NOME III. INDURATED MUD. 373 



Micronome 3. With Olivine, or Volcanic 

 Chrysolite. 



These lavas are remarkable, as the same sub- 

 stance is found in basalt, and in the native iron of 

 Siberia and South America. 



HYPONOME II. VESICULAR LAVA WITH A BASE OF 

 FELSITE. 



In this kind the vesicles are generally elongated, 

 and it sometimes passes into a fibrous appearance, 

 which, when predominant, is a characteristic of 

 pumice. 



Grey or white vesicular lava, from various vol- 

 canoes. 



Micronome 1. Felsite lava, with crystals of 

 siderite. 



Micronome 2. The same, with mica. 



NOME III. INDURATED MUD. 



The American volcanoes chiefly devolve tor- American 

 rents of mud, which seems to be strongly im- 

 pregnated with iron. Torrents of this kind have 

 also been said to occur in the eruptions of Etna, 



