JURIN V. ROBINS AND PEMBERTON 137 



Jurin appears with a 12-page article in the May, 

 1737, number of The Works of the Learned, say- 

 ing : "He stili ascribes to my words a meaning, 

 which I have again and again utterly disavowed ; 

 not only so, but he changes the words themselves, 

 putting any difference instead of any assignable differ- 

 ence'' {^. 388). As to the Introduction to Newton's 

 Quadratura Curvarum^ " in that very Introduction 

 Sir Isaac Newton has made use of infinitely little 

 quantities, in the sense I understand them, that is, 

 quantities which being at first finite, do by a graduai 

 diminution at last vanish into nothing and conse- 

 quently must, during their diminution, become less 

 than any quantity that can be assigned " (p. 389). 

 As to evanescent quantities being entities or non- 

 entities, "If this page were divided from top to 

 bottom into two equal parts, one black, and the 

 other white,^ and Dr. Pemberton were to ask me, 

 whether the middle line, which divides the two 

 parts, were black or white, I apprehend it would 

 be a direct answer to say, it is neither ; it cannot 

 properly be called either a black line, or a white 

 line ; it is the end of the white and beginning of 

 the black, or the end of the black and beginning of 

 the white" (p. 389). '*I was apprised that Mr. 

 Robins had ali along expressed the sentiments of 

 Dr. Pemberton " (p. 393). Dr. Pemberton stili 

 refuses to give his interpretation of Newton's 



^ As far as I know, Jurin is the first to use colour devices to illustrate 

 subtle points in evanescent quantity or in number. Jules Tannery, in 

 his Le^ons cf Algebre et cTAnalyse, Paris, 1906, p. 14, uscs colour imagery 

 to illustrate the discussion of irralional numbers. 



