Scientific Intelligence. —Mechanical Philosophy. 391 
not even excepting sinking, which effectually destroys the white ant. 
—Idem. 
4. Electricity of the Solar Rays. (Letter from Sig. Carlo Mat- 
trucci, of Forli, to Professor Gazzeri.)—* I hasten, Sir, to commu- 
nicate to you some experiments which appear to me to deserve the 
attention of philosophers. _ Having been for a long time persuaded of 
the existence of electricity in the solar rays, I wished to ascertain the 
fact by experiments. Having for the purpose exposed to the sun a 
delicate condensing electrometer of gold leaf, I soon perceived the 
leaves diverge and open themselves also on that side of the glass 
case which was. directly exposed to the solar action, as if they had 
been attracted by it. Being induced from this first fact to suspect 
glass in this situation electrified, I was anxious to know if this were 
the case: wherefore, having left some plates of it in the sun, in a few 
moments I touched them in different places with the ball electrome- 
ter, when a very perceptible divergence ensued, which, however, was 
much more apparent when I touched the plates, although lightly, with 
a flat surface, since the effects of the friction and the pressure did not 
afford a doubtful result. I concluded, then, that the solar rays had 
the power of electrifying glass, and it only remained for me to ascer- 
tain if this effect were owing to the real existence of electricity in 
these rays, or rather to the increased temperature of the glass, which 
I could easily determine by heating a plate of glass, and trying it with 
the electrometer. This I did several times, but never discovered 
any signs of electricity. I observed, also, that the glass plate ex- 
posed to the rays of the sun, never became electric if placed beneath 
another glass plate, or if the face of the sun was obscured by the in- 
tervention of a cloud. ‘These few experiments which I have been 
induced to perform, seem to me sufficient to prove the existence of 
electricity in the solar rays. The influence of such a fact on the 
meteorological phenomena of nature, will, I hope, induce yourself 
and other philosophers to pursue the subject farther.” (Antologia, 
No. 100. Forli April 25, 1829.)—Jdem. a 
Professor Saverio Barlocci, of Rome, in a Memoir on the influ- 
ence of Solar Light, in the Production of Electric and Magnetic Phe- 
nomena, inserted in Vol. XLI. of the Giornale Arcadico, relates the 
following experiments which he had performed, to ascertain the elee- 
tric power of the solar light. Having decomposed it with a prisin, he 
made the red ray and the violet ray fall upon two dises of blackened 
