 Brockendon later said in an affidavit that he never heard or knew of Hancock analysing the Goodyear samples, a claim Hancock verifies in his "Personal Narrative", where he claimed he had been experimenting with sulphur for many years himself.A number of chemists also swore that even if he had analysed Goodyear's material, this would not have given him enough information to duplicate the process.Alexander Parkes, inventor of the "cold cure" process (vulcanisation of fabrics using sulphur chloride in a carbon disulphide solution), claimed that both Hancock and Brockendon admitted to him that their experiments on the Goodyear samples had enabled them to understand what he had done.