524 Proceedings of the Royal Society 
It was analysed with the following result: — 
Magnesia 
0-2 
Ferrous oxide 
17*6 
Titanic acid 
6-2 
Ferric oxide 
75*6 
99-6 
Specific gravity 4-6. 
The sand was highly magnetic. 
Assuming that the magnesia is present as titanate of magnesia, 
and that the titanic acid, in excess of what is required to form 
titanate of magnesia, is united with ferrous oxide to form ferrous 
titanate, the residue of the ferrous oxide being united with ferric 
oxide, we obtain the following proximate composition : — 
MgO, Ti0 2 • 
0*6 
FeO, Ti0 2 . 
10-6 
FeO, Fe,0 3 . 
42-9 
Fe 2 0 3 .... 
45-5 
99-6 
The sand is obviously crystallised, but the grains are so rounded 
by rolling as to render it impossible to determine whether they are 
octahedral or rhombohedral. 
If we calculate the quantity of oxygen contained in the several 
oxides present, we find, — 
Oxygen. 
MgO 
0*2 
0-08 
FeO 
17*6 
444 
Ti0 2 . 
6-2 
1*21 
Fe 2 0 3 . 
75*6 
22-68 
Or arranged as above. 
Oxygen. 
MgO, Ti0 2 
0-6 
0-24 
FeO, Ti0 2 
10-6 
3-42 
FeO, Fe 2 0 3 
42-9 
12-00 
Fe 2 0 3 . 
45*5 
13-68 
