Sunday, September 30, 2012

Jean Perrin

Jean Baptiste Perrin was born on September 30, 1870 in Lille, France. He attended Ecole Normale Superieure in Lille and worked there as a physics assistant from 1894 to 1897. He earned his doctorate in 1897 for a thesis on cathode and x-rays. After graduation he was appointed to a readership in physical chemistry at the Sorbonne, University of Paris. He became a professor there in 1910. He served as an officer in the French Army's Engineering Corp. during the World War I and he was removed from his professorship when the Germans occupied Paris in 1940.

Perrin's early work on cathode rays proved that they were made of  negatively charged particles. His work covered a number of topics in physics including the effects of x-rays on the conductivity of gasses, fluorescence, and the radioactive disintegration of radium. He suggested that stars obtained their energy from the thermonuclear reactions of hydrogen. He wrote numerous books and papers including Les Atomes where he describes his studies on Brownian motion, which confirmed the atomic theory, that all matter is made of atoms.

In 1905 Albert Einstein had published a paper on Brownian motion describing how it was the result of atomic theory. Brownian motion is the random motion of particles suspended in a liquid, discovered in 1827 by Robert Brown, an English botanist who watched pollen particles suspended in water. Suspended in a liquid, the particles are constantly bombarded by moving molecules of the liquid. This causes the visible particles to move in random directions. Einstein's paper was theory and it was Perrin who experimentally demonstrated that matter is made of molecules. Perrin was able to use Brownian motion to determine a value for Avagadro's constant that closely agreed with the value obtained using Dalton's law of molecular motion. Avagadro's constant is the number of molecules in a mole of a substance. For his work, proving the atomic theory Perrin was awarded the 1926 Nobel Prize for Physics.

Perrin was the recipient of numerous other awards, including the Joule Prize from the Royal Society in 1896 and the La Caze Prize from the Paris Academy of Sciences in 1914. He was made a commander in the French Legion of Honor in 1926 and a commander in the Legion of Leopold (Belgium). He was awarded numerous honorary doctorates.

In 1940 he fled German occupied France to the United States where he died on April 17, 1942. After World War II, in 1948, his remains were returned to France aboard the light cruiser Jeanne d'Arc and he was buried in the Pantheon in Paris, France.


Allison, Andy; "Jean Perrin and Atomic Theory: Calculating Avagadro's Constant"; Physics @ Suite 101; October 3, 2008

Jean Perrin Nobel Biography

Jean Perrin Wikipedia Entry

Sunday, September 23, 2012

Alexandre Yersin

Alexander Yersin was born on September 22, 1863 in the village of Lavaux, on the shores of lake Geneva in Switzerland. He was the youngest of four children of a Swiss father and a French mother. His father, who as a high school teacher, died three weeks before he was born. He began his medical education in Lausanne, Switzerland, continued in Marburg, Germany and finished his PhD in medicine in Paris France, writing his thesis on tuberculosis in 1888.  In 1886 he became a French citizen. Also in 1886 he began working in the laboratories of Luis Pasteur at what would be the Pasteur Institute. With Pierre Roux he isolated the toxin from diphtheria and he participated in the development of rabies anti-serum.

Yersin quickly tired of working for Pasteur, who was notorious for taking credit for the work of those beneath him, so he signed on as a ship's doctor with Messangeries Maritimes, a shipping company. His duties were light and his first voyage took him to Saigon, Vietnam. Yersin spent many years in Vietnam, some on expeditions into unexplored parts and is a honored hero for the free medical consultations he gave. Streets bearing his name remained named after him following the communist revolution.

In 1894 he was sent by the Pasteur Institute and the French government to Hong Kong to investigate an outbreak of plague. When he arrived he found that Shibasaburo Kitasato, who had recently discovered the role of Clostridium tetani in lockjaw, was already working on isolating the bacterial cause of the plague. Yersin saw that Kitasato was culturing bacteria from the blood and organs of patients, but not the characteristic bubos of bubonic plague. Yersin was able to bribe two British sailors and gain access to the morgue. Using a sterile pipette he punctured the infected lymph node of a recently dead patient. He found faintly gram negative staining bacilli (rod-shaped bacteria) in the material he withdrew from the lymph node. He injected mice with the lymph node material and they quickly died. Autopsies showed the same slightly gram negatively staining bacilli.

Kitasato was quick to publish his results and claim credit for the discovery of the bacteria responsible for plague. Kitasato's cultures turned out not to be pure for the causative organism and Yersin was allowed to name the new bacteria. Pasturella pestis was his choice, honoring Pasteur, but since 1944 it has been Yersinia pestis. Yersina and Kitasato are considered co-discoverers of the organism.

In addition to his medical work, Yersin also tried his hand at agriculture, importing the Brazilian rubber tree and the quinine tree from the Andes to Vietnam. He was the director of the medical school at Ha Noi, Vietnam in its first two years (1902-1904).

He died on March 1, 1943.


Burns, William; "Alexandre Yersin and His Adventures in Vietnam"; Mill Hill Essays 2003; National Institute for Medical Research; 2003

Maki, Rebecca; "The Discovery of Yersinia pestis"; at

Alexandre Yersin Wikipedia Entry

Monday, September 17, 2012

Albrecht Kossel

Ludwig Karl Martin Leonhard Albrecht Kossel was born on September 16, 1853 in Rostock, Mecklenburg. His father was a merchant, bank director and Prussian Council. Kossel attended gymnasium in Rostock and then in 1872 he went to the newly founded University of Strasbourg. As a youth he had shown an interest in chemistry and botany and he continued those studies at the university. He finished his studies at the University of Rostock, passing the state medical examination in 1877 and earning his medical doctor degree in 1878. After graduation he worked in the laboratory of Felix Hoppe-Seyler, who had been one of his biochemistry professors at Strasbourg.

Hoppe-Seyler in addition to being a biochemist was an inorganic chemist and was interested in what chemical elements made up living tissues. In his lab Kossel studied "nucleins" the newly isolated contents of cell's nuclei. Nucleins had been discovered by Friedrich Miescher in 1869. He had determined that they were chemically different from protein, being more acidic. In 1883 Kossel became the director of the Chemistry Division of the Physiological Institute at the University of Berlin. In the period from 1885 and 1901 Kossel isolated from nuclein the five nucleic acid bases that make up DNA and RNA: adenine, guanine, cytosine, thymine and Uracil. These five bases are the letters of the genetic code that code for proteins. In DNA, the instructions for construction proteins are written in four nucleotides: adenine, guanine, cytosine and thymine. In messenger RNAs, the translations of the DNA code that are sent to ribosomes, where proteins are made, thymine is replaced with uracil.

In 1895 Kossel became a professor of physiology and director of the Physiological Institute at the University of Marburg. In Marburg Kossel began to investigate the structure of proteins. In 1896 Kossel isolated histidine, an amino acid with a imidazol functional group. Kossel also was the first to isolate theophyllin a therapeutic drug found in cocoa and tea. In 1901 Kossel became the director of the Physiological Institute at Heidelberg University. In  1910 Kossel was awarded the Nobel Prize "in recognition of the contributions to our knowledge of cell chemistry made through his work on proteins, including the nucleic substances". In 1924 Kossel became professor emeritus at Heidelberg, but continued teaching. His research also continued as he continued working on determining the structure of proteins.

Kossel died on July 5, 1927.


Jones, Mary Ellen; "A Biographical Sketch of Albrecht Kossel"; Yale Journal of Biology and Medicine(1953)26:80-97

Albrecht Kossel Nobel Biography

Albracht Kossel Wikipedia Entry

Sunday, September 9, 2012

Elliot Coues

Elliot Coues was born on Septermber 9, 1842 in Portsmouth, New Hampshire. His father Samuel Elliot Coues was a merchant and worked in the United States Patent Office, which caused him to be away from his family in New Hampshire starting when Coues was eleven. As a child Coues was fascinated by animals and was only interested in books that contained them.. When he moved to be with his father in Washington D.C, Coues went to the Smithsonian and there he met the naturalist Spencer Baird, the first curator of the Smithsonian, who would be his mentor. He published his first technical paper at the age of 19. He attended Gonzaga College High School in Washington D.C. and then Columbia College (which later would be renamed George Washington University) also in Washington D.C. Coues remained at Columbia College for ten years, earning a PhD and an MD.  Coues enlisted in the U.S. Army in 1862 as a medical cadet. In 1863 he was promoted to acting assistant surgeon and in 1864 to assistant surgeon. .

Coues' military career took him all over the United States, with postings in Arizona, North Carolina, California and North Dakota. Coues was an prolific writer and wrote many works on ornithology and natural history. In the Army he got the chance to join expeditions that explored parts of America, serving as both naturalist and surgeon on the United States Northern Boundary Commission form 1873-1876 and from 1876 to 1880 he served as secretary and naturalist to the United States Geological and Geographical Survey of the Territories. While in the army he authored 300 works and papers. He resigned from the army in 1881 to devote himself more fully to literary and scientific pursuits. After resigning from the Army he returned to Washington D.C. In 1877 he was appointed professor of Anatomy at the National Medical College and that same year he was elected to the National Academy of Sciences. He was one of the founders of the American Ornithologists Union and served as its president.

Coues' book A Key to North American Birds first edition was published in 1972. The book was at the time  a unique work of ornithology, one which for years other guides to animal species would follow. Other important works by Coues included A Checklist of North American Birds (two editions) and Field Ornithology. Coues identified for the first time many unknown bird species and introduced the trinomial nomenclature used to distinguish subspecies of animals. All living species are known by their scientific name composed of Latin genus and species names. Coues introduced using a third Latin name for subspecies. Coues was also important in mammology, publishing North American Fur Bearing Animals in 1877.

Coues died on December 25, 1899 at Johns Hopkins University Hospital in Baltimore, Maryland, during an operation to cure an afflicted throat.


Allen, A.J.; "Biographical Memoir of Elliot Coues: 1842-1889"; in Biographical Memoirs Vol 6; National Academy Press; 1909

Anonymous; "A Great Ornithologist"; The Outlook(1900)64:89-90

Elliot, D.G.; "In Memoriam: Elliot Coues"; The Auk(1901)18:1-11

Elliot Coues Wikipedia Entry

Sunday, September 2, 2012

Wilhelm Ostwald

Friedrich Wilhelm Ostwald was born on September 2, 1853 in Riga, Latvia.  His father, Gottfried, was a master cooper and he was the middle of three brothers. His family was German in origin, but he attended a local kronsschule with Latvian and Russian children and he attended the local real gymnasium school. He matriculated to the University of Tartu in 1872 and after briefly enjoying fraternity life the influence of his father convinced him to take his academics seriously. He started working in the laboratory of Karl Schmidt. From Schmidt's assistant Johan Lemburg he learned the essentials of inorganic analysis and he earned his bachelor's degree in 1875 and his doctorate in 1978 working in Schmidt's lab.

In 1887 he served as an unpaid lecturer at the University of Tartu. Four years later he became a professor of chemistry at Riga Polytechnic University and six years after that be became professor of physical chemistry at Lepzig University. Ostwald remained at Lepzig until his retirement in 1906, except for one year as the first exchange professor at Harvard University in 1904-5. Ostward's lab became a center for instruction in physical chemistry and among his students were many Nobel Prize winners including Arrhenius, Van 't Hoff and Nernst. Albert Einstein applied to work in Ostwald's lab.

Ostwald began his research in 1875 studying the law of mass action of water with the problem of chemical affinity and with special emphasis on electrochemistry. This led to the discovery of the law of dilution, which is named after him and governs the disassociation of a weak acid or base. Ostwald became one of the founders of modern physical chemistry and wrote several textbooks on the subject. Ostwald founded Zeitschrift fur physikalsche Chemie in 1887 and remained its editor until 1922 editing over 100 volumes. He is the inventor of the Ostwald process for producing nitric acid, which he patented in 1902. His development of the mole concept (a mole of a chemical being equal to its atomic mass in grams) was ironically part of his resistance to atomic theory, against which he was one of the last holdouts.

Ostwald won the 1909 Nobel Prize "in recognition for his investigations into the fundamental principals governing chemical equilibria and rates of reaction". Besides chemistry Ostwald had many insterests including philosophy and painting, for which he produced his own pigments. Later in his career he wrote several books dealing with color theory.

Ostwald died on April 4, 1932.


Kim, Mi Gyung; "Wilhelm Ostwald (1853-1932)"; 2006; at

May, Leopold; "Wilhelm Ostwald"; 2003; at

Wilhelm Ostwald Nobel Biography

Wilhelm Ostwald Wikipedia Entry