Somewhere in my files I have a picture of an anesthesia kit that contained what we call an ether cone. The kit also included tins for chloroform and ether, opium and spirits of ammonia. It had bundled sponges, a couple folding hand fans and some other misc stuff. The cone in the picture appeared to be japanned tin instead of copper like the repros are. I do not know if these were PEC or if it may have been something a surgeon brought along with him or had made up. Most of the sources I have seen speak to the folded up cloths.
your obedient servant,
Surgeon, 2nd Brigade
"not really a surgeon, but I did stay at a Holiday Inn Express"