THE GASES ING ROCKS BIS is: 
should, it would seem, behave similarly, though hindered by the slow- 
ness of diffusion. Nor should liquid magmas constitute any exception 
to the law. Both hydrogen and water gas, theoretically, should be 
present in liquid magmas and heated solid rocks. 
For reasons which cannot be discussed here, chemical equilibrium 
favors the formation of ferrous salts and water, as the temperature 
increases. Because of this, there is much reason to suppose that, 
at the depths where lavas originate, hydrogen and oxygen exist com- 
bined as water, since up to temperatures of 2,000° C. the dissociation 
of water takes place only to a limited extent. If a state of equilibrium 
between hydrogen, water, and the iron compounds were established 
in the heated interior where a magma originated, as soon as it com- 
menced its way upward and began to lose heat, the condition of equi- 
librium would be destroyed. With the falling temperature, the tend- 
ency to re-establish equilibrium would favor the formation of that 
system which was produced with the liberation of heat, i. e., magnetic 
oxide and free hydrogen. In ascending lavas, which are losing heat, 
the tendency, therefore, is to produce hydrogen and magnetite, or 
ferroso-ferric compounds. ‘This is doubtless an important source for 
the hydrogen which is so copiously exhaled during a volcanic eruption. 
At the same time this process accounts for the widespread occurrence 
of magnetite in igneous rocks. 
In general, these reversible reactions tend to show that it is but a 
short step from hydrogen to water, and from carbon dioxide to monox- 
ide, and vice versa, and that all of these must occur within the earth 
owing to the process tending toward equilibrium. Whether hydrogen, 
in a particular case, occurs in the magmas in the free state, or in the 
form of water gas, therefore becomes relatively unimportant. Because 
of this variation of state, the problem becomes more complex and 
broader in scope. For the most part, these water gases are to 
be regarded as truly magmatic, and not derived from surface waters 
penetrating to the liquid lavas. But this is a complex question and 
cannot be touched here. ‘These water gases are here put forward 
as essential factors in the evolution of the magmas from the original 
planetary matter. 
The reactions working toward equilibrium are able to supply 
hydrogen and carbon monoxide under conditions favorable to their 
