I have just read your message on the board about a Samuel Kanis born 25 May 1768 in Zwolle. My husband is a Kanis and I have a huge database on this surname. I have got Samuel in my database. He was born in Zwolle and married Maria Ester in 1st May 1791. They had a son, Jan Hendrik and had many descendants (60 in my database), the last generation being born in the 1970s. His father was Hendrik married to Johanna Vredeveld in Zwolle on 3 December 1747.
I can send you his tree if you want.