1864.] 393 [Lesley. 



Ignorant of the cause, the manner, and the extent of the ehanpe, the 

 imagination of savages would recast the facts in the mould of their 

 daily expeinence. 



We can understand, also, on this hypothesis, why the Arkisni of 

 mythology finds its classic land in Africa, and becomes Helio-arkism 

 only in Asia. A subject which I should be glad to find the time to 

 discuss at length before the Society. 



Neither the growth-rings of the trees on the Ohio valley mounds, 

 nor the cypress layers in the Delta of the Mississippi, nor the coral 

 reef series of Florida, nor the thickness of the Somme Valley peat, 

 nor that of the stalagmite cover of the fossil clay of the caves, nor 

 the borings made in the Memphis sands at the foot of the monu- 

 ments, have aiforded us even an approximate scale of years where- 

 with to measure man's residence on earth. The Cone of the Tin- 

 nifere, near Villeneuve, lias yielded to Prof. Morlot the first precise 

 statement of human time made by human fossils. As he reads it, 

 the bronze age dates back from our time from 2900 to 4200 years, 

 and the stone age from 4700 to 7000 years. (Etudes Geol. Archiv. 

 Bull. Soc. Vaud. vi, p. 325.) M. Gillieron makes the age of his 

 lake habitation relics at least 6750 years. (Actes de la Soc. Jurass. 

 d'Eniulation, 1860.) But these are both merely common historic 

 dates. 



If, however, I have not misunderstood a communication made to 

 me by our fellow-member, Dr. A. A. Henderson, of the U. S. Navy, 

 there exists a singularly perfect scale of years for archaeologists, 

 under the tropics, wherever the wet and dry seasons are semi-annual 

 and regular. Near Rio Janeiro are certain caves in limestone, con- 

 taining the usual accumulations of stalactitic and stalagmitic matter, 

 the latter covering a bone clay, in which the implements of man 

 have been found, chiefly arrowheads. Dr. Ildefonso, the well- 

 known botanist and naturalist of Eio Janeiro, informed Dr. Foltz 

 that he had made himself well acquainted with the caves of the 

 Provinces of Minas Duras, and Santos, and their contents, and that 

 his daughter had repeatedly counted the delicate layers of the lime 

 deposit over the bone clay, produced by the seasons of rain and 

 percolation, interrupted by dry seasons of dusty weather, during 

 which, there being no percolation from the surface through into the 

 caves, there consequently was no deposit of alabaster, but in lieu of 

 it a deposit of dust; and he declared that the number of the layers 

 amounted to twenty thousand (20,000). Should this curious obser- 

 vation be repeated and accepted, the question of the great antiquity 

 voii. IX. — 2aa 



