SO-CALLED 'BIOLOGICAL PROPERTIES' OF MILK 85 



temperatures and intervals, he compared them with the standard 

 colour scale for that experiment. 



Using the values thus obtained, he found that the reaction 

 followed the law for monomolecular reactions, and that the equation 



(where K = a constant, and a = concentration 



at time O, x = concentration at time T), was true, and that hence 

 the reaction was monomolecular in type. The effect evidently 

 depends upon the length of time over which the heat is maintained, 



Table showing the Inactivation-point for Peroxidase, after 

 different Authors. 



and van Eck points out that it is impossible with any one test to 

 discover both the temperature and the length of time of heating. 



There is no means of testing the amount of peroxidase present 

 in milk ; van Eck's work deals with the disappearance of such 

 amounts of peroxidase as are present in the particular sample of 

 milk considered, and not with absolute quantities. Further, the 

 test for peroxidase can readily be restored to heated milk by the 

 addition of a small amount of raw milk, if the presence of the reaction 

 is required. 



On the Presence of Reducing Ferments in Milk. The reductases 

 are bodies whose action consists in bringing about the chemical 

 reduction of a given substance. 



