India Rubber

India rubber had been known about and used for some time before Charles Macintosh developed a method of waterproofing fabric in 1823, the same year that the first rubber factory in England was established.  It was not until 1839 that Charles Goodyear discovered how to vulcanise rubber.  This process made it a more stable product and one which did not break down so easily under normal circumstances.  It appears that it was still a novelty when Richard gave Charlotte an india rubber pen in 1834.