No. XXIV. 



ON 



To the Secretary of the 



Connecticut Academy of Arts and Sciemcs, 

 SIB., 



J_T is known to most of the gentlemen, who usually as- 

 semble at our meetings, that my e}'es have long been 

 weak. In some respects, the disease, with which thej 

 are affected, is perhaps peculiar. At least I have never 

 seen some of the effects, which it produces, described 

 in any publication. As they seem to me to elucidate, 

 in a degree, the nature of light ; I beg leave, through 

 yonr good offices, to communicate this paper to the 

 Academy. 



The disease, whatever else may be its nature, appears 

 to consist, partly, in an uncommon irritability of the op- 

 tic nerve, and a consequent, uncommon susceptibility of 

 impressions from light ; and partly, of a relaxation, and. 

 enlargement, of the lymphatic vessels. Whether my 

 views of the disease are just, or not, I am not desirous 

 to determine : with regard to its effects, I cannot mis- 

 take. Among them this is one ; that at all times, when 

 it is dark, whether my eyes be closed or not, /?.■ ht, dis- 

 tributed into itmumerable little stars^ or sparks, is seen 

 floating' ever the field of vision i?i a great variety of di- 

 rections. In the appearance of these luminous points' 

 there is little regidarity. They become visible, and dis-' 

 appear, in many instances, almost in the same spot. In 

 many others, they move over a considerable distance, 

 before they vanish. The most general, and that, which 

 approaches nearest to a regular, motion, is from the up- 

 per, towards the lower, limit of vision. These stars 



