294
JOURNAL OF CHEMICAL EDUCATION
the 'Zehrbuch" as a transition stage in organic textbooks, advanced only a little beyond the 1900 plan with respect to connection of theory with facts. In other words, the next few years will wituesk in organic textbooks a wholly new interrelation and unification of modem theory with the great body of detailed information for which German scholars deserve so large a share of the credit. Such unification cannot come at once, in the face of widespread presumption that the modern study of reaction mechanism is an "sdvanced" topic which the youth studies after he ha8 mastered the fundamentals of organic chemistry proper. But the new sehwl of physical-organic chemists does not agree with such presumption, and it is very likely that these modernists will have their way. I t should also be remembered that physical organic chemistry is no longer merely the use of pbysical instruments on organic material for deciphering structure. A few minor criticisms come to light: Continued use of elongated hexagons to represent the benzene ring; use of line enclasures in structural equations-for example, surrounding H and OH symbols, leading students to infer that the reaction in question occurs because hydrogen is seeking bydroxyl-and finally, unnecessary complication in numbering of volumes. The reviewer wiahes to register vigorous disapproval of the old-time German publishers' habit, appearing once again, of numbering the units of a multivolume series in subnumbers (of uncertain tally) as well ae main numbers, to the confusion of booksellers, librarians, and readers. There seems to be no good reason why the "Lehrbuch" should not be numbered simply as Volumes I , 11,111, and IV. ~ the These items are, of course, i f minor import. ' B oontrast, splendid typography far outweighs the shortcomings. Skilful use of boldface tvDe and variation in sise of ordinttrv roman tvoe are highly commendable. The "Lehrbuch" should serve for a d&ade or two as a worthy follower of Meyer and Jscobson, and of von Richter, as an excellent main reference book in the private Library of the young German scientist. We wonder, however, where the poor fellow is going to get the money to pay for it at three cents a page. G. ROSS ROBERTSON U ~ m ~ n s r OF r r CAL~OXNIA Loa Awames, CALITD~NIA
0
MODERN ASPECTS OF pH
James Small, Professor of Botany, Queen's University. Belfast D. Van Nostrand ca., Ino.. New York, lgS4. Id + 247 PP. 30 figs. 26 tables. 14.5 X 22.5 om. $5. THIS book should appeal mainly to botanists and soil seientists, and it seems unfortunate that the title should not 80 indicate. The inclusion of a subheading, "with special reference to plants and soils," may not be adequate to attract all those interested. Those in the field probably will know the author's two previous books: "Hydrogen Ion Concentration in Plant Cells and Tissues," (1929) and "pH and Plants" (1946). In this new publication, the table of contents and casual examination show that more than three-aumters of the suhieet matter is devoted to
of activities of ions as compared to concentrations, and s, discus sion of buffer systems in general. To a chemist the relation between activity and concentration of ions is not new, as this is adequately covered in the common nhvsical chemistrv texts. A chemist would also reeret the dearth bf kquations in t
