And then, ſince Mr. Gaſcoin tells you, That the Experiment being of it ſelf extraordinary and ſurprizing , and beſides uſhering in new Principles into Opticks, quite contrary to the common and received , it will be hard to perſwade it as a truth, till it be made ſo viſible to all as it were a ſhame to deny it: if he eſteem it ſo extraordinary , he may have the priviledg of making it ſo viſible to all , that it will be a ſhame to deny it.