820 EXPERIMENT STATION RECORD. 



On the assimilation of the nitrogen of some organic compounds 

 in sterilized media, D. N". Pryanishnikov and A. N. Lyebyedyev 

 (Izv. Moscow SeUTcoTchoz. Inst., 3 (1*97), II, pp. 56-58). — The substances 

 selected for experiment were such as may get into the soil with the 

 manure or are formed in the plants themselves under certain circum- 

 stances, viz, hippuric acid, urea, leuciu, asparagiu, and aspartic acid. 

 The results of the experiments may be summed up as follows : (1) None 

 of the substances tested approached Ca(N0 3 ) 2 as an effective source of 

 nitrogen either in the sterilized or nonsterilized media; (2) sterilization 

 in all cases reduced the availability of the nitrogen of the organic sub- 

 stances, in most cases no grain being obtained in sterilized media. — 



P. FIREMAN. 



On the oxidation of the ammonia produced by soil organisms, E. 

 Demotjssy ( Gompt. Bend. Acad. Sci.Paris, 126(1898), No. 3, pp. 253-256). — 

 The transformation of organic nitrogen into ammonia and finally into 

 nitrites and nitrates by the action of the microorganisms of the soil 

 was studied in culture solutions containing organic nitrogen in the form 

 of monomethylamin, trimethylamin, anilin, pyridin, and quinolin. As a 

 result of the action of the microorganisms the nitrogenous organic com- 

 pounds experimented with were reduced by oxidation to simpler forms, 

 finally yielding ammonia which was con verted intonitrous and nitric acids. 

 The more complex the compounds used the slower was their transforma- 

 tion. In the case of the monomethylamin perceptible amounts of 

 ammonia were formed within 4 hours, but in the case of the trimethy- 

 lamin the formation of ammonia proceeded much more slowly. With 

 anilin barely a trace of ammonia was detected after 18 days. With 

 pyridin 2 months elapsed before any ammonia was detected, while with 

 quinolin barely a trace of ammonia was detected after 4 months. 



The use of vegetation experiments in soil analysis, H. Wil 

 farth (Chem. Ztg.j 21 (1897), No. 80, pp. 819, 820).— Vegetation experi- 

 ments are stated to be very valuable means of determining the needs 

 of soils, but it is claimed that present methods of conducting them are 

 as a rule too costly and time consuming. 



The following is one method suggested: Take samples of the soil to 

 a uniform depth with a cylindrical sampler (8 to 9 cm. in diameter). 

 Place a definite number of these soil samples in a vegetation pot and 

 prepare for the experiment by adding all the elements of plant food 

 except the one whose amount in the soil is to be determined. It is 

 assumed that the plant grown will take up all of this element that is 

 available. The amount thus taken up is shown by analysis of the 

 crop obtained. In this way the amounts assimilable by different crops 

 with different habits of growth may be determined. From the amount 

 found for each pot it is easy to calculate the amount per acre. Such 

 experiments are recommended simply as checks on field experiments. 



To lessen the labor and expense of running pots into and out of 

 glass houses, maintaining a uniform water content, etc., the author 

 suggests that the pots be permanently placed on a platform scale which 



