When Morny returned to Paris in 1838, he secured a solid position in the business world by establishing a major beet-sugar industry at Clermont-Ferrand in the Auvergne and by writing a pamphlet "Sur la question des sucres" in 1838. In these and other lucrative speculations he was helped by his mistress Françoise Mosselman, the beautiful and wealthy wife of the Belgian ambassador, Charles Aimé Joseph Le Hon, Comte Le Hon. Eventually there were few great commercial enterprises in Paris in which he did not have an interest.