The _Vestibulum_, although written and published after the _Janua_ and _Atrium_, was intended as a first book or Latin primer. The _Janua_ was found to be too difficult for the younger learners, and so this simple book was composed during his sojourn at Saros-Patak. The sentences were abbreviated, and they deal with simple things. The following are the chapter headings: (1) Concerning the accidents or qualities of things; (2) Concerning the actions and passions of things; (3) The circumstances of things; (4) Things in the school; (5) Things at home; (6) Things in the city; (7) Concerning the virtues. He expresses regret that he is unable to illustrate the text of the _Vestibulum_ with cuts to amuse the pupils and enable them the better to remember, but says that he could find no artists competent to do the required illustrative work. He urges the teachers to supply the want of such cuts by explanations of the things, or by showing the things themselves. Without some such devices, the instruction must necessarily be lifeless. “The parallelism of the knowledge of words and things is the deepest secret of the method.” _Orbis Pictus_ The idea of the use of pictures in elementary school work was suggested to Comenius by Professor Lubinus, of Rostock, who edited in 1614 a Greek testament in three languages. He suggested reforms in the simplification of language instruction, and advised the construction of a book containing pictures of things, with a certain number of brief sentences attached to each, until all the words and phrases of Latin were exhausted. While at Saros-Patak, he carried into effect the desires set forth in the _Vestibulum_ with reference to an illustrated child’s first Latin reader, although the book was not printed until some years later, because of unexpected difficulty in finding a skilful engraver in copper. In a letter to Michel Endter, of Nuremberg, who subsequently published the _Orbis pictus_, Comenius wrote in 1655: “It may be observed that many of our children grow weary of their books, because they are overfilled with things which have to be explained by the help of words. The pupils, and often the teachers themselves, know next to nothing about the things.”