Was it necessary that the active gloom of such a tyrant of a father, should commix with such a passive sweetness of a will-less mother, to produce a constancy, an equanimity, a steadiness, in the daughter, which never woman before could boast of?
-- Samuel Richardson, Clarissa, 1748
This man will harass the civilized world with an insupportable despotism: he will confound and commix all things spiritual and temporal.
-- Samuel Taylor Coleridge, The Friend, 1809
Commix is a backformation of commixt which was a combination of com- meaning "together" and the variant stem mix.