INTRODUCTION 5 



(3) The temperature or heat of the part must be normal. (If 



the part shows a temperature higher than the normal 

 and natural, then healthy assimilation is interfered 

 with. On the other hand, every one has read of a 

 man's toes being frozen off in the Arctic regions 

 through extreme cold, thus showing the necessity of 

 normal heat.) 



(4) All parts must be under the control or influence of the 



nervous system. 



12. Circumstances are, however, constantly arising which inter- 

 fere with the equilibrium of these functions, and then a perverted 

 nutritive process is established, disorder and disease being the result; 

 hence, health and disease are so intimately blended — like daylight 

 and darkness — that we cannot tell when one ends and the other 

 begins. 



■'fo' 



DEFINITION OF TERMS. 



13. Before proceeding further, it will be necessary to note and 

 define certain terms which are in general use in the veterinary 

 profession. 



(1) Pathology is the study of disease and its locality — the 



science of the nature, causes, and remedies of diseases. 



(2) Etiology shows the various causes of disease — external, 



internal, mechanical, chemical, climatic, predisposing, 

 predisposition, hereditary, exciting, age, sex, etc. 



(3) Symptomatology gives the various symptoms, negative 



and positive. In some cases there are very definite 

 symptoms, which indicate clearly the nature of an 

 ailment ; in others the indications are few, and lead 

 to no definite conclusion. In such a case the practi- 

 tioner resorts to the negative method ; the absence of 

 certain symptoms shows that the malady is not so- 

 and-so. Thus, he can exclude certain complaints from 

 being the actual one until the choice is brought down 



