68 Upon a Fourth Monobromphenol. 



simply in the exclusion of water ; that accordingly it could also 

 here be said that cyanate of ammonia did not exist. So, too, 

 according to the usual method (by means of hydrochloric acid 

 in an alcoholic solution), or also, from its silver-salt, by ethyl- 

 iodide containing iodine, malaeic acid* does not give its charac- 

 teristic ether, but that of fumaric acid, while malaeic acid-ether 

 is formed only where special precautions are taken, and so forth. 

 These are facts which are undisputed, and quite analogous to 

 those discovered by me. 



In the following, however, I believe I have furnished new 

 proofs for maintaining in good faith the existence of chemically 

 pure substances derived from benzol, which are not possible ac- 

 cording to the benzol-hypothesis. This time the methods of 

 preparation are also less difficult than before, and special "arti- 

 fices" of treatment are not needed. We may therefore be con- 

 fident that we can convince ourselves, with less trouble, oi the 

 correctness of my results. 



The new compounds prepared by me, are a fourth monobrom- 

 phenol and its derivatives. In regard to the new nitro-deriva- 

 tives of benzol, it might have been concluded, though on insuf- 

 ficient evidence, that the isometry of benzoic acid, in respect to 

 its phenol derivatives, was to be traced back to a different struc- 

 ture of the nitro-group N0 2 itself. It was therefore important 

 for me to prepare adequate new derivatives of benzol, of which, 

 from the very beginning, the structure of the "lateral series" 

 could not be discussed. Such bodies are the halogen derivatives 

 of phenol, and therefore, after very wearisome and lengthy ex- 

 periments, not having succeeded in preparing a new iodophenol, 

 I endeavored subsequently, and with success, to obtain a fourth 

 monobromphenol. Moreover, I had already proved the existence 

 of a r fourth oxybenzoic acid.f 



In what way the investigations made hitherto concerning the 

 equivalence of the benzol-hydrogen, or the internal arrangement 

 of the atoms in the benzol-molecule, will stand criticism, I 

 have discussed before.}; Meanwhile, new facts have come to my 



* Jahresb. d. Ckem., 1878, 713 ; 1879, 633. 



f The same, 1878, 757. 



\ Journal f. prakt. Chem. (2), 17, 428, etc. ; (2), 24, 2. 



