An interesting reminiscence of its early history is given by Joseph Priestley, the great English chemist of the last century, celebrated as the discoverer of oxygen. In 1770 he mentioned the use of the gum for erasing pencil marks, and speaks of its cost being three shillings, about seventy cents, for “a cubical piece of about half an inch.”
As we have seen, its solubility was early studied. In 1761 Hérissant added turpentine, ether and “huile de Dippel” to the list of solvents. In 1793 its solubility was utilized in France by Besson, who made waterproof cloth. In 1797 Johnson introduced for the same manufacture a solution in mixed turpentine and alcohol.
The year 1820 is the beginning of the period of its modern use on a more extended scale. Nadier developed the methods of cutting it into sheets and threads and of weaving the latter. Mackintosh in 1823 began the manufacture of waterproof cloth, using the solution of the gum in coal tar naptha, which was caused to deposit by evaporation a layer of the gum upon a piece of cloth which was covered by a second one. This protected the wearer from the gummy and sticky coating of raw india rubber. At the best the original Mackintoshes must have been very disagreeable articles for wear.
In 1825 india rubber shoes of raw india rubber were imported from South America and formed for a while an important article of commerce.
In 1839 Charles Goodyear, of Massachusetts, invented the art of vulcanizing, or combining india rubber with sulphur. It was patented on June 15, 1844, and covers only the manufacture of soft rubber. Vulcanite or hard rubber (whalebone rubber) is disputed as to its origin, its invention being assigned by some to Nelson Goodyear and by others to Austin G. Day, of Connecticut. Goodyear however succeeded in obtaining a patent on May 6, 1851. Day obtained a patent on August 10, 1858.
Vulcanization is the most important invention ever made in connection with india rubber and may fairly rank as one of the greatest discoveries of the present century. It is claimed by the English, an inventor named Handcock being cited as the rival of Charles Goodyear. The latter inventor had as an associate Nathaniel Hayward, who is probably entitled to some of the credit.
By vulcanization india rubber loses susceptibility to heat and cold, becomes non-adherent, and insoluble in almost all substances. It is converted from a comparatively useless substance into one of wide applicability.
The subject of india rubber is so interesting in its theoretical as well as practical bearings that it seems impossible that those who are workers in it should not feel an interest in its natural history. For such readers the chapter on the natural history and collection of india rubber has been written. As it is a product of widely separated lands on both hemispheres, and as it is yielded by an immense number of plants, it is impossible in the limits of a chapter to give a full outline of its natural history.
The chapter in question is, therefore, with this apology, inserted where it belongs, near the beginning of the book. Those who are entirely practical may pass it over. There is no doubt that the few minutes necessary for its perusal will be bestowed upon it by some.