Harmon Northrop Morse
Encyclopedia
Harmon Northrop Morse 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.
farmer, who considered all forms of recreation
objectionable. Northrop's mother died at an 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. Neverthelss 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 returned to the United States in 1875, and was given an assistantship at Amherst. There he worked for a year under Harris and Emerson. When Johns Hopkins University
opened in 1876, Morse moved there as an associate of Ira Remsen
, thanks in part to a letter of recommendation from Emerson. Remsen and Morse started the chemistry laboratory at Johns Hopkins together, and Morse's experience from Germany proved very valuable, as the American chemistry school was less developed at the time. Morse officially became an associate professor in 1883, a full professor of inorganic and analytical chemistry in 1892, and director of the chemical laboratory in 1908. He retired in 1916.
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. He was buried at Amherst, where he also had a summer house. In his obituary, Remsen remembers Morse as "quiet and uneffusive".
. In the first half of the 20th century, the Morse name was mainly associated with his work in this area. With the help of a grant from the Carnegie Institution of Washington, he published a report entitled The Osmotic Pressure of Aqueous Solutions, which summarized the work he performed between 1899 and 1913. For this work he was awarded the Avogadro Medal by the Academy of Sciences of Turin (Academia della Scienze di Turino)—the academy where Avogadro
had taught. The medal was a unique prize awarded on the centennial anniversary of Avogadro's law
.
In 1887 Jacobus Henricus van 't Hoff
published his landmark paper regarding the analogy between gas pressure and the osmotic pressure of solutions, 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, a problem that had affected Pfeffer as well. 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.
In a modern formulation, van 't Hoff's equation states that ΠV = nRT, where Π is the osmotic pressure, V is the volume of the solution, n is the number of moles of the solute
, R is the gas constant
, and T is the absolute temperature (compare with the ideal gas law
). This equation can also be written as Π = cRT, where c = n/V is the molarity (mol/m3) of the solution. Morse showed experimentally that Π = mRT, where m is the molality (mol/kg) yields a better approximation of osmotic pressure. This latter equation is named after him. Using these equations one can calculate the molar mass
of solutes from the osmotic pressure data.
Paracetamol
Paracetamol INN , or acetaminophen USAN , is a widely used over-the-counter analgesic and antipyretic . It is commonly used for the relief of headaches and other minor aches and pains and is a major ingredient in numerous cold and flu remedies...
, 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
Osmotic pressure
Osmotic pressure is the pressure which needs to be applied to a solution to prevent the inward flow of water across a semipermeable membrane....
, for which he was awarded the Avogadro Medal in 1916. The Morse equation for estimating osmotic pressure is named after him.
Life and career
Harmon Northrop Morse was a descendent of John Morse, who came from England in 1639 and settled in New Haven. His father, Harmon Morse, was a puritanPuritan
The Puritans were a significant grouping of English Protestants in the 16th and 17th centuries. Puritanism in this sense was founded by some Marian exiles from the clergy shortly after the accession of Elizabeth I of England in 1558, as an activist movement within the Church of England...
farmer, who considered all forms of recreation
Recreation
Recreation is an activity of leisure, leisure being discretionary time. The "need to do something for recreation" is an essential element of human biology and psychology. Recreational activities are often done for enjoyment, amusement, or pleasure and are considered to be "fun"...
objectionable. Northrop's mother died at an 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
Amherst College
Amherst College is a private liberal arts college located in Amherst, Massachusetts, United States. Amherst is an exclusively undergraduate four-year institution and enrolled 1,744 students in the fall of 2009...
, 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
Mineralogy
Mineralogy is the study of chemistry, crystal structure, and physical properties of minerals. Specific studies within mineralogy include the processes of mineral origin and formation, classification of minerals, their geographical distribution, as well as their utilization.-History:Early writing...
from the University of Göttingen in 1875. During Morse's time there, Friedrich Wöhler
Friedrich Wöhler
Friedrich Wöhler was a German chemist, best known for his synthesis of urea, but also the first to isolate several chemical elements.-Biography:He was born in Eschersheim, which belonged to aau...
had officially retired from active service, and Morse's thesis adviser, and head of the Laboratory, was Hans Hübner. Neverthelss 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
Physical chemistry
Physical chemistry is the study of macroscopic, atomic, subatomic, and particulate phenomena in chemical systems in terms of physical laws and concepts...
.
Morse returned to the United States in 1875, and was given an assistantship at Amherst. There he worked for a year under Harris and Emerson. When Johns Hopkins University
Johns Hopkins University
The Johns Hopkins University, commonly referred to as Johns Hopkins, JHU, or simply Hopkins, is a private research university based in Baltimore, Maryland, United States...
opened in 1876, Morse moved there as an associate of Ira Remsen
Ira Remsen
Ira Remsen was a chemist who, along with Constantin Fahlberg, discovered the artificial sweetener saccharin. He was the second president of Johns Hopkins University.-Biography:...
, thanks in part to a letter of recommendation from Emerson. Remsen and Morse started the chemistry laboratory at Johns Hopkins together, and Morse's experience from Germany proved very valuable, as the American chemistry school was less developed at the time. Morse officially became an associate professor in 1883, a full professor of inorganic and analytical chemistry in 1892, and director of the chemical laboratory in 1908. He retired in 1916.
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
Chebeague Island, Maine
Chebeague Island is an island town in Cumberland County, Maine, United States, located in Casco Bay, 10 miles from Portland. These islands are sometimes referred to as an older, now archaic term "The Calendar Islands" because there was once a belief that the approx. number of islands was about 365....
—a place he often visited. He was buried at Amherst, where he also had a summer house. In his obituary, Remsen remembers Morse as "quiet and uneffusive".
Scientific legacy
Although Johns Hopkins was a research university from the beginning, the early years of the chemistry department were marked by a lack of students and equipment. Morse was initially discouraged and spent most of his time teaching. Around the turn of the century Morse published a series of papers on the preparation of permanganic acid. This led him to study osmotic pressureOsmotic pressure
Osmotic pressure is the pressure which needs to be applied to a solution to prevent the inward flow of water across a semipermeable membrane....
. In the first half of the 20th century, the Morse name was mainly associated with his work in this area. With the help of a grant from the Carnegie Institution of Washington, he published a report entitled The Osmotic Pressure of Aqueous Solutions, which summarized the work he performed between 1899 and 1913. For this work he was awarded the Avogadro Medal by the Academy of Sciences of Turin (Academia della Scienze di Turino)—the academy where Avogadro
Amedeo Avogadro
Lorenzo Romano Amedeo Carlo Avogadro di Quaregna e di Cerreto, Count of Quaregna and Cerreto was an Italian savant. He is most noted for his contributions to molecular theory, including what is known as Avogadro's law...
had taught. The medal was a unique prize awarded on the centennial anniversary of Avogadro's law
Avogadro's law
Avogadro's law is a gas law named after Amedeo Avogadro who, in 1811, hypothesized that two given samples of an ideal gas, at the same temperature, pressure and volume, contain the same number of molecules...
.
In 1887 Jacobus Henricus van 't Hoff
Jacobus Henricus van 't Hoff
Jacobus Henricus van 't Hoff, Jr. was a Dutch physical and organic chemist and the first winner of the Nobel Prize in chemistry. He is best known for his discoveries in chemical kinetics, chemical equilibrium, osmotic pressure, and stereochemistry...
published his landmark paper regarding the analogy between gas pressure and the osmotic pressure of solutions, for which he won the first Nobel prize
Nobel Prize
The Nobel Prizes are annual international awards bestowed by Scandinavian committees in recognition of cultural and scientific advances. The will of the Swedish chemist Alfred Nobel, the inventor of dynamite, established the prizes in 1895...
in chemistry. He derived an analogue of Gay-Lussac's law
Gay-Lussac's law
The expression Gay-Lussac's law is used for each of the two relationships named after the French chemist Joseph Louis Gay-Lussac and which concern the properties of gases, though it is more usually applied to his law of combining volumes, the first listed here...
for the dependence of the osmotic pressure on absolute temperature. Van 't Hoff derived his analogy based on data from experiments that Wilhelm Pfeffer
Wilhelm Pfeffer
Wilhelm Friedrich Philipp Pfeffer was a German botanist and plant physiologist who was born in Grebenstein.- Academic career :...
, 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
Semipermeable membrane
A semipermeable membrane, also termed a selectively permeable membrane, a partially permeable membrane or a differentially permeable membrane, is a membrane that will allow certain molecules or ions to pass through it by diffusion and occasionally specialized "facilitated diffusion".The rate of...
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, a problem that had affected Pfeffer as well. 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.
In a modern formulation, van 't Hoff's equation states that ΠV = nRT, where Π is the osmotic pressure, V is the volume of the solution, n is the number of moles of the solute
Solution
In chemistry, a solution is a homogeneous mixture composed of only one phase. In such a mixture, a solute is dissolved in another substance, known as a solvent. The solvent does the dissolving.- Types of solutions :...
, R is the gas constant
Gas constant
The gas constant is a physical constant which is featured in many fundamental equations in the physical sciences, such as the ideal gas law and the Nernst equation. It is equivalent to the Boltzmann constant, but expressed in units of energy The gas constant (also known as the molar, universal,...
, and T is the absolute temperature (compare with the ideal gas law
Ideal gas law
The ideal gas law is the equation of state of a hypothetical ideal gas. It is a good approximation to the behavior of many gases under many conditions, although it has several limitations. It was first stated by Émile Clapeyron in 1834 as a combination of Boyle's law and Charles's law...
). This equation can also be written as Π = cRT, where c = n/V is the molarity (mol/m3) of the solution. Morse showed experimentally that Π = mRT, where m is the molality (mol/kg) yields a better approximation of osmotic pressure. This latter equation is named after him. Using these equations one can calculate the molar mass
Molar mass
Molar mass, symbol M, is a physical property of a given substance , namely its mass per amount of substance. The base SI unit for mass is the kilogram and that for amount of substance is the mole. Thus, the derived unit for molar mass is kg/mol...
of solutes from the osmotic pressure data.