Who is Felix Garrison, from "Calliope" from The Sandman and what is their importance?

Felix Garison is a doctor. He is an admirer or Richard Madoc's work, and he obtains a bezoar for Madoc, although he does not know why Madoc wants it. When Madoc is overwhelmed by the flood of ideas visited on him by the Sandman, Felix takes care of Madoc.