He was a Czech physiologist and anatomist who described the substance that makes up the living matter of plants and animals. However, it was Hugo von Mohl who further developed the concept and popularized the term in 1846.
While Purkinje's initial observation of "protoplasm" was based on the viscous, jelly-like substance he observed in plant cells, Mohl's research expanded on this and recognized its significance as the fundamental material of all living cells.