406 J, R. Mayer on Celestial Dynamics. 
ture. If, however, the water in its course meets with mineral 
or organic substances which it can dissolve and retain, it then 
reappears as a mineral spring. Examples of such are met with 
at Aachen, Carlsbad, &c. 
In a far more decided manner than by the high temperature 
the origin of the interior heat of the earth as follows:—“ No 
one of course can explain the final causes of things. This much, 
however, is clear to every thinking man, that there is Just as 
much reason that a body, like the earth for example, should be 
of, and requires explanation. 
_ Newton's theory of gravitation, whilst it enables us to deter~ 
mine, from its present form, the earth’s state of aggregation 10 
ages past, at the same time points out to us a source of heat 
_ seytdan enough to produce such a state of aggregation, power 
ul enough to melt worlds; it teaches us to consider the molten 
state of a planet as the result of the mechanical union of cosmica’ 
masses, and thus to derive the radiation of the sun and the heat 
the bowels of the earth from a common origin. fae 
e rotatory effect of the earth also may be readily explained 
collision of its constituent parts; and we must accord- 
