[ 25 * '] 
If, however, upon a more accurate examination, it 
fhould be found, that the quantity of light above 
afligned is not far from the truth, or if the difference 
of light (hould be greater than I have fuppofed it 
to be (in which cafe the argument will be ftill 
ffronger) ; this will add a confiderable degree of weight 
to the other arguments drawn from analogy, in favour 
of the Sun’s making one of a fyftem of ffars. 
If we would now inquire, which are probably thofe 
ffars, which compofe part of the fame fyftem with 
the Sun ; though it will not be poffible to point them 
out with certainty, yet there are fome marks, by 
which we may, with great probability include fome 
and exclude others, whilft the reff remain more doubt- 
ful. Thofe ffars which are found in clufters and 
furrounded with many others at a fmall diftance from 
them, belong probably to other fyffems and not to 
ours. And thofe ffars, which are furrounded with 
nebula;, are probably only very great ffars, which, 
upon account of their luperior magnitude, are fingly 
vifible, whilft the others, which compofe the remain- 
ing parts of the fame fyftem, are fo fmall as to efcape 
our light. And thofe nebulae, in which we can dis- 
cover either none, or only a few ffars, even with the 
affiffance of the beft telefcopes, are probably fyffems, 
that are ftill more diftant than the reff. 
The Pleiades, as they appear to the naked eye, 
have been fhewn above to be probably a fyftem by 
themfelves ; and if we examine them ftill farther 
by means of telefcopes, we {hall find, that they are 
furrounded with fo large a number of fmaller ffars, 
as to increafe the odds againft the contrary opinion 
many millions to one. Now fuppofing the Pleiades 
K k 2 to 
