The evidence offered by the defendant was to prove a substantive fact intended to be relied on by the defendant in avoidance of the action, and should therefore, under the provisions of St. 1852, c. 312, § 18, have been set forth in precise terms in the answer. It is no excuse for not doing this that the declaration alleges that “ the defendant wrongfully, wilfully and without right” dug and excavated a sluice way or ditch along the line of the highway and near the dwelling-house of the plaintiff, thereby injuring the plaintiff’s dwelling-house. Such form of declaring does not require the plaintiff to prove as a part of his case in the first instance that the same was not done by a surveyor of highways, acting under the written appro*14bation of the selectmen of the town. The proof of the acts set forth in the declaration, and the alleged injury to the plaintiff thereby, would require of the defendant to justify, if he would maintain his defence. Such justification or substantive defence should be stated in his answer. He not having done so, but merely filed a general denial of “ each and every allegation contained in the plaintiff’s declaration,” has no right upon these pleadings to justify his acts under any authority derived from a surveyor of highways. Exceptions overruled.