Me and a friend are arguing on which is correct. Which one would be more correct and why?
When cholera did break out in Britain Farr believed, like Chadwick, that it was caused by miasma.
When cholera did break out in Britain, Farr believed, like Chadwick, that it was caused by miasma.
The comma you add is not required; the author probably felt that putting it in would make the sentence choppy and harder to follow.
But I think the comma is advisable, to make the syntax clearer. I would rather eliminate the commas bracketing like Chadwick, which is a very light phrase which does not seriously obscure the syntax. Alternatively, like Chadwick could be bracketed in parentheses.
Source : Link , Question Author : 3lliot , Answer Author : StoneyB on hiatus