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$4-°°- This does not include the stove, or the boiling vessel, 

 both of which can be purchased near at hand. 

 The Sampling of the Milk : — 



The temperature of the milk when the sample is taken out 

 should be about 6o° F. , and should not vary more than 10 degrees 

 either way from this point ; the entire contents of the can should 

 be well mixed together ; too much attention cannot be paid to this 

 matter ; even when the milk is being shaken up so much as it is 

 on the way to the factory, supposing the analyses are to be made 

 there, the cream is rising somewhat. 



If the pipette is not dry within, dip the point into the milk, 

 suck at the upper, open end till the milk rises above the 5 c.c. mark 

 on the stem ; blow the milk out, and repeat this operation ; then, 

 what adheres to the inside is simply some of the milk that is to be 

 analysed, and not water. Now fill the pipette again, holding it 

 in the right hand, and taking hold of the upper stem, or slender 

 part, with the thumb and second and third fingers ; remove it from 

 the mouth, and immediately clap the ball of the index finger over 

 the opening ; this must be done so quickly that the milk will not 

 have time to fall below the mark on the neck ; if the first attempt 

 is a failure, try again. Then, while facing a window, hold the 

 pipette up so that the mark on the neck is on a level with the eye, 

 and, raising just a little the outer edge of the ball of the finger 

 that closes the opening, allow milk to drop out very slowly, till 

 the level falls just to the mark ; then let the milk flow out as fast 

 as it will with the upper opening entirely open, into the boiling 

 flask, which should be right at hand and ready for use ; do not 

 hurry the flow of the milk by blowing it out ; finally, let the 

 pipette drain a minute, and then blow the last drop that remains 

 in the point into the flask. After a little practice all this can be 

 done in a shorter time than it takes to describe the operation. 



If the pipette is now to be used to take a sample of another milk, 

 it should be filled and emptied two or three times with this milk, 

 just as it was with the first milk sampled. Measure out now, be- 

 fore beginning the analysis of any one of them, all the samples to 

 be taken from milk in hand. 



The Analysis : — 



Fill the boiling vessel with water up to about half an inch above 

 the perforated false bottom, and bring the water to boiling. Fill 

 the little measuring tube with sulphuric acid up to the mark, and 



