Oil the Analysis of Guano. 
305 
guano; and it is in fact widely different from all the fresh samples which 
have passed through my hands. It is described as " Knobby, being 
mixed with light laminated crystalline portions, in white grains, from 
the size of a pea to that of a pigeon's egg." Having some lumpy con- 
cretions of a similar asjiect in my possession, I submitted them to 
chemical examination. 
G. 1000 grains being digested in boiling water and strained, afforded a 
nearly colourless solution. This was concentrated till crystals of oxalate 
of ammonia appeared. It was then acidulated with hydrochloric acid, 
to protect the phosphoric acid from precipitation, and next treated care- 
fully .with solution of nitrate of lime equivalent to the oxalic acid 
present. The oxalate of lime thus obtained being converted into car- 
bonate weighed 80 '5 grains, corresponding to 100 of oxalate of am- 
monia, or 10 per cent, of the guano. 
The liquor filtered from the oxalate was precipitated by nitrate of 
barytes, and afforded 112 grains of sulphate of barytes=:38 sulphuric 
acid; and the last filtrate being mixed with a given measure of ferric 
acetate, and the mixture supersaturated with ammonia, yielded sub- 
phosphate of iron, equivalent to 5 per cent, of phosphoric acid. I 
digested with heat other 500 grains of the same guano in a weak solution 
of borax, filtered, acidulated the liquid, but obtained merely a trace of 
uric acid. It is clear therefore that the oxalate of ammonia had been 
formed in this guano at the expense of the uric acid, and that its con- 
creted state, and the crystalline nodules disseminated through it, were 
the result of transformation by moisture in a hot climate, which had 
agglomerated it to a density of 1 ' T5 ; whereas clean fresh guano friable 
and dry like the above, is seldom denser than 1*65. This guano con- 
tained only 3*23 of ammonia; 65 of insoluble matter, 53 of earthy 
phosphates, 5 silica, 3 alkaline salts (fixed), and 1 organic matter. 
Oxalate of ammonia, being readily washed away, is a bad substitute 
for the urate of ammonia, urea, and azotized animal matter, which it 
has replaced. Oellacher could find no urea in the guano which he 
analyzed ; another proof of its disintegration. 
Bartels' analysis of a brown-red guano is as follows : — 
1. 
Muriate of ammonia .... 
6 
•500 
2. 
Oxalate of ammonia .... 
13' 
•351 
3. 
Urate of ammonia .... 
3 
•244 
4. 
Phosphate of ammonia .... 
6' 
•450 
5. 
Substances resembling wax and resin 
0 
•600 
6. 
Sulphate of potash .... 
4' 
'277 
7. 
Sulphate of soda ..... 
1 
•119 
8. 
Phosphate of soda 
5 
•291 
9. 
Phosphate of ammonia and magnesia . 
4' 
•196 
10. 
Common salt ..... 
0 
100 
11. 
Oxalate of lime ..... 
16' 
360 
12. 
Alumina ...... 
0' 
•104 
13. 
Sand insoluble in nitric acid, and iron 
5' 
•800 
14. 
Loss (water and volatile ammonia and un- 
defined organic matter) 
22- 
718 
VOL. V. 
100-000 
X 
