CONTENTS IX 



Reduction by Electric Current, pp. 447-449. Method of Williams- 

 Warington ; Nitrogen in rain water ; Determination of ammonia ; Prep- 

 aration of the copper-zinc couple; Aluminum-mercury couple. 



lodometric Estimation of Nitric Acid, pp. 450-454. Method of de Kon- 

 inck and Nihoul; McGowan's apparatus; Method of Gooch and Gruener. 



Estimation of Nitric Acid by Colorimetric Comparison, pp. 455-467. 

 Delicacy of the method ; Hooker's method ; Influence of other bodies ; 

 Phenylsulfuric acid method; Method of Gill; Variation of Johnson; 

 Estimation of nitric in presence of nitrous acid ; Piccini process ; Colors 

 produced by diphenylamin. 



Estimation of Nitrous Acid, pp. 467-476. Metaphenylenediamin meth- 

 od; Sulfanilic acid method; Preparation of sulfanilic acid; Method of 

 Mason ; Lunge and Lwoff method ; Use of starch as indicator ; Method 

 of Chabrier; Ferrous salt process. 



Volumetric Process for Nitrous Acid, pp. 477-479. Decomposition 

 with potassium ferrocyanid; General observations. 



Determination of Free and Albuminoid Ammonia, pp. 480-484. Ness- 

 ler process ; Nessler reagent ; Conduct of the analysis ; Ilosvay's modi- 

 fication ; Pure water. 



PART THIRD 



Potash and Fertilising Materials in Fertilizers, pp. 485-526. Intro- 

 duction; Occurrence of Potash; Historical sketch; Deposits at Stassfurt; 

 Deposits in Alsace ; Mining the salts ; Concentrating the salts ; Compo- 

 sition of crude salts ; Kainit ; Carnallit ; Polyhalit ; Kruget ; Sylvin ; 

 Sylvinit ; Kieserit ; Schonit ; Potassium sulfate ; Potassium magnesium 

 carbonate ; Potash in factory residues ; Production of crude salts ; 

 Production of concentrated potash salts; Consumption of potash; 

 Amount of potash used in the different states ; Changes in potash salts ; 

 Theory of deposition ; Geological relations ; van't Hoff's theory ; Dia- 

 grams of crystallization; Potash from feldspar; Cushman's investiga- 

 tions ; Experiments with potash feldspar ; Effects of 'ground feldspar ; 

 Extraction of potash from ground rocks ; General conclusions. 



Organic Sources of Potash, pp. 526-537. Tobacco stems and waste; 

 Cottonseed hulls and meal ; Wood ashes ; Fertilizing value of wood ashes ; 

 Availability of potash in ashes ; Potash in beet molasses ; Potash in win- 

 ery residue ; Insoluble potash in plants ; Forms of potash in fertilizers ; 

 Quantity of potash removed by crops. 



Methods of Analysis of Potash. Preparation of Sample, pp. 538-577. 

 Destruction of organic matter by ignition ; Destruction of organic mat- 

 ter by sulfuric acid ; Qualitative detection ; The platinic-chlorid method ; 

 Official method ; Optional method ; French method ; German method ; 

 Dutch method; Swedish method; Methods of the potash syndicate; 



