The composition of this ambitious substance is as follows: One part,
by weight, of equal parts of wood tar oil and coal tar oil, or of the
latter alone, is heated for several hours at a temperature of from 252
to 270 degrees Fahrenheit, with two parts, by weight, of hemp oil,
until the mass can be drawn into threads. Then one-half part, by
weight, of linseed oil, thickened by boiling, is added. To each 100
parts of the compound one-twentieth to one-tenth part of ozokerite and
the same quantity of spermaceti are added.

The entire mixture is then again heated to 252 degrees Fahrenheit and
one-fifteenth to one-twelfth part of sulphur is added. The substance
thus obtained upon cooling is worked up in a similar manner to natural
India rubber. It has not been successfully used, however, without the
addition of a quantity of pure rubber to give it the requisite
elasticity.

A substitute for gutta percha is obtained by boiling the bark of the
birch tree, especially the outer part, in water over an open fire.
This produces a black fluid mass, which quickly becomes solid and
compact upon exposure to air.

Each gutta percha and India rubber factory has a formula of its own
for making up substances as nearly identical with the natural product
as possible, which are used to adulterate the rubber and gutta percha
used in the factory. No one has as yet, however, succeeded in
discovering a perfect substitute for either rubber or gutta percha.

The history of chemistry contains many instances where natural
products have been supplanted by artificial compounds possessing the
same properties and characteristics. One of the most notable of these
is the substance known as alizarine, the coloring matter extracted
from the madder root. This, like India rubber, is a hydrocarbon.

Prior to 1869 all calico printing was done with the coloring matter
derived from the madder root, and its cultivation was a leading
industry in the eastern and southern portions of Europe.

In 1869 alizarine was successfully produced from the refuse coal tar
of gas works and the calico printing business was revolutionized.

The essence of vanilla, made from the vanilla bean, and used as a
flavoring extract, has been supplanted by the substance christened
vanilla by chemists, which possesses the same characteristics and is
made from sawdust.

Isoprene, from which Dr. Tilden produced India rubber, is
comparatively a new product, as derived from oil of turp