6. Persons who are greatly disproportionate in size should not marry.

While good taste would suggest the propriety of this rule, there are important physiological reasons for its observance. While the lack of physical adaptitude may be the occasion of much suffering and unhappiness in such unions, especially on the part of the wife, being even productive of most serious local disease, and sometimes of sterility, it is in childbirth that the greatest risk and suffering is incurred. More might be said on this point, but this is sufficient for those who are willing to profit by a useful hint.

7. Persons between whom there is great disparity of age should not marry.

The reasons for this have already been given at length, and we will not repeat. In general, the husband should be older than the wife, from two to five years. The husband may often be ten or twelve years the senior of the wife; but when more than that, the union is not likely to be a profitable or happy one, if it is not absolutely productive of suffering and unhappiness. The ancient Greeks required that the husband should be twenty years older than the wife; but this custom was no more reasonable than that of another nation which required that only old and young should marry, so that the sobriety of the old might restrain the frivolity of the young.

8. Persons who are extremely unlike in temperament should not marry.

Persons who are so unlike in temperament and tastes as to have no mutual enjoyments, no congeniality of feeling, will be incompatible as husband and wife, and the union of such persons will be anything but felicitous. No definite rule can be laid down; but those seeking a companion for life would do well to bear this caution in mind, at the same time remembering that too great similarity of character, especially when there are prominent defects, is equally undesirable.

9. Marriage between widely different races is unadvisable.

While there is no moral precept directly involved in marriage between widely different nations, as between whites and blacks or Indians, experience shows that such marriages are not only not conducive to happiness, but are detrimental to the offspring. It has been proven beyond room for question that mulattoes are not so long-lived as either blacks or whites.

10. Persons who are unable to sustain themselves or a family should not marry.