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PROCEEDINGS OF THE GEOLOGICAL SOCIETT. 



If either or both of these definitions of life be accepted as satis- 

 factory, then, as I hope to demonstrate to you, the minerals which 

 build up the crust of our globe unquestionably "live." At all events 

 I am confident of being able to show that " in correspondence with 

 external co-existences and sequences," or, in other words, as the con- 

 ditions to which they are subjected vary, they undergo " a series of 

 definite and successive changes, both in structure and composition, 

 without losing their identity." 



It may seem paradoxical, but it is nevertheless true, that the 

 "vitality" of minerals — I really do not know what other term to 

 use to convey my meaning — is much greater than that of plants, 

 and, a fortiori, than that of animals ; and this is the direct and 

 necessary consequence of their less complex and more stable chemical 

 constitution. 



The Zoologist regards as a case of remarkable vitality the recovery 

 of snails which had been long affixed to a museum-tablet, upon 

 their immersion in warm water. The Botanist cites the germination 

 of seeds taken from ancient Egyptian tombs as a striking illustra- 

 tion of how long life may remain dormant in the vegetable world. 

 Let us now turn to the Mineral kingdom. A quartz-crystal develops 

 to certain dimensions, in accordance with the natural laws of its 

 being, and when the necessary conditions of growth cease to environ 

 it, its increase is arrested. But the crystal still retains its " vitality," 

 that is the power of further development which is dependent on its 

 particular " organization " or molecular structure. We may de- 

 stroy that " organization " and the " vitality " which is dependent 

 upon it in a single instant, by subjecting the crystal to the action 

 of hydrofluoric acid or of an oxyhydrogen flame. But unless its 

 " organization " and " vitality " be thus brutally stamped out, the 

 crystal and, indeed, every fragment of it retains, not the " promise" 

 only, but the very " potency of life." It may be worn by wind and 

 wave into a rounded and polished sand-grain ; it may be washed 

 from the beds of one formation, to form part of the materials of a 

 new one, and this process may be repeated again and again ; but 

 after countless wanderings and unnumbered " accidents by flood 

 and field," extending over millions on millions of years, let but the 

 necessary conditions of growth again environ it, and the battered 

 and worn fragment will redevelop, in all their exquisite symmetry, 

 its polished facets, it will assume once more the form of a quartz- 

 crystal, having at least as much claim to identity with the original 

 one, as a man has with the baby from which he has grown. 



