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Page:Popular Science Monthly Volume 61.djvu/76

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POPULAR SCIENCE MONTHLY.

we actually dissipate and waste it. But the results of this kind of fatigue do not usually produce any condition comparable with neurasthenia; they do not, for instance, produce visions. In neurasthenic states there is, however, a tendency to visionary effects—colored vision, intolerance of light, photopsiae, persistence of retinal impressions, etc.—and, moreover, in all temporary conditions of nervous fatigue in otherwise fairly healthy people the same tendency to abnormal color effects with open eyes, and vague visions with closed eyes, is apt to show itself. I find that some persons, when very tired, see shadows as unusually violet, while kaleidoscopic visions and processions of figures and faces are also seen with closed eyes after fatiguing days. I have myself noted effects faintly recalling those produced by mescal after periods of unusual brain activity. On the border-land between sleeping and waking color-visions are also sometimes seen, and Mrs. Christine Ladd Franklin has stated that in falling asleep over a book she sees colored shadows, especially violet, floating over the page. It is noteworthy, further, that in various conditions of abnormal color-vision fatigue increases the brilliancy of the colors. The same tendency rules the association between music and visions. Heine was a somewhat neurotic subject who constantly complained of very severe headaches, and Mr. MacDougall, in describing the physical conditions under which he finds that visual imagery is liable to occur, describes a state approaching that produced by mescal: "In the earlier stages of fatigue, before the final condition has been approached, a period of cerebral excitement occurs, often accompanied by slight frontal headache, in which my mental imagery becomes more varied and concrete than normal. I feel an unusual brilliancy and fertility of suggestion; my mental scenery becomes less schematic and algebraic; comparisons and illustrations suggest themselves on every hand; thought proceeds by object images." It may be pointed out that neurasthenia is widely regarded as a condition of depression with irritability of the higher cerebral centers. Binswanger, indeed, in his book on the pathology of neurasthenia, considers the parallel between fatigue and neurasthenia as so close that he is inclined to regard the latter as nothing else than a prolonged condition of over-fatigue. In mescal intoxication we may be said to have a neurasthenia which is very limited, but is very sudden and swift. The sensorial apparatus is allowed to run violently down, and in healthy persons the accompanying acute metabolic activity produces the pleasurable feelings which usually accompany nervous activity. It is perhaps due to the swiftness of this process, and also to the good physical condition of the subject, that no unpleasant after-effects are usually experienced. I have noticed that the pleasant or unpleasant effects and after-effects of mescal may be quite accurately foretold from a knowledge of the subject's general health, and that the better his general