203 



The plan of 1891 includes studies of the roots of leguminous plants, 

 culture experiments Avith six varieties of oats on twelve different farms, 

 and a comparison of the agricultural value of the phosphoric acid in 

 bone meal and in Thomas slag meal, for potatoes and oats. 



(!') l>((irij Lahoratory of the AgrkuHuml Institute of the Univer,sity; 

 Prof. ]]'. Flcisckmann, director. — At present the laboratory is mainly 

 used for purposes of instructiou. No report of iuvestigaticms is given. 



Marhurfi; Prof. Th. Dietrich, director. — The activity of the station ha?* 

 been confined very largely to the making of analyses, examinations 

 of various materials, and tests of seeds, 3,910 samples of all kinds 

 having been examined. 



]\[iinster; Prof J. KiJnUj, director. — The work at this station has been 

 largely analytical, the number of samples of feeding stuffs, fertilizers, 

 soils, seeds, etc., examined during the year being 3,748. The Alsatian 

 and French iron ores aie said to contain snmllcr amounts of phosphoric 

 acid than the German, so that Thomas slag derived from these ores con- 

 tains a lower percentage of phosphoric acid than the iionnal, that is, 17 

 ]ier cent. These poorer grades were found in the market to a consid- 

 erable extent at times. Phosphate meal with as low as 11 to 12 per cent 

 of phosphoric acid is mentioned. The adulteration of Thomas slag was 

 found to be very common, the adulterants noticed being Eedonda 

 phosphate meal, and a precipitate from phosphates of iron and alumina; 

 other mineral i)hosphates, as Atlas phosphate, have also been used for 

 adulteration. Eedonda phosphate is said to consist largely of phosphate 

 of alumina, and Atlas phosphate of phosi>liate of iron, the phosphoric 

 acid being in both cases almost entirely insoluble in acetic acid, while 

 about half the phosphoric acid of a genuine Thomas slag should be 

 soluble in acetic acid. Rut it was not found possible to detect adulter- 

 ation with these phosphates by the amount of phosphates of iron and 

 alumina X)resent, since Thomas slag contains normally more or less of 

 these compounds. 



PoppeUdorf; Prof. U. Ereusler, director. — The work of 1890 included 

 the following subjects: (1) Investigations of certain nitrogen-free 

 constituents of vegetable coloring matters; (2) the respiration and 

 assimilation of plants; (3) the j)rocesses of decomposition accompany- 

 ing fermentation, putrefaction, and decay, with special reference to 

 nitrification and the gains or losses of nitrogen; (4) the value of grains 

 grown under varying conditions, especially of wheat with reference to 

 baking qualities; (5) the value of brusliwood [Holzreisig) for feeding- 

 purposes; and (G) meteorological observations, 



Posen; Br. G. Loges, chemical director. — This station reports having 

 made examinations of 1,G24 samples of various materials, including 

 about 800 of fertilizers, nearly 000 of feeding stulfs, 100 of seeds, etc. 

 Numerous cases were noticed of adulteration of Thomas slag meal with 

 Eedonda phosphate, and less seldom with phosphorite. Of the 590 

 samples of feeding stuffs examined, 497 were tested as to iiuiity and 



