270 Scientific Intelligence. 
and absolutely white. Its whiteness does not depend upon the sigs olo- 
gical fact, that any color, if it be intensely brilliant, will seem white to 
the eye; but it is optically white, as is proved by prismatic examination, 
when all the ¢ i 
offers every intermediate rate of combustion, and emits rays of ev every 
ty. 
n like manner it may be shown that “oobi oxyd must burn with a 
bs flame, and cyanogen with a red. We can also foresee what must ee 
‘the optical result of resorting to unusual sisthiods of combustion, ‘as when — 
We throwinto the interior of a flame a jet of air from a blowpipe. In this 
e red and orange strata, ec them by bluer colors. — 
eh a blo owpipe cone by the prism, we have a beautiful de- 
= te 4 ‘monstration a such has actually taken R ore 
< There is one of these special cases dos hich deserves attentive considera 
tion in 
€0 Pntiebt ion with the appearance of the electric light: it is the 
. P 
of the sun and other the 
‘will be by an examination of the light they emit. Even at present, byt 
“— he 
we have given St re oF declinttl a 
peniteilin ino resemblance betwee 
of éleétric discharges with which We 
reject thi’ al ; and upon the 
