Under the term 'mania' are included all those forms of mental unsoundness in which there is undue excitement. It is divided into general, intellectual, and moral, and each of the two latter classes again into general and partial.

General Mania affects the intellect as well as the passions and emotions. Mania is usually preceded by an incubative period in which the patient's general health is affected. The duration of this period may vary from a few days to fifteen or twenty years. When the disease is established, the patient has paroxysms of violence directed against himself as well as others. He tears his clothes to pieces, either abstains from food and drink or eats voraciously, and sustains immense muscular exertion without apparent fatigue. The face becomes flushed, the eye wild and sparkling; there is pain, weight, and giddiness in the head, with restlessness.

General Intellectual Mania, attacking the intellect alone, is rare; but some one emotion or passion, as pride, vanity, or love of gain, may obtain ascendancy, and fill the mind with intellectual delusions.

A delusion may be defined as a perversion of the judgment, a chimerical thought; an illusion, an incorrect impression of the senses, counterfeit appearances; hence we speak of a delusion of the mind, an illusion of the senses. Lawyers lay great stress on the presence of delusions as indicative of insanity. An hallucination is a sensation which is supposed by the patient to be produced by external impressions, although no material object acts upon his senses at the time.

Partial Intellectual Mania, or Monomania, also called Melancholia, is a form of the disease in which the patient becomes possessed of some single notion, contradictory alike to common-sense and his own experience.

General Moral Mania.—This is a morbid perversion of the natural feelings, affections, inclinations, temper, habits, moral dispositions, and natural impulses, without any remarkable disorder or defect of the intellect, or knowing and reasoning faculties, and particularly without any insane illusion or hallucination. It is often difficult to distinguish this form of mania from the moral depravity which we associate with the criminal classes.

Partial Moral Mania—Paranoia—Delusional Insanity.—In this form one or two only of the moral powers are perverted. Delusions are always present, and very frequently are those of persecution. The patient's conduct is dominated by his delusion; thus murder and suicide may be committed. There are several forms:

Kleptomania, a propensity to theft; common in women in easy circumstances. Dipsomania, or Oinomania, an insatiable desire for drink. Morphinomania, a craving for morphine or its preparations. Erotomania, or amorous madness. When occurring in women this is also called Nymphomania, and in men Satyriasis. It consists in an uncontrollable desire for sexual intercourse. Pyromania, an insane impulse to set fire to everything. Homicidal mania, a propensity to murder. Suicidal mania, a propensity to self-destruction. Some consider suicide as always a manifestation of insanity.

Insanity of Pregnancy.—This may show itself after the third month of pregnancy in the form of melancholia. It is not recovered from until after delivery.

Puerperal Mania.—This form of mania attacks women soon after childbirth. There is in many cases a strong homicidal tendency against the child.

Insanity of Lactation comes on four to eight months after parturition, either as mania or melancholia. The mother may repeatedly attempt suicide.

Mania with Lucid Intervals.—In many cases mania is intermittent or recurrent in its nature, the patient in the interval being in his right mind. The question of the presence or absence of a lucid interval frequently occurs where attempts are made to set aside wills made by persons having property. In these cases the law, from the reasonableness of the provisions of the will, may assume the existence of the lucid interval. A will made during a lucid interval is valid. When an attempt is made to set aside the provisions of a will on the ground of insanity in a person not previously judged insane, the plaintiff must show that the testator was mad; when the provisions of the will of a lunatic are attempted to be upheld, the plaintiff must show that the will was made during a lucid interval.

A testator is capable of making a valid will when he has (1) a knowledge of his property and of his kindred; (2) memory sufficient to recognize his proper relations to those about him; (3) freedom from delusions affecting his property and his friends; and (4) sufficient physical and mental power to resist undue influence. The fact of a man being subject to delusions may not affect his testamentary capacity. He may believe himself to be a tea-kettle, and yet be sufficiently sound mentally to make a valid will.

Undue Influence.—Persons of weak mind or those suffering from senile dementia are often said to have been unduly influenced in making their wills, and subsequently their dispositions are disputed in court. Before witnessing the will made by such a person, the medical man should satisfy himself that the testator is of a 'sound disposing mind.' This he will do by questioning, and his knowledge of the home-life of the patient will either confirm or set aside the idea of influence.

A person who is aphasic may be competent to make a will. He may not be able to speak, but may understand what is said to him, and may be able to indicate his wishes by nods and shakes of the head. Ask him if he wishes to make a will, then inquire if he has £10,000 to leave, then if he has £100, and in this way arrive approximately at the sum. Then ask him if he wishes to leave it all to one person. If he nods assent, ask if it be to his wife or some other likely person. If he wishes to divide it, ascertain his intention by definite questions, and, having ascertained his views, commit them to writing, read the document over to him, and ask if it expresses his intentions. That being settled, a mark which he acknowledges in the presence of two witnesses, preferably men of standing, will constitute a valid document.

In certain forms of neurasthenia, the 'phobias' are common, but must not be regarded as evidence of insanity. 'Agoraphobia' is the fear of crossing an open space, 'batophobia' is the fear that high things will fall, 'siderophobia' is the fear of thunder and lightning, 'pathophobia' is the fear of disease, whilst 'pantophobia' is the fear of everything and everybody.

Epilepsy in Relation to Insanity.—The subjects of this disease are often subject to sudden fits of uncontrollable passion; their conduct is sometimes brutal, ferocious, and often very immoral. As the fits increase in number, the intellect deteriorates and chronic dementia or delusional insanity may supervene. (1) Before a fit the patient may develop paroxysms of rage with brutal impulses (preparoxysmal insanity), and may commit crimes such as rape or murder. (2) Instead of the usual epileptic fit, the patient may have a violent maniacal attack (masked epilepsy, epileptic equivalent, psychic form of epilepsy). (3) After the fit the patient may perform various automatic actions (post-epileptic automatism) of which he has no subsequent recollection. Thus the patient may urinate or undress in a public place, and may be arrested for indecent exposure. Epileptics who suffer from both petit and grand mal attacks are specially liable to maniacal attacks. Such insanity differs from ordinary insanity in its sudden onset, intensity of symptoms, short duration and abrupt ending. To establish a plea of epilepsy in cases of crime, one must show that the individual really did suffer from true epilepsy, and that the crime was committed at a period having a definite relation to the epileptic seizure.

Alcoholic Insanity.—This may occur in three forms:

1. Acute Alcoholic Delirium (mania a potu), due to excessive amount of alcohol consumed.
2. Delirium Tremens, due to long-continued over-drinking. The patient suffers from horrible dreams, illusions, and suspicions, which may lead him to attack people or commit suicide.
3. Chronic Alcoholic Insanity. Loss of memory is the chief symptom, with paralysis of motion, hallucinations and delusions of persecution.

Responsibility for Criminal Acts.—To establish a defence on the ground of insanity, it must be proved that the prisoner at the time when the crime was committed did not know the nature and quality of the act he was committing, and did not know that it was wrong. At the present time, however, the power of controlling his actions is usually made the test.

The plea of insanity is brought forward, as a rule, only in capital charges, so that the prisoner, if found guilty, will escape hanging. If proved 'guilty, but insane,' the person is sentenced to be kept in a criminal lunatic asylum 'during His Majesty's pleasure.'