When employed to purchase an agent can not sell his own property to his principal. Deep River, etc., v. Fox, 4 Ired. (N. C.) Eq. 61; Banks v. Judah, 8 Conn. 145; Matthews v. Light, 32 Me. 305; Copeland v. M. Ins. Co., 6 Pick. (Mass.) 198; Moore v. Mandlebaum, 8 Mich. 433; Moore v. Moore, 5 N. Y. 256; Sturdevant v. Pike, 1 Ind. 277; Segar v. Edwards, 11 Leigh (Va.) 213; Shannon v. Marmaduke, 14 Tex. 217; Cumberland, etc., Co. v. Sherman, 30 Barb. (N. Y.) 553.