Merchant Johann [John] Jacob Zornlin was born in October 1712 in Switzerland (details are lacking). He settled in the City of London about 1740 and went into in partnership with Basle-born Johann Rudolph Battier whose daughter Susanna Maria he married in June 1752.
A naturalised citizen, he purchased a freehold house at no. 15 Devonshire Square, Bishopsgate, which was held by the family until 1870. The partnership of Battier & Zornlin was dissolved in 1799. Johann Jacob had passed away by then. He died in London in February 1784. He son John Jacob married Elizabeth Alsager, sister of the journalist Thomas Massa Alsager who was one of the great Beethoven supporters in London.