Section 39: Statements by persons who cannot be called as witness.

Statements, whether written or oral of facts in issue or relevant facts made by a person-
a who is dead;
b who cannot be found;
c who has become incapable of giving evidence; or
d whose attendance cannot be procured without an amount of delay or expense which under the circumstances of the case appears to the court unreasonable, are admissible under section 40 to 50.