54. Mr. Mocnevz on the Means of difeovering the. 
quence of its gravitation towards the bodies from whence it i 
emitted and’ there fhould be feveral of the fixed tars large 
enough to make it fufficiently fenfible, a {et of obfervations 
upon this fubject might probably give us fome confiderable in- 
formation with regard to many circumftances of that part of 
the univerfe, whichis vifible to us. The quantity of matter 
contained in many’ of the fixed ftars might from hence be judged 
of, with a great degree of probability, within fome moderate 
limits; for though the exa& quantity muft fill depend upon 
their denfity, yet we muft fuppofe the denfity moft enormoutfly 
different from that of the fun, and more fo, indeed, than one 
can eafily conceive to take place in fact, to make the error of 
the fuppofed quantity of matter very wide of the truth, fince 
the denfity, as has been fhewn above in art. 11. and 12. which 
is neceflary to produce the fame diminution in the velocity of 
light, emitted from different bodies, is as the fquare of the 
quantity of matter contained in thofe bodies inverfely. 
36. But though we might poffibly from hence form fome 
reafonable guefs at the quantity of matter contained in feveral 
of the fixed ftars; yet, if they have no luminous fatellites 
revolving about them, we fhall ftill be at a lofs to form any 
probable judgment of their diftance, unlefs we had fome ana-~ 
log'y to go upon for their fpecific brightnefs, or had fome other 
means of difcovering it; there is, however, a cafe that may 
poftibly occur, which may tend to throw fome light upon this 
matter. 
37. have fhewn in my Enguiry into the probable Parallax, 
&c. of the Fixed Stars, publifhed in the Philofophical ‘Tranf- 
actions for the year 1767, the extremely great probability there 
is, that many of the fixed ftars ‘are colleCted together into 
groups; and that the Pleiades’ in “patticular’ ‘conftitute one of 
thefe 
