his·to·chem·o·graph \|hi(ˌ)stōkeməˌgraf, -rȧf\noun Etymology:hist- + chem- + -graph : a picture or pattern produced on a photographic plate by the chemical action of a histological specimen in contact with the emulsion • his·to·che·mog·ra·phy\-ˌkeˈmägrəfē, -_kə̇ˈ-\noun-es