Cramer was the director of the Zealand Society, a scientific society located in Flushing and a member of "Libertate et Concordia", a literary society in Amsterdam, which commissioned his book outlandish butterflies: "De uitlandische Kapellen".
Cramer was the director of the Zealand Society, a scientific society located in Flushing and a member of "Concordia et Libertate", based in Amsterdam. This literary society commissioned and/or financed the publishing of his book on outlandish butterflies: "De uitlandische Kapellen".