368 Sir Humphry Davy on the state of water and 
When, however, it is considered, that the solvent power 
of water depends upon its temperature, and its deposition of 
solid matters upon its change of state or of temperature ; and 
that being a gravitating substance, the same quantity must 
always belong to the globe, it becomes difficult to allow much 
weight to the arguments of the Wernerians or Neptunists, 
who have generally neglected, in their speculations, the laws 
of chemical attraction. 
There are many circumstances, on the contrary, favour- 
able to that part of the views of the Huttonians or Plutonists, 
relating to the cause of crystallization ; such as the form of 
the earth, that of an oblate spheroid flattened at the poles ; 
the facility with which heat, being a radiating substance, may 
be lost and dissipated in free space ; and the observations 
which seem to show the present existence of a high tempera- 
ture in the interior of the globe. 
I have often, in the course of my chemical researches, looked 
for facts or experiments, which might throw some light on 
this interesting subject, but without success, till about three 
years ago ; when, in considering the state of the fluid and 
aeriform matters included in certain crystals, it appeared to 
me, that these curious phenomena might be examined in a 
manner to afford some important arguments as to the causes 
of the formation of the crystal. 
It is well known that water, and all fluids at usual tem- 
peratures, are more expansible by heat than siliceous or other 
earthy matters ; and supposing these crystals to have been 
formed, and the water or fluid inclosed in them, at a pressure 
and temperature not very unlike those of our existing atmo- 
sphere, this fluid ought to fill nearly the same space as when 
