A blank book for scraps. The Romans applied the word to certain tables overlaid with gypsum, on which were inscribed the annals of the chief priests, the edicts of the prætors, and rules relating to civil matters. In the Middle Ages, “album” was the general name of a register or list; so called from being kept either on a white (albus) board with black letters, or on a black board with white letters. For the same reason the boards in churches for notices, and the boards in universities containing the names of the college men, are called albums.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894
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