> you'd like everyone who refers to pre-20th century humans who studied the properties of chemicals as "early chemists/alchemists",
"Alchemist" has a specific meaning, and it is not synonymous with "early chemist". Robert Boyle was
clearly an early chemist and predates Isaac Newton, who was an alchemist. There is no temporal hard line in the sand, the distinction is made based on methodology and goals. The two terms aren't necessarily mutual exclusive (as with the astronomy / astrology distinction you allude to), but that doesn't mean you can conflate them.
> Everyone had pseudo-religious beliefs back then!
Perhaps, but that doesn't mean there aren't relevant distinctions to be made about their beliefs and methodologies.
While this distinction is important, it is also irrelevant to my main point. "Vitriol" predates that alchemist and is arguably more of a word that arose than a name that was given.
"Alchemist" has a specific meaning, and it is not synonymous with "early chemist". Robert Boyle was clearly an early chemist and predates Isaac Newton, who was an alchemist. There is no temporal hard line in the sand, the distinction is made based on methodology and goals. The two terms aren't necessarily mutual exclusive (as with the astronomy / astrology distinction you allude to), but that doesn't mean you can conflate them.
> Everyone had pseudo-religious beliefs back then!
Perhaps, but that doesn't mean there aren't relevant distinctions to be made about their beliefs and methodologies.
While this distinction is important, it is also irrelevant to my main point. "Vitriol" predates that alchemist and is arguably more of a word that arose than a name that was given.