quences and the punishment to which they rendered themselves liable.

The knowledge of right and wrong, the consciousness of criminality, the realization of liability to punishment being possessed by insane persons, have in recent times led to the claim that only those individuals should be held irresponsible who have lost all power of control over their actions. The test of irresponsibility may be said to be, in this view then, the proof of a want of will-power— the power of choosing between good and evil being destroyed by disease. The accused would not, however, be held irresponsible if the crime was committed under the influence, temporarily, of liquor, or of a violent burst of passion, the latter condition being often attributed to impulsive or emotional insanity-a form of mental disorder for the existence of which there is no evidence.

Not unfrequently, medical experts in insanity are also called upon by the courts to state whether a criminal under sentence of death is insane, in order to stay execution.

Medico-Legal Terms Defined.—In connection with cases of insanity certain legal terms are frequently made use of rather loosely, such as illusions, hallucinations, delusions, lucid intervals; but these terms should be defined, in order that the medical examiner may be qualified to answer intelligently in court questions involving their use. An illusion may be defined as a false impression due to a material basis, the impression being, however, distorted through some defect in the avenue of sense, or of the perceptive centre, as in the mistaking a tree for a man at night. Hallucinations differ from illusions in being perverted impressions, but without a material basis, at least immediately. A person afflicted with this

disorder imagines he hears strange voices, sees people where there are none, etc. Delusions may be defined as beliefs in something purely imaginary, as when a pauper imagines he has become a millionaire, or when a millionaire believes he has lost everything. Should a delusion be so strong as to affect the disposal of an estate by will, as when a parent has come to hate, for no reason, his children, whom he had formerly loved, the capacity to make a will should be disputed. If, however, the delusion with which an individual is affected is not connected in any way with the act about to be performed, the responsibility of such a person would not be questioned. By a lucid interval is meant a temporary intermission of insanity, during which period the individual recovers his reasoning powers. It may last for months, weeks, or only for a few minutes. It not unfrequently occurs in mania, and occasionally in dementia, but never in idiocy or imbecility. During a lucid interval the law recognizes the power of a person to sign a contract, to make a will, to exercise civil rights, etc.

Feigned Mental Diseases are usually considered by writers upon medical jurisprudence separately from feigned bodily disorders. The expression mental disease, whether feigned or not, regarded as something distinct from bodily disease, is, however, an unphilosophical one, as there can be no disease, mental or otherwise, without some underlying change in organization. Whatever may be the psychological views held as to the nature of mind, whether it be regarded as an entity, a something independent-superadded to the body—an almost obsolete view now-or as a function of the nervous system, and, more especially in man, of the cerebral portion of it, a view accepted by all physiologists, is immate

rial, at least as far as it affects the view universally accepted that a healthy mind is always found in a healthy body.

In connection with the subject of insanity, and as a mere matter of convenience, the subject of feigned mental diseases may be as appropriately considered here as elsewhere. Mental diseases are most frequently feigned by criminals, in the hope of escaping imprisonment or capital punishment. It is frequently very difficult to prove in such cases that the criminal is malingering, insanity in one form or another being so well imitated. The criminal may keep up the deception for months, during which he may rave, beat the door, tear up his clothes and bedding, indulge in the foulest language and dirty habits, conduct himself in so outrageous a manner as to necessitate the use of a strait-jacket-and even then not confessing the fraud. In the investigation of these cases it is most important to determine whether the individual has any motive in simulating insanity-such as that of escaping punishment for some crime. Another point to be determined is, whether the particular crime committed was incidental to a life of crime, perhaps the last act of a long series such as a hardened criminal, but not an insane person, might be expected to commit. Another point to be ascertained is, whether the culprit endeavored to escape, it being well known that insane persons exhibit a perfect indifference to the consequences of their acts. It should be also remembered that insane persons never admit that they are insane; whereas, those simulating insanity are always anxious to impress every one with the fact that they are really insane. Of the different forms of insanity mania is that which is usually feigned by malingerers. As all maniacs are popularly supposed to be violent, the

malingerer in attempting to simulate mania is particularly so, usually overacting the part; while the impostor, however, usually sleeps soundly, the maniac is as violent by night as by day. Dementia is less rarely simulated than mania, as it is more difficult to imitate, while the fraud is more readily recognized, being at once disclosed by the slightest reasoning power manifested by the individual.

PART II. TOXICOLOGY.

CHAPTER I.

Frequency of Death from Poisoning-Definition of a Poison-Mode of Action of Poisons-Influence exerted on Action of Poisons by Habit, Sleep, Disease, etc.-Evidences of Poisoning derived from Symptoms, Post-mortem Appearances, Chemical Analysis, Experiments upon Animals, Circumstantial Evidence-Character of the Evidence the Chemical Expert may be Expected to give in Cases of Poisoning.

In most cases of poisoning the duty of the physician making the post-mortem examination is usually limited simply to removing the stomach, intestines, etc., of the deceased person supposed to have been poisoned, and placing them in the hands of the chemist especially employed by the Commonwealth to make an examination of their contents, with the view of determining the cause of death. It is important, however, that every physician should have some knowledge of toxicology; that is, of the symptoms of poisoning, the nature of poisons, their antidotes, etc., as well as of the medical relations of the subject. The subject of toxicology, like that of insanity, is such an extensive one that its thorough consideration would demand a special treatise, far exceeding the scope of the present work. All that the author can hope to accomplish within his prescribed limits is to point out, in a very general way, what his own experience suggests as to the kind of toxicological knowledge the medical expert, who is not an analytical chemist, should possess.