84 ESSAYS anp O®SERVATIONS 
and, fince him, the generality of philofo- 
phers, concerning the caufe of the vari- 
ous colours reflected by the clouds at 
fun-rifing and fetting, liable to great dif- 
ficulties? For, why fhould the particles 
of the clouds become, at that particular 
time, and never at any other, of tuch mag- 
nitude as to feparate thefe colours? And 
why are they rarely, if ever, feen tindu- 
red with blue and green, as well as red, 
crange, and yellow? Is it not more credi- 
ble that the feparation of rays is made in 
pafling through the horizontal atmo- 
fphere? and that the clouds only. refleé 
and tranfmit the fun’s light, as any half 
traniparent colourlefs body would do in 
their place? For, fince the atmofphere, 
as was faid'in the laft query, refle@s a 
ereater quantity of blue and violet rays 
than of the reit, the fun's light, trant- 
mitted through it, oughr ‘to draw to- 
wards yellow, orange, or red; efpecially 
when it pafles through the greateft tract 
of air: Accordingly, every one muft have 
remarked, that the fun’s horizontal light 
is fometimes fo deeply tinctured, that ob- 
jects 
