OF ARTS AND SCIENCES. 161 



lution. The behavior of sodic acetacetic ether towards acetic 

 anhydride * can also he easily explained by a twofold addition. 



Finally, the action of phenylhydrazine on acetacetic ether can- 

 not be regarded as taking place in a manner analogous to the three 

 cases discovered above (p. 150), i. e. that the first named substance 

 simply adds itself to the carbonyl group. Oxalacetic ether, 



COoR-COH 



II 

 C0 2 R-CH 



forms, as W. Wislecenus f has shown, with phenylhydrazine a 

 salt-like compound, which is instantly split into its components 

 by alkalies, whereas the three hydrazonehydrates described in this 

 paper are not changed by alkalies. 



A number of the objections brought forward by Bruhl t seem to 

 show that he has not fully understood my work on acetacetic ether; 

 as, for instance, his remarks on the proof " that a methylene group 

 between two carbonyl groups possesses no acid reaction." 



I have shown, 1st, that malonic ether is neutral, i. e. it pos- 

 sesses no acid properties ; 2d, that sodic malonic ether is instantly 

 decomposed by water, like sodiumethylate; 3d, that the free ma- 

 lonic ether shows a behavior entirely different from acetacetic 

 ether; and consequently, 4th, proved that malonic ether forms a 

 salt only in case sodic ethylate is present. 



That many acids exist which do not react with sodium in abso- 

 lute ethereal solution, seems to weaken the above proof in Bruhl's t 

 opinion; but this fact has absolutely no bearing on the point un- 

 der discussion. If, on the other hand, it is proposed to discuss 

 the question whether a substance can be an acid, which is not 

 soluble in soda or caustic soda, or which is not thereby converted 

 into an insoluble salt, that is another matter. 



Although Bruhl finds the refractive index of acetacetic ether to 

 be in favor of the ketone formula of this substance, I am able to 

 bring forward another physical property of this substance which 

 points to the contrary, namely, that acetacetic ether is an electro- 

 lyte, and therefore an acid; whereas malonic ether is a non-elec- 

 trolyte, and consequently not an acid. 



This shows how uncertain the conclusions are which can be 

 drawn from the physical properties of a substance with regard to 



* Loc. cit., XXV. 1046. 



t Ber. d. chem. Ges., XXIV. 3006. \ Ibid., XXV. 366. 



VOL. XXVII. (N. S. XIX.) 11 



