Encyclopedia Gallifreya
From Tardis Wiki, the free Doctor Who reference
Encyclopedia Gallifreya was a series of books, in the form of blue liquid/vapour in bottles, with at least eleven volumes. It could be found in the Doctor's TARDIS's library.
When Clara Oswald hid in the library, and a time zombie entered the room, volume four of the series spilled. (TV: Journey to the Centre of the TARDIS)