hether public sentiment at the present time
will allow the measure to be thoroughly carried out. Some results in
preventing unfit heredity may be attained by the greater extension of
asylum life, but the additional burden of this upon the labor of the
people would be difficult to bear. At best such measures would only be
carried out in the lower class of society.

CHAPTER XI

CHRONIC DISEASES.--DISEASE OF THE HEART AS AN EXAMPLE.--THE STRUCTURE
AND FUNCTION OF THE HEART.--THE ACTION OF THE VALVES.--THE PRODUCTION
OF HEART DISEASE BY INFECTION.--THE CONDITIONS PRODUCED IN THE
VALVES.--THE MANNER IN WHICH DISEASE OF THE VALVES INTERFERES WITH
THEIR FUNCTION.--THE COMPENSATION OF INJURY BY INCREASED ACTION OF
HEART.--THE ENLARGEMENT OF THE HEART.--THE RESULT OF IMPERFECT WORK OF
THE HEART.--VENOUS CONGESTION.--DROPSY.--CHRONIC DISEASE OF THE
NERVOUS SYSTEM.--INSANITY.--RELATION BETWEEN INSANITY AND
CRIMINALITY.--ALCOHOLISM AND SYPHILIS FREQUENT CAUSES OF
INSANITY.--THE DIRECT AND INDIRECT CAUSES OF NERVOUS DISEASES.--THE
RELATION BETWEEN SOCIAL LIFE AND NERVOUS DISEASES.--FUNCTIONAL AND
ORGANIC DISEASE.--NEURASTHENIA.

Chronic diseases are diseases of long duration and which do not tend
to result in complete recovery; in certain cases a cause of disease
persists in the body producing constant damage, or in the course of
disease some organ or organs of the body are damaged beyond the
capacity of repair, and the imperfect action of such damaged organs
interferes with the harmonious inter-relation of organs and the
general well-being of the body. The effect of damage in producing
chronic disease may not appear at once, for the great power of
adaptation of organs and the exercise of reserve force may for a time
render the damage imperceptible; when, however, age or the
supervention of further injury diminishes the power of adaptation the
condition of disease becomes evident. Chronic disease may be caused by
parasites when the relation between host and parasite is not in high
degree inimical, as in tuberculosis, gonorrhoea, syphilis, most of the
trypanosome diseases and the diseases produced by the higher
parasites. In certain cases the chronic disease represents really a
series of acute onsets; thus in the case of the parasites there may be
periods of complete quiescence of infection but not recovery, the
parasites remaining in the body and attacking when the defences of the
body are in some way weakened. In such c