Fredanus van Gelder Research Progress

I have finally made some significant progress in my research into the Fredanus van Gelder family history. I have discovered (through sheer effort and hours of search I might add) the death and burial dates of Sara Fredanus. Fredanus is a far less common name than van Gelder and therefore much easier to search for. My success was via various sites on the Internet one of which records Jewish history in the Netherlands. I found the details of her burial at Muiderburg cemetary in Amsterdam. This all gave me hope of progress at last which was further enhanced when I found that the Amsterdam City Archive provides a search service for a fairly reasonable fee, provided you can give them a starting point. So here is what I now know:

1. Machiel van Gelder was born 20 something January 1838
2. Sara Fredanus was born 26 September 1836
3. Machiel van Gelder married Sara Fredanus something August 1861
4. Louis Machiel van Gelder was born 11 January 1869 and appears to have been their only child
5. Louis Machiel changed his surname to Fredanus van Gelder 30 October 1885
6. Sara Fredanus died 15 February 1899
7. Machiel van Gelder remarried Anna Catharina Hazeloop (a Dutch Reformed rather than Jewish woman) on 5 May 1901
8. Machiel and Anna had two sons called Maurits Michel (21 October 1901 - do the maths) and Herman Michel (29 August 1904)
9. Machiel van Gelder died 2 January 1924

Why Louis Machiel changed his surname or why he emigrated to South Africa remains a mystery. Denise Samuels says she has some details but I've not managed to get those from her. What I have confirmed is that Louis earned his doctorate in law from the University of Amsterdam on 30 January 1894 and that his thesis was titled "Het samentreffen van dolus en cupla bij een delict". I found this in the Album Academicum of the Athenaeum Illustre (a register of past students, staff etc) via a Google book search. Both Amsterdam University Library and the International Institue for Social History in Amsterdam had copies and have sent me photocopies of the extract within days of my email enquiry to each. Interestingly Cambridge University also had copies but has never responded to my emails. Louis was 25 years old when he received his doctorate.

From the copies of documents that I have I now also know that Machiel's parents were Isaac van Gelder and Hester Jacobus Hamburg and that Sara's parents were Louis something Fredanus and Henderina Bronkhorst.

I have copies of Machiel and Sara's birth certificates and their marriage certificate as well as Louis' birth certificate which has been annotated by hand with the details of the Royal Decree allowing him use of the surname Fredanus van Gelder. Of course these documents are old and very hard to read (especially being photocopies). And the fact that they are in formal old Dutch makes it that much harder to guess what particular words might be. A Belgian colleague at work is helping me to try and translate them.

Next step is getting the details on Machiel and Sara's families including death certificates. I'm curious to know what she died of.