Rural School Leaflet. iooi 



8. After using the pipette wash it thoroughly, preferably in hot 

 water. This will tend to prevent the transmission of disease germs 

 from the mouth of one person to another, should any such germs be 

 present. 



9. The tester should be firmly fastened to a solid bench or table. 



10. The person operating the machine should give his or her whole 

 attention to it, and not allow the fingers or clothing to get in the path 

 of the bottle cups. 



11. Remove all objects from the vicinity of the tester. This will 

 prevent their being hit by the bottle cups when the machine is in motion. 



12. If acid is spilled upon anything pour on plenty of water, and then 

 add some alkali, such as lime or baking soda, to neutralize the acid. 



13. Do not leave the acid bottle uncorked. 



14. Keep all glassware perfectly clean. 



15. After washing the glassware, rinse it thoroughly in clean water 

 to remove soap powder. The soap powder and the acid form a violent 

 chemical reaction. 



IV 



The Value of the Babcock Test for Testing Buttermilk and Skimmed Milk 



C. A. PUBLOW 



Object. — To familiarize the pupil with the value of centrifugal separa- 

 tion of cream and the importance of careful, intelligent methods in 

 cream separation and churning. 



In all school communities some dairymen separate the cream from 

 the milk by the gravity method; that is, by setthng the milk in shallow 

 pans or deep cans. When the shallow pans are used, they are placed 

 in milk-houses or cellars on shelves or on the floor. By this method 

 about 20 per cent of the fat is lost in the skimmed milk. When the long 

 shotgun cans are used, they are placed in cold water for some twenty- 

 four hours. At the end of this time the cream is taken from the top 

 with a ladle, spoon, or cup. By this method some 10 per cent of the 

 fat in the milk is usually lost in the skimmed milk. 



Utensils. — A hand-power centrifugal tester, and at least two skimmed 

 milk test bottles having double necks. The rest of the equipment 

 is similar to that used for testing whole milk. 



Method. — Several pupils should bring from home samples of skimmed 

 milk separated by the gravity method. A pint of skimmed milk would 



