JACKSON AND GAZZOLO. — NITRO COMPOUNDS. 281 



sodic alcoholate added to the nitro group only (I.). I cannot find any 

 reason in their article for changing the conclusion to which I had already 

 come, that a quiuoid formula (II. or III.) explains all the observed facts 

 better than the formula (I.) adopted by them. Their most important 

 new facts are the isolation of the free acid from the addition product of 

 potassic methylate and trinitrotoluol, and the formation of the correspond- 

 ing acetyl compound, both of which are explained better by the quinoid 

 formula than by theirs. They also call attention to the fact that the 

 free acid is a weak one instead of being a strong one, as it should be, if 

 derived from a salt with their formula, and that the marked color of the 

 compounds would not be expected from this structure ; both of these 

 anomalies disappear if the quinoid formula is adopted. It seems, there- 

 fore, that their observations tend to confirm this quinoid formula. 



The authors also claim to have disproved definitely the theory of 

 Victor Meyer that these bodies are substitution products, but neglect to 

 mention that Lobry de Bruyn * in 1895 proved the incorrectness of this 

 theory by treating trinitrobenzol in boiling xylol with sodium. Therefore 

 all subsequent arguments against Victor Meyer's theory (of which I have 

 furnished three) must be considered as only confirmatory of Lobry de 

 Bruyn's work. 



It may not be out of place to repeat here that work on this subject is 

 still in active progress in this Laboratory. 



C. LoRiNG Jackson. 

 December 27, 1899. 



* Kec. Trav. Chim. Pays-Bas, XIV. 89. 



