[2] According to family legend, he was able to trace his ancestry to the important Torah scholar of the Middle Ages Moses Maimonides through his father, and to the writer Sarah Trimmer through his mother.
Lazarus-Barlow was educated at the City of London School and entered Downing College, Cambridge on a scholarship in 1884 from where he obtained his MB[clarification needed].
[1][2][5] Walter O'Connor writes in British Physiologists 1885–1914, that Lazarus-Barlow's life was "probably saved by the new antistreptococcal serum from the Pasteur Institute, used for the first time in Britain".
He was one of the first physicians to research the effects of X-rays and radium on that disease[2] and his use of living cells in his work achieved international recognition.
[6][7] He served as a captain in the Royal Army Medical Corps from 1914 to 1918,[5] spending two years in France, before returning to the Middlesex where he was appointed professor of experimental pathology in 1920.