188 



MEMOIRS OF THE NATIONAL ACADEMY OP SCIENCES. 



We have good reason, therefore, to fear that the intermarriage of congenital deaf-mutes, even 

 though the deafness in both cases might be sporadic, would result in many cases in the production 

 of deaf oflsi)ring. It is important, then, to arrive at some idea of the numbers of the deaf and 

 dumb who are deaf from birth. 



The Compendium of the Tenth Census of the United States shows us that there were living in 

 this country on the 1st of June, 1880, no less than 33,878 deaf-mutes, and that "more than one- 

 half" were congcnitally deaf.* 



The proportion can be obtained more exactly from an address delivered in Jacksonville, 111., 

 on the 29th day of August, 1882, before the tenth con\'eutiou of American instructors of the deaf 

 and dumb, by the Rev. Fred. H. Wines,t who had charge of the department of the census relating 

 to the deaf and dumb. Pending the full publication of the census returns, the statements of Mr. 

 Wines concerning the census of the deaf and dumb must evidently be received as authoritative. 



In the address referred to Mr. Wines gave the results of an analysis of 22,472 cases from the 

 census, from which it appears that of these deaf-mutes 12,154, or 54.1 jjer cent., were reported as 

 congenitally deaf, and 10,318, or 45.0 per cent., were stated to have lost their hearing after birth. 



If we apply these figures to the total mentioned in the Compendium of the Census (33,878) 

 we find that there are probably 18,328 congenital and 15,550 non-congenital deaf-mutes in the 

 United States. 



Deductions drawn from the breeding of animals would lead us to expect that the congenitally 

 deaf would be more likely than those who became deaf from accidental causes to transmit their 

 defect to their oflsi)iing. Another indication pointing in the same direction is to be found in the 

 fact that the proportion of the deaf and dumb who have deaf-mute relatives is very much greater 

 among the congeuital than among the uou-congenital deaf-mutes. 



The following tables (Tables XIY, XV, and XVI) have been compiled from the re])orts of 

 the American institutions for the deaf and dumb already referred to: 



Table XIV. 



* Compendium of the Tenth Census, Part II, papfe 1664. 



tSee Proceedings of the Tenth Convention of American Instructors of the Deaf and Dumb, Jacksonville, 111., 

 August, 1882, pp. 122-128, published by the Illinois Institutiou for the Deaf and Dumb, Jacksonville, 111., with the 

 twenty-first biennial rcjiort of that Institutiou. 



