18 ROYAL SOCIETY OF CANADA 



in obtaining the gluten from the flour. The nitrogen of the alcohol- 

 soluble proteid must thus have been over-estimated and stated in too 

 high a proportion to that contained in the original flour. This pro- 

 portion, by the method followed, varies according to the analyses given 

 by Konig and Rintelen from 43.49 to 57.21 per cent. 



After performing a large number of analyses of flours in the 

 Inland Eevenue Laboratory, the results of which were not entirely 

 satisfactory so far as the estimation of gliadin was concerned, the pro- 

 cesses described under the following numbers were adopted, and deter- 

 minations made by means of them Avhich gave fairly concordant results. 

 These results appear to indicate essential differences in the composition 

 of the various grades of wheaten flour examined. The nimibers indi- 

 cating the various processes have also reference to the columns in a 

 tabular statement which will be given later on: — 



1. The percentage of total proteids contained in the original sam- 

 ple of flour was ascertained by determining the nitrogen according to 

 Kjeldahl, and multiplying the percentage of the factor 5.7 in accord- 

 ance with the investigations of Osborne and Voorhees and the practice 

 of Snyder. 



2. Four tests each containing 10 grammes of flour were made up 

 with distilled water in the usual way and then allowed to remain in 

 the condition of dough for 30 minutes. Two of these tests were then 

 washed, one after the other, each "with 250 cubic centimetres of distilled 

 water. The water was placed in a separating funnel and delivered 

 •drop by drop on the dough while the latter was being kneaded. This 

 maimer of producing gluten was first suggested and practised by Mr. 

 A. Lemoine, Assistant Analyst in the Inland Eevenue Laboratory. The 

 wash water and starch were received in a sieve made of No. 12 bolting 

 cloth, and any particles of gluten caught in it were recombined with 

 the wet gluten ball under treatment. The, above mentioned quantity 

 of water, used as described, was found to be quite sufficient for the 

 elimination of the starch which passed through the sieve, and was col- 

 lected with the wash-water in a basin placed underneath. The gluten 

 was then deprived of as much water as possible, dried at 98° C. for 

 24 hours and weighed. Thus the percentage of dry crude gluten yielded 

 by the flour was ascertained in duplicate. 



3. The other two quantities of 10 grammes flour were treated in 

 exactly the same manner as the first two, up to the "point of obtaining 

 the balls of wet gluten. Then each of these, without being dried was 

 securely placed in a small piece of fine muslin, which had been pre- 

 viously weighed, and subjected to further washing by 250 cc. of 70 per 

 cent alcohol, contained in a separating funnel and delivered upon the 

 gluten ball contained in the muslin. The kneading was performed 

 at the same time and care taken not to do this so violently as to cause 



