199 



peculiar bitter taste. Tiie opalescent solution contains only basic 

 dinitroethylate of zinc, and the reaction is expressed by the following 

 equation : 



N 2 C 4 H 5 4 Zn+ C 4 H 5 Zn i r C 4 H 5 , H 



HO J lN 2 C 4 H 5 O 4 Zn + ZnO. 



Carbonic acid decomposes this basic salt, precipitating carbonate 

 of zinc, and leaving the neutral salt in solution. 



Dinitroethylate of zinc and zincethyl is also decomposed by dry 

 oxygen according to the following equation : 



N 2 C 4 H 5 4 Zn + C 4 H 5 Zn-i _ rN 2 C 4 H 5 O 4 Zn 

 O 2 J ~LZnOC 4 H 5 O. 



When the product of oxidation is treated with water, basic diui- 

 troethylate of zinc is produced along with alcohol. 



Neutral dinitroethylate of zinc crystallizes in minute colourless 

 needles containing half an equivalent of water. It fuses at 100 

 Cent., and gradually becomes anhydrous. It is very soluble in 

 water and in alcohol. Heated suddenly in air to about 300 Cent, 

 it burns rapidly with a bluish green flame. 



Dinitroethylic acid can only exist in dilute solution ; it can be 

 prepared, either by decomposing the zinc salt with dilute sulphuric 

 acid and distilling in vacuo, or by decomposing the baryta salt by 

 an exact equivalent of dilute sulphuric acid. The dilute acid thus 

 prepared possesses a pungent odour, somewhat resembling that of 

 the nitro-fatty acids, and an acid taste. It reddens litmus paper 

 strongly, and gradually decomposes even at ordinary temperatures. 

 Neutralized by the carbonates of the various bases, it yields the cor- 

 responding salts. The silver and magnesian salts thus prepared 

 were analysed. 



The salts of dinitroethylic acid are all soluble in water and in 

 alcohol, and most of them crystallize with more or less difficulty. 

 They are all violently acted upon by concentrated nitric acid, the 

 dinitroethylic acid being entirely decomposed and a nitrate of the 

 constituent base produced. Dilute nitric acid acts in the same 

 manner, but more slowly. They all fuse at a temperature little 

 above 100 Cent. The potash, soda, lime, and baryta salts de- 

 flagrate explosively, like loose gunpowder, at a temperature con- 

 siderably below redness. 



