It is the duty of an attorney and counselor at law to maintain inviolate the confidence, and at any peril to himself to preserve the secret of his client.

Source: PolC 1877, ch 18, § 4, subdiv 4; CL 1887, § 465, subdiv 4; RPolC 1903, § 697, subdiv 4; RC 1919, § 5262 (4); Supreme Court Rule 13, 1939; SDC 1939 & Supp 1960, § 32.1201 (4).