252 Proceedings of the Eoycd Society 
me that he frequently picked up pumice on the Great Barrier Beef 
of Australia. 
Volcanic Ashes. 
Near volcanic centres, and sometimes at great distances from 
land, we find much volcanic matter in a very fine state of division 
at the bottom of the sea. This consists of minute particles of 
feldspar, hornblende, augite, olivine, magnetite, and other volcanic 
minerals. In the South Pacific, many hundred miles from land, 
and from a depth of 2300 fathoms, the trawl brought up a number 
of pieces of tufa entirely composed of these comminuted fragments. 
These particles appear to me to have been carried to the areas 
where we find them, by winds, in the form of what is known as 
volcanic dust or ashes. Sir Bawson Bawson sent to Sir Wyville 
Thomson a packet of the volcanic ashes which fell on the Island of 
Barbadoes, after an eruption in 1812 on the Island of St Vincent, 
W. I., one hundred and sixty miles distant. I have examined this, 
and find it made up of fragments of the same character as those in 
the tufa to which I have just referred, some of the particles being 
perhaps a little larger. We have sometimes found this ash in con- 
siderable abundance mixed up with the shells in a globigerina ooze. 
In the deposits for hundreds of miles about the Sandwich Islands 
there are many fragments of pyroxenic lava, which I believe have 
been borne by the winds, either as ashes, or in the form of Pele’s hair. 
At Honolulu we were informed that threads of Pele’s hair were 
picked up in the gardens there after an eruption of Kilauea, one 
hundred^and eighty miles from the volcano. This Pele’s hair bears 
along with it small crystals of olivine. 
Obsidian and Lava Fragments. 
Small pieces of obsidian and of feldspathic and basaltic lavas were 
frequently found in deposits near volcanic islands. 
At two stations in the South Pacific, many hundred miles from 
land, we dredged pieces of this nature of considerable size larger 
than ordinary marbles. It is difficult to account for the transfer- 
ence of these fragments to the places where they were found. It 
is, however, in this region, and this alone, that it may be necessary 
to bring in a submarine eruption to account for the condition of 
things at the bottom. 
