Geognostic

To a ploughboy, a pebble is an insignificant thing, suggestive possibly of some discomfort in walking, and fit only to shy at a bird, may be; but to the geologist it appears worthy a volume, and speaks to him of strata may be a million of years old, of glacial attrition, of volcanic action, of chemical constituents, of mineralogical principles, and crystallogenic attraction, of mathematical laws and geometric angles, and of future geognostic changes.

Unfortunately I do not possess sufficient geognostic knowledge to be able to set this cavern down as an extinct volcano.

There is, indeed, one piece of evidence for the probability of the comparative youth of our system, altogether apart from human traditions and the geognostic appearances of the surface of our planet.