54 = Natural History of Volcanos and Earthquakes. 
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tend, that these processes take place near to the surface, else how 
could we explain the fact, that, in boring Artesian wells, the 
greater the depth, from which the water rises, the higher is its 
temperature. As little explanation could be given of the circum- 
stance, that springs rising in a small district near one another, 
often present no inconsiderable difference in their average tem- 
perature. In proof of the former assertion, I will cite out of 
many other instances that of the hole bored at Ridersdorf near 
Berlin, where water at 74°.3 F. was drawn by boring to a 
depth of 880 feet; and in proof of the latter, the numerous 
springs in Paderborn, whose temperature varies from 49° to 61°. 
EF. In the former case, then, these presumed chemical processes 
must take place far below the depth of 880 feet; in the latter 
they must be supposed to be going on, either entirely below the 
situation of the springs at a nearly equal depth, or at various 
depths beneath each separate spring. In the previous case, their 
different temperatures would be occasioned by one spring run- 
ning nearer, the other at a greater distance from, the common 
source of heat. 
Daubeny speaks, in general terms only, of chemical processes ; — 
if we may, however, judge from a note,* he seems to allude to 
the same processes as those which he assumes as the cause of 
volcanic phenomena, viz., the oxidation of metals of alkalies and 
earths by water. We may pause a little to consider these 
hypothetical chemical processes, as they ought to inform us 
whence the agent, viz., heat, is derived, which i is the point in 
question. 
As the presence of thermal springs is so universal, these met- 
als must be equally so. This hypothesis, especially in the ex- 
tent given it by those who maintain it, viz., that the whole nu- 
cleus of the earth consists of an unoxidized mass, cannot be rec- 
onciled with the proportionate density of our earth, as I have al- 
ready shown, Yet, let us admit for a moment the existence of 
these metals in a more limited proportion. Their oxidation re- 
quires the access of water; we must, therefore, suppose as many 
channels to conduct the water from the surface as there are ther- 
mal springs, or at least groups of thermal springs. Granting all 
this, the question yet remains to be answered, why the effects of 
* Report, &c., p. 68 and 69. 
