In ſcientifical propoſitions concerning natural bodies a definition is made, as of gold from its properties, ſuppoſe its colour, and ſpecific gravity, and another property or power joined to them, as a conſtant or common aſſociate. (Rewritten in modern spelling: In scientifical propositions concerning natural bodies a definition is made, as of gold from its properties, suppose its colour, and specific gravity, and another property or power joined to them, as a constant or common associate.)
Source: wiktionary