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X. On the magnetizing power of the more refrangible solar rays. 
By Mrs. M, Somerville. Communicated by W. Somerville, 
M. D. F. R . > S'. Feb. 2. 1826. 
Read February 2, 1826. 
Xn the year 1813, Professor Morichini of Rome discovered 
that steel, exposed to the violet rays of the solar spectrum, 
becomes magnetic. His experiments were repeated by Pro- 
fessor Configliachi at Pavia, and also by Mons. Berard, 
at Montpellier, without success. I am not aware of any 
one having attempted them in this country, perhaps from 
the belief that experiments which had sometimes failed 
in Italy, were not likely to succeed in our more northern 
climate. The unusual clearness of the weather last summer, 
however, induced me to try what could be accomplished in 
this country. Accordingly, in the month of July, an equi- 
angular prism of flint glass, the three sides of which were 
each 1,4 by 1,1 inches, was fixed in a slit made to receive it 
in a window-shutter : by this prism a coloured spectrum was 
thrown on an opposite panel, at the distance of about five 
feet. I used for the subject of experiment, a very slender 
sewing needle an inch long, having previously ascertained 
that it was quite free from magnetism, by repeated exposure 
of both ends of it to the north and south pole of a very sen- 
sible magnetic needle, when it was found equally to attract 
either pole in every instance. The magnetic needle employed 
as a test in this experiment, is made of a sewing needle mag- 
