On Phosphatic Guanos. 
445 
that the particles of the guano arc in a state of fine subdivision. 
In this respect jMejiUoncs guano is distinguished favourably from 
other phosphatic guanos, the majority of which are more dense, 
and apparently mineralised to a greater extent, than the Mejillones 
deposits. It, moreover, contains a larger proportion of organic 
matter, including from one-half to three-fourths per cent, of 
organic nitrogen and small quantities of ammoniacal salts, as 
will be seen by the following complete analyses of several 
cargoes, samples of which have been sent to my laboratory for 
examination during the last few years: — 
Composition of Mejillones Guako. 
No. 1. No. 2. 
No. 3. 
No. 4. No. 5. j No. 6. 
*Org<iuic mjittur uud salts ofl 
Alkaline salts, including .. 
Chloride of sudiuiu .. 
Insoluble siliceous matter . . 
* Containing nitrogen 
Equal to amuiouia 
t Equal to tribasic phos-'l 
l)bate of liiuc .. ../ 
X Equal to carbonate of lime 
8-76 
G-49 
34-40 
37 -GO 
•54 
2-83 
5-76 
(1-83) 
•45 
1-C8 
1-49 
7-45 
7^34 
30-72 
3G-81 
-38 
1 S-5g| 
(2-47) 
-'75 
6-76 
1-23 
6-61 
6-28 
32-52 
36-42 
-G4 
3- 42 
5-62 
1- 37 
4- 89 
2- 23 
7-09 
7-44 
33-97 
37-01 
-69 
) ..83j 
2-87 
-34 
2-76 
2-53 
2-47 
6-38 
6-79 
35-25 
35-50 
ill-69 
4.39 
7-45. 
7^34: 
30^72 
36^81 
•38 
1 8^56 
(2^47> 
•75 
6^76 
1-23 
100-00 
100-00 
100-00 
100-00 
100-00 100-oa 
1 
-98 
1-19 
75-09 
1-02 
•89 
1^08 
G4^06 
1^70 
-79 
-96 
70-99 
311 
-93 
1-12 
74.15 
6-25 
-72 
•87 
76-95 
•89 
1^08 
67^06 
1^70 
A glance at the preceding analyses shows, amongst other 
particulars — 
1. The samples of Mejillones guano analysed by me contained 
from 6 to 7 per cent, of organic matter. 
2. The organic matter in these guanos, on combustion with 
soda-lime, yielded an amount of nitrogen which is equivalent 
to about 1 per cent, of ammonia. The existence of nitrogenous, 
organic matter clearly proves the comparatively recent character 
of the Mejillones guano deposits. 
3. All the samples were rich in phosphoric acid. The per- 
centage of phosphoric acid expressed as tribasic phosphate of 
lime (bone-phosphate) ranged from 64 to 77 per cent, in round 
numbers. 
4. All contained but a small proportion of carbonate of lime> 
