CHAP, v.] 



GENERAL CONCLUSIONS. 



31' 



with oxide of iron ; many small mineral particles — mica, magnetite, feld- 

 spar, quartz, and hornblende. These mineral particles appeared wind- 

 blown, and had probably been carried to this area by the Harmattan 

 and trade-winds. 



No. 4.— Station VII. February 24th. Lat. 23° 23' N., Long. 31° 31' 

 W. Depth, 2750 fathoms. Bottom temperature, 2°'0 C. Chemical 

 composition : 



Loss on ignition after drying at 230° F 74,') 



Alumina 6"4(i 



Ferric oxide 15'4ii 



Portion soluble in Calcium phosphate Trace 



hydrochloric acid ■{ Calcium sulphate 1'6(» 



Calcium carbonate 411 



Magnesium carbonate 1.20 



Silica 24-25 



Alumina 6'00 



Ferric oxide 2'54 



Lime 1'06 



Magnesia 0'64 



Silica 29-33 



52-98. 



Portion insoluble 

 in hydrochloric 

 acid = 39-5*7. 



100-00 



A red clay, containing much amorphous clayey matter, and many 

 small mineral particles — quartz, mica, hornblende, feldspar, magnetic 

 iron. A few broken pieces of pelagic foraminifera. 



No. 5.— Station VIII. February 25th. Lat. 23° 12' N., Long. 32° 56' 

 W, Depth, 2800 fathoms. Bottom temperature, 2°'0 C. Chemical 

 composition : 



Loss on ignition after drying at 230° F 8-95 



' Alumina 8-95 



Ferric oxide 9-70 



Portion soluble in Calcium phosphate Large trace 



hydrochloric acid \ Calcium sulphate 2-24 



Calcium carbonate 16-42 



Magnesium carbonate 2-70 



Silica 2300 



Alumina 4-20 



Ferric oxide 210 



Lime 0.89 



Magnesia 0-60 



, Silica 20-25 



= 6301. 



Portion insoluble 



in hydrochloric 



acid — 28-04. 



100-00 



