Tliirteen Samples of Peruvian Guano. 545 



Percentage 

 of Nitric Acid in. 



No. 2 2 



01 

 61 

 04 

 90 

 20 

 40 

 50 

 29 

 87 

 46 

 35 

 25 

 10 



The occurrence of nitric acid in these deposits is no less 

 interesting from a practical than from a theoretical point of view, 

 for it throws some light on the formation of the large nitrate of 

 soda deposits in the province of Parapaean and other localities in 

 South Peru. 



Nitrate of soda probably owes its origin to the nitrogenous 

 organic matter of guano deposits, which in the course of time 

 have been subjected to the action of sea-water and the oxidizing 

 influence of the atmosphere. The search for guano deposits may 

 probably lead to the discovery of extensive nitre beds in the' 

 southern parts of Peru. 



All the samples, with the exception of one, which is evidently 

 a surface deposit, mixed with much sand, are unquestionably 

 valuable guanos which will command a ready sale in England, 

 especially as they are dry and in a fine powdery condition ; but, 

 as they vary in composition, it will, in my opinion, be found 

 necessary to have each cargo carefully sampled, and to fix the 

 price of the cargo according to the intrinsic value of the guano 

 as ascertained by analysis. 



Augustus Voelckee. 



Lahoratonj, 11, Salisbury-square, Fleet-street, E.G., 

 June 1874. 



[This Report was presented to the Council at the July Meet- 

 ing, and was ordered to be forwarded to the Secretary of State 

 for Foreign Affairs, together with a recommendation of the Coun- 

 cil, which is embodied in the following communication from 

 Earl Cathcart (acting for the President of the Society in his 

 absence) to the Earl of Derby, Secretary of State for Foreign 

 Affairs. 



" My Lord, — The Council of the Eoyal Agricultural Society have the 

 honour to submit to Her Majesty's Secretary of State for Foreign Affairs the 

 VOL. X.— S. S. 2 N 



