46 Dr. Kane*s Contributions to the Histortj 



ceased, a quantity of water is to be introduced into the retort 

 equal in volume to that of the pyroxylic spirit employed. 1 he 

 water rephicing the spirit in the combination with chloride of 

 calcium, the latter fluid is set free and distils, perfectly free 

 from oil, but mixed with water, from which it can readily be se- 

 parated by one or two distillations over recently ignited lime. 

 The substance thus obtained was employed in the following 

 experiments: 



The boihng point atO'74-4' met. barom. press, was 60° cent. 



Analysed with the apparatus of Liebig 0*765 gramme of 

 material gave 



Wat^ - 0-853 



Carbonic acid 1 •04'2 



From whcHce follows the composition : 



Carbon... = 37*66 Dumas's theory gives 2 car. = 37*97 

 Hydrogen 12*39 8 hyd. 12-40 



Oxygen... 49*95 2 oxy. 49*63 



100- 100* 



By the following experiment the specific gravity of the va- 

 pour was determined by the method devised by Dumas : 



Excess of weight of balloon filled with air ) 0-049 



over that of the same filled with vapour J & - 



Volume of balloon = 269*5 centim. cubic. 



Residual air 12*5 cub. cent. 



Temperature of vapour 97*75 cent. 



Temperature of air 17*0 cent. 



Barometer = 0*744 metre. 



From these data follow : 



Weiijht of a litre of vapour at 1 , . -„„ 



. /. ^ A /A -^ r = 1*4563 fframme. 



temp. cent, and pressure 0- , 6 J ° 



Density of vapour (air = 1) 1*1210 



The theoretical density is 1*1105 



The density found by Dumas ... 11200 



The results of Dumas and Peligot may, therefore, be consi- 

 dered as completely established. 



The formation of the first hydrate of methylene (the me- 

 thylene aether) is the most important fact in the whole of 

 Dumas's researches, as upon the idea of its basic reaction rests 

 the similarity of the methylene with the alcohol series. The 

 mode of analysis used by the French chemists consisted in 

 the detonation of the gas with oxygen : in the repetition of the 

 experiment I substituted a process in which the relation be- 

 tween the (juantities was expressed by weight, a method less 

 liable to error than that of measure. 



The gaseous rtiethylic aither was dissolved in water, which 



