136 



THE CEREALS IN AMERICA 



question may be required. Definite references to proper bulletins should be fur 

 nished each student. 



203. Relation of Color, Hardness, Size, Specific Gravity and Con- 

 tent OF gluten. — 



1. Take five varieties of wheat varying as wdely as may be in different quali- 

 ties mentioned, as for example, Fultz, Gold Coin, Rudy, Turkey, Kubanka. 



2. Note color and hardness. 



3. Find weight of 500 grains. 



4. Fill a 50-gram picnometer with benzene and weigh on balance sensitive to 

 1 mgm. Add twenty grams of wheat and weigh. Add weight of wheat to weight 

 of picnometer and benzene and subtmct last weight, which will give weight of vol- 

 ume of benzene equal to volume of grains of wheat. Divide this difference by 

 the specific gravity of benzene, which will give the weight of a volume of water 

 equal to the volume of grains of wheat. To determine the specific gravity of the 

 wheat, divide twenty grams of wheat by the weight of an equal volume of water. 



5. To find the relative size of grains, divide the weight of five hundred grains 

 by their sp3cific gravity. 



6. To determine content of gluten, take thirty grams 

 of ground wheat, work with water in a round bottomed 

 glass vessel with spatula, and wash off starch after gluten 

 has gotten into a sticky mass, and continue to ^^'ash until 

 there is no appearance of starch grains being carried off. 

 To be sure that all the starch is freed from gluten, test 

 washings with potassium iodide ; blue color shows the 

 presence of starch. Work mass of gluten in fingers until 

 all water that will run off has been expelled. Weight 

 will give amount of moist gluten. Place in drying oven 

 at no** C until constant weight is obtained. Weight 

 will give amount of dry gluten At same time find 

 weight of dry matter in ten grams of ground wheat 

 Calculate per cent of moist and dry gluten from data 

 obtained. 



If there is not time or facilities to carry out No. 6, 

 the instructor may determine the content of gluten in 

 advance and allow the student to compare Nos. 2 to 

 5 with the results thus obtained. 



204. Quality of Flour. — Furnish each student 

 with a sample of high grade and low grade flour and 

 have him determine the following: 



I. Character of granulations: Note under a high 

 placed and removed as de- power microscope (172) whether flour particles are round 

 sired — any size cloth cari ©r angular. 



be inserted; 8, wire clamp 2. Size of particles: By means of apparatus dc 

 holding apparatus in place. ^^^^ ^^ Snyder, determine the amount of flour io 

 twenty-five grams that will pass through bolting cloth Nos. 9 to 20. 



Snyder's apparatus for de- 

 termining the granulation 

 of flour. I, Erlenmeyer 

 flask; 2, suction connec- 

 tion ; 3, rubber cork; 4, 

 adapter; 5, rubber (tube) 

 packing, making air-tight 

 joint; 6, section of brass 

 crucible overlapping sec- 

 tion 7; between these two 

 parts bolting cloth Is 



