188 THE OCEAN. 



volcano. In breaking regularly on the shore, the wave brings each 

 time a certain quantity of sand which it spreads in a thin layer. The 

 air absorbed into the pores of the soil, immediately disengages itself 

 in bursting bubbles ; but here there are always a great number of 

 aerial particles which cannot penetrate the damp bed of sand, and 

 remain enclosed. Under the influence of the warmth of the ground or 

 of the surrounding air, these particles dilate little by little, the pressure 

 of the gas raises the hardened coating, and forms a cone, which some- 

 times bursts in consequence of the inward pressure, and throws out in 

 volleys little spouts of sand-grains. It is true that unobservant 

 persons walk over millions of these humble volcanoes without per- 

 ceiving even one, but those who love the earth under all its aspects, 

 and who contemplate with the same admiration the grain of sand and 

 the mountains, can easily discover and study them. For the naturalist, 

 who sees immense forests in every heap of algoe and a world of animals 

 in the remains which strew the sand, the thousand wonders of the 

 shore cannot fail always to awaken an intense pleasure. 



