In a study of the degradation of paper containing iron and copper, it was found that neutralisation of the of chelting compounds also showed differences between the two metals. The copper chelate encreased the paper's present in only trace quantities, deacidification of paper should notcreate problems. Abstractor's note: this this would not apply to the use of green copper pigments. Details of experimental work are given, with results expressed both graphically and in tables. References.