Henderson, Lawrence J. (Joseph)(1878–1942) biochemist, physiologist; born in Lynn, Mass. He spent his career as a research physician at Harvard (1904–42). His quantitative measurements of bodily buffer systems (1907–10) were expanded logarithmically by Danish biochemist K. A. Hasselbach to produce the Henderson-Hasselbach equation describing acid-base equilibria. He founded the department of physical chemistry at Harvard (1920) and established Harvard's Fatigue Laboratory (1927) to study chemical changes due to environmentally-induced stress. Further investigations of oxygen-carbon dioxide exchanges in blood led to his seminal book, Blood: A Study in General Physiology (1928). A philosopher and scholar with varied interests, Henderson related Vilfredo Pareto's classic writings on sociology to his own homeostatic approach to the buffering capability of the blood; his lectures on Pareto influenced numerous young sociologists.