The precipitation phenomenon in which solids such as crystals appear from substances dissolved in liquids is involved in various industrial fields.In addition, many diseases are known to be caused by abnormalities in which molecules in the body become solid.Therefore, elucidating the detailed mechanism of the precipitation phenomenon has the potential to lead to the development of new materials and the prevention of diseases.However, it is difficult to observe the movement of very small molecules and ions in detail in solution, and it has not been possible to observe the moment of precipitation until now.

　This time, when I tried to observe the moment of crystallization of sodium acetate by the method called X-ray single molecule tracking method developed by Professor Sasaki in 1998, sodium acetate gathers toward precipitation in a solution that exceeds the saturation amount. I was able to observe the situation.Until now, it was thought that the ions did not move much at the moment of crystallization, but unexpectedly, it turned out that there are lumps that move extremely fast.This movement is thought to be deeply involved in crystal formation.

　If we can elucidate the mechanism of motion newly discovered this time, we can expect that it will lead to the development of new materials that can control the precipitation of solids and utilize that state.From a medical point of view, it may be possible to prevent the formation of stones and the precipitation of proteins in the brain, which is said to be the cause of Alzheimer's disease.In the future, research will proceed toward the elucidation of new phenomena that have just been discovered.