A joint contract is one made by two or more promisors, who are jointly bound to fulfill its obligations, or made to two or more promisees, who are jointly entitled to require performance of the same. A contract may be “several” as to any one of several promisors or promisees, if he has a legal right (either from the terms of the agreement or the nature of the undertaking) to enforce his individual interest separately from the other parties. Rainey v. Smizer. 28 Mo. 310; Bartlett v. Bobbins, 5 Mete. (Mass.) 186.