The first mention of Mrs Gould, the anti-materialism altruist, is telling: her
gift is a pair of glasses for reading a Bible (the source of altruism), but the
glasses are mounted in silver from the mine (the source of materialism). Her life
is also "mounted" (i.e., lifted to importance) by silver, a foundation
of materialism that will eventually destroy her altruistic spirit. But I see an
even deeper philosophical comment here in the image of the Bible glasses whose
lenses are surrounded by a silver frame: it is as if to say, altruism can only
exist in the context of the materialism it despises.