PHOSPHORESCENCE. 51 
Borealis, certain portions of the heavens which 
were not illuminated, lit up and continued lumi- 
nous whenever a shooting star passed over them. 
M. Colla, formerly director of the Observatory 
of Parma, has often observed, since 1825, a sin- 
gular light in the northern sky, like a zone of 10 
or 12 degrees, parallel to the horizon, often of a 
yellow colour, and most intense in the direction of 
the magnetic meridian. He considers it to be 
“the permanent element of the Aurora Borealis.” 
That portion of the planet Venus which is not 
illuminated by the sun often shines with a phos- 
phorescent light of its own. 
Towards the latter end of June, 1861, the 
earth passed through a region of the heavens, 
then occupied by a portion of the great comet of 
that year. On this occasion Mr. Hind, Mr. Lowe, 
and others, observed a peculiar phosphoric glare 
in the atmosphere. It was remarked by many 
persons as something unusual. 
That portion of the moon which is not il- 
luminated by the solar rays shines with a grey 
light of its own, called by the French lwmieére 
cendrée. This is generally attributed to the light 
thrown upon our satellite by the illuminated por- 
tions of the earth; but it may be that the moon 
possesses phosphorescent qualities like other ce- 
lestial bodies. 
Doubtless other planets possess similar phos- 
