116 ESSENTIALS OF VETERINAEY LAW 



age medical witness appear far more ignorant than 

 he really is. One well posted witness is worth 

 several men with *' reputations, " but who show 

 inexactness in examination. Where a witness 

 guesses at an answer he is very likely to greatly 

 weaken the force of his testimony. If he does not 

 know he should say so, and then when he says a 

 thing it will be presumed that he knows that which 

 he pretends to know. 



It often happens that a lawyer gets from tlio 

 witness an admission of a certain fact, and then 

 asks if some other fact is not dependent upon the 

 acceptance of the first. While such a sequence 

 might be common, or very usual, it is unsafe for 

 the witness to give an unqualified approval. In 

 such cases the expression "Not necessarily" 

 proves often exceedingly valuable. 



87. Expert Testimony. Justice frequently de- 

 mands that special evidence be given, of a techni- 

 cal nature, and that the opinion of those competent 

 to decide as to technical points be given to the jury 

 to enable the latter to arrive at an equable deci- 

 sion. Not all technical witnesses, testifying as to 

 professional matters, are the givers of "expert 

 testimony," irrespective of their competency to 

 give such expert judgments or opinions. "The 

 value of professional services is not a question of 

 science to be proved by expert testimony. ' ' ^^ Such 

 a matter is a question of fact, to be determined by 

 usage and circumstances. Therefore, it has been 

 held that a person who is not an attorney is com- 

 petent to prove the value of an attorney's serv- 



4s Walker v. Cook, 33 111. 

 App. 561. 



