Lives and works with his wife Linda Johnston in California. He originally worked as a primary school teacher in the Netherlands from 1970 to 1978. He then began to train as a homeopath in the Hague, opening his own practice in 1979. At the same time, he translated several works of homeopathy. His first book appeared in 1985: “Kindertypes in Homoeopathie (Children's Types in Homoeopathy).” In 1990 he was appointed head of the school of homeopathy in Holland; soon afterwards, he started to give seminars around the world. Vermeulen has the rare ability to convey the essence of a remedy in a few well-chosen words. This ability is especially evident in his two works “Synoptic Materia Medica” volumes I and II. In his newest works, he deals particularly with nosodes. So far, two volumes have appeared, one on bacteria and viruses, and one on fungi.
Die deutsche Ausgabe der Konkordanz ist vergriffen. Eine empfehlenswerte Alternative ist die Klinische Materia Medica von Murphy. Sie ist noch umfangreicher und angereichert mit wertvollen klinischen Hinweisen von Clarke