It is an admitted principle, that a person shall not be permitted to claim under any instrument, whether it be a deed or a will, without giving full effect to it in every respect, so far as such person is concerned. When a testator, therefore, gives what belongs to another and not to him, and gives to the owner some estate of his own; this gift is under an implied condition, either that he shall part with his own estate, or not take the bounty. If, for example, a testator undertakes to dispose of an estate belonging to B, and devise to B other lands, or bequeath to him a legacy by the same will, B will not be permitted to keep his own estate, and enjoy at the same time the benefit of the devise or bequest made in his favor, but must elect whether he will part with his own estate, and accept the provisions in the will, or continue in possession of the former and reject the latter. 2. The foundation of the equitable doctrine of election, is the intention, explicit or presumed, of the author of the instrument to which it is applied, and such is the, import of the expression by which it is described as proceeding, sometimes on a tacit, implied, or constructive condition, sometimes on equity. See Cas. temp. Talb. 183; 2 Vern. 582; 2 Ves. 14; 1 Eden, R. 536; 1 Ves. 306. See, generally, 1 Swan. 380 to 408, 414, 425, 432, several very full notes. 3. As to what acts of acceptance or acquiescence will constitute an implied election, see 1 Swan. R. 381, n. a; and the cases there cited.