I forgot to label the bag and now it's been 6 months and I can't remember which chemical it is. They are both fine white powders. I know the fixer smells pretty strong so I suppose I could put some in water and see if I can smell it. Any better ideas?

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    \$\begingroup\$ I would use the taste test. Just kidding. \$\endgroup\$
    – dpollitt
    Commented Oct 6, 2011 at 0:33

2 Answers 2


Since developers are often alkaline, you could use a red or purple litmus paper to test for that - if it contacts with alkalies, it turns blue.

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    \$\begingroup\$ or just mix up a small batch and rub it between your fingers. The alkaline solution should have a slightly "soapy" feel to it :) \$\endgroup\$
    – jwenting
    Commented Oct 6, 2011 at 6:59
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    \$\begingroup\$ If you don't have litmus paper, put a drop of vinegar on a tiny amount of powder and see if it fizzes. do this in a well-ventilated area, just in case. \$\endgroup\$
    – AJ Finch
    Commented Oct 6, 2011 at 9:30

You could try a clearing test. Once you've mixed your mystery powder with water place a small amount in a graduate or glass and then snip a bit of the leader off of a roll of film. If it clears in the solution, then you have fixer. If the film remains opaque then it is probably something else. Your smell test would work as well, btw. Good luck.


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