0)1 Phosphatic Guanos. 441 
Composition of Two Samples of Angamos Guano. 
No. 1. 
No. 2. 
fPliosphates of lime and magnesia (bone-phosphate) 
Alkaline salts (salts of potash and soda) 
7-2-1 
69-01 
12-06 
9-02 
2-67 
S-7G 
(;9-9G 
12-07 
8-27 
•94 
100-00 
100-00 
Equal to tribasic phosphate of lime rendered^ 
21 15 
2.5 -68 
Not lietermi nd. 
19-30 
23-44 
3-01 
6-57 
on the Chincha Islands furnished guano yielding from 16^ to 
17 per cent, of ammonia. 
This is considerably less than I found in the two samples of 
Angamos guano to which reference has been made. On the 
other hand, the percentage of phosphate of lime and magnesia 
in the best samples of Chincha Island guano is much greater 
than in these two Angamos guanos. 
Recently deposited and rapidly dried dung of sea-birds, col- 
lected almost as soon as it is produced, in a hot climate, and 
not acted upon by rains, thus contains a larger percentage of 
nitrogenous organic matter and a smaller percentage of phos- 
phates than the birds' droppings Avhich have continued to 
accumulate probably for centuries, and have formed more or 
less extensive layers, varying from 20 to 40 feet in thickness. 
In the course of many years, a portion of the nitrogenous 
organic matters of guano appears to be dissipated even in places 
most favourably situated for the preservation of the soluble fer- 
( tilising constituents of birds'-dung. On fuller examination I 
found that the two samples of Angamos guano had undergone 
; no decomposition. This guano smelled fishy, and more like 
fresh urine than Peruvian guano. 
' Both samples, Avhen tested with blue litmus-paper, reddened 
i the test-paper distinctly, whereas Peruvian guano has always a 
somewhat pungent smell, and a decidedly alkaline reaction. 
The presence of uric acid and acid urates in the Angamos 
guano explains its acid reaction. Thoroughly wetted with 
water, and kept in a warm room, Angamos guano in the course 
of a couple of hours suffers decomposition, and gives rise to 
, carbonate of ammonia, the presence of which is readily indicated 
