Jacob Kaals first booklet, Apitherapy: Curing with bee products, appearedin 1986 (in Dutch). It was updated and translated into English in 1991and is now reprinted in the original. The book contains an impressive international bibliography and a systematic, detailed record of knownand potential medicinal properties of bee products. Propolis had become a forgotten substance in the West for over a century, until the 1960s, and Jacob was determined to promote its varied medicinal powers. Being a beekeeper, his research always touched ground with the life and wellbeing of bees and people.