in a feigned issue from
chancery, or as would assessors called upon under the canon law to
state, in proceedings under the law, what is the secular law of the land
on the pending question" (Wharton and Stille, sec. 274).

The matter of introducing some such practice into this country has been
agitated of late, and may by and by lead to beneficial results.
Dr. Shrady has taken steps to promote this object by striving to have a
law enacted by the New York legislature providing for the regulation of
expert medical testimony in jury trials. According to his plan, once
such a commission has been established, the court is to send the
medical issue to these experts, just as it sends other issues to special
juries to be decided. The regular petit jury will then decide only upon
the facts constituting the crime.

This would do away with special pleas of insanity before a jury that
knows little or nothing about the nature of the disease, and whose
sympathies may readily be worked upon by shrewd lawyers to render a
verdict of acquittal.

As things are now, the medical expert, summoned to testify in a case of
contested sanity or insanity of mind, ought to rise above minor
considerations, and promote the cause of justice, by giving all the
valuable information that his profession enables him to acquire on the
very difficult subject of mental unsoundness.

6. For this purpose, he must be skilled in three departments of science.

(_a_) In _law_--sufficiently to understand what are considered by the
courts as characteristic marks of an insane mind, and what amount of
sanity the courts require to hold a culprit responsible for his crime or
a contract valid in its effects.

(_b_) In _psychology_--to such an extent that the expert witness can
speak analytically and correctly as to the properties and actions of the
human mind.

(_c_) In _medicine_--so far as concerns the treatment of the insane, and
the understanding of their peculiarities, so as to reason from them by
induction to the real condition of the client's or patient's mind.

But the main requisite for an expert witness is to understand clearly in
what insanity properly consists, and how far it ought to excuse an
insane man from bearing the consequences of his acts.

III. This two-fold knowledge is obtained by the psychological study of
insanity, on which study we are now to enter, and it is the principal
point in this whole matter.

Insanity means a want of soundnes