196 Peruvian Guano. 
Guano and Salt Experiments. 
Before exposure to Air. ! 
After exposure to Air 
for 1 Month. 
Pure 
Guano. 
50 per Cent, 
of Guano, 
and 
50 per Cent, 
of Common 
Salt. 
Pure 
G uauo. 
50 per Cent, 
of Guano, 
and 
50 per Cent, 
of Common 
Salt. 
Percentage of ammonia driven off| 
with moisture at 212° Fahr. ../ 
Percentage of total amount of nitro- l 
gen of the guano in natural state J 
Equal to ammonia 
Percentage of total amount of nitro- j 
gen calculated for substance, dried 1 
at 212° Fahr ) 
Equal to ammonia 
12-82 
•75 
14-19 
17-24 
16*28 
19-77 
11-20 
•40 
7- 19 
8- 73 
8- 10 
9- 83 
17-65 
•69 
13-42 
16-30 
16-25 
19-73 
19-69 
•31 
6- 54 
7- 94 
8- 14 
9- 88 
The same guano which was used in the preceding experiments 
was kept for a period of more than a year, and then analysed ; it 
then yielded the following results : — 
Moisture .. 16'593 
♦Organic matter ajid ammoniacal salts 52-311 
Phosphates of lime and magnesia (bone-eavtli) .. .. 22-273 
Alkaline salts 7-380 
Insoluble siliceous matter (sand) 1-443 
100-000 
*Containing nitrogen 13-60 
Equal to ammonia _ 16-52 
Percentage of nitrogen in perfectly dried guano .. .. 15 - 90 
Equal to ammonia 19 31 
It will be seen that even in so long a period the guano scarcely 
lost any ammonia; the total amount of nitrogen in the dried 
guano was 10-28 per cent, in the preceding year ; now it is 15-90 
per cent. The difference between the two determinations — -38 
per cent. — is so small that it might fairly be regarded as a 
variation, which may occur in any two separate analyses of the 
same material. 
It follows unmistakably from these experiments that good 
Peruvian guano may be kept for any reasonable length of time in 
a dry place (such as a dry shed), without losing any of its fer- 
tilizing properties, and that there is no need of resorting to che- 
mical substances which are known to possess the property of 
fixing ammonia. The recommendation to cover up or mix it 
immediately after its delivery with some fixer or preserver of 
ammonia, therefore, possesses no practical value. 
