The present work was undertaken because of the interest in this Laboratory in petroleum hydrocarbons, in rearrangements in the aliphatic series, in the limitations of typical aliphatic reactions and in the relation of structure to physical properties of aliphatic compounds. Theoretically, thirty-five structurally isomeric nonanes are possible. Twelve were known when the present work was started, namely, n-nonane, the three monomethyloctanes, 2, 4 ...