22 ESSAYS anp OBSERVATIONS 
ofan inch, which {pace a particle of lighr 
deferibes in.23-eoe ties ee ee ee 
cond, With fo rapid a motion therefore 
may the internal part of bodies be agita- 
ted by the influence of light, as to per- 
form 125,000,000,000,000 vibrations or 
more in a fecond of time! The arrival ef 
different particles of light at the furface of 
‘the fame colorific particle in the fame 
or different rays, may difturb the re- 
gularity of their vibrations, but will e- 
~ vidently increafe their frequency, or raife 
ftill minuter vibrations among the parts 
which compofe thefe particles; by which 
means the inteftine motion becomes more 
fubtile and thoroughly diffufed. If the 
quantity of light admitted into the body 
be increa‘ed, the vibrations of the parti- 
cles muft likeways increafe in magnitude 
and velocity: Till, at laft, they may be fo 
violent as to make all the component par- 
ticles dafh one another to pieces by their. 
mutual! collifions: In which cafe, the co" 
lour and texture of the body muft be de-. 
Qroyed. Thus may we form, from known 
prin 
