agreed to let him have such chemicals as he needed on credit. He now proceeded to boil the gum, mixed with magnesia, in quicklime and water, and, as the result, obtained sheets of his compound whose firmness and smoothness of surface won them a medal at the fair of the American Institute in 1835. He seemed now on the point of success, and readily disposed of all the sheets he could manufacture. The newspapers spoke highly of his invention, for which he obtained a patent; and he was about to endeavor to enlist some persons of means in its manufacture on a large scale, when, to his dismay, he discovered that a single drop of the weakest acid, such as the juice of an apple, or diluted vinegar, would utterly destroy the influence of the lime in the compound, and reduce it to the old sticky substance that had baffled him so often.
His next step was to mix quicklime with the gum. In order to work the compound thoroughly, he used to carry the vessel containing it, on his shoulder, to a place three miles distant from his laboratory, where he had the use of horse power. The lime, however, utterly destroyed the gum, and nothing came of this experiment.
The discovery which followed was the result of accident, and brought him on the very threshold of success, yet