1902-3.] The Chemistry of Wheat Gluten. 503 



A large amount of gliadin was now prepared by extracting gluten 

 with 70 per cent, alcohol, filtering, concentrating to a small quantity, 

 precipitating with 95 per cent, alcohol, extracting in the Soxhlet 

 apparatus for sixteen hours with absolute alcohol to remove fat and 

 lecithin, and finally drying for three hours at i io°C. 



Analyses gave the following : — 



GLIADIN. 



C 52- 39 Av. 6. 



H 6.84 Av. 6. 



N 17.46 Av. 2. 



S 1. 12 Av. 2. 



O 21. Sq 



P o. 267 Av. 2. 



Fe 0.034 Av. 2. 



The iron was determined gravimetrically since the amount was so 

 small that only a few drops of 1/40 normal solution of potassium per- 

 manganate were necessary by the volumetric method, and the exact end 

 point was consequently difficult to determine. Taking all necessary 

 precautions to eliminate aluminium and calcium, results were obtained 

 by extracting the iron from the ash, which were concordant with those 

 obtained from the filtrate after precipitating the phosphorus as 

 ammonium phospho-molybdate. The weight of ferric oxide seldom ex- 

 ceeded 0.6 milligram. The analyses in other respects agree very well 

 with those of Osborne and Voorhees, except that the carbon and 

 nitrogen contents are slightly lower, and that they obtained no 

 phosphorus. 



A large quantity of gliadin was prepared and digested at 38''C. with 

 artificial gastric juice in litre flasks. Digestion was continued for three 

 weeks, the flasks being frequently shaken, and the clear supernatant 

 fluid renewed several times. The considerable residue was collected on 

 filters, washed free from proteoses and peptones with water, then with 

 70-95 per cent, alcohol which removed some fat. The residue dissolved 

 in 0.2 per cent, sodium hydrate solution, was filtered, and the solution 

 precipitated with excess of dilute hydrochloric acid, the process of solu- 

 tion and precipitation being repeated several times ; the precipitate was 

 thfen collected on " hardened " filters and washed with distilled water 

 till free from chlorides. Extracted with absolute alcohol in the Soxhlet 

 apparatus for sixteen hours, dried at no X., and analyzed, the residue 

 yielded the following results : — • 



