4. It serves as an historical laboratory, in which he makes practical application of acquired facts, in accordance with the most approved method of teaching History. 5. It presents a _few_ prominent facts, to which he is to add others _singly_ and _consecutively_. _In particular:_ 1. The exhibition, side by side, of different periods illustrates by the approximate identity of boundaries a real historical unity of development. 2. The student’s attention is called to the culmination of Saxon England, and the overweening power and disintegrating tendencies of the great earldoms just before the Norman conquest, as marking the turning-point of English History. 3. The water-shed has been sufficiently indicated by the insertion of a few rivers. 4. As an aid to the memory, the modern counties are grouped under the divisions of Saxon England. 5. Special attention is called to the insertion of Cathedral towns, as touching upon the ecclesiastical history of England. 6. This Map can be used effectively with a class in English Literature, to record an author’s birthplace, the scene of a story, poem, or drama, etc. +D. C. HEATH & CO., Publishers,+ Boston, New York, and Chicago. _SCIENCE._ _Organic Chemistry:_ _An Introduction to the Study of the Compounds of Carbon._ By IRA REMSEN, Professor of Chemistry, Johns Hopkins University, Baltimore. x + 364 pages. Cloth. Price by mail, $1.30; Introduction price, $1.20. _The Elements of Inorganic Chemistry:_ _Descriptive and Qualitative._ By JAMES H. SHEPARD, Instructor in Chemistry in the Ypsilanti High School, Michigan. xxii + 377 pages. Cloth. Price by mail, $1.25; Introduction price, $1.12. _The Elements of Chemical Arithmetic:_ _With a Short System of Elementary Qualitative Analysis_. By J. MILNOR COIT, M.A., Ph.D., Instructor in Chemistry, St. Paul’s School, Concord, N.H. iv + 89 pages. Cloth. Price by mail, 55 cts.; Introduction price, 50 cts. _The Laboratory Note-Book._ _For Students using any Chemistry._ Giving printed forms for “taking notes” and working out formulæ. Board covers. Cloth back. 192 pages. Price by mail, 40 cts.; Introduction price, 35 cts. _Elementary Course in Practical Zoölogy._ By B. P. COLTON, A.M., Instructor in Biology, Ottawa High School. _First Book of Geology._ By N. S. SHALER, Professor of Palæontology, Harvard University. 272 pages, with 130 figures in the text. 74 pages additional in Teachers’ Edition. Price by mail, $1.10; Introduction price, $1.00. _Guides for Science-Teaching._ Published under the auspices of the +Boston Society of Natural History+. For teachers who desire to practically instruct classes in Natural History, and designed to supply such information as they are not likely to get from any other source. 26 to 200 pages each. Paper.