Scientific Intelligence— Mineralogy. 181 
5. The minimum temperature of the deep waters of the Mediterranean 
is equal to the mean of the winter temperatures at the surface. This low 
temperature of the bottom is not, therefore, induced by the entrance of 
the waters of the ocean, but rather by the precipitation of the upper 
strata during the winter.* 
9. On Polarization of Light in reference to the Light of the Sun. Paris 
Academy of Sciences, Oct. 14. M. Arago made some remarks on the 
polarization of light, in reference to whether the light, produced by a 
solid incandescent body, proceeds from the surface or the interior. The 
state of polarization presented by the light, says M. Arago, proves that 
it proceeds from the interior of a solid body; an inflamed gas, on the 
contrary, gives no kind of refraction. Hence, it may be assumed, that the 
luminous portion of the sun isa gas. The light given out by a solid 
body comes partly from its interior, and is not the same which illumi- 
nates it. 
MINERALOGY. 
10. Discovery of Niobium, a New Metal.—In a valuable paper on 
the composition of Tantalite, just published in Poggendorff’s Annals, 
Professor Henry Rose of Berlin announces his discovery of a new metal, 
which he terms Niobium, from Niobe the daughter of Tantalus,—a 
name given to indicate its resemblance to Tantalum. He detected its 
oxide, which he designates Niobic acid, and which differs in many re- 
spects from Tantalic acid, in the Tantalite of Bodenmais in Bavaria. 
Assuming a similar atomic composition for Tantalic acid and Niobic 
acid, the atomic weight of Niobium is greater than that of Tantalum. 
The Niobic acid does not exist in the Tantalite of Finland. 
11. Da:brée on the Occurrence of Asinite in w fossiliferous Rock iv 
the Vosges.—Hitherto axinite does not appear to have been observed in 
any fossiliferous rock; and it may therefore not be uninteresting to 
mention, in some detail, the mode of oceurrence of this substance, as 
lately observed by me at Rothau, in the Vosges ; and I am the more in- 
duced to do this, because we have here a new example of the manner in 
which igneous rocks can alter stratified formations ; not only by their 
heat, but also by the introduction of new elements. Near the village of 
Rothau, in the valley of the Bruche, the transition formation is tra- 
versed by a blackish, very fine grained rock, in which hornblende is dis- 
seminated in small crystals. This rock, for which we may provisionally 
retain the name of trap, forms a hill, termed the le petit Donon de Ro- 
thaw. The transition formation of the locality consists principally of a 
very hard petrosiliceous rock, and, at a little distance from the trap, it 
contains numerous organic remains, and more particularly the Calomo- 
pore spongites of Goldfuss, and Flustra. Nodules of lamellar limestone 
are met with, where these remains of madrepores are accumulated, and 
it is precisely at the same points that epidote, hornblende, and quartz in 
a crystalline state, make their appearance. This association may lead us 
_ to believe, that the carbonate of lime of this rock is of madreporie ori- 
gin, and further, that the epidete and hornblende were formed at the 
* I'rom l'Institut, No, 658, p. 298. 
