[ 433 ] 
The only part of my reafoning which will be 
affected, by fuppofing the figure of the particles of 
light not to be ipherical, will be that, (p. 427, See.) 
in which I attempt to fhew, in what proportion the 
magnitude of each particle, and the matter, contained in 
each emifiion, muff be lefs than the maximum, in order 
to make the denfity of light no greater, than may be 
confident with the appearances of nature. Here in- 
deed the figure of the corpufcles is of great impor- 
tance. The diminution neceffary will be very different 
in different figures, and the figure, I confefs, may be 
fucb, as to make it much lets, than what I have 
fhewn to be requifite upon the fpherical hypothefis. 
However, if _^.i__th part of the denfity of our air 
be admitted to be as great a denfity, as can reafon- 
ably be allowed to light, at the furface of the orbis 
magnus, the 'matter of each emifiion muff not, upon 
any hypothefis of the figure of the corpufcles, exceed 
-^ T _th of the maximum. 
For, in order to bring the denfity down, from the 
maximum to any other given limit, either the matter 
muff remain unaltered, and the fpace, which it is 
fuppofed to occupy, be encreafed, in the proportion in 
which the denfity is to be diminifhed 3 or the fpace 
muff remain unaltered, and the matter be diminifh- 
ed in proportion to the denfity ; or, if both fpace 
and matter be altered, the matter muff be changed 
in the proportion compounded of the two, in which 
both fpace and denfity are varied. Now the fpace 
which we fuppofe the light to occupy, as it is emerg- 
ing from the furface of the fun, muff not exceed 
the fpace contained between the fpherical furface& 
egh,f kl (fig. p. 429.). For that fpace, as has been 
Vol. LX,. K k k oblerved,,. 
