We give the following
necessary and sufficient conditions for a ∗-derivation, A, on C[0,1], to generate a
continuous group of ∗-automorphisms: A must be equivalent to the closure of pD,
where (pD)f(x) ≡ p(x)f′(x), with (1∕p) not locally integrable at the zeroes of p. We
give similar necessary and sufficient conditions for a well-behaved ∗-derivation to
generate a positive contraction semigroup. We show that any ∗-derivation on C[0,1]
has an extension (possibly on a larger space) that generates a continuous group of
∗-automorphisms.