When we turn to their literature we find nothing to encourage any hope that we may penetrate further back into their history than we have hitherto been able to do. Dr. Caldwell, the best and latest authority on the subject, ascribes the oldest work in the Tamil, or any southern language, to the 8th or 9th century of our era,[31] and that even then can hardly be called native, as it undoubtedly belongs to the Jains, who are as certainly a northern sect. According to the same authority, it was superseded by a Vaishnava literature about the 12th or 13th century, and that again made way for one of Saiva tendency about the latter date. There is no trace of any Buddhist literature in the south, and nothing, consequently, that would enable us to connect the history of the south with the tolerably well-ascertained chronology of Ceylon or Northern India, nor am I aware of the existence of any ancient Buddhist monuments in the south which would help us in this difficulty.[32] Not having passed through Bactria, or having lived in contact with any people making or using coins, the Dravidians have none of their own, and consequently that source of information is not available. Whatever hoards of ancient coins have been found in the Madras Presidency have been of purely Roman origin, brought there for the purpose of trade, and buried to protect them from spoliation. The inscriptions, which are literally innumerable all over the Presidency, are the one source from which we can hope that new light may be thrown on the history of the country, but none of those hitherto brought to light go further back than the 5th or 6th century, and it is not clear that earlier ones may be found.[33] It is, at all events, the most hopeful field that lies open to future explorers in these dark domains. There is nothing, however, that would lead us to expect to find any Tamil or native inscription in the country extending so far back as the age of Constantine. Those on the raths at Mahavellipore, or the caves at Badami, which may be as old as the age of Justinian, are in Sanscrit, and consequently look more like an evidence of the northern races pushing southward than of the southern races extending themselves northward, or being sufficiently advanced in civilisation to erect for themselves the monuments on which these inscriptions are found.