128 



SCIENCE 



[Vol. V., No. 106. 



TABLE III. 



Percentage of the deaf-mute population who are other- 

 vrise defective. 





Totals. 



Percentage. 



Deaf-mutes returned as also blind . . 

 Deaf-mutes returned as also idiotic 

 Deaf-mutes returned as also insane 



493 



2,339 



298 



1.45 

 6.90 

 0.88 



Deaf-mutes returned as otherwise de- 



2,883 

 30,995 



8.51 



Deaf-mutes returned as simply deaf . 



91.49 



Total deaf and dumb 



33,878 



100.00 



TABLE IV. 



Percentage of the blind population who are otherwise 

 defective. 





Totals. 



Percentage. 



Blind persons returned as also deaf 



and dumb 



Blind persons returned as also idiotic, 

 Blind persons returned as also insane, 



493 



1,403 



558 



1.01 

 2.87 

 1.14 



Blind persons returned as otherwise 



2,207 

 46,721 



4.50 



Blind persons returned as simply 

 blind 



95.49 



Total blind 



48,928 



100.00 







TABLE V. 



Percentage of the idiotic population who are otherwise 

 defective. 





Totals. 



Percentage. 



Idiots returned as also deaf and dumb, 

 Idiots returned as also blind .... 



2,339 

 1,403 



3.04 



1.82 



Idiots returned as otherwise defective, 

 Idiots returned as simply idiotic . . 



3,525 

 73,370 



4.58 

 95.42 



Total idiots 



76,895 



100.00 



TABLE VI. 



Percentage of the insane population who are otherwise 

 defective. 





Totals. 



Percentage. 



Insane persons returned as also deaf 

 and dumb 



298 

 558 



0.32 

 0.61 



Insane persons returned as also blind, 



Insane persons returned as otherwise 

 defective 



826 

 91,133 



0.90 

 99.10 



Insane persons returned as simply in- 

 sane 





Total insane 



91,959 



100.00 



TABLE VII. 



Percentage of the doubly defective who are also trebly 

 defective. 



Of 493 blind deaf-mutes, 217, or 44.02 %, are returned as also 



idiotic. 

 Of 493 blind deaf-mutes, 30, or 6.09 %, are returned as also insane. 

 Of 2,339 idiotic deaf-mutes, 217, or 9.28 %, are returned as also 



blind. 

 Of 298 insane deaf-mutes, 30, or 10.07 %, are returned as also 



blind. 

 Of 1,403 blind idiots, 217, or 15.47 %, are returned as also deaf 



and dumb. 

 Of 558 insane blind persons, 30, or 5.38 %, are returned as also 



deaf and dumb. 



The tables seem to indicate that in the case 

 of deafness, blindness, idiocy, and insanity, 

 some correlation exists ; for persons having 

 one of those defects appear more liable to the 

 others than persons normally constituted, and 

 doubly defective persons appear to be more 

 liable to be otherwise defective than persons 

 having a single defect. For instance : — 



(a) Of 50,155,783 persons in the United States, 246,816, or 0.4921 %, 

 are defective. 



(b) Of 246,816 defective persons, 4,597, or 1.86 %, are doubly 

 defective. 



(c) Of 4,597 doubly defective persons, 247, or 5.37 %, are trebly 

 defective. 



The results obtained above, I think, merit 

 the consideration of scientific men, and are 

 calculated to throw light upon the subject of 

 correlated defects. 



Although the proportion of the insane who 

 are deaf or blind is abnormally large, the evi- 

 dences of a correlation between insanity and 

 the other defects noted above are not w T ell 

 marked ; but in regard to deafness, blindness, 

 and idiocy, a marked correlation appears to 

 exist. 



1 . Deaf-mutes. — There are fourteen and a 

 half times as many blind persons among the 

 deaf aud dumb in proportion to the population 

 as there are in the community at large, and 

 fort} T -six times as man} 7 idiotic. 



2. Blind. — There are fourteen times as 

 many deaf-mutes among the blind in propor- 

 tion to the population as there are in the com- 

 munity at large, and nineteen times as many 

 idiots. 



3. Idiotic. — There are forty-three times as 

 many deaf-mutes among the idiotic in propor- 

 tion to the population as there are in the com- 

 munity at large, and eighteen times as many 

 blind. 



The apparent correlation between deafness, 

 blindness, and idiocy, may possibly indicate 

 that in a certain proportion of cases these 

 defects arise from a common cause, perhaps 

 arrested development of the nervous system. 



It is of course possible that some of the 

 persons returned as ' blind deaf-mutes ' may 



