The Laboratory Summary
The poem starts out with a woman talking to someone about a "glass mask," white smoke, devils, and poison. Adding that up with the title, we can tell that we're in some kind of evil laboratory (cue the lightning strikes and ominous music). She goes on to tell a story about her lover, who left her for another woman, and how she's sure they're both making fun of her right now. Then she starts describing what the man she's talking to (the poison maker) is doing. She encourages him, asks him questions, and dreams about all the people she could kill with the poisons she sees around her. She describes one fantasy in particularly disturbing detail, imagining how she would kill three women she knows.
Suddenly, she breaks off and starts complaining about the poison the man is making for her. She's not happy with the color, and she thinks it won't be enough to kill her enemy. Then she gets going on her gruesome fantasies again, thinking about how painful and miserable she would like this poor woman's death to be. Finally, she notices that the poison is done, and offers the old man who made it all of her gold and jewels (as well as a kiss on the mouth) as a reward for making it. That's sweet of her, huh?