production of toluidine, vintage engraving

accelerators amine ancient antique apparatus art artwork aryl black carcinogens chemical chemistry component compound cyanoacrylate drawing dye engraved engraving etching forensics glue group illustration industrial industry isomer making manufacture manufacturing metatoluidine method methyl methylaniline mtoluidine old organic orthotoluidine otoluidine paratoluidine picture process processing production ptoluidine toluidine toxic vector vintage white