668 THE POPULAR SCIENCE MONTHLY. 



V 



two, pointing out the clay tliat was mixed with the metal supposed to 

 be pure, and relegating the baser substance to its proper place. The 

 fact that consciousness is a mere phase of nervous activity, pertaining 

 to the body and consequently of the earth, earthy, has nothing to do 

 with the mortality or the immortality of the ego ; it is an argument 

 neither for nor against the existence of a soul. A dog possesses clear- 

 ly defined consciousness, and yet it is not necessary to predicate a soul 

 as the accompaniment of this possession ; to argue thus is to degrade 

 the meaning of the word soul. Consciousness is but a part of normal 

 flesh-and-blood existence ; it is nourished and stimulated by a gener- 

 ous supply of healthy blood, and becomes changed and unhealthy by 

 disease. It seems probable that in the vast land of unconsciousness, 

 intellectual activity becomes manifold, and each of the many sides 

 of our nature, untrammeled by the restraints of conscious volition, 

 carries on a ceaseless activit}^ the results of which we sometimes 

 receive and recognize in consciousness. 



OUR ICE-SUPPLY AND ITS DANGERS. 



By T. MITCHELL TEUDDEN, M. D. 



IT is not easy to realize that the region which wc now call New 

 York was once a mass of bare, tangled rock, bound fast beneath 

 vast glacial ice-fields, which, stretching away to the north and west, 

 held all northern North America in the bonds of a dreary desolation. 



The gigantic fissure through which welled up from the earth's cen- 

 ter that vast mass of molten rock which we call the Palisades, had 

 closed fast upon its sides long before the last reign of ice began ; and 

 when at length the cold era was established, and the great glaciers, 

 with their slow, resistless flow, came sweeping down, year after year, 

 over the top of the Palisades, across the rocks on Avhich New York 

 stands, and at last broke off and melted in the sea, the ice-mass, and 

 the fragments of stone which it had torn loose in its progress and 

 held fast along its sides and bottom, planed down the rocks over which 

 it passed, and left upon their exposed surfaces broad grooves, shallow 

 channels, and innumerable scratches, which to-day tell silently the 

 story of that ancient reign of ice. The house-building furor is fast 

 removing these ancient records, but in the upper parts of the island 

 and on the top of the Palisades one still may see large numbers of 

 glacier grooves and scratches. 



How long this ancient Ice age lasted it would be useless to con- 

 jecture now ; but at length the climate changed, and by little and 

 little the ice relaxed its grasp. The stones and bowlders, with which 

 it was so relentlessly grinding olT the surface of the earth's crust here- 

 about, dropped from its fingers and lay much as we may see them 



