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, (Tex. Civ. App. 93), 24 S. W. 331; Ullman v. Land, 37 Tex Civ. App. 422; 84 S. W. 294. See See. 164.