viii CONTENTS 



Reading the barometer; Tension of aqueous vapor; Tables for calculat- 

 ing results. 



Methods of Determining Nitrogen. Continued. Soda-Lime Process, pp. 

 338-345. The official method; The French method; The hydrogen meth- 

 od ; Coloration of the product ; General considerations ; The Ruffle method ; 

 Observations; Boyer's modification. 



Method of Determining Nitrogen. Continued. The Moist Combustion 

 Process, pp. 346-372. Method of Kjeldahl; Theory of the reaction; Prepar- 

 ation of reagents ; Modification of the process ; Method of Wilfarth ; Dutch 

 method; German method; The Official method not applicable in the 

 presence of nitrates; Apparatus employed; The Gunning modification; 

 Reactions of the Gunning process. 



Method of Determining Nitrogen. Continued. Changes in Kjeldahl 

 Method to Include Nitric Acid, pp. 373-382. Modifications of Asboth ; Var- 

 iation of Jodlbauer ; The Dutch method ; The Halle method ; The salicylic 

 acid method ; Use of zinc sulfid and sodium thiosulfate ; Theory of the pro- 

 cess; The official method; Gunning method for nitric acid; The official 

 Gunning method. 



Determination of Nitrogen in Definite Forms of Combination, pp. 

 382-390. Introductory considerations ; Nitrogen as ammonia ; Method 

 of Boussingault ; Nitrogen as thiocyanates ; Separation of proteid from 

 amid nitrogen ; Separation of nitric and ammoniacal nitrogen ; French 

 method; German method; Perchloric acid in ChUe saltpeter. 



The Nitric Acid Process, pp. 391-424. Occurrence of oxidized nitro- 

 gen; Method of Schloesing; Schloesing's modified method; French agri- 

 cultural method ; Method of French sugar chemists ; Method of Schloes- 

 ing and Wagner ; Modification of Warington ; Preparation of the samples ; 

 Measurement of the gas; Spiegel's modification; de Koninck's modifi- 

 cation ; Schmidt's process ; Merits of the ferrous chlorid process ; The 

 Crum-Frankland process; Warington's modification; Wo/s method; 

 Lunge's nitrometer; Utility of the method; Method of Gantter; Analysis 

 of Chile saltpeter; Method of difference. 



Estimation of Nitric Acid by Oxidation of a Colored Solution. Indigo 

 Method, pp. 425-432. Method of Marx; Method of Boussingault; 

 Method of Warington; Experimental data; General directions. 



Determination of Nitric Acid by Reduction to Ammonia, pp. 433-440. 

 Classification of methods ; Reduction in alkaline solutions ; Qualitative 

 test* for nitrates ; Sodium-amalgam methods ; Method of the Mockern 

 agricultural station ; The Halle zinc-iron method ; Method of Beck ; 

 Method of Devarda ; Variation of Stoklasa ; Method of Sievert. 



Reduction in an Acid Solution, pp. 441-446. The sodium-amalgam pro 

 cess; Method of Schmitt; Method of Ulsch ; Ulsch method applied to 

 mixed fertilizers ; Kruger's method. 



