DEAF-MUTISM. 171 



of civilised life, a deaf variety of mankind should 

 not be founded, as Sir William Lawrence said we 

 might found a six-fingered variety. But congenital 

 deafness is not the simple absence of one of the senses 

 which is not absolutely necessary for life ; it is a sign 

 of a general decay, which, if deepened by intermar- 

 riage, must soon reach the necessarily fatal type and 

 extinguish the family.* 



Congenital deaf-mutism may, and does, occur at 

 times in families in which it is impossible to dis- 

 cover any signs ot decay of the stock. But even 

 here its appearance is generally to be explained. 

 In such cases, the blight most frequently depends 

 upon initial heredity, for the deaf-mute, like the 

 idiot, is often the result of drunkenness on the 

 part of the parent when the child was begotten. 

 In these cases the deafness is generally accompanied 

 by considerable imbecility or by some physical 

 deformity. Another common cause of deaf-mutism 

 is habitual drunkenness in the parent; but these 

 cases may well be classed with the great mass, for 

 it is always to be suspected that the habitual 

 drunkenness in the parent is itself the result of an 

 inherited taint, which is transmuted in passing to the 

 child. 



Another cause of deaf-mutism is syphilis in the 

 parent. This disease, as we have seen, often brings 



* Menckel has published cases showing how frequently the 

 children of deaf-mutes exhibit imbecility, i.e., a stage further on 

 the downward course. 



