TABLE XXIV. ------------------------------------------------------------------ | | Congenital deaf-mutes | |----------------------------------------------- | | | | | Parents cousins | | | | |---------------------- | | | |Average | | |Average | | |Number |number | | |number Censal | Total | |per | to a | |Per | to a year. |population|Number|million|family[A]|Number|cent.|family[A] ------------------------------------------------------------------ 1851[B]| 6,574,278| 4,127| 628 | ---- | 242 | 5.86| 1.66 1861 | 5,798,967| 4,096| 706 | 1.22 | 362 | 8.84| 1.72 1871 | 5,412,377| 3,503| 647 | 1.30 | 287 | 7.35| 1.76 1881 | 5,174,836| 3,163| 611 | 1.32 | 191 | 6.04| 1.69 1891 | 4,706,448| 2,570| 546 | 1.40 | 297 |11.56| 1.92 1901 | 4,456,546| 2,179| 489 | 1.40 | 249 |11.43| 1.73 ------------------------------------------------------------------ [A] From Table XXV. [B] 1851 data from Huth, "Consanguineous Marriage and Deaf-mutism." _The Lancet_, 1900. Table XXIV summarizes the most important points in the Irish data. It will be seen that while there has been an absolute diminution in the number of deaf-mutes in Ireland with the decrease in population, there has been a relative increase of deaf-mutism. There are two possible explanations for this phenomenon, both of which may have operated in part; first that in the great emigration the deaf-mutes have been left behind, and second that with the introduction of improved methods of census taking, the returns are more complete than a half century ago. Mr. Huth believes that there is still room for improvement in Irish census methods, and thinks there is reason to believe that in the enumeration of the deaf all children born deaf in a family are included whether living or not.