On Phosphatic Guanos. 
455 
been carried away, and the cargoes which now reach England 
arc generally poor in phosphates and contaminated with a good 
tleal ot carbonate and sulphate of lime, as will be seen by the 
analysis on the preceding page which I made this spring of a 
cargo of such inferior Jarvis Island guano. 
Crust guano of a superior character is also found on Jarvis 
Island. 
Birds' Island Guano. — This guano occurs on a small coral 
island in the South Pacific. According to the accounts of the 
explorers, the guano occurs on the island partly in the shape 
of a light-brown or yellowish powder, and partly in the shape of 
soft rock-like looking crusts. 
As far as I know, no Birds' Island guano has been imported 
into England for some years past. The specimen in my col- 
lection is a light-coloured, friable, and porous stone-like mass, 
not unlike lime-tufa in appearance. Submitted to partial 
analysis its general composition was ascertained to be as 
follows : — 
Composition of Birds' Island Guano. 
Moisture G-92 
Organic mat ter 4 ■ 80 
Phosphate of lime (tribasic pliospLate) .. .. SO "44 
Carbonate of lime, magnesia, &c G'88 
Alkaline salts 1-34 
Silica -12 
100-00 
Shaic's Island and Flint Island Guanos. — Shaw's Island lies 
in the South Pacific not far from Maiden Island. Where Flint 
Island is, I have not been able to ascertain. Judging from its 
composition it probably belongs to the same group of coral 
islands in the South Pacific from which we obtain the most 
valuable phosphatic guanos. 
Only one sample of Shaw's Island and another of Flint 
Island guano have passed through my hands. Their com- 
position I found as follows : — 
Shaw's Island 
Gaano. 
Flint Island 
Guano. 
Magnesia, sulphuric acid, alkaline salts, &^ 
13-67 
34-69 
43-26 
7-53 
•85 
13-26 
3713 
43-43 
5-99 
-19 
100-00 
100-00 
75-73 
81-05 
2 u 2 
