Dalibard, Thomas François

(b. Crannes, France, 1703; d. Paris, France, 1779)

natural history.

Dailbard was the first naturalist in France to adopt Linnaeus’ system. In 1749 he published a work entitled Florae Parisiensis prodomus, ou catalogue des plantes qui naissent dans les environs de Paris, in which the plants were classified according to Linnaeus’ principles. To show his appreciation, Linnaeus named a Canadian bramble for Dalibard.

At the request of Buffon (in whose shadow he developed), Dalibard translated Franklin’s Experiments and Observations on Electricity. He published this translation in 1752, with a foreword and short history of studies in electricity before Franklin. To a second edition of Franklin’s work (1756) Dalibard added a lengthy supplement describing the results he achieved as he reenacted Franklin’s experiments (results which he had previously revealed to the Académie des Sciences).

Two of these experiments are especially interesting. The first is the famous experiment performed on 10 May 1752 at Marly–la–Ville, in which Dalibard proved the accuracy of Franklin’s theory that the materials of thunder and lightning were similar.

The second experiment concerned the early history of electromagnetism. In a letter to Peter Collinson, Franklin described his experiments in magnetizing needles and reversing their polarities with electricity. Franklin did not assume the identity of magnetic and electrical materials, however. As he repeated the experiment, Dalibard erroneously concluded that he had discovered the electromagnetic relationships necessary to prove this identity. (Franklin himself wrote, erroneously, in 1773 that as to the magnetism apparently produced by electricity, his present opinion was that electricity and magnetic force have no connection with each other and that the production of magnetism is purely accidental.)

BIBLIOGRAPHY

I. Original Works. Dalibard’s works include his trans. of Grarcilasso de la Vaga’s Histoire des Incas, rois du Pérou (Paris, 1774); Florae Parisiensis Prodomus, ou catalogue des plantes qui naissent dans les environs de Paris (Paris, 1749); and his trans. of Franklin’s Experiments, Expériences et observations sur l’électricité faites à philadelphie en Amérique par M. Benjamin Franklin; et communiquées dans plusieurs letters à M. P. Collinson… (Paris, 1752; 2nd ed., Paris, 1756).

II. Secondary Literature. On Dalibard, see also articles by Michaud, in Biographie universelle, X (Paris, 1855), and Hoeffer, in Nouvelle biographie générale, XII (Paris, 1866); and see I. Bernard Cohen, Franklin and Newton (Philadephia, 1956).

Pierre G. Hamamdjian