246 
peculiar to the water expert, lies in the im- 
possibility of utilizing analytical results 
such as were made many years ago. 
Those who are not chemists fail to grasp 
the fact that the examinaton of water may 
not be looked upon from the same point of 
view as the analysis ofan iron ore. The 
statement that water analysis is of recent 
birth, and that it is yet in its infancy, is 
hard for them to appreciate, holding, as 
they naturally do, that what was true 
twenty years ago must be true to-day, if 
science does not lie. 
A pit into which many an expert witness 
falls is prepared for him by insidious ques- 
tions leading him to venture an opinion 
on matters outside of his specialty. Itis a 
fatal error to attempt to know too much. 
Terse, clear answers, well within the nar- 
row path leading to the point in question, 
are the only safe ones; and when the line 
of inquiry crosses into regions where the 
witness feels himself not truly an expert, 
his proper course is to refuse to testify out- 
side of the boundaries of his legitimate 
province. 
Unfortunately, the expert is as often in- 
vited to take these collateral flights by the 
side employing him as by the opposition. 
Affidavits in submitted cases are com- 
monly written by the lawyers and not by 
the expert, although they are, of course, 
based upon his reports. In the strength of 
his desire to win the case, the lawyer often 
prepares a much stronger affidavit than his 
witness is willing to swear to. 
The writer has had no little difficulty 
just at this point, and has had plenty of 
occasion to observe the irritation displayed 
by counsel upon a refusal to endorse state- 
ments which have been ‘too much ex- 
panded.’ 
Eyery expert witness, especially in his 
early cases, is sure to have adverse author- 
ities quoted against him ; therefore it be- 
hooves him to be so familiar with the litera- 
SCIENCE. 
[N. S. Vou. VI. No. 137. 
ture of his subject as to be capable of point- 
ing out thatsuch and sucha writer is not up 
to date, or that such and such a passage, if 
quoted in full, would not bear the adverse 
construction that its partial presentation 
carries. When the expert reaches a position 
of such prominence that he can state a 
thing to be so because he says it, irrespec- 
tive of whatever may be written on the sub- 
ject to the contrary, his course then is greatly 
simplified ; but long before he attains that 
altitude he will have put himself upon rec- 
ord in many cases, and happy for him if 
the record so made be suchas cannot be 
quoted to his disadvantage. 
“Tf I had only not written my first book,” 
is the reflection of many a distinguished au- 
thor; while one of the great masters of mu- 
sic, referring to an opera, said: ‘It is one 
of my early crimes.” 
Above all things, the expert should “‘ pro- 
vide things honest in the sight of all men.”” 
It is well for him to be deeply interested 
in his case, to feel in a measure as if it were 
his own, but it is unwise in him to become so 
partisan as to let his feelings affect his good 
judgment, and it would be indeed criminal 
should he permit his interest in any way to 
contort the facts. 
Before the case is brought to a final hear- 
ing, it may be apparent that experiments 
before the Court are possible and they may 
be demanded by the counsel in charge of 
the case. If such experiments he striking, 
easy of execution, and not too long, by all 
means make them. 
Practical illustrations, particularly such 
as involve some fundamental principle, have 
great weight with the Court; but these il- 
lustrations must not be such as would turn 
the court room into a temporary laboratory 
and involve the loss of much time in vexa- 
tious waitings. 
Such experiments as are determined upon 
should be thoroughly rehearsed beforehand, 
no matter how simple they may be; for, of 
