AGRONOMY 35 



into nitrates and nitrites, was first shown by Miintz 

 and Schloesing to be due to the action of bacteria in 

 the soil, but the isolation of the specific nitrifying 

 microbes was due to Frankland, Winogradsky, and 

 Warington. Organic matter and ammoniacal salts 

 are, as a rule, first converted into nitrites and then 

 into nitrates. They are ready for root-absorption 

 and subsequent conversion, within the plant, into 

 organic matter. 



Trees, as well as other plants, obtain their 

 supplies of nitrogen from the soil chiefly as 

 nitrogen, nitrates and nitrites ; but in some cases 

 ammoniacal salts and organic matter are absorbed. 

 The author ^ has proved that ammoniacal salts are 

 absorbed by the roots of plants. Concerning the 

 author's experiments on the direct absorption of 

 ammoniacal salts by plants, Prof. Achille Miintz 

 says : " Votre m^thode me semble tout k fait 

 irr^prochable et I'absorption directe des sels 

 ammoniacaux, qui n'avait jamais ^t^ absolument 

 d^montr^e est aujourd'hui appuy^e sur des 

 preuves certaines." 



The author's investigations on the direct absorp- 

 tion of ammoniacal salts by plants have been con- 

 firmed by Kossowitsch, Schloesing and others. 



' Gherrmal News, vol. 64, p. 147. -4 Treatise on Mamires, 

 pp. 399 and 438. 



D 2 



