ment, which enable the donees to create 29. 12. Revocation, or appointmentPrimary, or subsidiary.-Powers are also divisible into (1) powers of revocation, which give only the right of revoking exby custom.-Powers operator appoint new estates. When a power ing by virtue of a custom (e. g. a custom applicable to copyholds) resemble those under the Statute of Uses in their effect, but they are less flexible in their application. Chance Pow. 3, 27. 10. Appendant, or appurtenantIn gross, or collateral-Merely collateral, or naked.-Legal powers are (1) "appendant" or "appurtenant" when the donee has an estate in the land and the power is to take effect wholly or in part out of that estate, as in the case of a tenant for life having a power of leasing, or a mortgagee having a power of sale; (2) "in gross" or "collateral," either (a) where the donee has an estate in the land, but the power does not take effect out of it, as where a tenant for life has power to appoint an estate to commence after his death, or (b) where the donee has no present estate, but may exercise the power for his own benefit; (3) "merely collateral" or "naked," where the donee neither has an estate nor can exercise the power for his own benefit, as in the case of executors having a mere power of sale. If lands are devised to an executor with a trust or power of sale, this is sometimes called a "power coupled with an interest," to distinguish it from a bare or naked power. (Co. Litt. 113a.) This classification of powers is of importance with reference to the ability of the donee to release, suspend of appointment is not preceded by an existing estate, it is sometimes called a "primary power;" when it is preceded by an existing estate which the donee may revoke, it is called a "power of revocation and new appointment," or a "subsidiary power." (Wats. Comp. Eq. 759; Leake P. L. 374.) As to the operation of appointments with reference to the rule against perpetuities, see APPOINTMENT, & 1. 13. General.-Powers are either general [absolute] or limited. A general power enables the donee to appoint the property to any person or persons (including himself), for any estates, and on any conditions, and is therefore equivalent to ownership. (Sugd. Pow. 394.) If he dies having exercised it by will in favor of a volunteer, or if he becomes bankrupt, the power forms part of his assets for payment of his debts. (Wms. Sett. 40.) In the case of a person dying after having exercised a general power by his will, the doctrine is, that by exercising it he is in ordinary cases presumed to have meant to take the property out of the instrument creating the power for all purposes, so as to make it form part of his estate; and therefore if the appointment fails (e. g. by the appointee dying in the appointor's life-time), the property results to the appointor's estate, and not to that of the donor of the power. If, however, the donee only exercises the power