Exer. 1:
Write about the implications of these two phrases. How are they
different? What can their differences tell us about their difference
between Jekyll and Lanyon?

a) "unscientific balderdash" - Lanyon

Jekyll is a highly experimental scientist, preferring the cutting edge
to more rigorous study, which is why Lanyon denigrates his chemical
exploration.
Lanyon likely prefers more rigorous testing or just more conventional
medicine.
The context of drugs as medicine being a much newer profession than
surgery might also mean that Lanyon is calling Jekyll's science
balderdash because new fields have much less established truth so poor
scientific inquiry can happen.

b) "scientific heresies" - Jekyll

Jekyll, who is exploring drugs/chemicals even before discovering the one
that transforms him into Hyde (and exposes some of the Victorian morals
that Jekyll would like to abandon, which Lanyon might be seeing),
believes that his experiments are very scientific but because they are
untraditional, Lanyon is prejudiced against them.
His experiments are much more exploratory, so they are very likely less
rigorous, but they are nonetheless science because they are trying to
discover new things about the world.

Exer. 2:

Do Dr Jekyll and doctors like him preserve "health" and morality or do
they corrupt them?

This question has multiple answers dependent on if "morals" refers to
Victorian morals or more modern formulations (although they are not
entirely discrete).
Dr Jekyll's passion, even though it comes from a place of negative
desire, isn't intrinsically immoral.
Even though pain relievers and unsafe remedies dreamt up by mad
scientists are often diagnosed irresponsibly by those same doctors, the
drugs themselves (opioids, etc) improve overall health.
In and of himself, Jekyll corrupted his own morality, but motivation
isn't strictly important in reserach medicine.
Dr Markley mentions that doctors, in a bedside manner way, need to be
viewed as moral people, but research scientists don't have such a
reputation.