Of Rain.—Appendiz. 369 
in 7500 water. My gage water exhibited a 
trace of sulphuric acid, Mr. Blackwall’s 
none. 
Another storm of wind and rain succeeded 
this, on the 4th March. The wind was chiefly 
from the west, and extremely violent in the 
night; and on the morning of the 5th se- 
veral slates were blown from the roofs of 
houses. Next day the windows were visibly 
covered with salt. I collected from two 
squares of glass, salt sufficient to saturate 10 
grains of a solution of nitrate of silver of 
1.01 sp. gr. A portion of magnesia suffici 
ently visible was precipitated by lime water. 
My rain-gage water, but somewhat diluted 
with succeeding rain, yielded for 7500 grains, 
.27 grain of salt, and manifested sulphuric 
acid. Mr. Blackwall’s rain-gage water in- 
dicated for 7590 grains, .33 grain of salt, 
also a trace of sulphuricacid. Mr. Blackwall 
also collected a portion of rain in a clean 
glass vessel during the most violent period 
of the storm. This water indicated for 7500 
grains, 1.66 grain of salt, which ‘is the 
largest proportion I have yet found, except- 
ing that from the tub in the Society’s yard, 
which I have already observed is probably 
not a fair specimen. This portion of water 
3A 
