Sentence:  To "Hydroſtaticks" belong whatever relates to the Gravities and <WSD>Equilibria</WSD> of Liquors; with the Art of weighing Bodies in Water, in order to eſtimate the ſpecifick Gravities. 
Meaning of the word marked with <WSD> tags:  The condition of a system in which competing influences are balanced, resulting in no net change.