e is right. The
questions asked by the counsel for his side, the majority of which he
prepares or dictates himself, are glibly and positively answered. But
when the cross-examination begins, what do we see? An interesting
spectacle from a psychological standpoint. We see a man, honest in his
intentions, standing between two almost equal forces; the love of
himself and of his own opinions, on the one side, and upon the other
the love of scientific truth which is inherent in all truly
professional men. When a question is asked, to which he can reply
without injury to his pronounced opinion, how eagerly he answers. But
when a query is propounded, which his knowledge shows him in a moment,
indicates a reply which his quick intelligence sees will be against
his side, what does he do? We find that he fences with the question.
As anxious not to state what he knows to be false, as he is not to
injure his side of the case, he parries. He tells you in hesitating
tones, 'It may be so, in rare cases,' 'Other men have seen and
reported such instances, but I have not met them,' 'It might be
possible under extraordinary circumstances, but not in this case,' and
so on, and so on, reluctant to express himself so that he may be cited
afterwards. You have witnessed this very kind of evasion in this case,
so that you readily grasp my meaning. When I asked Professor Orton,
whether the action of morphine is modified by disease, his answer was,
'It might be'; and when I asked him whether, from continual dosage, it
could accumulate in the system, he said, 'The records contain reports
of such cases.' When I asked him if morphine would not be so retained
where Bright's disease were present, he tried evasion again by saying,
'I have never seen such a case,' after which he admitted that he had
read of them in good authorities.

"As I have told you, speaking generally, this sort of evasion under
cross-examination is a peculiarity common to nearly all experts, so
that in singling out Professor Orton as an example, I do so with no
intention of attacking his honesty of purpose. He was simply defending
himself, and upholding the side which pays him for his advocacy. But I
choose this testimony because if we analyze it I think we will find
more, much more than appears at a glance; and I can at the same time
show you how all expert testimony should be received. I will exemplify
the amount of caution to be displayed in accepting what a skilled
witness te