Finally, in 1839, when he was on the point of giving up in despair, he accidentally came upon the solution. He was experimenting in his kitchen, a place which, through lack of funds, he was often forced to use as a laboratory. Part of a mixture of rubber, sulphur and other chemicals, with which he was working, happened to drop on the top of the stove. It lay there sizzling and charring until the odor of the burning rubber called his attention to it. As he stooped to scrape it off the stove he gave a start of wonder as he noted that a change had come over the rubber during its brief contact with the stove.