166 DISSERTATION ON THE ATMOSPHERE. 
preserves the long descending stream of language, induces 
man to unite the past with the present, so that drawing 
incentives from an inner world, we seek to refer bygone 
changes to living principles. As the poet Schiller finely 
renders it, cc Man, amid ceaseless change, seeks the un- 
changing pole.” 
With much, therefore, of instinctive feeling, do we seek 
amid active atmospheric signs, some degree of light to 
illumine our research into those of pristine antiquity. Here, 
at the initial step of our inquiry, it should be observed, that, 
we deal more particularly wfith the atmospheric relations to 
the conservation of life, vegetable and animal. A rapid 
glance at the vital economy now existing, shows that plants 
and animals reciprocate a functional influence. Both realms 
of life receive their nutriment primarily from inorganic 
materials. The manner in which minerals are thus con- 
nected with plants, vegetables with animals, and the whole 
linked together, manifests in its elucidation a very admirable 
system of mutual dependence. All the phenomena of life 
are made up of chemical and physical influences, but con- 
trolled and modified by a cause or force, termed the vital 
force. It is called vital, because, wdienever developed, life 
manifests itself. How, or by what peculiar means, we do 
not know, and cannot imitate or reproduce. The laws regu- 
lating the elemental changes in organic beings, are, however, 
the same as those operating to produce the union and dis- 
union of elements, taking place on the earth’s crust. 
At present the source of vegetable food is twofold ; first, 
and chiefly, the atmosphere ; secondly, the soil. The former 
supplies carbonic acid, ammonia, and water, while the latter 
yields various earths. The constituents of earth may be, 
to a great extent, dispensed with, as in the singular race of 
“air-plants,” but carbonic acid, and other components of 
the air are indispensable. A grand distinctive peculiarity of 
vegetable life is a power consequent upon the actinic rays 
nestling within, by w hich it is enabled, in an exceeding quiet 
way, to decompose carbonic acid, fix its carbon, and liberate 
free oxygen, in so doing preserving vitality. Animals, on 
the other hand, are supported by the assimilation and com- 
bustion of different kinds of food in a current of air, the 
circulation of which is maintained by the respiratory organs. 
Now Lavoisier long since determined the amount of air 
inspired by an adult man to equal 746 lbs. per annum, and 
Menzies got a still higher figure. Both results expressed a 
weight far above that of any adult ; but from the beginning 
to the close of a year the individual absorbing this mass of 
