Composition and Value of Guano. 225 



potasli, as we find it in the sulphate and muriate^ at 2\d. per lb. ; 

 what will be the value of a ton weight, of an average specimen of 

 Peruvian guano ? The calculation is not difficult : — 

 The ammonia, at 17*41 percent., amounts to 388 lbs,, which -£• «• d. 



at Qd. a lb. is worth 9 14 



The phosphate of lime, at 24-12 percent., amounts to 540 lbs., 



which at ^d. is worth . . . . . . 1 13 9 



The potash, at 3^ per cent., amounts to 78^ lbs., which at 2J</. 



per lb. is worth . . 14 8 



Which together give . 12 2 5 



as the value of all the ingredients of a ton of good Peruvian guano. 

 I think it highly important that the above calculations should 

 not be misunderstood. There may be many persons who would 

 buy Peruvian guano solely for its ammonia ; although not unwilling 

 to enrich their soils with the phosphate of lime which accompanies 

 it, they would object to purchase the latter at the price set against 

 it in the table. There is indeed no absolute proof of the advan- 

 tage of always applying these two manures in the proportion in 

 which they exist in guano : take the instance of a farmer who is 

 in the habit of manuring liberally with bones or superphosphate 

 of lime for his root crop ; — it is quite conceivable (although the 

 case is only put here for argument sake) that in any subsequent 

 application of guano he would be using this substance only as a 

 source of ammonia. In this case he could only afford to pay for it 

 on its ammoniacal merits. Even in such a case Peruvian guano 

 will compete with advantage with sulphate of ammonia at its 

 present price ; for with guano at 1 0/. a ton the purchaser will 

 iDuy ammonia at the same price as in the sulphate, and will get 

 the phosphate of lime and the potash for the extra 65. 



The preceding observations apply even more strongly to potash, 

 for which some readers will be inclined to allow no money value 

 whatever. It is impossible for me to meet the different views 

 which may be entertained on these points. It is sufficient that 

 those who disallow any items in the above calculation can readily 

 make for themselves any alteration they may think fit. 



With its present composition Peruvian guano would seem to 

 bear a fair market price. Whether a reduction in price might 

 not remunerate the importers by a greatly increased sale it is 

 impossible, of course, to say ; but there can be no doubt that, if 

 it could be effected, such a measure would confer an inestimable 

 boon on the agricultural interest of this country. 



With the view of showing the farmer how great a loser he is 

 by the purchase of an inferior or adulterated guano, I will here 

 place in contrast with the average value of good guano_, an esti- 

 mate of that which is to be ascribed to an adulterated specimen. 

 No. 23 in the 4th Table will furnish such an example : — 



VOL. X. Q 



