206 Treatise on the Diseases of the Eye. 



gradual indistinctness of vision at sunset, when objects appear covered 

 with an ash-coloured veil. This continues for one or two days to 

 weeks, or months ; and after one attack the individual is liable to 

 relapses, during which the sight becomes dimmer as the twilight 

 advances, until vision is completely lost. 



When the eyes are examined, the pupils are found dilated and the 

 iris sluggish, and often immovable. There is no pain in the eye. 

 At first the person can see indistinctly in candle or moonlight. If 

 neglected, the sight becomes gradually weaker during the day, and 

 may terminate in amaurosis. The disease is produced by an ex- 

 haustion of the retina by its exposure to light under particular 

 circumstances, which can usually be removed by following a proper 

 plan of treatment. The treatment in Europe consists of local bleed- 

 ing, the repeated application of blisters to the temples and behind 

 the ears, with purgatives. In tropical climates, it consists of im- 

 proving the tone of the system by the use of tonics, aperients, and 

 nourishing diet ; and attention to the cure of any disease which may 

 accompany, and accelerate the disease of the eye. 



When the paralysis of the nerves of sight, which produces this 

 disease intermits, quinine during the intervals will be found an excel- 

 lent remedy, to diminish or check the disease. 



The following is an example of the manner in which this disease 

 becomes epidemic in certain situations. In September 1838, three 

 hundred and fifty followers of a person pretending to be the Rajah 

 of Burdwan, were incarcerated in the jail of Hooghly, until the 

 judicial examination of their case was completed. These prisoners 

 consisted of up-country men, often rather selected from their being 

 such, than from their physical powers. Many were old, others very 

 young ; and a third class debilitated. These people had been ac- 

 customed to live on a full diet of butter, bread, &c. and seemed to 

 have been deluded by having prospects of advancement held out to 

 them. While they were with the pretended Rajah, they were obliged 

 to remain contented with a small portion of their pay, which did not 

 admit of their obtaining their accustomed necessaries of life. In this 

 state they were suddenly seized, and placed in confinement. In jail 

 they were put upon the usual allowance of two pice a day, which was 

 not sufficient to procure them their accustomed food. The depres- 



