The Apothecary by Sir John Gilbert.
As soon as Romeo hears that Juliet is dead he decides to join her in death. He says, "Well, Juliet, I will lie with thee to-night. / Let's see for means: O mischief, thou art swift / To enter in the thoughts of desperate men! / I do remember an apothecary,--" (5.1.34-37). Romeo then describes the apothecary (druggist) and his shop, and remembers how he thought, when he first saw them, that this would be a place to buy poison. He knows that in Mantua death is the penalty for selling poison, but he thinks that the desperately poor apothocary would take the risk. He's right. The apothecary is afraid to sell the poison, but Romeo makes him an offer he can't refuse.