We see no error in the admission of the: St. of 1885, c. 382, in evidence. It was a law of the Commonwealth, which everybody was presumed to know, and which gave color to acts of the defendant relied on by the plaintiff. As bearing on the question whether the plaintiff’s dock was filled up and injured by sewage brought down and negligently discharged near the dock by the defendant, the quantity of sewage that came through the sewers was a material fact to be considered. It was therefore competent for the plaintiff to show that the flow through the sewers was largely increased in 1885 and 1886 by substituting water-closets for vaults and privies in a great number of houses along the line of the sewers which emptied their contents near the plaintiff’s wharf. Evir dence of this fact was introduced without objection, and, as characterizing the general substitution, and the act of substir tution in each house, it was competent to consider the statute which required it to be made. It was a substitution required by law, as distinguished from an unlawful substitution, or a substitution originally planned by the particular property owners who made it. Like a declaration accompanying and characterizing an act, which is competent as a part of the res gestee wherever the act itself is competent, the statute in this case, which required each of these acts, is so connected with the act that the act and the nature of it cannot be fully understood *402without knowledge of the statute. So far as it relates to the question at issue, perhaps the act of putting a water-closet in a house in the place of a vault or privy is no different, if done under the statute, from what, it would be if there were no law ón the subject; but if that be so, the plaintiff still had a right to prove the act as it was, with all the circumstances which showed its true quality. There is nothing to show that the defendant was in any way injured by the introduction in evidence of the statute. It does not appear whether there was any dispute as to the fact testified to, about the substitution of water-closets for vaults and privies. If not, then the existence of the statute was simply a competent fact, which turned out to be unimportant to either party. But if the fact or the extent of this substitution was in controversy, we think the jury might well consider the nature and quality of each act testified to, as shown by the statute, in determining whether the testimony of the witnesses was probably true. It is far more probable that a great number of changes required by law would be made in a short time than that such number of similar changes would result merely from the voluntary action of property owners. Pringle v. Woolworth, 90 N. Y. 502.
The only other exception argued was to the refusal to give an instruction, “that, if the jury were of the opinion that if it had not been for the wharves and the artificial deepening of the plaintiff’s docks the natural scour of the tide would have carried the whole or most of the matter out to sea, then the plaintiff cannot recover, if its damage was caused by its own interference with the harbor and the waters of it at that point.” The report states that the case was submitted to the jury under instructions which were not excepted to. It must be assumed that the plaintiff corporation was permitted to recover only on a finding by the jury that it was injured by the negligence of the defendant in the management of its sewers and the discharge of its sewage. Haskell v. New Bedford, 108 Mass. 208. Brayton v. Fall River, 113 Mass. 218. Boston Rolling Mills v. Cambridge, 117 Mass. 396. Morse v. Worcester, 139 Mass. 389.
The plaintiff had a right to erect wharves and artificially deepen its docks to make its property available for "use, and its doing so did not relieve the defendant from liability for the consequences of the defendant’s negligence. Davidson v. Boston *403& Maine Railroad, 3 Cush. 91, 106. Commonwealth v. Alger, 7 Cush. 53, 75, 79, 81. In determining whether the injury resulted from the defendant’s negligence, the jury must be presumed to have considered, under the instructions of the court, the condition of the plaintiff's property, and the use which was made of it, and they could not properly have been permitted to deprive the plaintiff of its remedy because a use was made of its property which changed somewhat the currents of the tide at that place, and made the matter negligently discharged by the defendant accumulate in larger quantities than it otherwise would have done. Judgment on the verdict.