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M. J. SALTER, F.I.C., F.C.S. 





[The sole right of Translation into English rests with the abocefinn.] 


THE rational utilisation of waste products forms at the 
present day, in all industries, a subject of the highest 
importance ; by a correct utilisation of the by-products 
it is often possible to dispose of the main product at a 
lower price, or when prices are more and more lowered 
by competition, a profit may even be made from the 

In all the industries which employ wood a quantity of 
waste material is obtained in such a form that its em- 
ployment as wood either for construction or for fuel is 
not possible unless special appliances are made use of 
for the purpose ; these, however, are in many cases not 
generally known, and the result is that a considerable 
amount of this valuable material is absolutely wasted. 
My object in the compilation of this book is to give infor- 
mation as to the most advantageous methods of utilising 
all wood-waste, and my endeavour has been to bring 
this treatise up to date with respect to practice and 


WITH the constant advance in the consumption of wood 
for building and other technical and industrial purposes, 
it naturally follows that the amount of wood-waste has 
also undergone an increase, and with the growth in the 
stringency of the conditions of production a greater value 
has attached to the utilisation of the waste. The ap- 
pliances for the combustion of sawdust, partly direct for 
the sake of its calorific effect, partly indirect for the 
production of charcoal, the manufacture of alcohol and 
acetic acid from wood-waste, have been improved in 
many ways, whilst other modes of employment have 
made a considerable advance. 

In revising my work, which in its first edition has 
met with a favourable acceptation, I have, to the utmost 
of my power, noticed all the novelties relating to the 
utilisation of waste materials, and have no doubt that 
the new edition will furnish valuable suggestions to 
those interested in the subject. 

E. H. 











Kraft's Sawdust Furnace 28 

Andre's Furnace for Sawdust 32 

Koch's Sawdust Furnace 34 

Sawdust and Tan Combustion-hearths 35 

Combustion-hearth of H. Bottger & Co. for Sawdust, Dye- 
wood, Tan, etc 41 

Sawdust Furnace for Gas Producers ..... 43 

Lundin's Furnace 47 

Godillot's Pyramidal Grate for Pulverulent Fuel . 49 
Swedish Charcoal Furnaces with Condensation ... 53 
Sawdust Furnace of C. Walter for the Manufacture of Wood- 
tar Oil . . . . . 55 

Combustion-hearth of Niederberger & Co. for Damp Wood- 
waste and Sawdust 59 

Zwillinger's Apparatus for Carbonising Sawdust, etc., with 

Recovery of Volatile Products . . ... .61 

Fischer's Apparatus for Carbonising Wood with Recovery of 

Volatile Products . . . . _. ..* . .66 

Halliday's Apparatus for the Manufacture of Pyroligneous 

Acid 69 



Columnar Distillation Apparatus . . . . . .70 

Waisbein's Still with Producer-gas . . . . . .72 

Petri's Process for the Production of Prepared Fuel, with the 

Apparatus for that purpose . .... . .76 

Manufacture of Illuminating Gas from Sawdust ... 81 


I. Process with Soda Lye . ... ..* . . . 84 

II. Thorn's Process . . . . . ... .87 

1. Formation of Oxalic Acid by Fusing Sawdust with 

Sodium Hydroxide Alone . . . . 88 

2. Formation of Oxalic Acid by Fusing Sawdust with 

a Mixture of Potassium Hydroxide and Sodium 
Hydroxide in Thick Layers 89 

3. Formation of Oxalic Acid by Heating Sawdust with 

a Mixture of Potassium Hydroxide and Sodium 
Hydroxide in Thin Layers 91 

4. Formation of Oxalic Acid by Heating Sawdust with 

Alkali Hydroxides in Thin Layers, with Simul- 
taneous Application of Hot Air ... . 92 

5. Formation of Oxalic Acid with the Co-operation of 

Manganese Dioxide . 93 

6. Yield of Oxalic Acid from Different Varieties of Wood 94 

7. Yield of Oxalic Acid with Varied Proportions of Wood 

and Alkali . . 94 

(1) Preparation of the Caustic Lye 97 

(2) Separation of the Sodium Oxalate from the Lye 97 

(3) Conversion of the Sodium Oxalate into Calcium 

Oxalate . .... . . . .98 

(4) Decomposition of the Calcium Oxalate with Sul- 

phuric Acid . . . . . .99 

(5) Crystallisation of the Oxalic Acid from the Sul- 

phuric Acid Liquor . . '. . . .99 

III. Bohlig's Process . . . . . . . . 100 

IV. Process of Roberts, Dale & Co. , . . . . 100 

V. Production of Oxalic Acid from Lignose .... 102 
VI. Zaiher's Method of Preparing Oxalic Acid . . . 103 




DYES) 109 




Various Processes 120 

Bois Durci of Latri 121 

Gottschalk's Hard Wood 124 

Harrass' Wood-composition from Cellulose .... 124 

Hurtig's Wood-composition 129 

Hurtig's Wood-composition, Improved Process . . . 131 

Kletzinsky's Wood-paste 133 

Wood Terra-cotta 134 

Palmer's Wood-composition . 134 

Billefeld's Artificial Wood 134 

Ribbach's Coating Compound from Sawdust .... 137 

Wiederhold's Artificial Wood-composition .... 139 

Artificial Wood of Back and Potin 138 

Cohnfeld's Wood-composition 139 

Sciffarin (Wood -cement) 139 



1. Sawdust Blasting Powder 140 

2. Heraklin . . . 142 

3. Lignose 142 

4. Robandi's Brise-rocs 142 

5. Carbazotine 143 

6. Reynaud's Pyronome 143 

7. Poch's Poudrolith 143 

8. Volkinann's Wood-powder 143 

9. Koppel's Safe Blasting Powder . . . . .143 
10. Diorrexin 144 



11. Pyrolith . ' 145 

12. New Dynamite No. III. . . . % . . . .145 

13. Powder of Kellow and Short . . . . . .145 

14. De Tret's Blasting Powder 146 

15. Haloxylin . . . . ,' . . . . .146 

16. Oiler's Blasting Powder . . . . . . .146 

17. Blasting Powder of Terre and Mercadier . . . . 147 

18. Schultze's White Gunpowder and Blasting Powder . . 147 

19. Dy's Yellow Gunpowder . . .... . 147 

20. Lannoy's White Powder . . . . .147 

21. Lithofracteur . . . . .... .148 

22. Brain's Blasting Powder 148 



Petroleum Briquettes with Sawdust 151 

Sawdust Briquettes with Molasses 151 

Sawdust Briquettes for Distillation 152 



Addition of Sawdust to Mortar ...... 156 

Stony Composition from Sawdust for a Building and Insu- 
lating Material 157 


Kapp's Wood-fibre 162 


4... Sawdust as a Material for Preventing Rough-cast from 

Flaking off under the Influence of Frost and Rain . 164 

Manufacture of Casks from the Waste-wood of Saw-mills . 164 

Manufacture of Calcium Carbide from Sawdust . . . 165 

Sawdust as Manure . . . . . . . . . 166 

1. Richardson's Artificial Manure . . . . . 167 

2. Carbonised Sawdust as Manure ..... 167 

3. Manure from Tan 168 

Wood-mosaic Plaques from Wood-shavings - , . . . 169 

Bottle Stoppers from Wood-shavings 170 



Employment of Waste-wood from Saw-mills for Parquetry . 170 
Fire-lighters from Sawdust and Shavings .... 171 
Manufacture of Carborundum from Sawdust .... 172 


THE PRODUCTION OF WOOD-WOOL . . . . * . . . 174 

Dyeing Wood-wool . . . . . . , . 175 

Anthon & Sons' Double-acting Wood-wool Machine . . 176 

Quadruple-acting Wood-wool Machine . . . 180 

Vertical Wood-wool Machine of Ernst Kirchner & Co. . . 183 

Rotating Wood-wool Machine of Otto Camillo Israel . . 186 

BABK . ... . ... . . . .186 

Utilisation of Birch Bark 187 

INDEX 189 



1. Kraft's Sawdust Furnace (Longitudinal Section) ... 28 

2. Kraft's Sawdust Furnace (Cross Section) .... 29 

3. Kraft's Sawdust Furnace (Horizontal Section) ... 30 

4. Andre's Sawdust Furnace (Section) 32 

5. Andre's Sawdust Furnace (Cross Section through Combustion 

Chamber) 33 

6. Furnace for Burning Sawdust or Tan for Heating a Single- 

tube Boiler 36 

7. Furnace for Burning Sawdust or Tan for Heating a Two- 

tube Boiler 36 

8. Sawdust and Tan Furnace with Step Grate and Truck for 

Conveyance of Fuel 37 

9. Sawdust and Tan Furnace with Step Grate and Feed Plate . 38 

10. Sawdust and Tan Furnace with Step Grate and Fuel Hopper 38 

11. Sawdust and Tan Furnace with Step Grate and Charging 

Slot 39 

12. Sawdust Furnace for Gas Producers (Section through the 

Furnace and the Condensers) 44 

13. Sawdust Furnace for Gas Producers (Ground Plan of the 

Furnace and Condensers) 45 

14. Godillot's Pyramidal Fire Grate (Longitudinal Section) . . 50 

15. Godillot's Pyramidal Fire Grate (Horizontal Section) . . 50 

16. Godillot's Pyramidal Fire Grate (Transverse Section) . . 51 

17. Plan of one of Godillot's Pyramidal Fire Grates ... 52 

18. Section of one of Godillot's Pyramidal Fire Grates . . . 52 

19. Walter's Sawdust Furnace and Stills (Vertical Section) . . 56 

20. Walter's Sawdust Furnace and Stills (Section through Grate) 57 

21. Walter's Sawdust Furnace (Oblique Section) .... 58 

22. Niederberger's Furnace (Transverse Section) .... 60 

23. Niederberger's Furnace (Longitudinal Section) I . . 60 

24. Zwillinger's Apparatus for Carbonising Sawdust (Vertical 

Longitudinal Section) ........ 62 


25. Zwillinger's Apparatus for Carbonising Sawdust (Horizontal 

Section) 63 

26. Zwillinger's Apparatus for Carbonising Sawdust (Transverse 

Section through the Superheater Furnace) .... 64 

27. Fischer's Apparatus for Carbonising Wood .... 67 

28. Halliday's Carbonisation Apparatus 69 

29. Distillation Column for Wood-refuse 71 

30. Waisbein's Experimental Apparatus 73 

31. Waisbein's Distillation Apparatus (Ground Plan) ... 74 
32-34. Waisbein's Distillation Apparatus . . . .75 
35-37. Petri's Combustion Apparatus . . . , ... 77 
38,39. Petri's Portable Combustion Apparatus . . . . 79 
40,41. Petri's Stationary Combustion Apparatus . . , . . 80 
42, 43. Apparatus for Preparing Paper-pulp from Wood-waste . 160 

44. Modified Apparatus for Preparing Paper-pulp from Wood- 

waste 161 

45. Double-acting Wood-wool Machine of Anthon & Sons . . 177 

46. Wood-wool Machine (Front View) 179 

47. Wood-wool Machine (Plan) 181 

48. Quadruple Wood-wool Machine without Scribing Knives . 182 

49. Vertical Wood-wool Machine of Kirchner & Co. ... 184 

50. Rotating Wood-wool Machine ....... 185 


THE various trades and industries which work up wood, 
from the simple mountain or forest saw-pit, in which the 
saw is worked by water power and where therefore no 
advantage is to be obtained from the combustion of the 
refuse as fuel, or from the large, well-arranged saw-mill, 
down to the furniture-maker and the cabinet-maker 
working on the smallest scale, the cutting up of tree 
trunks, the production of beams, and planks, etc., etc., all 
produce large quantities of sawdust, which often occasion 
serious inconvenience to the producers. The amount of 
this waste product is often so enormous that neither 
storage room nor means of transport is available, and the 
substance, by lying in the open air exposed to all the 
vicissitudes of weather, either rots away completely or at 
least undergoes very considerable decomposition. The 
transport of sawdust, on account of its bulkiness, and the 
want of means of communication, is in many cases impos- 
sible, and many timber producers are glad if their 
neighbours will relieve them of an onerous burden, either 
cost free or for a small payment. In the immediate 
neighbourhood of railways and roads the value of sawdust 
is somewhat enhanced; nevertheless, even with these 
appliances, the packing for carriage involves difficulties, 
and the substance can neither be so utilised, nor so readily 
sold, as according to its real value should be the case. 



Sawdust, in form and colour, is a very variable material. 
The product from large saw-mills, being for the most part 
obtained by the use of large saws, is coarse and fibrous, and 
is frequently mixed with fragments of wood and bark; 
moreover, in consequence of the use of unseasoned wood, 
it is often damp or even wet. The sawdust produced by 
those industries which make use of wood is generally 
finer, less fibrous, and drier, since it is the product of 
thinner saws with finer teeth; finally the waste obtained 
by working wood with the rasp is more or less floury. 
Only the sawdust of the softer woods (the coniferous 
woods, poplar, lime, etc.) is distinctly fibrous; that from 
harder woods (oak, beech, walnut) forms a coarser or finer 
powder, the condition of which depends nevertheless to 
some extent on the kind of saw used. The colour of saw- 
dust depends on that of the wood from which it is 
obtained. That from hard woods is usually brownish, 
that from mahogany, reddish, etc. 

Since the coarseness of the sawdust is dependent on the 
kind of saw used, and the degree to which the teeth are 
set out, as also on the dampness of the wood, it follows that 
the percentage of this waste product on the original timber 
is very variable; in large saw-mills, where tree trunks are 
cut up into baulks and deals, the proportion of sawdust 
will naturally be larger than in those industries which 
employ the wood already so prepared, and therefore it is 
from the former that the largest quantities of sawdust are 
obtained, and it is the owners of these who have the 
greatest interest in a favourable disposal of the material. 

It is of the greatest importance in saw-mills that this 
waste product should be preserved in as clean a condition 
as possible, that shavings and chips should be kept out of 
it, and that it should not be allowed to be injured by 
getting wet. 

The most obvious application of sawdust is, of course, 


its use as fuel. If only small amounts have to be dealt 
with, it may be burnt in the ordinary fire grates by 
throwing it a little at a time upon a coal or wood fire 
which is in a vigorous state of combustion. The quantity 
thrown on the fire at once must never be large, and it 
must occasionally be loosened with a poker in order to 
give access to the air necessary for the combustion. To 
burn larger quantities in the ordinary fire grates is diffi- 
cult in consequence of the want of the proper air supply, 
for sawdust is a substance which compacts itself together, 
and when in a damp condition is utterly unsuited for a 
fuel. Special furnaces and fire grates have therefore for 
a long time been in use for this purpose, whilst in recent 
times attempts have been made to consolidate the sub- 
stance into briquettes before burning it, which have met 
with a fair amount of success. The furnaces and grates 
which have been suggested for burning this material, as 
well as the appliances for charging them regularly, with 
sawdust, and for preventing the burning mass from 
collapsing, are described in a special section of this book, 
where the most recent improvements in these appliances 
will be found. A further step in the utilisation of this 
waste material is found in the combined employment of it 
as a fuel and as a source of distillation-products, such as 
acetic acid, wood-spirit, acetone, etc., which are obtained 
by submitting wood to destructive distillation. In the 
same way, exhausted, ground or chipped dye-woods from 
extract factories and dye works, as well as spent tan from 
the tanneries, can be burnt in any of these furnaces with 
a similar efficiency, so that in these industries verv con- 
siderable sums can be saved, which otherwise would have 
been lost. 

The use of sawdust in combination with binding and 
cementing substances, such as glue, albumin, blood, resin, to 
form plastic materials, such as the so-called artificial wood, 


is already somewhat old and well known, though it is only 
quite recently that it has been discovered how to cement 
sawdust together so as to form a really firm decorative 
material, capable of resisting changes of temperature and 
damp, and in no respect inferior to expensive but fragile 
wood carvings. Amongst these materials should be 
mentioned that called xylolith, a substance of stony hard- 
ness, which, supplied in thin slabs of various colours, is 
employed for flooring, wainscot, and similar purposes, and 
has proved very satisfactory. 

The production of blasting powders and gunpowder from 
sawdust has been repeatedly attempted, and although the 
results attained do not promise a very extensive con- 
sumption, some of the formulae for this purpose may well 
find a place in this work. For the manufacture of oxalic 
acid sawdust is still almost the only raw material avail- 
able, and affords a profit. The accumulation of sawdust 
in a great number of localities has, of course, given rise to 
numerous proposals for its utilisation, some of which, how- 
ever, have never been put into practice. 

Thus, in France, sawdust has long been used instead of 
sand for drying up ink. Sawdust has the advantage over 
sand that it is in no way injurious to books, pens, writing 
table, etc. And in countries where the minimum postage 
fee is restricted to letters under oz. in weight, the use 
of the far heavier sand may easily cause a letter to be 
over weight. For this purpose the sawdust oJ hard woods, 
cut with fine saws, as for instance in cutting veneers, is 
chiefly employed. And this is not used exactly in the 
state in which it is first obtained, but is passed through a 
coarse sieve so that splinters of wood may be taken out, 
and then is freed from dust by shaking it on an extremely 
fine gauze. As employed it is therefore in a finely 
granular condition, free from coarse particles and not 
dusty ; the harder the wood the better is the product. 


Sawdust for this purpose is commonly dyed and perfumed 
in order to give it a more pleasing appearance. The dyes 
used are those obtained from coal-tar; 3 to 5 parts of the 
selected dye are dissolved in 100 parts of water, the saw- 
dust is stirred into the solution and thoroughly wetted 
therewith, so that a uniform dyeing of every particle may 
be ensured, and after taking out from the dye-bath it is 
dried in moderately heated chambers for the removal of 
the excess of moisture. Any desired tint can thus be 
given to the powder, after which it is perfumed by placing 
it, together with very small quantities of ethereal oils, in 
vessels which can be closed and rotated until the perfume 
is uniformly absorbed. This mode of utilisation is especi- 
ally to be recommended to veneer cutters for working up 
their sawdust. If the sawdust from the various woods 
used in these workshops can be collected separately, the 
mahogany and rosewood could be employed for dyeing the 
lighter woods. The dark woods could be boiled with water 
containing a little alum, and the filtered extract used for 
dyeing alder, cherry, or elm wood, thus communicating to 
these light woods a mahogany or rosewood appearance. 

Sawdust of any sort may also be used in making plastic 
cements (Kitten) for filling up defective places in wood- 
work, and it is advantageous for this purpose to use the 
sawdust of the same sort of wood as that to be stopped up, 
rather than to dye another sort of sawdust so as to match 
the shade. 

The use of sawdust as a packing material for fragile 
articles, such as those of sheet metal or glass, is too well 
known to require remark here ; it may, however, be 
noticed that care should be taken to have it well dried 
and free from dust. The same is the case with regard to 
its use in a damp state for sweeping out the floors of 
dwelling rooms. Dry, clean sawdust is a good material 
both for packing and for preserving eggs, and is far to be 


preferred to chaff, which is often damp and malodorous. 
Less known is its use in paint works, for cleaning the paint 
mills, utensils, cans, etc., from the paint residues which 
cannot be removed with scrapers. The paint is completely 
removed, leaving the mills clean, and the metal work 

For the preparation of a substitute for bone ash, 
Maxwell Lyte proposes to mix mineral phosphates with 
peat, sawdust, tar, etc., or with animal substances such as 
blood, and to calcine and pulverise the mixture. 

The low conductivity for heat possessed by sawdust is of 
importance, and has gained for it extensive employment. 
The intermediate spaces between the joists in houses may 
advantageously be filled with sawdust instead of with 
builders' rubbish, which is often enough deleterious to 
health. Its use as a packing material for ice chests and 
ice houses is well known, and it may also be used with 
immense advantage for preserving the warmth of green- 

The well-known linoleum (Kork teppich) consists of 
ground cork refuse mixed with linseed oil and rolled out 
into sheets ; instead of cork powder, sawdust has often 
been used, or rather the wood-meal obtained by grinding 
sawdust between mill stones, and, especially for the cheaper 
qualities, has given favourable results. Also in the manu- 
facture of paper, wood-meal has here and there been used 
as a filling material instead of mineral substances. For 
laying down floors with cement plates, sawdust is better 
than sand, as it makes the floor warmer. When sawdust 
is mixed with tar-resin in various proportions, with the aid 
of heat, and the mixture is exposed to great pressure in 
moulds, a substance is obtained resembling wood, which 
can be cut, planed, bored, and polished, and which is very 
hard, tough, and imputrescible. The sawdust must first 
be baked until it is almost brown-black, after which it 


will be free from water. Plaster and cement planks (saw- 
dust boards) may likewise be prepared by mixing plaster 
of Paris or cement with sawdust and water and pouring 
the mixture into suitable moulds; these form a light and 
yet strong building material. Sawdust with plaster of 
Paris, or wood-wool refuse with pkister, forms a very suit- 
able material for packing steam boilers, steam pipes, etc. 

Combined with asphalt, sawdust is used in the damp- 
proof course of walls. Roofing felt intended for export is 
strewn with sawdust instead of with sand to diminish the 
weight and obtain greater elasticity. 

Wood-cement is prepared from sawdust, glue, and water- 
glass (sodium silicate). The addition of sawdust to clay 
intended for brick-making produces light, porous bricks. 
These are used for partition walls, and are very bad con- 
ductors of heat. By mixing a very large quantity of saw- 
dust with clay and kiln-burning the mixture, a cheap 
filtering material is obtained, which, as it contains wood- 
charcoal, serves as a disinfectant. Sawdust mixed with 
gas-tar forms an admirable damp course for the walls 
of buildings standing on damp ground. Mixed with 
balsam of sulphur it gives an elastic material, and with 
asphalt and a little linseed oil a harder mixture for coating 
damp walls and cold baths. 

In burning black clay pipes, a layer of sawdust and then 
a layer of pipes are placed in a muffle, which may hold 
500 to 600 pipes ; the muffle is then luted and heated to a 
dull red-heat in a furnace for 10 to 12 hours. The sawdust 
is carbonised, gives up its products of distillation, which 
are absorbed by the pipes and communicate a black colour 
to them. About 20 to 50 of the pipes are stuck upon a 
round disc furnished with pegs, and are held in the smoke 
of burning straw : they acquire an intense black colour, 
and are then polished with wax and a stiff brush. 

In the manufacture of wall paper, sawdust and even 


wood-meal, instead of the usual chopped wool, have been 
used for making low qualities of velvet paper, the pre- 
viously dyed sawdust being sifted over the paper which 
has been first printed with an adhesive paste ; also in 
other industries fine dyed sawdust may with advantage be 
employed instead of chopped wool. Wood-meal is used 
in the manufacture of artificial flowers to imitate the 
pollen, and when dyed in pale soft shades has a very good 

Sawdust wetted with sulphuric acid is placed in stables 
to absorb ammonia, for which purpose it answers better 
than the gypsum formerly employed. For this purpose 1 
part of sulphuric acid is diluted with 15 parts of water, 
the sawdust is soaked in the mixture, and after draining 
from superfluous liquid is spread on shelves in the stable. 
Every three days the supply of sawdust is renewed; that 
which is saturated with ammonia being thrown on the 
manure heap, the value of which is increased thereby. 

As litter for cow-sheds sawdust is superior to leaves or 
pine needles, as it is capable of absorbing more liquid than 
the latter, and nevertheless furnishes a dry bed for the 
beasts. Sawdust, especially that consisting of long fibres, 
saturated with animal excrement, makes a very good 
manure, because it rots easily. 

In the preparation of composts for garden work saw- 
dust is of great importance. To prepare it for use it is 
laid down in an open shady situation in heaps 75 to 100 cm. 
(30 to 40 inches) high, and turned over several times a year, 
until the whole mass is well rotted. This compost is 
lighter than leaf mould, and for some plants, as for 
instance orchids, may be used alone, or it may be mixed 
with cow dung or garden soil to make it heavier, or with 
heath mould or sand to make it lighter. Another use of 
sawdust is for the preparation of hot beds, instead of the 
tan commonly employed. It gives a higher temperature 


than tan, and maintains the heat for a full year. It is 
advisable to mix a little chopped straw with the sawdust 
to prevent it from becoming too much consolidated, in 
which case the heat would not be given out sufficiently. 

Far too little attention is paid to the applicability of 
sawdust for giving a loose texture to dense materials, and 
lightening heavy ones. Thus the well-known Laming's 
mixture employed for the purification of illuminating gas 
in gas works would be far too dense by itself, and must 
therefore be mixed with a large quantity of sawdust to 
give it a coarse, open texture. Both sawdust and wood- 
shavings may be used for the purification of coal gas if 
they are soaked in a solution of copper vitriol and the gas 
then passed over them. Mariot and Sugden proceed as 
follows : Instead of purifying coal gas from ammonia by 
passing it through sulphuric acid, it may be passed through 
vessels resembling dry lime purifiers, namely, boxes con- 
taining hurdles on which a loose material containing 
sulphuric acid is spread out. Sulphuric acid of 1'425 
specific gravity is the most suitable for this purpose. This 
sulphuric acid is mixed with sawdust in the proportion of 
84 parts of the acid to 50 of sawdust. The mixture is 
then heated to about 120 C., so that the sawdust becomes 
carbonised and the charcoal absorbs the acid. This yields 
a dry, porous material, which, when spread upon hurdles, 
allows the gas to pass readily. In charging the purifiers a 
layer of old material, already saturated with ammonia, is 
placed first on the hurdles in order that they may not be 
acted on by the acid, and the fresh mixture is then placed 
on this. 

Croll employs for the purification of coal gas the residue 
of manganous chloride from the chlorine stills, which he 
mixes with lime and sawdust, and exposes to the gas until 
it contains 30 to 40 per cent, of ammonium chloride, which 
can then be recovered by lixiviation or sublimation. 

f " OF THE ^ 


In the cementation process of making steel, the iron 
bars are packed with sawdust into an iron box, which is 
then closed with a clay luting and moderately heated for 
a longer or shorter time, according to the thickness of the 
bars. The steel obtained is melted in a closed iron (?) 
crucible under a layer of fresh sawdust, and may be poured 
into heated iron moulds. 

The acetates of potassium and sodium are said by 
Sonstadt to be producible from the sulphides of the two 
metals by evaporating their solutions to dryness with saw- 
dust and carbonising the mixture below a red-heat. The 
black mass is boiled down to dryness with milk of lime 
until a sample of the liquid is found after nitration to be 
free from sulphur. The whole quantity is then filtered, 
the filtrate evaporated to dryness and the residue gently 
roasted. The product is a tolerably pure acetate. 

Mortar made with sawdust has repeatedly been 
advocated as a means of getting rid of moisture from damp 
walls. This mortar is prepared in the following manner : 
Ordinary slaked lime is thinned with water ; sawdust is 
at once mixed with the lime instead of sand, using such a 
proportion that the lime still retains the necessary binding 
power. Solution of water-glass may also be added to this 
mixture. Such mortar is not only recommended for the 
building of new walls, but also for plastering existing walls, 
and is said to be especially suitable for stucco, so that 
whole facades may be constructed of it. A very good 
roofing material may be produced by mixing melted coal- 
tar, flowers of sulphur, finely powdered hydraulic lime, and 
sawdust, and pouring the plastic material into moulds or 
rolling it out into slabs. 

Mortelette has recommended sawdust for the prevention 
of boiler scale : the mixture employed consists of sawdust, 
soda, pine-wood charcoal, rye meal and clay. 

Dyes are manufactured by Croissant and Bretonniere 


from sawdust. The process consists in the removal of 
hydrogen from the wood by the action of sulphur at a high 
temperature. The products are called by their discoverers 
" organic sulphides," in which hydrogen is replaced by 
sulphur. These sulphides oxidise when exposed to the air, 
and give off sulphuretted hydrogen when treated with 

The manufacture of these dyes from sawdust is simple, 
requires no complicated apparatus, and little labour; they 
are cheaper and more permanent than those most commonly 
in use; a kilogram of dye from sawdust, for example, 
costing only about half as much as the same quantity of 
logwood extract, and possessing four times the dyeing 

The property which sawdust possesses of absorbing water 
is often utilised in public conveyances, omnibuses, tram- 
cars, etc., to keep the floor free from wet ; sawdust is 
strewn on pavements in frosty weather to prevent slipping 
and serve as a safeguard against accidents. 

Sawdust serves as a mild cleaning powder for tarnished 
silver, and beech sawdust as a polishing powder for gold. 
Sawdust may also serve as a kind of soap for the cleansing 
of house linen, since friction with it is very efficacious 
for removing the dirt. 

The Smith Consolidation Company in Argo undertake 
the conversion not only of small coal, but of sawdust, 
shavings, cotton wool fibres, etc., into briquettes, in order 
to utilise these substances as fuel. In the machine 
employed for this purpose a triple mould revolves round a 
vertical axis, and is so arranged that when one of the 
moulds is under the charging funnel, the second is under 
the compressing stamp, and the third is being emptied by 
another stamp. The machine is capable of converting 1500 
kilos. (H tons) of the sawdust of Weymouth pine-wood 
into blocks per hour. This process, the manufacture of 


briquettes from wood-waste, has in quite recent times 
made very great progress, both sawdust and wood-shavings 
being compressed, either with or without binding materials, 
into hard masses which either serve directly as fuel, or are 
carbonised in closed vessels for the recovery of the products 
of distillation. 

For the preparation of wood-pulp (according to Beth) 
the sawdust is disintegrated by an edge runner working 
in a stone bed ; the material thrown out at one side is 
immediately replaced at the other until it has the desired 
degree of fineness. The edge runner is arranged exactly 
like the beating roller of a paper mill. 

For the manufacture of short-fibred cellulose, sawdust 
may be treated by the soda, or sulphite processes. 

F. W. Wendenburg prepares wood-meal fodder in the 
following manner : The wood (sawdust) is ground to a fine 
meal, to 50 kilos, of which there is then added 1J kilo, 
of rock-salt, and enough hot distiller's wash mixed with 
y F kilo, of hydrochloric acid to form a thin pulp. After 
boiling for two hours this is ready for use as fodder, but 
it may also be dried and pressed into moulds, or can be 
baked in the form of dough. 

Sawdust finds extensive employment in all the metal 
industries, especially for drying articles which have been 
treated with acids, no other substance being so effective as 
sawdust in drying and cleaning the objects and prevent- 
ing subsequent oxidation (rust, or verdegris formation). 
Articles made of horn, ivory, tortoise-shell, and bleached 
bone cannot be better dried than in sawdust, since they 
then neither crack nor warp. For polishing metallic 
wares sawdust may be used with the greatest . advantage ; 
the articles to be polished are placed, together with a large 
quantity of sawdust, in rotating drums, and acquire their 
polish from the friction of the sawdust. The sawdust for 
this purpose must be perfectly dry. 


A very useful product can be obtained by mixing saw- 
dust and refuse wood-chips with the residues from the 
manufacture of turpentine and rosin, and pressing the 
mixture into moulds: it is used for kindling fires. The 
same waste materials have also quite recently been utilised 
in considerable quantities for the manufacture of car- 
borundum and of calcium carbide. 

A method of utilisation which will assume very large 
dimensions in the future, and which is perhaps even 
destined to produce a scarcity of sawdust, is the conver- 
sion of that substance into sugar and alcohol, if the 
difficulties encountered in carrying out on the large scale 
the processes elaborated on the small scale can be overcome. 

There are, without doubt, still other methods of making 
use of sawdust, some of which are of secondary import- 
ance, whilst others have not been made public, and it is 
probable that in the future still more uses will be found 
for this material. 

Most of the methods of utilisation which have been 
mentioned above may be applied to extracted dye-woods, 
etc., and in some cases, where large amounts of these waste 
materials are available, they may be re-extracted, and then 
utilised as fuel to evaporate the very weak decoctions so 
obtained, for which purpose ordinary fuel would be too 

A similar product, to which hitherto far too little 
attention has been directed, is tan (oak bark), the complete 
utilisation of which in tanneries is not possible with the 
primitive methods of extraction generally employed, and 
which therefore still contains considerable amounts of 
tannin, which by processes similar to that mentioned above 
can nevertheless be wholly extracted. A process has 
lately been adopted in France analogous to Schiitzenbach's 
method of extracting sugar from beet-root, which obtains 
all the tannin from oak bark in a perfect manner. A 


large number of round tubs, about 2 metres (6 feet 6| 
inches) deep and 1 metre (4 feet 1J inch) in diameter, 
in each of which a second perforated bottom is placed 1 
decimetre (4 inches) above the floor, are connected by 
pipes, each of which is inserted at one end under the false 
bottom of one tub and at the other 0'15 metre (6 inches) 
below the edge of the next tub. The tubs are filled with 
the bark and water is run into one of them ; the extract 
passes on to the second, third and fourth, etc., becoming 
stronger in its progress, and extracting less and less tannin 
from the charge in each succeeding tub. The strong solu- 
tion is finally drawn off from the bottom of the last tub. 
Supposing n tubs to be in use, the bark in the first tub 
will have been extracted n times when that in the last tub 
has only been extracted once. When n tubs of water have 
been run upon the charge in the first tub that charge will 
have been perfectly exhausted. The last water is drawn 
off, and the spent tan thrown out. The tub is refilled with 
fresh bark and is then made the last of the series. In the 
same way each charge as it becomes exhausted is replaced 
by fresh bark, and the process goes on continuously. This 
process not only exhausts the bark completely, but 
furnishes the tanner with extracts of varying degrees of 

Extracted bark and other tanning materials may 
further be employed for the manufacture of ink. The 
spent tan is treated with caustic soda, and the filtered 
liquor is mixed with iron vitriol (ferrous sulphate) and 
exposed to the air. Spent tan may be very advantageously 
used as a fuel if it is mixed with a little nitrate of lead, 
made into briquettes with lime, and dried; such fuel is 
said to be especially suitable for heating railway carriages.* 

*In Germany the passenger carriages are frequently warmed by 
stoves. (TRANS.) 


A considerable quantity of spent tan is used for 
spreading on riding roads and in equestrian circuses ; it is 
used in agriculture partly as a manure, partly for forming 
hot beds and keeping up the warmth of greenhouses. 
A certain amount is used in pleasure gardens. Flower 
beds which contain tan mixed with the earth remain free 
from weeds, the soil is kept in a loose condition, in the 
dryest season remains damp without any need of watering, 
and is altogether free from the larvae of the cockchafer. 
The growth of the trees is vigorous, the branches are given 
off at short intervals, and both leaf and fruit-bud forma- 
tion are strong. Root production is also greatly 
augmented. Old trees growing in a tan soil are parti- 
cularly fruitful and produce handsome fruit : standards 
exhibit the same result. By using spent tan not only is 
the cost of weeding saved, but the roots are preserved from 
the attack of insects, growth and fruit formation are pro- 
moted and therefore profit is increased. 

When we come to consider more closely the methods by 
which sawdust, waste wood in larger or smaller fragments, 
extracted dye-woods, spent tan, bark, nut-galls, etc., can 
be utilised, we find that the processes may be divided into 
two main groups, one of which may be called the chemical, 
the other the mechanical application. The chemical pro- 
cesses comprehend : 

1. Employment as fuel. 

2. Dry distillation. 

3. Treatment with various chemical reagents, for the 
production of cellulose, vinegar, alcohol, sugar, gum, 
oxalic acid. 

The mechanical processes, which, however, must not in all 
cases be regarded as strictly mechanical, since many of 
them involve chemical changes, embrace : 

1. The production of artificial wood. 

2. Employment in the manufacture of explosives. 


3. Use as a means of producing porosity and lightness. 

4. The manufacture of manure. 

5. A variety of other methods of utilisation. 

For the study of the mechanical processes a knowledge of 
the chemical constitution of wood is not necessary ; on the 
other hand, such knowledge, as well as an acquaintance 
with the changes which occur when wood is exposed to a 
high temperature, or treated with reagents, is indis- 
pensable, and to these points we will here devote a few 

Wood, chemically considered, consists of a number of 
different substances, the nature and proportions of which 
are dependent on the kind and the age of the plant from 
which it is derived. Broadly, we may distinguish in all 
varieties of wood two constituents, the woody fibres and 
the sap, the latter again consisting of water and the sub- 
stances held in solution. The woody fibres consist of cellu- 
lose or cell-substance, which forms elongated cells grouped 
into bundles, and of lignin or the incrusting substance. 

Cellulose belongs to the class of carbohydrates. To 
prepare it from wood, the wood must be treated with ether, 
alcohol, dilute acids and alkalis, and finally be copiously 
washed with water. Pure cellulose has the same composi- 
tion as starch powder, and in many of its chemical relation- 
ships exhibits a similar behaviour, but the one substance 
has never yet been converted into the other, although from 
either it is possible to prepare a fermentable sugar, and, 
from this again, alcohol. 

Experiments in this direction have indeed been attended 
with the result expected on theoretical grounds, but on the 
large scale, in consequence of the carbonisation of much of 
the woody substance and the considerable consumption of 
sulphuric acid, the process presents great difficulties. The 
action of hydrochloric acid on cellulose produces hydro- 
cellulose and sugar (wood-sugar) ; nitric acid produces 


nitro-cellulose ; cellulose melted with caustic alkalis yields 
compounds of oxalic acid. When cellulose is burnt with 
free access of air it leaves an ash ; if heated with exclusion 
of air it yields a series of the so-called fatty acids, also 
tar and charcoal. 

Wood-sap, besides water and mineral constituents, con- 
tains a variety of soluble bodies, such as the carbohydrates 
(sugar, gum), albuminoids, and pectous substances; also 
in individual species of plants, characteristic colouring 
matters, tannins, other extractive substances and resin. 

When wood is burnt with free access of air, gases are 
produced, whilst a certain amount of heat is developed, 
and an ash is left which contains the mineral constituents 
of the wood, the carbonates of potassium and of sodium, 
carbonate and sulphate of calcium, magnesia, phosphates, 
etc. In localities where timber is abundant, carbonate of 
potassium (potash) may be manufactured from wood-ash. 

If, on the contrary, wood is burnt with restricted access 
of air, or is heated in vessels from which air is excluded, 
which is the case when it is burnt in charcoal heaps 
(Meiler), or heated in retorts, it undergoes a more or less 
complete dry distillation and other products are obtained. 

The dry distillation of wood commences at a temperature 
of 100 to 130 C., the first substance to distil over being 
water, the proportion of which naturally depends on the 
degree of dampness of the wood. The dampness of wood- 
waste will largely depend upon whether it has been kept 
under cover or been left lying in the open, and this will 
materially influence the amount of fuel necessary for its 
distillation. It is therefore advisable, where it is practi- 
cable, to subject sawdust to a preliminary drying before 
it is introduced into the distilling apparatus. As the 
temperature is raised from 145 to 500 C. the products 
obtained are water, acetic acid, wood-spirit (methyl 
alcohol), and tar, as well as various gases, whilst wood- 



charcoal is left in the retort. When the temperature is 
rapidly raised acetic acid is the chief product; this must, 
however, be quickly removed from the heated vessel, or 
it will undergo further decomposition. 

The products of the distillation of wood vary both in 
kind and in amount according to the degree of heat to 
which it is exposed. The higher the temperature the 
greater is the proportion of gaseous products, and it is 
usual not to exceed an incipient red heat. 

With regard to the* process of distillation itself, two 
different modes of operating must be distinguished: 

1. The wood (sawdust and other refuse) is submitted to 
distillation with the object of obtaining the largest pos- 
sible yield of acetic acid and tar, with which object the dis- 
tillation is carried on slowly and at a low temperature ; 
even in this case a considerable amount of gas is produced, 
which, however, for the most part consists of carbon 
dioxide and carbon monoxide, burns with a very feebly 
luminous flame, and can best be utilised for the produc- 
tion of heat by passing it first through a layer of incan- 
descent carbon, by which the carbon dioxide is reduced to 
monoxide. This reduction takes place in those forms of 
furnace in which the gases from the distillation are con- 
ducted into the space below the fire grate. 

2. The wood is distilled with the intention of obtaining 
gas and tar, with but little acetic acid; in this case it is 
rapidly raised to a very high temperature; the greater 
part of the volatile products, consisting of carbon, 
hydrogen, and oxygen is further decomposed with forma- 
tion of hydrocarbons, which are partly liquid, partly 
gaseous. The gases so obtained have a higher illuminating 
power: whilst the yield of tar is considerable and that of 
acetic acid small. 

The pyroligneous acid resulting from the distillation is 
a mixture of methyl alcohol, methyl acetate,, acetone, 


acetic acid and water; the tar contains benzene, toluene, 
xylene, cumene, naphthalene, paraffin, phenol, cresol, etc. 
According to the temperature the products are : 

a. Gases from 160 to 360 : carbon dioxide (carbonic 

acid), carbon monoxide, marsh gas (methane) ; from 
360 to 432 : hydrogen, acetylene, propylene, 
butyl ene. 

b. Pyroligneous acid from 180 to 300 : formic and acetic 

aoids ; from 200 to 360 : propionic acid, butyric 
acid, valeric acid, caproic acid, methyl alcohol ; from 
250 to 360 : acetone, metacetone, acetic acid, methyl 
acetate, methylamine acetate and aldehyde. 

c. Tar from 360 to a red heat : the substances mentioned 


The charcoal, acetic acid and methyl alcohol obtained 
by the distillation of sawdust have hitherto been regarded 
as the principal products, the tar being looked upon as a 
by-product, and the process of distillation conducted 
accordingly. Lately, however, more attention has been 
paid to the tar, and from it have been obtained benzene, 
toluene, and naphthalene, hydrocarbons which are exten- 
sively employed in the manufacture of artificial (or so- 
called " aniline ") dyes. In carrying out a distillation it 
is therefore necessary in the first place to decide what 
products it is desired to obtain, and to arrange accordingly. 
To give further details respecting the products of distil- 
lation would carry us beyond the limits of this book, 
which is intended to deal only with the utilisation of wood- 
waste; the reader may be referred to the following special 
treatises on this subject : " Das Holz und seine Destilla- 
tionsproducte " (Wood and its Products of Distillation), by 
Dr. George Thenius ; " Die Verwerthung des Holzes auf 
chemischem Wege " (The Utilisation of Wood by Chemical 
Methods), by Dr. Jos. Bersch (2nd edition) ; and " Die 


Fabrikation der Anilinfarbstoffe " (The Manufacture of the 
Aniline Dyes), by the same (published by A. Hartleben). 

Altogether different are the products obtained when 
wood is acted on by chemical reagents. We have already 
seen that wood consists of two principal substances, cellu- 
lose, and lignin or the incrusting substance. By suitable 
treatment, boiling with nitric, sulphuric, or hydrochloric 
acid, with caustic soda, with sulphurous acid, and with 
sulphites under pressure, the cellulose may be obtained 
more or less pure, the incrusting substances being dis- 
solved out. In the decoctions there exist numerous gummy 
and saccharine substances, and many attempts have been 
made to bring these into use. 

By boiling or heating with dilute hydrochloric acid the 
cell walls of the wood become broken down, the incrusting 
substance is dissolved and converted into grape-sugar 
(glucose), whilst a substance called fibre cellulose or lignose 
is left, which is more easily attacked and dissolved by 
alkalis than cellulose. The following are the results of 
some experiments in this direction. 

In order to combine the production of grape-sugar and 

alcohol with that of wood-fibre, the first step was to 

ascertain the best proportion of acid to wood, and the most 

suitable concentration, in order to obtain a maximum 

quantity of sugar with a minimum quantity of acid. The 

following experiments were made with this object : 

A. 200 grams of sawdust (pine-wood with 15 per cent, of 

hygroscopic moisture) were boiled for 1 to 2 hours 

with 2 litres of hydrochloric acid of 5 Baume = 1*04 

specific gravity, corresponding to 162'2 grams of HC1. 

The sawdust, which acquired a reddish-brown colour, 

was thoroughly washed, the liquid neutralised with 

soda and mixed with lead acetate. An estimation 

with Fehling's solution showed the presence of 18' 12 

parts of grape-sugar (glucose) per 100 parts of wood 


taken. The greyish-brown lignose dried at 100, 
weighed 129 grams, corresponding to 64'5 per cent, of 
the wood taken. Erdmann gives for lignose the 
formula C 18 H 26 O U , and gives the following equation 
for its formation from cellulose : 

C 30 H 4r) 21 + 2H 2 = C 18 H 26 11 + 2C fl H 12 O tf . 
according to which pure cellulose should yield 5 6' 23 
per cent, of lignose. 

/?. 100 grams of sawdust similarly treated with 1 litre of 
cold hydrochloric acid of 10 Be*. (= 1'075 specific 
gravity, or 150 grams of HC1) gave 25 per cent, of 
glucose and 51 "6 per cent, of lignose. The colour of the 
lignose in the wet state resembled that of rotten oak ; 
in the dry state it was reddish-brown. When washed 
with dilute soda solution the washings were dark 
brown, which is not the case with ordinary wood-fibre. 
When thus treated the soda solution penetrates into 
the cells in which hydrochloric acid is present. An 
evolution of carbonic acid gas takes place, which has a 
disruptive action on the fibres, and would perhaps 
serve as a preparation for their subsequent employ- 

(-. 180 grams of sawdust with 800 cub. centimetres of 
hydrochloric acid of 6'5 Be*. (= 1'048 specific gravity, 
or 7 6' 8 grams of HC1), boiled for several hours, gave 
20'83 per cent, of glucose and 62' 22 per cent, of 
Two experiments with fine oak sawdust (6' 5 per cent. 

of moisture) gave 

Per cent, of glucose. Per cent, of lignose. 

13-22 62'75 

15-43 66-11 

The results of the three experiments with pine-wood 
were as follows : 


HC1 used per 100 
parts of wood. 

Glucose obtained per 
100 parts of wood. 

Glucose obtained per 
100 parts of HC1. 













It is said that these proportions are already employed in 
practice, and that after the acid solution of the sugar has 
been neutralised with lime down to 0'5 of Liidersdorfs 
acid scale, a fermentation of the mixture for 24 hours 
followed by distillation gives from 450 kilos. (9 cwt.) of 
sawdust, 26'5 litres (5'8 gallons) of 50 per cent, alcohol, 
free from any turpentine odour and of agreeable flavour. 



THE proportion of combustible matter in sawdust, and the 
calorific effect obtainable from its combustion, are exactly 
the same as those of the wood from which it was derived, 
since sawdust is nothing else than wood-fibre very finely 
subdivided by artificial means. But sawdust, when used 
as fuel, has the property of forming a layer which is very 
impervious to air, of falling through the fire grate in con- 
sequence of the fineness of its particles, and of giving off a 
large amount of water-vapour which impedes vigorous com- 
bustion. The compression of the heap of material prevents 
the due access of air, the layer of sawdust becomes car- 
bonised at the surface, and finally the heap becomes covered 
with ash to such an extent that combustion is completely 
arrested unless the heap is continually being turned over. 
When using sawdust for heating purposes the only object 
is to utilise its calorific power. If the sawdust is made 
up with peat, tan-refuse, coal slack, etc., into briquettes 
and thrown in this form upon the fire grate, its combus- 
tible matter can be more efficiently utilised than when 
trying to burn it in its loose condition. The making up of 
the sawdust into solid . blocks nevertheless makes it more 
expensive, and it is also difficult to find a completely 
suitable binding material, which will aid rather than 
impede the combustion, unless the substance is compacted 
by employing an exceedingly high pressure instead of using 


a binding material. The binding material must be so 
selected that it not only holds the sawdust together during 
transport, loading, and unloading, but possesses sufficient 
resistance to heat to prevent the briquettes from falling 
to pieces during combustion, and thus reproducing a bed 
of fuel impervious to air. Up to the present time there 
has very little practical use been made of these compacted 
sawdust briquettes ; attention has rather been directed to 
devising forms of furnace which will burn the loose saw-, 
dust directly. A better mode of utilising sawdust as fuel 
is to mix the dry sawdust with J of its weight of coal ; 
and it is of especial importance in using this material to 
take care to have a vigorous coal fire as a basis on which 
the sawdust can be thrown. With such a coal fire for a 
basis the following advantages are obtained : (1) The 
evaporation of the water in the sawdust, the proportion of 
which objectionable constituent may vary from 25 to 40 
per cent., is much accelerated ; (2) the combustible gases 
are more rapidly evolved and burn with a flame, whilst 
the carbon, being converted into carbon dioxide and not 
into carbon monoxide, gives a greater heating effect. 

A new process for converting sawdust into briquettes 
aims at heating the substance so far that the resin natur- 
ally contained in the wood (therefore with soft woods only) 
is softened, and then, without any further binding 
material, pressing into moulds at very high pressure. A 
fuel prepared in this manner is easily transportable, has an 
essentially higher heating power than brown coal, and is 
equally suitable for household and for technical use. 

It is obvious that for the advantageous employment of 
sawdust as a fuel the first consideration is to give an appro- 
priate form to the fire grate. The sawdust is generally 
thrown on the grate in a somewhat thick layer, and the 
spaces between the fire bars, which serve as channels for 
the supply of air, are to a great extent choked by it. But 


since combustion without a sufficient supply of air is quite 
impossible, it is obvious that the grate must in all patterns 
of furnace be so constructed that there shall be no de- 
ficiency of oxygen. The proportional area of the fire 
grate must be adapted to the nature of the fuel to be 
burnt on it, for a very different area will be required for 
burning on the one hand good coal, and on the other hand 
sawdust ; the correct proportion must therefore be adapted 
to the amount of steam which it is required to raise. 

No especial difficulties either in the construction of the 
grate or the furnace are required to be overcome, if only 
small amounts of sawdust have to be burnt in combination 
with other fuels; nothing is then necessary but from time 
to time to throw upon the coal fire when it is in a vigorous 
state of combustion a few shovelfuls of the well-dried saw- 
dust, and let it burn without disturbance, an operation 
which can easily be brought into practice in places where 
exhausted dye-wood, tan, etc., are obtained as refuse in 
amounts which it is easy to dispose of. The matter is, 
however, quite different when it is necessary to burn saw- 
dust either quite or almost alone. 

With this end in view a considerable number of furnaces 
for burning sawdust have in the course of time been 
invented, the chief of which will be here more minutely 
described and elucidated by figures. These are the Kraft 
sawdust furnace, the Lundin furnace, Koch's sawdust 
furnace, Walter's furnace for making wood-tar, the Andre* 
furnace for sawdust, the arrangement of Niederberger & 
Co. for burning damp wood-refuse and sawdust, Godillot's 
pyramidal grate for pulverulent fuel, gas generators and 
condensers for sawdust, "and the Zwillinger apparatus for 
carbonising sawdust, as well as a number of newer patterns 
which will also be minutely considered. These designs are 
exceedingly various in principle; they may nevertheless 
be easily divided into two groups : 


1. Patterns which are designed merely with the object 
of burning the sawdust for heating purposes, and in 
which therefore no value is attached to the condensation 
of volatile products derived from the wood. 

2. Patterns which are chiefly designed to accomplish the 
latter object, and with which, besides tar, wood-spirit, acetic 
acid, acetone, etc., a serviceable charcoal is also to be 
obtained. In furnaces of the second class it is especially 
to be recommended that the gas resulting from the distil- 
lation should be conducted into the fire. The apparatus 
of Niederberger & Co. allows the employment of damp 
material, so that such substances do not have to be dried 
first, which would require at least space and labour for 
turning the material over, even if no special drying 
arrangement was needed. Godillot's pyramidal fire grate 
also allows damp material to be employed. Zwillinger's 
furnace is constructed on very ingenious principles : the 
sawdust and other wood-refuse are not burnt directly, but 
are carbonised in closed vessels, so that all the volatile pro- 
ducts of the dry distillation of wood can be condensed, and 
the gases used either for lighting the works or for heat- 
ing purposes, thus utilising very completely this waste 
material, which is in the highest degree advantageous in 
localities where much timber is felled and cut up. In fact 
Zwillinger's furnace has already proved practically success- 
ful in several places, especially in G-alicia and Silesia, the 
tar and pyroligneous acid being either worked up on the 
spot or sent to chemical works. Weiss and Guttler have 
proposed to carry out the decomposition of the wood in an 
atmosphere of heated gases, heating the retorts from out- 
side. Waisbein devised a plan of decomposing sawdust in 
an atmosphere of producer-gas, whilst Giittier designed 
an apparatus for the preparation of powdered charcoal, in 
which the external heating of the retorts was dispensed 
with. A. Gustav, for carbonising wood or wood-refuse, in- 


troduces the material into tubes or channels and heats it 
under pressure, whilst allowing the evolved gases to escape 
gradually, so that a continuous solid carbon rod is formed 
which retains its coherence after removal from the tube or 
channel. G. Scheffer has constructed a special furnace 
from ordinary bricks, in which wood-refuse of all kinds, 
such as spent tan, sawdust, etc., is submitted to dry distil- 
lation by the partial incomplete combustion of the sub- 
stances themselves. In trials carried out on the large 
scale with tan containing 24 per cent, of water, complete 
combustion was effected. The vapours evolved from the 
furnace pass first through acetic acid saturated with lime, 
and then rise through a coke tower through which milk 
of lime is allowed to flow. The gases which escape finally 
are either burnt like producer-gas when there are several 
furnaces, or are allowed to escape into the chimney. Where 
there is no chimney shaft the necessary draught for the 
distillation furnaces is produced by a special furnace in 
communication with them. F. Frisch of Niederweise in 
Saxony likewise manufactures pyroligneous acid from spent 
tan, etc. Readfield and Halliday work up sawdust, and 
obtain a result which does not in any way agree with the 
statement in chemical treatises that resinous woods yield 
proportionally little acid. Eight retorts of 45 cm. diameter 
(18 inches) produce in 24 hours as much pyroligneous acid 
as 16 simple retorts of 1 metre (39 J inches) diameter. 
The wood-charcoal which is produced from the sawdust is 
employed in large amounts for the manufacture of arti- 
ficial manure, and possesses in a high degree the property 
of deodorising the urine used in dye works, furnishing 
therefore an easy means of getting rid of the disagreeable 
odour which escapes from the urine tanks. 




This furnace is shown in Figs. 1 to 3 ; Fig. 1 showing 
a longitudinal section through the middle ; Fig. 2 a trans- 
verse section, and Fig. 3 a horizontal section. The 
apparatus consists of retaining walls, A, B. of any desired 

FIG. 1. Kraft's Sawdust Furnace (Longitudinal Section). 

form, the simplest being an elongated quadrilateral, which 
is also that most easily constructed. The wall B is usually 
already existent, being that of the steam boiler or furnace 
hearth. The fuel is introduced from above through the 
opening c, which is covered by a sheet-iron cover as soon 
as the workman ceases to poke. The lifting of this cover 
is assisted by a counterbalance. At the level, a, b, the 
fireplace is widened out by the walls A and B being re- 



cessed. The lower part of the apparatus forms an ash- 
pit, and is furnished with two openings, D, which can be 
closed by tile or sheet-iron ash-pit doors. These openings 
are closed during the working of the apparatus, and are 
only opened for the removal of ashes or slag. Each of the 
ash-pit doors may have a small opening in it through which 
air can be allowed to enter if for any reason the combustion 
requires to be invigorated. In the front part of the 

FIG. 2. Kraft's Sawdust Furnace (Cross Section). 

apparatus there is a channel, E, which passes through the 
whole length of the brickwork, and is closed at both ends 
by wooden or iron discs. This channel communicates with 
the combustion chamber by a number of pigeon-holes, f, f, 
by which a supply of air is introduced. The combustion 
takes place in the lower part of the apparatus, and the 
gaseous products of combustion pass through the opening 
below the boiler or through the working hearth. The fuel 
burns therefore between the openings f and g. It often 



happens that arches form in the heap of sawdust, and in 
that case the whole concave surface of the arch is in a 
glowing state; small fragments of the burning matter 
detach themselves from the lower surface of the arch, fall 
to the floor and burn in the ash-pit. 

As it frequently happens that these arches collapse, the 
combustion would thereby be arrested or hindered if it 
were not for the recesses a and b, which keep the operation 
going. If the air is prevented by the collapse of an arch 

FIG. 3. Kraft's Sawdust Furnace (Horizontal Section). 

from passing directly from f to g, it takes a circular course 
round the apparatus and continues the combustion of the 
material. A lofty chimney, or a fan, produces a sufficient 
draught for this purpose, and in a few minutes the com- 
bustion reattains its original intensity. The walls of the 
furnace must in fact be of such a height that the falling 
in of such an arch does not uncover the channels g, g. 
The action of the furnace is a continuous one; the fuel 
both takes fire and burns readily, because the lower walls 
are very hot and radiate heat from all sides. The com- 


bustion is also a complete one, because the openings f, f, 
produce a very intimate admixture of combustible gases 
with atmospheric air at a high temperature. Together 
with the finely divided fuel (sawdust) larger fragments of 
the same may be burnt. Thus, in a trial made at a paper 
mill, wood billets were burnt along with the sawdust and 
with as good a result as with sawdust alone. 

After a short time the fire-bricks which line the channels 
g, g become white hot, and if dry sawdust is being used 
the temperature rises to a point which is sufficient for any 
furnace operation. 

The work of this furnace is continuous and is easily 
regulated; ft will burn the very worst kinds of fuel, such 
as rotten tree-trunks, pine needles, etc., whilst its erection 
is economical, and as the following experiments show, it 
seems to present very great advantages. In an experi- 
ment on raising steam in a steam boiler, the combustible 
material consisted of sawdust and shavings : the former 
was J pine, oak, the latter, J oak, J pine and J 
poplar. The trial lasted 15 hours. The fuel burnt 
amounted to 1544 kilograms of sawdust and 715 kilograms 
of shavings, or a total of 2262 kilograms. The quantity of 
water used amounted to 3680 litres. The temperature of 
the feed water was 18 C., and the tension of the steam 
produced was 4' 95 or 5 atmospheres (75 Ibs. per square 
inch). The substances burnt as fuel contained 38' 6 and 
27 per cent, of water respectively. The fuel lost therefore 
791 kilos, of water. Assuming that the heat required to 
evaporate this quantity of water in the furnace would have 
evaporated an equal quantity in the boiler, we may take it 
that 2262-791 = 1471 kilos, of combustible matter evapo- 
rated 3680+ 791 =4471 kilos, of water, or 3'04 parts of 
water for 1 part of combustible material. 

Another experiment with an 8 to 10 horse-power steam 
boiler gave the following result : The substances to be burnt 



were merely air-dry, and consisted of 413 kilos, of pine 
bark, 154 kilos, of oak sawdust, 18 kilos, of oak shavings, 
and 152 kilos, of oak waste, or in all 717 kilos. The engine 
ran for 10 hours and drove 2 water pumps, 3 circular saws, 
2 planing machines, and 2 drilling machines. The boiler 
was fed with water of 20 C., and a steam pressure of 













FIG. 4. Andre's Sawdust Furnace (Section). 

75 Ibs. was obtained. Although this experiment is an in- 
complete one, it sufficiently demonstrates the value of the 


This furnace is a modification of that of Kraft, and 
differs from tlie latter in having the abrupt widening of 


the combustion chamber replaced by one which increases 
gradually from above downwards, and also by the intro- 
duction of some structures of prismatic form, built of fire- 
bricks, into the lower part of the combustion chamber. 
In Fig. 4, A, B represents the front of the boiler which it is 
required to heat. The material to be burnt is introduced 
from above into the chamber, c, D, and falls on the prism r 
shaped walls, p, F, situated above the fire grate, E, which 

FIG. 5. Andre's Sawdust Furnace (Cross Section through Combustion 

may be replaced by a small arch. The principal com- 
bustion takes place in the chamber G with the air which 
enters from below the fire grate. With ordinary boilers 
this chamber G can be dispensed with. 

The following experiments on the efficiency of this 
furnace have been made : 

1. Spent tan burnt in 12 hours, 1420 kilos.; this had 
for several weeks been kept on the top of the boiler and 
was thoroughly dry. Water evaporated 1*85 kilos, per 



kilo, of tan; temperature of the gases at throat of 
chimney, 256 C. 

2. Material employed in the course of 12 hours, 340 
kilos, of tan, and 1025 kilos, of sawdust. Water evaporated 
T29 kilos, per kilo>. of fuel; temperature of gases, 250 C. 

3. Material burnt in 12 hours, 414 kilos, of coal. Water 
evaporated, 4'54 kilos, per kilo, of coal; temperature of 
gases, 250 C. 


Koch's sawdust furnace is simple in construction, and 
when used in tanneries for burning spent tan as fuel may 
also be employed for sawdust and peat. The problem to be 
solved was the combustion of a wet pulverulent or granular 
material without previous drying or agglomeration, as 
well as without having to force the air through the fire 
grate by mechanical means. Spent tan is a substance of 
this character; it is thrown out of the tan-pits saturated 
with water and in such a finely divided condition that it 
resembles sponge, and rarely contains granular fragments 
as large as a pea. In this condition it wo-uld be impossible 
to burn it on an ordinary grate without previous drying 
in the air, which would require a large space. 

In a particular case this apparatus was employed for 
heating steam boilers, and the tan, although pressed, con- 
tained 40 per cent, of water. 

The furnace consists essentially of a rectangular pit 
about 1'6 metre long, 1 metre wide, and 1'2 metre deep, 
the bottom of which contains two fire grates 0'45 and 0'5 
metre wide and 1 metre long. The front wall of the fire- 
place has two doors for cleaning the grate, and two flues 
for carrying off the products of combustion. Two arches 
are thrown across the combustion chamber about 0'3 
metre (12 inches) above the fire bars, leaving openings at 


the sides 0'2 to 0'3 metre (8 to 12 inches) wide between the 
arches and the walls of the chamber, for the descent of 
the fuel. The upper surface of these arches is constructed 
roof-shaped, the ridge running parallel with the fire bars. 
Iron bars are also stretched across the chamber, to obstruct 
the fall of the fuel and prevent it from settling down in a 
dense mass. The wet tan, thrown into the furnace, falls 
first on the upper surface of these arches, where it dries as 
it slides down towards the sides, and having passed through 
the side openings, it is delivered upon the fire grate in a 
perfectly dry condition. It there forms a layer 0'08 to O'l 
metre (3 to 4 inches) thick, which burns freely. There is 
no necessity for keeping a cover on the combustion 
chamber whilst the furnace is in use, but when work 
ceases in the evening the top is closed by cast-iron plates. 
The chimney, fire-doors, and ash-pit are likewise closed; 
by this means a -dull red heat is maintained during the 
night, and when fresh fuel is added combustion recom- 
mences immediately. In cases where the substance to be 
burnt contains other volatile products than water, the ash- 
pit may be closed and the air for the combustion obliged 
to pass through the mass of fuel from above downwards. 
In this case, however, the water-vapour which is drawn 
into the flues with the products of combustion reduces the 
heating effect considerably, and, before making any altera- 
tion in the original arrangement, it is desirable to con- 
sider which is the better mode of burning a material con- 
taining a determined proportion of moisture. 


The furnaces shown in Figs. 6 and 7 are intended for 
dye-woods, tan, and sawdust ; if the wet materials arc well 
pressed before use they can generally be employed as the 
sole fuel, without any admixture of coal. 



Fig. 6 shows the fireplace of a boiler with a single tube : 
the grate rises at both sides to meet the channels for the 

FIG. 6. Furnace for Burning Sawdust or Tan for Heating a Singh 
tube Boiler. 

FIG. 7. Furnace for Burning Sawdust or Tan for Heating a Two-tube 


descent of the fuel. These channels widen, out to larg< 
reservoirs, which can be closed by a cover. 


The fuel is charged into the reservoirs and is conducted 
to the grate through the side channels, for which purpose 
doors are constructed in the front wall of the fire chamber. 

Fig. 7 shows a similar construction for a two-tube boiler. 
In this case the fire grate is divided by a partition wall 
which serves both to strengthen the structure and to 
regulate the distribution of the fuel over the grate area, 
which in this case is wider. These furnaces are adapted 

FIG. 8. Sawdust and Tan Furnace, with Step Grate and Truck for 
Conveyance of Fuel. 

either to steam boilers with internal flues, or to boilers 
which are heated externally. In the latter case the fire- 
place must extend 1J to 2 metres (5 to 6J feet) in front of 
the boiler. 

The furnace shown in Fig. 8 is fitted with a step grate, 
such as is used in large works where a number of boilers 
are arranged side by side. The fuel is brought in trucks 



running on tram lines, and is shot from these into a hopper 

from which it can be brought down to the grate by a rake. 

This method of feeding, as well as the arrangements for 

FIG. 9. Sawdust and Tan Furnace with Step Grate and Feed Plate. 

FIG. 10. Sawdust and Tan Furnace with Step Grate and Fuel Hopper. 

the removal of the ash, are very suitable for large estab- 
lishments, but for small works, where there are only one or 
two boilers, it would not pay for the cost of construction. 



The step grate may, however, be used in a simpler form 
of furnace, the fuel hopper being replaced by a feed plate, 
from which the fuel is from time to time thrust with a 
hoe towards the grate. 

In Fig. 11 a construction is shown in which the fuel 
is thrown into a shaft, at the bottom of which it is carried 
forward by an endless screw to the fire grate. This is a 
very costly construction, on account of the mechanical 

FIG. 11. Sawdust and Tan Furnace with Step Grate and Charging Slot. 

complication and consumption of power, and will not as a 
rule prove remunerative. 

Respecting the above forms of furnace, the following 
remarks may be made : In most furnaces the condition 
should be fulfilled that fresh fuel should be placed on the 
grate only at such a rate as is required to replace that 
which burns away. When the fuel is fed to the grate by 
hoppers or shafts this condition is not fulfilled, for in the 
narrow parts of these hoppers or shafts the material is 


found to become tightly packed, in the way indicated by 
the dotted lines a in Figs. 6 and 7. 

Unless the stoker is constantly stirring the fuel, it burns 
down on the bars and leaves free spaces through which an 
excess of air enters and cools the gases. The steam pressure 
falls; the stoker is obliged to drive the fire, and usually 
throws a large quantity of fuel on the grate. Then, in 
consequence of the layer of fuel on the bars being too thick, 
the air supply is deficient, combustion is imperfect and 
smoke is produced. These disadvantageous conditions are 
repeated at longer or shorter intervals, according to the 
care bestowed on the stoking : in addition, cold air obtains 
entrance to the fireplace whenever the fire-doors are opened 
for the purpose of poking the fuel. 

In the earlier forms of furnace mentioned above, the 
rate of addition of fresh fuel is entirely dependent on the 
.greater or less attention which the stoker gives to the work. 
Every time fresh fuel is thrown on, it lowers the tempera- 
ture, and the admission of cold air when the fire-door is 
opened has the same effect. However careful the stoker 
may be it is impossible for him to keep the fire grate 
covered with an equally thick layer of burning fuel all 
over, or to avoid smothering the burning material by the 
addition of the fresh fuel, or the admission of either too 
much or too little air. 

The arrangement in Fig. 11 is designed to provide for 
an automatic supply of fresh fuel, independent of the 
stoker, but it does not altogether avoid the above defects. 
The supply of fuel by the action of the screws is only 
regular if the material itself is perfectly uniform. With a 
material of irregular coarseness there is a liability to the 
formation of open spaces on the fire grate, and the con- 
sumption of steam is never so regular that the supply of 
fuel to the grate will exactly keep pace with it; hence, at 


times, the air supply is either in excess or deficiency. The 
arrangement is likewise costly and complicated. 

None of these arrangements supplies the combustible 
material exactly at the rate at which it burns away, and 
this leads to a waste of fuel, the escape of the invisible gas 
carbon monoxide by the chimney being as much a loss of 
combustible matter as the production of smoke and soot, 
and on the other hand, when the air supply is in excess, the 
draught takes place principally through the uncovered 
places in the fire grate, whilst the thicker layer of fuel 
at other spots will be in a comparatively sluggish state of 


The principle of this furnace is the establishment of the 
correct proportion between fuel and air supply, and the 
intimate admixture of the fire-gases in the combustion 
chamber. The former object is attained by an automatic 
conveyance of the fuel to the grate, the latter by appro- 
priate subdivision of the gas currents in the combustion 
chamber. By this means a more complete utilisation of 
the combustible material is attained, and the formation of 
smoke and carbon monoxide, if not altogether prevented, 
is reduced to a minimum. 

The arrangement of the individual portions of the 
furnace aims at fulfilling this fundamental condition. The 
grate, which consists of several portions, and is laid with a 
certain slope, receives the fuel from a reservoir, and so 
distributes the layer of burning material that the air 
obtains proper access to it. The fuel reservoir, which is 
placed at the upper part of the fire grate, is so constructed 
that neither in the reservoir nor at the outlet from it to 
the fire grate can the fuel become packed. On the con- 


trary, it allows the fuel to fall gradually on the grate by 
its own weight as fast as it burns away. 

The fireplace is surrounded on four sides by brick walls at 
definite distances apart, with openings so arranged that the 
gas currents are subdivided and intimately mixed, thus 
ensuring the complete combustion of the hydrocarbons and 
carbon monoxide evolved from the layer of fuel. 

The fuel reservoir is replenished from time to time to 
prevent the amount of burning material on the grate from 
undergoing diminution; the layer of fuel on the sloping 
face of the grate is in a full state of combustion over the 
lower two-thirds of the grate area, whilst at the upper part 
water-vapour and combustible gases are escaping. The 
combustion is a gradual one, the drying of the material 
takes place in the reservoir, and at the outlet from the 
reservoir to the grate, the most intense combustion in the 
middle, and the complete combustion at the lower part of 
the grate. 

The principal advantages of Bottger's furnace are as 
follows : 

1. The proportion between combustible matter and air 
supply is the most favourable one, and the mixture of the 
gases is thorough. 

2. The evolution of smoke and carbon monoxide, if not 
completely avoided, is reduced to a minimum, and con- 
sequently the utilisation of the combustible matter is on 
the average 30 to 45 per cent, higher than in other cases. 

3. The supply of the fuel, however large the amount 
required, is simple and appropriate, and the labour small. 

4. The stoker has a complete view of the fireplace, and 
in most cases the fire maintains itself when unattended 
for more than 24 hours, so that there is no need to relight 
it in the morning. 

5. The fire requires less frequent stirring, and less 
chimney draught as a rule than other arrangements. 


6. The parts exposed to the action of the fire suffer less 
injury, and the fire-brick lining is of a simple character, 
consisting of smooth walls and arches which are easily con- 


An improvement in the utilisation of sawdust may be 
effected by heating it in an atmosphere of certain gases, 
and the experiments which have been made in this direc- 
tion have given good results as regards both the products 
of distillation and their yield, and the quality of the char- 
coal obtained. The gas employed may be either that de- 
rived from the sawdust itself or ordinary coal gas intro- 
duced into the retort from outside. 

In experiments made with coal gas, the gas was passed 
into the retort at a certain pressure, and had the effect 
of removing the products of distillation more rapidly from 
the region of high temperature. The results obtained 
were favourable, but the decomposition of the products of 
distillation could only be partially prevented. In conse- 
quence of this, the method was altered so that the heat, 
instead of being applied to the material after passing 
through the walls of the containing retort, was generated 
inside in direct contact with the substance to be distilled. 
All the gases employed in this manner must be completely 
free from oxygen, in order that no loss of the valuable pro- 
ducts of distillation may take place. 

One of the older arrangements is shown in Figs. 12 
and 13. The furnace is constructed of slag-bricks with 
an inner fire-brick lining, and the heat obtained from 
it is employed in roasting the ore in a copper refinery. 
The first gas generators constructed were furnished 
with charging cylinders of 0'89 metre (3 feet) dia- 
meter, since the consolidation of the fuel by the pro- 



duction of tar was feared, but with these a loss of gas 
was found to be unavoidable. At first the cylinders 
were closed by cast-iron covers, but small explosions were 
apt to occur in the gas tubes, especially with an excess of 
air in the refining furnace. For an equable distribution of 
the fuel in the generator a sheet-iron tube, a, is fixed with 
screws to the cover. A layer of the combustible material 
1'5 to 1'8' metre thick (5 to 6 feet) must be kept on the 

FIG. 12. Sawdust Furnace for Gas Producers (Section through the 
Furnace and the Condensers). 

grate; the height of the layer can be regulated by means 
of the rod, o x. The air-blast enters the furnace through 
a cast-iron pipe, z, which is covered with a cap to prevent 
the ash from falling into the air tube, and to subdivide the 
blast; above this is a pyramidal grate consisting of eight 
segments, on which the fuel rests. For cleaning the grate 
there 'are four openingis, c, c, opposite one to another. The 
air pressure employed is generally 19 millimetres (f inch) ; 
for sawdust it should not exceed 13 mm. (J inch). The 



older patterns, which had no grate, and in which the air- 
blast was introduced through three tuyeres, did not prove 
satisfactory. The grate is made of cast-iron; when saw- 
dust is used alone the spaces between the upper edges of 
the fire bars should be 15 mm. (about f inch) wide; for a 
mixture of sawdust and peat 31 mm. (1J inch); and for 
peat alone 43 mm. (1^ inch). Above one of the openings, 
c, c, there is another opening which serves for withdrawing 
the fuel when the work is discontinued. 

The openings are so constructed that the fire bars can 
be inserted or removed through them. It sometimes 

FIG. 13. Sawdust Furnace for Gas Producers (Ground Plan of the 
Furnace and Condensers). 

happens, especially when small peat is being used, that 
soot collects in the channel d which connects the generator 
with the condenser ; for the removal of this soot an opening 
in the wall of the gas generator is made use of. This 
opening is closed by a plate built into the brickwork, and 
pierced by a hole through which the shaft of a steel 
scraper, which fits the hole, passes. The scraper, when not 
in use, is drawn back into a recess in the wall. Through 
d the gases pass to the condenser, A, B. This consists of 
two cylindrical vessels closed at both ends, and containing 
tubes through which the gases are conducted, whilst cold 
water, introduced at the bottom and allowed to flow out at 


the top, circulates round them. The cylinders are con- 
structed of sheet-iron 3'3 mm. (-J inch) thick, the brass 
tubes are 2 '97 metres (9 feet 9 inches) long and 48 mm. (1J 
inch) in diameter. The water-supply pipe is 72 mm. (2| 
inches) in diameter. Usually only one condenser is used for 
each generator. When the gases have passed through the 
condensers they are conducted by pipes to the furnace. 
The water and tar condensed from the gas collect in the 
tank, D. This tank is constructed of two thicknesses of 
slag-bricks and one of fire-bricks, with intermediate layers 
of a mixture of tar and cement. The tar flows over into 
store vessels through the pipe g, whilst the water runs 
away by a gutter after it has been completely freed from 
tar by passing through a straw filter. 

A generator consuming 225 hectolitres (620 bushels) 
of sawdust daily yields about 20 hectolitres (440 gallons) 
of gas-water. When the blast is on, the temperature of the 
gas increases considerably ; to protect the brass tubes a jet 
of water is introduced through the roof of the vertical 
channel which conveys the gas from the generator to the 
condensers. The water pipe is inserted through a hole 
in the valve into which an iron plug is fitted. For dis- 
tributing the water a baffle plate is fixed opposite the jet. 
The tubes in the condenser very rarely get choked, but if 
this should occur the supply of cold water is diminished so 
that the gases may pass through the pipes warm, and the 
stoppage is soon cleared away. The apparatus is liable to 
the occurrence of small explosions, but these are generally 
occasioned by defective working of the generator. If the 
sawdust is too damp it often causes explosions; cavities 
are formed during the sinking of the charge, and in these 
air and gas become mixed. To provide against damage 
from these explosions, valves are placed in the roof opposite 
to the gas canal. These valves open when an explosion 
occurs and immediately close again. They are constructed 


of cast-iron, and are so arranged <that they cannot be lifted 
beyond a right angle, and therefore close again by their 
own weight. The air-supply pipe is fitted with a safety- 
valve, as close to the gas generator as possible, which, in 
the event of a stoppage of the blowing apparatus, closes 
the air pipe and prevents it from getting filled with the 
combustible gas. Such stoppages are very apt to occur 
from the driving-belt slipping from the pulley of the 
blowing apparatus. This valve consists of a wooden frame 
on which leather is stretched ; it is hung by a leather strap 
in a wooden valve-box, and the weight of the frame is such 
that it is lifted by the air pressure : if on the other hand 
a back pressure should occur, the frame falls and closes the 
air pipe. The top of the valve-box is formed of a stout 
sheet of paper glued down, and above this a wooden cover. 
These form a safety-valve in the event of gas obtaining 
admission to the tube between the generator and the valve. 
The combustible material employed in the generator may 
be sawdust, mixed with small coal, peat, etc. If it is 
desired to make a change in the material, it is only 
necessary to introduce the appropriate fire bars, and to 
increase the strength of the blast when the spaces between 
the bars are smaller. Each gas generator using sawdust 
yields 165 litres (36 J gallons) of tar daily. A special 
arrangement is employed for collecting the gases from 
several generators in a single main. It consists, for each 
of the four generators, of rectangular oast-iron chests of 
different sizes. The medium-sized one receives the gases 
from the smaller ones and delivers them to the hydraulic 
main : all the small chests are fitted with conical valves. 


In this furnace an air-blast is used both to supply 
the air required for the combustion and to generate gas. 


and a condenser is introduced to cool the gases and the 
water-vapour which they contain. The combustible 
gases produced in a gas generator fed with sawdust, 
and with an air-blast supplied below the fire grate, are 
conveyed by a syphon tube into a coffer-shaped condenser, 
through the cover of which several fine jets of water are 
introduced. The jets of water impinge upon pointed 
pieces of metal placed opposite to the openings, and the 
water being thus scattered in all directions cools and con- 
denses the vapours. In order that the condensation may 
be as perfect as possible, the gases, after leaving tne con- 
denser, pass upwards through a channel filled with iron 
lattice-work over which water is flowing, and thence into 
a valve-box from which they are distributed, through 
Siemens' regenerators, to the furnaces where they are to 
be used. When used to heat puddling furnaces each cwt. 
(Centner) of bar iron consumes a quantity of sawdust 
equivalent to 0'72 ton of wood-charcoal (2 tons of sawdust 
are equal to | of a ton of wood-charcoal). 

As the result of various trials the Lundin gas producer 
does not seem to be particularly advantageous in the iron 
manufacture. This is due to the fact that a producer 
worked with a blast furnishes more carbon dioxide and less 
monoxide than one worked with a chimney draught, and 
that in the condenser, not merely water but also tar is 
condensed, which otherwise would have added to the heat 
effect. For the complete condensation of the tar very 
large quantities of water are required (8640 cubic feet in 
24 hours). 

It is only as a sawdust furnace that the Lundin 
apparatus has any value, this material being obtained in 
enormous quantities in Sweden. 

The assertion that the system of condensing the tar, 
which would else have interfered with the working of the 
valves, has alone rendered the regenerative system pos- 



sible in Sweden, is not correct, since regenerative furnaces 
constructed on other patterns are in full and uninterrupted 

The introduction of water je.ts is a new and peculiar 
feature of the Lundin condenser. With the exception of 
the suitability of Lundin's apparatus for the combustion of 
sawdust, a very restricted use of that system is to be 
expected in countries where the same conditions do not 
obtain as in Sweden, since it would be only an expensive 
way of wasting any fuel of greater value. 

From another source we have the following report: 

" The use of this furnace deserves to spread rapidly; it 
permits the direct use of undried, comminuted, and 
sulphurous fuel; a considerable economy of combustible 
matter, diminished production of scoria, a good quality of 
iron, and great durability. 

" At Munksors in Warmland, a furnace worked with saw- 
dust turns out 50 tons of iron in 6 days, with a consump- 
tion of 11 to 14 cubic feet of sawdust per cwt. of finished 
iron, and a loss of 11 to 12 per cent. : compared with 
former times, the output has doubled, the expenditure of 
fuel diminished by i, and the loss of iron by 1 per cent." 



This furnace avoids the usual inconveniences of those 
which are fed with fuel, especially tan, sawdust, etc., 
through hoppers in the crown of the arch. The pulveru- 
lent material, falling on a horizontal grate, forms a heap 
which becomes consolidated by its own weight. Under 
these circumstances the air penetrates with difficulty into 
the interior of the heap and the combustion is incomplete. 

The system of pyramidal grates is applicable to all 
furnaces in which the fuel is introduced through hoppers. 



The grate, which is of pyramidal form, is placed above 
the ordinary fire bars, and serves as the support for the 
pulverulent fuel which falls on its inclined faces from the 
charging hopper above it. By this means a more uniform 

FIG. 14. Godillot's Pyramidal Fire Grate (Longitudinal Section). 

layer of fuel is formed, the air penetrates the whole mass 
more readily, and the combustion is greatly improved. 
Each of the charging orifices in the crown of the furnace 
is fitted with a tube, which is somewhat contracted towards 

FIG. 15. Godillot's Pyramidal Fire Grate (Horizontal Section). 

the upper part. This tube forms a sort of fuel-reservoir, 
which gives a continuous, automatic feed to the fire grate. 
The arrangement and mode of working the pyramidal 
grate are such that the stoker, without admitting cold air 
into the body of the furnace, is able to ascertain the state 



of the fire, and to remove ash and clinker from the hori- 
zontal grate by means of a poker. 

Fig. 14 shows a longitudinal section, Fig. 15 a hori- 
zontal section, and Fig. 16 a transverse section of the 
furnace with the pyramidal grate; Fig. 17 the ground plan 
of one of the pyramids, and Fig. 18 a section of the same, 
as adapted to a furnace for burning tan, sawdust, etc. 

FIG. 16. Godillot's Pyramidal Fire Grate (Transverse Section). 

The horizontal grate is partly covered by the pyramid. 
This pyramid has a number of faces, B, B, B, each of which 
constitutes an inclined grate,. It is slightly elevated above 
the horizontal grate A, so that a poker can be inserted 
between the two for cleaning the fire bars. 

For this purpose a cast-iron trunk c (Fig. 16) runs from 
the door D of the fireplace to the horizontal grate in 
the form of a gutter. The horizontal grate of the furnace 


is interrupted below the pyramidal grate B and the gutter 
c, the inner edge of which rests on it, and allows the ash 
to collect below the grate in the form of heaps. By this 

FIG. 17. Plan of one of Godillot's Pyramidal Fire Grates. 

arrangement the fuel slides down the inclined faces B, 
since these are inclined at a greater angle than the angle 
of repose of the material, that is to say, the inclination 

FIG. 18. Section of one of Godillot's Fire Grates. 

which the sides of a heap of the substance would naturally 
assume. It is therefore never necessary to clean the bars 
of the pyramidal grate B. Ash and clinker collect on the 
horizontal grate A. The pyramids may be constructed 


with a greater or smaller number of faces than are shown 
in Figs. 17 and 18. In these figures six faces are shown 
each having the form of a triangle. The triangles are held 
together at their bases by screw bolts, but are loose at 
their apices, so that they may be able to expand. The 
faces may also be of trapezoid shape, and then form a 
truncated pyramid, or the grate may be conical and made 
in one piece. The form of the grate is to some extent 
dependent on the form and situation of the hoppers, which 
may be cylindrical, square, etc. 

The dry or damp fuel is charged in through the openings 
G, G, in the crown, H, of the furnace (Fig. 14), but to pro- 
duce an automatic and uninterrupted feed, a tube, i, may 
be carried up from each of the openings, contracting some- 
what towards the upper part, and serving as a reservoir 
for fuel. 


The apparatus employed in Sweden for converting saw- 
dust into wood-charcoal consists of rectangular chambers 
10 metres (33 feet) long and 6'5 metres (21 feet 4 inches) 
wide below, but narrowed to 4 metres in width (13 feet) 
at the spring of the semicircular roof, and 6 metres (19 feet 
8 inches) high. The side walls have a slight slope in- 
wards. The bottom is flat except close to the side walls 
where it slopes down to a cast-iron pipe which serves for 
carrying off the gases and condensable products. The 
former escape through a vertical tube of sheet brass, whilst 
the latter form a tar deposit on the floor. A rectangular 
hearth, constructed of fire-bricks, covers half the width of 
the bottom of the chamber ; this is in communication with 
five narrower pipes, which lead to the ends and sides of 
the chamber, and by which air is introduced. These pipes 
rest on cone-shaped iron supports about 9 inches high. 


The crown of the furnace is protected against rain by a 
light roof. 

The sawdust and other waste from the saw-mills are 
brought by tram lines, and laid down to dry in the air 
until wanted for use. The charging takes place through 
doors, of which there is one at each end of the chamber. 
One of these doors, which is flush with the bottom of the 
chamber, measures 175 by 145 centimetres (5 feet 9 inches 
by 4 feet 9 inches), the other is at the base of the arch 
and measures 150 by 100 cm. (59 by 39J inches). The 
lower layer of the charge is formed of the larger waste 
pieces of wood for a height of about 30 cm. (1 foot) ; upon 
these the other materials are so placed that the length of 
the pieces runs parallel to the axis of the chamber. An 
experiment in which some of the layers were built up of 
pieces laid crosswise did not give a favourable result, but 
on the contrary occasioned a higher cost for labour. 

As soon as the whole charge of wood, which amounts to 
470 cubic metres (16,600 cubic feet), has been introduced, 
which can be done in 3 to 4 days by 10 men, the lower 
doors are closed and secured with bolts and the fire is lit. 
The upper doors are left open until the third day to furnish 
a free outlet for the water-vapour given off from the damp 
wood. A dark-coloured vapour is evolved up to the middle 
of the sixth day, after which it generally becomes bluish. 
The combustion is regulated according to the appearance 
of the vapour : should the combustion become too vigorous 
the pipes are partially closed, or the fire is damped in any 
convenient manner. In order to avoid exposing the 
building to internal pressure by thus closing the outlets, 
the side walls have, passing through them near the upper 
part, narrow tubes which are left permanently open. 
According to the dryness of the wood the carbonisation 
may take from 10 to 18 days; 16 days are required for 
cooling down, and the chamber can be emptied by two 


men in a day and a half. After any repairs required have 
been executed a new charge is immediately introduced. 

The annual output of one of these carbonisers amounts 
to 800 lasts (60,800 cubic feet) of charcoal and 160 
gallons of tar. The loss on carbonisation varies according 
to the dryness of the wood, and may on the average be put 
at 100 cubic feet, so that the quantity of the charcoal 
amounts to 85 to 90 lasts, or 6460 to 6840 cubic feet, from 
which it appears that the yield is 58 to 62 per cent, of the 
wood employed.* 

The charcoal obtained from sawdust is less suitable for 
the blast furnace (Hochofen) than for the refinery (Frisch- 
feuer), especially when it is mixed with ordinary wood- 
charcoal. The carbonising chambers described above have 
the advantage over the Meiler (mounds or heaps covered 
with turf, extensively used in the German charcoal-pro- 
ducing districts) of a smaller cost for labour, and a cleaner 
charcoal; besides which the work is independent of the 
weather and requires less skill on the part of the workmen. 


One of the principal advantages of this furnace is that 
the grate can never become choked and cause irregularity 
in the combustion; moreover, very fine sawdust can easily 
be burnt in this furnace without addition of any coarser 
material. It is used as a source of heat for a bench of two 
retorts. The fire is regulated by sliding dampers, and can 
at will be wholly shut off from either of the retorts. The 
products are charcoal, tar, crude tar-oils, and calcium 

*The mode of calculation employed is unintelligible, but the 
statement of yield must relate to bulk, not to weight, the usual yield 
of charcoal from wood being about 25 per cent, by weight. (Note 



acetate. ^ The retorts are set in pairs, and with a slight 
fall towards the back. They have at the back two holes 
at opposite sides of the diameter. The lower hole is used 
both for rotating the (cylindrical) retort when its lower 
side is burnt out, and also in the early stages of the dis- 
tillation for drawing off water, and in the latter stages 

FIG. 19. Walter's Sawdust Furnace and Stills (Vertical Section). 

pitch; the upper hole serves for the escape of gases and 
vapours. Very wide tubes are employed for carrying off 
the products of distillation. They rise perpendicularly 
to a height of 3 metres (10 feet), and are then carried with 
a slope of about 10 to the condensing apparatus, which is 
placed at a distance of 5 to 6 metres (16 to 19 feet). As 



the vapours have so long a course through these pipes, the 
more readily condensable vapours liquefy in them and 
flow back towards the retorts, whilst only the acetic acid 
vapours, and the more volatile empyreumatic oils pass on 
to the condensers and are collected as pyroligneous acid 
and crude tar-oil. In this way two tarry products are 

FIG. 20. Walter's Sawdust Furnace (Vertical Section through the 

line c D). 

obtained, a thick black tar, and a dark-coloured but fluid 
tar-oil resembling Finland tar in appearance, which is very 
much in demand for tarring ships, since it readily soaks 
into the wood and acts as a powerful preservative. 

Fig. 19 shows a vertical section of the furnace through 
the line E, F, of Fig. 20 ; Fig. 20 a transverse section 



through c, D, of Fig. 19, and Fig. 21 a section along the 
line A, B, of Fig. 19. 

Through the charging hopper a, which opens above in 
the floor of the factory, so that the material can readily 
be brought to it, the sawdust is charged from time to time 
into the furnace, a fire having first been lighted with some 
other material. The sawdust slides gradually down the 
sloping floor of the fire chamber towards the grate c in 

FIG. 21. Walter's Sawdust Furnace (Oblique Section through the 

line A B). 

such quantity as to supply the place of that which burns 
away : the amount thrown into the chamber should never 
be so large that the grate becomes completely covered. 
The heap of sawdust burns at the surface, and all that is 
necessary is that from time to time a poker should be 
inserted through the door h to spread it about. If the 
grate should momentarily get choked, which however can 
only happen if too much sawdust has been thrown in, or if 


it is desired to admit more air, the air channels, d, d, d, d, 
ait both sides of the furnace, may be opened. The ash falls 
partly through the grate, partly also into the channels, d, d, 
which therefore must be so arranged as to be easily cleared. 
Through the neck e of the combustion chamber the flame 
passes into the flues, /", f, /*, and is then distributed to the 
retorts. By means of the dampers, Z, /, I (Fig. 19), in the 
flues behind the retorts, the flame can be regulated or 
shut off from any of the pairs of retorts as required. 

A chimney-stack with a good draught is essential. The 
uncondensable gas which is evolved from the retorts, 
together with the vapours of acetic acid and tar, is returned 
from the condenser to the fire by the pipe, k, and contri- 
butes materially to the heating effect. 

This sawdust furnace differs from others mainly in the 
fact that, with the exception of the small quantity lying 
on the grate, the heap of sawdust burns only at its upper 
surface, so that the obstructions which in other forms of 
furnace are caused by the subsidence of the mass of fuel 
with which the furnace is filled cannot occur here. 


This furnace is designed for burning, without previous 
drying, the wet and finely subdivided wood-fibre which 
remains after the extraction of the dye from dye-woods ; 
it is also well adapted for the utilisation of damp sawdust. 

Fig. 22 shows the fireplace as arranged for heating a 
boiler. Fig. 23 is a transverse section through the line 
a, b. 

The upper space, A, open at the top and enclosed by a 
wall, serves for the reception of the combustible material, 
which is constantly being thrown into it and piled up in 
a heap. In the floor of the enclosure. A, there is a row 


of vertical apertures, B, B, B, under each of which an 
angle-iron girder, c, with a right-angled, or obtuse-angled 
edge placed upwards, is situated. The spaces between the 
lower edges of the girders are filled with fire bars, e, e, of 
the usual construction. The space H, below c and e, is 

FIG. 22. Niederberger's Furnace (Transverse Section). 

the ash-pit. In front, before the ends of the fire bars, 
there are doors or valves, through which the lower layer of 
the refuse wood resting on c and e can be set on fire ; the 
doors are tightly closed after this has been done. In the 
space above the grates an energetic evolution of gas and 

FIG. 23. Niederberger's Furnace (Longitudinal Section). 

smoke is produced from the combustible matter, which, 
as the lower layers burn away, sinks down on the sloping 
faces of the girders. The gases pass through the aperture, 
p, into the chamber, R, into which a separate supply of 
atmospheric air is admitted through tubes, d, which pass 


through the brickwork of which the bottom of the en- 
closure, A, is constructed, and which can be closed by either 
slides or valves so as to regulate the supply of air to the 
chamber, R. In this chamber the combustion of the gases 
takes place, and the flame is then conducted into the flues 
where its heating effect is to be expended. The wood as 
it descends from the enclosure, A, dries completely before 
it reaches the grates, e, and is regularly delivered to the 
fire grates by the sloping surfaces of the girders, c, so that 
the fire requires no attention as long as a supply of wood 
is kept up in the enclosure, A. 


The apparatus consists in general of a steam super- 
heater (with the requisite boiler for producing the steam), 
of a cast-iron cylinder for the carbonisation of the material, 
of the ammonia apparatus, hydraulic main, cooler, and lead 
vessels, and the apparatus for the illuminating gas, such 
as the gas purifier, holder, and tank. The carbonisation 
cylinder is filled from above from a charging reservoir of 
the same capacity, and it is emptied below into sheet-iron 
vessels of similar size. The carbonisation is effected in 
the cylinder by means of superheated steam of 750 to 
800 C., whilst at the same time the cylinder is surrounded 
through its whole length by the waste flue gases from the 
superheater, before these pass off by the chimney. A 
furnace with four cylinders will require 16 kilos. (35 Ibs.) 
of coal and 50 kilos. (110 Ibs.) of steam per hour. 

The superheated steam, which is admitted direct to the 
cylinders and passes thence through the hydraulic main 
and the cooler, raises the pressure in the cylinders and 
sweeps out the gases and vapours through the sulphuric 
acid absorbers and gas purifiers into the gas holders. 



The working of the apparatus is free from danger, pro- 
duces no nuisance, and is in the highest degree simple and 

The wear of the gas and ammonia apparatus is so small 
that its durability for many years without repairs may be 

FIG. 24. Zwillinger's Apparatus for Carbonising Sawdust (Vertical 
Longitudinal Section). 

counted on with certainty. The carbonising cylinder and 
the superheater, when worked, continuously, will run for at 
least three years without requiring any expenditure for 

In order to maintain a uniform heat in the superheater 
furnace, and to ensure complete combustion of the fuel, 



the fireplace is so built, by giving a batter to the side walls, 
a, a, lowering the fire bars, and introducing a vertical fire- 
brick partition wall, c, that two fireplaces, D, D, are formed, 
each of which is furnished with a fire-door, b (Figs. 24 
and 25). 

For regulating the air supply, each ash-pit, E, is fitted 
with an adjustable door, c. 

In the superheating chamber, A, straight tubes, e, e, are 
supported on dwarf walls, /', f, and are connected by 
elbows, d, d, which project beyond the dwarf walls on 

FIG. 25. Zwillinger's Apparatus for Carbonising Sawdust (Hori- 
zontal Section). 

both sides into narrow channels, f, g, which communicate 
with the fireplace by pigeon-holes. The superheating 
chamber is not arched over, but covered with flat plates, 
which are supported by the walls, f, f. The steam enters 
at g, traverses the pipes, e, e, which are kept at a dark red 
heat, and is then carried by the pipe, h, in a highly super- 
heated condition, to the carbonisers, G, G, G. The cylinder, 
G, which holds about 150 to 200 kilos. (330 to 440 Ibs.) of 
the material to be carbonised, is constructed of cast-iron, 
and is furnished with covers, I and T, at the top and bottom 
respectively, for filling and emptying it. Each cylinder 


contains a pipe, taken off from the steam pipe, h, which is 
pierced with small holes throughout its entire length, and 
through which the superheated steam is passed into the 
substance to be carbonised. The carbonisation cylinders, 
which are most advantageously 0'3 metre (12 inches) in 
diameter, may either be placed vertically or horizontally, 
and are so set in the brickwork that a flue is left all round 
them, which communicates by pigeon-holes with the super- 
heating furnace, A. 

FIG. 26. Zwillinger's Apparatus for Carbonising Sawdust (Trans- 
verse Section through the Superheater Furnace). 

The heated gases issuing from the fireplace, D, are caused 
to pass through the superheating chamber, A, and through 
the channel, k, into the flue, i, which surrounds the 
cylinder, G, by which means the steam pipes, cylinder, and 
surrounding brickwork are all raised to a high tempera- 
ture ; the products of combustion then pass to the chimney 
by the flue, p, p'. The containing walls must b.e thick 
enough to prevent any material loss of heait by radiation, 


and the heat of the gases is so far absorbed that they 
escape into the chimney at a temperature of about 160 C. 
The gases and vapours evolved during the carbonisation 
are carried by the pipe, m, m', into a hydraulic main, H, 
from which they pass by the pipe, n, to the cooler. A 
syphon tube, o, branching off from the hydraulic main, 
keeps the ammonia* water in the main always at a con- 
stant level. To prevent the iron pipes of the super- 
heating apparatus, and the cast-iron carbonisation cylinder 
from being burnt out by the oxygen in the hot gases, these 
are covered with a fire-resisting packing, which not only 
resists high temperatures but adheres firmly to the iron, 
does not crack, melt, or peel off. This is composed of 100 
parts of fire-clay, 20 parts of common clay, 40 parts of 
powdered bone-ash, and 2 parts of cow-hair or barley 
chaff. The fire-clay and the bone-ash must be dried and 
powdered, and then mixed with enough water to form a 
uniform plastic dough of the consistence of glazier's putty, 
into which the cow-hair or the barley chaff is then 
thoroughly kneaded. With this composition the super- 
heater tubes are covered to the thickness of 1 cm. ( 
inch), and the carbonisation cylinder with 3 cm. (1J inch). 
They are allowed to dry for 24 hours, and may then, at 
once and without risk, be exposed to a red heat of 1000 
C. Carbonisation apparatus, similar to the above, may 
advantageously be used for the production of coal gas with 
recovery of the by-products. 

The carbonisation apparatus serves for the production 
of charcoal from the waste materials mentioned above, 
and for the recovery of the products of distillation, such 
being sulphate of ammonia, pyroligneous acid, acetate of 

* There seems to be some confusion of thought here ; the distillation 
of wood yields but little ammonia, the chief product, besides tar, 
being acetic acid. (TRANS.) 



lime, acetic acid, illuminating gas, tar, Oleum cornu cervi, 
etc.; it can be employed for the utilisation of exhausted 
dye-woods, tan, sawdust, fir cones, horse chestnuts, fruit 
stones, nut and almond shells, etc., and performs the car- 
bonisation with superheated steam of a temperature of 
750 to 8000 c. 

The yield obtained from 100 parts of sawdust, exhausted 
dye-wood, or spent tan, is as follows: 

Charcoal . . ... . 21 to 23 per cent. 

Tar . . . ... . 7'9 8-6 ,, 

Pyroligneous acid (5 per cent, of 

wood-spirit and 6 per cent, of 

acetic acid) . . . 35 ,, 45 ,, 

Gas . . . . ,' . . . 20 23 

That is, 40 cubic metres (1400 cubic feet) from each charge 
of 100 kilo. (220 Ibs.), requiring 60 to 65 minutes to distil. 

The tar obtained by distillation with superheated steam 
is especially distinguished by the fact that the tar oils 
obtained from it are particularly easy to purify, and yield 
very pure products ; moreover, this method of carbonisation 
gives a larger yield than was the case with any carbonisa- 
tion furnace previously in use. 

The gas may either be employed for illumination, or, 
where there is no demand for such, may be used for raising 
steam in the boiler. 


This apparatus, shown in Fig. 27, consists of three super- 
posed portions, namely, two vessels set in brickwork, and 
a removable reservoir, which is omitted in the figure. 
These three vessels, which can be closed air-tight, are con- 
nected with one another by several tubes, carrying stop- 



cocks. Each vessel is furnished with a stirrer and a 
thermometer. The upper vessel (" Dryer ") is fitted with 

FIG. 27. Fischer's Apparatus for Carbonising Wood. 

a supply pipe for the admission of steam superheated by 
waste heat, or else of dry warm air; the lower vessel (" The 


Carboniser ") is in communication with a vacuum pump. 
The tubes which carry off the gas and volatile products 
from both vessels are closed at their outer ends by 
hydraulic lutes, and at their inner ends with arrangements 
for arresting dust. The " Dryer " is kept at as constant 
a temperature as possible, by the waste heiat from the 
lower vessel, as well as by the combustion of the uncon- 
densable gases obtained during the carbonisation. The 
" Carboniser " is heated by a direct fire or by producer-gas. 
The material to be carbonised is fed into the " Dryer," 
the stirrer of which is kept in motion, and in which a 
constant temperature of about 130 C. is maintained, 
whilst dry steam or heated air is blown in. By their 
direct contact with the wood a rapid drying, and at the 
same time a disintegration of the wood are caused. When 
the drying is complete the contents of the vessel are trans- 
ferred by the stirrer to the " Carboniser," by opening the 
valve between the two vessels. The stirrer of the lower 
vessel is kept running ; the temperature at the time of 
filling will be about 150 C. As soon as the upper vessel 
is empty its communication with the lower is closed, and 
it is recharged with wood, whilst the lower vessel is now 
heated to the carbonisation temperature at such a rate as 
gives the largest yield of crude acetic acid and the smallest 
proportion of uncondensable gases. Whilst the " Carbon- 
iser " is being raised from 150 to the carbonising tempera- 
ture, it is evacuated as completely as possible by the 
attached air pump, after which dry steam, or an inert gas, 
is admitted in place of air until the pressure in the vessel 
is again equal to that of the external atmosphere. The 
carbonisation then goes on in the absence of air, so that a 
partial combustion of the gaseous products of distillation 
is rendered impossible. The result is a higher yield, 
especially of wood-spirit (methyl alcohol), than is the case 
with earlier carbonisers. The volatile products are drawn 



over into a cooler. When the carbonisation is complete 
the stirrer is stopped, and the vessel and its contents are 
allowed to cool down to about 150, when the granular 
wood-charcoal is discharged by the stirrer into a reservoir 
in which it is allowed to get completely cold with exclusion 
of air. The " Carboniser " is then filled afresh. 


The apparatus constructed by Halliday is a continuous 
one, and consists of a cylinder with a feeding screw ; accord- 
ing to the speed with which the screw is driven the wood 

FIG. 28. Halliday's Carbonisation Apparatus. 

can be exposed for a longer or shorter time to the action of 
the heat, and thus a larger yield of acetic acid is obtained 
than is possible from the charcoal mounds (Scheiter 


Meiler). This fact is, however, not to be ascribed to an 
especially favourable construction of the apparatus, but 
exclusively to the form of the raw material. From small 
fragments of wood the distillate is much more rapidly 
evolved than from large billets, and the distillate under- 
goes less decomposition in the apparatus. 100 kilos. 
(220 Ibs.) of sawdust yield 45 to 54 litres (10 to 12 gallons) 
of a liquid containing 4 per cent, of acetic acid, besides 6 
to 8 litres (1 to Ij gallons) of tar. 

The sawdust is thrown into the hopper, B (Fig. 28). 

In this hopper a revolving screw, c, delivers the material 
at an appropriate rate into the horizontal cylinder. The 
latter is heated by the furnace, A. A second screw, D, keeps 
the material in the retort in constant motion, and at the 
same time conveys it gradually to the other end of the 
cylinder. The wood becomes carbonised as it traverses the 
cylinder, so that by the time it reaches the further end 
it has parted with all its volatile products. Two tubes 
are connected with this end of the cylinder. One of these, 
F, descends into an air-tight closed cast-iron receiver, or 
else into a cistern, G, filled with water ; the other, E, carries 
off the products of distillation to the condenser, which con- 
sists of tubes surrounded with cold water. Some dye- 
wood grinders convert all their waste wood into acetic 
ttcid in this manner, with great advantage to themselves. 
The yield of acid is almost as large as that obtained from 
original wood by the ordinary methods. 


This apparatus, which is also especially suited for saw- 
dust, dye-wood, wood-refuse, and tan, consists of a vertical 
sheet-iron cylinder 5'3 metres (17 J feet) high and 1'G 
metre (5J feet) in diameter, and contains a number of 
superposed bell-shaped rings, each 105 to 235 mm. (4 to 9 



inches) high, and forming thus a kind of annulated 
cylinder, the lower end of which has the form of an in- 
verted cone. 

FIG. 29. Distillation Column for Wood-refuse. 

The wood-refuse charged in at the top is heated in the 
annulated cylinder and the evolved vapours rise into the 


inverted bells, whilst the charcoal is removed at intervals 
from the bottom. As the lower part of the cylinder can 
be closed by a valve, the distillation can be carried on 
without intermission by continuously charging the wood 
in at the upper end. The small charcoal obtained from 
the distillation of wood-refuse may be made use of in 
various ways; one part is burnt on suitable grates (step 
grates) to furnish heat in the factory itself ; the remainder, 
especially when sawdust is carbonised, forms, in the finely 
divided condition in which it is obtained, a very service- 
able disinfectant; in Vienna, where charcoal has a high 
value as a fuel, it is well adapted for the manufacture of 


W>aisbein made experiments on the application of pro- 
ducer-gas to the dry distillation of wood. The gas was 
generated in the furnace, A, by the combustion of wood- 
charcoal, and was drawn by the ventilating fan, B, which 
was set in motion by water power, through the retort, c, 
cbntaining the material to be distilled. The operation was 
carried on in the following manner : After the retort was 
charged, the valve, D, and the tap, E (the latter of which 
supplied water to the fan), were opened as far as was 
necessary to bring the temperature of the entering gases 
to 150, the temperature being observed by the thermo- 
meter, t. The hot gases traversed the retort, and arrived 
at the condensing coil, K, loaded with water-vapour. In 
the coil the water-vapour was condensed, and flowed 
through the collector, M, into the receiver, N ; the cooled 
gases were drawn off by the fan. After the wood had 
become dry, the valve, D, and the tap, E, were further 
opened, so that the gas reached the retort at a tempera- 
ture of 280, and the oxygen compounds were collected 


separately. The valve, D, and the tap, E, were then fully 
opened ; the temperature of the gases rose to 430 C., at 
which temperature the tar distilled over. The products 
from birch-wood containing 15 per cent, of hygroscopic 
moisture were 

27 per cent, of water; 

27 ,, of pyroligneous acid, containing 21-8 per cent, of 
acetic acid ; 

1-2 of wood-spirit ; 

31 ,, of charcoal. 

Pine-wood yielded approximately the same proportions, 
but the pyraligneous acid contained only 12'9 per cent, 
of acetic acid. 

FIG. 30. Waisbein's Experimental Apparatus. 

In consequence of these results an experimental plant 
was constructed. In Figs. 31 to 34, A is the gas producer: 
the fuel is introduced through the doors at the top, 
through which also the air necessary for the combustion 
enters. B is the chimney, which, however, is only used 
when lighting the fire, and is shut off by the slide valve, a, 
before beginning the distillation. c is the tube which 
conveys the gas from the producer to the retorts, D, D. 
From the retorts the gases and volatile products issue by 
the tube, K or z, according to whether the valves, i or it, 
are opened. The hot gases, together with the gaseous pro- 


ducts of distillation, carried off by the tube, z, enter the 
cooler, N. Here the products of the distillation condense 
and flow into the receiver, M, whilst the gases pass into the 
vessel, P, and from thence are pumped out by a Korting's 
injector, which is employed to produce the draught 
through the whole system. 

The temperature of the gases entering and leaving the 
retorts was observed by the thermometers, t, t'. It appeared 
at the outset that certain errors in the planning of the 
apparatus had been made. It was discovered (1) that the 

FIG. 31. Waisbein's Distillation Apparatus (Ground Plan). 

temperature of the producer-gas where it entered the 
retorts was too high ; (2) that the cooling surface of the 
condenser was too small, so that the products of the dis- 
tillation could not be sufficiently cooled. Moreover, the 
sectional form of the retorts was not the most suitable. 
In consequence of the disadvantages thus introduced into 
the operation, the temperature of the gas which entered the 
retorts could not be controlled as completely as was desir- 
able. When a temperature of 280 was required the screw 
valve, g, could only be opened a very little way (5 turns out 


FIG. 32. Waisbein's Distillation Apparatus (Section through I., II.). 

FIG. 33. Waisbein's Distillation Apparatus (Section through III., IV.). 


FIG. 34. Waisbein's Distillation Apparatus (Section through V., VI.). 


of 35), and the distillation then occupied an unreasonably 
long time. If the valve was fully opened the distillation 
was finished in 45 to 55 minutes, but the temperature rose 
far above 280, and the resulting distillate was then con- 
taminated with tar. 

The yield obtained in the distillation of birch-wood 
amounted to 95'5 per cent, of the theoretical yield. 


The portable apparatus constructed by Petri was 
designed with the object of burning a pulverulent or 
granular fuel by submitting part of it, which was used for 
kindling the fire, to a preliminary preparation. This pre- 
paration is of such a character that by means of a small 
flame the combustible substance can be instantaneously 
brought into a condition of vigorous combustion, which is 
then transmitted to the whole mass. 

The composition of the powder is such that it absorbs 
the condensable and combustible vapours given off by 
heating the fuel. When the fuel has been sufficiently 
heated, and has given up part of its combustible vapour to 
the powder, becoming at the same time porous, the latter 
has undergone the necessary " preparation," and can be 
removed to the combustion chamber and set on fire. The 
powder then gives up the vapour of all the volatile hydro- 
carbons which it has absorbed with great facility ; these 
take fire, and by means of them the whole of the prepared 
material is gradually brought into a state of combustion, 
the porous condition of the heated wood assisting the 
action of the atmospheric oxygen. 

The powder consists of dry sawdust, or some other finely 
subdivided organic substance such as peat dust, with which 
finely powdered colophony, or some other readily combus- 



tible resin, is mixed. The quantity of colophony added is 
regulated according to the proportion of volatile constitu- 
ents already contained in the fuel, resinous fuels such as 
sawdust requiring a very small amount, coal a larger 
quantity, and peat and coke the largest of all. The 
apparatus for heating the kindling material may either be 
connected directly with the combustion chamber, so that 
the material which has undergone the necessary prepara- 

FIG. 35. Petri's Combustion Apparatus. 

tion may be directly transferred to the fire grate, or it may 
be entirely separate. 

The figures show two forms of the apparatus for the 
separate preparation of the material (Figs. 35 to 41). The 
forms in which the combustion chamber is connected with 
the heating apparatus operate in exactly the same manner 
as those we are now considering. In the apparatus shown 
in Figures 35, 36, 37 (Figs. 38 and 39 show a portable 
apparatus of the same character for locomotives) the fuel 



is introduced mixed with the powder into the space, a. 
The bottom of this space is formed of two four-sided hollow 



FIG. 36. Petri's Combustion Apparatus (Transverse Section). 

FIG. 37. Petri's Combustion Apparatus (Ground Plan). 

prisms, B, open at one side, of which the prismatic faces, 
6, c, d, and the base, a, are constructed of sheet-iron, whilst 
the fourth prismatic face consists of a fire grate, c. 


FIG. 38. Petri's Portable Combustion Apparatus (Transverse Section). 

FIG. 39. Petri's Portable Combustion Apparatus (Ground Plan). 



The prisms, B, can be rotated on a pivot, in, and can be 
kept in a horizontal position by the pulley, n. With these 
two prisms there is connected the vertical chamber, D, the 
walls of which are constructed of grate bars, and which 
opens above into the chimney. The fire which heats up 
the materials is lit in the chamber, F. The fire gases pass 

FIG. 40. Stationary Combustion Apparatus of Petri (Modification). 

through the chamber, D, parting with their heat on the 
way. When the material has been suitably prepared, that 
is to say, heated up, the chains, n, are released and the pre- 
pared material falls into cases, which are then transferred 
to the combustion chamber, emptied out upon the fire 
grate, and their contents set on fire. The forms shown in 



Figs. 38 and 39 can also he adapted to locomotives. In 
this case the material falls directly into the fire-box of the 

The apparatus shown in Figs. 40 and 41 consists of the 
fuel chamber, #, containing a coil filled with calcium 
chloride, and a copper tube, N, heated from the combustion 
chamber, o. The circulating liquid gives up its heat to 
the mixture of fuel and powder. 

After sufficient warming the valve, g, is opened by the 
rod, p, and the prepared material falls into the cases, p. 

FIG. 41. Stationary Combustion Apparatus of Petri (Modification). 

This apparatus is more expensive to construct than that 
first described, but affords a more uniform warming of the 
material and an accurate control of the temperature by 
means of a thermometer dipping into the calcium chloride 


The production of illuminating gas from wood is a 

process of dry distillation; as we have seen, this 

process yields acetic acid, tar, and charcoal, besides 



gases which consist of. carbon dioxide and monoxide, but 
possess little illuminating power when the distillation is 
canried on slowly. If, oil the contrary, wood is rapidly 
heated to a high temperature, the greater part of the 
volatile products undergoes decomposition, and hydro- 
carbons are formed which are partly liquid and partly 
gaseous. By rapid distillation wood yields large volumes 
of gas, which is easily purified, and possesses very consider- 
able illuminating power ; charcoal, tar, and small amounts 
of acetic acid are obtained as subsidiary products. The 
retorts are similar to those used for the distillation of 
coal ; they must be filled with wood (sawdust, refuse, etc.) 
only to one-third of their capacity. The retorts should be 
at a full red-heat before the wood is charged in, and the 
charging must be performed as rapidly as possible, because 
large volumes of gas are evolved ait an early stage of the 
distillation. The time required for working off a charge 
is 75 to 120 minutes. In consequence of the rapid de- 
composition of the wood a certain amount of pressure is 
developed in the retorts, which, however, is rather an 
advantage as it keeps the tar-vapours somewhat longer 
in contact with the hot walls of the retorts and promotes 
their decomposition. In the gas works of H. Walker at 
Deseronto (Ontario) illuminating gas has for some time 
been manufactured from sawdust, and similar wood-gas 
plant is at work in other localities, and is employed for 
illuminating the workshops. As raw material, well dried 
pine-wood sawdust is used, which yields 20,000 to 30,000 
cubic feet of gas per ton. The retorts used are similar to 
those ordinarily employed for making coal gas ; the process 
of purification is, however, different, since the impurities 
in wood-gas are different from those obtained from coal. 
Sulphuretted hydrogen and ammonia, which are the chief 
troubles of the coal-gas manufacturer, are almost entirely 
absent from wood-gas. Resinous wood is, of course, pre- 


ferred to other woods for the manufacture of wood-gas, as 
it not only gives a larger volume, but yields gas of higher 
illuminating power. The drying of the sawdust, which is 
one of the most essential conditions of a well-organised 
gasification, as well as the other preparation of the raw 
material, is, in the works mentioned above, carried out 
almost entirely by mechanical appliances. In localities 
where sawdust can be cheaply obtained, and where there is 
a demand for the by-products, such as charcoal, wood-tar, 
wood-vinegar, etc., the manufacture of wood gas is able to 
compete advantageously with that of coal gas. 

The crude wood-gas contains very considerable amounts 
of carbonic acid gas, which it is necessary to remove, since 
the presence of carbonic acid markedly diminishes the illu- 
minating power of the gas. Since this, however, can only 
be effected by the use of lime, and since 1000 cubic feet 
(about 30 cubic metres) of gas require 30 to 35 kilos. (66 
to 77 Ibs.) of lime, the cost of the gas is materially 
enhanced. The lime in the purifiers combines also with 
the creosote, and with any acetic acid which has not been 
condensed in the coolers. The amount of creosote absorbed 
is only small, since its compound with lime is decomposed 
by carbonic acid. 

100 kilograms (220 Ibs.) of wood yield 

34 to 40 cubic metres (1200 to 1400 cubic feet) of gas ; 

0-5 to 0-8 kilos, of pyroligneous acid ; 

2 kilos, of tar; 

15 to 20 kilos, of charcoal. 


THIS technically-important substance was first obtained 
in 1773 from salt of sorrel (acid potassium oxalate) by 
Savary. Oxalic acid appears not to exist in the free state 
in nature, but occurs in combination with potash as acid 
potassium oxalate, and in combination with lime as calcium 

At one time oxalic acid was manufactured by the very 
costly process of oxidising sugar with nitric acid, but at 
the present time it is made from cheaper organic sub- 
stances without using nitric acid. Among these organic 
substances sawdust is the most important, in consequence 
of the abundance of the supply and the low cost of this 


To prepare oxalic acid, 30 to 40 parts of sawdust are 
mixed with soda lye of specific gravity 1*35, containing 100 
parts of actual alkali, and the mixture is heated in shallow 
pans to evaporate the water. The temperature to be 
employed is variously stated as from 175 to 240 C., but 
the higher of these temperatures should not be exceeded, 
as the oxalate of soda would be decomposed into carbonate. 
As soon as particles of wood can no longer be seen in the 
mass, the melting process may be considered to be finished, 
and the mixture is allowed to cool. The product contains 
sodium oxalate and carbonate, together with substances of 
the nature of humus, and the excess of the alkali which 


was originally employed. The mass is lixiviated with the 
smallest possible quantity of cold water, taking care that 
the solutions which are run off are not weaker than 35 
Be. By this operation the more soluble salts are dissolved, 
whilst the sodium oxalate is left as the undissolved resi- 
due. Another method is to dissolve the mass completely 
in the smallest possible quantity of boiling water, adjust 
the strength of the solution to 38 Be*., and allow to cool. 
Sodium oxalate crystallises out, and can be freed from the 
mother liquor by a centrifugal hydro-extractor. 

The crystallised sodium oxalate is redissolved in boiling 
water and mixed with milk of lime in an iron vessel which 
is fitted with a mechanical stirrer : it is by this means con- 
verted into calcium oxalate and sodium hydroxide (caustic 
soda). To avoid an injurious excess of lime, the amount 
of quicklime for each operation is calculated and slaked ; 
the greater part is added slowly to the boiling solution of 
the sodium oxalate; during the addition of the remainder, 
samples are tested at short intervals by filtering, super- 
saturating with acetic acid and adding calcium chloride. 
As long as this produces a precipitate or turbidity, in- 
dicating that sodium oxalate is still present, the addition of 
the milk of lime is continued. The precipitate of calcium 
oxalate is then allowed to subside, and the supernatant 
soda lye is drawn off and used for another melt, so that 
no waste of the caustic alkali takes place. The calcium 
oxalate is repeatedly washed with water, the washings may 
be concentrated to recover the alkali they contain or may 
be used for lixiviating. The calcium oxalate is now to be 
decomposed : for this purpose it is mixed with water to the 
consistence of a thin pulp, heated by steam in a lead-lined 
vessel, and treated with sulphuric acid of 15 to 20 Be*., 
meanwhile continuing to pass steam through the liquid 
until it boils. The amount of sulphuric acid to be used 
is regulated best by the amount of lime which has been 


required for decomposing the sodium oxalate ; 56 parts of 
quicklime (calcium oxide) require 98 part* of real 
sulphuric acid (H 2 SO 4 ) for conversion into calcium sul- 
phate. If to 1 part of lime there be taken 2 parts of 
sulphuric acid of 66 Be'., or an equivalent quantity of a 
weaker acid, it will give an excess which will advan- 
tageously assist the decomposition. The oxalic acid solution 
is now decanted from the precipitated calcium sulphate, the 
precipitate is repeatedly stirred up with water and finally 
thrown on a filter or filter press to recover the adhering 
solution. A sample of the precipitate is thoroughly 
washed with water, treated again with sulphuric acid, and 
tested with potassium permanganate for oxalic acid. If 
the warm solution, decolorises the permanganate, oxalic 
acid is still present, and the precipitate requires a further 
treatment with sulphuric acid. The solution of oxalic acid 
is evaporated in a shallow lead pan. When the liquid 
reaches a specific gravity of 15 Be. the evaporation is 
stopped, and the liquid allowed to cool in order to allow 
the calcium sulphate, which was present in the weak solu- 
tion, to separate. The liquid, separated from the precipi- 
tate, is further concentrated in a second pan to about 30 
Be., and then run into shallow lead-lined wooden crystal- 
lisers. The degrees of concentration here mentioned must 
only be regarded as approximate, as they require to be 
regulated according to the temperature of the room in 
which the crystallisation is to take place. Thus, in winter 
the first concentration must be stopped at 10 Be"., other- 
wise oxalic acid would crystallise together with the calcium 

The mother liquor is separated from the crystals by a 
centrifugal machine ; it contains sulphuric acid, and can 
be employed in the next decomposition of calcium oxalate. 
The remainder of the mother liquor is removed by dissolv- 
ing the crystals in a little boiling water and reerystallising. 


Considering the relatively high cost of the alkali used, 
it is important to use the caustic lyes repeatedly ; they are, 
however, highly contaminated with organic matter, from 
which they are freed by evaporation and calcination. If, 
however, the lyes are merely evaporated and calcined, the 
organic matter will not be completely destroyed, however 
high a temperature may be employed, since the alkali fuses 
and protects the organic matter from the action of the air. 
It is better to operate as follows : The liquor is concen- 
trated to 40 Be. (sp. gr. 1'386), and then mixed with 
enough sawdust to absorb it completely. The mass is then 
calcined, either on iron plates or in a reverberatory 
furnace, in thin layers, until a sample extracted with warm 
water gives only a feebly coloured solution. 

The greyish-black calcined mass is a mixture of charcoal 
with caustic and carbonated alkali : it is very porous, and 
is therefore easily washed out. Instead of washing it with 
water, the weak liquors from the decomposition of sodium 
oxalate with lime may be used. The lye obtained is 
causticised with lime and concentrated to 42 Be*, (sp. gr. 
1'407), and is then used again in the process. 


There has been but little published on the subject of 
the most advantageous conditions for acting on sawdust 
with alkalies for the production of oxalic acid; it appears 
therefore desirable to give the results of the experiments 
made by Thorn on this subject. 

Thorn's earlier experiments were made in round iron 
pots 5 cm. deep, 10 cm. in diameter at the bottom and 13 
cm. diameter at the top; the whole quantity of sawdust 
taken was thrown into the boiling lye, which was of 30 
to 42 Be., and the heating was continued over a free flame, 
whilst stirring continuously. When using the more con- 


centrated lye of 42 Be 7 ., the whole of it was at once ab- 
sorbed by the sawdust, and the inconvenient splashing of 
the liquid was prevented. 

In the course of the experiments Thorn observed that 
variations in the yield resulted from heating the mixture 
in thicker or thinner layers : a second series of experiments 
was therefore made in shallow sheet-iron dishes, in which 
the mixture formed a layer only 1 to 1 \ cm. (f to | inch) 
thick. Pine-wood sawdust, containing 15 per cent, of 
hygroscopic moisture, was employed for the experiments. 
To estimate the oxalic acid produced, 1 gram of the melt 
was treated with warm water, the solution acidified with 
acetic acid, boiled to expel carbonic acid, and precipitated 
with calcium chloride ; the washed precipitate was con- 
verted into calcium sulphate for weighing, and the amount 
of crystallised oxalic acid. C 2 H 2 4 + 2H 2 per 100 parts 
of wood, was calculated. 

1. Formation of Oxalic Acid by Fusing Saiodust with Sodium' 
Hydroxide alone. 

In one series of experiments 1 part of sawdust was added 
to a quantity of the soda lye containing 2 parts of sodium 
hydroxide; in another series 4 parts of sodium hydroxide 
were taken. The following were the results obtained : 

50 grams of sawdust with 100 grams of NaHO fused in 
the iron pot : 

At 200 C. 36-0 parts of oxalic acid per 100 parts of wood. 

At 240 C. 33-2 
When the mixture was heated in a thin layer : 

At 200 C. 34-68 parts of oxalic acid per 100 parts of wood. 

At 220 0. 31-60 

Using 25 grams of sawdust to 100 grams of NaHO : 
In the iron pot : 

At 240 C. 42-30 parts of^oxalic acid per 100 parts of wood. 


In thin layers : 

At 240 C. 52-14 parts of oxalic acid per 100 parts of wood. 

The colour of the melt passed from brown to a bright 
turmeric^ yellow ; above 180 the mass assumed a green or 
brownish-green colour; at still higher temperatures a 
vapour with a disagreeable odour was evolved, indicating 
apparently that a more considerable decomposition was 
taking place. The heating above 200 required great care 
to prevent the temperature from rising too high and 
causing the redecomposition of the oxalic acid produced. 
This was especially the case with the smaller proportion of 

2. Formation of Oxalic Acid by Fusing Sawdust with a 
Mixture of Sodium Hydroxide and Potassium Hydroxide 
in Thick Layers. 

Earlier experiments had shown that by using a mixture 
of potassium hydroxide and sodium hydroxide in certain 
proportions the yield of oxalic acid was as large as, or 
even larger than, with potassium hydroxide alone. 

The proportions which give the most favourable result 
have been very variously stated. According to a report by 
Fleck, there was employed in an English works a mixture 
of 1J parts of potassium hydroxide to 1 part of sodium 
hydroxide : according to another statement 1 equivalent 
of potassium hydroxide to H equivalents of sodium 
hydroxide is taken : at Kunheim's factory in Berlin mole- 
cular proportions of KOH and NaOH are regarded as the 
most advantageous, which proportions agree approximately 
with those first stated above. 

Starting with a mixture of 10 parts of potassium 
hydroxide, 90 parts of sodium hydroxide, and 50 parts of 
sawdust, Thorn observed that with the alkalis in this 
ratio the mass underwent a peculiar decomposition. 
Whether the mixture was heated up slowly or rapidly the 


colour of the mass passed from brownish-yellow to greenish- 
yellow, and when 180 was reached the mixture had the 
consistence of stiff dough. A dense smoke now rose from 
the melt : the temperature, in spite of the removal of the 
flame, increased, at first slowly, then rapidly, in the course 
of a few minutes, to above 360. The mass intumesced, 
and formed craters from which issued large volumes of 
combustible gas : finally it became completely carbonised. 
The decomposition could not be arrested by blowing a 
strong current of cold air upon the mass. As often as 
Thorn repeated the experiment with these proportions he 
observed the same phenomena. When a mixture of 20 
parts of KOH, 80 of NaOH, and 50 of sawdust was used, 
the temperature could be raised to considerably above 
200 without the occurrence of this uncontrollable decom- 

As the proportion of potash is increased the colour of 
the finished melt passes from yellow more and more into 
brown, and higher temperatures are required to produce 
the same consistence. Above 200 the mixture again 
becomes fluid, and froths so violently that it comes over 
the edge of the pot; with further heating it again becomes 
viscous. It is then difficult to raise its temperature, but 
if, after heating to 200, it is cooled to 60 to 80, stirring 
all the time to prevent the formation of lumps and to 
obtain a loose granular mass, it can readily be reheated to 
240 to 250. At this temperature the humus appears to 
undergo decomposition to some extent, as is evident from 
the paler colour of the solution, compared with that of a 
less strongly-heated melt; on the other hand the forma- 
tion of oxalic acid increases at this high temperature, as 
is shown by the following experiments in which 50 grams 
of sawdusit were fused with 100 grams of alkali containing 
different proportions of KOH and NaQH. Each fusion 
lasted | to 1 hour : 


Proportion of 
KOH : NaOH. 

Temperature in 
degrees Celsius. 

Number of 

Percentage of 
Oxalic Acid. 

20:80 > 





























240 to 245 








240 to 245 



60 : 40 200 



60 : 40 240 to 245 



80:20 200 to 220 



80 : 20 240 








240 to 245 



Very different results were obtained when the mixture 
was heated in thin layers. 

3. Formation of Oxalic Acid by Heating Sawdust with a 
Mixture of Potassium Hydroxide and Sodium Hydroxide 
in Thin Layers. 

As before, 50 grams of sawdust was thrown into boiling 
lye of 42 Be., containing 100 grams of alkali hydroxide ; 
the sawdust absorbed the whole of the liquid, and the 
mixture was then heated on an iron plate in a layer about 
1 cm. thick. By vigorous stirring the melting of the mass 
was, as far as possible, prevented, but above 200 a certain 
amount of fusion took place, and the mass acquired a 
pasty, granular consistence : when both alkalies were used 
this tendency to crumble increased, whilst the colour of 
the melt remained paler. The mass remained more porous 
than when heated in a thick layer, and was therefore 
better exposed to the action of the air. The increased 
contact with the air is advantageous, inasmuch as it assists 



the evaporation ,of the water, and promotes the oxidation 
of the woody fibre, which conduces to the formation of 
oxalic acid as is shown by the following results. The 
heating lasted 1 to 1J hours: 

Proportion of 
KOH : NaOH. 

Temperature in 
degrees Celsius. 

Number of 

Percentage of 
Oxalic Acid. 


200 to 220 



10: 90 




20: 80 

240 to 250 



30: 70 

240 to 250 



40: 60 

240 to 250 



60: 40 

240 to 250 



80: 20 





240 to 250 



This method of heating in thin layers, avoiding fusion 
as far as possible, gave therefore a considerably larger 
yield of oxalic acid. The experiments showed further that 
a mixture of 40 parts of KOH and 60 of NaOH, which 
approximates to 1 equivalent of the former to 2 equi- 
valents of the latter, gives practically the same yield as 
KOH alone. With smaller proportions of potash the yield 
rapidly falls off. 

4. Formation of Oxalic Acid by Heating Sawdust with 
Alkali Hydroxide in Thin Layers in a Current of 
Heated Air. 

If a current of heated air is passed over the mixture 
during the heating up, the latter retains its pulverulent 
condition for some time, and first begins to soften at about 
220. The mass, which up to that temperature was of 
a uniform brown colour, began to show isolated black 
patches, which rapidly extended throughout the whole. 
The mixture was heated to 215 in air warmed to 100; 
the temperature then rose of itself to 240, whilst the 


mass became of a dark-brown colour. When a mixture of 
KOH and NaOH was used the reaction did not take place 
so violently as with KOH alone, and the mass remained 
of a paler colour. When air heated to 120 was employed 
the temperature rose rapidly from 190 to 250, and the 
time required for heating up was materially shortened by 
the employment of heated air. 

The experiments in which 50 grams of sawdust and 100 
grams of KOH were taken gave the following results : 

Temperature of 
the Air. 

Temperature to 
which the Mass 
was Heated. 

Temperature ac- 
quired by the 
Mass after ceas- 
ing to apply Heat. 

Number of 

Percentage of 
Oxalic Acid. 


























The yield of oxalic acid was therefore no larger than in 
the experiments without heated air, but a shorter time of 
heating was required for the formation of the oxalic acia. 

o. Formation of Oxalic Acid with the Assistance of Manganese 

In 1858 Possoz took out an English patent, according 
to which the formation of ulmates, acetate, formates, and 
carbonates was avoided by heating 100 parts of bran, or 
other organic substance, with 100 parts of potassium 
hydroxide and 500 parts of potassium manganate to 160 
to 240 C., but not exceeding 260. 

Instead of potassium manganate, Thorn endeavoured 
to act on the heated mixture of sawdust and alkali hydrox- 
ide with manganese dioxide. The sawdust (50 grams) 
was heated with the alkali in a thin layer, and at 150 



10 grams of manganese dioxide was scattered over the 
surface. When using 50 grams of wood, 100 grams of KOH 
and 100 grams of manganese dioxide, the average yield 
from four closely concordant experiments was 78' 74 per 
cent, of oxalic acid : the addition of the manganic peroxide 
was therefore without any influence on the yield, and it 
did not appear that the dioxide underwent any change. 

6. Yield of Oxalic Acid from Different Kinds of Wood. 

To ascertain whether the kind of wood used would 
influence the yield of oxalic acid, several different kinds 
were tried. For each experiment 50 grams of wood was 
heated with 40 grams of KOH and 60 grams of NaOH to 
240 to 250 C. in a thin layer, and the following were the 
average results of four fairly concordant experiments : 

Percentage of 

Percentage of 
Oxalic Acid. 

Percentage of 
Oxalic Acid on 
Dry Wood. 

White deal . . . 




Yellow deal . . 




Poplar .... 


80-10 93-14 

Beech .... 








The soft woods give therefore a larger yield than the 
hard woods. 

7. Yield of Oxalic Acid with Different Proportions of Wood 
and Alkali. 

If the quantity of wood is increased in proportion to the 
alkali, subsidiary decompositions of the wood take place ; 
it is evident that a dry distillation of the wood, and ulti- 
mate carbonisation, occur. When 75 grams of wood were 


taken together with 100 grams of KOH, the mass began 
to fuse at 210, and at 215 some black patches appeared 
in the pale-brown mass. The temperature rose slowlv by 
itself to 250 and the mass became completely black. 
With 100 grams of wood to 100 grams of KOH, the 
mixture became dark coloured even below 200. In each 
of the following experiments 100 grams of KOH was 
employed, and the mass was heated to 250 : 

Quantity of 

Yield of Oxalic 
Acid per 100 
of Wood. 

Yield of Oxalic 
Acid per 100 
of KOH. 

Mode of Heating. 









I Melted in 
I thick layers. 





50 81-00 



60 76-30 
75 68-90 
80 66-77 


I Heated in 
f thin layers. 

100 54-14 



In all the above cases the melting .in thick layers gave a 
smaller yield than the corresponding mixture heated in 
thin layers. With the former of the two methods of heat- 
ing the proportion of 75 of wood to 100 of KOH appears 
the most favourable when the yield is calculated on equal 
quantities of the potash used : but when heating in a thin 
layer, the yield, calculated on the alkali, rises as the pro- 
portion of wood is increased. Considering the relatively 
low cost of the sawdust compared with that of the potash, 
it would appear advisable to take such proportions as would 
give the largest yield for a given quantity of alkali ; but 
there are practical difficulties in conducting the fusion 
and in the subsequent purification of the oxalic acid, which 


prohibit the use of much more than 50 parts of wood to 
100 of alkali hydroxide. 

The extraction of the oxalic acid from the melt can be 
performed in two different ways : the aqueous extract of 
the melt may be at once boiled with milk of lime to pre- 
cipitate the oxalic acid as calcium oxalate, or, if both 
alkalis have been employed, the sodium oxalate may first 
be separated out by crystallisation. 

Working by the first of the two methods a large quan- 
tity of calcium carbonate is precipitated with the calcium 
oxalate ; this consumes an equivalent quantity of sulphuric 
acid, and therefore occasions a larger expenditure of both 
lime and acid than corresponds to the oxalic acid obtained. 
The size of the apparatus, and the amount of fuel also have 
to be increased, because the amount of washing required, 
and therefore the quantity of liquid to be dealt with in- 
creases as the quantity of precipitate augments. 

Besides this, it is difficult to obtain pure oxalic acid 
from the precipitate prepared in this manner, because the 
humus substances which the solution contains are pre- 
cipitated by the lime and adhere very obstinately to the 
precipitate, and on the subsequent decomposition with 
sulphuric acid yield a dark-coloured solution of oxalic 
acid. The whole of the alkali is recovered in the caustic 
state, but the liquor cannot be directly employed for 
another melting operation on account of the large quantity 
of organic matter which it contains, but must be evapo- 
rated, calcined, and again causticised, thus entailing a 
second consumption of lime. It is therefore far more 
advantageous to first crystallise out the sodium oxalate, 
the additional operation being quite compensated for by 
the avoidance of the above disadvantages. The process of 
manufacturing oxalic acid from the melt may therefore be 
divided into the following five operations : 

1. Preparation of the solution. 


2. Crystallisation of the sodium oxalate. 

3. Conversion of ' the sodium oxalate into calcium 

4. Decomposition of the calcium oxalate by sulphuric 

5. Crystallisation of the oxalic acid. 

1. Preparation of the Solution. - 

The mass obtained by melting sawdust with the alkalis 
is boiled with water until nearly the whole of it is dis- 
solved : the solution is then evaporated to 38 Be. 

2. Crystallisation of the Sodium Oxalate. 

The solution becomes very slimy during the concentra- 
tion, in consequence of the presence of the humus, and this 
introduces difficulties into the operation of separating the 
finely granular crystals of the sodium salt from the mother 
liquor. If 4 parts of alkali are used with only 1 part of 
wood, practically the whole of the oxalic acid crystallises 
out (as sodium oxalate) from a solution concentrated to 
38 Be'., and the mother liquor can be readily run off 
from the crystals, which are therefore left at once in a 
comparatively pure condition. If, however, only 2 parts 
of alkali are used with 1 part of wood the mother liquor 
is very syrupy, so that it cannot be removed from the 
crystals by decantation or by ordinary filtration, and 
special arrangements for the separation become necessary. 
In the small-scale experiments a Bunsen filter-pump was 
used. By this the mother liquor was sucked out from the 
crystalline magma as completely as possible, and the 
crystals were then washed with small quantities of cold 
waiter until oxalic acid began to appear in the filtrate : 
in this way a fairly pure pale brown sodium oxalate was 


or THE 


obtained. On the large scale filter presses or centrifugal 
machines are used for separating the mother liquor from 
the crystals. 

The sodium oxalate separates out in the form of a sandy 
powder which exhibits no definite crystalline forms. It 
forms round granules about the size of rape-seed ; the 
larger granules are frequently hollow, and at the edges 
of the crystalhser scales resembling the husks of hemp- 
seed are often observed. 

Another method consists in treating the melt with water 
of 16 C., by which the caustic and carbonated alkalis are 
dissolved whilst the sodium oxalate remains undissolved. 
But according to Thorn's experiments, although most of 
the sodium oxalate remains behind, a not inconsiderable 
amount of oxalic acid passes into solution, probably as 
potassium oxalate, which then must be- precipitated with 
lime. If on the contrary the melt is dissolved completely 
by boiling, and the sodium oxalate allowed to crystallise, it 
is possible to obtain a mother liquor practically free from 
oxalic acid, because the potassium oxalate present in the 
melt is completely converted into sodium oxalate during 
the boiling. 

3. Conversion of the Sodium Oxalate into Calcium Oxalate. 

The sodium salt is dissolved in boiling water, a small 
excess of milk of lime is gradually added, and the mixture 
is boiled for about 2 hours. It is advisable to thin the 
mixture well with water, since otherwise the decomposition 
is slow and more lime is necessary. If a filtered sample, 
acidified with acetic acid, still gives a precipitate with 
calcium chloride, more lime must be added; when the 
decomposition is complete, the caustic lye is drawn off, 
the precipitate is boiled several times with water, and col- 
lected on a filter. 


4. Decomposition of the Calcium Oxalate by Sulphuric Acid. 

For this operation a large excess of sulphuric acid is 
always necessary, 3 equivalents being required for 1 equi- 
valent of the oxalate. It is important in this operation 
to add an ample quantity of water to ensure the complete 
action of the acid. The calcium oxalate is therefore 
stirred up with water to a thin paste, and the requisite 
quantity of sulphuric acid of 15 to 20 Be. is added 
gradually with stirring. The paste becomes at first some- 
what stiff with the calcium sulphate (gypsum) formed, but 
after standing for a time becomes thinner and can then be 
easily stirred ; more water is added and the mixture is 
gently heated for 1 to 2 hours with frequent stirring. Too 
high a temperature must be avoided, as the solution would 
then acquire a dark colour. When the decomposition is 
complete the liquid is filtered off and the precipitated 
gypsum washed : it must be well stirred up with the water 
as it settles very rapidly. 

The gypsum can either be used as manure, or be burnt 
and used as a plastering material. 

5. Crystallisation of the Oxalic Acid. 

The solution obtained contains, besides the oxalic and 
sulphuric acids, a small quantity of calcium sulphate. It 
is concentrated to 15 Be*, (specific gravity 1'116), and on 
standing for 3 to 4 hours the calcium sulphate separates 
out in small asbestiform crystals. After removing these, 
the liquor is further concentrated to 30 Be', (sp. gr. 
1'261) ; the oxalic acid separates on cooling in long crystals, 
which are purified by several recrystallisations. The 
sulphuric acid is used in the next operation ; if too much 
contaminated by organic matter it is purified by con- 



Potash lye, of 36 Be*., is heated to boiling in a stout 
iron pan, and common deal sawdust is added until a thick 
paste is obtained. The heating is continued with constant 
stirring, and, when the water has evaporated, the mixture 
again becomes fluid, homogeneous, and of a turmeric 
yellow colour. The temperature is maintained at the 
same height for 2 to 2J hours; the fire is then drawn 
and the mass allowed to cool somewhat. Whilst it is still 
warm, so much water is added that a solution of 40 Be*. 
is obtained : this is allowed to get cold after it has been 
well mixed by stirring. A very considerable yield of 
potassium oxalate, which is completely insoluble in potash 
lye of 40 Be*., is obtained. This method of preparing 
potassium oxalate is not new, although considerably 
improved : the subsequent treatment is, however, entirely 

The well-washed and r crystallised potassium oxalate is 
dissolved in a large quantity of hot water, and the cooled 
solution is precipitated with magnesium chloride or 
sulphate (waste liquor from the manufacture of carbonic 
acid for soda water). The well-washed magnesium oxalate 
is heated in a wooden tub by a steam pipe, and concen- 
trated hydrochloric acid is added until it is entirely dis- 
solved. The clarified solution is run hot into stoneware 
pans, and on cooling yields oxalic acid in clean crystals, 
which after washing and a single recrystallisation are 
chemically pure. This rapid and economical process yields 
oxalic acid without any useless residues, so that it presents 
an evident advantage compared with previous methods. 


Messrs. Roberts, Dale & Co., at their soda works at 
Warrington, manufacture oxalic acid by gradually adding 


fine sawdust to a lye containing 14 parts of caustic potash 
and 1 part of caustic soda, in iron pans. The mixture is 
then evaporated witli constant stirring, so as to obtain a 
moist powdery residue. The caustic soda is by this means 
converted into sparingly soluble sodium oxalate, the 
caustic potash into potassium carbonate with small quan- 
tities of potassium oxalate. The mass has a brown colour 
due to the simultaneous formation of humus compounds. 
The material is thrown into iron filter boxes with wire- 
gauze false bottoms : water is run upon it, and by the 
action of a pump connected with the space below the 
gauze, is drawn through the saline mass, dissolving the 
potassium salts in its passage. The washed residue, which 
consists of sodium oxalate, is decomposed by heating with 
milk of lime in an iron pan with a horizontal stirrer, cal- 
cium oxalate and caustic soda being formed. The soda 
lye is evaporated and used over &gain : the calcium 
oxalate, after it has been washed in the same manner as 
the sodium oxalate, is decomposed by sulphuric acid in 
wooden vats lined with lead. The solution of the potash 
salts separated from the sodium oxalate is likewise boiled 
with lime, to remove the oxalic acid and causticise the 
potassium carbonate, and the caustic potash lye obtained 
is used again as before. The solution of oxalic acid 
obtained from the decomposition of the calcium oxalate 
is evaporated to the crystallising point in lead pans, and 
the crystals obtained from the first and second evapora- 
tions are repeatedly recrystallised to eliminate the adher- 
ing sulphuric acid. The last mother liquor, diluted with 
water and mixed with a further quantity of sulphuric acid, 
is used for the decomposition of fresh quantities of cal- 
cium oxalate. 

J. Dale has introduced an improvement on this process. 
It consists in treating the sawdust with a hot solution of 
soda or potash before fusing it with the caustic alkalis. 



This preliminary treatment removes most of the impurities 
from the wood-cellulose. 

(Chemically Prepared Wood.) 

The lignose prepared by treating wood with hydro- 
chloric acid may also be used as the raw material for the 
manufacture of oxalic acid, the process being the same a* 
that with sawdust. The action of sodium hycL oxide on 
lignose produces a darker mass than when wood is used, 
the melts are more fluid and more resemble those in which 
a mixture of potash and soda has been used. 

According to Bachet and Machard the treatment with 
hydrochloric acid dissolves the light spongy cellulose which 
forms the envelope of the incrusting substance, so that the 
proportion of lignin in the residue is increased, and the 
product, freed from the spongy cellulose is more readily 
soluble in alkalis. Experiments, in each of which 100 
grams of sodium hydroxide were employed, gave the 
following results : 

Lignose from 
50 grams of 



Oxalic Acid 
per 100 parts 
of Lignose. 

Oxalic Acid per 100 
parts of Wood. 







10*37 1 Me lted 





14-OQ ( in 
16-58 f tfaick 
29-04 J la y ers - 





22-58 \ He ^ d 





/ layer, 

According to these experiments the yield of oxalic acid 
is about 33 to 38 per cent, smaller than when the original 
wood is melted with sodium hydroxide. This would seem 


to indicate that the spongy cellulose contributes more to the 
formation of oxalic acid than the residue left after treat- 
ment with hydrochloric acid, containing a larger propor- 
tion of lignin, and more readily soluble in alkalis. 


In this process the formation of humus substances, 
which are products of decomposition and oxidation, is 
avoided by conducting the fusion in a vacuum. The use 
of a vacuum permits the preliminary fusion to .e per- 
formed at as low a temperature as 180. It is advan- 
tageous to deprive the sawdust of water and air by heating 
it in the vacuous vessel before admitting the caustic lye, 
as this is then readily absorbed by the dry sawdust, and 
the solution of .the cellulose in the alkali takes place more 
readily. It is also possible to boil the sawdust in the 
apparatus with water or weak alkaline lye (4 to 6 Be*.), 
run out this liquor, exhaust the vessel, and then draw in 
the strong lye and commence the fusion. The vessel used is 
a steam-jacketed boiler fitted with a stirrer, and with wide 
valves connected with a condenser or with an air pump, 
and which can either be heated by steam or cooled by 
water. After heating the boiler to 100-150, the cal- 
culated quantity of sawdust, or other material containing 
cellulose, is thrown in, the stirrer is set in motion, and the 
air is pumped out, by which means the sawdust is freed 
from air and water. The concentrated alkaline lye, pre- 
viously heated to a temperature not exceeding 130, is 
then drawn in, the stirrer is kept in slow rotation, and 
whilst maintaining as perfect a vacum as possible, the 
temperature is gradually raised to 180. The preliminary 
fusion, or preparation of the melt, requires several hours, 
but when the raw materials are alike it requires little 
attention. The mixture thus obtained is then reheated in 


the usual way with access of air, in shallow pans provided 
with suitable stirrers, and yields a dry, pulverulent, nearly 
colourless product. 

260 kilograms of white deal or poplar sawdust, contain- 
ing 20 per cent, of moisture, are placed tin the boiler, and 
dried at 100 to 150 in an almost perfect vacuum, with 
the stirrer in motion, which takes about 30 minutes : 940 
kilos, of hot (122) potash lye of 46 Be., containing 6 to 
7 per cent, of potassium carbonate, previously concentrated 
in a separate vessel, are then admitted, and the pre- 
liminary fusion is performed whilst stirring slowly. This 
is complete in 3 hours. The mixture is then cooled to 
about 160, and by reversing the motion of the stirrer the 
pale yellow fluid product is run out into a shallow pan, 
also provided with stirring apparatus. It is here slowly 
raised to 320, stirring lall the time, the operation requir- 
ing about 4 hours. The product is .a light-grey powder, 
which readily dissolves to a nearly colourless solution in 
which no undissolved cellulose is present. By direct pre- 
cipitation with lime it yields a nearly white calcium 
oxalate. The melt contains 32 per cent, of oxalic acid. 

The best proportions were found to be 2J parts of caustic 
potash to 1 part of dry sawdust. 



BY the prolonged boiling of wood, especially if first re- 
duced to fibres, with dilute mineral acids, part of the cellu- 
lose can be converted into sugar. If the saccharine liquid 
is suitably neutralised and then fermented, the sugar is 
converted into alcohol, which can then be distilled off. 

This process has the appearance of being a very simple 
and obvious method of manufacturing alcohol, nevertheless 
in practice a number of difficulties 'are encountered, so that 
hitherto very little use has been made of this property of 

Braconnot based his process for preparing alcohol from 
wood on the following facts : When dry cellulose, or wood 
in a finely divided condition, is mixed with concentrated 
sulphuric acid, avoiding heat, the wood is converted into 
a pulp. After several hours this is diluted with water 
and heated to boiling. After neutralising the acid with 
lime, the liquid can be fermented, and the fermented solu- 
tion, yields ordinary alcohol on distillation. 

In Payen's experiments 500 grams of pine-wood, in 
pieces 1 centimetre thick, were boiled for 10 hours with 
2 litres of 10 per cent, hydrochloric acid, when the liquid 
was found to contain 105 grams of dextrose, or 21 per 
cent, on the dry wood : the liquid was neutralised and 


In the process given by Zette/rlund, the sawdust was 
heated in a boiler with hydrochloric acid under a pressure 
of O'll kilo, per square centimetre (1 Ibs. per square 
inch); the liquid was neutralised and fermented in the 
usual way. The materials used were 

450 kilos, of very damp fir sawdust. 
35 of Irydrochloric acid of specific gravity 1-18. 
1550 of water. 

After boiling for 8 hours the mass contained 3'33 per 
cent, of sugar, and after 11 hours 4'38 per cent. : no further 
increase could be effected. The whole mass now contained 
88'5 kilos, of grape-sugar, equal to 19" 67 per cent, on the 
weight of sawdust employed. The acid in the mixture was 
then nearly neutralised with lime, leaving only an acidity 
equal to J degree of Ludersdorff s acid scale. At a tem- 
perature of 30 the yeast from 10 kilos, of malt was added. 
The fermentation was complete in 26 hours, and the wort 
yielded on distillation 26'5 litres of 50 per cent, alcohol, 
of agreeable flavour, and perfectly free from any odour or 
taste of turpentine. It may be assumed that the manu- 
facture of brandy from sawdust on the large scale will 
become a success when experiments have settled the quan- 
tity of water to be added to the acid, and the length of 
time that the mixture should be boiled, as these two 
factors have the greatest influence on the formation of the 
sugar. If it were possible to convert the whole of the cel- 
lulose otf the sawdust into grape-sugar, 100 kilos, of air- 
dried sawdust would yield at least 24 kilos, of 50 per cent, 
alcohol. The sawdust of foliage trees would probably give 
the best results. 

Bachet and Machard employ wood cut into discs, which 
they boil with dilute hydrochloric acid, and ferment the 
sugar solutions so obtained, after neutralising it with cal- 
cium carbonate. The calcium chloride which is formed is 
inimical to the complete fermentation of the sugar. This 


difficulty "may be met by substituting sulphuric acid for 
the hydrochloric. The sawdust is boiled for 10 hours 
under high pressure in a copper boiler with a liquid con- 
taining 1 to 1 J per cent, of concentrated sulphuric acid ; 
the dark amber-coloured liquid is neutralised with lime 
and submitted to fermentation with yeast. 

The calcium sulphate produced by the * neutralisation 
with lime opposes no obstacle to the complete fermenta- 
tion of the sugar, but it would seem that substances are 
formed by the action of the sulphuric acid on the wood 
which are antagonistic. 

The chief difficulties in the way of employing this pro- 
cess on the large scale are that unless we assume a supply 
of sawdust to be available very complicated machinery is 
required for comminuting the wood to the extent neces- 
sary fox obtaining a sufficiently large yield of spirit 
(9 litres from 100 kilos, of wood), and that in consequence 
of the bulkiness of the material very large vessels are neces- 
sary, and it is difficult to make these so that they will 
withstand the high pressure and the corrosive action of 
the acid fluid. 

Quite recently E. Simonsen has manufactured alcohol on 
the large scale at the works of Bache-Wiig. A steam 
boiler, with a heating surface of 14 square metres (150' 7 
square feet), heated by a coal fire, and an autoclave of 7'5 
cub. metres (1650 gallons) capacity, lined with lead, were 
employed. The autoclave was a cylinder, which could 
be rotated, and was furnished with two manholes, steam 
pipe, testing and drawing-off taps, and a thermometer. 
The pressing was effected with an ordinary hydraulic press. 
For the neutralisation, and subsequent fermentation, 
wooden tubs of 30 and 40 hectolitres (660 and 880 gallons) 
capacity were employed. Two other neutralising tubs, 
and six subsidiary tubs of 6J* and 7 hectolitres (143 and 
154 gallons) capacity, were required. 


The routine of the work was as follows : 

1. The autoclave was charged with 100 kilos. (220 Ibs.) 
of sawdust and 300 to 500 kilos, of sulphuric acid of 0*5 
per cent. 

2. Steam was admitted until the temperature reached 
100 C., part of the air was blown off and the taps were 
all closed. 

3. The mixture was heated to 174 C. (135 Ibs. pressure 
per square inch), and boiled for half an hour; the steam 
was blown off, the autoclave emptied, and the undissolved 
sawdust pressed. 

4. The saccharine solution was neutralised with lime, 
leaving it, however, feebly acid, and then, at 25 C., was 
separated from the sediment of gypsum. 

5. The necessary yeast, with a small quantity of nutrient 
material, was added, and the whole was allowed to ferment. 

6. At 25 C. the fermentation was generally complete 
in 3 to 5 days, though occasionally it required longer. Its 
progress was watched by methodical estimations of the 
decrease in the percentage of sugar present. 

7. Finally, the alcohol was distilled off : by a single dis- 
tillation, spirit of 15 per cent, was obtained; a second dis- 
tillation gave alcohol of 75 per cent. 

The results obtained may be summarised as follows : 

1. It does not seem to be important whether the saw- 
dust is fine or coarse; regard must be paid to the amount 
of moisture which it contains, and the amount of water 
and sulphuric acid regulated accordingly. 

2. Pine and fir-wood yield approximately the same 
amount of alcohol : birch sawdust gives a larger yield of 

3. Wood-shavings are quite as good for the purpose as 
sawdust, but they must be cut up small across the grain. 

4. The amount of liquid must be in the proportion of 
4 parts to 1 part of sawdust. 


5. The acid must amount to exactly 1'5 per cent, of the 
total liquid. 

6. The pressed residue may be used as fuel. 

7. The quantity of sugar solution obtained varies with 
the amount of condensed steam and the temperature of the 
liquid run into the autoclave. 

8. The proportion of sugar in the liquid generally 
approximates to 5 per cent. 

9. The total sugar produced amounts to about 22 parts 
per 100 of dry sawdust : in a small-scale experiment birch 
sawdust gave a yield of 30'8 per cent. 

10. The fermented liquor contains I'l to 1'7 per cent, 
df alcohol : in the most successful operations 7'2 litres of 
absolute alcohol were obtained from 100 kilos, of sawdust 
containing 20 per cent, of moisture. 

11. The quality of the alcohol is most satisfactory. 


By a process which has not become very generally 
known. Croissant and Bretonniere prepare dye-stuffs from 
sawdust, rotten wood, horn, bran, starch, gluten, etc., 
which they call organic sulphides because they contain 
sulphur replacing hydrogen. For example, to convert 
bran into a dye, it is placed in an iron pan which has a 
flanged edge ; certain proportions of caustic soda and 
flowers of sulphur are added, the whole is worked into a 
uniform mixture, the pan is closed with a cover, and heated 
to 250 to 300 C,- The sodium sulphide which is formed 
acts on the organic substance, removing hydrogen, which 
escapes as hydrogen sulphide, and adding sulphur. When 
the operation is complete, the pan contains a black, friable, 
hygroscopic mass, which dissolves completely in water with 
a fine sap-green colour. The solution has the odour of 


garlic or mercaptan and has a remarkable affinity for 
organic fibre, which it dyes without the use of a mordant. 
A single organic substance will give several shades accord- 
ing to the proportions and the temperature employed. 
Certain substances, such as dye-wood extracts, aloes, etc., 
yield dyes even at the temperature of boiling water ; 
others, such as wood-fibre, bran, etc., require a higher tem- 
perature. We give here two examples : 


Aloes . . . s . . ... . 3 kilos. 

Caustic soda solution of 40 Be. . . . . 10 litres. 

Water .- -. . 10 litres. 

Flowers of sulphur . . . . . .3 kilos. 

By operating at a boiling temperature a greyish-lilac is 
obtained ; at a higher temperature a dark brown. 


Humus (or rotten sawdust) 20 kilos. 

Normal sulphide 40 litres. 

The normal sulphide is made from 70 litres of soda lye of 
40 B, 65 litres of water and 20 kilos, of sulphur. By the 
combination of sulphur with various organic substances 
an almost unlimited series of entirely new dye-stuffs have 
been obtained. In some cases the sulphur appears to enter 
into direct combination with the organic substance, with- 
out displacing any of its constituents; the reaction in 
that case takes place at a moderately low temperature, 
such as 100 to 120 C. This is the case with aloes. But 
in by far the greater number of cases the sulphur com- 
bines with the hydrogen of the organic substance ; 
hydrogen sulphide is then evolved and the hydrogen is 
replaced by an atomic equivalent of sulphur. For this 
reaction, temperatures of 250, 300 and even higher are 
necessary. In both cases, however, the substance acquires 
dyeing properties which it did not previously possess. One 


and the same material can yield various shades according 
to the temperature, . the duration of the heating, and the 
proportion of sulphur compound employed. In general 
the dye obtained approaches black, or at least brown, is 
the more soluble in water, and gives the faster dyes the 
higher the temperature and the greater the length of 
the heating. The dye obtained from rotten oak is 
extremely soluble in water; its odour resembles that of 
garlic or petroleum, and it has great affinity for fabrics. 
The dye from wheat-bran may be regarded as the type of a 
series. It differs somewhat in the mode of its preparation 
from that made from humus, for which previously prepared 
sulphide is used, the bran being mixed with flowers of 
sulphur and caustic soda : when this mixture is heated 
sodium sulphide is formed, so that the same conditions are 
produced as in the former case. But as this method allows 
the proportions of sulphur and soda to be varied, and the 
resulting shade to be thereby modified, it is to be preferred 
to the other. 

The dye obtained from wheat-bran is easily and com- 
pletely soluble in water, has a garlic odour, and has great 
affinity for fibres, as well as an extraordinary dyeing power. 
The dyed fabrics are greenish when taken out of the dye- 
bath, but after immersing in a solution of bichromate of 
potash acquire a catechu-brown shade, which inclines to 
grey after treatment with boiling soda. This change 
is characteristic of the products from bran, etc., and 
generally of all nitrogenous substances. The tendency to 
be changed to grey by soda solution is also influenced by 
the amount of sulphide employed ; the larger the quantity 
of sulphide, the greener is the solution of the dye, and the 
more marked the change to grey produced by soda. 

The dyes obtained from sawdust give particularly fast 
shades. The best woods for the purpose are oak, beech, 
cherry, chestnut, etc., whilst the soft resinous woods are 


unsuitable. The sawdust must be dry, and be finely sifted. 
It may be converted into humus by piling it in heaps 
which are watered from time to time, and then gives 
results almost identical with those of old rotten wood. 

Sawdust, which for a few months has been moistened 
with urine with the object of rendering it nitrogenous, 
yields dyes which behave similarly to those from bran and 
other nitrogenous substances. The dye from sawdust is 
almost inodorous, and dissolves in water with a brownish- 
black colour. The dye is taken up readily by the fibre 
which it dyes a dark greenish-grey, not altered by bichro- 
mate or by soda. The shade is fast to light, acids, air, 
alkalis, and soap. 

These dye-stuffs are very hygroscopic ; they must be 
protected from damp by keeping them in well-closed tins. 
If this is noit done they gradually decompose, absorbing 
oxygen and becoming insoluble and therefore unfit for 
use. The same is the case if the dye-bath is prepared too 
long before it is wanted for use. In a lukewarm bath the 
dyes have a great affinity for fibres, and give fast shades 
without the use of any mordant. The older the dye-bath 
the smaller is the affinity of the dye for fabrics; after 4 
to 5 months it is destroyed completely. The baths should 
therefore only be made up in sufficient quantity for im- 
mediate use. The quality of the water used for the baths 
is not unimportant; calcareous waters are quite unfit for 
use, since they immediately produce an almost insoluble, 
flocculent precipitate. The advantages of these patent 
dyes may be stated as follows : (1) Their manufacture is 
the simplest possible, requiring neither expensive appli- 
ances nor complicated apparatus, and but little labour ; 
moreover, the result of the manufacturing operation is per- 
fectly certain. (2) The dyeing power of these products is 
considerably greater than that of most other dyes. (3) 
The dyes are very fast, and resist both acids and alkalis 


better than any hitherto employed. (4) They are cheaper 
than the commonest dyes, especially when their remark- 
able strength is taken into account. For example, a kilo, 
of dye from sawdust costs little more than half as much 
as logwood extract, but will dye four times as much stuff. 
The new process is therefore capable of converting into 
dyes, by a simple method and at a low cost, materials 
which are everywhere accessible and possess little value ; 
it is moreover capable of producing directly from these 
materials an unlimited series of completely new dye-stuffs 
of very varying shades. 




THE use of sawdust for the production of plastic com- 
positions, which may be shaped either by pouring or by 
pressing into moulds, has been known for a considerable 
time, and the methods for the preparation of these com- 
positions have been so much improved that articles are 
now produced by this means which leave nothing to be 
desired. Attempts have been made to manufacture 
planks, boards, beams, etc., from sawdust, but those 
endeavours have never met with success, because the 
lacerated wood-fibres, even when reunited by the most 
suitable binding materials, no longer possess the elasticity 
and strength of the natural wood. It is not to be expected 
that sawdust can ever be made to produce a material 
equal in all respects to the original wood, and we shall 
therefore confine our attention to those products which 
possess a practical value. 

The idea of replacing wood by artificial products seems 
to have originated in China and Japan. Thence the in- 
vention reached Europe as long ago as the last century, 
and was especially applied in England, where in 1772 
Clay took out a patent for the preparation of such 
materials. Numerous processes for the production of arti- 


ficial wood have been published, some of which differ 
widely from one another. The oldest methods are those in 
which finely disintegrated vegetable fibres, paper pulp, 
lime and rice starch are mixed. Later, Jennens introduced 
improvements, and is said to have had a factory at Bir- 
mingham where artificial wood articles were manufactured 
in great variety. The basis of these was chiefly a " half- 
stuff " paper pulp, which by the addition of glue solution, 
chalk, clay, and linseed oil was made into a dough which 
could be kneaded and shaped, and which then by drying 
acquired great hardness and durability. The product was 
employed for the ornamentation of ceilings, mirrors, 
picture frames, etc.. A similar material, which could be 
poured in the liquid state into moulds, was composed of 
sawdust or other finely subdivided vegetable fibre, 
refuse hair, and hemp, with glue solution, white of egg, 
caoutchouc, pitch, and turpentine. The " Simili bois," 
made in Paris, and used with good effect for imitation 
wood-carvings, is a preparation of the same character. 
According to a proposal of Brindly, who obtained a patent 
for its use in manufacturing lacquered wares, tea-caddies, 
etc., a mixture was made of half-stuff, paper waste, hard 
soap, and alum. 

The general method of preparing these compositions is 
to mix sawdust with a binding material, and then, accord- 
ing to its consistence, either pour or press the mixture 
into moulds. The articles so prepared may be used for 
all kinds of decorative work, instead of the more costly 
wood-carving, especially for frames, small boxes, and 
various fancy articles. Artificial wood is also employed in 
making brushes; the bristles are inserted into a slab of 
the soft composition, which is then covered with a plate 
perforated to let the bunches of bristle pass through. 
Pressure is then applied which binds both into a single 
mass, and the brushes so made are both cheaper and more 


durable than those made by the methods most commonly 
in use. 

The first artificial wood of this kind consisted of a 
mixture of sawdust, glue, and certain tanning solutions, 
or of sawdust, turpentine, resin, etc. Latry, in Paris, pre- 
pares artificial wood from sawdust and blood albumin by 
the application of heat and pressure. Very fine sawdust, 
especially that of poplar-wood, is soaked in diluted blood, 
and dried at 50 to 60 C. The mixture is submitted to 
high pressure in steel moulds, which- at the same time are 
heated to 170 to 200 by gas flames. At this temperature 
the blood undergoes a sort of fusion, and the whole becomes 
a blackish liquid resembling asphalt. The product is a 
hard material of woody texture, which can be sawn, glued, 
polished, lacquered, and gilt, exactly like wood. Articles 
made of this material were sold .as " Sciffarin ware." 
According to another formula, wood-fibre prepared as for 
paper-making, was saturated with glue solution, pressed, 
and dried. This furnished a hard material, which was then 
protected from the action of moisture by several coats of 
thick linseed oil varnish applied hot. 

Another composition, bearing a resemblance to these 
artificial woods, is the sio-called wood-marble, which is made 
from the sawdust of fine, hard woods, ivory waste and 
other waste materials, to which pigments tare often added. 
These, by the addition of water-glass, glue, etc., are made 
up into a hard mass, from which veneers are then cut, 
which naturally are not liable to warp or crack. The 
material takes an excellent polish, which gives it the 
appearance of the finest marble. 

A composition consisting of ^ of sawdust, ^ of calcium 
phosphate, and J of .a gelatinous or resinous material, goes 
by the name of " Simili bois," and is used for the reproduc- 
tion of sculptuary. 

Quite recently articles of this character have been made 


from sawdust compositions for the decoration of all kinds 
of wood work, such as door lintels, brackets, capitals of 
pillars, cornices of cabinets, panels of chests, decorative 
mouldings, etc., and it is well known in the furniture trade 
that ornamental articles of every kind, and imitation wood- 
carvings such as are used for furniture, fancy work, toys, 
as well as for house decoration are most extensively pre- 
pared by moulding. But whilst these manufactures are 
largely employed in France, England and America, they 
appear as yet to have obtained little footing in Germany 
and Austria. It is difficult to understand why, in spite of 
the great advances in cabinet work, very little wood- 
carving is employed in furniture. 

These products have been so perfected that for cheap 
furniture, wall and ceiling decoration, etc., they are capable 
of completely replacing wood-carving, and such decorations 
in half-relief have especially gained acceptance as sub- 
stitutes for wood-carvings. Articles of artificial wood 
must fulfil the following requirements : 

1. They must resemble wood as closely in appearance 
as possible, and have approximately the same specific 

2. They ought not to warp with heat or damp, and 
must be sufficiently tough, as well as hard, to prevent the 
angles from breaking off too readily. 

3. They must permit of being bored, filed, sawn, cut, 
and carved, without being brittle: they cannot of course 
be split, since their structure is perfectly uniform. 

4. They must admit of being glued without special 
difficulty to the objects to be decorated, and must adhere 

In G-ermany, B. Harrass of Bohlen (Thuringia) has for 
several years been engaged in the preparation of artificial 
wood, and the material which he produces completely 
deserves that name, since his manufactures exhibit the 


choicest forms in the various styles, and a great diversity 
in the individual articles, which are supplied by him as 
complete ornamental fittings both for furniture and house 
decoration. The panels and friezes of the Italian Re- 
naissance are altogether unlike the unsightly forms which 
are still exhibited by the wood-carvings of the German 
Renaissance. The ornamental objects supplied by Harrass 
have an artistic character of their own, whilst they are 
free from the objection to wood-carving which results from 
its costliness. 

Not furniture alone, but the walls and ceilings of our 
dwellings may by the use of artificial wood, at a cost which 
scarcely exceeds that of stucco, be decorated with panelling 
of high architectural quality. As in the dwelling-houses 
of the present day only the skirting boards and base 
mouldings are left to us from the heavy panelling of our 
predecessors, the patented invention of Harrass supplies 
the demand which is arising on all sides for the restora- 
tion to favour of wood architecture for chamber decora- 
tion, inasmuch as the use of artificial wood furnishes every 
builder with the means of producing, at a low cost, 
wainscotting equal to the few examples which have come 
doiwn to us from the best days of the Florentine School. 

The manufacture is, however, in no sense an imitation, 
nor, as the name would seem to imply, a substitute for 
wood, but in its outward layer consists of natural wood 
(walnut, oak, mahogany or rosewood), which Harrass 
makes plastic by giving them a basis of wood-fibre bound 
together by albumin into a homogeneous, insoluble mass. 
The artistic objects produced in this way are far more 
durable than those made by carving natural wood, are 
far cheaper, and at the same time better finished than 
most carvings. To their employment for artistic furniture 
and house decoration may be added their use for a great 
variety of other objects, as photograph frames, mirror 


frames, all of which are turned out in an equally finished 

In the above account I have endeavoured to give a 
general idea of the amplitude of the field which is open for 
utilising sawdust in the production of artificial wood. 
Many have been the attempts made to replace wood- 
carvings by other and cheaper forms of ornament, such as 
papier-mache", and even cast-zinc, but these, partly on 
account of the difficulty of affixing them, partly in conse- 
quence of their want of artistic finish, but mainly because 
they did not resemble wood in appearance, have never met 
with success. An obvious expedient therefore appeared to 
be the use of wood itself for such objects, and already a 
large number of processes are known, which in recent years 
have effected marked advances in this direction by means 
of the employment of wood-cellulose. 


As already mentioned all artificial wood-compositions 
consist of sawdust, or exhausted dye-woods, and a binding 
material, which may be of various kinds. The binding 
material is either soluble in water, remains soluble, or by 
special treatment is rendered insoluble, or is insoluble. 
According to the nature of the binding material the 
mixture is either of the consistence of dough, so that it 
can be pressed into moulds by hand, or it may be fluid 
and be poured into the mould ; lastly, the binding material 
may be used in such small proportion that the product is 
merely a more or less dry powder, which can be forced 
into moulds by a very high pressure, sometimes with the 
assistance of heat. Compositions which are either poured 
or gently pressed into moulds generally fill these some- 
what imperfectly : on drying, contraction takes place, and 
the contours are deficient in sharpness arid more or less 


rounded. On the other hand, compositions which are 
pressed into moulds in the form of powder are harder, 
more durable, and sharp in detail, because the high pres- 
sure fills all the minute depressions of the mould and 
causes them to produce their effect in the finished article. 

Various Processes. 

1. The sawdust of soft woods is boiled with a solution of 
glue and water-glass, and a further quantity of sawdust i,s 
then added and well mixed by kneading so that a plastic 
mass of the consistence of dough is produced. This is 
pressed between iron plates, then dried and cut up, 
yielding slabs of any desired size and thickness, which in 
the dry state are very hard, and fairly resistant to damp. 
By adding various pigments, as colcothar, vermilion, umber, 
etc., coloured tiles suitable for flooring, etc., are produced. 

2. A mixture is made of 

7 parts of finely sifted sawdust, 
1 part of powdered rosin, 

and placed on an iron plate covered with a sheet of paper. 
The plate has a rim as thick as the finished slab is intended 
to be. A second sheet of paper is laid over the mixture 
and then a hot iron plate, and the whole is then placed in 
a press and exposed to high pressure. 

3. The strongly dried and sifted sawdust is mixed to a 
suitable consistence with a solution of glue, which is so 
hot that it can be scarcely borne by the hand. The glue 
solution is made by soaking 5 parts of good pale glue and 
1 part of isinglass in water, heating up slowly and filtering 
carefully. The quantity of water (variable according to 
the quality of the glue) should be just large enough to 
prevent the liquid from gelatinising on getting cold. In 
some formula? gum-tragacanth and whiting are added to 
the glue solution, the former for the purpose of producing 


a consistence more resembling that of dough, the latter to 
give greater hardness. The moulds may be either of metal, 
plaster of Paris or sulphur, if oiled ; even wooden moulds 
may be employed if they are first varnished with an 
alcoholic solution of shellac. A thin layer of the mixture 
is first pressed into the mould by hand, the mould is then 
filled up with a mixture made with coarser sawdust, the 
surface covered with a thick plate and pressed. Before 
removal from the mould, which is easily done when the 
cast has dried and shrunk a little, the excess of material is 
removed by a thin broad knife, so as to give the cast a flat 
base. Such casts can then be lacquered, gilt, and in general 
treated like carved-wood decorations, but in consequence of 
the great shrinkage which occurs during the drying they 
have no sharpness, and do not exhibit the finer touches 
of the original. These casts require to be protected from 
damp, but if slowly dried they are fairly free from any 
tendency to warp. 

4. A mixture is made of 

10 parts of glue dissolved in hot water. 

4 ,, ground litharge. 

8 ,, white lead. 
10 ,, ,, fine sawdust. 

1 ,, ,, plaster of Paris. 

The mixture is poured into oiled moulds, which are made 
in two parts, and when cold is removed from the moulds 
and finished by painting, gilding, bronzing, etc. 

5. Bois Durci. 

This peculiar composition, invented by Latri in 
Paris, consists chiefly of fresh blood mixed with sawdust 
of hard and resinous woods, which is pressed by a 
hydraulic press into iron or steel moulds heated by gas. 
Under the combined action of heat and pressure the 


albumin of the blood solidifies to a very hard material, 
whilst the^iron in the blood unites with the tannins of the 
sawdust to produce a dark colour. If the interior of the 
mould is greased before filling, the sticky composition does 
not adhere to it and is easily removed. It is also 1 necessary 
to press the composition gradually intoi the mould, since 
the heat and pressure cause it to shrink considerably. 
Some salicylic acid is added to the mixture to prevent the 
blood from putrefying and developing a disagreeable 
odour. The composition of the mixture may be varied by 
adding whiting to the blood and sawdust: this obviates 
the addition of salicylic acid, and confers much greater 
hardness on the product. An improvement in the process 
consists in spreading the mixture on heated iron plates, 
and after drying, grinding it to powder and pressing it 
into heated metal moulds. Sawdust, especially that of 
poplar-wood, is ground to very fine powder, mixed with 
diluted blood, and dried at 50 to 60. This produces a 
very intimate mixture of the albumin of the blood with 
the wood-powder. The moulds consist of rings containing 
matrices of highly polished steel, finely and artistically 
wrought. The dry powder is filled into the moulds avoid- 
ing the use of a superfluity, so> that after pressing no seams 
are visible. The pressing is done by very powerful hy- 
draulic presses; the moulds are heated by gas, and kept 
during the whole operation at a definite temperature. The 
moulds run in grooves, which are so arranged as to allow 
no lateral shifting, and are arrested by stops in the proper 
positions for the presses. Each of the hot plates is fitted 
with gas burners which follow its up and down movement. 
The gas issues from an annular burner, through the 
middle of which a blast of air is blown by a fan: the 
regular heat so produced permits the production of very 
well-defined castings. The consumption of gas is, however, 
very considerable, but the convenience of the work com- 


pensates for the cost. The function of the albumin in this 
process is not clear. It was for a long time supposed to 
correspond with that of the varnish on fabrics, but that 
cannot be the case when the wood-powder mixed with 
blood albumin has first been dried. A closer investiga- 
tion has indicated the presence of a certain quantity of 
resin in the sawdust, and resin produces a solid compound 
with albumin. If the sawdust of a white, non-resinous 
wood, such as beech, is taken, a hard mass may be pro- 
duced, but it will have little strength, and will not resist 
the action of boiling water. If 33 per cent, of blood 
(blood albumin) is added the mass will be harder, but will 
fall to pieces after 10 to 15 minutes in boiling water. With 
66 per cent, of blood the objects are stronger, browner, 
and more durable, but are not equal to those from 
resinous wood. It appears therefore that the blood is not 
indeed indispensable, but is nevertheless extremely service- 
able in the manufacture. The blood is turned a deep 
brown colour by the drying, and exhibits glistening 
specks, which have a good effect in the finished objects. 
When heated to 170 to 200 C. the blood undergoes an 
incipient melting, and acquires great adhesive properties. 
If the mould is opened whilst hot it is found to contain a 
soft, blackish, semifluid mass, resembling asphalt. It is in 
this condition, apparently, that it fills all the fine depres- 
sions of the mould, which consequently are exhibited 
accurately after the cast is cold. The product of the whole 
operation is a hard, wood-like material, which can be 
worked in every respect like wood itself. Its specific 
gravity is 1'3,' that of the dried mixture of sawdust and 
albumin being 0'8. This material is worthy of general 
attention, not only from a technical but from an artistic 


6. Gottschalk's "Hartholz" (Hard Wood). 

Goffctscbalk of Berlin imitates ebony by means of a com- 
position similar to that of Latri, which he prepares with 
blood albumin and sawdust dyed black. Finely sifted saw- 
dust of hard woods is boiled for 10 hours with a solution of 
8 parts of logwood extract and 1 part of alum in 40 parts 
of water, then drained and immersed for 5 hours in a bath 
consisting of 1 part of copper vitriol in 15 parts of water. 
After removal from the bath the sawdust is put through a 
centrifugal machine and then dried. It is then mixed 
with blood albumin, and, in the state of coarse powder, 
is pressed into heated moulds by a stamping press. 

7. Harrass' Imitation Wood from Cellulose. 

The composition employed by Barrass consists mainly 
of cellulose, sawdust of sioft woods, and an albuminous 
binding material. The chief feature of this composition 
is the 'employment, together with sawdust, of wood-fibre 
which has been decorticated by chemical treatment, by 
which means greater durability and strength are secured. 
Harrass, having failed to get completely satisfactory 
results when using by itself wood-fibre prepared by merely 
mechanical grinding, turned his attention to cellulose, and 
with this obtained a most admirable composition. The 
cellulose is prepared by cutting up pine-wood, freed from 
bark and twigs, into small piece, which are then boiled 
with concentrated caustic soda under a pressure of 150 Ibs. 
per square inch in large iron boilers. By this treatment 
the wood is resolved into its constituent fibres. The 
fibrous pulp is thoroughly washed from the adhering 
alkali by a stream of water, then bleached by chloride of 
lime, rewashed and dried. This treatment removes both 
the natural colouring matters of the wood and those 


albuminous and gummy constituents which bind the fibres 
together, and the process of Harrass aims at reuniting the 
cellulose fibres by the addition of binding materials of 
similar character. 

Cellulose, as supplied by various manufacturers, is in 
the form of thin, soft slabs, which require to be soaked in 
water before using the material for the preparation of 
artificial wood. The excess of water is removed by 
squeezing the pulpy mass on a fine sieve. A mixture is 
then made of 4 parts of the cellulose, 4 parts of sawdust, 2 
parts of albumin, and 1 part of powdered galls or ground 
oak-bark ; enough water is added to form a stiff paste, and 
the whole is stirred until it is thoroughly mixed. The 
paste is then passed between rollers, which deliver it in 
slabs about half an inch thick and of any convenient 
length ; it is then dried, first in the air and then in stoves, 
on frames over which netting is stretched. The dried 
slabs are now in the form of fairly hard cakes of a greyish- 
yellow colour. They have the property of softening by 
heat, and therefore when compressed into strongly heated 
metal moulds they receive, and when cold retain, the 
impress of the dies. 

The metal moulds have the design hollowed out in them, 
and the presses employed are coining presses with either a 
lever or wheel, such as are used for stamping and punching 
metals. Larger or smaller presses, and higher or lower 
pressure are made use of according to the dimensions of the 
article to be produced. The presses most recently adopted 
have been on the principle of the mill-stamp, driven by 
gearing, and can be attended to by a single workman. The 
moulds receive their heat from the tables of the presses, in 
each of which there are two or three holes, into which gas 
is conveyed by flexible tubing, to produce the heat. The 
temperature must be kept uniform by regulating the gas 
flames, and must never be so high as a red-heat. The 


temperature is adjusted by observing the melting of certain 
metallic alloys, and the entire manipulation, simple as it 
appears, requires the greatest experience and precision. 
The moulds are either of cast-steel or bronze, and consist 
of two parts, the matrix and the core, which also forms the 
cover. The former is hollowed out to the exact shape of 
the model, whilst the latter has only the general contour 
of the model in relief, and when placed on the matrix the 
space between the two surfaces is exactly of the dimensions 
which the casting is to assume when complete. These 
moulds are prepared by casting from the design carved 
or modelled by the artist, and are finished by a metal 
engraver, to give them the sharpness of detail and smooth- 
ness in which the rough casting may be deficient. The 
moulds for producing the capitals of pillars, which are 
made in four or more portions, require the most exact and 
careful finishing, which considerably adds to the cost of 
production. The moulds themselves must have a suffi- 
cient thickness of metal to resist the high pressure to 
which they iare subjected. No definite rule for the neces- 
sary thickness can be laid down, as it depends on the depth 
of the matrix and the pressure to which it will be ex- 
posed. For small objects a thickness of 2 to 3 mm. (y^inch) 
is sufficient, whilst for large ones a thickness of 10 mm. 
(f inch) may be necessary. 

To commence an operation the empty mould is placed 
with its cover between the heated table and ram of the 
press, and is left there until it has acquired the tempera- 
ture of those plates. After the interior surfaces of the 
mould and core have been thinly and uniformly greased oo* 
oiled, the requisite quantity of the finely powdered com- 
position is filled into it, the cover is replaced, and by work- 
ing the press the mass is gradually compressed. The 
skill and attention of the workman are here called into 
play, as he has to judge the moment for ceasing to apply 


pressure, and the time for removing the finished article 
from the mould. If, when removed, the surface shows im- 
perfections, the object is immediately replaced in the 
mould, adding a little composition at the imperfect places, 
and is pressed again. Any excess of the composition 
escapes between the mould and the core, forming a flat 
border surrounding the base of the casting, and requiring 
to be removed with a knife or chisel when the casting is 
cold. The base or back of the object is then ground down 
on a revolving emery wheel, both to reduce the object to 
its proper elevation and to give it a flat base for attaching 
it by glue or screws. Instead of the emery wheel, a 
wooden wheel covered with sand-paper or glass-paper may 
be used. To prevent the freshly pressed objects from 
warping, it is necessary to lay them, whilst still warm, with 
their backs on a flat plate, and either to load them with 
weights or to clamp them down and then leave them to 
get .perfectly cold. 

The objects produced in this manner from the cellulose 
composition are in their original state either brownish- 
grey or yellowish-grey and have a metallic lustre ; they can 
either be coloured in the mass, especially when a black 
colour is desired, or by simple processes any desired wood 
colour, or other shade, can be given to their surfaces. 

The finished objects require, to be kept in dry, well- 
aired rooms; the damp, musty air of unventilated rooms 
is as injurious to them as to any other wood-work. They 
are attached in the same way as wood-carvings; being first 
warmed and then coated with moderately thick, freshly- 
melted, hot glue, and applied to the wood-surface to which 
they are to be attached, which is also previously warmed. 
When possible they should be held down with screw 
clamps until the glue has thoroughly hardened. When 
glueing to polished or lacquered surfaces the polish or 
lacquer must first be removed at the places where the 


moulding is to be attached. It is also very advisable to 
insert, here and there, small round-headed wood-screws, 
and in almost any moulding depressed spots can be found 
where the screw heads are out of sight. To obtain as 
large a surface for glueing as possible, the hollow at the 
back of the object may be filled up; this is best done by 
glueing in a piece of wood which fills the hollow exactly, 
or the hollow may be filled with a composition consisting 
of 2 parts of sawdust and 1 part of plaster of Paris made 
into a stiff paste with weak glue, and pressed into the 
hollow after the inner surface has been well brushed over 
with hot glue. The back is then struck off flat and 
smooth, and the composition allowed to get dry before it 
is attached to the surface which is to be decorated. 
Column and pilaster capitals are best attached if a square 
tenon is cut at the top of the wood-column or pilaster 
exactly the size of the hollow in the bottom of the moulded 
capital. The tenon is well coated with glue, and the 
capital attached firmly by screws. Should any of the 
objects have become warped, so that the hinder surface is 
no longer truly plane, which is generally due to want of 
care in storing, the object only needs to be warmed, when 
it will become flexible, and in that state can be glued in 
the desired situation and screwed down until the glue has 

By the same means flat pieces can if desired be bent to 
a curved or wavy shape, but the bending must be gradual 
and careful to avoid fracture. After cooling, the pieces so 
bent retain the form given to them. Small irregularities, 
occurring either in the glueing of the pieces to their sup- 
ports, or in fitting together the various parts of a moulding, 
can be .got rid of, as in the case of ordinary wood, by filing 
and filling up with some cement. If in fitting the various 
pieces together any small gaps should be left, these may be 
filled up with a special wood-cement which is supplied. 


Corners which do not exactly meet may be touched up 
with a file. Any smoothing required is best done with fine 
sand-paper or glass-paper, but it is advisable first to give 
the objects a coat of French polish and allow them to dry 

8. Hurtig's Wood- composition for Parquetry, Blocks, Tiles, 
and other Decorative Objects. 

Hurtig's process for the production of a wood-composi- 
tion consists in the manufacture of a waterproof, heat- 
resisting, compressible powder, and a special treatment of 
natural wood, together with the preparation of the requi- 
site waterproof binding material for uniting the two. The 
powder, like that of Harrass, when pressed into heated 
metal moulds, unites to a solid body of any desired shape. 

For the preparation of the powder, sawdust of any kind 
of wood is thoroughly incorporated with a strong aqueous 
solution of curd soap, and is then thoroughly dried. The 
powder is then treated with milk of lime and again dried, 
by which means a material is produced which is quite 
unaffected by water. To this powder a quantity of air- 
slaked lime is added, and the mixture is then thoroughly 
saturated with a solution of ordinary water-glass (sodium 
silicate), and once more air-dried. The water-glass serves 
as the binding material for the powder, and the air-slaked 
lime is added to produce an insoluble compound with this 
substance. The dry powder prepared in this way possesses 
the property of uniting into a solid body when pressed into 
heated moulds, 'and is then capable of resisting the action 
of water, heat, cold, etc. 

The following proportions afford serviceable results : 50 
kilograms (1 cwt.) of sawdust of any kind of wood are 
soaked in a solution of H kilos. (3 Ibs.) of common curd 
soap, with such a quantity of water that the sawdust can 



be thoroughly wetted with the solution. After drying it 
is mixed with milk of lime made from 2 kilos. (4J Ibs.) of 
slaked lime. It is again dried and then mixed with 2 kilos. 
of air-slaked lime. This mixture is then thrown into a 
bath prepared with 5 litres (8| pints) of water-glass of 33 
Be. and a sufficient quantity of water. The thoroughly 
weitted powder is once more dried, and is then ready for 
pressing. It yields blocks of stony hardness, which are 
particularly suitable for laying down parquet floors, as 
they are unaffected by weather and heat, which is not 
altogether the case with natural wood. It may also be 
used for the production of all sorts of household utensils, 
such as plates, cups, basins, etc. For this purpose the 
powder is filled into the previously heated moulds and then 
submitted to pressure; it penetrates into all the depres- 
sions of the mould, and on cooling hardens and retains 
the form imposed upon it. 

The pressed blocks may be furnished with an upper 
layer of natural wood (or any other material), with which 
object they are first coated with the following composi- 
tion : 2 parts of glue are melted with water, and poured 
into 1 part of hot linseed-oil varnish ; 1 part of rosin dis- 
solved in spirit, and mixed with J part of turpentine is 
then added. This mixture is well stirred together in a 
vessel immersed in boiling water, and is laid on hot. This 
cement is unaffected by water, and is not liable to the for- 
mation of air bubbles. After laying it on the surface of 
the pressed block it is allowed 'to cool until it forms a solid 
crust, and the block is then ready to receive the upper 
layer. This layer, when the blocks are intended for par- 
quetry, is a mosaic pattern of wooden slabs, and for other 
purposes may consist of thin plates of copper, brass, or 
alloy, or of plain veneer or inlaid wood, or of wood with 
metal fillets, or tarsiatura work of metal inlaid with 
tortoisenshell, or composite work of any desired description. 


When the upper layer is to consist of wood it is neces- 
sary that this should be so treated that it will be water- 
proof, which is effected in the following manner: A bath 
is prepared, consisting of 2 parts of concentrated sulphuric 
acid and 1 part of water, and in this the pieces of wood 
are immersed. As soon as the liquid has thoroughly pene- 
trated the wood, the latter is well washed by soaking in 
pure water, rinsed, and dried. It is then immersed in a 
solution of common curd soap in a convenient quantity of 
water, and when thoroughly saturated with this solution 
it is again dried. It is next placed in milk of lime made 
up with slaked lime and a quantity of water, which is 
adjusted in accordance with the porosity of the wood, and, 
when the lime has completely penetrated into it, it is once 
more dried. The wood is now perfectly waterproof, and 
is ready for employment in the production of parquetry, 
tarsiatura, marquetry, etc., or for forming the outer layer 
of any of the pressed objects made according to the above 
process. To ensure its firm adhesion, it is applied to the 
surface of the pressed object which has already been 
covered with the waterproof cement, and the composite 
object is then replaced in the same heated mould as was 
used for the compression of the powder. The heat softens 
the cement, and by a prolonged pressure the outer layer of 
wood is so firmly joined to the moulded object that after 
complete cooling the two cannot be separated. 

The articles prepared by the above process are said 
neither to swell nor shrink, neither do they get soft; they 
also resist the action of moisture and even of rain com- 

9. Hur tig's Improved Wood -composition. 

Hurtig has recently .improved his process, and now 
operates as follows: In the preparation of the powder for 


pressing into forms with a surface exhibiting relief it is 
desirable to add materials to the powder which will give 
it greater plasticity than is required for objects with 
plane surfaces. The mode of preparing the powder is 
varied according to whether high relief or low relief is 

A. Preparation of the Powder for Low Relief. To the 
sawdust, which has been treated with soap and milk of 
lime and then air-dried, a mixture of casein and air- 
slaked lime is added. The lime and casein should first be 
allowed to react until they form a pasty mass or liquid. 
After the sawdust has been thoroughly saturated with this 
liquid it is air-dried, and is then ready for pressing. Suit- 
able proportions are : 5 to 10 litres of sawdust, O'l to 0'5 
litre of soap, 3 to 8 litres of casein which has been com- 
bined with 0'5 to 3'0 litres of dry air-slaked lime. These 
proportions are the limits within which the quantities may 
be varied; but we do not assert that these limits are in 
no case to be exceeded. 

B. Preparation of the Powder for High Relief. For the 
production of objects in high relief, from deep moulds, 
it is necessary that the powder should not only possess 
great plasticity, but that whilst warm it should remain 
flexible in order that it may be removed from the mould 
without injury, and should harden only when it becomes 
cold. This is attained in the following manner : Ripe 
potatoes are dried in their skins till they have lost 20 to 
30 per cent, of their water. They are then crushed, and 
mixed with fine infusorial earth and a little Burgundy 
pitch. This mixture is added to the wet sawdust, and 
after mixing well the whole is air-dried. It is desirable 
to use unpeeled potatoes in order that the corky tissue of 
the skins, and the albuminous substances of the layer of 
cells immediately below the skin, may remain in the 
mixture. The proportions are as follows : 10 to 30 litres 


of prepared sawdust, 15 to 40 litres of crushed potatoes, 
1 to 5 litres of infusorial earth, and 0'5 to 2'5 litres of 
Burgundy pitch. These proportions also can be varied if 

The powder thus prepared has not only the high degree 
of plasticity required, but even in very hot moulds it 
retains its original pale colour. Any desired colour can 
be given to it by the addition of mineral pigments which 
are not altered by heat, so that in all cases where the outer 
layer is to consist of metal the colour of the body may 
harmonise with that of the applied coating. The pressing 
and other treatment of this powder is performed exactly 
as described above. 

10. Kletzinsky's Wood-paste. 

One hundred parts of wood-meal, best that of soft 
varieties of wood, are well boiled in a solution of 
100 parts of .aluminium sulphate, and then left to 
become cold : 50 parts of glue are dissolved in 100 
parts of boiling water and intimately mixed with the 
wood-meal pulp, the paste is rolled out into slabs and some- 
what strongly pressed. The slabs, which at first are 
very brittle, acquire by slow air-drying an extraordinary 
degree of hardness ; as soon as they are hard enough they 
are moistened with a 5 per cent, solution of potash in 
water three to five times, and are then finally dried; by 
this means the individual wood-particles become cemented 
together by a compound of gelatin and alumina, which is 
insoluble in water, and when dry has the 'hardness of 
horn. If it is desired to produce a coloured paste the 
meal of raw dye-woods may be used, or any suitable colour- 
ing matter may be added, or a mottled appearance may be 
given by adding variously coloured wood-meal and mixing 


11. Terra-cotta Wood. 

This artificial product is prepared by Gillmann's pro- 
cess in the following manner : According to the degree 
of porosity which it is desired to obtain, 1 to 2 
parts of sawdust of resinous wood are mixed with 
1 part of pulped china-clay, and by the addition of a 
suitable quantity of water a plastic mass of spongy 
texture is prepared, which is then submitted to the 
strong pressure of a steel piston in a metallic cylinder. 
This produces cylindrical blocks 20 to 30 cm. (8 to 12 
inches) in diameter and 1'2 to 1*9 metre (47 to 75 inches) 
long. These are first air-dried, then dried in a stove, and 
finally burnt at a white-heat in a kiln, and slowly cooled. 
The blocks are extraordinarily refractory, and are capable 
of being sawn, cut, planed, and poilished. Their density is 
about half that of ordinary bricks. These blocks have 
great strength, and are employed for architectural 

12. Palmer's Wood-composition. 

This material, which is alsoi used as a substitute for 
wood-carvings, consists of blood, sawdust, bone-dust, and 
glue. The blood is dried without coagulating its albumin, 
and is then mixed with a suitable quantity of sawdust, 20 
per cent, of bone-dust, and 10 per cent, of glue solution, 
and is strongly pressed into moulds at a temperature of 
1200 C. 

13. Billef eld's Artificial Wood. 

Ch. Billefeld has produced a number of these com- 
positions. That for making casts by pouring in a 
liquid state into a mould consists of a mixture of 
vegetable fibre, paper half-stuff, caoutchouc, glue, balsam 
of sulphur (a solution of sulphur in linseed oil), glycerine, 


and gluten. Another composition for the same pur- 
pose consists of half-stuff, vegetable fibre, tannin-gelatin, 
gutta-percha, Venetian turpentine, balsam of sulphur, 
and gum thus. The tannin-gelatin is prepared by treat- 
ing glue with the tannin from oak-bark. A third com- 
position, from which billiard-tables and similar articles 
can be made, is prepared from a paste of 80 parts of water, 
32 parts of flour, 9 parts of alum, and 1 part of iron 
vitriol; then 15 parts of rosin and 10 parts of linseed oil 
are boiled with 1 part of flake litharge, and finally 35 to 
60 parts of tow, or, better, wood-pulp, are added. The 
solid constituents are ground as fine as possible, and the 
whole paste is well kneaded together and then rolied out. 
It is then treated with hot linseed oil to render it water- 
proof. Objects, such as bas-reliefs, chapiters, cornices, 
etc., were shown by Billefeld in the London Exhibition of 
1862. These compositions can be worked up into the 
most varied articles. One of their applications is to the 
covering of walls, and for this purpose Billefeld's artificial 
wood is that mostly employed. Artificial wood presents 
the very great advantages of resisting the action of fire, of 
being a bad conductor of heat, and of not being attacked 
by vermin. Its hardness is equal to that of the hardest 
woods, it works well with tools, and can even be bent. On 
this account it has been recommended for making furni- 
ture, carriages, etc., and in such cases, to give it the power 
of resisting weather, it is soaked in a solution of asphalt. 
A specimen of such artificial wood was examined by Dr. 
Sauerwein. It comes into commerce in slabs of about half 
a square metre, and of different thicknesses. The thickest 
slabs have a glazed coating of a brownish-red colour on one 
side ; three other kinds were without the glazing, but were 
coated with coarse linen. The grey, fibrous composition is 
fairly hard, so that it can only be cut with some diffi- 
culty ; it cannot be bent far without fracture. Its strength 


is about that of fir-wood cut across the grain, as it is 
ruptured by a strain of 45 to 46 kilos, per square centi- 
metre, whilst the breaking strain of fir-wood cut across the 
grain is 39 to 59 kilos. It possesses a slight degree of 
flexibility, a slip of it 15 mm. wide, 7 mm. thick, and 33 
cm. (13 inches) long, supported at its ends and loaded in 
the middle, bent about 10 mm. before breaking. It softens 
when soaked in water, slowly if the water is cold, but very 
rapidly if hot. The filtered liquid gave on evaporation a 
residue which carbonised on heating, and with iodine gave 
the characteristic blue colour of starch paste, so that this 
substance was probably employed as a cement. Vegetable 
fibres consisting of refuse tow were easily recognised in 
the pulped mass. The material burnt with difficulty, and 
without giving a flame ; it carbonised and finally left about 
33 per cent, of ash. This consisted of gypsum, alumina, 
ferric oxide, and silica. The brownish-yellow glaze con- 
tained chiefly ochre, clay, and a little glue. 

Another composition consists likewise of large slabs, but 
only 3 to 4 mm. thick. It is covered on both sides with 
coarse canvas, does not admit of being bent, but breaks 
when this is attempted. It likewise softens in warm water, 
giving off a peculiar tarry odour, and the softened mass 
can also be recognised as made up of the refuse of tow. 
According to these results it appears to have been made 
from old rope and sails, with which its tarry odour agrees. 
The water in which it has been soaked shows also the 
presence of starch. When heated it carbonises, and on 
complete combustion leaves about 40 per cent, of ash, con- 
sisting of silica, alumina, ferric oxide, with some calcium 
sulphate. Clay or cement appears therefore to be one of 
its principal constituents. It is therefore composed of 
three main constituents; 1, plant fibre, such as waste flax 
or hemp ; 2, one or more mineral substances to which the 
mass owes its form and strength ; 3, a binding material, 


apparently starch paste. In preparing the material it 
seems to be a point of great importance to have the organic 
fibres sufficiently finely comminuted, in order that they 
may be the more intimately mixed with the other con- 
stituents, and that the composition should finally have 
been submitted to powerful pressure. 

Attempts were made to imitate the material on the 
basis of the analysis, by mixing finely chopped tow, plaster 
of Paris, clay, sawdust, and starch paste. The plaster and 
clay were finely powdered, tempered with the paste and 
then mixed with the chopped tow and the sawdust, well 
kneaded together, and then quickly pressed with a 
hydraulic press. Equal parts of tow and plaster, with \ 
part of clay, or in another experiment \ part of porcelain 
cement instead of clay, gave after drying a very firm 
material, closely resembling the commercial one. The 
glaze was imitated by laying on a mixture of ochre, cement, 
and glue solution. It is, of course, evident that this small- 
scale experiment is not absolutely conclusive as to the 
best materials and proportions for large-scale manufacture. 

14. Ribbach's Sawdust- composition for Coating Floor 
Boards, Table Tops, etc. 

Sawdust, or finely ground hard wood, powdered glass, 
quartz sand or fire-clay, zinc-white, and pigments, are 
intimately mixed in proportions appropriate to the 
different objects for which the material is to be used, 
sifted, and then stirred up with linseed-oil varnish. The 
mixture is then spread, under pressure, on the surfaces 
to be coated, which previously have been cleaned and 
rubbed over with varnish, and is smoothed down. The 
surface may first be divided into compartments by fillets, 
and the compartments filled with differently coloured com- 
positions. Such a flooring, after it has been well scrubbed 
with soap, can be waxed and polished. 


15. Wiederhold's Artificial Wood-composition. 

Wood-pulp, in the form in which it is supplied to paper- 
mills, is regarded by Wiederhold as a suitable material for 
making an artificial wood-composition. The simple com- 
pression to which this has been submitted confers on it a 
remarkable degree of hardness, such as to introduce difficul- 
ties into its employment, since the wood-pulp cakes, once 
dried, are only with difficulty softened by soaking in water. 
The pressed wood-pulp acquires, however, a still greater 
degree of firmness when it is wetted with a weak glue solu- 
tion. Wood-pulp takes the impression of the moulds accu- 
rately. The pressed articles, after drying, are coated with 
linseed-oil varnish boiled to a thick consistence, which is 
laid on boiling hot. By this treatment, which is repeated 
several times, the articles are rendered completely proof 
against the action of water; 'after drying they can be 
rubbed smooth and polished or painted, and then be 
varnished. Wood-pulp can be mordanted and dyed of any 
desired tint; the mordant must, of course, be applied 
before the linseed-oil varnish, or better still, before press- 
ing into the moulds, though this is not absolutely necessary. 

The employment of wood-pulp for the manufacture of 
moulded articles of the most varied kinds should prove 
more advantageous than the use of sawdusit and blood, 
and solves the problem of the preparation of wooden 
articles by pressing into moulds in a far simpler and mor^ 
economical manner. 

16. Artificial Wood of Back and Potin. 

Back and Potin of Paris have invented a process for the 
manufacture of artificial wood, which yields very beautiful 
products, imitating most closely the different varieties of 
natural wood. This artificial wood consists of sawdust and 
glue, which by treatment with either tannin or alum has 


been rendered insoluble in water after drying. In its 
original pulp form the product can take any shape or 
impression, and the most practised eye cannot distinguish 
the moulded objects from actual carvings. 

17. Wood-composition of Cohnfeld. 

To obtain an artificial wood-composition, Cohnfeld 
moistens the more or less finely subdivided waste of 
wood, straw, hay, leaves, bark, etc., singly or mixed, 
with a solution of zinc chloride of about T028 specific 
gravity, and allows the zinc chloride to act on the 
raw material until it becomes dry. Thereupon follows 
a treatment with basic magnesium chloride solution, 
of specific gravity T725 to 1'793, after which the well- 
mixed composition is pressed into moulds. The composi- 
tion is left under pressure for 10 to 12 hours, during which 
time it hardens in consequence of the heat which it de- 
velops. The objects are then allowed to dry for several 
days in a warm, airy place, and are then placed for 10 or 
12 hours in a strong solution of zinc chloride, of specific 
gravity about T205, and are finally dried. By this treat- 
ment it is said that a material is obtained which can be 
worked just like a hard wood, viz., sawn, planed, bored, and 
polished, which is fire and waterproof, unattacked by weak 
acids or caustic lyes, and not affected by changes of 
weather, and is therefore highly suitable for architectural 
or decorative use, with the advantage that it does not warp 
like wood, but reitains its original form unchanged. 

18. Sciffarin (Wood-cement} 

is a mixture of sawdust, hemp fibre, starch-meal, gelatinous 
and mineral substances, the preparation of which is kept 
secret, and which has been used for the production of 
ornamental articles. This very strong 1 and elastic com- 
position is capable of taking a high polish. 



IN the manufacture of explosives sawdust is used for 
three distinct purposes : (1) The sawdust is wetted with 
solutions of various salts, then dried and mixed with sub- 
stances which in contact with the salts absorbed by the 
sawdust produce an explosive action. (2) It is used for 
absorbing nitroglycerine, both on account of its great capa- 
city fo<r taking up liquids and of the large quantity of gas 
developed by the combustion. (3) The wood-fibre is con- 
verted into pyroxyline by nitrating it with nitric acid, 
although for this purpose it is usual to employ a purer 
cellulose than sawdust. In all cases in which sawdust is 
used for absorbing a liquid it must first be strongly dried, 
as the presence of any moisture would detract from its 
absorptive capacity. When sawdust is to be nitrated it is 
generally first boiled repeatedly with solutions suitable for 
removing from it as far as possible everything except the 
pure cellulose. These processes as well as the nitration are 
somewhat complicated and require special apparatus ; 
their description lies beyond the limits of the present work, 
otn which ^account I confine myself to the mere mention of 
some of the products, and a very brief notice of the 
methods of manufacture. 

1. Sawdust Blasting Powder. 

This explosive is made from nitrate of potash, nitrate of 
soda, chlorate of potash, sawdust, tan, and sulphur, and is 
prepared in the following manner : 


The nitrates of potash and soda and the chlorate of 
potash are dissolved together in boiling water in a pan. 
After boiling for 5 minutes the tan or sawdust, or the 
mixture of both, is thrown into the solution and thoroughly 
mixed. The mixture is turned over to a trough, mixed 
with flowers of sulphur and then dried. If tan is used it 
is either sifted and only the finer portions used, or it is 
ground. The blasting powder prepared by this process 
explodes very sharply, and is suitable for filling bore holes 
in rock where it is not possible to ram the powder 
down. This powder explodes by concussion, and on this 
account there should not be more than 25 per cent, of 
chlorate of potash present. To prepare a stronger powder 
which will not explode on concussion the two nitrates 
may be dissolved together without the chlorate; after 
absorbing this solution by sawdust, the boiling solution of 
the chlorate prepared apart is poured over the mixture, 
and the addition of sulphur, etc., proceeded with as before. 
To obtain a slower burning powder the chlorate may be 
mixed with the other materials as a fine powder instead of 
dissolving it. To obtain a weak powder the chlorate or 
the nitrate of potash, or both, may be omitted. 

The proportions for 100 kilos, of the mixture are: 

30 litres of water. 

35 kilos, of nitrate of soda (Chili saltpetre). 

4 ,, nitrate of potash. 
6 ,, chlorate of potash. 

5 sulphur. 

23 ,, sawdust or tan. 

30 litres of water. 
15 kilos, nitrate of soda. 

2 ,, nitrate of potash. 

3 ,, chlorate of potash. 
25 ,, sawdust or tan. 

For the most energetic explosive the quantity of nitrate of 
soda is diminished and that of chlorate of potash increased. 


adding the latter either in powder or in solution to the 
mixture of the nitrates with the tan. 

Another proportion which also gives a powerful ex- 
plosive is : 

10 kilos, of nitrate of potash. 

5 nitrate of soda. 

These are dissolved in warm water 'and the solution well 
mixed with 20 kilos, of sawdust ; the mixture is then trans- 
ferred to a tray, stirred up thoroughly with 5 kilos, of 
powdered chlorate of potash, and lastly 5 kilos, of flowers 
of sulphur are added and mixed in. 

2. Heraklin. 

This blasting powder has already been employed in the 
Austrian and French coal mines : the gaseous products it 
yields are harmless, and it burns somewhat slowly, so that 
the rock is merely torn down and not scattered about. 
According to the English patent of Dickerhoiff (Vienna) 
10 parts of siawdust saturated with a solution of picric acid 
and saltpetre and dried, are mixed with 17^ parts of salt- 
petre and 7J parts of sulphur. The solution for soaking 
the sawdust is made up with 1 part of picric acid and 
1 part of saltpetre in 60 parts of water for 30 parts of 

3. Lignose. 

A blasting powder made of wood-fibre (sawdust, ground 
wood or cellulose) soaked in nitroglycerine is called lignose 
by Trutzschler-Faltenstein ; the wood-fibre serves in this 
case merely for the absorption of the nitroglycerine instead 
of the infusorial earth usually employed. 

4. Robandi's Brise-rocs. 

This explosive consists of 40 parts of nitrate of potash, 
20 parts of nitrate of soda, 15 parts of sulphur, 1 part of 
rock-salt, 5 parts of coal, 15 parts of woody substance (saw- 
dust or tan). 


5. Carbazotine. 

The explosive known by the name of carbazotine con- 
sists of 50 to 60 parts of potassium, sodium, or calcium 
nitrate, 13 to 16 parts of tan or sawdust, 14 to 16 parts of 
sulphur and 9 to 18 parts of soot. 

6. Reynaud's Pyronome. 

For the preparation of this explosive 52J parts of sodium 
nitrate are dissolved in the least possible quantity of hot 
water, 27^ of spent tan or sawdust, and 20 parts of 
powdered sulphur are stirred in and the mixture is dried 
with the necessary precautions. 

7. Poch's Poudrolith. 

A mixture is made of 3 parts of spent tan, 5 parts of 
sawdust, 3 parts of barium nitrate, 3 parts of sodium 
nitrate, 6 parts of wood-charcoal, 12 parts of sulphur, and 
68 parts of potassium nitrate. The barium and sodium 
nitrates are first dissolved in hot water, the tan and saw- 
dust are thrown into the solution, and the mixture 
thoroughly dried at a gentle heat. The dried mixture is 
powdered and the other constituents, also in fine powder, 
are intimately mixed with it in a rotating drum. 

8. Volkmanris Wood-powder. 

This powder is made by soaking sawdust in solutions of 
yellow prussiate of potash (potassium ferrocyanide) and 
saltpetre, of which the proportions may be varied, and then 
strongly drying the product. 

9. KoppeVs Safe Blasting Powder. 

Two varieties of this blasting powder are manufactured, 
the first for hard, the second for soft rock. Their composi- 
tion is as follows : 


I. II. 

Potassium nitrate . . . ; . . 35-00 42-00 

Sodium nitrate 19-00 22-00 

Refined sulphur 11-00 12-50 

Sawdust 9-50 19-00 

Potassium chlorate .... 9-50 

Wood-charcoal . . . . . 6-00 7 -00 

Sodium sulphate . . . . 4-25 5*00 

Refined sugar . . . . ... 2-25 

Picric acid . . . ' . . . 1-25 1-50 

Potassium ferrocyanide . . . . 2-25 

Each of the materials is pulverised alone and they are then 
mixed in a wooden drum. The mixture is moistened with 
10 to 15 per cent, of water and stirred until somewhat 
large lumps are formed, which are then slowly dried and 
freed from dust by a sieve. The advantages of this blast- 
ing powder are its cheapness and its indifference to friction 
and concussion. It explodes only when brought in contact 
with burning or incandescent substances. 

10. Diorrexin. 

According to an analysis by Fels the composition of 
this explosive is as follows : 

On 100 parts 

of dry 

Picric acid . . . -..'-. 1'50 1-65 

Wood-charcoal . . . . . 6'82 7'49 

Beech-wood-sawdust . . . . 9-98 10-97 

Potassium nitrate . 38-93 42-78 

Sodium nitrate . . - . . . 21-07 23-16 

Sulphur . . . . . . . 12-20 13-40 

Water . . . .... 9-00 

Loss . . . . . . . . 0-50 0-55 

Equal volumes of diorrexin and ordinary powder exert the 
same explosive force. But the fact that diorrexin is 25 
per cent, lighter and costs i less than black powder gives it 
the preference. 


11. Pyrolith. 

Wattlen gives the name pyrolith to a blasting powder 
of which he makes two kinds, one for hard rock, such as 
granite, etc., the other for soft rock, such as limestone, 
coal, etc. 

The variety for hard rock consists of : 

12 '5 parts of sawdust. 

67'5 ,, ,, potassium nitrate. 

20-0 flowers of sulphur. 

That for soft rock is composed of : 
ll'O parts of sawdust. 
50'5 ,, potassium nitrate. 
16'0 ,, ,, sodium nitrate. 
1'5 ,, ,, powdered charcoal. 
20-0 flowers of sulphur. 

12. New Dynamite No. III. 

Under this name a blasting powder is now manufactured 
which is a mixture of charcoal (or wood-meal), sodium 
nitrate, and sulphur, impregnated with nitroglycerine. 
According to Munch the percentage composition is 20 
parts of nitroglycerine and 80 parts of a mixture consisting 
of 75 parts of sodium nitrate, 10 of sulphur and 12 of wood- 
meal. According to Gohl it contains 12' 15 per cent, of 
nitroglycerine, 13'9 per cent, of sulphur, 56'4 per cent, of 
sodium nitrate, 13'86 per cent, of charcoal (or wood-meal), 
and 4' 16 per cent, of water (inclusive of loss in analysis). 

13. Powder of Kellow and Short. 

The following formulae are given: 

i. n. in. 

Potassium chlorate . 12 parts 6 parts 10 parts 

Sodium nitrate . . 30 36 10 

Potassium nitrate 8 4 20 

Sulphur ... 10 10 

Tan and sawdust , , 42 50 46 



The tan and sawdust are soaked in a solution of the 
salts, the flowers of sulphur are then mixed in and the 
mixture is dried. According as the potassium chlorate is 
employed in the dissolved or solid state, and according as 
it is increased or decreased in proportion to the sodium 
nitrate, the powder develops more or less energy. 

14. De Tret's Blasting Powder. 

52'5 parts of sodium nitrate are dissolved in the requisite 
quantity of boiling water, and the solution is poured upon 
27'5 parts of tan, which is thoroughly saturated therewith. 
Then 20 parts of flowers of sulphur are mixed in. The 
mixture is dried and packed. 

15. Haloxylin. 

Most kinds of explosives contain sulphur; some, how- 
ever, are made without that ingredient, as for example 
Fehleisen's haloxylin. It consists of : 
45 parts of saltpetre. 
3 to 5 parts of wood-charcoal. 
9 parts of sawdust. 

1 part of potassium ferricyanide. 

The sawdust, charcoal, and saltpetre are intimately 
mixed, and to each 100 kilos, there is added a solution of 
potassium ferricyanide in 2 litres of water, to increase its 
explosive energy. The mass is then, like ordinary gun- 
powder, pressed, granulated, dried, and if necessary 

16. Oiler's Blasting Powder. 

Oiler's blasting powder consists of : 

66 parts of potassium nitrate. 

2 ,, potassium chlorate. 

20 ,, ,, sulphur. 

3 wood-charcoal. 

2 ,, ,, animal-charcoal. 
6 ., sawdust. 


17. Blasting Powder of Terre and Mercadier. 
51^ parts of potassium nitrate. 
16 sodium nitrate. 
Ifc coal. 
11 ,, sawdust. 
20 ,, sulphur. 

18. Schultze's White Gunpowder and Blasting Powder. 

Thin slices of wood are cut by a stamp into small cubical 
grains of the size of barley-groats. These are then boiled 
with dilute soda solution to remove the sap-constituents, 
then washed repeatedly, dried, submitted to the action of 
bleaching powder and again washed and dried. They are 
then nitrated with a mixture of nitric and sulphuric acids, 
the acid is removed by a centrifugal machine, the product 
is thoroughly washed and dried, then soaked in a solution of 
potassium or barium nitrate and again dried. 

Schultze's powder has greater ballistic energy than 
common gunpowder, its smoke affects the organs of respira- 
tion less, it leaves a very small ash, and it can be stored 
and transported without the slightest danger, because it 
can be wetted and redried. Although higher in price than 
ordinary powder it is more economical in consequence of 
its greater efficiency. 

19. Dy's Yellow Gunpowder. 

This product only differs from Schultze's in the respect 
that instead of wood-grains the ground wood prepared for 
paper-making is nitrated after granulating. Sawdust may, 
of course, be used with the same result. 

20. Lannoy's White Powder. 

This is a mixture of coarsely powdered sulphur and salt- 
petre with addition of some form of pyroxyline such as 
nitrated wood, nitrated sawdust, or nitrated bran. It 


dislodges the rock without any considerable shattering or 
scattering. It is difficult to ignite and burns slowly. In 
hard rock it is more effective than in coal or shale ; it is 
more costly to manufacture and gives a suffocating smoke, 
so that its freedom from danger is its only recommenda- 
tion. According to analysis it contains 65 parts of soda 
saltpetre, 13 of sulphur, and 22 of wood-fibre. 

21. Lithofracteur. 

The name lithofracteur is used for certain blasting 
powders which consist of nitroglycerine absorbed by 
materials which are themselves explosive. When exploded 
they are converted almost wholly into gases of high tem- 
perature and pressure. The absorbing substances are pre- 
pared sawdust, coal, bran, etc., and the finished product 
contains 55 per cent, of nitroglycerine. The preparation 
of the sawdust consists in freeing it from resin and satu- 
rating it with saltpetre. 

22. Brain's Blasting Powder 

consists of a mixture of potassium chlorate, potassium 
nitrate, wood-charcoal, and fine oak sawdust; 60 parts of 
this mixture are then caused to absorb 40 parts of nitro- 
glycerine. Its explosive force is 25 to 30 per cent, higher 
than that of an equal weight of dynamite. 

~ > A 




CONSIDERING the relatively high heating value of saw- 
dust, and the difficulty of burning it in the loose condition 
in ordinary fire grates, the obvious method suggests itself 
of bringing it into a compact form by the addition of some 
kind of binding material, and submitting it to high pres- 
sure, so that a handy, clean, compact fuel may be produced. 
The various binding agents, resin, tar, water-glass, Iceland 
moss, etc., which are used for making coal, coke, and char- 
coal briquettes, may also be used in this case, but as a rule 
the cost of converting sawdust into briquettes is too high 
to render possible an extensive use of the process. The 
making up of sawdust into briquettes, both for burning 
into charcoal, and for distillation, has, however, been 
adopted of late, and apparently with fairly good results. 

One of the most important conditions for the formation 
of briquettes is that the sawdust must be as dry as possible, 
another condition being that rather powerful presses must 
be employed for the mixture of sawdust and binding 

In pressing sawdust into briquettes, G. Grimm aims at 
obtaining a kind of felting of the material. A quantity 
of the sawdust sufficient to form a thin layer is first pressed 
into the mould ; a further quantity is then added and the 


pressure reapplied, and so on until the desired thickness 
is produced. By this method, in which each block is built 
up gradually from thin layers, a very perfect incorporation 
of the layers results from their mutual interpene-tration, 
and the product possesses a degree of cohesion which 
renders it well fitted both for carriage and handling in 
general. Moreover, when using the briquettes as fuel, a 
certain loosening of the layers is brought about by the 
heat, so that the whole mass is brought into a state of 
combustion more rapidly than would be the case if its 
contexture uniform throughout. This property is 
also valuable when the briquettes are submitted to dry 
distillation, since the volatilisation of the products of dis- 
tillation proceeds more rapidly and uniformly throughout 
the whole mass of the briquette than is the case with 
those prepared by other processes. 

Amongst the newer processes for the manufacture of 
briquettes may be mentioned that in which the waste 
liquors from the sulphide pulp manufacture is utilised. 
The sawdust also small charcoal and charcoal powder is 
mixed with the inspissated waste lye by a mixing machine, 
and very serviceable briquettes are obtained by pressing 
the mixture. The briquettes produced have an agreeable 
appearance, are firm, coherent, and do not become damp 
as would have been expected from the hygroscopic 
character of the dry residue of the lye. 

According to Meyer, waste or comminuted wood is 
steamed until its elasticity is destroyed, and the blocks 
obtained by pressing it are then submitted to distillation, 
whereby it is stated that a very solid charcoal is obtained. 

Pfropfe prepares briquettes from 2 parts of small wood 
and 1 part of tar, by shaping the mixture, either by hand 
presses or mechanical presses, into blocks or bricks, which 
are then distilled. The condensable products of distilla- 
tion separate into aqueous and oily layers which are 


separated automatically. The residue in the retort is said 
to be pure charcoal. 


Resin is dissolved in petroleum by stirring or shaking; 
and during this operation, which takes about 40 minutes, 
finely powdered caustic soda, or another alkali, is gradually 
added. At the same time dry sawdust, or some similar 
absorbent material, is put in. The soda may be crushed 
under petroleum to prevent it from taking up moisture 
from the air. Powdered soda which has been slightly 
moistened with water may indeed be used, but the quan- 
tity of water must not be large enough to make the soda 
pasty. The operation is conducted in a receptacle 
furnished with stirring, or better with shaking, machinery. 
After thorough blending the mixture is removed from the 
receptacle and very soon becomes solid. 


Molasses is a very suitable binding material for the pro- 
duction of briquettes from sawdust, small charcoal, and 
charcoal powder. Salterey describes his process, which can 
be employed for any combustible material, or even for ores, 
as follows : Experiments have shown that all kinds of sugar- 
molasses, whether dialysed or not, may be used for the pur- 
pose. The process is a very simple one. The sawdust, from 
which coars3 fragments of wood should be removed, is dried 
until at least the greater part of the moisture is removed, 
and then moistened with diluted molasses and thoroughly 
amalgamated in a mixing machine, such as is commonly 
employed for the manufacture of briquettes. The quantity 
of the binding material must be adjusted according to the 
dampness of the sawdust, only so much being added as to 
make the mixture feel moist. After the requisite blending 


the powder is strongly compressed into moulds, and the 
bricks are allowed to dry for some time in airy situations 
before they are put to use. 


In order to use up wood-waste most advantageously it is 
desirable to reduce the loose, pulverulent material to a 
compact form, and for this purpose the briquette form is 
the most appropriate and obvious. Amongst the newer 
processes which endeavour to solve the problem in this 
manner may be mentioned that of Bergmann, according to 
which the sawdust, after thorough drying, is merely com- 
pressed by high hydraulic pressure into the form of solid 
briquettes. This proved impracticable, even with a pres- 
sure of 300 atmospheres (2 tons per square inch), without 
previous heating to 130 C. A new patent prescribes a 
pressure of 1000 to 1500 atmospheres (6f to 10 tons per 
square inch), but it is obvious that the use of such 
enormous pressures is not only attended with many diffi- 
culties, high cost, and frequent repairs, but also with con- 
siderable danger and inconvenience. 

Fr. Arnold of Magdeburg has constructed a knee-press, 
in which by a steel lever a very high pressure can be 
obtained with a relatively small expenditure of force, and 
with which both sawdust and shavings can be compressed 
into solid blocks, convenient either for burning or car- 

According to a patent taken out by E. Leinhaas of 
Freiberg in Saxony (D.R.P. 86143) the preparation of such 
briquettes may be accomplished, without either high pres- 
sure or heat, by using the lime-mud residue from the dis- 
tillation of acetic acid as a binding material for sawdust. 

Waste vegetable substances, sawdust, tan, etc., are air- 
dried and then mixed with the limenmud in simply con- 


structed mixing machines. The mixture is made into 
briquettes by either screw presses, or other well-known 
briquette presses the adoption of the special form of press 
depending on the daily output required and is then car- 
bonised in a special apparatus (D.R.P. 30338), the gases 
being passed through a chamber in which the briquettes 
were stacked up before the fire was lit, and working at 
first at a low temperature. The tar-vapours are pre- 
cipitated on and are absorbed by the briquettes. The 
temperature is then gradually raised, whereupon the more 
volatile portion of the tar is driven off, whilst the heavier 
constituents of the tar carbonise in the interior of the 
briquettes and bind together the particles of wood. 
Simultaneously with the distillation products from the 
sawdust, etc., acetic acid is evolved from the lime-mud, 
chiefly in the form of acetone. The gases are freed from 
acetic acid, acetone, tar, etc., by cooling, and the uncon- 
densable gases are used for heating. The carbonisation is 
at an end as soon as the gases are found to be free from 
condensable products : the time required is easily judged 
after some experience. The carbonised briquettes are 
somewhat cooled in the furnace, and are then transferred 
to air-tight cooling chambers. These charcoal briquettes 
form a far more valuable combustible than ordinary wood- 
charcoal, and furnish an incandescent fuel such as is re- 
quired for heating railway carriages, flat irons, etc. Such 
a fuel was formerly obtained by powdering wood-charcoal, 
mixing it with soda, pressing into moulds and heating to 
redness. But by the above process the incandescent fuel 
is obtained direct at the first carbonisation, and the chief 
difference is the introduction of lime from the lime-mud 
instead of soda. 



The use of sawdust in the manufacture of potttery is con- 
nected with its property of lightening clay- the specific 
gravity of sawdust is very low and of carbonising or 
burning away completely to an ash during the subsequent 
firing, in consequence of which a further lightening, and at 
the same time porosity, are produced. It is, for instance, 
in this way that the Alkarazzas, those porous clay bottles 
formerly used by the Arabs for cooling water, which have 
continued in use in Spain and have lately been introduced 
into Germany, are made from clay with which fine saw- 
dust has been mixed. During the firing of the vessels the 
sawdust is burnt off, and the clay is left with a multitude of 
minute pores, by which the water oozes through the walls. 
On the exterior of the vessel the water evaporates, and by 
rendering heat latent keeps the contents cool. 

In the same way porous plates are manufactured for 
drying substances containing much water, as for example, 
starch. These plates are capable of absorbing much larger 
quantities of water than merely unglazed earthenware. 

Bricks of greater or less porosity for building purposes 
can be obtained by the addition of a larger or smaller pro- 
portion of sawdust to the brick-earth. When such bricks 
are used for house walls, they produce far warmer rooms 
than common bricks, because the air in the pores is a 
worse conductor of heat than the clay. Moreover their 
weight is considerably less than that of ordinary bricks, 
and they can therefore be used for the construction of fire- 
proof walls in situations where a heavy weight is inadmis- 
sible, or for building arches which will bear less heiaviiy 
on their abutments. The use of such bricks is of high 
antiquity ; in ancient Rome pumice was used in making 
them, but where that was not procurable clay was mixed 


with substances which became consumed whilst the bricks 
were being burnt. 

Sawdust is particularly suitable for this purpose, since 
the pores can be made larger or smaller according to the 
coarseness of the sawdust; moreover, it burns away at a 
low temperature, and leaves no detrimental residue, for the 
small amount of potash which the ash contains can have 
no injurious effect on the quality of the bricks. 

A very modern product is the cement composition used 
for light partition walls, for plastering ceilings, etc. It 
is prepared by mixing cement or plaster or Paris with saw- 
dust in various proportions, and casting the mixture into 
planks, or mouldings, either with or without a skeleton of 
wire netting. The use of sawdust as an addition to mortar 
for stuccoing the fronts of houses, etc., is well known, and 
such mortar finds various applications. Rohde, for plaster- 
ing walls and ceilings, and in damp rooms, employs a 
mortar composed of freshly slaked lime and the sawdust 
of soft wood, which should be in as fibrous a condition as 
possible. The quantity of lime should only be just large 
enough to allow the mixture to be laid on. This mortar 
forms a felt impregnated with lime, and is so light that if 
struck the injury does not extend beyond the spot on 
which the blow falls, whilst a coating of it which was laid 
on an extremely damp wall showed no change in solidity 
or in appearance in the course of eight years. Rohde 
especially recommends it for plastering mud walls and pise 
work, as well as for roofs coated with clay. Even on the 
plank walls of an ice-house, against which the ice was 
packed tight, a plaster coating of this material 1 centi- 
metre thick adhered firmly and remained sound. Rooms 
which have had their walls plastered with this composition 
can be papered in a few weeks. 

Two American inventors have proposed to use sawdust 
instead of sand in stucco and wall plaster, in order to 


lighten the mixture and secure firmer adhesion to the wall, 
An old practice was to use sawdust for covering up objects 
exposed to rain, cold, etc. ; one of these patents proposes 
simply the use of a mixture of equal parts of sawdust 
and plaster of Paris or cement; the other gives the 
fallowing : 

4 parts of a mixture of slaked lime and sawdust. 

1 part of plaster of Paris. 

| glue. 

rV glycerine. 


By the use of s<awdust the formation of cracks in wall 
plaster may be prevented, and on this subject the following 
statement has been made : 

" The house in which I dwell lies very high and exposed, 
so that the copious rain, which here in the neighbourhood 
of the sea falls almost continuously during the equinoxes, 
fills every chink in the outer cement on the weather side 
of the house, especially on the upper surfaces of the breast- 
mouldings and plinth-mouldings, with water. These 
crevices are then gradually widened and extended by the 
formation of ice, so that in the spring large surfaces of 
the cement peel off. To remedy this inconvenience, which 
annually repeated itself in the same situations, and which 
was the more expensive and troublesome because the 
freshly stuccoed surfaces always required painting with 
oil, I had, without success, employed the most varied 
means, when the idea occurred to me to prevent the forma- 
tion of crevices in the stucco by the addition of sawdust, 
which I expected to have a felting action similar to that 
of calf's hair. The sawdust was strongly dried, then passed 
through a common fruit sieve to remove co-arse chips, so 
that only the small woolly flocks were used. I made up 
the mortar with 1 part of cement, 2 parts of lime, 2 parts 


of sawdust and 3 parts of sharp sand. The sawdust was 
first thoroughly mixed with the cement and sand and then 
the lime added. This had the desired result, for since that 
time even those joints which were not bonded together, 
although, in the finishing cement-coat of these, sawdust 
could, of course, not be used, no crack has shown itself " 
Sawdust therefore fulfils the purpose of matting a plaster, 
so as to prevent it from cracking, far better than hair, 
and in such cases as the foregoing is strongly to be recom- 

Quite recently a commencement has been made in the 
use of sawdust as a non-conductor of heat, by mixing it 
with plaster of Paris, loam, mortar, hair, cork, etc., and 
applying a thick layer to steam pipes, cylinders, heaters, 
etc., round which cloth had first been wrapped, and after 
drying giving it a coat of oil paint. 


This invention relates to a stony composition which 
should be particularly suitable as a building material 
for the construction of walls, flooring, for drying damp 
rooms, for paving stone, and for the building of reservoirs 
and vessels of every kind. It consists principally of wood- 
meal and plaster of Paris, or cement. The wood-meal 
requires to be so prepared that an intimate union of it with 
the plaster or cement may be secured; it also needs to 
be made incombustible and prevented from absorbing 
moisture. It is used in the proportion of 2 parts of wood- 
meal to 1 part of plaster or cement. 

The wood-meal requires boiling for a long time with 
water-glass, powdered asbestos, and a little glue or other 
binding material, in order that the fine particles may be 
thoroughly penetrated by the water-glass, and coated with 


the asbestos. The meal so prepared is not only incom- 
bustible and non-hygroscopic, but, as already mentioned, is 
particularly capable of uniting with plaster of Paris to a 
homogeneous mass of great hardness, such as has not 
hitherto been obtained with wood-meal. 

The wood-meal so prepared is mixed with plaster or 
cement and water and is poured into a mould, in which if 
desired wire netting can previously have been placed. For 
applications of the material in which the greatest possible 
strength is to be attained, the contents of the mould may 
be exposed to pressure whilst hardening. 

After the mixture has hardened, the slabs or other 
objects are burnt in a kiln, or are dried in a stove specially 
constructed for the purpose. 

According to the purposes to which it is to be applied, 
sand, tar, asphalt, and other substances may be added to 
the wood-meal after the boiling with water-glass. 

The material obtained by this process is light and has 
little porosity; it has the great advantage of not being 
hygroscopic or permeable to moisture. Walls built of this 
material may have nails driven into them without any 
damage to the surrounding parts, whilst the nails, on 
account of the firmness of the substance, hold well. More- 
over, in consequence of the treatment of the saw-meal 
with water-glass and asbestos powder, the material is fire- 
proof. The addition of tar acts also as a protection against 
vermin, rotting, and growth of mould. 

The hardness of the substance and the other properties 
mentioned render this material peculiarly fit for paving 
stone. It lasts well, deadens sound, and does not wear 
out the horses' hoofs. 

This material is also a low conductor of electricity, and 
is therefore suitable for insulations. 

In comparison with the well-known practice of coating 
wood with water-glass to secure a better adhesion of 


plaster, it is to be borne in mind that in the new process 
each particle of the wood is thoroughly saturated with 
water-glass by the process of boiling the sawdust in a solu- 
tion of that substance. 


In the employment of wood for paper-making the 
endeavour is to obtain a cellulose as pure and as long 
fibred as possible; sawdust, however, furnishes only very 
short fibres, and is moreover so bulky that the boiling, or 
at least the circulation of the liquid in the boiler, is much 

The apparatus to be described here is intended to over- 
come this difficulty and to render possible the production 
of a serviceable wood-pulp from sawdust, shavings, and 
waste pieces of wood 5 to 8 mm. thick, by a combined 
boiling and grinding process. The apparatus represented 
in vertical section in Fig. 42, and in horizontal section 
through the line, a, a, by Fig. 43, consists of a steam-tight 
cylinder, A, which has a smooth inner surface and in which 
there rotates a central axle, H, carrying a number of 
forked plates, d, d. The forks are provided with adjust- 
able journals, which are connected with the adjusting 
screws, N, N, by springs. In these journals revolve the 
axles, P, of the rollers, K, which, by the rotation of the 
shaft, H, are caused to roll round on the inner surfa/ce of 
the cylinder, A, and to exert upon that surface a greater 
or less pressure according to the centrifugal force deve- 
loped bv a greater or less speed of rotation. 

Instead of the bearings with springs, the construction 
shown in Fig. 44 may be adopted. Here the rollers, K, are 
simply bored out so as to ride loosely on the axles, P, fixed 
to the arms, j, so that they press against the interior of 



the cylinder, A, solely by virtue of the centrifugal force 
developed by the rotation, and in doing so take up a more 
or less excentric position with regard to the axles, P. The 
process is as follows : Through a manhole in the cover of 
the cylinder an appropriate quantity of sawdust, shavings, 
or wood-chips are introduced; water is added in quantity 
sufficient to float the charge of wood. The manhole is 
closed, and through the tangential pipe, T, steam is 
admitted of at least 52 to 53 Ibs. to the inch pressure. 

FIG. 42. Apparatus for Preparing Paper-pulp from Wood-waste 
(Vertical Section). 

The steam throws the mixture into rotation, heats it up, 
and produces a pressure in the cylinder. This treatment 
causes the fibres to acquire a degree of tenacity which 
prevents them from breaking short during the subsequent 
action of the rollers. Some lime, soda, or potash may be 
added to the mass at the outset, by which the fibres would 
be rendered more pliant and be freed from all impurities. 
The mass remains exposed to the action of the steam until 
the fibres have acquired the requisite toughness and 


pliancy. This generally bakes two hours, after which for 
another two hours the mass is gently worked with the 
rollers. The main shaft, which drives the axle, H, by 
bevelled gearing, is fitted with pulleys of two sizes, c, c, to 

FIG. 43. Apparatus for Preparing Paper-pulp from Wood-waste 
(Section through the line a, a). 

FIG. 44. Modified Apparatus for Preparing Paper-pulp from 

give two different speeds. By running the shaft with the 
large pulley, a slow speed and light pressure on the interior 
of the cylinder are obtained. The rollers are arranged so 
as to bear upon almost the whole surface of the cylinder. 



Either a single long roller, or several superposed short 
ones may be employed. By reason of the yielding of the 
springs, the rollers are able to pass over any hard portions 
of the material without injury to the machinery. After 
the machine has been driven for two hours at a slow speed, 
the driving-belt is shifted to the small pulley and the 
rollers thrown into rapid rotation. This throws the wood 
outwards towards the walls of the cylinder, where the 
fragments become more and more crushed up and dis- 
integrated, without, however, any breaking up of the 
fibres themselves. And, as the pressure of the rollers on 
the cylinder is considerable, and the fragments of wood 
pass under them again and again, the individual fibres are 
at last completely separated one from the other. The 
process may be conducted without the addition of any 
alkali, trusting to the action of the steam to produce the 
requisite toughening of the fibres. But in that case the 
operation would require a much longer time. 


The wood-pulp obtained when wood is ground by mill- 
stones with addition of water is essentially different from 
cellulose. It is merely wood reduced to a fine state of sub- 
division, the fibres being still coated with the incrusting 
substance, and may be used as an addition to paper-pulp 
and rags in making common pasteboard. To grind waste 
wood and tail (but not sawdust) to wood-pulp, W. Kapp of 
Berk on the Lippe uses a stone mill with horizontal axes, 
above which is fixed a feeding-box fitted with plungers. 
The material to be ground is filled into the box below the 
plungers, the latter being meanwhile raised by a hand- 
wheel engaging in a pair of racks, which when raised are 
fixed by a ratchet. When the ratchet is released the 
plungers are depressed by a counterpoise. The lower 


edges of the feed-box should not actually touch the stones, 
but the intermediate space should be as small as possible : 
should it become increased by wear, the position of the box 
may be adjusted by means of screws, even whilst the 
machine is running. To prevent the wood-pulp from 
flowing over the ends of the stone rollers, wooden cheek- 
blocks are fitted close to the stones. Whereas, in ordinary 
mills, the use of hard stone is inadmissible, since such stone 
would produce an inelastic, brittle material, in Kapp's 
machine it is advantageous, since the disintegration process 
is a different one, because the material has already been 
partly reduced in size, which produces a much finer fibre. 
The stone requires to have a peripheral velocity of about 
500 metres (1640 feet) per minute. The water required is 
supplied by a pipe as in an ordinary wood-pulping mill. 



SAWDUST should serve very much better for this purpose 
than the hair commonly employed. It must first be well 
dried and then sifted to> remove all coarse particles. A 
mixture is then made with 2 parts of sawdust, 5 parts of 
sharp sand, and 1 part of cement, which are thoroughly 
commingled, and to which 2 parts of lime are then added. 


The outside planks of tree trunks, which are obtained as 
a refuse product when cutting the trees into deals, are cut 
lengthwise by an ordinary circular saw, and each of the 
pieces reduced to the length required for the cask staves. 
Each of these pieces is again cut to the proper width by 
a multiple circular saw, which is fed with the wood by 
means of grooved rollers. Lastly, a circular saw with 
vertical spindle and automatic feed cuts the pieces to the 
size required for the staves. This saw has a diameter of 
600 mm. (23J inches) ; in the middle of the spindle above 
the saw-bench there is a guide rod, at each side of which 
a grooved feed-roller is situated, by which arrangement 


it is possible to cut two pieces of different thickness 
simultaneously. These pieces are then conveyed to the 
trimming and chine-cutting machines, in order to have 
their ends cut to the right bevel and the chine notches 
cut out for the reception of the heads. This machine has 
an axle carrying the knives for cutting the chine notches, 
and two axles for the trimming saws. Both the trimming 
saw and the notching knives can be set to the proper 
distance apart for staves of any required length. 

The staves are fed into the machine by hand, each stave 
being laid with its hinder edge on a rod which moves back- 
wards and forwards in guides. The pieces so trimmed are 
now conveyed to the jointing saw, a machine with a small, 
strong circular saw, to which the pieces are brought upon 
a carriage which runs on rails. This machine gives the 
edges of the staves their exact bevel, no hand work being 
afterwards required to fit them together. For cheaper 
transport the casks are not made up, but the staves and 
heads for each cask are tied into a bundle. The heads are 
cut out in the same fashion from shorter waste pieces, and 
from pieces not suitable for staves. The head pieces are 
dowelled and cut to the circular form by a special machine. 
All the machines can be fed by boys. One set of machines 
will turn out several hundred casks a day. The demand 
for these is almost unlimited, since the users of such casks 
cement makers, millers, nail makers, and fruit merchants 
are always ready buyers. 


For the manufacture of calcium carbide, from which, by 
the action of water, acetylene gas is prepared, either coke, 
coal, or wood-charcoal may be used. According to a 
patent obtained by Wilson of Ontario, the charcoal of saw- 
dust and other wood-refuse can be employed. These sub- 


stances are carbonised by heating in suitable furnaces, and 
the finely powdered charcoal is then mixed with limestone. 
The mixture is then exposed for 10 hours to the heat of an 
electric arc, which is sufficiently powerful to< melt iron and 
boil lead. The product is calcium carbide, which, reduced 
to small fragments, is supplied to consumers in this form 
in tin canisters. 


Sawdust, by itself, has but little value as a manure, 
because it is non-nitrogenous, and even by decomposition 
in the soil by atmospheric influence is incapable of furnish- 
ing any nitrogenous materials to vegetation. Its value as 
a manure is far less than that of straw, nevertheless it 
would be incorrect to regard it as altogether valueless. 
For although the amount of phosphoric acid and potash 
in the wood of coniferous trees is extremely small, never- 
theless in the soil sawdust is rapidly converted into humus 
which for many varieties of soil has at least some value. 
On the other hand, however, it must be observed that 
the pure wood-fibre such as we have it in wood-meal is 
a particularly stable substance, very indisposed to rot 
spontaneously, and that it therefore decomposes so slowly 
that the carbonic acid which it generates is supplied far 
too slowly to have any marked effect on the vegetation 
with which it is in contact. If therefore we disregard its 
mechanical effect its manurial value is almost nothing. 
Its mechanical action, especially its great capacity for 
absorbing liquids, is however so considerable, that from 
this point of view alone it deserves notice, and as a matter 
of fact sawdust is largely used as a mulch. The practice, 
therefore, which has been frequently recommended, of 
mixing artificial manures with long-fibred, woolly sawdust, 
and throwing the mixture into heaps to undergo 1 fermenta- 
tion, is by no means to be rejected. One of the great 


advantages of this method is that the powdery manure 
when applied at a particular spot does not get blown all 
over the place; moreover, the decomposing sawdust ought 
to render the manure more soluble and more rapidly 

1. Richardson's Artificial Manure. 

For the preparation of his artificial manure, Richardson 
employs dry, sifted sawdust, which he moistens with 
muriatic or sulphuric acid and then heats to 130 F. The 
mixture is then either spread on the land as it is, or is 
mixed with blood and heated to 140 F., which causes the 
blood to coagulate. The dry mixture can be packed in 
sacks, distributed to consumers, and used as manure. 
Instead of blood, bone-ash, coprolites, animal charcoal, or 
natural phosphatic minerals such as phosphorite, etc., may 
be added to the mixture of sawdust and sulphuric acid. 
The mixture is thrown into heaps which are then covered 
with straw, old sacks, etc., whereupon by chemical action 
a heat of 100 to 150 F. is developed inside the heaps. 
When the temperature of the heaps has fallen to that of 
the surrounding atmosphere the process may be regarded 
as completed and the product be put to use. 

2. Carbonised Sawdust as Manure. 

To employ sawdust in agriculture it is most advantageous 
that it should be carbonised. With this object charcoal 
heaps (Meiler) are constructed of brushwood, such as broom 
and other dwarf shrubs, and these are gradually filled up 
with sawdust, which is thrown on lightly with the shovel 
in such a way as to leave numerous gaps for the admission 
of air. When the heap is covered with a layer of saw- 
dust, which must not be too thick, the fire is kindled. 
Wherever the fire begins to break through, more sawdust 
15 thrown on, and when the layer has reached a certain 


thickness the heap is allowed to cool. After complete 
cooling the heap is taken apart. The charcoal obtained in 
this way is mixed with liquid manure, urine, phosphates, 
blood, etc., laid up in heaps, and left to itself for some 
weeks. The sawdust must of course be dried before being 
carbonised, and the operation must be carried on in a dry 
locality. This manure has given excellent results with a 
variety of plants. 

3. Manure from Tan. 

1. The production of the manure depends on fermenta- 
tion, and for the formation of the compost heap it is 
desirable to select a place exposed to air and moisture. 
On the spot selected, a layer of tan about 35 cms. (14 inches) 
thick is spread out, and covered with 6 cms. (2| inches) of 
slaked lime : above this a second layer of tan is spread, 
and likewise covered with lime, and the heap is built up 
in this way with alternate layers to a height of 2 metres 
(6J feet). The heap is moistened with water until it heats 
strongly, and the bark, which, on account of the tannin it 
contains, does not readily rot by itself, is brought by the 
lime into a decomposed condition. If it is desired to 
obtain a strongly forcing manure, a layer of powdered 
gypsum (Terra alba) is spread upon the lime, then one of 
fresh, undecomposed horse dung, then tan again, and so on 
to the desired height. Liquid manure and urine are then 
poured into holes made by thrusting a stake into the heap, 
and the whole is left to rot. 

2. The following mixture also gives an admirable com- 
post : 10 parts of well-manured garden soil, 2 parts of 
gypsum, 1 part of quicklime, J part rock-salt, 2 parts of 
wood-ash, 1 part of tan. The whole is well mixed, and 
laid out in a long ridged heap. Whilst mixing, strong 
liquid manure (drainage from the dung heap) is added as 


long as it can be absorbed without causing the mixture to 
cling together. The heap is turned over and moistened 
with liquid manure twice a week for a month. It is 
necessary that it should heat up if it is to prove an effi- 
cient forcing manure. The heating is due to the tan. 
If tan is not obtainable, the dust or refuse from thrashing 
clover seed, rye, wheat, or buck-wheat may be used 
instead; also malt dust, fir sawdust, etc., may be used. 
The heap will begin to heat within 24 hours, and if it is 
regularly turned over and moistened twice a week it will 
be fit for use in a month. 


The curled shavings obtained in planing wood are 
flattened out by hand, after soaking in water or steaming. 
They are laid one on the other and gently pressed for some 
time. They thus become perfectly flat and can easily and 
rapidly be piled up in regular layers, after first dipping 
into thin glue. Care must be taken that the heaps are 
built up perpendicularly, with which object the thin and 
thick parts of the shavings are alternated. The block thus 
obtained should be pressed until the glue is perfectly dry, 
and the result is a solid mass, the thickness of which 
depends on the width of the shavings, and its other 
dimensions on the length and number of the shavings 

These blocks admit of being planed smooth on the sur- 
faces which exhibit the edges of the shavings, and several 
of them can then be glued together. The planed 
surfaces have a very agreeable appearance, and permit 
the construction of mosaic patterns of a very special 
character. With this object the shavings are dyed with 
various colours before they are glued together, care being 
taken that the dye penetrates the shavings thoroughly, and 


then after dipping them into glue the differently coloured 
shavings are alternated when superposing them one on 

By this process very pretty wood-mosaics can be pro- 
duced, which show fine, variously coloured veins, and are 
specially suited for inlaid work and for many other pur- 


These can be prepared as follows: The shavings are 
wound round a short cylindrical rod of wood, both the 
ro$ and the shavings, as well as the exterior of the com- 
posite plug, being smeared with a resinous or caoutchouc 
cement. The rod should be of the same length as the 
width of the shavings, and should have a solid handle by 
which to remove the stopper from the neck of the bottle 
or jar. 

The stoppers are finally immersed to half their length 
in melted paraffin wax, and are then ready for use. 


Parquetry blocks are generally either 59 or 64 cms. (23 
or 25 inches) square. The base blocks for veneered par- 
quetry are at the present day prepared as follows: Pieces 
somewhat shorter than the block to* be made are glued 
together, cut to size, and ledge pieces attached to their 
ends by grooving and tonguing. In Russia a special 
method is in use. The base block is formed of a frame, 
two cross rails, and four panels, and the frames are fur- 
nished with holes and pegs by which they are fitted 
together. The four panels are tongued and grooved into 
the rails and frame, and only the pegs require to be glued. 
The panels are so arranged that the grain of one runs at 


right angles to that of the other. This renders any 
warping of the block impossible, and the shrinkage is 
reduced to a minimum, since only the two frame pieces, 
which lie parallel to one another and the total width of 
which is at most 25 cms. (10 inches), are capable, under 
the most unfavourable variations of temperature, of slightly 
swelling or shrinking. Any waste pieces of wood may be 
used for making these base blocks, as the panels are at 
most 20 cms. (8 inches) long. By using a circular saw 
and a simple drill for boring the holes, these blocks can 
be made with the greatest ease. 

Wooden roof-shingles are still saleable articles, and are 
easily and cheaply cut out with a circular saw. 


Fire-lighters, which can be used for rapidly kindling 
any kind of fuel, are made from sawdust or shavings im- 
pregnated with rosin. The sawdust-lighters are made by 
melting the rosin (the cheapest, darkest quality) in an iron 
pot, adding the requisite quantity of sawdust gradually, 
and thoroughly mixing it in with an iron rabble. The 
sawdust must first be thoroughly dried or the rosin will 
froth up too much. The mixture is then spread out on a 
moulding bench which has been well oiled, and a well- 
greased roller passed over the mass, which presses the 
mixture into the furrows in the bench and at the same 
time reduces it to the proper thickness. The individual 
fire-lighters can then be separated from one another by 
breaking the mass at the indentations, and they are then 
packed and sent to market. 

Fire-lighters of another kind consist of shavings, which 
are unrolled, dipped into melted rosin, and rolled up again. 



Carborundum is prepared by fusing in the electrical 
furnace a mixture of coke and sand, to* which some common 
salt is added to increase its conductivity, and some saw- 
dust to render it porous and furnish an outlet for the gas 
evolved (carbon monoxide) so that explosions may not 

The dimensions of the furnaces are 2' 7 by 0'575 by 0'575 
metres (106 by 22 J by 22 J inches). 

The older practice was to establish an arc between the 
poles ; at the present time a cylindrical rod made of coke- 
powder is laid between them, and this being a bad con- 
ductor is heated by the current to intense white-heat, and 
this enables the process to be conducted much more 
economically. The production of 1 kilo. (2J Ibs.) of car- 
borundum requires at the present time 14' 7 horse-power. 
The current supplied by the Niagara Falls Power Co. has 
a tension of 2200 volts, and is stepped down to one of 185 
volts by a transformer, which was the largest in the world 
before the installation of the one at Buffalo. The effi- 
ciency of the transformer is 96 per cent., therefore out of 
each 1000 horse-power 40 are converted into heat, so that 
ample cooling appliances have to be provided. The thick 
oil with which the transformer is filled is cooled by a 
spiral water pipe, and is kept in constant circulation by a 

The course of an operation is thus described in the 
Journal of the Franklin Institute: During the first half- 
hour after charging the furnace and putting on the current, 
nothing is to be observed ; a peculiar odour is then deve- 
loped and the gas which escapes through the crevices in 
the furnace can be kindled. After three to four hours the 
walls and the upper part of the furnace are completely 
surrounded by the light-blue flame of the carbon monoxide 


produced from the coke and the oxygen of the sand. After 
four or five hours the crown of the furnace begins to sink 
in, and cracks open through which yellow sodium flames 
escape. It frequently happens that the uppermost layer 
is not sufficiently porous to allow the carbon monoxide to 
escape freely : a rent is then formed suddenly, a puff of 
burning gas escapes, and a small crater is instantaneously 
formed which throws out white-hot ashes, a blinding yellow 
flame, and a thick smoke which fills the whole workshop. 
In such cases it is often necessary to shut off the current 
and allow the furnace to cool slowly, so that the faulty 
part can be removed later on and filled up afresh. After 
24 hours the current is interrupted, and the charge of the 
furnace cleared out down to the amorphous outer layer 
of carborundum. This fritted crust, which surrounds the 
core, is broken away, and the crystallised carborundum is 
found inside. This is reduced to powder of different 
degrees of fineness by levigation, much in the same way as 
emery. Its price is from two to five times that of emery, 
but it is lighter and therefore goes further. The Car- 
borundum Co. maintain that their product does its work 
more quickly and neatly than emery. 



IN large saw-mills, carpentry and cabinet-making work- 
shops, etc., a large amount of wood-refuse accumulates for 
which no immediate use can be found, and which in many 
cases is simply burnt. Any of these waste pieces 
not measuring more than 16 \ by 5| inches may be very 
advantageously worked up for wood-wood. Wood-wool 
consists of filaments of various degrees of fineness, and 
with a correspondingly greater or less elasticity, which in 
the comparatively short time that has elapsed since it 
was introduced has already acquired an extensive employ- 

Wood-wool is a clean, dust-free, light, and very elastic 
packing material, and compared with straw, hay, etc., has 
the advantage of not rotting so readily. Being specifically 
lighter than any other packing material, 30 to 40 per cent, 
less of it is required. It is especially suitable for packing 
glass, porcelain, fancy goods, hardware, metal ware, per- 
fumery, drugs, and medical preparations in glass, and other 
vessels, for meat, sausages, fruit, eggs, flowers, etc. 

Wood-wool is employed in metal foundries for wrapping 
round the loam moulds ; it is also a very serviceable stable 
litter where straw is unobtainable, and is much to be pre- 
ferred to either leaves or pine needles. 

Wood-wool is used with advantage for stuffing. cushions, 


and retains its elasticity far better and longer than sea- 
weed, hair, etc. The resin contained in the pine- and fir- 
woods, which 'are almost exclusively employed, protects 
the articles which are stuffed with wood-wool from the 
attack of insects; moisture also has but small effect on 
this stuffing material. The investigations made by the 
Prussian War Office have shown that pine-wood fibre is 
a very agreeable, soft, and clean material for stuffing 
mattresses for hospitals and barracks, highly appreciated 
by the sick and free from all the disadvantages which have 
hitherto been unavoidable. 

The finest wood-wool has quite recently been employed 
for surgical dressings, for which it has been found very 
suitable. It also answers the purpose of a flesh brush, as 
it opens the pores of the skin and freshens and invigorates 
the surface. The very finest, the so-called lint-wool, is 
used in hospitals and infirmaries. The shavings produced 
by wood-wool machines serve also for filtering materials, 
for making vinegar, and for fire kindlings : those made 
from hazel-wood are used in breweries; beech-wood 
shavings in vinegar factories; and pine-wood shavings for 
fire kindlings. Wood-wool is also used instead of cotton- 
waste for cleaning machinery, as it is considerably cheaper, 
and is far less liable to spontaneous combustion. 

The machines employed for producing wood-wool will 
turn it out in a coarser or finer condition : the product 
may be dyed any colour by simply immersing it in a dye- 
bath, draining it on sieves and drying. The various 
colours may be obtained by the following formulae : 

1. Brown. 

Three parts of permanganate of potash are dissolved in 
200 parts of cold distilled water; the wood-wool is 
immersed in the solution for a few minutes and then taken 


2. Yellow. 

Five parts of ground turmeric root are boiled with 
150 parts of water and ^ part of 'alum ; the decoction is 
strained from the powder through a sieve and is ready for 

3. Green. 

Two parts of soluble aniline green are dissolved in 250 
parts of water. 

4. Blue. 

Two parts of soluble aniline blue are dissolved in 200 
parts of water. 

5. Bed. 

Two parts of soluble aniline red (eosin, po-nceau, or 
rosein, according to the shade desired) are dissolved in 250 
parts of water. 

6. Violet. 

Two parts of aniline violet are dissolved in 250 parts of 

The best mode of procedure is to put the wood-wool in a 
large sieve, dip the whole into the dye-bath, then take it 
out and allow it to drain, after which the dyed wool is 
dried on wicker racks in a moderately heated chamber. 

One of the best wood-wool machines is that of Anthon 
& Sons of Flensburg : it can be made double, triple, or 
quadruple acting. In the double-acting machines the 
carriage has no movable parts. These double-acting 
machines are employed wherever quantity rather than 
quality is required in the product; this arise from the 
fact that no piece of wood can be planed equally well in 
both directions, as any one can assure themselves by trying 
the experiment with a hand plane, when it will be found 
that whilst cutting against the grain the shavings are not 
so smooth as those cut in the opposite direction ; for coarse 


wood-wool this is of no consequence. When, on the other 
hand, the object is to produce extra fine and delicate wool, 
such as the patent carriage of the machine is intended to 
yield, it is necessary that the machine should be single- 
acting; each piece of wood must then be placed between 
the feed-rollers in the right direction for planing with the 
grain. A special advantage of this machine is that fila- 
ments of various widths can be obtained from it without 
the necessity of changing the slitting knives. 

FIG. 45. Double Acting Wood-wool Machine of Anthon & Sons. 

The whole machine (Fig. 45) is supported on a solid 
iron frame, which as a rule is arranged horizontally, being 
furnished with iron legs as shown in the figure. It 
can, however, where space considerations or the driving 
arrangements require it, be set up in a sloping position. 
The frame carries the driving-axle with fast and loose 
pulleys, a crank and fly-wheel. The crank, by means of a 
connecting rod, gives a reciprocating motion to an iron 
carriage, which latter carries the very simple cutters, one 
or sometimes two broad plane irons, and a set of pointed 
knives, which are set to the required width of the fila- 



ments, and which produce longitudinal cuts in the wood, 
whilst the plane which follows them takes off a shaving of 
the already scored surface, and the resulting wood-wool 
falls from the machine. Two toothed rollers arranged 
transversely across the carriage, and revolving to a certain 
distance backwards for each movement of the carriage, 
hold the wood which is to be planed, the roller nearest the 
crank being pressed against the wood by a rack and pinion 
acted on by a weight hanging from a cord which paisses 
over a pulley, and thus bringing the wood up to the plane 
through a definite distance at each cut. A lever connected 
with the pulley permits a more rapid to and fro motion 
of the pulley, and consequently a rapid backwards and 
forwards motion of the front roller, so that without 
stopping the machine piece of wood of different lengths 
can be introduced under the rollers one after another. 

The machine can easily be attended by a single work- 
man, who, after throwing the driving belt upon the driving- 
pulley has merely to thrust one piece of wood after another 
between the rollers ; this is done with the left hand, whilst 
with the right hand the front roller is moved nearer to or 
farther from the back roller, according to the length of 
the pieces. 

When the rollers have seized the piece of wood it is 
unnecessary that it should be held by the hand : the 
rollers push it forward automatically, so that unless the 
pieces are very small one workman can easily feed two 
machines. The machine has a length of 10 J feet and a 
breadth of 3 feet 4 inches. The driving-pulley is 20 
inches in diameter by 6 inches broad, and should make 
about 150 revolutions per minute. The output of a double- 
acting machine should amount in 10 hours to 6 to 12 cwt. 
of the coarsest wood-wool, according to the kind of wood : 
of finer wool a proportionally smaller quantity is produced. 
The thickness of the filaments is always the same ; but 




if desired, different worm-wheels can be supplied at an 
extra cost, which render it possible to vary the thickness : 
the most usual are 3, 5, 15, and 20 filaments to 1 milli- 
metre. The width of the filaments can be regulated by 
either clamping the scoring knives close together, or by 
inserting distance pieces of any desired thickness between 
them. The power required for a wood-wool machine is 
1 to 2 horse-power according to the yield. 

The machine will take round, square, or flat pieces of 
wood of the following maximum dimensions; about 20 
inches long by 5-J inches wide, and, of course, pieces which 
are smaller in either direction : the thickness is not 
restricted, but it is nevertheless not advantageous that it 
should exceed 20 inches. The material can be worked 
down to pieces of 1 inch in square section ; the waste is 
therefore very small. 

The machine can be driven equally well by wind, water, 
steam, or any other power, and is capable of reducing cane 
to wool. It is not clear, however, how far it is advan- 
tageous to work up cane into wool, for new cane is too 
costly and short thin pieces of waste cane >are not profitable 
because the yield is so small, and the wool would be very 
irregular; trials have also proved that though cane in 
rods is elastic, the wool from it possesses no greater 
elasticity than that from beech, oak, and other soft woods. 

Another construction is so distinctly shown in elevation 
and plan in Figs. 46 and 47 as to require no further expla- 
nation. The length of the machine is about 10 \ feet, its 
breadth 5J feet, the diameter of the driving-pulley 20 
inches and its width 6 inches, and the weight of the whole 
machine is about 12 cwt. For 150 revolutions per minute 
it requires 1 to 2 horse-power, and in 10 working hours 
will turn out 5 to 9 cwt. of wood-wool. 

The improved quadruple-acting wood-wool machine of 
Anthon & Sons consists of a very strong frame, which fs 





set on a brick foundation, or in cases where a brick founda- 
tion cannot be used, a strong wooden frame, or a cast-iron 






base may be employed. It is, however, always better 
where possible to set it on a brick foundation, as it will 


then work steadily and quietly even at a high speed. 
Gearing and machine are connected by a wrought-iron 
connecting rod. All the axles, etc., are of steel ; the 
carriage runs in exchangeable and adjustable guides; the 
knives are arranged vertically, and are divided into two 
sets, each consisting of a plane cutter and a toothed knife, 
which works immediately in front of it, and acts on two 
pieces of wood. The one set of knives cuts during the for- 
ward motion, the other during the backward motion, but 
each of them on a separate piece of wood. The rollers 
are divided into three groups, of which the middle one 
consists of two fixed rollers covering the whole width of 
the carriage, and which take the thrust of the knives, 
whilst the two outer groups are divided in the middle so 
that each short roller serves for holding a separate piece 
of wood, and is separately controlled by a hand-wheel and 
screw. A thin plate divides the face of the plane into 
upper and lower halves ; this serves at the same time as a 
bed for both the upper pieces of wood, and can be removed 
if thicker blocks of wood are to be worked up. The follow- 
ing additional parts are supplied with each machine : 

Interchangeable wheels for producing seven different 
sizes of wood-wool, varying from \ to ^ millimetre in 
thickness. Two plain and two toothed plane knives of 12 
or 13| inches long. The teeth are arranged for producing 
filaments 2 millimetres wide. To produce filaments either 
wider or narrower toothed knives of different sizes must 
be inserted. 


This machine is especially advantageous in places where 
there is but little space, or where the driving-shaft is 
high up, or where a cheap machine is required, from which 
an abundant output is not of special importance. 



The machine is similar to the single-acting machine, 
with the difference that it is set up in a vertical position 

FIG. 49. Vertical Wood-wool Machine of Kirchner & Co., Leipsic. 

and is mounted on a wooden frame. In small establish- 
ments, where wood-wool is prepared, not as an article of 


commerce but for internal consumption, this machine will 
suffice in many cases. The machine is constructed with 
either one or two cutters. The figure shows a pattern with 
one cutter. In the machine with two cutters the fast and 

FIG. 50. Rotating Wood-wool Machine. 

loose pulleys are arranged between the two crank-wheels, 
so that there are cutters both to the right and left of the 
driving-pulley, and two pieces of wood can be worked up 
into wool at the same time. The cranks of the two crank- 
wheels are set 180 apart. 


The machine is manufactured of three different sizes for 
pieces of wood up to 20, 24, and 28 inches in length. 
Power required is 2 to 4 horse-power. 


This machine is built with a strong cast-iron base, which 
enables it to be run at 250 revolutions per minute. In 
the vertical knife-wheel there are 4 sets of toothed 
knives, alternately with 4 plain knives. A sheet-iron 
screen covers this knife-wheel and protects the workman 
from injury. The pieces of wood, 10 inches long by 4| 
inches thick, and of any width, are brought by two grooved 
wheels into contact with the knives. By changing the 
knife-wheels, seven sizes, and by changing the toothed 
knives, 14 sizes of wool can be produced. The yield of the 
machine is the same as that of a triple-acting one. 


Tree bark, especially that of the oak and coniferous 
trees, as well as that of the birch, willow, and elm, is not 
to be regarded as a waste product, since in many places it 
finds extensive application as a tanning material. 

Nevertheless, in localities where there are no facilities for 
carriage, bark must be looked on as a waste product which 
can only be utilised as fuel. In such cases it is, however, 
profitable to extract the tannin, the carriage of which pre- 
sents less difficulty. This extract can be employed for 
tanning with the same result 'as bark itself, and since 100 
parts of extract are quite as efficient as 400 to 500 parts of 
bark, it follows that its higher commercial value allows it 
to be delivered to the consumer at far greater distances 
than is the case with bark. 


In his work on " Die Verwerthung des Holzes auf 
chemischem Wege " (The Utilisation of Wood by Chemical 
Methods) Dr. Bersch says : "In order that tannin extracts 
may be generally well received by tanners, at least two 
conditions must be fulfilled : The extracts must invariably 
be sent out of the same quality and containing a definite 
percentage of tannin, and the tanner must be made ac- 
quainted with the mode of employing the new material. If 
the tanner can be assured that 1 Ib. of the extract will have 
exactly the same tanning efficiency as a definite number of 
Ibs. of the best coppice bark, practical men will very soon 
accustom themselves to employ the extract instead of bark. 
The introduction of the extraction process furnishes, how- 
ever, the proprietors of forest lands with a means of bring- 
ing the one valuable constituent of bark, i.e., the tannin, 
into such a form that it can be delivered at great distances, 
whilst the use of the extract affords to the tanner the 
immense convenience that he is able to work with rapidly 
prepared solutions of the material, instead of having as 
formerly first to extract the tannin from the bark ; more- 
over, the large spaces required for the storage of bark, the 
drying of the spent tan, etc., are rendered quite super- 

To this intent I here merely indicate the mode in which 
the bark, when it has to be regarded as a waste product, 
can be utilised, and for further particulars respecting the 
preparation of tannin extracts the reader is referred to 
the above-mentioned treatise by Dr. Bersch. 

Utilisation of Birch-bark. 

The bark of the birch can be employed as a tanning 
agent in the same way as the barks of other trees. When 
birch-bark is submitted to dry distillation the usual pro- 
ducts, gases, pyroligneous acid, and tar are obtained, but 


the proportion of tar is somewhat considerable, amounting 
to about 60 per cent, of the weight of the bark employed. 
Birch-tar, or the product of its redistillation, birch-tar oil, 
has a very characteristic odour, which will be recognised 
as that of Russian leather, this leather being prepared with 
birch-tar. Fancy goods made from fictitious Russian 
leather are also treated with birch-tar to give them the 
characteristic odour of the genuine article. 

The distillation of the bark is best carried on in large 
iron pots, with an alembic head and cooling worm coil : 
the pyroligneous acid and tar are in this way completely 
and easily collected, and the distillate when left in repose 
separates into two sharply denned layers. Seeing that the 
yield of acetic acid from the distillation of bark is com- 
paratively trifling, it is not worth while to work it up for 
the production of acetic acid at the spot, but it is col- 
lected and sent to factories where the manufacture of wood- 
vinegar is a special feature. 

Besides these modes of utilising bark, it is used for 
architectural and decorative purposes. In forest localities, 
summer houses are either wholly built of bark or have 
their wood framework covered with bark ; also baskets for 
plants in pots, etc., can be made from bark, and command 
a ready sale. 


Acetates from sawdust, 10. 

Acetic acid, 3, 18, 19. 

Acetone, 3, 18, 19. 

Acetylene, 19. 

Albumin, 3. 

Alcohol from sawdust, 13, 16, 20, 22. 

from wood-waste, 105. 
Aldehyde, 19. 
Alkarazzas, 154. 

Alum, 176. 

Andre's sawdust furnace, 32. 

Aniline blue, 176. 

red, 176. 

Anthon's wood-wool machines, 176- 

Artificial flowers, use of wood-meal 

in, 8. 
Artificial wood, 3, 13, 119. 

analysis by Dr. Sauer- 

wein, 135. 

of Back and Potin, 138. 

Billefeld's, 134. 

various processes, 120. 

Wiederhold's, 138. 

Asphalt, 7. 

Back and Potin's artificial wood, 


Balsam of sulphur, 134. 
Bark, 186. 
Benzene, 19. 
Bersch, " Utilisation of Wood by 

Chemical Methods," 187. 
Billefeld's artificial wood, 134. 
Birch bark, 187. 
Black clay pipes, 7. 
Blasting powders, 4, 140. 

Brain's, 148. 

De Tret's, 146. 

Koppel's safe, 143. 

Oiler's, 146. 

Terre and Mercadier's, 147. 
Blood for binding, 3. 

Bohlig's process for manufacture 

ot oxalic acid, 100. 
Boiler scale, prevention of, 10. 
Bois durci, 121. 
Bone-ash substitute, 6. 
BSttger's sawdust furnace, 41. 
Bottle stoppers from shavings, 170. 
Brain's blasting powder, 148. 
Briquettes from sawdust, 11, 24, 


Brise-rocs, Robandi's, 142. 
Butylene, 19. 
Butyric acid, 19. 


Calcium carbide from sawdust, 165. 
Caproic acid, 19. 
Carbazotine, 143. 
Carbonisation apparatus, 69. 
Carbonised sawdust as manure, 


Carbon monoxide, 18, 19. 
Carborundum, 172. 
Casein, 132. 

Casks, manufacture from waste- 
wood, 174. 
Cellulose, 12, 16. 
Cement, composition containing 

sawdust, 155. 
Ceramic industry, use of sawdust 

in, 154. 
Charcoal, yield of, 66. 
Chemical methods of utilising 

wood-waste, 15, 19. 
Coal slack, 23. 

Cohnfeld's wood-composition, 139. 
Columnar apparatus for distilling 

sawdust, 70. 
Composts, sawdust for, 8. 
Creosote, 83. 
Cresol, 19. 
Croissant and Bretonniere, dyes 

from sawdust, 10, 109. 
Croll, purification of coal gas, 9. 
Cumene, 19. 




Damp course of walls, 7. 

De Tret's blasting powder, 146. 

Diorrexin, 144. 

Distillation for briquettes, 152. 

- of sawdust, 17, 26. 

- columnar apparatus, 70. 

- Fischer's apparatus, 66. 

Halliday's apparatus, 69. 

- Waisbein's apparatus, 72. 

Zwillinger's apparatus, 61. 
Double acting wood-wool machine, 


Dye-stuffs from sawdust, 10, 109. 
Dye-woods, 13. 
Dyes for sawdust, 5. 
Dynamite, 145. 
Dy's yellow powder, 147. 


Explosives, employment of saw- 
dust in, 140. 


Filtering material, 7. 
Fire kindlers, 13, 171. 
Fischer's apparatus for distilling 

sawdust, 66. 

Fodder from wood-meal, 12. 
Formic acid, 19. 
Furnaces for burning sawdust, 25. 


Gas from wood, 18, 19. 

- purifiers, use of sawdust in, 9. 
Glucose from sawdust, 20. 
Godillot's pyramidal grate, 49. 
Gottschalk's "Hartholz," 124. 
Grape-sugar, 20. 
Gunpowder, Dy's yellow, 147. 
Gypsum, substitute for, 8. 


Halliday's apparatus for distilling 

sawdust, 69. 
Haloxylin, 146. 

Harrass' artificial wood, 117, 124. 
" Hartholz," Gottschalk's, 124. 

Heraklin, 142. 
Humus, 110. 

Hurtig's wood-composition, 129, 


Illuminating gas from sawdust, 81. 
Ink, 14. 

Insulating material, 149, 157. 
Israel's rotating wood-wool ma- 
chine, 185. 


Kapp's wood-pulp, 162. 

Kellow and Short's powder, 145. 

Kirchner's wood-wool machine, 183. 

Kletzinsky's wood-paste, 133. 

Koch's sawdust furnace, 34. 

Koppel's safe blasting powder, 143. 

Kork teppich, 6. 

Kraft's sawdust furnace, 28. 

Laming's mixture, 9. 
Lannoy's white powder, 147. 
Lignin, 20. 
Lignose, 20. 

(blasting powder), 142. 

manufacture of oxalic acid 

from, 102. 
Linoleum, 6. 
Lithofracteur, 148. 
Litter, sawdust as, 8. 
Lundin furnace, 47. 


Manure, sawdust as, 8, 166. 

- tan as, 168. 
Mariot and Sugden, purification of 

coal gas, 9. 
Marsh gas, 19. 
Mechanical methods of utilising 

wood-waste, 15. 
Mercapto-dyes, 109. 
Metacetone, 19. 
Metal wares, sawdust for drying 

and polishing, 12. 
Methyl acetate, 18, 19. 
Methyl alcohol, 17. 
Methylamine acetate, 19. 



Molasses for binding sawdust, 151. 

Mortar containing sawdust, 10, 
154, 156. 

Mortelette, prevention of boiler 
scale, 10. 

Moulded decorations, use of saw- 
dust in, 114. 


Naphthalene, 19. 

Niederberger's furnace for sawdust, 


Oiler's blasting powder, 146. 
Organic sulphides, 109. 
Oxalic acid, 4. 

manufacture from sawdust, 


Bohlig's process, 100. 

- Possoz' patent, 93. 

Roberts, Dale & Co.'s 

process, 100. 

Thorn's experiments, 87. 

Zaiher's process, 103. 

yield of, from sawdust and 

different woods, 88, 91, 
93, 94. 


Packing, use of sawdust in, 5. 

Paint mills, cleaning with saw- 
dust, 6. 

Palmer's wood-composition, 134. 

Paper-pulp from wood, 159. 
apparatus for, 161. 

Paper, wood-meal as filling 
material, 6. 

Paper-making, 159. 

Paraffin, 19. 

Parquetry, Hurtig's wood-composi- 
tion for, 129. 

manufacture from waste- wood, 

Patent dyes, 105. 

Peat, 23. 

Permanganate of potash, 175. 

Petri's apparatus for manufacture 
of prepared fuel, 76. 

Petroleum briquettes, 151. 

Phenol, 19. 

Plastic compositions from sawdust, 

Poch's poudrolith, 143. 
Polishing silver and gold by saw- 
dust, 11. 

Potash from wood, 17. 
Pottery, use of sawdust in, 154. 
Poudrolith, Poch's, 143. 
Pounce, 4. 
Powder, Kellow and Short's, 145. 

Lannoy's white, 147. 
Prepared fuel from sawdust, Petri's 

apparatus for, 76. 
Propionic acid, 19. 
Propylene, 19. 

Pyramidal grate furnace, 49. 
Pyroligneous acid, 187. 
from sawdust, 18. 

yield of, 66, 73, 83. 

Pyrolith, 145. 

Pyronome, Beynaud's, 143. 

Resin, 3. 

Reynaud's pyronome, 143. 

Ribbach's sawdust composition, 


Richardson's artificial manure, 167. 
Robandi's brise-rocs, 142. 
Roberts, Dale & Co.'s process for 

manufacture of oxalic acid, 100. 
Roof shingles, 171. 
Roofing felt, 7. 

material with sawdust, 10. 
Rosin, 171. 
Rotating wood-wool machine of 

Camillo Israel, 185. 
Rough cast, addition of sawdust to, 


Sauerwein, analysis of artificial 

wood, 135. 
Sawdust, 1. 

as absorbing material, 11. 

blasting powder, 140. 

briquettes, 11, 14, 24, 149. 

composition, Ribbach's, 137. 

for composts, 8. 

- as detergent agent, 11. 

for drying and polishing metal 

wares, 12. 

dye-stuffs from, 109. 



Sawdust, use of in explosives, 140. 

for fire kindlers, 13, 171. 

as fuel, 2, 23. 

furnace for gas manufacture, 


furnaces, 35. 

- in gas purifiers, 9. 

illuminating gas from, 81. 

as litter, 8. 

as manure, 8, 166. 

as non-conductor of heat, 6. 

oxalic acid from, 84. 

as packing material, 5. 

plastic compositions from, 113. 

- in pottery, 154. 

- in rough cast, 164. 

in stucco, 155. 

Schutzenbach's process for exhaust- 
ing tan, 13. 

Sciffarin, 116, 139. 

Shavings, bottle stoppers from, 70. 

- mosaic plaques from, 169. 
Simili bois, 116. 

Smith Consolidation Co., 11. 

Soda lye in manufacture of oxalic 
acid, 84. 

Steel, use of sawdust in cementa- 
tion of, 10. 

Stony composition from sawdust, 

Stucco containing sawdust, 10. 

Sugar from sawdust, 13, 16, 20. 

Sulpho-dyes, 109. 

Superheater tubes, coating for, 65. 

Swedish wood-charcoal furnace, 53. 


Tan, complete extraction of, 13. 

furnaces, 35. 

- as manure, 15, 168. 

refuse, 23. 

use on riding roads, 15. 
Tannin extract, 186. 

- gelatine, 135. 

Tar from wood distillation, 19. 

yield of, 66. 
Terra-cotta wood, 134. 

Terre and Mercadier's blasting- 
powder, 147. 

Thorn's process of oxalic acid 
manufacture, 87. 

Toluene, 19. 
Turmeric root, 176. 


Valeric acid, 19. 
Venetian turpentine, 135. 
Volkmann's wood-powder, 143. 


Waisbein's apparatus for distilling 
sawdust, 72. 

Wall paper, use of wood-meal in, 

Walter's furnace for making wood- 
tar, 55. 

Wiederhold's artificial wood-com- 
position, 138. 

Wood-cement, 7, 139. 

charcoal, Swedish furnace for 


chemical composition of, 16. 

composition of Cohnfeld, 139. 
Palmer's, 134. 

- dry distillation of, 17. 

- marble, 116. 

meal, 145. 
fodder, 12. 

mosaic plaques from shavings, 


- paste, Kletzinsky's, 133. 

- powder, Volkmann's, 143. 

- pulp, 12, 159. 

sap, 17. 

- spirit, 3, 17. 

stopping, 5. 
tar, Ws 

r alter's furnace for, 55. 
- wool, 174. 

dyeing, 175. 

machines, 176-186. 

Xylene, 19. 
Xylolith, 4. 

Zaiher's process for manufacture 
of oxalic acid, 103. 

Zwillinger's apparatus for carbonis- 
ing sawdust, 61. 



Special Q)eef)nieal (A/orK$ 








Agricultural Chemistry ... 10 
Air, Industrial Use of ... 11 

Dyeing Marble 30 
Dyeing Woollen Fabrics ... 22 

Petroleum 6 
Pigments, Chemistry of ... 2 

Alum and its Sulphates ... 9 

Dyers' Materials 23 

Plumbers' Work 27 

Ammonia 9 

Dye-stuffs 23 

Porcelain Painting 18 

Aniline Colours 3 

Enamelling Metal ... 19, 20 

Pottery Clays 16 

Animal Fats 6 

Enamels ... ... ... 18 

Pottery Manufacture ... 14 

Anti- corrosive Paints ... 4 
Architecture, Terms in ... 30 

Engraving 31 
Essential Oils 7 

Power-loom Weaving ... 20 
Preserved Foods 30 

Architectural Pottery ... 16 
Artificial Perfumes 7 

Evaporating Apparatus ... 26 
External Plumbing 27 

Printing Inks 3 
Recipes for Oilmen, etc. .. 3 

Balsams ... ... 10 

Fats 5, 6 

Resins 10 

Bleaching 23 

Faults in Woollen Goods... 21 

Risks of Occupations .. 12 

Bone Products 8 

Gas Firing 26 

Rivetting China, etc. .. 16 

Bookbinding 31 

Glass-making Recipes ... 17 

Scheele's Essays 9 

Brick-making ... 15, 16 

Glass Painting 18 

Sealing Waxes 11 

Burnishing Brass 27 

Glue Making and Testing... 8 

Silk Dyeing 23 

Carpet Yarn Printing ... 21 

Greases 5 

Silk Throwing .. .. 19 

Ceramic Books ... 14, 15 

History of Staffs Potteries 17 

Smoke Prevention .. .. 25 

Charcoal 8 

Hops 28 

Soaps 7 

Chemical Essays 9 
Chemistry of Pottery ...17 

Hot-water Supply 28 
India-rubber 13 

Spinning ... 20 
Staining Marble, and Bone 30 

Chemistry of Dye-stuffs ... 23 

Inks ... 3, 11 

Steam Drying ... 11 

Clay Analysis 16 
Coal-dust Firing 26 

Iron-corrosion ... ... 4 
Iron, Science of 26 

Sugar Refining .. .. 31 
Steel Hardening .. .. 26 

Colour Matching 21 

Japanning ... ... ... 28 

Sweetmeats 30 

Colliery Recovery Work ... 25 

Lacquering 27 

Terra-cotta 16 

Colour-mixing for Dyers ... 21 

Lake Pigments 3 

Testing Paint Mater als .. 4 

Colouring Pottery 15 
Colour Theory 22 

Lead and its Compounds... 11 
Leather Industry 13 

Testing Yarns .. ..20 
Textile Fabrics .. ..20 

Combing Machines 24 

Leather-working Materials 14 

Textile Materials .. 19,20 

Compounding Oils ... ... 6 

Lithography 31 

Timber 29 

Condensing Apparatus ... 26 

Lubricants 5,6 

Varnishes ... 4 

Cosmetics 7 

Manures 8, 10 

Vegetable Fats 7 

Cotton Dyeing 22 
Cotton Spinning 24 

Mineral Pigments 2 
Mine Ventilation 25 

Waste Utilisation 10 
Water, Industrial Use ... 12 

Damask Weaving 20 

Mine Haulage 25 

Water-proofing Fabrics ... 32 

Dampness in Buildings .. 29 
Decorators' Books 28 

Oil and Colour Recipes ... 3 
Oil Boiling 4 

Weaving Calculations ... 32 
Wood Waste Utilisation ... 29 

Decorative Textiles .. 20 

Oils 5 

Wood Dyeing 30 

Dental Metallurgy 27 

Ozone, Industrial Use of.. 12 

Wool Dyeing 22 

Dictionary of Paint Ma 

Paint Manufacture 2 

Writing Inks 11 

terials 3 

Paint Materials 3 

X-Ray Work 13 

Drying Oils 5 

Paint-material Testing ... 4 

Yarn Testing .. ... 20 

Drying with Air 11 

Paper-pulp Dyeing 18 




Tel. No. 5403. Bank- 

Paints, Colours and Printing 

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. 1902. Price 10s. 6d. ; India and 
Colonies, 11s.; Other Countries, 12s.; strictly net. 

Introductory. Light White Light The Spectrum The Invisible Spectrum Normal 
Spectrum Simple Nature of Pure Spectral Colour The Recomposition of White Light- 
Primary and Complementary Colours Coloured Bodies Absorption Spectra The Appli- 
cation of Pigments. Uses of Pigments : Artistic, Decorative, Protective Methods of 
Application of Pigments : Pastels and Crayons, Water Colour, Tempera Painting, Fresco, 

jirge Vermilion Royal 

Zinc, Silver and Mercury Brunswick Green The Ochres Indian Red Venetian Red- 
Siennas and Umbers Light Red Cappagh Brown Red Oxides Mars Colours Terre Verte 
Prussian Brown Cobalt Colours Coeruleum Smalt Copper Pigments Malachite- 
Bremen Green Scheele's Green Emerald Green Verdigris Brunswick Green Non- 
arsenical Greens Copper Blues Ultramarine Carbon Pigments Ivory Black Lamp'Black 
Bistre Naples Yellow Arsenic Sulphides : Orpiment, Realgar Cadmium Yellow 
Vandyck Brown Organic Pigments. Prussian Blue Natural Lakes Cochineal Carmine 
Crimson Lac Dye Scarlet Madder Alizarin Campeachy Quercitron Rhamnus 
Brazil Wood Alkanet Santal Wood Archil Coal-tar Lakes Red Lakes Alizarin Com- 
pounds Orange and Yellow Lakes Green and Blue Lakes Indigo Dragon's Blood 
Gamboge Sepia Indian Yellow, Puree Bitumen. Asphaltum, Mummy Index. 

for Paint Manufacturers, Merchants and Painters. By J. CRUICKSHANK 
SMITH, B.Sc. Demy 8vo. 1901. 200pp. Sixty Illustrations and One 
Large Diagram. Price 7s. 6d. ; India and Colonies, 8s. ; Other 
Countries, 8s. 6d. ; strictly net. 


Preparation of Raw Material Storing of Raw Material Testing and Valuation of Raw 
Material Paint Plant and Machinery The Grinding of White Lead Grinding of White 
Zinc Grinding of other White Pigments Grinding of Oxide Paints Grinding of Staining 
Colours Grinding of Black Paints Grinding of Chemical Colours Yellows Grinding of 
Chemical Colours Blues Grinding Greens Grinding Reds Grinding Lakes Grinding 
Colours in Water Grinding Colours in Turpentine The Uses of Paint Testing and Matching 
Paints Economic Considerations Index. 

PIGMENTS. Containing Directions for the Manufacture 
of all Artificial, Artists and Painters' Colours, Enamel, Soot and Me- 
tallic Pigments. A Text-book for Manufacturers, Merchants, Artists 
and Painters. By Dr. JOSEF BERSCH. Translated by A. C. WRIGHT, 
M.A. (Oxon.), B.Sc. (Lond.). Forty-three Illustrations. 476 pp., demy 
8vo. 1901. Price 12s. 6d. ; India and Colonies 13s. 6d. ; Other 
Countries, 15s. ; strictly net. 


Introduction Physico-chemical Behaviour of Pigments Raw Materials Employed in 
the Manufacture of Pigments Assistant Materials Metallic Compounds The Manufacture 
of Mineral Pigments The Manufacture of White Lead Enamel White Washing Apparatus 
Zinc White Yellow Mineral Pigments Chrome Yellow Lead Oxide Pigments 
Other Yellow Pigments Mosaic Gold Red Mineral Pigments The Manufacture of Ver- 
milionAntimony Vermilion Ferric Oxide Pigments Other Red Mineral Pigments Purple 
of Cassius Blue Mineral Pigments Ultramarine Manufacture of Ultramarine Blue 
Copper Pigments Blue Cobalt Pigments Smalts Green Mineral Pigments Emerald 
Green Verdigris Chromium Oxide Other Green Chromium Pigments Green Cobalt Pig- 
ments Green Manganese Pigments Compounded Green Pigments Violet Mineral Pig- 
ments Brown Mineral Pigments Brown Decomposition Products Black Pigments Manu- 
facture of Soot Pigments Manufacture of Lamp Black The Manufacture of Soot Black 

without Chambers Indian Ink Enamel Colours Metallic Pigments Bronze Pigments 
Vegetable Bronze Pigments. 

PIGMENTS OF ORGANIC ORIGIN Lakes Yellow Lakes Red Lakes Manufacture of 
Carmine The Colouring Matter of Lac Safflower or Carthamine Red Madder and 
its Colouring Matters Madder Lakes Manjit (Indian Madder) Lichen Colouring Matters 
Red Wood Lakes The Colouring Matters of Sandal Wood and Other Dye Woods Blue 
Lakes Indigo Carmine The Colouring Matter of Log Wood Green Lakes Brown Organic 
Pigments Sap Colours Water Colours Crayons Confectionery Colours The Preparation 
of Pigments for Painting The Examination of Pigments Examination of Lakes The 
Testing of Dye- Woods The Design of a Colour Works Commercial Names of Pigments 
Appendix : Conversion of Metric to English Weights andJMeasures Centigrade and Fahrenheit 
Thermometer Scales Index. 

8vo. 380pp. 1901. Price 7s. 6d.; India and Colonies, 8s. ; Other 
Countries, 8s. 6d. ; strictly net. 

F.I.C., F.C.S. Sixteen Coloured Plates, showing Specimens of 
Eighty-nine Colours, specially prepared from the Recipes given 
in the Book. 136 pp. Demy 8vo. 1900. Price 7s. 6d. ; India and 
Colonies, 8s. ; Other Countries, 8s. 6d. ; strictly net. 


The Groups of the Artificial Colouring Matters The Nature and Manipulation ot Artificial 
Colours Lake-forming Bodies for Acid Colours Lake-forming Bodies' Basic Colours Lake 
Bases The Principles of Lake Formation Red Lakes Orange, Yellow, Green, Blue, Violet 
and Black Lakes The Production of Insoluble Azo Colours in the Form of Pigments The 
General Properties of Lakes Produced from Artificial Colours Washing, Filtering and Fin- 
ishing Matching and Testing Lake Pigments Index. 

AN ANALYTICAL CHEMIST. 350 pp. 1902. Demy 8vo. Price 7s. 6d. ; 
India and British Colonies, 8s. ; Other Countries, 8s. 6d. ; strictly net. 


Pigments or Colours for Paints, Lithographic and Letterpress Printing Inks, etc. 
Mixed Paints and Preparations for Paint-making, Painting, Lime-washing, Paperhanging, 
etc. Varnishes for Coach-builders, Cabinetmakers, Wood-workers, Metal-workers, Photo- 
graphers, etc. Soaps for Toilet, Cleansing, Polishing, etc. Perfumes Lubricating Greases, 
Oils, etc. Cements, Pastes, Glues and Other Adhesive Preparations Writing, Marking, 
Endorsing and Other Inks Sealing-wax and Office Requisites Preparations for the Laundry, 
Kitchen, Stable and General Household Uses Disinfectant Preparations Miscellaneous 
Preparations Index. 

EDGAR ANDES. Translated from the German. 215 pp. Crown 8vo. 
56 Illustrations. 1903. Price 5s. ; India and British Colonies, 5s. 6d. ; 
Other Countries, 6s. ; strictly Net. 


Linseed Oil Poppy Oil Mechanical Purification of Linseed Oil Chemical Purification of 
Linseed Oil Bleaching Linseed Oil Oxidizing Agents for Boiling Linseed Oil Theory of 
Oil Boiling Manufacture of Boiled Oil Adulterations of Boiled Oil Chinese Drying Oil and 
Other Specialities Pigments for House and Artistic Painting and Inks Pigment for 
Printers' Black Inks Substitutes for Lampblack Machinery for Colour Grinding and 
Rubbing Machines for mixing Pigments with the Vehicle Paint Mills Manufacture of 
House Oil Paints Ship Paints Luminous Paint Artists' Colours Printers' Inks: 
(See also Writing Inks, p. n.) 

MATERIALS. By A. C. WRIGHT, M.A. (Oxon.), B.Sc. 
(Lond.). Crown 8vo. 160 pp. 1903. Price 5s. ; India and British 
Colonies, 5s. 6d. ; Other Countries, 6s. ; strictly Net. 

Necessity for Testing Standards Arrangement The Apparatus The Reagents 
Practical Tests Dry Colours Stiff Paints Liquid and Enamel Paints Oil Varnishes 
Spirit Varnishes Driers Putty Linseed Oil Turpentine Water Stains The Chemical 
Examination Dry Colours and Paints White Pigments and Paints Yellow Pigments and 
Paints Blue Pigments and Paints Green Pigments and Paints Red Pigments and Paints 
Brown Pigments and Paints Black Pigments and Paints Oil Varnishes Linseed Oil 

CORROSIVE PAINTS. Translated from the German of 
Louis EDGAR ANDES. Sixty-two Illustrations. 275 pp. Demy 8vo. 
1900. Price 10s. 6d. ; India and Colonies, 11s.; Other Countries, 12s.; 
strictly net. 


Iron-rust and its Formation Protection from Rusting by Paint Grounding the Iron with 
Linseed Oil, etc. Testing Paints Use of Tar for Painting on Iron Anti-corrosive Paints 
Linseed Varnish Chinese Wood Oil Lead Pigments Iron Pigments Artificial Iron Oxides 
Carbon Preparation of Anti-corrosive Paints Results of Examination of Several Anti- 
corrosive Paints Paints for Ship's Bottoms Anti-fouling Compositions Various Anti-cor- 
rosive and Ship's Paints Official Standard Specifications for Ironwork Paints Index. 

FACTURE. By M. W. JONES, F.C.S. A Book for the 
Laboratories of Colour Works. 88 pp. Crown 8vo. 1900. Price 5s. ; 
India and Colonies, 5s. 6d. ; Other Countries, 6s. ; strictly net. 

Aluminium Compounds China Clay Iron Compounds Potassium Compounds Sodium 
Compounds Ammonium Hydrate Acids Chromium Compounds Tin Compounds Copper 
Compounds Lead Compounds Zinc Compounds Manganese Compounds Arsenic 
Compounds Antimony Compounds Calcium Compounds Barium Compounds Cadmium 
Compounds Mercury Compounds Ultramarine Cobalt and Carbon Compounds Oils 

Illustrations. [In the Press. 


Plant Chromes Blues Greens Earth Colours Blacks Reds Lakes Whites- 
Painters' Oils Turpentine Oil Varnishes Spirit Varnishes Liquid Paints Enamel Paints. 

Varnishes and Drying Oils. 

TRIES. Translated from the French of ACH. LIVACHE, 
Ingenieur Civil des Mines. Greatly Extended and Adapted to 
English Practice, with numerous Original Recipes by JOHN 
GEDDES MC!NTOSH. 27 Illustrations. 400 pp. Demy 8vo. 1899. 
Price 12s. 6d. ; India and Colonies, 13s. 6d. ; Other Countries, 15s.; 
strictly net. 


Resins Solvents : Natural, Artificial, Manufacture, Storage, Special Use Colouring : 
Principles, Vegetable, Coal Tar, Coloured Resinates, Coloured Oleates and Linoleates 
Gum Running : Melting Pots, Mixing Pans Spirit Varnish Manufacture: Cold Solution Plant, 
Mechanical Agitators, Storage Plant Manufacture, Characteristics and Uses of the Spirit 
Varnishes Manufacture of Varnish Stains Manufacture of Lacquers Manufacture of 
Spirit Enamels Analysis of Spirit Varnishes Physical and Chemical Constants of Resins 
Table of Solubility of Resins in different Menstrua Systematic qualitative Analysis of 
Resins, Hirschop's tables Drying Oils Oil Refining : Processes Oil Boiling Driers 
Liquid Driers Solidified Boiled Oil Manufacture of Linoleum Manufacture of 
India Rubber Substitutes Printing Ink Manufacture Lithographic Ink Manufacture 
Manufacture of Oil Varnishes Running and Special Treatment of Amber, Copal, Kauri, 
Manilla Addition of Oil to Resin Addition of Resin to Oil Mixed Processes Solution in 
Cold of previously Fused Resin Dissolving Resins in Oil, etc., under pressure Filtration 
Clarification Storage Ageing Coachmakers' Varnishes and Japans Oak Varnishes 
Japanners' Stoving Varnishes Japanners' Gold Size Brunswick Black Various Oil Var- 
nishes Oil- Varnish Stains Varnishes for "Enamels" India Rubber Varnishes Varnishes 
Analysis: Processes, Matching Faults in Varnishes: Cause, Prevention Experiments and 

LIQUID DRIERS. By L. E. ANDES. Expressly Written 
for this Series of Special Technical Books, and the Publishers hold 
the Copyright for English and Foreign Editions. Forty-two Illustra- 
tions. 342 pp. 1901. Demy 8vo. Price 12s. 6d. ; India and Colonies, 
13s. 6d. ; Other Countries, 15s. ; strictly net. 


Properties of the Drying Oils ; Cause of the Drying Property ; Absorption of Oxygen ; 
Behaviour towards Metallic Oxides, etc. The Properties of and Methods for obtaining the 
Drying Oils Production of the Drying Oils by Expression and Extraction; Refining and 
Bleaching; Oil Cakes and Meal; The Refining and Bleaching of the Drying Oils; The 
Bleaching of Linseed Oil The Manufacture of Boiled Oil ; The Preparation of Drying Oils 
for Use in the Grinding of Paints and Artists' Colours and in the Manufacture of Varnishes 
by Heating over a Fire or by Steam, by the Cold Process, by the Action of Air, and by Means 
of the Electric Current; The Driers used in Boiling Linseed Oil; The Manufacture of Boiled 
Oil and the Apparatus therefor ; Livache's Process for Preparing a Good Drying Oil and its 
Practical Application The Preparation of Varnishes for Letterpress, Lithographic and Copper- 
plate Printing, for Oilcloth and Waterproof Fabrics ; The Manufacture of Thickened Linseed 
Oil, Burnt Oil, Stand Oil by Fire Heat, Superheated Steam, and by a Current of Air Behaviour 
of the Drying Oils and Boiled Oils towards Atmospheric Influences, Water, Acids and Alkalies 
Boiled Oil Substitutes The Manufacture of Solid and Liquid Driers from Linseed Oil and 
Rosin; Linolic Acid Compounds of the Driers The Adulteration and Examination of the 
Drying Oils and Boiled Oil. 

Oils, Fats, Soaps and Perfumes. 


Origin, Preparation, Properties, Uses and Analyses. A Handbook for 
Oil Manufacturers, Refiners and Merchants, and the Oil and Fat 
Industry in General. By GEORGE H. HURST, F.C.S. Second Revised 
and Enlarged Edition. Sixty-five Illustrations. 317 pp. Demy 8vo. 
1902. Price 10s. 6d. ; India and Colonies, lls. ; Other Countries, 12s. ; 
strictly net. 


Introductory. Oils and Fats, Fatty Oils and Fats, Hydrocarbon Oils, Uses of Oils 
Hydrocarbon Oils. Distillation, Simple Distillation, Destructive Distillation, Products of 
Distillation, Hydrocarbons, Paraffins, Olefins, Napthenes Scotch Shale Oils. Scotch 
Shales, Distillation of Scotch Oils, Shale Retorts, Products of Distilling Shales, Separating 
Products, Treating Crude Shale Oil, Refining Shale Oil, Shale Oil Stills, Shale Naphtha 
Burning Oils, Lubricating Oils, Wax Petroleum. Occurrence, Geology, Origin, Composition, 
Extraction, Refining, Petroleum Stills, Petroleum Products, Cylinder Oils, Russian Petro- 
leum, Deblooming Mineral Oils Vegetable and Animal Oils. Introduction, Chemical 
Composition of Oils and Fats, Fatty Acids, Glycerine, Extraction of Animal and Vegetable 
Fats and Oils, Animal Oils, Vegetable Oils, Rendering, Pressing, Refining, Bleaching, Tallow, 

Tallow Oil, Lard Oil, Neatsfoot Oil, Palm Oil, Palm Nut Oil, Cocoanut Oil, Castor Oil, 
Olive Oil, Rape and Colza Oils, Arachis Oil, Niger Seed Oil, Sperm Oils, Whale Oil, Seal 
Oil, Brown Oils, Lardine, Thickened Rape Oil Testing and Adulteration of Oils. Specific 
Gravity, Alkali Tests, Sulphuric Acid Tests, Free Acids in Oils, Viscosity Tests, Flash and 
Fire Tests, Evaporation Tests, Iodine and Bromide Tests, Elaidin Test, Melting Point of 
Fat, Testing Machines Lubricating Greases. Rosin Oil, Anthracene Oil, Making Greases, 
Testing and Analysis of Greases Lubrication. Friction and Lubrication, Lubricant, Lubri- 
cation of Ordinary Machinery, Spontaneous Combustion of Oils, Stainless Oils, Lubrication of 
Engine Cylinders, Cylinder Oils Appendices. A. Table of Baume's Hydrometer B. Table 
of Thermometric Degrees C. Table of Specific Gravities of Oils Index 


World Their History, Geography and Geology Annual Production 
and Development Oil-well Drilling Transport. By HENRY NEU- 
BERGER and HENRY NOALHAT. Translated from the French by J. G. 
MclNTOSH. 550pp. 153 Illustrations. 26 Plates. Super Royal 8vo. 1901. 
Price 21s. ; India and Colonies, 22s. ; Other Countries, 23s. 6d. ; 
strictly net. 


Study of the Petroliferous Strata Petroleum Definition The Genesis or Origin of 
Petroleum The Oil Fields of Galicia, their History Physical Geography and Geology of 
the Galician Oil Fields Practical Notes on Galician Land Law Economic Hints on Working, 
etc. Roumania History, Geography, Geology Petroleum in Russia History Russian 
Petroleum (continued) Geography and Geology of the Caucasian Oil Fields Russian Petro- 
leum (continued) The Secondary Oil Fields of Europe, Northern Germany, Alsace, Italy, etc. 
Petroleum in France Petroleum in Asia Transcaspian and Turkestan Territory Turkestan 
Persia British India and Burmah British Burmah or Lower Burmah China Chinese 
Thibet Japan, Formosa and Saghalien Petroleum in Oceania Sumatra, Java, Borneo 
Isle of Timor Philippine Isles New Zealand The United States of America History- 
Physical Geology and Geography of the United States Oil Fields Canadian and other North 
American Oil Fields Economic Data of Work in North America Petroleum in the West 
Indies and South America Petroleum in the French Colonies. 

Excavations Hand Excavation or Hand Digging of Oil Wells. 

Methods of Boring Methods of Oil-well Drilling or Boring Boring Oil Wells with the 
Rope Drilling with Rigid Rods and a Free-fallFabian System Free-fall Drilling by Steam 
Power Oil-well Drilling by the Canadian System Drilling Oil Wells on the Combined 
System Comparison between the Combined Fauck System and the Canadian The American 
System of Drilling with the Rope Hydraulic Boring with the Drill by Hand and Steam 
Power Rotary Drilling of Oil Wells, Bits, Steel-crowned Tools, Diamond Tools Hand 
Power and Steam Power Hydraulic Sand-pumping Improvements in and different Systems 
of Drilling Oil Wells. 

Accidents Boring Accidents Methods of preventing them Methods of remedying them 
Explosives and the use of the " Torpedo " Levigation Storing and Transport of Petroleum 
General Advice Prospecting, Management and carrying on of Petroleum Boring Operations. 

General Data Customary Formulae Memento. Practical Part. General Data 
bearing on Petroleum Glossary of Technical Terms used in the Petroleum Industry Copious 


By AN EXPERT OIL REFINER. 100pp. 1898. DemySvo. Price 7s. 6d. ; 
India and Colonies, 8s. ; Other Countries, 8s. 6d. ; strictly net. 

Introductory Remarks on the General Nomenclature of Oils, Tallow and Greases 
suitable for Lubrication Hydrocarbon Oils Animal and Fish Oils Compound 
Oils Vegetable Oils Lamp Oils Engine Tallow, Solidified Oils and Petroleum 
Jelly Machinery Greases: Loco and Anti=friction Clarifying and Utilisation 
of Waste Fats, Oils, Tank Bottoms, Drainings of Barrels and Drums, Pickings 
Up, Dregs, etc. The Fixing and Cleaning of Oil Tanks, etc. Appendix and 
General Information. 

ANIMAL FATS AND OILS: Their Practical Production, 
Purification and Uses for a great Variety of Purposes. Their Pro- 
perties, Falsification and Examination. Translated from the German 
of Louis EDGAR ANDES. Sixty-two Illustrations. 240 pp. 1898. 
Demy 8vo. Price 10s. 6d. ; India and Colonies, 11s. ; Other Countries, 
12s. ; strictly net. 


Introduction Occurrence, Origin, Properties and Chemical Constitution of Animal Fats- 
Preparation of Animal Fats and Oils Machinery Tallow-melting Plant Extraction Plant 
Presses Filtering Apparatus Butter : Raw Material and Preparation, Properties, Adul- 
terations, Beef Lard or Remelted Butter, Testing Candle-fish Oil Mutton-Tallow Hare 
Fat Goose Fat Neatsfoot Oil Bone Fat: Bone Boiling, Steaming Bones, Extraction, 
Refining Bone Oil Artificial Butter: Oleomargarine, Margarine Manufacture in France, 
Grasso's Process, " Kaiser's Butter," Jahr & Miinzberg's Method, Filbert's Process, Winter's 
Method Human Fat Horse Fat Beef Marrow Turtle Oil Hog's Lard: Raw Material- 
Preparation, Properties, Adulterations, Examination Lard Oil Fish Oils Liver Oils 
Artificial Train Oil Wool Fat: Properties, Purified Wool Fat Spermaceti : Examination 
of Fats and Oils in General 

VEGETABLE FATS AND OILS: Their Practical Prepara- 
tion, Purification and Employment for Various Purposes, their Proper- 
ties, Adulteration and Examination. Translated from the German of 
Louis EDGAR ANDES. Ninety-four Illustrations. 340 pp. Second 
Edition. 1902. Demy 8vo. Price 10s. 6d. ; India and Colonies, 
11s.; Other Countries, 12s.; strictly net. 


General Properties Estimation of the Amount of Oil in Seeds The Preparation 

of, Vegetable Fats and Oils Apparatus for Grinding Oil Seeds and Fruits Installation 
of Oil and Fat Works Extraction Method of Obtaining Oils and Fats Oil Extraction 
Installations Press Moulds Non-drying Vegetable Oils Vegetable drying Oils- 
Solid Vegetable Fats Fruits Yielding Oils and Fats Wool-softening Oils Soluble Oils- 
Treatment of the Oil after Leaving the Press Improved Methods of Refining Bleaching 
Fats and Oils Practical Experiments on the Treatment of Oils with regard to Refining and 
Bleaching Testing Oils and Fats. 

SOAPS. A Practical Manual of the Manufacture of Domestic, 
Toilet and other Soaps. By GEORGE H. HURST, F.C.S. 390 pp. 
66 Illustrations. 1898. Price 12s. 6d. ; India and Colonies, 13s. 6d. ; 
Other Countries, 15s. ; strictly net. 


Introductory Soap-maker's Alkalies Soap Fats and Oils Perfumes Water as 
a Soap Material Soap Machinery Technology of Soap-making Glycerine in Soap 
Lyes Laying out a Soap Factory Soap Analysis Appendices. 

(Lond.), F.I.C., F.C.S. 411 pp. 20 Illustrations. 1899. Demy 8vo. 
Price 12s. 6d. ; India and Colonies, 13s. 6d. ; Other Countries. 15s.; 
strictly net. 

The General Properties of Essential Oils Compounds occurring in Essential Oils 

The Preparation of Essential Oils The Analysis of Essential Oils Systematic 

Study of the Essential Oils Terpeneless Oils The Chemistry of Artificial Perfumes 

Appendix : Table of Constants Index. 

Gosmetical Preparations. 

from the German of Dr. THEODOR ROLLER. Crown 8vo. 262 pp. 
1902. Price 5s. ; India and Colonies, 5s. 6d. ; Other Countries, 
6s. net. 


Purposes and Uses of, and Ingredients used in the_Preparation of Cosmetics Preparation of 
Perfumes by Pressure, Distillation, Maceration, Absorption or Enfleurage, and Extraction 
Methods Chemical and Animal Products used in the Preparation of Cosmetics Oils and Fats 
used 'in the Preparation of Cosmetics General Cosmetic Preparations Mouth Washes and 
Tooth Pastes Hair Dyes, Hair Restorers and Depilatories Cosmetic Adjuncts and 
Specialities Colouring Cosmetic Preparations Antiseptic Washes and Soaps Toilet and 
Hygienic Soaps Secret Preparations for Skin, Complexion, Teeth, Mouth, etc. Testing and 
Examining the Materials Employed in the Manufacture of Cosmetics Index. 

Glue, Bone Products and 

(Lond.), F.I.C. Fourteen Engravings. 144pp. DemySvo. 1900. Price 
10s. 6d. ; India and Colonies, 11s.; Other Countries, 12s.; strictly net. 


Constitution and Properties: Definitions and Sources, Gelatine, Chondrin and Allied 
Bodies, Physical and Chemical Properties, Classification, Grades and Commercial Varieties 
Raw Materials and Manufacture : Glue Stock, Lining, Extraction, Washing and Clari- 
fying, Filter Presses, Water Supply, Use of Alkalies, Action of Bacteria and of Antiseptics, 
Various Processes, Cleansing, Forming, Drying, Crushing, etc., Secondary Products Uses 
of Glue : Selection and Preparation for Use, Carpentry, Veneering, Paper-Making, Book- 
binding, Printing Rollers, Hectographs, Match Manufacture, Sandpaper, etc., Substitutes for 
other Materials, Artificial Leather and Caoutchouc Gelatine : General Characters, Liquid 
Gelatine, Photographic Uses, Size, Tanno-, Chrome and Formo-Gelatine, Artificial Silk, 
Cements, Pneumatic Tyres, Culinary, Meat Extracts, Isinglass, Medicinal and other Uses, 
Bacteriology Glue Testing: Review of Processes, Chemical Examination, Adulteration, 
Physical Tests, Valuation of Raw Materials Commercial Aspects. 

most recent Improvements in the Manufacture of Fat, Glue, Animal 
Charcoal, Size, Gelatine and Manures. By THOMAS LAMBERT, Techni- 
cal and Consulting Chemist. Illustrated by Twenty-one Plans and 
Diagrams. 162 pp. Demy 8vo. 1901. Price 7s. 6d. ; India and 
Colonies, 8s. ; Other Countries, 8s. 6d. ; strictly net. 


Chemical Composition of Bones Arrangement of Factory Crushing of Bones Treat- 
ment with Benzene Benzene in Crude Fat Analyses of Clarified Fats Mechanical 
Cleansing of Bones Animal Charcoal Tar and Ammoniacal Liquor, Char and Gases, from 
good quality Bones Method of Retorting the Bones Analyses of Chars "Spent" Chars 
Cooling of Tar and Ammoniacal Vapours Value of Nitrogen for Cyanide of Potash Bone 
Oil Marrow Bones Composition of Marrow Fat Premier Juice Buttons Properties 
of Glue Glutin and Chondrin Skin Glue Liming of Skins Washing Boiling of Skins 
Clarification of Glue Liquors Acid Steeping of Bones Water System of Boiling Bones 
Steam Method of Treating Bones Nitrogen in the Treated Bones Glue-Boiling and Clarify- 
ing-House Plan showing Arrangement of Clarifying Vats Plan showing Position of Evapora- 
tors Description of Evaporators Sulphurous Acid Generator Clarification of Liquors 
Section of Drying-House Specification of a Glue Size Uses and Preparation and Composi- 
tion of Size Concentrated Size Properties of Gelatine Preparation of Skin Gelatine 
Washing Bleaching Boiling Clarification Evaporation Drying Bone Gelatine Se- 
lecting Bones Crushing Dissolving Bleaching Boiling Properties of Glutin and Chondrin 
Testing of Glues and Gelatines The Uses of Glue, Gelatine and Size in Various Trades 
Soluble and Liquid Glues Steam and Waterproof Glues Manures Importation of Food 
Stuffs Soils Germination Plant Life Natural Manures Water and Nitrogen in Farm- 
yard Manure Full Analysis of Farmyard Manure Action on Crops Water-Closet System 
Sewage Manure Green Manures Artificial Manures Mineral Manures Nitro- 
genous Matters Shoddy Hoofs and Horns Leather Waste Dried Meat Dried Blood- 
Superphosphates Composition Manufacture Section of Manure-Shed First and Ground 
Floor Plans of Manure-Shed Quality of Acid Used Mixings Special Manures Potato 
Manure Dissolved Bones Dissolved Bone Compound Enriched Peruvian Guano Special 
Manure for Garden Stuffs, etc. Special Manures Analyses of Raw and Finished Products 
Common Raw Bones Degreased Bones Crude Fat Refined Fat Degelatinised Bones 
Animal Charcoal Bone Superphosphates Guanos Dried Animal Products Potash Com- 
poundsSulphate of Ammonia Extraction in Vacuo French and British Gelatines compared 

Chemicals, Waste Products and 
Agricultural Chemistry. 

SCHEELE. First Published in English in 1786. Trans- 
lated from the Academy of Sciences at Stockholm, with Additions. 300 
pp. Demy 8vo. 1901. Price 5s. ; India and Colonies, 5s. 6d. ; Other 
Countries, 6s. ; strictly net. 


Memoir: C. W. Scheele and his work (written for this edition by J. G. Mclntosh) On 
Fluor Mineral and its Acid On Fluor Mineral Chemical Investigation of Fluor Acid, 
with a View to the Earth which it Yields, by Mr. Wiegler Additional Information 
Concerning Fluor Minerals On Manganese, Magnesium, or Magnesia Vitrariorum On 
Arsenic and its Acid Remarks upon Salts of Benzoin On Silex, Clay and Alum Analysis 
of the Calculus Vesical .Method of Preparing Mercurius Dulcis Via Humida Cheaper and 
more Convenient Method of Preparing Pulvis Algarothi Experiments upon Molybdaena 
Experiments on Plumbago Method of Preparing a New Green Colour Of the De- 
composition of Neutral Salts by Unslaked Lime and Iron On the Quantity of Pure Air which 
is Daily Present in our Atmosphere On Milk and its Acid On the Acid of Saccharum Lactis 
On the Constituent Parts of Lapis Ponderosus or Tungsten Experiments and Observations 
on Ether Index. 

IRON. Their Uses and Applications as Mordants in Dyeing 
and Calico Printing, and their other Applications in the Arts, Manufac- 
tures, Sanitary Engineering, Agriculture and Horticulture. Translated 
from the French of LUCIEN GESCHWIND. 195 Illustrations. 400 pp. 
Royal 8vo. 1901. Price 12s. 6d. ; India and Colonies, 13s. 6d. ; Other 
Countries, 15s. ; strictly net. 


Theoretical Study of Aluminium, Iron, and Compounds of these Metals- 
Aluminium and its Compounds Iron and Iron Compounds. 

Manufacture of Aluminium Sulphates and Sulphates of Iron Manufacture of 
Aluminium Sulphate and the Alums Manufacture of Sulphates of Iron. 

Uses of the Sulphates of Aluminium and Iron Uses of Aluminium Sulphate and 
Alums Application to Wool and Silk Preparing and using Aluminium Acetates Employment 
of Aluminium Sulphate in Carbonising Wool The Manufacture of Lake Pigments Manu- 
facture of Prussian Blue Hide and Leather Industry Paper Making Hardening Plaster 
Lime Washes Preparation of Non-inflammable Wood, etc. Purification of Waste Waters 
Uses and Applications of Ferrous Sulphate and Ferric Sulphates Dyeing Manu- 
facture of Pigments Writing Inks Purification of Lighting Gas Agriculture Cotton Dyeing 
Disinfectant Purifying Waste Liquors Manufacture of Nordhausen Sulphuric Acid 

Chemical Characteristics of Iron and Aluminium Analysis of Various Aluminous 
or Ferruginous Products Aluminium Analysing Aluminium Products Alunite 
Alumina Sodium Aluminate Aluminium Sulphate Iron Analytical Characteristics of Iron 
Salts Analysis of Pyritic Lignite Ferrous and Ferric Sulphates Rouil Mordant Index. 

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. 114pp. 1901. Thirty-two Illustrations. Price 
5s. ; India and Colonies, 5s. 6d. ; Other Countries, 6s. ; strictly net. 

General Considerations: Various Sources of Ammoniacal Products; Human Urine 
as a Source of Ammonia Extraction of Ammoniacal Products from Sewage- 
Extraction of Ammonia from Gas Liquor Manufacture of Ammoniacal Com- 
pounds from Bones, Nitrogenous Waste, Beetroot Wash and Peat Manufacture of 
Caustic Ammonia, and Ammonium Chloride, Phosphate and Carbonate Recovery 
of Ammonia from the Ammonia-Soda Mother Liquors Index. 


from the German of Dr. KARL DIETERICH. Demy 8vo. 340pp. 1901. 
Price 7s. 6d. ; India and Colonies, 8s. ; Other Countries, 8s. 6d. ; 
strictly net. 


Definition of Resins in General Definition of Balsams, and especially the Gum Resins 
External and Superficial Characteristics of Resinous Bodies Distinction between Resinous 
Bodies and Fats and Oils Origin, Occurrence and Collection of Resinous Substances 
Classification Chemical Constituents of Resinous Substances Resinols Resinot Annols 
Behaviour of Resin Constituents towards the Cholesterine Reactions Uses and Identi- 
fication of Resins Melting-point Solvents Acid Value Saponification Value Resin Value 
Ester and Ether Values Acetyl and Corbonyl Value Methyl Value Resin Acid Syste- 
matic Re"sum of the Performance of the Acid and Saponification Value Tests. 

Balsams Introduction Definitions Canada Balsam Copaiba Balsam Angostura 
Copaiba Balsam Babia Copaiba Balsam Carthagena Copaiba Balsam Maracaibo 
Copaiba Balsam Maturin Copaiba Balsam Gurjum Copaiba Balsam Para Copaiba Balsam 
Surinam Copaiba Balsam West African Copaiba Balsam Mecca Balsam Peruvian 
Balsam Tolu Balsam Acaroid Resin Amine Amber African and West Indian Kino 
Bengal Kino Labdanum Mastic Pine Resin Sandarach Scammonium Shellac Storax 
Adulteration of Styrax Liquidus Crudus Purified Storax Styrax Crudus Colatus Taca- 
mahac Thapsia Resin Turpentine Chios Turpentine Strassburg Turpentine Turpeth 
Turpentine. Gum Resins Ammoniacum Bdellium Euphorbium Galbanum Gamboge 
Lactucarium Myrrh Opopanax Sagapenum Olibanum or Incense Acaroid Resin 
Amber Thapsia Resin Index. 


HERBERT INGLE, F.I.C., Lecturer on Agricultural Chemistry, the 
Yorkshire College; Lecturer in the Victoria University. 388 pp. 11 
Illustrations. 1902. Demy 8vo. Price 7s. 6d. ; India and Colonies, 8s. ; 
Other Countries, 8s. 6d. net. 


Introduction The Atmosphere The Soil The Reactions occurring in Soils The 
Analysis of Soils Manures, Natural Manures (continued) The Analysis of Manures The 
Constituents of Plants The Plant Crops The Animal Foods and Feeding Milk and Milk 
Products The Analysis of Milk and Milk Products Miscellaneous Products used in Agri- 
culture Appendix Index. 

on the Rational Utilisation, Recovery and Treatment of Waste Pro- 
ducts of all kinds. By Dr. THEODOR KOLLER. Translated from the 
Second Revised German Edition. Twenty-two Illustrations. Demy 
8vo. 280 pp. 1902. Price 7s. 6d. ; India and Colonies, 8s. ; Other 
Countries, 8s. 6d. ; strictly net. 


The Waste of Towns Ammonia and Sal-AmmoniacRational Processes for Obtaining 
these Substances by Treating Residues and Waste Residues in the Manufacture of Aniline 
Dyes Amber Waste Brewers' Waste Blood and Slaughter-House Refuse Manufactured 
Fuels Waste Paper and Bookbinders' Waste Iron Slags Excrement Colouring Matters 
from Waste Dyers' Waste Waters Fat from Waste Fish Waste Calamine Sludge- 
Tannery Waste Gold and Silver Waste India-rubber and Caoutchouc Waste Residues in 
the Manufacture of Rosin Oil Wood Waste Horn Waste Infusorial Earth Iridium from 
Goldsmiths' Sweepings Jute Waste Cork Waste Leather Waste Glue Makers' Waste 
Illuminating Gas from Waste and the By-Products of the Manufacture of Coal Gas 
Meerschum Molasses Metal Waste By-Products in the Manufacture of Mineral Waters 
Fruit The By-Products of Paper and Paper Pulp Works By-Products in the Treatment 
of Coal Tar Oils Fur Waste The Waste Matter in the Manufacture of Parchment Paper 
Mother of Pearl Waste Petroleum Residues Platinum Residues Broken Porcelain. 
Earthenware and Glass Salt Waste Slate Waste Sulphur Burnt Pyrites Silk Waste- 
Soap Makers' Waste Alkali Waste and the Recovery of Soda Waste Produced in Grinding 
Mirrors Waste Products in the Manufacture of Starch Stearic Acid Vegetable Ivory 
Waste Turf Waste Waters of Cloth Factories Wine Residues Tinplate Waste Wool 
Waste Wool Sweat The Waste Liquids from Sugar Works Index. 


Writing Inks and Sealing Waxes 

INK MANUFACTURE : Including Writing, Copying, Litho- 

fraphic, Marking, Stamping, and Laundry Inks. By SIGMUND LEHNER. 
hree Illustrations. Crown 8vo. 162 pp. 1902. Translated from the 
German of the Fifth Edition. Price 5s. ; India and Colonies, 5s. 6d. ; 
Other Countries, 6s. ; net. 


Varieties of Ink Writing Inks Raw Materials of Tannin Inks The Chemical Constitution 
of the Tannin Inks Recipes for Tannin Inks Logwood Tannin Inks Ferric Inks Alizarine 
Inks Extract Inks Logwood Inks Copying Inks Hektographs Hektograph Inks Safety 
Inks Ink Extracts and Powders Preserving Inks Changes in Ink and the Restoration of 
Faded Writing Coloured Inks Red Inks Blue Inks Violet Inks Yellow Inks Green 
Inks Metallic Inks Indian Ink Lithographic Inks and Pencils Ink Pencils Marking Inks 
Ink Specialities Sympathetic Inks Stamping Inks Laundry or Washing Blue Index. 

8vo. 96 pp. 1902. Price 5s. ; India and Colonies, 5s. 6d. ; Other 
Countries, 6s. ; strictly net. 


Materials Used for Making Sealing- Waxes The Manufacture of Sealing- Waxes- 
Wafers Notes on the Nature of the Materials Used in Making Adhesive Compounds Cements 
for Use in the Household Office Gums, Pastes and Mucilages Adhesive Compounds for 
Factory and Workshop Use. 

Lead Ores and Compounds. 


Technical and Consulting Chemist. Demy 8vo. 226 pp. Forty Illus- 
trations. 1902. Price 7s. 6d. ; India and Colonies, 8s. ; Other Countries, 
8s. 6d. ; net. Plans and Diagrams. 


History Ores of Lead Geographical Distribution of the Lead Industry Chemical and 
Physical Properties of Lead Alloys of Lead Compounds of Lead Dressing of Lead Ores 
Smelting of Lead Ores Smelting in the Scotch or American Ore-hearth Smelting in the 
Shaft or Blast Furnace Condensation of Lead Fume Desilverisation, or the Separation 
of Silver from Argentiferous Lead Cupellation The Manufacture of Lead Pipes and 
Sheets Protoxide of Lead Litharge and Massicot Red Lead or Minium Lead Poisoning 
Lead Substitutes Zinc and its Compounds Pumice Stone Drying Oils and Siccatives 
Oil of Turpentine Resin Classification of Mineral Pigments Analysis of Raw and Finished 
Products Tables Index. 

NOTES ON LEAD ORES : Their Distribution and Properties. 
By JAS. FAIRIE, F.G.S. Crown 8vo. 1901. 64 pages. Price 2s. 6d. ; 
Abroad, 3s. ; strictly net. 

Industrial Uses of Air, Steam and 


tions, Formulae, and Tables for Use in Practice. Translated from the 
German of E. HAUSBRAND. Two folding Diagrams and Thirteen Tables. 
Crown 8vo. 1901. 72 pp. Price 5s. ; India and Colonies, 5s. 6d. ; 
Other Countries, 6s. ; strictly net. 


British and Metric Systems Compared Centigrade and Fahr. Thermometers Estimation 
of the Maximum Weight of Saturated Aqueous Vapour which can be contained in 1 kilo, 
of Air at Different Pressure and Temperatures Calculation of the Necessary Weight and 
Volume of Air, and of the Least Expenditure of Heat, per Drying Apparatus with Heated 
Air, at the Atmospheric Pressure: A, With the Assumption that the Air is Completely Satur- 
ated with Vapour both before Entry and after Exit from the Apparatus B, When the 
Atmospheric Air is Completely Saturated before entry, but at its exit is only f , J or J Saturated 
C, When the Atmospheric Air is not Saturated with Moisture before Entering the Drying 
Apparatus Drying Apparatus, in which, in the Drying Chamber, a Pressure is Artificially 
Created, Higher or Lower than that of the Atmosphere Drying by Means of Superheated 
Steam, without Air Heating Surface, Velocity of the Air Current, Dimensions of the Drying 
Room, Surface of the Drying Material, Losses of Heat Index. 

(See also " Evaporating, Condensing and Cooling Apparatus," p. 26.) 

PURE AIR, OZONE AND WATER. A Practical Treatise 
of their Utilisation and Value in Oil, Grease, Soap, Paint, Glue and 
other Industries. By W. B. COWELL. Twelve Illustrations. Crown 
8vo. 85 pp. 1900. Price 5s. ; India and Colonies, 5s. 6d. ; Other 
Countries, 6s. ; strictly net. 


Atmospheric Air ; Lifting of Liquids ; Suction Process ; Preparing Blown Oils; Preparing 
Siccative Drying Oils Compressed Air; Whitewash Liquid Air; Retrocession Purification 
of Water; Water Hardness Fleshings and Bones Ozonised Air in the Bleaching and De- 
odorising of Fats, Glues, etc. ; Bleaching Textile Fibres Appendix: Air and Gases; Pressure 
of Air at Various Temperatures; Fuel; Table of Combustibles; Saving of Fuel by Heating 
Feed Water ; Table of Solubilities of Scale Making Minerals ; British Thermal Units Tables ; 
Volume of the Flow of Steam into the Atmosphere; Temperature of Steam Index. 


By H. DE LA Coux. Royal 8vo. 400 pp. 135 Illustrations. Translated 
from the French. [7n the press. 


Chemical Action of Water in Nature and in Industrial Use Composition of Waters 
Solubility of Certain Salts in Water Considered from the Industrial Point of View Effects on 
the Boiling of Water Effects of Water in the Industries Difficulties with Water Feed 
Water for Boilers Water in Dyeworks, Print Works, and Bleach Works Water in the 
Textile Industries and in Conditioning Water in Soap Works Water in Laundries and 
Washhouses Water in Tanning Water in Preparing Tannin and Dyewood Extracts Water 
in Papermaking Water in Photography Water in Sugar Refining Water in Making Ices 
and Beverages Water in Cider Making Water in Brewing Water in Distilling Preliminary 
Treatment and Apparatus Substances Used for Preliminary Chemical Purification Com- 
mercial Specialities and their Employment Precipitation of Matters in Suspension in Water 
Apparatus for the Preliminary Chemical Purification of Water Industrial Filters Indus- 
trial Sterilisation of Water Residuary Waters and their Purification Soil Filtration 
Purification by Chemical Processes Analyses Index. 

(See Books on Smoke Prevention, Engineering and Metallurgy, p. 26, etc.) 

Industrial Hygiene. 


By LEONARD A. PARRY, M.D., B.S. (Lond.). 196 pp. Demy 8vo. 1900 . 
Price 7s. 6d. ; India and Colonies, 8s. ; Other Countries, 8s. 6d. ; strictly 


Occupations which are Accompanied by the Generation and Scattering of Abnormal 
Quantities of Dust Trades in which there is Danger of Metallic Poisoning Certain Chemi- 
cal Trades Some Miscellaneous Occupations Trades in which Various Poisonous Vapours 
are Inhaled General Hygienic Considerations Index. 


X Rays. 

B.Sc. (Lond.), F.I.C., Member of the Roentgen Society of London ; 
Radiographer to St. George's Hospital ; Demonstrator of Physics and 
Chemistry, and Teacher of Radiography in St. George's Hospital 
Medical School. Demy 8vo. Twelve Plates from Photographs of X Ray 
Work. Fifty-two Illustrations. 200pp. 1901. Price 10s. 6d. ; India 
and Colonies, 11s. ; Other Countries, 12s. ; strictly net. 

Historical Work leading up to the Discovery of the X Rays The Discovery Appara- 
tus and its Management Electrical Terms Sources of Electricity Induction Coils 
Electrostatic Machines Tubes Air Pumps Tube Holders and Stereoscopic Apparatus- 
Fluorescent Screens Practical X Ray Work Installations Radioscopy Radiography 
X Rays in Dentistry X Rays in Chemistry X Rays in War Index. 

List of Plates. 

Frontispiece Congenital Dislocation of Hip-Joint. I., Needle in Finger. II., Needle in 
Foot. III., Revolver Bullet in Calf and Leg. IV., A Method of Localisation. V., Stellate 
Fracture of Patella showing shadow of " Strapping ".VI., Sarcoma. VII., Six-weeks-old 
Injury to Elbow showing new Growth of Bone. VIII., Old Fracture of Tibia and Fibula 
badly set. IX., Heart Shadow. X., Fractured Femur showing Grain of Splint. XL. Bar- 
rell's Method of Localisation. 

India^Rubber and Gutta Percha. 

from the French of T. SEELIGMANN, G. LAMY TORVILHON and H. 
FALCONNET by JOHN GEDDES MC!NTOSH. Royal 8vo. Eighty-six 
Illustrations. Three Plates. 412 pages. 1903. Price 12s. 6d. ; 
India and Colonies, 13s. 6d. ; Other Countries, 15s. ; strictly net. 

India- Rubber Botanical Origin Climatology Soil Rational Culture and Acclimation 
of the Different Species of India-Rubber Plants Methods of Obtaining the Latex Methods 
of Preparing Raw or Crude India-Rubber Classification of the Commercial Species of 
Raw Rubber Physical and Chemical Properties of the Latex and of India-Rubber 
Mechanical Transformation of Natural Caoutchouc into Washed or Normal Caoutchouc 
(Purification) and Normal Rubber into Masticated Rubber Softening, Cutting, Washing, 
Drying Preliminary Observations Vulcanisation of Normal Rubber Chemical and Physical 
Properties of Vulcanised Rubber General Considerations Hardened Rubber or Ebonite- 
Considerations on Mineralisation and other Mixtures Coloration and Dyeing Analysis 
of Natural or Normal Rubber and Vulcanised Rubber Rubber Substitutes Imitation Rubber. 

Gutta Percha Botanical Origin Climatology Soil Rational Culture Methods of 
Collection Classification of the Different Species of Commercial Gutta Percha Physical 
and Chemical Properties Mechanical Transformation Methods of Analysing Gutta Percha 
Substitutes Index. 

Leather Trades. 

DUSTRY. By A. M. VILLON. Translated by FRANK T. 
ADDYMAN, B.Sc. (Lond.), F.I.C., F.C.S. ; and Corrected by an Emi- 
nent Member of the Trade. 500 pp., royal 8vo. 1901. 123 Illustra- 
tions. Price 21s. ; India and Colonies, 22s. ; Other Countries, 23s. 6d. ; 
strictly net. 


Preface Translator's Preface List of Illustrations. 

Part I., Materials used in Tanning Skins: Skin and its Structure; Skins used in 
Tanning; Various Skins and their Uses Tannin and Tanning Substances: Tannin; Barks 
(Oak); Barks other than Oak; Tanning Woods: Tannin-bearing Leaves; Excrescences; 
Tan-bearing Fruits: Tan-bearing Roots and Bulbs; Tanning Juices; Tanning Substances 
used in Various Countries: Tannin Extracts; Estimation of Tannin and Tannin Principles. 

Part II., Tanning The Installation of a Tannary: Tan Furnaces; Chimneys, Boilers, 
etc.; Steam Engines Grinding and Trituration of Tanning Substances: Cutting up Bark; 
Grinding Bark; The Grinding of Tan Woods; Powdering Fruit, Galls and Grains; Notes on 


the Grinding of Bark Manufacture of Sole Leather: Soaking; Sweating and Unhairing; 
Plumping and Colouring; Handling; Tanning; Tanning Elephants' Hides; Drying; 
Striking or Pinning Manufacture of Dressing Leather: Soaking; Depilation ; New Pro- 
cesses for the Depilation of Skins; Tanning; Cow Hides; Horse Hides; Goat Skins; Manu- 
facture of Split Hides On Various Methods of Tanning: Mechanical Methods; Physical 
Methods; Chemical Methods; Tanning with Extracts Quantity and Quality; Quantity; 
Net Cost ; Quality of Leather Various Manipulations of Tanned Leather : Second Tanning ; 
Grease Stains; Bleaching Leather; Waterproofing Leather; Weighting Tanned Leather; 
Preservation of Leather Tanning Various Skins. 

Part III., Currying Waxed Calf: Preparation; Shaving; Stretching or Slicking; 
Oiling the Grain ; Oiling the Flesh Side ; Whitening and Graining ; Waxing ; Finishing ; Dry 
Finishing; Finishing in Colour; Cost White Calf: Finishing in White Cow Hide for 
Upper Leathers: Black Cow Hide; White Cow Hide; Coloured Cow Hide Smooth Cow 
Hide Black Leather Miscellaneous Hides: Horse; Goat; Waxed Goat Skin; Matt Goat 
Skin Russia Leather: Russia Leather; Artificial Russia Leather. 

Part IV., Enamelled, Hungary and Chamoy Leather, Morocco, Parchment, Furs 
and Artificial Leather Enamelled Leather: Varnish Manufacture; Application of the 
Enamel; Enamelling in Colour Hungary Leather: Preliminary; Wet Work or Prepara- 
tion; Aluming; Dressing or Loft Work; Tallowing; Hungary Leather from Various Hides 
Tawing : Preparatory Operations ; Dressing ; Dyeing Tawed Skins ; Rugs Chamoy Leather 
Morocco: Preliminary Operations, Morocco Tanning* Mordants used in Morocco Manu- 
facture; Natural Colours used in Morocco Dyeing; Artificial Colours; Different Methods 
of Dyeing; Dyeing with Natural Colours; Dyeing with Aniline Colours; Dyeing with 
Metallic Salts; Leather Printing ; Finishing Morocco ; Shagreen ; Bronzed Leather Gilding 
and Silvering: Gilding; Silvering; Nickel and Cobalt Parchment Furs and Furriery: 
Preliminary Remarks; Indigenous Furs; Foreign Furs from Hot Countries; Foreign Furs 
from Cold Countries ; Furs from Birds' Skins; Preparation of Furs; Dressing; Colouring; 
Preparation of Birds' Skins; Preservation of Furs Artificial Leather: Leather made from 
Scraps; Compressed Leather; American Cloth; Papier Mache; Linoleum; Artificial Leather. 

Part V., Leather Testing and the Theory of Tanning Testing and Analysis of Leather : 
Physical Testing of Tanned Leather; Chemical Analysis The Theory of Tanning and the 
other Operations of the Leather and Skin Industry: Theory of Soaking; Theory of Un- 
hairing; Theory of Swelling; Theory of Handling; Theory of Tanning; Theory of the 
Action of Tannin on the Skin; Theory of Hungary Leather Making; Theory of Tawing; 
Theory of Chamoy Leather Making; Theory of Mineral Tanning. 

Part VI., Uses of Leather Machine Belts: Manufacture of Belting; Leather Chain 
Belts; Various Belts, Use of Belts Boot and Shoe-making: Boots and Shoes; Laces 
Saddlery : Composition of a Saddle ; Construction of a Saddle Harness : The Pack Saddle ; 
Harness Military Equipment Glove Making Carriage Building Mechanical Uses. 

Appendix, The World's Commerce in Leather Europe; America; Asia; Africa; 
Australasia Index 

pendium of Practical Recipes and Working Formulae for Curriers, 
Bootmakers, Leather Dressers, Blacking Manufacturers, Saddlers, 
Fancy Leather Workers. By H. C. STANDAGE. 165 pp. 1900. Price 
7s. 6d. ; India and Colonies, 8s. ; Other Countries, 8s. 6d. ; strictly 


Blackings, Polishes, Glosses, Dressings, Renovators, etc., for Boot and Shoe Leather 
Harness Blackings, Dressings, Greases, Compositions, Soaps, and Boot-top Powders and 
Liquids, etc., etc. Leather Grinders' Sundries Currier's Seasonings, Blacking Compounds, 
Dressings, Finishes, Glosses, etc. Dyes and Stains for Leather Miscellaneous Information 
Chrome Tannage Index. 

Books on Pottery, Bricks, 
Tiles, Glass, etc. 

by Experts, and Edited by CHAS. F. BINNS. Revised Third Edition 
and Enlarged. 200 pp. 1901. Price 17s. 6d. ; India and Colonies, 
18s. 6d. ; Other Countries, 20s. ; strictly net. 

Introduction. The Rise and Progress of the Potter's Art Bodies. China and Porcelain 
Bodies, Parian Bodies, Semi-porcelain and Vitreous Bodies, Mortar Bodies, Earthenwares 
Granite and C.C. Bodies, Miscellaneous Bodies, Sagger and Crucible Clays, Coloured 
Bodies, Jasper Bodies, Coloured Bodies for Mosaic Painting, Encaustic Tile Bodies, Body 


Stains, Coloured Dips Glazes. China Glazes, Ironstone Glazes, Earthenware Glazes, 
Glazes without Lead, Miscellaneous Glazes, Coloured Glazes, Majolica Colours Gold and 
Gold Colours. Gold, Purple of Cassius, Marone and Ruby, Enamel Coloured Bases, 
Enamel Colour Fluxes, Enamel Colours, Mixed Enamel Colours, Antique and Vellum 
Enamel Colours, Underglaze Colours, Underglaze Colour Fluxes, Mixed Underglaze Colours, 
Flow Powders, Oils and Varnishes Means and Methods. Reclamation of Waste Gold, 
The Use of Cobalt, Notes on Enamel Colours, Liquid or Bright Gold Classification and 
Analysis. Classification of Clay Ware, Lord Playfair's Analysis of Clays, The Markets of 
the World, Time and Scale of Firing, Weights of Potter's Material, Decorated Goods 
Count Comparative Loss of Weight of Clays Ground Felspar Calculations The Conver- 
sion of Slop Body Recipes into Dry Weight The Cost of Prepared Earthenware Clay- 
Forms and Tables. Articles of Apprenticeship, Manufacturer's Guide to Stocktaking, 
Table of Relative Values of Potter's Materials, Hourly Wages Table, Workman's Settling 
Table, Comparative Guide for Earthenware and China Manufacturers in the use of Slop Flint 
and Slop Stone, Foreign Terms applied to Earthenware and China Goods, Table for the 
Conversion of Metrical Weights and Measures on the Continent and South America Index. 

CERAMIC TECHNOLOGY : Being some Aspects of Tech- 
nical Science as Applied to Pottery Manufacture. Edited by CHARLES 
F. BINNS. 100 pp. Demy 8vo. 1897. Price 12s. 6d. ; India and 
Colonies, 13s. 6d. ; Other Countries, 15s. ; strictly net. 

Preface The Chemistry of Pottery Analysis and Synthesis Clays and their Com- 
ponents The Biscuit Oven Pyrometry Glazes and their Composition Colours and 
Colour-making Index. 

WARE. By ALEX. BRONGNIART. With Notes and Additions 
by ALPHONSE SALVETAT. Translated from the French. 200 pp. 1898. 
Price 7s. 6d. ; India and Colonies, 8s. ; Other Countries, 8s. 6d. 
strictly net. 


Complete Manual for Pottery, Tile and Brick Works. By EMILE 
BOURRY. Translated from the French by WILTON P. Rix, Examiner 
in Pottery and Porcelain to the City and Guilds of London Technical 
Institute, Pottery Instructor to the Hanley School Board. Royal 
8vo. 1901. Over 700 pp. Price 21s.; India and Colonies, 22s.; 
Other Countries, 23s. 6d. ; strictly net. 

Part I., General Pottery Methods. Definition and History. Definitions and Classifi- 
cation of Ceramic Products Historic Summary of the Ceramic Art Raw Materials of 
Bodies. Clays : Pure Clay and Natural Clays Various Raw Materials : Analogous to Clay 
Agglomerative and Agglutinative Opening Fusible Refractory Trials of Raw Materials 
Plastic Bodies. Properties and Composition Preparation of Raw Materials: Disaggrega- 
tion Purification Preparation of Bodies: By Plastic Method By Dry Method By Liquid 
Method Formation. Processes of Formation: Throwing Expression Moulding by Hand, 
on the Jolley, by Compression, by Slip Casting Slapping Slipping Drying* Drying of 
Bodies Processes of Drying : By Evaporation By Aeration By Heating By Ventilation 
By Absorption Glazes. Composition and Properties Raw Materials Manufacture 
and Application Firing. Properties of the Bodies and Glazes during Firing Description 
of the Kilns Working of the Kilns Decoration. Colouring Materials Processes of 

Part II., Special Pottery Methods. Terra Cottas. Classification: Plain Ordinary, 
Hollow, Ornamental, Vitrified, and Light Bricks Ordinary and Black Tiles Paving Tiles 
Pipes Architectural Terra Cottas Vases, Statues and Decorative Objects Common Pottery 
Pottery for Water and Filters Tobacco Pipes Lustre Ware Properties and Tests for 
Terra Cottas Fireclay Goods. Classification : Argillaceous, Aluminous, Carboniferous, 
Silicious and Basic Fireclay Goods Fireclay Mortar (Pug) Tests for Fireclay Goods 
Faiences. Varnished Faiences Enamelled Faiences Silicious Faiences Pipeclay Faiences 
Pebble Work Feldspathic Faiences Composition, Processes of Manufacture and General 
Arrangements of Faience Potteries Stoneware. Stoneware Properly So-called: Paving 
Tiles Pipes Sanitary Ware Stoneware for Food Purposes and Chemical Productions 
Architectural Stoneware Vases, Statues and other Decorative Objects Fine Stoneware 
Porcelain. Hard Porcelain for Table Ware and Decoration, for the Fire, for Electrical 
Conduits, for Mechanical Purposes ; Architectural Porcelain, and Dull or Biscuit Porcelain 
Soft Phosphated or English Porcelain Soft Vitreous Porcelain, French and New Sevres 
Argillaceous Soft or Seger's Porcelain Dull Soft or Parian Porcelain Dull Feldspathic 
Soft Porcelain Index. 


ARCHITECTURAL POTTERY. Bricks, Tiles, Pipes, Ena- 
melled Terra-cottas, Ordinary and Incrusted Quarries, Stoneware 
Mosaics, Faiences and Architectural Stoneware. By LEON LEFEVRE. 
With Five Plates. 950 Illustrations in the Text, and numerous estimates. 
500 pp., royal 8vo. 1900. Translated from the French by K. H. BIRD, 
M.A., and W. MOORE BINNS. Price 15s. ; India and Colonies, 16s. ; 
Other Countries, 17s. 6d. ; strictly net. 


Part I. Plain Undecorated Pottery. Clays : Classification ; General Properties and 
Composition ; Working of Clay-Pits Open Pits Underground Pits. Preparation of the 
Clay. Bricks : Hand and Machine Moulding Expression Machines Dies Cutting-tables 
General Remarks on the Choice of Machines Types of Installations Estimates Plenishing, 
Hand and Steam Presses Drying, by Exposure to Air, Without Shelter, and Under Sheds 
Drying-rooms in Tiers, Closed Drying-rooms, in Tunnels, in Galleries Detailed Estimates 
of the Various Drying-rooms, Comparison of Prices Transport from the Machines to 
the Drying-rooms Firing In Clamps In Intermittent Kilns Continuous Kilns : with Solid 
Fuel : Round Kiln, Rectangular Kiln, Chimneys (Plans and Estimates) With Gas Fuel, 
Fillard Kiln (Plans and Estimates), Water-gas Kiln Heat Production of the Kilns ; Dimen- 
sions, Shapes, Colours, Decoration, and Quality of Bricks Hollow Bricks, Dimensions and 
Prices of Bricks, Various Shapes, Qualities Ube of Bricks Walls, Arches, Pavements, Flues, 
Cornices Facing with Coloured Bricks Balustrades. Tiles : Manufacture Moulding, by 
Hand, by Machinery : Preparation of the Clay Preparation of the Slabs, Transformation into 
Flat Tiles, into Jointed Tiles Screw, Cam and Revolver Presses Particulars of Tile-presses 
Drying Planchettes, Shelves, Drying-barrows and Trucks Firing Divided Kilns Instal- 
lation of Mechanical Tileworks Estimates; Shapes, Dimensions and Uses of the Principal 
Types of Tile Ancient Tiles Foreign Tiles Special Tiles Ridge Tiles. Coping Tiles, Border 
Tiles, Frontons, Gutters, Antefixes, Membron, Angular Roofing Accessories : Chimney-pots, 
Mitrons, Lanterns, Chimneys Qualities of Tiles Black Tiles Stoneware Tiles Particulars 
of Tiles. Pipes : Conduit Pipes Manufacture Moulding : Horizontal Machines, Vertical 
Machines Drying Firing Chimney Flues Ventiducts and " Boisseaux," " Waggons " 
Particulars of these Products. Quarries: Plain Quarries of Ordinary Clay: of Cleaned 
Clay Machines, Cutting, Mixing, Polishing Drying and Firing Applications Particulars of 
Quarries. Terra=cotta : History Manufacture Application : Balustrades, Columns, 
Pilasters, Capitals, Friezes, Frontons, Medallions, Panels, Rose-windows, Ceilings 
Appendix: Official Methods of Testing Terra-cottas. 

Part II. Made-up or Decorated Pottery. General Remarks on the Decoration of 
Pottery : Dips Glazes : Composition, Colouring, Preparation, Harmony with Pastes 
Special Processes of Decoration Enamels, Opaque, Transparent, Colours, Undergiaze, 
Over-glaze Other Processes : Crackling, Mottled, Flashing, Metallic Iridescence, Lustres. 
Glazed and Enamelled Bricks History: Glazing Enamelling Applications: Ordinary 
Enamelled Bricks, Glazed Stoneware, Enamelled Stoneware Enamelled Tiles. Decorated 
Quarries: Paving Quarries Decorated with Dips Stoneware: Applications Plain or In- 
crusted Stoneware; Manufacture Application Colouring, Manufacture, Moulding, Drying, 
Firing Applications Facing Quarries in Faience of Glazed Stoneware of Porcelain 
Applications of Facing Quarries Stove Quarries Preparation of the Pastes, Moulding, 
Firing, Enamelling, Decoration Applications Faiences for Fireplaces. Architectural De- 
corated Pottery: Faiences; Stoneware; Porcelain. Sanitary Pottery: Stoneware Pipes: 
Manufacture, Firing Applications Sinks Applications Urinals, Seats and Pans Applica- 
tions Drinking-fountains, ^Washstands Index. 

EARTHENWARE. By J. HOWARTH. Second Edition. 
1900. Paper Cover. Price Is. net; by post, home or abroad, Is. Id. 

HOW TO ANALYSE CLAY. Practical Methods for Prac- 
tical Men. By HOLDEN M. ASHBY, Professor of Organic Chemistry, 
Harvey Medical College, U.S.A. Twenty Illustrations. 1898. Price 
2s. 6d. ; Abroad, 3s. ; strictly net. 

NOTES ON POTTERY CLAYS. Their Distribution, Pro- 
perties, Uses and Analyses of Ball Clays, China Clays and China 
Stone. By JAS. FAIRIE, F.G.S. 1901. 132 pp. Crown 8vo. Price 
SB. 6d. ; India and Colonies, 4s. ; Other Countries, 4s. 6d. ; strictly net. 


A Reissue of 


With References to Genuine Specimens, and Notices of Eminent Pot- 
ters. By SIMEON SHAW. (Originally Published in 1829.) 265 pp. 
1900. Demy 8vo. Price 7s. 6d. ; India and Colonies, 8s. ; Other 
Countries, 8s. 6d. ; strictly net. 


Introductory Chapter showing the position of the Pottery Trade at the present time 
(1899) Preliminary Remarks The Potteries, comprising Tunstall, Brownhills, Green- 
field and New Field, Golden Hill, Latebrook, Green Lane, Burslem, Longport and Dale Hall, 
Hot Lane and Cobridge, Hanley and Shelton, Etruria, Stoke, Penkhull, Fenton, Lane Delph, 
Foley, Lane End On the Origin of the Art, and its Practice among the early Nations- 
Manufacture of Pottery, prior to 1700 The Introduction of Red Porcelain by Messrs. 
Elers, of Bradwell, 1690 Progress of the Manufacture from 1700 to Mr. Wedgwood's 
commencement in 1760 Introduction of Fluid Glaze Extension of the Manufacture of 
Cream Colour Mr. Wedgwood's Queen's Ware Jasper, and Appointment of Potter to Her 
Majesty Black Printing Introduction of Porcelain. Mr. W. Littler's Porcelain Mr. 
Cookworthy's Discovery of Kaolin and Petuntse, and Patent Sold to Mr. Champion re- 
sold to the New Hall Com. Extension of Term Blue Printed Pottery. Mr. Turner, Mr. 
Spode (1), Mr. Baddeley, Mr. Spode (2), Messrs. Turner, Mr. Wood, Mr. Wilson, Mr. Minton 
Great Change in Patterns of Blue Printed Introduction of Lustre Pottery. Improve- 
ments in Pottery and Porcelain subsequent to 1800. 

A Reissue of 

(Originally published in 1837.) 750 pp. 1900. Royal 8vo. Price 14s. ; 
India and Colonies, 15s. ; Other Countries, 16s. 6d. ; strictly net. 

PART I., ANALYSIS AND MATERIALS. Introduction : Laboratory and Apparatus ; 
Elements Temperature Acids and Alkalies The Earths Metals. 

PART II., SYNTHESIS AND COMPOUNDS.-Science of Mixing-Bodies : Porcelain 
Hard, Porcelain Fritted Bodies, Porcelain Raw Bodies, Porcelain Soft, Fritted Bodies, 
Raw Bodies, Stone Bodies, Ironstone, Dry Bodies, Chemical Utensils, Fritted Jasper, Fritted 
Pearl, Fritted Drab, Raw Chemical Utensils, Raw Stone, Raw Jasper, Raw Pearl, Raw Mortar, 
Raw Drab, Raw Brown, Raw Fawn, Raw Cane, Raw Red Porous, Raw Egyptian, Earthenware, 
Queen's Ware, Cream Colour, Blue and Fancy Printed, Dipped and Mocha, Chalky, Rings, 
Stilts, etc. Glazes: Porcelain Hard Fritted Porcelain Soft Fritted Porcelain Soft 
Raw, Cream Colour Porcelain, Blue Printed Porcelain, Fritted Glazes, Analysis of Fritt, 
Analysis of Glaze, Coloured Glazes, Dips, Smears and Washes; Glasses: Flint Glass, 
Coloured Glasses, Artificial Garnet, Artificial Emerald, Artificial Amethyst, Artificial Sap- 
phire, Artificial Opal, Plate Glass, Crown Glass, Broad Glass, Bottle Glass, Phosphoric Glass, 
British Steel Glass, Glass-Staining and Painting, Engraving on Glass, Dr. Faraday's Experi- 
mentsColours : Colour Making, Fluxes or Solvents, Components of the Colours; Reds, 
etc., from Gold, Carmine or Rose Colour, Purple, Reds, etc., from Iron, Blues, Yellows, 
Greens, Blacks, White, Silver for Burnishing, Gold for Burnishing, Printer's Oil, Lustres. 

Glassware, Glass Staining and 

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, blowing, etc., as well as the most costly 
crystal and ruby. Price for United Kingdom, 10s. 6d. ; Abroad, 15s. ; 
United States, $4; strictly net. 


Ruby Ruby from Copper Flint for using with the Ruby for Coating A German Metal 
Cornelian, or Alabaster Sapphire Blue Crysophis Opal Turquoise Blue Gold Colour 
Dark Green Green (common) Green for Malachite Blue for Malachite Black for Mela- 
chite Black Common Canary Batch Canary White Opaque Glass Sealing-wax Red 
Flint Flint Glass (Crystal and Demi) Achromatic Glass Paste Glass White Enamel- 
Firestone Dead White (for moons) White Agate Canary Canary Enamel Index. 


Prefaced with a Review of Ancient Glass. By ERNEST R. SUPPLING. 
With One Coloured Plate and Thirty-seven Illustrations. Demy 8vo. 
140 pp. 1902. Price 7s. 6d. ; India and Colonies, 8s. ; Other Countries, 
8s. 6d. net. 


A Short History of Stained Glass Designing Scale Drawings Cartoons and the Cut Line 
Various Kinds of Glass Cutting for Windows The Colours and Brushes used in Glass 
Painting Painting on Glass, Dispersed Patterns Diapered Patterns Aciding Firing 
Fret Lead Glazing Index. 

ENAMEL PAINTING. A Complete Introduction to the 
Preparation of all the Colours and Fluxes used for Painting on Porce- 
lain, Enamel, Faience and Stoneware, the Coloured Pastes and Col- 
oured Glasses, together with a Minute Description of the Firing of 
Colours and Enamels. By FELIX HERMANN, Technical Chemist. With 
Eighteen Illustrations. 300 pp. Translated from the German second 
and enlarged Edition. 1897. Price 10s. 6d. ; India and Colonies, 
11s.; Other Countries, 12s.; strictly net. 

History of Glass Painting The Articles to be Painted : Glass, Porcelain, Enamel, Stone- 
ware, Faience Pigments: Metallic Pigments: Antimony Oxide, Naples Yellow, Barium 
Chromate, Lead Chromate, Silver Chloride, Chromic Oxide Fluxes : Fluxes, Felspar, 
Quartz, Purifying Quartz, Sedimentation, Quenching, Borax, Boracic Acid, Potassium and 
Sodium Carbonates, Rocaille Flux Preparation of the Colours for Glass Painting The 
Colour Pastes The Coloured Glasses Composition of the Porcelain Colours The' Enamel 
Colours: Enamels for Artistic Work Metallic Ornamentation: Porcelain Gilding, Glass 
Gilding Firing the Colours : Remarks on Firing : Firing Colours on Glass, Firing Colours on 
Porcelain; The Muffle Accidents occasionally Supervening during the Process of Firing 
Remarks on the Different Methods of Painting on Glass, Porcelain, etc. Appendix : Cleaning 
Old Glass Paintings. 

Paper Staining. 

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 HUBNER, F.C.S., Lecturer on 
Papermaking at the Manchester Municipal Technical School. With 
Illustrations and 157 patterns of paper dyed in the pulp. Royal 
8vo, 180 pp. 1901. Price 15s. ; India and Colonies. 16s. ; Other 
Countries, 20s. ; strictly net. Limited edition. 


Behaviour of the Paper Fibres during the Process of Dyeing, Theory of the 
Mordant Colour Fixing Mediums (Mordants) Influence of the Quality of the Water 
Used Inorganic Colours Organic Colours Practical Application of the Coal Tar 
Colours according to their Properties and their Behaviour towards the Different 
Paper Fibres Dyed Patterns on Various Pulp Mixtures Dyeing to Shade Index. 

Enamelling on Metal. 

Workers in Gold and Silver, and Manufacturers of Objects of Art. 
By PAUL RANDAU. Translated from the German. With Sixteen Illus- 
trations. 180pp. 1900. Price 10s. 6d. ; India and Colonies, 11s.; 
Other Countries, 12s. ; strictly net. 


Composition and Properties of Glass Raw Materials for the Manufacture of Enamels 
Substances Added to Produce Opacity Fluxes Pigments Decolorising Agents Testing 
the Raw Materials with the Blow-pipe Flame Subsidiary Materials Preparing the 
Materials for Enamel Making Mixing the Materials The Preparation of Technical Enamels, 
The Enamel Mass Appliances for Smelting the Enamel Mass Smelting the Charge- 
Composition of Enamel Masses Composition of Masses for Ground Enamels Composition 
of Cover Enamels Preparing the Articles for Enamelling Applying the Enamel Firing 
the Ground Enamel Applying and Firing the Cover Enamel or Glaze Repairing Defects 
in Enamelled Ware Enamelling Articles of Sheet Metal Decorating Enamelled Ware- 
Specialities in Enamelling Dial-plate Enamelling Enamels for Artistic Purposes, Recipes 
for Enamels of Various Colours Index. 


NORMAN BROWN. Twenty-eight Illustrations. Crown 8vo. 60 pp. 
1900. Price 2s. 6d. ; Abroad, 3s. ; strictly net. 

Silk Manufacture. 


By ROLLINS RAYNER. Demy 8vo. 130 Illustrations. 

[In the Press. 

The Silkworm Cocoon Reeling and Qualities of Silk Silk Throwing Silk Wastes The 
Preparation of Silk Waste for Degumming Silk Waste Degumming, Schapping and Dis- 
chargingThe Opening and Dressing of Wastes Silk Waste "Drawing" or "Preparing" 
Machinery Long Spinning Short Spinning Spinning and Finishing Processes Utilisation 
of Waste Products Noil Spinning Exhaust Noil Spinning. 

Books on Textile and Dyeing 

FIBRES: Their Origin, Structure, Preparation, Washing, 
Bleaching, Dyeing, Printing and Dressing. By Dr. GEORG VON 
GEORGIEVICS. Translated from the German by CHARLES SALTER. 
320 pp. Forty-seven Illustrations. Royal Svo. 1902. Price 10s. 6d. ; 
India and Colonies, 11s.; Other Countries, 12s. net. 

The Textile Fibres Artificial Fibres Mineral Fibres Vegetable Fibres Cellulose- 
Cotton Bombax Cotton Vegetable Silk Flax Hemp Jute Ramie, Rhea, China Grass, 

Nettle Fibre Distinguishing Tests for the Various Fibres Animal Fibres : Silk Animal 
Hairs Sheep's Wool Goat Wool and Camel Wool Artificial Wool (Wool Substitutes) 
Conditioning Washing, Bleaching, Carbonising Bleaching Agents Cotton Bleaching 
Linen Bleaching Jute Bleaching Hemp Bleaching Ramie Bleaching Scouring and 
Bleaching Silk Washing and Bleaching Wool Blueing or White Dyeing Carbonising 
Mordants and Mordanting Dyeing Combination of Colours: Dyeing to Pattern 
Theory of Dyeing Classification of Dye Stuffs: Methods of Dyeing Application 
of Acid Dye Stuffs Application of Basic Dye Stuffs Application of Direct or Substantive 
Cotton Dyes Application of the Mordant Dyes Application of the Developing Dyes Dyeing 
on a Manufacturing Scale: Selection of Dye Stuffs for Dyeing Silk Dyeing Wool 
Dyeing Cotton Dyeing Dyeing Mixed Fabrics Sample Dyeings, Colorimetric Determina- 
tions, Reactions of Dye Stuffs on the Fibre, Tests for Fastness Printing Hand Printing 
Calico Printing: Reproduction of Pattern by Direct Printing: Thickening Agents Em- 
ployment of Mordant Dye Stuffs, Basic, Albumin, Direct, Developing, Vat, Acid Treatment 
of the Goods when Printed Combined Printing and Dyeing Discharge Style Printing 
Reserve Style Printing Topping Printing Wool Printing Silk Printing Printing Yarns, 
Warps, and Combed Sliver Dressing and Finishing Dressing and Finishing Substances 
used in Finishing Loading Ingredients Colouring for the Dressing Preparations Metals 
or their Sulphites Waterproofing Fireproofing Antiseptics for Prevention of Mould 
Application of Dressings Drying Stretching Finishing: Shearing, Damping, Calendering, 
Beetling, Moir or Watered Effects, Stamping Finishing Woollens Index, 



According to Various Systems, with Conversion Tables. Translated 
from the German of ANTHON GRUNER. With Twenty-Six Diagrams 
in Colours. 150 pp. 1900. Crown 8vo. Price 7s. 6d. ; India and 
Colonies, 8s. ; Other Countries, 8s. 6d. ; strictly net. 


Power=Loom Weaving in General. Various Systems of Looms Mounting: and 
Starting 1 the Power=Loom. English Looms Tappet or Treadle Looms Dobbies 
General Remarks on the Numbering, Reeling and Packing of Yarn Appendix Useful 
Hints. Calculating Warps Weft Calculations Calculations of Cost Price in Hanks. 

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 Illus- 
trations. 500 pp. Demy 8vo. 1901. Price 10s. 6d. ; India and 
Colonies, 11s.; Other Countries, 12s.; strictly net. 


PART I. The Raw Materials Used in the Textile Industry. 

PART II. The Technology of Spinning or the Conversion of Textile Raw 

Materials into Yarn. 

SPINNING VEGETABLE RAW MATERIALS. Cotton Spinning Installation of a Cotton 
Mill Spinning Waste Cotton and Waste Cotton Yarns Flax Spinning Fine Spinning Tow 
Spinning Hemp Spinning Spinning Hemp Tow String Jute Spinning Spinning Jute Line 
Yarn Utilising Jute Waste. 

PART III. Spinning Animal Raw Materials. 

Spinning Carded Woollen Yarn Finishing Yarn Worsted Spinning Finishing Worsted 
Yarn Artificial Wool or Shoddy Spinning Shoddy and Mungo Manufacture Spinning 
Shoddy and other Wool Substitutes Spinning Waste Silk Chappe Silk Fine Spinning- 

TILE FABRICS. With Reference to Official Specifica- 
tions. Translated from the German of Dr. J. HERZFELD. Second 
Edition. Sixty-nine Illustrations. 200 pp. Demy 8vo. 1902. Price 
10s. 6d. ; India and Colonies, 11s. ; Other Countries, 12s. ; strictly net. 


Yarn Testing. Determining the Yarn Number Testing the Length of Yarns- 
Examination of the External Appearance of Yarn Determining the Twist of Yarn 
and Twist Determination of Tensile Strength and Elasticity Estimating the 
Percentage of Fat in Yarn Determination of Moisture (Conditioning) Appendix. 


By R. T. LORD. Manufacturers and Designers of Carpets, Damask, 
Dress and all Textile Fabrics. 200 pp. 1898. Demy 8vo. 132 Designs 
and Illustrations. Price 7s. 6d. ; India and Colonies, 8s. ; Other 
Countries, 8s. 6d. ; strictly net. 


A Few Hints on Designing Ornamental Textile Fabrics A Few Hints on Designing Orna- 
mental Textile Fabrics (continued) A Few Hints on Designing Ornamental Textile Fabrics 
(continued) A Few Hints on Designing Ornamental Textile Fabrics (continued) Hints for 
Ruled-paper Draughtsmen The Jacquard Machine Brussels and Wilton Carpets Tapestry 
Carpets Ingrain Carpets Axminster Carpets Damask and Tapestry Fabrics Scarf Silks 
and Ribbons Silk Handkerchiefs Dress Fabrics Mantle Cloths Figured Plush Bed Quilts 
Calico Printing. 


By H. KINZER and K. WALTER. Royal 8vo. Eighteen Plates. Six 
Illustrations. Translated from the German. [In the press. 


The Various Sorts of Damask Fabrics Drill (Ticking, Handloom-made) Whole 
Damask for Tablecloths Damask with Ground- and Connecting-warp Threads Furniture 
Damask Lampas or Hangings Church Damasks The Manufacture of Whole Damask 

Damask Arrangement with and without Cross-Shedding The Altered Cone-arrangement 
The Principle of the Corner Lifting Cord The Roller Principle The Combination of the 
Jacquard with the so-called Damask Machine The Special Damask Machine The Combina- 
tion of Two Tyings, 




REISER. Translated from the Second German Edition. Crown 8vo. 

Sixty-three Illustrations. [In the press. 


Improperly Chosen Raw Material or Improper Mixtures Wrong Treatment of the 
Material in Washing, Carbonisation, Drying, Dyeing and Spinning Improper Spacing of the 
Goods in the Loom Wrong Placing of Colours Wrong Weight or Width of the Goods 
Breaking of Warp and Weft Threads Presence of Doubles, Singles, Thick, Loose, 
and too Hard Twisted Threads as well as Tangles, Thick Knots and the Like Errors in 
Cross-weaving Inequalities, i.e., Bands and Stripes Dirty Borders Defective Selvedges 
Holes and Buttons Rubbed Places Creases Spots Loose and Bad Colours Badly Dyed 
Selvedges Hard Goods Brittle Goods Uneven Goods Removal of Bands, Stripes, 
Creases and Spots. 

Dyeing, Colour Printing, 
Matching and Dye-stuffs. 


for Colour Chemists and Textile Printers. By DAVID PATERSON, 

F.C.S. Seventeen Illustrations. 136 pp. Demy 8vo. 1900. Price 

7s. 6d. ; India and Colonies, 8s. ; Other Countries, 8s. 6d. ; strictly net. 


Structure and Constitution of Wool Fibre Yarn Scouring Scouring Materials Water for 
Scouring Bleaching Carpet Yarns Colour Making for Yarn Printing Colour Printing 
Pastes Colour Recipes for Yarn Printing Science of Colour Mixing Matching of Colours 
" Hank " Printing Printing Tapestry Carpet Yarns Yarn Printing Steaming Printed 
Yarns Washing of Steamed Yarns Aniline Colours Suitable for Yarn Printing Glossary of 
Dyes and Dye-wares used in Wood Yarn Printing Appendix. 


tended for the use of Dyers, Calico Printers and Colour Chemists. By 
DAVID PATERSON, F.C.S. Forty-one Illustrations, Five Coloured Plates, 
and Four Plates showing Eleven Dyed Specimens of Fabrics. 132 

pp. Demy 8vo. 1900. Price 7s. 6d. ; India and Colonies, 8s. ; Other 
Countries, 8s. 6d. ; strictly net. 


Colour a Sensation ; Colours of Illuminated Bodies ; Colours of Opaque and Transparent 
Bodies; Surface Colour Analysis of Light; Spectrum: Homogeneous Colours; Ready 
Method of Obtaining a Spectrum Examination of Solar Spectrum; The Spectroscope and 
Its Construction ; Colounsts' Use of the Spectroscope Colour by Absorption ; Solutions and 
Dyed Fabrics; Dichroic Coloured Fabrics in Gaslight Colour Primaries of the Scientist 
versus the Dyer and Artist; Colour Mixing by Rotation and Lye Dyeing; Hue, Purity, 
Brightness; Tints; Shades, Scales, Tones, Sad and Sombre Colours Colour Mixing; Pure 
and Impure Greens, Orange and Violets; Large Variety of Shades from few Colours; Con- 
sideration of the Practical Primaries: Red, Yellow and Blue Secondary Colours; Nomen- 
clature of Violet and Purple Group ; Tints and Shades of Violet ; Changes in Artificial Light 
Tertiary Shades ; Broken Hues; Absorption Spectra of Tertiary Shades Appendix' Four 
Plates with Dyed Specimens Illustrating Text Index. 


tended for the use of Students of Colour Chemistry, Dyeing and 
Textile Printing. By DAVID PATERSON, F.C.S. Coloured Frontis- 
piece. Twenty-nine Illustrations and Fourteen Specimens of Dyed 
Fabrics. Demy 8vo. 132pp. 1901. Price 7s. 6d. ; India and Colonies, 
8s. ; Other Countries, 8s. 6d. ; strictly net. 


Colour Vision and Structure of the Eye Perception of Colour Primary and Comple- 
mentary Colour Sensations Daylight for Colour Matching Selection of a Good Pure Light 
Diffused Daylight, Direct Sunlight, Blue Skylight, Variability of Daylight, etc., etc. 
Matching of Hues Purity and Luminosity of Colours Matching Bright Hues Aid of Tinted 
Films Matching Difficulties Arising from Contrast Examination of Colours by Reflected 


and Transmitted Lights Effect of Lustre and Transparency of Fibres in Colour Matching 
Matching of Colours on Velvet Pile Optical Properties of Dye-stuffs. Dichroism, Fluor- 
escence Use of Tinted Mediums Orange Film Defects of the Eye Yellowing of the Lens 
Colour Blindness, etc. Matching of Dyed Silk Trimmings and Linings and Bindings Its 
Difficulties Behaviour of Shades in Artificial Light Colour Matching of Old Fabrics, etc. 
Examination of Dyed Colours under the Artificial Lights Electric Arc, Magnesium and Dufton, 
Gardner Lights, Welsbach, Acetylene, etc. Testing Qualities of an Illuminant Influence 
of the Absorption Spectrum in Changes of Hue under the Artificial Lights Study of the 
Causes of Abnormal Modifications of Hue, etc. 

Coloured Plates and Seventy-two Illustrations. 160 pp. Demy 8vo. 
1900. Price 7s. 6d. ; India and Colonies, 8s. ; Other Countries, 8s. 6d. ; 
strictly net. 


Colour and Its Production. Light, Colour, Dispersion of White Light, Methods of 
Producing the Spectrum, Glass Prism and Diffraction Grating Spectroscopes, The Spectrum, 
Wave Motion of Light, Recomposition of White Light, Hue, Luminosity, Purity of Colours, 
The Polariscope, Phosphorescence, Fluorescence, Interference Cause of Colour in Coloured 
Bodies. Transmitted Colours, Absorption Spectra of Colouring Matters Colour Pheno= 
mena and Theories. Mixing Colours, White Light from Coloured Lights, Effect of 
Coloured Light on Colours, Complementary Colours, Young Helmholtz Theory, Brewster 
Theory, Supplementary Colours, Maxwell's Theory, Colour Photography The Physiology 
of Light. Structure of the Eye, Persistence of Vision, Subjective Colour Phenomena, Colour 
Blindness Contrast. Contrast, Simultaneous Contrast, Successive Contrast, Contrast of 
Tone. Contrast of Colours, Modification of Colours by Contrast, Colour Contrast in Decorative 
Design Colour in Decoration and Design. Colour Harmonies, Colour Equivalents, 
Illumination and Colour, Colour and Textile Fabrics, Surface Structure and Colour 
Measurement of Colour. Colour Patch Method, The Tintometer, Chromometer. 

Handbook for the Dyer and Student. By FRANKLIN BEECH, Practical 
Colourist and Chemist. 272 pp. Forty-four Illustrations of Bleaching 
and Dyeing Machinery. Demy 8vo. 1901. Price 7s. 6d. ; India 
and Colonies, 8s. ; Other Countries, 8s. 6d. ; strictly net. 

Structure and Chemistry of the Cotton Fibre Scouring and Bleaching of Cotton Dyeing 
Machinery and Dyeing Manipulations Principles and Practice of Cotton Dyeing Direct 
Dyeing; Direct Dyeing followed by Fixation with Metallic Salts; Direct Dyeing followed by 
Fixation with Developers ; Direct Dyeing followed by Fixation with Couplers ; Dyeing on 
Tannic Mordant ; Dyeing on Metallic Mordant ; Production of Colour Direct upon Cotton 
Fibres ; Dyeing Cotton by Impregnation with Dye-stuff Solution Dyeing Union (Mixed Cotton 
and Wool) Fabrics Dyeing Half Silk (Cotton-Silk, Satin) Fabrics Operations following 
Dyeing Washing, Soaping, Drying Testing of the Colour of Dyed Fabrics Experimental 
Dyeing and Comparative Dye Testing Index. 

The book contains numerous recipes for the production on Cotton Fabrics of all kinds of a 
great range of colours. 

BEECH, Practical Colourist and Chemist. Thirty-three Illustrations. 
Demy 8vo. 228 pp. 1902. Price 7s. 6d. ; India and Colonies, 8s. ; 
Other Countries, 8s. 6d. net. 


The Wool Fibre Structure, Composition and Properties Prbcesses Preparatory to Dyeing 
Scouring and Bleaching of Wool Dyeing Machinery and Dyeing Manipulations Loose 
Wool Dyeing, Yarn Dyeing and Piece Dyeing Machinery The Principles and Practice of 
Wool Dyeing Properties of Wool Dyeing Methods of Wool Dyeing Groups of Dyes 
Dyeing with the Direct Dyes Dyeing with Basic Dyes Dyeing with Acid Dyes Dyeing 
with Mordant Dyes Level Dyeing Blacks on Wool Reds on Wool Mordanting of Wool 
Orange Shades on Wool Yellow Shades on Wool Green Shades on Wool Blue Shades on 
Wool Violet Shades on Wool Brown Shades on Wool Mode Colours on Wool Dyeing 
Union (Mixed Cotton Wool) Fabrics Dyeing of Gloria Operations following Dyeing 
Washing, Soaping, Drying Experimental Dyeing and Comparative Dye Testing Testing of 
the Colour of Dyed Fabrics Index, 


DYERS' MATERIALS : An Introduction to the Examination, 
Evaluation and Application of the most important Substances used in 
Dyeing, Printing, Bleaching and Finishing. By PAUL HEERMAN, Ph.D. 
Translated from the German by. A C. WRIGHT, M.A. (Oxon.), B.Sc. 
(Lond.). Twenty-four Illustrations. Crown 8vo. 150pp. 1901. Price 
5s. ; India and Colonies, 5s. 6d. ; Other Countries, 6s. ; strictly net. 

Indicators Standard Solutions Solutions and Reagents in General Use Water Textile 
Fibres Hydrochloric Acid Chlorides Fluorides and Bifluorides Sulphuric Acid Sulphates 
Nitric A cid and Nitrates Chlorine-Oxygen Compounds Sulphite Compounds Miscellaneous 
Compounds Alkalies Peroxides Zinc Dust Fatty Acids and Their Salts Cyanogen Com- 
pounds Derivatives of the Fats Tannins Aniline and Aniline Salts Thickening and 
Stiffening Materials : Starch, Prepared and Soluble Starch, Dextrine, Gum Arabic, Gum 
Senegal, Gum Tragacanth, Glue, Size Dyes Appendix : Atomic Weights of the Elements 
Molecular Weights of Certain Compounds Gravimetric Equivalents Volumetric Equi- 
valents Plate I., Microscopic Appearance of the Textile Fibres Plate II., Microscopic 
Appearance of the Different Varieties of Starch Index. 

Reissue of 

Translated from the French of M. HELLOT, M. MACQUER and M. LE 
PILEUR D'APLIGNY. First Published in English in 1789. Six Plates. 
Demy 8vo. 446 pp. 1901. Price 5s.; India and Colonies, 5s. 6d. ; 
Other Countries, 6s. ; strictly net. 


Part I., The Art of Dyeing Wool and Woollen Cloth, Stuffs, Yarn, Worsted, etc. 
Part II., The Art of Dyeing Silk. Part III., The Art of Dyeing Cotton and Linen 
Thread, together with the Method of Stamping Silks, Cottons, etc. 

GEORGIEVICS. Translated from the Second German Edition. 412 pp. 
Demy 8vo. 1903. Price 10s. 6d. ; India and Colonies, 11s.; Other 
Countries, 12s. ; strictly net. 


Introduction Coal Tar Intermediate Products in the Manufacture of Dye-stuffs The 
Artificial Dye-stuffs (Coal-tar Dyes) Nitroso Dye-stuffs Nitro Dye-stuffs Azo Dye-stuffs- 
Substantive Cotton Dye-stuffs Azoxystilbene Dye-stuffs Hydrazones Ketoneimides 
Triphenylmethane Dye stuffs Rosolic Acid Dye-stuffs Xanthene Dye-stuffs Xanthone Dye- 
stuffs Flavones Oxyketone Dye-stuffs Quinoline and Acndine Dye-stuffs Quinonimide 
or Diphenylamine Dye-stuffs The Azine Group : Eurhodines, Safranines and Indulines 
Eurhodines Safranines Quinoxalines Indigo Dye-stuffs of Unknown Constitution 
Sulphur or Sulphine Dye stuffs Development of the Artificial Dye-stuff Industry The 
Natural Dye-stuffs Mineral Colours Index. 

Bleaching and Washing. 


L. TAILFER, Chemical and Mechanical Engineer. Translated from the 
French by JOHN GEDDES MC!NTOSH. Demy 8vo. 303 pp. Twenty 
Illusts. 1901. Price 12s. 6d. ; India and Colonies, 13s. 6d. ; Other 
Countries, 15s. ; strictly net. 


General Considerations on Bleaching Steeping Washing: Its End and Importance 
Roller Washing Machines Wash Wheel (Dash Wheel) Stocks or Wash Mill Squeezing 
Lye Boiling Lye Boiling with Milk of Lime Lye Boiling with Soda Lyes Description of 
Lye Boiling Keirs Operations of Lye Boiling Concentration of Lyes Mather and Platt's 
Keir Description of the Keir Saturation of the Fabrics Alkali used in Lye Boiling 
Examples of Processes Soap Action of Soap in Bleaching Quality and Quantity of Soaps 
to use in the Lye Soap Lyes or Scalds Soap Scouring Stocks Bleaching on Grass or on 
the Bleaching Green or Lawn Chemicking Remarks on Chlorides and their Decolour- 


Damages arising from the Machines Examples of Methods used in Bleaching Linen 
Cotton The Valuation of Caustic and Carbonated Alkali (Soda) and General Information 
Regarding these Bodies Object of Alkalimetry Titration of Carbonate of Soda Com- 
parative Table of Different Degrees of Alkalimetrical Strength Five Problems relative to 
Carbonate of Soda Caustic Soda, its Properties and Uses Mixtures of Carbonated and 
Caustic Alkali Note on a Process of Manufacturing Caustic Soda and Mixtures of Caustic 
and Carbonated Alkali (Soda) Chlorometry Titration Wagner's Chlorometric Method- 
Preparation of Standard Solutions Apparatus for Chlorine Valuation Alkali in Excess in 
Decolourising Chlorides Chlorine and Decolourising Chlorides Synopsis Chlorine 
Chloride of Lime Hypochlorite of Soda Brochoki's Chlorozone Various Decolourising 
Hypochlorites Comparison of Chloride of Lime and Hypochlorite of Soda Water 
Qualities of Water Hardness Dervaux's Purifier Testing the Purified Water Different 
Plant for Purification Filters Bleaching of Yarn Weight of Yarn Lye Boiling 
Chemicking Washing Bleaching of Cotton Yarn The Installation of a Bleach Works- 
Water Supply Steam Boilers Steam Distribution Pipes Engines Keirs Washing 
Machines Stocks Wash Wheels Chemicking and Souring Cisterns Various Buildings 
Addenda Energy of Decolourising Chlorides and Bleaching by Electricity and Ozone 
Energy of Decolourising Chlorides Chlorides Production of Chlorine and Hypochlorites 
by Electrolysis Lunge's Process for increasing the intensity of the Bleaching Power of 
Chloride of Lime Trilfer's Process for Removing the Excess of Lime or Soda from De- 
colourising Chlorides Bleaching by Ozone. 

Cotton Spinning and Combing. 

Spinning Master, Bolton Technical School. 160 pp. Eighty-four Illus- 
trations. Crown 8vo. 1901. Price 3s. ; Abroad, 3s. 6d. ; strictly net. 

Syllabus and Examination Papers of the City and Guilds of London Institute Cultiva- 
tion, Classification, Ginning, Baling and Mixing of the Raw Cotton Bale-Breakers, Mixing 
Lattices and Hopper Feeders Opening and Scutching Carding Indexes. 

COTTON SPINNING (Intermediate, or Second Year). By 
THOMAS THORNLEY. 180pp. Seventy Illustrations. Crown 8vo. 1901. 
Price 5s. ; India and British Colonies, 5s. 6d. ; Other Countries, 6s. ; 
strictly net. 


Syllabuses and Examination Papers of the City and Guilds of London Institute The 
Combing Process The Drawing Frame Bobbin and Fly Frames Mule Spinning Ring 
Spinning General Indexes. 

COTTON SPINNING (Honours, or Third Year). By THOMAS 
THORNLEY. 216 pp. Seventy-four Illustrations. Crown 8vo. 1901. 
Price 5s. ; India and British Colonies, 5s. 6d. ; Other Countries, 6s. ; 
strictly net. 


Syllabuses and Examination Papers of the City and Guilds of London Institute Cotton 
The Practical Manipulation of Cotton Spinning Machinery Doubling and Winding Reeling 
Warping Production and Costs Main Driving Arrangement of Machinery and Mill 
Planning Waste and Waste Spinning Indexes. 

Spinning Master, Technical School, Bolton. Demy 8vo. 117 Illustra- 
tions. 300 pp. 1902. Price 7s. 6d. ; India and Colonies, 8s. ; Other 
Countries, 8s. 6d. net. 


The Sliver Lap Machine and the Ribbon Cap Machine General Description of the Heilmann 
Comber The Cam Shaft On the Detaching and Attaching Mechanism of the Comber 
Resetting of Combers The Erection of a Heilmann Comber Stop Motions : Various Calcu- 
lations Various Notes and Discussions Cotton Combing Machines of Continental Make 


Collieries and Mines. 

of the Principal Methods Pursued, especially in Fiery Mines, and of 
the Various Appliances Employed, such as Respiratory and Rescue 
Apparatus, Dams, etc. By ROBERT LAMPRECHT, Mining Engineer and 
Manager. Translated from the German. Illustrated by Six large 
Plates, containing Seventy-six Illustrations. 175 pp., demy 8vo. 1901. 
Price 10s. 6d. ; India and Colonies, 11s. ; Other Countries, 12s. ; 
strictly net. 


Causes of Pit Fires Preventive Regulations : (1) The Outbreak and Rapid Extension 
of a Shaft Fire can be most reliably prevented by Employing little or no Combustible Material 
in the Construction of the Shaft : (2) Precautions for Rapidly Localising an Outbreak of Fire in 
the Shaft ; (3) Precautions to be Adopted in case those under 1 and 2 Fail or Prove Inefficient. 
Precautions sg.iinst Spontaneous Ignition of Coal. Precautions for Preventing Explosions of 
Fire-damp and Coal Dust. Employment of Electricity in Mining, particularly in Fiery Pits. 
Experiments on the ignition of Fire-damp Mixtures and Clouds of Coal Dust by Electricity 
Indications of an Existing or Incipient Fire Appliances for Working in Irrespirable 
Cases: Respiratory Apparatus; Apparatus with Air Supply Pipes; Reservoir Apparatus; 
Oxygen Apparatus Extinguishing Pit Fires : (a) Chemical Means ; (6) Extinction with 
Water. Dragging down the Burning Masses and Packing with Clay; (c) Insulating the Seat 
of the Fire by Dams. Dam Building. Analyses of Fire Gases. Isolating the Seat of a Fire 
with Dams: Working in Irrespirable Gases ("Gas-diving"): Air-Lock Work. Complete 
Isolation of the Pit. Flooding a Burning Section isolated by means of Dams. Wooden 
Dams: Masonry Dams. Examples of Cylindrical and Dome-shaped Dams. Dam Doors: 
Flooding the Whole Pit Rescue Stations : (a) Stations above Ground ; (b) Underground 
Rescue Stations Spontaneous Ignition of Coal in Bulk Index. 

Engineer. Translated from the German. Royal 8vo. Thirty Plates 
and Twenty -two Illustrations. 240 pp. 1903. Price 10s. 6d. ; India 
and Colonies, 11s.; Other Countries, 12s.; strictly net. 


The Causes of the Contamination of Pit Air The Means of Preventing the 
Dangers resulting from the Contamination of Pit Air Calculating the Volume 
of Ventilating Current necessary to free Pit Air from Contamination Determination 
of the Resistance Opposed to the Passage of Air through the Pit Laws of Re- 
sistance and Formulae therefor Fluctuations in the Temperament or Specific Re = 
sistance of a Pit Means for Providing a Ventilating Current in the Pit Mechani= 
cal Ventilation Ventilators and Fans Determining the Theoretical, Initial, and 
True (Effective) Depression of the Centrifugal Fan New Types of Centrifugal Fan 
of Small Diameter and High Working Speed Utilising the Ventilating Current to 
the utmost Advantage and distributing the same through the Workings Artifici^ 
ally retarding the Ventilating Current Ventilating Preliminary Workings Blind 
Headings Separate Ventilation Supervision of Ventilation INDEX. 

MINING. By CARL VOLK. Translated from the German. 
Royal 8vo. With Six Plates and 146 Illustrations. [In the press. 


Haulage Appliances Ropes Haulage Tubs and Tracks Cages and Winding Appliances- 
Winding Engines for Vertical Shafts Winding without Ropes Haulage in Levels and 
Inclines The Working of Underground Engines Machinery for Downhill Haulage. 

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 Illustrations. 190pp. 
1901. Demy 8vo. Price 7s. 6d. ; India and Colonies, 8s. ; Other 
Countries, 8s. 6d. ; strictly net. 


Fuel and Combustion Hand Firing in Boiler Furnaces Stoking by Mechanical Means- 
Powdered Fuel Gaseous Fuel Efficiency and Smoke Tests of Boilers Some Standard 
Smoke Trials The Legal Aspect of the Smoke Question The Best Means to be adopted for 
the Prevention of Smoke Index. 

GAS AND COAL DUST FIRING. A Critical Review of 

the Various Appliances Patented in Germany for this purpose since 
1885. By ALBERT PUTSCH. 130 pp. Demy 8vo. 1901. Translated 
from the German. With 103 Illustrations. Price 7s. 6d. ; India and 
Colonies, 8s. ; Other Countries, 8s. 6d. ; strictly net. 

Generators Generators Employing Steam Stirring and Feed Regulating Appliances 
Direct Generators Burners Regenerators and Recuperators Glass Smelting Furnaces 
Metallurgical Furnaces Pottery Furnace Coal Dust Firing Index. 

Translated from the German of the Third Edition. Crown 8vo. 
120 pp. 1903. Price 5s. ; India and British Colonies, 5s. 6d. ; Other 
Countries, 6s. ; strictly net. 


Steel Chemical and Physical Properties of Steel, and their Casual Connection- 
Classification of Steel according to Use Testing the Quality of Steel Steel- 
Hardening -Investigation of the Causes of Failure in Hardening Regeneration of 
Steel Spoilt in the Furnace Welding Steel Index. 

stitution of Iron Alloys and Slags). Translated from German of 
HANNS FREIHERR v. JUPTNER. 350 pp. Demy 8vo. Eleven Plates 
and Ten Illustrations. 1902. Price 10s. 6d. ; India and Colonies, 11s. ; 
Other Countries, 12s. ; net. 


The Theory of Solution. Solutions Molten Alloys Varieties of Solutions Osmotic 
Pressure Relation between Osmotic Pressure and other Properties of Solutions Osmotic 
Pressure and Molecular Weight of the Dissolved Substance Solutions of Gases Solid Solu- 
tions Solubility Diffusion Electrical Conductivity Constitution of Electrolytes and Metals 
Thermal Expansion. Micrography. Microstructure The Micrographic Constituents of 
Iron Relation between Micrographical Composition, Carbon-Content, and Thermal Treat- 
ment of Iron Alloys The Microstructure of Slags. Chemical Composition of the Alloys 
Of Iron. Constituents of Iron Alloys Carbon Constituents of the Iron Alloys, Carbon- 
Opinions and Researches on Combined Carbon Opinions and Researches on Combined 
Carbon Applying the Curves of Solution deduced from the Curves of Recalescence to the De- 
termination of the Chemical Composition of the Carbon present in Iron Alloys The Constitu- 
ents of Iron Iron The Constituents of Iron Alloys Manganese Remaining Constituents of 
Iron Alloys A Silicon Gases. The Chemical Composition of Slag. Silicate Slags 
Calculating the Composition of Silicate Slags Phosphate Slags Oxide Slags Appendix 

PARATUS. Explanations, Formulae and Tables for Use 
in Practice. By E. HAUSBRAND, Engineer. Translated by A. C. 
WRIGHT, M.A. (Oxon.), B.Sc. (Lond.). With Twenty-one Illustra- 
tions and Seventy-six Tables. 400 pp. Demy 8vo. 1903. Price 
10s. 6d. ; India and Colonies, 11s.; Other Countries, 12s.; net. 

^Coefficient of Transmission of Heat, k/, and the Mean Temperature Difference, 0/m 
Parallel and Opposite Currents Apparatus~or Heating with Direct Fire The Injection of 
Saturated Steam Superheated Steam Evaporation by Means of Hot Liquids The Trans- 
ference of Heat in General, and Transference by means of Saturated Steam in Particular 
The Transference of Heat from Saturated Steam in Pipes (Coils) and Double Bottoms 
Evaporation in a Vacuum The Multiple-effect Evaporator Multiple-effect Evaporators 
from which Extra Steam is Taken The Weight of Water which must be Evaporated from 
100 Kilos, of Liquor in order its Original Percentage of Dry Materials from 1-25 per cent, 
up to 20-70 per cent. The Relative Proportion of the Heating Surfaces in the Elements 
of the Multiple Evaporator and their Actual Dimensions The Pressure Exerted by Currents 
of Steam and Gas upon Floating Drops of Water The Motion of Floating Drops of Water 


upon which Press Currents of Steam The Splashing of Evaporating Liquids The Diameter 
of Pipes for Steam, Alcohol, Vapour and Air The Diameter of Water Pipes The Loss 
of Heat from Apparatus and Pipes to the Surrounding Air, and Means for Preventing 
the Loss Condensers Heating Liquids by Means of Steam The Cooling of Liquids 
The Volumes to be Exhausted from Condensers by the Air-pumps A Few Remarks on Air- 
pumps and the Vacua they Produce The Volumetric Efficiency of Air-pumps The Volumes 
of Air which must be Exhausted from a Vessel in order to Reduce its Original Pressure to a 
Certain Lower Pressure Index. 

Dental Metallurgy. 


8vo. Thirty-six Illustrations. 190^ 200 pp. Price 7s. 6d. ; India 
and Colonies, 8s. ; Other Countries, 8s. 6d. ; strictly net. 

Introduction Physical Properties of the Metals Action of Certain Agents on Metals 
Alloys Action of Oral Bacteria on Alloys Theory and Varieties of Blowpipes Fluxes 
Furnaces and Appliances Heat and Temperature Gold Mercury Silver Iron Copper 
Zinc Magnesium Cadmium Tin Lead Aluminium Antimony Bismuth Palladium 
Platinum Iridium Nickel Practical Work Weights and Measures. 

Plumbing, Decorating, Metal 
Work, etc., etc. 

Work for Roofs. By JOHN W. HART, R.P.C. 180 Illustrations. 272 
pp. Demy 8vo. Second Edition Revised. 1902. Price 7s. 6d. ; India 
and Colonies, 8s. ; Other Countries, 8s. 6d. ; strictly net. 

Cast Sheet Lead Milled Sheet Lead Roof Cesspools Socket Pipes Drips Gutters- 
Gutters (continued) Breaks Circular Breaks Flats Flats (continued) Rolls on Flats 
Roll Ends Roll Intersections Seam Rolls Seam Rolls (continued) Tack Fixings Step 
Flashings Step Flashings (continued) Secret Gutters Soakers Hip and Valley Soakers 
Dormer Windows Dormer Windows (continued) Dormer Tops Internal Dormers 
Skylights Hips and Ridging Hips and Ridging (continued) Fixings for Hips and Ridging 
Ornamental Ridging Ornamental Curb Rolls <Jurb Rolls Cornices Towers and Finials 
Towers and Finials (continued) Towers and Finials (continued) Domes Domes (continued) 
Ornamental Lead Work Rain Water Heads Rain Water Heads (continued) Rain Water 
Heads (continued). 

Revised and Corrected. By JOHN W. HART, R.P.C. 184 Illustrations. 
313 pp. Demy 8vo. 1901. Price 7s. 6d. ; India and Coionies, 8s. ; 
Other Countries, 8s. 6d. ; strictly net. 

Pipe Bending Pipe Bending (continued) Pipe Bending (continued) Square Pipe 
Bendings Half-circular Elbows Curved Bends on Square Pipe Bossed Bends Curved 
Plinth Bends Rain-water Shoes on Square Pipe Curved and Angle Bends Square Pipe 
Fixings-^Joint-wiping Substitutes for Wiped Joints Preparing Wiped Joints Joint Fixings 
Plumbing Irons Joint Fixings Use of "Touch" in Soldering Underhand Joints Blown 
and Copper Bit Joints Branch Joints Branch Joints (continued) Block Joints Block 
Joints (continued) Block Fixings Astragal Joints Pipe Fixings Large Branch Joints 
Large Underhand Joints Solders Autogenous Soldering or Lead Burning Index. 

8vo. 1900. Price 2s. ; Abroad, 2s. 6d. ; strictly net. 


WORKSHOP WRINKLES for Decorators, Painters, Paper- 
hangers and Others. By W. N. BROWN. Crown 8vo. 128 pp. 1901. 
Price 2s. 6d. ; Abroad, 3s. ; strictly net. 


NORMAN BROWN. Eighty-eight Illustrations. 150 pp. Crown 8vo. 

1900. Price 3s. 6d. ; India and Colonies, 4s. ; Other Countries, 4s. 6d. ; 
strictly net. 

BROWN. Thirty-nine Illustrations. 96 pp. Crown 8vo. 1900. Price 
2s. 6d. ; Abroad, 3s. ; strictly net. 


WILLIAM NORMAN BROWN. 52 pp. and Illustrations. Crown 8vo. 

1901. Price 2s. ; Abroad, 2s. 6d. ; net. 


JOHN W. HART, R.P.C. With 129 Illustrations. 1900. 177 pp., demy 
8vo. Price 7s. 6d. ; India and Colonies, 8s. ; Other Countries, 8s. 6d. ; 
strictly net. 


Water Circulation The Tank System Pipes and Joints The Cylinder System Boilers 
for the Cylinder System The Cylinder System The Combined Tank and Cylinder System 
Combined Independent and Kitchen Boiler Combined Cylinder and Tank System with 
Duplicate Boilers Indirect Heating and Boiler Explosions Pipe Boilers Safety Valves- 
Safety Valves The American System Heating Water by Steam Steam Kettles and Jets 
Heating Power of Steam Covering for Hot Water Pipes Index. 

Brewing and Botanical. 

the Higher Agricultural College, Tetschen-Liebwerd. Translated 
from the German. Seventy-eight Illustrations. 1900. 340 pp. Demy 
8vo. Price 12s. 6d. ; India and Colonies, 13s. 6d. ; Other Countries, 
15s. ; strictly net. 


HISTORY OF THE HOP THE HOP PLANT Introductory The Roots The Stem 
and Leaves Inflorescence and Flower: Inflorescence and Flower of the Male Hop; In- 
florescence and Flower of the Female Hop The Fruit and its Glandular Structure : The 
Fruit and Seed Propagation and Selection of the Hop Varieties of the Hop: (a) Red Hops; 
(b) Green Hops; (c) Pale Green Hops Classification according to the Period of Ripening: 
Early August Hops; Medium Early Hops; Late Hops Injuries to Growth Leaves Turning 
Yellow, Summer or Sunbrand, Cones Dropping Off, Honey Dew, Damage from Wind, Hail 
and Rain ; Vegetable Enemies of the Hop: Animal Enemies of the Hop Beneficial Insects on 
Hops CULTIVATION The Requirements of the Hop in Respect of Climate, Soil and 
Situation: Climate; Soil; Situation Selection of Variety and Cuttings Planting a Hop 
Garden: Drainage; Preparing the Ground; Marking-out for Planting ; Planting; Cultivation 
and Cropping of the Hop Garden in the First Year Work to be Performed Annually in the 
Hop Garden : Working the Ground ; Cutting ; The Non-cutting System ; The Proper Per- 
formance of the Operation of Cutting: Method of Cutting: Close Cutting, Ordinary Cutting, 
The Long Cut, The Topping Cut; Proper Se-.son for Cutting: Autumn Cutting, Spring 
Cutting; Manuring; Training the Hop Plant: Poled Gardens, Frame Training; Principal 
Types of Frames; Pruning, Cropping, Topping, and Leaf Stripping the Hop Plant; Picking, 
Drying and Bagging Principal and Subsidiary Utilisation of Hops and Hop Gardens Life 
of a Hop Garden ; Subsequent Cropping Cost of Production, Yield and Selling Prices. 

Preservation and Storage Physical and Chemical Structure of the Hop Cone Judging 
the Value of Hops. 

Statistics of Production The Hop Trade Index. 


Timber and Wood Waste. 

TIMBER : A Comprehensive Study of Wood in all its Aspects 
(Commercial and Botanical), showing the Different Applications and 
Uses of Timber in Various Trades, etc. Translated from the French 
of PAUL CHARPENTIER. Royal 8vo. 437 pp. 178 Illustrations. 1902. 
Price 12s. 6d. ; India and Colonies, 13s. 6d. ; Other Countries, 15s. ; 


Physical and Chemical Properties of Timber Composition of the Vegetable Bodies 
Chief Elements M. Fremy's Researches Elementary Organs of Plants and especially of 
Forests Different Parts of Wood Anatomically and Chemically Considered General Pro- 
perties of Wood Description of the Different Kinds of Wood Principal Essences with 
Caducous Leaves Coniferous Resinous Trees Division of the Useful Varieties of Timber 
in the Different Countries of the Globe European Timber African Timber Asiatic 
Timber American Timber Timber of Oceania Forests General Notes as to Forests ; their 
Influence Opinions as to Sylviculture Improvement of Forests Unwooding and Rewoodmg 
Preservation of Forests Exploitation of Forests Damage caused to Forests Different 
Alterations The Preservation of Timber Generalities Causes and Progress of De- 
terioration History of Different Proposed Processes Dessication Superficial Carbonisation 
of Timber Processes by Immersion Generalities as to Antiseptics Employed Injection 
Processes in Closed Vessels The Boucherie System, Based upon the Displacement of the 
Sap Processes for Making Timber Uninflammable Applications of Timber Generalities 
Working Timber Paving Timber for Mines Railway Traverses Accessory Products 
Gums Works of M. Fremy Resins Barks Tan Application of Cork The Application of 
Wood to Art and Dyeing Different Applications of Wood Hard Wood Distillation of 
Wood Pyroligneous Acid Oil of Wood Distillation of Resins Index. 

the German of ERNST HUBBARD. Crown 8vo. 192 pp. 1902. Fifty 
Illustrations. Price 5s. ; India and Colonies, 5s. 6d. ; Other Countries, 
6s.; net. 


General Remarks on the Utilisation of Sawdust Employment of Sawdust as Fuel, 
with and without Simultaneous Recovery of Charcoal and the Products of Distillation 
Manufacture of Oxalic Acid from Sawdust Process with Soda Lye ; Thorn's Process ; 
Bohlig's Process Manufacture of Spirit (Ethyl Alcohol) from Wood Waste Patent Dyes 
(Organic Sulphides, Sulphur Dyes, or Mercapto Dyes) Artificial Wood and Plastic Com- 
positions from Sawdust Production of Artificial Wood Compositions for Moulded De- 
corations Employment of Sawdust for Blasting Powders and Gunpowders Employment 
of Sawdust for Briquettes Employment of Sawdust in the Ceramic Industry and as an 
Addition to Mortar Manufacture of Paper Pulp from Wood Casks Various Applications 
of Sawdust and Wood Refuse Calcium Carbide Manure Wood Mosaic Plaques Bottle 
Stoppers Parquetry Fire-lighters Carborundum The Production of Wood Wool Bark 

Building and Architecture. 


with Remarks on the Causes, Nature and Effects of Saline, Efflores- 
cences and Dry-rot, for Architects, Builders, Overseers, Plasterers, 
Painters and House Owners. By ADOLF WILHELM 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. 
115pp. 1902. Price 5s. ; India and Colonies, 5s. 6d. ; Other Countries, 
6s. ; net. 


The Various Causes of Dampness and Decay of the Masonry of Buildings, and the 
Structural and Hygienic Evils of the Same Precautionary Measures during Building against 
Dampness and Efflorescence Methods of Remedying Dampness and Efflorescences in the 
Walls of Old Buildings The Artificial Drying of New Houses, as well as Old Damp Dwellings, 
and the Theory of the Hardening of Mortar New, Certain and Permanently Efficient 
Methods for Drying Old Damp Walls and Dwellings The Cause and Origin of Dry-rot : its 
Injurious Effect on Health, its Destructive Action on Buildings, and its Successful Repres- 
sion Methods of Preventing Dry-rot to be Adopted During Construction Old Methods 
of Preventing Dry-rot Recent and More Efficient Remedies for Dry-rot Index. 


PASSMORE. Demy 8vo. About 403 pp. [In the press. 

Foods and Sweetmeats. 

SWEETMEATS. By A. HAUSNER. With Twenty-eight 
Illustrations. Translated from the German of the third enlarged 
Edition. Crown 8vo. 225 pp. 1902. Price 7s. 6d. ; India and 
Colonies, 8s. ; Other Countries, 8s. 6d. ; net. 


The Manufacture of Conserves Introduction The Causes of the Putrefaction of Food 
The Chemical Composition of Foods The Products of Decomposition The Causes of Fer- 
mentation and Putrefaction Preservative Bodies The Various Methods of Preserving Food 
The Preservation of Animal Food Preserving Meat by Means of Ice The Preservation 
of Meat by Charcoal Preservation of Meat by Drying The Preservation of Meat by the 
Exclusion of Air The Appert Method Preserving Flesh by Smoking Quick Smoking Pre- 
serving Meat with Salt Quick Salting by Air Pressure Quick Salting by Liquid Pressure 
Gamgee's Method of Preserving Meat The Preservation of Eggs Preservation of White 
and Yolk of Egg Milk Preservation Condensed Milk The Preservation of Fat Manu- 
facture of Soup Tablets Meat Biscuits Extract of Beef The Preservation of Vegetable 
Foods in General Compressing Vegetables Preservation of Vegetables by Appert's Method 
The Preservation of Fruit Preservation of Fruit by Storage The Preservation of Fruit 
by Drying Drying Fruit by Artificial Heat Roasting Fruit The Preservation of Fruit with 
Sugar Boiled Preserved Fruit The Preservation of Fruit in Spirit, Acetic Acid or Glycerine 
Preservation of Fruit without Boiling Jam Manufacture The Manufacture of Fruit 
Jellies The Making of Gelatine Jellies The Manufacture of " Sulzen " The Preservation of 
Fermented Beverages The Manufacture of Candies Introduction The Manufacture of 
Candied Fruit The Manufacture of Boiled Sugar and Caramel The Candying of Fruit- 
Caramelised Fruit The Manufacture of Sugar Sticks, or Barley Sugar Bonbon Making 
Fruit Drops The Manufacture of Dragees The Machinery and Appliances used in Candy 
Manufacture Dyeing Candies and Bonbons Essential Oils used in Candy Making Fruit 
Essences The Manufacture of Filled Bonbons, Liqueur Bonbons and Stamped Lozenges 
Recipes for Jams and Jellies Recipes for Bonbon Making Dragees Appendix Index. 

Dyeing Fancy Goods. 

WOOD. A Practical Handbook for the Use of Joiners, 
Turners, Manufacturers of Fancy Goods, Stick and Umbrella Makers, 
Comb Makers, etc. Translated from the German of D. H. SOXHLET, 
Technical Chemist. Crown 8vo. 168 pp. 1902. Price 5s. ; India and 
Colonies, 5s. 6d. ; Other Countries, 6s. ; net. 


Mordants and Stains Natural Dyes Artificial Pigments Coal Tar Dyes Staining 
Marble and Artificial Stone Dyeing, Bleaching and Imitation of Bone, Horn and Ivory 
Imitation of Tortoiseshell for Combs : Yellows, Dyeing Nuts Ivory Wood Dyeing Imitation 
of Mahogany : Dark Walnut, Oak, Birch-Bark, Elder-Marquetry, Walnut, Walnut-Marquetry, 
Mahogany, Spanish Mahogany, Palisander and Rose Wood, Tortoiseshell, Oak, Ebony, Pear 
Tree Black Dyeing Processes with Penetrating Colours Varnishes and Polishes: English 
Furniture Polish, Vienna Furniture Polish, Amber Varnish, Copal Varnish, Composition for 
Preserving Furniture Index. 


Lithography and Engraving. 

Demy 8vo. With Plates and Illustrations. [In the press. 


StonesTransfer Inks Transfer Papers Transfer Printing Litho Press Press Work- 
Machine Printing Colour Printing Substitutes for Lithographic Stones Tin Plate Printing 
and Decoration Photo-Lithography. 

Two Plates and Illustrations. Crown 8vo. Price 2s. 6d. ; Abroad, 
3s. ; strictly net. 


Its Inception Wood Engraving Metal Engraving Engraving in England Etching 
Mezzotint Photo-Process Engraving The Engraver's Task Appreciative Criticism 


from;the German. Demy 8vo. With 129 Illustrations. [In the press. 


Materials for Sewing and Pasting Materials for Covering the Book Materials For 
Decorating and Finishing Tools General Preparatory Work Sewing Forwarding, 
Cutting, Rounding and Backing Forwarding, Decoration of Edges and Headbanding 
Boarding Preparing the Cover Work with the Blocking Press Treatment of Sewn Books, 
Fastening in Covers, and Finishing Off Handtooling and Other Decoration Account Books 
School Books, Mounting Maps, Drawings, etc. Index. 

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 GEDDES MC!NTOSH. Demy 8vo. 83 Illus- 
trations. [In the press. 

Chemistry of Sucrose,' Lactose, Maltose, Glucose, Invert Sugar, etc. Purchase and 
Analysis of Beets Treatment of Beets Diffusion Filtration Concentration Evaporation 
Sugar Cane: Cultivation Milling Diffusion Sugar Refining Analysis of Raw Sugars 
Chemistry of Molasses, etc. 


New Textile Books. 

(S^ also pp. 19-24.) 

TEXTILE CALCULATIONS, especially relating to Woollens. 
From the German of N. REISER. Thirty-four Illustrations. Tables. 

[In the press. 


Calculating the Raw Material Proportion of Different Grades of Wool to Furnish a 
Mixture at a Given Price Quantity to Produce a Given Length Yarn Calculations Yarn 
Number Working Calculations Calculating the Reed Count Cost of Weaving, etc, 


Dr. S. MICRZINSKI. Twenty-nine Illustrations. [In the press. 


Preparing the Fabrics Impregnating the Fabrics Drying Paraffin Cupric Oxide of 
Ammonia Size Tannin Metallic Oxides, etc. 

SCOTT, GREENWOOD & Co. will forward any of the above Books, post 
free, upon receipt of remittance at the published price, or they can be obtained 
through all Booksellers. 

Full List of Contents of any of the books will be sent on application, and 
particulars of books in the press will be sent when ready to persons sending 
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