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Promoting Irish Culture and History from Little Rock, Arkansas, USA


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Birth of Henry Dixon, Biologist & Professor

Generated by IIPImageHenry Horatio Dixon, plant biologist and professor at Trinity College, Dublin, is born in Dublin on May 19, 1869. Along with John Joly, he puts forward the cohesion-tension theory of water and mineral movement in plants.

Dixon is the youngest of the seven sons of George Dixon, a soap manufacturer, and Rebecca (née Yeates) Dixon. He is educated at Rathmines School and Trinity College, Dublin. In 1894, after studying in Bonn, Germany, he is appointed assistant and later full Professor of Botany at Trinity. In 1906 he becomes Director of the Botanic gardens and in 1910 of the Herbarium also. He has a close working relationship with physicist John Joly and together they develop the cohesion theory of the ascent of sap.

Dixon’s early research includes work on the cytology of chromosomes and first mitosis in certain plants. Familiarity with work on transpiration and on the tensile strength of columns of sulfuric acid and water leads Dixon and Joly to experiment on transpiration. “On the Ascent of Sap” (1894) presents the hypothesis that the sap or water in the vessels of a woody plant ascends by virtue of its power of resisting tensile stress and its capacity to remain cohesive under the stress of great differences of pressure. Dixon and Joly further demonstrate that water is transported through passive vessels and not living cells.

Dixon writes Transpiration and the Ascent of Sap in Plants (1914), which brings various theories and experimental works together in a coherent argument. He also writes a textbook, Practical Plant Biology (1922).

In 1907 Dixon marries Dorothea Mary, daughter of Sir John H. Franks, with whom he raises three sons. He is the father of biochemist Hal Dixon and grandfather of Adrian Dixon and Joly Dixon.

In 1908 Dixon is elected a Fellow of the Royal Society. In 1916 he is awarded the Boyle Medal of the Royal Dublin Society. He delivers the society’s Croonian Lecture in 1937.

Henry Dixon dies in Dublin on December 20, 1953.

(Pictured: Henry Horatio Dixon, bromide print by Walter Stoneman, 1922, National Portrait Gallery, London)


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Death of Robert Boyle, Philosopher & Writer

robert-boyleRobert Boyle, Anglo-Irish natural philosopher, theological writer, chemist, physicist, inventor and a preeminent figure of 17th-century intellectual culture, dies on December 31, 1691 in London.

Boyle is born on January 25, 1627 at Lismore Castle, in County Waterford. At age eight, he begins his formal education at Eton College, where his studious nature quickly becomes apparent. In 1639 he and his brother Francis embark on a grand tour of the continent together with their tutor Isaac Marcombes. In 1642, owing to the Irish rebellion, Francis returns home while Robert remains with his tutor in Geneva and pursues further studies.

Boyle returns to England in 1644, where he takes up residence at his hereditary estate of Stalbridge in Dorset. There he begins a literary career writing ethical and devotional tracts, some of which employ stylistic and rhetorical models drawn from French popular literature, especially romance writings. In 1649 he begins investigating nature via scientific experimentation. From 1647 until the mid-1650s, he remains in close contact with a group of natural philosophers and social reformers gathered around the intelligencer Samuel Hartlib. This group, the Hartlib Circle, includes several chemists who heighten his interest in experimental chemistry.

Boyle spends much of 1652–1654 in Ireland overseeing his hereditary lands and performing some anatomic dissections. In 1654 he is invited to Oxford, and he takes up residence at the university until 1668. In Oxford he is exposed to the latest developments in natural philosophy and becomes associated with a group of notable natural philosophers and physicians, including John Wilkins, Christopher Wren, and John Locke. These individuals, together with a few others, form the “Experimental Philosophy Club.” Much of Boyle’s best known work dates from this period.

In 1659 Boyle and Robert Hooke, the clever inventor and subsequent curator of experiments for the Royal Society, complete the construction of their famous air pump and use it to study pneumatics. Their resultant discoveries regarding air pressure and the vacuum appear in Boyle’s first scientific publication, New Experiments Physico-Mechanicall, Touching the Spring of the Air and Its Effects (1660). Boyle and Hooke discover several physical characteristics of air, including its role in combustion, respiration, and the transmission of sound. One of their findings, published in 1662, later becomes known as “Boyle’s law.” This law expresses the inverse relationship that exists between the pressure and volume of a gas, and it is determined by measuring the volume occupied by a constant quantity of air when compressed by differing weights of mercury.

Among Boyle’s most influential writings are The Sceptical Chymist (1661), which assails the then-current Aristotelian and especially Paracelsian notions about the composition of matter and methods of chemical analysis, and the Origine of Formes and Qualities (1666), which uses chemical phenomena to support the corpuscularian hypothesis. He argues so strongly for the need of applying the principles and methods of chemistry to the study of the natural world and to medicine that he later gains the appellation of the “father of chemistry.”

Boyle is a devout and pious Anglican who keenly champions his faith. He sponsors educational and missionary activities and writes a number of theological treatises. He is deeply concerned about the widespread perception that irreligion and atheism are on the rise, and he strives to demonstrate ways in which science and religion are mutually supportive. For Boyle, studying nature as a product of God’s handiwork is an inherently religious duty. He argues that this method of study would, in return, illuminate God’s omnipresence and goodness, thereby enhancing a scientist’s understanding of the divine. The Christian Virtuoso (1690) summarizes these views and may be seen as a manifesto of his own life as the model of a Christian scientist.

In 1668 Boyle leaves Oxford and takes up residence with his sister Katherine Jones, Vicountess Ranelagh, in her house on Pall Mall in London. There he sets up an active laboratory, employs assistants, receives visitors, and publishes at least one book nearly every year. Living in London also provides him the opportunity to participate actively in the Royal Society.

Boyle is a genial man who achieves both national and international renown during his lifetime. He is offered the presidency of the Royal Society and the episcopacy but declines both. Throughout his adult life, he is sickly, suffering from weak eyes and hands, recurring illnesses, and one or more strokes. He dies at age 64 on December 31, 1691 after a short illness exacerbated by his grief over Katherine’s death a week earlier. He leaves his papers to the Royal Society and a bequest for establishing a series of lectures in defense of Christianity. These lectures, now known as the Boyle Lectures, continue to this day.


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Death of Thomas Andrews, Chemist & Physicist

thomas-andrewsThomas Andrews, chemist and physicist who does important work on phase transitions between gases and liquids, dies in Belfast on November 26, 1885. He is a longtime professor of chemistry at Queen’s University Belfast.

Andrews is born in Belfast on December 19, 1813, where his father is a linen merchant. He attends the Belfast Academy and the Royal Belfast Academical Institution, where at the latter of which he studies mathematics under James Thomson. In 1828 he goes to the University of Glasgow to study chemistry under Professor Thomas Thomson, then studies at Trinity College, Dublin, where he gains distinction in classics as well as in science. Finally, at the University of Edinburgh in 1835, he is awarded a doctorate in medicine.

Andrews begins a successful medical practice in his native Belfast in 1835, also giving instruction in chemistry at the Royal Belfast Academical Institution. In 1842, he marries Jane Hardie Walker. They have six children, including the geologist Mary Andrews.

Andrews first becomes known as a scientific investigator with his work on the heat developed in chemical actions, for which the Royal Society awards him a Royal Medal in 1844. Another important investigation, undertaken in collaboration with Peter Guthrie Tait, is devoted to ozone. In 1845 he is appointed vice-president and professor of chemistry of the newly established Queen’s University Belfast. He holds these two offices until his retirement in 1879 at the age of 66.

His reputation mainly rests on his work with liquefaction of gases. In the 1860s he carries out a very complete inquiry into the gas laws — expressing the relations of pressure, temperature, and volume in carbon dioxide. In particular, he establishes the concepts of critical temperature and critical pressure, showing that a substance passes from vapor to liquid state without any breach of continuity.

In Andrews’ experiments on phase transitions, he shows that carbon dioxide may be carried from any of the states we usually call liquid to any of those we usually call gas, without losing homogeneity. The mathematical physicist Josiah Willard Gibbs cites these results in support of the Gibbs free energy equation. They also set off a race among researchers to liquify various other gases. In 1877-78 Louis Paul Cailletet is the first to liquefy oxygen and nitrogen.

Thomas Andrews dies in Belfast on November 26, 1885 and is buried in the city’s Borough Cemetery.


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Birth of Physicist John Joly

John Joly, Irish physicist famous for his development of radiation therapy in the treatment of cancer, is born in Bracknagh, County Offaly, on November 1, 1857. He is also known for developing techniques to accurately estimate the age of a geological period, based on radioactive elements present in minerals.

Joly is a second cousin of Charles Jasper Joly, the astronomer. He enters Trinity College, Dublin in 1876, graduating in Engineering in 1882 in first place with various special certificates in branches of engineering, at the same time obtaining a First-Class Honours in modern literature. He works as a demonstrator in Trinity’s Engineering and Physics departments before succeeding William Johnson Sollas in the Chair of Geology and Mineralogy in 1897, a position which he holds until his death in 1933.

Joly joins the Royal Dublin Society in 1881 while still a student, and is a frequent contributor of papers. During his career he writes over 270 books and scientific papers.

On May 17, 1899 Joly reads his paper “An Estimate of the Geological Age of the Earth” to the Royal Dublin Society. In it, he proposes to calculate the age of the earth from the accumulation of sodium in the waters of the oceans. He calculates the rate at which the oceans should have accumulated sodium from erosion processes, and determines that the oceans are about 80 to 100 million years old. The paper is quickly published, appearing four months later in the Society’s Scientific Transactions. Although this method is later considered inaccurate and is consequently superseded, it radically modifies the results of other methods in use at the time.

In 1903 he publishes an article in Nature in which he discusses the possibility of using radium to date the Earth and goes on to study the radioactive content of the Earth’s crust to formulate a theory of thermal cycles, and examines the radioactive constituents of certain rocks as a means of calculating their age. Working in collaboration with Sir Ernest Rutherford, he uses radioactive decay in minerals to estimate, in 1913, that the beginning of the Devonian period could not be less than 400 million years ago, an estimate which is in line with modern calculations.

Joly serves as President of Section C (Geology) when the British Association for the Advancement of Science meets in Dublin in 1908, during which he presents his paper “Uranium and Geology” in an address to the society. This work describes radioactive materials in rocks and their part in the generation of the Earth’s internal heat.

Along with his friend Henry Horatio Dixon, Joly also puts forward the cohesion-tension theory which is now thought to be the main mechanism for the upward movement of water in plants.

In 1914 Joly develops a method of extracting radium and applies it in the treatment of cancer. As a Governor of Dr. Steevens’ Hospital in Dublin, in collaboration with Walter Stevenson, he devises radiation therapy methods and promotes the establishment by the Royal Dublin Society of the Irish Radium Institute where they pioneer the “Dublin method” of using a hollow needle for deep radiation therapy, a technique that later enters worldwide use. The Radium Institute also supplies capillary tubes containing radon to hospitals for some years for use in the treatment of tumours.

Joly is elected a Fellow of the Royal Society of London in 1892, is awarded the Boyle Medal of the Royal Dublin Society in 1911, the Royal Medal of the Royal Society of London in 1910, and the Murchison Medal of the Geological Society of London in 1923. He is also conferred honorary degrees by the National University of Ireland, the University of Cambridge, and the University of Michigan. After his death in 1933, his friends subscribe the sum of £1,700 to set up a memorial fund which is still used to promote the annual Joly Memorial Lectures at the University of Dublin, which were inaugurated by Sir Ernest Rutherford in 1935. He is also remembered by the Joly Geological Society, a student geological association established in 1960.

In 1973 a crater on Mars is named in Joly’s honour.