144 EXPERIMENT STATION. [Jan. 



The results of the analysis show the ash of the water solution 

 to contain relatively high per cents, of phosphoric acid, potas- 

 sium oxide and magnesium oxide. It is difficult to state in just 

 what way these various elements are combined ; it is probable 

 that they exist in part, at least, in organic combination. From 

 the relatively high per cents, of potassium oxide, magnesium 

 oxide, phosphoric acid and the presence of calcium oxide, it may 

 be inferred that the phosphorus in corn exists in a similar com- 

 bination as that in wheat bran, namely, as phytin, — a soluble 

 phospho-organic compound containing potassium, magnesium 

 and calcium.^ Phytin is soluble in water and insoluble in 

 alcohol and ether. Whether or not this compound, if present, 

 bears any relation to the acidity is yet to be determined. It is 

 probable, however, that in the concentration of the steep water 

 the phytin, if present, would undergo a decomposition, in which 

 case phosphoric acid would undoubtedly be formed. It is doubt- 

 ful if any free phosphoric acid exists in the feed ; it would j^rob- 

 ably be present as a salt. 



(e) Volatile Organic Acids. 

 To determine whether the acidity was due in part to free 

 volatile organic acids, such as lactic, butyric or acetic, etc., dis- 

 tillations of the watery extract were made in vacuo at a maxi- 

 mum temperature of 100° C. under 12 millimeter pressure. 

 In no case was there more than a mere trace of acid detected in 

 the distillate, indicating that the amount of free volatile acids 

 in the feed is small. The residue from the distillation was a 

 resinous material, dark brown in color and had a sharp, biting 

 taste. Distillations in vacuo, in presence of dilute sulphuric 

 acid, also gave negative results, indicating that little or none of 

 the acidity of gluten feeds is due to the salts of the volatile acids. 



(/) Acidity and Indicators. 

 The following table gives the acidity of a number of gluten 

 feeds, using both phenolphthalein and methyl orange as in- 

 dicators : — 



' iBol.ited from wheat bran by Patten and Hart, Bulletin No. 250, New York Experiment 

 Station. 



