The Progress of Invention in the Nineteenth Century.

by Edward W. Byrn

FIG. 160.—COLLECTING THE GUM.

India rubber, or caoutchouc, as it is more properly called, is a concentrated gum derived from the evaporation of the milky juice of certain trees found in South America, Mexico, Central America and the East Indies. The South American variety is called Jatropha elastica, and the East Indian variety the Ficus elastica. The South American Indians called it cahuchu. The province of Para, south of the equator, in Brazil, furnishes the largest part and best quality of gum. The tree from which the gum exudes grows to the height of eighty, and sometimes to one hundred feet. It runs up straight for forty or fifty feet without a branch. Its top is spreading, and is ornamented with a thick and glossy foliage. The gum is collected by chopping through the bark with a hatchet and placing under each series of cuts a little clay cup formed by the hands of the workman. About a gill of the sap accumulates in each cup in the course of a day, and it is then transferred to receiving vessels and taken to camp. The first use of the gum was made by the South American Indians, who made shoes, bottles, playing balls and various other articles from it. Their method for making a shoe was to take a crude wooden last, which they covered with clay to prevent the adhesion of the gum. It was then dipped in the sap, or the latter was poured over it, which gave it a thin coating. It was then held over a smoky fire, which gave it a dark color and dried the gum. When one coating became sufficiently hard another was added, and smoked in turn, and so successive coatings were applied until a sufficient thickness was obtained. When the work was completed it was exposed for some days in the sun, and while still soft the shoes were decorated as the fancy or taste of the maker suggested. The clay forms were then broken out, and the shoe stuffed with grass to keep it in shape for use or sale. In 1820 a pair of these clumsy shoes was brought to Boston and exhibited as a curiosity. They were covered with gilding, and resembled the shoe of a Chinaman. Subsequently considerable numbers of these shoes were brought from South America, and being sold at a large price, they served to stimulate Yankee ingenuity into devising methods of making them from the raw material, which being brought as ballast in the ships from Brazil, could be had cheaply. In France some attention had been given to the material, and the rubber bottles of the Indians had been cut into narrow threads which were woven into strips of cloth to form suspenders and garters. In England an application of it in thin solution had been made by a Mr. Macintosh, who spread it between two thicknesses of thin cloth to form Macintosh water-proof coats. The first practical use of the gum on a large scale was instituted by Mr. Chaffee in Roxbury, Mass., about 1830. He dissolved the gum in spirits of turpentine and invented steam-heated rolls for spreading it upon cloth. Companies were formed to exploit the products, and in the fall and winter of 1833 and 1834 many thousands of dollars’ worth of goods were made by the Roxbury Company, but the business proved a total failure, for in the summer the goods melted, decomposed and became so offensive as to be worse than useless, while the cold of winter rendered them stiff and liable to crack. With a knowledge of these facts and conditions Charles Goodyear commenced his experiments, believing that there was a great future for this material if it could only be prevented from melting in summer and stiffening in winter. He tried mixing it with many materials, first using magnesia, which, however, proved ineffective. On June 17, 1837, he took out patent No. 240, in which he proposed to destroy the adhesive properties of caoutchouc by superficial application of an acid solution of the metals, nitric acid with copper or bismuth being specially recommended. He also claimed the incorporation of lime with the gum to bleach it. Under this process Mr. Goodyear made various articles in the form of fabrics, toys and ornamental articles, using the fabric to make clothing for himself, which he wore to demonstrate its value and wearing qualities. A striking word picture of Mr. Goodyear at this time is given by the reply of a gentleman who, being asked by a man looking for Mr. Goodyear as to how he might recognize him, replied, “If you meet a man who has on an India rubber cap, stock, coat, vest, and shoes, and an India rubber money purse in his pocket, without a cent of money in it, that is he.”

Many useful and artistic articles were made under this first patented process, including maps, surgical bandages, etc., and were brought by Mr. Goodyear to the notice of President Jackson, Henry Clay and John C. Calhoun, from whom he received very encouraging letters. His efforts, however, to introduce his process commercially were not attended with success. Capitalists and manufacturers had been rendered so conservative by the large loss of money in the Roxbury Company, that they were disinclined to have anything further to do with it. Practically alone he was obliged to continue his work. By the kindness of Mr. Chaffee and Mr. Haskins he was allowed the use of the valuable machinery standing idle in their factory at Roxbury, and he made shoes, piano covers, table cloths and carriage covers of superior quality, and from the sale of these, and of licenses to manufacture, he for the first time was able to support his family in comfort. Mr. Goodyear had not yet discovered, however, the process of vulcanization, upon which the rubber industry is founded. In 1838 Mr. Nathaniel Hayward, of Woburn, Mass., who had been employed in the bankrupt rubber company, discovered that the stickiness of the rubber could be prevented by spreading a small quantity of sulphur on it. The same result had also been noticed by a German chemist. On Feb. 24, 1839, Mr. Hayward procured the patent, No. 1,090, on his process, and assigned it to Mr. Goodyear. The patent covered a process of dissolving sulphur in oil of turpentine and mixing it with the gum, and also included the incorporation of the dry flowers of sulphur with the gum, the product afterwards being treated by Mr. Goodyear’s metallic salt process. This was the starting point of vulcanization, for vulcanization consists simply in admixing sulphur with the rubber, and then subjecting it for six to eight hours to a temperature of about 300°. Its effect is to so change the nature of the gum to prevent it from melting or becoming sticky under the influence of heat, or of hardening and becoming stiff under the influence of cold, the vulcanized gum remaining elastic, impervious, and unchangeable under all ordinary conditions. This great discovery of the influence of heat on the sulphur treated gum was quite accidental and wholly unexpected. Heat above all things was the agency which in all previous observations was most to be feared, for it was this more than anything else that melted down, decomposed and destroyed all of his manufactured articles. While sitting near a hot stove engaged in an animated discussion concerning his experiments, a piece of the gum treated with sulphur, which he held in his hand, was, by a rapid gesture, thrown upon the stove. To his astonishment, he found that this relatively high heat did not melt it, as heretofore, and while it charred slightly, it was not made at all sticky. He nailed the piece of gum outside the kitchen door in the intense cold, and upon examining it the next morning found it as perfectly flexible as when he put it out. Goodyear had discovered the process which afterwards came to be known as “vulcanization.” The discovery was made in 1839, but was not accepted by those to whom it was submitted as possessing any importance. Prof. Silliman, of Yale College, however, in the fall of 1839 testified to the results claimed for it by Mr. Goodyear—that it did not melt with heat, nor stiffen with the cold. On June 15, 1844, Mr. Goodyear took out his celebrated patent, No. 3,633, covering this process, in which he not only used sulphur, but added a proportion of white lead. The proportions named were 25 parts of rubber, 5 parts of sulphur, and 7 parts of white lead, the ingredients either to be ground in spirits of turpentine, or to be incorporated dry between rolls. The odor imparted by the sulphur was to be destroyed by washing with potash or vinegar. This patent was reissued in two divisions Dec. 25, 1849, and again on Nov. 20, 1860, and was extended for seven years from June 15, 1858, which was the end of the first term. Under this patent two kinds of rubber were made and sold—“soft rubber,” containing only a small proportion of sulphur, while the other, known as the “vulcanite,” “ebonite,” or “hard rubber,” had from 25 to 35 per cent. of sulphur and was subjected to a longer heat.

The history of this patent is a remarkable one. Immensely valuable as it was, Goodyear reaped but a small share of the profit, for in the midst of his poverty and necessities he was obliged to sell licenses and establish royalties at a figure far below the real value of the rights conveyed. Some idea of the great value of the business which Mr. Goodyear had developed may be had from the fact that the companies who held rights under the patent for the manufacture of shoes paid at one time to Daniel Webster the enormous fee of $25,000 for defending their patent interests.

With the idea of extending his invention Mr. Goodyear visited England in 1851, where he found that Thomas Hancock, of the house of Macintosh & Co., had forestalled him, although not the inventor. A peculiar provision of the English patent law, which gives the patent to the first introducer, permitted this. Nothing daunted, however, he organized a magnificent exhibit for the Great International Exhibition held in Crystal Palace at Hyde Park, London, in 1851. This exhibit cost him $30,000, and he called it the Goodyear Vulcanite Court. It comprehended an elegantly constructed suite of open rooms made of hard rubber ornamented with handsome carvings, and furnished with rubber furniture, musical instruments, and globes made of rubber, and it was also carpeted with the same material. For his exhibit he received the “Grand Council Medal,” which was one of the highest testimonials of the exposition. This exhibit was afterwards moved from London to Sydenham, where it was exposed and used as an agency for some years for the sale of rubber goods.