Meconic adj. Pertaining to, or obtained from, the poppy or opium; specif. (Chem.), designating an acid related to aconitic acid, found in opium and extracted as a white crystalline substance.
... the Stomach.—Opium itself cannot be directly detected, but we test for morphine and meconic acid. These may be separated from organic mixtures thus: Boil the organic matter with distilled water, spirit, and acetic acid; filter, and to the fluid passed through add acetate of lead till precipitate ceases. Filter. ... — Aids to Forensic Medicine and Toxicology • W. G. Aitchison Robertson