I stumbled across a map of the population density of Jews in East End London
I had an ancestor living at an address on Ely Terrace in the 1901 census, but the image resolution of map copies of Jewish East London found online is insufficient to pin down the street. Fortunately LAC has a copy of the book in its rare book collection, and even more fortunately the map is intact, although in poor condition.
Ely Terrace is not indicated but was identified with nearby Friendly Place http://goo.gl/miqWA.
The Jewish population of the East End was around 100,000 in 1901 and had tripled in 30 years, due both to immigration from eastern Europe and large family size.
One section of the book that caught my attention, the only part where Dutch Jewish immigrants were mentioned, was a comment on a claim that " ... as the East End Jew becomes an Englishman, he ceases to remain a Jew."
"To test the accuracy of this statement it may be well to consider first the characteristics of the Jewish workman who has been domiciled in England for several generations. Numerous examples of this class are to be met with in Stepney, in the model dwellings between Houndsditch and Commercial Street, and in some of the streets and courts within the same area. The typical Jew, of the class we mention, has certainly been thoroughly Anglicised, although he may bear a Dutch name which indicates the country from which his family came originally. He thoroughly identifies himself with England, and takes, at any rate at election times, a keen and occasionally an intelligent interest in politics. If, as is often the case, he is a cigar-maker, he probably belongs to the Trades' Union, a peculiarly well and soberly managed society. On the other hand, he continues to regard himself as a Jew, although he is not usually very observant of the minutiae of his religion and only attends synagogue a little more regularly than the average Christian workman attends church. His attachment to his race and creed continues, however, to be strong, and may, indeed, be as real as that of his foreign coreligionist, although it is partially concealed by that acquired quality of British stolidity."