Harmon Northrop Morse facts for kids

Harmon Northrop Morse (born October 15, 1848 – died September 8, 1920) was an American chemist. Today, he is famous for being the first person to create paracetamol, a common medicine. However, it wasn't used widely until many years after he died. During his lifetime, he was most known for his work on something called osmotic pressure. He even won a special award, the Avogadro Medal, for this work in 1916. A scientific rule, the Morse equation, is named after him.

Early Life and Education

Harmon Northrop Morse was born in Cambridge, Vermont. His family had lived in America since 1639. His father was a farmer who believed in hard work and little schooling. Northrop's mother passed away when he was young. He grew up with his brother Anson and sister Delia.

Thanks to money left by his grandmother, Northrop Morse went to Amherst College in 1869. He studied chemistry and graduated in 1873. He then traveled to Germany to continue his studies. In 1875, he earned his PhD (a high-level university degree) in chemistry from the University of Göttingen. While there, he worked with famous chemists like Friedrich Wöhler and Hans Hübner.

Career at Johns Hopkins

Morse came back to the United States in 1875. He worked at Amherst College for a year. In 1876, he moved to Johns Hopkins University when it first opened. He worked with Ira Remsen to set up the chemistry lab there. Morse's experience from Germany was very helpful because American chemistry schools were still developing.

Morse became an associate professor in 1883. He became a full professor of chemistry in 1892. In 1908, he became the director of the chemistry laboratory. He retired from his work in 1916.

Personal Life

Harmon Northrop Morse was married twice. He had four children: one daughter and three sons. His second wife, Elizabet Dennis Clark, helped him prepare his scientific articles. After he retired, Morse became very private and rarely left his home. His health got worse, and he passed away during his yearly vacation in Chebeague Island, Maine. He was buried in Amherst, where he also had a summer house.

Discoveries and Research

Johns Hopkins University was a place for research from the start. However, in the early years, the chemistry department didn't have many students or much equipment. Morse spent a lot of his time teaching.

Around the year 1900, Morse published many papers about preparing permanganic acid. This work led him to study osmotic pressure. For many years, Morse was known for his work in this area. He received money from the Carnegie Institution of Washington to help with his research. He published a report called The Osmotic Pressure of Aqueous Solutions. This report summarized all the work he did between 1899 and 1913.

For this important work, he received the Avogadro Medal in 1916. This special medal was given by the Academy of Sciences of Turin in Italy. It was a unique award given on the 100th anniversary of Avogadro's law.

Understanding Osmotic Pressure

In 1887, a scientist named Jacobus Henricus van 't Hoff published an important paper. He showed how gas pressure and the osmotic pressure of solutions were similar. He later won the first Nobel prize in chemistry for his work.

Van 't Hoff based his ideas on experiments done by Wilhelm Pfeffer. Pfeffer was a botany professor who had measured osmotic pressure. He used special cells with a semipermeable membrane. This membrane allowed some things to pass through but not others.

After van 't Hoff's theory came out, other scientists had trouble repeating Pfeffer's measurements. This was mainly because they couldn't find good quality cells. Morse showed that Pfeffer's cells also leaked under high pressure.

Morse's big contribution was finding a new way to make these semi-permeable membranes. He used an electrolytic method. This new technology made it possible to check and improve van 't Hoff's theory.

The Morse Equation

Van 't Hoff's equation for osmotic pressure is often written as ΠV = nRT. Here, Π is the osmotic pressure, V is the volume of the solution, n is the number of moles of the solute (the substance dissolved), R is the gas constant, and T is the absolute temperature. This is similar to the ideal gas law.

This equation can also be written as Π = cRT, where c is the molarity of the solution. However, Morse's experiments showed that Π = bRT gave a better estimate of osmotic pressure. In this equation, b is the molality of the solution. This improved equation is named after him. Scientists can use these equations to figure out the molar mass of substances dissolved in a solution.