ETIOLOGY.—So far as heredity is concerned, general paralysis has not such close relations with mental diseases as insanity in general. It is estimated to be hereditary, in the sense of being closely related to other forms of insanity, about one-half as often, and it is nearly allied to apoplexy and epilepsy. My own experience leads me to the conclusion that in those cases of general paralysis without a previous history of syphilis (and the same statement is true in less degree of persons who have had syphilis) the vast majority occur in families in which there have been cases of insanity, epilepsy, or apoplexy. It is rare among people living simple agricultural lives, but is intimately connected with the faults and vices of civilization—specialized overwork, involving strain in the office, study, factory, mine, etc., especially if to bodily exhaustion and brain wear and worry there be added hard living and hard drinking, sexual excesses, and syphilis. The Scotch Highlander rarely has the disease until he comes to Edinburgh or Glasgow. In Ireland general paralysis is so rare that of 9271 cases of insanity in 1882, only 6 were general paralytics, as compared with 1151 out of 13,581 in England the same year; during which, in Scotland, of 238 deaths from insanity, 10 were from general paralysis; but the Irishman has no special exemption from general paralysis in American cities or in large English towns and mines and factories, where he works hard, drinks hard, and lives hard generally. It is, so far as I am able to learn, unreported thus far among our negro population until they come to the great centres of population; it is said to have been unknown among the slaves. Among the English, Scotch, and Americans it prevails most among those people who are in, or who have dropped down to, the lower strata of society. Of 2212 private patients in England, 139, or about 6 per cent., were general paralytics, while 1012, or about 9 per cent., were found among 11,359 pauper patients. French and German writers report it as most common among the brain-workers. In women of the upper class it exceedingly seldom occurs. In some of our Western asylums not more than 1 or 2 per cent., or even less, of the patients are reported as general paralytics, coming chiefly from farms. In the asylum for the centre of the manufacturing districts of Massachusetts about 9 per cent. of the patients are general paralytics. From the iron- and coal-mines of England from 14 to 17 per cent. of the insane confined in asylums are general paralytics. It is more common in cold climates than in warm, other things being equal. From one-sixth to one-tenth of the cases, varying in different localities, are women.