1 62 MARRIAGE AND DISEASE. 



class the deafness, and consequent ignorance of spoken 

 language (except in those cases in which the deafness 

 is caused by scrofulous disease, syphilis, &c.), are no 

 more hereditary than is the blindness of the child 

 whose eye has been poked out with a stick. The 

 two classes should be kept distinct. The first is by 

 far the larger, but a sufficient number belong to the 

 second to materially affect statistics ; and until the 

 two classes are clearly distinguished, opinions will 

 differ as to the part played by hereditary taint in the 

 production of deaf-mutism. 



With the second class we have nothing here to do. 

 Such cases generally arise from some destructive in- 

 flammatory affection of the middle ear as that which 

 frequently follows scarlet fever and so may occur in 

 any child. In the infant they are easily distinguish- 

 able from the congenital cases ; but later in life, 

 when the history becomes garbled, it is often difficult, 

 if not impossible, to distinguish to which class a case 

 properly belongs. 



Congenital deaf-mutism is, on the other hand, a con- 

 stitutional affection. It is a degenerate, a markedly 

 degenerate condition, and therefore a sign that the 

 family in which it appears has started on the down 

 'grade toward decay, except in such cases as it 

 depends upon some temporary depraved condition 

 in the parents at the time the child was begotten, as 

 drunkenness, &c. 



It is true that deaf-mutism is not, like the suicidal 

 impulse and some other conditions that we have con- 



