fer
the earnest student for further information to Wharton's and Stille's
"Medical Jurisprudence," in the volume on "Mental Unsoundness and
Psychological Law;" in particular to secs. 29, 38, 39, 40.

8. We must now return to the consideration of the manner in which the
disturbance of the brain may affect the mind. The brain is a storehouse
of records of things formerly noted there by the imagination, either as
the results of sense perception or of arbitrary combinations of
phantasms; it is a library of facts and fancies. And these are not
single, but grouped together, so that when one is stirred it will arouse
others as well. When the brain is affected, whether by an acute or a
chronic derangement, its images may become so disordered that records of
mere imaginations get mixed up with records of real perceptions in
inextricable confusion. You may have had occasion to notice the process
in the case of a man who is becoming intoxicated and then passes on to
_mania_ or _delirium tremens_: he gradually proceeds to mix up
brain-pictures with realities, and after a while he speaks and acts like
a very crazy man. He is in a kind of dream; his imaginations are wild
and disconnected, his language is incoherent.

The delirium arising from violent fevers, for instance from typhoid
fever, is very similar to that arising from the excessive use of
intoxicants and narcotics; similar in these respects; that the mania is
only temporary, and that the exciting cause is not altogether unknown.

The _bacilli_ of the infection, like the alcohol, the opium, the
morphine, or other drugs, are accountable for the disordered action of
the brain. But I do not pretend to know, nor do medical writers
generally pretend to understand, _how_ the poison, or whatever causes
the disease, gets to affect the brain. Does it do so directly, or by
means of the alteration it causes in the whole nervous system or in the
blood? We do not know; nor does it matter for the purposes of Medical
Jurisprudence.

IV. The questions with which the courts of justice, the lawyers, and the
expert witnesses are concerned are these: Is the man really insane? Or
was he insane at a given time when he performed a certain civil or
criminal act? Is he now, or was he then, so far controlled by his mental
unsoundness as to be incapable of acting like a rational being
accountable for his actions? Even if he is now, or was then, a
monomaniac, can the deed in question be traceable to