IDIOCY, med. jur. That condition of mind, in which the reflective, or all or a part of the affective powers, are either entirely wanting, or are manifested to the least possible extent.
2. Idiocy generally depends upon organic defects. The most striking physical trait, and one seldom wanting, is the diminutive size of the head, particularly of the anterior superior portions, indicating a deficiency of the anterior lobes of the brain. According to Gall, whose observations on this subject are entitled to great consideration, its circumference, measured immediately over the orbiter arch, and the most prominent part of the occipital bone, is between 11¥ and 14¥ inches. Gall, sur les Fonctions, p. 329. In the intelligent adult, it usually measures from 21 to 22 inches. Chit. Med. Jur. 248. See, ou this subject, the learned work of Dr. Morton, of Philadelphia*, entitled Crania Americana. The brain of an idiot equals that of a new born infant; that is, about one-fourth, one-fifth, or one-sixth of the cerebral mass of an adult's in the enjoyment of his faculties. The above is the only constant character. observed in the heads of idiots. In other respects their forms are as various as those of other persons. When idiocy supervenes in early infancy, the head is sometime remarkable for immense size. This unnatural enlargement arises from some kind of morbid action preventing the development of the cerebral mass, and producing serous cysts, dropsical effusions, and the like.
3. In idiocy the features are irregular; the forehead low, retreating, and narrowed to a point; the eyes are unsteady, and often squint the lips are. thick, and the mouth is generally open; the gums are spongy, and the teeth are defective; the limbs are crooked and feeble. The senses are usually entirely wanting; many are deaf and dumb, or blind and others are incapable of perceiving odors, and show little or no discrimination in their food for want of taste. Their movements are constrained and awkward, they walk badly, and easily fall, and are not less awkward with their hands, dropping generally what is given to them. They are seldom able to articulate beyond a few sounds. They are generally affected with rickets, epilepsy, scrofula, or paralysis. Its subjects seldom live beyond the twenty-fifth year, and are incurable, as there is natural deformity which cannot be remedied. Vide Chit. Med. Jur. 345; Ray's Med. Jur. c. 2; 1 Beck's Med. Jur. 571 Shelf. on Lun. Index, h. t.; and Idiot.