Every trust power unless its execution is made expressly to depend on the will of the trustee is imperative and imposes a duty on the trustee, the performance of which may be compelled for the benefit of the parties interested.

Source: CivC 1877, § 350; CL 1887, § 2866; RCivC 1903, § 373; RC 1919, § 440; SDC 1939, § 59.0453.