London Medical Officer of Health reports 1848-1972

Here’s a great resource few family historians will have explored, now opened up through digitization and placed online, free, thanks to the Wellcome Library. If you have London ancestry you'll be surprised what you might find.

The initial description is deceptively unpromising "statistical data about births, deaths and diseases."  More encouraging, "they also allowed the authors to express the diversity of their local communities and their own personal interests."

There's a good bet you'll find something beyond statistics relevant to a London ancestor. For example, from Stepney in 1923:

A search for "Ely Terrace" where my g-g-grandfather spent his last years with his daughter's family, found multiple reports of sanitary deficiencies.
A search for Ordish found a second cousin twice removed listed as a part time dentist and a note when he retired that he had served for 30 years.

Search for Canada and you'll find lots of examples of emigration. Usually only statistics are given but occasionally initials, for example, this saga from Woolwich in 1907:

From the 1902 report from Kensington:

Let anyone compare the gutter children of yesterday with the blooming, healthy boys to be seen on the training-ship, or in Homes, such as the " Waifs and Strays,"—hundreds, nay, thousands of them. Their parents would scarcely know them again ! Many, very many, of such children have been sent to Canada, where they have found an overflowing welcome in healthy and happy homes. And there is room for tens, nay, hundreds of thousands. Not long since, Sir Wilfrid Laurier, the Prime Minister, addressing the Chamber of Commerce at Liverpool said—" The Dominion has vast territories unpeopled, and what is needed is men and women to occupy them." " Canada could sustain a population of a hundred millions—it has six millions." For generations to come, therefore, that one great Dominion could absorb all our surplus population, and there is still a surplus, although, as this report shows, it is a declining quantity.   

Search from http://wellcomelibrary.org/moh/