PRIZE QUESTIONS OF SCIENTIFIC SOCIETIES. 429 



7. The electric light which is developed in a vacuum by means, 

 under certain conditions, of RuhmkorfFs apparatus, exhibits alter- 

 nately, bright and dark bands, which are not yet sufficiently accounted 

 tor. The society requires a precise explanation of the causes of this 

 phenomenon. 



8. Not only by the direct action of light upon the organs of sight, 

 but also by various action upon the nerves connected with those or- 

 gans, luminous appearances are produced, even when no light enters 

 the eye itself. The society requires a minute examination of every 

 thing connected with these phenomena, with a view to determining, 

 among other things, whether the appearances can produce second- 

 ary images, and if so, what relation do those images bear to the pri- 

 mary phenomenon. 



9. The researches of Goppert have shown that all or almost all 

 beds of coal have been formed on the spot or near the spot where 

 they are found. Nevertheless, it is not well known how this has oc- 

 curred; it still remains to be determined whether they were formed 

 in the sea, in fresh water, or upon dry land, or whether some have 

 been formed under one of these circumstances and some under 

 another. Nor is it more precisely known to what extent we may 

 compare the formation of pit coal with that of peat. 



The society requires researches, founded upon a personal exami- 

 nation of different coal beds and peat pits of different kinds, which 

 shall conduce to the most complete possible solution of these ques- 

 tions. 



10. The society asks exact researches relative to the means by which 

 the mammifera) and the molluscs are protected from the effects of the 

 great difference of pressure to which they are subject as they descend 

 from the surface of the sea to its successive depths. 



11. The most recent researches have proved that the spermato- 

 zoides penetrate into the egg. The society requires that observa- 

 tions with reference to this be made upon various mammifer^, and 

 that the account of these observations be accompanied by the neces- 

 sary figures. 



12. Messrs. Chapuis and Candeze have performed a useful work in 

 publishing, in volume 8 of the Liege Memoirs, a catalogue of the 

 larv« of the Coleoptera. The society would be glad to receive a 

 memoir containing a similar catalogue of the larvae of the Neuroptera. 



The society has this year proposed the following questions, and 

 requires replies to them before the first of January, 1860: 



1. The society requests new researches as to the development and 

 the first phases of life of the Nematoides, and especially of those 

 which inhabit the human body. 



' 2. The greater correctness of range obtained by balls and bombs, 

 the centre of gravity of which does not coincide with that of the pro- 

 jectiles, proves the very great importance of a precise understanding 

 of the influence of that eccentricity. The society requests the equa- 

 tion of the trajectory described by the centre of gravity of a sphere 



