(Received February 12, 1976)
Aluminium smokes in He, Ar and Xe at various pressures were studied. Their macroscopic shapes were roughly the same in 200 Torr He, 10 Torr Ar and l Torr Xe. Under these conditions the particle size in the inner zone of a smoke decreased with the molecular weight of the gas. In the course of the experiment, several electron micrographs showing the intermediate stages of particle coalescence in the smoke were obtained. When an inactive gas contained oxygen, the smoke particles were almost perfectly oxidized in the outer zone of the smoke, while the oxidation was slight in the inner zone.