used for Agricultural Purposes, 
A glance at the preceding analyses will show that the relative 
proportions of lime, and of oxide of iron and alumina, in the 
several samples vary to a much greater extent than the percent- 
ages of phosphoric acid ; from which it appears that some of the 
samples, for instance No. 2 and No. 5, contained a good deal of 
oxide of iron and alumina, partly combined with phosphoric 
acid. 
Composition of French Phosphate of Inferior Quality. 
No 
. 1. 
No 
. 2. 
No. 3. 
No 
. 4. 
No 
. 5. 
No. 6. 
Water of combination 
6 
99 
48 
>^ 
64 
6-81 
5 
64 
5 
62 
6-92 
26 
66 
26 
45 
25-96 
26 
45 
25 
02 
24-46 
32 
92 
38 
39 
31-51 
38 
39 
36 
98 
34-65 
Oxide of iron and alumina^ 
carbonic aoid, &c / 
23 
42 
19 
83 
21-63 
19 
83 
19 
90 
23-86 
Insoluble siliceous matter . . 
9 
53 
9 
69 
14-09 
9 
69 
12 
48 
10-11 
100 
00 
100 
00 
100-00 
100 
00 
100 
00 
100-00 
* Equal to tribasic phos-'l 
phate of lime . . . . / 
."58 
20 
57 
74 
56-67 
57 
_ 
74 
54 
62 
53-40 
Most of these and other inferior samples of French phosphate 
which I have analysed this year contained a large proportion 
of phosphate of iron and alumina, as well as hydrated oxide of 
iron and alumina ; and in this respect they intimately resembled 
inferior and impure Lahn phosphates. 
Both the German and French phosphates of low quality, 
showing from 50 to 54 per cent, of phosphate of lime, contain 
more oxide of iron and alumina than samples of English copro- 
lites equally rich in phosphoric acid, and are not worth a much 
money as the latter, 
9. South Carolina, or Charleston Phosphates. 
Phosphatic nodules, similar in many respects to the coprolites 
of the London Basin, have of late years been discovered in great 
abundance in the calcareous strata of the Charleston Basin. 
Although the material which at the present time is largely 
imported into England under the name of South Carolina, or 
Charleston phosphate, was known perfectly well in 1843, and 
probably as early as 1795, its value remained undetected ; and 
until within the last seven years it was regarded as worthless for 
all practical purposes ; nor was its true chemical character known 
previous to that period. The first shipments that can be traced, 
