174 



Milk (Did Its Products. 



is to add a spoouful of reunet of known strength 

 to a teacupful of milk and, after stirring the two 

 together thoroughly, to note carefully the time re- 

 quired for coagulation. Another and more exact 

 method, known as the Monrad test, is made as fol- 

 lows: To a measured quantity of milk at a given 

 temperature a measured quantity of rennet of known 

 strength is added; ordinarily the commercial rennet is 

 diluted nine times for this purpose. The rennet is 

 thoroughly stirred with themilk, and the time re- 

 quired for coagulation is carefully noted. This is 

 simply a development of the cup test, and is better 

 because of its greater delicacy and accuracy; the 

 milk and rennet being more carefully measured, and, 

 diluted rennet being used, a wider range of delicacy 



is reached. Still 

 another form of ren- 

 net test, known as 

 the Marschall test, 

 has been devised. 

 In this test the milk 

 is measured into a 

 vessel, one of whose 

 sides is graduated 

 and in the bottom 

 of which there is a 

 minute orifice. The 

 rennet is added to 

 the milk, and the 

 vessel so placed that the milk can escape from the 

 hole in the bottom. So long as the milk remains 



Fig. 24. Marschall rennet test. 



