My special opportunities, derived from constant companionship and the continuous discussion with DE QUINCEY of matters concerning his writings, gave me the key to some of the admirable papers here reprinted. It also entitles me to say, that he would have included a number of them in his Collected Works alongside the _Suspiria de Profundis_ (Sighs from the Depths), had he lived to continue his labours. When we find that most part of the _Suspiria_--perhaps the highest reach of his intellect in impassioned power--did not appear in the _Selections_ at all, the reader will at once understand that, in the Author's own opinion, the Essays and Stories now first collected, were neither less dignified in purpose nor less finished in style than those which had passed under his hand in the fourteen volumes he nearly completed. Rather like the _Suspiria_, some of these papers were reserved as material upon the revision of which his energy might be fitly bestowed when health would permit. * * * * * The interesting papers which appeared in _Tait's Magazine_ are all duly vouched for in that periodical. I have not touched any of the autobiographical matter which appeared in _Tait_,--the Author having recast that as well as the _Sketches from Childhood_, published in _The Instructor_ in the 'Autobiographic Sketches' with which he opened the _Selections_. _The Casuistry of Duelling_, indeed, appeared in _Tait_ as part of the Autobiographic Series, but, practically, it stood as an independent paper. The touching personal passage in this article reveals the misery caused by the unbridled scurrility of certain notorious publications of the last generation. The paper on _The German Language_ appeared in _Tait_ in June 1836, and the _Brief Appraisal of Greek Literature_ in December 1838 and June 1839. * * * * * Two long and valuable papers on _Education; Plans for the Instruction of Boys in Large Numbers_, which appeared in _The London Magazine_ for April and May, 1824, were duly authenticated by the following characteristic letter from DE QUINCEY to CHRISTOPHER NORTH. It appears in _Professor Wilson's Life_, written by his daughter, MRS. GORDON:-- '_London, Thursday, February 24th, 1825._ 'MY DEAR WILSON,