This is an action to recover for an unauthorized surgical operation performed by the defendant, a surgeon, upon the body of the plaintiff.
On March 21, 1916, the plaintiff suffered a rupture in his right groin while in the employ of the Boston and Albany Railroad, of whose road the New York Central Railroad Company was lessee; on the same day he consulted the defendant, and the next day was operated on by the latter. The following day the plaintiff discovered that the operation had been performed on his left side, and so stated to the defendant. The plaintiff *436testified that the defendant said: “I took you for another patient of mine that had a hernia on the left side. — Well, the only thing we cap do is to operate on the right side in about two or three days.” Afterwards an operation was performed by the defendant upon the plaintiff’s right side.
On July 19, 1916, the plaintiff made a settlement of his claim against the railroad company and executed and delivered to it a release of all claims and demands “ arising or which may arise out of said injury.”' This action having been brought since the settlement, an important question is whether it is barred by the' release.
If the plaintiff’s employer, in an action brought'against it to recover for the original injury, would have been liable for the negligence of the defendant in improperly treating the plaintiff, then the release included such damages and is a bar to the present action, for the reason that in such a case the plaintiff had a claim against both the railroad company and the defendant for the same cause of action and a release of one of the alleged wrongdoers would operate as a release of both. Brewer v. Casey, 196 Mass. 384. Stimpson v. Poole, 141 Mass. 502. Leddy v. Barney, 139 Mass. 394. Brown v. Cambridge, 3 Allen, 474.
It is the contention of the plaintiff that the alleged negligence of the defendant had no causal relation to the original injury, but created a new, separate and independent cause of action, the liability for which was not barred by the release.
It is well settled in this Commonwealth, and in many other jurisdictions, that in an action for personal injuries arising out of the alleged negligence of the defendant, the plaintiff is entitled to recover for the injuries resulting from the defendant’s negligence although such injuries are aggravated by thé negligence of an attending physician if, in his selection and employment, the plaintiff was in the exercise of reasonable care. McGarrahan v. New York, New Haven, & Hartford Railroad, 171 Mass. 211, 219. Gray v. Boston Elevated Railway, 215 Mass. 143, and cases cited.
The question is whether the act of the defendant in operating by mistake upon the plaintiff’s left side was a natural and probable result of the negligence of the railroad company. We are of opinion that the general rule as above stated is not applicable *437to the case at bar. There was sufficient evidence to show that the defendant made a mistake in the identity of the plaintiff at the time the operation was performed and that he then believed he was operating upon another patient who had a hernia on his left side. The reason why a wrongdoer is held liable for the negligence of a physician whose unskilful treatment aggravates an injury, is that such unskilful treatment is a result which reasonably ought to have been anticipated by him.
The railroad company could not be held liable because of the defendant’s• mistaken belief that he was operating upon some person other than the plaintiff. Such a mistake was not an act of negligence which could be found to flow legitimately as a natural and probable consequence of the original injury, and a ruling in effect to the contrary could not properly have been made. The fact that the mistake made by the defendant might possibly occur is not enough to charge the railroad company with liability; the unskilful or improper treatment must have been legally and constructively anticipated by the original wrongdoer as a rational and probable result of the first injury. This is the true test of responsibility, and it cannot be extended to cover the facts in the present case as shown by the record.
If a surgeon employed to operate upon a patient for hernia caused by the negligence of another, instead of performing that operation removes one of the patient’s kidneys (which is in sound condition) under the mistaken belief that he is treating another patient, can it reasonably be held that such a mistake is something that might sometimes follow, and as a matter of common knowledge and experience might be expected sometimes to follow, from an injury resulting in hernia? We think not. We are of opinion that the act of the defendant in operating on the wyong side, was a wholly wrongful, independent and intervening cause for which the original wrongdoer was in no way responsible.
All the cases cited and relied on by the defendant are distinguishable from the case at bar because of the fact that the defendant did not intentionally operate upon the plaintiff for the injury received, as he did in those cases, but mistakenly understood and believed" that he was operating upon another patient for a different injury.
It is unnecessary to decide whether the railroad company *438would have been liable for the aggravation of the plaintiff’s injury caused by the mistake of the defendant in operating upon the wrong side, had there been no mistake with reference to the identity of the patient.
In some jurisdictions it is held that in an action against the original wrongdoer, if a surgeon by mistake operates at a place other than at the seat of the injury and without the consent of the patient, such an act is a natural and probable consequence of the original injury for which the defendant is responsible. Martin v. Cunningham, 93 Wash. 517. Thompson v. Louisville & Nashville Railroad, 91 Ala. 496. Sauter v. New York Central & Hudson River Railroad, 66 N. Y. 50. Variety Manuf. Co. v. Landaker, 227 Ill. 22. Reed v. Detroit, 108 Mich. 224. Seeton v. Dunbarton, 73 N. H. 134. Lyons v. Erie Railway, 57 N. Y. 489. Goss v. Goss, 102, Minn. 346. See also Mohr v. Williams, 95 Minn. 261; Sullivan v. McGraw, 118 Mich. 39; Pratt v. Davis, 224 Ill. 300. The facts in the case at bar distinguish it from the cases above referred to.
If we assume that the release is valid and a bar to any claim which the plaintiff had against the railroad company, still a majority of the court are of opinion, for the reasons stated, that it is not a defence to the present action and was not admissible in evidence.
The exceptions to the admission in evidence of the release and the ruling that it was a bar to the action, must be sustained.
Ordered accordingly.