Although it cannot be difficult to form a diagnosis between the ebullitions of passion, the extravagance of intoxication, or the delirium of fever, and the violence of deportment arising from insanity, yet it may in some cases be not easy to discriminate between this latter condition and that which is associated with excessive enthusiasm; nor is it always easy to discriminate between eccentricity and insanity; do we not, says _Dr. Male_, see a wretch disinherit his own children, who have committed no fault, and bestow his wealth upon a stranger? another who prefers poverty and rags, and communion with vagabonds, to the social intercourse and proffered kindness of his friends and relations? yet who shall pronounce them to be insane? that they are so, there can be no doubt, and their disease is perhaps of the most unfortunate character, for all their other actions being consistent with sound reason, it is difficult to convince a jury of their insanity, and to divest them of the power of heaping ruin upon their families, and disgrace upon themselves. The bodily marks which distinguish the insane are, a peculiar cast of countenance, familiar to those versed in the malady; a quick, oftentimes protruded and glistening eye; the body is generally costive; in some cases the insane person is enabled to sustain cold with impunity, and he is insensible to the agency of ordinary stimuli; and the stomach and bowels, from deficiency of irritability, require large doses of medicine to move them; among the physical phenomena of insanity, _M. Esquirol_ observes that few are more constant or remarkable than want of sleep, and that peculiarly disagreeable odour from the body, as well as the excretions of the patients, which impregnates the clothes and bedding. They are devoured with a burning internal heat; and generally have a voracious appetite, and are afflicted with pain in some organ or part, especially the head, the chest, or the abdomen, which the unhappy sufferers are ready to attribute to the malevolence of their enemies. In deciding upon that species of insanity which is termed _Melancholia_, we must be cautious in not confounding its symptoms with those of _Hypochondriasis_, which is to be regarded as strictly a bodily malady; the following remarks of _Dr. Cullen_ may tend to direct our judgment upon this interesting subject.