"It must not be forgotten that the rules of Courts of equity are not, like the rules of the common law, supposed to have been established from time immemorial. It is perfectly well known that they have been established from time to time—altered, improved, and refined from time to time. In many cases we know the names of the Chancellors who invented them. No doubt they were invented for the purpose of securing the better administration of justice, but still they were invented. Take such things as these: the separate use of a married woman, the restraint on alienation, the modern rule against perpetuities, and the rules of equitable waste. We can name the Chancellors who first invented them, and state the date when they were first introduced into Equity jurisprudence; and therefore, in cases of this kind, the older precedents in equity are of little value. The doctrines are progressive, refined, and improved; and if we want to know what the rules of Equity are, we must look, of course, rather to the more modern than the more ancient cases."