Lat. Not of sound mind. A generic term applicable to all insane persons, of whatsoever specific type the insanity may be and from whatever cause arising, provided there be an entire loss of reason, as distinguished from mere weakness of mind. Somers v. Pumphrey, 24 Ind. 244; In re Beaumont, 1 Wliart. (Pa.) 53; Burn- ham v. Mitchell, 34 Wis. 130; Dennett v. Dennett, 44 N. II. 537, 84 Am. Dec. 97; Potts v. House, 0 Ga. 350, 50 Am. Dec. 329; Jackson v. King, 4 Cow. (N. Y.) 207, 15 Am. Dec. 354; Stanton v. Wetherwax, 10 Barb. (N. Y.) 2G2. Derangement. This term includes all forms of mental unsoundness, except of the natural born idiot. Hiett v. Shull, 3G W. Va. 5G3, 15 S. E. 147. Delusion is sometimes loosely used as synonymous with insanity. But this is incor- rect. Delusion is not the substance but the evidence of insanity. The presence of an in- sane delusion is a recognized test of Insanity in all cases except amentia and imbecility, and where there is no frenzy or raving mad- noss; and In this souse an insane delusion is a fixed belief in tlie mind of the patient of the existence of a fact which has no objective existence but is purely the fignieut of bis imagination, and which is so extravagant that no sane person would believe it under the circumstances of tlie case, tlie belief, nevertheless, being so unchangeable that the patient is incapable of being permanently disabused by argument or proof. The charac- teristic which distinguishes an “insane” delusion from other mistaken beliefs is that it is not a product of the reason but of the imagination, that is, not a mistake of fact In- duced by deception, fraud, insufficient evidence, or erroneous reasoning, but the spon- taneous conception of a perverted imagination, having 110 basis whatever in reason or evidence. Riggs v. Missionary Soc., 35 Hun (N. Y.) 658; Buchanan v. Pierie, 205 Pa. 123, 54 Atl. 583, 07 Am. St. Rep. 725; Gass v. Gass, 3 Humph. (Tenn.) 2S3; Hew v. Clarke, 3 Add. 79; In re Bennett’s Estate, 201 Pa. 485, 51 Atl. 330; In re Scott’s Estate, 128 Cal. 57, 60 Pac. 527; Smith v. Smith, 48 N. J. Eq. 566, 25 Atl. 11; Guiteau’s Case (D. C.) 10 Fed. 170; State v. Lewis, 20 Nev. 333, 22 Pac. 211; I11 re White, 121 N. Y. 400, 24 N. E. 935; Potter v. Jones, 20 Or. 239, 25 Pac. 709, 12 L. R. A. 101. As to the distinctions between “Delusion” and “Illusion” and “Hallucination,” see those titles. Forms and varieties of insanity. Without attempting a scientific classification of the numerous types and forms of insanity, (as to which it may be said that there is as yet no final agreement among psychologists and alienists either as to analysis or nomenclature,) definitions and explanations will here be appended of the compound and descriptive terms most commonly met with in medical jurisprudence. And, first, as to the origins or causes of the disease: Traumatic insanity is such as results from a wound or injury, particularly to the head or brain, such as fracture of the skull or concussion of the brain.