After returning Percy to school after the Easter holiday, Mary Shelley departed for France. In her journal, she describes succumbing to small-pox on her arrival in Paris.

See The journals of Mary Shelley, 1814–1844, ed. by Paula R. Feldman and Diana Scott-Kilvert, 2 vols (Oxford and New York: Oxford University Press; Clarendon Press, 1987), p. 507, n. 1.