With the development of the system of common schools, the educational work which had previously been carried on in the convents was very largely given up, thus throwing upon the hands of the monks a still greater proportion of leisure time. In 1492, Johann of Trittenheim, Abbot of Sponheim, wrote to the Abbot Gerlach of Deutz a letter, _De Laude Scriptorum_, in which he earnestly invokes the scribes (he was addressing the scribes of the monasteries) by no means to permit themselves to be deterred from their holy occupation by the invasion of the printing-presses. Such admonitions might continue the work of the monks in certain of the _scriptoria_, but were, of course, futile in the attempt to preserve for any length of time the business of circulating manuscript copies in competition with the comparatively inexpensive, and often beautiful, productions of the printers. An important part in the work of the preparation and distribution of manuscripts was taken by the so-called “Brothers of common life” (_clerici de vita communi_), who later, also occupied themselves with the new invention of printing. They cannot properly be classed with the scribes of the monasteries, for they made their work a trade and a means of revenue. This practice obtained, to be sure, also with certain of the monasteries, but it must be considered as exceptional with them. The Brothers differed also from the writers in the university towns and elsewhere, who prepared manuscripts for renting out to students and readers, partly because of the special conditions of their Brotherhood, under which the earnings of individual Brothers all went into a common treasury, but chiefly because they made their work as scribes a means of religious and moral instruction. The earnings secured from the sale of manuscripts were also largely devoted to the missionary work of the Brotherhood. The chief authority for the history of the Brotherhood is the work of Delprat, published in Amsterdam in 1856.