These hot waters, traversing the rocks in irregular fissures, readily dissolve out the more soluble constituents of the rocks, the amount and the character of the salts present varying somewhat with the nature and amount of gases held in the waters. Chemical analyses of geyser waters from the three regions described show no greater variation than those from different vents in any one of these regions.
That the source of steam is the still hot lavas below, and is in some way connected with volcanic action, is so evident from the facts that no other conclusion is possible. The geyser works on the principle of the volcano. When the lowest strata of water be comes heated to a certain point they burst up through the cooler water on top.