154 AMSTERDAM ISLAND. 
nor of the Plutonists, though both may serve to explain many 
of the inferior phenomena, will by any means solve the 
most difficult and important that present themselves to the 
researches of the natural philosopher. Thus, difficult as it 
may seem to account for the traces of the sea on secondary 
mountains, it is not less so to explain from whence proceeded 
the multitude of bones of elephants, rhinosceroses, bufFalos, 
and the huge mammoth, with others not existing in any part 
of the creation at the present day, which occur in Siberia, and 
even on islands in the midst of the icy sea, where, according 
to modern travellers, the soil is almost wholly composed of 
them. These and many other organic remains of the old 
world, found in climates where they could not possibly have 
supported life, give some colour of argument in favour of the 
ingenious and well-told theory of Mr. Bailly, contained in his 
letters on the Atlantic island of Plato, where he supposes 
that these northern regions, now condemned to everlasting 
frost and snows, were not always 
*' Dark Cimmerian deserts 
but that they might once have enjoyed a happy temperature of 
climate, a productive soil furnishing a supply of food for those 
animals whose remains are found in such abundance buried in 
the earth, their form remaining but their nature totally changed. 
A different inclination of the earth's axis to its orbit, being 
quite sufficient to explain the phenomenon, has generally 
been resorted to for this purpose ; but I am rather surprized 
that, among the various causes which have been assigned for 
altering the position of the axis with regard to the plane of 
the earth's orbit, the reactive force of volcanic eruptions has 
