NATURAL HISTORY NOTES. 
28 
Tiie Blue Moon ; Green Sun ; and Gorgeous Sunsets. —On 
December 4th, at 4.30 p.m., I saw the crescent moon of a distinctly 
greenisli-blue colour—electric blue my wife designated the tint; the 
phenomenon only lasted for about a quarter of an hour. The setting 
sun was concealed by stratus clouds of a coppery-red hue, while 
elsewhere masses of cumulus were separated by patches of blue sky. 
This “ blue moon ” was seen at several other places in England on 
the same evening, according to notices which have appeared in 
“ Nature,'’ “ Knowledge,” etc. Throughout this country generally, 
during the latter part of November and the beginning of December, 
the sunsets have been grand beyond description, and a rosy glow has 
hovered over the western sky for more than an hour after the sun’s 
disappearance below the horizon. From India and from the Soudan 
accounts of an abnormal greenish disc presented by the sun during 
the last few weeks have been received. How are these unusual 
meteorological phenomena to be accounted for ? Two theories have 
been advanced. Mr. Mathieu Williams found the snow which fell 
early in December to be full of particles of the magnetic oxide of iron, 
and he considers it possible that these were derived from a cloud of 
cosmic dust through which the earth has lately passed, or rather which 
has been attracted to the earth by the force of gravitation. Other 
scientists attribute the presence of this matter in the atmosphere to 
the terrible volcanic outbursts which have lately occurred in the East 
Indian archipelago. Enormous quantities of finely-divided matter 
have there been shot up to a great height from volcanic craters, and 
this matter, carried by air-currents, has gradually spread westward, 
until, at last, it has even invaded the skies of Britain. Each theory, 
it will be noticed, explains the phenomena actually observed by 
referring them to the action, upon sun-light, of finely divided matter 
in our atmosphere, and in this each is no doubt correct. It is not the 
sun which has varied in colour, but certain of the sun’s rays have been 
absorbed while passing through the air—the red rays chiefly—and 
therefore the sun appears green. So, also, the moon—which we see 
by reflected sun-light—has had a bluish tint instead of her usual 
silvery-white hue. The proverb, “ not once in a blue moon ! ” and the 
historical statement that “ the moon is made of green cheese ! ” would 
seem to have their origin in previous observations of a similar nature. 
By searching the meteorological (and other) records of the past, it 
may be possible to ascertain if any similar change of colour has 
accompanied former great volcanic outbursts.—W. Jerome Harrison. 
Fertilisation of the Boraginace^e. —The change of colour in various 
boraginaceous flowers would seem to bear relation to their fertilisation 
by insects. Hermann Muller remarks that he has observed that in¬ 
sects visit exclusively those which ore red or just beginning to change 
to blue. All the blue flowers which he examined in a locality about 
2 yards broad and 20 long, where many hundred flowers of Pulmonaria 
were in all stages of development, proved to be empty of honey, and all 
