"Kelly" wrote in
:

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!


Kelly -

Another replier has suggested putting a scrap of film into each of the
mystery chemicals, and the developer will be the one that causes the film
to turn black. But there are three other things that you might also try.

First, developers tend to have a pronounced odor, while PermaWash is
odorless. So take a sniff.

Second, some developers have a faint color (typically brown), while
PermaWash may have a slight blue cast. So pour a little of each into
glass containers, and then compare them.

Third, developers are what chemists refer to as "bases". Another replier
suggested using a pH meter - that will work, but another way to identify
bases is to stick a couple of fingers into the liquid, and then rub the
fingers together. Bases will cause your fingers to feel "soapy". In the
old days, soap was made by combining animal fat with lye, a strong base.
In a similar fashion, developers will cause a soap-like substance to be
created from the oils in your skin. By the way, unless you have
allergies, this is perfectly harmless. And if you are allergic to photo
chemicals, the time to learn this is now so that you can take appropriate
protective steps.