270 
ON CATARACT. 
of the lens is the consequence of external violence, a case which 
more frequently than any other gets well without an opera¬ 
tion.—“Frequently,” says a modern writer, “the cataract 
proceeds from an hereditary disposition, which has existed for 
several successive generations ; while, in other cases, it attacks 
several members of the same family, without any disposition of 
this kind being recognizable in their progenitors.” 
In reference to what happens in horses, the evidence Mr. Clay 
(V.S. Shrewsbury) gave on the trial I have alluded to is of such 
moment to us in this inquiry, that, although Mr. Cartwright 
in the last month’s No. revised it, I hope I shall stand excused 
for reiterating it in this place. Mr. Clay deposed, that “ cata¬ 
racts might be formed in a fortnight or three weeks; has known 
many instances where they had been formed in less time; has 
known them to be formed without active inflammation, and 
without any previous apparent disease of the eyes ; and has de¬ 
tected them when the owners had not the slightest suspicion of 
disease in the eye, and had declared that no previous inflamma¬ 
tion had been observed.” These are statements of a novel and 
highly interesting character ; and such as make me feel so de¬ 
sirous to have “ further particulars,” that I cannot help joining 
in prayer with Mr. Cartwright, that Mr. Clay will “ favour the 
public with the cases on which they are founded.” 
In the mean time, Mr. Cartwright himself—ever first in the field 
where facts are wanted—comes forward with two cases of his ow T n. 
The first is that of a five-year old horse that had “ tivo cataracts 
in each eye:” two of the magnitude of a large pin’s head; the 
other two, treble that volume. In other respects, the eyes were 
perfectly transparent; and the person who bred the animal de¬ 
clared that his eyes had never before shewn disease. The horse 
was sold in the month of December, 1831, “ with the cataracts 
evident enough ; but from that time they gradually disappeared, 
and in the autum of 1832 there was not the least to be seen of 
them.” The other case occurred in a five-year old cob-mare. 
In the month of November, 1832, Mr. Cartwright detected a 
cataract in her right eye, “of the size of a coriander seed.” In 
August 1833 the cataract had disappeared. No previous or con¬ 
comitant ophthalmia could be discovered. 
