154 THE CHEMISTRY OF CREATION. 



of this gas in water. In all probability, there- 

 fore, the boiling column of the mighty Geyser 

 itself is formed of particles of water which fell 

 as rain-drops on the mountain slope ! 



Having thus traced the origin of the springs? 

 let us seek in the depths of the earth, in this 

 singular region, the explanation of its varied 

 chemical phenomena. Exhalations of sulphur- 

 ous acid, sulphuretted hydrogen, sulphurous and 

 aqueous vapours, burst in certain districts in 

 wildest confusion from the hot soil, and spread 

 themselves far over the steaming fields, the soil 

 of which must be traversed with caution by the 

 traveller who would avoid the danger of being 

 drowned in the hot mud. On the declivities 

 of the mountains these exhalations burst, foam- 

 ing and hissing, in the form of vast columns 

 of vapour from the fissures and clefts of the 

 rocks, giving rise to sounds like thunder. In 

 the valleys, the traveller meets with pools of 

 boiling mud, in which a horrible bluish-black 

 clayey paste rises in huge bubbles, which, on 

 bursting, often throw the boiling mud to a 

 height of upwards of fifteen feet. These phe- 

 nomena constitute a picture of the wildest de- 

 vastation, only to be surpassed in horror by 

 the dread waste of the dark rocky masses by 

 which the scene is enclosed. 



The most important of the strata of rocks 



