The contrariety of human nature is a subject that has given a surprising amount of occupation to makers of proverbs and to those moral philosophers who make it their province to discover and expound the glaringly obvious; and especially have they been concerned to enlarge upon that form of perverseness which engenders dislike of things offered under compulsion, and arouses desire of them as soon as their attainment becomes difficult or impossible. They assure us that a man who has had a given thing within his reach and put it by, will, as soon as it is beyond his reach, find it the one thing necessary and desirable; even as the domestic cat which has turned disdainfully from the preferred saucer, may presently be seen with her head jammed hard in the milk-jug, or, secretly and with horrible relish, slaking her thirst at the scullery sink.