In an action or suit by or against a person who from any cause is incapable of testifying, or by or against a trustee, executor, administrator, heir or other representative of the person incapable of testifying, no judgment or decree founded on uncorroborated testimony shall be rendered in favor of a party whose interests are adverse to the person incapable of testifying or his trustee, executor, administrator, heir or other representative. In any such action or suit, if the adverse party testifies, all entries, memorandum and declarations by the party incapable of testifying made while he was capable, relevant to the matter in issue, may be received in evidence.
W.S. 1-12-102