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every patient who comes before us is made up of such a 

 mingling of temperaments, idiosyncrasies, and diatheses, as 

 can only be appreciated, and that imperfectly, by even the 

 keenest diagnosis ; and of inherited peculiarities of tissue, 

 and function, and dynamism, which may be active or latent ; 

 of potentialities or deficiencies which morbid processes can 

 alone reveal. 



But to return. Statistics are, and can only be, unreliable 

 and valueless in regard to the percentage of inherited cases 

 of phthisis, and we can only accept the concurrent testimony 

 of every age, which is so strong that it cannot be doubted 

 or rejected. Whole families have been exterminated by 

 phthisis, and according to Horlin, as stated by Hirsch, in the 

 island of Marstrand, where only one person had died of 

 consumption during seven years, there were five consump- 

 tives then living there, four of them sisters, whose mother 

 had died from this disease. The inherited predisposition to 

 consumption may reveal itself in different ways sometimes 

 in constitutional delicacy, sometimes in special local affections 

 of the thorax or its organs and these may or may not be 

 observed at birth or during childhood, but are generally 

 noticed at a later period, as, for example, at the time of 

 puberty, when growth and development are more rapid. 

 However we may subdivide the inheritability of phthisis we 

 cannot but regard it as a factor of prime importance in the 

 etiology of the disease. Although this predisposition is 

 commoner perhaps among women than men, and its trans- 

 mission more common through the mother than the father, 

 yet where one parent only is affected fathers transmit more 

 readily to sons, and mothers to daughters, than the converse. 

 Dr. Pollock lays stress on the influence of hereditary pre- 

 disposition in the acute forms of phthisis, and states that out 



