posed upon its elements, becomes an efficient cause of disease. But in
these cases there is either an original imperfection in the organization
of the nerve tissues, or the mental effort has been of that
exceptionally intense nature of which none but a few minds are capable.
Finally, in these cases, the resulting disease is seated in the brain or
spinal column.

This latter remark is of great importance for our purpose; for it tends
to show that diseases produced elsewhere within the range of the
ganglionic system of nerves--as the menstrual haemorrhage, that we are
especially considering--must be due to some other nervous act than that
of thought.

From the foregoing considerations, we believe, may be again inferred,
first, that the radical difference which exists between the cerebral
operations that result in thought, and those that accompany the
evolution of emotion, probably depends upon the fact, that in the former
central nervous action remains more or less localized on the surface of
the cerebral hemispheres, while, in the latter, the great ganglia lying
at the base of the brain, and hence nearer the vaso-motor centre, are
called into play; second, that the effects of such action are more
rapidly generalized throughout the nervous system, and, by causing the
dilatation of the blood-vessels in the manner described, exhaust the
central nervous system in a twofold manner, by a disturbance of its
circulation, and by a direct depression of its nutrition, when the
modifications of the circulation exaggerate the nutrition elsewhere.
Repeated excitement and consecutive paralysis of the vaso-motor nerves,
therefore, serve as the most efficient means of draining off the force
of the cerebro-spinal nervous system. And it has been seen, that a
depression of its power is followed by an exaggerated and irregular
activity of the ganglionic system, to which are due most of the
phenomena observed in hysteria and in ordinarily nervous women. These
are in many respects different from those observed in men suffering from
so-called nervous debility, for the reason, that in them the ganglionic
system of nerves is less prominent, and its irregularities of action
therefore less marked, when the control exercised by the cerebro-spinal
system has been diminished. If the vaso-motor centre of the brain is
only influenced when the ganglia at the base are called into activity,
and if their activity coincides with emotion, and not with though