done on board H.M.S. ' Challenger. 3 609 



piece of granite, also two varieties of basalt, one coarse-grained with 

 porphyritic olivine, and the other exceedingly fine-grained and compact, 

 without any separate crystals being visible to the naked eye. It was 

 chiefly remarkable from the fact that the stones, though fresh from the 

 bottom and still quite wet outside, were, when broken, perfectly dry 

 inside, the moisture not having penetrated beyond the thickness of a 

 sheet of paper. The edges of these stones were less rounded than those 

 of the other species which accompanied them. In order to be perfectly 

 sure that there was no mistake, I broke about a dozen of them, the 

 species being easily recognized by the edges of the stones being less 

 rounded than those of the others, and always with the same result ; while 

 those of the other species were not only wet inside, but, especially in the 

 trachytic ones, decomposition in concentric shells had made considerable 

 advances. As a drop of water applied to the fractured face was readily 

 and quickly absorbed, I can only account for the dryness inside by con- 

 sidering that the stones in question had passed but a very short time 

 under water. As they were found in lat. 52° $., and the first iceberg 

 was only met with in 60° S., it would be difficult to imagine that they 

 had come ice-borne from the Antarctic land ; at the same time it was 

 equally difficult to imagine any other adequate means of conveyance 

 than ice. I believe that they come from Heard Island, whose ice-bound 

 shores are constantly despatching miniature bergs into the sea, which, 

 from their insignificant size, would suffer rapid destruction alike from 

 the violence of the seas and from the temperature of the water, which, 

 on the occasion in question, was between 3° and 4° C. Many small ice- 

 masses, such as I have supposed, were floating off the southern shore of 

 Corinthian Bay, which on this side had a continuous icy coast-line formed 

 by a glacier descending from the central high grounds which culminate 

 in Kaiser Wilhelm Peak, and reaching the sea both on the west and on 

 the east side of the inhabited isthmus, as I have described in my short 

 note on the island. The position where the stones were dredged is 

 within 100 miles of Heard Island, and through the above-mentioned 

 agency there must be a constant conveyance of the debris of the island 

 out to sea, which would account for the very stony character of the 

 bottom found. 



Observations on Sea-water Ice. 



Many different opinions have been expressed as to the nature of ice 

 resulting from the freezing of sea-water, all agreeing, however, in one 

 point, that when melted the water is unfit to drink. During the 

 Antarctic cruise I took an opportunity of examining some of the broken 

 pack-ice, into which the ship made an excursion on the morning of the 

 25th of February, and also some ice which had formed over night in a 

 bucket of sea-water left outside the laboratory port. 



The piece of pack-ice which I examined was in substance clear, with 

 many air-bells, most of them irregularly shaped. Two portions of this 



2x2 



