ROBERT HEATH v. JOHN TURNER 211 



which, he tells us, himself, is not exactly the same 

 as that of Sir Isaac Newton." Mr. Simpson is also 

 charged with plagiarism from Cotes's Estimatio 

 Errorum. John Turner says : 



" Here his Remarks on the Author's Definition 

 of a Fluxion first demand our Consideration : Mr. 

 Simpson makes it to be, * the Magnitude by which 

 a flowing Quantity would be uniformly increased in a 

 given Time.' This Definition the Critic represents 

 as a very old one ; and with regard thereto advances 

 the two following, extraordinary, Positions : 



'* I. That, in Ouantities uniformly generated, the 

 Fluxion must (according to the said Definition) be 

 the Fluent itself, or else a Part of it. 



**2. And that, in other Quantities generated by 

 a variable Law, the Fluxion will not be a real, but 

 an imaginary Thing. 



'*To the first of these Objections I answer, that 

 the Fluxion is neither the Fluent itself nor a Part 

 of it : it is a Quantity of the same Kind with the 

 Fluent ; but the Fluent being the Quantity already 

 produced by the generating Point, Line or Surface, 

 supposed stili in Motion, and the Fluxion what will 

 arise, hereafter, from the Continuation of that 

 Motion ; the latter can no more be denominated 

 a Part of the former than the ensuing Hour a Part 

 of the Time past. 



"But his second Observation is a stili more 

 glaring Instance of his Disingenuity, and Want of 

 Judgment. Does it follow, because a Body, really, 

 moves over a certain Distance, in a given Time, 



