Not a few of my kind helpers, alas! are no longer among the living; more than ten years have gone by since I began my researches, and during that time Death has been reaping a rich harvest.
The Chopin letters will, no doubt, be regarded as a special feature of the present biography.

They may, I think, be called numerous, if we consider the master's dislike to letter-writing.

Ferdinand Hiller--whose almost unique collection of letters addressed to him by his famous friends in art and literature is now, and will be for years to come, under lock and key among the municipal archives at Cologne--allowed me to copy two letters by Chopin, one of them written conjointly with Liszt.

Franchomme, too, granted me the privilege of copying his friend's epistolary communications.

Besides a number of letters that have here and there been published, I include, further, a translation of Chopin's letters to Fontana, which in Karasowski's book (i.e., the Polish edition) lose much of their value, owing to his inability to assign approximately correct dates to them.
The space which I give to George Sand is, I think, justified by the part she plays in the life of Chopin.