LABORATORY EXERCISES 



239 



has grown three weeks, take it up and make drawings of the roots in 

 each case. At what depth have the permanent roots appeared? Has 

 the depth of planting influenced this? 



65. Visit to a Flour Mill. 



Visit a flour mill, or other similar manufacturing enterprise. Learn 

 as much as possible of the processes, and write a description of them. 



66. Good and Poor Flour. 



Materias. High-grade flour 

 and cheap flour. One teacup- 

 ful of each for five students. 



Moisten the flour just 

 enough to make dough. Work 

 it between the fingers, and then 

 wash it until the starch is 

 washed out. You will then have 

 a sticky mass of gluten. Com- 

 pare the color of the gluten in 

 high- and low-grade flour. How 

 many inches will each stretch 

 before it breaks? Why does the 

 high-grade flour make lighter 

 bread? Why does corn or rye 

 not make as light bread as 

 wheat? 



67. To Determine the Influence 

 of Fertilizers on the Yield 

 of Timothy Hay. 



Materials. Field of tim- 

 othy, 20 pounds nitrate of 

 soda, 1\ pounds acid phosphate, 

 3| pounds muriate of potash, 

 500 pounds (about one-fourth 

 load) of barnyard manure, 22 

 stakes, tape-measure. Arrange- g 

 ments can probably be made to - 1 

 have some student conduct the 

 experiment at home. 



Lay off ten plots, side by ^ 

 side, each one rod by four rods. 



4 RODS 



Check 

 No fertilizer 



5 pounds nitrate of soda 



5 pounds nitrate of soda 

 2i pounds acid phosphate 



Check 



5 pounds nitrate of soda 

 li pounds muriate c? potash 



2 pounds acid phosphate 

 \\ pounds muriate of potash 



Check 



5 pounds nitrate of soda 

 1\ pounds acid phosphate 

 li pounds muriate of potash 



i-load, about 500 pounds 

 cf manure 



Check 



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