Sir James Hall of Dunglass, 4th Baronet, geologist, geophysicist and politician, died on the 23rd of June, 1832.
Sir James Hall was a ‘Plutonist’, but he didn’t come from Pluto, and despite the fact he was interested in Bedrock, he wasn’t a neighbour of Fred Flintstone; in fact, he came from Dunglass in Scotland, which sometimes feels as cold as Pluto. Known as the founder of geochemistry, Sir James Hall became distinguished as the first scientist to establish practical experimental research in the field of geology. As a ‘Plutonist’, Hall was convinced of the involvement of heat and pressure in the formation of igneous rocks. That was contrary to the ‘Neptunists’ who believed that all rocks had been deposited from a primeval ocean. Hall undertook a series of pioneering experiments to illustrate the fusion of rocks, their vitreous and crystalline characters, and the influence of molten rocks in altering adjacent strata. Hall thus assisted in proving that granitic veins had been injected into overlying deposits after their consolidation.
Hall published his own research on the chemical composition of rocks and his work largely vindicated the theories of his friend and fellow Scot, James Hutton. Hall became the first to discover the composition of whinstone and basalt lava, and also showed that limestone, when subjected to considerable pressure while being heated, does not decompose, but becomes marble. Hall also invented a machine for regulating high temperatures, which became very useful in his experiments.
James Hall was born at Dunglass, Haddingtonshire (East Lothian) on the 17th of January, 1761. Jamesie Hall received a private education until his twelfth year, when he was sent to a public school near London, under the superintendence of his uncle and the King’s Physician, Sir John Pringle. Three years later, Hall inherited the Baronetcy of Dunglass from his father. About the same time, Hall entered himself in Christ’s College, Cambridge, where he studied for a number of years, before touring the Continent. During his time in Europe, Hall also studied at the military college in Brienne, in France, where Napoleon Bonaparte was a fellow student.
James Hall returned to Edinburgh when he was twenty years old and attended some of the classes at Edinburgh University for a year. This was the time of the Scottish Enlightenment and Hall mixed with many well known names. He studied chemistry under Joseph Black and natural history under John Walker. He became interested in geology and, on a certain occasion in 1788, played host to James Hutton and John Playfair at Dunglass. It was on a trip to Siccar Point during that visit that Hutton noticed what is now known as ‘Hutton’s Unconformity’, a pattern in the strata that underpinned many of his theories.
In 1782, Sir James Hall made a second tour to the Continent, where he remained for more than three years. In addition to accumulating his expertise in geology, chemistry, and Gothic architecture, Hall got acquainted with the learned scientific men at the Courts of Europe. He travelled extensively, conducting field work on geological formations in the Alps and in Italy. This allowed him to deduce that the ancient rock formations, old lava flows and numerous dikes in Scotland must have had a similar origin to the much more recent ones, with an undoubted volcanic origin, in Italy.
The problem with the Neptunians theory was that as feldspar fuses with less heat than quartz needs, it couldn’t explain why, in some granites where the two rocks were united, the respective crystals were found to have mutually created an impression on each other. To do that, they must have been in a mutual state of solution and then congealed at the same time, but as one melts at a higher temperature, the evidence couldn’t be explained.
Hall discovered through experiment, pulverizing the two substances and mixing them in proportions to their natural occurrence in granite, that a heat very little higher than that needed to melt feldspar fused both substances, with the feldspar acting like a flux to the quartz. This helped to prove Hutton’s theory, which maintained the crust of the Earth to be the production of heat and all its geological formations the natural consequences of fusion.
In 1798, Hall commenced other important experiments, which served to prove that calcination or change of state, and not fusion or change of form, was the practical effect of heat on most of the bodies that formed the crust of the earth. Knowing from Black’s experiments that, in the case of limestone, changes depend on the separation of carbonic acid gas from the earth, Hall concluded that, by applying heat at extremely high temperatures and ensuring that the gas didn’t escape, calcareous earths might indeed be fused. His first successful experiment procured a hard stony mass from powdered common chalk. Other experiments let to such stones being visibly covered with crystals, thus proving fusion and re-formation as a limestone mineral.
Seven years later, his results led to a paper, which he read before the Royal Society of Edinburgh and published in 1806. He produced a table, which illustrated that 1700 feet of sea, with the assistance of heat, is sufficient for the formation of limestone and that by 3000 feet, marble may be formed. Amusingly, a fragment of marble that he produced in the course of an experiment convinced a workman that it had been dug up in Scotland. After polishing it, the workman remarked that, if it had been a little whiter, the mine where it was found might be very valuable.
Sir James Hall, BART., served as a Member of Parliament for the old borough of St. Michael’s (Mitchell or Michaelborough) in Cornwall, between 1807 and 1812. He also served as President of the Royal Society of Edinburgh and is also remembered for his ‘Essay on the Origin, History and Principles of Gothic Architecture’, composed in 1813.
Sir James Hall died in Edinburgh on the 23rd of June, 1832, after a lingering illness lasting three and a half years. He is remembered by a small memorial on the wall of the semi-derelict Dunglass Collegiate Church.