Poisson and K.
Many are transcripts of works or portions of works already published and, therefore, require no notice.2 The works hitherto printed (neglecting reprints) are the following: - (I) Speculum Alchimiae (1541) - translated into English (1597); French, A Poisson (1890); (2) De Mirabili Potestate Artis et Naturae (1542) - English translation (1659); (3) Libellus de Retardandis Senectutis Accidentibus (1590) - translated as the "Cure of Old Age," by Richard Brown (London, 1683); (4) Sanioris Medicinae Magistri D.
Coulomb's researches provided data for the development of a mathematical theory of magnetism, which was indeed initiated by himself, but was first treated in a complete form by Poisson in a series of memoirs published in 1821 and later.
4 Poisson assumed the existence of two dissimilar magnetic fluids, any element of which acted upon any other distant element in accordance with Coulomb's law of the inverse square, like repelling and unlike attracting one another.
On this hypothesis Poisson investigated the forces due to bodies magnetized in any manner, and also originated the mathematical theory of magnetic induction.
The mathematical theory which was constructed by Poisson, and extended and freed from doubtful hypotheses by Kelvin, has been elaborated by other investigators, notably F.
Poisson in a paper read on the 10th of June 1808, was once more attacked by Lagrange with all his pristine vigour and fertility of invention.
Resuming the inquiry into the invariability of mean motions, Poisson carried the approximation, with Lagrange's formulae, as far as the squares of the disturbing forces, hitherto neglected, with the same result as to the stability of the system.
He proposed to apply the same principles to the calculation of the disturbances produced in the rotation of the planets by external action on their equatorial protuberances, but was anticipated by Poisson, who gave formulae for the variation of the elements of rotation strictly corresponding with those found by Lagrange for the variation of the elements of revolution.
Poisson brought forward as an objection to Fresnel's theory that it required at the centre of a circular shadow a point as bright as if no obstacle were intervening.
Poisson, although previously demonstrated by Laplace for the case when p=0.
The Poisson equation cannot, however, be applied in the above form to a region which is partly within and partly without an electrified conductor, because then the electric force undergoes a sudden change in value from zero to a finite value, in passing outwards through the bounding surface of the conductor.
Hence if we remove the charge -q at B and distribute electricity over the surface PO with a surface density a, according to the Coulomb-Poisson law, a = qAO/21rAP3, the field of force to the left of PD will fulfil the required boundary conditions, and hence will be the law of distribution of the induced electricity in the case of the actual plate.
The last of the three supplements to his Traite des fonctions elliptiques was published in 1832, and Poisson in his funeral oration remarked: " M.
Poisson; the flow of electromagnetic waves along wires (Sir J.
(Euprepes) vittata, the "poisson de sable" of Algeria, is semi-aquatic. Chalcides s.
1827), And Adolphe Poisson (B.
Poisson published his Memoir on the Deviations of the Compass caused by the Iron in a Vessel.
SIMEON DENIS POISSON (1781-1840), French mathematician, was born at Pithiviers in the department of Loiret, on the 21st of June 1781.
His father, Simeon Poisson, served as a common soldier in the Hanoverian wars; but, disgusted by the ill-treatment he received from his patrician officers, he deserted.
Poisson was first sent to an uncle, a surgeon at Fontainebleau, and began to take lessons in bleeding and blistering, but made little progress.
Billy, who, when he speedily found that his pupil was becoming his master, devoted himself to the study of higher mathematics in order to follow and appreciate him, and predicted his future fame by the punning quotation from Lafontaine': - "Petit Poisson deviendra grand Pourvu que Dieu lui prete vie."
This success at once procured for Poisson an entry into scientific circles.
Laplace, in whose footsteps Poisson followed, regarded him almost as his son.
His father, whose early experiences led him to hate aristocrats, bred him in the stern creed of the first republic. Throughout the empire Poisson faithfully adhered to the family principles, and refused to worship Napoleon.
As a teacher of mathematics Poisson is said to have been more than ordinarily successful, as might have been expected from his early promise as a repetiteur at the Ecole Polytechnique.
(1827), &c. In the first of these memoirs Poisson discusses the famous question of the stability of the planetary orbits, which had already been settled by Lagrange to the first degree of approximation for the disturbing forces.
Poisson showed that the result could be extended to a second approximation, and thus made an important advance in the planetary theory.
Poisson made important contributions to the theory of attraction.
Besides his many memoirs Poisson published a number of treatises, most of which were intended to form part of a great work on mathematical physics, which he did not live to complete.
Arago, Biographie de Poisson, read before the Academie des Sciences on the 16th of December 1850.
The French mathematicians, Coulomb, Biot, Poisson and Ampere, had been content to accept the fact that electric charges or currents in conductors could exert forces on other charges or conductors at a distance without inquiring into the means by which this action at a distance was produced.
James Clerk Maxwell (1831-1879) entered on his electrical studies with a desire to ascertain if the ideas of Faraday, so different from those of Poisson and the French mathematicians, could be made the foundation of a mathematical method and brought under the power of analysis.3 Maxwell started with the conception that all electric and magnetic phenomena are due to effects taking place in the dielectric or in the ether if the space be vacuous.
This fact and hypothesis brought electrical phenomena within the domain of mathematical analysis and, as already mentioned, Laplace, Biot, Poisson, G.
Poisson, he received the appointment of secretary to the Observatory of Paris.
Fresnel's arguments in favour of that theory found little favour with Laplace, Poisson and Biot, the champions of the emission theory; but they were ardently espoused by Humboldt and by Arago, who had been appointed by the Academy to report on the paper.
In 1831 Simeon Denis Poisson published his Nouvelle Theorie de action capillaire.
On these assumptions his results are certainly right, and are confirmed by the independent method of Gauss, so that the objections raised against them by Poisson fall to the ground.
But whether the assumption of uniform density be physically correct is a very different question, and Poisson rendered good service to science in showing how to carry on the investigation on the hypothesis that the density very near the surface is different from that in the interior of the fluid.
We have given several examples in which the density is assumed to be uniform, because Poisson has asserted that capillary B (25) e = c p (X' - 4 7rpe (0) ) -I-474°o(z)dz.
Poisson,' Goldschmidt, 2 L.
Poisson in the chair of mechanics in the Faculte des Sciences at Paris.