Double

(dub' -I). Two-fold. In pairs. D. Athetosis, a manifestation of infantile spastic paraplegia. D. Chin. See Buccu/a. D. Consciousne , periodic amnesia; a periodic failure of memory involving all the intellectual functions and the character of the individual; that condition in which a patient seems to have two distinct but alternating lives; it is seen mostly in somnambulists and hypnotics. D. Flap Amputation. See Amputation . D. Hearing. See Diplacusis . D. Monsters. Same as Composite Monsters, q.v. D. Personality, an abnormal condition in which the subject feels as if he were two distinct personalities, the one alternating continually with the other. It is a symptom of insanity and of poisoning by certain drugs. D. Staining, in microscopy, the impregnation of a structure with two colors in order to show its details. Bacteriologically the application of such staining-reagents as will stain the spores one color and the rods another. D. Touch, the exploration of the vaginal and rectal walls by inserting the thumb into the one cavity, and the index fingei into the other, so that, e.g., the presence of any abnormal growth may be ascertained. D. Vinegar. See Vinegar. D. Vision. See Diplopia . D. Vitriol, a mixture of copper and iron sulphates crystallized together. D. Voice. See Diphthong i a . D. Wedge, an instrument used in dentistry for removing an artificial crown from the root of a tooth upon which it has been set.