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