Letter from Simeon Denis Poisson to Thomas Young, dated at Paris Thanks for the election to the Royal Society. [Jean Baptiste] Biot has told Poisson that Young was largely responsible for the honour. Will send his essay on the theory of light wave when it is published later this month, [clarification, this is around the time of the Academie des sciences' prize on the diffraction of light won by [Augustin Jean] Fresnel which disproved Poisson's prior support for the particle theory of light] 10 May 1818