The anhydrides of succinic and glutaric acids are known and are monomeric rings of five and six atoms, respectively. The monomeric anhydride of the next member of the series, adipic acid, is a seven-atom ring, and therefore the direct preparation of this anhydride by the removal of water from the acid should give a polymolecular product, in accordance with the generalizations formulated in the previous papers in this series.'This has been found ...
