2 
It is composed of c,H,,0,. It may be considered as tritoxide 
of ethyl Az.o. or as corresponding in the methylene series 
to the acetal in the alcoholic, being a tribasic formome- 
thylic ether; thus, 
3Xc,H,0=C,H,,0, three atoms methylic ether. 
C,H», 0, one atom formic acid. 
C,H,,0;--2—C_8,,0,. 
the density of its vapour is 2,45. 
The pyroxylic spirit of Liebig, c,u,,0,, is considered by 
Professor Kane to be not a deutoxide of ethyl, but a tri- 
basie ether, containing the methylene aldehyd. Thus, 
3XC,H,O=C,H,,0, three atoms methylic ether. 
c,H, 0 methylic aldehydene. 
C, Hy, 0, 2—C, By, 0. 
The analysis of the heavy oily liquor obtained by the ac- 
tion of chlorine on methylic alcohol, as pointed out by Du- 
mas, is given by Professor Kane as leading to the formula 
c,cl,u,0,. The products of its decomposition by bases will 
form part of a subsequent paper. 
An oil which accompanies pyroxylic spirit gave for its 
composition C,,H,, 0. isomeric with the resinain of Fremy. 
Professor Kane has found pyroxylic spirit to form a 
compound with chloride of calcium crystallizing in plates, 
(hexagonal,) consisting of one atom of chloride of calcium 
with two of the pyroxylic spirit. 
A paper was also read, ‘‘ On the laws of Reflexion from 
Metals.” By James Mac Cullagh, M.R.I. A., Professor of 
Mathematics in the University of Dublin. 
The author observes that the theory of the action of me- 
tals upon light is among the deszderata of physical optics, 
whatever information we possess upon this subject being 
