First published in Tait’s (March 1846), pp. 192–6; reprinted in F, Note-book of an English Opium-Eater, 1855; in SGG, vol. 9 (1858), Essays Sceptical and Anti-sceptical, on problems neglected and misconceived, pp. 19–34. No manuscript of this article has been traced, but there is a set of page proofs to the version reprinted in SGG that has been extensively corrected in De Quincey’s hand. These corrections will be included in the Textual Notes to this essay.