Both Uses

oblivion
in
Frankenstein - 1831 version
(Auto-generated)

This man, whose name was Beaufort, was of a proud and unbending disposition and could not bear to live in poverty and oblivion in the same country where he had formerly been distinguished for his rank and magnificence.†
p. 33.5 *

oblivion = a state of being completely gone from memory, existence, or awareness
The same lulling sounds acted as a lullaby to my too keen sensations; when I placed my head upon my pillow, sleep crept over me; I felt it as it came and blessed the giver of oblivion.†
p. 98.9

Definitions:

(1) (oblivion)
state of complete loss—being totally forgotten, wiped out, or lost to awareness of what is going on
(2) (meaning too rare to warrant focus)