AGRICULTURAL CHEMISTRY — AGROTECHNY. 613 



abs. in Jour. Cliem. Soc. [Lotidon], 100 (1911), Wo. 579, II, pp. 67, 68).— The 

 nutlior points out that iu conducting tliis test the specifications must be strictly 

 adhered to in order to obtain correct results 



Tlie ammonia distilhite is collected in a receiver containing 15 cc. of normal 

 sulphuric acid until 100 cc. is obtained. In checking up the acid 15 cc. is 

 dilated with boiled water to a total bulk of 100 cc. Ten cc. of a 5 per cent 

 potassium iodid solution, 2 cc. of a 2 per cent starch solution (saturated with 

 sodium chlorid), and 4 cc. of a 4 per cent potassium iodate solution are added 

 to the solutions to be titrated. The iodin which is liberated during the process 

 represents the unneutrulized acid and is titrated with decinormal sodium thio- 

 sulphate solution. 



Various substances, e. g., glycin and hippuric acid, were tested with the 

 process. " In most cases Kjeldahl's original process (use of potassium perman- 

 ganate) is recommended; in such cases where there is danger of formation of 

 piperidiu rings the Gunning modification (use of potassium sulphate) is more 

 appropriate." 



Determination of nitrates in water by a sulphosalicylic acid reaction, H. 

 Cauon and D. Kaqukt (Bui. Soc. Chim. France, J,, ser., 7 (1910), No. 23, pp. 

 1025-1027). — The authors point out that with reagents composed of 1 per cent 

 salicylic acid (or salicylate of soda) in sulphuric acid, and ammonia, there is 

 a test for detecting nitrates and nitrate derivatives in water as sensitive as 

 the Grandval and Lajoux phenol-sulphuric acid test. 



A bacteriological method for determining available organic nitrogen, 

 J. M. McCandless and F. C. Atkinson (Jour. Indus, and Engin. Chcm., 3 

 (1911), No. 3, pp. 174, 175).— The method used was as follows: 



One gm. of cottonseed meal and 2 gm. of nitrolene or ammolene (leather 

 fertilizers) contiiining 8.2, 9.4, and 3.42 per cent of total nitrogen, respectively, 

 calculated as ammonia, were Icacheil out with hot water. The cottonseed 

 meal contained 0.73 per cent of water-soluble nitrogen, the nitrolene 5.34, and 

 the ammolene l.Gl per cent, and aliquot parts of the solution were shaken with 

 known amounts of soil. The filtrates from the mixture were placed in an 

 incubator for 210 hours at a temperature of from 38 to 40° C, and under aerobic 

 and anaerobic conditions. 



The anaerobic samples showed no nitrate or nitrite formation. The aerobic 

 tests with ammolene showed a conversion of nearly 100 per cent of the water- 

 soluble nitrogen to ammonia, while with nitrolene only about 63 per cent was 

 converted. Cottonseed meal had a conversion of 30 per cent. 



The soils were furthermore shaken up with a solution containing 1 gm. of 

 potassium phosphate, 2 gm. of sodium chlorid, 0.5 gm. of magnesium sulphate, 

 and 0.05 gm. of calcium chlorid, and 50 cc. of the filtrate, along with the resi- 

 dues remaining on the filter paper, was incubated for 26 days. The results 

 showed a solution of the nitrogenous substances corresponding to 74.9, 70.9, and 

 S2.5 per cent, respectively. 



It is apparent from this work that the bacteria must first convert the insolu- 

 ble proteins into soluble products and then into ammonia. 



The determination of the amid nitrogen in proteins, W. Denis (Jour. Biol. 

 CJiem., 8 (1910), No. 5, pp. 427-435). — The author utilized the principle of the 

 Folin method*' for estimating the ammonia in a mixture with amino acids re- 

 sulting from the acid hydrolysis of proteins, e. g., edestin, casein, gelatin, and 

 wool. 



Substances rich in cystin yield less ammonia by this method than by the 

 magnesia method. The procedure does not seem to interfere to any extent 



"Ztschr. Physiol. Chem., 37 (1902), p. 161; Amer. Jour. Physiol., 8 (1902-3); 

 p. 330. 



