Bigelow, C. J.
The rule of law regulating the authority of a master to sell a vessel under his command is stated with its proper limitations in Gordon v. Massachusetts Insurance Co. 2 Pick. 249; Hall v. Franklin Insurance Co. 9 Pick. 466, 477; and in several subsequent cases decided by this court, in which the original statement of the rule has been recognized and confirmed. On a consideration of the facts disclosed at the trial of this case which are fully set forth in the exceptions, we are clearly of opinion that they fail to show the existence of any suck *481necessity as to justify the defendant in making sale of the plaintiff’s share of the schooner. The vessel had sustained no damage ; nor does it appear that she would have encountered any peril if the sale had not been made. All that is shown is, the master had information that the vessel was liable to capture. It does not even appear that this information was true or that the alleged peril was in fact threatened. And there is evidence which tends to show that there was no actual danger of capture or seizure. On this state of facts, we cannot doubt that the evidence was wholly insufficient in law to warrant a verdict in favor of the defendant on the ground that the act of sale of the vessel was justifiable. Our only difficulty has been in determining whether the plaintiff is entitled to a new trial of the case on his exceptions as they stand. The instruction given to the jury was accurate as an abstract proposition. It contains a substantially correct statement of the rule of law as to the authority of the master to sell the vessel. The error, if any, consists in the omission of the court to tell the jury that there was no evidence which in law would warrant a verdict for the defendant on the ground stated in the instruction. But no such instruction appears to have been asked by the plaintiff. If such request had been made, it would have been the duty of the judge to have granted it, and his failure to do so would have been a valid ground of exception. A party has a right to ask the court to rule upon the legal effect of evidence. Denny v. Williams, 5 Allen, 1. We are also of opinion, after careful consideration, that there are cases in which it is the duty of this court to set aside a verdict for an omission to give an instruction, although no request for specific direction was made at the time. This should be the rule whenever it clearly appears by a bill of exceptions that a party has failed to offer evidence sufficient in law to prove his case. The reason is, that, if the judge gives an instruction which leaves the jury at liberty to find a verdict which the law will not support, he by implication leads them to infer that the rule of law is different from what it really is as applicable to the case on trial, and thereby commits an error quite as palpable and as detrimental to the rights of one party to the *482suit, as if he had given an instruction which was absolutely erroneous in point of law; and this is the rule laid down in Pond v. Williams, 1 Gray, 630, 634.
On the ground, therefore, that the judge submitted to the jury a case under instructions which permitted them to find a verdict for a party who had not offered evidence sufficient in law to sustain one in hís favor, we are of opinion that a new trial must be had. Exceptions sustained.