--
while theoretically sound, is more bersome than some of the other methods which have been described in THIS JOURNAL, particularly for thosensers who prefer t o express reactions in the form of molecular equations. Certain inconsistencies are noted in that the author writes on page 31: "Unless we are able t o state (and prove such statements) that an atom has lost seven electrons, we cannot state that the valence of that atom is +7." Nevertheless, in the work on pages 13 and 18 such assumptions have been made and the table on page 11 contains additional examples of this. One notes also a few careless expressions such as that on page 76: "The various states of oxidation given on page 67 can react with each other." I n the opinion of the reviewer, this monograph will not prove valuable for use in elementary courses in chemistry. The student in such courses cannot understand the logical development of the method a t the time he begins t o encounter o x i d a t i o n - r e d u c t i o n reactions. T h e method itself is somewhat more cumbersome than others which involve the application of electronic steps. Many teachers will object to the exclusive use of ionic instead of molecular equations, particularly during the early stages of the work. If the method presented hy Professor Jette is to be followed, it would appear t o be necessary for the student first to learn some other method of handlimg the equations for common ouidatianreduction reactions; and then in his mare advanced work t o take up such phases of this method as may prove ureful far considering the less common cases.
New Type Questions in Chemism. CHARLESG. COOK,Ph.D., Globe Book Co., New York. 1927. First edition. vi 91 pp. 12.5 X 19 cm. Cloth, 60 cents.
+
This little book sets as its task to
"make chemistry teaching more efficient and more interesting." Types of tests used are: , com"The old type . . , true-false , statements for pletion . . , evidence correction, and home tests." Advantages of use of new-type tests are that "a greater number of topics may be covered in short tests" and "the answer paper may he corrected rapidly." The hook contains in the neighhorhwd of a thousand requirements covering individual requirements for eleven elements, requirements for fifteen others grouped after the periodic arrangement with special test groups upon a number of typical compounds such as water, hydrogen peroxide, hydrochloric acid, oxides of sulfur, etc. Theories, atoms, molecules, nomenclature, Avogadra's hypothesis, molecular weights and formulas, electrolytic dissociation theory; reversible reactions and the periodic law come in also for individual test requirements. Five specimen sheets of examinations, presumably from the Regents' sets, though not so stated, are given as an appendix "to familiarize the student with the type of questions he is elmected t o he able t o answer." Criticisms that are likely to come t o the booklet are: too much space devoted t o equations; not enough numerical problems; acids, bases, and salts not recognized; oxidation and reduction not treated separately, and an undue use of true-false requirements. The book will undoubtedly be welcomed by a host of teachers, especially those teaching in high schools. While i t is hardly the last word in the field of testing it is a creditable pioneer offering from the hands of a teacher of experience. This is undoubtedly a field which the future will see more fully cultivated.
..
..
Essays on the Art and Principles of Chemistry. HENRY E. ARMSTRONG.The Macmillan Company, New York, 1927. 276 pp. 22 X 15 cm. $4.50. xvxi
+
