Comptes Rendus des Séances de l'Académie des Sciences'', Vol. 6, 629-649
Meeting of Monday, 7 May, 1838
The year after the Dumas-Liebig paper Berzelius replied by asking Pelouze to read a long letter with the following passages to the Academy of Sciences in Paris:
(p. 629) Chemistry has furnished us much food for thought since my last letter. Permit me to profit from it herein. The scientific proclamation of 23 October last year published by MM. Liebig and Dumas gave me enormous satisfaction. The theoretical ideas that it developed in such a clear, precise, and elegant manner gave me even more pleasure because they were totally in agreement with my way of thinking. I regret that a slight error slipped through the editing in that M. Dumas says that for the last ten years he has been working in the spirit of this theory, while everyone who has followed the annals of science has been able to admire the sagacity with which he has tried, during precisely these last ten years, to fight against several of its principal points. Once more in the Academy meeting of 3 April last year he tried to make us believe that camphor should be considerd as a combination of hydrocarbon with water, just like alcohol. Despite this I am in agreement with him, with all my heart, that he should henceforth employ his talents to develop and illuminate theoretical views that I consider more healthy and by which science will gain infinitely more.
(p. 633) The theory of substitutions established by M. Dumas, in which, for example, chlorine can exchange for hydrogen by putting an equal number of atoms in its place, has seemed to be to be a harmful influence on the progress of science: it casts a false light on objects and prevents distinguishing their true forms... An element as eminently electronegative as chlorine would never be able to enter into an organic radical : this idea is contrary to the first principles of chemistry ; its electronegative nature and its powerful affinities mean that it could only find itself therein as part of its own unique compound.
Note that Berzelius (age 59) is taking a dangerously patronizing attitude toward Dumas (age 38) and invoking his theory (that radicals are inviolable and held to one another by electrostatic attraction) to challenge the substitution theory that makes simpler assumptions.