258 



value of |)hosp]ioric acid in different compounds and in different raw 

 phospliates. The results of growing maize in unlimed moor soil, to which 

 was added in separate instances 60, 120, and 240 kg. of phosphoric acid 

 in the form of superphosphate, South Carolina phosphate, Lahn phos- 

 phorite, Norwegian apatite, and Kladno phosphate meal, indicated that 

 the a^id of the moor rendered the crude phosphorite valuable to the 

 plants in a high degree. The results with 240 kg. of phosphoric acid in 

 the form of Lahn pliosphorite and 120 pounds in the form of South Caro- 

 lina phosphate were practically the same. Similar experiments were 

 made \nth barley grown in soil which had received a dressing of lime. 

 These later c.\i)criments showe<l that tlie action of the raw phosplutrito 

 was less favorable in the limed than in the unlimed soil. (2) Experi- 

 ments as to the fixation of free atmosi)h eric nitrogen by papilionaceous 

 plants. The results indicated very strongly that the vetclics are to be 

 classed with those plants capable of assimilating the niti'ogen of the air. 

 The experiments are to be continued, (o) Field experiments with the 

 more important ]iapilionaceous plants, to determine the amount of 

 atmosjilioric nitrogen wliicli the jilaiit accumulates, and which in grcon 

 manuring would be ad(lc<l to tlic soil. Owing to tlie large number (»f 

 analyses necessary the results of these experiments have not yet been 

 ascertained. (4) Field tests of 17cm scpium, V. dinticfortnn, etc. (5) 

 Determination of the amount of nuistard oil yielded by the seeds of 

 cruciferre and by rape cake. Twenty-eight samples of rape cake were 

 tested. In most cases considerable amounts of this oil, up to 0.00 ]>er 

 cent, were found. (0) Investigations of the methods of determining 

 phosphoric acid. The percentage of ])liosphoric acid in nunuTous sam- 

 ples of Thomas jiliosphatemeal rang«'(l IVom 15 to 23; two samples were 

 found to contain IJedonda ]»hos])hate. 



The oxi>erimentson the above subjects will be continued in 1801, and 

 in addition the following work is proposed: (1) Experiments to com- 

 pare the agricultural value of the nitrogen in the forms of saltpeter and 

 ammonium suli>hate; (2) feeding experimcMits with i)igs; (.'?) investiga- 

 tions as to tlie occurrence of gypsum, lime, and marls in the Frovince 

 of Brandenburg, so far as they are of agricultural interest; (4) lield 

 experiments with the old and new varieties of potatoes, and (5) field 

 experiments with maize. 



Danzig; Dr. Giintz, chemical director. — The work of this station has 

 consisted largely of analyses of various materials and examinations of 

 seeds. In a large number of analyses of Thomas slag the highest per- 

 centage of pliosplioric acid found was 21. (50, the lowest 12.21; and ~^'.].6 

 I)er cent of the determinations showed 18 per cent or over of phos- 

 phoric acid. In seven cases liedonda phosphate was found to be mixed 

 with the slag meal. 



Eldena; A. von JToniri/er, director. — This is a control station, and its 

 work during the year was confined to the fertilizer, feeding stuff, and 

 seed controls, and the analysis of materials of interest to agriculture. 



