248 MILK 



that the milk actually contained complement, indicating colos- 

 trum or mastitis milk. 



Test for Rennin Inhibition (Schern). Milk from sick cows or 

 colostrum milk requires more rennin for coagulation than normal 

 milk. For this test the milk must be fresh and contain no free 

 acid. The chemical reaction should be the same as normal milk. 

 Rennet of known potency is diluted with physiologic salt solution 

 1 : 10, 1 : 20, 1 : 30, etc. Of each of these dilutions, 0.5 c.c. are 

 mixed with 4.5 c.c. milk. The relative dilution must be judged 

 according to the potency of the rennet. The tubes containing the 

 mixtures are placed in an ice-chest for an hour and then in a 

 water-bath at 37 C. Normal milk will be found coagulated after 

 this time, while abnormal milk will not. Small differences are 

 negligible. 



BIBLIOGRAPHY 



Bauer: Die Methodik der Biologischen Milchuntersuchung, Stuttgart, 1913, 



Ferdinand Enke. 



Ehrlich: Zeitschr. f. Hygiene, 1892, vol. 12, p. 183. 

 Ernst: Grundriss der Milchhygiene fur Tierarzte, Stuttgart, 1913, Ferdinand 



Enke. 



Romer: Sommerf eld's Handbuch der Milchkunde. 

 Romer and Much; Quoted from Sommerf eld's Handbuch. 

 Woodhead and Mitchell: Jour, of Pathology and Bacteriology, 1906-7, vol. 



11, p. 408. 



