DIATESSARON, in pharmacy, the name of a composition so called, from the four ingredients it comprehends: it is prepared thus.
Take of gentian root, bay-berries, myrrh, and roots of birthwort, of each two ounces; of honey, two pounds; mix them into an electuary. This, with the addition of the shavings of ivory, two ounces, is entitled diapente, or a composition of five ingredients.