o64 Chemical Composition and Commercial Value of 
in this rock is as high as in good samples of South American 
bone-ash. 
Phosphatic rocks similar in composition to the Sombrero Rock 
have lately been discovered in the Anguilla Isles, forming part 
of the Leeward Islands.* 
7. KooRiA MooRiA Guano. 
A considerable portion of the Kooria Mooria guano imported 
into England is bought up by manure manufacturers, and by 
means of sulphuric acid converted into useful turnip-manures. 
Although this guano may be used by itself as a manure for 
turnips or Swedes, it is better to add to it some sulphuric acid 
(say one-third of its weight), with a view to changing a portion 
of the insoluble phosphates, in which it is rich, into the more 
efficacious form of a soluble phosphate. 
Kooria Mooria guano varies considerably in composition, as 
the following analysis made in my laboratory will show : — 
Composition of Kooria Mooria Ouano. 
No. 1, 
No. 
2. 
No. 3. 
No. 4. 
No 
5. 
No. 6. 
No. 
r. 
9-63 
5- 
4^ 
12 
9 
53 
5 
43 
6 
21 
V 
84 
*Organic matter.. 
5-68 
&• 
49 
3 
49 
5 
19 
11 
45 
5 
01 
z- 
23 
Phosphates of limej 
aud magnesia (boiie-> 
53-93. 
46- 
39 
55 
21 
56 
09 
35 
04 
61 
20 
60 
03 
Sulphate of lime 
4-37 
11 
73 
14 
79 
2 
82 
13 
88 
8 
39 
2 
68 
Alkaline salts and) 
magnesia (chiefly > 
6-48 
5 
12 
1 
97 
6 
09 
5 
33 
5 
68 
S 
68 
common salt) .. ) 
Insoluble siliceous) 
19-91 
22 
33 
20 
42 
20 
28 
28 
87 
13 
51 
17 
54 
matter (sand) . . J 

100 -00 
100 
00 
100 
00 
100 
00 
100 
00 
100 
00 
100 
00 
* Containing nitrogen 
•33 
30 
21 
26 
33 
28 
26 
Equal to ammonia 
•40 
36 
25 
31 
40 
34 
31 
Kooria Mooria guano, it will be seen, contains but little 
organic matter, and hardly eny ammonia. It is generally met 
with in commerce in a tolerably fine powder, offering its phos- 
phates in that finely divided state which enables plants to assimi- 
late them more readily than those found in coprolites or other 
like substances which have become completely fossilized. 
8. Other Phosphatic Guanos. 
There are several species of African and West Indian guanos 
which at present are occasionally used in the manufacture of 
* Vide Communicatiou by Sir l{oderick Murchison, in Joumai, vol. xx. p. 31. 
