Indications which point to the probability of its increase in a greater ratio than that of the population: (1) in relation to the general conditions of society; (2) in occupations; (3) in the character or tendency of disease--Increased demand for hospitals for the insane not a conclusive evidence of increase of insanity; other reasons exist for this--Improvements in hospitals--The chronic as well as the acute insane now provided for more generally than formerly--Accumulations in asylums-- Statistics--Those of England and Scotland--Their character and import as presented in the yearly reports of the Boards of Lunacy Commissioners 11 CHAPTER III. INSANITY AND CIVILIZATION. Prevalence of disease among savage nations--Conditions of life not such as to produce insanity--Definitions of civilization-- Several conditions attending civilization combine to increase diseases of the brain--Increase of brain activity-- Over-stimulation of the brain in schools and by the use of alcoholic beverages--A community of interests exists in savage life which is lost in civilized life--In the latter the strong thrive at the expense of the weak--Monopolies in land and other forms of property--Inference to be drawn from the tendency of insanity to increase--The primary condition of insanity one of the brain--Investigations should relate to the nature and causes of this condition 33 CHAPTER IV. THE INSANE DIATHESIS. The _ideal_ human system--The _actual_ human system--Physical and mental differences among persons in health--Periods during which there exist considerable changes in the character of mental action in the case of many persons while in a state of health--Excitement and depression of mental activity--This tendency to unstable activity of the nervous system may be inherited or acquired--Illustrations from the effects of over-exertion, "writer's cramp," chorea--A similar condition of that portion of the brain which is concerned in mental operations may exist--Illustrations--The effects of sudden mental shocks and long-continued mental application-- Recapitulation--The condition which we term the Insane Diathesis is the prime factor in the causation of insanity 53 CHAPTER V. THE INFLUENCE OF EDUCATION.