ADDENDA 291 



of vvhich from it self, it is generateci ; that is 

 oa — a^a-\-a — a-Ya — a ec." In the " Advertize- 

 ment " foUowing p. 190 this is further explained 

 thus : ' ' Relative Nothing is said here to be generated 

 by a perpetuai Subtraction, tho' the Signs by alter- 

 nately -f- and — . For these Reasons, because 

 relative Infinite, was said to be generated by a 

 perpetuai Addition, and because that after the first 

 Term, every two succeeding ones in relative Nothing 

 I is equivalent to o\ thus i — i + i — i + i — i, &c. 

 . . . =\—oi—o\—o\ &c." 



247. These explanations are intended by Cheyne 

 merely as introductions to the later chapters, par- 

 ticularly that by John Craig, who (p. 167) declares 

 that cannot be an absolute nothing, "for an 

 infinite Number of absolute Nothings cannot make i, 

 but by is understood an infinitely small part, as 

 in the cale. diff. dx is an infinitely small part of x, 

 so that dx is as \.o x : Not that dx is absolutely 

 nothing, for it is divisible into an infinite Number of 

 Parts, each of which is ddx. " To make the point 

 stili plainer, John Craig continues (p. 168): "But 

 then it may be inquir'd what is the Ouotient that 

 ariscs from the Division of i by absolute Nothing. 

 I say there is no Ouotient because there is no 

 Division : Therefore it is a Mistake to say the 

 Quotient is i or Unity undivided, which is demon- 

 strably false, neither is the Ouotient = ^. For 

 properly speaking there is no Ouotient, and there- 

 fore it is an Error to assign any. In like manner, 

 it is an Error to say, that oy^a makes the Product 



