STATE DAIRY ASSOCIATION. 331 



I will give you a description of how a test should be made. In 

 making a test of milk, be sure to mix your sample thoroughly before 

 starting. Be sure your cow is thoroughly milked. Pour the milk to- 

 gether immediately after milking. Take a small sample and cork it up 

 or evaporation will take place and the milk become leathery. Then pro- 

 ceed with it to your laboratory. Pour it from one dish to another 3 or 

 4 times. Be careful not to let too much air get in the milk. Let it run 

 down the sides of the bottle, that keeps the air out. The Babcock test 

 is a test of weight and not measure. Take a sample of this milk with 

 a pipet — a glass instrument 18 inches long and put this in a test bottle 

 which has a clean neck. Keep this sample thoroughly mixed. Then we 

 add sulphuric acid tO' dissolve the cheesy substance in the milk. That 

 is whirled around in this bottle till a chemical change takes place. Then 

 we take this bottle two-thirds full and put it into a machine and it is 

 whirled for five minutes. The machine is 14 to 16 inches in diameter 

 and the bottle is whirled 600 to 800 revolutions per minute exerting 30 

 to 40 pounds of pressure per square inch. We stop our machine and our 

 bottles immediately take an upright position. Then we fill them to the 

 necks with water. Then you proceed to whirl them again, if you are 

 making a careful test. Whirl it a minute then take it again and fill to 

 top of the graduation on the neck. The butterfat being lighter than 

 water floats to the top. We whirl it two minutes more to be sure that 

 no particles are sticking to the sides, keeping it at a temperature of 120 

 or 130 degrees. By heat it expands and by cold it contracts. Take a 

 pair of pilars that have sharp points and place them on this bottle and 

 read the test. If it covers half this space in the neck, it is 5 per cent. 



The test is accurate, it determines the proportion of butter fat in 

 one hundred pounds of milk. It is a simple process and can be done 

 accurately if a man is careful. 



I have gone to creameries when I was instructor in the dairy school 

 in Minnesota and tested for one hundred patrons and I figured out with- 

 in ten pounds of how much butter that would make, and that on 500 

 or 600 pounds of butter is very accurate. I tell you when we can do 

 that, we have a very close test. 



Mr. Mallory — Do you have any trouble with your acid? Is that 

 standard? 



Mr. Glover — You ought to have an acid with a specific gravity of 

 1.82. If that is uncorked for any length of time, it would take up water. 

 Sulphuric acid has a wonderful affinity for water and it thereby becomes 

 weakened and will afifect the accuracy of the test. There will be white 

 specks coming on top which are undissolved portions of casein ; or ycni 



