Great importance is attributed to the immediate influence of the binocular function in establishing a perfect equi librium after tenotomy while the tendon is more or less completely detached from the eyeball. This function compels the eye to occupy the position in which single vision is possible, and thereby helps to determine the point at which reattachment of the tendon shall take place. If, on the other hand, the eye is bandaged, it assumes its position of rest; there is no tension or straining of the tendinous fibres induced by the desire for binocular single vision, and the reattach ment may take place at a point by no means the most favorable for that pur pose. F. W. Marlow (Ophthalmic Record, p. 117, '97).
The means employed in the educative treatment of strabismus include: 1. The occlusion of one eye by a shade or pad. Usually it is the "good" eye which is occluded to compel the use of the squint ing eye, to promote its true fixation, and to improve its visual acuteness. But if it becomes necessary at times to use the "good" eye, the shade should be trans ferred to the other. For the squinting eye had better be in darkness than con tinue to form images which the brain does not perceive.
2. liar-reading—that is, reading with a ruler or something of the kind held be tween the page and the face, so that a part of each line is hidden from either eye alone, and the two eyes must be used to read the whole of it. This helps the recovery of binocular vision by making the patient conscious each instant of the deviation, and by compelling the move ments necessary to fix with the squinting eye. It is not applicable to very young children.
3. The use of "fusion-tubes" is use ful for children who cannot read. These are two tubes each of which has a eon. vex lens in the end held toward the eye, and a shutter with a small hole covered with ground-glass in the other. The dis tance from the lens to the shutter is the focal distance of the lens. The tubes are connected by chains, so that they can be turned in the direction of the two visual axes in any case of squint. The exercise with them consists in making the two holes appear as one, and in keep ing them fused as the direction of the tubes is slowly changed. This cultivates the faculty of binocular fusion. Priest ley Smith (Ophthalmic Review, June, TS).
Analysis of 700 cases showed that it is impossible to determine what lenses are to he prescribed in ametropia unless a thorough knowledge of the perform ance of the muscular function is ob tained. The addition of a vertical prism
to the patient's curvature correction has often been fruitful of relief. The Mad dox rod considered of great value in these cases. Hyperphoria occurs in about one-sixth of the patients, but only becomes worthy of special notice in one-fifth of the refraction eases. In 33 per cent. of all eases it becomes more manifest after the thirtieth year. Cor rection with prisms is of service in about 50 per cent. of all the eases. Exercising insutlicient convergence and repressing an excess of convergence often bring about relief of the symp toms, which frequently are neuralgia, photophobia, and physical tiredness after continuous near work, the latter symptom generally being in dispropor tion to the amount of work done. As a last resort, tenotomy of one of the vertical muscles will have to be per formed. Wendell Reber (Phila. Med. Jour.. from Jour. Amer. Med. Assoc., Jan. 19, 1901).
STRONTIUM.—Strontium is an alkali metal haying a yellow color. It oxidizes quickly on exposure to the air, and must be kept under naphtha, benzene, or other liquid free from oxygen, like the other alkali metals. Strontium forms salts with the acids and with bromine, chlo rine, fluorine, etc. Three salts are offi cial: the bromide, the iodide, and the lactate.
Strontii bromidum (U. S. P.) occurs in long, deliquescent colorless needles, having a bitter, saline taste. It is solu ble in alcohol, in 1.05 parts of cold and in 0.5 part of boiling water. This salt must be kept from the air.
Strontii iodidum (U. S. P.) occurs in white, or faint-yellowish, microcrystal line, deliquescent powder or in almost colorless, hexagonal plates, having a bit ter, saline taste. It is soluble in alcohol and in ether, in 0.6 part of cold and in 0.27 part boiling water. This salt must be kept from the light and air.
Strontii lactas (U. S. P.) occurs as a white, granular powder, having a slightly-bitter taste. It is soluble in alcohol and in 4 parts of cold and in 0.5 part of boiling water. This salt is unaffected by the air.
Strontii acetas occurs as a white, crys talline powder, soluble in water. It is used as an anthelmintic and intestinal tonic. Dose, to grain.