The Boot and Shoe Manufacturers' Assistant and Guide. / Containing a Brief History of the Trade. History of India-rubber and Gutta-percha, and Their Application to the Manufacture of Boots and Shoes. Full Instructions in the Art, With Diagrams and Scales, Etc., Etc. Vulcanization and Sulphurization, English and American Patents. With an Elaborate Treatise on Tanning.

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India-rubber, when once reduced to a liquid state by heat, appears like tar, and is unfit for further manufacture.

Gutta-percha may be melted and cooled any number of times, without injury for future manufacture.

India-rubber, by coming in contact with oil or other fatty substances, is soon decomposed and ruined for future use.

Gutta-percha is not injured by coming in contact with oil or other fatty substances—in fact one good use of it is for oil cans.

India-rubber is soon ruined for future use, if brought in contact with sulphuric, muriatic, and other acids.

Gutta-percha resists the action of sulphuric, muriatic, and nearly all other acids—in fact one great use of it is for acid vats, &c., and other vessels for holding acids.

India-rubber is a conductor of heat, cold and electricity.

Gutta-percha is a non-conductor of electricity, as well as of heat and cold.

India-rubber, in its crude state, when exposed to the action of boiling water, increases in bulk, does not lose its elastic properties, and cannot be moulded.

Gutta-percha, in its crude state, when exposed to the action of boiling water, contracts and becomes soft like dough or paste, and may then be moulded to any shape—which shape it will retain when cool.