NITRIC ETHER. 279 



3. NITRIC ETHERS FROM ALCOHOLS PROPERLY so CALLED. 



General Remarks. 



1. Nitric ethers are obtained by the action of nitric acid upon 

 alcohols, accompanied by the substitution of the elements of 

 water for those of acid ; 1, 2, 3 to 6, and even more equivalents 

 of acid may take the place of H 2 0, 2H 2 0, 3H 2 to 6H 2 0, etc., in 

 the alcoholic molecule. For instance 



Nitric ether, C 2 H 4 (H 2 0) + HN0 3 = C 2 H 4 (HN0 3 ) + H 2 0. 

 Nitroglycerin, C 3 H 2 (H 2 0) 3 + 3HN0 3 = C 3 H 2 (HN0 3 ) 3 + 3H 2 0. 



2. The equations representing the formation of nitric ethers 

 are analogous to those for nitro-compounds. But there is a 

 fundamental reaction that characterises the nitric ethers ; 

 namely, that they reproduce the acid and original alcohol, under 

 the prolonged influence of water and dilute alkalis, which does 

 not happen in the case of nitro-compounds. Eeducing agents 

 also decompose the nitric ethers with reproduction of the 

 original alcohol, whereas, in the case of nitro-compounds, the 

 same agents form compound ammonias. 



3. These differences in reactions are correlative with the un- 

 equal quantity of heat given off in the action of nitric acid on 

 various organic compounds. If it gives rise to a nitro-derivative 

 (p. 276), it disengages on an average 4- 36 Cal., or, in the case of 

 an alcohol, properly so called, to an ether, it disengages 4- 5 to 

 4- 6 Cal., and 4- 1 1 Cal. at the most, in the case of complex 

 bodies with analogous functions, such as cellulose. It is this 

 that causes the greater instability of nitric ethers. The presence 

 of alkalis, or even moisture, is sufficient to cause a change in 

 them after a little while. 



But this circumstance gives greater energy to nitric ethers in 

 their use as explosives ; the combustive energy of the nitric acid 

 being much less weakened at the time of its first combination 

 with the organic compound. 



This being understood, we will now examine the thermal 

 formation of nitric ethers, beginning with those derived from 

 ordinary alcohol. 



1. Nitric Ether, C 2 H 4 (HN0 3 ) = 91 grms. 



The formation of this ether was effected in a calorimeter, in 

 a direct manner, by means of pure alcohol and nitric acid, 

 sp. gr. 1'5, and without the addition of any other auxiliary 

 body. The product is approximately the same as would be 

 expected from theory. The experiment, as has been said, can 

 be performed directly, but it is a very delicate operation. 



It is effected in the apparatus already described (p. 269), by 



