EXPERIMENT STATION BULLETINS. 



399 



periment was of the brown variety. After di'ying at 110° it contained 

 2.58 per cent nitrogen of which 9.18 per cent was in the form of acid 

 amides. This was determined by heating with sulfuric acid, filtering 

 and distilling with magnesium oxide. In the air-dry state it contained 

 11.18 per cent moisture and 16.00 per cent ash. It was obtained from 

 the so-called Chandler marsh just north of the city of East Lansing, 

 Michigan. For the following work it was dried at 110° after being 

 pulverized in a mill so that nearly all of it would pass through an 80 

 mesh sieve. Eight gram samples of tliis dry material were placed in flasks 

 with 200 c.c. of 25 per cent sulfuric acid and the flasks and contents 

 weighed. The flasks were then fitted with reflux condensers, heated in 

 an oil bath at a temperature of 95° for the desired length of time with 

 frequent shaking and again weighed. Water was added when necessary 

 to bring the weight up to the previous one and the solid residue filtered 

 off with suction. 25 or 50 c.c. samples of this solution were taken 

 and diluted with distilled water. A slight excess of magnesium oxide 

 was added and the ammonia distilled off. The solid residue was then 

 separated from the liquid with suction and thoroughly washed after 

 which the combined filtrate and washings were concentrated and made 

 up to a definite volume of which portions equivalent to 10 c.c. of the 

 original solution were taken for analysis. 



For the total soluble nitrogen 10 c.c. samples of the original solution 

 were taken and analyzed by the Kjeldahl method. 



TABLE II. 



Suzuki^ concluded from his work that amino acids as such were 

 present only in small quantities in humus. He claimed that they 

 were combined in a complex protein molecule which was broken down 

 by treatment with laboratory reagents with the formation of the free 

 amino acids or their salts. A sample of the brown peat used in the 

 above work was extracted with distilled water for forty-eight hours at 

 95°. It gave the following figures for amino nitrogen : 

 10 c. c. of the 200 c. c. used gave 0.27 c. c. N at 760 m. m. =1 .64% of the total N 



^Bul. Coll. of Agrlc. Tokyo 7, 513. Abs. in Chem. Cent. 1907, Vol. 2. 1650. 



