Section 18-4-19 - Circumstances permitting proof of instrument by handwriting The execution of an instrument may be established by proof of the handwriting of the party and of a subscribing witness, if there is one, in the following cases:
(1) When the parties and all the subscribing witnesses are dead;(2) When the parties and all the subscribing witnesses are nonresidents of the state;(3) When the place of their residence is unknown to the party desiring the proof and cannot be ascertained by the exercise of due diligence;(4) When the subscribing witness conceals himself or cannot be found by the officer by the exercise of due diligence in attempting to serve the subpoena or attachment; or(5) In case of the continued failure or refusal of the witness to testify for the space of one hour after his appearance. CivC 1877, § 663; CL 1887, § 3285; RCivC 1903, § 978; RC 1919, § 584; SDC 1939, § 51.1612.