PRIZE QUESTIONS. 405 
4. What difference is there between the perception of sounds with one and 
with both ears? Precise researches are requested regarding this difference, and 
on the influence in general of the duality in the organ of hearing. 
5. According to the researches of M. Pasteur and other savants, fermentation 
is owing to the development of cryptogams and infusoria. The Society wishes 
new and positive researches to be made on this subject, and, if necessary, an 
exact description to be given of these plants and animals, and their mode of 
action. . 
6. What is the best construction for steam vessels designed to clear rivers of 
the masses of ice which obstruct the course of the water? It is expected that 
in answering this question notice will be taken of all that practice has decided 
upon this subject, as well in our own country as abroad. 
7. With the exception of some formations on the eastern frontier of the king- 
dom of the low countries, the geolgoical strata of that region covered with 
deposits of alluvium and diluvium are still but little known. An account is 
desired of all that has been brought to light with certainty, whether by borings 
executed at different places or by other observations, respecting the nature of 
those formations. 
8. It is known, chiefly by the labors of M. Roemer, at Breslau, that many 
of the fossils which are found near Groningen belong to the same species with 
those occurring in the silurian formations of the island of Gothland. This has 
led M. Roemer to the conclusion that the diluvium of Groningen has been 
transported from the island just named; but such an origin appears to comport 
but little with the direction in which this diluvium is deposited—a direction 
which would rather indicate a transportation from the southern part of Norway. 
The Society desires to see this question decided by an exact comparison of the 
fossils of Groningen with the minerals and fossils of the silurian and other 
formations of that part of Norway, with a regard at the same time to the modi- 
fications which the conveyance from a remote country and its consequences 
may have caused those minerals and fossils to undergo. 
9. The combustion of steel, iron, and other metals in oxygen is accompanied 
by the apparition of a multitude of incandescent particles thrown off from the 
surface of the body in combustion, and which are found after the phenomenon 
at the bottom of the vessel in which the combustion is effected. The same 
fact is observed in the luminous electric arch of a strong battery between two 
metallic rheophores, one of which at least is of iron or steel. The Society 
asks an explanation, based upon new and decisive researches, of the cause of 
this phenomenon. 
10. We request a continuation of the remarkable researches of M. Brewster 
on the liquids and gases which fill the small cavities sometimes found in crys- 
tallized minerals. 
11. The Society invites an exact anatomical comparison between the skeleton 
of the Cryptobranchus japonicus and that of the fossil salamanders of Oeningen, 
as well as that of the salamander of Roth. 
12. An exact description, with figures, of the skeleton and muscles of the 
Sciurus vulgaris, compared with what is known on this subject of the Lemurides 
and Chiromys, is requested, in order that the place to be assigned to this last 
species in the natural classification may be determined with more certainty than 
has been heretofore possible. 
13. The Society wishes an anatomical description, with figures, of the Ameri- 
can Potto, (Cercoleptes Illiger, Vivera candivolvula Pallas,) compared with the 
structure of other mammifers, as the Nasuwa aud Procyon, and with that of the 
quadrumana. The attention of the author is especially directed to the commu- 
nication of Mr. Owen, (Proceedings of Zoological Society 1835, p. 119-124.) 
14. The physiological action of carbonic acid on the animal organism, espe- 
cially that of man, is recommended as the object of new and decisive experiments. 
