The third year's crop was mustard, sown in the pots after the 

 oats, nitrogenous manure only being added to eaeh pot, and the 

 following arc the results : 



These experiments may be disconcerting and unpalatable facts 

 to those who feel it difficult to give up long cherished ideas as to 

 the different values of manures. But they are facts, and facts that 

 it would not be advisable to discard, if one wishes to make the best 

 of the soil and manure applied to the crop. They point out that 

 the most profitable manure is that which has the quickest action on 

 the crop and produces the greatest yield, and that it is more 

 economical to manure the crop than the soil. 



GUANOS. 



These manures are varied in their composition and equally as 

 varied in their action upon crops. Many of the so-called guanos 

 would be more properly called mineral phosphates, as they are of 

 little more value as manures than mineral phosphates. No matter 

 what their origin and composition may be, they have passed 

 through a transition of partial decomposition into a state differing 

 but little from a deposit of mineral phosphates. Since the intro- 

 duction of guano into England in 1841, by the Earl of Derby, its 

 use as a manure has passed through many stages. So rapid was the 

 increased consumption of this product, that it rose from about 2,000 

 tons in 1841 till it reached, in 1870, almost 300,000 tons annually, 

 since when it has declined until it probably does not now reach 

 50,000 tons a year. The reasons for this are that the rich 

 Peruvian guano deposits have been worked out and large quantities 

 of inferior guanos have been brought into the market, but the chief 

 reason of all for this decline in the use of guano is the introduction 

 of superphosphates, which are found to be not only cheaper but 

 to give better results than most of the guanos now on the market. 



