od of his life which we may call his Wanderjahre (years of travel).
This change in his position and circumstances demands a simultaneous
change in the manner of the biographical treatment. Hitherto we have
been much occupied with the agencies that made and moulded the man,
henceforth we shall fix our main attention on his experiences, actions,
and utterances. The materials at our disposal become now more abundant
and more trustworthy. Foremost in importance among them, up to Chopin's
arrival in Paris, are the letters he wrote at that time, the publication
of which we owe to Karasowski. As they are, however, valuable only
as chronicles of the writer's doings and feelings, and not, like
Mendelssohn's and Berlioz's, also as literary productions, I shall,
whilst fully availing myself of the information they contain, confine my
quotations from them to the characteristic passages.

Chopin's long-projected and much-desired visit to Berlin came about in
this way. In 1828 Frederick William III of Prussia requested the Berlin
University to invite the most eminent natural philosophers to take part
in a congress to be held in that city under the presidency of Alexander
von Humboldt. Nicholas Chopin's friend Dr. Jarocki, the zoologist and
professor at the Warsaw University, who had studied and obtained his
degree at Berlin, was one of those who were honoured with an invitation.
The favourable opportunity which thus presented itself to the
young musician of visiting in good company one of the centres of
civilisation--for the professor intended to comply with the invitation,
and was willing to take his friend's son under his wing--was not allowed
to slip by, on the contrary, was seized eagerly. With what feelings,
with what an infinitude of youthful hopes and expectations, Chopin
looked forward to this journey may be gathered from some expressions in
a letter of his (September 9, 1828) addressed to Titus Woyciechowski,
where he describes himself as being at the time of writing "like a
madman," and accounts for his madness by the announcement: "For I am
going to-day to Berlin." To appear in public as a pianist or composer
was not one of the objects he had in view. His dearest wishes were to
make the acquaintance of the musical celebrities of Berlin, and to
hear some really good music. From a promised performance of Spontini's
Ferdinand Cortez he anticipated great things.

Professor Jarocki and Chopin left Warsaw on the 9th of September