抄録
Crystals of common salt are investigated by a microscope and some interresting results are found.(1) Crystals of solar salt are classified to three types according to the directions of crystal growth.(2) Relation between evaporation velocity and cavity formation (containing mother liquid)in salt crystals is considered, and there are more cavities, where evaporation velocity is great.(3) water content in salt, estimated from the volume of cavities by microscopic observation, coincides with that acquired by drying method.
