CHAPTER Vili 



ROBERT HEATH AND FRIENDS OF EMERSON IN 

 CONTROVERSY WITH JOHN TURNER AND 

 FRIENDS OF SIMPSON 



i8i. The principals, Simpson and Emerson, do 

 not themselves appear in this controversy. During 

 the period of this debate, Robert Heath was editor 

 of The Ladies' Diary, which appeared once every 

 year as an ahiianac. We begin with one of his 

 articles. 



Robe7-t Heath ^ 1746 



182. In an article, Of the Idea, and Nature of 

 Fliixions,^ Heath says : 



' * The Distinction betwixt the Increments and 

 Fluxions of Magnitudes, has been this ; that the 

 former approach in Ratio infinitely near the latter, 

 so that their Difference is unassignable. . . . What 

 we cali the Fluxions, or Velocities of Magnitudes, 

 are only the Fluxions in Chief, or in Part, with 

 which they are born ; the Part neglected in the 

 Ratio exactly corresponding with what is rejected 

 in the finite Ratio of the infinitely small Increments, 

 which is therefore the same as the Ratio of our 



^ The Ladies Diary : or, the IVoman^s Almanack.for 1746. 

 207 



