cavities of the body. The diminished flow of blood through the lungs
prevents its proper oxygenation; this may also be interfered with by
the accumulation of fluid within the air spaces of the lungs.

Every additional burden thrown upon the heart increases the evil. In
women the additional burden of pregnancy may suffice to overcome a
compensation which has been perfect, and the same may result from an
acute attack of disease. Age, diminishing as it does the capacity for
work in all organs, diminishes the compensation capacity of the heart,
and a heart which at the age of forty acts perfectly may break down at
the age of fifty. Compensation may be gained in other ways, as by
reducing the demand made upon the heart by changing the mode of life,
by leading an inactive rather than an active life, by avoiding
excitement or any condition which entails work of the heart. Social
conditions are of great importance; it makes a great difference
whether the unfortunate possessor of such a heart be a stevedore whose
capital lies in the strength of his muscles, or a more fortunately
placed member of society for whom the stevedore works and whose
occupation or lack of occupation does not interfere with the
adjustment of his external relations to the condition of his heart.

Disease of the nervous system does not differ from disease elsewhere.
The system is complex in structure and in function. It consists in
nerves which are composed of very fine fibrils distributed in all
parts of the body and serve the purpose of conduction, and a central
body composed of the brain and spinal cord which is largely cellular
in character; it receives impressions by means of the nerves and sends
out impulses which produce or affect action in all parts. By means of
the organs of special sense, the brain receives impressions from the
outer world which it transforms into the concepts of consciousness.
Many of the impressions which the central nervous system receives from
nerves other than those of special sense and even many of the
impressions from these and the impulses which it sends out do not
affect consciousness. The memory faculty is seated in the brain and
all parts of the brain are closely connected by means of small nerve
fibres. The nervous system plays an important part in the internal
regulation and coordination of all parts of the body, and it is by
means of this that the general adjustment of man with his environment
is effected.

Malf