38 University Geological Survey of Kansas. 
principle. The higher the temperature of the water the more 
rapidly the liquid will flow through the interstices in the rocks, 
and of course the greater will be the solvent action. It is a 
familiar fact that the minute cavities of rocks and crystals often 
contain concentrated solutions of the material of which the rock 
is composed. There is, in fact, a mother-liquor left in the 
crystal after it has been formed. As these crystals disintegrate 
this mother-liquor escapes and adds its mite of mineral salts to 
the water that flows over the rocks. | 
Many experiments have been made on the solvent action of 
liquids upon rocks at a high temperature under pressure. Or- 
dinary glass is a silicate which in its composition suggests that 
of some of the rocks on the surface of the earth. Every chemist 
is aware of the action of ordinary chemicals on glass, and 
knows that in accurate analyses he cannot neglect the action 
even of boiling distilled water upon it. When water is used as 
a solvent for chemicals, especially for those which are alkaline 
in character, it becomes a still better solvent for glass. On this 
account we use platinum vessels in chemical analyses where 
great accuracy is required. 
THERMAL OR WARM SPRINGS. 
The high temperature of some waters as they issue from the 
earth is ascribed to several causes. Some argue that it is on 
account of the interior heat of the earth, as it has been noticed 
in some borings that there was a uniform increase in tempera- 
ture as the drill descended. This is far from uniform in differ- 
ent localities, however, possibly on account of the varying 
thickness of the crust of the earth. 
Others suppose that chemical action causes the heat of some 
waters. It is true that oxidation, of sulfur compounds espe- 
cially, does cause heat, and this and similar reactions may have 
warmed the water in some localities. 
It has been noticed furthermore that more thermal springs 
are found in volcanic districts or where there are evidences of 
former volcanic action than elsewhere. Thus, in the United 
States there are hardly any warm springs in the Northeastern 
states, but in the main body of the Appalachian chain, from 
