Csapodi, Csaba: Conservation of the Manuscript and Old Book Collections at the Library of the Hungarian Academy of Sciences. Methods and Results. 1949–1964 (A MTAK kiadványai 44. Budapest, 1965)

Not only is water harmful to books because it initiates the development of mould, but in itself is destructive, even if direct contact did not occur but only a high relative humidity. It not only dissolves the glue of the binding, the ink, the colours of the painted initials, but it soaks off the surface sizing which provides the old rag paper its strength. Hence this dissolved glue appears at the edge of the water stain as a brownish margin and the paper, losing its protective covering, becomes spongy just like an ink blotter (Plate 16). In our Library the problems of damage caused by dampness and mould were met in various ways. Our old books are frequently filled with black, pink and lilac spots, old inactive signs of destroyed mould mixed with the brown stripes of the soaked size. If such mould has been dry for decades then it is harmless for the mould does not live forever. If it is not so old then we can always count on the possibility of its becoming virulent again under favourable conditions. Under all circumstances, both the old and new mould have to be removed as best as possible from the surface of the binding or the paper. For this a common, very soft eraser and wiping with alcohol are usually enough. However for the spores remaining invisibly on the surface and for mould penetrating the fibres of the paper — and thus cannot be erased — a fungicide such as thymol should be applied at the end. In trying to eliminate fungi we experienced good results from the drying effect of our vacuum process. In our Library we had to fight danger of active mould on two occasions. The first instance occured when one of the walls of our archive (containing the bound manuscripts and folio-type old Hungarian books in cabinets) which touches the well of the neighbouring apartment building was wet by the great amount of water leaking from a burst pipe. The wall of the Library building was even penetrated after a two-three week period and for several days there was an unexplainable mouldy smell which could not be eliminated by ventilation. From day to day green mould spots appeared on the surfaces of the mentioned volumes. After removing the cabinets — built directly to the wall — we learned the cause of the trouble and only by immediately separating the intact volumes and by ventilation did we prevent the colonization of the mould. The affected volumes were carried to a bright and airy place where the task of carefully removing the mould with alcohol could begin. We succeeded in erasing the mould stains. In the second instance the roof of one of the store rooms leaked in a large area not where the old books were stored but above the stands containing the periodicals which were thereby damaged. The urgently set up fans and dehydrating material prevented the appearance of mould on the books. (The periodicals were prevented from moulding by exposure to infrared lamps and ventilation with hot air. Methods of Conservation a) Treatment of Damaged Paper and Parchment The removal of various stains, the bleaching of completely yellowed pages, were always the goal of manuscript and book restoration from the viewpoint of bibliophily. Undoubtedly an old printed book is extremely lovely 13