but not
sufficient to manifest itself under ordinary conditions; when,
however, the action of toxic substance is superadded to the effect of
the alcohol the delirium of fever is more marked.

Probably of greater importance than the acquired pathological
conditions of the brain in producing insanity is a congenital
condition in which the nervous system is defective. The most fertile
cause of insanity lies in the inheritance; by this it must not be
understood that insane parents produce insane offsprings, but that
conditions inherited from immediate or remote ancestors appear in a
diminished resistance of the nervous system which is sooner or later
expressed as insanity. Given such a defective nervous system,
extrinsic conditions which would have no effect on another individual
or would be felt in different ways may produce insanity. In these
cases occupation plays a great role. The excitement and privations of
war especially in the tropics and the ennui of camps leads to insanity
in soldiers; occupations such as that of the baker in which there is
loss of sleep and the mental strain of students can all act in the
same way. A woman who gives no sign of nervous defect may become
insane under the strain of pregnancy.

Although insanity is determined by the social relations of man, that
part of the social organization which is termed _Society_, and
which has been developed by the idle as a diverting game, is a fertile
source of nervous disease and even of insanity, affecting particularly
females. The strenuosity of the life, the nervous excitement
alternating with ennui, the lack and improper times of sleep, the lack
of rest and particularly of restful occupation, the not infrequent use
of alcohol in injurious amounts, are all factors calculated to make a
defect operative. The so-called "coming out" of young girls is an
important element in the game, and their headlong plunge into such a
life at a period under any conditions full of danger to the nervous
system is especially to be reprobated. If we consider the influence of
the game in other respects as conducing to lack of moral sense, to
alcoholic abuse (for without the seeming stimulation, but which is
really the blunting of impressions which alcohol brings, the game
would not be possible), to discontent, to mental enfeeblement, it is
all bad. Curiously enough the game is one which in all periods has
been played by the idle, but its evil influence is greater now than
b