In the 16th century, a Swiss - born physician commonly known as Paracelsus made chickens breathe sweet vitriol and noted that they not only fell asleep but also felt no pain. Like Lullus before him, he did not experiment on humans.
१७३० साली जर्मन रसायनशास्त्रज्ञ फ्रोबेनियस याने या पदार्थाला ईथर नाव दिले जे आजही वापरले जाते.