Mich. Comp. Laws § 750.431: Poisons and antidotes; marking name by retailers.

Sec. 431.

Retailers of poisons to mark same poisons and name antidote-Any apothecary, druggist or other person who shall sell and deliver at retail, any arsenic, corrosive sublimate, prussic acid, or any other substance or liquid usually denominated poisonous, without having the word "poison", and the true name thereof, and the name of some simple antidote, if any is known, written or printed upon a label attached to the vial, box, or parcel containing the same, shall be guilty of a misdemeanor.