My friend and I made a leyden jar. We have to test the charge. We thought it was positive. We charged it up with PVC pipe and whool and saw that the pvc pipe attracted it, showing that it was positive. (according to the triboelectric series) But then we rubbed together stryfoam and silk and both things were attracted to the wire on our leyden jar. What is up? Shouldn't the silk have repelled the wire?