38 On Vision: 
like others, fond of sporting, and seldom liked to miss 4 
day if I could any way go out. From my own house I set 
out on foot and pursued my diversion on a foggy days and 
after I had been out some time the fog or mist increased to 
so great a degree, that however familar the hedges, trees; 
&c. were to me, I lost myself, insomuch that ¥ did not 
know whether I was going to or from home: In W. 
field, where T then was, I stiddenly diseovered what I ima= 
gined was a well known hedge-row, interspersed with pol- 
lard trees, &c:, under which I purposed to proceed home- 
ward; but to my great surprise, tipon approaching this ap-. 
pearance, I discovered a row of the plants known. by the 
name of rag, and by the vulgar canker-weed, growing on 2 
meer balk dividing ploughed fields; the whole height of both 
could not exceed three feet or hice feet and a half: It 
struck me so forcibly that I shall never forget it: this, too, 
in a field which 1 knew as well as any man could know a 
field.’ 
The following account respecting the effects of mist on 
vision, was related to me on the spot where it happened : 
A shepherd upon one of the mountains in Cumberland 
was suddenly enveloped with a thick fog or mist, through 
which every object appeared so greatly increased in magni+ 
tude, that he no longer knew where he was. In this state 
of confusion he wandered in search of some known. object, 
from which he might direct his future steps: . Chance, at 
last, brought this lost shepherd within sight of what he sup- 
posed to be a very large mansion, which he did not remem- 
ber ever to have seen before; but on his entering this vi- 
sionary castle to inquire his way home, he found it inha- 
bited by his own family. It.was nothing more than his 
own cottage. But his organs of sight had so far misled his 
mental faculties, that some little time elapsed before he could 
be convinced that he saw real objects. Instances of the 
same kind of illusion, though not to the same degree, are 
not unfrequent in those mountainous regions. 
From these effects of mist on vision, it is evident that the 
pupil, and the picture of an object within the eye, increase 
at the samme time. 
The 
