CONVENTION OF OFFICIAL AGRICULTURAL CHEMISTS. 323 



to the referee, by increasing 1 the heat gradually after the 30 minutes 

 ligestion. 



A paper by (J. S. Fraps briefly summarized the results of studies on 

 the nitrification test for availability of nitrogenous fertilizers. 



A report on the separation of vegetable proteids, by J. S. Chamber- 

 lain, associate referee, gave the results of a study of wheat proteids, 

 and referred mainly to the difficulty of securing a clear separation of 

 groups by the use of alcohol and salt solution as solvents. The referee 

 recommended that for the present no attempt be made to separate the 

 proteids of wheat into individuals, but that they be given designations 

 according to their solubility or insolubility in alcohol and dilute salt 

 solution. It was also recommended that the total proteids be calculated 

 from the total nitrogen as determined by the Gunning method, using 

 the factor 5.68. 



A report on the separation of meat proteids, b} r W. D. Bigelow, 

 associate referee, was confined to the separation of the nitrogenous 

 bodies in meat extracts, and was mainly a repetition of the work 

 reported on last year. Zinc sulphate, phosphotungstic acid, and 

 tannin salt were employed as precipitants and tested singly and in 

 combinations. The combination precipitating the greatest amount of 

 nitrogen was phosphotungstic acid followed by the tannin salt reagent. 

 The amount of nitrogen precipitated by phosphotungstic acid was 

 greater in each case than that precipitated b}^ any other single reagent. 

 " From the present results, confirming in the main those reported a 

 year ago, it is believed that the most complete precipitation of all 

 proteid bodies, including albumoses and peptones, ma} T be obtained fry 

 means of phosphotungstic acid, followed by tannin salt reagent in the 

 filtrate from the phosphotungstic acid precipitate." Results with zinc 

 sulphate "do not have the conformity that is desired." In his recom- 

 mendations the associate referee outlined methods for ammonia, acidity, 

 phosphorus, chlorin, and xanthin bases (Schittenhelm\s method) for 

 adoption by the association. 



Recommendations. — On recommendation of the referee (C. H. Jones), 

 a modified form of the alkaline permanganate method was made pro- 

 visional, and the referee was instructed to further compare the alkaline 

 and neutral permanganate methods, with a view to determining the 

 amount of material to be used in each test. The modified alkaline per- 

 manganate method is as follows: Using an amount of sample containing 

 0.045 gm. of organic nitrogen, digest for 30 minutes below the boil- 

 ing point in a 600 cc. distilling flask connected with condenser to which 

 the receiver containing standard acid has been attached, with 100 ee. 

 of alkaline permanganate solution (16 gm. KMn0 4 and 150 gm. of 

 NaOH dissolved in water and made to 1 liter). Then boil until 85 cc. 

 of distillate is obtained. If the material shows a tendency to adhere 



