New Yokk Agricultural Experiment Station. 671 



In connection with the data contained in the preceding table, at- 

 tention is called to the following points : 



(1) For each of the three elements the number of samples showing 

 results above the guaranteed statement of analysis is much larger 

 than the number below. 



(2) The largest number below guaranty is in case of nitrogen (166 

 samples), followed by potash (151 samples), while the smallest num- 

 ber (112 samples) below is in case of phosphoric acid. 



(3) Comparatively few samples are below guaranty more than 0.50 

 per ct., 11 in case of nitrogen, 18 in case of phosphoric acid and 38 in 

 case of potash. 



(4) Balancing all the cases of excess and deficiency, we find that 

 there is an average excess of 0.08 per ct. of nitrogen, 0.44 per ct. of 

 available phosphoric acid and 0.34 per ct. of potash; these amounts 

 have a money value of about SI. 08 for one ton of fertilizer. 



In the table following we give the composition, guaranteed and 

 actual, of the fertilizing materials and mixtures other than those al- 

 ready considered : 



DIFFERENCE BETWEEN GUARANTEED AND ACTUAL PERCENTAGES OF 



NITROGEN. 



Table XXI. — Phosphoric Acid, Potash and Calcium in Fertilizing 



Materials. 



