R' Chanina, administrator of the Kohanim, says: In all the days of the Kohanim, never did they refrain from burning [sacrificial] meat that had been contaminated by a secondary tumah together with [sacrificial] meat that had been contaminated by a primary tumah, although [by so doing] they added contamination to its contamination.  R' Akiva added, saying: In all the days of the Kohanim, never did they refrain from lighting oil that had become unfit [through contact] with a t'vul yom in a lamp that had been contaminated by one contaminated by a corpse, although [by so doing] they added contamination to its contamination.