These are very numerous. The following are the principal forms:

Onomatomania: an irresistible desire to pronounce certain words, sometimes obscene words (coprolalia).

Arithmomania: an irresistible desire to count certain objects, add certain figures, etc.

Kleptomania: a morbid impulse to steal objects which are entirely useless, or which the subject can easily pay for.

Dipsomania: an irresistible impulse to drink alcoholic beverages of every description (wines, liquors, eau-de-Cologne, spirits of camphor, etc.), occurring in a person of temperate habits, who may at other times have even a dislike for alcohol. The attacks may recur, and the dipsomaniac may become an alcoholic. He differs radically from the ordinary drunkard, however. "The one is alienated before beginning to drink, the other (the alcoholic) becomes alienated because of his drinking " (Magnan).

Pyromania; Suicidal and Homicidal Impulses:1 These three obsessions are of equal gravity from a social standpoint and may be placed in the same group. The first consists in a morbid impulse to set buildings on fire; the other two require no definition.

In some cases the patients obey their fatal impulses.

1 Vallon. Obsession homicide. Ann. med. psych., Jan.-Feb., 1896. - Carrier. Contribution & l'etude des obsessions et des impulsions & l'homicide et au suicide. These de Paris, 1900.

Vallon has reported a case of a young man who, having a homicidal obsession, struggled against the impulse, but was finally overcome and yielded.

Such cases, however, are rare. Usually the patients succeed by various, and at times singular, means in resisting their impulse. Many take flight at the moment of the paroxysm; others request to be restrained or held; still others voluntarily have themselves committed. One patient of Joffroy's, while walking in the street, was seized with the idea of throwing her child under the wheels of a passing car; she entered a wine merchant's shop, placed her child upon the counter and took flight.

Similarly, it is rare for patients to yield to a suicidal impulse. The means they make use of to escape their obsessions are innumerable. A woman possessed by the idea of throwing herself out of the window had all the windows of her house protected with iron bars. Another such unfortunate condemned herself never to cross the Seine river to prevent herself from yielding to the impulse to drown herself.

As to family suicide, it is almost never the result of an obsession, but of a fixed idea which is developed by imitation.