412 On the Chemical Composition of Phosphatic Minerals 
General Composition of Twelve Cargo-samples of Si'anish 
Phosphorite imported into England in 1875. 
No. 1. 
No 
2. 
No. 3. 
No 
4. 
No 
5. 
No. 6. 
•m 
1 
10 
4-99 
54 
34 
1-14 
34-47 
33 
26 
32-30 
31 
07 
30 
53 
29-45 
45-73 
48 
20 
47-20 
42 
42 
45 
79 
42-65 
Fluorine, and a little oxide 1 
of iron and alumina, car-> 
4-08 
9 
21 
10-53 
4 
21 
13 
56 
9-35 
Insoluble siliceous matter . . 
15-14 
8 
23 
4-98 
21 
76 
9 
78 
17-41 
UU 
1 c\(\ • no 
UU 
UU 
lUU UU 
* Equal to tribasic phos-l 
phate of lime . . . . / 
75-25 
72 
60 
70-51 
67 
83 
6G 
G5 
64.38 
yin 
Q 
> 0. 
i^O. 
XV 0. 
1 1 
Va 19 
-84 
44 
-55 
2 
24 
47 
-9» 
27-94 
27 
87 
26-61 
26 
55 
25 
74 
18-71 
40-99 
36 
50 
37-85 
38 
13 
34 
06 
33-14 
Fluorine, oxide of iron, alu-\ 
mina, carbonic acid, &c. ) 
10-03 
2 
73 
10-24 
10 
18 
2 
52 
18-02 
Insoluble siliceous matter . . 
20-20 
32 
46 
24-75 
22 
90 
37 
21 
29-14 
100-00 
100 
00 
100-00 
100 
00 
100 
00 
100-00 
* Equal to tribasic phos-1 
phate of lime . . . . / 
60-99 
GO 
84 
58-09 
57 
96 
56 
19 
40-84 
In concluding this section, I add a complete analysis of a 
sample of Spanish phosphate which I made some time ago : — 
Detailed Composition of a Sample of Spanish Phosphorite, 
Water 3 -51) 
*Phosphoric acid 33 • ;18 
Lime 47-10 
Magnesia traces. 
{Carbonic acid 4-10 
Sulphuric acid -.57 
Oxide of iron 2-51) 
Alumina -80 
Fluorine and loss in analysis 4 "01 
Insoluble siliceous matter 3-71 
100-00 
* Equal to tribasic phosphate of lime 72-87 
-f Equal to carbonate of lime 9-31 
The better qualities of Spanish or Portuguese phosphates 
