On P/toxjihatic Guanos. 
457 
Composition of Enderbury Powdery Guano. 
Moisture 8 * 76 
•Organic matter 8'81 
tPhos[)horic acid 28*7-!: 
Lime 40* 7G 
JCarbonic acirl 7 '26 
Magnesia, alkaline salts, &c 5*58 
Silica '09 
100-00 
* Cllontaining nitrogen 'SS 
Equal to ammonia -46 
+ Equal to tribasic phosphate of lime .. 02" 74 
X Equal to carbonate of lime 16 -50 
The sample contained 16J per cent, of carbonate of lime and 
only 62| per cent, of phosphate of lime. It was almost com- 
pletely soluble in acid, and no doubt the guano would have 
turned out richer in phosphates if more care had been taken to 
collect it on a spot where the deposit was less contaminated 
with fragments of coral than the sample analysed by me. 
Two samples of crust guano from the same island I found 
much richer in phosphoric acid than the powdery deposit, as 
will be seen by the following figures : — 
Composition of Two Samples of Enderbury Crust Guano. 
No. 1. 
No. 2. 
833 \ 
6-45 / 
37-79 
41-96 
1-46 1 
3-95 ) 
•06 
11-67 
38-67 
42-83 
6-65 
-18 
100-00 
100-00 
* Equal to tribasic phosphate of lime.. 
82-49 
3-31 
84-42 
Not determined. 
Starbuch Island Guano. — Starbuck Island is another of the 
small guano islands in the South Pacific. It lies south of 
Maiden Island, and furnishes both powdery and crust guano, 
which in appearance or composition are scarcely distinguish- 
able from similar deposits occurring on Baker or Jarvis Island. 
The following is an analysis of a good sample of powdery 
Starbuck Island guano : — 
