120 Dr. Kane on Pyroxylic Spirit and its Combinations, 



The result allows no other interpretation, although the sub- 

 stance was evidently impure, and unfortunately the quantity 

 remained too small to allow of the necessary operations for ob- 

 taining it quite pure. Under such circumstances an accurate 

 determination of the density of the vapour could not be ex- 

 pected ; nevertheless, the following experiment was made: 



Weight of the balloon with air = 46*372 gram. 



vapour 46*505 — 



Volume of the balloon 285*6 cub. cent. 



Residual air vS*0 ■■ 



Temperature of the air 19*6° c. 



. vapour 97*6 c. 



Barometer 0*74<8 metre. 



Weight of a litre of va}K)ur 2-3674' gram. 



Specific gravity ...(air=l) 1'824' — 



The theoretical com}iositioii gives 



4 volumes of gaseous carbon = 3*3712 



10 hydrogen 0*6880 



2 oxygen 2*2052 



3 -T- 6-2644 = 2*0881. 

 The difference between the calculated and experimental re- 

 sult is here considerable, but yet not so considerable as to cast 

 any doubt on the real composition of the substance. 



This fluid presents, in connexion with that previously de- 

 scribed, some interesting relations. It is evident that both may 

 be considered as degrees of oxidation of the same radical 

 ethyle A E = C4 Hjo; but a still moie remarkable connexion 

 results from considering Liebig's pyroxylic spirit as 



3 atoms of methylene aether = Cg HjgO./l p tt ci 



1 atom of methylene aldehydene Cc, H^ 6 J^^ "20 ^^' 

 In this point of view it resembles formal, the formic acid of 

 the latter being replaced by a lower degree of oxidation of the 

 same radical, by, in fact, the aldehydene of the methylene se- 

 ries, formed by the subtraction of four atonjs of oxygen from 

 methyl ic aether. 



I shall return to the liistory of the methylene aldeiiyd in 

 another paper. 



The properties and composition of the bodies just described, 

 as well as those of the chloral of Liebig, the chloroform and 

 their congeners, point out the existence of a series which may 

 now be tabulated, although some of its members are as yet 

 known only in a state of combination. I shall therefore con- 

 clude this abstract by a resume of these compounds in the form 

 they appear naturally to assume. 



Hypothetic radical. Formyl C^ H, = Fo. 



