SYMMER, ROBERT

(b. Galloway, Scotland [?], ca. 1707; d. London, England, 19 June 1763)

electricity.

Nothing is known of Symmer’s life before 1719, when he matriculated at the University of Edinburgh. Among fellow students who became his friends were Andrew Mitchell, Patrick Murdoch, and the poet James Thomson. All took an interest in contemporary natural philosophy, and all, though born and bred in Scotland, made their careers in England. Mitchell, Murdoch, and Symmer became fellows of the Royal Society of London (in 1735, 1745, and 1752, respectively), while their older contemporary Thomson, the best-known of the group, made his reputation with poems celebrating Newtonian science.

In 1735 Symmer took a belated M.A., perhaps to qualify as traveling companion to Francis Greville, Lord Brooke, later earl of Warwick; it was then a common practice for well-educated impecunious Scots to serve as tutors to influential English families, through whose connections they expected to obtain preferment. Symmer followed or conducted Brooke to London and there rejoined Mitchell, Murdoch (who had left Scotland by the tutorial route in 1729), and Thomson, all of whom had begun to prosper. Symmer found preferment in financial administration, for which he may have prepared under Abraham de Moivre, who gave private lessons in practical arithmetic and who, together with two of his students, signed Symmer’s certificate for election to the Royal Society. Symmer eventually became head clerk of the office of the Treasurer of the Chamber, which paid the bills of the King’s Household. When he lost this position upon a change of ministries in 1757, he preferred retirement to accepting an offer of the governorship of New Jersey.

Symmer devoted his leisure to wooing a young lady (Eleanora Ross of Balkailley, whom he married in 1760), to keeping Mitchell (then plenipotentiary to the court of Frederick the Great) current with English politics, and to experimenting with electricity. He took up this last study in 1758 on discovering that a pair of silk stockings, one black and one white, worn upon the same leg, would strongly attract one another when removed and separated. Symmer wore this peculiar double hosiery to keep mourning (and warm) during winter. Unfortunately for his reputation, he continued to use his stockings to generate the electricity for his experiments-and this, as he wrote to Mitchell, was “enough to disgust the Delicacy of more than one Philosopher.”¹

From the facts that the stockings attracted strongly when separated and weakly when joined, and that the attraction reappeared on every separation, Symmer concluded that the contrary electricities of Franklin derived from two distinct, opposed, positive principles, perhaps materialized as two essentially different, counterbalancing fluids. His conception therefore differed from Dufay’s and Nollet’s, in which the two electricities were not contrary, and Franklin’s, in which one was a privation of the other. Symmer confirmed this insight by studying the condenser, which, when charged and insulated, bore an evident analogy to his superposed stockings. He found that he could charge a Leyden jar with either a black or a white stocking, and he argued that the circumstances of explosion–the shock or the perforation of paper placed in the circuit² – suggested that a real fluid sprang from each surface of a discharging condenser. Another, and more important, experiment was suggested by the analogy: since each stocking substitutes for one surface of a Leyden jar, a charged parallel-plate condenser with glass dielectric should cohere if cut longitudinally through its middle. On the other hand, two complete condensers, electrified in series, should not cohere, since at the interface the independent contrary electricities counterbalance. It was essential to Symmer’s argument that they counterbalance but not destroy one another, as appears from the fact that the condensers can be exploded separately.

Symmer hoped that his two powers would not only start a revolution in electricity but also “prove to be the genuine Principle of the Newtonian Philosophy.”³ But the English electricians preferred to follow Franklin or Benjamin Wilson. Symmer therefore decided to try his chances abroad, and sent Mitchell copies of his papers for distribution in the Germanies. He himself took charge of converting Nollet, which proved a consequential move. Although Nollet would not accept Symmer’s theory, he endorsed the experiments, which he deemed so many proofs of his own views, and which he improved by replacing the stockings with ribbons resting on a plate of glass. He also sent an account of the modified experiments to Giovanni Francesco Cigna in Turin, in the hope that he would use them to destroy the Franklinist theories of Nollet’s rival Beccaria.

Cigna in turn improved the experiments, particularly by substituting an insulated lead plate for Nollet’s glass. He observed that if the ribbon were electrified and removed, and the plate discharged, it could be recharged as often as desired by grounding it when the ribbon was returned. Cigna here hit upon the principle of the electrophore. Volta, to whom it is usually ascribed, also came to it inspired indirectly by Symmer: when Cigna announced that Nollet’s experiments did not decide between Franklin and Symmer, Beccaria bent theory and experiment to prove his Franklinist views; and in answering Beccaria, Volta invented the electrophore, a device as important as the Leyden jar for the development of electrical theory.

Symmer’s expectations were almost realized. Before the end of the eighteenth century, his dualist theory had captured the Continent; and although his countrymen remained singlist, both sides agreed that no experiment known to them could settle whether electricity came in one power or two.

NOTES

1. Symmer to Mitchell, 7 Apr. 1761. British Museum. Add. MS 6839, fols. 220–221.

2. Franklin helped Symmer strike holes in quires of paper; they hoped that the contours of the punctures would show the direction of the discharge, but the results were ambiguous.

3. Symmer to Michell, 19 June 1760. British Museum, Add. MS 6839, fil. 183.

BIBLIOGRAPHY

I. Original Works. Symmer’s only published work is “New Experiments and Observations Concerning Electricity,” in Philosophical Transactions of the Royal Society, 51 , no. 1 (1759), 340–389, comprising four parts read between Feb. and Dec. 1759. His other accessible work is a volume of MS letters addressed to Mitchell: British Museum, Add. MS 6839.

II. Secondary Literature. Biographical information about Symmer has been inferred from the Mitchell letters. See J. L. Heilbron, “Robert Symmer, F.R.S. (c. 1707–1763) and the Two Electricities,” in Isis, which includes an estimate of Symmer’s work. See also Joseph Priestley, The History and Present State of Electricity, 3rd ed. (London, 1775), I , 308–333, and II , 41, 47; and I. B. Cohen, Franklin and Newton (Philadelphia, 1956), 543–546.

J. L. Heilbron