<p>no, not any specific classes, but 1/4th classes should be in the social sciences and humanities.
I believe you when you say there’s a lot of reading/writing in a cam course 
so Achilles09 would surely be ready to analyze different types of texts, but as far as I know reading chemistry wouldn’t let him take classes in sociology, psychology, and English (let alone develop fluency in a foreign language).
Some schools actually like it better if the applicants have a humanities or social science major AND have pulled A’s or near all-A’s in all their science prerequisites (1 year biology, 2 years chemistry, biochemistry/neuroscience, 1 year calculus-based physics, 1 year calculus + further math up to linear algebra if possible) plus research, shadowing, and medical internships/volunteering.
If Achiles is not certain about med school, however, his path is well thought-out. He’d get superior preparation in chem at Cambridge and would be very competitive to apply to grad schools.</p>