In academic writing, is there a proper way to reference a chemical which was sourced from a defunct source?

For example, if you have a chemical bottle from Aldrich, do you reference Merek? Do you reference the entity which manufactured the bottle?

When did bottles stamped with "Aldrich" stopped being made? They merged with Sigma in 1975, but I'm sure I've seen more recent containers with only "Aldrich" printed on it.