H. E. Woodman 241 



hauistive extractions of the sample with 70 per cent, alcohol failed to 

 reveal the presence of even traces of ghadine. 



In view of the second possible objection, the following tests were 

 carried out. A 0-5 per cent, solution of Manitoba flour glutenine in 

 0-2 per cent. KOH, to which was added a drop of toluene, was allowed 

 to stand at room temperature for about a month and the specific rota- 

 tion was determined from time to time. The initial specific rotation 

 was — 95-0", and during the period of the trial this value did not suffer 

 any measurable diminution. It is reasonable to assume, therefore, that 

 the optical properties of the glutenines were not affected as a result of 

 their mode of extraction by means of 0-2 per cent. KOH. 



Moreover, the rate of diminution of rotation of a 0-5 per cent, solution 

 of Manitoba flour glutenine in N/25 NaOH when kept at 37° C. was 

 exceedingly slow, as is evidenced by the following series of determina- 

 tions : 



Time in hours Specific rotation 



2 - 990' 



25 -97-0 



98 -910 



267 -79-0 



It will be observed that the specific rotation of the Manitoba flour 

 glutenine solution had barely fallen to the initial value of the specific 

 rotation of the English flour glutenine even after standing 267 hours 

 at 37° C. 



Both objections become untenable in view of the fact that similar 

 investigations carried out on further samples of tlie glutenines from the 

 same flours yielded confirmatory results. If the differences observed 

 between the two glutenines arise from the operation of factors involved 

 in the objections 1 and 2, then it would be a remarkable coincidence 

 if such factors should operate with exactly equal eft'ect in the case of the 

 independent samples which were examined. 



The results of the investigation may therefore be interpreted as de- 

 monstrating the non-identity of the glutenines from strong and weak 

 flours. 



If, as seems probable, the characteristic physical differences between 

 the glutens of the two flours are related to the differences existing be- 

 tween the glutenine fractions, then it would at first sight appear feasible 

 to produce a "strong" gluten by preparing a moist mixture of English 

 flour gliadine with Manitoba flour glutenine, or a "weak" gluten by 

 mixing together Manitoba flour gliadine with English flour glutenine. 

 Attempts to demonstrate this possibihty, however, met with no success, 



17—2 



