of Edinburgh , Session 1876 - 77 . 
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Over the surface of some of these serpulm and algae were growing, 
and crystals of sinadin projected, or were imbedded in the feldspar. 
During our visit to Ascension there was a very heavy fall of rain, 
such as had not been experienced by the inhabitants for many 
years. For several days after, many pieces of scoriae, cinders, and 
the like were noticed floating about on the surface of the sea near 
the island. Such fragments may be transported to great distances 
by currents. 
On the shores of Bermuda, where the rock is composed of blown 
calcareous sand, we picked up fragments of travelled volcanic rocks. 
The same observation was made by G-eneral Nelson at the Bahamas. 
Mr Darwin noticed pieces of pumice on the shore of Patagonia, and 
Prof. L. Agassiz and his companions noticed them on the reefs of 
Brazil. During a recent eruption in Iceland, the ferry of a river 
is said to have been blocked for several day by the large quantity 
of pumice floating down the river and out to^sea. All the pumice 
which we find need not be of quite recent origin. Mr Bates informs 
me that great quantities of pumice are continually being floated 
down the Amazon. These come from near the foot of the Andes, 
where the head-waters cut their way through fields of pumice stones. 
In the province of Wellington, New Zealand, two of the rivers run 
through areas covered with pumice, and during floods bear great 
quantities out to sea. 
Prof. Alex. Agassiz has kindly furnished me with the following 
note : — 
“The river Chile, which flows through Arequipa, Peru, has cut 
its way for some thirty miles through the extensive deposits of 
volcanic ashes which form the base of the extinct volcano Misti. 
Some of the gorges are even 500 feet in depth, forming regular 
canons. The whole length of the river bottom is covered by well- 
rolled pieces of pumice from the size of a walnut to that of a man’s 
head. In the dry season (winter) there is but little water flowing, 
but in the summer, or rainy season, the river, which has a very 
considerable fall (7000 feet in a distance of about 90 miles), drives 
down annually a large mass of these rolled pumice stones to the 
Pacific. The volcanic ashes are not recent. There is no tradition 
among the Indians of any eruption within historic times.” 
Captain Evans, the present hydrographer to the navy, informs 
2 L 
von. IX. 
