In English practice, a defense to an action on grounds which, priorto tlie passage of the common-law procedure act. (17 & 18 Vict c. 125,) would havebeen cognizable only in a court of equity. In American practice, a defense which iscognizable in a court of equity, but which is available there only, and not in an action atlaw, except under (he reformed codes of practice. Kelly v. Hurt. 74 Mo. 570: New Yorkv. Ilolzderber, 44 Misc. Itep. 509, 90 X. Y. Supp. 63.