RECTIFIED PERUVIAN GUANO. 335 



Valuation per ton of two thousand pounds : — 



163 pounds of nitrogen . 

 249.4 pounds of soluble phosphoric acid 

 14.8 pounds of reverted phosphoric acid 

 18.2 pounds of insoluble phosphoric acid 

 32.4 pounds of potassium oxide 



132 60 



31 17 



1.33 



1.09 



2.43 



.$68 62 



The commercial advertisements of the dealers in Feruvian 

 guano contain quite a list of different kinds of the genuine 

 article, varying, for well-known reasons, widely from each 

 other in composition, as may be seen in the price-list of our 

 fertilizers printed in the introduction of this report. They 

 are offered for sale with guaranteed composition, and at 

 acceptable prices at our present rates of valuation. From 

 a mere commercial stand-point, no objection can be raised 

 against the lately adopted system of selling by analysis ; for 

 both parties in the transaction accept their respective re- 

 sponsibilities without any further reserve on either side. 

 Looking, however, at the question from an agricultural 

 stand-point, grave doubts must arise, whether, on the whole, 

 the general verdict of farmers regarding the results they 

 obtained in consequence of using Peruvian guano as fer- 

 tilizers will be as favorable as the dealers may feel entitled 

 to claim, assuming, that, in the majority of cases, the selection 

 made on the part of the farmers has been a judicious one. 

 A simpler mode of classification in the price-lists seems to 

 the writer quite desirable in the interest of a better under- 

 standing on the part of the farmer. The introduction of 

 many names, referring to cargoes, &c. (an information of 

 no interest to the practical farmer), and the frequent 

 changing of names referring to the particular locality in 

 Peru whence the article has been obtained (a statement 

 of interest only to a few parties, comparatively speaking, 

 who may be reached as well by some other simple mode of 

 communication), render the present advertisements rather 

 complicated, without bringing the particular information 

 generally needed in a more conspicuous position. Next to 

 the statements of the absolute amount of nitrogen and of 

 phosphoric acid which a genuine guano contains, we are 

 interested to know the relative proportion of these two lead- 



