2 



It is composed of c 4 h 10 o 3 . It may be considered as tritoxide 

 of ethyl ae. o. or as corresponding in the methylene series 

 to the acetal in the alcoholic, being a tribasic formome- 

 thylic ether ; thus, 



oXc 6 H 6 ozc 6 H lg o 3 three atoms methylic ether. 

 c„h, o, one atom formic acid. 



C 8 H 20°6^-2= C 4 H 10°3- 



the density of its vapour is 2,4>5. 



The pyroxylic spirit of Liebig, c 4 h I0 o 2 , is considered by 

 Professor Kane to be not a deutoxide of ethyl, but a tri- 

 basic ether, containing the methylene aldehyd. Thus, 

 3xc 2 H 6 orrc 6 H 18 o 3 three atoms methylic ether. 

 c,h 2 o methylic aldehydene. 



C 8 H 20 O 4 -f-2 = C 4 H 10 O 2 . 



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 c£.<H 4 .o s . 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 20 h 30 o. 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 desiderata of physical optics, 

 whatever information we possess upon this subject being 



