xvn MOLECULAR ARCHITECTURE 411 



view of his colleague Laurent that (as he expressed it some 

 years later) 



" In the phenomena of substitution the type is conserved, 

 that is to say that not only does the chlorine take the place of 

 the hydrogen, but that it plays the same part" (Dumas, 

 "Note on Substitutions," Ann. Chim. Phys., 1857, 49, 

 487-496, p. 496). 



At the same time he repudiated, definitely and finally, 

 Berzelius's electrochemical theories, as being neither " based 

 on evident facts," nor even valuable as a hypothesis in 

 " explaining and predicting facts " (Comptes rendus, 1839, 8, 

 621). 



Liebig also was soon compelled to break away from the 

 complexities into which Berzelius's electrochemical theories 

 had led him and, in footnotes to two of Berzelius's papers, 

 added that : 



" I do not share the views of Berzelius, since they rest 

 upon a mass of hypothetical assumptions, for the correct- 

 ness of which proof of every kind is lacking." 



" I do not share the views, by which he explains the com- 

 position of the compounds discovered by Malaguti, 1 I 

 believe on the contrary, that these materials are produced by 

 simple substitutions" (Ann. Chem. P/iqrm., 1839, 31, 119, 

 32, 72). 



E. ORGANIC TYPES, NUCLEI AND RESIDUES 



Dumas (1839) adopts the theory of types, Dumas was 

 led to believe in the direct replacement of hydrogen by 

 chlorine mainly through his own experiments on TRICHLORO- 

 ACETIC ACID. He added small quantities of acetic acid to 

 a series of fifteen to twenty five-litre flasks filled with chlorine, 

 exposed them to sunlight, and on the next day found the 

 interiors frosted over with a crystalline acid, readily soluble 

 in water and deliquescent on exposure to air. The acid 

 1 Chlorinated ethers, e.g. C 4 H 6 C1 4 O from C 4 H 10 O (p. 410). 



