49 samples of paper from books published between 1912 and 1957 were examined for fiber composition, brightness, folding endurance, ash content, ash composition, water content, and pH. The results show that the degradation of books does not always depend on how old the paper is but depends more upon the social situation of the time when it was made. Thus papers made during and just after World War II showed the highest degradation. The authors conclude that the highest degradation was caused by the very low quality of pulp fiber and low pH of paper during the war. -- AATA