274 
THE VOYAGE OF H.M.S. CHALLENGER. 
Oiie-half of an earbone of Balwna (?) was analysed, and for that purpose the man- 
ganese filling the cavity of the bone was scraped out and analysed separately. The 
white siliceous-looking core gave the following results : — 
Insoluble in acid, 
Moisture, 
Combined water. 
Phosphates of iron and alumina. 
Phosphoric acid. 
Carbonic acid. 
Fluorine, l‘4 = (Fg— 0), . 
Sulphuric acid, . 
Chlorine, 
Lime, 
Magnesia, 
Alkalies and loss, 
0-06 
2-21 
2-22 
0-42 
34'13 = 74‘5 per cent, tricalcic phosphate. 
6-61 
0-81 
0-81 
trace 
49-85 
0-77 
2-11 
100-00 
The contents of the cavity gave on analysis the following results : — 
Insoluble in acid. 
Total water, 
Manganous oxide. 
Loose oxygen. 
Ferric oxide. 
Lime, 
Magnesia, 
Alumina, 
Silica, 
Phosphoric acid, 
Potash, . 
S(xla, 
Nickel and copper, 
13-66 
27-00 
27-13 
3- 13 
8-34 
4- 34 
4-03 
6-54 
1- 31 
2- 39 
107 
2-39 
traces 
101-33 
The insoluble residue was apparently all amorphous silica. The soluble portion 
apparently consists of hydrated scsquioxides of manganese and iron and decomposible 
silicates. 
The inner, alrao.st uncoloured, portion of an earbone of Balmioptera was used for 
the following determinations: — 
Moisture, 
1-60 
CVmibined water, 
1-34 
Phosphoric acid. 
31-21 
Fbioriiie, 
1-89 
j)er cent. 
II « 
„ =68-13 per cent, tricalcic phosphate. 
II 
