Page:Popular Science Monthly Volume 7.djvu/37

Rh In 1850 Captain Penny collected in Assistance Bay, in Kingston Bay, and in Melville Bay, which lie between 73° 45' and 74° 40' north, specimens of the residuum left by melted surface-ice, and of the sea-bottom in these localities. Dr. Dickie, of Aberdeen, sent these materials to Ehrenberg, who made out that the residuum of the melted ice consisted for the most part of the silicious cases of diatomaceous plants, and of the silicious spicula of sponges; while, mixed with these, were a certain number of the equally silicious skeletons of those low animal organisms, which were termed Polycistinæe of Ehrenberg, but are now known as Radiolaria.

In 1856 a very remarkable addition to our knowledge of the nature of the sea-bottom in high northern latitudes was made by Prof. Bailey of West Point. Lieutenant Brooke, of the United States Navy, who was employed in surveying the Sea of Kamtchatka, had succeeded in obtaining specimens of the sea-bottom from greater depths than any hitherto reached, namely, from 2,700 fathoms (16,200 feet) in 66° 46' north, and 168° 18' east; and from 1,700 fathoms (10,200 feet) in 60° 15' north, and 170° 53' east. On examining these microscopically, Prof. Bailey found, as Ehrenberg had done in the case of mud obtained on the opposite side of the arctic region, that the fine mud was made up of shells of Diatomaceæ, of spicula of sponges, and of Radiolaria, with a small admixture of mineral matters, but without a trace of any calcareous organisms.

Still more complete information has been obtained concerning the nature of the sea-bottom in the cold zone around the south pole. Between the years 1839 and 1843, Sir James Clark Ross executed his famous antarctic expedition, in the course of which he penetrated, at two widely-distant points of the antarctic zone, into the high latitudes of the shores of Victoria Land and of Graham's Land, and reached the parallel of 80° south. Sir James Eoss was himself a naturalist of no mean acquirements, and Dr. Hooker, the present President of the Royal Society, accompanied him as naturalist to the expedition, so that the observations upon the fauna and flora of the antarctic regions made during this cruise were sure to have a peculiar value and importance, even had not the attention of the voyagers been particularly directed to the importance of noting the occurrence of the minutest forms of animal and vegetable life in the ocean.

Among the scientific instructions for the voyage drawn up by a committee of the Royal Society, however, there is a remarkable letter from Von Humboldt to Lord Minto, then First Lord of the Admiralty, in which, among other things, he dwells upon the significance of the researches into the microscopic composition of rocks, and the discovery of the great share which microscopic organisms take in the formation of the crust of the earth at the present day, made by Ehrenberg