FEKMENTATION BACTERIOLOGY. 115 



heat of 80 to 100° C. Nitric and nitrous bacteria grew in the same 

 medium without interference, and inoculating- material was prepared 

 by drying previously sterilized calcareous soil to which both forms of 

 nitrifying organisms had been added. 



Pot experiments are reported in which grasses and cereals grown on 

 sterilized sand, to which sterilized humus, ammonium sulphate, and 

 minerals were added, were much benefited by inoculation with the 

 nitrifying organisms. 



The results obtained indicate that denitritication is hindered and loss 

 of free nitrogen prevented by the presence of an abundance of nitrify- 

 ing organisms. When, however, denitrifying organisms predominate, 

 the action of the nitrifying bacteria is interfered with, especially if 

 the supply of oxygen is limited. 



On the nitrification of organic nitrogen, V. Omelianski {Cenibl. 

 Bait. u. Par., 2. Alt., 5 {1899), No. 13, pp. 4,73-490).— An account is 

 given of various culture experiments, the results of which led to the 

 conclusion that pure cultures of nitrifying bacteria are incapable of 

 nitrifj'ing organic nitrogen. Nitrogen in this form must first be con- 

 verted into ammonia by the action of other nitro-organisms before the 

 nitrifying organisms can utilize it. It is claimed that the opposite 

 conclusions reached by Frankland, Warington, and Stutzer and his 

 associates were based upon inaccurate observations. 



Denitrification and fermentation, K. Wolff {Ilyg. Hundschau, 9 

 {1899), x>P' 1169-1172; ahs. in Ohem. Cenibl., 1900, T,'j>p. 52, 53; Jour. 

 Chem. Soc. [London], 78 {1900), M. 450, II, p. 298).— hx experiments 

 with typhus-like bacilli, including B. coll commune and others, and 2 

 hay bacilli, one apparentlv B.fitzlanus from ginger root and the other 

 from meal, it was found that while all the organisms reduced nitrates 

 to nitrites in 1 per cent dextrose broth containing 0.05 to 0.23 per 

 cent of potassium nitrate, the hay bacilli were much more active in 

 this respect than the others, although only one of the bacilli can be 

 compared with the real denitrifying organisms. The activity of the 

 organisms was not affected by the strength of the sugar solution, but 

 was decidedly influenced by the amount of nitrate present, an excess 

 of the latter checking fermentation without otherwise disturbing the 

 functions of the organisms. Complete disappearance of nitric nitro- 

 gen took place simultaneoush' with fermentation. The author concludes 

 that denitrification is not due to the direct action of the organisms, 

 but that the products of fermentation reduce nitrates to nitrites and 

 eventual!}' convert them into carbonates. 



Recent investigations on the development of aromatic princi- 

 ples by alcoholic fermentation in the presence of certain leaves, 

 G. Jacquemin ( 6'om^.>z!. Rend. Acad. Sci. Paris, 128 {1899), No. 6, 

 2J2>. 369-371). — In a previous number of this publication^ the author 



'Compt. Kend. Acad. Sci. Paris, 125 (1897), No. 2, p. 114. 



