After allowing all that, which we can, in its fullest limit, to religion, family, or social habit, there is still a wide margin to be accounted for. This has naturally let the inquiry, followed in the course of this book, into a careful review of the Jewish people; into their religion and its character, its relation to other creeds, and to the world's history; into their many wanderings, and into the dispersion, and we have even been obliged to follow them into the midst of the people among whom they have become nationed, to try, if possible, to find the cause of this racial difference in health, resistance to disease, decay, and death. It has been necessary, in following out the research, to give a condensed _resume_ of the religious, political, and social condition of the Jewish commonwealth, which, although in a state of dispersion, still exists. I need offer no apology for the extended notice this has received in the course of the book. We read with increasing interest either Hallam or May, Buckle or Guizot, through the spasmodic, halting, retrograding, advancing, erratic, aimless, and accidental phases that England has plowed through, from the days of goutless, simple, and chaste, but barbarian England of the Saxons, to the present civilized, enlightened, gouty, "Darkest England" of General Booth; and, after all is said and done, we are no wiser in any practical resulting good. We simply know that the English people, so to speak, have, as it were, gone through the figures of some social aspects, as if dancing the "Lancers," with its forward and back movements, gallop, etc., and have finally sat down, better dressed and better housed, but in an acquired state of moral and physical degeneration. The Briton of Queen Victoria is not the Briton of Queen Boadicea, either morally or physically. On the other hand, the system of sociological tables adopted by Herbert Spencer would have but little to record for some six thousand years--either in religion, morals, or physique--as making any changes in the history of that simple people which, in the mountainous regions of Ur, in distant Armenia, started on its pilgrimage of life and racial existence; in one branch of the family--that of Ishmael--the changes to be recorded are so invisible that its descendants may really be said to live to-day as they lived then. So that I do not feel that I need to apologize for the space I have given to this subject in the course of the book. The causes that make these racial distinctions should be of interest alike to the moralist, theologist, sociologist, and to the physician.