IDIOCY. In Medical Jurisprudence. Men tal deficiency of varying grades down to ex treme stupidity resulting/ from imperfect de velopment or disease of the nervous centers either prenatal or occurring before the evolu tion of the mental faculties in childhood. Brush in Cyclopwdia of Diseases of Children. A condition of defective brain-development. See 3 Witth. & Beck. Med. Jur. 364 et seq.; 2 Ham. Leg. Med. 80 et seq.
It always implies some defect or disease of the brain, which is generally smaller than the standard size and Irregular in its shape and proportions. Hydrocephalus Is an occasional cause of idiocy. The senses are very imperfect at beat, and one or more are often entirely wanting. None can articu late more than a few words;' while many utter only cries or muttered sounds. Some make known their wants by signs or sounds which are Intel those who have charge of them. The bead, the features, the eXpression, the movements,—a? convey the idea of extreme mental deficiency. The reflective' faculties are entirely wanting, whereby they are utterly incapable of any effort of reason ing. The perceptive faculties exist in a very limit ed degree, and hence they are rendered capable of being improved somewhat by education, and re deemed, in some measure, from their brutish con dition. They have been led into habits of propriety and decency, have been taught some of the elements of /learning, and have learned some of the coarser industrial occupations. The moral sentiments, such as self-esteem, love of approbation, veneration, be nevolence, are not unfrequently manifested ; while some propensities, such as cunning, destructiveness, sexual impulse, are particularly active.
In some parts of Europe a form of idiocy prevails endemically, called cretinism. It is associated with disease or defective development of other organs besides the head. Cretins are short in stature, their
limbs are attenuated, the belly tumid, and the neck thick. The muscular system is. feeble, and their voluntary movements restrained and undecided. The power of language is very imperfect, if not en tirely wanting. In the least degraded forms of this disease the perceptive powers may be somewhat developed, and the individual may evince. some talent at music or construction. In Switzerland they make parts of watches. Cretinism like idkicy is frequently congenital, and its causation is very obscure.
Absence of the Internal secretion of the thyroid gland is a common cause of the so-called sporadic cretinism which exists the world over.
Both idiocy and cretinism exhibit various degrees of mental deficiency, but they never approximate to any description of men supposed to be rational, nor can any amount of education efface the chasm which separates them from their better-endowed fellow-men. The older law-writers, whose observa tion of mental manifestations was not very pro found, thought It necessary to have some test of idiocy; and accordingly, Fitzherbert says, if be" hsve sufficient understanding to know and under stand his letters, and to read by teaching or infor mation, he is not an idiot. Nature Brevium 583. Again, he says, a man is not an idiot if he hath any glimmering of reason, so that he can tell his par ents, his age, or the like common matters. The in ference was, no doubt, that such a man is respon sible for his criminal acts. At the present day, such an idea would not be entertained for a mo ment; nor are we aware of any case on record of an idiot suffering capital punishment. Sea INSAN ITY ; DEMENTIA ; IMBECILITY.