Robert Bunsen

Robert Whilhelm Eberhard Bunsen was born on March 31, 1811 in Gottengen, Germany. His father, Christian Bunsen was the chief librarian and a professor at the University of Gottengen where Bunsen studied chemistry earning a PhD in 1831 at the age of nineteen. After finishing his doctorate Bunsen spent three years traveling through Europe, partially at the expense of the German government during which he studied a multitude of subjects. When he returned to Gottengen he served as a lecturer in chemistry. Beginning in 1836 he taught chemistry at the Polytechnic School of Cassel, and in 1839 he was appointed professor of chemistry at the University of Marburg where he remained until 1851. After a brief stint at the University of Breslau, in 1852 he became chair of chemistry at the University of Heidelberg, where he remained until retirement in 1889.

Bunsen's early research involved compounds of arsenic. He developed the use of iron oxide hydrate to precipitate arsenate which is still used to treat arsenate poisoning. He continued his studies of arsenic at the cost of almost poisoning himself and with the loss of an eye, injured by exploding glassware. One of his most lasting contribution to science was the invention of his eponymous burner. At the time chemists used oil and alcohol lamps as a source of flame. In 1854 Bunsen had gas piped into his laboratory and when none of burners available met his needs he developed his own, that produced a colorless flame, the intensity of which could be adjusted.

Using his new burner Bunsen tested different chemicals and observed different colors and was able to detect different elements based on the colors produced. Sometimes color produced by one element would mask another and he used colored glass to mask some elements. Not satisfied with this solution, he mentioned his problem to Gustav Kirchoff, a Russian physicist and using two parts from telescopes, a prism, and a cigar box with its inside covered in black the pair made a prototype spectroscope. Using their new spectroscope Bunsen and Kirchoff quickly were able to identify different elements by their spectra. In order to find undiscovered elements Bunsen had 40 tons of mineral water evaporated and he was able to identify for the first time the alkali metal elements cesium (from the Latin ceasium, sky blue, named for its blue spectral lines) and rubidium (from the Latin rubidius, or dark red, named for its red spectral lines). Today spectroscopes are widely used in chemical analysis.

Bunsen died on August 16, 1889 in Heidelberg.


References:

Fujinaka, Pam and Kerekes, Christina; "Robert Wilhelm Bunsen (1811-1899)"; retrieved from woodrow.org

Morris, Richard; Last Sorcerers: Path from Alchemy to the Periodic Table; Joseph Henry Press; 2003

Robert Whilhelm Bunsen NNDB profile

Robert Bunsen Wikipedia Entry

Sidney W. Fox

Sidney Walter Fox was born on March 24, 1912 in Los Angeles, California. His father, Jacob Fox, was a wigmaker and his mother, Louise Berman, was a Ukrainian immigrant. He attended the University of California Los Angeles, earning a bachelors in chemistry and the California Institute of Technology, earning a PhD in 1940. He taught briefly at the University of California Berkeley and the University of Michigan before moving to Iowa State University in 1943 and where he was a professor of biochemistry from 1947 to 1954. He was professor of chemistry at Florida State University from 1954 to 1964 when he became director of the Institute of Molecular and Cellular Evolution at the University of Miami. He retired in 1989.

Fox's biochemical research dealt with the study of the origin of life. Fox's research showed that amino acids, when subjected to heat, will spontaneously form polypeptide compounds, Fox dubbed proteinoids (the earlier Miller-Urey experiment had shown that amino acids could have been generated by conditions of the Earth's primordial atmosphere). Fox hypothesized that these poly-amino acid molecules could be the origin the protein molecules that make up living things.  When put into water or salt solution these proteinoids form microspheres, that are one or two microns in diameter. These microspheres behave like cellular membranes, budding off and forming new microspheres. Fox believed that these proteinoid microspheres were the origin of bacterial cell walls. Fox's proteinoid theory for the origin of life has its detractors, who believe that concentrations of the particular amino acids that Fox used in his experiments could not have been present in the primordial environment. Fox was one of the first scientists to examine moon rocks brought back to Earth by NASA.

Fox died on August 10, 1998 in Mobile, Alabama.


References:

Daintith, John; "Fox, Sydney Walter" in Biographical Encyclopedia of Scientists, Third Edition; CRC Press; 2010

"Sydney W Fox, Analyzed First Moon Rocks"; Los Angeles Times; August 18, 1998

Sydney W. Fox Wikipedia Entry

Walter Hess

Walter Rudolf Hess was born on March 17, 1881 in Frauenfeld in the Swiss canton of Thurgau. He was the second of three children on Clemens and Gertrude Hess. His father was a physics teacher in a grammar school and ran a weather station. Hess learned physics from his father and helped the family electrify the family's apartment. He began studying medicine in Lausanne in 1899, finishing his studies in Berlin, Kiel, and Zurich. After passing his qualifying medical exam in Zurich, in 1906, he served as a surgeon's assistant. While a surgeon's assistant he developed a device to measure blood viscosity that was widely used clinically but has been replaced by the measurement of blood sedimentation rate. He was later an ophthalmologists's assistant and then an ophthalmologist. Hess's interest was in physiology and in 1912 he gave up a prosperous practice to take the position of a physiologist's assistant, working under Justus Gaule. In 1916, with Gaule's retirement, Hess first became interim director and then director and professor of the Department of Physiological Institute at the University of Zurich. He remained there until his retirement in 1951.

Hess's physiological studies included the circulatory system, but he is most remembered for his research into brain function. Using a fine tipped electrode he was able to stimulate regions of the mid-brain and develop a map of its functions. Mammalian brains are largely divided three regions: the hindbrain, the midbrain, and the forebrain, moving up from the spinal cord to the head (for a diagram of the brain showing some of the functions of different regions see here). Different regions of the brain have different functions with the hind brain, or brain stem, having body maintenance functions including body temperature, heart and breathing control. The forebrain includes the four lobes of the cerebellum which control thought, memory, and movement. Hess, using his electrode to stimulate regions of the hypothalamus, a region of the mid brain, found that he could stimulate excitement or apathy. He also found regions where he could stimulate hunger and thirst. For his researches he was awarded the 1949 Nobel Prize in medicine and physiology "for his discovery of the functional organization of the interbrain as a coordinator of the activities of the internal organs."

Other honors won by Hess include the Marcel Benoist Prize in 1932 and honorary doctorates from the Universities of Bern, Geneva, and Freiburg and from McGill University.

He died on August 12, 1973.


References:

Hess, C.W.; "Walter Hess (17.3.1881-12.6.1973)"; Schwiezer Archiv fur Neurologie und Psychiatrie (2008)159:259-261

Walter Hess Nobel Biography

Walter Hess Wikipedia Entry

Jeremias B. Richter

Jeremias Benjamin Richter was born on March 10, 1762 in Hirschberg, in Silesia, then part of Prussia, but now part of Poland. He became a mining official in Breslau in 1794 and in 1800 was appointed assessor of the Department of Mines and chemist to the royal porcelain factory in Berlin. He died in Berlin on April 4, 1807.

Richter is most remembered for deducing the law of equivalent proportions. The law of equivalent proportions states that when two or more elements are combined, the weights of these elements are proportional to their equivalent weights, so as such the two are related. This concept, that elements combine in definite ratios to form compounds, is the basis of stoichiometry, a word coined by Richter to describe, "the art of chemical measurements, which has to deal with the laws according to which substances unite to form chemical compounds". This discovery hinted at the existence of atoms, which today we know combine in definite ratios to form compounds.

At the time Richter's work was largely ignored due to his obscure and clumsy writing style and his emphasis on mathematics, which chemists at the time were not interested in. His discoveries were wrongly ascribed to Carl Wenzel and it was not until 1841 when Henri Hess gave Richter proper credit.


References:

Leicester, Henry Marshall and Klickstein, Herbert S.; "Jeremias Benjamin Richter: 1762-1807"; found in A Source Book in Chemistry, 1400-1900; Harvard University Press; 1969

"Richter, Jeremias Benjamin"; Encyclopedia Britannica; 1911

Jeremias Benjamin Richter Wikipedia Entry