Indian Epigraphy: A Guide to the Study of Inscriptions in Sanskrit, Prakrit, and the Other Indo-Aryan Languages c7.s3.t7.2

c7.s3.t7.2

Among the characters which do show clear chronological development, *sa* is often cited as the most reliable “test letter.” In the early forms of Kharoṣṭhī of the Aśokan and Indo-Greek period, the head portion of *sa* is usually closed (𐨯). In the middle period of the Indo-Scythian and Indo-Parthian era, the head is typically open, but the vertical line still has a projection toward the top of the letter (𐨯). Finally, in the later phase of the script during the Kuṣāṇa period, the head is fully open (𐨯). This character, along with a few other test letters such as *ya* and *ca*, can be used to date Kharoṣṭhī documents in a broad fashion. But, as pointed out by Das Gupta (DKS, 102, 146), the three types of *sa* actually overlap considerably throughout the history of the script, so that to use it alone as a criterion for paleographic dating is an uncertain method at best (see 5.4.1).