1863-1872 - demonstrator at the Pharmaceutical Society. 1868 - BSc in chemistry from the University of London. 1871 - DSc in chemistry from the University of London. 1876 - published textbook 'Introduction to the Study of Chemical Philosophy'. 1884 - discovered that isoprene (the building block of natural rubber) could be prepared by passing turpentine oil vapour through a red-hot iron tube. 1892 - a sealed bottle of isoprene was found to contain yellowish lumps, similar to natural rubber; vulcanized this forerunner of synthetic rubber with sulphur. 1894 - professor of chemistry at the Royal College of Science (became part of the Imperial College of Science and Technology in 1907). 1909 - retired. 1918 - biography of the chemist Sir William Ramsay.