Volcanos and Earthquakes. 361 



going on in the earth as the cause of thermal springs, then must 

 these processes be as universally distributed as the thermal springs. 

 Those who entertain these views, however, do not surely contend, 

 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 tem- 

 perature. 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 Riidersdorf 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° F. In the former case, then, these presumed chemical pro- 

 cesses must take place at least far below the depth of 880 feet ; 

 in the latter they must be supposed to be going on, either en- 

 tirely 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 occa- 

 sioned by one spring running nearer, the other at a greater 

 distance from, the common source of heat. 



Daubeny speaks, in general terms only, of chemical proces- 

 ses ; 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 hy- 

 pothetical chemical processes, as they ought to inform us 

 whence the agent, viz. heat, is derived, which is the point in 

 question. 



As the presence of thermal springs is so universal, these me- 

 tals must be equally so. This hypothesis, especially in the ex- 

 tent given it by those who maintain it, viz. that the whole nucleus 

 of the earth consists of an unoxidized mass, cannot be reconciled 

 with the proportionate density of our earth, as I have already 

 shewn. Yet, let us admit for a moment tl^e existence of these 

 metals in a more limited proportion. Their oxidation requires 

 the access of water ; we must, therefore, suppose as many chan- 



♦ Keport, &c., p. 68 and 69. 

 VOL. XXVI. NO. LII. APRIL 1839. A a - 



