A transaction by which certain pieces of property are given for others, a definite price being put on each, and the difference paid in cash, is a sale and not an exchange. Thornton v. Moody (Tev. Civ. App. '93), 24 S. W. 331; Ullman v. Land, 84 S. W. 294, 37 Tex. Civ. App. 422.

To constitute an exchange, the value of the estates should be equal. Bouvier, L. D., citing Coke-Litt. 50.