The drug phencycledine, more commonly known as PCP or angel dust, in a powder form. Tic is either snorted, or sprinkled on a marijuana or tobacco cigarette, and smoked. This form of PCP was very common in the 1970s and 1980s, where as, in recent years, it has been replaced by a liquid form of the drug known as "wet" (e.g. "Dippers," "sherm sticks")
Back in the 80s we used to snort that tic, now all I can find is "wet".