Previous to the sixteenth century the Jews in Germany spoke the dialects of their immediate surroundings; there is no evidence to prove any introduction of Hebrew words at that early period, although it must be supposed that words relating purely to the Mosaic ritual may have found their way into the spoken language even then. The sixteenth century finds a large number of German Jews resident in Bohemia, Poland, and Lithuania. As is frequently the case with immigrants, the Jews in those distant countries developed a greater intellectual activity than their brethren at home, and this is indicated by the prominence of the printing offices at Prague and Cracow, and the large number of natives of those countries who figure as authors of Judeo-German works up to the nineteenth century. But torn away from a vivifying intercourse with their mother-country, their vocabulary could not be increased from the living source of the language alone, for their interests began to diverge. Religious instruction being given entirely in Hebrew, it was natural for them to make use of all such Hebrew words as they thus became familiar with. Their close study of the Talmud furnished them from that source with a large number of words of argumentation, while the native Slavic languages naturally added their mite toward making the Judeo-German more and more unlike the mother-tongue. Since books printed in Bohemia were equally current in Poland, and _vice versa_, and Jews perused a great number of books, there was always a lively interchange of thoughts going on in these countries, causing some Bohemian words to migrate to Poland, and Polish words back to Bohemia. These books printed in Slavic countries were received with open hands also in Germany, and their preponderance over similar books at home was so great that the foreign corruption affected the spoken language of the German Jews, and they accepted also a number of Slavic words together with the Semitic infection. This was still further aided by the many Polish teachers who, in the seventeenth and eighteenth centuries, were almost the only instructors of Hebrew in Germany.[15]