Phenomena of Volcanoes. 275 



The prize will be a gold medal of the value of a kilo- 

 gramme, and will be decreed in the public fitting of the 

 ijth of Nivofe, year 10. The papers muft be written in 

 French, and fent in before the i ft of Vendemiaire the fame 

 year. 



In the fittting of the T5th of Germinal (April 4), at which 

 Bonaparte fat as prefident, C. Cuvier read an account of the 

 labours of the Mathematical and Phyfical Clafs during the 

 preceding three months. 



It is in the department of natural hiftory in particular that 

 the labours of the Clafs, during the laft quarter, have enlarged 

 the boundaries of fcience. It has treated fome queftions of 

 the utmoft importance in regard to the hiftory of minerals 

 and that of animals. 



Philofophers, for example, have long been embarrafled 

 with volcanoes, on account of the difficulties which occur in 

 explaining the phenomena of them, and in the attempts 

 made to difcover the fources of thofe immenfe quantities of 

 fubftances of every kind thrown up by them during eruptions. 

 C. Patrin, on this fubjeft, has given fome views which dif- 

 play a bold imagination, and has called in to his aid all the 

 refources of modern chemiftry. He fuppofes that the water 

 of the fea is continually attracted between the itrata of fchift, 

 which generally forms the bafis of volcanoes : that the ma- 

 rine fait is there decompofed : that its acid becomes fur- 

 charged with oxygen bv paOing over the oxyds of iron and 

 manganefe : that it decompofes the fulfures of iron, and even 

 the water, by the intervention of carbon : that the diflerent 

 produces of thefe decompofilions, combining under other 

 forms, give petroleum and hydrogen gas, which take fire, 

 and produce the moft brilliant part of the volcanic pheno- 

 mena ; while ele6lricity, joining itfelf to thefe elements, al- 

 ready fo numerous, forms fulphur and phofphorus. It is the 

 laft-mentioned fubftancc above all, which, in the opinion of 

 C. Patrin, a6ls the moft diftinguiftied part. By it he fup- 

 pofes the oxygen is fixed under an earthy appearance, and 

 confequently, it is by it that volcanoes are enabled to furnifti 

 that inmienfe quantity of lava which they are continually 

 pouring forth 011 the furrounding dillrifts without exhaufting 

 N n 21 the 



