My first task in this work is accordingly to delimit the 'popular Rigveda,' which has generally been vaguely described as consisting of certain hymns appended to the first nine Mandalas, and the majority of those of Mandala x. For this purpose an examination of the language has proved the most effective method: but the evidence is greatly strengthened by the fact that the differences found in the language are throughout accompanied by differences of metre. These differences are sometimes broadly marked, sometimes subtle: but they can alway be clearly recognized when expressed by numerical calculations.