Birch bark manuscripts are documents written on pieces of the inner layer of birch bark, which was commonly used for writing before the advent of mass production of paper. Evidence of birch bark for writing goes back many centuries and in various cultures. The oldest dated birch bark manuscripts are numerous Gandhāran Buddhist texts from approximately the 1st century CE, from what is now Afghanistan. They contain among the earliest known versions of significant Buddhist scriptures, including a Dhammapada, discourses of Buddha that include the Rhinoceros Sutra, Avadanas and Abhidharma texts. Sanskrit birch bark manuscripts written with Brahmi script have been dated to the first few centuries CE. Several early Sanskrit writers, such as Kālidāsa (c. 4th century CE), Sushruta (c. 3rd century CE), and Varāhamihira (6th century CE) mention the use of birch bark for manuscripts. The bark of Betula utilis (Himalayan Birch) is still used today in India and Nepal for writing sacred mantras. Russian texts discovered in Veliky Novgorod have been dated to approximately the 9th to 15th century CE. Most of those documents are letters written by various people in the Old Novgorod dialect. The Irish language's native writing system Ogham, sometimes called the "tree alphabet", was traditionally attributed to the god Ogma who wrote a proscription on birch to Lugh, warning him; the text of this proscription can be found in the Book of Ballymote. The first letter of Ogham is beith; beithe means "birch". Gandhāran Buddhist manuscripts Buddhist manuscripts written in the Gāndhārī language are likely the oldest extant Indic texts, dating to approximately the 1st century CE. They were written on birch bark and stored in clay jars. The British Library acquired them in 1994. They were written in Kharoṣṭhī and were believed to have originated from Afghanistan, because similar birch bark manuscripts had been discovered in eastern Afghanistan. Since 1994, a similar collection of Gāndhārī texts from the same era, called the Senior collection, has also surfaced. The British Library birch bark manuscripts were in the form of scrolls. They were very fragile and had already been damaged. They measured five to nine inches wide, and consisted of twelve- to eighteen-inch long, overlapping rolls that had been glued together to form longer scrolls. A thread sewn through the edges helped to hold them together. The script was written in black ink. The manuscripts were written on both sides of the scrolls, beginning