Etch-decoration reveals that the rate of removal of carbon atoms exposed at monolayer steps on graphite surfaces depends on the population density of these edge atoms (the rate is higher at a low-density surface) and that carbon removal continues for a prolonged period after the oxygen supply in the gas phase has been shut off. The edge carbons are removed by both oxygen from the gas phase and oxygen in the adsorbed oxides which migrate from the neighboring basal carbon atoms.

The free‐radical polymerization of phenylacetylene initiated by azobisisobutyronitrile at 50°C was studied in bulk and in the presence of benzene and toluene. The polymerization rate is approximately first‐order with respect to the initiator concentration. The number‐average molecular weight of the polymer is independent of the initiator concentration in bulk and is approximately proportional to the monomer concentration in the presence of the two diluents, but independent of their nature. The data are consistent with a mechanism based on first‐order decay of active to inactive radicals. This step appears to exert the major control over kinetic and molecular chain lengths. Chain transfer to the monomer is concluded to be absent or to make only a small contribution to molecular termination.