1920] SCHEkTZ— SUDAN GRASS SEED 73 



and consequently the extraction was prolonged for another 12 hours 

 or more. The extraction was conducted at the boiling point of the 

 solvent, using the Koch extractor. 



Ft and F 2 . — All of the alcohol, water, and ether extracts were 

 added to each other, and then the whole was rapidly evaporated 



down 



It was then transferred 



to a vacuum desiccator and dried until nearly a constant weight was 

 obtained. This took from one to three weeks. The air in the 

 desiccator was changed once or twice daily. This gave the weight 

 of F x and F 2 . The dry mixture of F x and F 2 was now extracted with 

 anhydrous ether; this extract was F x , and the residue was F 2 . The 

 evaporating dish plus F 2 was dried and again weighed, giving the 

 weight of F x by difference, and also the weight of F 2 . The ether 

 extract F x was divided into two portions, one portion being used for 

 the determination of sulphur and phosphorus, and the other for 

 nitrogen. The residue was dissolved or suspended in 70 per cent 

 alcohol and made up to a volume of 1000 cc. Of this, 50 cc. was 

 used to determine the total sugars; 100 cc. for ash and for solids; 

 200 cc. for nitrogen; 100 cc. for free reducing sugars; and 550 cc. 

 for sulphur and phosphorus. 



F 3 . — F 3 was then dried at 105 C. in an electric oven to nearly a 

 constant weight. The whole was then pulverized thoroughly 

 and fractions of it, ranging from 0.5 to 2.0 gm., were used for the 

 determination of sulphur, phosphorus, nitrogen, total carbohy- 

 drates, ash, and crude fiber. 



Moisture was obtained by difference. Nitrogen w r as estimated 

 by means of the Kjeldahl method as modified by Gunning and 

 Arnold. The nitrogen was multiplied by 6.25 to give the protein. 

 Sulphur was estimated by the fusion (Na 2 C0 3 +KN0 3 ) method, 

 precipitated, and weighed as BaS0 4 . The filtrate from the sulphur 

 determination was used and the phosphorus was determined from 

 it by the Neumann-Pemberton method, by titration. Organic 

 matter was determined by taking the weights of the ash F a and F 3 

 from the dry weights of F 2 and F 3 respectively. Sugars were 

 estimated by the Bertrand volumetric method in connection with 

 the Munson and Walker tables. Total reducing sugars were 

 found by adding 10 cc. of HC1 (sp. gr. 1.125) for every 100 cc. 



