to be applied to the language is unclear, as is the precise etymology of the name. The earliest attested use of the name is found in Tholkappiyam, which is dated as early as late 2nd century BC. The Hathigumpha inscription, inscribed around a similar time period (150 BCE), by Kharavela, the Jain king of Kalinga, also refers to a Tamira Samghatta (Tamil confederacy) The Samavayanga Sutra dated to the 3rd century BC contains a reference to a Tamil script named 'Damili'. Southworth suggests that the name comes from > "self-speak", or "our own speech". Kamil Zvelebil suggests an etymology of , with meaning "self" or "one's self", and "" having the connotation of "unfolding sound". Alternatively, he suggests a derivation of < < * < *, meaning in origin "the proper process (of speaking)". However, this is deemed unlikely by Southworth due to the contemporary use of the compound 'centamiḻ', which means refined speech in the earliest literature. The Tamil Lexicon of University of Madras defines the word "Tamil" as "sweetness". S. V. Subramanian suggests the meaning "sweet sound", from tam — "sweet" and il — "sound". Old Tamil Old Tamil is the period of the Tamil language spanning the 3rd century BC to the 8th century AD. The earliest records in Old Tamil are short inscriptions from 300 BC to 700 AD. These inscriptions are written in a variant of the Brahmi script called Tamil-Brahmi. The earliest long text in Old Tamil is the Tolkāppiyam, an early work on Tamil grammar and poetics, whose oldest layers could be as old as the late 2nd century BC. Many literary works in Old Tamil have also survived. These include a corpus of 2,381 poems collectively known as Sangam literature. These poems are usually dated to between the 1st century BC and 5th century AD. Middle Tamil The evolution of Old Tamil into Middle Tamil, which is generally taken to have been completed by the 8th century, was characterised by a number of phonological and grammatical changes. In phonological terms, the most important shifts were the virtual disappearance of the aytam (ஃ), an old phoneme, the coalescence of the alveolar and dental nasals, and the transformation of the alveolar plosive into a rhotic. In grammar, the most important change was the emergence of the present tense. The present tense evolved out of the verb (), meaning "to be possible" or "to befall".