8 METHODS OF ELUCIDATING DISEASE. 



sites, and (c) the specific results following inoculation by 

 specific animal virus, in whatever form transmitted from animal 

 to animal. 



II. Semiology, or Symptomatology. 



Whatever may be the nature or extent of the significance 

 which we may attach severally to the terms symptom and sign 

 of disease, whether Ave regard them as simply every occurrence 

 or circumstance taking place or happening in the diseased 

 body, which is capable of being perceived or appreciated as 

 indicating a state of disease, or as something in addition, as, in 

 fact, a part of the disease itself, and as virtually a constituent 

 of its existence and identity as any specific lesion or structural 

 change, we must remember that for the proper collection of 

 these symptoms appropriate means and methods must be 

 employed; and when possession of these is obtained, much 

 thought and reflection is needful for their correct interpreta- 

 tion. Symptom must be weighed against symptom, the rela- 

 tion of one to the other, and of the wdiole to each, considered ; 

 in this way only can we arrive at any just conclusion as to the 

 nature of the disease, the probability of its course and termina- 

 tion, or of the treatment requisite. 



Symptoms are sjaoken of as general when they affect, to a 

 greater or less extent, the whole system ; local, when confined to 

 a particular part or organ ; 'premonitory, when they precede the 

 full appearance of the diseased action ; p>ositive, or direct, ^vhen 

 consisting of phenomena actually present or connected with 

 the diseased part ; indirect, when such phenomena are absent 

 or developed in some situation remote from the seat of the 

 disease ; characteristic, when seen in the same or a similar 

 disease ; commemorative, when developed during the course of 

 the disease. 



They are also spoken of as diagnostic when they lead us to 

 distinguish one disease from another; pathognomic, when 

 j)eculiar to some particular disease ; p>rognostic, when they 

 enable us to predict the course of the disease. 



In following out this study of the practice of equine medi- 

 cine, which is in reality the recognition of veterinary medicme 

 as an art, inasmuch as it is directed to observe and to ascertain 

 as far as possible the causes, the nature, the means of cure or 



