Harmon Northrop Morse

Harmon Northrop Morse (October 15, 1848 – September 8, 1920) was an American chemist. Today he is known as the first to have synthesized paracetamol, but this substance only became widely used as a drug decades after Morse's death. In the first half of the 20th century he was best known for his study of osmotic pressure, for which he was awarded the Avogadro Medal in 1916. The Morse equation for estimating osmotic pressure is named after him. He viewed all forms of recreation as objectionable. Northrop's mother died at a young age, leaving behind Northrop, his brother Anson and his sister Delia.

Thanks to an endowment left by his grandmother, Northrop Morse studied chemistry at Amherst College, which he entered in 1869 and graduated in 1873. He continued his studies in Germany, and obtained a PhD in chemistry with a minor in mineralogy from the University of Göttingen in 1875. During Morse's time there, Friedrich Wöhler had officially retired from active service, and Morse's thesis adviser, and head of the Laboratory, was Hans Hübner. Nevertheless, Wöhler occasionally spent part of his time in the laboratory and a few favored students, generally Americans, were given the privilege of working with him. Hübner was an organic chemist, so Morse's initial work was in that area, but later Morse would work in what is now known as physical chemistry.

Morse married twice and had four children—a daughter and three sons. His, second wife, Elizabet Dennis Clark, helped him in preparing articles for publication. After his retirement, Morse became quite reclusive, seldom left his house and his health deteriorated. He died during his annual vacation in Chebeague Island, Maine—a place he often visited. which summarized the work he performed between 1899 and 1913. for which he won the first Nobel Prize in Chemistry. He derived an analogue of Gay-Lussac's law for the dependence of the osmotic pressure on absolute temperature. Van 't Hoff derived his analogy based on data from experiments that Wilhelm Pfeffer, a professor of botany, had published a decade earlier under the title "Osmotische Untersuchungen" — an account of his endeavors to measure osmotic pressure by means of porous cells lined with a semipermeable membrane consisting of copper(II)-hexacyanoferrate(II). After van 't Hoff's theory was published, experimenters had trouble to replicate Pfeffer's measurements, mainly because they could not find or make clay cells of suitable quality to support the semipermeable membrane, Furthermore, Morse showed that Pfeffer's cells were leaky at high pressure. Morse's main experimental contribution was an electrolytic method of depositing semi-permeable membranes. This technological advancement made possible the verification and correction of van 't Hoff's theory.