Both Uses of

inferior
in
Frankenstein - 1831 version

Wealth was an inferior object, but what glory would attend the discovery if I could banish disease from the human frame and render man invulnerable to any but a violent death!
p. 42.2 *

inferior = of less importance

The delight of Clerval was proportionably greater than mine; his mind expanded in the company of men of talent, and he found in his own nature greater capacities and resources than he could have imagined himself to have possessed while he associated with his inferiors.
p. 166.7

inferiors = less capable people

Definitions:

(1) (inferior)
of low quality, or of lower quality or rank than something else -- sometimes used as a noun to refer to a person of lower rank or status
(2) (meaning too rare to warrant focus)
meaning too rare to warrant focus:

Less commonly, specialized senses include:
- anatomy and botany -- a lower position on a body or plant (or pointed downward)
- typography -- a character that drops beneath a printing line (such as with subscript)
- astronomy -- having an orbit relative to the sun that is lower than earth's (making Mercury and Venus inferior planets)