NARRATIVE OE THE CRUISE. 
1049 
ANALYSES OF DEPOSITS. 
Analysis of a Blue Mud. 
By Dr. Hornung. 
Station 323, February 21, 1876; 1900 fathoms, South Atlantic. 
I. 0'8069 grm. of substance dried at 110°, fused with carbonates of soda and potash, 
gave 0*4804 grm. of silica, 0*1566 grm. of alumina, 0 '05 76 grm. of ferric oxide, 0*0135 
grm. of lime, 0*0155 grm. of magnesia, 0*0503 grm. of loss on ignition. 
II. 1 '4212 grms. of substance dried at 110° C., treated with hydrofluoric and 
sulphuric acids, gave 0'0202 grm. of potash and 0‘0382 grm. of soda. 
Silica (Si0 2 ), ......... 59‘54 
Alumina (A1 2 0 3 ), . . . . . . . . .19-42 
Ferric oxide (Fe 2 0 3 ), ........ 7T5 
Lime (CaO), . . . . . . . . 1-68 
Magnesia (MgO), . . . . . . . . .1‘93 
Potash (K 2 0), ......... 1-35 
Soda (Na 2 0), . . . . . . . . 2'68 
Loss on ignition, . . . . . . . . 6‘24 
Phosphoric and sulphuric acids, ....... traces 
Analysis of a Red Clay. 
By Dr. Hornung. 
Station 9 ; 3150 fathoms, North Atlantic. 
I. 1*1459 grms. of substance dried at 110°, fused with carbonates of soda and potash, 
gave 0*6519 grm. of silica, 0*2323 grm. of alumina, 0*1148 grm. of ferric oxide, 0*0150 
grm. of lime, 0*0293 grm. of magnesia, and 0*0770 grm. of loss on ignition. 
II. 1*1162 grms. of substance dried at 110°, treated with sulphuric and hydrofluoric 
acids, gave 0*0219 grm. of potash and 0*0092 grm. of soda. 
I. 
II. 
Mean. 
Silica (Si0 2 ), 
. 56-89 
56-89 
Alumina (A1 2 0 3 ), 
20-28 
20-28 
Ferric oxide (Fe 2 0 3 ), 
. 10-02 
10-02 
Lime (CaO), 
1-31 
1-31 
Magnesia (MgO), . 
2-56 
2-56 
Potash (K 2 0), . 
1-91 
1-91 
Soda (Na 2 0), 
0-81 
0-81 
Loss on ignition, . 
6-72 
6-72 
Barium, manganese, and phosphoric acid, 
traces 
100-50 
