"If this be so, why has this question been so frequently and elaborately discussed, not only in the English, but in our courts of equity? How are the cases of Bilbie vs. Lumley and of Brisbane vs. Dacres to be reconciled with this principle? What ground of conscience or equity had Admiral Dacres for retaining the money paid him. He had neither incurred hazard nor rendered any labor or service in his transportation. Captain Brisbane was not his servant, nor was the ship which carried it his property. Chief Justice Mansfield, in his solicitude to avoid collision with the dicta of Chief Justice DeGrey and Lord Mansfield, does indeed suggest a ground of equity for the defendant. He says, 'so far from its being contrary to aequum et bonum, I think it would be most contrary to aequum et bonum if he were obliged to repay it; for see how it is; if the sum be large, it probably alters the habits of his life; he increases his expenses; he has spent it over and over again; perhaps he cannot pay it at all, or not without great distress.' If the fact of having expended the money, or of its being inconvenient to repay it, is a sufficient ground of equity to enable the party who has received it under a mistake of law to retain it, I apprehend that it will practically amount to the same thing as holding that it shall not be recovered back. But with great respect, I think his Lordship might better have denied those dicta to be law, as Lord Ellenborough did in Bilbie vs. Lumley, than to have sought to evade them by this gloss.

' 'Chief Justice Marshall thought there was a distinction between a mistake in fact and a mistake in law, when he said, in Hunt vs. Rousmanier, 8 Wheat., 215: 'Although we do not find the naked principle that relief may be granted, on account of ignorance of law, asserted in the books we find no case in which it has been decided that a plain and acknowledged mistake in law is beyond the reach of equity.' Chancellor Kent, thought such a distinction existed, when he said, in Lyon vs. Richmond, 2 Johns, 51: 'Courts do not undertake to relieve parties from their acts and deeds fairly done, on a full knowledge of facts, though under a mistake of the law. Every man is to be charged at his peril with a knowledge of the law; there is no other principle which is safe or practicable in the common intercourse of mankind.' The principle upon which courts refuse to relieve against mistakes in law is, that in judgment of law there is no mistake; every man being held, for the wisest reason, to be cognizant of the law. The act, therefore, against which the party seeks relief is his own voluntary act, and he must abide by it. This principle steers entirely clear of the conscience or equity of the transaction."