CHAPTER X 

 LATER BOOKS AND ARTICLES ON FLUXIONS 



Encyclopcedia Britannica^ ^77^, 1/79) ^797 



207. The article ''Fluxions" in the first edition 

 of the Encyclopcedia Britannica, Edinburgh, 1771, 

 gives this definition : "The fluxion of any magni- 

 tude at any point is the increment that it would 

 receive in any given time, supposing it to increase 

 uniformly from that point ; and as the measure will 

 be the same, whatever the time be, we are at liberty 

 to suppose it less than any assigned time." The 

 fluxion of a rectangle is the increment, with the small 

 rectangle at the corner omitted ; the latter *' is owing 

 to the additional velocity wherewith the parallelo- 

 gram flows during that time and therefore is no 

 part of the measure of the fluxion." "The incre- 

 ment a quantity receives by flowing for any given 

 time, contains measures of ali the different orders of 

 fluxions; for if it increases uniformly, the whole in- 

 crement is the first fluxion ; and it has no second 

 fluxion. If it increases with a motion uniformly 

 accelerated, the part of the increment occasioned by 



the first motion measures the first fluxion, and the 



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