Peruvian Guano. 
207 
cent, of acid only per cent, more of soluble phosphates were 
found in the guano than with 5 per cent, in these two instances. 
It will be seen that the proportion of bi-phosphate of lime is 
almost the same, but that the phosphoric acid in combination 
with alkalies was rather larger when more acid was used. • 
On the whole, the additional 5 per cent, of sulphuric acid were 
not expended to much advantage. 
Composition of Guano dried with 15 per cent, of Oil of Vitriol 
(S 0 3 ,HO). 
"Water driven off on long drying at 212° Fahr. .. 4-77 \S 
Bi-pliosphate of lime 274 *§ g 
Equal to bone-earth render soluble (4-28) "g ig 
Sulphatc of lime 3*74 I s> „ 
Alkaline salts 11-02 jfjg 
Containing phosphoric acid C^'ll) § $ 
Equal to tribasic phosphate of lime (15-40) s - 
*Soluble organic matter and salts of ammonia . . . . 45'41 ' 
■{•Insoluble organic matter 10-37 1 c 
Insoluble phosphates 8-23 
Oxalate of lime ' 12-23 f | | P g 
Insoluble siliceous matter 1'49 J Ph -~ -5 
100-00 
*Containing nitrogen 12'07 
Equal to ammonia 14 - 66 
•)■ Containing nitrogen 2"34 
Equal to ammonia 2'83 
On looking over these results, it will be seen that the solubility 
of the guano is again increased by the additional quantity of 
acid. 
The proportion of bi-phosphate of lime is greater than in the 
sample treated with 10 per cent, of acid, but the amount of soluble 
phosphoric acid combined with the alkalies is about the same in 
both cases. 
Corresponding with the proportion of soluble phosphoric acid 
in the alkalies, the amount of oxalate of lime in this experiment 
remained about the same as in the preceding one. 
Lastly, it will be seen that the nitrogenous matter is made 
more soluble by the larger amount of sulphuric acid. 
It will be noticed that the solubility of the guano is still further 
increased, so that only 26£- per cent, remained insoluble in water. 
The additional quantity of sulphuric acid acted upon the in- 
soluble phosphates ; about 8 per cent, were rendered soluble, and 
only 3 per cent, were left in an insoluble state. 
It may be inferred from this experiment that 25 per cent, of 
oil of vitriol, or one-fourth the weight of the guano, would have 
rendered the whole of the phosphates, and nearly the whole of the 
nitrogenous matter, perfectly soluble in water. 
