UNHEALTHY ENVIRONMENTS 217 



seems but little chance in these cases that selection will 

 cease or even diminish. 



The effect of an unhealthy environment upon sections of 

 a race has already been dealt with. 1 Here, though it would 

 seem that the race is not injured by slum conditions, it is 

 not improved except with regard to power of resisting the 

 evils of the particular environment. Hence if slum condi- 

 tions are removed permanently, good is done to the indi- 

 vidual and the race does not lose any useful characters. 



If civilised races are deteriorating the cause is not the 

 existence of slums in their towns, but that comparatively 

 unfit individuals who would formerly have died early survive 

 to produce children. Beneficial as the advance of knowledge 

 in medicine, surgery, hygiene, and sanitation is to individuals, 

 it must tend to lower the physical standard of the race, 

 through the preservation of individuals who would not have 

 survived under more stringent conditions of selection. 



The increase of lunatics is a most serious problem, and 

 will probably call for very stringent measures in the near 

 future. 2 Lunacy is undoubtedly hereditary, 3 and unfortu- 



1 See pp. 154-5. 



2 In 1859 there was one certified lunatic in every 536 individuals of the 

 general population in England and Wales ; in 1900 there was one lunatic to 

 every 301 of general population (Fifty-fourth Report of the Commissioners in 

 Lunacy). In Scotland the number of lunatics had increased 180 per cent, 

 between 1858 and 1900 (op. cit.). In Ireland there was one lunatic or idiot in 

 657 individuals of the general population in 1851. In 1901 there was one 

 in 178 (Edinburgh Medical Journal, May 1903). 



"One cannot fail to observe the large number of our patients who are 

 related to one another. We have at the present time in this asylum examples 

 of brothers, sisters, brother and sister, father and daughter, father and sons, 

 mother and daughter, uncle and niece, aunt and nephew, besides many cases 

 of more distant relatives. Out of a total of 1934 persons admitted during the 

 past five years I have discovered evidence of insanity in the family, and often 

 in many members, in 828 instances, or 42*7 per cent An analysis of these 

 828 cases brings into prominence three very important facts : 



"1. That the disease makes its appearance early in life. 



' ' 2. Should the patients be discharged they are prone to relapse. 

 ' 3. Should they remain and die here they usually do so at a good old age. 



' ' The conclusion of the whole matter is this that our asylum population is 

 constantly recruited from and maintained by persons who have some inherited 

 defect of brain-cell which renders them unfit to meet the ordinary stress of life, 



