198 DAIRY FARMING 



3. Hold the bottle in a slanting position when adding acid, 

 and do not allow the mouth of the bottle to point toward any 

 one while the milk and acid are being mixed, as occasionally the 

 contents may be forced out suddenly. 



4. Wash the pipette thoroughly, and dip it in hot water after 

 using. 



5. The testing machine must be fastened securely to a heavy 

 table or bench. Start and stop the machine slowly. 



6. If black sediment appears in the fat column, the indications 

 are that the acid was too strong. Use slightly less. If white specks 

 are present, it is probable the action of the acid was too weak. Use 

 a little more, or warm the milk 10 or 20 degrees before adding the acid. 



7. Wash the test bottles at once after using by means of hot 

 water and some washing powder. Rinse thoroughly in clean water 

 to remove all traces of washing powder. 



8. Remember the acid is poison and will burn the clothing or 

 skin. If spilled on anything, pour on plenty of water and add some 

 lime, soda, or washing powder to neutralize the acid. 



21. Cream Testing. When cream is sold on the basis of the 

 fat content, the samples for testing must be weighed rather than 

 measured. A test may be made by the following method, but it 

 must be kept in mind that the results are not entirely accurate 

 and tend to be lower than the true reading. 



Mix the cream thoroughly and by the use of the milk-testing 

 pipette, place 17.6 c.c. in a clean cup or beaker. Next fill the pipette 

 to the mark with water and add to the cream. Add a second pi- 

 pette full of water in the same manner. Mix thoroughly and test in 

 the same manner as would be done for milk. Since the mixture 

 tested is only one-third cream, the percentage of fat found must be 

 multiplied by three to give the percentage of fat in the cream. 



VARIATIONS IN AMOUNT OF FAT IN MILK 



22. Fat in Milk of Different Cows. Obtain samples of milk 

 from several different cows and determine the percentage of fat in 

 each with the Babcock tester. If the weight of milk can be taken 

 at the same time, calculate the amount of butter-fat each cow 

 produced. Samples for testing should be taken by thoroughly 

 mixing all the milk produced by the cow before taking out the 

 small portion from which the test is to be made. 



23. Fat in Milk of Different Breeds. Take samples from cows 

 of as many breeds as are available and test each for fat. 



