Sunday, January 29, 2012
After graduation Ferrel moved to Liberty, Missouri where he continued to work as a schoolteacher. In Liberty he purchased a copy of Newton's Principia which had been ordered by a earlier school teacher but never collected, which interested him in the actions of tidal forces. He stopped teaching for a while due to ill health and when he recovered he took another school teaching position in Allensville, Kentucky, where he taught from 1850 to 1854. In 1853, at the age of 36, after studying a translation of Pierre-Simon Laplace's work on celestial mechanics, Ferrel published his first scientific paper, contradicting Laplace and saying that the gravitational effects of the sun and moon on the tides tend to retard the rotation of the earth. A year later he moved to Nashville, Tennessee, where he set up his own school.
In Nashville Ferrel had a much greater access to scientific books and interaction with other men of science. His interests turned to the subject of meteorology and in 1856 he published an article entitled, "An Essay on the Winds and Currents of the Ocean" in which he described what have come to be known as Ferrel cells, circulating air currents of the middle latitudes that give rise to westerly winds between 30 and 60 degrees of latitude (see here for an interesting video describing Ferrel cells and their place in the three cell model of atmospheric circulation). With this publication he become the founder of the study of geophysical fluid dynamics.
In 1857 he moved to Cambridge, Massachusetts and joined the staff of The American Ephemeris and Nautical Almanac. In 1858 he published another important paper on the effects of the Earth's rotation on bodies in motion at its surface. In the currents of air or water moving horizontally in the northern hemisphere is deflected to the right. In the southern hemisphere it is deflected to the left. This is a description of how air and ocean currents are affected by the Coriolis effect which is caused by the rotation of the Earth. This effect was independently described by Dutch meteorologist Christoph Buys Ballot and is sometimes called the Buys Ballot law. Buys Ballot later acknowledged Ferrel's priority.
In 1867 Ferrel joined the U.S. Coastal and Geodetic Survey and moved to Washington D.C. While there he researched tides and developed a machine that determined tidal maxima and minima. Due to the lack of a capable machinist, it was not constructed until 1883. The machine, once constructed did the work of forty people carrying out hand calculations and remained in service for over 25 years. In 1882 Ferrel joined the U.S. Army Signal Corp. working in what would become the U.S. Weather Bureau. He remained working there for four years, retiring in 1886 at the age of seventy.
Initially he planned to spend his retirement living with his brother Jacob in Kansas City, Missouri, but unable to keep abreast of scientific advancements in 1889 he moved to Martinsburg, West Virginia, where he died on September 18, 1891.
Abbe, Cleveland; "A Biographical Sketch of William Ferrel: 1817-1891" in Biographical Memoirs Vol. 3; National Academy Press; 1895
Davis, William M.; "A Sketch of William Ferrel"; Popular Science Monthly (1892)40:686-695
O'Connor, J.J. and Robertson, E.F.; "Ferrel Biography"; 2002; at www-history.mcs.st-andrews.ac.uk
William Ferrel Wikipedia Entry
Sunday, January 22, 2012
It was during his residency that Neisser made both of his principal discoveries. At the time of his residency the practice of dermatology was combined with vernereology, the study of sexually transmitted diseases. In 1879, at the age of 24, Neisser published his first and most famous paper where he described "micrococci" in smears, stained with methyl violet, isolated from 25 men and 9 women with purulent urethritis and two patients with acute ophthalmia, but not from patients with syphilis or balanitis. At the time there was still confusion about the identities about the causative organisms of gonorrhea and syphilis and Neisser's discovery of what would be identified as the causative agent of gonorrhea was a step in alleviating this confusion. The "micrococci" isolated by Neisser would later be named Neisseria gonorrhoeae in Neisser's honor. Cocci (pronounced kok-see) is the word microbiologists use to describe generally spherically shaped bacteria.
Neisser's other important discovery was the co-discovery of the causative agent of leprosy. Before his discovery it was believed that leprosy was a combination of inherited and environmental factors. In 1874 Norwegian physician Armaur Hansen had isolated "staff like bodies, much like bacteria" from leprous tissue imperfectly stained with osmotic acid, but he was unsure if they were the cause the disease. In 1879 Neisser visited Norway and took home tissues from leprous patients, most of them given to him by Hansen, and using more advanced staining techniques he identified rod shaped bacilli that he and colleagues thought were a new species and possibly the cause of leprosy. Bacilli (pronounced buh-sil-ahy) is the word microbiologists use to describe rod shaped bacteria. Because in his paper Neisser did not ancknowledge Hansen's earlier finding there emerged a dispute over the priority of the discovery between Neisser and Hansen.Today Hansen is generally given the priority.
Nessier spent two years at the University of Leipzig after which he returned to the University of Breslau as associate professor and director of the dermatology clinic. Neisserr remained at the University of Breslau for the remaining 34 years of his life. Under his influence the Breslau clinic became an important center for dermatological research and Neisser made contributions to the understanding of many dermatological diseases including anthrax, actinomycosis, psoriasis, mycosis fungoides, and vitiligio. Neisser spent much effort to study syphilis, but was never able to isolate the causative agent. In 1892 in the attempt to give immunity to syphilis, without their knowledge or consent, he injected four young prostitutes with serum from syphilitic patients. All four subsequently developed syphilis and Neisser was condemned for "maliciously inoculating children with syphilis poison".
Through his work at the Breslau dermatology clinic Neisser was a staunch advocate for public health and promoted preventive and educational measures against sexually transmitted diseases. In 1899 he co-founded the German Dermatological Society and in 1902 the German Society for Combating Venereal Disease. In 1905 and 1906 Nessier traveled to Java to study the possible transmission of syphilis between apes and humans. He later co-operated with August Paul von Wassermann to develop a test for the causative agent of syphilis and worked with his school friend Paul Ehrlich in testing Salvarsan or "formula 606" an arsenic compound which was the first chemotherapeutic treatment for syphilis.
Neisser died of septicemia on July 16, 1916.
Benedek, Thomas G.; "Albert L. Neisser (1855-1916), Microbiologist and Venerologist"; reprinted at microbe.org
Oriel, J.D.; "Eminent Venereologists: 1. Albert Neisser"; Genitourinary Medicine (1989)65:229-234
Albert Ludwig Sigesmund Neisser Wikipedia Entry
Sunday, January 15, 2012
After graduation Prout went to London and took rooms off of Leicester Square. In order to gain experience in medical practice he walked the wards of the United Hospitals of St. Thomas' and Guy's. He was licensed by the Royal College of Physicians in 1812 and set up a practice. Each day he would rise early so that he could conduct chemical research before he breakfasted at 7, and then saw patients during the day. Prout was not primarily a clinician and was lax in charging his patients, but he spared no expense in devising apparatus for his chemical experiments, which was why he was not as financially successful as many of his medical colleagues. Prout was part of the medical revolution of the early 19th century, understanding the causes of disease, rather than just the symptoms.
Prout's chemical research made many breakthroughs in the understanding of the importance of chemistry in human physiology. In 1817 Prout isolated purified urea (the nitrogenous waste product in urine) and described its reactions. In 1823 he showed that hydrochloric acid is the acidic component of gastric juice. In 1827 he proposed a classification of food substances, including sugars and starches, oily bodies, and albumins, which today we classify as carbohydrates, fats and proteins. Prout's belief in the importance of chemistry in physiology put him at odds with the vitalists, who believed that chemistry did not play an important role in physiology, and this disagreement played out in the medical journals of the day.
Despite his his many advances in the science of physiology Prout's most famous discovery was in physical chemistry and not physiological chemistry. In 1815, observing the tables of elemental atomic weights that were available, he anonymously hypothesized that atomic weights of the elements were multiples of the atomic weight of hydrogen and that the hydrogen atom was a fundamental particle (which he called the protyle) of which the other elements were built. While we know now that atomic weights used today are not exact multiples of the weight of hydrogen (due to the mass converted into binding energy holding nuclei together and the averaging of isotopic weights), Prout's insight was so important that in 1920 Ernest Rutherford chose to name the newly discovered proton, giving credit to Prout.
Honors won by Prout include election into the Royal Society in 1819 and the Copely Medal, the oldest and most prestigious award given by the Royal Society, in 1827. As Prout aged he became increasingly hard of hearing, eventually going totally deaf. It was this deafness that caused Prout to drop out of scientific circles and discontinue his researches.
Prout died on April 9, 1850.
Brock, W.H.; "The Life and Work of William Prout"; Medical History(1965)9:101-126
Rosenfeld, Louis; "William Prout: Early 19th Century Physician-Chemist"; Clinical Chemistry(2003)49:699-705
William Prout Wikipedia Entry
Sunday, January 8, 2012
In 1894 at the age of 26 he was appointed to be the chief assistant at the Royal Observatory in Greenwich. The appointment of such a young man to this lofty position gave rise to some criticism, but time showed that Dyson was up to the task. At the time Dyson started at Greenwich work on the Astrographic Catalogue was already underway and Dyson played an important part in this research measuring the movements of stars. Dyson remained at the Greenwich Observatory until 1905 when he was appointed Astronomer Royal for Scotland. In Edinburgh he worked on observing polar double stars, that were not observable from Greenwich.
In 1910 Dyson was appointed Astronomer Royal, and he returned to Greenwich, where he remained until his retirement in 1933. During his time as Astronomer Royal Dyson devoted himself to the advancement of practical astronomy, stressing the importance of having observations made with the greatest possible care. Innovations attributed to Dyson include the "six pips", the six tones broadcast by many BBC stations to signal the start of each hour. Dyson is also responsible for organizing the expeditions to observe the 1919 solar eclipse which demonstrated the effect of gravity on light, providing proof of Einstein's theory of relativity. With the sun's light blocked out by the moon, the stars in the region behind the sun were observed to have moved, caused by the effect of the sun's gravitational field on their light.
Honors won by Dyson during his career include election to the Royal Society in 1901, the Royal Medal from the Royal Society in 1921, the Bruce Medal from the Astronomical Society of the Pacific in 1922 and a knighthood in 1915. He served as the president of the Royal Astronomical Society from 1911 to 1913 and president of the British Astronomical Society from 1916-1918. He has a crater on the moon and a asteroid named after him.
Dyson died on May 25, 1939, while traveling back to England from Australia, and was buried at sea.
Aitken, R.G.;"Frank Watson Dyson 1868-1939"; Publications of the Astronomical Society of the Pacific(1939)51:336-338
Jackson, J., Obituary: Frank Watson Dyson; Monthly Notices of the Royal Astronomical Society
Frank Watson Dyson Wikipedia Entry
Sunday, January 1, 2012
Damacay established a private laboratory in Paris where he became an expert reading the spectra of inorganic elements. It was said that, he could read a spectra "like the score of an opera". He built an spark spectrum instrument which allowed him to purify and study rare earth elements. Rare earth elements are a group of metallic elements which include scandium, yttrium, and the entire lanthanide series of elements. Despite their name they are relatively common (with the exception of promethium which is radioactive) but because of their geo-chemical properties they are not found in large, economically exploitable amounts. Today China is the world leader in the production and export of these elements, which are used in the manufacture of electronics.
In 1898 when Marie and Pierre Curie isolated the radioactive element polonium, they saw that the sample from which it had been removed remained radioactive. The Curies took their remaining radioactive sample to Demarcay for analysis. Demarcay examined the spectra of the sample and determined that there was a spectral line unaccounted for and told the Curies there was an new element in their sample. This spectral line was caused by radium in their sample, which the Curies were eventually able to isolate in 1902.
Demarcay is most famous for the discovery of the rare earth element europium. In 1892 Paul Boisbaudran while working with a sample of the element samarium, which he had discovered, found a spectral line not accounted for. Demarcay examined spectra of samples of samarium and gadolinium and proposed that there was an undiscovered element between them on the periodic table. Using a crystallization technique of his own invention Demarcay was able to isolate the new element in 1902, which he named europium, after the continent of Eruope.
The date of his death in many references is incorrect. Demarcay died on March 5, 1903.
Daintith, John, editor; "Demarcay, Eugene Anatole (1854-1904)" in Biographical Dictionary of Scientists Third Edition; CRC Press, 2008
Marshall, John L. and Marshall, Virginia R.; "Discovery of the Elements: Europium-Eugene Demarcay"; The Hexagon; Summer 2003, p.19-21
Eugene-Anatole Demarcay Wikipedia Entry