Jesse Francis McClendon
Encyclopedia
Jesse Francis McClendon (December 21, 1880 – November 22, 1976) was an American
chemist
, zoologist and physiologist. He is remembered today mainly for the first pH
measurement of human stomach
in situ
.
Jesse F. McClendon made substantial contributions in a variety of fields, including invertebrate
zoology, nutrition
, life processes of cell membrane
s, the importance of pH control , the role of iodine
in human health and specifically its relation to prevention of goiters .
In the early 1930s Jesse F. McClendon tested the healthfulness of hamburger
s by putting a University of Minnesota
medical student on only hamburgers and water diet for 13 weeks.
. First time he married in 1911 and had two children in this marriage. Second time McClendon married in 1936. He died on November 22, 1976 in Harleysville, Pennsylvania
.
He completed his B.S. in 1903 and M.S. in 1904, both from the University of Texas. In 1903 he worked in University of Texas under Dr. William Morton Wheeler
.
Then he received a Ph.D.
in zoology from the University of Pennsylvania
in 1906.
1907–1910: McClendon taught biology at Randolph-Macon College
, then zoology at the University of Missouri
.
1910–1914: McClendon was Assistant, Instructor in histology and embryology of the Weill Cornell Medical College of Cornell University. He investigated frog blastomeres.
1914–1939: McClendon worked at Physiological Laboratory of the University of Minnesota Medical School
, Minneapolis (1920–1939—he was Professor of Physiological Chemistry). In the Laboratory McClendon realized some pioneer researches: Low iodine-goiter relationship; Micromanipulation—Frog egg development and others.
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
chemist
Chemist
A chemist is a scientist trained in the study of chemistry. Chemists study the composition of matter and its properties such as density and acidity. Chemists carefully describe the properties they study in terms of quantities, with detail on the level of molecules and their component atoms...
, zoologist and physiologist. He is remembered today mainly for the first pH
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
measurement of human stomach
Stomach
The stomach is a muscular, hollow, dilated part of the alimentary canal which functions as an important organ of the digestive tract in some animals, including vertebrates, echinoderms, insects , and molluscs. It is involved in the second phase of digestion, following mastication .The stomach is...
in situ
In situ
In situ is a Latin phrase which translated literally as 'In position'. It is used in many different contexts.-Aerospace:In the aerospace industry, equipment on board aircraft must be tested in situ, or in place, to confirm everything functions properly as a system. Individually, each piece may...
.
Jesse F. McClendon made substantial contributions in a variety of fields, including invertebrate
Invertebrate
An invertebrate is an animal without a backbone. The group includes 97% of all animal species – all animals except those in the chordate subphylum Vertebrata .Invertebrates form a paraphyletic group...
zoology, nutrition
Nutrition
Nutrition is the provision, to cells and organisms, of the materials necessary to support life. Many common health problems can be prevented or alleviated with a healthy diet....
, life processes of cell membrane
Cell membrane
The cell membrane or plasma membrane is a biological membrane that separates the interior of all cells from the outside environment. The cell membrane is selectively permeable to ions and organic molecules and controls the movement of substances in and out of cells. It basically protects the cell...
s, the importance of pH control , the role of iodine
Iodine
Iodine is a chemical element with the symbol I and atomic number 53. The name is pronounced , , or . The name is from the , meaning violet or purple, due to the color of elemental iodine vapor....
in human health and specifically its relation to prevention of goiters .
In the early 1930s Jesse F. McClendon tested the healthfulness of hamburger
Hamburger
A hamburger is a sandwich consisting of a cooked patty of ground meat usually placed inside a sliced bread roll...
s by putting a University of Minnesota
University of Minnesota
The University of Minnesota, Twin Cities is a public research university located in Minneapolis and St. Paul, Minnesota, United States. It is the oldest and largest part of the University of Minnesota system and has the fourth-largest main campus student body in the United States, with 52,557...
medical student on only hamburgers and water diet for 13 weeks.
Biography
Jesse F. McClendon was born in Lanett, AlabamaLanett, Alabama
Lanett is a city in Chambers County, Alabama, United States. At the 2000 census the population was 7,897. Lanett, originally called Bluffton, is located in eastern Alabama, on the Chattahoochee River, southwest of Atlanta, Georgia...
. First time he married in 1911 and had two children in this marriage. Second time McClendon married in 1936. He died on November 22, 1976 in Harleysville, Pennsylvania
Harleysville, Pennsylvania
Harleysville is a census-designated place in Montgomery County, Pennsylvania, United States. The population was 9,286 at the 2010 census. It is located within Lower Salford Township...
.
He completed his B.S. in 1903 and M.S. in 1904, both from the University of Texas. In 1903 he worked in University of Texas under Dr. William Morton Wheeler
William Morton Wheeler
William Morton Wheeler, Ph.D. was an American entomologist, myrmecologist and Harvard professor.-Early life:...
.
Then he received a Ph.D.
Ph.D.
A Ph.D. is a Doctor of Philosophy, an academic degree.Ph.D. may also refer to:* Ph.D. , a 1980s British group*Piled Higher and Deeper, a web comic strip*PhD: Phantasy Degree, a Korean comic series* PhD Docbook renderer, an XML renderer...
in zoology from the University of Pennsylvania
University of Pennsylvania
The University of Pennsylvania is a private, Ivy League university located in Philadelphia, Pennsylvania, United States. Penn is the fourth-oldest institution of higher education in the United States,Penn is the fourth-oldest using the founding dates claimed by each institution...
in 1906.
1907–1910: McClendon taught biology at Randolph-Macon College
Randolph-Macon College
Randolph–Macon College is a private, co-educational liberal arts college located in Ashland, Virginia, United States, near the capital city of Richmond. Founded in 1830, the school has an enrollment of over 1,200 students...
, then zoology at the University of Missouri
University of Missouri
The University of Missouri System is a state university system providing centralized administration for four universities, a health care system, an extension program, five research and technology parks, and a publishing press. More than 64,000 students are currently enrolled at its four campuses...
.
1910–1914: McClendon was Assistant, Instructor in histology and embryology of the Weill Cornell Medical College of Cornell University. He investigated frog blastomeres.
1914–1939: McClendon worked at Physiological Laboratory of the University of Minnesota Medical School
University of Minnesota Medical School
The University of Minnesota Medical School is the medical school of the University of Minnesota. It is a combination of two campuses situated in Minneapolis and Duluth, Minnesota....
, Minneapolis (1920–1939—he was Professor of Physiological Chemistry). In the Laboratory McClendon realized some pioneer researches: Low iodine-goiter relationship; Micromanipulation—Frog egg development and others.
Description of McClendon pH-probe
In measuring the acidity of the gastric contents, it was found possible to lower an electrode into the stomach. The apparatus designed for work on the stomach contents consists chiefly of a rubber tube 60 cm. long and 3 mm. bore, and two No. 40 silk covered copperCopperCopper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...
wires, that were coated with rubber cementRubber cementRubber cement is an adhesive made from elastic polymers mixed in a solvent such as acetone, hexane, heptane or toluene to keep them fluid enough to be used. Water-based formulas, often stabilised by ammonia, are also available...
and dried several times. One wire, M, extends through the rubber tube, JJ, and the other, N, passes down outside of it until by entering the hole, E, it connects with a platinumPlatinumPlatinum is a chemical element with the chemical symbol Pt and an atomic number of 78. Its name is derived from the Spanish term platina del Pinto, which is literally translated into "little silver of the Pinto River." It is a dense, malleable, ductile, precious, gray-white transition metal...
wire that is fused into the lower end of a short piece of glass tube that is inserted into the rubber tube. The lower end of the glass tube and copper-platinum junction is covered with sealing wax, A. A drop of pure mercuryMercury (element)Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver or hydrargyrum...
is dropped into the lower end of the glass tube so as to connect with the platinum wire at the level of B. Above the mercury a little calomel washed with concentrated KClKCLKCL or KCl may stand for:*KCl, the chemical symbol for potassium chloride*Kirchhoff's current law*King's College London, constituent college of the University of London*Kyoto Common Lisp...
solution, C, is placed, and the rest of the glass tube packed with moist KC1 crystals, D, and the hole, E, stuffed with cotton soaked in KC1 solution. This forms a calomel electrode, and is separated off from the remainder of the tube by a short piece of glass rod, F. Above F several holes are cut in the rubber tube at the level of G, and from this point a fine platinized platinum wire extends through the lumen of the tube and is held in place by fusion to a bump on the inside of a short piece of glass tube at the level of I. This platinum wire then connects with the wire M and the junction is coated with rubber. The rubber tube is connected at K with a tube, L, leading from a hydrogenHydrogenHydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...
generator, and a slow stream of H2 passes down the rubber tube and out at G, thus converting the platinum wire from H to F into a hydrogen electrode.