7o 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 neuras- 

 thenic states there is, however, a tendency to visionary effects — colored 

 vision, intolerance of light, photopsiae, persistence of retinal impres- 

 sions, 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 sleep- 

 ing 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 note- 

 worthy, 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 approach- 

 ing 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 condi- 

 tion of depression with irritability of the higher cerebral centers. 

 Binswanger, indeed, in his book on the pathology of neurasthenia, con- 

 siders the parallel between fatigue and neurasthenia as so close that he 

 is inclined to regard the latter as nothing else than a prolonged con- 

 dition 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 pleasur- 

 able feelings which usually accompany nervous activity. It is perhaps 

 due to the swiftness of this process, and also to the good physical condi- 

 tion of the subject, that no unpleasant after-effects are usually ex- 

 perienced. I have noticed that the pleasant or unpleasant effects and 

 after-effects of mescal may be quite accurately foretold from a knowl- 

 edge of the subject's general health, and that the better his general 



