4S8 
THE VOYAGE OF H.M.S. CHALLENGER. 
Tho fornuila M 11 O 2 + iHjO requires 9'18 per cent, of water. Consequently 26‘46 per cent, of manganous 
o.\ide, which corresponds to 32 42 per cent, of manganese binoxide, is equivalent to 3’28 per cent, of water. 
26 ‘7 per cent, of ferric oxide requires as limonite 4 ‘50 per cent, of water. 
'Water, 
Silica, 
Lime, 
Alumina, 
Ferric oxide. 
Magnesia, 
Manganous oxide. 
Nickel oxide. 
Oxygen, 
101-48 
19-34 
3-19 
6-36 
26-70 
1-79 
26-46 
1-82 
6-31 
137. Shark’s Tooth. — Station 285. 
Lat. 32° 36' S., long. 137° 43' W., 2375 fathoms (Brazier). 
Portion 
soluble 
Acid = 
in Hydrochloric "I 
= 84-00 J 
Portion insoluble in Hydrochloric \ 
Acid = 5 -00 / 
Loss on ignition after drying at 230° Fahr., 11-00 
Copper, ...... trace 
Alumina, . . . . .13-00 
Ferric oxide, ..... 6-87 
Calcium phosphate, . . . .21-63 
Manganese oxide, . . . . .28-49 
Calcium sulphate, . . . . 1 -60 
Calcium carbonate, . . . . 4"17 
Magnesium carbonate, . . .2-64 
( Silica, ...... 5-6O 
J Insoluble residue, principally alumina and ferric ■> 
\ oxide, with silica, / 
100-00 
Note. — The teeth used in Analyses 137 and 138 gave evidence of fluorides. The interior of this tooth had evidently 
decayed away, and the space had subsequently become filled up with the mixture of manganese and iron oxides, along with 
some silica. 
138. Sharks’ Teeth. — Station 285, 
Lat. 32° 36' S., long. 137° 43' W., 2375 fathoms (Brazier). 
Ia) 88 on ignition after drying at 230° Fahr., ....... 4'00 
Alumina, ........... 3-00 
Ferric oxide, . . . . . . . .6-60 
Calcium pho.sphatc, .......... 75-00 
Manganese oxide, . . . . . . trace 
Calcium sulphate, .......... trace 
Calcium carbonate, . . . . . . .7-50 
Magnesium carbonate, . . . . . . . .1-50 
General residue, consisting of soluble silica with the iu.soluble silicates, . 2-50 
100 00 
Note. — Two teeth, hollow but not so completely filled ns tho one used in Analysis 137. Total weight for analysis only 11 
grains. 
