THEORY CONFIRMED BY PHENOMENA. 51 



The angular velocity of one of these upper clouds was 

 taken; it was found to rise from 25 to 32, m two and a 

 half minutes. Its absolute velocity, therefore, at this great 

 height, was nearly two miles a minute. This great velocity 

 is not at all inconsistent with the velocity with which 

 storms are known generally to travel towards the north east, 

 in our latitude, even on supposition that this direction is 

 given to the upward vortices of these storms, by this upper- 

 most current, as explained before; for the inertia of the air 

 in the vortices must be overcome, and. therefore, the velo- 

 city of the storm, at least the hinder part of it, cannot be so 

 great as the velocity of this uppermost current. 



82. There are many well authenticated accounts of 

 showers of dust, and bloody, or, as I imagine, reddish rain, 

 having fallen, and also of hail, with earthy or stony matter 

 contained in the stones, and some with green leaves of 

 forest trees ; all these facts are mere corollaries from the 

 theory. Professor Zimmerman analyzed the sediment of 

 some red rain which fell on the 3d of May, 1821, near 

 Geisseri, and found it to contain chrome, oxide of iron, silex, 

 lime, carbon, and a trace of magnesia, but no nickel. On 

 the 13th of August, 1824, in the city of Mendoza, in Buenos 

 Ayres, dust fell from a black cloud, and at the same time, 

 in another place, distant forty leagues, the same phenomenon 

 occurred. 



In Persia, near Mount Ararat, there fell, in the month of 

 April, 1827, a shower of seeds, which, in some places, 

 covered the earth to the depth of six inches. The sheep 

 ate of it, and men made a tolerable bread of it. The French 

 ambassador in Russia obtained some specimens of this grain, 

 and sent them to Paris, where they were analyzed and ex- 

 amined by MM. Desfontaines and Thenard, and determined 

 to be lichens of the genus Lecidea. 



Now, as neither leaves of forest trees, nor seeds of lichens, 

 can grow in the upper regions of the atmosphere, or be pre- 



