Parke-Davis Throat Troches

These throat troches (equivalent to a cough drop) were a weird shade of greenish-grey, they came in a cardboard box no more than 1/2 inch deep, were about the size of a dime, and the box was about 3 or 4 inches square; the discs were stacked three high (3 layers). When you sucked on them they made your mouth feel like you had ice in it and then all of a sudden the medicine kicked in and they were a bit on the hot side! It's a memory from my youth I am trying to find. Can you help granny?