In 1860, Williams analyzed rubber by destructive distillation and obtained a large quantity of a light oil which he termed isoprene (polymer of the monomer isoprene—formula CH2:C(CH3)CH:CH2).
In 1860, Williams examined rubber by thermal decomposition and obtained a significant amount of a light hydrocarbon which he termed isoprene (a polymer formed from the monomer isoprene).