Who May not Marry.--Many writers devote much space in laying down rules which are to be implicitly followed by those seeking life partners. We have attempted nothing of the sort, both from its impracticability, and from the fact that such rules are never followed; and if the attempt should be made to follow the prescribed rules, we are not sure that more good than harm would be the result. Hence, we shall content ourselves with calling attention to a few facts of great importance respecting the conditions which imperatively forbid marriage, and which cannot be violated without the certain entailment of great suffering. _1. Persons suffering with serious disease of a character communicable to others by contagion or by hereditary transmission._ Many people wonder why it is that diseases are so much more numerous and varied in modern times than in the earlier ages of the race. There has been an evident increase within a few centuries. While there are, undoubtedly, numerous influencing causes, one which cannot be overlooked is the hereditary transmission of disease, which preserves those disorders which already exist, and adds new ones which originate from new exciting causes. By this means, the human race is undoubtedly being weakened, human life shortened, and diseases multiplied. Compare the average age of human beings of the present day, less than forty years, with the longevity of the early members of the race, who lived more than as many score of years. Some mighty deteriorating influence has been at work; and we hazard nothing in the assertion that the marriage of diseased persons and kindred violations of the laws of human hygiene have been not unimportant factors in producing this most appalling diminution in the length of human life. Among the diseases which are most certain to be transmitted are pulmonary tuberculosis, or consumption, syphilis, cancer, leprosy, epilepsy, and some other nervous disorders, some forms of skin disease, and insanity. The list might be extended; but these are the more common. Persons suffering with these disorders have no right to marry, for at least four reasons:-- (1) It is a sin against the offspring of such unions, who have a right to be born well, but are forced to come into the world with weakly constitutions, diseased frames, and the certainty of premature death. The children of consumptive and syphilitic parents rarely survive infancy. If they do, it is only to suffer later on, as they surely will, and, perhaps, to communicate the same destructive diseases to other human beings; but these diseases rarely extend beyond the third generation, the line becoming extinct. The most heart-rending spectacles we have ever met have been the children of parents suffering with the diseases mentioned. Their appearance is characteristic; no physician of experience can fail to detect the sins of a profligate parent in a syphilitic child. Every feature indicates the presence of a blighting curse.