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The crystal growth kinetics of two organic substances with low melting entropiessuccinonitrile and cyclohexanol -was studied in the wide range of supercoolings. It has been noted (CHERNOV; JACKSON) that crystals of substances with low melting entropies are to possess atomically rough interfaces and solidify by normal growth mechanism (continuous growth). The experimental data of crystal growth of two organic substances with low melting entropies (succinonitrile and cyclohexanol) are reported in present paper. The melting points of these substances are below 373.15 K (100 "C), succinonitrile having the bcc structure and cyclohexanol -the fcc structure.The growth shapes of these substances were observed in vacuum glass dishes charged with purified and degassed stock material. The dishes with metal platelet were used for intensive heat removal froin the specimens. In these dishes thin specimen layer (0.3-0.5 mm) contacted with polished silver or copper platelet of 0.2 mm thickness. The dishes were bathed with thermostated water with precision of +O.Ol K.The growth shapes of regular crystals were studied a t small supercoolings, [ 1001 being parallel t o microscope optical axis. Such orientation was reached by a number of partial meltings and subsequent growings of the same crystal. After achieving the regular orientation of small crystal the melt used t o be supercooled below 0.1 K and growth shapes were photographed. The small crystals of succinonitrile and cyclohexanol had round stable shapes at low supercoolings, Figure 1. Stability loss, dendrites and other growth shapes were observed at supercooling increase (ALFINTSEY, 43 *

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