spinning to the City and Guilds of London
Institute. Demy Svo. 19U7. With 92 Illustrations. 200 pp. Price
7s. 6d. net. (Post free, 7s. 9d. home : Ss. abroad.)

FIBRES USED IN TEXTILE AND ALLIED INDUS-
TRIES. By C. Aln'sworth Mitchell, B.A. (Oxon.j, F.I.C.,
and R. M. Prideaux F.I.C. With 6-S Illustrations specially drawn
direct from the Fibres. Demy Svo. 200 pp. Price 7s. 6d. net.
(Post free, 7s. lOd. home : Ss. abroad.)

Contents.

Classification of Fibres.— General Characteristics of Fibres — .Microsco-ical Hxamination
of Fibres— Stegmata— Chemical Examination— Ultimate Fibres— .Methyl Value— .Moisture in
Fibres. Wool,— .Nature of Wool— Commercial Varieties— Characteristics of Good Wool—
Merino— .Microscopical Appearance— .Mould in Wool— Feling Prope "ty- Curl of w ool—
ChemicHl Composition— .Action of Reagents on Wool— Cnjorinised Wool— Deiection of Dyed
Fibres in Wooi-C nditionmg of Wool. Vicuna— Camel Hair— Alpaca— Llama Hair-
Mohair— Cashmere— Goats' Hair— Cow Hair— Horse Hair— Deer Hair— Reindeer Hair
—Rabbits' Hair— Cats* Hair— Dogs' Hair— Kangaroo's Hair— Human Hair. Silk.—
Origin of Silk— Reeling— Waste Silk— History— Commercial Varieties of Thread— Size of
Yarns— WilJ Silks— Microscopical Characteristics— Colour of Silk— Size of Fibres— Strength
and Elasticity — Specific Gravity— "Chemical Composition — Fibroin— Sericin— Hydrolysis of
Silk Proteins— .Action of Chemical Agents— .Absorpt. on of Tannin— Weighting— Di'fFerentiation
and Separation from other Fibres. Cotton. —History — Commercial Varieties — Structure of
the Fibre— Cell Walls— Dimensions of Fibre— Chemical Composition— Cellulose— Action of
Reagents — Xitrated Cotton — Examination of Bleached Fabrics — Absorption of Tannin —
Absorption of Gases — Absorption of DyestufTs— " Animalizing " ot Cotton— Sized Cotton-
Polished Cotton — Mould in Cotton— Waterproofed Cotton. Mercerised Cotton.— History-
Structural Alteration of Fibres— Affinity for Dyestuffs— Chemical Chanties in .Mercerisation—
Elfect upon Strength of Fibre— .Measurement of Shrinkage— Reactions and Tests for .Mercer-
ised Cotton— Dyestuff^ Tests. Artificial Silks, Linen and Ramie —Linen : Source—

25

Varieties of Commercial Flax — Retting of Flax — Lustrous Linen— Use of Linen as a Textile
—Characteristics of the Fibre— Structure— Action of Reagents— Physical Properties— Com-
position— Flax Wax. Ramie : Source— Preparation— History— Properties— Composition.
Jute and other Fibres. Brush Fibres Vegetable Downs and Upholstery Fibres.—

Bombax Cottons— Kapok— Ochroma Down— Kumbi or Galgal— Vegetable Siik— Airclepias
Cotton— Calotropis Down— Beaumantia Down— Other Vegetable Suks— Vegetable Wool—
Tillandsia Fibre— Vegetable Horsehair. Index.

Ring Spinning.

THE RING SPINNING FRAME FOR OVERLOOKERS
AND STUDENTS. By N. Booth. Crown 8vo. 76 pages.
Price 3s. net. (Post free, 3s. 3d. home ; 3s. 6d. abroad.) [yust published.

Collieries and Mines.

RECOVERY WORK AFTER PIT FIRES. By Robert

Lamprecht, Mining Engineer and Manager. Translated from the
German. Illustrated by Six large Plates, containing Seventy-six
Illustrations. 175 pp., demy 8vo. Price 10s. 6d. net. (Post free,
10s. lOd. home; lis. abroad.)
VENTILATION IN MINES. By Robert Wabxer, Mining
Engineer. Translated from the German. Royal Svo. Thirty Plates
and Twenty-two Illustrations. 240 pp. Price lOs. 6d. net. (Post free,.
lis. home ; lis. 3d. abroad.)

HAULAGE AND WINDING APPLIANCES USED IN
MINES. By Carl Yolk. Translated from the German.
Royal Svo. With Six Plates and 148 Illustrations. 150 pp. Price
8s. 6d. net. (Post free, 9s. home ; 9s. 3d. abroad.)

Contents.

Haulage Appliances— Ropes— Haulage Tubs and Tracks— Cages and Winding Appliances-
Winding Engines for Vertical Shafts— Winding without Ropes— Haulage in Levels and
Inclines— The Working of Underground Engines— Machinery for Downhill Haulage.

THE ELECTRICAL EQUIPMENT OF COLLIERIES. By

W. Galloway Duncan, Electrical and xMechanical Engineer, Member
of the Institution of Mining Engineers, Head of the Goxernment School
of Engineering, Dacca, Ind'ia ; and David Penman, Certificated Colliery
xManager, Lecturer in Mining to Fife County Committee. Demy Svo.
310 pp. 155 Illustrations and Diagrams. Price 10s. 6d. net. (Post

free, lis. home ; Us. 3d. abroad.)

Contents.
General Principles, Magnetism, Units, Ceils, etc.— Dynamos and Motors— Trans=
mission and Distribution of Power-Prime Movers-Lighting by Electricity-lnitial
Outlay and Working Cost of Electrical Installations— Electricity Applied to Coal=
cutting- Electric Haulage, Winding, and Locomotives— Electric Pumps and Pump=
ing—Electric= Power Drills and Underground Coal Conveyers— Typical Colliery
Electrical Installations-Miscellaneous Applications of the Electric Current-Com-
parison of the Different Modes of Transmitting Power— Dangers Occurring from the
Use of Electricity in Colleries— Appendix : Questions suitable for students preparing tor
colliery managers' examinations — Index.

Dental Metallurgy.

DENTAL METALLURGY : MANUAL FOR STUDENTS

AND DENTISTS. By A. B. Griffiths, Ph.D. Demy

8vo. Thirty-six Illustrations. 200 pp. Price 7s. 6d. net. (Post free,

7s. lOd. home; 8s. abroad.)

Contents .

Introduction— Physical Properties of the Metals— Action of Certain Agents on Metals—
AUovs— Action of Oral Bacteria on Alloys— Theory and Varieties of Blowpipes— Fluxes-
Furnaces and Appliances— Heat and Temperature— Gold— Mercury— S.lver-Iron-Copper—
Zinc— Magnesium— Cadmium— Tin— Lead — Aluminium — Antimony— Bismuth — Palladium—
Platinum— Iridium— Nickel— Practical Work— Weights and Measures.

26

Engineering, Smoke Prevention

and Metallurgy.

CHEMICAL WORKS : Their Design, Erection, and Equip-
ment. By S. S. Dyson and S. S. Clarkson. Royal 8vo. 220 pp.
With Plates and Illustrations. Price 21s. net. (Post free, 21s. 6d.
home ; 22s. abroad.) [^ust p2ibllshed.

Contents.

Choice of Site— Notes on Materials used m Construction— First Principles in Laying out a
Works— Workshops— The Drainage System— Foundations— Retaining Walls— Fire Station
and Appliances— Fire Engines— Ambulance Brigade— The Power House, Valves— Flues, etc.
—Automatic Stokers— Steam Raising— Mechanical Stokers— Steam Engines— Sulphuric Acid
Plant— The Glover Tower— The Gay-Lussac Tower— Hydrochloric Acid Plant— Nitric Acid
Plant— Notes on High Explosives Plant— Sulphate of Ammonia Plant— The Still— The
Saturator— Notc-s on Artificial Manure Plant— Burners— Manure Dens— Mixers- General
Plant— Water-driven Centrifugals— Crystallization in Motion Plant— Acid Elevators— Osmose
or Dialysis Apparatus— Schuler's Porus Filter Plates— Pressure Filters for Acid Liquors-
Fused Silica Ware or " Vitreosil "—Homogeneously Lead-lined Pipes, etc.— Kestner's
" Climbing-Film " Evaporator.

THE PREVENTION OF SMOKE. Combined with the
Economical Combustion of Fuel. By W. C. Popplewell, M.Sc,
A.M.Inst., C.E., Consulting Engineer. Forty-six Illustrations. 190 pp.
Demy 8vo. Price 7s. 6d. net. (Post free, 7s. lOd. home ; 8s. 3d. abroad.)

Contents.

Fuel and Combustion— Hand Firing in Boiler Furnaces— Stoking by Mechanical Means-
Powdered Fuel— Gaseous Fuel— Efficiency and Smoke Tests of Boilers— Some Standard
Smoke Trials— The Legal Aspect of the Smoke Question— The Best Means to be adopted for
the Prevention of Smoke — Index.

GAS AND COAL DUST FIRING. A Critical Review of
the Various AppHances Patented in Germany for this purpose since
1885. By Albert Putsch. 130 pp. Demy 8vo. Translated from the
German. With 103 Illustrations. Price 5s. net. (Post free, 5s. 4d.
home; 5s. 6d. abroad.)

Contents.

Generators— Generators Employing Steam— Stirring and Feed Regulating Appliances-
Direct Generators— Burners— Regenerators and Recuperators — Glass Smelting Furnaces-
Metallurgical Furnaces — Pottery Furnace — Coal Dust Firing — Index.

THE HARDENING AND TEMPERING OF STEEL
IN THEORY AND PRACTICE. By Fridolin Reiser.
Translated from the German of the Third Edition. Crown 8vo.
120 pp. Price 5s. net. (Post free, 5s. 3d. home; 5s. 4d. abroad.)

Contents
steel— Clieniical and Physical Properties of Steel, and their Casual Connection-
Classification of Steel according to Use— Testing the Quality of Steel — SteeU
Hardening— Investigation of the Causes of Failure in Hardening— Regeneration of
Steel Spoilt in the Furnace— Welding Steel— Index.

SIDEROLOGY: THE SCIENCE OF IRON (The Con-
stitution of Iron Alloys and Slags). Translated from German of
Hanns Freiherr v. Juptner. 350 pp. Demy 8vo. Eleven Plates
and Ten Illustrations. Price 10s. 6d. net. (Post free, lis. home;
lis. 6d. abroad.)

EVAPORATING, CONDENSING AND COOLING AP-
PARATUS. Explanations, Formulae and Tables for Use
in Practice. By E. Hausbrand, Engineer. Translated by A. C.
Wright, M.A. (Oxon.), B.Sc. (Lond.). With Twenty-one Illustra-
tions and Seventy-six Tables. 400 pp. Demy 8vo. Price 10s. 6d. net.
(Post free, lis. home; lis. 6d. abroad.)

Contents.

i?eCoefficient of Transmission of Heat, k/, and the Mean Temperature Difference, Olm—
Parallel and Opposite Currents— Apparatus for Heating with Direct Fire — The Injection of
Saturated Steam— Superheated Steam— Evaporation by Means of Hot Liquids— The Trans-
ference of Heat in General, and Transference by means of Saturated Steam in Particular
—The Transference of Heat from Saturated Steam in Pipes (Coils) and Double Bottoms
—Evaporation in a Vacuum— The Multiple-effect Evaporator— Multiple-effect Evaporators

27

from which Extra Steam is Taken — The Weight of Water which must be Evaporated from
100 Kilos, of Liquor in order its Original Percentage of Dry Materials from 1-25 per cent,
up to 20-70 per cent. — The Relative Proportion of the Heating Surfaces in the Elements
of the Multiple Evaporator and their Actual Dimensions — The Pressure Exerted by Currents
of Steam and Gas upon Floating Drops of Water — The Motion of Floating Drops of Water
upon which Press Currents of Steam — The Splashing of Evaporating Liquids — The Diameter
of Pipes for Steam, Alcohol, Vapour and Air — The Diameter of Water Pipes — The Loss
of Heat from Apparatus and Pipes to the Surrounding Air, and Means for Preventing
the Loss — Condensers — Heating Liquids by Means of Steam — The Cooling of Liquids —
The Volumes to be Exhausted from Condensers by the Air-pumps — A Few Remarks on Air-
pumps and the Vacua they Produce — The Volumetric Efficiency of Air-pumps — The Volumes
of Air which must be Exhausted from a Vessel in order to Reduce its Original Pressure to a
Certain Lower Pressure — Index.

Sanitary Plumbing, Electric
Wiring, Metal Work, etc.

EXTERNAL PLUMBING WORK. A Treatise on Lead
Work for Roofs. By John W. Hart, R.P.C. 180 Illustrations. 272
pp. Demy 8vo. Second Edition Revised. Price 7s. 6d. net. (Post
free, 7s. lOd. home : 8s. abroad.)

HINTS TO PLUMBERS ON JOINT WIPING, PIPE
BENDING AND LEAD BURNING. Third Edition,
Revised and Corrected. By John W. Hart, R.P.C. 184 Illustrations.
313 pp. Demy 8vo. Price 7s. 6d. net. (Post free, 8s. home ; 8s. 6d.
abroad.)

Contents.

Pipe Bending — Pipe Bending (continued) — Pipe Bendinj (continued) — Square Pipe
Bendings — Half-circular Elbows — Curved Bends on Square Pipe — Bossed Bends — Curved
Plinth Bends — Rain-water Shoes on Square Pipe — Curved and Angle Bends — Square Pipe
Fixings — Joint-wiping — Substitutes for Wiped Joints — Preparing Wiped Joints — Joint Fixings
— Plumbing Irons — Joint Fixings — Use of "Touch" in Soldering — Underhand Joints — Blown
and Copper Bit Joints — Branch Joints— Branch Joints (continued) — Block Joints — Block
Joints (continued) — Block Fixings — Astragal Joints — Pipe Fixings— Large Branch Joints —
Large Underhand Joints — Solders — Autogenous Soldering or Lead Burning — Index.

SANITARY PLUMBING AND DRAINAGE. By John
W. Hart. Demy 8vo. With 208 Illustrations. 250 pp. 1904. Price
7s. 6d. net. (Post free, 7s. lOd. home ; 8s. abroad.)

ELECTRIC WIRING AND FITTING FOR PLUMBERS
AND GASFITTERS. By Sydney F.Walker, R.N., M.I.E.E.,
M.I.Min.E., A.M.Inst.C.E., etc., etc. Crown 8vo. 150 pp. With Illus-
trations and Tables. Price 5s. net. (Post free, 5s. 3d. home ; 5s. 6d.
abroad.)

THE PRINCIPLES AND PRACTICE OF DIPPING,
BURNISHING, LACQUERING AND BRONZING
BRASS WARE. By W. Norman Brown. Revised and
Enlarged Edition. 48 pp. Crown 8vo. Price 3s. net. (Post free,
3s. 3d. home and abroad.) {^ust published.

THE HISTORY OF INCANDESCENT LAMPS. By G.

Basil Barham, A.M. I.E. E. Illustrated. Demy 8vo. [In the press.

WIRING CALCULATIONS FOR ELECTRIC LIGHT
AND POWER INSTALLATIONS. A Practical Hand-
book containing Wiring Tables, Rules, and Formulae for the Use of
Architects, Engineers, Mining Engineers, and Electricians, Wiring
Contractors and Wiremen, etc. By G. Lummis Paterson. Crown 8vo.
Twenty-two Illustrations. About 120 pp. [In the press.

Contents.

Systems of Electrical Distribution— Direct Current Wiring Calculations — Data Relating to
Direct Current Motors — Data Relating to Direct Current Dynamos— Alternating Current
Wiring Calculations — Alternating Current Motor Wiring Calculations — Calculation of Alter-
nating Current Exposed Wiring Circuits — Data Relating to Alternating Current Motors —
Insulation Resistance — Minimum Insulation Resistance of Electric Light Installation — 1 Lamp
to 150 Lamps — Particulars of Electrical Conductors — Approximate Wiring Capacity of Metal
Conduits— Carrying Capacity of Conductors in 16 Candle Power Lamps at Various Voltages
and Sfficiencies — Current Density in Conductors 1000 Amperes per square inch.

28

A HANDBOOK ON JAPANNING AND ENAMELLING
FOR CYCLES, BEDSTEADS. TINWARE, ETC. By

' William Xorman Brown. 52 pp. and Illustrations. Crown Svo.
Price 2s. net. (Post free, 2s. 3d. home and abroad.)

THE PRINCIPLES OF HOT WATER SUPPLY. By

John \V. Hart, R.P.C. With 129 Illustrations. 177 pp., demy Svo.
Price 7s. 6d. net. (Post free, 7s. lOd. home ; 8s. abroad.)

House Decorating and Painting.

THREE HUNDRED SHADES AND HOW TO MIX
THEM. For Architects, Painters and Decorators. By A.
Desaint, Artistic Interior Decorator of Paris. The book contains 100
folio Plates, measuring 12 in. by 7 in., each Plate containing specimens
of three artistic shades. These shades are all numbered, and their
composition and particulars for mixing are fully given at the beginning
of the book. Each Plate is interleaved with grease proof paper, and
the volume is very artistically bound in art and linen with the Shield
of the Painters' Guild impressed on the cover in gold and silver. Price
21s. net. (Post free, 21s. 6d. home ; 22s. 6d. abroad.)

HOUSE DECORATING AND PAINTING. By W.

Norman Brown. Eighty-eight Illustrations. 150 pp. Crown Svo.
Price 3s. 6d. net. (Post free, 3s. 9d. home and abroad.)

A HISTORY OF DECORATIVE ART. By W. Norman
Brown. Thirty-nine Illustrations. 96 pp. Crown Svo. Price Is. net.
(Post free. Is. 3d. home and abroad.)

WORKSHOP WRINKLES for Decorators, Painters, Paper-
hangers and Others By \V. X. Brown. Crown Svo. 128 pp. Second
Edition. Price 2s. 6d. net. (Post free. 2s. 9d. home ; 2s. lOd. abroad.)

Brewing and Botanicals

HOPS IN THEIR BOTANICAL, AGRICULTURAL
AND TECHNICAL ASPECT, AND AS AN ARTICLE
OF COMMERCE. By Emmanuel Gross, Professor at
the Higher Agricultural College, Tetschen-Liebwerd. Translated
from the German. Seventy-eight Illustrations. 340 pp. Demy Svo.
Price 10s. 6d. net. (Post free, lis. home; lis. 6d. abroad.)

Contents.

HISTORY OF THE HOP— THE HOP PLAXT-Varieties of the Hop-Classification
according to the Period of Ripening— Injuries to Growth— Vegetable Enemies of the Hop:
Animal Enemies of the Hop— BeneHcial Insects on Hops— CULTIVATION— The Require-
ments of the Hop in Respect of Climate, Soil and Situation— Selection of Variety and
Cuttings — Planting a Hop Garden: Drainage: Preparing the Ground; Marking-out for
Planting: Planting: Cultivation and Cropping of the Hop Garden in the First Year— Work
to be Performed Annually in the Hop Garden : Working the Ground : Cutting : The Xon-
cutting System : The Proper Performance of the Operation of Cutting: Proper Se^son
for Cutting: Manuring: Training th^ Hop Plant: Principal Types of Frames. Pruning,
Croppmg, Topping, and Leaf Stripping the Hop Plant: Picking, Drying and Bagging—
Principal and Subsidiary Utilisation of Hops and Hod Gardens — Life of a Hop Garden;
Subsequent Cropping— Cost of Production, Yield and Selling Prices.

Preservation and Storage— Physical and Chemical Structure of the Hop Cone— Judging
the Value of Hops.
S«:ati.stics nf Production— The Hop Trade— Index.

INSECTICIDES. FUNGICIDES, AND WEED KILLERS.

Translated from the French of E. Bourcart. Demv Svo. About 400
pages. ' \_ln the press.

29

Wood Products, Timber and

Wood Waste.

WOOD PRODUCTS : DISTILLATES AND EXTRACTS.

By P, DuMESNY, Chemical Engineer, Expert before the Lj^ons Com-
mercial Tribunal, Member of the International Association of Leather
Chemists; and J. Noyer. Translated from the French by Donald
Grant. Royal Svo. 320 pp. 103 Illustrations and Numerous Tables.
Price 10s. 6d. net. (Post free, lis. home ; lis. 6d. abroad.)

TIMBER : A Comprehensive Study of Wood in all its Aspects
(Commercial and Botanical), showing the Different Applications and
Uses of Timber in Various Trades, etc. Translated from the French
of Paul Charpentier. Royal Svo. 437 pp. 178 Illustrations. Price
12s. 6d. net. (Post free, 13s. home ; 14s. abroad.)

Contents.

Physical and Chemical Properties of Timber— Composition of the Vegetable Bodies
— Chief Elements — M. Fremy's Researches — Elementary Organs of Plants and especially of
Forests — Different Parts of Wood .Anatomically and Chemically Considered — General Pro-
perties of Wood — Description of the Different Kinds of Wood— Principal Essences with
Caducous Leaves — Coniferous Resinous Trees — Division of the Useful Varieties of Timber
in the Different Countries of the Globe — European Timber— African Timber — Asiatic
Timber — American Timber — Timber of Oceania — Forests — General Notes as to Forests ; their
Influence — Opinions as to Sylviculture — Improvement of Forests — Unwooding and Revvooding
— Preservation of Forests — Exploitation of Forests — Damage caused to Forests — Different
Alterations — The Preservation of Timber — Generalities — Causes and Progress of De-
terioration— History of Different Proposed Processes — Dessication — Superficial Carbonisation
of Timber — Processes by Immersion — Generalities as to Antiseptics Employed — Injection
Processes in Closed Vessels — The Boucherie System, Based upon the Displacement of the
Sap— ^-Processes for Making Timber Uninflammable — Applications of Timber — Generalities
— Working Timber — Pa\'ing — Timber for Mines — Railway Traverses — Accessory Products —
Gums — Works of .M. Fremy — Resins — Barks— Tan — Application of Cork — The Application of
Wood to Art and Dyeing — Different Applications of Wood — Hard Wood— Distillation of
Wood — Pyroligneous Acid — Oil of Wood — Distillation of Resins — Index.

THE UTILISATION OF WOOD WASTE. Translated from
the German of Ernst Hubbard. Crown 8vo. 192 pp. Fifty Illustra-
tions. Price 5s. net. (Post free, 5s. 4d. home ; 5s. 6d. abroad.)

Building and Architecture.

ORNAMENTAL CEMENT WORK. By Oliver Wheatley.
Demy Svo. 83 Illustrations. 128 pp. Price 5s. net. (Post free,
5s. 4d. home; 5s. 6d. abroad.) [yiistpicblished.

Contents.

Introduction — Chapters I., Workshop — II., Plain Work— III., Technique— IV., Choice of
Ornaments — V., Extended Uses.

THE PREVENTION OF DAMPNESS IN BUILDINGS;

with Remarks on the Causes, Nature and Effects of Saline, Efflores-
cences and Dry-rot, for Architects, Builders, Overseers, Plasterers,
Painters and House Owners. By Adolf Wilhelm Kelm. Translated
from the German of the second revised Edition by M. J. Salter, F.I.C,
F.C.S. Eight Coloured Plates and Thirteen Illustrations. Crown Svo.
115 pp. Price 5s. net. (Post free, 5s. 3d. home; 5s. 4d. abroad.)

HANDBOOK OF TECHNICAL TERMS USED IN ARCHI-
TECTURE AND BUILDING, AND THEIR ALLIED
TRADES AND SUBJECTS. By Augustine C. Passmorr
Demy Svo. 3S0 pp. Price 7s. 6d. net, (Post free, 8s. home ; 8s. 6d.
abroad.)

30

Foods, Drugs and Sweetmeats.

FOOD AND DRUGS. By E. J. Parry, B.Sc, F.I.C, F.C.S.
Volume 1. The Analysis of Food and Drugs (Chemical and Microscopi-
cal). Volume I., Royal 8vo. 724 pp. Price 21s. net (Post free, 21s. 8d.
home; 22s. abroad). Volume II. The Sale of Food and Drugs Acts,
1875-19U7. Volume II., Royal 8vo. 184 pp. Price 7s. 6d. net (Post free,
7s. lOd. home; Ss. abroad). [Just published.

Contents of Volume I.

Tea, Cocra and Chocolate, Coffee— Milk, Cheese, Butter, Lard, Suet, Olive Oil— The Car-
bohydrate Foods — The Starches and Starchy Foods — Spices, Flavouring Essences, etc.—
Alcoholic Beverages — Flesh Foods — Microscopical Analysis — Drugs containing Alkaloids, etc.
— Drugs (generally) — The Essential Oils of the British Pharmacopoeia — Fatty Oils, Waxes, and
Soaps of the British Pharmacopoeia — The Chemicals of the British Pharmacopceia.

Contents of Volume II.

The Sale of Food and Drugs Act, 1875 — Description of Offences— Appointment and D ties
of Analysts, and Proceedings to obtain Analysis — Proceedings against Offenders — Expenses of
executing the Act — The Sale of Food and Drugs Amendment Act, 1879 — The Sale of Food
and Drugs Acts, 1899— The Margarine Act, 1887- The Butter and Margarme Act, 1907.

THE MANUFACTURE OF PRESERVED FOODS AND

SWEETMEATS. By A. Hausxer. With Twenty-eight
Illustrations. Translated from the German of the third enlarged
Edition. Crown 8vo. 225 pp. Price 7s. 6d. net. (Post free, 7s, 9d.
home; 7s. lOd. abroad.)

Contents.

The Manufacture of Conserves — Introduction — The Causes of the Putrefaction of Food
— The Chemical Composition of Foods — The Products of Decomposition — The Causes of Fer-
mentation and Putrefaction — Preservative Bodies— The Various Methods of Preserving Food
— The Preservation of Animal Food — Preserving Meat by Means of Ice — The Preservation
■ of Meat by Charcoal — Preservation of Meat by Drying — The Preservation of Meat by the
Exclusion of Air — The Appert Method — Preserving Flesh by Smoking — Ouicit Smoking — Pre-
serving Meat with Salt — Quick Salting by Air Pressure — Quick Salting by Liquid Pressure —

• Gamgee's Method of Preserving Meat — The Preservation of Eggs — Preservation of White
and Yolk of Egg — Milk Preservation — Condensed Milk — The Preservation of Fat — Manu-
facture of Soup Tablets — Meat Biscuits — Extract of Beef — The Preservation of Vegetable
Foods in General — Compressing Vegetables — Preservation of Vegetables by Appert's Method
— The Preservation of Fruit — Preservation of Fruit by Storage — The Preservation of Fruit
by Drying — Drying Fruit by Artificial Heat — Roasting Fruit — The Preservation of Fruit with
Sugar — Boiled Preser\ed Fruit — The Preservation of Fruit in Spirit, Acetic Acid or Glycerine
— Preser\ation of Fruit without Boiling — Jam Manufacture — The Manufacture of Fruit
Jellies — The Making of Gelatine Jellies — The Manufacture of " Sulzen " — The Preservation of
Fermented Beverages — The Manufacture of Candies — Introduction — The Manufacture of

• Candied Fruit — The Manufacture of Boiled Sugar and Caramel — The Candying of Fruit —
Caramelised Fruit — The Manufacture of Sugar Sticks, or Barley Sugar — Bonbon Making —
Fruit Drops — The Manufacture of Dragees — The Machinery and Appliances used in Candy
Manufacture — Dyeing Candies and Bonbons — Essential Oils used in Candy Making — Fruit
Essences — The Manufacture of Filled Bonbons, Liqueur Bonbons and Stamped Lozenges —
Recipes for Jams and Jellies — Recipes for Bonbon Making — Dragees — Appendix — Index.

RECIPES FOR THE PRESERVING OF FRUIT, VEGE-
TABLES AND MEAT. By E. Wagner. Translated
from the German. Crown 8vo. 125 pp. With 14 Illustrations. Price
5s. net. (Post free, 5s. 3d. home; 5s. 4d. abroad.)

Dyeing Fancy Goods.

•THE ART OF DYEING AND STAINING MARBLE,
ARTIFICIAL STONE, BONE, HORN, IVORY AND
WOOD, AND OF IMITATING ALL SORTS OF
WOOD. A Practical Handbook for the Use of Joiners,
Turners, Manufacturers of Fancy Goods, Stick and Umbrella Makers,
Comb Makers, etc. Translated from the German of D. H. Soxhlet,
Technical Chemist. Crown 8vo. 168 pp. Price 5s net. Post free,
5s. 3d. home ; 5s. 4d. abroad.)

31

Celluloid.

CELLULOID : Its Raw Material, Manufacture, Properties and
Uses. A Handbook for Manufacturers of Celluloid and Celluloid
Articles, and all Industries using Celluloid ; also for Dentists and
Teeth Specialists. By Dr. Fr. Bockmann, Technical Chemist. Trans-
lated from the Third Revised German Edition. Crown 8vo. 120 pp.
With 49 Illustrations. Price 5s. net. (Post free, 5s. 3d. home ; 5s. 4d.
abroad.)

Contents.

Chapters I., Raw Materialsfor the Manufacture of Celluloid : Cellulose and Pyroxylin.
— Gun-cotton — Properties of Gun-cotton — Special Gun-cottons for Celluloid Manufacture —
Nitrating Centrifugalisers— Collodion Wool — Methods of Preparing Collodion Wool — Cam-
phor— Japanese (Formosa) Camphor, O'dinary Camphor — Borneo Camphor (Borneol),
Sumatra Camphor, Camphol, Baros Camphor) — Properties of Camphor — Artificial Camphor
— Camphor Substitutes. 1 1„ The Manufacture of Celluloid; Manufacturing Camphor by
the Aid of Heat and Pressure — Manufacture of Celluloid by Dissolving Gun-cotton in an
Alcoholic Solution of Camphor — Preparing Celluloid by the Cold Process — Preparation with
an Ethereal Solution of Camphor — ^Preparation with a Solution of Camphor and Wood
Spirit. III., The Employment of Pyroxylin for Artificial Silk : Denitrating
and Colouring Pyroxylin — Uninflammable Celluloid — Celluloid and Cork Composition —
Incombustible Celluloid Substitute — Xylonite or Fibrolithoid. IV., Properties of
Celluloid, v., Testing Celluloid. VI., Application and Treatment of Celluloid:
Caoutchouc Industry — Making Celluloid Ornaments — Working by the Cold Process —
Working by the Warm Process — Celluloid Combs — Celluloid as a Basis for Artificial
Teeth — Stained Celluloid Sheets as a Substitute for Glass — Celluloid Printing Blocks
and Stamps — Collapsible Seamless Vessels of Celluloid — Making Celluloid Balls — Celluloid
Posters — Pressing Hollow Celluloid Articles — Casting Celluloid Articles — Method for Pro-
ducing Designs on Plates or Sheets of Celluloid. Xylonite, etc. — Imitation Tortoiseshell —
Metallic Incrustations — Imitation Florentine Mosaic — Celluloid Collars and Cuffs — Phono-
graph Cylinder Composition — Making Umbrella and Stick Handles of Celluloid — Celluloid
Dolls — Celluloid for Ships' Bottoms — Celluloid Pens— Colouring Finished Celluloid Articles —
Printing on Celluloid — Employment of Celluloid (and Pyroxylin)in Lacquer Varnishes — Index.

Lithography, Printing and

Engraving.

PRACTICAL LITHOGRAPHY. By Alfred Seymour.
Demy 8vo. With Frontispiece and 33 Illus. 120 pp. Price 5s.
net. (Post free, 5s. 4d. home ; 5s. 6d. abroad.)

Contents.

Stones — Transfer Inks — Transfer Papers — Transfer Printing — Litho Press — Press Work —
Machine Printing — Colour Printmg — Substitutes for Lithographic Stones — Tin Plate Printing
and Decoration — Photo-Lithography.

PRINTERS' AND STATIONERS' READY RECKONER
AND COMPENDIUM. Compiled by Victor Graham.
Crown 8vo. 112 pp. 1904. Price 3s. 6d. net. (Post free, 3s. 9d. home ;
3s. lOd. abroad.)

Contents.

Price of Paper per Sheet, Quire, Ream and Lb. — Cost of 100 to 1000 Sheets at various
Sizes and Prices per Ream — Cost of Cards — Quantity Table — Sizes and Weights of Paper,
Cards, etc. — Notes on Account Books — Discount Tables — Sizes of spaces — Leads to a lb. —
Dictionary — Measure for Bookwork — Correcting Proofs, etc.

ENGRAVING FOR ILLUSTRATION. HISTORICAL
AND PRACTICAL NOTES. By J. Kirkbride. 72 pp.
Two Plates and 6 Illustrations. Crown 8vo. Price 2s. 6d. net. (Post
free, 2s. 9d. home ; 2s. lOd. abroad.)

Bookbinding.

PRACTICAL BOOKBINDING. By Paul Adam. Translated
from the German. Crown 8vo. 180 pp. 127 Illustrations. Price 5s.
net. (Post free, 5s. 4d. home ; 5s. 6d. abroad).

Sug;

32

ar Refining.

THE TECHNOLOGY OP SUGAR : Practical Treatise on
the Modern Methods ot Manufacture of Sugar from the Sugar Cane and
Sugar Beet. By John Geddes McIntosh. Second Revised and
Enlarged Edition. DemySvo. Fully Illustrated. 436pp. Seventy-six
Tables. 1906. Price 10s. 6d. net. (Post free, lis. home; lis. 6d.
abroad.)

{See " Evaporating, Condensing, etc., Apparatus,^^ p. 26.)

Emery.

EMERY AND THE EMERY INDUSTRY. Translated
from the German of A. Haenig. Crown 8vo. 45 Illustrations. 104 pp.
Price 5s. net. (Post free, 5s. 3d. home ; ns. 6d. abroad.)

[ytcst Published.

Libraries and Bibliograpliy.

CLASSIFIED GUIDE TO TECHNICAL AND COM-
MERCIAL BOOKS. Compiled by Edgar Greenwood.
Demy 8vo. 224 pp. 1904. Being a Subject-list of the Principal
British and American Books in print ; giving Title, Author, Size, Date,
Publisher and Price. Price 5s. net. (Post free, 5s. 4d. home ; 5s. 6d.
abroad.)

HANDBOOK TO THE TECHNICAL AND ART
SCHOOLS AND COLLEGES OF THE UNITED
KINGDOM. Containing particulars of nearly 1,000 Techni-
cal, Commercial and Art Schools throughout the United Kingdom.
With full particulars of the courses of instruction, names of principals,
secretaries, etc. Demy 8vo. 150 pp. Price 3s. 6d. net. (Post free,
3s. lOd. home ; 4s. abroad.)

THE LIBRARIES, MUSEUMS AND ART GALLERIES
YEAR BOOK. 1910-11. Being the Third Edition of Green-
wood's 'British Library Year Book". Edited by Alex. J. Philip.
Demy 8vo. 286 pp. Price 5s. net. (Post free, 5s. 4d. home ; 5s. 6d.
abroad.) .___»_

THE PLUMBING, HEATING AND LIGHTING
ANNUAL FOR 1911. The Trade Reference Book for
Plumbers Sanitary, Heating and Lighting Engineers, Builders' Mer-
chants, Contractors and Architects. Quarto. Bound m cloth and gilt
lettered. (Published in December, 1910.) Price 3s. net. (Post free,
3s. 4d. home ; 3s. 8d. abroad.)

SCOTT, GREENWOOD & SON,

XLccbnicni mooh anD ^vaDe journal publisbers,

8 Broadway, Ludgate Hill,
London, E.G.

Telegraphic Address, " Printeries, London ".

jfanuary, 1912.

w r :»:

■■XiP-

4. ■<■*-,

RETURN
TO

AGRICULTURE LIBRARY

40 Giannini Hall

642-4493

LOAN PERIOD 1

waasm

' 14 DAYS

3

4

5

6

ALL BOOKS MAY BE RECALLED AFTER 7 DAYS

Quarter loans are not renewable by phone

Renewed books are sub ect to immediate recall

DUA AS STAMPED BELOW

JUN iU 1978

i

REC'D IN AGRI LIB FEB 3 "

1979

"

i

J

1

FORM NO. DD 1, 7m, 6'76

UNIVERSITY OF CALIFORNIA, BERKELEY
BERKELEY, CA 94720

>>'* 1 1¥ '

■i^' ^y.<:^^iiM:^.

^^hM^