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LXIL On the Authorship of the Account of the Commercium 

 Epistolicum, published in the Philosophical Transactions. By 

 Professor De Morgan*. 



IN Number 342 (Jan. to Feb. 1714-15) of the Philosophical 

 Transactions, is the celebrated paper headed " An Account 

 of the Book entituled Commercium Epistolicum . . . ," which was 

 translated into Latin and French, the former in the prelimi- 

 naries of the second edition of the Comm. Epist. itself, the latter 

 in vol. vii. of the Journal hitter aire. Tbis paper has been attributed 

 to Newton by some ; but in England it seems to be generally 

 supposed that Keill was the author. Many writers offer no 

 opinion. Sir David Brewster says that it is falsely ascribed to 

 Newton, but without stating any reason beyond the groundless 

 character of the ascription. Biot says that it appeal's to have 

 been written by Newton. Montucla, on information received 

 from England par des notes de bonne main, states that the notes 

 to the Comm. Epist. are by Newton : this I suspect to be a con- 

 fusion between the avowedly new and separate matter of the 

 second edition, arid the running notes in the first. And so the 

 matter now stands. 



Halley's letter to Keill of Oct. 3, 1715 (Edleston's Corre- 

 spondence, &c. p. 184) concerning the French translation, may 

 be interpreted in favour of the authorship of either Keill or 

 Newton ; but seems to render it probable that it must have been 

 one or the other. What we can get from Keill himself amounts 

 to the following. In his epistle to John Bernoulli, separately 

 printed f in 1720, we find "Est etiam ejusdem Commercii Re- 

 censio sive Epitome in Actis Londinensibus edita : Prodierunt et 

 nostra; Responsiones ad tuas amicorumque tuorum calumnias " 

 (p. 8) : and again, " In Commercio Epistolico ejusque Epitome, 

 et in aliis scriptis a me editis. . . ." (p. 20). In the first extract the 

 Recensio is distinguished from Keill s own reply inserted in vol. iv. 

 of the Journ. Litteraire. The second extract is ambiguous : if it 

 give some help to those who would make Keill the author of 

 the Epitome, it gives just as much to those (Watt and others) 

 who set him down as the editor of the Comm. Epist. itself. 



I shall now proceed to the evidence, external and internal, on 

 which my mind is satisfied that Newton is really the author of 

 the paper in question. 



James Wilson, M.D., the witness in this matter, was probably 



* Communicated by the Author. 



t The Biogr. Britann. ' Keill,' states that this tract has the thistle on its 

 title-page, with Nemo me, &c. My copy has no such thing, but only Cohibe 

 linguam tuam it malo, et labia tua ne loquantur dolum. It may be that this 

 was the original title-page, and that remonstrance or second thought sug- 

 gested the erasure of this rather offensive motto. 



