In just six lines, the speaker comes across a man who talks about murdering the sun. The title, "Solicidal," seems to blend "sun" or "sol" with "suicide" or "homicide," so the man's violent talk may carry a self-destructive edge too. The speaker doesn't react or judge; he simply reports what he finds, which gives the scene a flat, strange calm.
The images that follow are odd and don't explain themselves. The man is compared to "a bat in the palace," something out of place, a creature of darkness trapped among grandeur and light. Then he goes to London "to hang like a picture, all gilt and ash." That line suggests someone turned into an ornament, shiny on the surface but burnt out underneath. The poem leaves it unclear whether this is escape, defeat, or death. The mood is eerie and sad, with a dreamlike detachment, as if the speaker is watching a fading life from a distance.