to make any formal statement of intention to qualify the 
witness as an expert. If the qualification as an expert has 
inadvertently been omitted, opposing counsel will doubt¬ 
less object as soon as questions involving opinion are intro¬ 
duced, whereupon the qualification as an expert can be 
made, and the evidence in question admitted by the 
court if the qualification be deemed sufficient by him. 
KINDS OF PROOF BY WHICH FACTS IN ISSUE MAY BE 
ESTABLISHED. 
Fads regularly proven .—It is the general rule that courts 
in deciding issues of fact will consider only such evidence 
as may have been presented by the respective parties and 
will entirely disregard all facts not regularly proven. To 
this rule there are two exceptions, the first being as to 
certain facts of which the courts take “judicial notice,’ 
or recognize as within their own knowledge without re¬ 
quiring any proof thereof, the second being as to such 
facts as are formally admitted by both sides. The latter 
class is not of so much importance in criminal cases as in 
civil actions, where a mutual agreement on such points 
may materially reduce the ground necessary to be covered 
by proof. 
Primary and secondary evidence .—Ordinarily the most 
natural and satisfactory method of proving the existence 
or nonexistence of any fact is by the direct oral testimony 
of witnesses; but to this there are certain exceptions. 
Oral evidence may not ordinarily be given of any trans¬ 
action of a public nature of which the law requires a 
record to be kept. For example, judicial proceedings 
must be proved from the records of the court and not by 
the oral testimony of persons who were present at the 
trial. The contents of a written instrument ordinarily 
can only be proved by production of the document itself. 
The terms of a contract or grant which the parties have 
reduced to writing and which it is sought to prove by one 
of the parties must be proved by production of the docu¬ 
ment itsalf, except in certain cases. The general rule is 
that all facts must be proved by the best kind of evidence 
obtainable, called “primary evidence”; but under cer- 
