Page:Popular Science Monthly Volume 12.djvu/344

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THE POPULAR SCIENCE MONTHLY.
'Tis negation's hour of triumph,

In the absence of the sun;
'Tis the hour of endings, finished,
Of beginnings unbegun.

Yet the voice of awful silence
Bids my waiting spirit hark;
There is action in the stillness,
There is progress in the dark.

In the drift of things and forces,
Comes the better from the worse,
Swings the whole of Nature upward,
Wakes, and thinks—a universe.

There will be more life to-morrow,
And of life, more life that knows;
Though the sum of force be constant,
Yet the Living ever grows.

So we sing of Evolution,
And step strongly on our ways,
And we live through nights in patience,
 And we learn the worth of days.

In the silence of murk midnight
Is revealed to me this thing:
Nothing hinders, all enables

Nature's vast awakening.

HISTORY OF THE DYNAMICAL THEORY OF HEAT.[1]

By PORTER POINIER.

II.

ABOUT one year after the reading of the famous paper of Rumford, in the early part of 1799, Sir Humphry Davy, then but twenty years of age, published his first scientific memoir, entitled "An Essay on Heat, Light, and the Combinations of Light." Clearly enunciating the two systems of hypothesis previously held, he chose to follow Newton in rejecting the materiality of heat, while still clinging to the corpuscular or emission theory of light.

His position with respect to the existence of caloric he asserted in this thesis:

"The Phenomena of Repulsion are not dependent on a peculiar Elastic Fluid for their Existence, or Caloric does not exist;"

  1. Introduction to an unpublished work on Thermo-Dynamics.