On the Analysis of Guano. 
299 
in the double magnesian phosphate. In the urate and double phosphate 
are 1 '35 of ammonia, which, with the 2 '55, make 3" 9 parts; the other 
0"3 parts may be traced to the urea. 
As these results differ very considerably in many respects from those 
of the analyses made by respectable German chemists, I was careful to 
verify them by manifold variations of the process. 
1. Tlie soluble matter, with acid reaction, of 100 parts of the lumps 
of the Bolivian guano, was examined by per-acetate of iron and am- 
monia, for phosphoric acid, and afforded 4 parts of it, which is more 
than had been found in the neutral pulverulent guano. After the 
phosphoric acid was separated by that method, chloride of calcium gave 
no cloud with the filtered liquor, proving that no oxalic acid was pre- 
sent in these nodules. The waslied insoluble matter, when gently 
ignited, and treated with dilute nitric acid, afibrded no effervescence 
whatever, and therefore showed that no oxalate of lime had been present, 
for it would have become a carbonate. 
It is necessary lo determine from time to time the quantity of ferric 
oxide in the acetate or nitrate, as it is liable to be deposited from the 
solution, when this is kept for some time. If this point be not at- 
tended to, serious errors would be committed in the estimation of the 
phosphoric acid. 
2. The quantity of uric acid was verified by several repetitions, and 
found to be 14 per cent. 
3. The undefined organic matter, when deprived of the uric acid by 
prolonged digestion with weak borax water, being subjected to ignition 
along with hydrate of soda, yielded the quantity of ammonia requisite to 
constitute the whole sum, that producible from the uric acid alone being 
taken into account. 
4. The little lumps of the guano afforded, by distillation along with 
quicklime, 5 '27 per cent, of ready formed ammonia, probably from the 
uric acid being partially decomposed by the moisture which had con- 
creted them. It is a curious tact, that the solution of borax, from being 
of an alkaline, becomes of an acid reaction, after digestion with the 
Bolivian guano. 
5. For distinguishing and separating the soda salts from those of 
potash, I tried the antimoniate of potash, according to Wackenroder's 
prescription, but I found reason to prefer very much the crystallised 
soda — chloride of platinum, for that purpose. 
6. From another specimen of the Bolivian guano, I extracted 3'5 
per ceat. of the ammonia-phosphate of magnesia. 
B. A sample of guano from the Chincha Islands, of nearly the same 
light colour as the preceding, and the same dryness, being an early im- 
portation of 250 tons in the present year, was subjected by me to a 
careful analysis. 
1. The solution in water of this guano had an alkaline reaction from 
carbonate of ammonia, which, being neutralised by test acid, indicated 
0*34 per cent, of ammonia, equivalent to about 1 of the smelling sesqui- 
carbonate. 
2. Of this guano, 41 per cent, were soluble in water, and 53 per cent, 
remained, after drying at a heat of 212° F. Of the above 47 parts, 
8 ' 5 were moisture in the guano. 
