The latter two are distinct from the former two, in that in the distillation is not used as a true purification method, but more to transfer all volatiles from the source materials to the distillate.

• 后两者与前两者截然不同，前两者不是被当作真正的提纯法使用，而是为了将全部挥发物从原料转移到蒸馏物。