ECONOMICAL GEOLOGY. 



Ill 



Prof. Way, an eminent agricultural chemist, in England, 

 and some in our own country, have computed the value 

 of guano from the amount of ammonia and phosphates, or 

 phosphoric acid it contains; considering the other ingre- 

 dients as of little comparative value. The phosphates are 

 allowed, by them, to be worth about one eighth, and phos- 

 phoric acid one fourth as much as ammonia. Taking 

 these valuations as the basis of calculation, the ammonia, 

 and one eighth of the phosphates of the Peruvian guano, 

 amount to 20.42, or are equivalent to that percentage of 

 ammonia ; the ammonia, and one fourth of the phosphoric 

 acid in the cancerine, are in the same way equivalent to 

 11.43 per cent, of ammonia; and the values of the two will 

 be as the numbers 20.42 and 11.43; or when guano is 

 worth $60 per ton, as it is now, the. cancerine is worth 

 133.58. 



An analysis of guano was made in my Laboratory for 

 the purpose of comparing it with the cancerine. The 

 sample was obtained by taking small quantities of guano 

 from each of a large number of bags in the storehouse of a 

 merchant, and mixing them carefully. It was said to be 

 an average quality of guano. 



