CONVENTION OF OFFICIAL AGRICULTUKAL CHEMISTS. 109 



coagulable by heat in neutral solution, caseoses (albunioses), amido- 

 acid compounds, peptones, annnonia, and unsaturated paracasein lac- 

 tate. Methods for the determination of nitrogen in milk in the form 

 of casein, albumin and syntonin, caseoses, amido-aeid compounds, 

 peptones, and ammonia were also given. The referee recommended 

 that the methods presented be adopted as provisional methods under 

 the head of dairy products. 



The association, upon motion of Dr. Van Slyke, authorized the 

 appointment of a conmiittee of three as referees to take charge of the 

 work relating to the separation of nitrogen compounds, the work to 

 be distributed among the members of the conmiittee on the following 

 lines: (1) ^Nleat proteids, (2) vegetable proteids, (3) milk and cheese 

 proteids. 



POTASH. 



The report on this subject was read by the referee, H. B. McDon- 

 nell. Results from 14 analysts on the determination of potash by the 

 Lindo-Gladding and milk-of-lime methods and a modification of the 

 alternate method used by the referee were reported as well as deter- 

 minations of moisture in potash salts. The different methods gave 

 (juite concordant results and showed a loss of potash in mixed fer- 

 tilizers of about 7 per cent of the total amount present. The referee 

 recommended further work for the purpose of getting a method of 

 dissolving all the potash in mixed fertilizers, and also further experi- 

 ments with methods for the determination of moisture in potash salts, 

 which suggestions were adopted. 



A ])aper by C. L. Hare on the determination of potash in fertilizers 

 b}' substituting milk of lime for ammonia and ammonium oxalate as 

 the precipitant was read ])y B. B.Ross. ''The modification possesses 

 several advantages over the Lindo-Gladding method. First, the pre- 

 cipitation of lime is immediate, and there is no delay at this point. 

 Second, evaporation to expel ammonia salts is eliminated. Third, 

 proba])le loss of potash during the evaporation is obviated. Fourth, 

 washing the potassium platinic chlorid with alcohol and ammonium 

 chlorid ' wash ' may be performed thoroughly with greater ease and 

 rapidity, while no larger amount of platinum is re<|uired than by the 

 Lindo-Gladding method."" The modification is not applicable to fer- 

 tilizers containing ammonium salts. The milk of lime and the Lindo- 

 Gladding methods were compared on 60 samples of fertilizers contain- 

 ing no organic materials, the results showing a maximum difference of 

 0.27 per cent in .58 determinations and less than 0.20 per cent in 46 

 determinations. The two methods were also compared on fertilizers 

 contaming organic matter. In 53 determinations in which the samples 

 for both methods were ignited with sulphuric acid the extreme differ- 

 ence was 0.48 per cent, 41 samples showing a variation less than 0.20 

 8994— No. 2—02 2 



