me rests, the _Grammar of the Romance
Languages_ (1836-1844), and the _Lexicon of the Romance
Languages--Italian, Spanish and French_ (1853); in these two works Diez
did for the Romance group of languages what Jacob Grimm did for the
Teutonic family. He died at Bonn on the 29th of May 1876.

The earliest French philologists, such as Perion and Henri Estienne,
had sought to discover the origin of French in Greek and even in
Hebrew. For more than a century Menage's _Etymological Dictionary_
held the field without a rival. Considering the time at which it was
written (1650), it was a meritorious work, but philology was then in
the empirical stage, and many of Menage's derivations (such as that of
"rat" from the Latin "mus," or of "haricot" from "faba") have since
become bywords among philologists. A great advance was made by
Raynouard, who by his critical editions of the works of the
Troubadours, published in the first years of the 19th century, laid
the foundations on which Diez afterwards built. The difference between
Diez's method and that of his predecessors is well stated by him in
the preface to his dictionary. In sum it is the difference between
science and guess-work. The scientific method is to follow implicitly
the discovered principles and rules of phonology, and not to swerve a
foot's breadth from them unless plain, actual exceptions shall justify
it; to follow the genius of the language, and by cross-questioning to
elicit its secrets; to gauge each letter and estimate the value which
attaches to it in each position; and lastly to possess the true
philosophic spirit which is prepared to welcome any new fact, though
it may modify or upset the most cherished theory. Such is the
historical method which Diez pursues in his grammar and dictionary. To
collect and arrange facts is, as he tells us, the sole secret of his
success, and he adds in other words the famous apophthegm of Newton,
"hypotheses non fingo." The introduction to the grammar consists of
two parts:--the first discusses the Latin, Greek and Teutonic elements
common to the Romance languages; the second treats of the six dialects
separately, their origin and the elements peculiar to each. The
grammar itself is divided into four books, on phonology, on flexion,
on the formation of words by composition and derivation, and on
syntax.

His dictionary is divided into two parts. The first contain