Here the action brought by the quondam infant is one for money had and received-the payments under the disaffirmed contract having been either in money or in property converted into money before the disaffirmance. Such an action, though brought at law, is in its nature a substitute for a suit in equity; and it is to be determined by the application of equitable principles. In other words, the rights of the parties are to be determined as they would be upon a bill in equity. The defendant may rely upon any defense which shows that the plaintiff in equity and good conscience is not entitled to recover in whole or in part.