Remarks upon the Newtonian philosophy [microform] : as propos'd by Sir Isaac Newtion in his Principia philosophiæ naturalis : and by Dr. Gregory in his Principia astronomiæ physicæ : wherein the fallacies of the pretended mathematical demonstrations, by which those authors support that philosophy are clearly laid open : and the philosophy itself fully proved to be false and absurd both by mathematical and physical demonstration / by George Gordon