On light and other high frequency phenomena 

(Lecture before Franklin Institute, Philadelphia, Feb. 1893); Journal of Franklin Institute, Philadelphia, (July 1893); National Electrical Light Association Proceedings, St. Louis, (1893).

Delivered before the Franklin Institute, Philadelphia, February 1893,
and before the National Electric Light Association, St. Louis, March 1893.

INTRODUCTORY

« When we look at the world around us, on Nature, we are impressed with its beauty and grandeur.  Each thing we perceive, though it may be vanishingly small, is in itself a world, that is, like the whole of the universe, matter and force governed by law,—a world, the contemplation of which fills us with feelings of wonder and irresistibly urges us to ceaseless thought and inquiry.  But in all this vast world, of all objects our senses reveal to us, the most marvelous, the most appealing to our imagination, appears no doubt a highly developed organism, a thinking being.  If there is anything fitted to make us admire Nature’s handiwork, it is certainly this inconceivable structure, which performs its innumerable motions of obedience to external influence.  To understand its workings, to get a deeper insight into this Nature’s masterpiece, has ever been for thinkers a fascinating aim, and after many centuries of arduous research men have arrived at a fair understanding of the functions of its organs and senses.  Again, in all the perfect harmony of its parts, of the parts which constitute the material or tangible of our being, of all its organs and senses, the eye is the most wonderful.  It is the most precious, the most indispensable of our perceptive or directive organs, it is the great gateway through which all knowledge enters the mind.  Of all our organs, it is the one, which is in the most intimate relation with that which we call intellect.  So intimate is this relation, that it is often said, the very soul shows itself in the eye.

It can be taken as a fact, which the theory of the action of the eye implies, that for each external impression, that is, for each image produced upon the retina, the ends of the visual nerves, concerned in the conveyance of the impression to the mind, must be under a peculiar stress or in a vibratory state, It now does not seem improbable that, when by the power of thought an image is evoked, a distinct reflex action, no matter how weak, is exerted upon certain ends of the visual nerves, and therefore upon the retina.  Will it ever be within human power to analyse the condition of the retina when disturbed by thought or reflex action, by the help of some optical or other means of such sensitiveness, that a clear idea of its state might be gained at any time?  If this were possible, then the problem of reading one’s thoughts with precision, like the characters of an open book, might be much easier to solve than many problems belonging to the domain of positive physical science, in the solution of which many, if not the majority: of scientific men implicitly believe.  Helmholtz has shown that the fundi of the eye are themselves, luminous, and he was able to see, in total darkness, the movement of his arm by the light of his own eyes.  This is one of the most remarkable experiments recorded in the history of science, and probably only a few men could satisfactorily repeat it, for it is very likely, that the luminosity of the eyes is associated with uncommon activity of the brain and great imaginative power.  It is fluorescence of brain action, as it were. »

Read the full article here