The extreme distortion of face produced by acute mania, or melancholia in its higher degree, is easily recognised. It may, however, be needful to distinguish it from the expression of cerebral inflammation, or of fever. The distinguishing characteristics of cerebral inflammation attended by maniacal symptoms are, a greater suffusion of countenance, a firm knitting of the brows expressive of intense pain, and a fierce, prominent, and blood-shot eye. It is in meningitis rather than in mania that it may be truly said—“And each strained ball of sight seemed bursting from his head.” The patient suffering from cerebral inflammation has a motiveless ferocity of aspect, rarely met with in pure mania. The stage of effusion in meningitis, and all the stages of some forms of deep-seated cerebral inflammation, in which the meninges are not affected, require to be distinguished from dementia, rather than from mania. The history of the case, however, and the affection of the muscular system, will generally render the diagnosis easy.