Keely mentions observing a "wonderful variation of gravital sympathy between the molecules of gaseous elements and gaseous chemical compounds, all coming under the molecular subdivision." This strongly indicates the existence of gas-crystals, the plus-molecular aggregation applying to their gaseous state. Inductive sympathetic negative mass attraction also, when applied to gases, mixture of gases and gas compounds, would very likely have often times a frequency which would not induct resonance, simply by formation of these gas crystals in a great variety of degrees, with corresponding complex variations in the mass chord of each combination. These variations would be caused by the residual molecular affinities causing formation of these plus-molecular aggregates. This feature caused Keely a great deal of trouble at one stage of his experiments.