[macfarlanb] on the ANALYSIS OF WHEATEN FLOUR 59 



Tho numbers placed at the head of the various coluinns in this 

 table are the same as used in my paper last year, but for the sake 

 of Iconvenience, the manner in which the figures were obtained is now 

 explained as briefly as possible: — 



0. — In this column the percentage of moisture which the flours 

 contain is given in duplicate, the determinations having been made by 

 distributing the flours in chrysotile fibre and drying over night (18 

 houre) at 70°c. 



1. — The percentages of total proteids in this column were ascer- 

 tained by determining the nitrogen in the undried flour by the Kjeldab.l 

 method and multiplying the percentage of nitrogen by the factor 5-7 in 

 accordance with the results of the investigations of Osborne & Voorhees. 



2. — In determining the dry gluten the old method of making a 

 dough ball and washing out the starch with an indefinite quantity of 

 water was abandoned. Ten grammes of flour were made up with just 

 sufficient distilled water in the usual way, and after waiting 30 minutes, 

 the dough ball was treated with 250 cubic centimetres of distilled water. 

 The latter was placed in a separating funnel and delivered drop by drop 

 on the dough while it was being kneaded. 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 suflicient for the elimination of the starch in 10 

 grammes of flour. The starch passed through the sieve and was col- 

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

 was deprived of as much water as possible, dried at 98 °c for 28 hours 

 and weighed. This determination was done in duplicate like that of the 

 others still to be described. 



3. — Ten grammes of the flour were treated in the manner just 

 described up to the point of obtaining the wet gluten. Then the latter, 

 without being dried, was securely enclosed in a small piece of fine 

 muslin which had been previously dried and weighed. The whole was 

 then subjected to treatment with 250cc of 70 per cent alcohol, contained 

 in a separating funnel, and delivered drop by drop upon the wet gluten 

 contained in the muslin whicih was being carefully kneaded at the same 

 time. This operation has to be performed very gently and without 

 causing any particles of the gluten to be expressed. After drying, tho 

 weight of the resulting content of the muslin gives the quantity of the 

 crude glutenin contained in the fiour. The drying and weighing is done 

 in the muslin, the weight of the latter being deducted. 



4. — The percentage of crude glutenin (3) subtracted from that of 

 the dry gluten (2) gives the percentage of loss which the gluten had 



