TESTING ACIDITY OF MILK AND MILK PRODLXTS 99 



THE PURDUE ALKALI TEST 



This test was devised by H. E. Van Norman (Bul- 

 letin No. 104, Purdue Univ. Agr. Exp. Sta., 1905.) 

 The following- apparatus (Fig. 40) is used: (i) An 



A 



I76CC 

 \ 



c.c. 



62° F. 



00 c 



10 10 



50 20 



70 30 



60 40 



50 50 



40 60 



30 — ^70 

 20— » 

 10 90 



DILUTE ALKAU 

 SOLUTION 



icc=.oiyo WITH 



17.6 CC PIPETTE 

 OF CREAM ETC.. 



FIG. 40 — PURDUE ALKALI TEST 



ordinary 17.6 cc. pipette, (2) a 100 cc. cylinder, such 

 as is used in the alkaline-tablet test, (3) a 2-Quart bot- 

 tle graduated at 1850 cc, (4) sealed bottles, each con- 

 taining ^y cc. of normal solution of sodium hydroxide 

 (caustic soda), (5) a bottle of phenolphthalein indi- 



