BULLETIN OF THE 



MPMIIOFAflOJIM 



No. 97 



Contribution from the Bureau of Soils, Milton Whitney, Chief. 

 June 12, 1914. 



(PROFESSIONAL PAPER.) 



IDENTIFICATION OF COMMERCIAL 



MATERIALS. 



FERTILIZER 



By William H. Fry, Scientist in Soil Laboratory Investigations. 



INTRODUCTION. 



In working with commercial fertilizers it is often desirable to know 

 not only the percentages of the various ingredients as given by chemi- 

 cal analysis but also the compounds in. which these occur in the fer- 

 tilizer, i. e., the carriers of these ingredients. The calculation of the 

 rational composition from the ultimate analysis in the case of salts 

 gives results which are open to doubt and requires a much more com- 

 plete analysis than is usually made. In the case of organic materials 

 such a calculation is practically impossible. It, therefore, becomes 

 necessary to identify a great number of the substances occurring in 

 commercial fertilizers by means which give the compounds as dis- 

 tinguished from the chemical ingredients of these compounds. 



The following substances were chosen for examination : 



Potassium chloride. 



Potassium sulphate. 



Ammonium sulphate. 



Kainite. 



Sodium nitrate. 



Superphosphate. 



Calcium nitrate. 



Lime. 



Apatite. 



Phosphate rock. 



Gypsum. 



Limestone. 



Calcium cyanamid. 



Basic slag. 



Ground rocks and minerals. 

 Cottonseed meal. 

 Raw bone meal. 

 Steamed hone meal. 

 Peat, humus, muck, etc. 

 Dried blood. 

 Slaughterhouse tankage. 

 Garbage tankage. 

 Fish scrap. 



Dissolved bone black. 

 Shells. 



Note. — This bulletin gives methods for identifying the carriers of the various fertilizing ingredients, 

 and is intended to serve as a laboratory guide to those studying this phase of the fertilizer question. 

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