Page:Popular Science Monthly Volume 17.djvu/152

 obey the will; the failure giving rise to sudden interruptions of the voice, while the articulating power may remain unaffected. As in other impediments of speech the harmonious action of the muscles engaged in articulation may be disturbed, in this case the disordered coordination affects the voice only. The movements required for articulating syllables are perfectly performed, but the production of vocal sound is at intervals suspended. The affection may cause the patient to stop speaking, as he is conscious of what he sometimes calls a "catch in the breath"; or he may continue a sentence from which some words will be lost to the listener. Isolated sounds are usually correctly articulated, even by confirmed stammerers; and the same is true in these vocal impediments; but it is in the rapid emission of certain combinations of sounds that the sudden arrest is liable to occur. Dr. James states that after long and patient observation of the action of the vocal cords, aided by appliances specially devised for the purpose, he was able to obtain ocular demonstration of the presence of the affection; and, once distinguished from other impediments of speech, he found it amenable to treatment.

Stature of the Japanese.—Mrs. Chaplin Ayrton, M. D., has recently published the results of nearly three hundred observations of the height and span of the Japanese. She found the average height to be five feet three inches, and the span four feet eleven inches. In the case of twenty-four women, taken at random, the tallest was a trifle over five feet two inches, and the average was four feet eight inches, with an average span of four feet six inches. The shortness of the span as compared with the height is a general characteristic that is especially marked in the case of the women. Sixty per cent, of the persons measured had the span less than the height, and thirty-three per cent, greater than the height, while in only 6·8 per cent, were the height and span equal. Climate can hardly be made to account satisfactorily for the smallness of the Japanese, for they live in a temperate region, though it is subject to sudden and marked changes. The general use of charcoal-braziers for heating may have something to do with it, by causing them to inhale the carbonic oxides. The characteristic of their food is the rarity of meat and the abundance of salt. Many of the additional causes of the smallness of the Japanese may be so remote as to cease to affect the nation except by hereditary influence.

Aids to Hearing: the Osteophone.—The audiphone and dentaphone, which have been extensively advertised as instruments for aiding the hearing of the deaf, have been objected to on account of mechanical difficulties in using them. The audiphone to a certain extent obscures the features of the person using it the dentaphone is held more or less in the line of vision; and both instruments require the constant service of the hands when in use. Dr. Charles II. Thomas, of Philadelphia, has devised an instrument that is intended to obviate these difficulties, which he has named the osteophone. It consists of a large receiving diaphragm attached in an arched form to a rod of wood or metal, which rod is bent in the form of a pipe-stem. One end of the rod is to be held firmly between the teeth as a pipe is held, leaving the hands of the listener free for other occupations, while he is able to hear all the sounds that may be conveyed by the diaphragm. The diaphragm is below and away from the face, and comparatively inconspicuous. The inventor suggests that ornamental fans, coated with shellac and tipped with ivory or hard rubber, may be made to answer fairly well for occasional use, but will be unsatisfactory if depended on permanently. Fuller's cardboard, treated with shellac varnish, and dried, makes one of the best of resounding mediums. A piece of yellow pine turned into a trumpet-shape, and placed in the mouth of the deaf person, will convey a good volume of sound, and even a string connecting the upper teeth of the persons conversing perceptibly aids the sound. A small rod of hard wood, connecting the teeth of the two persons, gives a volume of sound many times exceeding that transmitted either by the audiphone or the dentaphone. Sensible vibrations, produced by and corresponding to those of the voice, are propagated in the hard palate and base of the skull of persons speaking in the ordinary tones; and the rod