As to the appearance of the Sinaitic MS., we have the testimony of Dr Tregelles that, "though the general semblance of the whole work is somewhat less worn than that of Cod. Vaticanus (whose extensive hiatus prove how carelessly it has been kept), when it comes to be contrasted with such a MS. as the illustrated Dioscorides at Vienna (whose age is fixed by internal evidence at about a.d. 500), that interesting and valuable MS. looks comparatively quite fresh and modern ” (Scrivener’s Coll, of Cod. Sin. p. xxxi.).
Kevin McGrane uses the Tregelles comment and argues that the thinness of Sinaiticus helps keep it flexible. (Although it should also have had iron gall ink acid destruction much more easily with the thin parchment.)
The "Vienna Dioscorides" is an illustrated manuscript made for the Imperial Princess Anicia Juliana of Byzantium about the year A.D. 512. The main part of the work consists of a Herbarium taken from the work of Dioscorides (first century A.D.). There are 479 paintings, 392 of them full-page. In the course of time the parchment had become brittle and weakened. Holes and breaks needed repair and flaking paint needed restoration. The stages of restoration were as follows. (1) Separation of the leaves, and removal of old glue. Softening of the glue was aided by the use of weak vinegar solution or a wetting agent "Invadin met.", made by Ciba Ltd. (2) Removal of dirt and candle drippings. (3) Removal of the worst foxing. A solution of hydrogen peroxide plus 2 per cent anhydrous ammonia was used. (4) Neutralization of the ink-corroded parts using a solution of calcium hydroxide or sodium bicarbonate. (5) Regeneration. Each leaf was wetted with alcohol, stretched, and sprayed with parchment size. Several sprays were generally necessary. (6) Softening of brittle leaves, where necessary, with an emulsion as described above. (7) Mending of tears. (8) Mending of perforations. (9) Completion of missing parts of the parchment with equivalent parchment. (10) Final stretching. Garry Thomson
....The restoration of this codex has been avoided for a long time because of its great value. However, the condition of its parchment leaves has now made conservation treatment imperative.
A trained palaeographer will learn to distinguish the relative antiquity of different writings ; and thus, by allowing a reasonable space of time for each stage of development, it is possible to arrive at approximate dates in cases in which there is nothing but palaeographical evidence to go upon. A copy of Dioscorides, at Vienna, is known to have been written for Juliana, daughter of Flavius Anicius Olybrius, Emperor of the West in 472, and this supplies us with an approximately dated example of writing about the beginning of the sixth century.
