102 Scientific Intelligence. 
SCIENTIFIC INTELLIGENCE. 
I. Puysics anp CHEMIsTRY. 
1. Gun-Cotton.—It was announced last summer by Prof. Schénbein 
of Basle, that he had discovered a method of producing a substance 
from vegetable fibre, more explosive and powerful than gunpowder, 
and much interest was excited at the late meeting of the British Asso- 
ciation, by an exhibition of its wonderful effects. It has since been 
not as ye 
identical with the Xyloidine of Braconnot and Pelouze. The suggestion 
thrown out eight years ago by M. Pelouze, regarding its possible appli- 
cation in artillery, seems to have escaped attention, and to have been 
l Pe 
carded, and it is fit for use. As thus repared, it retains the appear- 
ance and fibre of common cotton, but is harsher and more wool-like to 
the touch. It inflames at a temperature of about and, as is Jate- 
ly asserted,t it sometimes happens that it is spontaneously inflamed at 
212° F. The greatest caution is therefore required in the preparation, 
to avoid its accidental combustion.+ 
_ * Comptes Rendus, Oct. 15, 1838. L'Institut, No. 670, p. 367. 
_ iit may not be amiss to mention in this place, that the writer and his assist 
were burned by the accidental combustion of about 1200 grains of gun cotton, 
which they were drying over a hot-air flue where the temperature was probably 
very little above ¢ #°. At the instant when they considered the mass as dr , it 
took fire and was dissipated in a large volume of brilliant yellow flame, without 
