Both Uses of

monetary
in
The Mill on the Floss

He had no male audience to-day except Mr. Moss, who knew nothing, as he said, of the "natur' o' mills," and could only assent to Mr. Tulliver's arguments on the a priori ground of family relationship and monetary obligation; but Mr. Tulliver did not talk with the futile intention of convincing his audience, he talked to relieve himself; while good Mr. Moss made strong efforts to keep his eyes wide open, in spite of the sleepiness which an unusually good dinner produced in his hard-worked frame.†
Chpt 2.2

But to men of Mr. Deane's stamp, what goes on among the young people is as extraneous to the real business of life as what goes on among the birds and butterflies, until it can be shown to have a malign bearing on monetary affairs.†
Chpt 6.8 *

Definitions:

(1) (monetary)
relating to or involving money
(2) (meaning too rare to warrant focus)
meaning too rare to warrant focus:

Much less common in literature, but commonly in financial news, monetary can relate to a nation's money supply. Monetary policy is set to try to influence inflation and unemployment levels.