DIRECTIONS FOR USING THE BABCOCK TEST TIME: WHENEVER CONVENIENT Object: To learn the method of testing milk for butter fat by the use of the Babcock test. Material needed: Babcock tester with equipment, samples of milk. DIRECTIONS I. Ask students and patrons for funds to purchase a Babcock tester for the school. One can be bought for $5. 17.5 FIG. 48-BOTTLE AND MEASURE 2. Let students bring fresh milk from their homes to be tested. Samples should be taken while the milk is still warm after it has been thoroughly mixed. 3. When the milk has been well mixed measure out with a pipette 17.5 cubic centimeters and put into the bottles. Blow in the upper end of the pipette to expel all the milk. 4. Measure out an equal amount of acid for each bottle, holding the bottle slantingly; let the acid run down the side of the bottle so as not to come in contact with the milk too suddenly, lest the milk be acted upon unevenly. Gently shake the bottles in the hands until the acid and milk are thoroughly mixed. The mixture will become hot and change to a dark brown. Care must be taken in handling the acid so as not to get any on the skin or clothing: drop a little on a rag and find out why. 5. Place an even number of bottles in the machine, replace the cover, and rotate about 700 to 1,200 revolutions a minute for six or seven minutes. 6. Add enough hot water to bring the mixture up to the bottom of the neck; place the bottles back in the machine and rotate again for three minutes. Now add more hot water and bring the fat up in the neck where it can be measured. Suppose the bottom of the fat column stands at the figure 2 and the top at the figure 6, this would show 4 per cent. of fat. Each per cent. means one pound of butter fat in 100 pounds of milk. DECAY IN APPLES TIME: WHENEVER APPLES ARE OBTAINABLE Object: To show that apples should not be shaken from the tree if they are to be kept. Material needed: Three ripe apples. DIRECTIONS Select three apples of the same variety and of the same degree of ripeness. Strike one against an object so as to bruise one side without breaking the skin; strike another so that the skin is just broken, and leave the third uninjured. Place the three apples somewhere in the room where they will not be disturbed, and examine from time to time. QUESTIONS 1. Which decays first? 2. What is the function of the skin of an apple? Select two apples of very nearly the same size; peel one and weigh both. After 24 hours weigh again. 3. Which has lost the most in weight? Why? DIFFERENT FORMS OF APPLES TIME: FALL TERM Object: To learn to classify apples according to form. Material needed: Apples of various forms. DIRECTIONS Study well the forms of apples as given in Fig. 57. Practice drawing these forms until you become 000 OdOG FIG. 49-FORMS OF APPLES A, oblate; B, conical; C, ovate; D, obovate; E, oblong; F, acute; G, round-ovate; H, oblate-conical. 1, stem or stalk; 2, cavity; 3, calyx; 4, basin; 5, core; 6, axis. familiar with them. Make a collection of different varieties of apples; let the class learn all the |