On Phosphatic Guanos. 
449 
The first of the four samples, it will be seen, yielded 2^ per 
cent, of ammonia, and the fourth only J per cent. All contained 
a large proportion of sand — ^No. 3 as much as half its weight. 
The percentage of phosphate of lime in the best sample 
amounted to only 27 J per cent., and in the worst sample it fell 
as low as 16^ per cent. Altogether, Patagonian guano, as a 
rule, is a poor manure ; and in many cases it is not worth the 
freight and working expenses. 
Patos Island Guano. — Patos Island lies off the coast of Lower 
California, and on it are found deposits of phosphatic guanos, 
which, however, appear to be now nearly exhausted. A sample 
of Patos Island guano, analysed by me some years ago, had the 
following composition : — 
Composition of Patos Island Guano. 
Moisture 34* 35 
*Organic matter and salts of ammonia 10 "24 
Phosphate of lime and magnesia (bone-plios^iliatcs) .. 53'48 
Carbonate of lime 2*58 
Alkaline salts 4-63 
Insoluble siliceous matter 14 "72 
100-00 
* Containing nitrogen '96 
Equal to ammonia 1 • 16 
Gulf of California and Raza Island Guano. — Much more 
valuable phosphatic guanos than that from Patos Island are now 
imported into England from Raza Island and other islands in the 
Gulf of California, as will be seen by the following analyses : — 
Composition of Phosphatic Guasos from the Gulf of Califoenia. 
Ko. 1. 
No. 2. 
ITo. 3. 
4-83 
1 
30 
3-70 
'Organic matter and combined ^ater . . 
12-72 
9 
SO 
1113 
34-33 
40 
•31 
34-81 
37-36 
37 
21 
34-07 
1-7G 
■50 
1 . 
•81 
IS 
9-54 
•46 
) 
5-54 
1-Gi) 
4 
20 
G-7.5 
100-00 
100 
00 
100-00 
1-01 
•86 
1-20 
45 
1-04 
t Ei|r.al to tribasic phosphate of lime 
74 
ss 
01 
75-99 
