240 MULE-HUNTING EXPEDITION. 



from one of the springs so as to fill a small room 

 with steam. 



It is one of the most singular and interesting 

 places I have ever visited. There can be no 

 doubt that the springs rise from the crater of 

 an extinct volcano, and that there is some active 

 volcanic action still going on in the depths 

 below. Incrustations of various salts and sul- 

 phur covered the edges of the pools and rocks 

 over which the water runs. The water they 

 drink has to be brought from a spring the other 

 side of the encircling hills. 



Although at this place I observed more direct 

 evidence of some great internal fire or subter- 

 ranean laboratory, in which Nature is ever trans- 

 forming the elemental forms of crude matter into 

 available materials for the supply of organic life ; 

 still throughout Oregon and California I have 

 constantly come across similar sulphurous and 

 saline eruptions, particularly soda-water springs, 

 where the water rises through the earth, tho- 

 roughly impregnated with carbonic-acid gas. 

 At Nappa, not far from San Francisco, native 

 soda-water is collected and bottled at the springs 

 for the supply of the San Francisco market. 

 Olympian nectar was never more grateful to the 



