i88i.J 
The Formative Power in Nature. 
269 
may be prevented from descending to a level which would 
bring it within the grasp of oxygen by some influence from 
the presence of water vapour, it descending only when the 
atmosphere is greatly denuded of its water vapour. 
If now refrigeration of the earth’s surface should become 
sufficient to solidify all its liquid water, or to convert all 
existing and all new-formed water vapour into snow and ice, 
what would result ? Certainly an increasing gravitative 
vigour, and an atmospheric denudation which must be re- 
placed by some form of new condensation. It is not incon- 
ceivable that, if the present atmospheric constituents were 
measurabty exhausted, they might be replaced by other ele- 
ments capable of yielding new cycles of terrestrial evolution. 
Yet if we are to judge by the apparent conditions of other 
spheres, it may be possible that hydrogen is the lightest 
available chemical element, and that a waterless sphere 
would be a dead world. 
III. THE FORMATIVE POWER IN NATURE. 
By Sidney Billing. 
t CORRESPONDENT (H. B.) in your issue of April 
comments on the article “ The Formative Power in 
Nature,” written by me, and which appeared in the 
February number of your Journal, of which, I suppose, 
generally he approves, although “ the arguments and illus- 
trations are not new ones.” I did not pretend to novelty in 
idea, or to originality ; my intention was merely to bring to- 
gether such fa<5ts as I deemed to be incontrovertible, and I 
endeavoured so to marshal them that they should present 
that outcome which common reasoning would assign to 
them, — with what success I leave to the judgment of your 
readers. 
The subject in comment is large and varied, and may be 
considered as the vexed question of the day ; it is only im- 
portant because casual readers and half-thinking men are 
caught by the glitter of words, and are thus led away from 
the significance of the proposition, accepting too frequently 
