Part 10

III.—Fuse together shellac and gutta percha in equal weights.

IV.—India rubber 8 ounces Gutta percha 4 ounces Isinglass 2 ounces Bisulphide of carbon 32 ounces

V.—India rubber 5 ounces Gum mastic 1 ounce Chloroform 3 ounces

VI.—Gutta percha 16 ounces India rubber 4 ounces Pitch 4 ounces Shellac 1 ounce Linseed oil 1 ounce

Amalgamate by heat.

VII.—Mix 1 ounce of oil of turpentine with 10 ounces of bisulphide of carbon in which as much gutta percha as possible has been dissolved.

VIII.—Amalgamate by heat:

Gutta percha 100 ounces Venice turpentine 80 ounces Shellac 8 ounces India rubber 2 ounces Liquid storax 10 ounces

IX.—Amalgamate by heat:

India rubber 100 ounces Rosin 15 ounces Shellac 10 ounces

Then dissolve in bisulphide of carbon.

X.—Make the following solutions separately and mix:

(a) India rubber 5 ounces Chloroform 140 ounces

(b) India rubber 5 ounces Rosin 2 ounces Venice turpentine 1 ounce Oil of turpentine 20 ounces

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«Cement for Patching Rubber Boots and Shoes.»—

I.—India rubber, finely chopped 100 parts Rosin 15 parts Shellac 10 parts Carbon disulphide, q. s. to dissolve.

This will not only unite leather to leather, india rubber, etc., but will unite rubber to almost any substance.

II.—Caoutchouc, finely cut 4 parts India rubber, finely cut 1 part Carbon disulphide 32 parts

Dissolve the caoutchouc in the carbon disulphide, add the rubber, let macerate a few days, then mash with a palette knife to a smooth paste. The vessel in which the solution is made in both instances above must be kept tightly closed, and should have frequent agitations.

III.—Take 100 parts of crude rubber or caoutchouc, cut it up in small bits, and dissolve it in sufficient carbon bisulphide, add to it 15 parts of rosin and 10 parts of gum lac. The user must not overlook the great inflammability and exceedingly volatile nature of the carbon bisulphide.

«Tire Cements.»—

I.—India rubber 15 grams Chloroform 2 ounces Mastic 1⁠/⁠2 ounce

Mix the india rubber and chloroform together, and when dissolved, the mastic is added in powder. It is then allowed to stand a week or two before using.

II.—The following is recommended as very good for cementing pneumatic tires to bicycle wheels:

Shellac 1 ounce Gutta percha 1 ounce Sulphur 45 grains Red lead 45 grains

Melt together the shellac and gutta percha, then add, with constant stirring, the sulphur and red lead. Use while hot.

III.—Raw gutta percha 16 ounces Carbon bisulphide 72 ounces Eau de Cologne 2 2⁠/⁠3 ounces