powdered opium

pow·dered o·pi·um

dried and finely powdered opium containing 10% morphine.
References in classic literature ?
Finally, an analysis has shown that the remains of his supper left by the stable-lad contain an appreciable quantity of powdered opium, while the people at the house partook of the same dish on the same night without any ill effect.
What chemist sold him the powdered opium? Above all, where could he, a stranger to the district, hide a horse, and such a horse as this?