He came to the United States in 1835, and for ten years resided in the family of Piero Maroncelli, the intimate friend of the revolutionist Silvio Pellico.
Other significant influences were the social theorist Albert Brisbane and the theologian George Bush.
He decided to make the change of location permanent and soon had a large homeopathic practice in that city.
[3] His health failing, he traveled to Italy and Germany in 1872,[3] but the change was not beneficial, and he returned to Grand Rapids, where he died.
Hempel was one of the earliest honorary members of the British Homeopathic Society, and was the recipient of diplomas and certificates of membership from many medical colleges and associations.