FIGURES UPON ICE. 
167 
III. 
Observations respecting the Figure of a drowned Man formed in 
the Ice of the Pond in Halnaker Park, and upon the Explana- 
tions which have been offered of that singular Phenomenon „ 
In a Letter from Sir George Cayley, Bart. 
To Mr. Nicholson. 
SIR, 
Brompton, May 29, 183 3. 
I N No. 159 of the Chemical Journal, I observe an ingenious Whether the 
paper of your’s respecting the singular phenomenon of the f c ^ U1 b e °weli e 
figure of a drowned person being exhibited in the ice above accounted for, 
him. I have read with attention the very ingenious expla- 
nation you have given of this fact ; and it may, perhaps, be the 
true mode of accounting for it j but I am not perfectly satis- 
fied with your theory, and wish to draw your attention to ano- 
ther cause that may have operated in producing this appearance, 
and which I think worthy of investigation by a simple experi- 
ment in the same pond next winter, through the medium of 
any gentleman residing near it. 
You must frequently have observed, that in muddy ponds Carburetted 
a great quantity of gas (carburetted hydrogen) rises in bubbles hydrogen 
from the bottom, and that, although this effect is produced r * ses p0i3tJs * 
with greater rapidity in summer than in winter, yet that pond 
ice is very frequently quite full of bubbles and blisters from 
this source, some of which are very minute, and others form- 
ing large flat circles resembling smooth shillings or half crowns 
within the ice at different depths, according to the thickness 
it possessed when the bubble ascended. 
Water parts with the small portion of air it held in solution The large bub- 
during freezing, and thus a number of minute bubbles are hies in ice sup- 
found in almost all ice ; but the copious supply of bubbles I ]> rom t j ie >j 0t „ 
allude to, certainly arise from the bottom, as the portion of tom, 
water congealed at the surface is not sufficiently large to pro- 
duce them. If, under these circumstances, any convex body 
rested lightly upon the mud, as that of the drowned person 
alluded to, all the pond would become affected with the bub- and liable to 
bles, excepting that portion of it immediately above the body, be intercepted 
where 
