By 1799 the number of Martha Washington's dower slaves had grown to 153; George Washington owned 124 people, and at least a dozen Washington-owned slaves intermarried.
Hund's rule of maximum multiplicity is a rule based on observation of atomic spectra, which is used to predict the ground state of an atom or molecule with one or more open electronic shells.
Naegele's rule - rule for calculating an expected delivery date; subtract three months from the first day of the last menstrual period and add seven days to that date law of parsimony, Occam's Razor, Ockham's Razor, principle of parsimony - the principle that entities should not be multiplied needlessly; the simplest of two competing theories is to be preferred