[Footnote 141: The "_Bibliotheque Curieuse, Historique et Critique, ou Catalogue raisonne de Livres difficiles a trouver_," of DAVID CLEMENT, published at Gottingen, Hanover, and Leipsic, in 9 quarto volumes, from the year 1750 to 1760--is, unfortunately, an unfinished production; extending only to the letter H. The reader may find a critique upon it in my _Introduction to the Greek and Latin Classics_, vol. i., p. 370; which agrees, for the greater part, with the observations in the _Bibl. Crevenn._, vol. v., 290. The work is a _sine qua non_ with collectors; but in this country it begins to be--to use the figurative language of some of the German bibliographers--"scarcer than a white crow,"--or "a black swan." The reader may admit which simile he pleases--or reject both! But, in sober sadness, it is very rare, and unconscionably dear. I know not whether it was the same CLEMENT who published "_Les cinq Annees Litteraires, ou Lettres de M. Clement, sur les ouvrages de Litterature, qui ont parus dans les Annees 1748--a 1752_;" Berlin, 1756, 12mo., two volumes. Where is the proof of the assertion, so often repeated, that Clement borrowed his notion of the above work from WENDLER'S _Dissertatio de variis raritatis librorum impressorum causis_, Jen., 1711, 4to.?--Wendler's book is rare among us: as is also BERGER'S _Diatribe de libris rarioribus, &c._, Berol. 1729, 8vo.]