full liberty to make a Character denote, either a poſitive or a negative Quantity, or nothing at all, we may therefore in a geometrical Caſe, limited by Hypotheſes and Reaſonings from particular Properties and Relations of Figures, claim the ſame Licence?
Qu. 28. Whether the Shifting of the Hypotheſis, or (as we may call it) the fallacia Suppoſitionis be not a Sophiſm, that far and wide infects the modern Reaſonings, both in the mechanical Philoſophy and in the abſtruſe and fine Geometry?
Qu. 29. Whether we can form an Idea or Notion of Velocity diſtinct from and excluſive of its Meaſures, as we can of Heat diſtinct from and excluſive of the Degrees on the Thermometer, by which it is meaſured? And whether this be not ſuppoſed in the Reaſonings of modern Analyſts?
Qu. 30. Whether Motion can be conceived in a Point of Space? And if Mo-
