C 90 ] 
were very luminous, others not at all. Of many 
opaque Subftances, whether rough, polifhed, or finely 
powder’d, lbme were luminous, others not. So that 
it appears, that not only the external, but the in- 
ternal Texture of Bodies alfo, may conduce fome- 
times to their being luminous. 
From the preceding Experiments, the Author is led 
to make fome Inquiries into the Caufe of this lumi- 
nous Appearances and takes notice, that almoft all 
Bodies, by a proper Treatment, have that Power of 
fliining in the dark, which, at firft, was fuppofed to 
be the Property of one, and afterwards only of a few. 
How this is brought about, is not very eafy to folve. 
If we fuppofe with fome (to which our Author, in 
feveral Paffages of this Work, feems not averfe), that 
the Light from a luminous Body enters and abides 
in the c Phofphori , we fhall find fomewhat new to ad- 
mire in Light itfelf. It is no new Opinion, that this 
Fluid confifts of very fine Particles, which are conti- 
nually darted forth from a luminous Body, in all Di- 
rections, with a very great Velocity : But it has by 
nobody been laid down hitherto, that thefe Particles 
arc not diffolved by the Violence of their Agitation, 
not difperfed, nor immediately ceafe to exift; but 
fubfift flill, and adhere to what Bodies come in their 
Way, as Heat does, and are the Caufes of Odours. 
If therefore the Panicles of Light are not difiolved 
as foon as they are emitted from a radiant Body, but 
continue fome time, what eife is required, but that 
we allow its Atmofphere to every lucid Appearance? 
If the Phofphori fhine with a borrowed Light, but 
not with their own, and that only when putin Mo- 
tion, and fired by the Rays of a fhining Body, which 
fome 
