The water adsorption capacity of zeolites is a function of pressure and temperature. Desorption of zeolites may be of three types, wherein the crystal lattice undergoes (1) no or little change, (2) a reversible change, or (3) an irreversible change. In the first two cases, the divariance of the zeolite-water vapor equilibrium results in networks of isobars, isotherms, and isosteres which can be transformed into a “characteristic” curve following the Polanyi-Dubinin theory. Because the volume of the micropores of a zeolite structure is constant, the isotherms and “characteristic” curve can be transformed linearly. During desorption, if the volume of the micropores varies due to a change of structure, the curves show linearity breaks.

On the basis of X-ray diffraction, differential thermal, and thermal gravimetric analyses, the equilibrium curves and structural changes of heulandite and stilbite were determined, using specially designed equipment. In the reversible adsorption range, heulandite shows no linearity breaks in the transforms and no structural variation. Stilbite, however, shows a linearity break in the transforms corresponding to a structural change.

Electrical double layer theory is used to analyze an idealized model unit of a clay particle system with the purpose of describing the mechanical stability in terms of an equilibrium of attractive and repulsive forces. Restricting the analysis to two dimensions, a symmetrical parallelogram formed by four typical clay mineral particles is taken as a representative unit of a flocculated clay and the interactions of mineral faces and associated electrolyte is investigated. The distortion energy of the system thus found is then directly related to the mechanical stability of the model unit’s structure as it varies from parallel to perpendicular orientation. The general pattern of behaviour of the model unit will be shown to be compatible with the mechanical behavior of the clay mass.

The reaction of phlogopite with a trimethylsilylating reagent yielded organosilicate compounds which are soluble in various organic solvents. Gas chromatographic analysis of the soluble products indicates that they consist of the trimethylsilylated derivatives of silicic acids which have been formed in the decomposition of phlogopite by hydrochloric acid and that silicic acids formed by the acid attack are monomelic and also oligomeric. The increase of the ratio of GC peak areas of monomer derivative to dimer one with an increase of the reaction time shows that silicic acids in the reaction system tend to depolymerize. The difference between phlogopite and biotite in the ease of trimethylsilylation also is discussed.

The history of religion has long and with some justification been under the tutelage of the positivists who have been content to line up witnesses, to catalogue rites and to compile an index of divine epithets—all this with great patience. But it is now being taken away from them, for it seems that it can no longer be confined to description; it must also make an effort to understand.

The subject is therefore evolving along several lines. Sometimes “the religious” is treated as a separate category and subjected to a kind of morphological analysis; sometimes it is viewed in the perspective of other social sciences like psychology and sociology. Each of these points of view is justified by itself to the extent that it agrees with the facts of the matter. But it also exposes the student of religion to the dangers of systematic exclusiveness and excessive generalization.

At the library of the Ecole Normale Supérieure in Paris, the dissertations in the Humanities are arranged in chronological order. A single glance suffices to tell us that this classification by years coincides almost exactly with a classification by bulk. As we pass along through time, year by year, the volumes grow thicker; pamphlets merge imperceptibly into modest books, these into larger books, these in turn into weighty tomes; until finally we come across works embracing several volumes, each volume imposing in its own right. The explanation is simple: every author is normally led to consider the opinions of his predecessors in the same field or in neighbouring fields; these opinions he discusses, contests, approves, or amends; and finally this leads to the growth in bulk, gradual but unlimited, so evident on the shelves at the library.

The uses of economics are many, as are also the methodologies by which its various purposes can be defended or elucidated. In this paper I shall confine my attention, however, to but one of its many aims—the predictive intent that constitutes a distinguishing characteristic of so much economic work. Lest I be accused of claiming that prediction is an integral part of all economics, let me explicitly point out that the discipline has taxonomic, structural, purely formal, normative, and still other aspects, none of which involves prediction, and all of which have their useful roles to play. Nonetheless, I do not think that most economists would disagree with my contention that a predictive purpose lies at the heart of much of economic science today, in particular when that science is used on behalf of policy.

The electron spin resonance (ESR) technique has been used to study the motion and segregation of an organic spin probe cation (4-amino-2,2,6,6-tetramethylpiperidine N-oxide) on K+-hectorite as a function of average surface concentration. The organic cation tends to concentrate in certain interlayers of aqueous hectorite suspensions even when it occupies a small fraction of the cation-exchange sites. This demixing effect is not evident in methanol-solvated hectorite. The average mobility of the probe increases at higher adsorption levels as a result of the shift of the equilibrium in favor of the solution state. Calculated time-averaged orientations of the probe on the clay surfaces are quite different for methanol- and water-solvated systems, emphasizing the importance of the solvent in modifying the surface-cation interaction.

There is a periodic need for a general survey and stock-taking in almost every field, but in the domain of the pre-Islamic history of Iran, to my knowledge, there has been little scholarly assessment of the picture of the past in light of changes wrought by new source materials. One important reason is that the sources for this history have increased considerably in the past few decades, and scholars have devoted the bulk of their time to the elucidation of these sources, with little time left for a study of their historical consequences. Another point which should be made is the difference between the requirements, on the one hand, for the work of ancient and medieval historians and, on the other hand, for that of modern colleagues. Historians of more recent times like to emphasize the homogeneity of the historical profession and the continuity of methods in the entire field. But in practice it is the classicist who, in our universities, concerns himself with ancient history. I mean by this one who is trained in the methods of textual analysis and the tools of the classicist, and it is the Orientalist or philologist who writes the history of the pre-modern Orient. Given the difficulties of ancient oriental languages and the need to gather source material from the archeologist, epigraphist, numismatist, and art historian, one can understand the great demands on these specialists who would write history. It is no wonder that the methods of the modern historian, evolved from work with an abundance of material and the need for comparison of various sources in evaluating a multitude of factors and roles played by individuals in a given situation, are of a somewhat different nature from those of the scholar who investigates the more distant past. The modern historian is dependent on the economist and political scientist for aid in reconstructing his story. This is the result, of course, of the differentiation and great expansion of knowledge in modern times. The disciplines become defined, and specialization is a necessity in view of the great mass of documentation. Before the advent of writing, archeology, history, and other disciplines are undifferentiated. With its invention, however, the process of ordering subjects and fields at once begins. With the increase of material remains, archeology, for example, divides into the history of architecture, with art, epigraphy, numismatics, the history of technology, and so on. This is inherent in the process of understanding.

Adsorption studies indicate that paraquat, diquat, and thionine are bound on bentonite by amounts greater than the measured cation-exchange capacity (CEC) of the clay. Methylene blue, new methylene blue, and malachite green are bound by amounts equal to the CEC. The unipositive organocations form aggregates on the clay surface. Aggregation increases with ionic strength and increases the apparent adsorption capacity by 25%. The aggregates are removed by washing with distilled water. Desorption studies show that the dyes are irreversibly bound, whereas the dipositive organocations are reversibly bound. Ionic strength variation reduces adsorption by 15 and 36% in the monovalent and divalent organocation-clay systems, respectively. In the clay-divalent organocation systems adsorption is greater on Na-saturated clay than on K-saturated clay. Adsorption is unchanged over the pH range 4.5–8.5 and decreases steadily below pH 4.0. Changes in adsorption due to changes in temperature are small. The study indicates that ionic strength is the most important variable in clay-organocation interactions.

Vermiculite, mixed-layer vermiculite-phlogopite, and smectite are presently forming from igneous and metamorphic bedrock in the alpine zone of the northern Cascades, Washington. In addition, south-facing exposures of quartz-diorites and metadiorites above snow line are weathering to ferruginous bauxite. Calculations indicate that vermiculite is presently forming from phlogopite schists in this environment at a unit area rate that is approximately six times the average estimated rate of clay erosion for North America. The mineralogical data indicate that chemical weathering in this region is a quantitatively significant process, and suggest that in the development of current geomorphic concepts researchers may have generally underestimated the importance of chemical weathering in alpine environments.

Sodium-lithium exchange equilibria between dilute aqueous chloride solutions and 0.2–62 μ Transvaal, South African vermiculite were studied at 25° and 50°C using a dialysis technique. The K content of the vermiculite was reduced to < 1% of the exchange capacity of 2·14 me/g by exhaustive extraction using Na-tetraphenylboron. The thermodynamic equilibrium constants and in turn the standard free energies and heats of exchange were evaluated from the equilibrium selectivity coefficients at the two temperatures. The standard entropy of exchange, ΔS°, was calculated according to the relationship ΔG° = ΔH° − TΔS°. Similar results were obtained for Na → Li and Li → Na exchange at 25°C, thus confirming the reversibility of the reaction.

Sodium preference increased with Na saturation of the vermiculite and equilibrium selectivity coefficients ranged from 6·0 to 22·0 at 25°C. In comparison, selectivity coefficients for Na-Li exchange on montmorillonite ranged from 1·0 to 2·0 and became smaller with increasing Na saturation. The standard free energy and heat of exchange on vermiculite at 25°C were −1444 and −5525 cal mole−1, respectively, resulting in a ΔS° value of −13·7 e.u. This relatively large entropy change is probably due to differences in ion hydration in the solution and surface phases.

The idea of progress is essentially socio-historical. I mean by that that the idea and its meaningful content are the outcome of socio-historical processes in connection with the socio-cultural development of mankind, with which the idea of progress is inextricably linked. Before proceeding to any investigation of its nature it is necessary to dissociate its meaning from two fundamental concepts of modern natural and social science, evolution and change. Evolution is here taken in its strict biological connotation, not in its metaphysical implications. This point is made clear by Bradley who distinguishes between Darwinism as a theory of natural evolution and Darwinism as a metaphysics of existence. From the standpoint of the social universe, within which the idea of progress acquires its meaningfulness, natural evolution is not indeed indifferent, but amoral, and has to be accounted for as an external condition. The same applies to cosmic evolution or changes occurring within the physical universe. Although not indifferent to man, these are devoid of moral content and have to be taken as objectively given conditions.

A method using the bombardment of samples with protons and other positive ions of energy in the MeV range is described: the prompt atomic (γ-rays) and nuclear (γ-rays and charged particles) events generated during the bombardment, are detected with energy sensitive solid state detectors: cooled Ge(Li) for γ-rays and hard γ-rays, cooled Si(Li) detectors for soft γ-rays (3–20 keV) and Si-barrier detectors for charged particles. These 3 types of detectors can be simultaneously used for multipurpose experiments. These techniques are particularly useful for simultaneous detection of all the elements of interest in the sample. Comparisons are made with other microtechniques. Analyses of Li, Na, K, Ca, Rb, Cs and Cl exchanged in appropriate chloride solutions have been achieved for several clays (Geisenheim, Isola di Ponza, Layton). A new phenomenon relative to the anion contribution in cation exchangers is observed. A method of profile analysis of Na by resonant nuclear reactions is discussed.

Moslem thinkers have treated the idea of justice from a religious and human point of view by examining it on two planes: God and Man. Whatever their inclinations may be, their concept of justice is linked to other connected notions such as beauty and ugliness, good and evil, free will, the volition and wisdom of God, and predestination. In the framework of this study of the idea of justice and its related concepts, we shall confine ourselves to setting out the points of view of the principal sects (the Ash'arites, the Mu'tazilites and Maturidism) and of certain philosophers such as Averroes and some mystics including Ibn'Arabi. We shall probably be led to a brief comparison of the ideas of Ibn'Arabi with those of Leibniz. For more ample details on this subject, we refer the reader to a series of articles already published in which we underlined the points of convergence between these two philosophers with regard to the infinite, monadism, optimism, good and evil, and predestination.

The word “structure” is now too often used as a password. But in linguistics it appears to have been adopted independently, before the current vogue. Here it has retained its most narrow connotation. The study of linguistic structures means the study of the construction of certain linguistic fragments: the attempt to uncover, according to their linguistic function, the real units that make up these fragments and the rules for using these units in constructing the fragments. This method of analysis, functional and structural, forty years ago transformed the description of language, whether it was a question of phonemics, of morphology, or even of syntax. But for a long time the structuralists themselves insisted upon the resistances that semantics raise—and its most apparent formal manifestation, the lexicon—to any attempt at analysis of this sort.