18-4-17. Means of proving instrument not acknowledged.
Proof of the execution of an instrument, when not acknowledged, may be made either:
(1)By the party executing it, or either of them;
(2)By a subscribing witness; or
(3)By other witnesses, in cases mentioned in §§18-4-19 and 18-4-20, relating to proof of handwriting.
Source: CivC 1877, §662; CL 1887, §3283; RCivC 1903, §976; RC 1919, §582; SDC 1939, §51.1610.