Chapter IX

MANUFACTURE OF GELATINE, AND PRODUCTS PREPARED FROM IT.

Properties of gelatine; Change in the chemical constitution of
gelatine produced by concentrated sulphuric or nitric acid; Tannin as
a test for the presence of gelatine; Use of gelatine for culinary and
medicinal purposes 165

Skin gelatine; Method of manufacture introduced and patented, in 1839,
by George Nelson; Process patented, in 1844, by Messrs. J. & G.
Cox of Edinburgh 166

G. P. Swinborn’s improved patented process for the preparation
of gelatine from hides, skins and glue pieces; Modern process of
preparing skin gelatine; “Steeping” the skins 167

Washing and bleaching the skins 168

Digesting the skins; Clarifying the liquors 169

Evaporation of the liquors in vacuo; Drying the cut cakes; Bone
gelatine; Materials for this purpose; Crushing the bones; Solution of
the glue cartilage 170

Apparatus and improved manner of manufacture employed in the factory
of D. J. Briers, described and illustrated 171

Modern process of preparing bone gelatine 179

Colored gelatine; Uses of colored gelatine; Harmless coloring matters;
Colors for coloring leaves of gelatine with aniline colors for
technical purposes 181

Gelatine for fining purposes; _Gelatine Lainée_; Fining powder for
wine and beer; Liquid fining gelatine; Preparation of gelatine from
ordinary glue 182

Preparation of gelatine for photographic printing and for photographic
purposes in general; Removal of the salts from the gelatine 183

Gelatine capsules for medicinal purposes; Court plaster 184

Gelatine foils; Mode of coloring the foils 185

Gelatine veneers; Principal operations in the manufacture of gelatine
veneers 186

Preparation of the plates; Preparation of the glue solutions;
Proportions by weight of the mixtures for ten different varieties of
imitations of marble and enamel 187

Imitation of mother-of-pearl veneers 188

Pouring the colored solutions of glue upon the plates 189

Preparation of imitations of malachite 190

Transferring the layer of glue to a layer of gelatine 191

Drying and detaching the veneers 192

Water-proofing gelatine veneers; Uses of gelatine veneers;
Formo-gelatine and its uses 193

Use of gelatine in bacteriology 194

Artificial silk from gelatine 195

CHAPTER X.

ISINGLASS AND ITS SUBSTITUTES.

Sources of isinglass; Properties of a good quality of isinglass;
Imitations of isinglass and their detection; Adulteration of isinglass
and its detection 196

Russian isinglass; Siberian purse isinglass; Preparation of isinglass
in Russia 197

North American or New York isinglass 198

East India isinglass; Hudson Bay isinglass; Brazilian isinglass 199

German isinglass; Isinglass from the scales of shad and herring;
Bleaching inferior qualities of isinglass; Ichthycolle
Française 200

Isinglassine; Chinese isinglass 201

Irish moss; Fish glue; Jennings’ process for the preparation of fish
glue 203

Treatment of fish scales; Production of fish glue on the Norwegian
coast; Substitute for isinglass according to C. A. Sahlström’s
process 203

Whale glue 204

CHAPTER XI.

TESTING GLUE AND GELATINE.

Determination of moisture; Determination of ash; Determination of
acidity 205

Determination of glutin; Bisler-Beumat’s method 206

Analysis of samples of American glue by S. Dana Hayes; Deduction of
the quality of glue from indirect properties 207

Lipowitz’s method of testing the strength of a glue, described and
illustrated 208

Results obtained by comparative experiments 209

Facts shown by the results 210

Weidenbusch’s method of testing glue 211

Preparation of the plaster of Paris stick and of the glue solution
used in this test 212

Apparatus for testing the strength of the plaster of Paris sticks,
described and illustrated; Test adopted by the “Artillerie Werkstätte”
at Spandau 213

Determination of adulterations 214

Kissling’s results in testing a large number of samples of glue 215

Practical tests of glue 216

PART II.

CEMENTS, PASTES, MUCILAGES.

CHAPTER XII.

CLASSIFICATION OF CEMENTS.

Stohmann’s division of cements and pastes; Groups of cements 218

Chemical nature of cements; Oil cements 219

Resinous cements; Definition of resins 220

Properties of resinous cements 221

Rubber and gutta-percha cements; Glue and starch cements 222

Lime cements 223