Library Hippolytus Refutation of All Heresies
Book 4
Chapter 29: Display of Different Eggs
But different eggs they display after this manner. Perforating the top at both ends, and extracting the white, (and) having again dipped it, throw in some minium and some writing ink. Close, however, the openings with refined scrapings of the eggs, smearing them with fig-juice.
English translation by J.H. MacMahon, in Ante-Nicene Fathers, Vol. V (eds. Alexander Roberts and James Donaldson; Buffalo: Christian Literature Publishing Co., 1886). Public domain. Digital text via New Advent Church Fathers.