380 Royal Society : — 



The crystals of dinitroethylate of zinc and ziiicethyle instantly 

 become opake on exposure to the air, owing to the formation of an 

 oxidized product. They are tolerably soluble in anhydrous ether 

 without decomposition, but are instantly decomposed by anhydrous 

 alcohol and by water. Exposed to the gradually increasing heat of 

 an oil-bath, dinitroethylate of zinc and zincethyle fuses at 1 00° Cent., 

 froths up, and begins slowly to evolve gas. At 180° the colour 

 darkens, a small quantity of a highly alkaline liquid distils over, and 

 a large amount of gas is evolved. The latter consists of carbonic 

 acid, olefiant gas, hydride of ethyle, nitrogen and protoxide of ni- 

 trogen. When brought into contact with water, dinitroethylate of 

 zinc and zincethyle is immediately decomposed with lively efferves- 

 cence, due to the evolution of pure hydride of ethyle. An opalescent 

 soluiion is formed, possessing a powerfully alkaline reaction and a 

 peculiar bitter taste. The opalescent solution contains only basic 

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

 equation : — 



N, C4 H5 O4 Zn-f- C4 H5 Zn -I _ r C, H^, II 



HO /-tKC^HsOjZn + ZnO. 



Carbonic acid decomposes this basic salt, precipitating carbonate 

 of zinc, and leaving the neutral salt in solution. 



Dinitroethylate of zinc and zincethyle is also decomposed by dry 

 oxygen according to the following equation : — 



N,C4H5 04Zn-f-C4H5Zn\ _ rN2C4H,04Zn 

 Oj-lZnOC4H50. 



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

 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. 



BinitroetJiylic 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 magnesiau 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 diflficulty. 

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

 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- 



