Lastly, let us observe that the barley-corn appears as the basis of the system in the tables of Brahmegupta and Bhascara, although the _ṛaktika_ evidently overmasters it in the course of time. This is very interesting, for it indicates that the Hindus had learned the art of weighing in a comparatively northern region, where barley was the chief cereal under cultivation. If the system had been invented in the more southern parts of India, the grain of rice, the staple of life in the southern regions, would certainly have appeared as the sub-multiple of the _ṛaktika_, instead of the barley. As a matter of fact, rice-grains seem to have been occasionally used locally, for Colebrooke remarks that “it is also said that the _ṛaktika_ is equal in weight to four grains of rice in the husk.” This supposition is completely in accord with what we found in Persia, where the modern weight system for gold, silver and medicine runs thus: 3 _gendum dsho_ (barley-corn) = 1 _nashod_. 4 _nashod_ (a kind of pea, lupin?) = 1 _dung_. 6 _dung_ = 1 _miscal_[234]. Although the _miscal_ and _habba_ denote Arabic influence, we may, without straining probabilities, conjecture that the use of the _barley-corn_ here as well as in India, where we found it at a period anterior to Muhammadan conquest, indicates that in Persia it existed likewise from the earliest times. The close relationship between the ancient Hindus and ancient Persians makes it all the more likely. It is also pointed out that formerly the _nashod_ was divided into _three_ instead of four grains. As the Arabs divide their _karat_ into four _habbas_, it is all the more likely that the 3 barley-corns = 1 _nashod_ belong to the ancient system. The Arab weight system is based on the grain of wheat, four of which make a _karat_ (the seed of the carob or St John’s Bread)[235]. Occasionally in the Arab writers mention is made of a karat divided into 3 _habbas_[235]. The weight of the karat remains unchanged, but the grains in this case are barley grains, since, as we shall see presently, 3 grains of barley are equal to 4 grains of wheat (·063 × 3 = ·047 × 4). It will now be most convenient for us to begin in the extreme west, and once more from that work back towards the coast of the Aegean Sea, in which our chief interest must always be centred.