title: A simple technique of screening narcotic analgesics.
mesh_terms: D000701:Analgesics, Opioid / Q000494:pharmacology*; D000818:Animals; D004353:Drug Evaluation, Preclinical / Q000295:instrumentation*; D005260:Female; D006245:Hardness Tests / Q000295:instrumentation; D008297:Male; D011312:Pressure; D051381:Rats
chemical_list: D000701:Analgesics, Opioid