Hans Sower was born the son of a Huguenot family in Smithfield in the Orange Free State. He studied medicine under Sir Joseph Lister at Edinburgh, and qualified in 1881. Attracted by the diamond fields, he reached Kimberley during the Cape's small pox epidemic in 1882, and at the age of 25, accepted the appointment as quarantine officer on the Moda river. For more than a year he examined, quarantined and vaccinated all travelers from a high court judge to would be miners.