We meet also, among the productions of the literature of this period, a few catechisms and postillac, written expressly for the instruction of the common people by some eminent Lutheran and reformed Polish ministers. But the want of means for acquiring even the most elementary information, was so great, that only a very few among the lower classes were able to read them. The doctrines of the Reformers, which every where else were favoured principally by the middle and lower classes, in Poland found their chief support among the nobility. Comparatively few of the people adhered to them. There was a time, between 1550 and 1650, when half the senate,[19] and even more than half of the nobility, consisted of Lutherans and Calvinists. In the year 1570, these two denominations, together with the Bohemian Brethren, formed a union of their churches by the treaty of Sendomir for external or political purposes. In 1573, by another treaty known under the name of _pax dissidentium_, they were acknowledged by the state and the king, and all the rights of the Catholics were granted to the members of these three denominations, and also to the Greeks and Armenians. The want, however, of an accurate determination of their mutual relation to each other, occasioned repeatedly in the course of the following century bloody dissensions. The Protestants succeeded, nevertheless, in maintaining their rights, until the years 1717 and 1718, when their number having gradually yet considerably diminished, they were deprived of their suffrages in the diet. Their adversaries went still further; and, after struggling against oppression of all sorts, the dissidents had at length, in 1736, to be contented with being acknowledged as _tolerated sects_. After the accession of Stanislaus Poniatowsky to the throne in 1766, the dissidents attempted to regain their former rights. In this they were supported by several Protestant powers; but more especially by Russia, who thus improved the opportunity of increasing its influence in Polish affairs. In consequence of this powerful support, the laws directed against the dissidents were repealed; and in 1775 all their old privileges were restored to them, except the right of being eligible to the stations of ministers of state and senators. In more recent times the Protestants have been admitted to all the rights of the Catholics; although the Roman Catholic is still the predominant religion of the kingdom of Poland. We have permitted ourselves this digression, and anticipation of time; although we shall have an opportunity of again returning to this subject. The influence of Protestantism on the literature of Poland cannot be denied; although its doctrines and their immediate consequence, the private examination and interpretation of the Scriptures, have occupied the minds and pens of the Poles less than those of any other nation among whom they have been received. We now return to the sixteenth century.