Two important periods in the history of mechanochemistry

Some form of mechanochemical experience has existed from fine grinding of materials since prehistoric times, yet the first systematic investigations on the chemical effects of mechanical action were carried out only at the end of the nineteenth century. Walth,re Spring studied the consolidation and reactions of powdered materials due to high pressure at the University of LiSge, in order to understand the formation of minerals in the earth's crust and M. Carey Lea carried out experiments on the decomposition of compounds by grinding in a mortar. In some of his experiments mechanical action produced distinctly different result from the effect of heat. The first part of this paper compares the circumstances and results of Spring and Lea. The other important period in the history of mechanochemistry was the 1960s, the time when the first dedicated conferences were organized and a broader community of mechanochemists formed. This happened in the Soviet Union and Eastern Europe where several groups were working on subjects related to mechanochemistry. In 1968, the first dedicated conference was organized as a special session of the yearly meeting of Soviet colloid chemists. An attempt is made to reconstruct the circumstances leading to that event and the roles played by Rebinder and Thiessen in bringing it together. The next conference on mechanochemistry was already a separate event and it started a yearly series. Extensions have led to the INCOME conferences, including this one in Koice in 2017.