What does Emerson mean in the following quote from "Self-Reliance"? "Though I confess with shame I sometimes succumb and give the dollar, it is a...

This quote is
from the essay "."  In this essay, Emerson's main argument is that people should trust
their own thoughts and beliefs rather than bowing to what society thinks is right.

In the passage you quote, Emerson is telling himself that he lacks "manhood"
when he gives money to popular charities rather than just giving them to ones he himself
believes in.  This idea is connected to the main idea of the essay -- he thinks he ought to go
with what he believes, not what society tells him and he is annoyed with himself when he
doesn't.  He hopes that one day he'll believe in himself enough to withhold that dollar from the
charity that he doesn't believe in.