A SUGGESTION to write the present book reached me in the spring of 1898. At that time my library contained several hundreds of volumes of the best Judeo-German (Yiddish) literature, which had been brought together by dint of continued attention and, frequently, by mere chance, for the transitoriness of its works, the absence of any and all bibliographies, the almost absolute absence of a guide into its literature, and the whimsicalness of its book trade made a systematic selection of such a library a difficult problem to solve. Not satisfied with the meagre details which could be gleaned from internal testimonies in the works of the Judeo-German writers, I resolved to visit the Slavic countries for the sake of gathering data, both literary and biographical, from which anything like a trustworthy history of its literature could be constructed.