THE SENSE OF SIGHT. 3 73 



We hope to have conveyed to the reader of the above sketch, in as intelligible 

 a form a? possible, what is correctly known of the mechanism and action of our 

 organ of hearing. At least, let not the inquirer who turns away unsatisfied from 

 these pages impute it as a fault to the author that he has, so often and upon so 

 many important points, been obliged to accuse science of ignorance. It is, on 

 the whole, well for us whose lives are dedicated to such pursuits that science 

 still hides under a thick veil so many precious treasures to reward the assiduous 

 research and penetration of future explorers. 



v.— THE SENSE OF SIGHT. 



When his corporeal mechanism was giving way and refused further service to 

 the exalted genius of our greatest poet, its last effort in obedience to the parting 

 spirit was the cry : '' Light ! more light I " These words are ambiguous and 

 have been differently interpreted ; their sense, however, lies more on the surface 

 than that which has been often assigned to them. There was here nothing 

 mystical ; no solemn decoration thrown around the close of a glorious life. It 

 was the failing sight — the death of the most precious sense — which, pressing upon 

 the yet lingering consciousness, called forth the wish implied in the expressions 

 we have quoted. To thousands and thousands of the ordinary dwellers upon 

 earth must the hour of death have brought the same mournful perception of 

 withdrawing sensibility, alike whether they were still able to express it in words, 

 or whether the organs of speech no longer obeyed the impulse, or the impulse 

 itself were wanting ; alike in whatever form, whatever words, the soul made 

 known its last impressions. The simple expression, so often heard, "It grows 

 dark before the eyes," is in its origin and signification wholly identical With the 

 dying utterance of Goethe. 



A glance at the physiological conditions of the sense of sight renders the fre- 

 quent positive perception of its extinction in the case of the dying fully con- 

 ceivable, while that of every other sense takes place for the most part without 

 any distinct recognition. No one remarks when the organs of taste and smell 

 resign their activity ; few, except under peculiar circumstances, perceive when 

 the auditory nerve loses its susceptibility to the impressions of the waves of 

 sound which reach its extremities ; and quite as few are conscious when the skin 

 surrenders its function of recognizing warmth and pressure; but to most, perhaps 

 to all men, whose consciousness is not extinguished before the death of the senses, 

 the perception of a darkening of the organ of vision makes itself so urgently 

 felt as to arouse the already slumbering consciousness to one last, painful effort, 

 and communicates a reaction by the wonted paths to the organs of speech. But 

 whence the perogative of this one sense 1 The answer is not far to seek. No 

 sense is during our whole life so uninterruptedly active ; on none is the attention 

 of the soul so constantly bent; the functions of no other sense supply so habit- 

 ually and variously the materials of thought and imagination. So long as we 

 are awake the eye conveys to the mind in unbroken succession images upon 

 ■which it acts, whether the other senses be simultaneously in activity or repose ; 

 even while concentrating, for example, with feverish solicitude, our attention on 

 the sensations of the ear, no impression of the sight escapes us, however evanes- 

 cent may be our consciousness of the perception. While we close our eyes in 

 order to think with less distraction — while we slumber and dream — the activity 

 of the sense of sight continues amidst our thoughts and dreams, the objective 

 perceptions which are wanting being supplied by subjective ones ; nor do we 

 lose in dreaming the distinction between darkness and light. What other sense 

 can boast of being equally indispensable ? Hours and even days may pass 

 without action on the part of the sense of taste or of smell, and without atten- 



