HEREDITY OF DISEASES. 27 



were affected, 53 inherited the disease from the fa- 

 ther, 62 from the mother, and 12 from both. 1 



A comparison of 1,031 consumptives with 1,031 

 non-consumptives, insured in the Mutual Life In- 

 surance Company of New York, shows that " nearly 

 twice as many of the former had consumptive blood- 

 relations as of the latter, or, to speak more accurately, 

 18.81 per cent, of the consumptives, and only 10.89 

 per cent, of the non-consumptives, had near relations 

 (parents or brothers or sisters) who died of consump- 

 tion." 



These " cases were all healthy lives, selected after 

 medical examination, and one of the rules of this ex- 

 amination tended to exclude persons with a decided 

 family taint ; hence we should expect to find here a 

 much smaller number of tainted families than among 

 consumptives in general." a 



The transmission of mental peculiarities, referred 

 to in the preceding chapter, is not confined to those 

 idiosyncrasies that are compatible with what may be 

 termed a healthy condition of the nervous system, but 

 extend also to the various forms of mental disease. 

 Among 1,375 lunatics, Esquirol found 337 cases of 

 hereditary transmission.* 



In 50 cases of insanity examined by Maudsley, 16 



1 " On the Nature, Symptoms, and Treatment of Consumption," by 

 R. P. Cotton, M. D., London, 1852, p. 61 ; quoted in the Journal of 

 the Royal Agricultural Society, vol. xvi., p. 35. 



2 " Mortuary Experience of the Mutual Life Insurance Company of 

 New York," vol. ii., pp. 71-73. 



3 Popular Science Monthly, November, 1873, p. 58 ; London Lancet, 

 quoted in the Pacific Medical and Surgical Journal, February, 1877, 

 p. 406. 



