TESTS USED IN CHEESE-MAKING 44! 



Apparatus. (i) Two 50 cc. burettes, accurately 

 graduated to one-twentieth cc. Automatic burette 

 fillers save much time in making many determinations. 



(2) Flasks, so-called volumetric, holding 200 cc. 

 and accurately marked. Flasks having necks 4^2 to 5 

 inches long and ^-inch inside diameter are desirable 

 for greatest convenience. 



(3) Pipette (Babcock test form), accurately grad- 

 uated to deliver 17.5 cc. (18 grams) of milk. 



(4) Pipette graduated to deliver 100 cc. 



(5) Pipette graduated to deliver about I cc. and 

 provided with a rubber bulb (so-called dropper). 



(6) Cups, plain white, holding 200 cc. or more. 



(7) Funnels, glass or granite-ironware, 3 to 4 

 inches in diameter. 



(8) Filter-papers cut round, 6 to 7 inches in diam- 

 eter ; or fine linen filters cut to proper size and shape, 

 which can be washed after use and used repeatedly. 



(9) Measuring-cylinders, accurately graduated and 

 holding 1,000 cc. 



Solutions. (i) Sodium hydroxid (caustic soda). 

 This solution may be made most conveniently by pre- 

 paring a regular tenth-normal solution in the manner 

 recommended by Publow (p. 427), and then diluting 

 795 cc. of this to one liter (or one may directly dilute 

 the 50 cc. of concentrated alkali to 2,900 cc.). In 

 such a solution I cc. corresponds to 0.09 gram of casein 

 (or i per cent). In making standard solutions, pure 

 distilled water should be used if possible, or else as 

 pure rain-water as can be obtained. Alkali solutions 

 must be kept in tightly-stoppered bottles to prevent 

 loss of strength. "Alkaline tablets" cannot be used 

 for the casein test. 



