If a physician gives a person a potion without any intent of doing him any bodily hurt, but with an intent to cure or prevent a disease, and contrary to the expectation of the physician it kills him, this is no (culpable) homicide, and the like of a chirurgeon; _1 Hale_, _P. C._ 429; _4 Bl. Comm._ 197. But query if he were not a regular physician or surgeon? on this there appears to be some difference of opinion; it was anciently holden that if one, that is not of the mystery of a physician or surgeon, take upon him the cure of a man, and he dieth of the potion or medicine, this is covert felony. _Si un que nest physition ou surgeon emprent sur luy un cure, que murrust in sa main, que cest felonie_; _Stanford’s Pleas of the Crown_, _cap._ 9; _Fitzherbert_, _tit. coron._ _p._ 311; _Briton_, _fol._ 14; _Lombard_, _Eiren. tit. Felonie_ saith thus; that _Thorpe_, _43 Ed. 3_, 33, saith he knew one to be indicted accordingly. _Dalton_, _p._ 470, queries this case, as it is difficult to determine the actual cause of death, and there appeareth no will to do harm, but rather to do good, and “the _34 Hen. 8_, _c._ 8, leaveth so great a liberty of such practice to unskilful persons, that it will be hard now to make it felony.” Now the statute of _Henry the eighth_ applies only to the cure of certain diseases or sores, particularly specified, and others like to the same, by external applications, and to drinks for the stone, strangury, or agues, provided (if the preamble may be relied on) “the said persons have not taken any thing for their pains or cunning, but have ministered the same to the poor people only, for neighbourhood, and God’s sake, and of pity, and charity;” in such sense the act is reasonable even to this day, much more then, when from the scarcity of regular practitioners, the charitable in the country were frequently called upon to administer on emergencies, where no medical aid could be procured; but surely this act can never have been intended to warrant the administration of dangerous medicines, arsenic, corrosive sublimate, or cantharides, such indeed as may be fairly classed as absolute poisons, except when in skilful hands, nor the performance of surgical operations. _Dalton_ indeed adds “But if a smith or other person (having skill only in dressing or curing the diseases of horses or other cattle) shall take upon him the cutting, or letting blood, or such like cure of a man, who dieth thereof, this seemeth to be felony; for the rule is, _quod quisque norit, in hoc se (non) exerceat_.” And if it were otherwise, great evils might arise; for persons intending to commit murders, need only cover their design by a pretence of administering medicine;[507] thus in _Vaux’s_ case, the professed purpose of administering the cantharides, was not illegal, yet the prisoner was found guilty of murder. In _Donellan’s_ case, what would a plea have availed, that the chemical principle of laurel water was, in