444 PEIZE QUESTIONS OF SCIENTIFIC SOCIETIES. 



tempted to deduce from the apparent movement of the fixed stars the 

 movement of the sun with its phinetary system through space. Airy 

 has proposed an entirely new method for attaining the same end, a 

 method which he has applied to only a very few stars. In view of 

 these facts, the society invites new and exact researches on the move- 

 ment of the sun with the planetary system, based upon all the fixed 

 stars whose proper movement has been determined with sufficient 

 exactness for that purpose. 



8. Bodies in motion, illuminated by the electric spark, appear 

 as if they were in a state of perfect repose; new researches are re- 

 quested to be made by means of the application of this principle. 



9. The society calls for new researches on the arrangement as- 

 sumed b}'- particles of iron floating upon or suspended in a liquid, 

 under the influence of a surrounded electrical current, and an appli- 

 cation of this phenomenon to that which occurs in a bar of iron 

 which is undergoing magnetization. 



10. It is required to be decided by exact experimental researches 

 up to what point the dispersion in transverse lines of a filament of 

 metal by an electric discharge, as it has been described and figured 

 by Van Marum in the Memoirs of the Teylerian Society, is analogous 

 to the stratification of light in rarefied gases and ought to be attri- 

 buted to thg same cause. 



11. Notwithstanding the experiments of Arago, there is still a pre- 

 vailing uncertainty respecting the state of polarization of difiused 

 light. The society invites new experimental researches, as complete 

 as possible, on the nature and the state of polarization as well of dif- 

 fused light as of the light radiated by incandescent bodies. 



12. What is the nature of the solid bodies observed in some dia- 

 monds? Do they pertain to the mineral or to the vegetable king- 

 dom ? Researches on the subject, even if relating but to a single 

 diamond, will be distinguished, provided they lead to any interesting 

 result. 



13. As the development and original seat of the BothriocepJialus 

 latus [Tcenia lata, L.) are still unknown, the society suggests re- 

 searches for elucidating the natural history of this entozoon from the 

 egg to the perfect state. 



14. We know by the researches of Cramer that the adjustment 

 of the eye depends on a- change in the form of the lenses, but the 

 mechanism which produces this change is not yet well understood. 

 The society invites new researches on this subject, based upon the 

 comparative anatomy of the apparatus which serves to produce the 

 adjustment. 



15. The society requests researches on the nature of the sub- 

 stances contained in the aqueous vapor produced by the respiration 

 as Avell of man in a state of health as of animals. It is desirable that 

 these researches should, if possible, extend to the substances exhaled 

 in ce^'tain maladies, especially contagious ones, and that not only the 

 chemical analysis of thorn should be made, but that their injurious 

 effect on animals should be examined. 



16. The fishes of the Indian archipelago have furnished an' object 

 of research to one of our learned countrymen. The society is desirous 



