Among the many lessons to be learnt are these:
How much emphasis can we place on either peer review or indicators of popularity such as the science citation index, in assessing the importance of research?
We need all health professionals doing epidemiology- Snow was, primarily, an anaesthetist for whom epidemiology was a passion.
Confronting an established theory (miasma here) is a formidable challenge.
Society could conquer disease by organised research and action.