442 PEIZE QUESTIONS OF SCIENTIFIC SOCIETIES. 



korff consists of two distinct parts — the spark, properly so called, and 

 a luminous aureole. New researches are requested as to the causes 

 of this division, and the phenomena which accompany it, and on the 

 different qualities of these two parts of the same luminous discharge. 



10. The society desires that in the different seas specimens of the 

 bottom should be procured b}' sonnding; and that after examination 

 everything of interest which these specimens disclose on the nature 

 of the submarine deposits should be communicated. 



11. We solicit exact researches in regard to the transparence of 

 the atmosphere of the island of Java, as compared with that of some 

 European country. 



12. In the mountainous country of the left bank of the Rhine, 

 known by the name of the Eijffel, there are several conic mountains 

 to be seen, which evidently owe their existence to volcanic action. 

 The society would be pleased to have it decided by exact researches 

 made on the spot whether there exist traces of the upheaval of the 

 older strata, or whether these mountains are only cones of eruption. 



The society has this year proposed the following questions, and 

 solicits a response to them before the \st of January^ 1864: 



1. It desires a complete embryology of the Squalus spinax and of 

 the Sqiiahs acanthias, from the egg in the ovary to the complete for- 

 mation of the young fish. 



2. It calls for a critical nomenclature, based on the author's own 

 researches, of the annulata and turbellaria, which are found in the 

 interior and on the coasts of the Netherlands. 



3. It desires a comparative myology of the anterior members of 

 reptiles and birds, Avith reference to the denomination of the corre- 

 sponding or homologous muscles in mammifers, and especially in the 

 human anatomy. 



4. The form of the so-called Lichtenberg figures differs accord- 

 ing as they have been produced by positive or negative electricity. 

 The society requests a new and satisfactory explanation of this dif- 

 ference. 



5. Researches are desired on the molecular change produced in 

 the filaments of different metals by the sustained action of an electric 

 current as strong as it is possible to be without producing fusion. 



6. A complete embryology of the Lcpas anatfera is requested. 



7. A comparative anatomical description is desired of the re- 

 mains of birds found in different geological deposits. 



8. In regard to many rocks geologists are left in doubt whether 

 they have been deposited from a solution in water or have become 

 solid after fusion b}^ heat. The society desires that one of these 

 rocks, at the choice of the inquirer, should be submitted to researches 

 which shall lead to a decisive judgment respecting its origin, and at 

 the same time, if possible, cast some light on the origin of other 

 rocks more or less analogous. 



9. Since at present carbonic acid may be easily solidified and with- 

 out danger, it is desired that complete researches be made respecting 

 the physical properties of the solid acid. 



10. A microscopic and chemical examination is requested of the 



