_All material Bodies have an Attraction for the ethereal Medium, by
means of which it is accumulated within their Substance, and for a
small Distance around them, in a State of greater Density, but not of
greater Elasticity._
It has been shewn, that the three former hypotheses, which may be
called essential, are literally parts of the more complicated NEWTONIAN
system. This fourth hypothesis differs perhaps in some degree from
any that have been proposed by former authors, and is diametrically
opposite to that of NEWTON; but, both being in themselves equally
probable, the opposition is merely accidental; and it is only to be
inquired which is the best capable of explaining the phenomena. Other
suppositions might perhaps be substituted for this, and therefore I do
not consider it as fundamental, yet it appears to be the simplest and
best of any that have occurred to me.