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Chemical Digest ABSTRACTS Chemistry in the Six-Year "Realschule." 2. physik. ekem. Untewicht, 38, 41-2 (1925).-An abstract of a portion only of the report of a committee appointed by the Institute fur Erziehung und Unterricht, for which see "Die Realschule," by Gustave Louis (163 pp.), Leipzig, Quelle and Meyer, 1924. That portionpertaining t o chemistry was written by B. Leiserung. The chief purpose of chemistry in the Realschule is to develop an understanding of chemical phenomena and their relation t o daily life. The student should become familiar with (1) the most important chemical elements and their minerals, (2) the principal types of reactionsanalysis, synthesis, substitution, oxidation and reduction, and (3) the acid and basic character of the oxides. Chemical symbols should be introduced early. The following topics should also find a place: the atomic theory, Avogadro's hypothesis, stoichiometrical calculations, energy relations, particularly heat balance and the laws of electrolysis, solution, osmotic pressure, etc. No chemical compound and no reaction is of itself so important that i t belongs in the course unless (1) i t leads to an understanding of chemical relationships; (2) it has a bearing on the other natural sciences and serves t o round out a knowledge of our physical world; (3) it is of fundamental importance in daily life. Intensive study of technological applications is avoided; also as many chemical details as possible. Very little laboratory work is possible since a t present but 2 hrs. a week for 1 year are allotted to chemistry. B. The Necessity of Chemistry in High-School Training. C. A. AMICK. Sch. S&. Math., 25, 385-9 (April, 1925).-The great strides of the immediate future will be in chemical rather than in mechanical perfection, particularly in the prevention of waste. Every worker in the various walks of life needs the spirit of knowing how and why. I t puts certainty where chance ruled before. The production and use of foods requires that knowledge which will guide habit-formation in the way of health. The knowledge that gives the possessor the ability t o judge quality in all wmmodities from medicines t o machines. Science workers in particular should protect the public from frauds based on so-called science. The highachool teacher is the outpost of science in contact with the public that will soon occupy the posts of action in life. The value of science in daily hv these .vounr..~ e . o o l eif science is to function in life should be thorourhlv . a~ureeiated .. education as i t is abie. H. R. SMITH The Periodic Sphere and the Position of the Rare Earth Metals. J. NEWTON FRIEND. Chem. News, 130, 1 9 6 7 (March, 1925).-.'In an attempt to include the rare earth metals in the Periodic Chart without undue disturbance of its svmmetrv. i t has been found helpful to arrange the elements in the form of a spiral coil& roundthe surface of a sphere, as shown in Figs. 1 and 2. In the first short series the cells or spaces occupied by the elements are of minimum size, but in the second coil the spaces are larger and the elements tend to orient themselves ex-centrally. Sodium, for example, is not thus immediately below lithium, but lies slightly t o the left side of its cell. So that lithium lies longitudinally between sodium and calcium but nearer to sodium. The resemblance of lithium t o the alkaline earths is thus illustrated. "The cells in the third spiral are still larger and elements take up definite positions t o the left or right, as indicated hy the broken lines, thus yielding sub-groups A and R to each normal vertical group. I n general, only one element lies in each cell, save in Group VIII, which now comes into being through division in Group 0. "Round the equator the cells have a maximum area, and are sufficiently large t o hold two elements each. There is thus a rare earth belt containing elements closely packed together, the nearest approach to isotopes possible for elements with separate atomic numbers. Isotopes would clearly occupy identical positions in the cells, but, if lighter in weight, lying possibly nearer t o the center of the sphere. Hence they, too, should not be absolutely identical. "Below this equatorial belt the elements tend t o bewme unstable. The similarity of sub-equatorial metals, e. g., thorium, t o those in corresponding positions above the equator, e. g., zirconium, rather than t o their wngeners is clearly illustrated by their positions
"The n r e wrth metali appear to fit into this scheme quite well, and reveal many regularities not hitherto attarnable see Tahle I,. "Thus, La, 1% nud Lu are appropriately placed in Group 111. Ce and Ct are k n o ~ n
FIG. 2. as suitable intermediaries to Zr and Th. PI yields Pr01and N d in the presence of traces of cerium and praseodymium yields oxide approximating toNdO., their oxides comparing with CbOl and TaOn.
"Sm resembles Mo and W in yielding parallel series of chlorides and oxides. The
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LO,. Dy in DyCL and Dyzbr, finds fittinganalogy witcCsIa and GO;: "Ho, Er and Tm are very rare, but little is known about them. "It is of interest that according to thas scheme the misztny element, No. 61, does not fall into ( h u p VII, as other schemes postulate, but into ( h u p V, and may bc expected to show analogies with Sb 2nd Bi."
4cis and
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Social Values of High-School Chemistry. T. D. KFLSEY. Sch. Sci. M d h . 25, 37884 (April. I!l2j,.-l'hr grratwl :~.:hirvcmentof the tmcher lies in his work as n buildcr of character. Norhinu that the lcnchtr can cuntnbute to the dc\~cloomentof his ~ u o i l scan be of more dirert or more practical value. What bovs and xi& rlbtudv is of l&~cipifrcanccin qunlifving thcm 10; the w a t i o n of bucinrss than Itow they have donr their work, ard how wrll they have been grounded in the fun
