HETEROLOGY n.
the same substance, or of the analogous members of different series; as, ethane, ethyl alcohol, acetic aldehyde, and acetic acid are in heterology with each other, though each in at the same time a member of a distinct homologous series. Cf. Homology.
INTERNAL-COMBUSTION; INTERNAL-COMBUSTION ENGINE a.
er, as in a steam- engine boiler. The gas used may be a fixed gas, or one derived from alcohol, ether, gasoline (petrol), naphtha, oil (petroleum), etc. There are three main classes: (1) gas engines proper, using fixed gases, as coal, blast-furnace, or producer gas; (2) engines using the vapor of a volatile fluid, as t…