I'm taking an introductory B&W darkroom class at my art college, and we
mixed our three batches of chemicals last week: developer, fixer, and Heico
Permawash. In pulling out the bottles from the locker this week, I
discovered I'd labeled the fixer, but in the general confusion of the school
darkroom had left blank tape on the two other brown bottles. Is there any
way to pour out a small amount to determine which is which? (The developer
is TMax developer, if that makes a difference.) Or do I need to go through
teh development process with a small piece of test film to see if things
work?

Thank you in advance!