52 CREAMERY BUTTER MAKING 



Most of the sampling is done by either of two methods : 

 (i) by means of a half ounce dipper, shown in Fig. i6, 

 or (2) by means of long narrow tubes, one of which is 

 shown in Fig. 17. 



The dipper furnishes a simple and easy means of 

 sampling milk. Wliere the milk is thoroughly mixed, 

 and the variations in quantity from day to day are slight, 

 the dipper method of sampling is accurate. 



The other method of sampling is illustrated by the 

 Scovell sampler (Fig. 17). The main tube of the sampler 

 is open at both ends, the lower of which closely fits into 

 a cap provided with three elliptical openings. As the 

 sampler is lowered into the milk the latter rushes through 

 the openings filling the tube to the height of the milk in 

 the can. When the cap strikes the bottom of the can 

 the tube slides over the openings, thus permitting the 

 sample to be withdrawn and emptied into the composite 

 jar. 



This sampler has the advantage of always taking an 

 aliquot portion of the milk, and furnishing an accurate 

 sample when the sampling is somewhat delayed, because 

 it takes as much milk from the top as it does from the 

 bottom of the can. 



The McKay sampler designed by McKay, works on 

 the same principle as the Scovell and has proven very 

 satisfactory. 



Preservatives. Milk cannot be satisfactorily tested 

 after it has loppered owing to the difficulty of securing 

 an accurate sample. This makes it necessary to add some 

 preservative to the composite samples to keep them sweet. 



The best preservatives for this purpose are corrosive 

 sublimate, formalin, and bichromate of potash. All of 

 these are poisons and care must be taken to place them 



