But all at once light dawns on us from an unexpected quarter. While we can learn nothing concerning the history of India from its literature, and nothing from its inscriptions or carved temples, _language_, comes to our aid. The fugitive and airy sounds, which seem so fleeting and so changeable, prove to be more durable monuments than brass or granite. The study of the Sanskrit language has told us a long story concerning the origin of the Hindoos. It has rectified the ethnology of Blumenbach, has taught us who were the ancestors of the nations of Europe, and has given us the information that one great family, the Indo-European, has done most of the work of the world. It shows us that this family consists of seven races,--the Hindoos, the Persians, the^ Greeks, the Romans, who all emigrated to the south from the original ancestral home; and the Kelts, the Teutons, and Slavi, who entered Europe on the northern side of the Caucasus and the Caspian Sea. This has been accomplished by the new science of Comparative Philology. A comparison of languages has made it too plain to be questioned, that these seven races were originally one; that they must have emigrated from a region of Central Asia, at the east of the Caspian, and northwest of India; that they were originally a pastoral race, and gradually changed their habits as they descended from those great plains into the valleys of the Indus and the Euphrates. In these seven linguistic families the roots of the most common names are the same; the grammatical constructions are also the same; so that no scholar, who has attended to the subject, can doubt that the seven languages are all daughters of one common mother-tongue. Pursuing the subject still further, it has been found possible to conjecture with no little confidence what was the condition of family life in this great race of Central Asia, before its dispersion. The original stock has received the name Aryan. This designation occurs in Manu (II. 22), who says: "As far as the eastern and western oceans, between the two mountains, lies the land which the wise have named Ar-ya-vesta, or _inhabited by honorable men_." The people of Iran receive this same appellation in the Zend Avesta, with the same meaning of _honorable_. Herodotus testifies that the Medes were formerly called Ἄριοι (Herod. VII. 61). Strabo mentions that, in the time of Alexander, the whole region about the Indus was called _Ariana_. In modern times, the word _Iran_ for Persia and _Erin_ for Ireland are possible reminiscences of the original family appellation.