"The of mineral or organic material was one of the few preparative methods available to the alchemists and the first chemists. That materials could undergo profound changes at high temperatures became a well-recognized principle... emphasized by... landmarks as the formation of by heating ferrous sulfate (copperas) described by ... Brandt's discovery of in 1669 by destructive distillation of residues from ... isolation of benzene from oil gas by Faraday in 1825 and of pyrrole from bone oil by Runge in 1834."