Purkinje, a Czech anatomist and physiologist, was studying the structure of living cells and observed a jelly-like substance within them. He named this substance "protoplasm" from the Greek words "protos" (first) and "plasma" (form).

It's important to note that the understanding of protoplasm has evolved over time. The term is no longer considered a definitive scientific term as modern science has broken down the complex structure and functions of the cell into various organelles and molecules. However, "protoplasm" still serves as a historical reminder of early cell theory and our understanding of the fundamental components of life.