These two chapters are short ones, I know. But they do have some points to make, not least of which is the artificial value of money. Hugo sees it, correctly, I think, as of value only for the worth of what it will purchase. Consider, in contrast, the common perception in our present world of money being of value for itself, independent of its purchasing power, but rather as a measure of its possessor's status in society, and therefore of an intrinsic worth which, rationally speaking, it does not have.
Oh, the Sherlock Holmes quote. It's from Arthur Conan Doyle's The Sign of Four, which, if I recall correctly, is the very first of the long Holmes canon, introducing both Holmes and Dr. Watson to their public.