A study of the histories of seven thousand six hundred and fifty-seven cases of insanity covering a period of thirty-two years may be summarized briefly in the following general observations: (1) The ratio of the insane to the general population is much larger than most statisticians have estimated it to be, but the increase in the proportion of the insane is very much smaller than has been determined heretofore. (2) The foreign element of our community shows much the larger proportion of insane than does the native. The native insane, however, have increased to a considerable extent, but not in the same proportion as the foreign insane. (3) The cities show a much larger percentage of the insane than do the counties, but the counties show an increasing proportion of insane in the later years. (4) We have also seen that the large proportion coming from the cities is due to the larger percentage of the foreign element in the city, also that with increase of the foreign element in the country there is an increase in the insane. (5) The Irish show the largest percentage of the insane. The Germans are next in proportion. The native Americans show the least insane to population. In general the middle period (1880-1890) shows the largest proportion of the foreign insane. (6) In proportion to population, the Irish lead all other nationalities in the production of insanity. (7) The cities, as a whole, send much larger numbers of foreign insane in proportion to the population than the counties. (8) As compared with the whole State, Hartford and New Haven have larger proportions of foreign insane than the cities as a whole over the counties of the State. (9) Fairfield, Litchfield and Windham counties show the lowest proportion of native insane.I have to acknowledge the hearty cooperation of Dr. Allen R. Diefendorf, psychiatrist and pathologist at the Connecticut Hospital for the Insane, who has given much time to the supervision and criticism of the work. I am also greatly indebted to Dr. Charles W. Page, former Superintendent of the Institution, for many privileges granted. To these and to all others, who by criticism and suggestion have aided in the work and especially to those who have helped in the laborious collaboration of the tables which have made this work possible, I am exceedingly grateful.Abstract Teaser