Sentence:  Fluxions are very nearly as the Augments of the Fluents, generated in equal, but infinitely ſmall parts of Time ; and to ſpeak exactly, are in the "Prime Ratio" of the <WSD>naſcent</WSD> Augments : but they may be expounded by any Lines that are proportional to 'em. 
Meaning of the word marked with <WSD> tags:  Describing a quantity of object that is starting to grow from zero or an infinitesimal beginning. Also the creation or identification of an infinitesimal delta.