His first attempt to be elected to the Institute was in 1806 when he was backed by Laplace, Lagrange, Lacroix, Legendre and Biot for a place in the Mathematics Section. Bossut was 76 years old at the time and, had he died, Poisson would have gained a place. However Bossut lived for another seven years so there was no route into the mathematics section for Poisson. He did, however, gain further prestigious posts.
Kanyang unang pagtatangka na elected sa Institute ay sa 1806 kung kailan siya ay back sa pamamagitan ng Laplace, Lagrange, Lacroix, Legendre at Biot para sa isang lugar sa Mathematics Section. Bossut ay 76 years old at ang mga oras at, nagkaroon siya namatay, Poisson ay nagkamit ng isang lugar. Subalit Bossut buhay para sa iba pang pitong taon kaya wala ang ruta papunta sa matematika na seksyon para sa Poisson. He did, gayunpaman, makakuha ng karagdagang prestihiyoso posts.