CONTENTS 



PART FIRST 



Definitions, Sampling and Preliminary Treatment, pp. 1-22. Waste 

 matters as fertilizing materials ; Waste materials as fertilizers ; Valuation 

 of fertilizers ; Trade valuations of fertilizers ; General principles of sampl- 

 ing; Object of sampling; Sampling a gas; Sampling a liquid; Sampling a 

 solid ; Subdivision of sample ; Sampling of fertilizers ; Mixed fertilizers ; 

 Barn-yard manures ; Sampling of materials used for road building ; 

 Methods of sampling; Preparation of sample in laboratory. 



Drying Samples of Fertilisers, pp. 22-25. Difficulties of desiccation; 

 Official methods ; General observations ; Moisture in monocalcium phos- 

 phates. 



Mineral Phosphates, pp. 25-40. Natural occurrence of phosphates ; 

 Florida phosphates ; Tennessee phosphates ; Occurrence of black phos- 

 phate ; Occurrence of white phosphate ; Origin of the white phosphates ; 

 Utilization of white phosphate. 



Statistics and Composition, pp. 40-49. Tennessee phosphates ; Blue phos- 

 phate ; South Carolina phosphates ; Magnitude of product ; Production in 

 the United States ; Marketed production ; World's production ; Quantity 

 of phosphoric acid removed by crops ; General conclusions. 



Analytical Processes, pp. 49-121. Constituents to be determined; Dis- 

 solving phosphates ; Incineration ; Loss of phosphoric acid on incineration ; 

 Official methods ; General methods for estimating phosphoric acid ; Prepa- 

 ration of reagents ; Formula for the reactions ; Official method for total 

 phosphoric acid; Influence of insoluble silica; Use of tartaric acid; Water- 

 soluble phosphoric acid ; Citrate-insoluble phosphoric acid ; Examination of 

 the pyrophosphate; Determination of available phosphoric acid; Interna- 

 tional methods; Molybdic acid method; French official method; Swedish 

 official method ; Dutch official method ; Sources of error in the molybdate 

 method; Influence of aluminum, magnesium and calcium; Color of the 

 magnesium pyrophosphate ; The citrate method ; German experiment 

 station method ; The Swedish citrate method ; Methods adopted by the 

 Brussels Congress ; Dutch citrate method ; Method of Lasne ; Compara- 

 tive accuracy of the citrate and molybdate methods ; The citrate precipi- 

 tate purity ; The citrate method applied to samples with small content 

 of phosphoric acid ; Direct precipitation of the citrate-soluble phosphoric 

 acid ; Determination of phosphoric acid with preliminary precipitation as 



