he science were laid down in Stensen's little book,
which he intended only to be an introduction to a more extensive work,
but the latter was unfortunately never completed, nor, indeed, so far
as we are able to decide now, ever seriously begun.

One of the basic principles of the science of geology Stensen taught
as follows: "If a given body of definite form, produced according to
the laws of nature, be carefully examined, it will show in itself the
place and manner of its origin." This principle he showed would apply
so comprehensively that the existence of many things, hitherto
apparently inexplicable, became rather easy of solution. It must not
be forgotten that before this time two explanations for the existence
of peculiar bodies, or of ordinary bodies, in peculiar places, had
been offered. According to one school of thought, the fossils found
deep in the earth, or sometimes in the midst of rocks, had been
created there. It was as if the creative force had run beyond the
ordinary bounds of nature and had produced certain things, ordinarily
associated with life, even in the midst of dead matter. The other
explanation suggested was that the flood had in its work of
destruction upon earth caused many anomalous displacements of living
things, and had buried some of the {155} animals under such
circumstances that later they were found even beneath rocks, or deep
down in the earth, far beyond where the animals could be supposed to
have penetrated by any ordinary means during life.

Stensen had observed very faithfully the various strata that are to be
found wherever special appearances of the earth's surface were
exposed, or wherever deep excavations were made. His explanation of
how these various strata are formed will serve to show, perhaps better
than anything else, how far advanced he was in his realization of
ideas that are supposed to belong only to modern geology. He said:
"The powdery layers of the earth's surface must necessarily at some
time have been held in suspension in water, from which they were
precipitated by their own weight. The movement of the fluid scattered
the precipitate here and there and gave to it a level surface."

"Bodies of considerable circumference," Stensen continues, "which are
found in the various layers of the earth, followed the laws of gravity
as regards their position and their relations to one another. The
powdery material of the earth's strata took on so completely the form
of