126 EXPERIMENT STATION RECORD. 



solul)lo ])liosi)horic acid in the presence of gypsum; (2) dicalcium and 

 tricalciniii pliospliates; (3) preparations containing- ffyi)suin and mono, 

 di, and tri pbosi)hates of lime, as well as of iron and alumina; (4) the 

 iiitluenceof y:ypsum on jihospliate of ammonia, and (5) the influence'of 

 carbonate of annnonia on free and water-soluble phosphoric acid as free 

 as possible of gypsum. 



It is claimed that the results show that under the above conditions 

 the soluble phosphoric acid present w^as largely converted to the 

 citrate soluble or insoluble forms, while a certain i)ortion still remained 

 in the form of soluble phosphate of ammonia. The greater part of the 

 ammonia was combined with sulphuric acid. Gypsum at ordinary 

 temperatures in the i)resence of water converts monophosphate of 

 annnonia into monophosphate of lime, diphosphate of ammonia into 

 diphosphate of lime, and triphosphate of ammonia into triphosphate 

 of lime, at the same time forming sulphate of ammonia. Where pre- 

 cautions were taken to have the solutions as free as possible from gypsum 

 much less soluble phosphoric acid was transformed to the diflicultly 

 soluble forms than where it was present in large amounts. The appli- 

 cation of these methods and results in studying the reversion of soluble 

 phosphoric acid by the use of various preservatives in the manure heap 

 is briefly pointed out. 



On the action of potash salts in the soil, M. Hollrung (Fiih- 

 Ihiff.s landw. Ztg., 43 [189 J), No. lo, pp. 415-417). — In the report for 1803 

 of the Experiment Station for Nematode Control at Halle the author 

 reports the results of pot experiments to determine the action of the 

 various constituents of potash salts in the soil as follows: 



(1) The commonly applied Stassfurt jjotash salts, such as kainit, 

 cartiallit, kieserit, artificial carnallit, as well as calcined manure salts, 

 possess a comparatively high capacity for absorbing the moisture of the 

 air and returning it to the soil. This property is possessed in a less 

 degree by sulphate of i)otash, double sulphate of x>otash and magnesia, 

 carbonate of potash and magnesium, and chlorid of sodium. Kock 

 salt, sylvinit, and calcined kieserit occupy a middle position in this 

 respect. 



(2) The most active of the associated salts are chlorid of magnesium, 

 sulphate of magnesium, and chlorid of sodium. 



(3) It is doubtful whether the mitigation of "beet sickness" by the 

 application of potash salts in dry seasons is to be exclusively attributed 

 to the hygroscopic properties of the associated salts. 



(4) In dry weather certain potash salts, such as kainit and carnallit, 

 and rock salt, improve the texture and fineness of the soil. Suli^hate of 

 potash is entirely inactive in this respect. 



(5) During dry periods soils fertilized with kainit, carnallit, rock salt, 

 chlorid of sodium, and also with kieserit, artificial carnallit, and (;al- 

 cined manure salts eagerly seize upon atmospheric precipitation and 



