to 8th century CE. The Bower Manuscript is one of the oldest Sanskrit texts on birch bark in the Brāhmī script. It includes several texts covering subjects including a medical treatise and proverbs. It was discovered in Kucha (currently in Aksu Prefecture in Xinjiang, China), an ancient Buddhist kingdom on the northern Silk Road, and is estimated to be from around 450 CE. The Gilgit Manuscripts were Buddhist texts discovered in the Gilgit area of Pakistan in 1931 and include various sutras, including the Lotus Sutra, along with folk tales, medicine, and philosophy. They are dated to approximately the 5th to 6th centuries AD, and were written in Buddhist Sanskrit in the Śāradā script. Manuscripts containing the Devīkavaca text, a hymn praising the goddess Durga, were thought to protect the person who carries them from evil influences like an amulet or charm. An example of one of these texts in Devanagari script from Nepal is held at Cambridge University Library (MS Add. 1578). Birch bark is still used in some parts of India and Nepal for writing sacred mantras. This practice was first mentioned c. 8th or 9th century CE, in the Lakshmi Tantra. In Indian sculpture, a birch bark manuscript is easily identified by the droop. A palm leaf manuscript is stiff. Old Slavonic script On July 26, 1951, during excavations in Novgorod, an expedition led by Artemiy Artsikhovsky discovered the first birch bark manuscripts in Russia in a stratigraphic layer dated to around the year 1400. Since then, more than 1,000 similar documents were discovered in Staraya Russa, Smolensk, Polatsk, Vitebsk, Mstsislaw, Torzhok, Pskov, Tver, Moscow, Ryazan, and Vologda, although Novgorod remains by far the most prolific source of them. In Ukraine, birch bark documents were found in Zvenyhorod, Volynia. In Belarus, several documents were unearthed in Vitebsk and Mstislavl. The late discovery of birch documents, as well as their amazing state of preservation, is explained by a deep culture layer in Novgorod (up to eight meters, or 25 feet) and heavy waterlogged clay soil which prevents the access of oxygen. Serious excavations in Novgorod started only in 1932, although some attempts had been made in the 19th century. Although their existence was mentioned in some old East Slavic manuscripts (along with a mention of Slavs writing upon "white wood" by Ibn al-Nadim), the discovery of birch bark documents (, berestyanáya grámota, and also grámota in those documents)