Upon (i Fourth Monobromphenoh ( >t> 



knowledge which confirm my views. Menschutkin* explained 

 already, in 1877, when speaking of his experiments on the forma- 

 tion of ether, that aromatic compounds behave simply like u non- 

 saturated " compounds ; hence there could not be the question 

 of a specially-constructed "main substance. Briihl,t in his 

 treatise on the "thermal aud optical properties of liquid organic 

 compounds,"' arrived at the conviction that the so-called "double 

 bonds " of the hydrocarbons do not signify a more intimate, 

 but, on the contrary, a weaker attraction of the atoms in respect 

 to the simple chain — an explanation which, in the first place, 

 must put in question the constitution of benzol according to the 

 prevailing opinion. 



GroldschmidtJ recognized, in his investigation upon the action 

 of '' molecular" silver upon carbon-chlorides, that the affinities 

 of carbon are not equivalent — results with which my own inves- 

 tigations are in perfect harmony. 



To what monstrosities in general the upholding at any cost of 

 the benzol-hypothesis may lead, Schoonmaker and Van Mater§ 

 have but lately shown. Because the formation of their isomeric 

 fluid p — dibrom-mononitro-benzol from p — dibrombenzol, can- 

 not be harmonized with the hypothesis, they suppose, in a simple 

 nitration, a so-called atom-wandering within the molecule, and 

 determine also most accurately (p — dibrom-mononitro-benzol 

 being converted by sulphuric acid into the liquid isomere), 

 that this atom-wandering could only take place after the intro- 

 duction of the nitro-group. To seek to support a hypothesis 

 with such forced suppositions, can under no circumstances be of 

 any advantage to it. 



Every advance of science consists, generally, in a simplification 

 of the fundamental ideas. So it was in abandoning the notions 

 about the philosopher's stone, the tartarus, the alkahest, 

 phlogiston and the vital force. And so, likewise, when the be- 

 lief in the equivalence of the carbon-affinities is completely 

 abandoned — as we may expect in not too long a time — not a 



* JahreSb. d. Chem., 1877, 323. 

 f The same, 1881, 1108, etc. 

 % The same, 1881, 375, etc. 

 £ The same, 1881, 541. 



