Green’s Dictionary of Slang

(drugs) morphine.

1969		R.R. Lingeman Drugs from A to Z (1970).
2003		‘Worksheet 9: Self study of drug abuse’ St Alban’s College 🌐 Opiates e.g. opium (oupa, poppy); morphine (M, morph, Miss Emma, monkey dust, mooch, white stuff, dreamer).