134 Remarks on Atmospheric Dust. 
There was also, two years before, a fall of hail in the 
same county, which was to me in some respects new.— 
‘he hail stones were generally about one fourth or three 
eighths of an inch thick and of sufficient dimension in length 
and breadth to hide a shilling, and in many cases a cent, and 
almost every one perforated in the middle as if they had 
‘been held between the fingers, ull the mt by their: 
When 
warmth had melted away the middle and had me 
the perforation was not complete, there was in noise case 
an inclination to perforation. The storm was tremendous, 
but of short duration and took place in the heat of summer. 
T observed then and have many times observed since, 
that hail is usually accompanied by contrary winds which 
seem striving over our heads for the mastery. I wish sir, 
you, isnot the hail always produced by conflicting 
sind which, in the place where they meet, force the 
mosphere above the freezing point, and cause the vapour 
to congeal ? And if this be the fact will not the hail be lar- 
ting ieee can support its 2 Weigin, and thus be o> the 
longer time above the freezing point and become so muce 
the larger. The perforation in the case above mentioned 
was, I suppose, effected while falling, but by what means 
LT know not. The hail might have been strung like so many 
beads. 
Art. XV. Remarks on Atmospheric Dust, in reply to Mr. 
RaFINESQuE. 
TO PROFESSOR SILLIMAN. . 
Sir, 
BEING a subscriber to your Journal, I observe, (Vol. 1. 
No. IV. p. 597,) an article from the ingenious and learned 
Mr. Rafne esque, on Atmospheric Dust. 1 confess I can 
hardly agree with that gentleman in several opinions. which 
