1880. | Recent Literature. 887 
engravings are good, showing with great detail the surface fea- 
tures of the island, pictorially and topographically. But to the 
naturalist and geologist, the second part, by M. Velain, is of 
greater interest. This volume is illustrated with twenty-seven 
quarto plates, eight of which are by the photoglyptic process, 
and are microscopic studies of the volcanic rocks. The island 
itself is of volcanic origin, and entirely composed of igneous 
rocks. This volume is a most elaborate monograph of the min- 
eralogical and structural history of the island, by means of sec- 
tions and colored maps, and it certainly is a model of careful 
study and bookmaking. Many actual volcanoes are shown to exist 
on the island, in operation at the present time. The publication of 
these important volumes is very creditable to the Government of 
France as well as to the authors. 
. Velain has recently published a small brochure of great 
interest in Bulletin No. 7 of the Mineralogical Society of France, 
on the microscopic study of the glass or slag resulting from the 
fusion of the ashes of grasses. It is illustrated with an excellent 
octavo plate showing the production, artificially, of the crystals 
of tridymite, anortheite, wollastonite and augite—F. V. H. 
SicsBee’s. Deep SEA SounDING AND DREDGING.!—It is greatly 
to the credit of American science and to our government, that it 
has taken so prominent a part in deep sea explorations. This is 
due largely to the labors and energy of the lamented Count 
Pourtales, who was a distinguished physical geographer and 
or a long time an assistant in the U. S. Coast Survey. He 
was the first to show that the warmer waters of the tropics, nota- 
biy the Floridan seas, with their profusion of tropical life, were 
underlaid by a colder bottom stratum of water with a nearly 
equal profusion of what was hitherto supposed to be purely Arc- 
tic life. The Norwegian marine zodlogists had previously demon- 
strated the existence of a deep-sea fauna off the coast of Norway, 
and the Swedish naturalist, Lovén, had suggested that this deep 
sea fauna was widespread over the ocean bottom, but Pourtales 
demonstrated it, and the subsequent deep sea explorations of the 
English Navy, especially the Challenger Expedition, carried out 
and extended Pourtales’ discoveries. 
Pourtales was aided and advised by his friend Agassiz, and the 
work-of exploration of the ocean bottom under the Gulf Stream 
off the Floridan peninsula, and in the Gulf of Mexico, as well as 
off the southern coast of the United States, has of late years been 
extended by the officers of the U. S. Coast Survey, Mr. Alexan- 
der Agassiz being the naturalist of the recent expeditions. The 
Coast Survey has now a beautiful steamer, the B/ake, of 350 tons, 
1 United States Coast and Geodetic Survey. CARLISLE P. PATTERSON, Superin- 
tendent. Deep sea Sounding and Dredging. Jescription and discussion of the 
oar 
