English law regarding proscribed marriage partners was based entirely on those laid down by the Anglican Church and stemmed from Henry VIII's reformation of the English Church. These laws almost exactly correspond with those set out in Leviticus, which, whilst explicitly naming the parties forbidden to marry, makes no mention of a deceased wife's sister. Thus, the status of such a union was arguable until laws passed in 1835 rendered it illegal in England and Wales [It was to remain so until the law was repealed through the Deceased Wife's Sister's Marriage Act of 1907]. See here for more info.
As with all laws, however, those set on circumventing them would always find ways to do so.
On the death of his wife, Elizabeth, it seemed practical for John Michaelis Barnardo to marry her sister, Abigail, who had been in charge of the household since her sister's death. However, the Bill which was to permit marriage with a deceased wife's sister had not yet been passed, and according to the law as it stood it would have been illegal. By coming to London and by having the ceremony performed in a German church by a German pastor, John Michaelis was able to avoid the legal impediment to his marriage, for as a Prussian subject he was not bound by English law. The full story can be found here 'Birth and boyhood and the melting pot 1845 - 1866'.
The Wesleyan minister, William Morley Punshon (1824-1881) married three times. His first wife, Maria Ann Vickers of Gateshead, by whom he had 6 children, died of consumption in 1858 and was buried at Kensal Green. After her death, her sister Fanny came to live with Punshon to help care for his remaining children. Over the years, Punshon fell in love with her but, as it was illegal in English law, he was advised to send her away and marry someone else. Punshon, clearly a man of honour, decided his only course was to leave England. Invited by the Canadian Methodist Conference to become their President and, such unions not being illegal in that country, the couple were duly married in Toronto in 1868. More details available in a Biography here.
Jewish law imposed no such restriction and, indeed, it is specifically included in the list of those whom it is permissible for a man to marry. viz: His deceased wife’s sister, but not his divorced wife’s sister (unless the former is deceased already). Chabad.org provides a summary here.
But a combination of the passing of the 1835 Marriage Act and the introduction of Civil Registration in 1837, meant that Jews, along with the rest of their fellow citizens, would have had to go outside the country in order to enter a legal contract of marriage: Paris, Amsterdam and Brussels were the most likely destinations.
This would explain why no English marriage can be found for Ernst Falck who, on the death in 1877 of his first wife, Helene Samuel was to marry her younger sister, Matilda some time between 1877 and 1881.
If anyone has any information about this marriage, we should be pleased to hear from them.