46 



CONTROL SERIES No. 90 



These analyses show the products to be quite similar in composition. Based 

 upon the 1937 analysis we should judge that the actual composition of the 

 product was about as follows: 



Percent 

 1.30 

 2.18 



42.43 

 3 20 

 3.95 



13.41 

 1.54 



.4.64 

 9.94 



17.41 



Total 100.00 



Magnesium carbonate (MgCOs) 

 Calcium carbonate (CaCOj) . 

 Tri-calcium phosphate (Cag (PO4) 2) 

 Aluminum phosphate (AIPO4) 

 Iron phosphate (FeP04) 

 Aluminum oxide (AI2O3) 

 Ferric oxide (Fe203) 

 Moisture .... 

 Organic and volatile matter 

 Insoluble matter, largely clay 



Wright's Plant Aid 



Manufactured and registered by Wright Co., Old Bridge, N. J. 



Percent 



Moisture 14.26 



Organic matter 26.14 



Total phosphoric acid .57 



Total potassium oxide .23 



Water soluble potassium oxide .19 



Total nitrogen 1.44 



Ammoniacal nitrogen .08 



Nitrate nitrogen .07 



Water soluble organic nitrogen .22 



Water insoluble organic nitrogen 1.07 



Activity of insoluble nitrogen by alkaline permanganate method 33.40* 



* Indicates low grade quality: the passing mark by this method is 50. The product is used 

 largely in planting shrubs and flowering plants. 



Menderth 



Manufactured by Menderth, Inc. 



Note: The product contained .08% water soluble potassium oxide and 

 73.82% insoluble matter. The commercial value of the plant food contained 

 in one ton of the product, based upon its content of potash, phosphoric acid, 

 calcium, and magnesium, soluble in strong hydrochloric acid, would be about 

 $1.75. Any potash, phosphoric acid, calcium or magnesium that may be 

 present in the product in a form insoluble in strong hydrochloric acid would 

 have little or no value. 



