Liz

It is morphine. The genesis for the song was that Phillips found one of the little tins in which miners in Utah carried morphine underground so that their death could be peaceful should they become hopelessly trapped or in danger of being burned or slowly suffocated. He says that many of the miners were European immigrants and catholics for whom suicide was a mortal sin - hence the practice was secret and few were willing to talk to him about it.

--Stewie.