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L,E.AiSDES

OIL COLOURS AND PRINTERS' INKS

OIL COLOURS
AND PRINTERS' INKS

A PRACTICAL HANDBOOK

TREATING OP

LINSEED OIL, BOILED OIL, PAINTS, ARTISTS'

COLOURS, LAMPBLACK AND PRINTERS'

INKS, BLACK AND COLOURED

LOUIS EDGAE ANDifeS

AUTHOB OF "drying OILS AND SOLID AND LIQUID DRIERS," "VEGETABLE
FATS AND OILS," " IRON CORROSION AND ANTI-CORRORIVE PAINTS," ETC.

TRANSLATED PROM THE GERMAN BY

ARTHUR MORRIS and HERB. ROBSON, B.Sc. (Lond.)

WITH FIFT1^-^I^:IJjTjVSTUaP.0NS

LONDON

SCOTT, GKEENWOOD & SON

"THE OIL AND COLOUR TRADES JOURNAL" OFFICES
8 BROADWAY, LUDGATE HILL, E.C.

CANADA: THE COPP CLARK CO., LTD., TORONTO
UNITED STATES: D. VAN NOSTRAND CO., NEW YORK

1903

[ The sole right of translation into English rests with Scott, Greenvjood d; Son]

* • ' A. ^

PREFACE TO GERMAN EDITION.

Having been engaged uninterruptedly for a series of
years in the manufacture of varnishes, pigments and
coloured printing inks, I may well feel impelled, without
presumption, to write a book upon these subjects, the
more so as literature is somewhat deficient with regard
to them.

My book, in addition to distinct information with
regard to linseed oil, the chief raw material, its purifica-
tion and bleaching for making varnishes and pigments,
contains short dissertations on the theory of drying oil
and of the pigments that can be used with it, and the
chief adulterations. I have thought that any descrip-
tion of pigment manufacture, with the exception of
lampblack, to which I have devoted a special chapter,
would be superfluous, as excellent and copious books
on the subject have appeared.

Attention has been chiefly given to the manufacture
of pigments, their mixing and grinding, and to the
manufacture of printers' varnishes and coloured inks,
including all the latest patented products. The section
dealing with artists' colours is quite new and has
appeared in no other work of this kind. I trust this
part of my work will meet with a good reception in
trade circles, and will establish my reputation as an
expert in matters concerning this special industry.

334270 L. E. ANDi5:s.

Vienna, 1889.

TABLE OF CONTENTS.

CHAP. PAOB

PbBFACB' V

I. Introduction 1

II. LiNSBBD Oil—

Extraction by Pressure 4

Eirtraction by Solvents ....... 5

Properties 7

Adulterations and tests for same 9

III. Poppy Oil . . 13

IV. Mechanical Purification op Linseed Oil—

Purification by stocking 15

Rieck's Machine 16

Cataract Machine 17

Ure's Oil Filter 18

Upward Oil Filter 19

Oil Refining Kettle 21

V. Chemical Purification of Linseed Oil—

Combret's Apparatus 25

Vli Bleachino Linseed Oil—

Sun Bleaching 28

Peroxide Bleaching 29

Sulphuric Acid Bleaching 30

Sulphurous Acid Bleaching 30

Bleaching with Sulphurous Acid to Kdrting's Apparatus . 30
VII. Oxidizing Agents for Boiling Linseed Oil—

New Driers : Linoleates 36

Manganous Linoleate 36

Soluble Lead and Manganese Preparations . ... 37

Introduction of Driers 38

VIII. Theory of Oil Boiling . 40

IX, Manufacture of. Boiled Oil—

Boiling over the open fire or with steam . . . .43

Zwieger* 8 Process . . .... . 46

Lehmann's Superheater . ... . . . 46

vm TABLE OP CONTENTS.

OHAP. PAOB

Andres' Process . . . • 48

Walton's Process . . . . . . . . 48

Vincent's Process 48

Schrader & Dumeke's Ozone Process 49

Electrical Process of Muthel and Liitke .... 50

Zimmermann & Holzwich's Apparatus .... 54

Process of D.R.P. 12825 56

X. Adultbrations op Boilbd Oil 61

XI. Chinese Drying Oil and other Speoialitibs—

Neumann's Cement Oil 69

Carbolic Oil 70

TarVarmsh , . . 70

XII. Pigments for House and Artistic Painting and Inks—

Hue, Body and Fastness 72

Antimony Colours 74

Arsenic Colours 74

Barium Colours 74

Lead Colours 75

Cadmium Colours 76

Chrome Colours 76

Iron Colours .77

Cobalt Colours 78

Copper Colours . . . . ' 78

Manganese Colours 79

Mercury Colours 79

Zinc Colours 80

Carmine 80

Lakes 80

Indigo 81

Frankfort Black 81

Ivory Black 81

XIII. Pigments for Printers' Black Inks—

Thenius* Oven for making Lampblack from Oil . . . 85

Oven for Asphalt and Pitch 86

Oven for Rosin, Pitch and Ceresine . . . . - . 87

Preparation of Real Lampblack 89

Apparatus for Use with Oil 93

Dreyer's Apparatus 96

Tighe's Process 108

Chemical Manufacture of Lampblack 109

Calcining Lampblack 110

XIV. Substitutes for Lampblack—

Black from Tar 113

Tannin Black 115

l^ABlifi OF COK'PENTS.

CSU^. VAQ9

.' :XV, Maphin^by for Qoloub GaiNDiNa and Rubbing—

Pug.MiU . . ... . . 117

.Bonner Ball Mill. ........ 117

Disijitegrator .... . . . , , . . 120

Centrifugal Sifting and Winnowing Machine . . . 123

Sieving and Mixing Machine . . . . . 124

XVI. Machines for Mixing -Pigments with the Vehicle—

. Quack's Universal Machine 125

, Weimer & Pfleiderer's Machine ..... . . . 127

. Lehniann.'8 Machine 129

XVII, Paint Mills—

, Ordinary. Machine . . 131

. Ordinary, Machine Improved with Air Pressure . . . 132

. Plate Machines 133

. Roller Machines .134

XVIIl, Manufacture of Bouse Oil Paints —

Requirements asked for in a Paint 136

. Choice, Mixing and Rubbing-up Paints . . . . 137

. Whitelead Paints 140

Zinc White Paints 140

,Zina Grey Paints .140

Yellow Paints 140

, Red Paints 141

, Green Paints . . . . . 141

Blue Paints 142

Brown Paints 142

.Black Paints 142

- Hugoulin's Process , 143

Weathernresistirig Wall Paint 144

. Universal Artists' Colours 145

Grunzweig's Oil Paint 147

. To make Oil Paints resist High Temperatures . . . 147

. Glasenapp's Black Paint . 147

. Vehicles and Binders for. Pigments . . . . . 148

- Substitute for. Boiled Oil . . . . . '. .148
. BruchhoWs Weather-resisting Paint . . . 149
. KallkoUth . . . . . .... . . . 149

XIX. Ship Paints—

. Schnitger's Paint for Hulls of Ships . . . , . 154
Other AntifouUng Paints . . . . . . .155

. Paints for Iron Ships . . - 155

XX. Luminous Paint— ...

. White Luminous Paint . ' . ♦ . . . i . 156
Red Luminous Paint . . . . ... .161

X TABLE OF CONTENTS.

CHAP. 9AQM

Orange Luminous Paint 161

Yellow Luminous Paint 161

Green Luminous Paint 162

Violet Luminous Paint 162

Grey Luminous Paint 162

Yellowish-brown Luminous Paint 162

XXI. Artists' Colours—

Whites 166

Yellows 165

Reds 165

Browns 165

Blues 165

Greens 165

Blacks 166

Schnitger's Oil Paints 168

The Mussini Colours 174

The Normal Colours of the German Society for Promoting

Rational Painting 176

Detection of Cotton Oil in Oil Paints 180

XXII. Printers' Inks: Vbhiclbs—

Andres' Boiling Apparatus 188

Boiling Process 190

Boiled Oil with Rosin 192

Rosin Oil Vehicles 193

Weak Boiled Linseed Oil Vehicle . . . . .193

Medium Linseed Oil Vehicle 194

Strong Linseed Oil Vehicle 194

Weak Raw Boiled Linseed Oil Vehicle .... 194

Strong Raw Boiled Linseed Oil Vehicle .... 194

Composition Vbhiclbs 194

XXIII. Printers' Inks : Pigments and Manufactubb—

Mixing the Lampblack with thb Vbhiolb .... 197

Recipes for Printing Inks 197

Inks for Rotary Presses 198

Inks for Rapid Process 198

Daily Paper Inks 199

Book Inks 199

Illustration Inks 199

Brackenbusch's Impbovbmbnts 199

Dry Printing Inks 200

Soft Printing Inks . . , 200

Jobbing Inks 200

Gunthbr's Black Printing Ink 200

Artus' Printing Ink 202

TABLE OF CONTENTS. XI

PAGK

ROsL's Printing Ink 202

Black Printing Ink prom Coal Tar 208

Schmidt's Black Printing and Stamping Ink ... 204

Black Printing and Stamping Ink of Eirchbr & Ednbr . 206

Black Printing and Stamping Inks with Iron . . . 206

Thbnius* Blaok Printing Ink 206

INDBX 208

CHAPTER I.

INTRODUCTION.

The great technical progress that has been made in every
direction has naturally made itself felt in the manufacture of
pigments for all purposes. This has been especially the
case during the last forty years.

Before that time the industry was in a very primitive
state. Pigments were rubbed up by hand on a glass or
stone plate by means of a muUer. This method certainly
yielded finely divided colours, but the output per man was
so small that in large factories more hands were employed
in grinding the colours than in making them. Artists^ too,
looked upon the labour of grinding their own colours as a
most important necessity. In this way only were they
always able to use fresh pigments, and were not obliged to
struggle with a medium which through long keeping had
become immanageable. In view of the fact that artists use
a comparatively small amount of pigment, they were prob-
ably quite right to take this trouble at the period, but with
house-painters and others who use large quantities the case
was very different. With the increase of demand the pig-
ment-makers found their stone and muller method utterly
inadequate to cope with requirements, and the invention and
introduction of machinery inevitably followed.

Printers* colours underwent the same evolution. Formerly
the printer always prepared them himself. On fine days
the printing-office staff went out into the garden or the fields

2/ :: .-.•/iMfOCSCiOjiftS *AtrD printers* inks.
• •♦ ••• .' ••»•••,-.•

and rigged up their boiling pot. Then the assistants had a
festival, oulminating in roasting bread in the hot linseed oil
and eating it. The boiled oil was then mixed with the pig-
ment and the finished ink was taken home. What would a
modem printer say if asked to use such a lumpy mixture ?
Here then, too, machinery had to be introduced before a
product which made modern printing possible could be pro-
duced. The substitution of power-driven printing machines
for hand presses had a. great deal to do with producing this
change.

That the progress in colour manufacture has not been
solely* a question of grinding is easily understood, and we
have sifting and mixing machinery to describe, and to these
a special part of the book is devoted.

As a vehicle for oil-colours linseed oil has always been
the mainstay of the industry, and we also use poppy oil and
nut oil in the manufacture of artists' colours. Of the other
drying oils — hemp, sunflower, cotton, grape-seed, tobacco-
seed, dodder, croton, castor, madia, etc. — ^hemp oil is used
locally, in GaHcia and Kussia. The bankul oil of Aleurites
triloba might advantageously be imported from Martinique,
Guadeloupe, New Caledonia, Tahiti, Guiana, and Eeunion,
and used for pigments and varnishes, but so far no quantities
worth mentioning have been brought to Europe.

The siccative properties of linseed oil are developed either
with reducible metallic oxides or other bodies rich in oxygen,
or, still better, by means of oxygen itself. The oil may also
be purified or bleached for colour mixing. The artist in oils
should only use linseed, poppy, or nut oil that has been
nature bleached, especially for delicate shades, but manu-
facturers have already gone so far as to use cotton-seed oil
in manufacturing even comparatively high-priced artists'
colours.

The purification and bleaching of linseed oil, and its boiling
are matters of great importance in colour preparation, and

INTRODUCTION. 3

shall be desoribed with corresponding minuteness. For the
printer, linseed oil and lampblack are the most important raw
materials, and the practice of centuries has shown that a
pure, clear, long-stocked linseed oil is the only suitable oil
for his use. This, then, the modem manufacturer must
remember and pay he'ed to.

The number of pigments used for painting of all kinds and
by printers has steadily increased with the lapse of time, and
although many are now offered of excellent appearance
which fall short of the claims put forward on their behalf,
yet experience will soon teach the user how to make his
choice. This book will enable the colour- maker to improve
his somewhat defective knowledge, and to give him the
certainty in judgment that he most certainly requires.

Although in our industry the preparation of dry colours is
only occasionally undertaken by the manufacturer of mixed
paints, yet in all cases the maker of printers' ink should
produce his own lampblack, and the methods of doing so are
detailed in a special part of this work.

It is unnecessary to dwell on the fact that a time so rich
in inventions as the present has not stood still as regards
colour manufacture, and that many proposals have been and
are still being made to replace drying oils as vehicles for
pigments by cheaper or better substitutes. I feel myself
called upon, however, to remark in this connection that no
substitute hitherto suggested is superior to the drying oils,
and that at present a good paint, whether for artistic, print-
ing or general purposes, can only be made with a drying
oil.

CHAPTEK IL

LINSEED OIL.

Linseed oil is made from the seeds of the flax plant, Linum
usitatissimum. The plant is largely cultivated in Holland,
Kussia, Austria, Germany and France. These European
sources of supply are, however, inadequate for the enormous
consumption, and most of the linseed oil of commerce is now
made from East Indian seed, which comes in cargoes to
Holland and England, where the oil is extracted. The native
place of the flax plant is Asia, and it was known to the
ancients, who made linen from it, as is proved by micro-
scopical examination of mummy-cloths.
The oil is obtained : —

1. By cold pressure, if the oil is to be used as an article
of food.

2. By hot pressing for technical purposes only, as the oil
obtained has a disagreeable taste.

3. By extraction.

Each method gives a different yield of oil.

Cold pressing gives 20-21 per cent.

Hot „ „ 27-28 „

Extraction „ 33-33 „

Oil from fresh seeds is mucilaginous and turbid, the seeds
therefore are stocked for from two to six months before
pressing.

The seeds are then broken up by stamps, rollers, or in a
pugmill, and next heated by steam or over the fire in suitable
vessels. Various advantages are secured by heating the
seeds. The oil becomes thinner, and flows out more easily

LINSEED OIL. 5

under the pressure. The yield is increased, the albuminous
bodies in the seed are coagulated and the mucilaginous
substances are dried up. There is, however, the disadvantage
that the hot oil dissolves colouring matter and extractives
with a disagreeable taste out of the residue of the seeds.
Hence, as we have already said, hot pressed linseed oil is
used only for technical purposes.

The pressure is applied with hydrauhc or wedge-presses
and either horizontally or vertically. All large oil factories
now use hydrauhc presses.

The production of oil by pressure has been frequently
described and the apparatus is well known, but as the
extraction process is less familiar I will describe it more
fully. Deite says in his Technologie der Fette und Oele : —

** Even by the use of the greatest pressures at our command
it is impossible to press all the oil out of the seeds. It is this
residual oil that gives value to the press-cakes, which contain
about 10 per cent, of it. To get the full yield from the seeds,
solvents must be used. Schrotter showed the method of
manufacturing bisulphide of carbon in 1838, and Jesse Fisher,
of Birmingham, the introducer of the employment of the
bisulphide industrially, first used it for extracting linseed
oil in 1843. Deiss and Sufiferth of Brunswick followed in
Fisher's footsteps. Besides bisulphide of carbon other sol-
vents are available, especially petroleum-ether, benzole,
canadol, etc., introduced by Vohl Eichardson and Hirzel."

Lampadius, the discoverer of bisulphide of carbon in 1796,
made it by the method still used, viz., passing sulphur vapour
over red-hot carbon, and oil factories using it always make
their own. The apparatuses in which the bisulphide is put
to the linseed are all alike in the main features of their action,
including the recovery of the bisulphide of distillation. The
bisulphide passes vertically through the seeds, but sometimes
upwards and sometimes downwards. The bisulphide can be
added to the seeds themselves, previously crushed as above

6 OIL COLOUES AND PEINTERS' INKS.

described, and then dried, or may be used to extract the
residual oil from the press-cakes. For this purpose the
press-cakes are ground up. Air-tight iron cylinders are used
for the extraction.

As soon as carbon bisulphide had been introduced for oil
extraction a controversy arose as to its merits. The farmer
lamented the loss of oil-cake for fodder. The cows would
not eat the sulphur-smelling residues from the extraction
process. The oil-dealer complained of the disagreeable
smell and taste of the oil, the soap-boiler of the odour the
oil communicated to his soap, and the painter because the
oil blackened white lead, whether it was stirred up with that
pigment or applied to it in the form of another paint.

Chemists complained that colouring matter was dissolved
by the bisulphide and also a resinous sticky body, which
favoured absorption of oxygen, and caused rapid resinification
and rancidity of the oil. The oil also contained seed meal
which unfitted it for many purposes. All these things com-
bined killed the extraction process. The existing factories
did not prosper, and most of them stopped altogether. Just
at this time, moreover, the opening out of the petroleum
industry in America caused a use to be sought for petroleum -
ether, and it was speedily adopted instead of bisulphide of
carbon for oil extraction.

A Hght petroleum-ether boiling at 60° C. enables us to get
a very pure oil from seeds as it does not dissolve resins,
whence Vohl called it canadol. Eaw canadol itself contains
sulphur, and must therefore be treated with bichromate and
sulphuric acid, and then rectified.

Opinions as regards the comparative merits of canadol
and bisulphide of carbon for extraction purposes were formerly
very divided. Now, when the manufacture of the bisulphide
has been so improved that repeated rectification gives us a
product which will extract oil of perfect purity, and with an
agreeable smell, and when the cost of producing the bisul-

LINSEED OIL. 7

phide is so low that it can compete with canadol, the question
which of the two is to be preferred comes up, and must be
considered. The answer is that when the oil is to be used
for food or for perfumery extraction with canadol is to be
preferred. For all other purposes the choice must be deter-
mined by the current market prices of the two solvents. In
favour of bisulphide of carbon it must be mentioned that it
is more convenient to use, as it is employed cold for extrac-
tion, while canadol must be boiling. Hence the apparatus
required is less expensive in the case of bisulphide. Again,
very old seeds are not perfectly exhausted of oil by canadol,
whereas the full yield is obtained with carbon bisulphide.

Practice has now got rid of all the troubles attending the
use of bisulphide of carbon. The residues have no longer
the least smell, and have long since regained favour as fodder.
The result has been that the factories of bisulphide existing
when the improvement in the manufacture was made were
soon unable to cope with the demand, and during the last
ten years the output of bisulphide and its use for oil extraction
have greatly increased. It is found that it is cheaper to
extract the oil than to press it out, and that it can be done
with a less outlay of capital. The oil works using the ex-
traction process have propitiated the farmers by abandonment
of complete exhaustion of the oil, and this step has by the
way almost quadrupled the output of the factories.

Cold-pressed oil is nearly colourless, having only a very
pale yellow tint, while hot-pressed oil is distinctly yellow, or
even brown. The dissolved-out oil is of a very pale yellow.
The taste of linseed oil differs from that of the non-drying
oils, and is a characteristic bitter with a rough after- taste.
The smell of the oil is also peculiar, and Mulder does not
think it due solely to volatile fatty acids, such as butjrric,
valerianic and caproic.

Linseed oil does not freeze until far below zero G. Gusseron
says that it will freeze at -16° C. if kept several days at

8 OIL COLOURS AND PRINTERS* INKS.

that temperature. Saussure says- 27^° C, and I would put
its freezing point still lower, as I have never succeeded in
getting solid Hnseed oil at temperatures of - 28 or - 29° C.
It dissolves in sixteen times its weight of ether and in forty
times its weight of cold alcohol, or in five times its weight of
boiling alcohol. With oil of turpentine it mixes in all pro-
portions. Its specific gravity is : —

•9395 at 12° 0.
•9300 at 25° 0.
•9125 at 60° C.
•8815 at 94° 0.

Linseed oil boils at 130° C. On the oil-balance it should
show 30°, but the indications of the instrument are not
altogether trustworthy. At from 360 to 400° C. the stinking
vapours which began to come off at 210° will catch fire, and
burn with a red flame and with much smoke.

Fresh linseed oil is saponifiable, and forms a yellow soft
soap with soda. A solution of this soap treated with hydro-
chloric acid gives a fluid supernatant layer, which forms
crystals of stearic and palmitic acid on cooling.

By boiling linseed oil in the air we get first boiled oil, and
by further heating to a high temperature a tough mass which
will not make a greasy mark on paper. It is usual to set
fire to the fumes, but this is not indispensable. If heated
beyond a certain point linseed oil loses its drying power, and
becomes sticky and elastic. To remain drying it must be
heated till the linoleine begins to decompose. Among the
first products which the heat volatilises are derivatives of
oleine, myristine and palmitine.

When linseed oil has been heated to a tough mass that
mass will become solider if boiled in dilute nitric acid. The
acid promotes the separation of the linoleic acid from the
glycerine, so that the smell of scrolein becomes noticeable.
Finally, according to Jones, the mass becomes a sort of
india-rubber, and is no longer sticky to the touch, and no

LINSEED OIL. 9

longer fusible. It is, however, still soluble in bisulphide of
carbon to an emulsion. If this india-rubbery mass is boiled
in concentrated potash lye, it combines with it, but is not
dissolved. The compound is decomposed by acids, setting
the india-rubbery substance free again. In alcohol-containing
ether the india-rubbery substance swells up, and dissolves
if more ether is added. It is reprecipitated by alcohol. In
petroleum it swells up but does not dissolve. It will dissolve
in a large quantity of oil of turpentine.

When linseed oil is dry distilled, we get as a distillate
acrolein, partly oxidised to acrylic acid, saUcylic acid, pal-
mitic acid and myristic acid, with linoleic anhydride as a
residue.

The ultimate composition of linseed oil is : —

Cold pressed. Hot pres^d.

per cent. per cent.

Carbon 78-11 75-27

Hydrogen 10-96 10-88

Oxygen 10-93 13-85

The oil is a mixture of linoleine (C^g Hgg 0)3 Cg H5 O3, the
glyceride of Hnoleic acid with oleine, palmitine and myristine,
the linoleine forming about 81 per cent. Hence the saponi-
fication products are glycerine, linoleic acid and oleic or some
aUied acid, those of dry distillation being acids yielding
sebacic acid, palmitic and myristic acids.

Linseed oil has more power than any other drying oil,
absorbing oxygen from the atmosphere and on boiling with
metallic oxides, whereby its composition is considerably
altered and we get boiled oil.

Linseed oil is much adulterated, less, however, by the
makers than by the middlemen. The adulterations used
depend upon prices. They include rape, cotton and hemp
oils, and also petroleum, fish oil, resin oil, colophony, etc.

Adulteration with fish oil is detected by stirring up ten
parts of the oil to be tested with three of sulphuric acid. On

10 OIL COLOURS AND PRINTERS* INKS.

standing the oil and acid separate. If the oil contains fish
oil it rises to the surface of a dark brown colour, while the
acid below it is orange or brownish yellow. If the oil is
pure, it is at first green, then a dirty yellowish green, while
the acid assumes a purer yellow colour. This adulteration
can also be detected by chlorine which bleaches pure linseed
oil, but turns all animal fats first brown and finally black.

Adulteration with colophony and other resins may be
detected by boiling the oil for a few minutes with S.V.E. of
from '88 to 99 sp. gr., drawing off the solution when cold,
and treating it with a solution of acetate of lead in alcohol.
If the oil was pure, a turbidity results, but the presence of
resins causes the appearance of a white curdy precipitate.

To detect resin oil, the senses of smell and taste are best
reHed upon. Even small quantities of resin oil can be re-
cognised in linseed oil by the taste. A good plan is to rub
a drop of the oil to be tested between the palms of the hands,
for on separating them the smell of the resin oil can be
detected. The following method is also said to be reliable.
Mix at the ordinary temperature (not however below 16° C.)
equal volumes of the linseed oil and nitric acid of sp. gr.
1*4. Shake the mixture well for half a minute, and then
allow it to stand. When the oil and acid have separated we
have the following colours : —

Nature of Sample.

Oil.

Acid.

ure

linseed oil

Pale cinnamon

brown

Colourless.

ins

Bed oil + 5 per cent.

resin

oil

n M

»>

Straw-yellow.

»»

,, + 12 .,

Dark olive

Dark yellow.

„

» +50

»>

Blackish

Pale orange.

For accurate methods of testing linseed-oil adulteration
with other vegetable oils, which only happens when their
price relative to that of linseed oil makes it worth while, I
refer the reader to Dr. Benedikt's Analyse der Fette, and
will only give here Morawaki and Demski's method for
detecting unsaponifiable fats (petroleum and resin oil), because

LINSEED OIL. 11

it is with these liiat linseed oil is mostly adulterated at
present.

The complete separation of the layers of liquid got by
treating the soap with a volatile solvent is often difficult, but
the following process enables it to be done always quickly
and easily in the separating funnel. Ten grammes of the oil
are treated with 50 c.c. of alcohol and a concentrated solution
in water of 5 grammes of caustic potash. The whole is
heated for half an hour with a reflux condenser. Then 50
c.c. of water are added, and the mass is cooled by standing
the containing flask in cold water. The mass is then shaken
up in the separating funnel with petroleum-ether. When the
two liquids have separated the lower layer is drawn off as
completely as possible. What remains in the funnel is
washed repeatedly with water, but the washings are not
added to what was first drawn off. Finally, the last washing
is drawn off as completely as possible. As even with the
greatest care drops of water accompany the ether when it is
drawn off in its turn, it is not poured at once into the tared
dish in which it is to be evaporated, but into another dry
dish. It is then transferred thence to the tared dish,
leaving the water behind adhering to the sides of the other
dish. The first portion drawn off from the separating funnel
is then treated with more ether, which after washing, etc.,
as above described, is also transferred to the tared dish.

To ascertain quickly whether the unsaponifiable fat is
resin oil or petroleum, shake it with its own volume of
acetone. If perfect mixture ensues, the fat is resin oil or a
mixture of petroleum with a large excess of resin oil, but if
not, the fat is either all petroleum or there is very little
resin oil. Alcohol of sp. gr. '95 can also be used, in
which resin oil sinks and petroleum floats. If saponifiable
oils are also suspected, we may determine what vegetable
oil is present as an adulterant by finding the iodine and
saponification values of the original substance, or by ex-

12 OIL COLOURS AND PRINTERS* INKS.

amining the fatty acids set free from the soap, first separated
from the unsaponifiable matters, by a mineral acid. This
examination may include the determination of the saponifica-
tion number, temperatures of fusion and solidification, iodine
number, etc. The iodine number must be first determined
for the free fatty acids, as Hubl's process is only for neutral
fats. The author has found for the iodine numbers of the
fatty acids the following figures : —

Acids from rape oil . . , . , , 96'3 - 99*02

Acids from earth-nut oil 95*5 - 96*9

Acids from sesamum oil 108*9 - 111*4

Acids from cotton oil 110*9 - 111*4

Acids from linseed oil 155*2 - 155*9

Acids from hemp oil 122*2 - 125*2

Acids from castor oil 86*8 - 88*3

Acids from cocoanut oil 8*39 - 8*49

It is sufficient to act directly on the fatty acids with Hubl's
iodine solution. If it is wished to calculate the iodine number
J of the saponified fat from the iodine number Jg of the un-
saponifiable fat of the original mixture and the iodine number
Jj of the whole original substance, it can be done by the
equation

J = (a : 100 Ji - 6 Jg).

Here a is the percentage of saponifiable fat, and h that of
unsaponifiable fat. The first described method is, however,
to be preferred, i,e, making use of the separated fatty acids,
because the same material can be used for the determination
of fusion and soHdification points, which are very important
data in the recognition of fats.

CHAPTER III.

POPPY OIL.

Poppy oil is got by pressure from the seeds of Papaver
somniferum, specially the black variety, and its production
is an important industry in the north of France. About
half the oil produced there is used at home, and most of
the other half goes to the south of the same country,
where it is used for making grain -soap. In Germany
poppy oil comes mostly from Baden, Bavaria and Wiirtem-
burg. The poppyheads are opened at a certain degree of
ripeness, and their contents are shaken out on to sheets
of iron, winnowed to get rid of fragments of capsule, and
ground to meal in a mill. This meal is put into bags of
ticking, and in them into the press. The oil is collected
and allowed to settle till clear, when it is sold. The
French distinguish two classes : white, for culinary pur-
poses ; and red, for technical uses.

Poppy oil is of a pale yellow to a light gold colour,
clear, fluid, of pleasant taste, and with a characteristic
though feeble smell. It is much used for food, and is
sometimes even preferred to olive oil, with which it is used
as an adulterant. It does not become rancid easily. The
older oils are used as fuel, but give too bad a light to be
employed as illuminants.

The second quality, got by hot pressing, has a rough
taste and smell.

14 OIL COLOUES AND PEINTBBS' INKS.

The specific gravity of the oil is : —

•9285 at 10^ C.
•9271 „ 12<' „
•926 „ 16° „
•9216 „ 20° „

At 15° 0. the oil is 13-6, and at 7-5** C. 18-3 tunes
thicker than water. It freezes with difficulty. It is still
clear, though thick, at 15° C, and does not solidify above
20° C. Once frozen to a white mass it does not thaw again
till heated to 2° C, when it begins to fuse rapidly.

Poppy oil dissolves in its own volume of ether, and in
25 volumes of cold, 6 of boiling, alcohol. If consists chiefly
of linoleine, together with the glycerides of oleic, stearic,
palmitic, myristic and lauric acids.

Its ultimate analysis is : —

Per Cent.

Carbon 78*63

Hydrogen 11-63

Oxygen 11*74

Poppy oil is easily saponified, and gives a hard soap.

OHAPTEE IV.

MECHANICAL PURIFICATION OF LINS ED OIL. .

Linseed oil is brought upon the market for rapid sale, and
contains considerable amounts of such foreign bodies as
water and linseed-meal, which, when the oil comes to be
used for paints and varnishes, must be removed if a fault-
less product is to be obtained.

The simplest method of purification requires no plant or
outlay, and consists in simply stocking the oil in a receptacle
fitted with draw-off cocks at different depths, and leaving
it then for weeks or months, or even a year, with free
access of air all the time. If the top of the vat must be
covered on account of dust, holes should be made in the
sides above the surface of the oil.

Where, however, space does not permit of this procedure,
mechanical means of purifying the oil must be resorted to.
To these means belong : —

1. Machines in which the oil is first stirred up for a long
time and then allowed to stand.

2. Machines in which the oil is filtered, either by its own
weight or by artificial pressure.

3. Mixing with the oil heavier liquids which when they
separate out carry the impurities to the bottom with them.

4. Heating and bubbhng hot air through the oil.

These mechanical methods have so far proved themselves
superior to chemical means because when drugs are used
they have themselves tb be got rid of afterwards, and that is
always the longest and most troublesome part of the series

16 OIL COLOURS AND PRINTERS' INKS.

of operations. Acids are employed and it is absolutely
necessary to get rid of them, as the presence of traces would
affect the pigments when the oil was used for paint-mixing.
Time has also to be allowed for the oil to clear, and there is
a loss by the saponification of part of the oil, which forms a
layer which would have to be treated with ether to get the
oil from it.

Although in spite of this I shall mention some chemical
methods of purification, it is only to make my work com-
plete.

In working on a small scale, it is always best to purify the
oil by stocking rather than to use chemicals. On a large
scale, one of the machines about to be described is essential,
and especially that alluded to in the last of the four cate-
gories just mentioned, which allows of rapid and uninter-
rupted working.

Eieok's Machine.

In the machine of Otto Eieck of Mulheim A is the
cylinder fastened in the vessel B and enlarged below. C is
a hollow piston, which moves freely, but closely fitting, in
A, and has a perforated bottom D is a hollow piston rod
attached to the piston and passing through a stuffing box at
E into the lower vessel. G is the perforated top of the piston
which can be pressed by the screw H doWn on the filtering
material contained in the hollow of the piston. J are weights
to enable the pressure of the piston to be regulated, and K is
a hand wheel for raising the piston. M is the cleaning hole,
and N a cock.

The apparatus works as follows : The oil to be purified is
put into B, and by means of K the piston is lifted. This
causes the oil to flow through the valve to the under side of
the piston. The piston is then allowed to descend slowly
by means of the weights J. This forces the oil upwards
through the filtering material. When it arrives above the

MECHANICAL PURIFICATION OF LINSEED OIL. 17
piston and flows through a hole in the hollow piston rod intio

Fig. 1.

the lower receptacle F, the dirt filtered from the oil can be
removed through M.

Cataract Machine.

This is made by the Actiengesellschaft fiir Maschinenbau
und Eisenindustrie at Barel in Oldenburg. It is represented
in vertical section by fig. 2. The oil to be purified is filled
into the cylindrical iron vessel up to a mark. By turning
the wheel S, the stirrer Fl is set in rapid motion. The
centrifugal force thereby set up in the oil causes it to rise
against the sides of the vessel. Thus it is caught by the pro-

OIL COLOURS AND PRINTERS INKS.

jections K and a ring above them, and driven down again
through the centre, to be again acted on by Fl. This vigorous
stirring brings about an intimate contact between the particles
of the oil and the atmospheric air, such as is impossible by
any other means or by any other machine. This makes the

Pig. 2.

machine very suitable for purifying oil, and it can also be
used for mixing boiled oil or varnish with pigments.

The Actiengesellschaft makes sizes of the cataract machine
holding from 20 to 400 litres. One holding 100 to 125 litres
with wheel for hand-driving costs M.250 at Barel. Larger
machines are provided with pulleys for belt-driving by power.

Urb's Oil Filter.

Ure has proposed a very practical filter for the mechanical
purification of linseed oil. In it the oil is put in a reservoir.
This has a tube with a cock near the bottom whereby it can

MECHANICAL PURIFICATION OF LINSEED OIL. 19

be put into communication with a cistern of water. The
oil filter consists of a cylinder divided into three storeys
by perforated plates. The lower storey communicates with
the oil reservoir by a short knee- tube. The middle storey
contains the filtering material, such as cotton, coarsely
powdered charcoal, felt, etc., and the upper storey receives
the filtered oil and is provided with a draw-off cock. When
the cistern is full of water and the reservoir of oil, the con-
necting tubes are opened. The water enters the oil reservoir
and drives the oil through the filter by hydrostatic pressure.
When sediment has accumulated in the lower storey of the
filter it is drawn off by a cock. We are thus enabled to
separate the clear oil quickly and easily from the sediment it
deposits by being purified.

Bags were formerly used for oil filtering, but they soon get
clogged. Cotton and loose stuff were tried instead, but these
wanted constant changing at a great expense in time and
material. When upward filtration was first introduced, the
filtering material was almost invariably sawdust. This how-
ever has drawbacks which caused its replacement by other
materials.

The Upward Oil Filter.

This is packed with linen, tow, moss, or oakum only.
The filter-case is of iron lined with lead, and is fed from
below through a valve by the hydrostatic pressure of oil from
a vessel placed high above the filter. The valve permits of
the regulation of the supply of oil to the filter, according to
the time available for the filtration.

At the bottom of the filter a cross-piece, H, carries a per-
forated wooden disc. This is covered with a piece of coarse
linen with a finer piece over it. Then comes a thin layer of
oakum, E, then one of moss, M, and linen. Then another
perforated disc, more oakum and moss, and so on to the.top.
The screw, S, not only serves for supplying the pressure

OIL COLOURS AND PRINTERS INKS.

which keeps the filtering layers together but by regulating
their density decides upon the rapidity with which the oil
passes through. The moss used for filtering the oil must
have been gathered in a dry season of the year, and must be
freed from sand and earth by shaking in a sieve. Moss —
Hyolocomium triquetrum Schimp ; Hypnum splendens Hedw ;
Polytrichum commune L. — is a most excellent oil-filtering
medium, and can be used without tow or any other adjimct.

Fig. 3.

If moss alone is used for packing the filter, it must be
packed properly by means of the screw S. The moss must
naturally be renewed from time to time. If the oil has been
stocked for some time before filtering a renewal about every
three weeks is sufficient. After a lot of moss has been used
for filtration for the last time, hot water and strong pressure
are used to get from it the oil which it would otherwise re-
tain.

MECHANICAL PURIFICATION OF LINSEED OIL. 21

Oil-Ebfininq Kettle.

This new apparatus, shown in fig. 4, is intended for the
refining of fresh pressed oils in general and is specially
advantageous for use with linseed oil, because the oxygen

Fig. 4.

action involved in the working of the apparatus makes that
oil much more drying.

The boiler or kettle, A, is about 1*4: metre in diameter and
contains the steam coil, D, both ends of which pass through
the lid. On the hd is a tube carrying the vessel E with an
air-ejector, E. When this ejector is set to work, after the

22 OIL COLOURS AND PRINTERS* INKS.

kettle has been two thirds filled with oil, .it causes a vacuum
to. form over the oil. As this vacuum is produced air forces
its way through the oil by means of the tube L. About the
same time steam is passed through the coil. Hence the oil
is heated, stirred, and brought into intimate contact with
atmospheric oxygen all at the same time. The heat removes
any water present with the oil, while the oxygen acts upon
it chemically.

Oil treated by this apparatus becomes as clear and pure
as if it had been through the processes carried out in a
regular oil refinery. The apparatus can be used with direct
as well as with indirect steam. The precipitates settle quickly
and can be drawn off through the cock Z. The water left
with the oil can readily be evaporated by setting the ejector
to work. A specially interesting feature of this apparatus is
that a higher temperature is reached in it than can be ob-
tained with the steam coil. This is due to the friction of the
oil particles among one another, just as a rise of temperature
is got by shaking a liquid.

CHAPTEE V.

CHEMICAL PURIFICATION OP LINSEED OIL.

Fob purifying linseed oil we use sulphuric and hydrochloric
acids, alum, common salt, bichromate of potash, permanganate
of potash, etc.

Take for 300-400 kilos, of linseed oil 1 kilo, of fuming sul-
phuric acid, and add it to the oil in a thin stream and with
constant stirring. Then add to the oil a third of its weight
of boiling water, stir thoroughly once more, and allow the
mass to stand. When the oil has completely risen to the top
of the acid water, it is run off and mixed in another vessel
with 3 per cent, of dry common salt. The salt removes from
the oil the water which makes it turbid and nothing remains
but to filter the oil through a bag filled with bran. When
these bags are dirty the bran is used for fodder and the bags
are cleaned with Ume- water or potash lye. The water is not
added to the oil in the above process directly after the sul-
phuric acid, but after the oil and acid have remained together
overnight. This enables the sediment to settle well and to
consolidate at the bottom, so that the oil can easily be drawn
off clear. One should then dissolve for every 100 kilos, of
oil 250 grammes of common salt in 10 Utres of water, and
pour the solution as hot as possible into the decanted oil, and
stir for one or two hours, or as long as is necessary to form
a delicate white froth on the oil. The appearance of this
froth is a good sign, but it is also an indication that the
stirring must be stopped, or the oil will become dirty and

24 OIL COLOURS AND PRINTERS* INKS.

thick and never get dear. If we now leave the oil for about
two days in a fairly warm place it separates perfectly bright
and clear. It is then filtered either through well-washed
and perfectly dry river sand or through felt hats with wide
crowns.

According to Evrard, oil is purified by shaking it up with
a dilute solution of caustic potash or soda, drawing off the
unsaponified oil which rises to the top, and shaking it with
water, and again allowing it to separate. Wagner considers
that zinc chloride may be substituted for sulphuric acid with
advantage. It is said to dissolve the mucilaginous bodies,
and in time to carbonise them, without affecting the oil. A
syrupy solution of chloride of zinc is shaken up with fifteen
times as much oil. The oil becomes turbid, but by treat-
ment with steam or warm water after standing again clears.
Tilchmann recommends sulphurous acid for purifying oil.
He passes the gas in a stream through the oil heated to 260°
C (?) 1 for four hours, and then drives off the acid present by
means of steam. The effect can be produced at lower
temperatures, but takes longer. Probably the sulphurous
acid becomes sulphuric in the linseed oil, and forms sulpho-
fatty acids. Another, and very excellent method, is to use
permanganate. The process is not only decidedly quick, but
partially bleaches the oil, which is an additional advantage.
The salt not only bleaches but destroys fragments of cellular
tissue, etc., and hence its purifying action. To purify 100
kilos, of linseed oil we prepare a solution of one kilo, of
crystallised permanganate in 30 kilos, of distilled water at
the ordinary temperature, and stir the solution into the oil.
Keep the mass stirred for two hours, and then leave it to
stand. The oil separates completely from the permanganate
solution in the course of a day or two, and can then be drawn
off, paler in colour than before, and free from all impurity.

^ The query is And^s's.

CHEMICAL PURIFICATION OF LINSEED OIL.

Combbet's Apparatus.

The apparatus of Eaymond Gombret enables us to combine
mechanical with chemical purification. In it thin streams of
oil are purified by passing through various solutions of salts.
The process is carried out in the cylinders B (figs. 5 and 6),
of which several are used, to permit of continuous working.

The oil is placed in the reservoir A and goes through a
pipe C and rose D into the tinned iron cyHnder B, which
opens above into another cylinder of larger diameter closed
by a lid. The cylinders contain water or solutions of
chemicals.

The tube C brings the oil to a T shaped tube, E, connected
with the steam pipe F for heating the solutions in the

OIL COLOURS AND PRINTERS INKS.

cylinders. The tube leading downwards with the cook C
serves to clean out the tube E. The rose distributes the oil
through the contents of the cylinder,
which rises through the Hquid to float
on the surface in the wide upper part
of the cylinder. Thence the oil can
be drawn off by the cock H, while
the cock J leads the oil to the next
cylinder or to the filter. The sur-
face of the liquid in the cyUnders can
be brought accurately to the height
of the cocks H and J by drawing it off
through the cock K or by adding more
through the tube L. The cylinder is
emptied by means of , M. The battery
of cylinders must be so arranged that
the bottom of the wide upper part of
the first is above the whole of the
second, and that the same relationship
subsists between the second and the
third, and so on, so that the oil may
flow through the battery by its own
weight. It is led by a pipe after
leaving the last cylinder into the
filtering apparatus. It is a very good
plan to insert a small rotatory pump
N in the tubes J and C, so as to in-
crease the velocity of the oil as it enters
the cylinder, and if necessary to drive
the purified oil through a tube O, fixed
to the cock D, back to the bottom of
the same cylinder.
By this process we are enabled to use the various chemicals
applicable to the purification of oil, such as sulphuric acid.

Fig. 6.

CHEMICAL PURIFICATION OF LINSEED OIL. 27

ohromic acid, manganic acid, sulphites, etc., according to the
effect they are to produce.

For certain purposes, e,g,y in the preparation of extra pale
oils for white pigments, the foregoing processes are insuf-
ficient, and bleaching must be resorted to in addition to
them, as they affect the yellow colour of the oil only imper-
fectly or not at all.

CHAPTEB VI.

BLEACHING LINSEED OIL.

BiiEACHiNQ may be natural or artificial, that is to say it may
be done by the action of the sun or with chemicals, and the
natural method is distinguished by its name from the more
rapid process of chemical bleaching.

Sun Bleaching.

Schadler says in his Technologie den Oele und Fette, speak-
ing of bleaching and the action of various bleaching agents :
" The usual chemical action of light is to separate oxygen
from various bodies, for light promotes the combination of
atmospheric oxygen with the hydrogen and carbon of the
organic substance of the dyes, whereby the latter are usually
destroyed or changed into lighter shades. In many cases
the special action of Ught may depend on its promoting the
formation of ozone or peroxide of hydrogen, which when
formed oxidise the colouring matters more easily than the
oxygen of the air. The most powerful bleaching action is
naturally exerted by the light of the sun. For chemical
bleaching many various things are used, but all may be
reduced to the action of ozone, peroxide of hydrogen,
chlorine, and sulphurous acid. The first two act by oxida-
tion. Chlorine removes hjdrogen, forming hydrochloric acid
and replaces it by itself. Sulphurous acid forms a colourless
compound with the colouring matter."

To carry out oil-bleaching by the sun on a large scale, we
use wooden vats Hned with zinc, or make the vessels entirely

BLEACHING LINSEED OIL. 29

of lead. In the latter case, the increased durability of the
receptacles under constant use well repays the extra initial
cost. These vessels are best made one metre long by half
that width, and 15 to 20 cm. deep. They must be provided
with well-fitting hds, so as to protect the oil from rain. The
lid has a large pane of glass in it, and is slightly slanted for
rain to run off it easily by having one of the sides of the
vessel 2 to 3 cm. higher than the other. It is also of im-
portance that air should have free access to the oil. Hence
two tubes open at both ends are put through the sides of the
vessel, opposite each other, so that a constant current of
fresh air is supplied to the oil. In the course of a fortnight
the oil in the vessels will become quite white and clear, and
only requires to be drawn off. The sediment can be added
to common oil for boiling. To accelerate the operation
chemicals may be added to the oil. For example, a small
addition of 96 per cent, spirit is of great advantage, and the
action soon becomes noticeable. Linseed oil is almost always
mixed with ferrous sulphate, peroxide of manganese, or
hydrochloric acid, to hasten the bleaching.

Eapid bleaching can also be effected in rooms of which
the atmosphere is kept full of ozone by electrical apparatus,
or by keeping sticks of damp phosphorus about.

Peroxide Bleaching.

Peroxide of hydrogen, which is now made on a large scale
in many chemical factories, and put on the market in the
form of a 10 per cent, solution, is a good medium for oil
bleaching, as it only requires to be well shaken up with the
oil, and bleaches it in a few days. The bleached oil also
separates very readily and completely from the peroxide
solution and can easily be drawn off. For linseed oil 5 per
cent, of its weight of 10 per cent, peroxide is enough.
Bleaching with permanganate, manganate or bichromate of

30 OIL COLOUBS AND PBINTEBS' INKS.

potash depends upon the action of ozone. The bleaching is
done in large wooden vessels lined with lead, and provided
with a stirrer and a heating coil. A solution of permanganate
or bichromate made strongly acid with sulphuric acid is
gradually stirred in, and the stirring is then continued for
thirty to sixty minutes longer, unless the bleaching is finished
sooner. Then after standing six to twelve hours the oils
will have risen clear above the green chrome alum-containing
or brown manganese alum-containing solution. The acid
liquid is run off and the oil is washed two or three times
with warm water and left to stand. The clear oil is then
ladled off. Between the clear oil and the water, a layer of
emulsion will be found. This is best treated with 10 to 15
per cent, of petroleum-ether, which at once separates the oil
in it from the water. The ether is recovered by distillation
after enough of it has been collected from several bleaching
operations, and is used over again for the same purpose.
One hundred kilos, of linseed oil require from 600 to 600
grammes of bichromate or permanganate, together with twice
the quantity of sulphuric acid. The acid is diluted with five
to six times its bulk of water before use.

Sulphuric Acid Bleaching.

For bleaching with sulphuric acid, we take a litre of the
acid for 100 kilos, of oil, first diluted with 30 litres of water.
The whole mixture having been warmed up by the steam
coil is additioned gradually with very finely powdered per-
oxide of manganese, till the at first brown mass has nearly
turned white. At the close, the oil is washed, and then
treated as before directed.

Sulphurous Acid Bleaching.

As all fats, even linseed oil, are much attacked in bleaching
by chlorine, I consider the method quite inapplicable, and
proceed to discuss bleaching with sulphurous acid. For this

BLEACHING LINSEED OIL.

we use the cheap acid sodium
bisulphite, a concentrated solu-
tion of which shaken up with
the oil is of great service. But
to bring all the sulphurous acid
present into play we also add
dilute sulphuric acid. This is
done on a large scale in vats
lined with lead. For a metric
hundredweight ^ of linseed oil
from 1 to li kilo, of the
bisulphite is required. The
sulphuric acid must be added
in excess, but very gradually.
If the acid is put in too quickly
the sulphurous acid is evolved
so rapidly that it escapes with-
out doing any work.

According to Schadler, Kort-
ing's aspirator or a steam aspi-
rator is very suitable for use in
bleaching with sulphurous acid.

The steam apparatus (fig. 7)
is made of hard lead. The
high pressure steam enters it
as shown by the arrow, and
passes inside through a number
of hollow cones. This sucks in
the air at high velocity and
drives it out from another
opening.

This apparatus can be used
to produce either suction or
pressure, i.e., to rarefy or com-
press air, according to require-

1 About llOi lb.

Fia. 7.

OIL COLOUBS AND PBINTERS INKS.

ment. It is so constructed that with a steam pressure of
three atmospheres it will control by suction a water column
of 3 to 8 metres and one of 3 to 4 metres by pressure.

In fig. 8 an air aspirator is shown fixed to the top of a vat

ii^

••m

spp

Fig. 8.

containing the oil to be bleached. It sucks, through the
pipe and a perforated coil, sulphurous acid, which passes
through the oil in an extremely finely divided state, till the
bleaching is perfect. The vat must of course be closed and

BLEACHING LINSEED OIL. 33

air-tight. The sulphurous acid is generated in a very simply
built stove by burning sulphur in a draught of air, also pro-
duced by the aspirator which draws the gas into the oil. A
steam valve is provided to regulate the rate at which the gas
passes through the vat. The apparatus works very reliably
indeed, and can be used even with viscid oils. The oil is
finally rinsed from the acid by the methods already described.

CHAPTBB VII.

OXIDISING AGENTS FOR BOILED OIL MAKING.

According to the principle established by Mulder, that to
give hnseed oil good drying properties it must be acted upon
by oxygen at a high temperature, oxidising agents play no
small part in the manufacture of boiled oil. How long we
remained in ignorance as to the nature of the substances to
be used is sufficiently shown by the fact that both text-books
and old oil- boilers recommend the use of such driers as fish
bones, whiting, onions, garlic, verdigris, lime, tin, lead, alum,
ferrous hydrate, etc. All these substances are utterly useless,
and the progress of chemistry has taught us that the follow-
ing are the agents which can be employed with success in
making boiled oil : atmospheric oxygen, red lead, litharge,
suboxide of lead, sugar of lead, manganous borate, acetate
and oxalate and the Hnoleates of lead and manganese.

I can pass over these substances as they are already well
known, and will only mention that very lately attempts have
been made to abandon the oxidation of hnseed oil by heating
in it certain compounds of lead or manganese which decom-
pose at a particular temperature, and to use nothing but
oxygen or ozone. The reason of this change of front is that
the metaUic driers always darken the oil more or less, which
is for many purposes a very great drawback. In a subsequent
part of this work several proposals of this nature will be
exhaustively discussed. Here I will content myself with
describing some new linoleate driers.

Among the many drawbacks involved in the use of the

OXIDISING AGENTS FOR BOILED OIL MAKING. 35

ordinary chemicals employed in making boiled oil, such
as litharge, lead acetate, red lead, peroxide of manganese,
manganous borate or hydrate, etc., one is that they never de-
compose completely. Hence quantities of them are wasted.
Again, the boiled oil made with them is hard to clarify. They
remain long suspended in the oil. These evils have insti-
gated a search for new driers, among which the Hnoleates
deserve special mention.

But before I discuss these new driers fully, I will make
some remarks on hnoleic acid, which is the chief constituent
of linseed oil, from Schadler's much-quoted work.

Linoleic acid (C^g H27 HO), or according to K. Peter's
Gig H32 O, is called linolein by Mulder. It and its salts are
little known, on account of their instability. To make it,
linseed or poppy oil is completely saponified with caustic
soda lye, and the soap is purified by repeated relarging.
The soap is dissolved in an excess of water and precipitated
by calcium chloride. The lime salts of the fatty acids thus
thrown down are washed with water, drained, pressed to get
rid of most of the water, and treated with ether. This
dissolves only the linoleate, thus separating it from the other
lime salts. The ethereal solution is mixed with cold dilute
hydrochloric acid, when linoleic acid is set free and remains
dissolved in the ether floating on the watery liquid.

The solution of Hnoleic acid in ether is decanted, and the
ether is distilled off in a stream of hydrogen at the lowest
possible temperature. The residue is dark yellow and is
impure Hnoleic acid. It is dissolved in alcohol and pre-
cipitated as barium Hnoleate with chloride of barium and
aiiimonia. The precipitate is washed, drained, pressed,
dissolved in ether, and crystalHsed from ether several times.
The pure crystals of barium Hnoleate are then shaken up
with, ether and dilute hydrochloric acid and the ethereal
solution of Hnoleic acid is distilled in hydrogen as above
described. The linoleic acid, which does not distil off, is

36 OIL COLOURS AND PRINTERS* INKS.

dried in a desiccator over sulphuric acid and a mixture of
lime and ferrous sulphate. The sulphate is to absorb oxygen,
and prevent oxidation of the linoleic acid. A nearly pure
linoleic acid is got by decomposing lead linoleate with
sulphuretted hydrogen, and dissolving the linoleic acid from
the lead sulphide with ether.

Linoleic acid is a thin, pale yellow oil, of -9206 sp. gr.
at 15° C, with a high refractive index, and a weak acid
reaction. It has a mild taste, followed by a rough after-
taste. It is still liquid at - 18° C. It is insoluble in water,
but freely soluble in alcohol or ether. On exposure to the
air it greedily absorbs oxygen to the extent of about 2 per
cent, of its weight, thereby becoming tough and thick like a
varnish. Thin layers of it dry on wood in the air, but on
glass never become quite dry. Linoleic acid is not volatile
without decomposition and on distillation gives different
products from oleic acid. No sebacic acid is then formed.
Nitrous acid thickens linoleic acid, but causes no separation
of crystals of elaidic or any related acid. Nitric acid forms
a slimy resinous mass with much frothing.

New Driers — Linoleates.

It is difficult to produce pure linoleates, because they readily
decompose, forming acid salts. They are white, for the most
part uncrystalhsable, and separate out in flakes on cooling
from solution in hot alcohol or ether. By spontaneous
evaporation a jelly is left. These salts turn brown in the
air and acquire a characteristic odour.

Manganous linoleate is sold by Dr. J. Wilhelmi of Keudnitz-
Leipzig in the form of a pale brown solid. This is really a
solid manganese soap, and serves for the preparation of all
manner of liquid siccatives. According to Wilhelmi* s direc-
tions for the preparation of a well-drying boiled oil 100 lb.
of raw linseed oil are kept at about 150° C. for five hours, with '

OXIDISING AGENTS FOE BOILED OIL MAKING. 37

1 lb. of the manganous linoleate, previously dissolved in a
little linseed oil. When cold, the mass, if painted thin on
glass, dries quite hard within twenty-four hours. The doctor's
factory also supplies a Uquid drier, which will at once produce
a clear pale yellow oil.

Dr. Wilhelmi is said to have discovered that the formation
of boiled oil is not (?) ^ due to oxidation, but to a solution of
the manganese in the oil, and for this reason adds a soUd
compound of hnseed oil with manganese to the boiling raw
oil, using the manganese compound as a carrier of oxygen.

Another new sort of drier for making boiled oil quickly has
been lately made by Dr. Hohn & Co. of Dusseldorf in the
form of

Soluble Manganese and Lead Preparations,

two sorts of the former and one of the latter.

The manganese preparation No. 1 is the richer in man-
ganese and therefore the more active of the two. It is,
however, darker than No. 2, which has no influence on the
colour of the hnseed oil. The manganese preparations have
distinct advantages over the usual insoluble ones at present
on the market. By virtue of their solubility their high per-
centage of manganese is made fully available, the manganese
is completely taken up by the oil and dissolved clear, so that
even small quantities of the drier give well-drying oils which
remain clear, and require no keeping in stock.

As the preparations make quite clear solutions, any required
proportion of manganese can be added to the oil, while in
using insoluble or only partially soluble preparations of
manganese we must always remain in doubt whether the
oil has taken up exactly the desired amount of manganese.
The preparations dissolved at low temperatures, and mere
fractions of the quantities of manganese hitherto required are
suflBcient to make the oil fully drying.

^ The ^uery is And^s'g,

38 OIL COLOURS AND PRINTERS* INKS.

To get a good drying oil we proceed as follows : The linseed
oil is heated to 120° to 140° C, and then 1 per cent, of
manganese preparation No. 1, or i to 2 per cent, of manga-
nese preparation No. 2, is added with constant stirring. The
oil froths at first, but this soon ceases, and when it does the
oil is ready. If the lead preparation is also used, we take 1
per cent, of it together with J to J per cent, of manganese
preparation No. 1, or J to f per cent, of manganese prepara-
tion No. 2. The result dries well and gives a specially hard
coat.

If I make some more remarks here on the method of adding
driers, I do so in order to combat erroneous notions.

Formerly it was beheved that the drier ought not to come
into contact with the oil, so that it was hung in the oil in
linen bags, often in an unpowdered state. As, however, the
oxidising substance was exposed to the oil in a compact mass,
it was impossible to oxidise the oil properly. The parts of
the substance nearest the sides of the bag certainly parted
with their oxygen, but the inside of the mass remained un-
changed, so that the oil got too Uttle oxygen, and the result
was naturally very inferior. The oxidising chemicals added
to the oil cannot act powerfully unless offering the greatest
possible surface to it, i.e., unless in the finest possible powder,
so that every particle of it comes into contact with the hot oil
If these preparations are added to the hot oil, the evolution
of oxygen is visible, and extraordinarily rapid and energetic.
The oil froths tremendously and will easily boil over if care
is not taken. Trials with large quantities of oil have con-
vinced me that driers had a greater effect on the drjdng
qualities of the oil when added to the hot oil than if put
into the cold oil and heated up with it. It is of course
necessary to add them to the hot oil a Httle at a time, or else
the pan boils over, with great waste of oil and danger of
fire.

The (quantities of single driers which are required to make

OXIDISING AGENTS FOR BOILED OIL MAKING. 39

a good boiled oil depend, firstly, on the nature of the oil, and,
secondly, upon the amount of drying power required. In
general, we require less of a manganese preparation than of
a lead one, which is less energetic. The usual amounts
necessary are : —

Per cent.
Manganese preparations 1-lJ

Lead preparations ' 3-5

they being kept with the oil at a boiling temperature for three
hours ; then we shall get an oil drying within thirty-six
hours. For quicker drying, larger proportions must be taken
than those just given, and the percentages may rise for
manganese preparations to 2 to 3 per cent., for lead prepara-
tions to 5 to 8 per cent., and the boiling time to 5 to 8 hours.
A further increase of the quantity of drier is impracticable,
as larger amounts would partially saponify the oil. If other
preparations, e.^., peroxide of manganese, are used, the above
percentages must be increased in order to make up for the
diminished amount of manganese in the drier.

CHAPTEE VIII.

THEORY OF OIL-BOILING.

The Dutch chemist Mulder was the first to occupy himself
seriously with the drying oils, and the changes they undergo
on drying and boiling, and we have to thank him for some
knowledge of the theory of the preparation of boiled oil.

Linoleic acid forms about 80 per cent, of linseed oil, as
already stated. When a great surface of it is exposed to the
atmosphere it readily becomes oxidised to linoxic acid, a
change which is rapid or slow in proportion to the freedom
or the reverse with which air has access to the oil. The
oxidation is accelerated if the oil is heated while in contact
with oxygen, and we may proceed in three ways, acting on the
oil with pure oxygen, or with air from which the oil absorbs
that gas, or with metallic oxides or other compounds rich in
oxygen. The oxidised linoleic acid thus obtained is the chief
cause of the drying properties of all boiled hnseed oils. If
linseed oil is boiled by itself in a wide shallow vessel, it becomes
better drying than before by taking up oxygen, and if linseed
oil is exposed for a long time to the air without being heated
its drying properties are again somewhat increased, but never
to the same extent as with boihng. It follows that to get dry-
ing linseed oil a high temperature is required, and at the same
time the action of oxygen in some form.

Boiling linseed oil sets free more or less of its glycerine,
and time and Ught and oxygen have a similar action. It is
clear that boiling must begin, promote, and finally complete
the separation, leaving behind more or less free linoleic acid.

THEORY OF OIL-BOILING. 41

Every drying oil has its drying power increased by boiling,
and it would appear that such is the more the case the
longer the boiling has been kept up.

In this boiling three different processes are involved: 1.
All the anhydride of linoleic acid present in boiled oil does
not need to dry, it is dry, elastic, and can dry no more. 2.
All the free linoleic acid still present turns later to linoxic
acid, which dries very slowly. 3. All the imchanged linoleine
still present dries later to linoxine. The anhydrite gives an
elastic india-rubber-like coat, the second resembles turpentine,
and the third coat is like leather.

Boiled linseed oil then in the main is more or less decom-
posed Unoleine, containing the anhydride of linoleic acid,
while glycerine is still combined in the imdecomposed part
of the linoleine. In proportion to the duration of the boil
there will be more or less oleine, palmitine and myristine
present.

In making boiled oil for ordinary painting we have first in
view the necessity of obtaining a product which will dry as
quickly and as hard as possible. This result is obtained, not
when the boiUng oil is acted on with air or oxygen, but with
oxidising compounds. By oxidation of the linoleic acid to
linoxyn, and by compounds of linoleic acid the oil becomes
rapidly hard drying, and if we boil linseed oil with red lead,
sugar of lead, or litharge we get more or less linoleate of lead
formed, and Hnoleate of manganese if we boil it with com-
pounds of manganese. If we examine these salts, we find
that linoleate of lead is a hard pulverisable substance, while
manganese linoleate is tough and elastic. These circum-
stances have to be noted by any one who wishes his boiled
oil to answer the purpose for which it is intended.

The researches of Mulder have shown that the formation
of boiled oil proceeds —

1. From the setting free of a part of the linoleic acid and
other fatty acids of the linseed oil,

42 OIL COLOUBS AND PRINTERS* INKS.

2. From the formation of salts of the fatty acids by the
bases of the driers.

3. From the formation, or the creation of the possibility of
the formation, of anhydride of linoleic acid.

4. From the co-operation of two or more of the above.
Every drying oil will give, without special treatment, the
leathery linoxyn and free fatty acid, which are more quickly
formed by boiling the oil.

CHAPTEK IX.
MANUFACTURE OF BOILED OIL.

The theory of this and a description of the various driers
have already been given, and I can therefore now proceed
to a minute description of the processes.

Boiling over the Open Fire or with Steam.

Boiled oil can be made from ordinary mercantile oil,
after the usual lying by, by boiling in iron or copper pans
over an open fire or by means of steam. Care should be
taken that the form of the pan is such that the oil offers
as much surface as possible to the air. Otherwise the
shape is immaterial. The size of the boiling vessels
depends on the scale in which the manufacture is carried
out, and all sorts and sizes are in use, from those of
a capacity of 50 kilos, only to those holding 1,000 kilos.
Small vessels are usually so arranged that they can easily
be lifted off the fire, while the larger ones are bricked-
in and provided with special safeguards against accidental
fire, or flie boiling over of the oil. Among the safeguards
against fire may be mentioned heavy iron lids, which are
slung to the roof of the boiling house and are lowered
from above, so as to close the mouths of the vessels if
a conflagration is started and put out the flames by ex-
cluding the air. Another plan is to provide means whereby
the oil can be run off from the bottom of the pan to
a cold receptacle at some distance. The arrangements
directed q^gainst a boiling over of the oil, and especially
a^inst any that may boil over finding its way into th^

44 OIL COLOURS AND PRINTERS* INKS.

fire, consist in a gutter surrounding the mouth of the
pan, which catches the oil that overflows, and from which
the overflow is led away by a pipe. Another way is to
have the pan so large that there is no necessity to fill
more than two-thirds with oil, and to brick it in so that
the fire has no access to the empty part of the kettle,
and that no oil which boils over can get into the fire.
The pan can also be provided with a head from which
a pipe leads the vapours into a chimney, where a small
fire is maintained in order to burn them.

The highest temperature which should be used in making
boiled oil by means of the driers, specially mentioned above,
is 230° to 250° C. A heat above this makes the oil too
dark in colour. According to my latest experience, I re-
commend the following boiling method for all boiled linseed
oil, whatever driers may be being boiled with them. The
linseed oil is heated, at first slowly, then more quickly,
until it begins to froth. It is then quickly brought to the
maximum temperature, at which its original golden yellow
colour turns to a pale greenish yellow. Either the kettle
is now lifted off the fire, or the fire is drawn, and the oil
is allowed to cool to 130° to 150° C. At this temperature
the desired driers are added in proper quantities, a little
at a time. The boiling is then resumed until the oil is
ready, and has the proper drying power. Care must be
taken to keep the temperature between the limits, neither
below 230° nor above 250°. This process gives pale boiled
oil under all circumstances, while the ordinary method
usually darkens the oil by the time it is ready.

However the boiling has been conducted the oil must
be left to stand at the conclusion of the operation, in order
that the organic matter carbonised by the boiling and any
undissolved driers may separate out, and settle to the
bottom. As long as the oil is hot it is thin, and the
specifically heavier bodies suspended in it, whatever may

MANUFACTURE OF BOILED OIL. 45

be their state of subdivision, will separate from it then much
more readily than when it thickens on cooling. The sedi-
ment consists of original impurities as well as substances
added during or formed by the boiling, and the amount
of it is naturally various for those reasons. It averages
however from 5 to 8 per cent. Its colour depends on the
quahty of oil used and may be white, yellowish, dark green
or even black. According to my experience, white or yellow
sediment is a mark of an inferior oil having been used.
The sediment from a good oil is dark coloured, and should
show no granular or crystalline structure. The drying
power of the sediment, which constitutes the only loss if
the oil has not been heated above 220° C, is very great
indeed, on account of its richness in driers, so that it is
used for numerous purposes.

It is specially advantageous to substitute steam for a naked
fire in the preparation of boiled oil, and if the use of steam
for this purpose is not yet so common as it ought to be, the
reason is that it does not pay to provide steam for this purpose
alone. There must be a steam-engine, and hence the method
is only practicable in places where much capital is or can be
sunk in plant. Steam-boiling of oil is mostly practised in
jacketed pans, but occasionally by means of a steam coil.
The latter has the disadvantage as compared with the former
arrangement that it is very difl&cult with it to get a high
enough temperature. According to the construction of the
apparatus the steam is or is not superheated. In the latter
case its use is attended with difficulties and dangers, but
most oil-boiUng factories are nowadays worked with super/-
heated steam, so much has the management of it improved
of late years.

One of the most simple plants consists of a pan, wider than
it is deep, and made of strong boiler-plate, and which has
been tested to a pressure of from four and a half to five
atmospheres, and has a double bottom. The pan is provided

46 OIL COLOURS AND PRINTERS* INKS.

with a safety valve, an inlet and an outlet pipe for steam,
and a pipe for running off condensed steam from the jacket.
The pan is filled with oil and steam is passed through the
jacket at a steady pressure of four and a half to five atmo-
spheres. An improved form of this apparatus has a steam
coil in the oil, as well as a jacket, and also a mechanical
stirrer, so as to increase the surface which the oil exposes to
the air.

Another plan is to superheat steam by means of an ordinary
superheater or system of piping, and then to blow it direct
through the oil to be boiled. The temperature of the steam
must of course be known and be carefully regulated.

Zwieger's Process.

H. Zwieger of Zwickau has patented in Austria Hungary
(No. 1,768) a process for making boiled oil and oil varnishes,
in which the steam proceeding from the fusion apparatus at
about 350° C. is used for boiling.

Lehmann's Superheater.

The process of Holzwich and Zimmermann (D.R.P. 9,444),
which shall be specially mentioned later on in tins section,
has lately been improved by R. Lehmann of Dresden.
Lehmann uses steam superheaters of the following con^strue^
tion. In contrast to most or perhaps all the older tjrpes,
consisting either of sets of tubes connected by elbows or
stuffing boxes, or coils welded together into a single piece,
Lehmann uses in his improved superheater elastic joints so
that the superheater can expand in the fire without risk of
becoming cracked or leaky at the joints. Each tube is double,
i.e., consists of two co-axial tubes. The inner tube opens
near one end of the outer, which is closed. The steam flows
from one inner tube into the tube surrounding it, from -that
into the next inner tube, then into the tube surrounding that.

MANUFACTURE OF BOILED OIL.

and so on. This increases the exposure of the steam in tha
superheater to twice the usual amount without increasing

Fig. 9b.

the^ number of tubes or the space occupied by the apparatus.
In other words, this superheater combines great heating

48 OIL COLOURS AND PRINTERS* INKS.

surface with economy of space, and hence of fuel, while at
the same time that the construction secures those advantages
it improves the superheating effect, and makes the substitu-
tion of fresh parts in case of accidents very easy.

Fig. 9 shows Lehmann's superheater arranged below the
boiling kettle, so that the gases which have heated the
superheater can help to heat the oil before they finally pass
into the chimney.

Andres' Process.

According to Andres, it is unnecessary in boiled-oil making
to use steam, as hot air will do as well. If his method is to
be adopted a fan is used to drive a stream of air through a
superheater, then through the oil, and thence back to the
fan, and so round and round, always working with the same
lot of air.

Walton's Process.

According to an English patent by F. Walton, the inventor
of linoleum, a process for boiling oil consists in heating the
linseed oil in wide open pans by steam. It is then raised
into a chamber heated by steam, where it is beaten by paddle
wheels. Being thus scattered through the air in drops, it
offers a very large surface for the absorption of oxygen. The
chamber may have glass windows so that the light of the
sun may co-operate in producing the effect. The oil finally
collects in a gutter on the floor of the chamber, whence it
can be returned to the pans if more heating is still required.

Vincent's Process.

Vincent's apparatus for boiling oil by steam is a pan, pre-
ferably of copper, with a circular transverse section. Its
depth is about the same as its diameter, and its bottom is
convex. Up to its middle the pan is surrounded by a strong
iron jacket for the admission of steam. Both pan and jacket

MANUFACTUBB OF BOILED OIL. 49

must be capable of standing a pressure of eight atmospheres.
The mouth of the pan is closed by a head provided with a
manhole. Through a stufl&ng box in the middle of the head
passes a vertical hollow cylinder with a solid one inside it.
These rotate in opposite directions, and operate the stirrers
which work up the oil. The combustible vapours escaping
from the hot oil are led beneath the pan to economise fuel.

The oil to be boiled, which is first stocked for some time
in large vats, is heated to about 35° C, and then pumpisd
into, the pan. Full steam is then turned into the jacket,
and the stirrer is set in motion. When the pressure has
risen to two to three atmospheres, air is admitted. The oil
immediately froths and swells up greatly, and the mass
previously a dark brown becomes a pale yellow. If a darker
oil is wanted the driers — the choice of which is generally
regarded as a secret — ^are rubbed up with oil and poured into
the pan in a thin stream through a funnel. The proportion
is 375 grammes of driers to every 50 kilos, of oil. When the
driers have been added, nothing more has to be done but to
see that the steam pressure does not sink below six atmo-
spheres. It is best to keep it at seven atmospheres, so that
the air pump which drives the air through the oil, and also
the stirrers, may not stop. Vincent has not ascertained how
much air is necessary to oxidise any given quantity of oil.
Some oils, as a matter of fact, require more air than others,
but the usual course is to drive in as much as the oil will
take up without priming and coming over into the tube
which leads away the vapours caused by the heating. After
treatment for about four hours the oil can be run out of the
pan into a vat in which it is allowed to stand until it has
completely deposited all sediment.

SCHRADER AND DUMEKE*S PROCESS.

Drs. Schrader and Dumeke have made numerous re-
searches, as a result of which they have discovered that

50 OIL COLOUBS AND PRINTERS* INKS.

ozone, after a brief contact with raw linseed oil, not only
converts it into ** boiled oil," but bleaches it at the same
time. The ozonised oil is completely bleached by a single
day's exposure to light and air in shallow vessels. The
" boiled oil " thus prepared from raw unbleached linseed oil
is said to be as colouriess as water, to dry quickly, and to be
made without heat and with perfect safety, and without any
loss or waste. The ozone is aspirated or forced through the
oil in suitable vessels, and can be prepared by any of the
known processes.

MtjTHBL AND LuTKE's PROCESS.

The patent of Miithel and Liitke (D.E.P. 29,961) protects
the manufacture of boiled oil by treating the raw oil with
various gases, which will give nascent oxygen on electrolysis.
Such mixtures are chlorine and steam, sulphurous and nitrous
acids, nitrogen, oxygen and steam and nitrous oxide and air.
One of these mixtures is exposed in the apparatus shown in
fig. 10 to a long and powerful silent dark electrical discharge,
whereby a high degree of oxidation is given to the oil, if the
quantity of gas is sufficient. It is impossible to give an
exact chemical formula of the product formed, as it depends
on the gaseous mixture used, and on the proportions of its
ingredients. Thus if chlorine and steam are used we get
hydrochloric acid and oxygen, and with oxygen and sulphur-
ous acid they must be present in such proportions that the
electrical discharge can produce SO. It appears to be ad-
vantageous, as giving the highest oxidation, to have the
oxygen-compound in the gaseous mixture in excess. The
apparatus used by the inventors to prepare the oxidised
gases consists of a series of so-called condensers, in which
the gases are exposed to the electrical action for a very long
time, see figs. 10 and 11.

The electricity is produced by a dynamo, into the circuit

MANUFACTUEE OF BOILED OIL.

of which the primary coil of the induction apparatus is
inserted. The secondary coil is connected up with the
condensers, which are arranged according to the E.M.F.
required. Fig. 10 shows the complete plant. From the
steam boiler A a main pipe takes to the cylinder of the steam
engine; from a two branches, h and c proceed. Steam is
carried by h to the coil S in the container B, to heat the

oil therein which is admitted by the pipe c. At the bottom
of B is a flattened coil D, full of perforations, and which is
continued to form the tube g. This tube communicates
with the oxidation apparatus P, to which the gas to be
oxidised is brought by the pipe h. Fig. 11 represents an

OIL COLOURS AND PRINTERS INKS.

oxidation apparatus in detail. It is made of glass and con*
sists of two tubes, A and B, one inside the other. The two
are fixed together hj x x. A is closed below and is enclosed
in an iron vessel C, and rests on the somewhat projecting
rim of the latter. The axis of B is occupied by a tube E,
which opens into the space between A and B and brings in
the gas to be oxidised. The gas then passes out through D
into another oxidiser, and so through the entire battery.
The parts shaded in the figure are filled with any good con-

FlG. 11.

ducting material, and connected with the dynamo by the
wires + and - . In fig. 11 the apparatus is represented
diagrammatically only. The boiler B contains one or more
paddle wheels C, on an axle passing through a stuffing box
at a?.

The practical carrying out of the process is as follows :
When the apparatus is set to work B is half filled with the
linseed oil to be oxidised, by means of c ; e is then shut, and
the oil is heated by means of the steam coil to from 60° to
80" C. The vessel B is then connected up, by mean^ of d^

MANUFACTUBE OF BOILED OIL. 53

with the air-pump, which will give a 73 mm. vacuum. The
oxidation apparatus is next put into the dynamo-circuit,
while a mixture of sulphurous acid (SOg) with oxygen and
air in equal volumes is passing through it. At the same
time g is opened, so that the gas oxidised in P is driven
through the linseed oil in fine streams, these being a partial
vacuum above the oil. All the time the gas is passing the
paddle' wheel is at work, making the oil expose as much
surface to the gas as possible by energetically stirring it up.
This greatly accelerates the decomposition of the compounds
of the fatty acids, and in a correspondingly short time we
get a pale thinly flowing product, which readily dries in the
air to a tough and soHd mass. The same success attends
the use of a mixture of nitrous oxide (NgO) with three-
quarters of its volume of. atmospheric air, or of nitrous oxide
alone.

The use of the other gaseous mixtures above mentioned
may also be resorted to, and the patentees keep them before
them, as it is a question of producing from any suitable
materials, and by means of the silent electrical discharge,
either nascent oxygen or highly oxidising compounds of
oxygen, the latter being decomposed by contact with the hot
oil. The products of decomposition pass away through the
air pump together with a little unused gaseous mixture, and
the whole can either be regenerated or used to help the firing
of the steam boiler. When the oxidation is finished, a point
which is ascertained by taking samples from time to time,
the pipe is closed, the stirrer is stopped, and a short time
afterwards the pipe d is closed and E is opened. Steam
now enters the vacuum, and drives the boiled oil through/,
which is opened for the purpose, into the apparatus, W,
which is itself full of very dilute ammonia, and is heated by
the coil S' which is fed by the exhaust from S. The oil
passes up through this ammoniacal water, which frees it
from any adhering acid. It then passes direct through h

OIL COLOUBS AND PRINTERS INKS.

into the stock vats. It may pass through a refrigerating
apparatus on its way thither if it is preferred that it should
do so.

ZiMMEBMANN AND HoLZWICH'S PbOGESS.

All apparatus or utensils which come into contact either
with raw or with boiled linseed oil must be made of, or lined

Fig. 12.

with, lead, because we thereby save adding litharge to the oil
The linseed oil used must be of good pale quality, and have
been air bleached, if a pale boiled oil is expected. The boiled
oil is made by an apparatus represented in figures 12, 13 and
14. Fig. 12 is a bird's-eye view ; fig. 13 a vertical section,
and fig. 14 an elevation. The apparatus consists of three
main parts, viz,, (1) a box. A, of black sheet iron for heating
the linseed oil; (2) an iron receptacle, B, hned with lead;

MANUFACTUEE OF BOILED OIL.

and (3) two closed iron boilers, GG, lined with lead. The oil
flows from B through the cook F and the funnel g into
the uppermost box a, passes then through the opening G
into the box a directly underneath, and so through all the
boxes a a, etc., till it gets into the lowest box a. Thence
it passes through the tube dd, and the branch tube there -

Fig. 13. Fig. 14.

from, ddy which is provided with cocks, into one of the iron
cyUnders, GG, lying below. The air in this escapes by the
air-cock k, which must be kept open during the filling.
When such a boiler, G, is filled with linseed oil, the oil is
pumped back again up into the reservoir through the leaden
pipe e, and travels the circuit from A to G over and over
again, till converted into boiled oil. The pumping is done

56 OIL COLOUBS AND PEINTERS* INKS.

by compressed air, forced by an air-pump into the cylinder
of oil, arid which drives the latter up the tube ee. Two
boilers are hence necessary for continuous work, so that one
can be being pumped out while the other is being filled.
The combination of this apparatus with the mel-ting apparatus
is with the object of utilising the air, which escapes at x at
a temperature of still about 130° C. for heating the linseed
oil. This air passes through h into A, where it helps heat
up the oil passing through to the temperature required. We
recognise by the consistency of the oil arriving in B out of
C how far the process has gone, and whether the oil has to
be sent round again. The handles, h, in the sides of the box,
A, are stoppers, whereby it is made possible to inspect the
surfaces, a a, over which the linseed oil runs, and to clean
them when necessary. To lead off the vapours arising from
the boiling oil, which are bad for the eyes, we have the adjust-
able valve i, which leads these combustible gases into the
chimney.

A German Patent Process.

The object of this invention (D.E.P. 12,825) is to convert
linseed or other drying oil into boiled oil by exposing it to
the action of hot air until it has acquired a syrupy consistency.

Fig. 15 is the ground plan, fig. 16 a view and partly a
section of the apparatus used for the treatment of oil. AA is
a series of reservoirs to receive the oil. Each of these can
be supplied with hot air by the tubes BBB. These air tubes
are divided into radiating branches, which are so arranged
that they hang directly over the bottom of the reservoir,
without however touching it. These branch tubes are per-
forated, so that the air conveyed by them passes in thin
streams through the oil. The tubes B of the various reser-
voirs are connected with a tube, B', which is provided with
hot air straight from the coil C of the heater D.

The coil C is connected with a pressure pump E (a Eoot*s
blower is to be recommended), to drive the air on its course.

MANtJPACTUEE OF BOILED OIL.

OIL COLOUBS AND PBINTEBS IKKS.

MANtJFACTURB OP BOILED OIL. 59

T is a oook to regulate the amount of air supplied to the ooil
by the blower. G is a loaded safety valve ; the branch tubes,
BBB, are provided with similar cocks, F, for regulating the
supply of air to the individual oil reservoirs, and to cut off the
air from each as soon as the operation is concluded in it.
The cocks F and F are three-way cocks, of a construction
shown in fig. 17. They are so arranged that they can pass
either all or part of the air current away into the open air.

If, for example, all the reservoirs are in use together, the
supply of air must be at a maximum, and if the air is heated
to about 312° C. the cock F must be partly open. If the
temperature of the air issuing from the coil is above 312° C.
the cock must be wider open, so as to lead less of the air from
the blower into the exhaust-pipe F and more into the coil.
By this, taking more air into the heater, burning of the oil is

Fig. 17.

prevented. The temperature of the oil should never be above
206° C. It is most convenient so to arrange the process that
the oil in different reservoirs is in different stages of progress,
so that the reservoirs can be emptied singly and refilled when
the process is finished without interfering with the work of
others, and so a continuous action of the battery is ensured.
As soon as the treatment of the oil in one reservoir is finished,
the cook F' is turned, the supply of hot air is cut off, where-
by it is prevented that the temperature of the oil in the other

OIL COLOURS AND PRINTERS* INKS.

reservoirs should be made too great. If, for example, the
reservoirs contain 227 litres, so much hot air is passed into
it as will raise the temperature of the oil to about 120**
C. This temperature is kept up for about five hours, and
it is then raised to about 205°, taking care however that-
this latter temperature is not exceeded. It is maintained
in its t\im for from five to six hours, to drive off the sharp
vapours. As a sign of the conclusion of the process, the
cessation of the evolution of these fumes serves very well.
When they cease to come off, the oil thickens suddenly

Fig. 18.

to a syrupy consistency. When this point is reached, the
hot air is turned off, and the oil is run through the cock a
into the storage vat. When cold the oil is quite free from
the fatty substances and has the appearance of a pale jelly.
The vapours expelled consist principally of oleine. They
can be condensed and collected for the various uses of that
substance. Fig. 18 shows a modification of the pipe bring-
ing the hot air into the oil. Here the pipe ends in a T piece,
not perforated at the sides, but open at each end, so that the
hot air passes through ihe oil in two streams. This form is
used with oil-holders, which are about twice as long as they
are wide.

CHAPTER X.

ADULTERATIONS OF BOILED LINSEED OIL.

All boiled oils are subjected not only to a very large number
of different kinds of adulteration, but in their manufacture
such methods and processes can be resorted to as to have an
unfavourable effect on the quality of the oil, and are adopted
for various reasons, chiefly, of course, for the purpose of
diminishing the cost of production.

Good boiled oil can only be got by boiling pure stocked
linseed oil at a temperature not below 132° C. under the
action of oxygen. It is indifferent whether this temperature
is produced by a naked fire or by steam, and whether the
oxygen is added through the agency of chemical compounds
of oxygen, or by the introduction of air or pure oxygen.
Boiled oil is, as has been said more than once already,
oxidised linseed oil. It is in the main more or less decom*
posed linoleine containing the anhydride of linoleic acid, while
it contains glycerine in the undecomposed portion of the
linoleine. According to the duration of the boil there are
present more or less oleine, palmitine and myristine, and
the longer the boil the more the linoleine is changed into
linoxyn and the quicker the oil will dry. Hence the nature
of the boiled oil depends upon the boiUng time, and also on
the amount of oxygen incorporated with it both the rapidity
with which it dries and the durability of the coats which it
forms.

A good boiled oil must be somewhat thicker than the raw
oil, but must not be too thick, or it will become necessary to
thin it with oil of turpentine before it can be painted with in

62 OIL COLOURS AND PRINTERS' INKS.

thin coats. If it can only be applied thickly the coats never
dry through, and the paint is sure to crack sooner or later.

The colour of boiled oil depends on its manufacture, and as
a rule is pale or brownish yellow or reddish brown, never
dark brown. Boiled oils prepared with the help of steam
are usually paler than those boiled over a naked fire, and
are manganese-prepared oils more usually than lead-prepared
oils, and come nearest in colour to the products oxidised by
air or oxygen. The duration of the boil is also not without
influence on the colour. The longer the boil and the higher
the temperatiire the darker the oil, from the carbonisation of
the solid organic substances suspended in it.

Many makers of boiled oil heat the oil for too short a time,
to save expense of manufacture, and so put upon the market
a badly drjdng product. Such oil is generally very pale for
boiled oil, but dries nearly as slowly as the raw oil and does
not fulfil its purpose properly. Such a product can only be
detected by comparing the time it takes in drying with that
of an oil known to be satisfactory, by painting with both at
the same time and drying under the same conditions.

The smell of good boiled oil is that of linseed oil with a
slight scent of burning, such as that characterising the vapours
evolved from the boihng oil. It may be unpleasant but it
should in no case be nauseous, or have any resemblance to
the odour of resin oil or fish oil; if it has it is probably
adulterated with these oils, a conclusion which can be
confirmed by the tests given below. If the boiled oil has
been burnt by overheating, the fact betrays itself by an
empyreumatic and nauseous smell, and a dark and dirty
brown colour.

The taste is a good test of a boiled oil. In a gooJ oil,
except that it is bitter and more disagreeable, it resembles
that of the raw oil. Adulteration with fish or resin oil is
detected more quickly and certainly by the taste than in any
other way.

ADULTERATIONS OF BOILED LINSEED OIL. 63

Boiled oil must be clear, without being rendered turbid by
suspended solid matter. If it is not oleaj, it must be left for
at least a fortnight at perfect rest in a fairly weirm place. In
this time it will have become quite clear, unless it is adul-
terated with resin oil, and the amount of sediment will show
whether the oil is good or bad. Even well-stocked boiled
oil gradually deposits, but even after months the sediment
will not exceed i per cent., and is not worth taking into
account. Many makers, however, only give the boiled oil
time to clarify superficially, and sell it a few days after it is
made. Such oils come turbid to the consumer. They will
certainly clear if he will keep them for from two to four
weeks, but the amount of sediment may amount to 7 per
cent., and the boiled oil must be considered as of very inferior
quality.

The drying power is one of the chief tests of a boiled oil.
It ought to dry in thin coats on wood, glass, or metal, in
twenty-four hours to such a point that although still sticky
it cannot be wiped off, and in another twenty-four hours it
ought to have dtied solid, retaining, however, some elasticity
and softness. If it dries quicker than this, so much the
better, but if it dries slower, that is a sign that it has either
been improperly prepared, or that it is adulterated. It is
possible that it has never been boiled at all, but prepared by
cold processes, i.e., by being mixed with from 6 to 10 per
cent, of the so-called ** extract". Such a product has no
claim to be called boiled oil, for to make that a high tem-
perature and the addition of oxygen are both indispensable,
and cannot be replaced by mechanical admixture of the
linseed oil even with the strongest driers.

The commonest adulterants of boiled oil are colophony,
resin oil, and fish oil, all having the single object of lowering
the cost of production and of offering under the temptation
of a lower price an article which only in the rarest cases will
answer the expectations of the buyer. All the above adul-

64 OIL COLOURS AND PRINTERS* INKS.

terations radically affect the drying power. Boiled oil
adulterated with colophony and resin gives coats which
after any period become sticky with the heat of the hand,
and in spite of their softness soon come off. Boiled oil
adulterated with fish oil will not dry at all and is absolutely
unusable. The adulterations named may be detected by the
following means.

Colophony.

Boiled oil adulterated with colophony is generally thicker
than it ought to be. It dries in from thirty-six to forty-eight
hours to an apparently solid film, which, however, becomes
sticky by the heat of the hand laid upon it. The coats readily
collect dust, and become grey and dirty, and exposure to the
weather soon destroys the coat, which crumbles away. If we
shake up boiled oil suspected of adulteration with colophony
with 95 per cent, spirit at frequent intervals during a few
hours, and then allow the mixture to stand, the colophony
can be detected in the tincture after decanting off. To effect
this the tincture is distilled till all the spirit has evaporated.
This point is easily recognised if the spirit was weighed before
use, by the weight of the distillate. If the residue has more
than one-fortieth of the spirit the adulteration is resin if the
residue is sohd, resin oil if it is liquid. The result is of course
quantitative, and the nature of the adulterant can be confirmed
by appealing to its smell and taste.

A somewhat more complicated test for colophony is to
boil the oil for a few minutes with 95 per cent, spirit, draw
off the spirit when the mass is cold, and add to it a solution
of acetate of lead. If the oil was pure, the result is a
turbidity merely, but if it contained colophony we get a
clotted white precipitate which by repeated washing and
fusing can be converted into pure colophony.

Kesin Oil.
Besin oil is the commonest of all adulterants of boiled oil,
nd can be detected in most cases simply by its smell. The

ADULTERATIONS OF BOILED LINSEED OIL. 66

resin-oil smell becomes more distinct if a few drops of the oil
are rubbed between the palms of the hands until it is warm.
Taste affords also an excellent means of detection to any one
who knows the characteristic rough and nauseous taste of
resin oil, of which very small quantities may be at once and
with certainty detected by this means.

If boiled oil containing resin oil is mixed with dilute
sulphuric or hydrochloric acid, shaken, and then left to
stand, these show themselves in the white lead or manga-
nese precipitates formed, whitish sticky lumps, while with
pure boiled oil only the first-mentioned precipitates appear,
and the oil appears fully cleared in a few hours at most.
The oil-hydrometer can also be used. Pure manganese-
boiled oil shows 26° and lead- boiled oil 24°, while the
adulterated oil will be from 20° to 22° only.

Fish Oil.

Adulteration with fish oil may also be detected both
chemically and by taste and smell. If we mix ten parts
of the suspected oil with three parts of sulphuric acid by
stirring, and then allow oil and acid to separate by standing,
there will be a white precipitate containing the metallic
drier, and the oil will have assumed a dark brown, the acid
orange-yellow or yellowish-brown colour, if fish oil is
present. If on the other hand the oil is unadulterated,
it will be green, turning later to a brownish green, while
the acid has a nearly pure yellow colour. If the suspected
oil is treated with pure chlorine, it will become dark brown
at once, and black ultimately if fish oil is present. Un-
adulterated oil on the other hand is bleached more or less
by the chlorine. Chlorine bleaches all vegetable fats, but
turns all animal fats, with the single exception of neat's foot
oil, darker and darker, and finally black. If boiled oil is
mixed with one-fifth of its volume of caustic soda lye of

66 OIL COLOURS AND PRINTERS* INKS.

1*34 3p. gr. the emulsion formed is yellow with pore oil,
but red if fish oil is present.

Other Adulterations.

When boiled oil is very dear we find occasional adultera-
tion with turpentine, and even with benzole. If a few drops
of the oil are rubbed between the palms of the hands, the
smell of turpentine or benzole becomes recognisable. A
more certain means, however, of detecting the adulteration
is to distil the oil, when the volatile turpentine or benzole
easily comes over, leaving the linseed oil in the still. If the
amount distilled was first weighed the test can be made a
quantitative one.

It is easy to see whether a boiled oil has been prepared
by the use of lead manganese or other metallic drier. If the
reagents employed to test for them give negative results, i.e.
no precipitates, we can only conclude that the oil was pre-
pared with oxygen or atmospheric air. All oils prepared
with metals contain linoleate of whatever metal has been
employed, and if dilute sulph\irio or hydrochloric acid is
added to the oil, the metal is either dissolved by the acid or
precipitated, and in either case is separated from the oil.

The oil to be tested is mixed with about its own volume of
dilute sulphuric acid, and notice is taken whether a precipi-
tate forms or not. If a white precipitate goes down, and
turns black when treated with sulphuretted hydrogen, the
boiled oil contains lead. If no precipitate is formed, but the
acid becomes itself somewhat coloured, and blackened by
the subsequent addition of sulphuretted hydrogen, the oil
contains copper. If the sulphuric acid precipitate is not
blackened by sulphuretted hydrogen, no lead is present, and
further testing must be resorted to, first with ammonia and
then with sulphide of ammonium. This reagent gives a
black precipitate in the presence of iron, a fiesh-coloured one
with manganese, and a white one with zinc. Further in-

ADULTERATIONS OF BOILED LINSEED OIL. 67

formation is obtained if we treat the original acid solution
with a solution of carbonate of soda in water. If this gives
a dirty green precipitate, which soon turns black on exposure
to the air, iron is present. This may be confirmed by treat-
ing the acid solution with ferrocyanide of potassium, which
gives a blue precipitate with iron. A white precipitate with
the carbonate of soda, turning dark brown in the air, shows
manganese. If zinc is present, the acid solution from the
boiled oil will give with ammonia a white precipitate, readily
soluble in excess "of ammonia.

W. Fox has made known a process for detecting raw
linseed oil as an adulterant of boiled oil. It is based upon
the decomposition of the oil on boiling, the fatty acids being
oxidised and the glycerine forming compounds with acryhc
acid, which escape and cause the well-known smell.

Oils are frequently put on the market either consisting of
boiled oil adulterated with raw oil, or more frequently of raw
oil containing a little liquid siccative. Such products have
naturally comparatively small drying power. To test for
glycerine, 5 grammes of the oil are saponified in the usual
way, the soap is decomposed by hydrochloric acid, and, after
standing, the acid liquid containing the glycerine is run off
from under the layer of fatty acids, made strongly alkaline,
and then mixed with crystals of permanganate of potash till
the solution remains a light red. The excess of permangan-
ate is next decomposed with a little sodium sulphite, the
precipitated peroxide of manganese is filtered off, and the
filtrate is made acid with acetic acid, raised nearly to boiling,
and then treated with solution of calcium chloride. If this
forms a white precipitate, glycerine was originally present
and has formed oxalic acid according to the equation : —

CjHA + 30a = 3H2O + COa + HaC204.
The oxalate of lime can be converted into carbonate by
ignition, and weighed. Every 100 parts of the carbonate
correspond to 92 of glycerine.

CHAPTEE XI.

CHINESE DRYING OIL AND OTHER SPECIALITIES.

In making Chinese drying oil by H. X.' Basse's patent,
coarsely but uniformly powdered bone-charcoal, previously
purified with hydrochloric acid, is placed in a narrow-necked
funnel, and old stocked linseed oil is filtered through it into
large shallow pans of lead containing crystalline basic acetate
of lead, red lead, and borate of manganese. The mass is
exposed to diffused daylight under glass plates, and the
leaden pans are kept at 120° C. for six hours, while a stream
of air at the same temperature and containing 16 per cent, of
steam is passed through them. The oil is then placed in
shallow leaden dishes which are piled up in large closed iron
cylinders, so as to allow free circulation of air over all the
surface of the oil. In the upper part of the cylinder is placed
a wide-necked flask containing chloroform, 2 kilos, of this
for every 50 kilos, of the prepared oil. A current of air at
100° C. is then passed through the cylinder from above
downwards, issuing from a regulatable valve. After eight to
ten hours the oil becomes thick and tough, and it is then
heated with American oil of turpentine, first heated to 300°
C. in closed vessels with 10 per cent, of its weight of absolute
alcohol. This mixture is allowed to cool to 100° C. and is
then mixed with its own weight of the thickened oil.

The yellow solution formed is at first turbid, and is allowed
to clarify at a low temperature in iron containers.

If a httle of this drying oil is added to linseed oil or to an
oil-paint it gives it the best drying qualities. On standing

CHINESE DRYING OIL AND OTHER SPECIALITIES. 69

it removes all vegetable albuminous bodies from drying oils.
With linseed oil it gives a straw yellow mixture which dries
in from eighteen to twenty-four hours to a tough india-
rubbery elastic coat.

Cement-Boiled Oil.

By the process of C. Neumann (D.R.P. 25,139) a cheap
durable and paintable varnish, soluble in water, and intended
to replace ordinary boiled oil for all purposes is manufactured.
It consists essentially in partly saponifying oil and resins, or
solutions of them both, with water-glass, then boiling, and
completing the saponification with ammonia. The varnish
is separated out by adding a concentrated solution of alum
and chromate of potash, and after dilution with water is
ready for use. To explain the process more exactly, the
following description is given of the manufacture of cement-
boiled oil. The ingredients may naturally be replaced by
others of similar nature without any of the steps of the
process requiring modification.

For the preparation of 500 parts of the preparation we
treat 16 parts of Portland cement with 160, or 16 per cent.,
potash lye. After five to six hours the insoluble lime com-
pounds have settled to the bottom, while the silicates in the
cement have gone into solution, forming water-glass with the
potash.

The lye, which has become about 4 per cent, heavier, is now
boiled for about two hours with 100 parts of linseed oil and
40 parts of Burgimdy pitch. At the end of this time 40 parts
more of lye are added, but 20 per cent, lye this time, and the
boiling is continued for another haK-hour.

The hot lye saponifies the greater part of the Burgundy
pitch and the oil^ and the saponification is now finished by
stirring in about 4 parts of alcohol and 3i parts of ammonia.

By this saponification an extraordinarily intimate com-

70 OIL COLOURS AND PRINTERS* INKS.

bination or mixture of the material is secured, so that a
very homogeneous product is obtained.

Next we prepare a concentrated solution of 4 parts of alum
and 1 part of bichromate of potash, which is diluted till the
hyacinth-red colour changes to a chrome yellow. This fairly
consistent solution is gradually stirred into the above sa-
ponified mass, till the result is a fairly thick mass of a clear
brown colour.

This mass is then treated with 400 parts more, and the
whole is again boiled up. The product is then ready. The
addition of the salt solution causes on the one hand a coagu-
lation, effected by the chromic acid, and on the other a
formation of palmitate of alumina by the action of the alum
on the fats or resins. This palmitate of alumina dissolves in
the ammonia present, but when the varnish dries becomes
insoluble, and so produces a durable coat.

Carbolic Varnish.

To make a preservative varnish for painting wood, so as to
keep it from mould and dry rot, and also for painting over
walls which show growths of mould, dissolve in an iron
kettle 10 lb. of borax and 5 b. of caustic soda in 40 gals, of
water. Then boil, and while boiling stir in 45 lb. of shellac.
When the shellac is dissolved, let the solution cool till it is
lukewarm and then add 20 lb. of 90-95 per cent, carbolic
acid. This varnish is applied lukewarm, and according to
the material to be painted with it is diluted with hot water
up to about one- third of its volume. This varnish is perhaps
a substitute for carbolineum.

Tar Varnish.

In a box heated by a steam pipe or in a pan over a fire
keep 40 kilos, of tar at 70° C, with constant stirring for some
time to dry it as far as possible. Then stir in, keeping up

CHINESE DRYING OIL AND OTHER SPECIALITIES. 71

the temperature, 40 kilos, of hydraulio lime or of Portland
or Eoman cement. The mass gradually becomes saponified,
and in spite of the large amount of cement added to it remains
quite liquid, and even when cold it is soft and smeary. It is
ready for use except that it has to be used warm. If it is
attempted to use ordinary quicklime instead of hydraulic
lime, even 25-30 per cent, of it added to the tar will at once
solidify it so that painting with it is impossible. By the
saponification of the tar by the cement the volatile oils of
the tar are retained, so that a varnish is got which resists
weather perfectly, while ordinary tar weathers off in time.

Neither hydrochloric nor nitric acid attacks the taj-varnish
above described, and it will not only resist the weather but
mould. It is thus excellent for woodwork exposed to water
or in places where it is subject to the attacks of mould or dry
rot.

The tar preparation has also the property of drying soft
so that the coats cannot crack or get brittle. It is a good
application for roof-tiles, and prevents them from being
damaged by frost, as they are made waterproof. It is also
good for earthenware pipes.

CHAPTEE XII.

PIGMENTS FOR PAINTERS, ARTISTS AND PRINTERS.

Pigments come from all the three natural kingdoms, animal,
vegetable and mineral. Some of them occur ready-made in
nature, while others are manufactured from natural or arti-
ficial raw materials or both. On the whole they may be
classed as : —

1. Inorganic or mineral colours.

2. Organic colours.

3. Mixtures of the two.

The value of all pigments depends upon the following pro-
perties, or on the extent to which they are possessed : —

1. Shade of Colour, — The purer this is, i.e., the nearer it
is to the spectrum colour, the better. The shade is always
estimated by comparison with a standard sample.

2. Body or Intensity. — This is determined by seeing how
much of the pigment is needed to give the same result as a
given quantity of the standard pigment, of course on a sur-
face of the same size as that to which the standard has been
applied.

The body of glazing colours can be determined colorimet-
rically, by dissolving equal weights of a standard colour and
that to be tested in equal weights of the same solvent, and
comparing the heights of two columns, one of each solution,
which give the same intensity. The body is inversely pro-
portional to the depth of Hquid required to produce any given
intensity of colour. Another plan is to dilute the two solu-
tions till their intensity of colour is the same. Then the

PIGMENTS FOB PAINTEKS, ARTISTS AND PRINTERS. 78

body of the pigment under test is to that of the standard
inversely as the quantity of each present. Two simple glass
burettes of equal size answer for this kind of test. Into one
is put a known quantity of the pigment to be tested, into the
other the same quantity of the standard. The deeper is then
diluted with the solvent till it has the same intensity as the
other. Then if, for example, the volume of the standard liquid
is twice that of the other, the standard pigment has twice the
body of the other.

Another method, chiefly used for body colours, consists in
mixing the finely powdered pigment with a white solid having
no action on it, and comparing the colour of the mixture with
a similar one made from the standard pigment. A good
substance to use for this purpose is kaolin or white porcelain
clay. Stein carries out the test by adding kaolin, 5 grammes
at a time, to 500 grammes of the pigment under test. If the
hue is different for the same quantity of kaolin, the bodies of
the two pigments are different. In this case the deeper is
mixed with more kaolin till both are the same. Then the
respective bodies of the two colours are in the same pro-
portion as the two total amounts of kaolin added to them.

3. Fastness. — Many pigments behave very differently to
air, light, soap, alkalis, acids, bleaching agents, etc. The
greater the resistance offered by a colouring matter or an
object coloured with it to the above agencies, the faster tho
pigment is. There are great differences in the amount of
fastness expected according to the purpose to which the
colouring matter is to be applied. For example, artists' pig-
ments have to be permanent for many years, while a green
or yellow pigment intended for house-painting will have lost
its colour partially or entirely in only a few years.

It cannot of course be considered a part of my duty to give
descriptions of the manufacture and use of every colouring
matter used, because such information must be sought in
special books, such as Bersch's Fahrikation der Mineral und

74 OIL COLOURS AND PRINTERS* INKS.

Lack Farben, Fahrikation der Erdfarhen, and Fabrikation
der Anilinfarhen (published by A. Hartleben, Vienna and
Leipzig), where it will be found exhaustively given. I con-
fine myself to mentioning the separate categories, each with
its chief representatives, and to showing how the consumer
can test them for fastness and purity. It is clear that this
cannot be done exhaustively, and for those who wish still
further information I recommend Dr. Dammer's Lexicon der
Verfalschungeriy of which I have partly made use in writing
this part of my book.

The categories are as follow : colours of antimony, arsenic,
barium, lead, cadmium, chromium, iron, cobalt, copper, man-
ganese, mercury, zinc, animal colours and vegetable colours
(lake-colours).

Antimony Colours.

Antimony cinnabar gives with oils a fine red colour. It
is soluble in hydrochloric acid, but insoluble in other dilute
acids, and is destroyed by alkalis.

Arsenic Colours.

Eealgar, red arsenic, ruby sulphur, are hardly used now,
and orpiment.

Barium Colours.

Heavyspar is in pigment manufacture a much used
addition to colours. As the body of finely ground heavy-
spar, especially in oil, is very small, pigments mixed with
it lose considerably in value, and every addition of heavy-
spar not distinctly revealed by the manufacturer must be
regarded and treated as a fraud. In the case of those
pigments which cannot be made without heavyspar, such
as Victoria green, the quantity of heavyspar is generally
guaranteed by the manufacturer.

Heavyspar is distinguished by its inactivity and its in*

PIGMENTS FOR PAINTERS, ARTISTS AND PRINTERS. 75

solubility in acids or alkalis. These properties, together
with its white colour, make it very suitable for toning down
dark shades, or for making cheaper white pigments with
white lead, lithopone, or zinc white. The colour of heavy-
spar is a very important test of its quality. The whiter and
the finer ground it is the better. As many varieties of
heavyspar contain gypsum or celestine (strontiimi sulphate),
we often find these bodies in the ground heavyspar of
commerce without being able to regard them as adultera-
tions. Besides gypsum and celestine, natural heavyspar
almost invariably contains oxide of iron, alumina, and silica,
but not as a rule in important quantities.

Lead Codours.

White lead varies in body according to the method of
preparation, i.e., according to its molecular constitution.
That made by the Dutch method has more covering power
than English, which again has more body than French
white lead. White lead leaves the factory : (1) Finely
ground; (2) In shaly leaves (shale- white), as it is got by
hammering the leaden sheets; and (3) in quadrangular or
conical lumps made by moulding or pressing a paste made
by grinding the pigment with water.

White lead is largely adulterated with inferior mineral
whites, especially heavyspar, and sometimes with chalk,
gypsum, clay and sulphate of lead. These additions show
themselves as insoluble residues when the white lead is
dissolved in acid. Chalk, however, may dissolve with the
white lead, so to test for it we precipitate the lead from the
solution by means of sulphuretted hydrogen, and test the
filtrate, after evaporating it and driving off the sulphuretted
hydrogen, for lime.

Naples yellow, a yellow pigment for artists : not known to
be adulterated.

76 OIL COLOUES ANB PRINTEES* INKS.

Red lead, Paris red or lead red, is a scarlet red for oil
painting, and is often adulterated with brickdust, red ochre,
red oxide of iron, heavyspar, gypsum, sulphate of lead, clay,
and sand. Unadulterated red lead will dissolve on heating
in a solution of sugar containing nitric acid, with evolution
of carbonic acid, but the above-named adulterants remain
undissolved.

Cadmium Colours.

Cadmium yellow is a yellow pigment for artists and
printers. It dissolves in concentrated hydrochloric acid,
which leaves adulterations imdissolved. It is not affected
by sulphuretted hydrogen or ammonium sulphide, but chrome
yellow is destroyed by them.

Chromium Colours.

Chrome green, Guignet's green, permanent green, chrome
hydroxide, Victoria green, oil green, chrome colours in a
pm'e state, are only used by printers. By mixing them with
other pigments a whole series of greens is produced. If we
mix pure chrome green with a white, such as gypsum, heavy-
spar, or clay, to make the shade lighter, we get shades verging
into greyish blue, and which by the addition of a little pure
yellow, such as chrome yellow, or chromate of zinc or barium,
become very warm. These greens can only be regarded as
adulterated with the whites when they are described as
chemically pure. Purity is tested by fusing the pigment
with soda and saltpetre in a platinum crucible, when the
chromium passes into a soluble alkaline chromate, while the
sulphuric acid and the heavyspar forms sulphate of soda,
and the barium remains insoluble as chromate or carbonate.
The insoluble residue after washing on the filter, can be
tested for barium by dissolving it in cold dilute hydrochloric
acid, and adding solution of calcium sulphate. The formation

PIGMENTS FOE PAINTEBS, ARTISTS AND PRINTERS. 77

then of a white precipitate or turbidity shows the presenof
of barium. The blowpipe flame of barium is green. Chrome
yellow, chrome orange, chrome red, yellow pigments of from
the palest lemon yellow to the deepest cinnabar red ; the
colouring substance of the yellows is neutral lead chromate,
that of the oranges and reds basic lead chromate. They
answer for house painters, artists and printers. Of real
adulteration with sulphate or carbonate of lead, lead spar or
gypsum, it can only be a question when they are added with-
out being allowed for in the price, for chemically pure lead
chromates are useless as pigments. Unless mixed with other
materials they always change colour and spoil. These other
materials may be added to the extent of 60 per cent, or even
more. Barium yellow has almost gone out of use

Zinc yellow, yellow ultramarine is chiefly used by printers.
It is distinguished from chrome yellow by not being precipi-
tated black from solution in hydrochloric acid. For house
painters and artists.

Iron Colours.

Paris blue, Berlin blue, TurnbulFs blue, for house painters,
artists and printers. The best pigments are the pure steel-
blues (Milori blue, steel blue, bleu d'acier) and those which
show a coppery lustre. Pure Paris blue is mixed with starch,
heavyspar, kaoHn, or gypsum, partly to cheapen it and partly
to get lighter shades. Much more of the lighter adulterants
can be added than of heavyspar, and the value of the pigment
depends simply upon how much Paris blue it contains. The
testing to ascertain the same is rather troublesome. Tumbull's
blue is distinguished from Paris blue by being made by pre-
cipitating a ferrous instead of a ferric salt.

The iron colours include the numerous pigments found
ready made in nature which have oxides of iron as their main
essential constituent, such as ochres, bole, Siena earth, Poz-
zuoH earth, etc. As these pigments occur ready-made in

78 OIL COLOUBS AND PRINTERS' INKS.

nature, so that nothing can be said about any admixture of
particular foreign bodies, chemical investigation, pure and
simple, gives no idea of their value.

The testing of them depends, therefore, mainly on seeing
that they are finely ground and free from coarse particles,
especially of sand, which show imperfect levigation. The
colour is of the greatest importance and the warmer and
more beautiful it is the more valuable the pigment. The
various shades are partly provided by nature, but are in many
cases got by the use of artificial heat. Of late, aniline dyes
have been used to enhance the fire of ochres and various
other red mineral colours. Ochres so treated, however,
gradually turn pale when exposed to Ught, and nothing is
left in time but the original colour of the ochre. Such
falsification is readily recognised by dissolving out the dye
with alcohol or water, in one of which the dye will dissolve,
and then filtering the solution from the insoluble earth.

Cobalt Colours.

Smalts, Thenard's blue, coeruleum, Rinmann's green.
Smalts is a blue cobalt glass, but is not now much used, and
Cobalt or Thenard's blue has been almost completely super-
seded by ultramarine. It is still used, however, in porcelain-
painting and by artists in oils, Binmann's green is not even
manufactured now.

Copper Colours.

Mountain blue, mountain green, Brunswick green, Bremen
blue, Scheele's green, Schweinfurt green.

Mountain blue and green occur in nature and are also
made artificially. They are constantly adulterated with
heavyspar or gypsum.

Brunswick green, used as an oil pigment, is adulterated in
the same way.

PIGMENTS FOR PAINTERS, ARTISTS AND PRINTERS. 79

Soheele's or mineral green contains arsenic. The most
important copper-pigment is: —

Schweinfnrt green, a compound of copper arsenite with
copper acetate. The darker shades are more crystalline
than the paler ones, and for this reason have less body. To
detect admixtures of gypsum or heavyspar a weighed quantity
of the pigment is treated with hydrochloric acid, the excess
of acid is removed by evaporation on the water bath. The
whole mass is then mixed with twice its volume of strong
spirit. After twelve hours' standing the sediment is filtered
off, washed on the filter with a mixture of 2 vols, of alcohol
and 1 vol. of water, dried, ignited and weighed. The spirit
may be omitted throughout if gypsum is not present.

Manganese Colours.

Browns, such as umber, chestnut brown, roe- brown, etc.,
which are not made artificially, but are dug from mines.
They owe their colour to compounds of iron and manganese
and are the less valuable the more earthy impurities, such as
clay, are mixed with them. By roasting at particular tem-
peratures, levigating and grinding, the natural products,
which chiefly occur in beds of iron ore, are made of very
beautiful brown hues of good body. The pigments must be
judged by their colour and body, and tested for artificial dyes
with alcohol or water as described under the head of iron
colours.

Mercury Colours.

Cinnabar is the only pigment made for all purposes. It is
adulterated with brickdust, oxide of iron, red lead, chrome red,
cinnabar imitation, and red coal-tar dyes. The first four re-
main behinJ when cinnabar is volatilised by heat. Cinnabar
imitation is red lead or chrome red plus eosine. Lead and
chrome remain behind in the residue after heating and eosine
is extracted, before heating, with alcohol.

80 OIL COLOURS AND PRINTERS* INKS.

Zinc Colours.

Zinc white, zinc grey, lithopone.

In testing zinc white we usually confine ourselves to test-
ing the solubility in acid and alkali. The usual adulterant is
heavy spar, which remains undissolved in either case.

Zinc grey is zinc oxide mixed either with the metal or
with finely powdered charcoal, or is ground blende (zinc
sulphide). Its value depends on its colour and body.
Lithopone is a mixture of zinc sulphide, zi»c oxide and
heavyspar. It may be adulterated with chalk to make it
give a larger proportion of matters soluble in acids, the
chalk being then taken for zinc oxide. We should never
omit to heat a solution obtained from the lithopone by
strong nitric acid with ammonia in excess. This ammonia
should give no precipitate, showing the absence of iron and
alumina. When satisfied on this point, we make the solution
acid again, but with acetic acid, and precipitate the zinc
with sulphuretted hydrogen. The filtrate is tested with
oxalate of ammonia for lime, and with sodium phosphate for
magnesia.

Carmine.

The colouring matter of cochineal is subjected to many
adulterations, on account of its high price. Among them are
starch, clay and brickdust. As pure carmine is completely
soluble in ammonia, which dissolves none of these things,
falsification is readily detected by the use of that reagent.

Carmine lake, Munich lake, cochineal lake, Florentine
lake, etc. , are made by precipitating a decoction of cochineal
with alum and alkali. Mineral adulterations are found by
burning and examining the ash.

Lake Colours.

Under this title we understand colours obtained by pre-
cipitating organic dyes on minerals such as heavyspar, clay.

PIGMENTS FOR PAINTERS, ARTISTS AND PRINTERS. 81

gypsum, etc. There is an enormous number of such pig-
ments : madder lake, garancine lake, carmoisine lake, Vienna
lake, ball lake, Venetian lake, cochineal red, purple lake,
gamboge lake, blue lake, green lake, etc., etc. They are
beautified by the addition of aniline dyes, and also with large
quantities of mineral matter or starch.-

Indigo

Is adulterated with mineral matter, starch, gums, glue,
sugar, dye-extracts, Prussian blue. It is very little used in
oil-painting.

Frankfort Black.

This is made by charring grape-stalks and other vegetable
matter. Its value depends on its colour. The less brown
there is about it the better. Good vegetable black must,
when burnt, leave hardly any ash. It is largely adulterated
with wood-charcoal, which cannot be detected chemically.
Adulteration with ordinary coal has also been noticed.

Bone black and ivory black are black pigments of various
fineness and depth, according to the raw material. They are
got by heating bones with exclusion of air. They are hardly
likely to be adulterated with mineral substances and such
could be easily detected by burning and testing the ash.

CHAPTBE XIII.

PIGMENTS FOR PRINTERS' BLACK INKS.

The chief pigment for printing ink is now, as it always has
been, lampblack, obtained by burning organic substances
rich in carbon. It is the most suitable body for the purpose,
on account of its fine black colour, its small weight, and
many other advantages. Many attempts have been made to
oust it from its position, but no satisfactory substitute has so
far been discovered.

Printers' ink consists of boiled oil and pigment only. It is
not sufficient for the manufacturer to take pains in the making
of the vehicle, and in the amalgamation of it with the pigment ;
he must see to it that his pigment is satisfactory, and to
escape trouble and to be able to meet competition it is essen-
tial that he should not purchase lampblack, but make his
own. It is true that the various makers offer very fine and
praiseworthy products, but you can never be sure of getting
the same quality twice. The printing-ink maker, in order to
be able without fail to make the same ink at different times
with the same vehicle, should be able to make a pigment of
the same quality in every batch. If, for example, a lot of
lampblack is lighter and flakier than the last, it will make a
thicker ink for the same quantities. If the change is of the
reverse kind, the ink will turn out thinner, and in both cases
the customer is dissatisfied. As a matter of fact the cardinal
principle that a printing-ink maker should manufactm'e his
own lampblack, and make himself independent of the market
article, is now recognised in all large printing-ink factories.

PIGMENTS FOE PRINTERS* BLACK INKS. 83

For the manufacture of lampblack a very varied selection
of raw materials is employed, such as American resin,
ozokerite, and the hydrocarbons got as bye-products in the
refining of petroleum and the distillation of brown coal.
Besides these fish oils and vegetable oils in a fresh or rancid
state, light and heavy tar oils, wood-tar oils, supply raw
materials very suitable for lampblack manufacture, being
readily combustible and rich in carbon. With regard to the
vegetable oils it should here be mentioned that it is advan-
tageous to use them when they are very rancid, as they then
give a greater yield of the black pigment. The reason of this
is that a rancid oil requires a freer air supply to burn without
smoke than the same oil in a fresh condition. This circum-
stance also shows that a part of the carbon of the rancid oil
requires a higher temperature for its combustion than is the
case with a fresh oil. Hence the use of rancid oil in lamp-
black making has a double advantage. It not only gives a
larger yield, but is cheaper than fresh oil. There is only one
disadvantage attending the use of rancid oil, and it is not one
of great importance. It is that the oil, on account of the
large quantity of free fatty acid which it contains, rapidly
corrodes the metallic parts of the lamps in which it is burnt,
especially in the case of copper or brass. Hence it is best to
avoid copper and brass as much as possible in making the
lamps, and to make as much of them as possible, especially
the oil reservoir, of tinned iron.

Of the tar oils got by distilling ordinary and brown coal,
we have the heavy and the light, which differ not merely in
specific gravity, but in boiling point, which with these oils
varies within rather wide Hmits. They show great differences
between the amounts of oxygen which they require for com-
plete combustion, i.e., for burning with a luminous and
non-smoky flame. The more oxygen an oil needs to burn
smokelessly, the better it is for lampblack making, as it is
easier by restricting the air-supply to make them burn smokily.

84 OIL COLOURS AND PRINTERS* INKS.

Such oila may generally be recognised by possessing' both
high specific gravity and high boiling point.

The whole installation of a lampblack factory consists of
two main portions, the room in which the combustion takes
place, and in the arrangements for collecting the lampblack.
In the newer processes of manufacture, of which we shall
presently treat, the usual chambers for collecting the product
are dispensed with.

It is advisable, as conducing both to uniformity of the
product and to safety from fire, to make the receptacles for
the lampblack entirely of brickwork, which should be well
pointed to prevent too much lampblack lodging in crevices.
The end of the lampblack channel should communicate with
a high chimney provided with a well-fitting damper, so that
the draught may be regulated at pleasure, or cut off altogether.
Such a plant, although somewhat expensive, has a large
number of important advantages. It is all of fireproof con-
struction, and if it gets warm slowly, once warm it keeps its
heat a very long time, because bricks are bad conductors of
heat. Once the channel is hot, water ceases to condense in
it, and all steam passes through it with the products of com-
bustion to the chimney. Another advantage is that the
lampblack channels do not often have to be entered. They
can be cleared at wide intervals, and hence the combustion
has only seldom to be interrupted. The lampblack collects
on the walls of the passages in flakes which finally fall to the
floor. There should be only one opening for emptying the
the passages, and this must be provided with an iron door,
which should be luted up except when the combustion is
stopped, and the passages are being emptied. Unless this
door can be closed air-tight it is futile to think of regulating
the supply of air to the lamps by means of the chimney-
damper. When it is necessary to clear out the lampblack,
a workman goes into the passages with an iron pail and a
soft brush, and gathers the lampblack off the walls and floor.

PIGMENTS FOR PRINTERS BLACK INKS.

It is of the greatest importance that he should put nothing
into his pail but lampblack. Hence his brush must be too
soft to disturb the mortar of the brickwork, and he must wear
felt slippers while at work, as nails or even leather soles to
boots are apt to scrape foreign matter off the floors of the
passages. The least bit of sand or hard stuff in the lamp-
black will do much harm in the subsequent processes.

The lamps for burning the raw material are of the most
varied construction, and the same lamp will not do for every
kind of combustible. Lampblack is usually divided into two
kinds, flame-black and lampblack proper. For the first no
lamps are used, and we shall describe its manufacture first.

Thenius's Oven.

Here the raw material is the last oil got in distilling coal-
tar, and freed as far as possible from naphthalene. This is
burnt in a special stove, represented in fig. 19. The com-

FiQ. 19.

partment a contains an iron plate kept always red hot. On
to it the oil drops from the tube c. The smoke resulting
passes in succession through chambers 1, 2, 3 and 4, through
the small openings /.

When enough pigment has been made, the oven is left for
a few days, and the chambers are then entered by the

86 OIL COLOURS AND PRINTERS INKS.

windows d. No. 4 contains the finest product, and that in
No. 3 is very good. That in Nos. 1 and 2 is second quahty
only. Four hundred kilos, of the oil yield about 70 kilos, of
black, about half being got from chambers 3 and 4. The
iron plate is then cleaned, and the process is started again.
The coke knocked off the iron plate is used for fuel.

Oven for Burning Asphalt.

The oven can be built of masonry or brickwork, but the
inner room C must be lined with thick plates of iron. The
doors d are also of strong iron plates and also the door a.

Fig. 20.

which has a few holes in it to admit the air required for
combustion, but which can be closed at pleasure. The
chimney C has at ^ a communication with the lampblack
chambers, which are arranged as in Thenius's apparatus.
In the oven asphalt or pitch is burnt with as little air as
possible. The asphalt is fed in through the doors a a, and
the lampblack passes into the chambers through the chimney
and there it sorts itself according to its fineness. When the
lampblack is to be removed, operations are suspended for a
few days before the doors are opened. Five hundred kilos.

Pigments foU peinters' black inks. 87

of smiths' pitch give about 200 kilos, of total lampblack.
The coky residue has to be broken up with hammer and
chisel. It amounts to about 200 kilos, and is used for fuel.
This oven will burn for the manufacture of black the
various dry residues of the purification of raw oils and creosote.
These residues may contain potash or soda but they are rich
in oil and resin. They are used, however, not alone but
mixed with the asphalt, as they do not bum well separately,
although they give as good a black under the above conditions.
When the chambers have been cleared out a wood fire is
lighted in the oven to burn the black alkali-containing residues
to a grey ash, which can be sold as a manure, when powdered
after they have got cold.

Oven for Eesin, etc.

Another oven for burning resin, pitch, ceresine, etc., is
shown in fig. 21. The iron dish G stands in contact with
the water in another G^. This water must be replaced as it
evaporates, as it has the important fimction of keeping the
fused material in G from getting too hot. If that happened,
a dry distillation would take place, the products of which
would accompany the smoke, and spoil the lampblack, per-
haps even reduce the product of the chambers to a smeary
paste, which would have to be burnt all over again. The
pipe B leads to the chambers, and the smoke and combustion
gases enter it by the opening O. O is really along sHt only
a few cm. wide, but reaching nearly the full width of the
combustion chamber. The lid D is only removed to renew
the supply of combustible. The supply of air is regulated by
altering the position of a damper inserted into D. This, how-
ever, has to be assisted, for the necessary control over the air
supply, by a damper in the chimney. In order that the
progress of the combustion may be observed a glass window
is provided. At the commencement of an operation the

Sa OIL COLOURS AND PRINTERS' INKS.

damper in D is fully opened, and the chimney damper
is regulated so as to produce a strong draught. As soon,
however, as thick black smoke begins to come out of the
chimney, we have a sign that the passages are full of the
combustion gases, and that they are being regularly drawn
through the flues. We then diminish the strength of the
draught with the dampers until the chimney only shows a

Fig. 21.

just perceptible smoke, and the flame in the combustion
chamber becomes a dirty red instead of white.

Oils too can be burnt in this stove if a proper hearth is
provided for them. These hearths are so constructed that
while the surface is burning more oil is entering from below.
As is the case with pitch or resin, it is indispensable that the
hearth should be kept cold by a constant supply of water
below it, or it would soon become so hot as to evaporate a
lot of the oil, which would then escape combustion, and also
make the flame very difficult to regulate.

PIGMENTS FOE PRINTERS BLACK INKS. 89.

Eeal Lampblack.

For burning liquid fats, such as train oil and vegetable and
mineral oils, lamps are used. The construction of these is
directed to the point that they shall burn no more carbon
than is absolutely necessary to keep up the combustion.
At the same time the temperature of the flame must be kept
as low as possible to prevent it from burning any of its own.
smoke. The lamps have fish-tail burners and must be
enclosed in an iron case provided with a damper, which must
be very accurately fitted, or else air will get in through the
crevices, and the use of the damper will become illusory.
To prevent the fuel of the lamp from getting too hot, which
would entail great loss by evaporation, especially in the case
of mineral oils, the reservoir of it must be outside the metal
case of the lamp.

The burner B is represented in fig. 22 in its cyhndrical
case, which is bent above, but must be gradually curved and
not in a sharp knee. This bend directs the products of
combustion into a chamber K, from which the passages for
the deposition of the pigment proceed. The form of the
upper part of the lamp-case is important. If it has an
angular bend, the angle catches a lot of lampblack. This
forms lumps which fall off, and partly get burnt in the flame
and partly accumulate at the bottom of the lamp-case. A
proper bend stops no lampblack, all of which goes to its
appointed place.

The damper S is fitted into the lower part of the lamp-case,
and must rotate easily. The wider the slots are left open by
it, the more oxygen gets to the flame, and the faster the
combustion proceeds. At one part of the lamp-case a w^ell-
fitting little door is made, to allow access to the wick, and
there is also a window to permit the flame to be observed
without opening the case. The screw R raises or lowers the
wick. O is the reservoir for the lamp fuel, outside the case.

OIL COLOURS AND PRINTERS* INKS.

In the older types of lamp, the wick sucks up the fuel, and
the attendant had always to take care to keep a supply of it
in the reservoir. If this is neglected, the wick bums. This
makes it suck up too much fuel, more than the lamp can
burn. Most of the excess is simply distilled, and gives the
lampblack the greasy smeary character above alluded to as
making it unfit for further treatment. A careless and in-
attentive person can easily make this mistake, if he has a

large number of lamps to look after. But from the reservoir
shown in the figure the fuel does not flow out until its
surface is below the line N. As soon as a little has been
burnt, a little air enters the reservoir, which consequently
supplies the lamp by gravitation until the opening N is again
closed by the liquid. This make of lamp, however, only
answers well with thin oils, and the greatest attention has
to be paid to keeping the lamps clean.

PIGMENTS FOR PRINTERS* BLACK INKS. 91

All makes of lamp have disadvantages more or less. They
have to be constantly cleaned, and there is always a waste
of fuel when they are filled. There is a remedy for this,
however, which consists in substituting for the separate fuel
reservoir for each lamp one in common to a great number,
and fitted to supply the lamps automatically. The attendant
has then nothing to do but to supervise the air supply to
each lamp, and to see that the mechanical arrangements for
feeding the lamps with fuel are kept in good order.

With this automatic feed, all the burners must be in the
same horizontal line, and must be immovably fixed. From
each lamp a tube goes to a common tube running below
the lamps. This latter opens into the free reservoir, and
this is supplied from another larger one at a somewhat
higher level. A cock in the tube between the two re-
servoirs is opened by a float in the lower one. If the
level of the liquid in the latter sinks below a certain level
the float opens the cock, so that the lower is kept supplied
from the upper one up to a constant level. The float is
so arranged, too, that the level of the liquid in the lower
reservoir is just a little above that in the lamps. Thus
there is just enough hydrostatic pressure to feed the lamps,
and there is no difficulty ia regulating the supply to the
amount burnt. It is not easy to do so at first with a fuel
of which one has had no experience, so as to burn all and
waste none. To prevent any waste, the circular damper
is made with a shallow concave bottom ending in a tube
which opens above a small vessel, into which the funnel-
shaped bottom of the damper directs any drippings.

In fig. 23, S is the damper and T the vessel to catch
the waste. L is the tube bringing the fuel from the lower
reservoir to the lamp by means of the common pipe H. A
is the lower reservoir itself. When we use tar oils for
lampblack making, and especially if we use thin light
mineral oils, the tubes bringing the combustible to the

OIL COLOUES AND PRINTERS INKS.

lamps may be small, but in burning thick liqtiids, such
as fish oils, wider tubes must be used, as narrow ones
would offer too great a resistance to the passage of the
liquid.

It is well known that fats increase in fluidity with rise
of temperature. Hence the stock reservoir should be in
the same room with the lamps, so that in winter the liquid

in it will be prevented by the heat from becoming too thick,
and flowing too sluggishly through the pipes.

The reverse is, however, the case in using hydrocarbons
from tar, brown coal, etc. In view of the low boiling
points of these highly inflammable liquids special care is
necessary in burning them. As they are always very fluid,
even at low temperatures, it is advisable as a precaution
against fire to keep the reservoir outside the lamp room,
and to provide it with an air-tight cover pierced with only

PIGMENTS FOR PRINTERS BLACK INKS.

a small hole to permit the. necessary access of air ft*
drawing off the liquid. Special care is necessary with such
combustible and volatile bodies in regulating the supply to
the lamps, or a large amount will be wasted by evapora-
tion without being burnt.

The lampblack from the lamp is led into similar chambers
to those already described, and removed from them as above
stated.

Apparatus for Making Lampblack from Oil.

The patent apparatus (D.E.P. 9,426) represented in figs.
24 and 25 consists of a tube A closed at its lower end

Fig. 24.

a, and supported by its point in the bearing B. This pipe
is provided at b with a funnel c, which is used for pour-

94 OIL COLOURS AND PRINTERS* INKS.

ing in cooling water, which leaves the tube again through
the holes dd. These holes are directly below a circular
plate C of thin cast or wrought iron and is perpendicular
to A which passes tightly through its centre. The plate
is enclosed in the circular case, DD, of iron. From the
top of this case the pipe e takes the cooling water into
the circular gutter B, which is drained by the pipe I. A
is supported above by passing through the bearing FF,
and is rotated by the gearing GG. Near the bearing B
is fixed a scraper H, the edge of which carries a strip of

Fig. 26.

leather. Opposite the scraper is the lamp J with a wide
flat wick.

The manufacture takes the following course : the appar-
atus having been set in slow rotation and cooling water
having been set to flow gradually through the funnel e and
out at ddy so as to keep the plate CO cold, the lamp
J, previously filled with paraffin got by the distillation of
brown coal, is lit at such a distance below the plate CO as is
necessary to get, by the cooling effect of the plate on the
flame, as much as possible of the carbon of the paraffin
deposited on the plate in the form of lampblack. This lies
light on the cold plate and also damp, because the coldness
of the plate condenses the steam produced by the combustion.

PIGMENTS FOR PRINTERS BLACK INKS.

The rotation of the plate is constantly offering a clean
surface to the flame as the lampblack is perpetually being
removed by the horizontal edge of the strip of leather on H,
and sent by the gutter K into its destined receptacle.

Another apparatus on the same principle is shown in fig.
26.

The cylinder is a thin walled one of cast iron, with its
exterior turned quite smooth. It is surrounded at a distance
of a few cm. by an iron case. It turns in bearings on a

Fig. 26.

hollow axle, so that water can flow by gravitation through
the inside of the cylinder. Below the cylinder are fixed the
smoky lamps, in a row, and a soft brush extends over the
whole length of the cylinder. This brushes off the lampblack
over a sloping plate of iron into the receiver. The cylinder
is kept in slow rotation by any suitable means.

The action of this apparatus is as follows. The lamps are
so constructed as to produce a smoky flame and the lamp-
black they deposit on the outside of the cylinder is collected

OIL COLOURS AND PRINTERS INKS.

from it by the brush. All the time the cylinder is kept cool
by the water passing through it. The collected lampblack
shows in consequence of this rapid coohng, which condenses
other products, viz., those of destructive distillation, a rather
strong brown colour, and has to be made fit for use by
subsequent ignition.

Dreyer's Apparatus.

The apparatus of R. Dreyer of Halle also depends on the
fact that if a cold surface is brought into a luminous flame
it becomes coated with a deposit of soot, as the temperature

Fig. 27.

is brought below that necessary for the combustion of the
carbon in the fuel, and is left behind in a finely divided free
state. Fig. 27 is an elevation of the lower part of the
apparatus ; fig. 28 a longitudinal section ; fig. 29 an end
view, and fig. 30 a transverse section. Fig. 31 is a section

PIGMENTS FOR PRINTERS BLACK INKS.

of 1ihe counterpoise ij/ of the cylinder B and of the manhole
TT. Fig. 32 is a bird's-eye view of the bed plate of one
side of the framing. Fig. 33 is an elevation of the upper
part of the apparatus, and fig. 34 an end view of the same.
Fig. 35 is a longitudinal section of the upper part, and fig.

Fig. 28.

36 a transverse section of it. Fig. 37 is a bird's-eye view of
it; fig. 38 a transverse section through the lampblack col-
lectors a, and fig. 39 shows the cam n, and the hfting rod o.
The principal parts are the frame A A, the cylinder B, the
casing 0, the lamp-guard D, the scraper B, the collecting
funnels F, the gearing H and the aspirator K.

The frame consists of two side walls AA of cast iron

OIL COLOURS AND PRINTERS INKS.

closely united by the screws a. The framing is bolted down
to a suitable masonry foundation.

By means of the bearings b and bj^ the frame bears the
cylinder B, with its outside turned smooth, and with hollow
trunnions. The trunnion at b^ has a hollow piece cast on to
it to take the worm-wheel c, by which the motion of the

Fia. 29.

driving shaft e and the worm d the motive power is trans-
mitted to the cyhnder. The driving axle moves in the
bearings / in the side- walls of the framing. To lessen cog
frictic a lubricator g is placed so that the worm touches the
oil in it. Both the trunnion at b and the production of it at
b^ are provided with stuffing boxes, to receive water-tight the

PIGMENTS FOR PRINTERS BLACK INKS.

tubes /i and h^ respectively ; h^ brings cold water in the direc-
tion of the arrow for cooling the interior of the cylinder,
while the other carries off the warm water as it is replaced by
fresh. So that the temperature of the outflow may be ascer-

FiG. 30.

tained for the purpose of regulating the supply of cold water,
and knee-tube i is inserted in the outflow tube, and in it is
the thermometer E fitted into it by means of a cork. Under
the cylinder B is the series of lamps D. The combustion

100

OIL COLOURS AND PRINTERS INKS.

arrangement consists of the lamps I, the tube m distributing
fuel to them, the indiarubber tube n and the mechanism
attached to the side walls of the framing for regulating the
distance between the lamps and the cylinder. This mechanism
consists of upright screw threads at either end of the lamp
series; The lamps and supply tubes are supported on nuts
on these screws, so that their distance below the cylinder can
be regulated by turning the nuts. The closed ends of the
supply tubes have forks g at their closed ends by means of
which they keep their position between the plates r. If more
than one row of lamps is used the additional rows are sup-

FiG. 31.

ported in their place by special screws ^, as shown in fig. 29 in
dotted lines. The various distribution tubes are then brought
into communication by the cross- tubes u. These are of india-
rubber to permit arranging the lamps under the cylinder, so
as to save room and get a better distribution of the lampblack
on the cylinder. In a channel under the apparatus is the
main tube J which brings the combustible to the lamps. The
supply can be regulated by the cock v, and J is in flexible
communication with the separate supply tubes by means of
the india-rubber tube n. At a distance from the cyhnder B
of a few cm. is the iron casing C, which rests by means of
the handles w on the side walls of the frame. The lower
part of this casing consists of two lids x and x. One of these

PIGMENTS FOR PRINTEll'^'oBIiicK- IhSs?-: : /-lOl

is to facilitate access to the lamps, the other to the stripper
E. The stripper B consists of the axle y, which is kept fixed
by screws and nuts to projections in the side walls of ' the
framing ; the three knee levers a with counterpoises B, the
guides yy, with the elastic steel plate d between them which
scrapes the lampblack from the cylinder. The nearer the
lamps can be got to this steel plate the better, as the lamp-
black is delivered in a drier state. The steel plate is fixed to
the rails yy by screws which work in slots so as to permit
the edge of the scraper to be brought nearer to the cylinder
as it wears. To fill up the slits in the end of the casing
where the trunnions of the cylinder pass, various pieces y are
inserted, which are kept in place by grooves and bolts. On

Fig. 32.

the casing C two projections are made which support the
aspirator K with the draw-off pipes. A manhole tt with a
cover is provided to enable the inside of the cylinder to be
cleaned. The manhole cover is balanced by the counter-
weight j/r. The funnels for collecting the lan^pblack are at
one side of the casing, and are carried by the angle iron i/r,
which is fixed to the side walls of the framing. In order that
the collecting vessels G can be changed for emptying pur-
poses without allowing any lampblack to fall on the ground,
a door with a handle is attached to each funnel and can be
secured to a bolt^

10^\: ^':.biti «c(iEio¥it6-'A'ND printers' inks.

The upper part of the apparatus shown in figs. 33 t»o 39
inclusive consists of the aspimtor K, and dra%v-off pipes

Fig. 33.

communicating with an exhaustor. The object of this arrange-
ment is to prevent the so-called sweating of the workroom,

PIGMENTS FOR PRINTERS BLACK INKS.

103

and to ventilate it for the better health of the operatives, as
well as to catch any lampblack which does not settle on the

Fig. 34.

cylinder, and save waste thereby, and at the same time to
prevent the deposition of such lampblack in wrong places.
With the intentionally imperfect combustion of the fuel not

104

OIL COLOURS AND PRINTERS INKS.

only lampblack but water is produced, which becomes steam
through the heat of the cylinder. This steam mixed with air
out of the factory, and kept in by the casing, is drawn by the
exhaustor through the aspirator K, where it is freed from any
particles of lampblack, and sent out as warm damp air into

Fig. 35.

the outer world. To this aspirator belongs the wooden box
aa. This is divided by a partition and lined with tin-plate
and felt to keep the inside warm. Each of the two compart-
ments of this box is accessible by a little door and contains a
lampblack-catcher, consisting of a saw-shaped piece of iron
covered with flannel. To make these flannel walls c and the
wooden frame d are employed. The wooden frame is sup-
ported by the edgings e. To prevent the filters from being

PIGMENTS FOR PRINTERS BLACK INKS.

105

choked by accumulations of lampblack, an automatic arrange-
ment for tapping them is attached to the cover of the wooden
box. The necessary motive power for this is brought by a
belt F from the cylinder axle to the pulley h on the axle g.
By means of a suitable gearing the axle k is driven from the

Fig. 36.

axle g, but at a much slower rate. On the axle k are the two
discs 1 and 1'. In the circumferences of each of these is a
gap, the two being exactly opposite each other. On the axle
g sit opposite the pulleys m and m^ which have near them
and on the same axle the pulleys n and n^ each with a corre-
sponding number of cams which engage in the correspondingly

106

OIL COLOUES AND PEINTEES INKS.

slotted lifters o and o^ These lifters are at their lower ends
hinged to the flannel filters, partly directly and partly through
the intermediate levers p and p^. The upper ends of the
lifters are guided in the slots q and q^. For the better
regulation of the movements of the flannel filters, the parts
of them by which they are connected with the levers which
are not directly connected with the slotted lifters are provided
with guide pieces tt and ttj. Over the pulleys ZZ, d, m, m^,
are the levers r and r^ supported at one end. These levers,
by means of rods s and s^ attached to the slotted lifters, permit
the flannels to be raised and keep them in that position.

Fig. 37.

Each of the draw-off pipes t and t^ is provided at its upper
end with a valve {u and u{). These valves are made to shut
the draw-off pipes by means of chains, passing over the small
rollers v and v^, the levels r and r^, and the pulleys w and w^.
The valves are opened by the counterweights x and x^. When
the pulley I and the cam m have arrived at the positions
shown in fig. 36 the projection y on the lever r lies in the
notch of the pulley Z, and closes partly by its own weight
and partly by the help of that of the descending flannel filter,
the valve u of the draw-off pipes, at the same time raising
the counterweight which opens the valve. As soon as this
has taken place, the pulley n comes into play. By the cams
the slotted lifter of the flannel filter is lifted up and let drop

PIGMENTS FOE PRINTEBS BLACK INKS.

107

repeatedly. At the same time the lifters strike the metal
plates z and z-^ and so knock the lampblack off the filters.
To make the execution of these movements exact, the
spiral springs a^ and a^ are also added. After the flannel
filter has again come to rest, the cam m comes into action
once more, by raising the roller-provided projection p of the
lever r, which in its turn raises the slotted lifter o. Hence
the slotting of the lifter comes into such a position that the
cam n can no longer act. The cam I has been all this time
approaching with its notch the projection <^, so far as to keep
the lever r, the lifter d, and the flannel filter h in their

Fig. 38.

nighest positions, and its outer edge comes under the pro-
jection <^. To further ensure proper working of the cam Z,
the cam n has a corresponding circumference. At the same
time the counterpoise x comes into play, and opens the draw-
off pipe t by means of the throttle valve u.

To prevent the lampblack knocked off the filters from
falling back on to the cylinder B, the covers y^ y^ and the
projections d and d-^ are added. The feet under these covers
leave so much free opening that the warm moist air from the
casing can get into the inside of the wooden box. The use
of two lampblack-catchers produces a permanent ventilation
of the workroom, and at the same time an uninterrupted
removal of the steam, for as the notches in the cams I and l^
are directly opposite each other, one compartment of the box

108

OIL COLOURS AND PRINTERS INKS.

at least is always ventilating while the way through the other
is closed by the throttle-valve so that there is no air current
through it.

In order that it may be seen whether the flannel filters are
acting properly, a vacuum gauge i/r is fitted on the cover of
each compartment of the wooden box. By proper choice of
the diameter of the belt pulley and the relative numbers of
teeth in the gearing wheels, the shaking off of the lampblack

Fig. 39.

from the filters may be arranged to take place at any desired
intervals. The two draw-off pipes t and ^^ are connected
with the exhauster, and if more than one of the pieces of
apparatus described is used the draw-off pipes of each are
connected by elbows with a common main L which proceeds
to the exhauster. A cock is provided for drawing off condense
water from this main.

Tighe's Process.

In the preparation of lampblack according to the American
patent of Tighe of Pittsburg, the vapour of hydrocarbons is

PIGMENTS FOR PRINTERS* BLACK INKS. 109

exposed to a high temperature in a retort, so that no com-
bustion, but dissociation, ensues. On cooling the products
lampblack is deposited. It may be questioned whether this
process will give carbon finely enough divided in view of the
graphite-like nature of carbon deposited in glass retorts.

Chemical Preparation of Lampblack.

With whatever care the manufacture of lampblack may be
carried out, we never get a perfectly black product, because
the carbon is invariably accompanied by a greater or less
quantity of the products of distillation, partly solid and partly
liquid. The effect of the presence of these bodies is that the
lampblack is more or less of a brownish shade, which becomes
best seen when the lampblack is spread out on paper. When
the layer is of a certain thickness it will be clear that the
colour is not black, but an impure brown. If we analyse such
lampblack just as it comes from the flues, we shall see that
various chemical solvents dissolve ingredients of the lamp-
black, sometimes in large quantities. It is, in fact, possible
by proper chemical treatment to remove the foreign bodies
from the carbon almost entirely, so that a substance is left
consisting practically of pure carbon. This rightly purified
product can be got by boiling the lampblack repeatedly in
strong caustic soda lye until the lye remains colourless.
When caustic soda has dissolved out all it can, but not before,
the residue is boiled with aqua regia till that has dissolved
all it can. When the aqica regia too remains colourless, every
trace of acid is washed away with water, and the lampblack
is then finally dried.

As a result of this treatment the lampblack becomes an
extremely soft powder of the purest black hue known, and
consists of chemically pure carbon in the amorphous state.
When heated on platinum foil, it burns to pure carbonic acid,
without the production of either smoke or smell. In practice,
the purification of the lampblack is not carried quite so far as

110 OIL COLOURS AND PRINTERS' INKS.

to get chemically pure carbon. If this were done, the yield
would be made too small, without sensibly improving the
product as an article of commerce. The object of the
manufacturer is gained as soon as his lampblack is no longer
brown but black.

We can use the solvent action of caustic soda lye to get rid
of the brown bodies which are mixed with the raw product.
For this purpose we boil the lampblack several times in iron
vessels with the strong lye. It is, however, unnecessary to
keep on until the lye remains colourless ; we may stop when
it has a pale brown colour only. Even at this stage, the
lampblack has no perceptible tinge of brown and appears as
a velvety black and extremely soft powder, of very great
covering power. Even although caustic lye is now fairly
cheap, this method of purifying lampblack must be regarded
as a rather costly one, because it requires much labour.
Hence it is only employed in making the finest lampblack
for special purposes.

Calcining Lampblack.

As already mentioned, the substances which make lamp-
black brown are products of dry distillation and are therefore^
volatile. The lampblack can hence be purified from them
by heating it without contact of air. The temperature
required to get rid of them entirely is somewhat high and it
is necessary to raise the pigment to a bright red heat to be
sure of success. If the heating is too rapidly done or the
temperature is too high, the lampblack suffers a change which
injures its quality, as the flaky form of the pigment is lost,
and it takes the shape of grains which require much longer
rubbing up with boiled oil to produce a uniform mass. The
flaky lampblack on the other hand mixes with the oil easily
and rapidly.

For the ignition of lampblack boxes of sheet iron are used,
painted outside to protect the metal from the fill. This

PIGMENTS FOR PRINTERS* BLACK INKS. Ill

painting is best done with an ordinary plaster of loam and
hair. The loam is stirred up with water to a very thin paste,
which is painted uniformly over the outside of the iron box
with a brush, repeating the application several times, but
never applying another coat till the last is dry. When this
is finished, several more coats are applied, the loam being
this time mixed with chopped tow or cowhair. This is
repeated until the total thickness of the coating is several
mm. Such a coating, carefully laid on sticks very close,
enables the boxes to be used for a very long time, while un-
protected ones are quickly burnt through.

Very special care must be used with the boxes. Their
bottoms should be coated with loam, and the covers must fit
accurately and the join must be caulked with loam while the
box is in use. The lampblack must be rammed into the
boxes to a solid mass. A very small hole is made in the
cover to allow of the escape of the volatile bodies. When the
boxes are placed in the furnace, they are gradually heated,
applying the heat first at one end.

The temperature is gradually raised, and extended over
the rest of the box. Finally a bright red heat is reached at
which the box is kept for half an hour. This treatment
drives off the volatile matters almost entirely and gives the
lampblack its proper black colour. As above stated the
greatest care must be taken to protect the lampblack from
the air while it is red hot, as it is very combustible. The
small opening in the cover for letting out the volatile bodies
must be the only orifice of any kind. Even a crevice in-
visible to the naked eye will let in quite enough air as the
box cools to produce a very noticeable loss of lampblack by
combustion.

To prevent this loss altogether the cooling of the boxes
must be attended by special precautions. When the boxes
are withdrawn from the fire with tongs and left to cool, air
can get in at the small hole in the lid ; if, however, a red-

112 OIL COLOURS AND PRINTERS* INKS.

hot coal is laid on this hole the oxygen of the air is converted
into carbonic acid as it enters, and hence any burning of the
lampblack is rendered impossible, as no oxygen but carbonic
acid only comes into contact with it. As soon as all the
boxes are taken out of the furnace, they are exposed to a
free current of air to cool them as quickly as possible.

As finely divided carbon burns at a temperature much
below redness, the boxes must not be opened till their
contents are quite cold. An attempt to empty them while
hot might cause the whole contents to burn.

To get lampblack of great fineness and depth of black,
a single calcination is insufficient. The procedure must be
repeated as often as five times, and for specially fine kinds
even oftener.

CHAPTEK XIV.

SUBSTITUTES FOR LAMPBLACK.

The unavoidably complicated nature of lampblack manu-
facture, and the want of uniformity of the products delivered
by manufacturers, have necessarily created attempts to find
substitutes for lampblack. Whether these substitutes have
justified themselves in practice has not become known, but
I think they might at all events be used for common
pigments, so long as their specific gravity is not too great,
and there is no danger of their separating out from the
mixed paint. Among these substitutes are blacks from tar,
and tannin-black from leather-cuttings, the production of
which will here be fully described.

Black from Tar.

A factory recently erected for the manufacture of black
pigment from tar, and which sends its product mostly to
England, has six boilers, heated by tar, which supply steam
for an 8 h.p. engine. The boilers are arranged so as to afford
free access to each of them. Each boiler is 4 metres long
and '65 metre in diameter. Each is carried on brickwork by
two bearers, and both open into a common steam chest above
them. The tar is brought in casks by a small railway
to the front of each boiler, where there is a container
holding 2 caskfuls, and emptied into it. Behind each boiler
is a chamber, in which the black smoke developed from
the burning tar, which has been gradually cooled by pass-
ing under the boiler, deposits the lampblack on iron plates
disposed horizontally and vertically in various parts of the

114

OIL COLOURS AND PRINTERS INKS.

chamber. The lightest black is deposited in the upper
parts of the chamber which have not to be emptied so
often as the middle and lower parts, which are relieved of
their contents after the combustion of each charge of tar,
i.e., after the combustion of the two caskfuls from the
container in front of the boiler. Three boilers are fired

Fig. 40.

at a time, so that steam is kept up by one trio while the
charge of lampblack is being drawn from the other. The
residue on the grates is fine coke. The chamber 9 are
covered with iron plates, and rise to a height of 5 metres,
being 1 metre above the roof, so that the upper part
can be emptied from without by means of an iron ladder,
while the lower divisions of the chambers are emptied from
inside the boiler house by means of iron doors in them.
Tho largest part of the black settles in the lower compart-

SUBSTITUTES FOR LAMPBLACK. 115

ments as above stated. The lampblack from these is for
the most part mixed with peat, finely ground in a pug-
mill, and is then packed in barrels. A small part of it,
however, is sent away without any admixture of peat.
The 8-horse engine provides the power for driving the
pug-mill, the peat-preparing apparatus, the mixing plant,
as well as for a packing machine, a cask-making machine^
etc. The cost of installing a factory, such as above de-
scribed, with the six boilers is from M.8,000 to M.9,000.

Pbeparation of Tannin Black.

The raw material for this product is waste leather of every
kind, old leather and leather articles, and also animal waste
containing gelatine, and tanniferous products of all sorts,
barks, fruits, leaves and roots. These substances are dis--
solved with or without steam in two different operations.

1. Five hundred kilos, of the mass is mixed with about
1,600 litres of water in a vessel, and the whole is then heated
by steam for a few hours without, however, being allowed
to boil. This first decoction is then drawn off, and another
lot of water is added with about 25 kilos, of caustic soda or
the equivalent quantity of carbonate. The whole is then
boiled for a few hours, and the decoction is added to the
first one, to which have been added in the meantime about
4 kilos, of ferrous sulphate or the equivalent amount of
chloride, acetate, or sulphide, to precipitate the gallotannic
acid. This should be down by the time the second decoction
is ready. After the second decoction has been run off, 14
kilos, more of ferrous sulphate or an equivalent amount of
one of the above alternatives is added, with a little alum
to complete the precipitation. After careful stirring the
mass is left to stand for a time and then pimiped through a
filter-press to free it from water. The black is got from the
filter-press in solid cakes. To prevent any liability on the
part of the black to get mouldy, about 16 litres of heavy tar

116 OIL COLOURS AND PRINTERS* INKS.

oil are added to each of the two decoctions. The oil owes
its preservative power to the presence in it of creosote and
carbolic acid.

2. We treat 500 kilos, of leather exactly as in No. 1,
except that 15 kilos, of caustic soda (or its equivalent of
carbonate) is used for the first decoction and 20 kilos,
instead of 25 kilos, for the second decoction. The same
amounts of iron salts, of water, and of tar oil are used as
given above, and the whole process is identical with the
exception mentioned.

If the black is to be used for printers' ink, a little cyanide
of potassium or logwood extract or decoction is mixed with
the precipitate, so as to give it a blue or violet tinge.

After leaving the filter-press, the mass is washed with
steam to free it from adhering salts. The quantities given
above can be altered without affecting the principle of the
invention.

For printers' ink the black is dried till it has lost half its
weight, and will then make with boiled oil a mixture in any
proportion which may be desired. To make oil paints we
proceed in similar fashion with black and drjdng oil.

An improved process is described as follows. The leather
cuttings are mixed with a suitable quantity of iron-salt,
preferably the chloride, corresponding to the amount of
tannin in the leather. On the average 500 kilos, of cuttings
require 30 kilos, of solid chloride. The mass is then covered
with water and boiled up with direct steam. The boiling
lasts five or six hours, until the whole mass has become
black. The boiling can also be done by a steam jacket or
a naked fire. The mass is then thoroughly washed with
hot water or steam, the acid washings are neutralised with
powdered iron ore or scrap iron, and can then be used instead
of part of the next lot of chloride of iron.

The solid residue is dried and ground fine. It can be used
for making printers' ink instead of lampblack.

CHAPTEK XV.

MACHINERY FOR GRINDING AND RUBBING UP PIGMENTS.

Although nearly all the pigments which the maker of oil-
paints and printing inks uses are dehvered to him in the
finest powder, it may happen that he has to grind a lump
pigment or that the pigment he has bought, although it has
been ground, has not been ground fine enough for his purpose.
Experience has taught us that pigments when in the form of
the finest possible powder can not only be worked up the
most quickly and easily, but give the best products, as they
are much more ready to mix uniformly with the vehicle.
When rubbing up thick colours, i.e., with a small amount of
vehicle, care must be taken that the machinery is not clogged,
and so perhaps stopped altogether.

Earth-colours, such as the ochres, ball when stocked damp
or have become damp during carriage, and when dried again
form hard lumps which must be ground before being mixed
with any vehicle.

The most simple apparatus for grinding such lumps is a
pug-mill, which consists of two flat circular stones, which
move in a metal or wooden pan with a bottom of metal or
stone, by means of toothed gearing, and crush the lumps by
their weight, converting them into a powder more or less
fine.

Bonner Ball-mill.

The ball-mill of the Bonner Bergwerks und Huttenvereins
consists of a casing having the form of a cylinder with ends

118

OIL COLOURS AND PRINTERS INKS.

consisting of segments of spheres. This includes a loose ball
of only slightly less diameter than the cylinder. The apparatus
is represented in fig. 41. The casing is made of cast iron or
steel, and should be in as few pieces as possible. The one in
the figure consists of four segments B and two side walls
C C, which are kept together by bolts c. As a result of this
very simple construction it is possible to replace a damaged
or worn one with great quickness and ease.

The side walls C C are pierced by the hollow tnmnions
C C'^, whose bearings are on the framing G G, and on which

Fig. 41.

the casing rotates. The axles are hollow, so that the material
to be ground and the products of the grinding can be passed
through them. The mill is filled through C^ and an exhauster
sucks the ground stuff out through C^. The grinding ball is
of iron or steel and weighs from 1,500 to 3,000 kilos, according
to the nature of the material to be ground. As above stated
the ball has a little side-play between the sides of the cylinder.
This arrangement has a great advantage over the old-fashioned
contrivance of a stone-roller running in a casing, as it never

MACHINEBY FOB GEINDING PIGMENTS.

119

causes clogging, which so frequently occurs with the roller.
Most of the grinding is done by the sideway play of the ball.
The casing is best turned direct by putting a belt round it, as
shown in fig. 42. It is of great advantage in increasing the
work done by the machine to have niches a along the path of
the ball. These get filled with partly ground stuff which is
constantly emptied out of them by the rotation of the casing
and thrown back on to the ball again. The niches thus serve
to lift up the material and distribute it. The running of the
ball in its path and its side-play make the action analogous to
that of rollers without the complexity and unreliability of the
roller-mill. The ball should not have too much play, as if it
has the grinding will be slower.

^^^

When the grinding is finished the product is removed by
the exhauster. It is a good plan to insert between the mill
and the exhauster a series of chambers in which the product
will sort itself, the finest being deposited in that farthest from
the mill, and the coarsest in that farthest from the exhauster.

Another very excellent machine for grinding pigments is

12a

OIL COLOUBS AND PRINTEBS INKS.

Glaser's Disintegrator.
The action of this new form of mill, shown in fig. 43,
depends upon the rotation of a disc armed with projecting

Fig. 43.

beaters, which knock the material against the sides of the
casing in which the disc runs till it is broken up small enough
to fall through a sieve out of the mill.

This mill has great advantages over other similar systems.

MACHIKEEt FOE GBINDING PIGMENTS.

12X

It is built much more simply and solidly, has only one driving
belt, is easier and quicker to clean, wears out less and requires
no special foundation. The characteristic action of this mill
explains its extremely large output for a comparatively small
amount of wear and consumption of energy. The new mill
requires no sharpening, and worn parts can be cheaply and
easily replaced. In grinding wet, sticky, or resinous material,
it is very rare for the mill to choke, and if it does it can be
cleared in a few minutes. It is also an excellent apparatus
for intimately mixing bodies together.

Fig. 44.

The machine can be fed with pieces the size of a hazelnut
or the fist, according to the size of the mill and the character
of the stuff to be ground. To bring the material into small
enough pieces to go in the mill, other apparatus has to be
used when necessary. A preliminary breaking apparatus
which will take pieces twice the size of a fist may be had
attached to the mill. A hand wheel permits the regulation
and the clearance of the disc carrying the beaters from the
inside of the case, so that the material can be ground coarser

122

OIL COLOURS AND PRINTERS INKS,

or finer at will, a correspondingly sized sieve be^Jng, of course,
also used.

Wherever, as in colour grinding, a very finely powdered
and absolutely uniform product is demanded, a sieve is
essential, and various well-constructed sifters are to be had.
In Glaser's mill the regular feeding is provided for by
elevators which raise the material to the necessary height, and
then carry it horizontally into the mill, such as Archimedean

Fig. 45.

screws, etc. In order to get the proper speed, complete
series of belt pulleys should be provided. The mills for a
daily output of 400, 1,500, 4,000, 8,000 and 15,000 kilos, for
medium, heavy and hard material, and for a medium fineness
of grinding at from 120 to 1,200 gulden Austrian currency
require, with a speed of 4,000, 3,000, 2,000, 1,000 and 300
revolutions, a power of i, 2, 4, 6 and 10 h.p.

A very pretty combined mill and sifting apparatus by the
same firm is represented in fig. 44. It consists of a mill.

MACHINEBY FOR GRINDING PIGMENTS.

123

elevator, sieva, dust-chamber, a feeding hopper, gearing, etc.
It can be put down anywhere convenient without special
fixing, and started at once by connecting it with a belt to the
driving power. No attention is required except to keep the
hopper supplied, and to remove the stuff as it is ground. ' To
remove bits of iron which are common in grist in the shape
of nails, etc., magnetic apparatus is provided.

The fine powder got with these various mills is not in all

/ Fig. 46.

cases fit for immediate use, but must be sieved for sorting it
into various degrees of fineness. As this is impossible with
hand sieves, partly on account of the large quantities to be
dealt with and partly because the dust would be injurious to
the health of the sifter, various kinds of sifting and winnowing
machines of known construction are employed.

Centrifugal Sifting and Winnowing Machine.
The centrifugal sifting and winnowing machine represented
in fig. 45, by Zemsch of Wiesbaden, is used when the sifting

124 OIL COLOUBS AND PRINTERS* INKS.

of similar substances is to be done, or some amount of ad-
mixture in the sifting of the substance with others previously
sifted is unimportant, as the drum inside the case is awkward
to clean. Quick rotation is given to the sifting cylinder, in
which beaters are moved by gearing, as soon as the rotation
begins. The grist enters through a safety basket to catch
stones, nails, etc., into one end of the machine. Dust cannot
iiy about and the finest brass or silk gauze can be used for
the sifting.

Sieving and Mixing Machine.

The machine shown in fig. 46 serves for simultaneous
sifting and mixing. It is the only existing arrangement
whereby the whole of the bolting cloth can be taken out
quickly and easily if it is desired to substitute a different
mesh. The brush roller, set with the best stiff bristles,
rotates in a semi-cylindrical sieve, and can be approached
thereto as the brushes wear. It is enclosed hermetically so
that no dust can fly about. Any lumps in the grist are com-
pletely destroyed by the rotating cylinder. The product of
the machine falls into a receptacle below, while anything too
coarse to go through the machine leaves it at one end. The
sieves are made of strong iron or brass wire, and fixed into
their place by soldering. They are very durable. A corru-
gated iron half cylinder is substituted for the sieve for mixing
powders with liquids. The arrangement of the brushes, like
an Archimedean screw, provides a horizontal as well as a
rotatory motion, which makes the mixing more complete and
more rapid.

CHAPTEE XVI.

MECHANICAL CONTRIVANCES FOR MIXING VEHICLES
WITH PIGMENTS.

When large quantities of pigment have to be dealt with mixing
them by hand is a toilsome and time-wasting process, and
must be replaced by mechanical mixers. Such contrivances
are the more essential when the paint has to be mixed very
stiff, i.e., with very little vehicle, or when, as in printing inks,
the vehicle itself is tough and the pigment (like lampblack
for example) is very light, in which case the amalgamation of
the two is very difficult. In fact it is practically impossible
to effect it at all by hand, except in extremely small quantities.
For thin colours containing much vehicle the machines may
be dispensed with, but for thick and tough mixtures they are
indispensable.

Quack's Machine.

A very simple apparatus for the purpose is the mixing and
kneading machine of E. Quack.

Figs. 47 and 48 show the machine in vertical section and
in elevation respectively. In the cylinder with smooth walls
turn two blades overlapping as shown. They turn in opposite
directions, and work the contents of the machine into a perfect
mixture in a very short time and with a less expenditure of
power than any other machine. The work goes on with
mechanical accuracy to its termination. The particles under
treatment are driven about until the whole mass has been
worked through. The rotating blades scrape each, other and
also the walls of the cylinder, so that nothing can escape them.

126

OIL COLOUBS AND PRINTERS INKS.

Fia. 47.

Fig. 48.

The machine is emptied by just tilting it, the blades being
kept going on all the time to prevent anything from remain-

MECHANICAL CONTBIVANCES FOR MIXING.

127

ing sticking to the walls of the cylinder. When the machine
wants cleaning it can be at once taken to pieces by loosening
a few wedges.

Werner and Pfleiderer's Machine.

The kneading and mixing machine of Werner and Pfleiderer
of Cannstatt has the most simple principle imaginable (see
figs. 60a, 50b), and it is said to have achieved results hitherto
impossible. The machines are made in all sorts of sizes

128

OIL COLOUBS AND PRINTERS INKS.

from a capacity of i up to 1,400 kilos. The charge that can
be worked up at one time depends not only on the sp. gr. of
the substance, but to a large extent on its consistency and
other properties. In most cases a machine of the stronger
class is well suited by its shovel form and general construc-
tion to do the work of a small machine on occasion, but the

Fig. 50a.

use the machine is to be put to, e.g.^ whether it is for oil-paint
or for printers' ink, should be specified on ordering.

In working the kneading knives rotate in opposite directions
inside the case. To save time and increase the action the
motion must be reversed from time to time. The machine
works best when not too full for the lively and characteristic
movements of the mass to be observed. With dry materials
even when the blades are entirely covered these movements
can be seen. The machine is tipped up to empty it. Some

MECHANICAL CONTRIVANCES FOR MIXING.

129

of the machines can be: readily taken to pieces: to bejjleiaiied,
the trough and the blades separately, c

Lehmann's Machine.

M. Lehmann of Dresden Lobtau mixing machine "for

pigments is represented in figs. 49 and 51. The machine
represented in fig. 51 consists as will be seen of a strong iron

Fig. 606.

stand bearing a cylindrical trough, which can be rotated on
its longest axis. It contains a mixing arrangement consisting
of segment-shaped blades which, when the trough is rotated,
produce a thorough amalgamation of the contents of the
trough, whether dry powder, boiled oil, or mixtures of oil
and pigment.

130

OIL COLOURS AND PRINTERS INKS.

The machine is made in two sizes for 200 and for 40 kilos,
of pigment, and costs M.600 and M.400 respectively.

All these machines mix together oil and pigment in a com-
plete manner, but do not make the pigment any finer-grained.
They do not give the ointment-like consistency characteristic

Pig. 61.

of a good oil paint, but a lumpy mass which has to be rubbed
down with the hand or on a stone by means of a muUer.

To get the ointment-like consistency, further treatment
is required, which combines mixing with crushing. For
very small quantities a stone and muller suffice, but special
machinery called paint mills is needed for large quantities.

OHAPTEE XVIL

PAINT MILLS.

These machines may be classified as follows : —

1. Those which work by taking the material between two
slanting corrugated surfaces, one of which is stationary while
the other rotates.

2. Those which take it between two flat-ribbed surfaces,
• which both move eccentrically but in opposite directions.

3. Those which take it through a system of from two to
four rotating rollers of steel, bronze, stone, or porcelain.

Tho first class is the one most used. The machines be-
longing to it are cheap and are made in all sizes, and several
of them are to be found in every paint factory.

Their simple construction is shown in fig. 52. They are
entirely of iron, except the rubbing surfaces which are of
bell or gim metal. The mixed colour is put into the funnel
T, the grinding disc M is pressed more or less on to the funnel
T by means of the set screw S, according to whether the
scraper P is to deliver a finer or a coarser colour. The
grinding disc is provided inside with notches which run to-
wards the conical point in the centre of it. The interior of
the funnel is als9 grooved. As these grooves wear they
must be filed out again, because on them depends the fine-
ness of the colour. The machine stands on a tripod. In an
improved form specially introduced by the Brockhaus firm
for printing inks there is a massive stand, and the funnel is
more than twice as deep.

The chief drawback of this machine is that its output is
small, as the colour stays in it long after it is finished. The

132

OIL COLOURS AND PRINTERS INKS.

finer the colour has to be rubbed down, the more this incon-
venience makes itself felt, and in fact when very thick colours
are being rubbed very fine hardly anything will come out of
the machine. Schlager of Ybbs has improved the machine
by taking away the stand, and putting the grinding disc and
funnel on a common vertical axis. The funnel is also closed,

and air pressure is exerted upon the pigment within it by
means of a pump. This pressure drives the finished colour
out of the machine. The pump is geared with the machine
so that both are set in motion together, and very little power
is required. Many tests have shown that these alterations
have not only greatly increased the output of the machine,
but that the machines can be made very much lighter. .

PAINT MILLS.

133

Plate Machines.

The plate machines belong to the second class, and give
an excellent output. They rub extraordinarily fine and last
for years without repairs on account of their very solid
construction. The machine consists of a massive cast-iron

Fig. 63.

stand, two plates, the spindle or axle, which is closely united
to the funnel, and has a strong spiral spring inside of iron
wire, the funnel to receive the colour, and the set-screw
under the lower plate. When the machine is to be started,
we put the plates close together by means of the set screw,
fill the funnel with paint, release the plates a little and set
the gearing in motion. The upper plate and the funnel then

134 OIL COLOURS AND PRINTERS* INKS.

rotate with a screw-like motion, while the lower plate rotates
in the opposite direction. The object of the spiral is to hold
the scraper which is placed where the edges of the two
plates, which have not a vertical axis, meet. To clean the
machine we remove the spindle, funnel and plates^ and the
spiral from the inside of the spindle.

EoLLEK Machines.
The best makes of paint-mill are those which act by means
of rollers made of various hard substances. They are

Fig. 54.

certainly rather expensive, but they make up so fully for
that by the fineness of the colour they produce and by the
magnitude of their output that no colour factory is complete
without them. For artistic painting they give colours rubbed
finer than is possible with any other system.

Fig. 54 shows the roller machine of J. M. Lehmann for
printing and lithographic inks, and oil paint. The various
sizes of this machine include three very finely polished rollers
of green porphyry, which are harder than steel, and have

PAINT MILLS. 135

the property of clinging to the colour, whereby great fineness
of colour and large yield are ensured. If the machine is
rightly handled the colour cannot escape at the ends of the
rollers. Unequal speeds are imparted to the rollers, and
the front one has also a lateral motion. One very valuable
character of the machine is that at the end of the work the
porphyry rollers run off quite clean, so that they waste no
appreciable amount even of quite small charges, which can
therefore be taken by the larger sizes of mill.

The paint, etc., is poured between the first and the second
roller, and is rubbed fine by the stones, passing to the scraper,
which delivers it into a receptacle placed below the mill.

The enormous output of these machines may be illustrated
by the following figures : —

No. 1 delivers about 3,000 kilos, white lead or 200 kilos, printing ink
» 2 .. „ 2,500 „ „ 160 „

» 3 „ „ 1,600 „ „ 100 „

» 4 „ „ 1,000 „ „ 70 „

per day, and other pigments in proportion. This is with the
finest grinding. The four sizes require 2i, li, 1, and i h.p.
respectively. Other sizes are made for hand-power, e,g,, No.
5, which will deal with 300 kilos, of white lead daily.

Similar machines are built by H. F. Stolberg of Offenbach
a. M., Beyer Fr^res of Paris, and others, but Lehmann has
the best reputation in Germany and Austria, and his machines
are practical and well made.

The fineness demanded of the colour naturally affects the
output and it is unreasonable to expect a machine to deliver
as much fine colour for art work as it will coarser colour for
house -painting, independently of the great toughness, and
many things, such as printers' ink. This too has an effect
upon the output of any mill. The striking difference made
in the output of Lehmann's machine by using it for printing
ink instead of white lead, as given above, shows this very
clearly.

CHAPTBE XVIII.

MANUFACTURE OP HOUSE OIL PAINTS.

Ordinary house paint consists of pigment and vehicle. The
latter may be according to circumstances linseed oil, bleached
linseed oil, boiled oil, or bleached boiled oil. Both the essen-
tial parts of the paint must have certain qualities to produce
a good, usable, and durable paint, which may be stated as
follows : —

We require of the pigment : —

1. That it should be perfectly dry.

2. That it should be in the finest possible powder, without
admixture of sand, and that it should feel soft to the fingers.

3. That it should be as free from adulteration as is consist-
ent with the price paid for it.

4. That it should have the necessary fastness to light and
air.

5. That it should have sufficient body.
^ We require from the vehicle : —

- 1. That it should have the proper consistency, neither too
thin nor too thick. If it errs in the second particular, the
paint will not go on easily with the brush; if in the first,
the colour will not stick on, and is apt on inclined or vertical
surfaces to run down before it dries.

2. That it should not perceptibly affect the colour of the
paint, especially when that is to be white.

3. That it should dry properly.

4. That it gets hard, and has a sufficient resistance to
weather and atmospheric influences.

Raw and boiled linseed oil, exposed to the action of the air.

MANUFACTUHK OF HOUSE OIL PAINTS. 137

^ter by ct^^dation and the heat o! the sun. Free linoleic acid
becomes linoxic acid, the nndecomposed linoleine becomes
linoxin. The coat thus formed is durable and resistant to
outward influences, but after a long time the hnoxin itself
ddcomppses, becomes brittle, and flakes off.

Linseed oil itself is the best vehicle for pigments, but it
dries top slowly, and must therefore be replaced by boiled
linseed oil. The driers added to the oil during the boil make
it dry not only quicker but harder, while at the same time,
especially with lead driers, they make the coat less durable
than if the raw oil had been used alone.

The qualities to be demanded of a house paint may be
divided into those which can be recognised by inspecting the
paint, and those which can only be known by its behaviour
after use. In the first class we have four properties : —

1. That the paint has the proper consistency, i.e., is ready
for the immediate use of the brushy and can be applied to the
surface to be coated in a satisfactory manner.
; 2. That the paint has been properly rubbed up. Every
particle of the pigment must be wrapped up in the vehicle
and be penetrated by it, so that the whole is Uke an ointment,
perfectly uniform and free from perceptible grains.

3. That the paint dries quickly and hard enough.

4. That the paint covers well enough. It must be of
sufficient body to conceal entirely the surface to which it is
applied.

; In the second class we have three properties : —

1. The paint must not injure the surface to which it is
applied, either by its own chemical properties, or by its own
in conjunction with those of the vehicle, whether by galvanic
action or otherwise. Neither on the other hand must there
be any appreciable effect exerted on the paint by the surface
to which it is applied.

2. The paint must adhere well to the surface painted, and
must at the same time be elastic enough to prevent changes

138 OIL COLOURS AND PRINTERS^ INKS.

of temperature from producing cracks by alternate contraction
and expansion.

3. The paint must be durable, i.e., must resist the destruc-
tive influences of the environment, whether they are mechan-
ical or chemical, and must form a coat hard enough to permit
of being cleaned and polished.

To make the paint answer all these conditions, however,
something more is necessary than depends upon the paint,
viz. : —

1. The vehicle must be chosen with care and with reference
to the use the paint is to subserve. This choice is dependent
partly on the nature of the surface to be painted and partly
on the influences to which it is subsequently to be subjected.

2. The materials used must be pure and suitable for the
object of the painting.

3. The application of the paint must be done in a careful
and workmanlike manner.

We can now see that before a paint can be pronounced
good a whole list of requirements must be satisfied, and also
that it may not be the fault of a paint that it does not answer,
if it has been improperly used.

Assuming that the pigment has been properly chosen, I
proceed to the manufacture of oil-paints, i.e., to the mixing
of the pigment with the vehicle. All pigments must be in
a proper condition before they go to the paint-mills, because
the machine is not intended to mix and grind at the same
time. On a small scale we stir the pigment a little at a time
into raw or boiled linseed oil imtil we have a perfect mixture
in which no solid matter is distinguishable. On a large scale
we use one of the machines already described.

As regards the proportion between vehicle and pigment, it
must be remarked that the paints of commerce are usually
mixed very thick, partly because it is to the interest of the
manufacturer to use as little vehicle as possible, because the
vehicle is usually dearer than the pigment, and partly because

MANUFACTUBE OF HOUSE OIL PAINTS. 139,

oonsumers think that a thick paint is better than a thin one,
and also because thick paints are better for sending to a dis-
tance. These circumstances have to be carefully borne in
mind. If we want thin paints, the process of mixing is very
easy. We simply take the pigment and stir it up in as much
vehicle as is necessary till we get a uniform product. It is,
however, quite another matter to make a thick paint, i.e.,
pigments containing no more liquid than is necessary to make
them into a paste, so that they can be diluted just before use.
In making such paints we soon find that there is an excess
of pigment over vehicle which cannot be exceeded, and which
in any case makes the mixing more and more difficult, and
makes it require more time and more power. Certain
pigments, such as the ochres, require far more vehicle than
others, but the manufacturer, on account of the greater price
of the vehicle, uses only from two-thirds to three-quarters of
the weight of the pigment. This being the case with the
Ughter pigments, the heavier ones, such as lead and chrome
colours, want evdn less vehicle. With these a weight of
vehicle amounting to one-quarter to one-third of the weight
of the pigment will give thick paints.

It is often impossible for the paint manufacturer to deUver
pure paints for the price, and he has therefore to thin with
heavyspar. If in his dealings with the pigment manufacturer
he buys only cheap kinds he gets the heavyspar in without
having the trouble of getting it and mixing it in himself, al-
though he had better do so. In these cases it is very hard to
draw a line between adulterated and unadulterated goods,
and a pigment can then only be regarded as the latter when it
contains foreign ingredients out of all proportion with its price.

When the mixing has been perfectly done, the mixture is
put through the paint mill, where it is brought to the desired
degree of fineness. In special cases, where extra fineness is
needed, the paint must be put twice or even three times
through the paint mill.

140 OIL coLOUBS AKi) Pointers' Inks.

I now give various recipes for partieular mixed paints,
which would require too much space to specify more par-
ticularly.

White Lead Pigments.

Kilos.
Pure white lead in powder . . . . . . 23

Bleached or ordinary linseed oil . . . . . 6

Pure white lead in powder ... . . . 18

Pure white heavyspar ....... 5

Linseed oil . . . . . . . . . 6

Pure white lead in powder . . . . . . 18

Pure white heavyspar ....... 6

Linseed oil ... 7

Pure white lead in powder 13

Pure white heavyspar 15

Linseed oil l3

Zinc White Figments.

Kilos.

Finest zinc white . 11 '

Bleached or ordinary linseed oil 5

Finest zinc white . . . . . . . . 11

Pure white heavyspar 6

- Linseed oil 7

Grey Colours

are made by mixing any of the above whites with a black
such as graphite or lampblack, or with a blue such as ultra-
marine or Prussian blue, or an ochre.

Yellow Pigments.

Kilos.

Ochre 33

Heavyspar . . . ... . . . 15

Boiled oil 18

Ochre ] , . . , . 26

Pure white lead . 6

Boiled oil . . 10

MANUFACTURE OF HOUSE OIL. PAINTS.

141

Pure white lead
Ochre
Heavyspar
Boiled oil

Chrome yellow
Boiled oil

Chrome yellow
White lead .
Heavyspar
Boiled oil

Bed lead
Heavyspar
Boiled oil

Venetian red .
Heavyspar
Boiled oil

Venetian red .
Heavyspar
Ochre
Boiled oil

Cinnabar
Chrome orange
Linseed oil

Bed Pigments.

Green Pigments.

Chrome green
Boiled oil

Chrome green
Boiled oil
Heavyspar

Schweinf urt green
Zinc white
Boiled oil

Zino green
Boiled oil

Kilos.

30
5

15
21

Kilos.
30
22
12

10
5
5

20
10
10

Kilos.
11

11
6
5

13
12

142

OIL COLOURS AND PRINTERS INKS.

Blue Pigments.

Kilos.

Ultramarine blue 7

Zinc white 10

Boiled oil 6

Ultramarine blue 7

Zinc white 10

Heavyspar 6

Boiled oil 8

Prussian blue 10

Zinc white 5

Boiled oil 8

Brown Pigments.

Kilos.

Umber 21

Boiled oil 8

Umber 21

Heavyspar 10

Boiled oil . 10

Velvet brown 16

Boiled oil 8

Filling up * 20

Boiled oil 8

Black Pigments.

KUos.

Vegetable black 22

Boiled oil 10

Vegetable black 11

Heavyspar 5

Boiled oil 6

Lampblack 10

Boiled oil . 11

* Sic in the original. — Tr.

MANUFACTUBE OF HOUSE OIL PAINTS. 143

Hugoulin's Pbocbss.
We prepare in a glass or earthenware vessel a thin homo-
geneous paste with water and one of the following substances
in fine powder in the proportions given.

To 1,000 kilos, white zinc oxide 300-400 kilos, water
» ., » grey „ „ 160-180 „
„ „ „ white lead 160-180 „ „

„ „ „ red lead 80-160 „ „

„ „ tj lampblack about 1,000 „ „

To this paste we add enough linseed oil to make a con-
sistent colour by thorough stirring until the oil has taken the
pigment from the water. The water is then decanted from
above the mass, which is then kneaded up exactly like butter
to get all the water out of it. Finally a greasy mass remains,
which, when it has to be used, is diluted to painting con-
sistency with oil. This colour is shown by the throwing out
of the water to be a true compound (this it is not, but the pig-
ment has more tendency to mix with oil than with water) ^ and
has all the appearance of one. If other minerals than those
given are used, e,g,, ochre, earth-colours, copper compounds,
etc., no throwing out of water takes place and however long
we stir, the mass remains a mixture of oil, water and pig-
ment. Combination only takes place beween linseed oil and
white or red lead, white or grey zinc oxide, or chrome yellow,
or lampblack, whereby the preference that these pigments
enjoy as a consequence of practical experience of their power
of protecting wood and metal is explained.

The process for making these house paints on any scale,
small or large, is as follows : One of the above-mentioned pig-
ments is worked to a paste with water and a wooden spatula.
This paste is then thinned with more water, and run through
a silk sieve. It is best to have the paste very thin so that
it will flow freely through the sieve. The sieve usually

^ This is evidently an interjection of Andes in a quotation from a
speoifioation.

144 OIL COLOURS AND PRINTERS* INKSw^

keeps back about J per cent, of the pigment, which is kept
for fiirther grinding, and also any impurities which may. have
been present, and which neither the paint-mill nor the nciuller
is competent to get rid of . -

The filtered paste is allowed to stand in a vessel to settle,
which may take any time from a few hours to a few days.
The water is then run off, and the pigment is stirred up with
oil for a few minutes. The paste balls together at the bottom
of the vessel. The kneading is then done, and all the re-
maining water squeezed out of the mass and poured away.
Just before use the colour is properly thinned with oil and
siccative. By the above-described process a single workman
can turn out over 100 kilos, of faultless oil paint within two
hours.

The new process is already used to a fairly large extent in
cases where it is a question of making several hundred kilos,
of oil paint at a time, and has always given excellent results.
When it becomes further extended it will perhaps be found
convenient to bring pigments on the market in the form of
the pastes that it requires instead of in the usual dry form.

Zinc grey must be put through the sieve dry, because it
oxidises by long contact with water and forms a solid mass
which will not easily combine with oil. Lampblack is not
eWetted by water, so that in its case 10 per cent, of alcohol
must be added to the water. The lampblack is mixed with
this dilute spirit till it-has the dampness of fresh snuff. In
this form it mingles readily with water. It is then treated
<as above by decanting the water, stirring up with oil, And
kneading out the remaining water.

Process s-or Making Weather-Proop Paint for Walls.

^ The process of.E. G, Thmn (P.|l,P.. 25,137) is as fpllowe :
Mix and grind thoroughly in a mill a mass consisting of 20
per cent, dry silicate of potash, 10 per cent, felspar, 27 per

MANUFACTURE OF HOUSE OIL FAINTS. 146

o§nt. artificially precipitated silicic, hydrate, 90 per cent,
cryolite, 14 per cent, of any natural silicate readily attackable
by caustic potash lye, e.g., pumice, and 19 per cent, of crystal-
lised carbonate of potash. This mixture is then mixed with
about half its weight of pure well-levigated earth-colour, or
other pigment not affected by caustic lime or potash. The
whole mass is thoroughly mixed and sieved through a sieve
with 600 meshes to one square centimetre.

The vehicle consists of thick milk of Ume which has been
passed through a sieve of the same fineness as the dry mass,
and is added to the dry mass in the proportions of about 2
vols, of milk of lime to 1 of pigment. The whole mass is
then put again through the sieve.

The colour is applied like an ordinary Hme-wash. When
dry, which takes about twenty-four hours, the surface is gone
over with clean water several times to accelerate its hardening.
This object is attained still sooner if the water is used hot.
Eain and natural dampness of the air have, of com-se, the
same effect. If the paint has to resist unusual severe
mechanical influences, it is a good plan to harden with a 15
per cent, solution of potash waterglass instead of with plain
water.

The hardening action consists essentially in the formation
of silicate of Ume, formed by the interaction of the silicate of
potash and carbonate of lime. The advantages of the appli-
cation are its resistance to weather, cheapness, handsome
appearance and washability.

Universal Pigment for Use as Water, Oil or Lake
Colour.

By the process of J. Strenli & Co., of Horgen, a colour is
obtained which can be used with oil or water, or as a lake
colour, and may therefore be called universal. Dissolve 1
kilo, of raw caoutchouc in small pieces, by heating it with
about 20 kilos, of linseed oil. At the same time boil 2i kilos.

146 OIL COLOURS AND PRINTERS* INKS.

of Panama wood ^ or flax-seeds in 100 kilos, of water for about
half an hour. We thus get a decoction having an oily
character in virtue of the flax seeds used, which is intended
to facilitate saponification of the materials. Panama wood
has the advantage that a colour rubbed up with a mixture
containing it adheres very strongly to the painted objects,
whether they are of wood, stone or iron. Besides its extract
is very much like the purest soapy water whereby intimate
union with the indiarubber solution is much facilitated.

While this decoction is boiling, the indiarubber solution is
diluted at a temperature of about 100° C. with more linseed
oil, in the proportion of about five times its volume. This
dilute indiarubber solution is then mixed with four-thirds of its
own volume of the decoction, and well stirred up with it to
a thin soapy liquid. The dry pigment is then diligently
stirred up in it till a paste is produced which can be rubbed
up in the paint mill, through which it is at once put. Only
chemically pure pigments can be used for making this uni-
versal colour, for if, for example, heavyspar is added, it is
impossible to get a uniform mixture. The oil would unite
with the pigment and the heavyspar and the water would be
thrown out, and the result would not be a universal colour
but an ordinary oil-colour.

On leaving the paint-mill, the universal colour is ready,
and can be delivered up to the painter for further manipula-
tion.

The materials contained in the universal colour permit of
its uniting easily with water, oil, or varnish, so that the
painter can mix it with water and so get water colour or
distemper, or with oil and so get an oil colour, or with varnish
and so get a coloured varnish. As distemper, the colours are
durable and not liable to mouldiness; as oil colours, they
form lif surface-skin, and without the use of wax give a very

1 Ouillaia bark.

MANUFACTURE OF HOUSE OIL PAINTS. 147

fine and durable coat which can be washed with soap or sdda.
It is cheap as it does not contain wax.

The colours got in the manner just described set harder
than ordinary ones, resist weather, and can be used in or
out of doors either in winter or summer.

Grunzweig's Oil Paint.

Grunzweig mixes a paint consisting of 10 per cent, umber,
5 per cent, yellow ochre, 10 per cent, red lead, 5 per cent,
ultramarine, 5 per cent, zinc white, 25 per cent, white lead,
10 per cent, of graphite, and 25 per cent, of boiled oil.

The surface to be painted with this must have been care-
fully cleaned and dried, and if of iron must have been freed
from rust. The mass can be diluted with boiled oil only.
This heterogeneous colour has probably been patented in
England, so that it may be called " patent ".

To Make Oil Colours Eesist High Temperatures.

This object is reaHsed, according to D.E.P. 17,459, by using
a solution of shellac, camphor and boiled oil in spirit. The
tincture is made paler by treatment with chalk. The surface
to be painted is grounded with a mixture of this tincture with
plaster of Paris, and then painted with pigment rubbed up
with the tincture.

Glasenapp's Black Paint.

This is not exactly a black but rather a dark grey, but has
very great body. It was invented by Glasenapp.

100 lb. of boiled oil made with lead are heated till they
begin to fume, and then 15 lb. of litharge or red lead are
gradually added and digested to complete solution. We then
add gradually 14 lb. of flowers of sulphur and stir diligently.
Finally we add 2 lb. more of the lead oxide and continue
the heat for thirty to sixty minutes longer, to get all the
sulphur (which dissolves readily in the oil) into combination.

143 OIL eOLQURS AND PRINTERS* INKS.

T)i<^ final rather thick liquid is thinned with oil of turpentine^
This application rightly made will dry in ten hours, but if
there is any uncombined sulphur it will take longer. The
presence of free sulphur in the unfinished paint may be
known by the gases given off having a characteristic and
disagreeable smell. The sulphide of lead gradually settles,
but the paint is easily made fit for use by stirring it up.

Vehicle and Fixer for House Paints.

The invention (D.E.P. 3,420) consists in mixing organic or
inorganic colouring matters with the following paste : —

Glue, 25 grammes; glycerine, 534 grammes; water, 208
grammes ; ammonia, 12i grammes ; wax, 208 grammes ; and
resin, 12i grammes. Paints made with this vehicle are suit-
able for a variety of industrial purposes. They form an
advantageous substitute for pastels, and are usable for both
oil and water colour painting. They are easily applied to
fabrics, and also to porcelain, earthenware, etc. By dint of
these properties, and their rapid drying, they are of great
value to landscape painters. The paste is made as follows : —

Mix by heating together 208 grammes of pure white wax
and about 260 of glycerine. When the wax is quite fused,
a solution of 12i grammes of resin in ether is added. JPinally
we add a solution of 25 grammes of fish or other glue in about
260 grammes of glycerine. Then dilute with water and stir
till cold. The paste is then rubbed up with the pigments
£)..nd the paint is ready. The amount of glycerine used has
to be regulated according to the drying power the paint is to
have.

Preparation op a Substitute for Linseed or Turpen-
tine Oil.
. This oil extract (D.R.P. 3,420) is made from colophony
free from turpentine, crystal soda, Uquid ammonia and water,
and is a syrupy mass which can be used witii great advantage
in house painting. The product is made as follows : — ■.

MANUFACTUBE OF HOUSE OIL PAINTS. 149

lOQ-lb* of the colophony, 20 of crystal soda and 50 *^
water are boiled together, and then mixed intimately: with
250 of water and 24 of ammonia.

The resulting product can be used with great success in
the manufacture of all paints as a substitute for oil of turpen-
tine or linseed, and the pigments simply need to be rubbed
up with it.

The paint so got has the property of drying quickly and
easily without any siccative, and can readily be varnished
over. The coats withstand changes of temperature perfectly,
keep under water as well as dry and get very hard. Paints
made with this substitute can be diluted at will simply with
water, even to be very thinly flowing indeed. In comparison
with the methods hitherto known of making house paints
with linseed or turpentine oil, this substitute has the impor-
tant advantage that it can be made at one- third of the cost
of the original vehicle, and gives a still more durable ^oat.

Bruchhold's Weatherproof Paint.
Bruchhold's new paint consists of boiled oil which must
be free from every artificial siccative, with a little oil of
creosote and powdered silver slag from a silver refinery. The
exact proportions are : —

Per cent.
Slag 76

Boiled oil 24

Creosote 1

The essential ingredient is the slag, the great hardness

of which gives the paint much resistance to water or acid,

and contains no metals liable to oxidation.

Kallkolith.

Under this name a product has been for some years on
the market as a paint, having been ostensibly discovered
by Otto Kail of Heidelberg.
. KallkoUth is used with great advantage as a substitute

150 OIL COLOUBS AND PRINTERS' INKS.

for the usual priming colours on wood and iron, and instead
of boiled oil on stone, cement and all kinds of plaster. It
prevents all blistering and gives an exceedingly hard, smooth
and durable surface, as it combines firmly not only with the
surface but with the paint subsequently laid over it. It has
the following advantages : —

1. Cheapness. — It is half the price of ordinary priming
and linseed oil.

2. Yield, — It goes three times as far as ordinary priming.

3. Convenience, — It is very easily applied and with great
economy of pigment, which is made to cover well in the
thinnest coats, and will have more durabiUty than on an
ordinary oil priming.

4. Drying powers, — The drying only takes two to three
hours. Hence we have

5. Contimtance of the work ensured.

6. Oil colours on kallkolith on wood and plaster have
greater beauty and

7. Greater durability and specially very great

8. Hardness y so that, as the experience of several years
has shown, the lasting of the substance on outside fronts
exposed to the weather is most satisfactory. Hence any
work done with kallkolith may be fully guaranteed.

On wood, kallkolith is applied thinly and with care. It
dries in from one to two hours and the smoothing with
pumice may be omitted, only brushing when dry with
a brush before stopping. We thus get a solid, smooth
surface with great saving of time, and one coat of good
oil paint will be found to have all the body required. This
single coat is sandpapered and dusted, and the finishing
colour can now be laid on, and will remain perfectly bright.
A dull wax paint can also be used, and one coat of it
will be enough on a priming of kallkolith.

Woodwork, preserved in its natural colour by kallkolith,
acquires, when the application has been carefully made,

MANUFACTUBE OF HOUSE OIL PAINTS. 151

a fine, antique shade, and can be waxed, varnished or
polished over the kallkolith.

If the objects are to be decorated, they can be painted
on with kallkolith and beautiful work can be done in this
way. In polishing the wood we proceed as follows: If
the wood is to retain its natural colour, from one to three
coats of kallkolith are applied, according as the wood has
fine or coarse pores, and when dry sandpapered is
polished in the usual way. If a deeper colour of the wood
is wanted, a larger number of kallkolith coats is applied,
and the surface is well rubbed with soft paper before
polishing.

Poker-work and intarsia can be imitated with great
fidelity on soft as well as on hard wood. To do this,
kallkolith is painted on the wood, diluting it for light tints and
putting in the shadows afterwards with undiluted kallkolith.

In imitating other woods, it is advisable to mix the graining
colours with kallkolith and water instead of vinegar. The
kallkolith completely prevents any creeping on to the oil
ground, thereby saving a good deal of time, and has t o addi-
tional advantage that when the work is varnished less varnish
is required to give the proper lustre.

As a priming for oil colours on iron, kallkolith is applied
thinly and carefully.

As a priming for oil colours on stone, cement and plaster,
instead of boiled oil, kallkolith is used diluted with twice its
volume of water. The surface is carefully dried, and freed
from dust, and then the diluted kallkolith is applied fully, and
with as little frothing as possible, with large brushes. In
favourable weather, the application dries in from one to two
hours, and then can be at once thinly covered with any paint.
If the work is carefully done, as good and durable an effect
can be produced as in any other way, and with much less
time and labour.

Old weather-worn oil-painted fronts can be saved from the

152 OIL COLOURS AND PRINTERS' INKS.

need of Having the paint fully renewed if they are well cleaned
and then painted with dilute kallkohth. Kallkolith is applied
to cement exactly as to plaster, but the plaster should be dry,
and the kallkolith should be applied during fine weather.
All lime- washed fronts must be well scraped and washed, and
should then be painted over with kallkolith diluted with seven
times its volume of water, and then, when that is dry, treated
as if they were fresh plaster.

As a priming for distemper instead of soap kallkolith is
used diluted with seven times its volume of water, and the
distempering is done as usual when the kallkolith is dry,
although the distemper colour should be a little thinner than
usual. It does no harm if the priming has for any reason to
stand uncovered for a time, which cannot be allowed with a
priming that wants sand-papering.

For preparing walls for decoration kallkolith is used diluted
with seven times its volume of cold water. For this purpose
it has the advantage that the decorative painting is more
durable on it than on size. Kallkolith comes on the market
as a thickish dark brownish -red liquid, which on shaking
becomes covered with a soapy lather and has a very disagree-
able ammoniacal smell. The colour alone seems to be rather
a drawback to its use, and its nauseous smell, which of course
becomes very obvious when painting is done with it, must in
my opinion entirely prevent its use in some cases.

I have mentioned in a former work that Dr. von Scherzer
brought about thirty years ago from China a cement or paint
called schio-laio, consisting of pig's blood, quicklime and
alum, and specially used for painting boxes and other articles
of wood to make them waterproof both within and without.
It has long been known that all albuminous bodies make
compounds with lime which are excellent for paint, and
blood is no exception to the rule. The German Government
had analyses made of schio-laio^ to determine the recipe if
possible, and then to make some and experiment with it.

MANUFACTURE OF HOUSE OIL PAINTS. 153

According to the determinations of nitrogen and lime, the
proportion between fresh blood and slaked lime was put
at three to four, and in fact if- we mix 3 lb. of whipped or
defibrinated blood with 4 lb. of lime, slaked to a powder,
we get a thin tenacious mass. With more lime the mass
is thicker, and quite as tenacious as before.

In accordance with these researches, I have drawn up the
following formula for a vehicle : —

Whipped fresh blood 6 lb.

Slaked Ume IJ lb.

Water 1 gat

This composition can be mixed with all manner of paints,
except white, and acts as a vehicle for them.

Kairs patent (D.E.P. 18,307) says : To 10 lb. of whipped
blood from the slaughter-house add through a sieve 1 lb.
of old quicklime which has fallen to dust, stir, and let
the mixture stand for twenty-four hours. Then skim the
impurities off from the surface, remove the rest from the sedi-
ment and put it aside, and stir up the latter with water and
allow it to settle. Then pour the water off into what has
been put on one side, so as to dilute it. Let the mass then
stand quiet for from ten to twelve days after mixing it with
a solution of permanganate of potash, which partly bleaches
it and prevents it from turning mouldy.

At the end of this time the mass is stirred up and more
water is added till it is of the consistency of quite thin glue.
It is best, to secure uniformity of mixture, always to get a
predetermined gravity by means of a hydrometer.

This liquid is filtered, mixed with a little oil of lavender,
and kept in well-closed casks, when it will keep for a very
long time.

CHAPTEK XIX.

SHIP PAINTS.

A GOOD paint for hulls of ships, in iron or steel, to resist
water, has not only to preserve the material in the ordinary
way, but to prevent the growth of sea- weeds and animals
upon it.

This object is attained by smooth hard-clinging coats which
contain substances poisonous to sea-growths, both vegetable
and animal, and have also the property after they have killed
the organisms of flaking off and leaving the hull bare.

There are already poisonous paints known, but they will
not flake off, and the shell fish, etc., make as much friction
as the ship moves when dead as they did when living. On
the other hand paints are known which slowly flake off, but
they are not poisonous, and allow the organisms to attain
considerable development before flaking off.

Schnittger's Paint.

Schnittger's process seeks to combine both properties in
one paint, and is in this respect chiefly to be regarded as a
novelty. The manufacture of it proceeds as follows : —

Take 100 lb. of copal, and heat it till it has lessened to
about 80 lb., and condense and retain the fumes, stirring
during the heating with a suitable stirrer. When the dis-
tillation is over the copal is removed from the still so as to
cool as quickly as possible. It is a good plan to run it into
cold water. When cold the copal is broken up and dissolved
by heating it on a sandbath in 96 per cent, spirit, at as low
a temperature as possible. The oil which came over during

SHIP PAINTS. 165

the distillation is added to the solution, but not the water
which would cause precipitation, whereupon the whole is
then filtered. In the meantime the following solutions in
spirit are prepared : —

Of 20 lb. powdered aloes in 40 lb. of 96 per cent spirit ;
of 20 lb. Japan camphor in 40 lb. of 96 per cent, spirit;
of 20 lb. pitch in 40 lb. of 96 per cent, spirit ; and of 50 lb.
colophony in 30 lb. of 96 per cent, spirit. These four tinc-
tures are then mixed into the copal solution, cleared by allow-
ing time to settle, and then the whole is decanted from the
sediment.

To this carefully prepared solution we add, with continual
stirring, for every 33 lb. of it 28 lb. of caput mortuum, 3
lb. linseed oil, 3 lb. castor oil, and finally, after long stirring,
10 lb. of red oxide of mercury ; stir for two hours more, and
then add 5 lb. of crystallised carbolic acid. After mixing
this in, leave to stand for twenty-four hours and pack into

Paint fob Ships, and Submabinb Constructions.

In the process of Bessy G. Benedict and Frank Lee Bene-
dict of Viareggio, copper sulphate is reduced with grape sugar
and caustic potash. The precipitate of cuprous oxide is mixed
with carbolic acid, gently heated, and mixed with linseed oil
and mineral pigments. A cuprous phenylate is said to be
formed and to be very poisonous to animal and vegetable
life.

Paint for Iron Ships.

600 kilos, of asphalt or black pitch are mixed warm with
480 lb. of boiled linseed oil. The mixture is cooled to 24° F.,
and to it is added a mixture of 600 kilos, graphite, 120 kilos,
arsenite of copper and 640 kilos, of purified coal-tar oil. The
whole is thoroughly mixed and applied to the hull in several
coats. The arsenic in it is said to prevent the growth of
barnacles, etc., on the ship.

CHAPTEK XX.

LUMINOUS PAINT.

Luminous paint is a product which excites much interest,
and meeting with much false judgment is distrusted by many
people. It is therefore a matter of common interest to give
below the results of accurate investigations, which lead us to
form a correct opinion on the question.

The attempts to make a luminous paint date very far back,
and the Chinese are said to have been able to make from the
most remote antiquity a paint out of oyster-shells and sulphur
which shone in the dark. At the same time such things
used to be looked upon as playthings, as they were too
inefficient and too expensive for practical use on a large
scale.

The first to succeed in making luminous paint whjch would
glow even under oil or water on a large scale was Balmain,
a native of Heligoland. Then and not before did such paints
become of practical value. The price of such colours, which
was M. 110 per lb. seven years ago, has now been brought
down to one-twenty-fifth of that by improved machiniBry and
methods of manufacture.

In chemical composition the paint is a compound of alkaUne
earth, sulphur, oxygen and a little water. It contains no
phosphorus. Chemical analysis alone, however, is no criterion
of its quality, as the light-giving power depends not only on
proper composition but on a particular kind of molecular
aggregation. It has consequently been found impossible to
imitate Balmain's paint, now made by an English company
which has acquired the patent. .^ ■•

. . \.LUMmOUS PAINT: -; 15J

, !^Iii^aiii's limiinout paint, whioh oaA: ^ ^^ either as an
oil ^r a water colour, has the remarkable property of, as it
were, storing dayUght or other strong Hght, and giving it out
again ia the dark, and is so excessively sensitive to light that
a single spark from an induction coil will at once make it
luminous. The power of the paint to give out light depends
upon the power and duration of the light to which it has
been pretiously exposed, as wellas upon the mass of the
paint itself, for the Hght penetrates through the whole mass
of paint, and neither acts on nor proceeds from the surface
only.

Hence the thicker the colour is laid on, and the longer
lastirig and more powerful the light which has acted upon it
has been, the longer and stronger it will shine in the dark.
If suddenly brought from Hght to darkness the paint first
glows with a violet Hght, which finally becomes white, and
then gradually gets weaker and weaker until the stock of
stpr^d-up energy is entirely expended.

■If the paint is then brought from darkness to Hght it begins
to store up again, and if exposed during the daytime it will
absorb enough to shine throughout the longest winter night.
Accumtdation of dirt on the surface naturally hinders both
absorption and radiation. Heat has a special effect upon
luminous paint, and by making the Hght it gives out stronger
only allows it to last for a correspondingly shorter time.

Hydrochloric and ' nitric acids destroy the luminosity as to
vai^ipi^hes, vehicles and pigments containing lead, so that as a
vehicle and as a protection for luminous paint special pre-
parations are needed, and if anything has to be written on
the surf ace a special pigment must be used.
, Objects which are already painted with an ordinary oil
colour mu6t be primed with a neutral ground colour before
having luminous paint applied to them. Such a priming is
cbej^, and; it is to be recommended even on unpainted sur-
faces if tbey.are rough or porous, as they enable the luminous

168 OIL COLOUBS AND PRINTERS* INKS.

painir to appear to much greater advantage by ^ving k a
smooth surface. Three coats of luminous paint are enough
in all cases, and it is at least as durable as the best oil paint,
especially when varnished over by a suitable varnish. One
pound of luminous paint will cover with three coats an area
of twelve square feet.

Luminous water colour has the same general properties as
the oil paint. But like all water colours it should only be
used indoors, and not in the open air or on objects exposed
to the weather. It is sold as a dry powder which is stirred
up with a litre and a half of lukewarm water to every 10 lb.
of pigment. The resulting mixture is enough to give three
coats to 70 square feet of surface. Objects of unpainted
wood, plaster, papier-ma,ch6, etc., are grounded before the
application of luminous paint with a solution of pure gelatine
in 12 parts of hot water, to fill the pores and prevent waste
of the luminous paint. Luminous paint must be appHed
with perfectly clean brushes and must be kept stirred up
during use. Every coat must be dry before another is laid
on.

Although success is certain when a luminous paint has
been used with rigid attentions to the directions,* it is import-
ant to note that it is only properly effective in real darkness.
Where there is partial light or in artificial light the effect is
spoiled and the use of the paint only leads to mistaken judg-
ment. It would, for example, be folly in towns which are
lighted at night, while a finger-post by a country roadside
needs merely the application of luminous paint to make it as
useful by night as by day.

Many trials made with luminous paint in unsuitable places
have caused it to be depreciated. It must be remembered,
too, that a luminous paint only shines by emitting stored
energy, and must consequently be afforded the necessary
intervals for renewing its stock, if it is to continue to be of
service. At the entrances of and inside dark rooms in which

LUMINOUS PAINT. 159

highly inffammable goods are stored it is an excellent plan to
use placards painted in luminous paint, only remembering
that they must be exposed to daylight at intervals. They
should therefore be placed where they are exposed to light
in the daytime, or they may be made movable so that they
can be taken out of the room occasionally. They will then
allow people to go about freely in the darkened room and
save much time and trouble.

As luminous paint shines equally well under water, divers
can work in deep water, if their apparatus is painted with
luminous paint. Mr. Hedger, of the Southampton Dock Com-
pany, in a report on the raising of a ship sunk off that port,
states that by means of luminous paint the divers were able
to see the seams and bolts in the hull at a depth of eight
metres well enough to be able to work with ease. It is
possible for an object which has been exposed to a corre-
sponding day's light to be recognised at the end of a following
fifteen hours' night so much that large and clear writing can
be distinctly read.

Most people know from experience how convenient the use
of luminous paint is on many small objects, such as match-
boxes, lamp-shades, door-signs, etc., as it enables them to be
foimd in the dark, and besides these uses of luminous paints
there are others which show the great advantages of them,
and which will now be briefly mentioned.

For navigation purposes : buoys painted with luminous
paint can be clearly seen 200 metres off in the darkest night
and so show the way. Many lives would 'be saved if life
belts were painted with luminous paint so that a drowning
person could see by night the belt thrown over to him.
What other chance has he of finding it ? The paint is also
good for the piers of bridges, piles, lightships, railings, etc.,
etc.

On railways: for painting the insides of goods trucks,
indicating level boards, numbers, level crossings which are

^60; OIL COLOURS AND printers' inks.

i^t lighted, all of which oaa thea be seen at a distance^ and
people can see whether gates are shut or not.

In the country : for painting finger-posts, milestones, notice
boards, etc., in places destitute of artificial light and in country
towns for the names of streets, the numbers of houses, hydrants,
etc.

In military works : for painting objects destined for use in
engineering works, such as piles, etc., and for making out the
profiles and outlines of such works.

In stores of gunpowder, spirit, petroleum, and the painting
inside mines, ships' holds and other dark localities where
there is fire-risk, we use tablets painted with luminous paint
that can be removed on occasion so as to get the necessary
exposure to daylight. These tablets may be of wood, glass,
or zinc, and enable short jobs to be done in such places with-
out the risk attending the use of lamps.

Luminous paints cannot be too much recommended for
theatres, factories and other places where large crowds
assemble, to indicate exits and give other directions. If by
any chance the ordinary illumination of the place should
suddenly fail, every one can direct his steps with certainty.

Luminous water colours are specially good for room walls,
ceiHngs, passages, staircases, which get daylight in the day-
time and for painting the stairs themselves in barracks and
hospitals. They can also be used in wall-paper-making and
photography, and for painting all kinds of paper work, and
generally all objects which are not usually in the open air.

Luminous paint is also made up with wax, and in this way
is largely used by jewellers, makers of glass ornaments, and
in making fish-bait.

The preparation of luminous paint is as follows : —

Oyster-shells are cleaned with warm water, and put in the
fire for half an hour, then taken out, allowed to cool, ground,
and freed from worthless grey particles. The powder is inter-
stratified with layers of sulphur in a crucible, and the lid is

LUMINOUS PAINT. 161

then luted on with a thick paste of sand and beer. When
the crucible has been red-hot for an hour, it is allowed to
cool. The white powder in it is then carefully sieved, and
mixed with gum-water as a vehicle.

An invention patented by G. Schatte of Dresden some time
ago has the object of preparing durable white or coloured
paints which are luminous, but of which the colour remains
the same in daylight. To effect this, Zanzibar or akuri copal
is fused over a charcoal fire and 15 parts of the mass are
dissolved in 60 parts of French oil of turpentine, filtered, and
mixed with 25 parts of pure Unseed oil which has been heated
and partially cooled again. The varnish thus obtained is
worked up into a luminous paint in a paint-mill by one of the
following processes. Iron rollers must not be used, as any
fragments of iron which got into the paint would impair its
luminosity.

The varnish as sold almost always contains lead or man-
ganese, which has a tendency to impair the luminosity of the
calcium sulphide.

A pure white luminous paint is prepared by mixing 40 lb.
of the above varnish with 6 lb. of prepared sulphate of barium,
6 lb. of prepared calcium carbonate, 12 lb. of prepared
white zinc sulphite, and 36 lb. of good luminous calcium
sulphide to an emulsion,- and then making the whole very
fine in the paint-mill.

A red luminous paint is prepared by mixing 50 lb. of the
varnish with 8 lb. of prepared sulphate of barium, 2 lb. of
prepared madder-lake, 6 lb. of prepared realgar (red sulphide
of arsenic) and 34 lb. of good luminous calcium sulphide,
worked up in the paint-mill.

For an orange paint, 46 lb. of the varnish are mixed with
17i lb. of prepared barium sulphate, 1 lb. of prepared Indian
yellow, li lb. of prepared madder-lake and 34 lb. of good
luminous calcium sulphide.

For a yellow paint, 48 lb. of the varnish are mixed with

162 OIL COLOURS AND PRINTERS* INKS.

10 lb, of prepared barium sulphate, 8 lb. of barium ohromate,
and 34 lb. of good luminous calcium sulphide.

For a green paint, 48 lb. of the varnish are mixed with 10
lb. of prepared barium sulphate, 8 lb. of chrome-green, 34 lb.
of good luminous calcium sulphide.

For a blue paint, 42 lb. of the varnish are mixed with 10*2
of prepared barium sulphate, 6-4 of ultramarine, 5*4 of cobalt
blue and 36 lb. of good luminous calcium sulphide.

For a violet paint, 42 lb. of the varnish are mixed with
10*2 lb. of prepared barium sulphite, 2*8 lb. of ultramarine
violet, 9 lb. of arsenate of cobalt and 36 lb. of good luminous
calcium sulphide.

For a grey paint, 45 lb. of the varnish are mixed with 6 lb.
of prepared barium sulphate, 9 lb. of prepared carbonate of
Hme, i lb. of ultramarine blue, i lb. of zinc sulphite grey
and 36 lb. of good luminous calcium sulphide.

For a yellowish-brown paint, 48 lb. of the varnish are
mixed with 10 lb. of prepared barium sulphate, 8 lb. of
orpiment and 34 lb. of good luminous calcium sulphide.

Luminous paints for artistic purposes are prepared by
substituting for the varnish in the above recipes the same
quantity of pure poppy oil and grinding especially fine.

For luminous oil paints, the varnish is replaced by an equal
quantity of cold pressed linseed oil, thickened by boiling.

All the luminous paints above given can be used for coloured
papers and other purposes by leaving out the varnish and
grinding up the soHds with water and a vehicle free from
acid. Luminous wax paints can also be made for painting
on glass vessels and the like, by substituting 10 per cent, of
Japan wax, and 2J per cent, of olive oil for the varnish. The
80 prepared wax-paints can be used on porcelain, which are
then baked without access of air, or varnished over with
waterglass.

CHAPTBK XXL
ARTISTS' COLOURS.

These include pigments rubbed up with poppy, linseed or
nut oil, and used by artists for their special purposes, and
the principles of their manufacture are the same as for
ordinary oil paints. We only choose purer and more reli-
able pigments and are more particular in choosing the oil,
and give the paints a much more thorough rubbing up in the
paint-mill or with the muUer.

With reference to pigments it must be remembered that
we have now many more of them than formerly ; it may be
a question whether this is an advantage from an artistic
point of view. Although in former times the choice of pig-
ments was limited, they were at least reliable, and have lasted
for centuries as fresh as at first. Now we have an untold
number of pigments of every conceivable v.shade of which a
large proportion change in a short time so much that the
painter fails to recognise his own work.

With four pigments only, says John (Die Malerei der Alien,
Berlin, 1846), viz,, white, Attic yellow ochre, Sinope red, and
lampblack or ivory black, Apelles, Echion, Melanthus and
Nicomachus, all very famous painters, executed those im-
mortal works single specimens of which were the treasures
of a city. Pliny, from whom this information is derived,
continues as follows: "But now that purple glitters on the
walls, and India sends us the mud of its rivers, and the blood
of its dragons and elephants, noble painting has ceased to
exist ".

164 OIL COLOURS AND PRINTERS' INKS.

Among the Egyptians the number of paints which were
allowed to be used for artistic purposes was limited, at first
to five, but later to seven. The tools which- served them for
maulstick and palette at the same time show a row of seven
hollows intended to receive the paints.

It would naturally .take us too far to follow up the further
increase in the number of pigments. The fact is that the
masters of the old Itahan and of the later Dutch schools knew
and used a very considerable number of them. Even then
artists used colours which have no pretension to permanency,
and which the artists of to-day will not use. The oldest
Florentine painters, for example, had not only real ultra-
marine, but biadetto or what we now call mountain blue,
and indigo. For yellow they had massicot, for orange orpi-
ment, besides gamboge and Naples yellow. Gamboge has
now almost gone out of use in oil-painting. As a red they
used pink from Brazil wood, as well as English red lead,
dragon's blood, vermilion, and hematite or sinopia ; for green
they had verdigris and another copper-green. We also hear
of a red called kermes,^ as a rich Enghsh colour which was
extracted out of dyed cloth imported from England. The
Venetians seem to have used this as an oil paint at a very
early period. Madder and cochineal were used in very early
times, and also asphaltum, which first appears in the time of
Titian; and we also have accounts of colours made from
flowers, yellow from the crocus (saffron), red from violets,
and pink from ivy-sap. Thus the number of colouring
matters in use was continually increasing, and while the
Egyptians, Assyrians, Pompeians and Herculaneans used as
pigments first the natural earths and then those made from
stones, and finally chemical compounds for the preparation
of which no small skill is required, we find in the studios of
the Middle Ages complete colour laboratories, because in
those days the painters preferred to prepare their own colours.
^ Closely allied to the cochineallnsect. — Tr.

ABTISTS* COLOURS. 165

Now things have changed. The artist buys his colours
from manufacturers, and it is no uncommon thing for. price
lists to contain the names of over 300 possible and im-
possible pigments, including shades which cannot be got
except by the most desperate mixing. We also have whole
series of lakes made with aniline dyes and alumina,
which lose their colour very quickly when exposed to light,
to say nothing of earth-pigments beautified with anilines,
which have the same degree of durabiUty. With regard
to much of the material now offered by dealers to artists,
the German Society for the Promotion of Eational Methods
of Painting,* which is located in Munich, has decided on
fixing upon a scale of normal colours, in which only those
colours which are known to be fast to light and air are
included. Such alone should be used and the scale is
here given: —

Whites.

Kremser white, zinc white.

Yellows.

Pale Naples yellow, dark Naples yellow, reddish Naples
yellow, pale and dark cadmium, orange cadmium, pale ochre,
pale gold ochre, dark gold ochre. Sienna earth, Pozzuoli
earth.

Beds.

Pale and dark English red, mountain cinnabar, Chinese
cinnabar, patent cinnabar, dark and violet madder lake.

Browns.

Dark ochre, burnt dark ochre, burnt green ochre (Bo-
hemian), burnt Sienna, Cyprian umber, burnt Cyprian umber,
asphalt, mummein.

Blues.
. Cobalt blue, dark and light ultramarine, Prussian blue.
Greens.

Warm chrome green, chrome green, pale and dark cobalt
green, green Bohemian ochre, Veronese earth.

166 OIL OOLOUBS AND PRINTERS' INKS.

Blaoes.

Ivory blacky lampblack.

All these pigments, to be fit for artists' use, must be
ground as fine as possible and be very carefully levigated
so as to get a very soft and delicate powder. Thorough
drying of this powder at from 80° to 100° C, until cessa-
tion of loss of weight shows that all water has been ex-
pelled, has been recommended of late, because the colour
then requires much less oil, and this is, as we shall see
presently, of great advantage to the purity of the tint.

As vehicles, the brothers Van Eyck in the fourteenth
century used oil, so that they are the founders of painting
in oils, as contrasted with the previous encaustic style,
although it is now said that Heraclius, who lived in the
tenth century, has left an account among many other
secrets of the use of pigments with oil and even with
boiled oil.

The oils chiefly used are linseed, poppy and nut oil,
and there appears to be no doubt that many painters
early employed in addition colophony and mastic, even
amber and copal, and also wax, to make the pigments
give a smooth mass. Baron von Tankenheim in 1770 pro-
posed a pomatum -like composition of wax and oil (of
which, however, no more detailed particulars are given) as
a colour- vehicle ; and Paillot de Montabert used a solution
of wax in cold turpentine mixed with a Httle naphtha, and
a little solution of copal and elemi in oil of turpentine.

The pause of these additions is to be found in the fact that
many colours mixed with linseed, poppy, or nut oil, particu-
larly the last, become tough on keeping, and thus very diflB-
oult to use. This occurs with lead- white and many of the
earth-colours, and many heavy pigments, such as cinnabar,
cannot be kept with oil alone, as their great specific gravity
makes them settle out. In the making of oil paints, poppy and
nut oil have shown themselves the best^ because they contain

artists' colours. 167

the least linoxyn ready made, and hence the destructive in-
fluences of air and light take longer to affect them than other
drying oils. Nut oil cannot be used for all purposes, especially
for whites or pale hues, on account of its dark colour, and
bleached poppy and linseed oils have therefore to be used.

Pigments rubbed up thick with these oils, and having to
be thinned for use, have other drawbacks besides the toughen-
ing. Among these are darkening of colour after use, whites
turning yellow if deprived of light, slow drying and the un-
equal drying times of different colours, hardening from above
downwards by the formation of a skin over the colour, and
attempts to explain these matters seem to have shown that
they are to a large extent due to the use of unnecessary
quantities of oil.

** It seems paradoxical," says Professor Petruschefifsky of
St. Petersburg, ** but it is nevertheless true, that in oil paint-
ing as little oil should be used as possible." We should
therefore use as far as we can such paints as contain the
least oil, because it is only in that way we can avoid the
above-mentioned troubles. As a proof that oil paints should
be made up with as little oil as possible we may mention
water colours, where very small quantities of gum or honey
form a sufficient vehicle. As, however, the pigment cannot
be used with only just sufficient oil to bind it, we must add
something besides which is not oil, e.g.^ an ethereal oil, such
as oil of turpentine, of rosemary or lavender. When the
colour is used, these evaporate, and the pigment is left with
only the necessary amount of oil to bind it.

This explanation is most instructive, and shows that we
must give up the old process of rubbing up pigments with a
pure drying oil only, and introduce instead a method depend-
ing on the use of a mixed vehicle, consisting

1. Of drying oil with a varying amount of ethereal oil
according to the nature of the pigment, or

2. Of drying oil, ethereal oil, and wax, or resin of a par-

168 OIL COLOURS AND PRINTERS' INKS.

tieular kind. This is the principle of the Mussini colours!
As the various pigments have various drying powers with the
same vehicle, care must be taken in the manufacture to mix
such pigments as dry quickly (such as lead-pigments) with
raw oil, and those which dry slowly with oil which has been
boiled or otherwise made more drying. Great care is here
necessary to use no lead compounds, for making the oil drying,
as the oil will then have a bad effect on the shade of certain
pigtnents. Only pure manganese compounds should be used,
and the oil should always be bleached afterwards in the sun
to restore the original colour to the oil which has been
darkened by the boiling.

Schnitger's Oil Paints.

According to the present practice, pigments for artists' use
are rubbed up with oil, usually also with tallow or beeswax
at the ordinary temperature, and in such proportions as to
produce a mass of the consistency of butter.

As experience has shown, an oil paint has more durability
and less tendency to darken the less oil has been used with
the pigment.

(The first part of this assertion wants proof, as all our
experience so far goes to show the contrary.)

The object of the process of P. C. Schnitger of Berlin is to
lessen the amount of oil while still securing the necessary soft-
ness. The pigment is first mixed with the oil, but, in contrast
with the practice hitherto prevailing, so as to make it thicker
than it is to be when the paint is finished, and then has
a preliminary passage through the paint- mill. The mass is
then heated for some time, whereby it becomes first hard and
brittle, and then again gradually softer and thinner, and
finally tough. The heating is stopped at the soft stage and
before toughness has set in, and the mass is quickly cooled.

It is not now, however, very suitable for further grinding,
and has to be put through the mill several times at the

ABTISTS* COLOURS. 169

ordinary temperature. Finally, however, it acquires the
necessary fineness, and can then be filled into tubes.

The duration of the heating and the temperature to be
employed varies in different cases. Paints which will stand
a high temperature without alteration of shade are heated,
about a kilo, at a time, for two hours on the average, at a rather
high temperature. The larger the mass heated at once the
longer the heating must last.

To determine exactly whether the heating has lasted long
enough, we take a small sample, cool it, and fill it into a tube,
and see whether it can be pressed uniformly and easily out
of the narrow orifice. If this is the case, the operation is
finished. But if the paint only comes out by fits and starts,
and requires great force, the heating must be continued.
Paints which will not bear much heating, such as pale vege-
table colours, are not to be heated above 100° C, and then
take a day or two to finish, A few hours can be saved, how-
ever, by heating the mass under a high pressure of air.

To get this pressure, the vessel has to have only a Httle
mass put into it and is closed with an air-tight cover. The
expansion of the enclosed air on heating gives the pressure.
Or a condensing pump may be used to force air into the vessel
to any desired point. The test of the completion of the opera-
tion is the same as that given above.

The possible minimum of vehicle varies with the pigment
and may be as high as 40 per cent, of the latter. The
advantages of paints prepared by this method are : —

1. Less darkening on account of the small amount of oil
used. 2. Greater body because there is a larger proportion
of pigment in the paint. 3. The colours dry on the canvas,
even where thick, much sooner and more evenly than ordinary
paints, especially than those containing beeswax and tallow,
when the interior remains soft long after the surface has dried,
i. Painting over is much sooner possible. S. The colours in
the tubes retain their consistency unchanged for long periods.

170 OIL COLOURS AND PRINTERS* INKS.

I do not think I can better characterise this process than
by quoting the remarks of Dr. W. Reissig of Munich on the
subject.

The expression ** oil-vehicle " is here use! in a sense
which admits of many interpretations and is therefore un-
reliable. What is an oil- vehicle? If we rub up any pigment
fine with linseed or other drying-oil, and paint with the
mixture, it dries, even if slowly, to a solid mass — the paint.
Here pure raw linseed oil is the vehicle. On the other hand
we know that the drying is much quicker if the oil has been
boiled, with or without driers, so as to get boiled oil. Is this
— made from the oil — also an oil- vehicle ; or only so when
used without the addition of wax, etc. ? It is therefore clear
that it is not permissible to use the term in question, as we
do not know what materials the inventor has taken to make
his paints. A further important point is the manner, stated
by the inventor, in which the pigments behave when heated
with the oil- vehicle : "As the heating proceeds, the mixture
becomes first hard and brittle, and then softer again ". All
this points to a decomposition occurring on account of the
heat, and this is the more probable because ** when the mass
becomes soft again the heating must be stopped ". A de-
composition of the oil-vehicle with the pigment means either
that the oil-vehicle is changed by the heat, or by chemical
reaction with the hot pigment, or that the pigment itself is
decomposed.

It is hence very probable that the oil has an altering action
on the pigment. In this respect however various pigments
must behave very differently, and nothing is said in the
specification about anything of the kind. Science leads to
the following conclusions. We know that certain mineral
pigments, such as zinc oxide, ordinary lead-salts, etc., have
the power of entering into combination with hot Unseed oil
and saponifying it. Others, however, and the greater niunber,
have no action on heated linseed oil, the ochres for example.

ABTISTS' COLOURS. 171

But we must also here bear in mind that protracted heating
alters the molecular constitution of bodies. This slightly
affects the colour of pigments as a rule, and can only be
excluded in the case of the process in question, when pig-
ments are used for it which have been previously strongly
heated, in their manufacture for example. Yellow iodide of
mercury affords an example of this molecular change on
heating. A temperature not far above 40° C. turns it red,
and prolonged heating will convert soft transparent phos-
phorus into an opaque brown mass, the so-called amorphous
phosphorus.

Such an action would certainly make the pigment more
durable, because it would usually make it heavier and closer,
just as great pressure would. These facts might give the
process a very rational basis, but no allusion is made to them
in the specification. Not a word is said about any change,
however sHght, in the colour of the heated paint, and as
such changes would certainly occur with certain pigments,
we can only suppose that there are reasons for abstaining
from mentioning them. With organic colouring matters, too,
it is hard to see how molecular change can be avoided,
although, as a temperature of 100° C. is not exceeded, its
effects might be hardly perceptible.

Finally one circumstance of theoretical importance must
be mentioned. This is that solid bodies are better conductors
of heat than fluids. It is therefore certain that when ac-
companied by such large quantities of solid as the inventor
uses, the oil would be heated much more rapidly and uni-
formly than if heated by itself. Whether this might not
change the vehicle itself may well be doubted. But with
the special circumstances which must be maintained during
the process, we have no direct evidence that such is the case.

We stand then face to face with, an invention which we
should wish t6 be a step forward in paint manufacture. But
to be able to judge of it rightly we were obliged to experi-

172 OIL COLOURS AND PRINTERS* INKS.

ment, and we have entered upon an accurate investigation^
the results of which are here briefly described.

1. Experiments with Pure Linseed Oil, — As the specifica-
tion does not exclude the use of pure linseed oil in paint
manufacture, we began our researches with that substance.
To be quite sure of our ground we used no bleached oil, as
that substance may contain impurities resulting from its
manufacture which would have had a bad effect.

The oil we used was a perfectly natural, beautifully cleajr,
and old-stocked sample.

In the manner directed by the inventor, 1. pure zinc
white, 2. pure ochre, 3. chrome yellow, were rubbed up
with the oil in the proportions of 6 vols, pigment to 1 vol.
linseed oil.

The mixtures were put into suitable porcelain dishes and
weighed. For the purposes of comparison and to see what
effect the increase of temperature produces, some of the oil
and some of the pigment were heated, each by itself, on the
same sand-bath. The temperature was raised gradually and
steadily. At 120" C. a few bubbles of gas were disengaged,
and the mixtures became thicker, but not tough or brittle.
The heating was continued with constant stirring. The
mixture then turned liquid again, and remained so till the
end of the two hours demanded by the specification. The
dishes were then removed from the bath and r9.pidly cooled.
Their contents could then be used without any more oil.

It was interesting to note if the heating had caused any
loss, indicating decomposition. When, however, the dishes
were weighed it was found that the pure linseed oil had lost
02 per cent, of its weight, the ochre mixture '05 per cent.,
and the zinc white mixture '03 per cent. These quantities
are quite insignificant and afford no ground for assuming
any marked decomposition (the chrome yellow dish had
spurted over, so that it had to be left out of the reckoning).

Neither the linseed oil nor the mixtures were much changed

ARTISTS* COLOURS. 173

in colour by the heat. In fact it was difficult to tell the
heated from the unheated. The pigments heated by them-
selves were just a trifle darker.

The masses obtained by this treatment did not dry as
tapidly as might have been expected. The mixtures painted
on glass took nearly five days to dry. The glass plates lay
in a room only slightly heated, and the weather was wet and
cold. The comparison sample made of ordinary linseed oil
took about the same time, so that no noticeable advantage
existed.

2. Experiments with Boiled Oil. — We convinced ourselves
that the material used was quite pure. Its colour was a pale
yellow.

It was rubbed up with, 1. zinc white, 2. ochre, 3. chrome
yellow, in the proportion of 5 vols, pigment to 1 vol. oil.

The -mixtures were heated on a sand-bath in porcelain
dishes, as above, and some of each of the pigments and some
of the boiled oil were heated separately on the same bath
with the mixtures.

The temperature was raised with great care and steadiness,
and with constant stirring. As in the other experiments the
masses became thick between 120 and 160° C, but only the
ochre appeared friable. As before a few gas bubbles appeared ;
but there were perceptible changes in the appearance of the
mixtures. The zinc-white mixture became paler, and the
chrome yellow one much darker. The ochre mixture, how-
ever, hardly changed at all. At the end of the two hours'
treatment and stirring, the dishes were rapidly cooled and
the drying properties at once tested.

It must be mentioned that subsequent grinding diminished
the change in colour suffered by the zinc white and the
chrome yellow, but did not bring them back to the purity of
colour possessed before heating. No difference was percep-
tible in the case of the ochre.

The products painted very well, but did not dry so quickly

174 OIL COLOURS AND PRINTEBS' INKS.

as the inventor claims. The zinc- white mixture took five
days to dry, the ochre mixture four days, the chrome yellow
mixture four and a half days. In any case they have no ad-
vantage as regards drying over ordinary good oil paint.
Some pigments, in fact, painted on at the same time were
dry sooner. Whether the pigments prepared by the patent
process are more durable than others time, of course, can
alone decide.

From these experiments we may conclude that the chief
advantage in the patent process must consist in economy of
vehicle, and that it will give good oil paints with pure and
dry materials of good quality. If 40 per cent, of oil is really
saved cannot be ascertained, as we had none of the paints
prepared by the inventor to analyse.

MussiNi Paints.
These are a new sort of artists' oil colours invented by
Professor Cesare Mussini, and put on the market by Schminke
& Co. of Dusseldorf . They may be considered, according to
Horadan's report of 18th February, 1887, to the German
Society for the Promotion of Eational Painting, as ethereal
resin oil colours. If the name Mussini is retained it will be
in honour of a man whose knowledge of the quaHties neces-
sary in fine paints has enabled him to establish a principle
highly favourable to the users. The Mussini colours have
the eminent advantage over ordinary ** novelties " in the fact
that they have been tested by the existence of pictures painted
with them fifty years ago. In 1873 the Kussian artist
Airasowsky wrote how splendidly the pictures painted in
St. Isaac's Cathedral at St. Petersburg by Mussini in 1843
to 1846 had lasted in comparison with others painted at the
same time with ordinary oil paints. These pictures still
remain in all their original freshness and clearness. The
Florentine Academy also testifies to the excellent preservation
of some large pictures which Mussini painted on a lime ground

ARTISTS* COLOURS. 176

in Florence. Von Olfers of Berlin testifies to an extremely
convincing proof of the durability of the Mussini colours.
When Mussini travelled from Berlin to St. Petersburg, in
1846, one brick was painted with ordinary oil paint, another
with fresco, and a third with Mussini colours. The three
were put together on to the roof of the museum. When
Mussini came back two years afterwards, the bricks were
examined. The exposure to the weather had entirely de-
stroyed the applications to the first two bricks, but the
Mussini colours on the third brick were unchanged.

Mussini colours have three chief differences from ordinary
poppy oil paints.

1. Each paint is treated with regard to its own special
nature, and contains only as much fatty oil as is absolutely
indispensable to bind it. The rest of the vehicle consists of
ethereal oils, which give the necessary thinness.

2. Every colour contains a certain amount of resin pro-
portioned to the oil also put with the pigment.

The paints dry uniformly. They quickly become plastic,
and then dry from within out^yards, i.e.y in the exact reverse
way to ordinary oil paints. With these a skin forms on the
outside, and the inside remains moist for a long time.

The following analyses show the differences between
Mussini and ordinary paints with reference to the amount
of oil in them : —

Pigment.
White lead

Percentage of

oil usually.

Percentage of oil in

Mussini paint.

Chrome yellow

Ochre

Gassel brown .

Cobalt blue

126

Sienna earth .

131

The rest of the vehicle is an essential oil, which evaporates
and makes the paint dry very clear,

Mussini called the vehicle of his paints sago (from sugare,
to dry). What the fatty oil in it is, and what the resin is

176 OIL COLOURS AND PRINTERS' INKS.

(soft resins should make the paint dry uniformly) Horadan
does not say, because he is bound to silence, but hut oil is
not far from the mark, and is much more suitable for the
purpose than either linseed or poppy oil.

The preparation of Mussini colours varies according to
their intended use. One description is prepared for picture
painting ; another for wall decoration.

They ofifer no difficulties in use for easel-painting, but on
the contrary much facilitate it. They can be applied to wood,
stone, metal, paper, in short to any soHd surface without
any fear that the colour will come off, as Mussini colours
adhere much better than ordinary oil-paints. The surface
to be painted should first be well rubbed over with medium,
which increases the adhesion of the paint. The characteristic
method of drying of the Mussini paints has special advantages.
Effects can be produced from the first which are unattainable
with ordinary oil paints. A specially important property in
picture painting is that every coat sets at once, so that no
colour runs, and it is possible to paint on a new coat over
the first in a very short timie.

The Normal Pigments op the German Society for the
Promotion op Rational. Painting.

This society, wishing to free the market from the many
non-durable pigments which many makers offer to aJrtists, to
the injury of the artists and of art, has founded an institution
for testing pigments and vehicles, and permits every manu-
facturer who offers the necessary guarantees and who will
conform to the conditions to be presently stated to sell his
products as ** normal colours of the German Society for the
Promotion of Rational Painting ".

These conditions are : —

1. Every manufacturer wishing to sell his goods under the
above title must send notice to the society and at the same

ARTISTS COLOURS.

177

time samples of his pigments to the testing station of the
society.

2. The testing station haying examined the pigments, the
manufacturer may be called upon to make a first and only
payment to the station of M. 100.

3. The manufacturer must bind himself always to use for
his colours the same pigments as he has sent to the testing
station and which have been there approved, and, when he
has begun business, to send two sets of filled tubes to the
society.

4. Permission to use the title will not be given until the
raw materials have been approved by the testing station and
will emanate from the committee of the society.

5. The control is continuous, and the permission will be
withdrawn if the manufacturer alters the composition of his
paints without notice to the society, or does not make them
of the same quality as before.

6. The title will only extend to substances included in the
list of the committee. (This has been already given, see
p. 165.)

7. The normal-colours must be labelled according to the
following form : —

Normal Paint
of the German Society for the Promotion
of Rational Painting.

Finest prepared oil paint.

Light ochre.
Gere clair.

Louis Edgar Andes, Vienna.

No. 1 must be exactly as set forth.

No. 2 is filled up by

178 OIL COLOUBS AND PRINTERS* INKS.

lihe manufacturer, and shows how the paint is made, t.e.,
whether it is an oil paint, an oil- wax paint, or resin paint or
prepared after Mussini or Keim, etc.

No. 3 gives the name of the paint as determined by the
society, and both in German and French. It is specially im-
portant that there should be uniformity of terminology.

No. 4 gives the name of the manufacturer, and is filled up
as he chooses.

8. The control over the normal paints is confined to the
pigments. It does not extend to the vehicles, as at present
no standard for these can be fixed. The fixing of such a
standard is however kept in sight. Nevertheless the com-
mittee considers it desirable that the oil present should be
named, and it recommends the adoption of vehicles free from
lead.

The general method of testing the normal paints is as
follows : —

(a) The pigment is subjected to a complete qualitative and
quantitative analysis, carried out if possible by specialists, to
get an accurate idea of its composition.

(b) The pigment undergoes a special microscopic examina-
tion.

(c) To ascertain accurately all the chemical, physical, and
optical characters considered important as regards the use of
the pigment, it is subjected to the action of —

1. The air.

2. Sunlight or electric light, both dried and diflfused.

3. Atmospheric agencies, e,g,, rain, frost, snow, etc.

4. Acids and alkalies.

5. A red heat and

6. Various vehicles.

The tests of exposure to light and air are carried out both
with and without vehicle, in the following manner, so as to
get accurate results.

Tests with the Powdered Pigment. — Thepigment is powdered

ABTISTS' COLOURS. 179

SO as to go through a sieve with about 500 meshes to the
square centimetre, and then exposed both in open and closed
glasses, some samples to direct, some to diffuse light, while
others are kept in the dark, and the various changes are
noted.

Tests with the Pigment Buhhed up with Vehicle, — The
rubbed pigment is exposed to the same series of tests as
above, being painted on ground glass, the most inactive basis
that can be found.

Each sample is divided into three, one being left unvar-
nished, another varnished with a solution of pure mastic in
oil of turpentine, and the third both varnished and covered
air-tight with a glass plate cemented over it. The paint is
varnished as soon as it ceases to be sticky, and the glass
plate is laid on as soon as the varnish is dry.

The vehicles used in the tests are : —

1. Purified unbleached linseed oil.

2. Purified unbleached poppy oil.

3. As a water-soluble vehicle, gelatine.

4. As a strong alkaline vehicle, waterglass.

In all tests the proportion between vehicle and pigment is
accurately recorded.

The pigment to be tested is well washed, dried at 100° C.
until its weight is constant, and used when cold. Wherever
possible full particulars of the time when and the place
whence the pigment was received are to be recorded.

Finally it is to be remarked that we are not to understand
that normal paints are new paints or paints made by particu-
lar makers, but that only long known, durable, and pure
pigments can have a claim to the title, and those whose
composition is known to the society and is controlled by it,
and which therefore the artist can accept and use as normal
paints guaranteed as to purity. The same name will then
always mean exactly the same pigment.

180 OIL COLOURS AND PRINTERS* INKS.

Cotton Seed Oil, and Its Detection in Oil Paints,
Particularly in Artists' Colours.

Dr. Hans Stockmeier of Nuremberg has instituted tests of
a number of artists' colours to see whether they were really
made of pure linseed or poppy oil, and has established beyond
the possibihty of doubt that no small part of the artists' oil-
colours sold are made with cotton oil, which is at present
decidedly cheaper than either poppy or linseed.

Dr. Stockmeier tested the following paints : —

1. Permanent flake white, from a London firm.

2. Light red, from Winsor and Newton, of London.

3. Burnt sienna, from Dr. Schonfield & Co., of Dusseldorf.

4. Chinese ochre, from G. B. Moeves, of Berlin.

6. Brown red, a sketching colour from Schminke & Co., of
Dusseldorf.

The five tube-colours were first extracted in weighed
quantities and in closed vessels with ether in four separate
portions. The collective ethereal extract from each was
evaporated down on the waterbath, and the remaining oil
was then dissolved in petroleum ether. The petroleum ether
was then distilled off and the residual oil was weighed. The
results were as follows : —

1. 44*078 grammes gave 7 '162 grammes oil = 16-23 per cent.

2. 8-1845

3. 19-8926

4. 13-286
6. 36-233

The oil from —

1. Was thin, nearly colourless, with a yellow tinge.

2. Thin and yellowish.

3. Thick, nearly colourless, with a yellow tinge.

4. Thick and yellowish.

6. Butter-like in consistency and yellow.

Bach oil was now tested by Hiibl's iodine method as follows :
A known weight of the oil was weighed out, dissolved in
chloroform, and then left for two hours in a closed vessel

3-429

„ =41-89

11-769

„ =59-16

5-9923 „

„ =45-1

10-9632

,, =31-11

ABTISTS' COLOUBS.

181

with an accurately measured volume of solution of mercury
iodo-ohloride. Then water and a 10 per cent, solution of
potassium iodide were added, the solution was bleached with
sodium thiosulphate and then titrated back with 1 per cent,
starch paste and the mercury iodo-chloride, till a blue colour
appeared. The strengt.h of the iodine solution was accurately
known, and 10 c.c. of it corresponded to 8*34 c.c. of the solu-
tion of thiosulphate. The strength of the latter was got with
sublimed iodine as 26*738 grammes iodine per litre. Two
tests were made with each sample.

Sample.

OUused.
Grammes.

C.C. of Mercury

lodcMshloride

used.

c.c. of Sodium

Thiosulphate

used.

Iodine No.

hence
Calculated.

Avenm^e

Value of

Iodine No.

»{S
MS
'IS
»{8

•4727

•393

-222

•3594

•3775

•2291

•451

•3081

•531

•2657

32-2
31-4
20-6
21-6
31-1
20-5
31-1
20-9
41-4
29-9

5-4
8-2
4-6
61
9^4
7-1
9-2
5-9
15-1
7-5

121-6\

122-4/

151-7 \

151-0/

116-9 \

116-7/

99-1 \

99-8/

97-7 \

98-6/

122

151-4

116-8

99-5

98-2

When the iodine numbers had thus been obtained, the
fusion and solidifying points of the fatty acids present were
determined.

For this purpose a sample of each oil was boiled with
alcoholic potash, and the soap was decomposed with hydro-
chloric acid. The following table describes the fatty acids : —

Sample.

Fusion Point
Deg.C.

Solidifying Point

Remarks.

1
2

3
4
6

28
35
35

Partly solidified

at 18

Did not solidify

at ordinary

temperatures

The acid was a
blood red.

182

OIL COLOUBS AND PRINTERS INKS.

These high fusion points created a presumption that cotton
oil was present in Nos. 1,3,4 and 5, and no other oil in 4 and
5, and that linseed oil was also present in Nos. 1 and 3. The
iodine number and general behaviour of the fatty acid of No.
2 showed that the paint was made with linseed oil only.

Further special tests were made from cotton oil and
checked by control tests made with a sample of pure cotton
oU.

The elaidine test with nitric acid and copper gave a negative
result at first with all the samples, but after two days pure
cotton oil, and Nos. 4 and 5 were ointment-like, Nos. 1 and 3
partly so. No. 2 remained liquid.

On treatment with nitric acid of sp. gr. 1*33 the following
results were obtained : — ^

Sample.

Action in the Cold.

Action on the Water-bath.

Cotton oil.

Yellowish brown.
Brownish.
Pale yellow.
Yellowish brown.

>» »»
>» »»

Brownish red ^ » ,.

\ Action vigorous.

»» »» J
Yellow.

Red ^
Brownish red I Action vigorous.

>, »> J

After eighteen hours all the samples had an ointment-like
consistency.

These results confirm the former conclusions as to the
nature of the vehicle.

Further tests for resins, parafl&n and resin oils gave
negative results. For the presence of resins the full solubility
of the oils in petroleum is partial evidence.

The results obtained also show that the cotton oil present
had been boiled and in every case bleached afterwards. This
is shown by the low iodine number (that of raw cotton oil is
105 to 108), and the strong acid reaction of the ethereal
solution observed, especially with Nos. 4 and 5, and finally
by the ointment-like consistency produced by the presence

ARTISTS^ COLOURS. 188

of free acid shown at the ordinary temperature by the oil
from No. 5.

Boiled cotton oil is about on a par with poppy oil as regards
drying, and the cotton oil is evidently intended as a substitute
for the dearer poppy oil. The Hnseed oil in No. 2 has also
evidently been boiled or at least was a mixture of boiled and
imboiled oil. This is the more probable supposition. Here,
too, the low iodine number is a sufficient indication, and also
the blood-red colour of the fatty acid. This colour points to
the presence of a large proportion of linoxic acid.

Pure linseed oil has an iodine number of 166 to 160, with
a mean of 158. Von Hiibl found that of boiled linseed oil to
be 148.

If we sum up our results, we find that

No. 1 has a vehicle consisting of 72 per cent, cotton oil
and 28 per cent, linseed oil.

No. 2 was prepared with linseed oil alone. Here we
cannot lay much stress on the iodine number, 148, for boiled
oil, which can only be accepted with great reserve, as further
determinations of it are necessary. But we may say, with
this reservation, that the vehicle consisted of 66 per cent,
boiled and 34 per cent, unboiled linseed oil.

In No. 3 the oil was a mixture of 82*4 per cent, of cotton
oil and 17*6 per cent, of linseed oil.

In Nos. 4 and 5 it was cotton oil only.

We are now met by the question how far the artist is
injured by the most inferior of these products, whether, that
is, such a composition of the paint will have any adverse
influence on the properties for which it is valued in picture
painting, namely, beauty and durability. There is no positive
experience to be appealed to in this matter, but it behoves
the manufacturer to abstain from using vehicles of which the
effects are unknown.

These results are also here stated to show how widely the
tendency to use cheaper oils has penetrated into the trade.

CHAPTEB XXII.

PRINTERS' INKS : VEHICLES.

Printers' inks may be divided into two great groups :
Black printing inks ; Coloured printing inks.

This classification is, of course, obvious.

Both classes consist of vehicle and pigment. The same
vehicle may be used for either kind, but the pigments are
necessarily different, and while with black ink we have
to do with lampblack, an extremely light pigment, we find
for coloured inks many heavy ones used, such as lead,
mercury and chrome compounds.

Far more black than coloured ink is used, and we shall
consider it first after discussing the vehicle used for both
kinds.

The vehicle being one of the two essential ingredients
of a printers' ink must, of course, be made of faultless
quality before a good ink can be got from it. The pro-
perties which the ink itself must have must be kept in
view in the manufacture of the vehicle. These I now
give, and will follow them with a recapitulation of the
properties which the vehicle must have in consequence.

A good printing ink must —

1. Have a perfectly uniform syrupy consistency, and if
black must be of a shining blue black, not a grey black.
No lumps of pigment must be discoverable in it, or any
other impurities.

2. It must come freely off the rollers and on to the
type in the machine.

3. Its colour must be pure. It must not smudge the
types, and must be easily washed off them.

PRINTERS* INKS : VEHICLES. 185

4. It must dry neither too fast nor too slowly. If it
dries too slowly, it hinders moving and folding the sheets,
which would be very awkward in printing a daily paper.
If it dries too fast, it would set on the types, during print-
ing, and make the paper stick to them and tear, and so
stop the press. It would also tear pieces out of the ink-
ing rollers, which would get on to the types.

6. The ink when dry must not set off on to another
sheet, or else two printed sides which had come together
would become illegible, and it would also dirty the hands
of readers, a circumstance ' which has caused trouble to
newspaper owners before now.

6. The ink must have no strong smell, or if it has the
smell must vanish when the ink is dry.

7. The ink must not leave greasy margins round the
letters when it is dry. This is specially important in book
printing, but is to be avoided in newspaper work, although
newspapers are printed and read to-day, and thrown away
to-morrow.

From these we deduce the following requirements for
the vehicle: —

1. It must be of perfectly uniform consistency, without
any bits of film, or soHd lumps of any kind. It must be
filtered after it is made and kept in clean and well-closed
vessels, so that no dust or dirt can get at it.

2. It must be tough but not sticky from resin mixed with it.

3. It must not be too weak, or the printing will smudge,
and compositions which contain resin, resin oil, parafl&n oil,
etc., are very difficult to dissolve in printers' lye, so that
the formes are difficult to clean when they are used.

4. It must take the right time to dry, but the oxidising
agents used in making ordinary boiled oil for paints must
not be used in its manufacture.

^ - 5. It must have the necessary power of binding the lamp-
black or other pigment.

186 OIL COLOUBS AND PRINTERS* INKS.

6. It must have no disagreeable smell. When linseed oil
and resin are used in making it, the smell is never unpleasant,
but with resin oil or parafl&n oil, additions which cannot
always be avoided for reasons of price, the case is otherwise.

7. All unbound oil must be avoided, so that all linseed oil
must be boiled thick, for such oil gives no greasy border
round the letters.

A vehicle consisting only of linseed oil answers all these
requirements, and they must not be expected too strictly
from those containing resin, coal-tar, parafl&n or resin oil, etc.

Linseed oil at a temperature of 380° to 400° C, i.e., when
it may be expected to catch fire every moment, changes to
a thick, tough, sticky mass, which makes no greasy mark
on paper either by itself or when mixed with pigment. By
regulating the duration of this high temperature we are able
to govern the thickness of the oil, and can even by long
boiling get a perfectly solid mass which will not yield to the
pressure of the finger.

No oxidising agents may be added to accelerate the manu-
facture of a vehicle intended for printing ink, because they
produce the stickiness which we have said must be avoided,
and because oil boiled with lead or manganese compounds
alters for the worse when kept.

According to the thickness required the oil is boiled for
a longer or shorter time. The practice formerly universal
and considered essential, of setting fire to the linseed oil, is
not followed now in any well-managed factory, as it darkens
the oil very much, and that makes it unsuitable for coloured
inks of light tints, although it does not matter for black ones.

The demand for cheap ink, especially for newspaper print-
ing, has led to attempts to get rid of thick boiled linseed oil
in favour of cheaper materials, such as resin oil, resin, parafl&n
oil, coal-tar, turpentine and soap. With these we get com-
position vehicles, and they have already been brought to
such perfection that practically all newspaper ink is made

PRINTERS INKS ! VEHICLES.

187

with them. For better class printing, however, they have
not yet been made suitable. For that we have still to restrict
ourselves to a vehicle of boiled linseed oil only.

Any strong and heat-resisting vessel will serve for this

manufacture, and no particular shape is indicated. Iron or
copper is the best material.

In former times pear-shaped vessels with narrow mouths
were used, made of iron or copper, but this shape has been
entirely discarded and vessels are used which are deeper than
they are wide. Experience has shown that there is a bulk

188 OIL COLOtJRS AND PRINTERS* INKS.

above which the oil becomes unmanageable, and it is there-
fore advisable not to use vessels holding over 100 kilos., even
with mechanical appliances for lifting them, while in the
absence of such, the capacity of the vessel should in no case
exceed 30 kilos, ot 40 at the most. Enamelled cast-iron is
an excellent material for these vessels, while copper, which
is very apt to oxidise and turn the oil green, is to be avoided.
I use for boiling the arrangement shown in fig. 66. It
consists of a brickwork fireplace, ashpit, and flues, an iron
grate, and a plate of iron 2 cm. thick with a circular hole in
the middle of it to receive the oil kettle. The brickwork
hearth is a square of about 1} metre wide, and about a foot
high. The kettle, of enamelled cast-iron, is of the same
diameter at top and bottom, but somewhat contracted in the
centre and with a concave bottom. Its height is 65 cm. and
its width about 45, and it holds if filled to the brim between
60 and 60 kilos, of oil. For lifting the kettle there are two
wrought-iron rods, 2 to 3 metres long, which are passed
through rings attached to the sides of the kettle. This en-
ables the workmen carrying the kettle to be at some little
distance from it, which is very necessary in case of the oil
catching fire. An iron stand or tripod is provided to take
the kettle when it is off the fire. As can be clearly seen from
the figure the kettle is heated at the bottom only, but that is
quite enough to raise the contents to the high temperature
necessary. To keep up the fire charcoal, coal, or coke is
used.

Andres' Boiling Apparatus.

Andres has invented a very pretty apparatus which is
shown in fig. 56.

It consists of a cylinder C of sheet copper. Half-way up
it is surrounded by an annular basin E. The mouth of the
cylinder is surrounded by a strong iron ring to which the
chains K of a tackle are fixed, whereby the cylinder can be

printers' inks : vehicles.

189

quickly lifted out of the fire. There is also a cover D which
fits nearly air-tight on to the mouth of the cylinder. The
whole apparatus should stand under a brick arch as a safe-
guard against fire. This arch should have an opening above
into a chimney with a good draught, to get rid of the fumes
from the hot oil. The attendant must have a stool high
enough to let him get samples out of the cylinder. An

Fig. 66.

apprentice has charge of the crane, to lift the cylinder and
move it to one side when ordered.

Other arrangements of this apparatus are also made ; one
is to put the cylinder in a carrier on rails, as a substitute for
the crane, so that Ithe cylinder can easily be put over or off
the fire as may be required, or even into the open air, where
it may be left to cool.

190 OIL COLOURS AND PRINTERS' INKS.

In the factory of Kast and Bhinger, of Feuerbach-SttittgiBirti,
the following precautions are taken to prevent accidents
arising from the oil boihng over. In one apparatus, iihe
kettle is supported on a frame running on wheels on rails,
so that, when an iron door in the walled-up hearth is opened,
a single man can quickly remove it from over the fire. The
other arrangement is to make the fire movable instead of the
kettle. The firegrate consists of a wheeled carriage running
on rails, so that it can be easily moved from under the kettle.
To get less energetic heating, and to save labour, brown coal is
used for fuel instead of ordinary coal.

Boiling Process.

The process of boiling is as follows : When the kettle has
been filled about two-thirds full with good long-stocked
pure linseed oil, it is brought over the fire, or the fire is
brought under it, and it is heated till it begins to froth. Then
the fire is increased. When a temperature of 230° to 250° C.
is reached, as is shown by the oil changing colour almost
suddenly and becoming a pale greenish yellow, the firing is
managed so as to keep it at that temperature for about half
an hour, and it is then increased again. The oil now begins
to fume strongly with evolution of acrolein, and presently, say
in from one and a half to two hours from the start, begins
to froth again. Care is necessary, for the oil is near that
temperature when it catches fire, and if it froths very much
it is best to stop the heating for a time. Now the thickening
of the oils begins and the temperature is kept constant as it
thickens. The fumes and the acrolein-smell continually in-
crease, and the danger of the oil igniting spontaneously is
always present.

If it does so, with a slight report, the flame is easily put
out with a damp, not dripping, cloth and a cover, but both
must be at once removed, and one must be prepared to use
them again as required. This method of treatment has how-

printers' inks: vehicles. 191

ever the drawback that it confines the oontinually increasing
vapours, as there is no rapid cooling, and it is a better plan
to put out the flame with a wire grating. A thick wire
grating on a handle will at once extinguish the flame without
confining the fumes. If strong frothing occurs before or
after the oil catches fire, cold oil is added, or better some
cold already boiled oil, which will not check the incipient
thickening.

The progress of the thickening must be tested by taking
samples from time to time. These samples are taken with
a spatula and rapidly cooled on an iron plate. The length
of the threads into which the cooled oil can be drawn and its
adhesiveness are the signs. It is possible to push the heating
so far as to get a solid elastic non-adhesive substance, the
so-called oil-caoutchouc, which however does not concern
us.

It goes without saying that with an open fire which does
not allow change of temperature to be made regularly, or
a uniform temperature to be maintained, a boiling process
regular under all circumstances is an impossibility, so that
no times can be stated as required for getting any given
thickness of the oil : hence the necessity for testing samples
at intervals, to determine whether the oil wants more heating
or not. Another cause of this necessity is difierences in the
oils treated.

To get exact standards for the thickness of an oil, it is best
to use the hydrometer, and then by mixing different boilings
in the proper proportions we can always obtain exactly any
given thickness required.

No addition of any kind, driers, resin, etc., should be added
if the vehicle is to be used or sold as a pure linseed oil.
It is a question of giving the oil the necessary thickness to
hold the pigment and to lose the property of making ^easy
stains. The process above described is necessarily dangerous
^nd tedious, so that for a long time other materials have been

192 OIL COLOURS AND PRINTERS* INKS.

used, which have not those drawbacks, it is true, but which
only give a proper vehicle for certain purposes in the printing
trade. Among these are : (1) Boiled linseed oil and resin ; (2)
boiled linseed oil, resin, and resin oil ; (3) raw linseed oil,
resin and resin oil ; and (4) composition vehicles.

Vehicles op Linseed Oil and Eesin.

The basis of these is thick boiled linseed oil, prepared as
above described. The oil, however, is only boiled till it will
not grease paper. The thickness then wanting is given by
the addition of resin, so that a cheaper ink may be made with
the vehicle. When the oil has been boiled it is left to clear
for a short time, and then reheated to receive the resin, which
must be as dry as possible, and broken into smaU pieces.
These pieces are fused over a gentle fire and then mixed first
with some resin soap cut up, and when that has dissolved
with the hot oil. The mass is constantly stirred, left for half
an hour on the fire till it is very thin, and then filtered through
a linen cloth to stop all the impurities of the resin. The
finished vehicle is allowed to deposit all particles too fine to
be stopped by the cloth, and after a few days is drawn off
from the sediment.

The following recipes can be varied according to require-
ments. Larger quantities of boiled oil can only improve the
quality of the vehicle by making it stronger and smoother
and forming a better ink. The numbers mean kilos in all
cases.

Thin. Medium. Thick.

Resin 25 25 25

Boiled linseed oil . . . . . 100 100 100

Resin soap 8 8 8

Weak boiled oil . . . .7 4 —

Resin 50 50 50

Boiled linseed oil 100 100 100

Besin soap 10 10 10

Weak boiled oil 9 6 —

PRINTERS* INKS : VEHICLES. 193

Thin. Medium. Thick.

Resin . . * 77 77 77

Boiled linseed oil 100 100 100

Resin soap 7 7 7

Weak boiled oil ..... 12 9 —

Ebsin Oil Vehicles.

The use of resin oil for this purpose was first proposed in
1848 by Pratt of New York. His formula is

KUos.

Resin oil 20

Resin 8

Yellow soap 2

amalgamated by heat. If the mass is to be thioker, the soap
and resin are increased, and vice versa, A later recipe is

Kilos.

Resin oil 50

Resin 39

White soap 9

amalgamated by heat with constant stirring till the mixture
is quite perfect. The thickness is regulated by increasing
the amount of soap and resin, or that of the oil.

Eesin oil first began to be largely used for this purpose in
1860, when the progress of the resin industry enabled it to
be more generally employed by producing resin oil of a less
penetrating odour than was before possible. Newspaper inks
are now made from resin-oil vehicles almost exclusively,
although the public often complain about the smell.

In the manufacture, the resin and the resin oil are heated
together, the soap being added later. Finally boiled linseed
oil is added and the whole is kept for a few hours at 120" to
140° C, to get rid of the smell of the resin oil, and to obtain
a perfect mixture of the ingredients. In the following recipes
the quantities are in kilos.

1. Thin vehicles with boiled Unseed oil.

194

OIL COLOURS AKD PRINTERS' INKS.

Thin boiled Resin BoUed. Resin Resin
' linseed oil soap linseed oil

oil

(a) .... 7 3 50 50 25

(6) .... 9 5 50 50 50

2. Medium vehicles with boiled Unseed oil.

Thin boiled Resin BoUed Resin Resin

linseed oil soap linseed oil

(a) .... 4 S 50 50 25

(6) .... 6 5 50 50 50

3. Thick vehicles with boiled linseed oil.

Resin Boiled Resin Resin
soap linseed oil
oU

(a) 3 50 50 25

{b), 6 50 50 60

4. Thin vehicles with raw linseed oil.

Resin Thick Resin Linseed Resin Raw linseed
turpentine soap oil oil oil

(a) . — " 2 2 52 96 84

(6) . 100 — 7 35 95 —

5. Medium vehicles with raw Unseed oU.

Resin Resin Thick Linseed Resin Linseed
soap turpentine oil oil oil

(a) . . — 6 5 1050 240 210

(b) . . 100 70 — 3500 80 —

6. Thick vehicles with raw linseed oil.

Resin Resin Thick Linseed Resin Linseed
soap turpentine oil oil oil

(a) . . — 6 5 87 240 210

(6) . . 100 7 — 26 80 —

Composition Vehicles.

For Fine Work, — 1. Copaiva balsam, 70 kilos. ; ordinary
Unseed oU, 60 kilos. ; colophony, 110 kilos. ; almond benjamin,
3 Mlos. ; Tolu balsam, 2 kilos.

2. Copaiva balsam, 85 kilos. ; ordinary Unseed oil, 40 kilos. ;
colophony, 115 kilos. ; almond benjamin, 3 kilos. ; Tolu
balsam, 2 kilos.

printers' inks: vehicles. 195

Goyneau's Becipe. — 1. Linseed oil^ 979 parts; resin, 7215

parts,; Byrup, 245 kilos. ; litharge, 125 kilos.

2. Linseed oil, 400 kilos. ; resin, 380 kilos.; syrup, 490
kilos. ; litharge, 60 kilos.

3. Linseed oil, 980 kilos. ; resin, 958 kilos,; syrup, 980
kilos. ; litharge, 122 kilos.

The oil is mixed with the litharge, while a slow fire is kept
up under the kettle, until the oil begins to swell and to show
a froth. In the meantime the resin is melted with a little
linseed oil, and added to the oil when the latter has ceased
to froth. Then the mass is well stirred, and when it has
somewhat cooled the syrup is added.

Savage's Becipe. — 32 kilos, of copaiva balsam are mixed
with 12 kilos, of resin soap.

KnecMs Becipe, — 5 kilos, of Venice turpentine, 15 kilos,
of castor oil, and 1 kilo, of white wax are mixed well together
over the water bath.

BosVs Becipe, — 9 kilos, thick turpentine, 10 kilos, of soft
soap, and 4 kilos, of oleine are mixed together hot.

Besin Soap Vehicle for Gold Printing, — This composition
consists of a solution of resin soap with glue and glycerine.
It is made as follows : —

We dissolve 50 kilos, of soda in 150 kilos, of water in a
copper kettle, and raise it to the boil. "We then gradually
add with continual stirring 100 kilos, of powdered colo-
phony, and then keep up the boiling for two or three hours,
or at least until the liquid becomes clear and quite transparent.
We then allow the liquid to cool, and pour it off from the
tough brown resin lying at the bottom. We then add 100
kilos, and 15 kilos, of soaked glue and heat up till everything
is dissolved. The vehicle thus prepared dries quickly. If it
is wanted to dry slowly, it is additioned with from 10 to 20
kilos, of glycerine of 28° B.

Thenius's Becipe, — Take 25 kilos, linseed oil, 3 kilos, of
fine litharge, and boil until the linseed oil, on cooling, begins

196 OIL COLOURS AND PRINTERS* INKS.

to get thick, and then allow to settle. In the meantime melt
10 kilos, of pale American resin, and add it to the oil, and
boil for a time longer. Finally add 5 kilos, of coal-tar varnish,
heat again for a time, and stir till cold. The vehicle must
be thick and of the consistency of honey.

CHAPTEE XXIII.

PRINTERS' INKS : FIGMENTS AND MANUFACTURE.

As we have already said, black printers* ink consists of
vehicle and lampblack. When you see the statement in a
book that it is difficult to say exactly the proper constitution
of printers* ink, you may be sure that the author is a cautious
man. Here we shall give precise directions.

We have now to get our product to mix together vehicle
and lampblack, a process which was carried out at the
beginning of the printing art, just as it is now, except that
the rubbing together is now done by machinery of the best
construction.

On account of the great toughness of the vehicle and the
great lightness of the lampblack, the mixing of the two is best
done in a closed mixing machine, such as those described
earlier in this book. The rubbing up in the machine must
be very perfect to get a faultless product, such as those of
Lehmann and others. The finished ink must contain no
lumps of any kind, and it must have the finest ointment-like
and uniform consistency, as is only possible with the above-
named machines, whose suitability for printers' ink has been
already mentioned.

The proportion between lampblack and vehicle is various,
and depends chiefly on the nature and origin of the pigment.
In general, the finer the lampblack, the less of it is required
to make a good printing and good covering ink, for the fine
lampblack always goes farther. The proportion varies from
21 to 40 parts of lampblack to 100 parts of vehicle, whether
the ink is to be thin, medium or thick. The quantity of lamp-

198 OIL COLOURS AND PRINTERS* INKS.

black oannot affect the thickness of the ink, which depends
mainly on the consistency of the vehicle used. Unfortu-
nately, manufacturers fall over this wrong notion occasionally
that they can make a thick ink by putting a lot of lampblack
to a thin vehicle, and then discover when too late that their
ink is unusable.

As an ink with a certain blue- black colour and lustre is
required for fine illustrations and sumptuous painting, and
this cannot be got with lampblack alone, these inks also
contain Prussian blue or indigo, or aniline dyes which have
been already used with success. Prussian blue and indigo
being hard pigments, must be subjected to a preliminary
treatment to enable them to be rubbed up more easily. This
consists in soaking them for a day or two in 96 per cent,
spirit, then grinding them, and finally spreading them out to
allow the alcohol to evaporate. Aniline dyes, principally
blue and violet, must be soluble in oil, so as to dissolve in the
varnish without leaving any residue.

As already mentioned, the proportion of lampblack in the
ink depends upon the nature of the former, so the recipes now
about to be given for making printers' ink cannot be regarded
as correct in all cases, but must be taken as subject to many
modifications.

Inks for Kotary Machines.

Thin. Medium. Thick.

1. Vehicle 70 72 72

Lampblack 30 28 28

2. Vehicle 72 74 74 '

''Lampblack 28 26 26

Inks for Kapid Printing.
Newspaper Inks.

Thin. Medium.

Vehicle 78 76

Lampblack . , . . , 22 24

PRINTERS* INKS : PIGMENTS AND MANUFACTURE. 199

Book Inks,

Thin. Medium. Thick.

Vehicle 77 79 80

Lampblack 23 21 20

IlltLstration Inks.

Thin. Medium Thick.

Vehicle 78 78 78

Lampblack 20 19 19

Prussian blue 2 2 1

Indi'o — 1 —

Steel blue — — 2

As we have seen, the vehicle in all the inks is on an un-
changed basis. It is therefore evident that it is on the quality
of the lampblack that the beauty and value of the ink chiefly
depends. It is impossible to incorporate the pigment with
anything better than the proper amount of pure oil vehicle,
and this shows that all inks would be of the same quaHty if
there were no differences in the quality of the lampblack,
which has the chief influence on the nature of the ink. Hence
in order to make a newspaper ink at a medium price we must
use a common lampblack made from tar or paraffin, or in
some cases from resin, while better lampblack is used for
book-work, and for illustrations the lampblack is calcined
several times. For these reasons it is difficult to give formulae,
and in what follows I will only indicate the usual proportion.
The true formulsB can be arrived at only by practice.

Brackenbusoh's Impbovements.

The object of this inventor is to replace the linseed oil
vehicle now used in printing-ink manufacture, either altogether
or with such additions as are required either to lower the
price or to give some special lustre. These substitutes are
mixtures of the heavy hydrocarbons and resins, and these
are cheaper, dry quicker, and give more uniform inks.

Consistent Black Printers* Ink. — 25 parts of paraffin oil and
45 of fine colophony are mixed either by melting the resin

200 OIL COLOURS AND PRINTERS' INKS.

at about 80° C, or by mechanical grinding at the ordinary
temperature. The mass then receives a further addition of
15 parts of lampblack.

Soft Ink for Botary Machines, — In place of the 45 parts
of fine colophony take 40 only. "With this exception the
process is the same as the last.

Jobbing Printers' Ink, — Here the proportions of the first
recipe are employed, but dammar is substituted for colophony.

The recipes given must depend on the quality of the raw
materials used.

Differences in the resin and hydrocarbon can be corrected
by alternating the proportion of lampblack present. The
figures given above, however, are in most cases the best, and
may be regarded as giving typical normal inks.

If other colours than black are required the proper amount
of the suitable pigment is substituted for the lampblack. In
order to manufacture a specially cheap ink resin oil may be
substituted for the paraffin, and the colophony may be replaced
by ordinary resin, Burgundy pitch or pine pitch. Fillings,
used to increase the volume of the ink, can also be put in to
a reasonable extent.

Gunther's Ink.

This is a black printers' ink which can also be used as an
etching ground and a stamping colour. The ingredients are
pitch or asphalt ; the highest fractions of tar oil, or anthracene
oil, after special preparation ; spirit-soluble aniline, soft soap,
that made with fish oil being the best for the purpose ; and
a drying Greenland fish oil.

These ingredients are mixed together at a temperature of
60° to 80° C.

To diminish the unpleasant smell of the green oil it is first
prepared by being acted on by chlorine at a temperature of
over 100° C, or by heating with an energetic oxidising agent
such as nitric acid ; then probably the amido bases are com-

PRINTERS* INKS : PIGMENTS AND MANUFACTURE. 201

bined and become less evil-smelling compounds than those
originally existing as natural constituents of the green oil.
The oil is then boiled with 5 per cent, of chloride of copper
to deepen its brown colour. The following proportions have
proved to be the best : 45 parts of green oil previously heated
with chloride of copper, 40 of pitch or asphalt, 12 of soap, 5
to 8 of fish oil, according to the time of the year, and from
3 to 15 parts of spirit-soluble aniline dye in powder.

In an earlier patent Gunther protected the following pro-
cess : The pigment ingredients are pitch or asphalt ; rectified
ter oil ; mixtures of aniline violet with various fatty acids ;
and the fatty residue from the distillation of heavy resin oil ;
these materials are intimately mixed by being stirred together
with heat and combine readily. The following proportions
have been found to be good, but may be altered according to
circumstances : 40 parts of asphalt, 28 of rectified tar oil, 8
of the fatty aniline violet, and 24 of the resin oil residue. If
the mass is too thick it is diluted with more tar oil.

Still another patent of Gunther is concerned with the pre-
liminary treatment of the heavy tar oil used in making these
inks, and obtained as a residue in anthracene manufacture.
The object of this treatment is to give the oil a brownish
black colour, and the process consists in heating it with about
10 per cent, of chloride of copper which has previously been
evaporated to get rid of its excess of acid. The chloride is
then dissolved in warm water or stirred into the anthracene
oil. This is then boiled until all the water has evaporated.
The oil thus acquires a dark brown colour, and therefore
requires a far smaller amount of aniline violet than would
otherwise be necessary to give the required tint ; ^ per cent,
of the dye-stuff is enough. The product then obtained can be
substituted for the rectified tar oil and aniline violet and can
be used without any addition as a stamping ink, especially
for post-oliice work in cancelling postage stamps.

202 OIL COLOURS AND PRINTERS' INKS.

Dr. Artus's Ink.

Heat 60 kilos, of Venice pitch gently with 30 kilos, of oleic
acid, as free as possible from stearine, and carefully rub the
mixture up with 80 kilos, of soft soap. Then add 50 kilos,
of calcined lampblack, first passed through a fine hair-sieve,
and finally a solution of 40 kilos, of Prussian blue and 20
of oleic acid in 20 of water. Instead of the solution of
Prussian blue indigo-carmine may be used, and of this 20
kilos, will be sufficient instead of the 40 of Prussian blue.
The indigo-carmine must first be thoroughly rubbed up with
water. Trials of this ink are said to have given very satis-
factory results, and the ink is considered to be an improve-
ment on BosFs.

E6sL*s Ink.

This consists of 9 parts of Austrian turpentine, 10 of soft
soap, 4 of oleine, and 4 or more of lampblack. When these
ingredients have been well mixed by the aid of heat they are
thoroughly worked up in a paint mill, and the ink is then
ready. The types are moistened and cleaned by means of a
sponge dipped in a 1 per cent, solution of soda in water.

The advantages of this not very original ink in addition to
its great divisibility, which allows it to be spread very thinly
over the types, and therefore to give a very clear impression,
are as follows : 1. It is easily made. 2. The cost of manu-
facture is one- third less, and the ink goes farther. 3. Its
durability is such that it can be recovered from old printed
matter by means of the above solution of soda, and the paper
pulp can be bleached again for the manufacture of fresh paper
by the same means. The ink also does away with the use of
printers' lye, and also obviates the necessity of brushing the
types. Hence they are not so quickly worn out as when
ordinary inks are used.

printers' inks : pigments and manufacture. 203

Ooal-Tab Inks.

Heat coal tar over a gentle fire and add, according to
the degree of toughness to be produced, from 6 to 16
per cent, of co^opbtotiy, raising the temperature until the
resin is completely dissolved. Then stir into the mass
10 per cent, of parafl&n oil, and pass the whole through
a cloth or fine sieve. Then allow it to cool. Next correct
the intense smell of the tar and paraffin by stirring in
a mixture of bleaching powder and hydrochloric acid,
until the chlorine evolved has destroyed the odour. About
300 grammes of acid are required for 50 of bleaching
powder. The bleaching agents may also be advantageously
added during the mixing of the ingredients, and the sub*
sequent filtering will get rid of the residual bleaching
powder. The disinfected vehicle is next heated, and is
mixed slowly with constant stirring, with 20 to 25 per
cent, of crude glycerine and 12 to 18 per cent, of lamp-
black. The resultant paste is then rubbed up in a roller
paint mill till it is thoroughly fine and uniform. In order
to combine the glycerine better, and to get the desired
deep black, bluish black or violet black ink, a little nigro-
sine, aniline blue or aniline violet is dissolved in the gly-
cerine by heating on the water bath before it is added to
the ink.

According to a supplementary patent, 100 kilos, of coal
tar are gradually mixed with constant stirring with 2i to
3 kilos, of sulphuric acid. The mass is then vigorously
worked up, and gradually heated until it swells. "When
taken from the fire 1 kilo, of calcined soda is stirred in,
and the stirring is kept up until the tar is nearly cold.
Then from 2i to 3 kilos, more of the soda are put in,
and the mass is replaced on the fire and boiled until the
tar froths strongly. It is then quickly removed from the
fire and allowed to become quite cold.

204 OIL COLOURS AND PRINTERS' INKS.

It should be allowed to remain for a few days, and in
the meantime it is disinfected with chlorine, either bubbled
through it by means of a glass tube or generated in it by
the addition of bleaching powder and hydrochloric acid.
The black mass is then mixed with from 2^ to 3 kilos, of
lard and 4 to 5 kilos, of glycerine, or 8 to 10 of soap
instead of glycerine, the whole being boiled together.
When the mass is thin, it is filtered through a cloth.
For finer inks, 2 to 5 kilos, of logwood extract in solution
can be added to improve the black colour of the ink, and
any required shade of deep black, blue black or violet black
ink can be obtained by adding bichromate of potash, alum,
tartar or copper solution. The filtered black ink is rubbed
up with from iV to ^ of lampblack. To still further im-
prove the shade of black, a little aniline black, blue or
violet, may be dissolved in the glycerine before it is mixed
with the tar.

Schmidt Brothers' Ink.

Ordinary printers' ink consisting of lampblack and lin-
seed oil can only be removed from paper with dijB&culty
and never completely, for although the vehicle can be dis-
solved and removed the lampblack resists all chemical
agents and solvents. Hence paper printed with such ink
can never be remade into white paper again. To remedy
this, the lampblack is replaced by other substances which
can be removed by various chemical processes.

In order to make a removable ink, peroxide of manganese,
a bye-product of many chemical industries, is employed, but
other oxidised manganese compounds may be substituted,
such as natural manganite and pyrolusite, with perfect suc-
cess. The following is the recipe, which must be under-
stood, however, to be variable according to the destined
employment of the ink.

40 kilos, of the manganese compound are mixed with 60 of

printers' inks : pigments and manufacture. 205

boiled linseed oil, and finely rubbed up with it. The usual
substitutes for linseed oil in printing ink manufacture, such
as soft oleine soap, turpentine, glycerine, resin soap, etc.,
may be used instead, and the usual additions for producing
a special tint, such as nigrosine, may be employed exactly
as in ordinary inks. If paper printed with this ink is to
be remade into white paper it is treated with cold or hot
solution of carbonate of soda, and the whole is then rinsed
to get rid of the ink. Any small traces of the manganese
compound remaining can be removed with hyposulphite of
soda. The remaining pulp is treated with acid or with the
vapour of acid, hydrochloric being the best to use, as with
the traces of manganese still left it develops chlorine, which
helps to bleach the pulp.

ElBCHER & EbNER's InE.

This is a similar ink to that of Schmidt Brothers^ and the
patent for it was taken out by Kircher in Austria, Germany
and America fifteen years ago. It is prepared with sulphu-
retted hydrogen and compounds of iron, with the special
purpose of securing an ink which should be removable, and
allow the paper to be worked up over again. The State
printing office of Vienna made experiments with it and ob-
tained good results, but it never came into general use in
Austria, and I know that the manufactory at Gannstatt had
to shut down. Kircher employed the following processes : — -

1. Dissolve a salt of iron in 6 times its bulk of clean
water, and precipitate it with the sulphide. Wash the pre-
cipitate well, dry it quickly, and work it up with the vehicle
in a paint mill.

2. Mix very fine iron filings with their chemical equivalent
of sulphur, and fuse in a covered crucible at a gentle heat.
Grind the cooled residue finely and mix with the vehicle.

3. Pass sulphuretted hydrogen over ferric oxide in a red-

206 OIL COLOURS AND PRINTERS* INKS.

hot tube until all action oeases. Mix the contents of the
tube cold, and finely ground with the vehicle as before.

4. Eeduce ferric or ferrous sulphate with carbon at not
too high a temperature, and work the cold mass with the
vehicle.

Iron Printing and Stamping Inks.

Ferric or ferrous salts, or metallic iron, are added to the
printing or stamping inks made with lampblack and linseed
oil; the iron combines intimately with the cellulose and
size of the paper, and can be detected there even after all
visible traces of ink have been removed.

Thbnius'b Ink.

Take 25 kilos, of linseed oil and 3 kilos, of fine litharge
and boil until the oil thickens on cooling. Then allow it
to settle. Melt also 10 kilos, of light American colophony,
put it into the thickened oil, heat for a short time longer
with 5 kilos, of coal-tar oil, and finally stir until cold. The
coalttar oil is made from the second fraction of the distilla-
tion of crude coal tar, and has a specific gravity of '85 to
'89. The first distillate from the tar may also be used,
mixed with the other, the two combined having a specific
gravity of •9. To make the oil from the mixture about
100 kilos, of it are put into a vat, Hned with lead,
with i kilo, of bichromate of potash, i kilo, of pyrolusite
and 2 kilos, of pure sulphuric acid. The whole mass is
stirred continuously for an hour, then allowed to stand for
a few hours, and the darkened oil is poured off from the
sediment, which contains the acid and many resinous bodies.
The oil is washed first with warm water, and next with
2 per cent, of caustic soda-lye of 5** B., which frees it from
large quantities of resinous impurities. The finished oil is
thick, like honey, and is rubbed up with lampblack.

Or take 10 kilos, of fine, half-calcined oil lampblack, rub

printers' inks : pigments and manufacture. 207

it up very fine on the stone and add, gradually, rectified oil
of turpentine until it becomes a thick paste, then continue
rubbing until the mass acquires a lustre and is very fine.
Mix with the same quantity of oil black like the first, but
with the above coal-tar oil instead of turpentine. Eub
on the stone 2 kilos, of fine Prussian blue to a very fine
powder, and add to it i kilo, of powdered siccative, and
a thick printers* varnish made from coal tar, so as to obtain
the same thick consistency as before.

INDEX.

Adulterations of linseed oil, 9, 61.

Adulterations of boiled linseed oil,

61.

with colophony, 64.

fish oil, 66.

resin oil, 64.

other adultera-
tions, 66.
Air aspirator, 32.
Andres' boiling apparatus, 188.
Antimony colours, 74.
Apparatus for making lampblack

from oil, 93.
Arsenic colours, 74.
Artists' colours, 163.

Blacks, 166.

Blues, 166.

Browns, 166.

Greens, 166.

Beds, 166.

Whites, 166.

Yellows, 166.

Barium colours, 74.
Bisulphide of carbon, 6.
Black from tar, 113.

— pigments, 142.
Blacks for artists, 166.
Blue pigments, 142.
Blues for artists, 166.
Body of pigments, 72.

Boiling linseed oil over the open
fire or with steam, 43.

— point of linseed oil, 8.
Bonner ball-mill, 117.
Book inks, 199.

Brackenbusch's improvements in

printing inks, 199.
Brown pigments, 142.
Browns for artists, 166.
Bruchhold's weatherproof paint,

149.

Cadmium colours, 76.

Calcining lampblack, 110.

Canadol, 6.

Carbolic varnish, 70.

Carbon bisulphide, 6.

Carmine, 80.

Cataract machine, 17.

Cement-boiled oil, 69.

Centrifugal sifting and winnowing
machine, 123.

Chemical preparation of lamp-
black, 109.

Chinese drying oil, 68.

Chromium colours, 76.

Coal-tar inks, 203.

Cobalt colours, 78.

Combret's apparatus, 26.

Composition of linseed oil, 9.

— poppy oil, 14.

— vehicles for printers' inks, 194.
Consistent black printers' ink, 199.
Copper colours, 78.
Cotton-seed oil, and its detection in

oil paints, 180.

Dr. Artus's ink, 202.
Dreyer's apparatus

lampblack, 96.
Driers, 34, 36.

for making

210

INDEX.

Bvrard'g process of purifying lin-
seed oil, 24.
Experiments with boiled oil, 173.

pure linseed oil, 172.

Extraction process for linseed oil, 5.

Fastness of pigments, 78«
Frankfort black, 81.
Freezing point of linseed oil, 7.
poppy oil, 14.

Ink, Thenius's, 206.
Inks, book, 199.

— coal-tar, 203.

— for rapid printing, 198.
rotary machines, 198.

— illustration, 199.

Iodine numbers of fatty acids, 12.

Iron colours, 77.

—^ printing and stamping inks, 206.

— ships, paint for, 165.

Jobbing printers* ink, 200.

German Society for the Promotion
of Bational Painting, normal
pigments of the, 176.

Glasenapp's black paint, 147.

Glaser's disintegrator, 120.

Green pigments, 141.

Greens for artists, 165.

Grey colours, 140.

Grinding pigments, 117.

Grunzweig's oil paint, 147.

Gunther's ink, 200.

High temperatures, to make oil

colours resist, 147.
House oil paints, manufacture of,

136.
Hugoulin's process, 143.

Illustration inks, 199.

Indigo, 81.

Ink, Brackenbusch's, 199.

— Dr. Artus's, 202.

— Gunther's, 200.

^^, iron printing and stamping, 206.
'— • feircher & Ebner*s, 205.

— Rosl's, 202.

— Schmidt Brothers', 204.

Kallkolith, 149.

Kircher & Ebner's ink, 205.

Korting's aspirator, 31.

Lake colours, 80.
Lampblack, 83.

— calcining, 110.

— chemical preparation of, 109.

— real, 89.

— substitutes for, 113.
Black from tar, 113.
Tannin black, 115,

Lead and manganese preparations,
soluble, 37.

— colours, 75.

Lehmann's machine for mixing

vehicles with pigments, 129.
Linoleates, 36.
Linoleic acid, 35.
Linseed oil, sbdulteration of, 9, 61.

with colophony, 64.

fish oil, 66.

resin oil, 64.

other adulterations,

66.

and resin as a vehicle for

printers' inks, 192.

boiling, theory of, 40.

by pressure, 5.

extraction, 5.

INDEX.

211

Linseed oil plant, 4.
bleaching, 28.

with peroxide, 29.

with sulphuric acid, 30.

with sulphurous acid, 30.

by the sun, 28.

boiling point of, 8.

composition of, 9.

freezing point of, 7.

manufacture of boiled, 43.

Andres* process, 48.

German patent process,
56.

Lehmann's superheater,
46.

Muthel and Ltitke's pro-
cess, 50.

Schrader and Dumeke's
process, 49.

Vincent's process, 48.

Walton's process, 48.

Zimmetmann and Holz-
wich's process, 54.

Zwieger's process, 46.

purification of, 15, 23.

specific gravity of, 8.

substitute for, 148.

^ testing, 10, 62.

Luminous paint, 156.

Machinery for grinding and rub-
bing up pigments, 117.
Bonner's ball-mill, 117.
Centrifugal sifting and winnow-
ing machine, 123.
Glaser's disintegrator, 120.
Sieving and mixing ma.chine, 124.
Machines for purifying linseed oil,
14, 25.
Cataract machine, 17.
Combret's apparatus, 25.
Oil-refining kettle, 21.
Rieck's machine, 16.
Upward oil filter, 19.
Ure's oil filter, 18.
Manganese and lead preparations,

soluble, 87.
— colours, 79.
Mercury colours, 79.

Mixing vehicles with pigments, 125.

Lehmann's machine, 129.

Quack's machine, 125.

Werner and Pfleiderer's ma-
chine, 127.
Mussini paints, 174.

New driers, 36.
Newspaper inks, 198.

Oil-refining kettle, 21.

Oven for burning asphalt, 86.

resin, etc., 87.

Oxidising agents for boiled oil
making, 34.

Paint fot ships and submarine con-
structions, 155.
— mills, 131.

Peroxide bleaching of linseed oil, 29.
Pigments for painters, artists and

printers, 72.
Plate paint miUs, 133.
Poppy oil, composition of, 14.

freezing point of, 14.

obtained by pressure, 13.

specific gravity of, 14.

Printers' inks, 82, 197.

mixing vehicle and pigment,

197.
Progress in the manufacture of

pigments, 1.
Purification of linseed oil, 15, 23.

Quack's machine for mixing vehi-
cles with pigments, 125.

Rapid printing, inks for, 198.
Red pigments, 141.

212

INDEX.

Reds for artists, 165.

Kesin oU sis a vehicle for printers'

ink, 193.
Bieck's ma.chine, 16.
Roller paint mills, 184.
Rdsl's ink, 202.
Rotary machines, ink for, 198.

Schmidt Brothers* ink, 204.

Schnittger's paints, 154, 168.

Shade of pigments, 72.

Ship paints, 154.

Siccative properties of linseed oil, 2.

Sieving and mixing machine, 124.

Soft ink for rotary ma.chines, 200.

Soluble manganese and lead pre-
parations, 37.

Specific gravity of linseed oil, 8.

poppy oil, 14.

Substitute for linseed or turpentine
oil, 148.

Substitutes for lampblack, 113.

Sulphuric acid bleaching of linseed
oil, 30.

Sulphurous acid bleaching of lin-
seed oil, 30.

Sun bleaching of linseed oil, 28.

Tannin black, 116.
Tar varnish, 70.
Testing linseed oil, 10.
Thenius's ink, 206.
— oven, 86.
Theory of oil-boiling, 40.
Tighe's process for making lamp-
black, 108.
Turpentine oil, substitute for, 148.

Universal pigment for use as water,

oil or lake colour, 146.
Upward oil filter, 19.
Ure's oil filter, 18.

Varnish, carbolic, 70.

— tar, 70.

Vehicle and fixer for house paints,

* 148.
Vehicles for printers' inks, 184.

Compositions, 194.

Linseed oil and resin, 192.

Resin oil, 193.

Weatherproof paint, Bruchhold's,
149.

— — for walls, 144.

Werner & Pfleiderer's mcbchine
for mixing vehicles with pig-
ments, 127.

White lead pigments, 140.

Whites for artists, 165.

Yellows for artists, 166.
Yellow pigments, 140.

Zinc colours, 80.

— white pigments, 140.

THE ABEBDBEN UNIYEBSITY PBESS LIMITED.

Special Weedniedl 5Boo/is.

PAGE

Adhesives 10

Agricultural Chemistry ... 9
Air, Industrial Use of ... 10
Alcohol, Industrial ... 9

Alum and its Sulphates ... 8

Ammonia ' 8

Aniline Colours 3

Animal Fats 6

Anti-corrosive Paints ... 4
Architecture, Terms in ... 22
Architectural Pottery ... 12

Artificial Lighting 20

Artificial Perfumes ... 7

Balsams 9

Bleaching Agents, etc. ... 17

Bone Products 8

Bookbinding 23

Brick-making ... 11, 12

Burnishing Brass 21

Carpet Yam Printing ... 16

Casein 4

Celluloid 23

Cement 22

Ceramic Books ... 11, 12

Charcoal 8

Chemical Analysis 8

Chemical Essays 8

Chemical Reagents ... 8

Chemical Works 8

Clays 12

Coal dust Firing 19

Colliery Recovery Work... 18
Colour Matching (Textile) 16
Colour-mixing for Dyers... 16

Colour Recipes 3 f

Colour Theory 16

Combing Machines ... 17 '

Compounding Oils, etc. ... 6
Condensing Apparatus ... 19

Cosmetics 7

Cotton Dyeing 16

Cotton Spinning ... ... 17

Cotton Waste 18

Cranes and Hoists ... 20

Damask Weavinjg 15

Dampness in Buildings ... 22
Decorators' Books ... 4

Decorative Textiles ... 15

Dental Metallurgy 18

Disinfection 9

Driers 5

Drugs 22

Drying Oils 5

Drying with Air, etc. ... 10

Dyeing Marble 23

Dyeing Woollen Fabrics... 17

Dyers' Materials 16

Dye-stuifs 17

Edible Fats and Oils ... 7
Electric Lamp Develop-
ment 21

Electric Wiring 21

Electricity in Collieries ... 18

Emery 24

Enamelling Metal 13

Enamels 13

Engineering Handbooks ... 19

INDEX TO SUBJECTS.

PAGE

Engraving 23

Essential I Oils 7

Evaporating Apparatus .. 19
External Plumbing ... 20

Fats 6,7

Faults in Woollen Goods 15

Flax Spinning 18

Food and Drugs 22

Foundry Machinery ... 20

Fruit Preserving 23

Gas and Oil Engines ... 19

Gas Firing 19

Glass-making Recipes ... 13

Glass Painting 13

Glue-making and Testing... 8

Greases 6

Guttapercha 11

Hat Manufacturing ... 15

Hemp Spinning 18

History of Staffs Potteries 12

Hops 21

Hot-water Supply ... 21

India-rubber 11

India-rubber Substitutes 5

Inks 3, 4, 5, 9

Insecticides, etc 21

Iron-corrosion 4

Iron, Science of 19

Iron and Steel Work ... 19

Japanning 21

Jute Spinning 18

Lace-Making 15

Lacquering 21

Lake Pigments 3

Lead 10

Leather-working Mater'ls 6,1 1

Libraries 24

Linoleum 5

Lithographic Inks 5

Lithography , 23

Lubricants 6

Manures 8, 9

Meat Preserving 23

Medicated Soaps 7

Metal Polishing Soaps ... 7

Mineral Pigments 3

Mineral Waxes 6

Mine Ventilation 18

Mine Haulage 18

Mining, Electricity ... 18

Motor Car Mechanism .. 20

Needlework ... 15

Oil and Colour Recipes ... 3

Oil Boiling ... 5

Oilmen's Sundries ... 3 I

Oil Merchants' Manual ... 6

Oils 5,6,7

Ozone, Industrial Use of... 10
Paint Manufacture ... 3

Paint Materials 3

Paint-material Testing ... 4
Paint Mixing ... 3, 4

Paper-M ill Chemistry ... 13
Paper-pulp Dyeing ... 13

Petroleum 6

Pigments 3, 9

Plumbers' Books ... 20, 21 t

Pottery Clays
Pottery Decorating
Pottery Manufacture
Pottery Marks
Power-loom Weaving
Preserved Foods

PAoa
... 21
... II
II, 12
... 12
... 14
23

Printers' Ready Reckoner 23
Printing Inks ... 3, 4, 5

Recipes 3, 13

Reinforced Concrete ... 19

Resins 9

Ring Spinning Frame
Risks of Occupations
Riveting China, etc.
Scheele's Essays ...
Sealing Waxes
Shale Oils and Tars

Shoe Polishes 6

Silk Dyeing 16

Silk Throwing, etc. ... 17

Smoke Prevention 18

Soap Powders 7

Soaps 7

Spinning 15, 17, 18

Spirit Varnishes 5

Staining Marble, and Bone 23

Stain-removing Soaps
Steam Drying
Steam Turbines ...
Steel Hardening ...
Sugar Technology

Sweetmeats

Tallow

Technical Schools, List .,

Terracotta ,

Testing Paint Materials .,

Textile Design
Textile Fabrics
Textile Fibres

Textile MateriaU ,

Timber ...

Toilet Soapmaking

Toothed Gearing

Varnishes

Vegetable Fats and Oils ..
Vegetable Preserving

Warp Sizing

Waste Utilisation

Water. Industrial Use ...
Water-proofing Fabrics ...

Waxes

Weaving Calculations ...
White Lead and i^inc
Wiring Calculations
Wood Distillation

Wood Extracts

Wood Waste Utilisation...

Wood-Dyeing

Wool Dyeing

Woollen Goods
Woven Fabrics
Writing Inks
X-Ray Work
Yam Sizing ...
Yarn Numbering and Test-
ing 14

Zinc White Paints

14. IS

... 14

... 22

... 7

... 19

•

22
23

... 14
15, 16, 17
... 15
... 9
... 11

PUBLISHED BY

SCOTT, GREENWOOD & SON,

« RPOAHWAV I linOATP. KONDON. B.C. rEnsrland).

FULL PARTICULARS OF CONTENTS

Of the Books mentioned in tliis ABRIDGED CATALO&UE
will be found in the following Catalogues of

CURRENT TECHNICAL BOOKS.

LIST I.

Artists' Colours — Bone Products — Butter and Margarine Manufacture— Casein —
Cements— Chemical Works (Designing and Erection) — Chemistry (Agricultural, Indus-
trial, Practical and Theoretical) — Colour Mixing— Colour Manufacture — Compounding
Oils — Decorating — Driers— Drying Oils— Drysaltery — Emery— Essential Oils — Fats
(Animal, VegetsU>le, Edible) — Gelatines — Glues — Greases — Gums — Inks — Lead —
Leather — Lubricants — Oils — Oil Crushing — Paints — Paint Mauufacturing — Paint
Material Testing— Perfumes— Petroleum— Pharmacy— Recipes (Paint, Oil and Colour
— Resins — Sealing Waxes— Shoe Polishes — Soap Manufacture — Solvents — Spirit
Varnishes — Varnishes — White Lead — Workshop Wrinkles.

LIST II.

. Bleaching — Bookbinding — Carpet Yarn Printing — Colour (Matching, Mixing
Theory)— Cotton Combing Machines— Dyeing (Cotton, Woollen and Silk Goods) —
Dyers' Materials — Dye-stuffs— Engraving — Flax, Hemp and Jute Spinning and Twisting
— Gutta-Percha — Hat Manufacturing — India-rubber — Inks — Lace-making — Litho-
graphy—Needlework—Paper Making — Paper-M ill Chemist — Paper-pulp Dyeing —
Point Lace— Power-loom Weaving— Printing Inks— Silk Throwirig^Smoke Preven-
tion — Soaps— Spinning —Textile (Spinning, Designing, Dyeing, Weaving. Finishing
—Textile Materials— Textile Fabrics— Textile Fibres— Textile Oilsr-Textile Soaps-
Timber — Water (Industrial Uses) — Water-prooRng — Weaving — Writing Inks— Yams
Testing, Sizing).

LIST III.

Architectural Terms — Brassware (Bronzing, Burnishing, Dipping, Lacquering) —
Brickmaking— Building— Cement Work — Ceramic Industries— China— CkMil-dust Firing
— Colliery Books— Concrete — Condensing Apparatus — Dental Metallurgy— Drainage—
Drugs— Dyeing— Earthenware— Electrical Books— Bnamellinsf— Enamels— Engineer-
ing Handbooks— Evaporating Apparatus— Flint Glass-making— Foods— Food Preserv-
ing — Fruit Preserving— Gas Engines — Gas Firing — Gearing — Glassware (Painting,
Riveting) — Hops — Iron (Construction, Science) — Japanning — Lead — Meat Preserving
— Mines (Haulage, Electrical Equipment, Ventilation, Recovery Work from)— Plants
(Diseases, Fungicides, Insecticides)— Plumbing Books — Pottery (Architectural. Clays,
Decorating, Manufacture, Marks on) — Reinforced Concrete — Riveting (Chma,
Earthenware, Glassware) — Sanitary Engineering — Steam Turbines — Steel (Hardening,
Tempering) — Sugar — Sweetmeats — ^Toothed Gearing — ^Vegetable Preserving — Wood
Dyeing— X-Ray Work.

COPIES OF ANY OF THESE LISTS WILL BE SENT
POST FREE ON APPLICATION.

(Paints, Colours, Pigments and
Printing Inks.)

THE CHEMISTRY OF PIGMENTS. By Ernest J,
Parry, B.Sc. (Lond.), F.I.C.; F.C.S., and J. H. Coste, F.I.C.,
F.C.S. Demy 8vo. Five Illustrations. 285 pp. Price 108. 6d.
net. (Post free, 10s. lOd. home ; I Is. 3d. abroad.)

TH55 MANUFACTURE OF PAINT. A Practical
Handbook for Paint Manufacturers, Merchants - and Painters,
By J. Cruickshank Smith, B.Sc. Demy 8vo.

[New- Edition in Preparation,

DICTIONARY OF CHEMICALS AND RAW
PRODUCTS USED IN THE MANUFACTURE
OF PAINTS, COLOURS, VARNISHES ANI?
ALLIED PREPARATIONS. By George H. Hurst,
F.C.S. Demy 8vo. 380 pp. Price 7s. 6d. net. (Post fre?, 8s.
home ; 8s. 6d. abroad.)

THE MANUFACTURE OF LAKE PIGMENTS
FROM ARTIFICIAL COLOURS. By Francis H.
Jennison, F.I.C, F.C.S. Sixteen Coloured Plates, showinsr
Specimens of Eisrhty-nine Coiours, speoiaiiy prepared from
the RecipM given in the Boole. 136 pp. Demy 8vo. Price
7s. 6d. net. (Post free, 7s. lOd. home; 8s. abroad.)

THE MANUFACTURE OF MINERAL AND LAKE
PIGMENTS. Containing Directions for the Manu-
facture of all Artificial, Artists and Painters' Colours, Enamel,
Soot and Metaffic 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. 330 pp. Second Revised
and Enlarged Edition. Demy 8vo. Price 10s. 6d. net. (Post
free, lls< home ; lis. 3d. abroad.)

OILMEN'S SUNDRIES AND HOW TO MAKE THEM.

Being a Collection of Practical Recipes for Boot Polishes, 31ues,
Metal Polishes, Disinfectants, etc., compiled from ♦• Oils, Col-
ours and Drysalteries *'. Crown 8vo. 130 pages. Price 2s. 6d.
net. (Post free, 2s. 9d. home ; 2s. lOd. abroad.)

OIL COLOURS AND PRINTERS' INKS. By Louis
Edgar Andes. Translated from the German. 215 pp. Crown
8vo. 56 Illustrations. Price58.net. (Post free, 5s. 4d. home;
58. 6d. abroad.)

MODERN PRINTING INKS. A Practical Handbook
for Printing Ink Manufacturers and Printers. By Alfred Sey-
mour. Demy 8vo. Six Illustrations. 90 pages. • Price 5s. net.
(Post free, 5s. 4d. home ; 5s. 6d. abroad.).'

THREE HUNDRED SHADES AND HOW TO MIX
THEM. For Architects, Painters and Decorators. By
A. Dbsaint. Artistic Interior Decorator of Paris. The book con-
tains 100 folio Plates, measuring 12 in. by 7 in., each Plate con-
taining 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. Bach Plate is inter-
leaved with grease-proof paper, and the volume is very artistic-
ally bound in art and linen with the Shield of the Painters* Guild
impressed on the cover in gold and silver. Price 21 s. net. (Post
free, 21s. 6d. home ; 228. 6d. abroad.)

HOUSE DECORATING AND PAINTING. By W.

Norman Brown. Eighty-eight Illustrations. 150 pp. Crown
8vo. 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 8vo. Price
Is. net. (Post free, Is. 3d. home and abroad.)

WORKSHOP WRINKLES for Decorators, Painters,
Paperhangers, and Others. By W. N. Brown. Crown 8vo.
128 pp. Second Edition. Price 2s. 6d. net. (Post free, 28. 9d.
home; 2s. lOd. abroad.)

CASEIN. By Robert Scherer. Translated from the
German by Chas. Salter. Demy 8vo. Illustrated. Second
Revised English Edition. 160 pp. Price 78. 6d. net. (Post free,
7s. lOd. home ; 8s. abroad.)

SIMPLE METHODS FOR TESTING PAINTERS'
MATERIALS. By A. C. Wright, M.A. (Oxon.),
B.Sc. (Lond.). Crown 8vo. 160 pp. Price Ss. net. (Post free,
5s. 3d. home ; 5s. 6d. abroad.)

IRON-CORROSION, ANTI-FOULING AND ANTI-
CORROSIVE PAINTS. Translated from the German
of Louis Edoar Andes. Sixty-two Illustrations. 275 pp.
Demy 8vo. Price lOs. 6d. net. (Post free, 10s. lOd. home;
lis. dd. abroad.)

THE TESTING AND VALUATION OP RAW
MATERIALS USED IN PAINT AND COLOUR
MANUFACTURE. By M. W. Jones, P.C.S. A
Book for the Laboratories of Colour Works. 88 pp. Crown 8vo.
Price 5s. net. (Post free, 58. 3d. home and abroad.)

For contents of these hookSy see List /.

THE MANUFACTURE AND COMPARATIVE
MERITS OF WHITE LEAD AND ZINC WHITE
PAINTS. By G. Petit, Civil Engineer, etc. Trans-
lated from the French. Crown 8vo. 100 pp. Price 4s. net.
(Post free, 4s. 3d. home ; 4s. 4d. abroad.)

STUDENTS' HANDBOOK OF PAINTS, COLOURS,
OILS AND VARNISHES. By John Furnell.
Crown 8vo. 12 Illustrations. 96 pp. Price 2s. 6d. net. (Post
free, 2s. 9d. home and abroad.)

PREPARATION AND USES OF WHITE ZINC
PAINTS. Translated from the French of P. Flbury.
Crown 8vo. 280 pages. Price 6s. net. (Post free, 6s. 4d. home ;
6s. 6d. abroad.)

(Varnishes and Drying Oils.)

THE MANUFACTURE OF VARNISHES AND
KINDRED INDUSTRIES. By J. Geddes McIntosh.
Second, greatly enlarged, English Edition, in three* Volumes,
based on and including the work of Ach. Livache.)

Volume 1.— OIL CRUSHING, REFINING AND
BOILING, THE MANUFACTURE OF LINO-
LEUM, PRINTING AND LITHOGRAPHIC
INKS, AND INDIA-RUBBER SUBSTITUTES.

Demy 8vo. 150 pp. 29 Illustrations. Price 7s. 6d. net.
(Post free, 7s. lOd. home ; 8s. abroad.)

Volume II.— VARNISH MATERIALS AND OIL-
VARNISH MAKING. Demy 8vo. 70 Illustrations.
220 pp. Price 10s. 6J. net. (Post free, 10s. lOd. home;
lis. 3d. abroad.)

Volume III.— SPIRIT VARNISHES AND SPIRIT
VARNISH MATERIALS. DemySvo. Illustrated.
4S4 pp. Price 12s. 6d. net. (Post free, 13s. home; 138. 6d.
abroad.)

DRYING OILS, BOILED OIL AND SOLID AND
LIQUID DRIERS. By L. E. And^s. Expressly
Written for this Series of Special Technical Books, and the
Publishers hold the Copyright for English and Foreign Editions.
Forty-two Illustrations. 342 pp. Demy 8vo. Price 128. Gd.
net. (Post free, 13s. home ; 13s. 3d. abroad.)

{Analysis of Resins, see page P.)

(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 Gborob H. Hurst,
F.C.S. Third Revised and Enlarged Edition. Seventy-four
Illustrations. 384 pp. Demy 8vo. Price 10s. 6d. net. (Post
free, lis., home ; lis. 3 J. abroad.)

TECHNOLOGY OF PETROLEUM . Oil Fields of the
World — Their History, Geography and Geology — Annual Pro-
duction and Development — Oil-well Drilling — ^Transport. By
Henry Neuberger 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.)

MINERAL WAXES: Their Preparation and Uses. By
Rudolf Greoorius. Translated from the German. Crown 8vo.
250 pp. 32 Illustrations. Price 6s. net. (Post free, 6s. 4d.
home ; 6s. 6d. abroad.)

THE PRACTICAL COMPOUNDING OF OILS,
TALLOW AND GREASE FOR LUBRICA-
TION, ETC. By An Expert Oil Refiner. Second
Edition. 100 pp. Demy 8vo. Price 7s. 6d. net. (Post free,
7s. lOd. home ; 8s. abroad.)

THE MANUFACTURE OF LUBRICANTS, SHOE
POLISHES AND LEATHER DRESSINGS. By

Richard Brunner. Translated from the Sixth Gern>an BdiUon
by C HAS. Salter. 10 Illustrations. Crown 8vo. 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. Sherripp. Second Edition Revised and Enlarged.
PemySvo. 214 pp. With Two Sheets of Tables. Price 7s. 6d.
net. (Post free, 7s. lOd. home ; 8s. 3d. abroad.)

ANIMAL FATS AND OILS: Their Practical Pro-
duction, Purification and Uses for a great Variety of Purposes.
Their Properties, Falsification and Examination. Translated
from the German of Louis Edgar Andes. Sixty-two Illustrations.
240 pp. Second Edition, Revised and Enlarged. Demy 8vo.
Price 10s. 6d. net. (Post free, 10s. lOd. home: Us. 3d. abroad.)

F.or contents oj these books ^ see List I.

VEGETABLE FATS AND OILS: Their Practical
Preparation, Purification and Employment for Various Purposes,
their Properties, Adulteration and Examination. Translated
from the German of Louis Edgar Andes. Ninety-four Illus-
trations. 340 pp. Second Edition. Demy 8vo. Price lOs. (-d.
net, (Post free, lis. home; lis. 6d. abroad.)

EDIBLE FATS AND OILS : Their Composition, Manu-
facture 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. lOd. home ; 8s. abroad.)

(Essential Oils and Perfumes.)

THE CHEMISTRY OF ESSENTIAL OILS AND
ARTIFICIAL PERFUMES. By Ernest J. Parry,
B.Sc. (Lond.), F.I.C., F.C.S. Second Edition, Revised and
Enlarged. 552 pp. 20 Illustrations. Demy 8vo. Price 12s. 6d.
net. (Post free, 13s. home; 13s. 6d. abroad.)

(Soap Manufacture.)

SOAPS. A Practical Manual of the Manufacture of
Domestic, Toilet and other Soaps. By Georob H. Hurst, F.C.S.
2nd edition. 390 pp. b6 Illustrations. Demy 8vo. Price 12s. 6d.
net. (Post free, 13s. home ; 13s. 6d. abroad.)

TEXTILE SOAPS AND OILS. Handbook on the
Preparation, Properties and Analysis of the Soaps and Oils used
in Textile Manufacturing, Dyeing and Printing. By Georob
H. Hurst, F.C.S. Crown 8vo. 195 pp. Price 5s. net. (Post
free, 5s. 4d. home ; 5s. 6d. abroad.)

THE HANDBOOK OF SOAP MANUFACTURE.

By Wm. H. Simmons, B.Sc. (Lond.), F.C.S. and H. A. Appleton.
Demy 8vo. 16U pp. 27 Illustrations. Price 8s. 6d. net. (Post
free, 8s. lOd. home ; 9s. abroad.)

MANUAL OF TOILET SO APM AKIN G, including
Medicated Soaps Stain-removing Soaps, Metal Polishing Soaps,
Soap Powders and Detergents. Translated from the German
of Dr. C. Deite. Demy quarto. 150 pages. 79 Illustrations.
Price I'is. 6d. net. (Post free, 13s. home; 13s. 6d. abroad )

(Cosmetical Preparations.)

COSMETICS; MANUFACTURE, EMPLOYMENT
AND TESTING OF ALL COSMETIC
MATERIALS AND COSMETIC SPECIALITIES.

Translated from the German of Dr. TheOdor Koller. Crown
8vo. 262 pp. Price 5s. net. (Post free, 5s. 4d. home; 5s. 6d-
abroad.)

(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 ; 1 Is. abroad.)

BONE PRODUCTS AND MANURES : An Account
of the most recent Improvements in the Manufactut'e of Fat,
Glue, Animal Charcoal, Size, Gelatine and Manures. By Thomas
Lambert, Technical and Consulting Chemist. Second Revised
Edition. Demy 8vo. 172 pages. 17 Illustrations. Price 7s. 6d.
net. (Post free, 7s. lOd. home ; 8s. abroad.)

(Sie also Chemical Manures^ p, 9.)

(Chemicals, Waste Products, etc.)

REISSUE OF CHEMICAL ESSAYS OF C. W.
SCHEELE. First Published in English in 1786.
Translated from the Academy of Sciences at Stockholm, with
Additions. 300 pp. Demy 8vo. Price 5s. net. (Post free, 5s. 6d.
home ; 5s. 9d. abroad.)

THE MANUFACTURE OF ALUM AND THE SUL-
PHATES AND OTHER SALTS OF ALUMINA
AND IRON. Their Uses and Applications as Mordants
in Dyeing and Calico Printing, and their other Applications in
the Arts, Manufactures, Sanitary Engineering, Agriculture and
Horticulture. Translated from the French of Lucien Gesch-
wiND. 195 Illustrations. 400 pp. Royal 8vo. Price 12s. 6d.
net. (Post free, 13s. home ; 13s. 6d. abroad.)

AMMONIA AND ITS COMPOUNDS : Their Manu-
facture and Uses. By Camille Vincent, Professor at the
Central School of Arts and Manufactures, Paris. Translated
from the French by M. J. Salter. Royal 8vo. 114 pp. Thirty-
two Illustrations. Price 5s. net. (Post free, 5s. 4d. home;
58. 6d. abroad.)

CHEMICAL WORKS : Their Design, Erection, and
Equipment. By S. S. Dyson and S. S. Clarkson. Royal 8vo.
220 pp. With 9 Folding Plates and ^0 Illustrations. Price 21s.
net. (Post free, 21s. 6d. home ; 22s. abroad.)

MANUAL OF CHEMICAL ANALYSIS, as applied to
the Assay of Fuels, Ores, Metals, Alloys, Salts and other Mineral
Products. By E. Prost, D.Sc. Translated by J. Cruickshank
Smith, B.Sc. Royal 8vo. 300 pages. 44 Illustrations. Price
12s. 6d. net. (Post free, 133. home ; 13s. 6d. abroad.)

TESTING OF CHEMICAL REAGENTS FOR
PURITY. Translated from the German of Dr. C.
Krauch. Royal 8vo. 350 pages. Price 12s. 6d. net. (Post free,
13s. home ; 13s. 6d. abroad.)

For contents of these books^ see List /.

SHALE OILS AND TARS and their Products. By
Dr. W. ScHEiTHAUER. Translated from the German. Demy 8vo.
190 pages. 70 Illustrations and 4 Diagrams. Price Ss. 6df. net.
(Post free, 8s. lOd. home ; 98. abroad). [y«^^ published,

INDUSTRIAL ALCOHOL. A Practical Manual on the
Production and Use of Alcohol for Industrial Purposes and for
Use as a Heating Agent, as an lUuminant and as a Source of
Motive Power. By J. G. McIntosh, Lecturer on Manufacture
and Applications of Industrial Alcohol at The Polytechnic,
Regent Street, London. Demy Svo. 1907. 25a pp. With 75
Illustrations and 25 Tables. Price 7s. 6d. net. (Post free, 7s. lOd.
home ; 8s. 3d. abroad.)

THE UTILISATION OP WASTE PRODUCTS. A

Treatise on the Rational Utilisation, Recovery and Treatment of
Waste Products of all kinds. By Dr. Theodor Koller. Trans-
lated from the Second Revised German Edition. Twenty-two
Illustrations. Demy Svo. 280 pp. Price 7s. 6d. net. (Post free,
7s. lOd. home ; 8s. 3d. abroad.)

ANALYSIS OF RESINS AND BALSAMS. Trans-
lated from the German of Dr. Karl Dieterich. Demy 8vo. 340
pp. Price 7s. 6d. net. (Post free, 7s. lOd. home; 8s. 3d. abroad.)

DISTILLATION OF RESINS, RESINATE LAKES
AND PIGMENTS, CARBON PIGMENTS AND
PIGMENTS FOR TYPEWRITING MACHINES,
MANIFOLDERS, ETC. By Victor Schweizer.
Demy8vo. 185 pages. 68 Illustrations. Price7s.6d.net. (Post
free, 8s. home ; 8s. 3d. abroad.)

DISINFECTION AND DISINFECTANTS. By M.

Christian. Translated from the German. Crown 8vo. 112
pages. 18 Illustrations. Price 5s. net. (Post free, 5s. 3d. home ;
5s. 6d. abroad.) [ynst published.

(Agricultural Chemistry and Manures.)

MANUAL OF AGRICULTURAL CHEMISTRY. By

Herbert Ingle, F.I.C, Late Lecturer on Agricultural Chemistry,
the Leeds University; Lecturer in the Victoria University.
Third and Revised Edition. 400 pp. 16 Illustrations. Demy
Svo. Price 7s. 6d. net. (Post free, 8s. home ; 8s. 6d. abroad.)

CHEMICAL MANURES. Translated from the French
of J. Fritsch. Demy 8vo. Illustrated. 340 pp. Price 10s* 6d.
net. (Post free, Us. home; lis. 6d. abroad.)

(See also Bone Products and Manures^ p. 8.)

(Writing Inks and Sealing Waxes.)

INK MANUFACTURE: Including Writing, Cop5ing,
Lithographic, Marking, Stamping, and Laundry Inks. By
SiGMUND Lehnbr. 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
ADHESIVES FOR THE HOUSEHOLD, OFFICE,
WORKSHOP AND FACTORY. By H. C. Standage.
Crown 8vo. 96 pp. Price 5s. net. (Post free, 5s. 3d. home ;
5s. 4d. abroad.)

(Lead Ores and Lead Compounds.)

LEAD AND ITS COMPOUNDS. By Thos. Lambert,
Technical and Consulting Chemist. Demy 8vo. 226 pp. Forty
Illustrations. Price 7s. 6d. net. (Post free, 7s. lOd. home ;
88. 3d. abroad.)

NOTES ON LEAD ORES : Their Distribution and Pro-
perties. By Jas. Fairie, F.G.S. Crown 8vo. 64 pages. Price
Is. net. (Post free, Is. 3d. home ; Is. 4d. abroad.)

{White Lead and^Zinc White Paints^ see p. 5.)

(Industrial Hygiene.)

THE RISKS AND DANGERS TO HEALTH OP
VARIOUS OCCUPATIONS AND THEIR PRE-
VENTION. By Leonard A. Parry, M.D., B.Sc.
(Lond.). 196 pp. Demy 8vo. Price 7s. 6d. net. (Post free,
7s. lOd. home ; 8s. abroad.)

(Industrial Uses of Air, Steam and
Water.)

DRYING BY MEANS OF AIR AND STEAM. Ex-
planations, Formulae, and Tables for Use in Practice. Trans-
lated from the German of E. Hausbrand. Second Revised
English Edition. Two folding Diagrams, Thirteen Tables, and
Two Illustrations. Crown 8vo. 76 pp. Price 5s. net. (Post
free, 5s. 3d. home ; 5s. 6d. abroad.)
(See also " Evaporating y Condensing and Cooling Apparatus y"" p. 19.)

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 Illus-
trations. Crown 8vo. 85 pp. Price 5s. net. (Post free, 5s. 3d.
home ; 5s. 6d. abroad. )

THE INDUSTRIAL USES OF WATER. COMPOSI-
TION— EFPE GTS— TROUBLES — REMEDIES —
RESIDUARY WATERS — PURIFICATION— AN-
ALYSIS. By H. DE la Coux. Royal 8vo. Trans-
lated from the French and Revised by Arthur Morris. 364 pp.
135 Illustrations. Price 10s. 6d. net. (Post free, lis. home;
lis. 6d. abroad.)

(See Books on Smoke Prevention^ Engineering and Metallurgy y p, 19, etc.)
For contents of these books^ see List IIL

11
(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. Fitty-two Illustrations. 200 pp.
Price 10s. 6d. net. (Post free, 10s. lOd. home; lis. 3d. abroad.)

(India "Rubber and Qutta Percha.)

INDIA-RUBBER AND GUTTA PERCHA. Second
English Edition, Revised and Enlarged. Based on the French
work of T. Seeligmann, G. Lamy Torrilhon and H. Falconnet
by John Geddes McIntosh. Royal 8vo. 100 Illustrations. 400
pages. Price 12s. 6d. net. (Post free, 13s. home; 13s. 6d.
abroad.)

(Leather Trades.)

THE LEATHER WORKER'S MANUAL. Being a
Compendium of Practical Recipes and Working Formulae for
Curriers, Bootmakers, Leather Dressers, Blacking Manufac-
turers, Saddlers. Fancy Leather Workers. By H. C. Standage.
Demy 8vo. 165 pp. Price 7s. 6d. net. (Post free, 7s. lOd. home;
8s. abroad.)

(See also Manufacture of Shoe Polishes^ Leather Dressings^ etc, p, 6.)

(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.)

THE MANUAL OF PRACTICAL POTTING. Com-
piled by Experts, and Edited by Chas. F. Binns. Fourth Edition,
Revised and Enlarged. 200 pp. Demy Svo. 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 Svo. 250 pp. Twenty-
two Illustrations. Price 7s. 6d. net. (Post free, 7s. lOd. home ;
Ss. abroad.)

A TREATISE ON CERAMIC INDUSTRIES. A

Complete Manual for Pottery, Tile, and Brick Manufacturers. By
Emile Bourry. a Revised Translation from the French, with
some Critical Notes by Alfred B. Searle. Demy Svo. 308
Illustrations. 460 pp. Pricel2s.6d.net. (Post free, 13s. home;
13s. 6d. abroad.)

ARCHITECTURAL POTTERY. Bricks, Tiles, Pipes,
Enamelled Terra-cottas, Ordinary and Incrusted Quarries, Stone-
ware Mosaics, Faiences and Architectural Stoneware. By Leon
Lef^vre. 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
158. net. (Post free, 158. 6d. home ; 16s. 6d. abroad.)

THE ART OF RIVETING GLASS, CHINA AND
EARTHENWARE. By J. Howorth. Second
Edition. Paper Cover. Price Is. net. (By post, home or abroad,
Is. Id.)

NOTES ON POTTERY CLAYS. The Distribution,
Properties, Uses and Analyses of Ball Clays, China Clays and
China Stone. By Jas. Fairie, F.G.S. 132 pp. Crown 8v6.
Price 3s. 6d. net. (Post free, 3s. 9d. home; 3s. lOd. abroad.)

HOW TO ANALYSE CLAY. By H. M. Ashby. Demy
8vo. 72 pp. 20 Illustrations. Price 3s. 6d. net. (Post fr^e,
3j8. 9d. home ; 3s. lOd. abroad.)

A Reissue of

THE HISTORY OF THE STAFFORDSHIRE POT-
TERIES; AND THE RISE AND PROGRESS
OF THE MANUFACTURE OF POTTERY AND
PORCELAIN. With References to Genuine Specimens,
and Notices of Eminent Potters. By Simeon Shaw. (Originally
published in 1829.) 265 pp. Demy 8vo. Price 5s. net. (Post
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 8vo.
Price 10s. net. (Post free, 10s. 6d. home ; 12s. abroad.)

BRITISH POTTERY MARKS. By G. Woolliscroft
Rhead. Demy 8vo. 310 pp. With over Twelve-hundred Illus-
trations of Marks. Price 7s. 6d. net. (Post free, 8s. home ;
88. 3d. abroad.)

For contents of these books, see List III.

(Glassware, Glass Staining and Painting.)

BKCIPES FOB FLINT GLASS MAKING. By a

British Glass Master 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, blow-
ing, etc., as well as the most costly crystal and ruby. Second
Edition. Crown 8vo. Price 10s. 6d. net. (Post free, 10s. 9d.
home ; 10s. lOd. abroad.)

A TREATISE ON THE ART OF GLASS PAINT-
ING. Prefaced with a Review of Ancient Glass. By
Ernest R. Suppling. With One Coloured Plate and Thirty-
seven Illustrations. Demy 8vo. 140 pp. Price 7s. 6d. net.
(Post free, 7s. lOd. home ; 8s. abroad.)

(Paper Making, Paper Dyeing, and
Testing.)

THE DYEING OF PAPER PULP. A Practical
Treatise for the use of Papermakers, Paperstainers, Students
and others. By Julius Erfurt, Manager of a Paper Mill.
Translated into English and Edited with Additions by Julius
HUbnbr, F.C.S., Lecturer on Papermaking at the Manchester
Municipal Technical School. With illustrations and 157 patterns
of paper dyed in the pulp. Royal Svo, 180 pp. Price 15s. net.
(Post free, 15s. 6d. home; 16s. 6d. abroad).

THE PAPER MILL CHEMIST. By Henry P. Stevens,
M.A., Ph.D., F.I.C. Royal 12mo. 60 illustrations. 300 pp.
Price 7s. 6d. net. (Post free, 7s. 9d. home ; 7s. lOd. abroad.)

THE TREATMENT OF PAPER FOR SPECIAL
PURPOSES. By L. B. Andes., Translated from the
German. Crown Svo. 48 Illustrations. 250 pp. Price 6s. net.
(Post free, 6s. 4d. home ; 6s. 6d. abroad.)

(Enamelling on Metal.)

ENAMELS AND ENAMELLING. For Enamel
Makers, Workers in Gold and Silver, and Manufacturers of
Objects of Art. By Paul Randau. Second and Revised
Edition. Translated from the German. With 16 Illustrations.
Demy Svo. 200 pp. Price 10s. 6d. net. (Post free, lOs. lOd.
home; lis. abroad.)

THE ART OF ENAMELLING ON METAL. By

W. Norman Brown. Second Edition, Revised. Crown Svo.
60 pp. Price ^s. 6d. net. (Post free, 3s. 9d. home ; 3s. lOd.
abroad.) [y«^^ publishe'

(Textile and Dyeing Subjects.)

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 Univer-
sity of Leeds ; Author of " Colour in Woven Design " ; •♦ Woollen
and Worsted Cloth Manufacture " ; ** Woven Fabrics at the
World's Fair " ; Vice-President of the Jury of Award at the Paris
Exhibition, 1900 ; Inspector of Textile 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 Demy 8vo. 260 pp. Price 10s. 6d. net. (Post free,
10s. lOd. home; lis. 3d. abroad.)

FIBRES USED IN TEXTILE AND ALLIED IN-
DUSTRIES. By C. Ainsworth Mitchell, B.A.
(Oxon.), F.I.C., and R. M. Prideaux, F.I.C. With 66 Illustra-
tions specially drawn direct from the Fibres. Demy 8vo.
200 pp. Price 7s. 6d. net. (Post free, 7s. lOd, home ; 8s. abroad.)

DRESSINGS AND FINISHINGS FOR TEXTILE
FABRICS AND THEIR APPLICATION. De-
scription of all the Materials used in Dressing Textiles : Their
Special Properties, the preparation of Dressings and their em-
ployment 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. Demy 8vo. 280 pp. Sixty
Illustrations. Price 7s. 6d. net. (Post free, 7s. lOd. home ;
8s. abroad.)

THE CHEMICAL TECHNOLOGY OF TEXTILE
FIBRES : Their Origin, Structure, Preparation, Wash-
ing, Bleaching, Dyeing, Printing and Dressing. By Dr. Georo
VON Georgievics. 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 NUMBER-
ING, According to Various Systems, with Conversion
Tables. Translated from the German of Anthon Gruner. With
Twenty-8ix Diagrrams In Colours. 150 pp. Crown 8vo. Price
7s. 6d. net. (Post free, 7s. 9d. home ; 8s. abroad.)

TEXTILE RAW MATERIALS AND THEIR CON-
VERSION INTO YARNS. (The Study of the Raw
Materials and the Technology of the Spinning Process.) By
Julius Zipser. Translated from German by Charles Salter.
302 Illustrations. 500 pp. Demy 8vo. Price 10s. 6d. net.
(Post free, lis. home ; lis. 6d. abroad.)

For contents of these books, see List II,

GRAMMAR OF TEXTILE DESIGN. By H. Nisbet,
Weaving and Designing Master, Bolton Municipal Technical
School. Demy 8vo. 280 pp. 490 Illustrations and Diagrams.
Price 6s. net. (Post free, 6s. 4d. home ; 6s. 6d. abroad.)

ART NEEDLEWORK AND DESIGN. POINT
LACE. A Manual of Applied Art for Secondary Schools
and Continuation Classes. By M. E. Wilkinson. Oblong
quarto. With 22 Plates. Bound in Art Linen. Price 3s. 6d.
net. (Post free, 3s. lOd. home ; 4s. abroad.)

HOME LACE-MAKING. A Handbook for Teachers and
Pupils. By M. E. W. Milroy. Crown 8vo. 64 pp. With 3
Plates and 9 Diagrams. Price Is. net. (Post free, Is. 3d. home ;
Is. 4d. abroad.)

THE CHEMISTRY OF HAT MANUFACTURING.

Lectures delivered before the Hat Manufacturers' Association.
By Watson Smith, F.C.S., F.I.C. Revised and Edited by
Albert Shonk. Crown 8vo. 132 pp. 16 Illustrations. Price
7s. 6d. net. (Post free, 7s. 9d. home ; 7s. lOd. abroad.)

THE TECHNICAL TESTING OF YARNS AND
TEXTILE FABRICS. With Reference to Official
Specifications. Translated from the German of Dr. J. Herzfeld.
Second Edition. Sixty-nine Illustrations. 200 pp. Demy 8vo.
Price 10s. 6d. net. {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 8vo.
132 Designs and Illustrations. Price 7s. 6d. net. (Post free,
7s. lOd. home; 8s. abroad.)

THEORY AND PRACTICE OF DAMASK WEAV-
ING. By H. KiNZER and K. Walter. Royal 8vo.
Eighteen Folding Plates. Six Illustrations. Translated from
the German. 110 pp. Prlce8s.6d.net. (Post free, 9s. home;
9s. 6d. abroad.)

FAULTS IN THE MANUFACTURE OF WOOLLEN
GOODS AND THEIR PREVENTION. By

Nicolas Reiser. Translated from the Second German Edition.
Crown 8vo. Sixty-three Illustrations. 170 pp. Price 5s. net.
(Post free, 5s. 4d. home ; 5s. 6d. abroad.)

SPINNING AND WEAVING CALCULATIONS,

especially relating to Woollens. From the German of N.
Reiser. Thirty-four Illustrations. Tables. 160 pp. Dem.
Svo. 1904. Price 10s. 6d. net. (Post free, 10s. lOd. home ; lis.
abroad.)

ANALYSIS OF WOVEN FABRICS. By A. F. Barker
and E. MiDGLEY. Demy Svo. About 200 pages [In the press.

WATERPEOOPING OF FABRICS. By Dr. S. Mier-
ZiNSKi. ' Second Edition, Revised and Enlarged. Crown 8vo.
140 pp. 29 Illus. Price 5s. net. (Post free, 5s. 4d. home ;
5s. 6d. abroad.) [7ust published.

HOW TO MAKE A WOOLLEN MILL PAY. By
John Mackie. Crown 8vo. 76 pp. Price 3s. 6d. net. (Post
free, 38. 9d. home ; 3s. lOd. abroad.)

YARN AND WARP SIZING IN ALL ITS
BRANCHES. Translated from the German of Carl
Krbtschmar. Royal 8vo. 123 Illustrations. 150 pp. Price
10s. 6d. net. (Post free, 10s. lOd. home; lis. abroad.)

{For '« Textile Soaps and Oils " see p. 7.)

(Dyeing, Colour Printing, Matching
and Dye-stuffs.)

THE COLOUR PRINTING OF CARPET YARNS.

Manual for Colour Chemists and Textile Printers. By David
Paterson, F.C.S. Seventeen Illustrations. 136 pp. Demy
Svo. Price 7s. 6d. net. (Post free, 7s. lOd. home ; 8s. abroad.)

THE SCIENCE OF COLOUR MIXING. A Manual
intended for the use of Dyers, Calico Printers and Colour
Chemists. By David Paterson, F.C.S. Forty-one Illustrations.
Five Coloured Piates, and Four Plates showingr Eleven Dyed
Speoimens of Fabrics. 132 pp. Demy8vo. Price 7s. 6d. net.
(Post free, 7s. lOd. home ; 8s. abroad.)

DYERS' MATERIALS : An Introduction to the Examina-
tion, Evaluation and Application of the most important Sub-
stances 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 8vo. 150pp. Price 5s.net. (Post free, 5s. 4d. home;
5s. 6d. abroad.)

COLOUR MATCHING ON TEXTILES. A Manual
intended 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 8vo. 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
8vo. Price 7s. 6d. net. (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*Apligny. First Published in
English in 1789. Six Plates. Demy Svo. 446 pp. Price 5s. net.
(Post free, 5s. 6d. home ; 6s. abroad.)

For contents of these books^ see List II,

THE CHEMISTRY OF DYE-STUFFS. By Dr. Georo
Von Georoibvics. Translated from the Second German Edition.
412 pp. Demy 8vo. 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 Bbbch,.
Practical Colourist and Chemist. 272 pp. Forty-four Illus-
trations of Bleaching and Dyeing Machinery. Demy 8vo. Price
78. 6d. net. (Post free, 73. lOd. home; Ss. abroad.)

THE DYEING OF WOOLLEN FABRICS. By
Franklin Beech, Practical Colourist and Chemist. Thirty-
three Illustrations Demy 8vo. 228 pp. Price 7s. 6d. net.
(Post free, 7s. lOd. home ; 8s. abroad.)

(Silk Manufacture.)

SILK THROWING AND WASTE SILK SPIN-
NING. By HoLLiNS Rayner. Demy 8vo. 170 pp.
117 lUus. Price 5s. net! (Post free, 5s. 4d. home ; 5s. 6d. abroad.^

(Bleaching and Bleaching Agents.)

A PRACTICAL TREATISE ON THE BLEACHING
OF LINEN AND COTTON YARN AND FABRICS.

By L. Tailfer, Chemical and Mechanical Engineer. Trans-
lated from the French by John Gbddes McIntosh. Demy 8vo.
303 pp. Twenty Illus. Price 125. 6d.. net. (Post free, 13s,
home; 13s. 6d. abroad.)
MODERN BLEACHING AGENTS AND DETER-
GENTS. By Professor Max Bottler. Translated
from the German. Crown 8vo. 16 Illustrations. 160 pages.
Price 5s. net. (Post free, 5s. 3d. home ; 5s. 6d. abroad.)

(Cotton Spinning, Cotton Waste and
Cotton Combing.)

COTTON SPINNING (First Year). By Thomas
Thornley, Spinning Master, Bolton Technical School. 160 pp.
84 Illustrations. Crown 8vo. Second Impression. Price 3s^
net^ (Post free, 3s. 4d. home; 3s. 6d. abroad.)

COTTON SPINNING (Intermediate, or Second Year).
By T. Thornley. 2nd. Impression. 180 pp. 70 Illus. Crown 8vo.
Price 5s. net. (Post free, 5s. 4d. home ; 5s. 6d. abroad.)

COTTON SPINNING (Honours, or Third Year). By
T. Thornley. 216 pp 74 Illustrations. Crown 8vo. Second
Edition. Price 5s. net. (Post free, 5s. 4d. home; 5s. 6d. abroad. ^

COTTON COMBING MACHINES. By Thos. Thorn-
ley, Spinning Master, Technical School, Bolton. Demy 8vo.
117 Illustrations. 300 pp. Price 7s. 6d. net. (Post free, 8s«
home ; 8s. 6d. abroad )

COTTON WASTE : Its Production, Characteristics
Regulation, Opening, Carding, Spinning and Weaving. By Thomas
Thornley. DemySvo. 286 pages. 60 Illustrations. Price 7s 6d.
net. (Post free, 7s. lOd. home ; 8s. abroad.)

THE RING SPINNING FRAME : GUIDE FOR
OVERLOOKERS AND STUDENTS. By N. Booth.
Crown 8vo. 76 pages. Price 3s. net. (Post free, 3s. 3d. home ;
3s. 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 8vo. 1907. With 92 Illustrations.
200 pp. Price 7s. 6d. net. (Post free, 7s. 9d. home ; 8s. abroad.)

(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 Wabner,
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. Sd. abroad.)

HAULAGE AND WINDING APPLIANCES USED
IN MINES. By Carl Volk. Translated from the
German. Royal Svo. With Six Plates and 148 Illustrations.
150 pp. Price 88. 6d. net. (Post free, 9s. home ; 9s. 3d. abroad.)

THE ELECTRICAL EQUIPMENT OF COLLISRIES.

By W. Galloway Duncan, Electrical and Mechanical Engineer,
Member of the Institution of Mining Engineers, Head of the
Government School of Engineering, Dacca, India; and David
Penman, Certificated Colliery Manager, Lecturer in Mining to
Fife County Committee. Demy 8vo. 310 pp. 155 lUus. and Dia-
grams. Price 10s. 6d. net. (Post free, lis. home ; lis. 3d. abroad.)

(Dental Metallurgy.)

DENTAL METALLURGY: MANUAL FOR STU-
DENTS 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.)

(Engineering, Smoke Prevention and
Metallurgy.)

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 Illus-
trations. 190 pp. Demy 8vo Price 7s. 6d. net. (Post free,
7s. lOd. h ome ; 8s. 3d. abroad.)

For contents of these books, sec Lists II and III.

X»AS AND COAL DUST FIRING. A Critical Review
of the Various Appliances Patented in Germany for this purpose
since 1885. By Albert PCtsch. 130 pp. Demy 8vo. Trans-
lated from the German. With 103 Illustrations. Price 5s. net.
(Post free, 5s. 4d. home ; 5s. 6d. abrotid.)

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.)

SIDEROLOGY: THE SCIENCE OF IRON (The
Constitution of Iron Alloys and Slags). Translated from
German of Hanns Frriherr v. JUptner. 350 pp. Demy8vo.
Eleven Plates and Ten Illustrations. Price 10s. 6d. net. (Post
free, Us. home; lis. 6d. abroad.)

EVAPORATING, CONDENSING AND COOLING
APPARATUS. 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 Illustrations and Seventy-six Tables. 400 pp. Demy 8vo.
Price 10s. 6d. net. (Post free, lis. home; lis. 6d. abroad.)

(The '* Broadway" Series of Engineering
Handbooks.)

Uniform in Size : Narrow Crown 8vo. (Pocket Size.)

Volume I.— ELEMENTARY PRINCIPLES OF RE-
INFORCED CONCRETE CONSTRUCTION. By

EwART S. Andrews, B.Sc. Eng. (Lond.). 200 pages. With 57
Illustrations. Numerous Tables and Worked Examples. Price
38. net. (Post free, 3s. 3d. home ; 3s. 6d. abroad.)

Volume II.— GAS AND OIL ENGINES. By A.
K1R8CHKE. Translated and Revised from the German, and
adapted to British practice. 160 pages. 55 Illustrations.
Price 3s. net. (Post free, 3s. 3d. home ; 3s. 6d. abroad.)

Volume III. — IRON AND STEEL CONSTRUC-
TIONAL WORK. By K. Schindler. Translated
and Revised from the German, and adapted to British practice.
140 pages. 115 Illustrations. Price 3s. 6d. net. (Post Irec,
3s. 9d. home ; 4s. abroad.)

Volume IV.— TOOTHED GEARING. By G. T. White,
B.Sc. (Lond.). 220 pages. 136 Illustrations. Price 3s. 6d. net.
(Post free, 3s. 9d. home ; 4s. abroad.)

Volume V.— STEAM TURBINES : Their Theory and
Construction. By H. Wilda. Translated from the German ;
Revised and adapted to British practice. 200 pages. 104 Illus-
trations. Price 3s. 6d. net. (Post free, 3s. 9d. home ; 4s. abroad. >

Volume VI.— CRANES AND HOISTS. Their Con-
struction and Calculation. By H. Wilda. Translated from the
German ; revised and adapted to British practice. 168 pages.
399 Illustrations. Price 3s. 6d. net. (Post free, Ss. 9d. home;
4s. abroad.) [7 ust published.

Volume VII.— FOUNDRY MACHINERY. By E.
Treibbr. Translated from the German ; revised and adapted to
British practice. 148 pages. 51 Illustrations. Price 3s. 6d. net.
(Post free, 3s. 9d. home ; 4s. abroad.) [J ust published.

Volume VIII —MOTOR CAR MECHANISM. By
W. B. DOMMETT, A.M.I.A.B.B. 200 pages. 102 Illustrations.
Price 3s. 6d. net. (Post free, 3s. 9d. home ; 4s. abroad.)

[^ust published.

Volume IX.— ELEMENTARY PRINCIPLES OP
ILLUMINATION AND ARTIFICIAL LIGHTING.
B^ A. Blok, B.Sc, A.M.I.B.E. 240 pages. 124 Illustrations and
Diagrams, and 1 Folding Plate. Price 3s. 6d. net. (Post free,
38. 9d. home ; 4s. abroad.) [ynst published.

[IN PREPARATION.]

THE CALCULUS FOR ENGINEERS. By E. S.
Andrews, B.Sc. Eng. (Lond.), and H. Bryon Heywood, D.Sc.

HYDRAULICS. By E. H. Sprague, A.M.I.C.E.

LAND SURVEYING. By M. T. Ormsby, Mrl.C.E.I.

PORTLAND CEMENT. Its Properties and Manu-
facture. By P. C. H. West, F.C.S.

DESIGN OF MACHINE TOOLS. By G. W. Burlby.

LATHES. By G. W. Burley.

REINFORCED CONCRETE IN PRACTICE. By
Alban H. Scott, M.S.A., M.C.I.

BRIDGE FOUNDATIONS. By W. Burnside, M.I.C.E.

WORKS MANAGEMENT. By J. Batey.

CALCULATIONS FOR A STEEL FRAME BTHLD-
ING. By W. C. Cocking, M C.I.

GEAR GUTTING. By G. T. White, B.Sc. (Lond.).

MODERN GAS WORKS PRACTICE. By Alwynb
Meade, A.M.I.E.E.

STEAM BOILERS AND COMBUSTION. By J.
Batey.

MOVING LOADS BY INFLUENCE LINES AND
OTHER METHODS. By E. H. Sprague, A.M.I.C.E.

THE STABILITY OF ARCHES. By E. H. Sprague,
A.M.I.C.E.

(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 Illustra-
tions. 272 pp. Demy 8vo. Second Edition Revised. Price
7s. 6d. net. (Post free, 7s. lOd. home; 8s. abroad.)

For contents of these books^ see List III.

HINTS TO PLUMBERS ON JOINT WIPING, PIPE
BENDING AND LEAD BURNING. Third Edition,
Revised and Corrected, By John W. Hart, R.P.C. 184 Illus-
trations. 313 pp. Demy 8vo. Price 7s. 6d. net. (Post free,
88. home ; 8s. 6d. abroad.)

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. By Sydney R
Walker, R.N., M.I.E.E., M.I.Min.E., A.M.Inst.C.E., etc., etc.
Crown 8vo. 150 pp. With Illustrations and Tables. Price 58.
net. (Post free, 5s. 3d. home ; 5s. 6d. abroad.)

THE PRINCIPLES AND PRACTICE OF DIPPING,
BURNISHING, LACQUERING AND BRONZ-
ING BRASS WARE. By W. Norman Brown. 48 pp.
Crown 8vo. Price 3s. net. (Post free, 3s. 3d. home and abroad.)

THE DEVELOPMENT OF THE INCANDESCENT
ELECTRIC LAMP. By G. Basil Barham, A.M.I.B.E.
Demy 8vo. 200 pages. 2 Plates. 25 Illustrations and 10 Tables.
Price 5s. net. (Post free, 5s. 4d. home ; 5s. 6d. abroad.)

WIRING CALCULATIONS FOR ELECTRIC
LIGHT AND POWER INSTALLATIONS. A
Practic&l Handbook containing Wiring Tables, Rules, and
Formulae for the Use of Architects, Engineers, Mining Engineers,
and Electricians, Wiring Contractors and Wiremen, etc. By G.
W. LuMMis Paterson. Crown 8vo. 96 pages. 35 Tables.
Price 5s. net. (Post free, 5s. 3d. home ; 5s. 6d. abroad.)

A HANDBOOK ON JAPANNING. For Ironware,
Tinware, and Wood, etc. Bv William Norman Brown.
Second Edition. 70 pages. 13 Illustrations. Crown 8vo. Price
38. 6d. net. (Post free, 3s. 9d. home : 4s. abroad.)

THE PRINCIPLES OF HOT WATER SUPPLY. By
John W. Hart, R.P.C. With 129 Illustrations. 177 pp. Demy
8vo. Price 7s. 6d. net. [Post free, 7s. lOd. home ; 8s. abroad.)

(Brewing and Botanical.)

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. 78 Illus. 340pp. Demy 8vo. Price
10s. 6d. net. (Post free, lis. home; lis. 6d. abroad.)

INSECTICIDES, FUNGICIDES AND WEED-
KILLERS. By E. BouRCART, D.Sc. Translated from
the French. Revised and Adapted to British Standards and
Practice. Demy 8vo. 450 pages, 83 Tables, and 12 Illustrations.
Price 128. 6d. net. (Post free, 13s. home ; 13s. 6d. abroad.)

(For Agricultural Chemistry ^ see p. 9.)

(Wood Products, Tfmber and Wood
Waste.)

WOOD PRODUCTS ; DISTILLATES , AND ^EX-
TRACTS. By P. DuMESNY, Chemical Engineer,
Expert before the Lyons Commercial Tribunal, Memoer* of the
International Association of Leather Chemists; and J. NCyer.
Translated from the French by Donald Grant. Royal 8vo.
320 pp. 103 Illustrations and Numerous Tables. Price 10s. 6d.
net; (Post free, lis. hoijie ; 11^. 6d.^abroad.)

TIMBER: A Comprehensive Study of Wood in all its
Aspects (Commercial and Botanical)^ showing- the different
Applications and Uses of Tijnber in Various Traaes, etc. Trans-
lated from the French of Paul Charpentier. Royal 8vo. 437
pp. 178 Illustrations. Price 12s. 6d. net. (Post free, 13s.
home ; 14s. abroad.)

THE UTILISATION OP WOOD WASTE. Trans-
lated from the German of Ernst Hubbard. Crown 8vo. 192 pp.
50 lUus. Price 5s. net. (Post free, 5s, 4d. home ; 5s. 6d. abroad.)
{See also Utilisation of Waste Products^ p. 9.)

(Building and Architecture.:)

ORNAMENTAL CEMENT WORK. By Oliver
Wheatley. Demy 8vo. 83 Illustrations. 128 pp. Price 5s.
net. (Post free, 5s. 4d. hortie ; 5s. 6d. abroad.)

THE PREVENTION OF DAMPNESS IN BUILD-
INGS; with Remarks on the Causes, Nature and
Effects of Saline, Efflorescences and Dry-rot, for Architects,
Builders, Overseers, Plasterers, Painters and iHopse Owners.
By Adolf Wilhelm Keim. 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 8vo. 115
pp. Price 5s. net. (Post free, 5s. 3d. home ; 5s. 4d. abroad.)

HANDBOOK OF TECHNICAL TERMS l^SED IK
ARCHITECTXJRE AND BUILDINGrAKD THEIR
ALLIED TRADES AND SUBJECTS. By Augus-
tine C. Passmore. Demy 8vo. 380 pp. Price 7s, 6d. net.
(Post free, 8s. home ; 8s. 6d. abroad.)

(Foods, Drugs and Sweetmeats.)

FOOD AND DRUGS. By E. J. Parry, B.Sc., F.I.C;, F.C.S.
Volume 1. The Analysis of Pood and Drugs (Chemical and
Microscopical). Royal 8vo. 724 pp. Price 21 s. net. (Post
free, 21s. 6d. home ; 22s. 6d. British Colonies; 23s. 3d. other
Foreign Countries.)
Volume II. The Sale of Food and Drugs Acts, 1875-1907.
Royal 8vo. 184 pp. Price 7s. 6d. net. (Post free, 7s. lOd.
home ; Ss. abroad,)

For contents of these books, see List III.

THE MANUFACTURE OF PBESEBVED FOODS
AND SWEETMEATS. By A. Hausner. With

Twenty-eight Illustrations. Translated from the German of the
third enlarged Edition. Second English Edition. Crown 8vo. 22&
pp. Price 7s. 6d. net. (Post free, 7s. 9d. home ; 7s. lOd. abroad.)

RECIPES FOR THE PRESERVING OF FRXHT,
VEGETABLES 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, Manufocturers 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.)

(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. B5ckmann, Tech-
nical Chemist. Translated from the Third Revised German
Edition. Crown Svo. 120 pp. With 49 Illustrations. Price Ss.
net. (Post free, 5s. 3d. home ; 5s. 4d. abroad.)

(Lithography, Printing and
Engraving.)

ART OF LITHOGRAPHY. By G. T. Rhodes.

[In the press*

PRINTSRS' ANP STATIONERS' READY
RECKONER AND COMPENDIUM. Compiled by
Victor Graham. Crown 8vo. 112 pp. 1904. Price3s.6d.net.
(Post free, 3s. 9d. home ; 3s. lOd. abroad.)

ENGRAVING FOR ILLUSTRATION. HISTORI-
CAL AND PRACTICAL NOTES. By J. Kirkbride.
72 pp. Two Plates and 6 Illustrations. Crown Svo. Price
2s. 6d. net. (^ost free, 2s. 9d. home ; 2s. lOd. abroad.)
{For Printing Inks, see p, 4.)

(Bookbinding.)

PRACTICAL BOOKBINDING. By Paul Adam.
Translated from the German. Crown Svo. ISO pp. 127 Illus-
trations. Price 5s. net. (Post free, 5s. 4d. home ; 5s. 6d. abroad.

(Sugar Refining.)

THE TECHNOLOGY OP SUGAR: Practical Treatise
on the Modern Methods of Manufacture of Sugar from the Sugar
Cane and Sugar Beet. By John Gbddbs McIntosh. Second
Revised and Enlarged Edition. Demy 8vo. Fully Illustrated.
436 pp. Seventy. six Tables. 1906. Price 10s. 6d. net. (Post
free, lis. home; lis. 6d. abroad.)

{Sie ** Evaporating, Condensing^ etc., Apparatus" p. 19.)

(Emery.)

1^^ EMERY AND THE EMERY INDUSTRY. Trans-
lated from the German of A. Haenig. Crown 8vo. 45 Illus.
104 pp. Price 5s. net. (Post free» 5s. 3d. home ; 5s. 6d. abroad.)

(Libraries and Bibliography.)

CLASSIFIED GUIDE TO TECHNICAL AND COM-
MERCIAL BOOKS. Compiled by Edgar Green-
wood. 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
Technical, Commercial and Art Schools throughout the United
Kingdom. With full particulars of the courses of instruction,
names of principals, secretaries, etc. DemySvo. 150 pp. Price
3s. 6d. net. (Post free, 3s. lOd. home; 4s. abroad.)

THE LIBRARIES, MUSEUMS AND ART GAL.
LERIES YEAR BOOK, 1910-11. Being the Third
Edition of Greenwood'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' Merchants, Contractors and Architects. Including
the translation of Hermann Recknagel's '* Kalender fur Gesund-
heits - Techniker," Handbook for Heating, Ventilating, and
Domestic Engineers, of which Scott, Greenwood & Son have
purchased the sole right for the English Language. Quarto.
Bound in cloth and gilt lettered. Price 3s. net. (Post free,
3s. 4d. home ; 3s. 8d. abroad.)

Scott, (3reenwoob d Son,

Technical Book and Trade Journal Publishers,

8 Broadway, Ludgate, London, E.G.

Telegraphic Address, "Printeries, Cent. -London**. yanuary, 1914.

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UNIVERSITY OF CALIFORNIA LIBRARY

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Full text of "Oil colours and printers' inks; a practical handbook treating of linseed oil, boiled oil, paints, artists' colours, lampblack and printers' inks, black and coloured"

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