We granted further appellate review in this case to consider the Commonwealth’s challenge to the Appeals Court’s determination in Commonwealth v. Jenkins, 34 Mass. App. Ct. 135, 144 (1993), that it was “unable to conclude- that unanimity [of the jury] was reached in accordance with the letter and the spirit of’ G. L. c. 234, § 34 (1992 ed.). As a guard against the coercion of a jury to reach a verdict, § 34 limits the circumstances under which a judge may require a jury to continue deliberations.2
If, after due and thorough deliberation, the jury twice advise the judge that they are unable to reach a verdict, the judge may not properly send the jury out again without their consent, unless the jury ask for some further explanation of the law. G. L. c. 234, § 34. Section 34 “stands guard to prevent jurors . . . from being coerced into reaching a verdict in the face of views conscientiously reached and held.” Commonwealth v. Winbush, 14 Mass. App. Ct. 680, 682 (1982). See Lambright v. State, 34 Fla. 564, 574 (1894) (similar statute confers legal right on juries to be free from coercion); State v. Simon, 126 S.C. 437, 444 (1923) (similar statute confers right on juries to indicate when they believe that deliberations have been due and thorough and that they are unwilling to deliberate further); State v. Stephenson, 54 S.C. 234, 238-239 (1899) (intent of statute is to prevent verdicts coerced by confinement of jury); Douglass v. State, 4 Wis. 387, 393 (1854) (similar provision was intended for protection of jury).3 Under early English law, juries could be CO*738erced into agreement by withholding “meat, drink, fire, or candle, unless by permission of the judge, till they [were] all unanimously agreed.” 3 Blackstone, Commentaries *375. No doubt this practice had been abandoned by 1836, when the first predecessor of § 34 appeared in substantially its present form. See Rev. Stat. (1836) c. 95, § 32. See also St. 1807, c. 140, § 15 (similar provision applicable only to civil juries). But even as late as 1924, it was held that a Massachusetts civil jury were not coerced when they were obliged to deliberate continuously for almost twenty-three hours (except for time for meals and a short walk) without sleeping accommodations. See Dixon v. A.J. Cunningham Co., 257 Mass. 63, 69-71 (1926).
We conclude that the jury were not coerced to reach a verdict and thus the spirit of § 34 was not violated. Moreover, because the jury consented to the continuation of their deliberations, neither the spirit nor the letter of § 34 was violated.
We shall discuss the three returns of the jury that are significant.4 We accept the Appeals Court’s view that, where there is nothing to indicate the contrary, the giving of a Rodriquez charge on the first return of the jury that is significant for our purposes (Commonwealth v. Rodriquez, 364 Mass. 87, 101-102 [1973]) implied that the judge had concluded that the jury’s deliberations were “due and thorough,” in the words of § 34. Cf. Commonwealth v. Valliere, 366 Mass. 479, 496 (1974) (judge was warranted in concluding that jury’s deliberation was not “due and thorough,” although jury had deliberated for thirteen hours). We also agree that, where at that time the jury made no request for a further explanation of the law, the jury’s return without a verdict was the first of the two returns without a verdict to which §34 refers.
*739The first issue for our close attention arises from the jury’s note to the judge sent after the return we have just discussed and after almost fifteen hours of deliberation. In that note the jury said: “The jury has voted 8 times. The jury has not reached a verdict. Deliberation [s] have at times become heated. Each juror has expressed their [mc] vote as their [szc] own best decision. Each juror has said they [sz'c] do not wish to change their [sz'c] vote. The jury requests that the judge suggest a further course of action. Some members have requested release from the trial.” Defense counsel moved for a mistrial, arguing that the jury were at an impasse. The judge responded that the note did not state that the jury were hopelessly deadlocked. He fastened on the jury’s request for a suggestion for a further course of action. After hearing the views of the prosecutor, the judge stated that he did not think that the note required him to discharge the jury and declare a mistrial. Then, for the first time someone, the judge, not defense counsel, referred to § 34. The judge stated: “I don’t think this note satisfies the provision of Chapter 234, section 34, relative to not being able to send the jury out more than twice unless the jurors so consent.” The judge decided to give the jury “a mixii-Tuey charge” and did so.
Fifteen minutes later the jury sent their final note to the judge in which they indicated that they felt strongly that there was no hope of progress and requested further instructions. The judge concluded that under § 34 he could not force them to deliberate further without their consent. He then told the jury that the law did not permit him to send them out again, unless they agreed to continue deliberations in the case. “I cannot force you to continue deliberations unless you agree to continue deliberations. That’s what the law states.” He then asked the jury to retire and decide whether further deliberations on the next day would be fruitful. “Write out your answer to me, and at that point I’ll make my decision.” Fifteen minutes later the jury came back with a verdict of guilty of murder in the second degree.
*740The significant point here is that, fully informed that the law allowed them to terminate deliberations and go home, the jury agreed to continue deliberations, did so, and promptly reached a verdict. The object of § 34 was fulfilled because the jury consented to continue their work. Even if the judge was wrong in rejecting the next prior note as a second statutory return that triggered the requirement of the jury’s consent (a point we need not decide), the jury’s return of a verdict after sending their last note implicitly satisfied the statutory requirement of jury consent.
We turn to the question whether, quite apart from § 34, the jury were coerced into a verdict. What we have already said points to a negative answer to that question. The jury knew that at last, if they wished, they could go home without reaching a verdict. The law allowed them to do so. The judge explicitly told the jury what the law permitted and that he had no control over them. The judge’s statement that, after the jury had decided whether they wanted to continue, he would make his decision does not detract from the jury’s right to stop deliberations. His decision would be, he said it had to be, that if they wanted to go home, they had the right to do so. We disagree with the Appeals Court’s view that the judge indicated to the jury that he had a say in the matter if they wanted to go home.
The fact that the jury returned fifteen minutes later with a guilty verdict does not point to coercion. It suggests instead that a jury who knew that they did not have to return a verdict did so voluntarily. It is not likely, moreover, that jurors who had stood adamantly divided for two days, unwilling to break the deadlock, would suddenly and involuntarily coalesce on a verdict when they had just learned that they could walk away from the task unless they all agreed to continue.5 *741In matters of this sort we give substantial weight to the discretion of the trial judge who was fully alert to the issues of coercion and the jury’s right to call it quits.
We agree with the Appeals Court’s treatment of other issues, those that it identified as likely to arise at the new trial that it had ordered. Commonwealth v. Jenkins, supra at 144-146. As to the admissibility of the testimony of the witness Debra Howard at the defendant’s probable cause hearing and before the grand jury, see also the discussion in Commonwealth v. Tanso, 411 Mass. 640, 646-649 (1992).
We are left with two issues that the Appeals Court did not consider because they were not likely to arise at the anticipated new trial. The defendant requested that the judge instruct the jury that “[n]o adverse inference against him may be drawn by you because he did not take the witness stand.” The judge instead told the jury that “[t]he fact that the defendant did not testify is absolutely not to be considered by you in your deliberations in this case.” A reference to “no adverse inference” is the preferable form, but the judge’s words are not grounds for reversible error. See Commonwealth v. Thomas, 400 Mass. 676, 679-680 (1987). Cf. Commonwealth v. Feroli, 407 Mass. 405, 410-411 (1990) (G. L. c. 278, § 33E, review).
The judge did not abuse his discretion in asking the jury for their collective, oral response when the defense asked that the. jury be polled. The judge ruled that each juror had answered resoundingly in. agreement with the verdict. A show of hands would be better than a voice vote, however, when a judge declines a request to poll the jurors individually.
Judgment affirmed.
ection 34 reads as follows: “If a jury, after due and thorough deliberation, return to court without having agreed on a verdict, the court may state anew the evidence or any part thereof, explain to them anew the law applicable to the case and send them out for further deliberation; but if they return a second time without having agreed on a verdict, they shall not be sent out again without their own consent, unless they ask from the court some further explanation of the law.”
At one time, there were at least three other States with statutes substantially identical to G. L. c. 234, § 34: South Carolina (S.C. Code Ann. § 14-7-1330 [Law Co-op. 1977]), Florida (Fla. Stat. ch. 54.22 [1965]), and Wisconsin (Wis. Stat. § 270.23 [1973]). The Florida provision was repealed in 1967 (Fla. Laws 1967, ch. 67-254, § 49), and the Wisconsin *738provision in 1976 (repealed by Supreme Court Order, 67 Wis. 2d 585, 760 [1976]).
Other pdstcharge jury communications between the jury and the judge are set forth in the Appeals Court opinion. Commonwealth v. Jenkins, 34 Mass. App. Ct. 135, 138-141 (1993).
We agree with the Appeals Court’s conclusion that the jury’s problem was not whether the defendant was the person who committed the unlawful act but, rather, whether the defendant’s act should be viewed as manslaughter or murder and, if murder, in what degree. See Commonwealth v. Jenkins, supra at 143. One supposition, the most likely, is that the jurors who were holding out for murder in the first degree gave in at the last *741minute when they saw the prospect of no conviction and a new trial. We do not know, of course, what issue divided the jury. Our decision does not rely on any supposition on this point.