EARTHQUAKES AND VOLCANOES. 



oxygen and liberating the hydrogen. If the existence of the metals 

 in their simple state in the lower strata of the earth be admitted, 

 any accession of water to them would immediately produce this 

 sort of combustion. 



Our limits, and the object of this tract, preclude us from 

 entering upon this question here beyond this mere indication of 

 the ingenious hypothesis of the illustrious chemist ; and as the 

 theory proposed has been generally abandoned, such a discussion 

 is the less necessary. 



To illustrate the generally received theory, we have here sub- 

 joined an hypothetical section of the crust of the earth, showing the 

 progress upwards of the igneous fluid from the internal liquid 

 nre, FF, to the mouth of the crater at c. 



176 



