Page images
PDF
EPUB

BINOCULAR PERSPECTIVE

63

Decenter the small circles the other way (Fig. 14) and we reverse the position of the cone.

It has been shown by Worth, of London, that

FIG. 13. DIAGRAM TO DEMONSTRATE BINOCULAR PERSPECTIVE; THE SMALLER END SHOULD APPEAR TO BE TOWARD THE OBSERVER.

the movements of the two eyes are largely controlled by a fusion sense, and that a faulty development of this faculty is frequently the cause of cross eyes. If taken early many of these cases can be cured without operation by developing the fusion faculty.

For this purpose he has devised an instrument called the amblyoscope, with which even a cross

[ocr errors]

DIAGRAM TO DEMONSTRATE

[ocr errors]

FIG. 14. BINOCULAR PERSPECTIVE; THE LARGER END SHOULD APPEAR TO BE TOWARD THE OBSERVer.

eyed person can fuse simple images. This he cannot do with the ordinary stereoscope.

This instrument does not allow of one's watching the eyes while they are being exercised. In order I Squint : : Its Causes, Pathology, and Treatment.

to observe the motions of the eyes and make it possible to measure exactly the deviation during binocular vision, the author has devised a stereoscopic attachment to a well-known instrument called the phoro-optometer. With this instrument the strength of the prisms may be varied to suit the individual case.

[graphic][subsumed][subsumed][subsumed]

FIG. 15. AUTHOR'S STEREOSCOPIC ATTACHMENT TO THE PHORO-OPTOMETER.

In order to ensure the use of both eyes for one's reading, writing, etc., and other near work, the author has contrived a control device which consists of a band of blackened aluminum, held by a headband midway between the eyes and the printed page. The fields seen by the two eyes overlap, and if binocular vision exists one experiences no difficulty in reading thru the obstruction, but if either eye is

[blocks in formation]

suppressed the band obscures some of the letters in each line.

Without entering into a discussion of the peculiar mental condition which causes a cross-eyed person to suppress the image seen by the squinting eye, the fact is here mentioned as an illustration of the intimate relation between psychology and medicine. Le Conte says: "As a means of scientific culture the study of vision seems to me almost exceptional. It makes use of and thus connects the sciences of physics, physiology, and even psychology. It makes the cultivation of the habit of observation and experiment possible to all; for the greatest variety of experiments may be made without expensive apparatus, or indeed apparatus of any kind. And, above all, it compels one to analyze the complex phenomena of sense in his own person, and is thus a truly admirable preparation for the more difficult task of analysis of those still higher and more complex phenomena which are embraced in the science of psychology."

[ocr errors]

I Sight, p. 4.

CHAPTER V

SUMMARY

Hypnotism. Historical. Neuro - hypnotism. - Nerve sleep,

-

[ocr errors]

so called by Braid, 1843. Phenomena are as old as civilization. Early religions show many instances. - Evident in religious fanaticism of to-day. — Mesmer. "De Planetarium Influxa," 1776. — The action and virtue of animal magnetism. -The Paris establishment; mystery. Investigation by Academy of Sciences: "Not worthy of further scientific investigation." Second investigation of mesmerism. - Eliotson, 1837, University Hosp., London. - Resignation and publication of journal. - Esdaile, 1845, India. - Painless surgery. — Braid, 1843, “ Neurypnology.”—Rechristened "Hypnotism.” Result of subjective causes. Liébeault, 1864, Nancy, socalled "school."— Charcot, 1878, Salpêtrière school.― Society for Psychic Research, 1882, International. - Bramwell, England, best living exponent. Quackenboss, New York, moral reformation. - Morton Prince, Boston, multiple personalities. Petersen, Boston, translator of Wetterstrand. Sidis, Brookline, "Psychology of Suggestion," "Psycho-pathological Researches," "Multiple Personality.”—Methods of hypnotizing. Physical means not essential but useful.Patient should be told what to expect. - Narcotics and anesthetics. Susceptibility, almost universal. -- Well-balanced individuals best subjects. — Hysterical and weak-willed difficult. Hypnotism a physiological function.

[ocr errors]

[ocr errors]
[blocks in formation]
[ocr errors]

HYPNOTISM is a contraction of the term neurohypnotism (nerve sleep), coined by Dr. James

HYPNOTISM — HISTORICAL

67

Braid, of Manchester, Eng., 1843, to cover certain psychic phenomena, which under varied forms and names are as old as civilization. The well-known power of the snake to "charm" the bird while he approaches his prey, would suggest that it even antedates the evolution of man.

The early history of all religions is to such an extent a record of trances, ecstasies, and visions of their votaries that we must believe that these now comparatively unusual manifestations were, in the childhood of the race, of rather common occurrence. The priests of all ancient peoples have exercised these arts, and no doubt owed their unlimited power over the common herd to their knowledge of this mysterious force. This was not limited to any one nation, as it was practised by the Chaldeans, Babylonians, Persians, and Egyptians.

Aristides, a Grecian who lived about 120 A. D., has left a description of a disordered mental state, which possessed him for thirteen years, which was probably a form of auto-hypnosis. The lives of Christian saints furnish many instances.

Even to-day the power to "throw a fit" is in some communities regarded as a manifestation of divine approval. Besides the religious element there was in all this a therapeutic power; wonderful cures were effected in and by the person thus talented.

The first important effort at therapeutics without theology was the appearance of Mesmer. He was

« PreviousContinue »