ectoplasm

I just completed a curious substance and gave the wizard ectoplasm but I still have the ectoplasm in my inventory because I picked up 2. The wiki says it should disappear when I give it to the wizard but it didn’t. Do I just have ectoplasm now to feed to my cows and make super cows or something?

Please can someone help? With 2 days left I found an ectoplasm and raced to the Wizard's tower, no joke, arrived at 11pm and it wouldn't let me in. Instead of sneaking round the witches way I went to sleep. Woke up with, what should have been, 1 day left but the quest has disappeared and even...