C 574 ) 
we tfrcn think it a hard fuppofition that the Internal 
parts of this Bubble of Earth ftiould be replete with 
fuch Saline and Vitriolick Particles as may contribute 
to petrifadion, and difpofe the tranfuding Water to 
Ihoot and coagulate into Stone, fo as continually to for- 
rifie, and if need were to confolidate any breach or flaw 
in the Concave Surface of the Shell. ■• 
And this ptrhaps may nor Without rtfifon befuppofed 
to be the final Caufeof the adtfJiHture of the Magnetical 
Matter in the Mafs of the Tert^ftfial parts of our Globe, 
W2, To make good and maintain the Concave Arch of 
this Shell : for "by what the 'excellent Mr. Newton has 
fhewn in his Trinctpia Philofop/j/te, it will follow that ac- 
cording to the general Principle of Gravity, vifible 
throughout the whole Univerfe, all thofe Particles that 
By length of time or otherwife fhall molder away or be- 
come loofe on the Concave Surface of the External 
Sphere, would fall in, and with great force defcend on the 
Internal, unlefs thofe Particles were of another fort of 
Matter capable by their ftronger tendency to each other, 
tofufpend the force of Gravity 5 but we know no other 
fubftances capable of fupporting each other by their mu- 
tual Attra&ion but the Magnetical, and rhefe we fee 
miraculoufly to perform that Office, even where the 
power of Gravity has its full effe£h much more within 
the Globe where it is weaker. Why then may we not 
fuppofe thele faid Arches to be lined throughout with & 
Magnetical Mattery, or rather to be one great Concave 
Mafgnet* whofe two Poles are the Poles we have before 
obferved to be fixt in the -Surface of our Globe. 
Another Argument favouring this Hypothefis is drawn 
from a Propofition oir the fame Mr. Newton, where he 
determines the force wherewith the Moon moves the Sea 
in producing th& Tides : his wordis are 3 Denjitas Luna eft 
ad denfitatem Terra ut 680 ad ^87 feu 9 ad 5 quam- 
femxime^ Eft igitur corpus LuH& denpus ac magh tereftre 
quant; 
