_Doctrine of Leading Case of Com. v. Thompson._—In Com. _v._ Thompson (6 Mass., 134), Parsons, C. J., observes: “There was no evidence to induce the belief that the prisoner by his treatment intended to kill or injure the deceased and the ground of express malice must fall. It has been said that implied malice may be inferred from the rash and presumptuous conduct of the prisoner in administering such violent medicines. Before implied malice can be inferred, the judges must be satisfied that the prisoner by his treatment of his patient was wilfully regardless of his social duties, being determined on mischief.... To constitute manslaughter, the killing must have been the consequence of some unlawful act. Now there is no law which prohibits any man from prescribing for a sick person with his consent; and it is not a felony, if through his ignorance of the quality of the medicine prescribed, or of the nature of the disease, or of both, the patient, contrary to his expectations, should die. The death of a man killed by voluntarily following a medical prescription cannot be adjudged felony in the party prescribing unless he, however ignorant of medical science in general, had so much knowledge or probable information of the fatal tendency of the prescription that it may be reasonably presumed by the jury to be an act of wilful rashness at least, and not of honest intention and expectation to cure.” _The Doctrine of the Thompson Case Too Broad._—This lax statement of the law, made by the learned chief justice in this case, has been much doubted and criticised. It appears to be unsound in the length to which it goes in requiring, in order to constitute criminal liability, what may be termed excessive gross carelessness or wilful gross carelessness. It apparently runs counter to the prevailing opinions of the English judges, and to the later decisions of the courts in the United States, although it is followed and approved in Rice _v._ The State, 8 Mo., 561. In Rex _v._ Long (4 Car. & P., 308-310), Park, J., said: “I call it acting wickedly when a man is grossly ignorant and yet affects to cure people, or when he is grossly inattentive to their safety.” So in Rex _v._ Spiller (5 Car. & P., 353), the Court said: “If a person, whether a medical man or not, professes to deal with the life and health of another, he is bound to use competent skill and sufficient attention; and if he causes the death of another through gross want of either he will be guilty of manslaughter.” Bishop, in his work on Criminal Law, lays down the rule that not every degree of carelessness renders a practitioner liable to criminal prosecution, and that it must be gross, or, as more strongly expressed, “the grossest ignorance or most criminal inattention.”[189]