Hall, Sir James

(b. Dunglass, East Lothian, Scotland, 17 January 1761; d. Edinburgh, Scotland, 23 June 1832)

geology, chemistry.

James Hall was the son and heir of Sir John Hall of Dunglass. He was educated in London at Elin’s Military Academy, Kensington. He succeeded to the baronetcy and a considerable fortune at the age of fifteen, while still at school. Thereafter his education was directed by his guardian and granduncle, Sir John Pringle, president of the Royal Society. He entered Christ’s College, Cambridge, in 1777 but left after two years without graduating. He then spent some months in France and about a year in Geneva to further his education. In the autumn of 1781 he entered Edinburgh University and during the sessions 1781–1782 and 782–1783 attended the lectures of John Robison, professor of natural philosophy, and Joseph Black the chemist, taking a particular interest in the latter. Later in 1783 he set out on a grand tour of Europe lasting three years. During this tour he met a number of European scientists and became actively interested in geology and chemistry. He investigated volcanic activity in Italy, the Lipari Islands, and Sicily. He then spent several months in Paris, studying the new chemical ideas of Antoine Lavoisier, to which he became a convert after meeting Lavoisier himself on a number of occasions.

Hall returned to Edinburgh in 1786 and on 9 November of that year married Lady Helen Douglas, second daughter of the earl of Selkirk. For the rest of his life he lived either at his country estate at Dunglass or in Edinburgh, where he took part in the social and scientific activities of the city. Hall was among the earliest British chemists to accept Lavoisier’s new chemical views. In 1788 he addressed the Royal Society of Edinburgh on the subject and is said to have made several converts.

In 1791 Hall revisited Paris and renewed his friendship with Lavoisier. He was elected fellow of the Royal Society of Edinburgh in 1784 (and became president in 1812) and fellow of the Royal Society (London) in 1806. He served as member of parliament for a Cornish constituency, Michael Borough, from 1807 to 1812 but did not play a very active part in politics.

Hall is remembered chiefly for the experimental work he carried out to counter certain criticisms of James Hutton’s Theory of the Earth, although he made other important contributions to geology. His first reaction to the Theory had been unfavorable, and it was only after numerous conversations with Hutton that he was persuaded to accept most of its fundamental principles. Once convinced, he provided strong support for Hutton, not only by his experiments but also by field observations.

Hall’s first experiments were undertaken to refute the claim that if igneous rocks had originated as molten masses injected into overlying strata, they would be found to occur naturally as masses of glass, not as crystalline rocks. This claim was made because earlier experimenters had found that artificially melted basalt and similar rocks, when cooled, formed a glass. Hall had read accounts of René Réaumur’s experiments on porcelain; and in a local glass foundry he had noticed that a mass of molten glass which had been allowed to cool slowly had congealed to a stony mass containing some crystals. He conceived the idea that igneous rocks, if they had cooled slowly, as seemed probable under natural conditions, would form crystalline rocks rather than a glass. Not long after Hutton’s death in 1797 he carried out a series of experiments to prove this.

Hall melted specimens of intrusive and extrusive basalt (“whinstone and lava”) from fifteen British and foreign localities and allowed the fused masses to cool slowly. The cooled melts he obtained were stony masses, sometimes containing obvious crystals; but none, so far as is known, resembled at all closely the rocks from which they had been derived. Some of his cooled melts have been preserved, and subsequent microscopic examination has shown that one of them contained small crystals of feldspar, augite, olivine, and iron ore, minerals characteristic of the rocks used in the experiments. Hall’s results were sufficiently convincing to prove that fused basalt does not necessarily cool to a glass; but he had not taken into account the fact that, under natural conditions, igneous rocks take very much longer to cool than the time that he had allowed.

The second criticism dealt with by Hall was the obvious one that if the consolidation of limestones had been effected in the manner Hutton supposed—by the action of subterranean heat—they would have decomposed with loss of carbon dioxide. Hutton had in fact suggested that this would not happen if the limestones were heated under great pressure, such as that which would be exerted by an overlying mass of seawater. Hall proved this experimentally.

The task proved extremely difficult, but Hall showed great determination and remarkable experimental skill in bringing his investigation to a satisfactory conclusion. Between 1798 and 1805 he carried out more than 500 separate experiments. It was a classic case of proceeding by trial and error. No apparatus suitable for his purpose existed, and Hall had to design and construct his own. His method was to insert small weighed amounts of various types of limestone or carbonate of lime into a tubular container. Among many difficulties he encountered, the principal ones were the selection of suitable material for the container (which had to be nonporous and capable of withstanding both high temperature and high pressures) and the devising of an effective method of sealing the container after inserting the carbonate of lime.

Hall used Wedgwood pyrometers to regulate the temperature and related the Wedgwood scale to the melting point of silver. On this basis it seems probable that he attained temperatures in excess of 1000°C. To estimate the pressures reached, he adapted to his purpose a method devised by Count Rumford to measure the explosive power of gunpowder. He converted his results to a figure significant in relation to Hutton’s theory, the highest pressure obtained being equivalent to a column of seawater 2,720 meters in height.

Hall certainly proved that limestone can be heated to high temperatures under high pressure without suffering decomposition. In the most successful of his experiments the loss in weight of the heated limestone was insignificant. It is probable that in some experiments he produced crystalline marble. He also claimed to have fused limestone; recent research suggests that possibly he may have done so, but this is uncertain. It was many years before Hall’s experiments were repeated successfully, and his results aroused great interest in Europe. Some of the apparatus he used and the end products of his experiments on basalt and limestone are now in the Geological Museum in London and in the British Museum (Natural History).

Hall made other geochemical experiments of less importance, but his propensity for experiment found expression in another direction in his paper “On the Vertical Position and Convolutions of Certain Strata” (1815). He had recognized that the Lower Paleozoic rocks in southern Scotland occur in a series of closely packed folds with approximately vertical limbs, and he conceived the idea that these folds had been formed by lateral pressure. He constructed a machine in which layers of clay, representing strata, when subjected to lateral pressure from opposing directions, reproduced a series of folds closely comparable in appearance with those found in the rocks. Hall suggested that lateral pressures, exerted on partially consolidated sediments during the intrusion of large masses of granite, might have produced folding. In discussing this suggestion he described a number of detailed observations he had made on the junctions of granite and grauwacke in the south of Scotland.

These observations illustrate Hall’s skill as a field geologist; but he was candid enough to admit that, so far as the south of Scotland was concerned, they did not support his proposed explanation (although they provided strong support for Hutton’s conclusion that granite was an intrusive igneous rock). Hall’s suggested explanation of this type of folding would not now be accepted, but it did contain the germ of later theories which accepted lateral pressure as an explanation of folding in strata; and it marked a stage in the advancement of geological thought.

Hall’s next contribution to geology, “On the Revolutions of the Earth’s Surface” (1815), again demonstrates his powers of observation in the field and records a further attempt to reproduce a geological process experimentally. In this paper Hall discussed certain surface features (later shown to have been caused by the ice sheets that covered Europe in the glacial period) and concluded that they resulted from the passage of enormous tidal waves (tsunamis).

Hall was familiar, partly from personal observation, with the distribution of erratic blocks in Switzerland and elsewhere in Europe. Rather surprisingly, because he once crossed much of Switzerland (including a glacier) on foot, he did not accept Hutton’s suggestion that former glaciers might have distributed erratics. In fact, he attempted to disprove it, as far as Switzerland was concerned, although he did suggest that the transport of exceptionally large erratics by a tidal wave might have been assisted if they were embedded in ice.

Hall had also examined numerous manifestations of former glacial action in the region of Edinburgh, including deposits of boulder clay and fluvioglacial gravel, and features such as “crag and tail” and roches moutonnées. He had also noted the presence of glacial grooves and striae on the surface of the latter and had made careful records of their direction with a compass, showing they indicated movement in one well-defined direction. These observations led him to conclude that a tidal wave had crossed mid- Scotland in a particular direction, and he suggested that a similar explanation would account for the distribution of erratics in Europe.

Hall had studied the effects of tidal waves recorded in the literature, and his suggested explanation was based at least in part on observed facts. He supposed these tidal waves to have been caused by some deepseated and powerful submarine manifestation of igneous activity. He attempted to produce a tidal wave by exploding gunpowder under water, but the experiment appears to have done no more than produce a violent upheaval of the water above the explosion.

In this paper Hall indicated certain points of disagreement with Hutton. He was inclined to believe that the elevation of the land had proceeded by occasional discontinuous upheavals, rather than slowly and continuously; and he rejected Hutton’s view that the slow and continuous action of rivers accounted for valley systems.

In Hall’s last paper, “On the Consolidation of the Strata of the Earth” (1826), he attempted to prove experimentally that loose sand, heated in concentrated brine, would consolidate into a firm sandstone; but this was perhaps the least successful of his experiments, and the results were unconvincing.

One of Hall’s interests was Gothic architecture, which came to his notice during his visits to France. He wrote a book on this subject, in which he expressed ingenious views as to its origin—but these are not now considered sound.

BIBLIOGRAPHY

I. Original Works. The following papers were all published in the Transactions of the Royal Society of Edinburgh: “Sir James Hall on Granite,” 3 (1794), pt. 1, History of the Society, 8–12 (a summary of two papers read 4 Jan. and 1 Mar. 1790, at Hall’s request not published in full); “On the Origin and Principles of Gothic Architecture,” 4 (1798), pt. 2, Papers of the Literary Class, 3–27, also published separately (London, 1813); “Experiments on Whinstone and Lava,” 5 (1805), 43–75; “Account of a Series of Experiments, Shewing the Effects of Compression in Modifying the Action of Heat,” 6 (1812), 71–185; “On the Vertical Position and Convolutions of Certain Strata, and Their Relations With Granite,” 7 (1815), 79–108; “On the Revolutions of the Earth’s Surface,” ibid., 139–211; and “On the Consolidation of the Strata of the Earth,” 10 (1826), 314–329.

Hall also published his two most important papers in William Nicholson’s Journal of Natural Philosophy, Chemistry, and the Arts, both in abstract and in full, no doubt to secure a wider circulation: “Curious Circumstances Upon Which the Vitreous or the Stony Character of Whinstone and Lava Respectively Depend; With Other Facts. In an Account of Experiments Made by Sir James Hall” (an abstract), 2 (1798), 285–288; “Experiments Upon Whinstone and Lava,” 4 (1800), 8–18, 56–65; “Experiments on the Effects of Heat Modified by Compression” (an abstract), 9 (1804), 98–107; “Account of a Series of Experiments, Shewing the Effects of Compression in Modifying the Action of Heat,” 13 (1806), 328–343, 381–405; 14 (1806), 13–22, 113–128, 196–212, 302–3l8—the last five pages are an appendix (not in the Transactions paper), a catalog of 31 specimens “shewing the results of Sir James Hall’s experiments on the effect of heat modified by compression,” deposited by him in the British Museum.

A French translation of the last paper by M. A. Pictet appeared as a separate book: Description d’une suite d’expériences qui montrent comment la compression peut modifier l’action de to chaleur (Geneva, 1807).

The Royal Society Catalogue of Scientific Papers, III (1866), 137, lists some translations and abstracts in foreign journals.

Hall’s unpublished diaries and letters, the principal source of biographical information, are in the National Library of Scotland and the Scottish Record Office Edinburgh.

II. Secondary Literature. V. A. Eyles, “Sir James Hall, Bt. (1761–1832),” in Endeavour, 20 (1961), 210–216, illustrates some of Hall’s original apparatus and melts of basalt, with microscopic sections of the latter; and his “The Evolution of a Chemist: Sir James Hall, Bt., F.R.S., P.R.S.E.... and His Relations With Joseph Black, Antoine Lavoisier, and Other Scientists of the Period,” in Annals of Science,19 (1963), 153–182, contains many biographical details of Hall’s life. See also J. S. Flett, “Experimental Geology,” presidential address to Section C, British Association for the Advancement of Science, Edinburgh, 1921, pp. 1–19, a general account of Hall’s experimental work. J. A. Chaldecott, “Contributions of Fellows of the Royal Society to the Fabrication of Platinum Vessels,” in Notes and Records. Royal Society of London,22 (1967), 155–172, refers to Hall’s use of platinum vessels in his experiments; and his “Scientific Activities in Paris in 1791,” in Annals of Science, 24 (1968), 21–52, contains extracts from diaries kept by Hall during his visit to Paris in 1791.

V. A. Eyles