14 



Bitter : Bitter milk developes its taste only some time after it 

 was milked, and is accompanied by souring. The chemical changes 

 which take place in such milk are not known, but the development 

 of gas seems to indicate a fermentation, the whole being, perhaps, 

 merely an incipient state of putrid decomposition. 



Milk is said to become bitter also after the feeding with bitter 

 herbs, like dbsynthum. 



Medicinal : Medicines may likewise impart to milk a pe- 

 culiar taste. 



Putrid : The taste of milk in putrid fermentation. 



Sour : Milk sours most frequently in sultry weather during 

 the summer. It may also be caused by diseases of the udder, or 

 when the cows have not been completely milked. Such milk cur- 

 dles when heated. 



The Microscopical Examination. 



This examination is to determine qualitatively whether a milk 

 is normal, diseased, or partially adulterated. For the construction 

 and use of the microscope we must refer to such works as treat 

 this branch of science as a specialty. 



Normal milk: Milk, like blood, is an emulsion containing 

 some substances in solution, while others, the so-called milk globules, 

 are held in suspension, thus producing the color and opacity pe- 

 culiar to milk. 



Butter globules : The butter or milk globules are highly re- 

 fracting globules, with an average diameter of 0.017 to 0.025 m.m. 



