We have no doubt that the legislature intended the act in question — Sess. L. 1867, p. 89 — -to affect only the causes of action which should accrue subsequent to its taking effect as law. There is nothing in-the act itself from which we can gather any different intent, and it is a sound rule of construction that legislation is to have a prospective operation only, except where the contrary intent is expressly declared or is necessarily to be implied from the terms employed.