COMPENSATION 121 
decision; but having made such an examination 
he becomes a witness of fact, and may be com- 
pelled to testify as to the result of the examination 
made by him.®? He made his decision as to testi- 
fying when he made the examination. 
We have previously said that a witness should 
be impartial. Too frequently both witness and 
spectators seem to imagine that an expert, like 
an attorney, is hired to get one side out of trouble. 
Theoretically this should not even be true of the 
lawyer. He is an officer of the court to secure 
justice; but since he is opposed by contending 
counsel, justice can only be secured when each side 
is presented in its strongest color. This excuse 
does not avail for biased testimony, whether of 
fact or of expert opinion. The witness is sworn 
to tell the truth. A contract with an expert wit- 
ness for compensation, conditional on the success 
of the suit in which he is to testify, is void, as 
against public policy.*? It should be sufficient 
grounds for impeaching the expert’s entire tes- 
timony, for it throws doubt upon the honesty of 
his opinion, and raises a suspicion that there may 
have been imposition upon the court of a plea for 
a client, disguised as evidence. It is such unlawful 
abuse of privilege which has tended to bring re- 
proach upon the name of expert testimony in 
American courts. 
An agreement by one to go into court at a future 
day and testify as an expert in regard to a matter 
which he had examined as a civil engineer (or as 
a veterinarian), is sufficient consideration for a 
e2 Summers v. State, 5 Tex. 63 Pollak v. Gregory, 9 
App. 365. Bosw. 116. 
