INTRODUCTION. 53 



Define an epizootic disease. 



It comes from epi, "upon,". and zoon, "an animal." It is 

 a disease that is widely spread over a community. 



What terms in human medicine describe similar con- 

 ditions ? 



The terms endemic and epidemic. 



Define a panzootic disease. 



This is a disease that is infectious or contagious, and spreads 

 from one country to another. 



What is a zymotic disease? 



This is a disease of a contagious nature, but produced by the 

 action of a ferment. 



Name some of the uses of the ferments. 



Diastatic, which change starch into sugar; proteolytic, which 

 make proteids soluble; tryptic, which are gelatin liquefiers; inver- 

 iin, which change cane sugar into grape sugar, ferments that 

 curdle milk. 



3. TERMINATION OF DISEASE. 



How do diseases terminate ? 



It may occur in one of three ways : either by a cure, secondary 

 processes, or death. 



A cure may take place in what way? 



It may take place by a lysis, which is a gradual withdrawal of 

 the diseased action — that is, a slow return to health. Or by a crisis, 

 which is an abrupt ending, generally with a critical discharge — that 

 is, it is a sudden change, for better or worse. Or by a metastasis, 

 which is the changing from one location to another, or the shifting 

 of the disease. 



What is understood by the secondary processes? 



By this is meant when the diseased action is substituted by 

 a new morbid process, as rheumatism followed by heart trouble, or 

 apoplexy by cerebral softening. 



What is death? 



It is a complete cessation of tissue change, or a cessation of all 

 functions, the aggregation of which constitutes life ; or a complete 



