SCIENTIFIC SUMMARY. 
109 
was seen, probably owing to the cloudy state of the sky. But the author 
remarked there is now no doubt that on that evening a very splendid aurora 
was seen at Moscow and other observatories better placed for the purpose. 
M. Wild then gave long quotations from the reports of MM. Struve, Wagner, 
Gylden, and others. 
How to prove the Constitution of Flame. — In the Chemical News of Octo- 
ber 8, M. Dufour describes an ingenious method of doing this with an 
ordinary gas jet. 
j Does Light alter the Colour of Glass f — M. Bon temps says, Yes. M. Bon- 
temps has found that all glasses with a soda base are coloured in a very 
short time by sunlight. It is different in the lead glasses. The ordinary 
green glass loses this green colour in a few years, and becomes yellow, and 
then red or violet. Glass with an azure hue and that with a lead base do 
not change colour under like circumstances. — Comptes rendus , Nov. 22. 
ZOOLOGY AND COMPARATIVE ANATOMY. 
I)r. Carpenter' s Expedition. — At one of the recent meetings of the Royal 
Society, Dr. Carpenter gave a sketch of his report on the results of the deep- 
sea expedition. Perhaps the actual dredgings constitute the most reliable 
portions of the novelties of this report, and these belong mostly to this section of 
our summary. They include silicious sponges and foraminifera, together with 
zoophytes, echinoderms, molluscs, annelids, and crustaceans. One hundred 
and twenty-seven species of mollusca not previously known to exist in 
British seas were among the captives, and a large number of these are alto- 
gether new to science. The expedition has nearly doubled the number of 
British echinoderms, and at one spot, w 7 here the dredge brought up little or 
nothing, and where Captain Calver devised a plan for sweeping the bottom 
with hempen tangles, the first haul of these tangles secured, at a moderate 
estimate, 20,000 specimens o± a single form of echinus. In the cold area 
arenaceous foraminifera, creatures which construct habitations by the agglu- 
tination of particles of sand, were so abundant that it will be difficult to find 
names for the new varieties. Many new sponges, some differing widely 
from previously known varieties, were also discovered. 
Fresh-water Crustacea. — A very valuable memoir has been presented to 
the Belgian Academy by M. F. Plateau, and has been specially reported 
on by the elder Van Beneden. The subject of the memoir is the Natural 
History of the Fresh-water Crustacea of Belgium, a point to which M. 
van Beneden and others have lately given much attention. In Part I. 
of his paper M. Plateau dealt with the genera Gammarus , Lynceus , 
and Cypris. In the second part he has investigated the genera Daphnia, 
JBosmina, and Polyphemus ; and in the third he treats upon Cyclopsina, 
Canthocamptus, and Cyclops. The author shows that in the JDaphnice 
there exist beneath the test and valves all the parts which enter into 
the constitution of the carapace of Decapods, and he considers the two 
I morphologically identical. The valves he considers as an appendage of the 
fourth somite. The reporter, however, takes exception to these opinions. 
