thence to the blood; when these and very many other
like facts were brought into prominence by modern research, it became
necessary to admit that animated beings do not constitute the exception
once supposed, and that organic operations are the result of physical
agencies.

'If thus, in the recesses of the individual economy, these natural
agents bear sway, must they not operate in the social economy too?

'Has the great, shadeless desert nothing to do with the habits of
the nomade tribes who pitch their tents upon it--the fertile plain
no connection with flocks and pastoral life--the mountain
fastnesses with the courage that has so often defended them--the
sea with habits of adventure? Indeed, do not all our expectations
of the stability of social institutions rest upon our belief in the
stability of surrounding physical conditions? From the time of
Bodin, who nearly three hundred years ago published his work 'De
Republica,' these principles have been well recognized: that the
laws of nature cannot be subordinated to the will of man, and that
government must be adapted to climate. It was these things which
led to the conclusion that force is best resorted to for northern
nations, reason for the middle, and superstition for the southern.'

The importance of physical agents and physical laws in the social as
well as in the individual economy, is variously illustrated by Professor
Draper, who points out the essential part they play in several
departments of nature. To the merely mechanical inclination of the
earth's axis of rotation toward the plane of her orbit of revolution
around the sun, we owe the changing seasons and the method of life which
is dependent on these. The alteration of that physical arrangement would
involve a corresponding alteration in the whole life of the globe. So,
again, the possibility of existence upon the earth, in any way, depends
upon conditions altogether of a material kind. It is necessary that our
planet should be at a definite mean distance from the source of light
and heat, the sun; and that the form of her orbit should be almost a
circle, since it is only within a narrow range of temperature, secured
by these conditions, that life can be maintained.

It is through natural agents also that the means of regulation are
secured in the present economy of the globe. Through heat, the
distribution and arrangement of