42 



SCIENCE. 



[Vol. II., No. 23. 



component parts varies sufficiently'to adniit'of deter- 

 mining its fluctuations by the most exact analytical 

 methods, and whether, in that case, it were possible 

 to deduce some definite rule regarding them. 



As the result of the analyses, L. Sohmelck con- 

 cludes, "The hypothesis which assumes the ocean to 

 consist throughout its entire depth of one homoge- 

 neous fluid, in which the most accurate of chemical 

 analyses shall fail to detect dissimilarity of composi- 

 tion, has received from the experiments here described 

 probably stronger confirmation than from any that 

 have gone before them." Some of the most interest- 

 ing results are tabulated as follows, the first table 

 showing the mean amounts of certain substances in 

 sea-water at various depths, and the second showing 

 the same for different parallels of latitude: — 



Specific gravity 

 Chlovine . . . 

 Calcium osid' 

 Magnesium o: 

 Sulphuric oxide 



de 



Surface. Bottom 



0.0576 

 0.2205 

 0.2211 



0.0581 

 0.2207 

 0.2208 



Inter- 

 mediate 

 depths, 



1.0266 

 1.934 

 0.0577 

 0.2200 

 0.2223 



1.0265 

 1.932 

 0.0578 

 0.2203 

 0.2214 



Specific gravity 

 Chlorine . . . 

 Calcium oxide . 

 Magnesium oxid< 

 ■Sulphuric oxide 



1.0264 

 1.929 

 0.0680 

 0.2190 

 0.2208 



0.0577 

 0.2205 

 0.2223 



The mean value of the salts occurring in sea-water 

 is given as follows : — 



CaCOj, CaSOj, MgSOj, MgClj, KCl, NaHCOj, NCI. 

 0.002, 0.1395, 0.2071, 0.3661, 0.0747, 0.0166, 2.682. 



Hence 100 parts of dry sea-salt contain — 

 CaCOs, CaSOi, MgSOj, MgCI., KCl, NaCOj, KaCI. 

 0.067, 4.00, 6.93, 10.20, 2.14, 0.476, 76.84. 



The ocean-bottom studied is especially interesting 

 from the amount of present and past volcanic and 

 glacial activity in the lands surrounding it. Here, as 

 elsewhere, depth was found to be the principal factor 

 in determining the character of the deposits. Along 

 the coasts of Norway and Spitzbergen, generally at a 

 less depth than five hundred fathoms, the bottom 

 was found to be covered with a more or less plastic 

 gray clay. Its coarseness or fineness varies consid- 

 erably; and grains of quartz, as a rule with rounded 

 edges, constitute the chief portion of the mineral 

 particles in it. At the approximate depth of from 

 five hundred to a thousand fathoms, a brown clay is 

 found, forming a transition from the gray clay to the 

 true oceanic deposits. 



At nearly all depths below a thousand fathoms, and 

 oftentimes at less depths, is a fine light t© dark brown 

 colored deposit containing minute white shells of the 

 genus Biloculina, in size and shape like a pin-head. 



This shell gives name to the clay, which corresponds 

 approximately to the Globigerina ooze of the Chal- 

 lenger expedition. The ground is taken, that the 

 power of sea-water to dissolve the carbonate of lime 

 of the foraminiferal shells is not owing to the greater 

 amount of carbonic acid at great depths in the ocean; 

 for the observations of Mr. Torm^ie showed that the 

 sea-water invariably reacted as an alkali, and hence 

 the carbonic acid could not be free. Again: the 

 latter was found to be about the same in the depths 

 of the ocean as on the surface; while the general 

 uniformity of composition of the sea-water, as shown 

 by numerous investigations, renders it improbable 

 that any deviation in amount of carbonic acid oc- 

 curs; hence the power possessed by sea-water to 

 dissolve carbonate of lime does not depend upon the 

 greater or less proportion of free carbonic acid. 



The bottom of the shallow ocean between Norway, 

 Beeren Eiland, Spitzbergen, and Novaia Zemlaia, was 

 found to be covered with a greenish-gray clay con- 

 taining but few animal remains. Minute and gen- 

 erally sharp-edged quartz grains were the principal 

 constituent. This deposit was termed the Ehabdam- 

 mina clay, from a genus of Foraminifera which often 

 abounds in that part of the ocean-bed. This clay, 

 according to Schmelck, originates from the ' decom- 

 position of quartzitic rocks,' especially those of 

 Beeren Eiland. 



Off the volcanic island of Jan Mayen, above the 

 six-hundred-fathom line, occurs a deposit of dark- 

 gray sand, and sabulous clay containing fragments of 

 basaltic lava, olivine, augite, etc., which seem to have 

 been derived from the volcanic debris of the island. 



An important fact bearing on the question of the 

 distribution of debris by bottom-currents in the 

 ocean is the statement that "all samples of water 

 brought up from the bottom were perfectly clear, 

 without a trace of floating particles." 



The occurrence of numerous stones and pebbles on 

 the sea-floor, as well as not uncommonly a rocky bot- 

 tom, is of interest. The pebbles decrease in size and 

 number in going from the shore towards deep water. 

 While rare in the deep water south of the 72d par- 

 allel, they are quite common in that to the west 

 of Spitzbergen and Beeren Eiland, where drift-ice 

 abounds. Out of three hundred and seventy-five 

 stations, pebbles and fragments of minerals and rocks 

 were dredged at a hundred and twenty-three of 

 them, while at many others no sample of the bottom 

 could be obtained on account of its rocky condition. 

 Of especial interest is the finding of numerous frag- 

 ments of flint and chalk, a fossil (belemnite) from 

 the chalk, fragments of coal, and some striated stones. 

 Other pebbles and fragments found were marble, 

 limestone, granite of various kinds, sandstone, argil- 

 lite, quartzite, flint, chalk, granitic veinstone, quartz 

 porphyry, gabbro, basalt, pumice, amygdaloidal rocks; 

 chloritic, hornblendic, quartz, mica, and other crystal- 

 line schists; calcite, quartz, mica, hornblende, fel- 

 spar, asbestos, coal, olivine, augite, coral, shells of 

 various kinds, rotten wood, etc, 



Schmelck concludes that organic agency is a sub- 

 ordinate factor in the formation of the floor-deposits 



