The supposed analogy between hydrogen montmorillonite and a weak organic acid has encouraged several investigators, notably Berger and Deuel, to attempt to esterify the exchange positions using standard organo-chemical methods.

In our opinion the experimental evidence so far presented to establish the course and extent of the esterification reaction is inconclusive. Thus Berger determined the methoxyl content of the product obtained by treating dry hydrogen montmorillonite with diazomethane in ether without showing that sorbed methyl alcohol was absent. This omission is particularly relevant when Berger states that he dried his starting material at 150°C. Data on the dehydration of hydrogen montmorillonite has shown that under these conditions Berger's sample probably contained more than 2% sorbed water. Taking into account the difficulty of washing montmorillonite free of methyl alcohol, this amount of water would be sufficient to hydrolyse enough diazomethane to account for the observed methoxyl contents.