451 
0« Phosphatic Guanos. 
Eaker Island guano seldom contains any ammonia, the 
nitrogen shown in two of the above analyses being present in 
the shape of organic matter. It varies much in quality. The 
sample No. 1 mav be regarded as a good average one, No. 2 as 
unusually rich, and No. 3 as poor. 
Howland Island Guano. — Rowland Island, another West 
Indian coral island, is situated in 0° 49' N. latitude and 
176" 52' w. longitude. Its greatest length from north to south 
\6 2783 yards, its breadth 825 yards, and its elevation above 
the level of the sea 22 feet at low water, and about 12 feet at 
high water. 
The guano deposits on Howland Island are very similar in 
composition and physical characters to those on Baker Island, 
as will be seen by the subjoined analyses : — 
CojTPosiTioN OF Three Samples of Howland Island Guano. 
No. 1. 
No. 2. 
No. 3. 
^lagnesia, sulphuric acid, alkaline salts, &c. 
10-01 
5- 72 
34-21 
43-03 
6- 83 
20 
15-31 
7-26 
33-35 
39-36 
4-56 
•16 
8-95 
1 6-15 
34-80 
43*26 
6-54 
•30 
100 00 
lOU-00 
100-00 
Equal to tribasic phospliate of lioie 
74-68 
72-80 
75-97 
Jarvis Island Guano. — Jarvis Island, situated in 0' 22' N. 
latitude and 159° 55' W. longitude, is 1487 yards long and 
1870 yards broad, and about 30 feet above the level of the sea. 
Like Baker and Howland Islands, it is surrounded by coral 
reefs, which much impede the shipping of the guano. 
Composition of Jarvis Island Guano. 
Moisture 11 '27 
Organic matter 9 "93 
*Phosphoric acid 23-88 
Lime 37-18 
jCarbonic acid 5-02 
Magnesia, sulphuric acid, &c 12-63 
In.soluble siliceous matter '09 
100-00 
* Equal to tribasic phosphate of lime .. 52-13 
t Equal to carbonat of lime 11 -41 
Jarvis Island guano is similar in appearance to Baker and 
liowland Island guanos. The better deposits have nearly all 
