The inhalational anesthetics
can be divided into two classes based on their physical properties. N2O
and cy-clopropane are gases at room temperature and are sup-plied in gas tanks
that are regulated by the anesthesia machine. The others are liquids that are
volatile follow-ing the application of low heat, which is supplied by a
vaporizer attached to the anesthesia machine. The halo-genated hydrocarbons are
among the most potent volatile anesthetics.