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.

Something more than one hundred and thirty years ago there graduated at Harvard College a delicate youth, who lived an invalid life and died at the age of about fifty.  His two children were both of moderate physical power, and one of them diminutive in stature.  The next generation rose in physical development, and reached eighty years of age and more in some of its members.  The fourth generation was of fair average endowment.  The fifth generation, great-great-grandchildren of the slender invalid, are several of, them of extraordinary bodily and mental power; large in stature, formidable alike with their brains and their arms, organized on a more extensive scale than either of their parents.

This brief account illustrates incidentally the fallacy of the universal-degeneration theory applied to American life; the same on which one of our countrymen has lately brought some very forcible facts to bear in a muscular discussion of which we have heard rather more than is good for us.  But the two series, American and English, ascending and descending, were adduced with the main purpose of showing the immense difference of vital endowments in different strains of blood; a difference to which all ordinary medication is in all probability a matter of comparatively trivial purport.  Many affections which art has to strive against might be easily shown to be vital to the well-being of society.  Hydrocephalus, tabes mesenterica, and other similar maladies, are natural agencies which cut off the children of races that are sinking below the decent minimum which nature has established as the condition of viability, before they reach the age of reproduction.  They are really not so much diseases, as manifestations of congenital incapacity for life; the race would be ruined if art could ever learn always to preserve the individuals subject to them.  We must do the best we can for them, but we ought also to know what these “diseases” mean.