The subject is important at this day only as serving to define the nature of the "cruel and unusual punishments" prohibited by the thirty-first article of the Declaration of Rights, in our state Constitution, since this mode of punishment, having continued after the adoption of the Constitution, cannot have been considered by the framers of that instrument either as "cruel" or "unusual" in the sense in which they used these words. The particulars of the crime for which the malefactors, Mark and Phillis, were executed are briefly as follows: Captain John Codman, a thrifty saddler, sea-captain, and merchant, of Charlestown, was the owner of several slaves whom he employed either as mechanics, common laborers, or house servants. Three of the most trusted of these, Mark, Phillis, and Phebe,--particularly Mark,--found the rigid discipline of their master unendurable, and, after setting fire to his workshop some six years before, hoping by the destruction of this building to so embarrass him that he would be obliged to sell them, they, in the year 1755, conspired to gain their end by poisoning him to death. In this confederacy some five or six negroes belonging to other owners were more or less directly implicated. Mark, the leader, was able to read, and signed his examination, hereafter referred to, in a bold, legible hand. He professed to have read the Bible through, in order to find if, in any way, his master could be killed without inducing guilt, and had come to the conclusion that according to Scripture no sin would be committed if the act could be accomplished without bloodshed. It seems, moreover, to have been commonly believed by the negroes that a Mr. Salmon had been poisoned to death by one of his slaves, without discovery of the crime. So, application was made by Mark, first to Kerr, the servant of Dr. John Gibbons, and then to Robin, the servant of Dr. Wm. Clarke, at the North End of Boston, for poison from their masters' apothecary stores, which was to be administered by the two women. Essex, the servant of Thomas Powers, had also furnished Mark with a quantity of "black lead" for the same purpose. This was, unquestionably, not the harmless plumbago to which that name is now usually given, but galena, or _plumbum nigrum_, a native sulphuret of lead, probably used for a glaze by the potters of Charlestown. Kerr declined to have any hand in the business; but Robin twice obtained and delivered to Mark a quantity of arsenic, of which the women, Phebe and Phillis, made a solution which they kept secreted in a vial, and from time to time mixed with the water-gruel and sago which they sometimes gave directly to their victim to eat, and at other times prepared to be innocently administered to him by one of his daughters. They also mixed with his food some of the "black lead," which Phillis seems to have thought was the efficient poison, though it appeared from the testimony that he was killed by the arsenic.