OP ARTS AND SCIENCES. 155 



group was first shown by Goldschmidt,* and later proved with all 

 precision by Hantzsch.f Up to the present time no fact exists 

 which could be brought against the above formula for the /3 oxime, 

 and the great majority are explained more simply by it than by the 

 assumption of geometrical isomerism of the nitrogen. This suf- 

 fices to show on how uncertain a basis the assumption rests that the 

 two oximes of benzaldehyde are alike constituted. 



Finally, the presence of geometrical isomerism has been assumed 

 in a number of cases where it certainly does not exist: so, for 

 example, in the case of the so called /3 oximidobutyric acid, 



CH3ONOH 



I 

 H 2 OC(\H 



and its anhydride, J 



CH,-C=N x 



I )o. 



H 2 C-CO 



These substances cannot possess the constitution given them : it 

 follows with certainty, from the work on acetoacetic ether, § that 

 the substances have the following constitution, 



CH3-CNHOH CH 3 -C-NH X 



II and II }0, 



HCC0 2 H HC - OO 



where a geometrical isomerism on account of the nitrogen is 

 impossible. 



Also the two substances that have been described as oximido- 

 succinic acids, || are certainly of different chemical constitution. 



Oxalacetic ether, 



COoR-COH 



II 

 C0 2 R-CH 



must react with hydroxylamine, just as acetacetic ether with phe- 

 nylhydrazine, and form an oxid of the constitution, 



C0 2 R-ONHOH 



II 

 C0 2 RCH 



i. e. a fumaric acid derivative. 



* Ber. d. Chem Ges., XXIII. 2176. 



t Hantzsch, Ber. d. Chem. Ges., XXIV. 16. 



J Ibid., XXIV. 497. 



§ Ann. Chem. (Liebig), CCLXVI. 64 and 70. 



|| Cramer, Ber. d. Chem. Ges., XXIV. 1198. 



