fLUXIONS. COMMERCIUM EPISTOLICUM 51 



In Edition B this sentence with the note is left out, and the following inserted in its 

 place : 



' Qua de Questionibus Philosophies disputata sunt D. Des Maizeaux collegit <5r in lucem 

 edidit.' 



The printers in reprinting this leaf were careful to use the same wood block at the end 

 of the Ad Lectorem, so that a casual glance does not notice the change. 



Messrs. Biot and Lefort, in their edition of the Commercium Epistolicum, quote the 1725 

 edition, and give the following note concerning it (p. ix) : 



' Ce titre, porte par un assez grand nombre d'exemplaires de la 2e edition du Commercium 

 Epistolicum, est un carton, en style de typographic. Dans les exemplaires qui portent ce 

 titre, il est facile de reconnaitre que : i le feuillet de tete est colle sur la page qui contient 

 VAd lectorem ; 2 la vergeure du papier n'est pas la meme pour le titre et pour le corps de 

 1'ouvrage. ' 



The editors might have also proved that the two editions they knew (Nos. 239 and 241) 

 were the same, except for the title-page the errors in the paging, the list of books ' Lately 

 Published' are identical in these editions. But the editors did not know that there was more 

 than one issue of each of the 1722 and 1721; editions. They certainly did not know of the 

 Edition B of the 1725 edition, or they would have noted the variation in the Ad Lectorem in 

 their work. The existence of these various issues I believe to be now known for the first 

 time. 



Commercium Epistolicum J. Collins et aliorum de analysi promota, 

 etc., ou correspondance de J. Collins et d'autres savants celebres 

 du xvir siecle, relative a 1'analyse superieure, reimprimee sur 

 1'edition originale de 1712 avec 1'indication des variantes de 

 1'edition de 1722, comple"tee par une collection de pieces justifi- 

 catives et de documents ; et publiee par J. B. Biot, et F. Lefort. 

 Paris, Mallet-Bachelier, gendre et successeur de Bachelier, etc., 

 1856. 4to. [243 



Collation: pp. xvi + (293) + i page of Errata. 



Contents : Title, Advertisement (by the Editors) i viii ; Table des matieres, ix xvi ; 

 the Commercium Epistolicum, 1712, with the additions and alterations of the 1722 edition, 

 and notes by the Editors, (i) (190) ; 

 Pieces justificatives et documents : 



I. Supplement au Commercium Epistolicum, (191) (251). 

 II. Sommaire des principaux travaux mathematiques qui, au xviie siecle, ont prepare 



1'invention de 1'analyse infinitesimale, (253) 281) : 

 Cavalieri. Geometric des indivisibles. 

 Descartes. Methode des Tangentes, deduite de la theorie des racines egales et de la 



methode des coefficients indetermines. 

 Fermat. Methode des maxima et minima, et application a la recherche des 



Tangents. 



Hudde. Theorie des racines e'gales, methode des maxima et minima, et application 

 & la determination des Tangentes. 



