The Handbook of Soap Manufacture | Page 2

Soaps--Curd Mottled--Blue
and Grey Mottled Soaps--Milling Base--Yellow Household
Soaps--Resting of Pans and Settling of Soap--Utilisation of
Nigres--Transparent soaps--Saponifying Mineral Oil--Electrical
Production of Soap.
CHAPTER VI.
TREATMENT OF SETTLED SOAP 60
Cleansing--Crutching--Liquoring of Soaps--Filling--Neutralising,
Colouring and Perfuming--Disinfectant
Soaps--Framing--Slabbing--Barring--Open and Close
Piling--Drying--Stamping--Cooling.
CHAPTER VII.
TOILET, TEXTILE AND MISCELLANEOUS SOAPS 77
Toilet Soaps--Cold Process soaps--Settled Boiled Soaps--Remelted
Soaps--Milled Soaps--Drying--Milling and Incorporating Colour,
Perfume, or Medicament--Perfume--Colouring matter--Neutralising
and Superfatting
Material--Compressing--Cutting--Stamping--Medicated Soaps--Ether

Soap--Floating Soaps--Shaving Soaps--Textile Soaps--Soaps for
Woollen, Cotton and Silk Industries--Patent Textile
Soaps--Miscellaneous Soaps.
CHAPTER VIII.
SOAP PERFUMES 95
Essential Oils--Source and Preparation--Properties--Artificial and
Synthetic Perfumes.
CHAPTER IX.
GLYCERINE MANUFACTURE AND PURIFICATION 111
Treatment of Lyes--Evaporation to Crude
Glycerine--Distillation--Distilled and Dynamite Glycerine--Chemically
Pure Glycerine--Animal Charcoal for Decolorisation--Glycerine
obtained by other methods of Saponification--Yield of Glycerine from
Fats and Oils.
CHAPTER X.
ANALYSIS OF RAW MATERIALS, SOAP, AND GLYCERINE 117
Fats and Oils--Alkalies and Alkali Salts--Essential
Oils--Soap--Lyes--Crude Glycerine.
CHAPTER XI.
STATISTICS OF THE SOAP INDUSTRY 140
APPENDIX A.
COMPARISON OF DEGREES, TWADDELL AND BAUMÉ, WITH
ACTUAL DENSITIES 147
APPENDIX B.

COMPARISON OF DIFFERENT THERMOMETRIC SCALES 148
APPENDIX C.
TABLE OF THE SPECIFIC GRAVITIES OF SOLUTIONS OF
CAUSTIC SODA 149
APPENDIX D.
TABLE OF STRENGTH OF CAUSTIC POTASH SOLUTIONS AT
60° F. 151
INDEX 153
CHAPTER I.
INTRODUCTION.
Definition of Soap--Properties--Hydrolysis--Detergent Action.
It has been said that the use of soap is a gauge of the civilisation of a
nation, but though this may perhaps be in a great measure correct at the
present day, the use of soap has not always been co-existent with
civilisation, for according to Pliny (Nat. Hist., xxviii., 12, 51) soap was
first introduced into Rome from Germany, having been discovered by
the Gauls, who used the product obtained by mixing goats' tallow and
beech ash for giving a bright hue to the hair. In West Central Africa,
moreover, the natives, especially the Fanti race, have been accustomed
to wash themselves with soap prepared by mixing crude palm oil and
water with the ashes of banana and plantain skins. The manufacture of
soap seems to have flourished during the eighth century in Italy and
Spain, and was introduced into France some five hundred years later,
when factories were established at Marseilles for the manufacture of
olive-oil soap. Soap does not appear to have been made in England
until the fourteenth century, and the first record of soap manufacture in
London is in 1524. From this time till the beginning of the nineteenth
century the manufacture of soap developed very slowly, being
essentially carried on by rule-of-thumb methods, but the classic

researches of Chevreul on the constitution of fats at once placed the
industry upon a scientific basis, and stimulated by Leblanc's discovery
of a process for the commercial manufacture of caustic soda from
common salt, the production of soap has advanced by leaps and bounds
until it is now one of the most important of British industries.
Definition of Soap.--The word soap (Latin sapo, which is cognate with
Latin sebum, tallow) appears to have been originally applied to the
product obtained by treating tallow with ashes. In its strictly chemical
sense it refers to combinations of fatty acids with metallic bases, a
definition which includes not only sodium stearate, oleate and palmitate,
which form the bulk of the soaps of commerce, but also the linoleates
of lead, manganese, etc., used as driers, and various pharmaceutical
preparations, e.g., mercury oleate (Hydrargyri oleatum), zinc oleate and
lead plaster, together with a number of other metallic salts of fatty acids.
Technically speaking, however, the meaning of the term soap is
considerably restricted, being generally limited to the combinations of
fatty acids and alkalies, obtained by treating various animal or
vegetable fatty matters, or the fatty acids derived therefrom, with soda
or potash, the former giving hard soaps, the latter soft soaps.
The use of ammonia as an alkali for soap-making purposes has often
been attempted, but owing to the ease with which the resultant soap is
decomposed, it can scarcely be looked upon as a product of much
commercial value.
H. Jackson has, however, recently patented (Eng. Pat. 6,712, 1906) the
use of ammonium oleate for laundry work. This detergent is prepared
in the wash-tub at the time of use, and it is claimed that goods are
cleansed by merely immersing them in this solution for a short time and
rinsing in fresh water.
Neither of the definitions given above includes the sodium and
potassium salts of rosin, commonly called rosin soap, for the acid
constituents of rosin have been shown to be aromatic, but in view of the
analogous properties of these resinates to true soap, they are generally
regarded as legitimate constituents of soap, having been used in Great
Britain since 1827, and receiving legislative sanction in Holland in

1875.
Other definitions of soap have been given, based not upon its
composition, but upon its properties,