In painting a Nudity, be not too rigid and exact in marking the Muscles; that being not only tedious and troublesome in the Execution, but even displeasing to the Eye when effected: remember further, to make them the most visible on that side of any Member which it puts forwards to Action; the nature of a Muscle being such, that in working, its Parts assemble, and unite themselves together; several of them, by this Means, discovering themselves, which before were unperceiv'd.