between persons descending in a direct line from parents to their children downwards; or ascending from parents to grand parents upwards, in both
directions in infinitum. The collateral line differs from the direct, in that the relatives do not descend the one from the other.
The primary degrees in these comprise, brothers and sisters, uncles and aunts, nephews and nieces. Collateral kinsmen spring
from one common ancestor, who is the stirps or stipes, the root or stock, from whence those relations have branched; but they do not
immediately depend the one upon the other. The nearness or distance of relation in the collateral line is therefore calculated by the degrees or interval
between them and their same progenitor. This forms what is called by civilians the "vinculum personarum ab codem stipite descendentium."
The scale or steps agreeably to which the degrees of relation are computed, are too well known to need any reference or enumeration.
AFFINITY is a relation produced by marriage. It originates in the union which God has established between husband and wife; and refers primarily
to the degree of kindred contracted by the husband to
the relatives of his wife, and by the wife to those of her husband. In this sense it is distinguished from consanguinity or relation by blood. The term
affinity is derived from the two latin words AD to, and FINISH an end or boundary; because two families by intermarriage, not only approach to, but come
within the boundaries of each other. Agreeably to the maxim in law; quod duae cognationes per nuptias copulantur, et altera AD alterius
congnationis FINEM accredit.
The PROPERTIES of affinity are obvious. An attention to them will illustrate the subject.
1. Affinity constitutes a REAL RELATION. It is not merely nominal, or a matter of courtesy, but a
relation firm, legal and perfect. It is recognized by God in his law, as such, and the nearness of kin, or degree of relation, as it respects the husband and
wife, is as sacred in affinity as in consanguinity. If this be not the result of marriage, the union is nothing, it is a word without any meaning. Upon
this principle, affinity enters into the list of prohibitions as fully and expressly as consanguinity, and without any line of difference between them.