Abstract
More than these ten years, several researches have been made to know the nature and the concentration of freezing nuclei in the actual atmosphere. Most of them were experiments where an expansion or a cold chamber was used to find the concentration of potential nucleating particles. Studies of the actual nuclei in natural snow crystals have been developed along two lines. The one is the electron microscopic study to which Kumai (1951), Okita (1952), and Isono (1955) have made contributions. The other is the study on the freezing temperature of melted snow. Vaughan (1954), Kiryuhkin and Pevzner (1956) measured the freezing temperature of melted snow collected in bulk. Recently Hama and Itoo (1956) measured the freezing temperatures of melted individual snow crystals where volumes of the melted crystals had a variance according to their original sizes.
Here the author presents the freezing temperatures of supercooled water drops with a constant volume which contain a melted snow crystal.
