Sorry, I have to disagree with you.
"Amyl nitrate and the drug amyl nitrite are chemically distinct and are not interchangeable."
Have a little look here.
http://en.wikipedia.org/wiki/Amyl_nitrate
Of course they're CHEMICALLY distinct. One's a nitrite and ones a nitrate.
The point is, that Bars' use is in line with the generally accepted usage of the term.
Also, whatever the rights and wrongs in this particular case, I wouldn't take Wikipedia as your gospel.