43^ 



Journal of Agriculture, Victoria. [lo July, 1911^ 



Making the test. — When the milk has stood for a few days, the cream 

 will have risen to the surface and become tough and leathery, and will not 

 mix thoroughly by shaking until it is heated. Stand the sample bottle in 

 water, 100 to no degrees Fah., until the cream is softened; then agitate- 

 gently until the cream is thoroughly mixed with the milk, no small lumps 

 remaining. The milk must then be cooled to between 60 and 70 degrees 

 Fah., wrhiph is the correct temperature to mix the milk and acid in the flask, 

 both being as nearly as possible the same temperature. 



Now take 17.6 c.c. milk, giving the sample a shake first, and run 

 this into the flask; to this add 17.5 c.c. sulphuric acid. When running 

 ir the milk and acid, hold the flask in a slanting position and allow the 

 liquid to run gently down the inside of the neck. Shake the flask with a 

 rotary motion until all the curd (casein) is dissolved. Place the flasks in 

 the machine so that they balance and rotate for five minutes at the speed 

 indicated on the machine. Fill up to the bottom of the neck with boiling 

 water, run for two minutes more, fill to within f inch of the top of the- 

 neck with more boiling water, run for one minute, take the flasks out of 

 the machine and stand in a water bath (Fig. \K) at 140 degrees Fah. for 

 a few minutes. Then read off the tests. The butter fat should now be 

 separated and collected in a clear compact column, like olive oil, in the- 

 neck of the flask on top of the water. 



n\ % 



MILK TEST EOTTLE. 6. CREAM TEST BOTTLE. 



SKIM MIlK BOTTLE.. 



Reading the test. — By the illustration (Fig. 5) it will be clearly seen 

 how the flasks are graduated. Each division marked by long lines and 

 numbered, represents one per cent., and each division between marked by 

 short lines equals .2 or two-tenths of one per cent. It will be easy to 

 measure ito one-tenth of one per cent., or half one of the small divisions. 

 With the compass (Fig. 4^) the full length of the fat column is taken 

 where the fat comes in contact with the glass (Fig. 8). 



It will be noticed that while the bottom line of the fat column is straight 

 and distinct the top shows a meniscus or hollow, and one may be in doubt 

 how to take the measure. This should be the full length of the column 

 where the fat is in contact w^th the glass, or. as is shown in the illustration, 

 measure from a to h — not to c or d. Measure the fat column with the 



