Humour is the describing the ludicrous as it is in itself; wit is the exposing it, by comparing or contrasting it with something else. Humour is, as it were, the growth of nature and accident; wit is the product of art and fancy.
Languages happily restrict the mind to what is of its own native growth and fitted for it, as rivers and mountains bond countries; or the empire of learning, as well as states, would become unwieldy and overgrown.