1952 Volume 30 Issue 12 Pages 379-385
Ice crystals were captured on Mt. Zao and their nuclei were studied by using the electron-microscope and hydrogen fluoride. The record of radio sounding indicates these ice crystals were formed at a temperature of about -9°C.
The observation shows that most of the nuclei are soil particles, such as hematite, limonite, etc. On the other hand, very few combustion nuclei are found.