Disease and death, if we may judge by the records of creation, are inherently and essentially necessary in the present order of things. A perfect intelligence, trained by a perfect education, could do no more than keep the laws of the physical and spiritual universe. An imperfect intelligence, imperfectly taught,--and this is the condition of our finite humanity,--will certainly fail to keep all these laws perfectly. Disease is one of the penalties of one of the forms of such failure. It is prefigured in the perturbations of the planets, in the disintegration of the elemental masses; it has left its traces in the fossil organisms of extinct creations. [Professor Agassiz has kindly handed me the following note: “There are abnormal structures in animals of all ages anterior to the creation of mankind. Malformed specimens of Crinoids are known from the Triassic and Jurassic deposits. Malformed and diseased bones of tertiary mammalia have been collected in the caverns of Gailenreuth with traces of healing.”] But it is especially the prerogative, I had almost said privilege, of educated and domesticated beings, from man down to the potato, serving to teach them, and such as train them, the laws of life, and to get rid of those who will not mind or cannot be kept subject to these laws. Disease, being always an effect, is always in exact proportion to the sum of its causes, as much in the case of Spigelius, who dies of a scratch, as in that of the man who recovers after an iron bar has been shot through his brain. The one prevalent failing of the medical art is to neglect the causes and quarrel with the effect. There are certain general facts which include a good deal of what is called and treated as disease. Thus, there are two opposite movements of life to be seen in cities and elsewhere, belonging to races which, from various persistent causes, are breeding down and tending to run out, and to races which are breeding up, or accumulating vital capital,--a descending and an ascending series. Let me give an example of each; and that I may incidentally remove a common impression about this country as compared with the Old World, an impression which got tipsy with conceit and staggered into the attitude of a formal proposition in the work of Dr. Robert Knox, I will illustrate the downward movement from English experience, and the upward movement from a family history belonging to this immediate neighborhood. Miss Nightingale speaks of “the fact so often seen of a great-grandmother, who was a tower of physical vigor, descending into a grandmother perhaps a little less vigorous, but still sound as a bell, and healthy to the core, into a mother languid and confined to her carriage and house; and lastly into a daughter sickly and confined to her bed.” So much for the descending English series; now for the ascending American series.