Yet, in order to determine the difference of structure in their organs of voice, Cuvier, as he says in his Legons (iv.
His academic lectures for 1843-1844 were published in 2 vols., 1845-1849, under the title Legons de geologie pratique.
In addition to many memoirs he wrote Legons de physique expdrimentale (1743), Essai sur l'electricite des corps (1747), Recherches sur les causes particulieres des phenomenes eiectriques (1749 and 1754), Recueil de lettres sur l'electricite (1753), L'Art de faire les chapeaux (1764) and L'Art des experiences (1770).
Besides a little pamphlet upon Danton, he has written a Histoire politique de la Revolution francaise (1901), and a number of articles which have been collected in volumes under the title Etudes et legons sur la Revolution francaise (5 vols., 1893-1908).
Of another work of Poincare, Legons de mecanique celeste, the first volume appeared in 1905.