An essential feature of Germanic languages is their consonantal system, namely the result of the so-called first consonant shift. The phenomena stated in the law of the first consonant shift were found out by comparative linguistics early in the 19th century. Two famous names are to be mentioned in this connection: the Danish scholar Rasmus Christian Rask (1787-1832) and the great German linguist and fairy-tales collector Jacob Ludwig Grimm (1785-1863). The earliest statement of the shift was given in the second edition of Grimm's work German Grammar (Deutsche Grammatik), which was published in 1822. Accordingly, the law is also often called Grimm's Law. It expresses regular correspondences between consonants of Germanic and those of other Indo-European languages.