The publishers take the liberty to call the attention of the reader to the great amount of information condensed within the space given to each lesson. Students have told us that they have found it necessary to read and study each lesson carefully, in order to absorb the varied information contained within its pages. They have also stated that they have found it advisable to re-read the lessons several times, allowing an interval between each reading and that at each re-reading they would discover information that had escaped them during the course of the previous study. This has been repeated to us so often that we feel justified in mentioning it, that other readers might avail themselves of the same course and plan of study.