Comparison of Accelerated Aging of Book Papers in 1937 with 36 Years Natural Aging

The study of the same papers aged naturally and artificially resulted in the following conclusions: 1) reasonably good correlations exist between changes in alpha cellulose and copper number; 2) pH is a reasonably good criterion of stability; and 3) the data indicate that zero span tensile and wet strength as a percent of dry strength should be useful criteria.