EXPERIMENTAL. 



79 



Fraction I was immediately evaporated on the water-bath with hydro- 

 chloric acid, the residue dissolved in alcohol, and the solution saturated with 

 dry hydrochloric acid gas. The solution was concentrated to a small volume 

 at a low temperature under a pressure of 10 mm., the residue taken up in 

 alcohol, its solution cooled to o and saturated with hydrochloric acid gas. 

 On prolonged standing 0.22 gram of glycocoll ester hydrochloric separated, 

 which melted at 144 to 145 . When mixed with pure glycocoll ester 

 hydrochloride, the melting-point was unchanged. 



Chlorine : 0.1058 gram substance gave 0. 1063 gram AgCl = CI 2X 

 Calculated for C 4 H m O,NC1, CI 25.40 p. ct 



Neither fraction II nor the ether distilled from the esters gave evidence of 

 glycocoll. 



This preparation of gliadin did, in fact, contain a very small amount of 

 glycocoll, which is possibly due to a slight contamination with glutenin, in 

 which there has since been found a notable quantity of this amino-acid. 



Fraction II was saponified, and the solution evaporated under highly 

 reduced pressure from a bath at 40 , and the residue extracted with alcohol, 

 in which about 18 grams dissolved. 



Fraction III, by similar treatment, yielded 24 grams of alcohol-soluble 

 substance. The alcoholic solutions were united and evaporated to dryness 

 from a bath at 40 c . The crystalline residue, when dried to constant weight 

 in vacuo, weighed 39.59 grams. From this, by extraction with alcohol, 8.7 

 grams of substance insoluble therein were separated. 1 The total proline 

 thus found was 30. S9 grams, equal to 7.03 per cent. 



1 Emil Fischer employs this method for estimating the proportion of pro-ine in pro- 

 teins, but stated that the result obtained is too high ^Berichte d*er deutschen chemischen 

 Gesellschaft, 19:6, xxxrx, p. 530). 



