...Although physicians such as Benjamin Rush had claimed tobacco use (including smoking) negatively impacted one's health as early as 1798,[26] it was not until the early 20th century that serious medical studies began to be conducted. One of the true breakthroughs came in 1948, when the British physiologist Richard Doll published the first major studies that proved that smoking could cause serious health damage...

The rise of the modern anti-smoking movement in the late 19th century did more than create awareness of the hazards of smoking; it provoked reactions of smokers against what was, and often still is, perceived as an assault on personal freedom and has created an identity among smokers as rebels or outcasts, apart from non-smokers...

Pipe smoking, until recently one of the most common forms of smoking, is today often associated with solemn contemplation, old age and is often considered quaint and archaic. Cigarette smoking, which did not begin to become widespread until the late 19th century, has more associations of modernity and the faster pace of the industrialized world...

However, I would think that when EBD was writing there were no widespread campaigns about it being bad for you. People probably knew that it wasn't very good for you, but not to what extent, in the same way that we now know that eating and drinking too much of certain things isn't good for you but don't have the same "fear factor" with them that we do with smoking. Does that make any sense whatsoever

And Roger Richardson refuses to smoke because he knows it will spoil 'his wind for rugger' or something like that.

I know in the late 80's a friend of mine with mental health issues was encouraged to smoke as an alternative to taking medication.