CHAPTER III. 



TATROLOGY— continued. 



THE MOEBID PHENOMENA— SYMPTOMS AND SIGNS OF 

 DISEASE— SEMIOLOGY. 



" For my own part " (says Watson), " if I were called to define 

 a symptom, I should say, ' Every thing or circumstance happening 

 in the body of a sick person, and capable of being perceived by 

 himself or others, which can be made to assist our judgment 

 concerning the seat or nature of his disease, its probable course 

 and termination, or its jDroper treatment.' Every such thing or 

 circumstance is a symptom." 



Symptoms are signs of disease, but it is only by mental effort 

 and experience that the practitioner is able to convert symptoms 

 into signs. The idea associated with symptom is much more 

 vague than that which is connected with sign. Some writers 

 have endeavoured to restrict the word symptom to the pheno- 

 mena depending on vital properties, whilst those phenomena of 

 disease wliich are more directly physical are by them called 

 signs. Again, some restrict the term sj'^mptom to the pheno- 

 mena manifested by present disease only ; but this is contrary 

 to the custom by which we speak of precursory and consecutive 

 symptoms. Symptoms of disease are obvious to all persons 

 alike : for example, the manifestation of pain, the symptoms in 

 an animal suffering from enteritis, are plainly seen by all the sur- 

 rounding attendants, but it is only the skilled and experienced 

 veterinarian who can detect the expression, the condition of the 

 pulse, &c., the signs by which this malady is diagnosed or 

 distinguished from a mere colic. " Symptoms may be con- 

 sidered as resembling so many words. When taken separately, or 

 when put together at random, the words have no force or signiii- 



