[333] _Special Reports, Bureau of the Census_, "Insane and Feebleminded," 21. [334] _Minnesota Executive Documents, 1900_--statistics for the insane for 1890, 1896, and 1900; The North, Dec. 18, 1889; _Wisconsin State Board of Control_ [biennial], 1890 to 1902. [335] _Special Reports, Bureau of the Census, 1904_, "Insane, etc., in Hospitals," 21. Nelson, _History of the Scandinavians_, II, ch. i, makes a conscientious, but rather lame, attempt at analyzing available statistics of insanity, and gives his conclusions for two periods, 1881-2 and 1890-4: ratio of insane in total population, 1:2718 and 1:1719; in American-born, 1:4120 and 1:3009; in foreign-born, 1:1480 and 1:1144; in Irish, 1:1061 and 1:769; in German, 1:1461 and 1:1439; in Scandinavian, 1:1588 and 1:819. If one seeks for adequate reasons for this unusual tendency to insanity, he will not find ready satisfaction. Undoubtedly the difference of environment and the severer strain upon muscle and nerve imposed by American industrial conditions, by which the machinery of the individual must run at a higher and unwonted speed, will account for part of the phenomena, but these causes operate alike upon all classes of immigrants. The change from the mountains of Norway, or from the rugged sea-coast of the great Northern peninsula, to the rolling prairies and the vast silent plains of the interior of the United States, has also its depressing effect. The very flatness of the land, its extremes of temperature, the fierce tornadoes of wind, the bewildering, imprisoning storms of snow, with no friendly mountain or forest to offer a body of protection or a face of comfort, and the isolation of the life of the frontier farmer and his family, together with the severity of their labor--all these are causes operating with peculiar force in the case of the Norwegian and Swedish immigrants. Dr. Gronvald, writing in 1887, stated his conviction that the women of these classes, especially the Norwegians, were predisposed to nervous disorders and insanity by early and frequent child-bearing, and from early rising from child-bed.[336] [336] Gronvald, "The Effects of the Immigration on the Norwegian Immigrants," _Sixth Annual Report of the State Board of Health of Minnesota_, 520.